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Sample records for acid metabolism cell

  1. Fatty acid metabolism in the regulation of T cell function.

    PubMed

    Lochner, Matthias; Berod, Luciana; Sparwasser, Tim

    2015-02-01

    The specific regulation of cellular metabolic processes is of major importance for directing immune cell differentiation and function. We review recent evidence indicating that changes in basic cellular lipid metabolism have critical effects on T cell proliferation and cell fate decisions. While induction of de novo fatty acid (FA) synthesis is essential for activation-induced proliferation and differentiation of effector T cells, FA catabolism via β-oxidation is important for the development of CD8(+) T cell memory as well as for the differentiation of CD4(+) regulatory T cells. We consider the influence of lipid metabolism and metabolic intermediates on the regulation of signaling and transcriptional pathways via post-translational modifications, and discuss how an improved understanding of FA metabolism may reveal strategies for manipulating immune responses towards therapeutic outcomes. PMID:25592731

  2. Evaluation of endogenous acidic metabolic products associated with carbohydrate metabolism in tumor cells

    PubMed Central

    Mazzio, Elizabeth A.; Smith, Bruce

    2010-01-01

    Tumor cells have a high tolerance for acidic and hypoxic microenvironments, also producing abundant lactic acid through accelerated glycolysis in the presence or absence of O2. While the accumulation of lactate is thought to be a major contributor to the reduction of pH-circumscribing aggressive tumors, it is not known if other endogenous metabolic products contribute this acidity. Furthermore, anaerobic metabolism in cancer cells bears similarity to homo-fermentative lactic acid bacteria, however very little is known about an alternative pathway that may drive adenosine triphosphate (ATP) production independent of glycolysis. In this study, we quantify over 40 end-products (amines, acids, alcohols, aldehydes, or ketones) produced by malignant neuroblastoma under accelerated glycolysis (+glucose (GLU) supply 1–10 mM) ± mitochondrial toxin; 1-methyl-4-phenyl-pyridinium (MPP+) to abate aerobic respiration to delineate differences between anaerobic vs. aerobic cell required metabolic pathways. The data show that an acceleration of anaerobic glycolysis prompts an expected reduction in extracellular pH (pHex) from neutral to 6.7±0.006. Diverse metabolic acids associated with this drop in acidity were quantified by ionic exchange liquid chromatography (LC), showing concomitant rise in lactate (Ctrls 7.5±0.5 mM; +GLU 12.35±1.3 mM; +GLU + MPP 18.1±1.8 mM), acetate (Ctrl 0.84±0.13 mM: +GLU 1.3±0.15 mM; +GLU + MPP 2.7±0.4 mM), fumarate, and a-ketoglutarate (<10μM) while a range of other metabolic organic acids remained undetected. Amino acids quantified by o-phthalaldehyde precolumn derivatization/electrochemical detection–LC show accumulation of L-alanine (1.6±.052 mM), L-glutamate (285±9.7μM), L-asparagine (202±2.1μM), and L-aspartate (84.2±4.9μM) produced during routine metabolism, while other amino acids remain undetected. In contrast, the data show no evidence for accumulation of acetaldehyde, aldehydes, or ketones (Purpald/2

  3. The Role of Fatty Acid Oxidation in the Metabolic Reprograming of Activated T-Cells

    PubMed Central

    Byersdorfer, Craig Alan

    2014-01-01

    Activation represents a significant bioenergetic challenge for T-cells, which must undergo metabolic reprogramming to keep pace with increased energetic demands. This review focuses on the role of fatty acid metabolism, both in vitro and in vivo, following T-cell activation. Based upon previous studies in the literature, as well as accumulating evidence in allogeneic cells, I propose a multi-step model of in vivo metabolic reprogramming. In this model, a primary determinant of metabolic phenotype is the ubiquity and duration of antigen exposure. The implications of this model, as well as the future challenges and opportunities in studying T-cell metabolism, will be discussed. PMID:25566254

  4. Effect of fatty acids on human bone marrow mesenchymal stem cell energy metabolism and survival.

    PubMed

    Fillmore, Natasha; Huqi, Alda; Jaswal, Jagdip S; Mori, Jun; Paulin, Roxane; Haromy, Alois; Onay-Besikci, Arzu; Ionescu, Lavinia; Thébaud, Bernard; Michelakis, Evangelos; Lopaschuk, Gary D

    2015-01-01

    Successful stem cell therapy requires the optimal proliferation, engraftment, and differentiation of stem cells into the desired cell lineage of tissues. However, stem cell therapy clinical trials to date have had limited success, suggesting that a better understanding of stem cell biology is needed. This includes a better understanding of stem cell energy metabolism because of the importance of energy metabolism in stem cell proliferation and differentiation. We report here the first direct evidence that human bone marrow mesenchymal stem cell (BMMSC) energy metabolism is highly glycolytic with low rates of mitochondrial oxidative metabolism. The contribution of glycolysis to ATP production is greater than 97% in undifferentiated BMMSCs, while glucose and fatty acid oxidation combined only contribute 3% of ATP production. We also assessed the effect of physiological levels of fatty acids on human BMMSC survival and energy metabolism. We found that the saturated fatty acid palmitate induces BMMSC apoptosis and decreases proliferation, an effect prevented by the unsaturated fatty acid oleate. Interestingly, chronic exposure of human BMMSCs to physiological levels of palmitate (for 24 hr) reduces palmitate oxidation rates. This decrease in palmitate oxidation is prevented by chronic exposure of the BMMSCs to oleate. These results suggest that reducing saturated fatty acid oxidation can decrease human BMMSC proliferation and cause cell death. These results also suggest that saturated fatty acids may be involved in the long-term impairment of BMMSC survival in vivo.

  5. Patterns of Amino Acid Metabolism by Proliferating Human Mesenchymal Stem Cells

    PubMed Central

    Schop, Deborah; Spitters, Tim W.G.M.; van Dijkhuizen-Radersma, Riemke; Bracke, Madelon; de Bruijn, Joost D.; Martens, Dirk; Karperien, Marcel; van Boxtel, Anton; van Blitterswijk, Clemens A.

    2012-01-01

    The nutritional requirements of stem cells have not been determined; in particular, the amino acid metabolism of stem cells is largely unknown. In this study, we investigated the amino acid metabolism of human mesenchymal stem cells (hMSCs), with focus on two questions: Which amino acids are consumed and/or secreted by hMSCs and at what rates? To answer these questions, hMSCs were cultured on tissue culture plastic and in a bioreactor, and their amino acid profile was analyzed. The results showed that the kinetics of hMSCs growth and amino acid metabolism were significantly higher for hMSCs in tissue culture plastic than in the bioreactor. Despite differences in culture conditions, 8 essential and 6 nonessential amino acids were consumed by hMSCs in both tissue culture plastic and bioreactor cultures. Glutamine was the most consumed amino acid with significantly higher rates than for any other amino acid. The metabolism of nonessential amino acids by hMSCs deviated significantly from that of other cell lines. The secretion of alanine, glycine, glutamate, and ornithine by hMSCs showed that there is a strong overflow metabolism that can be due to the high concentrations of amino acids provided in the medium. In addition, the data showed that there is a metabolic pattern for proliferating hMSCs, which can contribute to the design of medium without animal serum for stem cells. Further, this study shows how to implement amino acid rates and metabolic principles in three-dimensional stem cell biology. PMID:21943055

  6. Amino Acid Metabolism Disorders

    MedlinePlus

    ... defects & other health conditions > Amino acid metabolism disorders Amino acid metabolism disorders E-mail to a friend Please ... baby’s newborn screening may include testing for certain amino acid metabolism disorders. These are rare health conditions that ...

  7. Contributions of Cell Metabolism and H+ Diffusion to the Acidic pH of Tumors1

    PubMed Central

    Schornack, Paul A; Gillies, Robert J

    2003-01-01

    Abstract The tumor microenvironment is hypoxic and acidic. These conditions have a significant impact on tumor progression and response to therapies. There is strong evidence that tumor hypoxia results from inefficient perfusion due to a chaotic vasculature. Consequently, some tumor regions are well oxygenated and others are hypoxic. It is commonly believed that hypoxic regions are acidic due to a stimulation of glycolysis through hypoxia, yet this is not yet demonstrated. The current study investigates the causes of tumor acidity by determining acid production rates and the mechanism of diffusion for H+ equivalents through model systems. Two breast cancer cell lines were investigated with divergent metabolic profiles: nonmetastatic MCF-7/s and highly metastatic MDA-mb-435 cells. Glycolysis and acid production are inhibited by oxygen in MCF-7/s cells, but not in MDA-mb-435 cells. Tumors of MDAmb-435 cells are significantly more acidic than are tumors of MCF-7/s cells, suggesting that tumor acidity is primarily caused by endogenous metabolism, and not the lack of oxygen. Metabolically produced protons are shown to diffuse in association with mobile buffers, in concordance with previous studies. The metabolic and diffusion data were analyzed using a reaction-diffusion model to demonstrate that the consequent pH profiles conform well to measured pH values for tumors of these two cell lines. PMID:12659686

  8. Red blood cell fatty acid composition and the metabolic syndrome: NHLBI GOLDN study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different fatty acids may vary in their effect on the metabolic syndrome (MetS). We tested whether fatty acid classes measured in red blood cells (RBC) are associated with the MetS or its components. Included were men (n=497, 49+/-16 y) and women (n=539, 48+/-16 y) from 187 families in the Genetics ...

  9. [Metabolism of nicotinic acid in plant cell suspension cultures, IV: Occurrence and metabolism of nicotinic acid N-alpha-arabinoside (author's transl)].

    PubMed

    Leienbach, K W; Heeger, V; Barz, W

    1976-08-01

    Application of nicotinic acid to cell suspension cultures of Petroselinum hortense Hoffm., Daucus carota, Nicotiana tabacum and Nicotiana glauca leads to the formation of the recently isolated[2] nicotinic acid N-alpha-L-arabinoside. In these cell cultures the arabinoside is a metabolically active compound; the nicotinic acid moiety is used for NAD synthesis and nicotinic acid degradation involving decarboxylation and ring fission. N-Methylnicotinic acid (trigonelline) and nicotinic acid N-alpha-L-arabinoside occur alternatively in plant cell suspension cultures, but seem to fulfil the same function as a reserve form for nicotinic acid. Catabolism of nicotinic acid in parsley cell suspension cultures does not involve 6-hydroxynicotinic acid as an intermediate.

  10. Sulfur amino acid metabolism in doxorubicin-resistant breast cancer cells

    SciTech Connect

    Ryu, Chang Seon; Kwak, Hui Chan; Lee, Kye Sook; Kang, Keon Wook; Oh, Soo Jin; Lee, Ki Ho; Kim, Hwan Mook; Ma, Jin Yeul; Kim, Sang Kyum

    2011-08-15

    Although methionine dependency is a phenotypic characteristic of tumor cells, it remains to be determined whether changes in sulfur amino acid metabolism occur in cancer cells resistant to chemotherapeutic medications. We compared expression/activity of sulfur amino acid metabolizing enzymes and cellular levels of sulfur amino acids and their metabolites between normal MCF-7 cells and doxorubicin-resistant MCF-7 (MCF-7/Adr) cells. The S-adenosylmethionine/S-adenosylhomocysteine ratio, an index of transmethylation potential, in MCF-7/Adr cells decreased to {approx} 10% relative to that in MCF-7 cells, which may have resulted from down-regulation of S-adenosylhomocysteine hydrolase. Expression of homocysteine-clearing enzymes, such as cystathionine beta-synthase, methionine synthase/methylene tetrahydrofolate reductase, and betaine homocysteine methyltransferase, was up-regulated in MCF-7/Adr cells, suggesting that acquiring doxorubicin resistance attenuated methionine-dependence and activated transsulfuration from methionine to cysteine. Homocysteine was similar, which is associated with a balance between the increased expressions of homocysteine-clearing enzymes and decreased extracellular homocysteine. Despite an elevation in cysteine, cellular GSH decreased in MCF-7/Adr cells, which was attributed to over-efflux of GSH into the medium and down-regulation of the GSH synthesis enzyme. Consequently, MCF-7/Adr cells were more sensitive to the oxidative stress induced by bleomycin and menadione than MCF-7 cells. In conclusion, our results suggest that regulating sulfur amino acid metabolism may be a possible therapeutic target for chemoresistant cancer cells. These results warrant further investigations to determine the role of sulfur amino acid metabolism in acquiring anticancer drug resistance in cancer cells using chemical and biological regulators involved in sulfur amino acid metabolism. - Research Highlights: > MCF-7/Adr cells showed decreases in cellular GSH

  11. Hydroxycarboxylic acid receptors are essential for breast cancer cells to control their lipid/fatty acid metabolism

    PubMed Central

    Stäubert, Claudia; Broom, Oliver Jay; Nordström, Anders

    2015-01-01

    Cancer cells exhibit characteristic changes in their metabolism with efforts being made to address them therapeutically. However, targeting metabolic enzymes as such is a major challenge due to their essentiality for normal proliferating cells. The most successful pharmaceutical targets are G protein-coupled receptors (GPCRs), with more than 40% of all currently available drugs acting through them. We show that, a family of metabolite-sensing GPCRs, the Hydroxycarboxylic acid receptor family (HCAs), is crucial for breast cancer cells to control their metabolism and proliferation. We found HCA1 and HCA3 mRNA expression were significantly increased in breast cancer patient samples and detectable in primary human breast cancer patient cells. Furthermore, siRNA mediated knock-down of HCA3 induced considerable breast cancer cell death as did knock-down of HCA1, although to a lesser extent. Liquid Chromatography Mass Spectrometry based analyses of breast cancer cell medium revealed a role for HCA3 in controlling intracellular lipid/fatty acid metabolism. The presence of etomoxir or perhexiline, both inhibitors of fatty acid β-oxidation rescues breast cancer cells with knocked-down HCA3 from cell death. Our data encourages the development of drugs acting on cancer-specific metabolite-sensing GPCRs as novel anti-proliferative agents for cancer therapy. PMID:25839160

  12. Hydroxycarboxylic acid receptors are essential for breast cancer cells to control their lipid/fatty acid metabolism.

    PubMed

    Stäubert, Claudia; Broom, Oliver Jay; Nordström, Anders

    2015-08-14

    Cancer cells exhibit characteristic changes in their metabolism with efforts being made to address them therapeutically. However, targeting metabolic enzymes as such is a major challenge due to their essentiality for normal proliferating cells. The most successful pharmaceutical targets are G protein-coupled receptors (GPCRs), with more than 40% of all currently available drugs acting through them.We show that, a family of metabolite-sensing GPCRs, the Hydroxycarboxylic acid receptor family (HCAs), is crucial for breast cancer cells to control their metabolism and proliferation.We found HCA1 and HCA3 mRNA expression were significantly increased in breast cancer patient samples and detectable in primary human breast cancer patient cells. Furthermore, siRNA mediated knock-down of HCA3 induced considerable breast cancer cell death as did knock-down of HCA1, although to a lesser extent. Liquid Chromatography Mass Spectrometry based analyses of breast cancer cell medium revealed a role for HCA3 in controlling intracellular lipid/fatty acid metabolism. The presence of etomoxir or perhexiline, both inhibitors of fatty acid β-oxidation rescues breast cancer cells with knocked-down HCA3 from cell death.Our data encourages the development of drugs acting on cancer-specific metabolite-sensing GPCRs as novel anti-proliferative agents for cancer therapy.

  13. Inhibition of arachidonic acid metabolism decreases tumor cell invasion and matrix metalloproteinase expression.

    PubMed

    Koontongkaew, Sittichai; Monthanapisut, Paopanga; Saensuk, Theeranuch

    2010-11-01

    Head and neck cancers are known to synthesize arachidonic acid metabolites. Interfering with arachidonic acid metabolism may inhibit growth and invasiveness of cancer cells. In this study we investigate effects of sulindac (the non-selective COX inhibitor), aspirin (the irreversible, preferential COX-1 inhibitor), NS-398 (the selective COX-2 inhibitor), NDGA (nordihydroguaiaretic acid, the selective LOX inhibitor) and ETYA (5,8,11,14-eicosatetraynoic acid, the COX and LOX inhibitor) on cell viability, MMP-2 and MMP-9 activities, and in vitro invasion of cancer cells derived from primary and metastatic head and neck, and colon cancers. The inhibitors of COX and/or LOX could inhibit cell proliferation, MMP activity and invasion in head and neck and colon cancer cells. However, the inhibitory effect was obviously observed in colon cancer cells. Inhibition of arachidonic acid metabolism caused a decrease in cancer cell motility, which partially explained by the inhibition of MMPs. Therefore, COX and LOX pathways play important roles in head and neck cancer cell growth. PMID:20654727

  14. Amino Acid Pools and Metabolism During the Cell Division Cycle of Arginine-Grown Candida utilis

    PubMed Central

    Nurse, P.; Wiemken, A.

    1974-01-01

    Synchronous cultures obtained by isopycnic density gradient centrifugation are used to investigate amino acid metabolism during the cell division cycle of the food yeast Candida utilis. Isotopic labeling experiments demonstrate that the rates of uptake and catabolism of arginine, the sole source of nitrogen, double abruptly during the first half of the cycle, while the cells undergo bud expansion. This is accompanied by a doubling in rate of amino acid biosynthesis, and an accumulation of amino acids. The accumulation probably occurs within the storage pools of the vacuoles. Amino acids derived from protein degradation contribute little to this accumulation. For the remainder of the cell cycle, during cell separation and until the next bud initiation, the rates of uptake and catabolism of arginine and amino acid biosynthesis remain constant. Despite the abrupt doubling in the rate of formation of amino acid pools, their rate of utilization for macromolecular synthesis increases steadily throughout the cycle. The significance of this temporal organization of nitrogen source uptake and amino acid metabolism during the cell division cycle is discussed. Images PMID:4591945

  15. Phytanic acid and docosahexaenoic acid increase the metabolism of all-trans-retinoic acid and CYP26 gene expression in intestinal cells.

    PubMed

    Lampen, A; Meyer, S; Nau, H

    2001-10-31

    Retinoids are essential for growth and cell differentiation of epithelial tissues. The effects of the food compounds phytol, the phytol metabolite phytanic acid, and the fatty acid docosahexaenoic acid (DHA) on the retinoid signaling pathway in intestinal cells were studied. Phytol inhibited the formation of all-trans-retinoic acid (RA) from dietary retinol in intestinal cells. Phytanic acid, a known retinoic X receptor (RXRalpha) and peroxisome proliferator activating receptor (PPARalpha) activator, also activated PPARdelta, and to a lesser degree PPARgamma, in a transactivation assay. Phytanic acid had no effect on intestinal RA hydroxylase CYP26 (also named P450RAI) gene expression and metabolism of all-trans-RA in intestinal Caco-2 cells. However, in combination with retinoic acid receptor (RAR)-ligands (all-trans-RA or synthetic Am580) phytanic acid enhanced the induction of CYP26 and RA-metabolism in comparison to treatments with all-trans-RA or Am580 alone. Also treatment with DHA did not affect CYP26 gene expression and RA-metabolism but cotreatment of the cells with DHA and all-trans-RA or Am580 enhanced the induction of CYP26, in comparison to the induction caused by all-trans-RA or Am580 alone. This study indicates that food compounds such as phytanic acid and DHA that are RXR-agonists and have an impact on intestinal CYP26 gene expression and metabolism of all-trans-RA in intestinal cells.

  16. Disorders of Amino Acid Metabolism

    MedlinePlus

    ... Aspiration Syndrome Additional Content Medical News Disorders of Amino Acid Metabolism By Lee M. Sanders, MD, MPH NOTE: ... Metabolic Disorders Disorders of Carbohydrate Metabolism Disorders of Amino Acid Metabolism Disorders of Lipid Metabolism Amino acids are ...

  17. Dynamics of amino acid metabolism of primary human liver cells in 3D bioreactors

    PubMed Central

    Zeilinger, K.; Sickinger, S.; Schmidt-Heck, W.; Buentemeyer, H.; Iding, K.; Lehmann, J.; Pfaff, M.; Pless, G.; Gerlach, J.C.

    2006-01-01

    The kinetics of 18 amino acids, ammonia (NH3) and urea (UREA) in 18 liver cell bioreactor runs were analyzed and simulated by a two-compartment model consisting of a system of 42 differential equations. The model parameters, most of them representing enzymatic activities, were identified and their values discussed with respect to the different liver cell bioreactor performance levels. The nitrogen balance based model was used as a tool to quantify the variability of runs and to describe different kinetic patterns of the amino acid metabolism, in particular with respect to glutamate (GLU) and aspartate (ASP). PMID:16550345

  18. Eicosapentaenoic and dihomo gamma linolenic acid metabolism by cultured rat mesangial cells

    SciTech Connect

    Scharschmidt, L.A.; Gibbons, N.B.; Neuwirth, R.

    1989-01-01

    To better understand the effects of dietary fatty acid manipulations on glomerular function, we compared mesangial incorporation, release, and metabolism of arachidonic (AA), eicosapentaenoic (EPA), and dihomo gamma linolenic (DHG) acids. We found marked differences in mesangial handling of these fatty acids. AA was incorporated into lipids of mesangial cells much more rapidly than EPA or DHG. Ionophore-induced stimulation of fatty acid release from mesangial cells prelabeled with (/sup 14/C)AA, (/sup 14/C)EPA, or (/sup 14/C)DHG caused a release of labeled AA greater than DHG much less than EPA, respectively. Preloading mesangial cells with DHG or EPA for 24 h reduced subsequent basal, ionophore-, and hormone-stimulated prostaglandin E2 (PGE2) synthesis. Finally, unlike AA, neither EPA nor DHG was converted to a significant extent by mesangial cyclooxygenase or lipoxygenase. Thus the mesangial metabolism of DHG and EPA differs both quantitatively and qualitatively from that of AA. Furthermore, EPA and DHG inhibit metabolism of AA at the level of mesangial cyclooxygenase.

  19. Amino Acid Metabolism Disorders

    MedlinePlus

    Metabolism is the process your body uses to make energy from the food you eat. Food is ... One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup ...

  20. Retinol metabolism in LLC-PK1 Cells. Characterization of retinoic acid synthesis by an established mammalian cell line.

    PubMed

    Napoli, J L

    1986-10-15

    Specific assays, based on gas chromatography-mass spectrometry and high-performance liquid chromatography, were used to quantify the conversion of retinol and retinal into retinoic acid by the pig kidney cell line LLC-PK1. Retinoic acid synthesis was linear for 2-4 h as well as with graded amounts of either substrate to at least 50 microM. Retinoic acid concentrations increased through 6-8 h, but decreased thereafter because of substrate depletion (t1/2 of retinol = 13 h) and product metabolism (1/2 = 2.3 h). Retinoic acid metabolism was accelerated by treating cells with 100 nM retinoic acid for 10 h (t1/2 = 1.7 h) and was inhibited by the antimycotic imidazole ketoconazole. Feedback inhibition was not indicated since retinoic acid up to 100 nM did not inhibit its own synthesis. Retinol dehydrogenation was rate-limiting. The reduction and dehydrogenation of retinal were 4-8-fold and 30-60-fold faster, respectively. Greater than 95% of retinol was converted into metabolites other than retinoic acid, whereas the major metabolite of retinal was retinoic acid. The synthetic retinoid 13-cis-N-ethylretinamide inhibited retinoic acid synthesis, but 4-hydroxylphenylretinamide did not. 4'-(9-Acridinylamino)methanesulfon-m-anisidide, an inhibitor of aldehyde oxidase, and ethanol did not inhibit retinoic acid synthesis. 4-Methylpyrazole was a weak inhibitor: disulfiram was a potent inhibitor. These data indicate that retinol dehydrogenase is a sulfhydryl group-dependent enzyme, distinct from ethanol dehydrogenase. Homogenates of LLC-PK1 cells converted retinol into retinoic acid and retinyl palmitate and hydrolyzed retinyl palmitate. This report suggests that substrate availability, relative to enzyme activity/amount, is a primary determinant of the rate of retinoic acid synthesis, identifies inhibitors of retinoic acid synthesis, and places retinoic acid synthesis into perspective with several other known pathways of retinoid metabolism. PMID:3759984

  1. Primary fatty acid amide metabolism: conversion of fatty acids and an ethanolamine in N18TG2 and SCP cells.

    PubMed

    Farrell, Emma K; Chen, Yuden; Barazanji, Muna; Jeffries, Kristen A; Cameroamortegui, Felipe; Merkler, David J

    2012-02-01

    Primary fatty acid amides (PFAM) are important signaling molecules in the mammalian nervous system, binding to many drug receptors and demonstrating control over sleep, locomotion, angiogenesis, and many other processes. Oleamide is the best-studied of the primary fatty acid amides, whereas the other known PFAMs are significantly less studied. Herein, quantitative assays were used to examine the endogenous amounts of a panel of PFAMs, as well as the amounts produced after incubation of mouse neuroblastoma N(18)TG(2) and sheep choroid plexus (SCP) cells with the corresponding fatty acids or N-tridecanoylethanolamine. Although five endogenous primary amides were discovered in the N(18)TG(2) and SCP cells, a different pattern of relative amounts were found between the two cell lines. Higher amounts of primary amides were found in SCP cells, and the conversion of N-tridecanoylethanolamine to tridecanamide was observed in the two cell lines. The data reported here show that the N(18)TG(2) and SCP cells are excellent model systems for the study of PFAM metabolism. Furthermore, the data support a role for the N-acylethanolamines as precursors for the PFAMs and provide valuable new kinetic results useful in modeling the metabolic flux through the pathways for PFAM biosynthesis and degradation.

  2. Proteomics-Based Metabolic Modeling Reveals That Fatty Acid Oxidation (FAO) Controls Endothelial Cell (EC) Permeability*

    PubMed Central

    Patella, Francesca; Schug, Zachary T.; Persi, Erez; Neilson, Lisa J.; Erami, Zahra; Avanzato, Daniele; Maione, Federica; Hernandez-Fernaud, Juan R.; Mackay, Gillian; Zheng, Liang; Reid, Steven; Frezza, Christian; Giraudo, Enrico; Fiorio Pla, Alessandra; Anderson, Kurt; Ruppin, Eytan; Gottlieb, Eyal; Zanivan, Sara

    2015-01-01

    Endothelial cells (ECs) play a key role to maintain the functionality of blood vessels. Altered EC permeability causes severe impairment in vessel stability and is a hallmark of pathologies such as cancer and thrombosis. Integrating label-free quantitative proteomics data into genome-wide metabolic modeling, we built up a model that predicts the metabolic fluxes in ECs when cultured on a tridimensional matrix and organize into a vascular-like network. We discovered how fatty acid oxidation increases when ECs are assembled into a fully formed network that can be disrupted by inhibiting CPT1A, the fatty acid oxidation rate-limiting enzyme. Acute CPT1A inhibition reduces cellular ATP levels and oxygen consumption, which are restored by replenishing the tricarboxylic acid cycle. Remarkably, global phosphoproteomic changes measured upon acute CPT1A inhibition pinpointed altered calcium signaling. Indeed, CPT1A inhibition increases intracellular calcium oscillations. Finally, inhibiting CPT1A induces hyperpermeability in vitro and leakage of blood vessel in vivo, which were restored blocking calcium influx or replenishing the tricarboxylic acid cycle. Fatty acid oxidation emerges as central regulator of endothelial functions and blood vessel stability and druggable pathway to control pathological vascular permeability. PMID:25573745

  3. Rethinking the paradigm: How comparative studies on fatty acid oxidation inform our understanding of T cell metabolism.

    PubMed

    Chiaranunt, Pailin; Ferrara, James L M; Byersdorfer, Craig A

    2015-12-01

    The classic paradigm of T cell metabolism posits that activated Teff cells utilize glycolysis to keep pace with increased energetic demands, while resting and Tmem cells rely on the oxidation of fat. In contrast, Teff cells during graft-versus-host disease (GVHD) increase their reliance on oxidative metabolism and, in particular, on fatty acid oxidation (FAO). To explore the potential mechanisms driving adoption of this alternative metabolism, we first review key pathways regulating FAO across a variety of disparate tissue types, including liver, heart, and skeletal muscle. Based upon these comparative studies, we then outline a consensus network of transcriptional and signaling pathways that predict a model for regulating FAO in Teff cells during GVHD. This model raises important implications about the dynamic nature of metabolic reprogramming in T cells and suggests exciting future directions for further study of in vivo T cell metabolism. PMID:26359186

  4. Tumor cell metabolism

    PubMed Central

    Romero-Garcia, Susana; Lopez-Gonzalez, Jose Sullivan; B´ez-Viveros, José Luis; Aguilar-Cazares, Dolores

    2011-01-01

    Cancer is a genetic disease that is caused by mutations in oncogenes, tumor suppressor genes and stability genes. The fact that the metabolism of tumor cells is altered has been known for many years. However, the mechanisms and consequences of metabolic reprogramming have just begun to be understood. In this review, an integral view of tumor cell metabolism is presented, showing how metabolic pathways are reprogrammed to satisfy tumor cell proliferation and survival requirements. In tumor cells, glycolysis is strongly enhanced to fulfill the high ATP demands of these cells; glucose carbons are the main building blocks in fatty acid and nucleotide biosynthesis. Glutaminolysis is also increased to satisfy NADPH regeneration, whereas glutamine carbons replenish the Krebs cycle, which produces metabolites that are constantly used for macromolecular biosynthesis. A characteristic feature of the tumor microenvironment is acidosis, which results from the local increase in lactic acid production by tumor cells. This phenomenon is attributed to the carbons from glutamine and glucose, which are also used for lactic acid production. Lactic acidosis also directs the metabolic reprogramming of tumor cells and serves as an additional selective pressure. Finally, we also discuss the role of mitochondria in supporting tumor cell metabolism. PMID:22057267

  5. Effect of endothelial cell denudation on fatty acid metabolism by the rabbit aorta

    SciTech Connect

    Takasaki, I.; Cohen, R.A.; Chobanian, A.V.; Brecher, P. )

    1990-02-26

    The regulatory role of aortic endothelial cells in fatty acid uptake and metabolism by vascular tissue was studied in vitro using aortic strips from New Zealand white rabbits. Endothelium was left intact or removed either by scraping with forceps or with a cotton swab. Removal of endothelium was assessed morphologically by silver staining and pharmacologically by endothelium-dependent vasorelaxation. Aortic strips were incubated with {sup 14}C-oleate (OA) or {sup 14}C-arachidonate (AA) and oxidation and esterification was measured. Denudation by forceps caused a 50% decrease in oxidation and esterification into phospholipid (PL) and triglyceride (TG) for both OA and AA. In contrast, removal by cotton swab caused a smaller but significant reduction in oxidation (OA; 26%, AA; 24%), and esterification into PL was reduced by only 8% (OA) or 17% (AA) and TG incorporation was not affected for either fatty acid. In the presence or absence of endothelium, esterification of AA into PL was significantly higher than that of OA, with a differing distribution among PL classes between OA and AA. The studies suggest endothelium has a role in fatty acid uptake and metabolism, and that fatty acid oxidation may be a sensitive index of vascular injury.

  6. Metabolic responses of CHO cells to limitation of key amino acids.

    PubMed

    Duarte, Tiago M; Carinhas, Nuno; Barreiro, Laura C; Carrondo, Manuel J T; Alves, Paula M; Teixeira, Ana P

    2014-10-01

    Chinese hamster ovary (CHO) cells are the predominant host for production of therapeutic glycoproteins. In particular, the glutamine-synthetase (GS) expression system has been widely used in the biopharmaceutical industry for efficient selection of high-yielding clones. However, much remains unclear on how metabolic wiring affects culture performance. For instance, asparagine and serine have been observed to be the largest nitrogen sources taken up by GS-CHO cells, but their roles in biosynthesis and energy generation are poorly understood. In this work, a comprehensive profiling of extracellular metabolites coupled with an analysis of intracellular label distributions after 1-(13) C-pyruvate supplementation were used to trace metabolic rearrangements in different scenarios of asparagine and serine availability. The absence of asparagine in the medium caused growth arrest, and was associated with a dramatic increase in pyruvate uptake, a higher ratio of pyruvate carboxylation to dehydrogenation and an inability for de novo asparagine synthesis. The release of ammonia and amino acids such as aspartate, glutamate, and alanine were deeply impacted. This confirms asparagine to be essential for these GS-CHO cells as the main source of intracellular nitrogen as well as having an important anaplerotic role in TCA cycle activity. In turn, serine unavailability also negatively affected culture growth while triggering its de novo synthesis, confirmed by label incorporation coming from pyruvate, and reduced glycine and formate secretion congruent with its role as a precursor in the metabolism of one-carbon units. Overall, these results unfold important insights into GS-CHO cells metabolism that lay a clearer basis for fine-tuning bioprocess optimization.

  7. Bile Acid Metabolism and Signaling

    PubMed Central

    Chiang, John Y. L.

    2015-01-01

    Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684

  8. Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells.

    PubMed

    Maruta, Hitomi; Yoshimura, Yukihiro; Araki, Aya; Kimoto, Masumi; Takahashi, Yoshitaka; Yamashita, Hiromi

    2016-01-01

    Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK) in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4) genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A), which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin.

  9. Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells.

    PubMed

    Maruta, Hitomi; Yoshimura, Yukihiro; Araki, Aya; Kimoto, Masumi; Takahashi, Yoshitaka; Yamashita, Hiromi

    2016-01-01

    Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK) in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4) genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A), which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin. PMID:27348124

  10. Activation of AMP-Activated Protein Kinase and Stimulation of Energy Metabolism by Acetic Acid in L6 Myotube Cells

    PubMed Central

    Maruta, Hitomi; Yoshimura, Yukihiro; Araki, Aya; Kimoto, Masumi; Takahashi, Yoshitaka; Yamashita, Hiromi

    2016-01-01

    Previously, we found that orally administered acetic acid decreased lipogenesis in the liver and suppressed lipid accumulation in adipose tissue of Otsuka Long-Evans Tokushima Fatty rats, which exhibit hyperglycemic obesity with hyperinsulinemia and insulin resistance. Administered acetic acid led to increased phosphorylation of AMP-activated protein kinase (AMPK) in both liver and skeletal muscle cells, and increased transcripts of myoglobin and glucose transporter 4 (GLUT4) genes in skeletal muscle of the rats. It was suggested that acetic acid improved the lipid metabolism in skeletal muscles. In this study, we examined the activation of AMPK and the stimulation of GLUT4 and myoglobin expression by acetic acid in skeletal muscle cells to clarify the physiological function of acetic acid in skeletal muscle cells. Acetic acid added to culture medium was taken up rapidly by L6 cells, and AMPK was phosphorylated upon treatment with acetic acid. We observed increased gene and protein expression of GLUT4 and myoglobin. Uptake of glucose and fatty acids by L6 cells were increased, while triglyceride accumulation was lower in treated cells compared to untreated cells. Furthermore, treated cells also showed increased gene and protein expression of myocyte enhancer factor 2A (MEF2A), which is a well-known transcription factor involved in the expression of myoglobin and GLUT4 genes. These results indicate that acetic acid enhances glucose uptake and fatty acid metabolism through the activation of AMPK, and increases expression of GLUT4 and myoglobin. PMID:27348124

  11. Surfactant-induced alteration of arachidonic acid metabolism of mammalian cells in culture.

    PubMed

    De Leo, V A; Harber, L C; Kong, B M; De Salva, S J

    1987-04-01

    Primary irritancy in human and animal skin is characterized by an inflammatory reaction mediated, in part, by membrane-derived arachidonate metabolites. One of the mechanisms of this reaction was investigated in cultured mammalian cells using three surfactants: linear alkyl benzene sulfonate (LAS), alkyl ethoxylate sulfate (AEOS), and TWEEN 20. These compounds listed in order in vivo irritancy are LAS greater than AEOS greater than TWEEN 20. Each of these compounds was studied in C3H-10T1/2 cells and human keratinocytes which had been prelabeled with 3H-labeled arachidonic acid (AA). After labeling, media were removed, cells were washed, and fresh media with or without surfactant were added. Cells were then incubated for 2 hr, media were removed and centrifuged, and an aliquot was assayed by liquid scintillation for release of label. In C3H-10T1/2 cells LAS and AEOS in 5-50 microM concentration stimulated 2 to 10 times the release of [3H]AA as compared to controls. In contrast, concentrations of 50-100 microM of TWEEN were required to release [3H]AA. With keratinocytes the same rank order of surfactant concentrations necessary for release was obtained as found with C3H-10T1/2 cells. High-performance liquid chromatography of media extracts of both cell systems revealed surfactant stimulation of the production of cyclooxygenase AA metabolites. These results confirm the induction of release by primary irritants of fatty acid groups from membrane phospholipids. Subsequent metabolism of these fatty acid groups are an integral part of the primary irritant response. Data presented with three known irritants in this in vitro model show a direct correlation with in vivo studies.

  12. Uptake and metabolic effects of salicylic acid on the pulvinar motor cells of Mimosa pudica L.

    PubMed

    Dédaldéchamp, Fabienne; Saeedi, Saed; Fleurat-Lessard, Pierrette; Roblin, Gabriel

    2014-01-01

    In this paper, the salicylic acid (o-hydroxy benzoic acid) (SA) uptake by the pulvinar tissues of Mimosa pudica L. pulvini was shown to be strongly pH-dependent, increasing with acidity of the assay medium. This uptake was performed according to a unique affinity system (K(m) = 5.9 mM, V(m) = 526 pmol mgDW(-1)) in the concentration range of 0.1-5 mM. The uptake rate increased with increasing temperature (5-35 °C) and was inhibited following treatment with sodium azide (NaN3) and carbonyl cyanide m-chlorophenylhydrazone (CCCP), suggesting the involvement of an active component. Treatment with p-chloromercuribenzenesulfonic acid (PCMBS) did not modify the uptake, indicating that external thiol groups were not necessary. KCl, which induced membrane depolarization had no significant effect, and fusicoccin (FC), which hyperpolarized cell membrane, stimulated the uptake, suggesting that the pH component of the proton motive force was likely a driving force. These data suggest that the SA uptake by the pulvinar tissues may be driven by two components: an ion-trap mechanism playing a pivotal role and a putative carrier-mediated mechanism. Unlike other benzoic acid derivatives acting as classical respiration inhibitors (NaN3 and KCN), SA modified the pulvinar cell metabolism by increasing the respiration rate similar to CCCP and 2,4-dinitrophenol (DNP). Furthermore, SA inhibited the osmoregulated seismonastic reaction in a pH dependent manner and induced characteristic damage to the ultrastructural features of the pulvinar motor cells, particularly at the mitochondrial level.

  13. Antigen receptor control of amino acid transport coordinates the metabolic re-programming that is essential for T cell differentiation

    PubMed Central

    Sinclair, Linda V.; Rolf, Julia; Emslie, Elizabeth; Shi, Yun-Bo; Taylor, Peter M.; Cantrell, Doreen A.

    2013-01-01

    Summary T lymphocytes regulate nutrient uptake to meet the metabolic demands of immune activation. The present study shows that the intracellular supply of large neutral amino acids (LNAAs) in T cells is regulated by pathogen and the T cell antigen receptor (TCR). A single System L transporter, Slc7a5, mediated LNAA uptake in activated T cells. Slc7a5-null T cells could not metabolically reprogram in response to antigen and failed clonal expansion and effector differentiation. The metabolic catastrophe caused by Slc7a5 loss reflects the requirement for sustained uptake of the LNAA leucine for activation of mammalian target of rapamycin complex 1 (mTORC1) and for expression of c-myc. Pathogen control of System L transporters is thus a critical metabolic checkpoint for T cells. PMID:23525088

  14. Differences in phosphatidic acid signalling and metabolism between ABA and GA treatments of barley aleurone cells.

    PubMed

    Villasuso, Ana Laura; Di Palma, Maria A; Aveldaño, Marta; Pasquaré, Susana J; Racagni, Graciela; Giusto, Norma M; Machado, Estela E

    2013-04-01

    Phosphatidic acid (PA) is the common lipid product in abscisic acid (ABA) and gibberellic acid (GA) response. In this work we investigated the lipid metabolism in response to both hormones. We could detect an in vivo phospholipase D activity (PLD, EC 3.1.4.4). This PLD produced [(32)P]PA (phosphatidic acid) rapidly (minutes) in the presence of ABA, confirming PA involvement in signal transduction, and transiently, indicating rapid PA removal after generation. The presence of PA removal by phosphatidate phosphatase 1 and 2 isoforms (E.C. 3.1.3.4) was verified in isolated aleurone membranes in vitro, the former but not the latter being specifically responsive to the presence of GA or ABA. The in vitro DGPP phosphatase activity was not modified by short time incubation with GA or ABA while the in vitro PA kinase - that allows the production of 18:2-DGPP from 18:2-PA - is stimulated by ABA. The long term effects (24 h) of ABA or GA on lipid and fatty acid composition of aleurone layer cells were then investigated. An increase in PC and, to a lesser extent, in PE levels is the consequence of both hormone treatments. ABA, in aleurone layer cells, specifically activates a PLD whose product, PA, could be the substrate of PAP1 and/or PAK activities. Neither PLD nor PAK activation can be monitored by GA treatment. The increase in PAP1 activity monitored after ABA or GA treatment might participate in the increase in PC level observed after 24 h hormone incubation.

  15. Ozone-induced alterations in arachidonic acid metabolism in cultured lung cell types

    SciTech Connect

    Madden, M.C.

    1986-01-01

    One of the most sensitive cells to ozone (O/sub 3/) damage is the pulmonary endothelial cell which may mediate the response of the lung to injury by productions of the autacoid prostacyclin (PGl/sub 2/), a metabolite of arachidonic acid. Exposure of endothelial cell cultures to ozone produced a concentration dependent decreases in the synthesis of PGl/sub 2/. Release of /sup 3/H-arachidonic acid from endothelial cells was increased after two hours of 0.3 and 1.0 ppm O/sub 3/ exposure while incubation of cells with 20 ..mu..M and arachidonate (4 min) after exposure resulted in a decreased PGl/sub 2/ synthesis. Cells exposed to 1.0 ppm O/sub 3/ did not have a decreased PGl/sub 2/ production when incubated with 5 ..mu..M PGH/sub 2/ immediately after exposure. These results are consistent with an O/sub 3/-induced inhibition of cyclooxygenase activity. O/sub 3/ exposure (1.0 ppm) produced a rapid decrease in endothelial PGl/sub 2/ synthesis. The data suggest that cyclooxygenase was not inactivated by increased autooxidation due to metabolism of increased free arachidonate. PGl/sub 2/ synthesis returned to control amounts within 12 hours after ozone exposure similar to the recovery time of irreversibly inhibited cyclooxygenase suggesting that recovery was due to de novo synthesis of enzyme. Lipid peroxides and/or hydrogen peroxide (H/sub 2/O/sub 2/) may have caused the inhibition of cyclooxygenase. Incubation of cells with catalase (5 U/ml) protected against the O/sub 3/-induced depression in PGl/sub 2/ synthesis. Exogenously added H/sub 2/O/sub 2/ (greater than or equal to 75 ..mu..M) caused a stimulation of basal PGl/sub 2/ production but depressed arachidonate-stimulated synthesis. O/sub 3/ exposure (2 hr, 1.0 ppm) produced altered metabolism of arachidonate in other important lung cell types, e.g., a decreased PGl/sub 2/ synthesis in smooth muscle cultures. Exposure of lung macrophages to O/sub 3/ caused an increase in almost all arachidonate metabolites produced.

  16. Endocrine control of oleic acid and glucose metabolism in rainbow trout (Oncorhynchus mykiss) muscle cells in culture.

    PubMed

    Sánchez-Gurmaches, Joan; Cruz-Garcia, Lourdes; Gutiérrez, Joaquím; Navarro, Isabel

    2010-08-01

    The effects of insulin and IGF-I on fatty acid (FA) and glucose metabolism were examined using oleic acid or glucose as tracers in differentiated rainbow trout (Oncorhynchus mykiss) myotubes. Insulin and IGF-I significantly reduced the production of CO(2) from oleic acid with respect to the control values. IGF-I also significantly reduced the production of acid-soluble products (ASP) and the concentration of FA in the medium, while cellular triacylglycerols (TAG) tended to increase. Only insulin produced a significant accumulation of glycogen inside the cells in glucose distribution experiments. Incubation with catecholamines did not affect oleic acid metabolism. Cells treated with rapamycin [a target of rapamycin (TOR) inhibitor] significantly increased the oxidation of oleic acid to CO(2) and ASP, while the accumulation of TAG diminished. Rosiglitazone (a peroxisome proliferator-activated receptor gamma agonist) and etomoxir (a CPT-1 inhibitor) produced a severe and significant reduction in the production of CO(2) and ASP. Rosiglitazone and etomoxir also produced a significant accumulation of FA outside and inside the cells, respectively. No significant effects of these drugs on glucose distribution were observed. These data indicate that insulin and IGF-I act as anabolic hormones in trout myotubes in both oleic acid and glucose metabolism, although glucose oxidation appears to be less sensitive than FA oxidation to insulin and IGF-I. The use of rapamycin, etomoxir, and rosiglitazone may help us to understand the mechanisms of regulation of lipid metabolism in fish. PMID:20484701

  17. Fatty acid synthase is a metabolic marker of cell proliferation rather than malignancy in ovarian cancer and its precursor cells.

    PubMed

    Veigel, Daniel; Wagner, Renate; Stübiger, Gerald; Wuczkowski, Michael; Filipits, Martin; Horvat, Reinhard; Benhamú, Bellinda; López-Rodríguez, María Luz; Leisser, Asha; Valent, Peter; Grusch, Michael; Hegardt, Fausto G; García, Jordi; Serra, Dolors; Auersperg, Nelly; Colomer, Ramón; Grunt, Thomas W

    2015-05-01

    Ovarian cancer (OC) is caused by genetic aberrations in networks that control growth and survival. Importantly, aberrant cancer metabolism interacts with oncogenic signaling providing additional drug targets. Tumors overexpress the lipogenic enzyme fatty acid synthase (FASN) and are inhibited by FASN blockers, whereas normal cells are FASN-negative and FASN-inhibitor-resistant. Here, we demonstrate that this holds true when ovarian/oviductal cells reside in their autochthonous tissues, whereas in culture they express FASN and are FASN-inhibitor-sensitive. Upon subculture, nonmalignant cells cease growth, express senescence-associated β-galactosidase, lose FASN and become FASN-inhibitor-resistant. Immortalized ovarian/oviductal epithelial cell lines—although resisting senescence—reveal distinct growth activities, which correlate with FASN levels and FASN drug sensitivities. Accordingly, ectopic FASN stimulates growth in these cells. Moreover, FASN levels and lipogenic activities affect cellular lipid composition as demonstrated by thin-layer chromatography. Correlation between proliferation and FASN levels was finally evaluated in cancer cells such as HOC-7, which contain subclones with variable differentiation/senescence and corresponding FASN expression/FASN drug sensitivity. Interestingly, senescent phenotypes can be induced in parental HOC-7 by differentiating agents. In OC cells, FASN drugs induce cell cycle blockade in S and/or G2/M and stimulate apoptosis, whereas in normal cells they only cause cell cycle deceleration without apoptosis. Thus, normal cells, although growth-inhibited, may survive and recover from FASN blockade, whereas malignant cells get extinguished. FASN expression and FASN drug sensitivity are directly linked to cell growth and correlate with transformation/differentiation/senescence only indirectly. FASN is therefore a metabolic marker of cell proliferation rather than a marker of malignancy and is a useful target for future drug

  18. Novel Metabolic Abnormalities in the Tricarboxylic Acid Cycle in Peripheral Cells From Huntington's Disease Patients.

    PubMed

    Naseri, Nima N; Bonica, Joseph; Xu, Hui; Park, Larry C; Arjomand, Jamshid; Chen, Zhengming; Gibson, Gary E

    2016-01-01

    Metabolic dysfunction is well-documented in Huntington's disease (HD). However, the link between the mutant huntingtin (mHTT) gene and the pathology is unknown. The tricarboxylic acid (TCA) cycle is the main metabolic pathway for the production of NADH for conversion to ATP via the electron transport chain (ETC). The objective of this study was to test for differences in enzyme activities, mRNAs and protein levels related to the TCA cycle between lymphoblasts from healthy subjects and from patients with HD. The experiments utilize the advantages of lymphoblasts to reveal new insights about HD. The large quantity of homogeneous cell populations permits multiple dynamic measures to be made on exactly comparable tissues. The activities of nine enzymes related to the TCA cycle and the expression of twenty-nine mRNAs encoding for these enzymes and enzyme complexes were measured. Cells were studied under baseline conditions and during metabolic stress. The results support our recent findings that the activities of the pyruvate dehydrogenase complex (PDHC) and succinate dehydrogenase (SDH) are elevated in HD. The data also show a large unexpected depression in MDH activities. Furthermore, message levels for isocitrate dehydrogenase 1 (IDH1) were markedly increased in in HD lymphoblasts and were responsive to treatments. The use of lymphoblasts allowed us to clarify that the reported decrease in aconitase activity in HD autopsy brains is likely due to secondary hypoxic effects. These results demonstrate the mRNA and enzymes of the TCA cycle are critical therapeutic targets that have been understudied in HD. PMID:27611087

  19. Equine tracheal epithelial membrane strips - An alternate method for examining epithelial cell arachidonic acid metabolism

    SciTech Connect

    Gray, P.R.; Derksen, F.J.; Robinson, N.E.; Peter-Golden, M.L. Univ. of Michigan, Ann Arbor )

    1990-02-26

    Arachidonic acid metabolism by tracheal epithelium can be studied using enzymatically dispersed cell suspensions or cell cultures. Both techniques require considerable tissue disruption and manipulation and may not accurately represent in vivo activity. The authors have developed an alternate method for obtaining strips of equine tracheal epithelium without enzymatic digestion. In the horse, a prominent elastic lamina supports the tracheal epithelium. By physical splitting this lamina, they obtained strips ({le}12 x 1.5 cm) of pseudostratified columnar epithelium attached to a layer of elastic tissue 30-100 {mu}m thick. Epithelial strips (1.2 x 0.5 cm) were attached to plexiglass rods and incubated with ({sup 3}H)arachidonic acid in M199 medium (0.5 {mu}Ci/ml) for 24 hours at 37C. The strips incorporated 36{+-}4% (mean {+-} SEM) of the total radioactivity and released 8.0{+-}1.2% of incorporated radioactivity when stimulated by 5.0 {mu}M calcium ionophore A23187. The extracted supernatant was processed using HPLC, resulting in peaks of radioactivity that co-eluted with authentic PGE{sub 2}, PGF{sub 2}{alpha}, and 12-HETE standards. The greatest activity corresponded to the PGE{sub 2} and PGF{sub 2}{alpha} standards, which is a similar pattern to that reported for cultured human tracheal epithelium.

  20. Regulation of Glucose Metabolism and Cell Wall Synthesis in Avena Stem Segments by Gibberellic Acid 1

    PubMed Central

    Montague, Michael J.; Ikuma, Hiroshi

    1978-01-01

    Gibberellic acid (GA) stimulated both the elongation of Avena sativa stem segments and increased synthesis of cell wall material. The effects of GA on glucose metabolism, as related to cell wall synthesis, have been investigated in order to find specific events regulated by GA. GA caused a decline in the levels of glucose, glucose 6-phosphate, and fructose 6-phosphate if exogenous sugar was not supplied to the segments, whereas the hormone caused no change in the levels of glucose 6-phosphate, fructose 6-phosphate, UDP-glucose, or the adenylate energy charge if the segments were incubated in 0.1 m glucose. No GA-induced change could be demonstrated in the activities of hexokinase, phosphoglucomutase, UDP-glucose pyrophosphorylase, or polysaccharide synthetases using UDP-glucose, UDP-galactose, UDP-xylose, and UDP-arabinose as substrates. GA stimulated the activity of GDP-glucose-dependent β-glucan synthetase by 2- to 4-fold over the control. When glucan synthetase was assayed using UDP-glucose as substrate, only β-1,3-linked glucan was synthesized in vitro, whereas with GDP-glucose, only β-1,4-linked glucan was synthesized. These results suggest that one part of the mechanism by which GA stimulates cell wall synthesis concurrently with elongation in Avena stem segments may be through a stimulation of cell wall polysaccharide synthetase activity. PMID:16660524

  1. Injuries to cultivated BJA-B cells by ajoene, a garlic-derived natural compound: cell viability, glutathione metabolism, and pools of acidic amino acids.

    PubMed

    Scharfenberg, K; Ryll, T; Wagner, R; Wagner, K G

    1994-01-01

    Ajoene (4,5,9-trithiadodeca-1,6,11-triene-9-oxide), a garlic-derived natural compound, which had been shown to have cytostatic/cytotoxic properties, was tested with a B cell lymphoma-derived cell line (BJA-B cells) in order to elucidate its mechanism of cytotoxic action. Viability of the cells was determined by the Trypan blue exclusion test and the colorimetric tetrazolium (MTT) assay, whereas metabolic disturbance was evaluated by measuring the pools of reduced (GSH), oxidized glutathione (GSSG) and the acidic amino acids, Glu and Asp. Fast uptake of ajoene was accompanied by an immediate reduction of the GSH and increase in the GSSG levels. The extent of these changes, as well as the further development of the metabolite pools, depended on the ajoene dose per cell. At a sublethal ajoene dose the GSH and GSSG pools rose at the later stages to levels much higher than in the control experiment. Bleb formation at the cytoplasmic membrane was a further rapid phenomenon, although injuries detected by Trypan blue exclusion developed only at a later stage. The MTT assay, performed in a parallel experiment (48 h after ajoene addition), showed, however, that reduction of cell viability was established at the very beginning of ajoene exposure. Altogether, the action of ajoene strongly resembled oxidative stress (i.e., interference with SH homeostasis and its pleiotropic consequences to cell physiology and metabolism.

  2. Effects of fatty acids on benzo[a]pyrene uptake and metabolism in human lung adenocarcinoma A549 cells.

    PubMed

    Barhoumi, Rola; Mouneimne, Youssef; Chapkin, Robert S; Burghardt, Robert C

    2014-01-01

    Dietary supplementation with natural chemoprotective agents is receiving considerable attention because of health benefits and lack of toxicity. In recent in vivo and in vitro experimental studies, diets rich in n-3 polyunsaturated fatty acids have been shown to provide significant anti-tumor action. In this investigation, the effects of control fatty acids (oleic acid (OA), linoleic acid (LA)) and n-3 PUFA, e.g., docosahexaenoic acid (DHA) on the uptake and metabolism of the carcinogenic polycyclic aromatic hydrocarbon, benzo[a]pyrene (BaP) was investigated in A549 cells, a human adenocarcinoma alveolar basal epithelial cell line. A549 cells activate BaP through the cytochrome P450 enzyme system to form reactive metabolites, a few of which covalently bind to DNA and proteins. Therefore, multiphoton microscopy spectral analysis combined with linear unmixing was used to identify the parent compound and BaP metabolites formed in cells, in the presence and absence of fatty acids. The relative abundance of select metabolites was associated with altered P450 activity as determined using ethoxyresorufin-O-deethylase activity in cells cultured in the presence of BSA-conjugated fatty acids. In addition, the parent compound within cellular membranes increases significantly in the presence of each of the fatty acids, with the greatest accumulation observed following DHA treatment. DHA treated cells exhibit significantly lower pyrene-like metabolites indicative of lower adducts including DNA adducts compared to control BSA, OA or LA treated cells. Further, DHA reduced the abundance of the proximate carcinogen BaP 7,8-dihydrodiol and the 3-hydroxybenzo[a]pyrene metabolites compared to other treatments. The significant changes in BaP metabolites in DHA treated cells may be mediated by the effects on the physicochemical properties of the membrane known to affect enzyme activity related to phase I and phase II metabolism. In summary, DHA is a highly bioactive chemo

  3. Metabolomic profiling reveals a role for androgen in activating amino acid metabolism and methylation in prostate cancer cells.

    PubMed

    Putluri, Nagireddy; Shojaie, Ali; Vasu, Vihas T; Nalluri, Srilatha; Vareed, Shaiju K; Putluri, Vasanta; Vivekanandan-Giri, Anuradha; Byun, Jeman; Pennathur, Subramaniam; Sana, Theodore R; Fischer, Steven M; Palapattu, Ganesh S; Creighton, Chad J; Michailidis, George; Sreekumar, Arun

    2011-01-01

    Prostate cancer is the second leading cause of cancer related death in American men. Development and progression of clinically localized prostate cancer is highly dependent on androgen signaling. Metastatic tumors are initially responsive to anti-androgen therapy, however become resistant to this regimen upon progression. Genomic and proteomic studies have implicated a role for androgen in regulating metabolic processes in prostate cancer. However, there have been no metabolomic profiling studies conducted thus far that have examined androgen-regulated biochemical processes in prostate cancer. Here, we have used unbiased metabolomic profiling coupled with enrichment-based bioprocess mapping to obtain insights into the biochemical alterations mediated by androgen in prostate cancer cell lines. Our findings indicate that androgen exposure results in elevation of amino acid metabolism and alteration of methylation potential in prostate cancer cells. Further, metabolic phenotyping studies confirm higher flux through pathways associated with amino acid metabolism in prostate cancer cells treated with androgen. These findings provide insight into the potential biochemical processes regulated by androgen signaling in prostate cancer. Clinically, if validated, these pathways could be exploited to develop therapeutic strategies that supplement current androgen ablative treatments while the observed androgen-regulated metabolic signatures could be employed as biomarkers that presage the development of castrate-resistant prostate cancer. PMID:21789170

  4. Metabolomic Profiling Reveals a Role for Androgen in Activating Amino Acid Metabolism and Methylation in Prostate Cancer Cells

    PubMed Central

    Putluri, Nagireddy; Shojaie, Ali; Vasu, Vihas T.; Nalluri, Srilatha; Vareed, Shaiju K.; Putluri, Vasanta; Vivekanandan-Giri, Anuradha; Byun, Jeman; Pennathur, Subramaniam; Sana, Theodore R.; Fischer, Steven M.; Palapattu, Ganesh S.; Creighton, Chad J.; Michailidis, George; Sreekumar, Arun

    2011-01-01

    Prostate cancer is the second leading cause of cancer related death in American men. Development and progression of clinically localized prostate cancer is highly dependent on androgen signaling. Metastatic tumors are initially responsive to anti-androgen therapy, however become resistant to this regimen upon progression. Genomic and proteomic studies have implicated a role for androgen in regulating metabolic processes in prostate cancer. However, there have been no metabolomic profiling studies conducted thus far that have examined androgen-regulated biochemical processes in prostate cancer. Here, we have used unbiased metabolomic profiling coupled with enrichment-based bioprocess mapping to obtain insights into the biochemical alterations mediated by androgen in prostate cancer cell lines. Our findings indicate that androgen exposure results in elevation of amino acid metabolism and alteration of methylation potential in prostate cancer cells. Further, metabolic phenotyping studies confirm higher flux through pathways associated with amino acid metabolism in prostate cancer cells treated with androgen. These findings provide insight into the potential biochemical processes regulated by androgen signaling in prostate cancer. Clinically, if validated, these pathways could be exploited to develop therapeutic strategies that supplement current androgen ablative treatments while the observed androgen-regulated metabolic signatures could be employed as biomarkers that presage the development of castrate-resistant prostate cancer. PMID:21789170

  5. The Fatty Acid Signaling Molecule cis-2-Decenoic Acid Increases Metabolic Activity and Reverts Persister Cells to an Antimicrobial-Susceptible State

    PubMed Central

    Morozov, Aleksey; Planzos, Penny; Zelaya, Hector M.

    2014-01-01

    Persister cells, which are tolerant to antimicrobials, contribute to biofilm recalcitrance to therapeutic agents. In turn, the ability to kill persister cells is believed to significantly improve efforts in eradicating biofilm-related, chronic infections. While much research has focused on elucidating the mechanism(s) by which persister cells form, little is known about the mechanism or factors that enable persister cells to revert to an active and susceptible state. Here, we demonstrate that cis-2-decenoic acid (cis-DA), a fatty acid signaling molecule, is able to change the status of Pseudomonas aeruginosa and Escherichia coli persister cells from a dormant to a metabolically active state without an increase in cell number. This cell awakening is supported by an increase of the persister cells' respiratory activity together with changes in protein abundance and increases of the transcript expression levels of several metabolic markers, including acpP, 16S rRNA, atpH, and ppx. Given that most antimicrobials target actively growing cells, we also explored the effect of cis-DA on enhancing antibiotic efficacy in killing persister cells due to their inability to keep a persister cell state. Compared to antimicrobial treatment alone, combinational treatments of persister cell subpopulations with antimicrobials and cis-DA resulted in a significantly greater decrease in cell viability. In addition, the presence of cis-DA led to a decrease in the number of persister cells isolated. We thus demonstrate the ability of a fatty acid signaling molecule to revert bacterial cells from a tolerant phenotype to a metabolically active, antimicrobial-sensitive state. PMID:25192989

  6. Acidosis Drives the Reprogramming of Fatty Acid Metabolism in Cancer Cells through Changes in Mitochondrial and Histone Acetylation.

    PubMed

    Corbet, Cyril; Pinto, Adán; Martherus, Ruben; Santiago de Jesus, João Pedro; Polet, Florence; Feron, Olivier

    2016-08-01

    Bioenergetic preferences of cancer cells foster tumor acidosis that in turn leads to dramatic reduction in glycolysis and glucose-derived acetyl-coenzyme A (acetyl-CoA). Here, we show that the main source of this critical two-carbon intermediate becomes fatty acid (FA) oxidation in acidic pH-adapted cancer cells. FA-derived acetyl-CoA not only fuels the tricarboxylic acid (TCA) cycle and supports tumor cell respiration under acidosis, but also contributes to non-enzymatic mitochondrial protein hyperacetylation, thereby restraining complex I activity and ROS production. Also, while oxidative metabolism of glutamine supports the canonical TCA cycle in acidic conditions, reductive carboxylation of glutamine-derived α-ketoglutarate sustains FA synthesis. Concomitance of FA oxidation and synthesis is enabled upon sirtuin-mediated histone deacetylation and consecutive downregulation of acetyl-CoA carboxylase ACC2 making mitochondrial fatty acyl-CoA degradation compatible with cytosolic lipogenesis. Perturbations of these regulatory processes lead to tumor growth inhibitory effects further identifying FA metabolism as a critical determinant of tumor cell proliferation under acidosis. PMID:27508876

  7. β-alanine suppresses malignant breast epithelial cell aggressiveness through alterations in metabolism and cellular acidity in vitro

    PubMed Central

    2014-01-01

    Background Deregulated energetics is a property of most cancer cells. This phenomenon, known as the Warburg Effect or aerobic glycolysis, is characterized by increased glucose uptake, lactate export and extracellular acidification, even in the presence of oxygen. β-alanine is a non-essential amino acid that has previously been shown to be metabolized into carnosine, which functions as an intracellular buffer. Because of this buffering capacity, we investigated the effects of β-alanine on the metabolic cancerous phenotype. Methods Non-malignant MCF-10a and malignant MCF-7 breast epithelial cells were treated with β-alanine at 100 mM for 24 hours. Aerobic glycolysis was quantified by measuring extracellular acidification rate (ECAR) and oxidative metabolism was quantified by measuring oxygen consumption rate (OCR). mRNA of metabolism-related genes was quantified by qRT-PCR with corresponding protein expression quantified by immunoblotting, or by flow cytometry which was verified by confocal microscopy. Mitochondrial content was quantified using a mitochondria-specific dye and measured by flow cytometry. Results Cells treated with β-alanine displayed significantly suppressed basal and peak ECAR (aerobic glycolysis), with simultaneous increase in glucose transporter 1 (GLUT1). Additionally, cells treated with β-alanine exhibited significantly reduced basal and peak OCR (oxidative metabolism), which was accompanied by reduction in mitochondrial content with subsequent suppression of genes which promote mitochondrial biosynthesis. Suppression of glycolytic and oxidative metabolism by β-alanine resulted in the reduction of total metabolic rate, although cell viability was not affected. Because β-alanine treatment reduces extracellular acidity, a constituent of the invasive microenvironment that promotes progression, we investigated the effect of β-alanine on breast cell viability and migration. β-alanine was shown to reduce both cell migration and proliferation

  8. PGC-1 coactivators in β-cells regulate lipid metabolism and are essential for insulin secretion coupled to fatty acids

    PubMed Central

    Oropeza, Daniel; Jouvet, Nathalie; Bouyakdan, Khalil; Perron, Gabrielle; Ringuette, Lea-Jeanne; Philipson, Louis H.; Kiss, Robert S.; Poitout, Vincent; Alquier, Thierry; Estall, Jennifer L.

    2015-01-01

    Objectives Peroxisome proliferator-activated receptor γ coactivator 1 (PPARGCA1, PGC-1) transcriptional coactivators control gene programs important for nutrient metabolism. Islets of type 2 diabetic subjects have reduced PGC-1α expression and this is associated with decreased insulin secretion, yet little is known about why this occurs or what role it plays in the development of diabetes. Our goal was to delineate the role and importance of PGC-1 proteins to β-cell function and energy homeostasis. Methods We investigated how nutrient signals regulate coactivator expression in islets and the metabolic consequences of reduced PGC-1α and PGC-1β in primary and cultured β-cells. Mice with inducible β-cell specific double knockout of Pgc-1α/Pgc-1β (βPgc-1 KO) were created to determine the physiological impact of reduced Pgc1 expression on glucose homeostasis. Results Pgc-1α and Pgc-1β expression was increased in primary mouse and human islets by acute glucose and palmitate exposure. Surprisingly, PGC-1 proteins were dispensable for the maintenance of mitochondrial mass, gene expression, and oxygen consumption in response to glucose in adult β-cells. However, islets and mice with an inducible, β-cell-specific PGC-1 knockout had decreased insulin secretion due in large part to loss of the potentiating effect of fatty acids. Consistent with an essential role for PGC-1 in lipid metabolism, β-cells with reduced PGC-1s accumulated acyl-glycerols and PGC-1s controlled expression of key enzymes in lipolysis and the glycerolipid/free fatty acid cycle. Conclusions These data highlight the importance of PGC-1s in coupling β-cell lipid metabolism to promote efficient insulin secretion. PMID:26629405

  9. Skeletal muscle-specific eukaryotic translation initiation factor 2α phosphorylation controls amino acid metabolism and fibroblast growth factor 21-mediated non-cell-autonomous energy metabolism.

    PubMed

    Miyake, Masato; Nomura, Akitoshi; Ogura, Atsushi; Takehana, Kenji; Kitahara, Yoshihiro; Takahara, Kazuna; Tsugawa, Kazue; Miyamoto, Chinobu; Miura, Naoko; Sato, Ryosuke; Kurahashi, Kiyoe; Harding, Heather P; Oyadomari, Miho; Ron, David; Oyadomari, Seiichi

    2016-02-01

    The eukaryotic translation initiation factor 2α (eIF2α) phosphorylation-dependent integrated stress response (ISR), a component of the unfolded protein response, has long been known to regulate intermediary metabolism, but the details are poorly worked out. We report that profiling of mRNAs of transgenic mice harboring a ligand-activated skeletal muscle-specific derivative of the eIF2α protein kinase R-like ER kinase revealed the expected up-regulation of genes involved in amino acid biosynthesis and transport but also uncovered the induced expression and secretion of a myokine, fibroblast growth factor 21 (FGF21), that stimulates energy consumption and prevents obesity. The link between the ISR and FGF21 expression was further reinforced by the identification of a small-molecule ISR activator that promoted Fgf21 expression in cell-based screens and by implication of the ISR-inducible activating transcription factor 4 in the process. Our findings establish that eIF2α phosphorylation regulates not only cell-autonomous proteostasis and amino acid metabolism, but also affects non-cell-autonomous metabolic regulation by induced expression of a potent myokine.

  10. Uptake and metabolism of (11-/sup 3/H) all-trans retinoic acid by rabbit tracheal epithelial cells

    SciTech Connect

    Bhat, P.V.; Jetten, A.M.

    1986-01-01

    Retinoic acid (RA) inhibits squamous cell differentiation of rabbit tracheal epithelial cells in culture at concentrations as low as 10/sup -9/ - 10/sup -10/ M. These cells take up 11-(/sup 3/H)-RA readily when added to the cells either as free RA or as RA complexed to serum retinol binding protein (SRBP) or albumin. The uptake of RA by RTE cells as SRBP or albumin complexes was significantly lower than that of free RA. Metabolites were analyzed by high pressure liquid chromatography. This analysis showed that RTE cells metabolized RA to polar metabolites (Peak I) and to a less polar metabolite (Peak III). The metabolite in Peak III constituted 13-20% of the cell-associated radioactivity after 24 hrs. incubation with RA. Formation of the Peak I and Peak III metabolites from RA was observed both in undifferentiated as well as in cells that underwent terminal differentiation to squamous cells and their synthesis appeared constitutive. When cells were treated for 6 hrs with /sup 3/H-RA and then further in the absence of RA 75% of the cell-associated radioactivity was released in the medium within 24 hrs, thereafter the release was slow. Analysis of the metabolites secreted by the cells into the medium showed only the presence of Peak I metabolites. The authors data show that RTE cells metabolize RA into polar metabolites which are rapidly released into the medium and into a less polar metabolite, possibly an ester of retinoic acid, which is retained by the cell.

  11. Regulatory mechanisms of cellular respiration. III. Enzyme distribution in the cell. Its influence on the metabolism of pyruvic acid by bakers' yeast.

    PubMed

    BARRON, E S G; ARDAO, M I; HEARON, M

    1950-11-01

    The rate of the aerobic metabolism of pyruvic acid by bakers' yeast cells is determined mainly by the amount of undissociated acid present. As a consequence, the greatest rate of oxidation was observed at pH 2.8. Oxidation, at a slow rate, started at pH 1.08; at pH 9.4 there was no oxidation at all. The anaerobic metabolism, only a fraction of the aerobic, was observed only in acid solutions. There was none at pH values higher than 3. Pyruvic acid in the presence of oxygen was oxidized directly to acetic acid; in the absence of oxygen it was metabolized mainly by dismutation to lactic and acetic acids, and CO(2). Acetic acid formation was demonstrated on oxidation of pyruvic acid at pH 1.91, and on addition of fluoroacetic acid. Succinic acid formation was shown by addition of malonic acid. These metabolic pathways in a cell so rich in carboxylase may be explained by the arrangement of enzymes within the cell, so that carboxylase is at the center, while pyruvic acid oxidase is located at the periphery. Succinic and citric acids were oxidized only in acid solutions up to pH 4. Malic and alpha-ketoglutaric acids were not oxidized, undoubtedly because of lack of penetration.

  12. Perturbation of energy metabolism by fatty-acid derivative AIC-47 and imatinib in BCR-ABL-harboring leukemic cells.

    PubMed

    Shinohara, Haruka; Kumazaki, Minami; Minami, Yosuke; Ito, Yuko; Sugito, Nobuhiko; Kuranaga, Yuki; Taniguchi, Kohei; Yamada, Nami; Otsuki, Yoshinori; Naoe, Tomoki; Akao, Yukihiro

    2016-02-01

    In Ph-positive leukemia, imatinib brought marked clinical improvement; however, further improvement is needed to prevent relapse. Cancer cells efficiently use limited energy sources, and drugs targeting cellular metabolism improve the efficacy of therapy. In this study, we characterized the effects of novel anti-cancer fatty-acid derivative AIC-47 and imatinib, focusing on cancer-specific energy metabolism in chronic myeloid leukemia cells. AIC-47 and imatinib in combination exhibited a significant synergic cytotoxicity. Imatinib inhibited only the phosphorylation of BCR-ABL; whereas AIC-47 suppressed the expression of the protein itself. Both AIC-47 and imatinib modulated the expression of pyruvate kinase M (PKM) isoforms from PKM2 to PKM1 through the down-regulation of polypyrimidine tract-binding protein 1 (PTBP1). PTBP1 functions as alternative splicing repressor of PKM1, resulting in expression of PKM2, which is an inactive form of pyruvate kinase for the last step of glycolysis. Although inactivation of BCR-ABL by imatinib strongly suppressed glycolysis, compensatory fatty-acid oxidation (FAO) activation supported glucose-independent cell survival by up-regulating CPT1C, the rate-limiting FAO enzyme. In contrast, AIC-47 inhibited the expression of CPT1C and directly fatty-acid metabolism. These findings were also observed in the CD34(+) fraction of Ph-positive acute lymphoblastic leukemia cells. These results suggest that AIC-47 in combination with imatinib strengthened the attack on cancer energy metabolism, in terms of both glycolysis and compensatory activation of FAO.

  13. Exposure to 2,4-dichlorophenoxyacetic acid alters glucose metabolism in immature rat Sertoli cells.

    PubMed

    Alves, M G; Neuhaus-Oliveira, A; Moreira, P I; Socorro, S; Oliveira, P F

    2013-07-01

    The purpose of this study was to determine the effects of 2,4-D, an herbicide used worldwide also known as endocrine disruptor, in Sertoli cell (SC) metabolism. Immature rat SCs were maintained 50h under basal conditions or exposed to 2,4-D (100nM, 10μM and 1mM). SCs exposed to 10μM and 1mM of 2,4-D presented lower intracellular glucose and lactate content. Exposure to 10μM of 2,4-D induced a significant decrease in glucose transporter-3 mRNA levels and phosphofructokinase-1 mRNA levels decreased in cells exposed to 100nM and 10μM of 2,4-D. Exposure to 100nM and 10μM also induced a decrease in lactate dehydrogenase (LDH) mRNA levels while the LDH protein levels were only decreased in cells exposed to 1mM of 2,4-D. Exposure to 2,4-D altered glucose uptake and metabolization in SCs, as well as lactate metabolism and export that may result in impaired spermatogenesis.

  14. A comparative study on glycerol metabolism to erythritol and citric acid in Yarrowia lipolytica yeast cells.

    PubMed

    Tomaszewska, Ludwika; Rakicka, Magdalena; Rymowicz, Waldemar; Rywińska, Anita

    2014-09-01

    Citric acid and erythritol biosynthesis from pure and crude glycerol by three acetate-negative mutants of Yarrowia lipolytica yeast was investigated in batch cultures in a wide pH range (3.0-6.5). Citric acid biosynthesis was the most effective at pH 5.0-5.5 in the case of Wratislavia 1.31 and Wratislavia AWG7. With a decreasing pH value, the direction of biosynthesis changed into erythritol synthesis accompanied by low production of citric acid. Pathways of glycerol conversion into erythritol and citric acid were investigated in Wratislavia K1 cells. Enzymatic activity was compared in cultures run at pH 3.0 and 4.5, that is, under conditions promoting the production of erythritol and citric acid, respectively. The effect of pH value (3.0 and 4.5) and NaCl presence on the extracellular production and intracellular accumulation of citric acid and erythritol was compared as well. Low pH and NaCl resulted in diminished activity of glycerol kinase, whereas such conditions stimulated the activity of glycerol-3-phosphate dehydrogenase. The presence of NaCl strongly influenced enzymes activity - the effective erythritol production was correlated with a high activity of transketolase and erythrose reductase. Therefore, presented results confirmed that transketolase and erythrose reductase are involved in the overproduction of erythritol in the cells of Y. lipolytica yeast.

  15. Treatment of Amino Acid Metabolism Disorders

    MedlinePlus

    ... Treatment of amino acid metabolism disorders Treatment of amino acid metabolism disorders E-mail to a friend Please ... this page It's been added to your dashboard . Amino acid metabolism disorders are rare health conditions that affect ...

  16. [Effect of reduced oxygen concentrations and hydrogen sulfide on the amino acid metabolism and mesenchymal cells proliferation].

    PubMed

    Plotnikova, L N; Berezovskii, V A; Veselskii, S P

    2015-01-01

    We investigated the effect of hydrogen sulfide donor (10(-12) mol/l NaHS--I group) alone and together with the reduced oxygen concentrations (5% O2--II group, 3% O2--III group, 24 h) on the biological processes of human stem cells culture. It was shown that the cells proliferation by the third day of cultivation in I, II and III group decreased 1,7; 2,8 and 4,2 times. On the 4th day of culture proliferation inhibited in I, II and III group by 29; 33 and 54% compared to the control. Thus, adverse effects NaHS enhanced by reducing the oxygen concentration. It was established that in all experimental versions rapidly absorbed from the culture medium amino acids: cysteine and cystine, serine and aspartic acid, valine and tryptophan, proline and hydroxyproline, which are involved in the synthesis of proteins, in particular collagen. In the culture medium increased the concentration of free amino acids of the three factions: arginine, histidine and taurine; glycine and methionine; alanine and glutamine. We believe that in the applied concentration of hydrogen sulfide donor in conditions of low oxygen in a gaseous medium incubation inhibits the proliferation and alters the amino acid metabolism of human cells line 4BL.

  17. Acetylsalicylic acid and salicylic acid decrease tumor cell viability and glucose metabolism modulating 6-phosphofructo-1-kinase structure and activity.

    PubMed

    Spitz, Guilherme A; Furtado, Cristiane M; Sola-Penna, Mauro; Zancan, Patricia

    2009-01-01

    The common observation that cancer cells present higher glycolytic rates when compared to control cells leads to the proposal of glycolysis as a potential target for the development of anti-tumoral agents. Anti-inflammatory drugs, such as acetylsalicylic acid (ASA) and salicylic acid (SA), present anti-tumoral properties, inducing apoptosis and altering tumor glucose utilization. The present work aims at evaluating whether ASA could directly decrease cell glycolysis through inhibition of the major regulatory enzyme within this pathway, 6-phosphofructo-1-kinase (PFK). We show that ASA and SA inhibit purified PFK in a dose-dependent manner, and that this inhibition occurs due to the modulation of the enzyme quaternary structure. ASA and SA promote the dissociation of the enzyme active tetramers into quite inactive dimers, a common regulatory mechanism of this enzyme. The inhibitory effects of ASA and SA on PFK are fully reversible and can be prevented or reverted by the binding of the enzyme to the actin filaments. Both drugs are also able to decrease glucose consumption by human breast cancer cell line MCF-7, as well as its viability, which decrease parallelly to the inhibition of PFK on these cells. In the end, we demonstrate the ability of ASA and SA to directly modulate an important regulatory intracellular enzyme, and propose that this is one of their mechanisms promoting anti-tumoral effects.

  18. Contact sensitizers modulate the arachidonic acid metabolism of PMA-differentiated U-937 monocytic cells activated by LPS

    SciTech Connect

    Del Bufalo, Aurelia; Bernad, Jose; Dardenne, Christophe; Verda, Denis; Meunier, Jean Roch; Rousset, Francoise; Martinozzi-Teissier, Silvia; Pipy, Bernard

    2011-10-01

    For the effective induction of a hapten-specific T cell immune response toward contact sensitizers, in addition to covalent-modification of skin proteins, the redox and inflammatory statuses of activated dendritic cells are crucial. The aim of this study was to better understand how sensitizers modulate an inflammatory response through cytokines production and COX metabolism cascade. To address this purpose, we used the human monocytic-like U-937 cell line differentiated by phorbol myristate acetate (PMA) and investigated the effect of 6 contact sensitizers (DNCB, PPD, hydroquinone, propyl gallate, cinnamaldehyde and eugenol) and 3 non sensitizers (lactic acid, glycerol and tween 20) on the production of pro-inflammatory cytokines (IL-1{beta} and TNF-{alpha}) and on the arachidonic acid metabolic profile after bacterial lipopolysaccharide (LPS) stimulation. Our results showed that among the tested molecules, all sensitizers specifically prevent the production of PMA/LPS-induced COX-2 metabolites (PGE{sub 2,} TxB{sub 2} and PGD{sub 2}), eugenol and cinnamaldehyde inhibiting also the production of IL-1{beta} and TNF-{alpha}. We further demonstrated that there is no unique PGE{sub 2} inhibition mechanism: while the release of arachidonic acid (AA) from membrane phospholipids does not appear do be a target of modulation, COX-2 expression and/or COX-2 enzymatic activity are the major steps of prostaglandin synthesis that are inhibited by sensitizers. Altogether these results add a new insight into the multiple biochemical effects described for sensitizers. - Highlights: > We investigated how contact sensitizers modulate an inflammatory response. > We used macrophage-differentiated cell line, U-937 treated with PMA/LPS. > Sensitizers specifically inhibit the production of COX metabolites (PGE2, TxB2). > Several mechanisms of inhibition: COX-2 expression/enzymatic activity, isomerases. > New insight in the biochemical properties of sensitizers.

  19. Inhibition of arachidonic acid metabolism and its implication on cell proliferation and tumour-angiogenesis.

    PubMed

    Hyde, C A C; Missailidis, S

    2009-06-01

    Arachidonic acid (AA) and its metabolites have recently generated a heightened interest due to growing evidence of their significant role in cancer biology. Thus, inhibitors of the AA cascade, first and foremost COX inhibitors, which have originally been of interest in the treatment of inflammatory conditions and certain types of cardiovascular disease, are now attracting attention as an arsenal against cancer. An increasing number of investigations support their role in cancer chemoprevention, although the precise molecular mechanisms that link levels of AA, and its metabolites, with cancer progression have still to be elucidated. This article provides an overview of the AA cascade and focuses on the roles of its inhibitors and their implication in cancer treatment. In particular, emphasis is placed on the inhibition of cell proliferation and neo-angiogenesis through inhibition of the enzymes COX-2, 5-LOX and CYP450. Downstream effects of inhibition of AA metabolites are analysed and the molecular mechanisms of action of a selected number of inhibitors of catalytic pathways reviewed. Lastly, the benefits of dietary omega-3 fatty acids and their mechanisms of action leading to reduced cancer risk and impeded cancer cell growth are mentioned. Finally, a proposal is put forward, suggesting a novel and integrated approach in viewing the molecular mechanisms and complex interactions responsible for the involvement of AA metabolites in carcinogenesis and the protective effects of omega-3 fatty acids in inflammation and tumour prevention. PMID:19239926

  20. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation.

    PubMed

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian; Wagtberg Sen, Jette; Rasmussen, Søren Kofoed; Kontoravdi, Cleo; Weilguny, Dietmar; Andersen, Mikael Rørdam

    2015-03-01

    Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylation-related product quality. In this work, different fed-batch processes with two chemically defined proprietary media and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards energy and recombinant product, respectively. Accumulation of by-products such as NH4(+) and lactate as a consequence of unbalanced nutrient supply to cell activities inhibits cell growth. The levels of Leu and Arg in the culture, which relate to cell growth and IgG productivity, need to be well controlled. Amino acids with the highest consumption rates correlate with the most abundant amino acids present in the produced IgG, and thus require sufficient availability during culture. Case-by-case analysis is necessary for understanding the effect of media and process optimization on glycosylation. We found that in certain cases the presence of Man5 glycan can be linked to limitation of UDP-GlcNAc biosynthesis as a result of insufficient extracellular Gln. However, under different culture conditions, high Man5 levels can also result from low α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase (GnTI) and UDP-GlcNAc transporter activities, which may be attributed to high level of NH4+ in the cell culture. Furthermore, galactosylation of the mAb Fc glycans

  1. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation.

    PubMed

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian; Wagtberg Sen, Jette; Rasmussen, Søren Kofoed; Kontoravdi, Cleo; Weilguny, Dietmar; Andersen, Mikael Rørdam

    2015-03-01

    Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylation-related product quality. In this work, different fed-batch processes with two chemically defined proprietary media and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards energy and recombinant product, respectively. Accumulation of by-products such as NH4(+) and lactate as a consequence of unbalanced nutrient supply to cell activities inhibits cell growth. The levels of Leu and Arg in the culture, which relate to cell growth and IgG productivity, need to be well controlled. Amino acids with the highest consumption rates correlate with the most abundant amino acids present in the produced IgG, and thus require sufficient availability during culture. Case-by-case analysis is necessary for understanding the effect of media and process optimization on glycosylation. We found that in certain cases the presence of Man5 glycan can be linked to limitation of UDP-GlcNAc biosynthesis as a result of insufficient extracellular Gln. However, under different culture conditions, high Man5 levels can also result from low α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase (GnTI) and UDP-GlcNAc transporter activities, which may be attributed to high level of NH4+ in the cell culture. Furthermore, galactosylation of the mAb Fc glycans

  2. Decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by Escherichia coli.

    PubMed

    Cerboneschi, Matteo; Corsi, Massimo; Bianchini, Roberto; Bonanni, Marco; Tegli, Stefania

    2015-10-01

    Escherichia coli strain DH5α was successfully employed in the decolorization of commercial anthraquinone and azo dyes, belonging to the general classes of acid or basic dyes. The bacteria showed an aptitude to survive at different pH values on any dye solution tested, and a rapid decolorization was obtained under aerobic conditions for the whole collection of dyes. A deep investigation about the mode of action of E. coli was carried out to demonstrate that dye decolorization mainly occurred via three different pathways, specifically bacterial induced precipitation, cell wall adsorption, and metabolism, whose weight was correlated with the chemical nature of the dye. In the case of basic azo dyes, an unexpected fast decolorization was observed after just 2-h postinoculation under aerobic conditions, suggesting that metabolism was the main mechanism involved in basic azo dye degradation, as unequivocally demonstrated by mass spectrometric analysis. The reductive cleavage of the azo group by E. coli on basic azo dyes was also further demonstrated by the inhibition of decolorization occurring when glucose was added to the dye solution. Moreover, no residual toxicity was found in the E. coli-treated basic azo dye solutions by performing Daphnia magna acute toxicity assays. The results of the present study demonstrated that E. coli can be simply exploited for its natural metabolic pathways, without applying any recombinant technology. The high versatility and adaptability of this bacterium could encourage its involvement in industrial bioremediation of textile and leather dyeing wastewaters.

  3. [THE OPTIMIZATION OF NUTRITION FUNCTION UNDER SYNDROME OF RESISTANCE TO INSULIN, DISORDER OF FATTY ACIDS' METABOLISM AND ABSORPTION OF GLUCOSE BY CELLS (A LECTURE)].

    PubMed

    Titov, V N

    2016-01-01

    The phylogenetic processes continue to proceed in Homo Sapiens. At the very early stages ofphylogenesis, the ancient Archaea that formed mitochondria under symbiotic interaction with later bacterial cells conjointly formed yet another system. In this system, there are no cells' absorption of glucose if it is possible to absorb fatty acids from intercellular medium in the form of unesterfied fatty acids or ketonic bodies--metabolites of fatty acids. This is caused by objectively existed conditions and subsequent availability of substrates at the stages ofphylogenesis: acetate, ketonic bodies, fatty acids and only later glucose. The phylogenetically late insulin used after billions years the same dependencies at formation of regulation ofmetabolism offatty acids and cells' absorption of glucose. In order that syndrome ofresistance ceased to exist as afoundation of metabolic pandemic Homo Sapiens has to understand the following. After successful function ofArchaea+bacterial cells and considered by biology action of insulin for the third time in phylogenesis and using biological function of intelligence the content ofphylogenetically earlier palmitic saturated fatty acid infood can't to exceed possibilities of phylogenetically late lipoproteins to transfer it in intercellular medium and blood and cells to absorb it. It is supposed that at early stages of phylogenesis biological function of intelligence is primarily formed to bring into line "unconformities" of regulation of metabolism against the background of seeming relative biological "perfection". These unconformities were subsequently and separately formed at the level of cells in paracrin regulated cenosises of cells and organs and at the level of organism. The prevention of resistance to insulin basically requires biological function of intelligence, principle of self-restraint, bringing into line multiple desires of Homo Sapiens with much less extensive biological possibilities. The "unconformities" of

  4. Uptake and metabolism of 12-hydroxyeicosatetraenoic acid (12-HETE) by cultured renal tubular epithelial cells (RTEC)

    SciTech Connect

    Gordon, J.A.; Spector, A.A.

    1986-03-01

    To determine if 12-HETE, a lipoxygenase product that mediates inflammation and tissue injury, can interact with RTEC, confluent Madin Darby Canine Kidney (MDCK) cells were incubated for 2-16 hr with 1.0 ..mu..M (/sup 3/H)-12-HETE. Initial uptake of 12-HETE was rapid; at 16 hrs. 70% of the 12-HETE uptake was incorporated into phospholipids (PL). The distribution among the choline, ethanolamine, inositol, and serine PL was 36, 36, 20 and 8%, respectively. Incubation of MDCK cells with 0.5 to 5.0 ..mu..M (/sup 3/H)-12-HETE for 1 hr indicated linear uptake without evidence of saturation. Incubation with 1.0 ..mu..M 12-HETE and 0.25-10.0 ..mu..M arachidonic acid for 1 hr revealed no competition for uptake at the lower concentrations but a 40% reduction in 12-HETE uptake at 10.0 ..mu..M. Polarity of 12-HETE uptake was indicated by a preference of the basolateral surface over the apical surface by 1.4. After 2 hr, analysis of the medium by reverse phase HPLC revealed that 12-HETE was converted to three polar metabolites which eluted at 25.9, 29.4 and 31.3 min respectively; 12-HETE eluted at 37.5 min. The appearance of these polar metabolites was not prevented by ibuprofen (50 ..mu..M) nordihydroguaiaretic acid (30 ..mu..M), allopurinol (15 mM), or butylated hydroxytoluene (20 ..mu..M). These findings suggest that the lipoxygenase product 12-HETE may affect RTEC through incorporation into membrane PL and/or conversion to polar metabolites.

  5. Fatty acid metabolism meets organelle dynamics.

    PubMed

    Walch, Laurence; Čopič, Alenka; Jackson, Catherine L

    2015-03-23

    Upon nutrient deprivation, cells metabolize fatty acids (FAs) in mitochondria to supply energy, but how FAs, stored as triacylglycerols in lipid droplets, reach mitochondria has been mysterious. Rambold et al. (2015) now show that FA mobilization depends on triacylglycerol lipolysis, whereas autophagy feeds the lipid droplet pool for continued fueling of mitochondria.

  6. Acid base properties of cyanobacterial surfaces I: Influences of growth phase and nitrogen metabolism on cell surface reactivity

    NASA Astrophysics Data System (ADS)

    Lalonde, S. V.; Smith, D. S.; Owttrim, G. W.; Konhauser, K. O.

    2008-03-01

    Significant efforts have been made to elucidate the chemical properties of bacterial surfaces for the purposes of refining surface complexation models that can account for their metal sorptive behavior under diverse conditions. However, the influence of culturing conditions on surface chemical parameters that are modeled from the potentiometric titration of bacterial surfaces has received little regard. While culture age and metabolic pathway have been considered as factors potentially influencing cell surface reactivity, statistical treatments have been incomplete and variability has remained unconfirmed. In this study, we employ potentiometric titrations to evaluate variations in bacterial surface ligand distributions using live cells of the sheathless cyanobacterium Anabaena sp. strain PCC 7120, grown under a variety of batch culture conditions. We evaluate the ability for a single set of modeled parameters, describing acid-base surface properties averaged over all culture conditions tested, to accurately account for the ligand distributions modeled for each individual culture condition. In addition to considering growth phase, we assess the role of the various assimilatory nitrogen metabolisms available to this organism as potential determinants of surface reactivity. We observe statistically significant variability in site distribution between the majority of conditions assessed. By employing post hoc Tukey-Kramer analysis for all possible pair-wise condition comparisons, we conclude that the average parameters are inadequate for the accurate chemical description of this cyanobacterial surface. It was determined that for this Gram-negative bacterium in batch culture, ligand distributions were influenced to a greater extent by nitrogen assimilation pathway than by growth phase.

  7. Cellular Metabolism of Unnatural Sialic Acid Precursors

    PubMed Central

    Pham, Nam D.; Fermaintt, Charles S.; Rodriguez, Andrea C.; McCombs, Janet E.; Nischan, Nicole; Kohler, Jennifer J.

    2015-01-01

    Carbohydrates, in addition to their metabolic functions, serve important roles as receptors, ligands, and structural molecules for diverse biological processes. Insight into carbohydrate biology and mechanisms has been aided by metabolic oligosaccharide engineering (MOE). In MOE, unnatural carbohydrate analogs with novel functional groups are incorporated into cellular glycoconjugates and used to probe biological systems. While MOE has expanded knowledge of carbohydrate biology, limited metabolism of unnatural carbohydrate analogs restricts its use. Here we assess metabolism of SiaDAz, a diazirine-modified analog of sialic acid, and its cell-permeable precursor, Ac4ManNDAz. We show that the efficiency of Ac4ManNDAz and SiaDAz metabolism depends on cell type. Our results indicate that different cell lines can have different metabolic roadblocks in the synthesis of cell surface SiaDAz. These findings point to roles for promiscuous intracellular esterases, kinases, and phosphatases during unnatural sugar metabolism and provide guidance for ways to improve MOE. PMID:25957566

  8. Novel Metabolic Abnormalities in the Tricarboxylic Acid Cycle in Peripheral Cells From Huntington’s Disease Patients

    PubMed Central

    Naseri, Nima N.; Bonica, Joseph; Xu, Hui; Park, Larry C.; Arjomand, Jamshid; Chen, Zhengming; Gibson, Gary E.

    2016-01-01

    Metabolic dysfunction is well-documented in Huntington’s disease (HD). However, the link between the mutant huntingtin (mHTT) gene and the pathology is unknown. The tricarboxylic acid (TCA) cycle is the main metabolic pathway for the production of NADH for conversion to ATP via the electron transport chain (ETC). The objective of this study was to test for differences in enzyme activities, mRNAs and protein levels related to the TCA cycle between lymphoblasts from healthy subjects and from patients with HD. The experiments utilize the advantages of lymphoblasts to reveal new insights about HD. The large quantity of homogeneous cell populations permits multiple dynamic measures to be made on exactly comparable tissues. The activities of nine enzymes related to the TCA cycle and the expression of twenty-nine mRNAs encoding for these enzymes and enzyme complexes were measured. Cells were studied under baseline conditions and during metabolic stress. The results support our recent findings that the activities of the pyruvate dehydrogenase complex (PDHC) and succinate dehydrogenase (SDH) are elevated in HD. The data also show a large unexpected depression in MDH activities. Furthermore, message levels for isocitrate dehydrogenase 1 (IDH1) were markedly increased in in HD lymphoblasts and were responsive to treatments. The use of lymphoblasts allowed us to clarify that the reported decrease in aconitase activity in HD autopsy brains is likely due to secondary hypoxic effects. These results demonstrate the mRNA and enzymes of the TCA cycle are critical therapeutic targets that have been understudied in HD. PMID:27611087

  9. Bile acids as metabolic regulators

    PubMed Central

    Li, Tiangang; Chiang, John Y. L.

    2015-01-01

    Summary Small molecule ligands that target to TGR5 and FXR have shown promise in treating various metabolic and inflammation-related human diseases. New insights into the mechanisms underlying the bariatric surgery and bile acid sequestrant treatment suggest that targeting the enterohepatic circulation to modulate gut-liver bile acid signaling, incretin production and microbiota represents a new strategy to treat obesity and type-2 diabetes. PMID:25584736

  10. Expression of Cell-Surface Marker ABCB5 Causes Characteristic Modifications of Glucose, Amino Acid and Phospholipid Metabolism in the G3361 Melanoma-Initiating Cell Line

    PubMed Central

    Lutz, Norbert W.; Banerjee, Pallavi; Wilson, Brian J.; Ma, Jie; Cozzone, Patrick J.; Frank, Markus H.

    2016-01-01

    We present a pilot study aimed at determining the effects of expression of ATP-binding cassette member B5 (ABCB5), a previously described marker for melanoma-initiating cells, on cellular metabolism. Metabolic profiles for two groups of human G3361 melanoma cells were compared, i.e. wildtype melanoma cells with intact ABCB5 expression (ABCB5-WT) and corresponding melanoma cell variants with inhibited ABCB5 expression, through shRNA-mediated gene knockdown (ABCB5-KD). A comprehensive metabolomic analysis was performed by using proton and phosphorus NMR spectroscopy of cell extracts to examine water-soluble metabolites and lipids. Parametric and non-parametric statistical analysis of absolute and relative metabolite levels yielded significant differences for compounds involved in glucose, amino acid and phospholipid (PL) metabolism. By contrast, energy metabolism was virtually unaffected by ABCB5 expression. The sum of water-soluble metabolites per total protein was 17% higher in ABCB5-WT vs. ABCB5-KD G3361 variants, but no difference was found for the sum of PLs. Enhanced abundance was particularly pronounced for lactate (+ 23%) and alanine (+ 26%), suggesting an increase in glycolysis and potentially glutaminolysis. Increases in PL degradation products, glycerophosphocholine and glycerophosphoethanolamine (+ 85 and 123%, respectively), and redistributions within the PL pool suggested enhanced membrane PL turnover as a consequence of ABCB5 expression. The possibility of glycolysis modulation by an ABCB5-dependent IL1β-mediated mechanism was supported by functional studies employing monoclonal antibody (mAb)-dependent ABCB5 protein inhibition in wildtype G3361 melanoma cells. Our metabolomic results suggest that the underlying biochemical pathways may offer targets for melanoma therapy, potentially in combination with other treatment forms. PMID:27560924

  11. Expression of Cell-Surface Marker ABCB5 Causes Characteristic Modifications of Glucose, Amino Acid and Phospholipid Metabolism in the G3361 Melanoma-Initiating Cell Line.

    PubMed

    Lutz, Norbert W; Banerjee, Pallavi; Wilson, Brian J; Ma, Jie; Cozzone, Patrick J; Frank, Markus H

    2016-01-01

    We present a pilot study aimed at determining the effects of expression of ATP-binding cassette member B5 (ABCB5), a previously described marker for melanoma-initiating cells, on cellular metabolism. Metabolic profiles for two groups of human G3361 melanoma cells were compared, i.e. wildtype melanoma cells with intact ABCB5 expression (ABCB5-WT) and corresponding melanoma cell variants with inhibited ABCB5 expression, through shRNA-mediated gene knockdown (ABCB5-KD). A comprehensive metabolomic analysis was performed by using proton and phosphorus NMR spectroscopy of cell extracts to examine water-soluble metabolites and lipids. Parametric and non-parametric statistical analysis of absolute and relative metabolite levels yielded significant differences for compounds involved in glucose, amino acid and phospholipid (PL) metabolism. By contrast, energy metabolism was virtually unaffected by ABCB5 expression. The sum of water-soluble metabolites per total protein was 17% higher in ABCB5-WT vs. ABCB5-KD G3361 variants, but no difference was found for the sum of PLs. Enhanced abundance was particularly pronounced for lactate (+ 23%) and alanine (+ 26%), suggesting an increase in glycolysis and potentially glutaminolysis. Increases in PL degradation products, glycerophosphocholine and glycerophosphoethanolamine (+ 85 and 123%, respectively), and redistributions within the PL pool suggested enhanced membrane PL turnover as a consequence of ABCB5 expression. The possibility of glycolysis modulation by an ABCB5-dependent IL1β-mediated mechanism was supported by functional studies employing monoclonal antibody (mAb)-dependent ABCB5 protein inhibition in wildtype G3361 melanoma cells. Our metabolomic results suggest that the underlying biochemical pathways may offer targets for melanoma therapy, potentially in combination with other treatment forms. PMID:27560924

  12. Oleanolic Acid Inhibits High Salt-Induced Exaggeration of Warburg-like Metabolism in Breast Cancer Cells.

    PubMed

    Amara, Suneetha; Zheng, Mu; Tiriveedhi, Venkataswarup

    2016-09-01

    Cancer cells have a proliferative advantage by utilizing intermediates of aerobic glycolysis (Warburg effect) for their macromolecule synthesis. Although the exact causes of this Warburg effect are unclear, high osmotic stress in solid tumor microenvironment is considered one of the important factors. Oleanolic acid (OA) is known to exert anti-inflammatory and anti-cancer effect. In our current studies, using breast cancer cell lines, we determined the protective role of OA in high salt-mediated osmotic stress-induced cancer growth. Hypertonic (0.16 M NaCl) culture conditions enhanced the cancer cell growth (26 %, p < 0.05) and aerobic glycolysis as marked by increased glucose consumption (34 %, p < 0.05) and lactate production (25 %, p < 0.05) over untreated cells. This effect was associated with increased expression and activity of key rate-limiting enzymes of aerobic glycolysis, namely hexokinase, pyruvate kinase type M2, and lactate dehydrogenase A. Interestingly, this high salt-mediated enhanced expression of aerobic glycolytic enzymes was efficiently reversed by OA along with the decreased cancer cell proliferation. In cancer cells, enhanced aerobic glycolysis is associated with the decreased mitochondrial activity and mitochondrial-associated caspase activity. As expected, high salt further inhibited the mitochondrial related cytochrome oxidase and caspase-3 activity. However, OA efficiently reversed the high salt-mediated inhibition of cytochrome oxidase, caspase activity, and pro-apoptotic Bax expression, thus suggesting that OA induced mitochondrial activity and enhanced apoptosis. Taken together, our data indicate that OA efficiently reverses the enhanced Warburg-like metabolism induced by high salt-mediated osmotic stress along with potential application of OA in anti-cancer therapy. PMID:27236294

  13. Nonesterified Fatty Acid-Induced Endoplasmic Reticulum Stress in Cattle Cumulus Oocyte Complexes Alters Cell Metabolism and Developmental Competence.

    PubMed

    Sutton-McDowall, Melanie L; Wu, Linda L Y; Purdey, Malcolm; Abell, Andrew D; Goldys, Ewa M; MacMillan, Keith L; Thompson, Jeremy G; Robker, Rebecca L

    2016-01-01

    Reduced oocyte quality has been associated with poor fertility of high-performance dairy cows during peak lactation, due to negative energy balance. We examined the role of nonesterified fatty acids (NEFAs), known to accumulate within follicular fluid during under- and overnutrition scenarios, in causing endoplasmic reticulum (ER) stress of in vitro maturated cattle cumulus-oocyte complexes (COCs). NEFA concentrations were: palmitic acid (150 μM), oleic acid (200 μM), and steric acid (75 μM). Abattoir-derived COCs were randomly matured for 24 h in the presence of NEFAs and/or an ER stress inhibitor, salubrinal. Total and hatched blastocyst yields were negatively impacted by NEFA treatment compared with controls, but this was reversed by salubrinal. ER stress markers, activating transcription factor 4 (Atf4) and heat shock protein 5 (Hspa5), but not Atf6, were significantly up-regulated by NEFA treatment within whole COCs but reversed by coincubation with salubrinal. Likewise, glucose uptake and lactate production, measured in spent medium samples, showed a similar pattern, suggesting that cumulus cell metabolism is sensitive to NEFAs via an ER stress-mediated process. In contrast, while mitochondrial DNA copy number was recovered in NEFA-treated oocytes, oocyte autofluorescence of the respiratory chain cofactor, FAD, was lower following NEFA treatment of COCs, and this was not reversed by salubrinal, suggesting the negative impact was via reduced mitochondrial function. These results reveal the significance of NEFA-induced ER stress on bovine COC developmental competence, revealing a potential therapeutic target for improving oocyte quality during peak lactation. PMID:26658709

  14. Intercellular transport of lysosomal acid lipase mediates lipoprotein cholesteryl ester metabolism in a human vascular endothelial cell-fibroblast coculture system.

    PubMed Central

    Sando, G N; Ma, G P; Lindsley, K A; Wei, Y P

    1990-01-01

    We present results from studies of human cell culture models to support the premise that the extracellular transport of lysosomal acid lipase has a function in lipoprotein cholesteryl ester metabolism in vascular tissue. Vascular endothelial cells secreted a higher fraction of cellular acid lipase than did smooth muscle cells and fibroblasts. Acid lipase and lysosomal beta-hexosaminidase were secreted at approximately the same rate from the apical and basolateral surface of an endothelial cell monolayer. Stimulation of secretion with NH4Cl did not affect the polarity. We tested for the ability of secreted endothelial lipase to interact with connective tissue cells and influence lipoprotein cholesterol metabolism in a coculture system in which endothelial cells on a micropore filter were suspended above a monolayer of acid lipase-deficient (Wolman disease) fibroblasts. After 5-7 d, acid lipase activity in the fibroblasts reached 10%-20% of the level in normal cells; cholesteryl esters that had accumulated from growth in serum were cleared. Addition of mannose 6-phosphate to the coculture medium blocked acid lipase uptake and cholesterol clearance, indicating that lipase released from endothelial cells was packaged into fibroblast lysosomes by a phosphomannosyl receptor-mediated pathway. Supplementation of the coculture medium with serum was not required for lipase uptake and cholesteryl ester hydrolysis by the fibroblasts, but was necessary for cholesterol clearance. Results from our coculture model suggest that acid lipase may be transported from intact endothelium to cells in the lumen or the wall of a blood vessel. We postulate that delivery of acid hydrolases and lipoproteins to a common endocytic compartment may occur and have an impact on cellular lipoprotein processing. PMID:2150334

  15. Effects of receptor-selective retinoids on CYP26 gene expression and metabolism of all-trans-retinoic acid in intestinal cells.

    PubMed

    Lampen, A; Meyer, S; Nau, H

    2001-05-01

    Retinoids mediate most of their function via interaction with retinoid receptors [retinoic acid receptors (RARs) and retinoid X receptors (RXRs)], which act as ligand-activated transcription factors controlling the expression of a number of target genes. The complex mechanistic pattern of retinoid-induced effects on gene expression of CYP26 and intestinal metabolism of all-trans-retinoic acid (RA) was investigated here by studying the effects of retinoid ligands with relative selectivity for binding and transactivation of the retinoid acid receptors, RARs and RXRs, in human intestinal Caco-2 cells. We show here that CYP26 is expressed in human duodenum and colon. In Caco-2 cells not only all-trans-RA but also synthetic agonists of the RAR induced intestinal CYP26 gene expression and all-trans-RA metabolism as well. The RARalpha ligand Am580 induced the CYP26 gene expression more than the RARbeta ligand CD2019 or the RARgamma ligand CD437 suggesting the highest specificity for RARalpha on intestinal CYP26 gene regulation. RXR ligands alone did not induce CYP26 gene expression or RA metabolism in Caco-2 cells at all. But together with the RARalpha ligand, Am580, there were enhanced effects on the induction of CYP26 gene expression and on the induction of the metabolism of all-trans-RA. We conclude that gene regulation of CYP26 and the metabolism of all-trans-RA in intestinal cells is regulated through RXR and RAR heterodimerization. When coadministered, RAR agonists showed the highest potency for CYP26 gene regulation. Receptor-selective retinoids showed enhanced effects on induction of CYP26 gene expression and all-trans-retinoic acid metabolism.

  16. Fatty Acid-binding Protein 4, a Point of Convergence for Angiogenic and Metabolic Signaling Pathways in Endothelial Cells*

    PubMed Central

    Harjes, Ulrike; Bridges, Esther; McIntyre, Alan; Fielding, Barbara A.; Harris, Adrian L.

    2014-01-01

    Fatty acid-binding protein 4 (FABP4) is an adipogenic protein and is implicated in atherosclerosis, insulin resistance, and cancer. In endothelial cells, FABP4 is induced by VEGFA, and inhibition of FABP4 blocks most of the VEGFA effects. We investigated the DLL4-NOTCH-dependent regulation of FABP4 in human umbilical vein endothelial cells by gene/protein expression and interaction analyses following inhibitor treatment and RNA interference. We found that FABP4 is directly induced by NOTCH. Stimulation of NOTCH signaling with human recombinant DLL4 led to FABP4 induction, independently of VEGFA. FABP4 induction by VEGFA was reduced by blockade of DLL4 binding to NOTCH or inhibition of NOTCH signal transduction. Chromatin immunoprecipitation of the NOTCH intracellular domain showed increased binding to two specific regions in the FABP4 promoter. The induction of FABP4 gene expression was dependent on the transcription factor FOXO1, which was essential for basal expression of FABP4, and FABP4 up-regulation following stimulation of the VEGFA and/or the NOTCH pathway. Thus, we show that the DLL4-NOTCH pathway mediates endothelial FABP4 expression. This indicates that induction of the angiogenesis-restricting DLL4-NOTCH can have pro-angiogenic effects via this pathway. It also provides a link between DLL4-NOTCH and FOXO1-mediated regulation of endothelial gene transcription, and it shows that DLL4-NOTCH is a nodal point in the integration of pro-angiogenic and metabolic signaling in endothelial cells. This may be crucial for angiogenesis in the tumor environment. PMID:24939870

  17. Anion channel sensitivity to cytosolic organic acids implicates a central role for oxaloacetate in integrating ion flux with metabolism in stomatal guard cells.

    PubMed

    Wang, Yizhou; Blatt, Michael R

    2011-10-01

    Stomatal guard cells play a key role in gas exchange for photosynthesis and in minimizing transpirational water loss from plants by opening and closing the stomatal pore. The bulk of the osmotic content driving stomatal movements depends on ionic fluxes across both the plasma membrane and tonoplast, the metabolism of organic acids, primarily Mal (malate), and its accumulation and loss. Anion channels at the plasma membrane are thought to comprise a major pathway for Mal efflux during stomatal closure, implicating their key role in linking solute flux with metabolism. Nonetheless, little is known of the regulation of anion channel current (I(Cl)) by cytosolic Mal or its immediate metabolite OAA (oxaloacetate). In the present study, we have examined the impact of Mal, OAA and of the monocarboxylic acid anion acetate in guard cells of Vicia faba L. and report that all three organic acids affect I(Cl), but with markedly different characteristics and sidedness to their activities. Most prominent was a suppression of ICl by OAA within the physiological range of concentrations found in vivo. These findings indicate a capacity for OAA to co-ordinate organic acid metabolism with I(Cl) through the direct effect of organic acid pool size. The findings of the present study also add perspective to in vivo recordings using acetate-based electrolytes.

  18. Effects of water turbulence on variations in cell ultrastructure and metabolism of amino acids in the submersed macrophyte, Elodea nuttallii (Planch.) H. St. John.

    PubMed

    Atapaththu, K S S; Miyagi, A; Atsuzawa, K; Kaneko, Y; Kawai-Yamada, M; Asaeda, T

    2015-09-01

    The interactions between macrophytes and water movement are not yet fully understood, and the causes responsible for the metabolic and ultrastructural variations in plant cells as a consequence of turbulence are largely unknown. In the present study, growth, metabolism and ultrastructural changes were evaluated in the aquatic macrophyte Elodea nuttallii, after exposure to turbulence for 30 days. The turbulence was generated with a vertically oscillating horizontal grid. The turbulence reduced plant growth, plasmolysed leaf cells and strengthened cell walls, and plants exposed to turbulence accumulated starch granules in stem chloroplasts. The size of the starch granules increased with the magnitude of the turbulence. Using capillary electrophoresis-mass spectrometry (CE-MS), analysis of the metabolome found metabolite accumulation in response to the turbulence. Asparagine was the dominant amino acid that was concentrated in stressed plants, and organic acids such as citrate, ascorbate, oxalate and γ-amino butyric acid (GABA) also accumulated in response to turbulence. These results indicate that turbulence caused severe stress that affected plant growth, cell ultrastructure and some metabolic functions of E. nuttallii. Our findings offer insights to explain the effects of water movement on the functions of aquatic plants.

  19. Effects of water turbulence on variations in cell ultrastructure and metabolism of amino acids in the submersed macrophyte, Elodea nuttallii (Planch.) H. St. John.

    PubMed

    Atapaththu, K S S; Miyagi, A; Atsuzawa, K; Kaneko, Y; Kawai-Yamada, M; Asaeda, T

    2015-09-01

    The interactions between macrophytes and water movement are not yet fully understood, and the causes responsible for the metabolic and ultrastructural variations in plant cells as a consequence of turbulence are largely unknown. In the present study, growth, metabolism and ultrastructural changes were evaluated in the aquatic macrophyte Elodea nuttallii, after exposure to turbulence for 30 days. The turbulence was generated with a vertically oscillating horizontal grid. The turbulence reduced plant growth, plasmolysed leaf cells and strengthened cell walls, and plants exposed to turbulence accumulated starch granules in stem chloroplasts. The size of the starch granules increased with the magnitude of the turbulence. Using capillary electrophoresis-mass spectrometry (CE-MS), analysis of the metabolome found metabolite accumulation in response to the turbulence. Asparagine was the dominant amino acid that was concentrated in stressed plants, and organic acids such as citrate, ascorbate, oxalate and γ-amino butyric acid (GABA) also accumulated in response to turbulence. These results indicate that turbulence caused severe stress that affected plant growth, cell ultrastructure and some metabolic functions of E. nuttallii. Our findings offer insights to explain the effects of water movement on the functions of aquatic plants. PMID:25959623

  20. Salicylic Acid Biosynthesis and Metabolism

    PubMed Central

    Dempsey, D'Maris Amick; Vlot, A. Corina; Wildermuth, Mary C.; Klessig, Daniel F.

    2011-01-01

    Salicylic acid (SA) has been shown to regulate various aspects of growth and development; it also serves as a critical signal for activating disease resistance in Arabidopsis thaliana and other plant species. This review surveys the mechanisms involved in the biosynthesis and metabolism of this critical plant hormone. While a complete biosynthetic route has yet to be established, stressed Arabidopsis appear to synthesize SA primarily via an isochorismate-utilizing pathway in the chloroplast. A distinct pathway utilizing phenylalanine as the substrate also may contribute to SA accumulation, although to a much lesser extent. Once synthesized, free SA levels can be regulated by a variety of chemical modifications. Many of these modifications inactivate SA; however, some confer novel properties that may aid in long distance SA transport or the activation of stress responses complementary to those induced by free SA. In addition, a number of factors that directly or indirectly regulate the expression of SA biosynthetic genes or that influence the rate of SA catabolism have been identified. An integrated model, encompassing current knowledge of SA metabolism in Arabidopsis, as well as the influence other plant hormones exert on SA metabolism, is presented. PMID:22303280

  1. p-Hydroxyphenylacetic Acid Metabolism in Pseudomonas putida F6

    PubMed Central

    O'Connor, Kevin E.; Witholt, Bernard; Duetz, Wouter

    2001-01-01

    Pseudomonas putida F6 was found to metabolize p-hydroxyphenylacetic acid through 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxymandelic acid, and 3,4-dihydroxybenzaldehyde. Cell extracts of P. putida F6 catalyze the NAD(P)H-independent hydroxylation of p-hydroxyphenylacetic acid to 3,4-dihydroxyphenylacetic acid which is further oxidized to 3,4-dihydroxymandelic acid. Oxidation and decarboxylation of the latter yields 3,4-dihydroxybenzaldehyde. A red-brown color accompanies all of the above enzyme activities and is probably due to the polymerization of quinone-like compounds. 3,4-Dihydroxybenzaldehyde is further metabolized through extradiol ring cleavage. PMID:11208791

  2. Preventive effect of geniposide on metabolic disease status in spontaneously obese type 2 diabetic mice and free fatty acid-treated HepG2 cells.

    PubMed

    Kojima, Kazuko; Shimada, Tsutomu; Nagareda, Yasuhiro; Watanabe, Michiru; Ishizaki, Junko; Sai, Yoshimichi; Miyamoto, Ken-ichi; Aburada, Masaki

    2011-01-01

    Accumulation of visceral fat induces various symptoms of metabolic syndrome such as insulin resistance and abnormal glucose/lipid metabolism and eventually leads to the onset of ischemic cerebrovascular diseases. Geniposide, which is iridoid glycoside from the fruit of Gardenia jasminoides ELLIS, is recognized as being useful against hyperlipidemia and fatty liver. In order to clarify the effect of geniposide on metabolic disease-based visceral fat accumulation and the relevant molecular mechanism, experiments were performed in spontaneously obese Type 2 diabetic TSOD mice and the free fatty acid-treated HepG2 cells. In the TSOD mice, geniposide showed suppression of body weight and visceral fat accumulation, alleviation of abnormal lipid metabolism and suppression of intrahepatic lipid accumulation. In addition, geniposide alleviated abnormal glucose tolerance and hyperinsulinemia, suggesting that geniposide has an insulin resistance-alleviating effect. Next, in order to investigate the direct effect of geniposide on the liver, the effect on the free fatty acid-treated HepG2 fatty liver model was investigated using genipin, which is the aglycone portion of geniposide. Genipin suppressed the intracellular lipid accumulation caused by the free fatty acid treatment and also significantly increased the intracellular expression of a fatty acid oxidation-related gene (peroxisomal proliferator-activated receptor: PPARα). From these results, it was confirmed that geniposide has an anti-obesity effect, an insulin resistance-alleviating effect and an abnormal lipid metabolism-alleviating effect, and the metabolite genipin shows a direct effect on the liver, inducing expression of a lipid metabolism-related gene as one of its molecular mechanisms. PMID:21963504

  3. The effect of chronic exposure to high palmitic acid concentrations on the aerobic metabolism of human endothelial EA.hy926 cells.

    PubMed

    Broniarek, Izabela; Koziel, Agnieszka; Jarmuszkiewicz, Wieslawa

    2016-09-01

    A chronic elevation of circulating free fatty acids (FFAs) is associated with diseases like obesity or diabetes and can lead to lipotoxicity. The goals of this study were to assess the influence of chronic exposure to high palmitic acid (PAL) levels on mitochondrial respiratory functions in endothelial cells and isolated mitochondria. Human umbilical vein endothelial cells (EA.hy926 line) were grown for 6 days in a medium containing either 100 or 150 μM PAL. Growth at high PAL concentrations induced a considerable increase in fatty acid-supplied respiration and a reduction of mitochondrial respiration during carbohydrate and glutamine oxidation. High PAL levels elevated intracellular and mitochondrial superoxide generation; increased inflammation marker, acyl-coenzyme A (CoA) dehydrogenase, uncoupling protein 2 (UCP2), and superoxide dismutase 2 expression; and decreased hexokinase I and pyruvate dehydrogenase expression. No change in aerobic respiration capacity was observed, while fermentation was decreased. In mitochondria isolated from high PAL-treated cells, an increase in the oxidation of palmitoylcarnitine, a decrease in the oxidation of pyruvate, and an increase in UCP2 activity were observed. Our results demonstrate that exposure to high PAL levels induces a shift in endothelial aerobic metabolism toward the oxidation of fatty acids. Increased levels of PAL caused impairment and uncoupling of the mitochondrial oxidative phosphorylation system. Our data indicate that FFAs significantly affect endothelial oxidative metabolism, reactive oxygen species (ROS) formation, and cell viability and, thus, might contribute to endothelial and vascular dysfunction. PMID:27417103

  4. Metabolic danger signals, uric acid and ATP, mediate inflammatory cross-talk between hepatocytes and immune cells in alcoholic liver disease.

    PubMed

    Petrasek, Jan; Iracheta-Vellve, Arvin; Saha, Banishree; Satishchandran, Abhishek; Kodys, Karen; Fitzgerald, Katherine A; Kurt-Jones, Evelyn A; Szabo, Gyongyi

    2015-08-01

    Inflammation defines the progression of ALD from reversible to advanced stages. Translocation of bacterial LPS to the liver from the gut is necessary for alcohol-induced liver inflammation. However, it is not known whether endogenous, metabolic danger signals are required for inflammation in ALD. Uric acid and ATP, 2 major proinflammatory danger signals, were evaluated in the serum of human volunteers exposed to a single dose of ethanol or in supernatants of primary human hepatocytes exposed to ethanol. In vitro studies were used to evaluate the role of uric acid and ATP in inflammatory cross-talk between hepatocytes and immune cells. The significance of signaling downstream of uric acid and ATP in the liver was evaluated in NLRP3-deficient mice fed a Lieber-DeCarli ethanol diet. Exposure of healthy human volunteers to a single dose of ethanol resulted in increased serum levels of uric acid and ATP. In vitro, we identified hepatocytes as a significant source of these endogenous inflammatory signals. Uric acid and ATP mediated a paracrine inflammatory cross-talk between damaged hepatocytes and immune cells and significantly increased the expression of LPS-inducible cytokines, IL-1β and TNF-α, by immune cells. Deficiency of NLRP3, a ligand-sensing component of the inflammasome recognizing uric acid and ATP, prevented the development of alcohol-induced liver inflammation in mice and significantly ameliorated liver damage and steatosis. Endogenous metabolic danger signals, uric acid, and ATP are involved in inflammatory cross-talk between hepatocytes and immune cells and play a crucial role in alcohol-induced liver inflammation.

  5. Molecular Genetics of Crassulacean Acid Metabolism.

    PubMed Central

    Cushman, J. C.; Bohnert, H. J.

    1997-01-01

    Most higher plants assimilate atmospheric CO2 through the C3 pathway of photosynthesis using ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, when CO2 availability is reduced by environmental stress conditions, the incomplete discrimination of CO2 over O2 by Rubisco leads to increased photorespiration, a process that reduces the efficiency of C3 photosynthesis. To overcome the wasteful process of photorespiration, approximately 10% of higher plant species have evolved two alternate strategies for photosynthetic CO2 assimilation, C4 photosynthesis and Crassulacean acid metabolism. Both of these biochemical pathways employ a "CO2 pump" to elevate intracellular CO2 concentrations in the vicinity of Rubisco, suppressing photorespiration and therefore improving the competitiveness of these plants under conditions of high light intensity, high temperature, or low water availability. This CO2 pump consists of a primary carboxylating enzyme, phosphoenolpyruvate carboxylase. In C4 plants, this CO2-concentrating mechanism is achieved by the coordination of two carboxylating reactions that are spatially separated into mesophyll and bundle-sheath cell types (for review, see R.T. Furbank, W.C. Taylor [1995] Plant Cell 7: 797-807;M.S.B. Ku, Y. Kano-Murakami, M. Matsuoka [1996] Plant Physiol 111: 949-957). In contrast, Crassulacean acid metabolism plants perform both carboxylation reactions within one cell type, but the two reactions are separated in time. Both pathways involve cell-specific changes in the expression of many genes that are not present in C3 plants. PMID:12223634

  6. Skeletal muscle–specific eukaryotic translation initiation factor 2α phosphorylation controls amino acid metabolism and fibroblast growth factor 21–mediated non–cell-autonomous energy metabolism

    PubMed Central

    Miyake, Masato; Nomura, Akitoshi; Ogura, Atsushi; Takehana, Kenji; Kitahara, Yoshihiro; Takahara, Kazuna; Tsugawa, Kazue; Miyamoto, Chinobu; Miura, Naoko; Sato, Ryosuke; Kurahashi, Kiyoe; Harding, Heather P.; Oyadomari, Miho; Ron, David; Oyadomari, Seiichi

    2016-01-01

    The eukaryotic translation initiation factor 2α (eIF2α) phosphorylation-dependent integrated stress response (ISR), a component of the unfolded protein response, has long been known to regulate intermediary metabolism, but the details are poorly worked out. We report that profiling of mRNAs of transgenic mice harboring a ligand-activated skeletal muscle–specific derivative of the eIF2α protein kinase R-like ER kinase revealed the expected up-regulation of genes involved in amino acid biosynthesis and transport but also uncovered the induced expression and secretion of a myokine, fibroblast growth factor 21 (FGF21), that stimulates energy consumption and prevents obesity. The link between the ISR and FGF21 expression was further reinforced by the identification of a small-molecule ISR activator that promoted Fgf21 expression in cell-based screens and by implication of the ISR-inducible activating transcription factor 4 in the process. Our findings establish that eIF2α phosphorylation regulates not only cell-autonomous proteostasis and amino acid metabolism, but also affects non–cell-autonomous metabolic regulation by induced expression of a potent myokine.—Miyake, M., Nomura, A., Ogura, A., Takehana, K., Kitahara, Y., Takahara, K., Tsugawa, K., Miyamoto, C., Miura, N., Sato, R., Kurahashi, K., Harding, H. P., Oyadomari, M., Ron, D., Oyadomari, S. Skeletal muscle–specific eukaryotic translation initiation factor 2α phosphorylation controls amino acid metabolism and fibroblast growth factor 21–mediated non–cell-autonomous energy metabolism. PMID:26487695

  7. Dissecting Germ Cell Metabolism through Network Modeling

    PubMed Central

    Whitmore, Leanne S.; Ye, Ping

    2015-01-01

    Metabolic pathways are increasingly postulated to be vital in programming cell fate, including stemness, differentiation, proliferation, and apoptosis. The commitment to meiosis is a critical fate decision for mammalian germ cells, and requires a metabolic derivative of vitamin A, retinoic acid (RA). Recent evidence showed that a pulse of RA is generated in the testis of male mice thereby triggering meiotic commitment. However, enzymes and reactions that regulate this RA pulse have yet to be identified. We developed a mouse germ cell-specific metabolic network with a curated vitamin A pathway. Using this network, we implemented flux balance analysis throughout the initial wave of spermatogenesis to elucidate important reactions and enzymes for the generation and degradation of RA. Our results indicate that primary RA sources in the germ cell include RA import from the extracellular region, release of RA from binding proteins, and metabolism of retinal to RA. Further, in silico knockouts of genes and reactions in the vitamin A pathway predict that deletion of Lipe, hormone-sensitive lipase, disrupts the RA pulse thereby causing spermatogenic defects. Examination of other metabolic pathways reveals that the citric acid cycle is the most active pathway. In addition, we discover that fatty acid synthesis/oxidation are the primary energy sources in the germ cell. In summary, this study predicts enzymes, reactions, and pathways important for germ cell commitment to meiosis. These findings enhance our understanding of the metabolic control of germ cell differentiation and will help guide future experiments to improve reproductive health. PMID:26367011

  8. Development of a Microfluidic-Based Optical Sensing Device for Label-Free Detection of Circulating Tumor Cells (CTCs) Through Their Lactic Acid Metabolism

    PubMed Central

    Chiu, Tzu-Keng; Lei, Kin-Fong; Hsieh, Chia-Hsun; Hsiao, Hung-Bo; Wang, Hung-Ming; Wu, Min-Hsien

    2015-01-01

    This study reports a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs), a rare cell species in blood circulation. Based on the metabolic features of cancer cells, live CTCs can be quantified indirectly through their lactic acid production. Compared with the conventional schemes for CTC detection, this label-free approach could prevent the biological bias due to the heterogeneity of the surface antigens on cancer cells. In this study, a microfluidic device was proposed to generate uniform water-in-oil cell-encapsulating micro-droplets, followed by the fluorescence-based optical detection of lactic acid produced within the micro-droplets. To test its feasibility to quantify cancer cells, experiments were carried out. Results showed that the detection signals were proportional to the number of cancer cells within the micro-droplets, whereas such signals were insensitive to the existence and number of leukocytes within. To further demonstrate its feasibility for cancer cell detection, the cancer cells with known cell number in a cell suspension was detected based on the method. Results revealed that there was no significant difference between the detected number and the real number of cancer cells. As a whole, the proposed method opens up a new route to detect live CTCs in a label-free manner. PMID:25808775

  9. Metabolic profiling of Arabidopsis thaliana epidermal cells

    PubMed Central

    Ebert, Berit; Zöller, Daniela; Erban, Alexander; Fehrle, Ines; Hartmann, Jürgen; Niehl, Annette; Kopka, Joachim; Fisahn, Joachim

    2010-01-01

    Metabolic phenotyping at cellular resolution may be considered one of the challenges in current plant physiology. A method is described which enables the cell type-specific metabolic analysis of epidermal cell types in Arabidopsis thaliana pavement, basal, and trichome cells. To achieve the required high spatial resolution, single cell sampling using microcapillaries was combined with routine gas chromatography-time of flight-mass spectrometry (GC-TOF-MS) based metabolite profiling. The identification and relative quantification of 117 mostly primary metabolites has been demonstrated. The majority, namely 90 compounds, were accessible without analytical background correction. Analyses were performed using cell type-specific pools of 200 microsampled individual cells. Moreover, among these identified metabolites, 38 exhibited differential pool sizes in trichomes, basal or pavement cells. The application of an independent component analysis confirmed the cell type-specific metabolic phenotypes. Significant pool size changes between individual cells were detectable within several classes of metabolites, namely amino acids, fatty acids and alcohols, alkanes, lipids, N-compounds, organic acids and polyhydroxy acids, polyols, sugars, sugar conjugates and phenylpropanoids. It is demonstrated here that the combination of microsampling and GC-MS based metabolite profiling provides a method to investigate the cellular metabolism of fully differentiated plant cell types in vivo. PMID:20150518

  10. Snail modulates cell metabolism in MDCK cells

    SciTech Connect

    Haraguchi, Misako; Indo, Hiroko P.; Iwasaki, Yasumasa; Iwashita, Yoichiro; Fukushige, Tomoko; Majima, Hideyuki J.; Izumo, Kimiko; Horiuchi, Masahisa; Kanekura, Takuro; Furukawa, Tatsuhiko; Ozawa, Masayuki

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  11. Red cell metabolism studies on Skylab

    NASA Technical Reports Server (NTRS)

    Mengel, C. E.

    1977-01-01

    Blood samples from Spacelab crewmembers were studied for possible environment effects on red cell components. Analysis involved peroxidation of red cell lipids, enzymes of red cell metabolism, and levels of 2,3-diphosphoglyceric acid and adenosine triphosphate. Results show that there is no evidence of lipid peroxidation, that biochemical effect known to be associated with irreversible red cell damage. Changes observed in glycolytic intermediates and enzymes cannot be directly implicated as indicating evidence of red cell damage.

  12. IDH1 mutations alter citric acid cycle metabolism and increase dependence on oxidative mitochondrial metabolism.

    PubMed

    Grassian, Alexandra R; Parker, Seth J; Davidson, Shawn M; Divakaruni, Ajit S; Green, Courtney R; Zhang, Xiamei; Slocum, Kelly L; Pu, Minying; Lin, Fallon; Vickers, Chad; Joud-Caldwell, Carol; Chung, Franklin; Yin, Hong; Handly, Erika D; Straub, Christopher; Growney, Joseph D; Vander Heiden, Matthew G; Murphy, Anne N; Pagliarini, Raymond; Metallo, Christian M

    2014-06-15

    Oncogenic mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in several types of cancer, but the metabolic consequences of these genetic changes are not fully understood. In this study, we performed (13)C metabolic flux analysis on a panel of isogenic cell lines containing heterozygous IDH1/2 mutations. We observed that under hypoxic conditions, IDH1-mutant cells exhibited increased oxidative tricarboxylic acid metabolism along with decreased reductive glutamine metabolism, but not IDH2-mutant cells. However, selective inhibition of mutant IDH1 enzyme function could not reverse the defect in reductive carboxylation activity. Furthermore, this metabolic reprogramming increased the sensitivity of IDH1-mutant cells to hypoxia or electron transport chain inhibition in vitro. Lastly, IDH1-mutant cells also grew poorly as subcutaneous xenografts within a hypoxic in vivo microenvironment. Together, our results suggest therapeutic opportunities to exploit the metabolic vulnerabilities specific to IDH1 mutation.

  13. [Metabolism of nicotinic acid in plant cell suspension cultures: II; Isolation, characterization and enzymology of nicotinic acid N-alpha-arabinoside (author's transl)].

    PubMed

    Leienbach, K W; Barz, W

    1976-08-01

    A very hydrophilic compound was isolated from parsley cell suspension cultures in high yield after application of nicotinic acid. Using chemical, chromatographic and spectroscopic procedures the structure of this new plant constituent has been elucidated as nicotinic acid N-alpha-L-arabinopyranoside. This structure has been proved by chemical synthesis. An arabinosyltransferase was isolated from parsley cell suspension cultures and purified about 19-fold. The enzyme converted nicotinic acid N-alpha-arabinoside with UDP to nicotinic acid and UDP-arabinose. pH-Optimum (pH 7.0-8.0), Km value for nicotinic acid N-alpha-L-arabinoside (2.2 X 10(-4) mol/l) and mol. wt. (app. 70 000) of the transferase were measured. Function and biosynthesis of the arabinoside in cell cultures are discussed.

  14. Dendritic cell metabolism

    PubMed Central

    Pearce, Edward J.; Everts, Bart

    2015-01-01

    The past 15 years have seen enormous advances in our understanding of the receptor and signalling systems that allow dendritic cells (DCs) to respond to pathogens or other danger signals and initiate innate and adaptive immune responses. We are now beginning to appreciate that many of these pathways not only stimulate changes in the expression of genes that control DC immune functions, but also affect metabolic pathways, thereby integrating the cellular requirements of the activation process. In this Review, we focus on this relatively new area of research and attempt to describe an integrated view of DC immunometabolism. PMID:25534620

  15. Metabolism of fatty acid-labeled cerebroside sulfate in cultured cells from controls and metachromatic leukodystrophy patients. Use in the prenatal identification of a false positive fetus.

    PubMed

    Kudoh, T; Sattler, M; Malmstrom, J; Bitter, M A; Wenger, D A

    1981-11-01

    Metachromatic leukodystrophy is the name given to a group of diseases in patients having a deficiency of CS sulfatase activity. The diagnosis usually can be made by using leukocytes, urine, and cultured skin fibroblasts. The low level of enzyme activity can be measured with an artificial substrate, NCS, or suitably labeled CS. In a number of families, healthy carriers of this autosomal recessive disease have been found to have enzyme levels near those of affected patients. We prepared (14)C-stearic acid-labeled CS and studied its metabolism in cultured human cells from patients and controls, In vitro, CS sulfatase requires bile salts to stimulate the enzymatic reaction. The (14)C-CS also can be added to the medium on cultured cells, and its metabolism in the cells can be followed without the addition of bile salts. A child with late infantile MLD was identified by studies on urine and leukocytes. Studies on leukocytes from the parents revealed a very low enzyme level in the father (false positive) and a typical carrier level in the mother. A pregnancy in this family was monitored, and in vitro studies on cultured AFC revealed low CS and NCS sulfatase levels. However, the addition of (14)C-CS to the culture medium revealed normal metabolism in these cells. An unaffected fetus was predicted on the basis of the cell feeding studies. The couple elected to abort this pregnancy, and studies on the fetus confirmed it would not have been affected with MLD.

  16. Biosynthesis and metabolism of salicylic acid

    SciTech Connect

    Lee, H.; Leon, J.; Raskin, I.

    1995-05-09

    Pathways of salicylic acid (SA) biosynthesis and metabolism in tobacco have been recently identified. SA, an endogenous regulator of disease resistance, is a product of phenylpropanoid metabolism formed via decarboxylation of trans-cinnamic acid to benzoic acid and its subsequent 2-hydroxylation to SA. In tobacco mosaic virus-inoculated tobacco leaves, newly synthesized SA is rapidly metabolized to SA O-{beta}-D-glucoside and methyl salicylate. Two key enzymes involved in SA biosynthesis and metabolism: benzoic acid 2-hydroxylase, which converts benzoic acid to SA, and UDPglucose:SA glucosyltransferase (EC 2.4.1.35), which catalyzes conversion of SA to SA glucoside have been partially purified and characterized. Progress in enzymology and molecular biology of SA biosynthesis and metabolism will provide a better understanding of signal transduction pathway involved in plant disease resistance. 62 refs., 1 fig.

  17. Regulation of the expression and activity of glucose and lactic acid metabolism-related genes by protein kinase C in skeletal muscle cells.

    PubMed

    Otake, Sho; Kobayashi, Masaki; Narumi, Katsuya; Sasaki, Shotaro; Kikutani, Yurika; Furugen, Ayako; Watanabe, Meguho; Takahashi, Natsuko; Ogura, Jiro; Yamaguchi, Hiroaki; Iseki, Ken

    2013-01-01

    Protein kinase C (PKC) modulators are very attractive therapeutic targets in cancer. Since most cancer cells display increased glycolysis, elucidations of the effects of PKC activation on glycolysis is necessary for the development of effective medicine. In the present study, to clarify the role of PKC in the regulation of glycolysis, we examined the effect of phorbol 12-myristate 13-acetate (PMA), a PKC activator, on the expression and activity of glucose and lactic acid metabolism-related genes in human rhabdomyosarcoma cells (RD cells). In parallel to increases in glucose uptake and mRNA levels of glucose transporters (GLUTs) induced by PMA treatment for 6 h, the hexokinase (HK) mRNA level and activity were also significantly increased in RD cells. On the other hand, a significant increase in lactate dehydrogenase (LDH) mRNA level and activity was seen when the cells were incubated with PMA for 24 h, but not for 6 or 12 h, and was associated with lactic acid production. These effects by PMA treatment were markedly suppressed by Bisindolylmaleimide (BIM), a PKC inhibitor. Furthermore, chetomin, a hypoxia-inducible factor 1 (HIF-1) inhibitor, completely abrogated the increment of LDH mRNA level and activity as well as monocarboxylate transporter (MCT) 4, a lactic acid efflux transporter. In conclusion, we found that HK and LDH activity induced by PKC activation was associated with the glucose uptake and lactic acid level and that LDH and MCT4 are modulated by a common factor, HIF-1.

  18. Intestinal transport and metabolism of bile acids

    PubMed Central

    Dawson, Paul A.; Karpen, Saul J.

    2015-01-01

    In addition to their classical roles as detergents to aid in the process of digestion, bile acids have been identified as important signaling molecules that function through various nuclear and G protein-coupled receptors to regulate a myriad of cellular and molecular functions across both metabolic and nonmetabolic pathways. Signaling via these pathways will vary depending on the tissue and the concentration and chemical structure of the bile acid species. Important determinants of the size and composition of the bile acid pool are their efficient enterohepatic recirculation, their host and microbial metabolism, and the homeostatic feedback mechanisms connecting hepatocytes, enterocytes, and the luminal microbiota. This review focuses on the mammalian intestine, discussing the physiology of bile acid transport, the metabolism of bile acids in the gut, and new developments in our understanding of how intestinal metabolism, particularly by the gut microbiota, affects bile acid signaling. PMID:25210150

  19. Understanding the effects of mature adipocytes and endothelial cells on fatty acid metabolism and vascular tone in physiological fatty tissue for vascularized adipose tissue engineering.

    PubMed

    Huber, Birgit; Volz, Ann-Cathrin; Kluger, Petra J

    2015-11-01

    Engineering of large vascularized adipose tissue constructs is still a challenge for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Communication between mature adipocytes and endothelial cells is important for homeostasis and the maintenance of adipose tissue mass but, to date, is mainly neglected in tissue engineering strategies. Thus, new co-culture strategies are needed to integrate adipocytes and endothelial cells successfully into a functional construct. This review focuses on the cross-talk of mature adipocytes and endothelial cells and considers their influence on fatty acid metabolism and vascular tone. In addition, the properties and challenges with regard to these two cell types for vascularized tissue engineering are highlighted.

  20. Understanding the effects of mature adipocytes and endothelial cells on fatty acid metabolism and vascular tone in physiological fatty tissue for vascularized adipose tissue engineering.

    PubMed

    Huber, Birgit; Volz, Ann-Cathrin; Kluger, Petra J

    2015-11-01

    Engineering of large vascularized adipose tissue constructs is still a challenge for the treatment of extensive high-graded burns or the replacement of tissue after tumor removal. Communication between mature adipocytes and endothelial cells is important for homeostasis and the maintenance of adipose tissue mass but, to date, is mainly neglected in tissue engineering strategies. Thus, new co-culture strategies are needed to integrate adipocytes and endothelial cells successfully into a functional construct. This review focuses on the cross-talk of mature adipocytes and endothelial cells and considers their influence on fatty acid metabolism and vascular tone. In addition, the properties and challenges with regard to these two cell types for vascularized tissue engineering are highlighted. PMID:26340984

  1. 2-Chloro-1,3-propanediol (2-MCPD) and its fatty acid esters: cytotoxicity, metabolism, and transport by human intestinal Caco-2 cells.

    PubMed

    Buhrke, Thorsten; Frenzel, Falko; Kuhlmann, Jan; Lampen, Alfonso

    2015-12-01

    The food contaminants 3-chloro-1,2-propanediol (3-MCPD) and 3-MCPD fatty acid esters have attracted considerable attention in the past few years due to their toxic properties and their occurrence in numerous foods. Recently, significant amounts of the isomeric compounds 2-chloro-1,3-propanediol (2-MCPD) fatty acid esters have been detected in refined oils. Beside the interrogation which toxic effects might be related to the core compound 2-MCPD, the key question from the risk assessment perspective is again-as it was discussed for 3-MCPD fatty acid esters before-to which degree these esters are hydrolyzed in the gut, thereby releasing free 2-MCPD. Here, we show that free 2-MCPD but not 2-MCPD fatty acid esters were able to cross a monolayer of differentiated Caco-2 cells as an in vitro model for the human intestinal barrier. Instead, the esters were hydrolyzed by the cells, thereby releasing free 2-MCPD which was neither absorbed nor metabolized by the cells. Cytotoxicity assays revealed that free 2-MCPD as well as free 3-MCPD was not toxic to Caco-2 cells up to a level of 1 mM, whereas cellular viability was slightly decreased in the presence of a few 2-MCPD and 3-MCPD fatty acid esters at concentrations above 10 µM. The observed cytotoxic effects correlated well with the induction of caspase activity and might be attributed to the induction of apoptosis by free fatty acids which were released from the esters in the presence of Caco-2 cells. PMID:25354796

  2. Toward systems-level analysis of agricultural production from crassulacean acid metabolism (CAM): scaling from cell to commercial production.

    PubMed

    Davis, Sarah C; Ming, Ray; LeBauer, David S; Long, Stephen P

    2015-10-01

    Systems-level analyses have become prominent tools for assessing the yield, viability, economic consequences and environmental impacts of agricultural production. Such analyses are well-developed for many commodity crops that are used for food and biofuel, but have not been developed for agricultural production systems based on drought-tolerant plants that use crassulacean acid metabolism (CAM). We review the components of systems-level evaluations, and identify the information available for completing such analyses for CAM cropping systems. Specific needs for developing systems-level evaluations of CAM agricultural production include: improvement of physiological models; assessment of product processing after leaving the farm gate; and application of newly available genetic tools to the optimization of CAM species for commercial production. PMID:26094655

  3. Transgenesis of humanized fat1 promotes n-3 polyunsaturated fatty acid synthesis and expression of genes involved in lipid metabolism in goat cells.

    PubMed

    Fan, Yixuan; Ren, Caifang; Wang, Zhibo; Jia, Ruoxin; Wang, Dan; Zhang, Yanli; Zhang, Guomin; Wan, Yongjie; Huang, Mingrui; Wang, Feng

    2016-01-15

    The n-3 fatty acid desaturase gene fat1 codes for the n-3 desaturase enzyme, which can convert n-6 polyunsaturated fatty acids (PUFAs) to n-3 PUFAs. The n-3 PUFAs are essential components required for normal cellular function and have preventive and therapeutic effects on many diseases. Goat is an important domestic animal for human consumption of meat and milk. To elevate the concentrations of n-3 PUFAs and examine the regulatory mechanism of fat1 in PUFA metabolism in goat cells, we successfully constructed a humanized fat1 expression vector and confirmed the efficient expression of fat1 in goat ear skin-derived fibroblast cells (GEFCs) by qRT-PCR and Western blot analysis. Fatty acid analysis showed that fat1 overexpression significantly increased the levels of total n-3 PUFAs and decreased the levels of total n-6 PUFAs in GEFCs. In addition, qRT-PCR results indicate that the FADS1 and FADS2 desaturase genes, ELOV2 and ELOV5 elongase genes, ACO and CPT1 oxidation genes, and PPARa and PPARγ transcription factors are up-regulated, and transcription factors of SREBP-1c gene are down-regulated in the fat1 transgenic goat cells. Overall, fat1-overexpression resulted in an increase in the n-3 fatty acids and altered expression of PUFA synthesis related genes in GEFCs. This work lays a foundation for both the production of fat1 transgenic goats and further study of the mechanism of fat1 function in the PUFAs metabolism. PMID:26474750

  4. Transgenesis of humanized fat1 promotes n-3 polyunsaturated fatty acid synthesis and expression of genes involved in lipid metabolism in goat cells.

    PubMed

    Fan, Yixuan; Ren, Caifang; Wang, Zhibo; Jia, Ruoxin; Wang, Dan; Zhang, Yanli; Zhang, Guomin; Wan, Yongjie; Huang, Mingrui; Wang, Feng

    2016-01-15

    The n-3 fatty acid desaturase gene fat1 codes for the n-3 desaturase enzyme, which can convert n-6 polyunsaturated fatty acids (PUFAs) to n-3 PUFAs. The n-3 PUFAs are essential components required for normal cellular function and have preventive and therapeutic effects on many diseases. Goat is an important domestic animal for human consumption of meat and milk. To elevate the concentrations of n-3 PUFAs and examine the regulatory mechanism of fat1 in PUFA metabolism in goat cells, we successfully constructed a humanized fat1 expression vector and confirmed the efficient expression of fat1 in goat ear skin-derived fibroblast cells (GEFCs) by qRT-PCR and Western blot analysis. Fatty acid analysis showed that fat1 overexpression significantly increased the levels of total n-3 PUFAs and decreased the levels of total n-6 PUFAs in GEFCs. In addition, qRT-PCR results indicate that the FADS1 and FADS2 desaturase genes, ELOV2 and ELOV5 elongase genes, ACO and CPT1 oxidation genes, and PPARa and PPARγ transcription factors are up-regulated, and transcription factors of SREBP-1c gene are down-regulated in the fat1 transgenic goat cells. Overall, fat1-overexpression resulted in an increase in the n-3 fatty acids and altered expression of PUFA synthesis related genes in GEFCs. This work lays a foundation for both the production of fat1 transgenic goats and further study of the mechanism of fat1 function in the PUFAs metabolism.

  5. Metabolic changes associated with tumor metastasis, part 2: Mitochondria, lipid and amino acid metabolism.

    PubMed

    Porporato, Paolo E; Payen, Valéry L; Baselet, Bjorn; Sonveaux, Pierre

    2016-04-01

    Metabolic alterations are a hallmark of cancer controlling tumor progression and metastasis. Among the various metabolic phenotypes encountered in tumors, this review focuses on the contributions of mitochondria, lipid and amino acid metabolism to the metastatic process. Tumor cells require functional mitochondria to grow, proliferate and metastasize, but shifts in mitochondrial activities confer pro-metastatic traits encompassing increased production of mitochondrial reactive oxygen species (mtROS), enhanced resistance to apoptosis and the increased or de novo production of metabolic intermediates of the TCA cycle behaving as oncometabolites, including succinate, fumarate, and D-2-hydroxyglutarate that control energy production, biosynthesis and the redox state. Lipid metabolism and the metabolism of amino acids, such as glutamine, glutamate and proline are also currently emerging as focal control points of cancer metastasis.

  6. Unique metabolic features of stem cells, cardiomyocytes, and their progenitors.

    PubMed

    Gaspar, John Antonydas; Doss, Michael Xavier; Hengstler, Jan Georg; Cadenas, Cristina; Hescheler, Jürgen; Sachinidis, Agapios

    2014-04-11

    Recently, growing attention has been directed toward stem cell metabolism, with the key observation that the plasticity of stem cells also reflects the plasticity of their energy substrate metabolism. There seems to be a clear link between the self-renewal state of stem cells, in which cells proliferate without differentiation, and the activity of specific metabolic pathways. Differentiation is accompanied by a shift from anaerobic glycolysis to mitochondrial respiration. This metabolic switch of differentiating stem cells is required to cover the energy demands of the different organ-specific cell types. Among other metabolic signatures, amino acid and carbohydrate metabolism is most prominent in undifferentiated embryonic stem cells, whereas the fatty acid metabolic signature is unique in cardiomyocytes derived from embryonic stem cells. Identifying the specific metabolic pathways involved in pluripotency and differentiation is critical for further progress in the field of developmental biology and regenerative medicine. The recently generated knowledge on metabolic key processes may help to generate mature stem cell-derived somatic cells for therapeutic applications without the requirement of genetic manipulation. In the present review, the literature about metabolic features of stem cells and their cardiovascular cell derivatives as well as the specific metabolic gene signatures differentiating between stem and differentiated cells are summarized and discussed.

  7. Metabolism of hop-derived bitter acids.

    PubMed

    Cattoor, Ko; Dresel, Michael; De Bock, Lies; Boussery, Koen; Van Bocxlaer, Jan; Remon, Jean-Paul; De Keukeleire, Denis; Deforce, Dieter; Hofmann, Thomas; Heyerick, Arne

    2013-08-21

    In this study, in vitro metabolism of hop-derived bitter acids was investigated. Besides their well-known use as bitter compounds in beer, in several studies, bioactive properties have been related to these types of molecules. However, scientific data on the absorption, distribution, metabolism, and excretion aspects of these compounds are limited. More specific, in this study, α-acids, β-acids, and iso-α-acids were incubated with rabbit microsomes, and fractions were subjected to LC-MS/MS analysis for identification of oxidative biotransformation products. Metabolism of β-acids was mainly characterized by conversion into hulupones and the formation of a series of tricyclic oxygenated products. The most important metabolites of α-acids were identified as humulinones and hulupones. Iso-α-acids were found to be primarly metabolized into cis- and trans-humulinic acids, next to oxidized alloiso-α-acids. Interestingly, the phase I metabolites were highly similar to the oxidative degradation products in beer. These findings show a first insight into the metabolites of hop-derived bitter acids and could have important practical implications in the bioavailability aspects of these compounds, following ingestion of hop-based food products and nutraceuticals.

  8. 2-Hydroxy Acids in Plant Metabolism

    PubMed Central

    Maurino, Veronica G.; Engqvist, Martin K. M.

    2015-01-01

    Glycolate, malate, lactate, and 2-hydroxyglutarate are important 2-hydroxy acids (2HA) in plant metabolism. Most of them can be found as D- and L-stereoisomers. These 2HA play an integral role in plant primary metabolism, where they are involved in fundamental pathways such as photorespiration, tricarboxylic acid cycle, glyoxylate cycle, methylglyoxal pathway, and lysine catabolism. Recent molecular studies in Arabidopsis thaliana have helped elucidate the participation of these 2HA in in plant metabolism and physiology. In this chapter, we summarize the current knowledge about the metabolic pathways and cellular processes in which they are involved, focusing on the proteins that participate in their metabolism and cellular/intracellular transport in Arabidopsis. PMID:26380567

  9. Cell Surface Proteomic Map of HIV Infection Reveals Antagonism of Amino Acid Metabolism by Vpu and Nef

    PubMed Central

    Matheson, Nicholas J.; Sumner, Jonathan; Wals, Kim; Rapiteanu, Radu; Weekes, Michael P.; Vigan, Raphael; Weinelt, Julia; Schindler, Michael; Antrobus, Robin; Costa, Ana S.H.; Frezza, Christian; Clish, Clary B.; Neil, Stuart J.D.; Lehner, Paul J.

    2015-01-01

    Summary Critical cell surface immunoreceptors downregulated during HIV infection have previously been identified using non-systematic, candidate approaches. To gain a comprehensive, unbiased overview of how HIV infection remodels the T cell surface, we took a distinct, systems-level, quantitative proteomic approach. >100 plasma membrane proteins, many without characterized immune functions, were downregulated during HIV infection. Host factors targeted by the viral accessory proteins Vpu or Nef included the amino acid transporter SNAT1 and the serine carriers SERINC3/5. We focused on SNAT1, a β-TrCP-dependent Vpu substrate. SNAT1 antagonism was acquired by Vpu variants from the lineage of SIVcpz/HIV-1 viruses responsible for pandemic AIDS. We found marked SNAT1 induction in activated primary human CD4+ T cells, and used Consumption and Release (CoRe) metabolomics to identify alanine as an endogenous SNAT1 substrate required for T cell mitogenesis. Downregulation of SNAT1 therefore defines a unique paradigm of HIV interference with immunometabolism. PMID:26439863

  10. Stimulation of arachidonic acid metabolism in primary cultures of osteoblast-like cells by hormones and drugs

    SciTech Connect

    Feyen, J.H.; van der Wilt, G.; Moonen, P.; Di Bon, A.; Nijweide, P.J.

    1984-12-01

    The effects of parathyroid hormone (PTH), dihydroxycholecalciferol (1,25-(OH)2 D3), thrombin, epidermal growth factor (EGF) and 12-o-tetradecanoylphorbol-13-acetate (PMA) on the biosynthesis and release of arachidonic acid metabolites were studied in primary cultures of osteoblast-like cells isolated from 18-day-old chick embryo calvaria. Cells were labelled with (/sup 14/C)-arachidonic acid for 30 h. The radioactive eicosanoids were extracted from the cell culture media after a further 30 h stimulation period and analysed on a PRP-1 column by HPLC. The radioactive products were characterized by co-elution of (/sup 3/H) standard prostanoids. Osteoblasts showed a basal release of the prostanoids 6-keto-PGF1 alpha, TXB2, PGF2 alpha, PGE2, PGD2 and PGB2, the latter being the most abundant one. Indomethacin (10(-5) M) effectively inhibited the basal release, but not that of an as yet unidentified compound. The release of prostanoids was stimulated by PTH (2 U/ml), thrombin (0.4 NIH/ml), EGF (50 ng/ml) and PMA (25 ng/ml), the latter being by far the most potent one. 1,25-(OH)2D3 was found to slightly inhibit the prostanoid release. These results indicate: (1) primary cultures of osteoblasts synthesize several prostaglandins, thromboxane B2 and one unidentified product. (2) the action on bone of PTH and the various drugs tested may be, at least partly, mediated by an increased prostaglandin production by osteoblasts. Clearly this does not apply to 1,25-(OH)2D3.

  11. Alteration of membrane fatty acid composition and inositol phosphate metabolism in HT-29 human colon cancer cells.

    PubMed

    Awad, A B; Fink, C S; Horvath, P J

    1993-01-01

    The present study was designed to investigate the role of membrane fatty acid (FA) composition on inositol phosphate (InsP) release by a human colon tumor cell line. Cells were supplemented for five days in culture with 0, 10, 30, or 100 microM sodium stearate (18:0), linoleate [18:2(omega-6)], or linolineate [18:3(omega-3)]. These FAs were supplied as a complex with FA-free bovine serum albumin. InsP release was examined in these cells with or without stimulation with deoxycholic acid (DCA) after they were labeled with [3H]myoinositol. FA enrichment was found to influence inositol incorporation into membrane lipids. Although 18:0 had no effect, 18:2(omega-6) decreased the incorporation. On the other hand, 18:3(omega-3) increased the incorporation of inositol compared with the cells supplemented with the other FAs, but they were not different from control. Basal release of total InsP was elevated only with supplementation of 10 and 30 microM 18:3(omega-3). FA supplementation with 18:0 at 30 microM and 18:2 at 30 and 100 microM resulted in downregulation of bsal release of InsP. Enrichment of HT-29 cell membranes with polyunsaturated FAs resulted in a significant increase in stimulated release of InsP, but this was not seen with saturated FA supplementation. At 10 microM supplementation, 18:2 had the greatest effect on stimulated InsP release. This effect of 18:2 disappeared at 30 microM. However, the increase in the stimulated InsP release caused by 18:3 occurred at 10 and 30 microM. DCA-stimulated release of InsP was not downregulated by any FA supplementation. This study showed that enrichment of the membranes with polyunsaturated FAs increases the response of the phosphatidylinositol cycle to DCA stimulation. In addition, enrichment with 18:3(omega-3) increases the basal turnover of InsP. It is concluded that alteration of membrane FAs has a profound effect on the phosphatidylinositol cycle.

  12. Titer of trastuzumab produced by a Chinese hamster ovary cell line is associated with tricarboxylic acid cycle activity rather than lactate metabolism.

    PubMed

    Ishii, Yoichi; Imamoto, Yasufumi; Yamamoto, Rie; Tsukahara, Masayoshi; Wakamatsu, Kaori

    2015-04-01

    Achieving high productivity and quality is the final goal of therapeutic antibody development, but the productivity and quality of antibodies are known to be substantially dependent on the nature of the cell lines expressing the antibodies. We characterized two contrasting cell lines that produce trastuzumab, namely cell line A with a high titer and a low aggregate content and cell line B with a low titer and a high aggregate content to identify the causes of the differences. We observed the following differences: cell growth (A > B), proportion of defucosylated oligosaccharides on antibodies (A < B), and proportion of covalent antibody aggregates (A > B). Our results suggest that the high monoclonal antibody (mAb) titers in cell line A is associated with the high proliferation and is not caused by the lactate metabolism shift (switching from lactate production to net lactate consumption). Rather, these differences can be accounted for by the following: levels of tricarboxylic acid cycle intermediates (A > B), ammonium ion levels (A ≤ B), and oxidative stress (A > B). PMID:25449760

  13. ROS-Mediated Autophagy Induced by Dysregulation of Lipid Metabolism Plays a Protective Role in Colorectal Cancer Cells Treated with Gambogic Acid

    PubMed Central

    Zhang, Haiyuan; Lei, Yunlong; Yuan, Ping; Li, Lingjun; Luo, Chao; Gao, Rui; Tian, Jun; Feng, Zuohua; Nice, Edouard C.; Sun, Jun

    2014-01-01

    Gambogic acid (GA), the main active component of gamboge resin, has potent antitumor activity both in vivo and in vitro. However, the underlying molecular mechanisms remain unclear. In this study, we found that GA could initiate autophagy in colorectal cancer cells, and inhibition of the autophagy process accelerated the effect of proliferative inhibition and apoptotic cell death induced by GA, implying a protective role of autophagy. Two-dimensional electrophoresis-based proteomics showed that GA treatment altered the expression of multiple proteins involved in redox signaling and lipid metabolism. Functional studies revealed that GA-induced dysregulation of lipid metabolism could activate 5-lipoxygenase (5-LOX), resulting in intracellular ROS accumulation, followed by inhibition of Akt-mTOR signaling and autophagy initiation. Finally, results using a xenograft model suggested ROS-induced autophagy protect against the antitumor effect of GA. Taken together, these data showed new biological activities of GA against colorectal cancer underlying the protective role of ROS-induced autophagy. This study will provide valuable insights for future studies regarding the anticancer mechanisms of GA. PMID:24810758

  14. Phylogenomic reconstruction of archaeal fatty acid metabolism

    PubMed Central

    Dibrova, Daria V.; Galperin, Michael Y.; Mulkidjanian, Armen Y.

    2014-01-01

    While certain archaea appear to synthesize and/or metabolize fatty acids, the respective pathways still remain obscure. By analyzing the genomic distribution of the key lipid-related enzymes, we were able to identify the likely components of the archaeal pathway of fatty acid metabolism, namely, a combination of the enzymes of bacterial-type β-oxidation of fatty acids (acyl-CoA-dehydrogenase, enoyl-CoA hydratase, and 3-hydroxyacyl-CoA dehydrogenase) with paralogs of the archaeal acetyl-CoA C-acetyltransferase, an enzyme of the mevalonate biosynthesis pathway. These three β-oxidation enzymes working in the reverse direction could potentially catalyze biosynthesis of fatty acids, with paralogs of acetyl-CoA C-acetyltransferase performing addition of C2 fragments. The presence in archaea of the genes for energy-transducing membrane enzyme complexes, such as cytochrome bc complex, cytochrome c oxidase, and diverse rhodopsins, was found to correlate with the presence of the proposed system of fatty acid biosynthesis. We speculate that because these membrane complexes functionally depend on fatty acid chains, their genes could have been acquired via lateral gene transfer from bacteria only by those archaea that already possessed a system of fatty acid biosynthesis. The proposed pathway of archaeal fatty acid metabolism operates in extreme conditions and therefore might be of interest in the context of biofuel production and other industrial applications. PMID:24818264

  15. Plant cell wall imaging by metabolic click-mediated labelling of rhamnogalacturonan II using azido 3-deoxy-D-manno-oct-2-ulosonic acid.

    PubMed

    Dumont, Marie; Lehner, Arnaud; Vauzeilles, Boris; Malassis, Julien; Marchant, Alan; Smyth, Kevin; Linclau, Bruno; Baron, Aurélie; Mas Pons, Jordi; Anderson, Charles T; Schapman, Damien; Galas, Ludovic; Mollet, Jean-Claude; Lerouge, Patrice

    2016-02-01

    In plants, 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) is a monosaccharide that is only found in the cell wall pectin, rhamnogalacturonan-II (RG-II). Incubation of 4-day-old light-grown Arabidopsis seedlings or tobacco BY-2 cells with 8-azido 8-deoxy Kdo (Kdo-N3 ) followed by coupling to an alkyne-containing fluorescent probe resulted in the specific in muro labelling of RG-II through a copper-catalysed azide-alkyne cycloaddition reaction. CMP-Kdo synthetase inhibition and competition assays showing that Kdo and D-Ara, a precursor of Kdo, but not L-Ara, inhibit incorporation of Kdo-N3 demonstrated that incorporation of Kdo-N3 occurs in RG-II through the endogenous biosynthetic machinery of the cell. Co-localisation of Kdo-N3 labelling with the cellulose-binding dye calcofluor white demonstrated that RG-II exists throughout the primary cell wall. Additionally, after incubating plants with Kdo-N3 and an alkynated derivative of L-fucose that incorporates into rhamnogalacturonan I, co-localised fluorescence was observed in the cell wall in the elongation zone of the root. Finally, pulse labelling experiments demonstrated that metabolic click-mediated labelling with Kdo-N3 provides an efficient method to study the synthesis and redistribution of RG-II during root growth. PMID:26676799

  16. Renal acid-base metabolism after ischemia.

    PubMed

    Holloway, J C; Phifer, T; Henderson, R; Welbourne, T C

    1986-05-01

    The response of the kidney to ischemia-induced cellular acidosis was followed over the immediate one hr post-ischemia reflow period. Clearance and extraction experiments as well as measurement of cortical intracellular pH (pHi) were performed on Inactin-anesthetized Sprague-Dawley rats. Arteriovenous concentration differences and para-aminohippurate extraction were obtained by cannulating the left renal vein. Base production was monitored as bicarbonate released into the renal vein and urine; net base production was related to the renal handling of glutamine and ammonia as well as to renal oxygen consumption and pHi. After a 15 min control period, the left renal artery was snared for one-half hr followed by release and four consecutive 15 min reflow periods. During the control period, cortical cell pHi measured by [14C]-5,5-Dimethyl-2,4-Oxazolidinedione distribution was 7.07 +/- 0.08, and Q-O2 was 14.1 +/- 2.2 micromoles/min; neither net glutamine utilization nor net bicarbonate generation occurred. After 30 min of ischemia, renal tissue pH fell to 6.6 +/- 0.15. However, within 45 min of reflow, cortical cell pH returned and exceeded the control value, 7.33 +/- 0.06 vs. 7.15 +/- 0.08. This increase in pHi was associated with a significant rise in cellular metabolic rate, Q-O2 increased to 20.3 +/- 6.4 micromoles/min. Corresponding with cellular alkalosis was a net production of bicarbonate and a net ammonia uptake and glutamine release; urinary acidification was abolished. These results are consistent with a nonexcretory renal metabolic base generating mechanism governing cellular acid base homeostasis following ischemia. PMID:3723929

  17. Branched tricarboxylic acid metabolism in Plasmodium falciparum.

    PubMed

    Olszewski, Kellen L; Mather, Michael W; Morrisey, Joanne M; Garcia, Benjamin A; Vaidya, Akhil B; Rabinowitz, Joshua D; Llinás, Manuel

    2010-08-01

    A central hub of carbon metabolism is the tricarboxylic acid cycle, which serves to connect the processes of glycolysis, gluconeogenesis, respiration, amino acid synthesis and other biosynthetic pathways. The protozoan intracellular malaria parasites (Plasmodium spp.), however, have long been suspected of possessing a significantly streamlined carbon metabolic network in which tricarboxylic acid metabolism plays a minor role. Blood-stage Plasmodium parasites rely almost entirely on glucose fermentation for energy and consume minimal amounts of oxygen, yet the parasite genome encodes all of the enzymes necessary for a complete tricarboxylic acid cycle. Here, by tracing (13)C-labelled compounds using mass spectrometry we show that tricarboxylic acid metabolism in the human malaria parasite Plasmodium falciparum is largely disconnected from glycolysis and is organized along a fundamentally different architecture from the canonical textbook pathway. We find that this pathway is not cyclic, but rather is a branched structure in which the major carbon sources are the amino acids glutamate and glutamine. As a consequence of this branched architecture, several reactions must run in the reverse of the standard direction, thereby generating two-carbon units in the form of acetyl-coenzyme A. We further show that glutamine-derived acetyl-coenzyme A is used for histone acetylation, whereas glucose-derived acetyl-coenzyme A is used to acetylate amino sugars. Thus, the parasite has evolved two independent production mechanisms for acetyl-coenzyme A with different biological functions. These results significantly clarify our understanding of the Plasmodium metabolic network and highlight the ability of altered variants of central carbon metabolism to arise in response to unique environments. PMID:20686576

  18. Kupffer Cell Metabolism and Function

    PubMed Central

    Nguyen-Lefebvre, Anh Thu; Horuzsko, Anatolij

    2015-01-01

    Kupffer cells are resident liver macrophages and play a critical role in maintaining liver functions. Under physiological conditions, they are the first innate immune cells and protect the liver from bacterial infections. Under pathological conditions, they are activated by different components and can differentiate into M1-like (classical) or M2-like (alternative) macrophages. The metabolism of classical or alternative activated Kupffer cells will determine their functions in liver damage. Special functions and metabolism of Kupffer cells suggest that they are an attractive target for therapy of liver inflammation and related diseases, including cancer and infectious diseases. Here we review the different types of Kupffer cells and their metabolism and functions in physiological and pathological conditions. PMID:26937490

  19. Cell biology. Metabolic control of cell death.

    PubMed

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  20. Metabolomic analysis on the toxicological effects of TiO₂ nanoparticles in mouse fibroblast cells: from the perspective of perturbations in amino acid metabolism.

    PubMed

    Bo, Yang; Jin, Chengyu; Liu, Yumin; Yu, Wenjuan; Kang, Hongzhang

    2014-10-01

    Titanium dioxide nanoparticles (nano-TiO2) have been widely applied in daily life and subsequent problem on the potential health risk are raised. Studies on the toxicity of nano-TiO2 have shown that they could lead to toxic effects on human and environment. However, the mechanisms are still unclear. We investigated the change of amino acid levels in L929 cells after nano-TiO2 exposure using gas chromatography with time-of-flight mass spectrometry (GC/TOFMS)-based metabolomics approach. Spectral profiles were subjected to multivariate statistics, namely, Principal Component Analysis (PCA), and Orthogonal Projections to Latent Structures-Discriminant Analysis (OPLS-DA). Using MetaboAnalyst 2.0, it was found that 7 metabolic pathways (impact-value >0.10) among the regulated pathways were significantly perturbed. Twelve distinct amino acids are identified from these pathways, including L-α-alanine, β-alanine, glycine, L-aspartate, L-methionine, L-cysteine, glutamate, L-pyroglutamate, L-asparagine, L-glutamine, S-adenosylmethionine, and L-lysine. These results show that the disturbed amino acids played an important role in the nano-TiO2-induced cytotoxicity. Along with earlier findings, we successfully used the metabolomics approaches to manifest nano-TiO2 toxicity through triggering cellular oxidative stress, energy damage and the inhibition of DNA and RNA synthesis.

  1. The retinoic acid-metabolizing enzyme CYP26A1 upregulates fascin and promotes the malignant behavior of breast carcinoma cells.

    PubMed

    Osanai, Makoto; Lee, Gang-Hong

    2015-08-01

    The retinoic acid (RA)-metabolizing enzyme CYP26A1 has been shown to efficiently enhance the oncogenic potential of breast cancer, suggesting a potential oncogenic function. We previously demonstrated that CYP26A1 confers unique cell survival properties by modulating the expression of a variety of genes and identified a number of genes that drive the cells into the oncogenic state. Accumulating evidence suggested that fascin is overexpressed in various types of cancer, primarily leading to increased cell motility. Therefore, in the present study, we examined fascin, an actin-bundling protein, using immunohistochemical and SA-β-gal staining as well as TUNEL and colony forming assays. The results of the present study showed that the expression levels of fascin increased significantly in response to CYP26A1 overexpression and, conversely, treatment with all-trans RA downregulated the expression of fascin. In addition, primary breast carcinoma samples, particularly hormone receptor-negative carcinomas and CYP26A1-overexpressing cancers, expressed elevated levels of fascin. Notably, fascin contributed to the ability of breast carcinoma cells to escape premature senescence and exhibit enhanced cell apoptotic resistance, promoting anchorage-independent growth properties. Fascin also promoted cell motility and the invasiveness of CYP26A1-expressing breast carcinoma cells. These data suggest that fascin expression is modulated by the intracellular RA status regulated by the expression of CYP26A1 and plays a significant role in the malignant behavior of CYP26A1-expressing breast carcinoma cells. CYP26A1 exerts oncogenic functions during breast carcinogenesis. Therefore, CYP26A1-mediated oncogenic characteristics may be partially responsible for the elevated expression of fascin. PMID:26058854

  2. Microbial metabolism of methanesulfonic acid

    PubMed

    Kelly; Murrell

    1999-12-01

    Methanesulfonic acid is a very stable strong acid and a key intermediate in the biogeochemical cycling of sulfur. It is formed in megatonne quantities in the atmosphere from the chemical oxidation of atmospheric dimethyl sulfide (most of which is of biogenic origin) and deposited on the Earth in rain and snow, and by dry deposition. Methanesulfonate is used by diverse aerobic bacteria as a source of sulfur for growth, but is not known to be used by anaerobes either as a sulfur source, a fermentation substrate, an electron acceptor, or as a methanogenic substrate. Some specialized methylotrophs (including Methylosulfonomonas, Marinosulfonomonas, and strains of paragraph signHyphomicrobium and Methylobacterium) can use it as a carbon and energy substrate to support growth. Methanesulfonate oxidation is initiated by cleavage catalysed by methanesulfonate monooxygenase, the properties and molecular biology of which are discussed.

  3. Hypoxia and metabolic adaptation of cancer cells

    PubMed Central

    Eales, K L; Hollinshead, K E R; Tennant, D A

    2016-01-01

    Low oxygen tension (hypoxia) is a pervasive physiological and pathophysiological stimulus that metazoan organisms have contended with since they evolved from their single-celled ancestors. The effect of hypoxia on a tissue can be either positive or negative, depending on the severity, duration and context. Over the long-term, hypoxia is not usually consistent with normal function and so multicellular organisms have had to evolve both systemic and cellular responses to hypoxia. Our reliance on oxygen for efficient adenosine triphosphate (ATP) generation has meant that the cellular metabolic network is particularly sensitive to alterations in oxygen tension. Metabolic changes in response to hypoxia are elicited through both direct mechanisms, such as the reduction in ATP generation by oxidative phosphorylation or inhibition of fatty-acid desaturation, and indirect mechanisms including changes in isozyme expression through hypoxia-responsive transcription factor activity. Significant regions of cancers often grow in hypoxic conditions owing to the lack of a functional vasculature. As hypoxic tumour areas contain some of the most malignant cells, it is important that we understand the role metabolism has in keeping these cells alive. This review will outline our current understanding of many of the hypoxia-induced changes in cancer cell metabolism, how they are affected by other genetic defects often present in cancers, and how these metabolic alterations support the malignant hypoxic phenotype. PMID:26807645

  4. Liraglutide protects pancreatic β-cells against free fatty acids in vitro and affects glucolipid metabolism in apolipoprotein E−/− mice by activating autophagy

    PubMed Central

    WANG, JIA; WU, JIE; WU, HONG; LIU, XINGZHEN; CHEN, YINGJIAN; WU, JIANYING; HU, CHENGJIN; ZOU, DAJIN

    2015-01-01

    The aim of the present study was to determine whether liraglutide (LRG), a long acting glucagon-like peptide 1 analogue, exerted a protective effect on free fatty acid (FFA)-treated pancreatic β-cells via activating autophagy. INS-1 insulinoma pancreatic islet cell lines were treated with FFA and the levels of cell necrosis, apoptosis and autophagy were detected using an MTT assay, flow cytometry and electron microscopy (ECM). A type 2 diabetes mellitus mouse model was established through treatment of mice with a high-fat diet for 8 weeks and injection of streptozotocin. LRG and autophagy inhibitors were used to investigate the protective effect of LRG on pancreatic β-cells in vivo. Metabolic indices were measured and pancreatic autophagy was detected. In the INS-1 cells, viability was higher in the FFA + LRG group compared with the FFA group, while the apoptotic rate was lower (P<0.05). The light chain 3B and p62 autophagy-associated proteins were upregulated by LRG, while ATG7 and Beclin1 were downregulated. Autophagy inhibitors reduced the protective effect of LRG in the FFA-treated INS-1 cells. The type 2 diabetes mouse model was successfully established, termed the HF group, in which LRG was observed to reduce body weight and decrease levels of fasting blood glucose, total cholesterol, serum insulin, triglyceride, low density lipoprotein-cholesterol and glycosylated hemoglobin (P<0.05), compared with the HF group. However, chloroquine treatment abrogated these effects (P<0.05, compared with the HF + LRG group; P>0.05, compared with the HF group). Autophagosomes were also observed under ECM in the pancreatic tissues of mice in the HF + LRG group. Therefore, LRG induced autophagy and exerted protective effects on pancreatic β-cells in vitro and in vivo. PMID:26080706

  5. Higher plant metabolism and energetics in hypogravity: Amino acid metabolism in higher plants

    NASA Technical Reports Server (NTRS)

    Mazelis, M.

    1976-01-01

    Laboratory's investigation into the amino acid metabolism of dwarf marigolds exposed to an environment of simulated hypogravity is summarized. Using both in vivo, and/or in vitro studies, the following effects of hypogravitational stress have been shown: (1) increased proline incorporation into cell wall protein, (2) inhibition of amino acid decarboxylation, (3) decrease in glutamic acid decarboxylase activity; and (4) decrease in the relative amount of a number of soluble amino acids present in deproteinized extracts of marigold leaves. It is concluded from these data there are several rapid, major alterations in amino acid metabolism associated with hypogravitational stress in marigolds. The mechanism(s) and generality of these effects with regard to other species is still unknown.

  6. Docosahexaenoic acid modulates the enterocyte Caco-2 cell expression of MicroRNAs involved in lipid metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of the long-chain omega-3 (n-3) polyunsaturated fatty acid docosahexaenoic acid (DHA) is associated with a reduced risk of cardiovascular disease and greater chemoprevention. However, the mechanisms underlying the biologic effects of DHA remain unknown. It is well known that microRNAs (m...

  7. Effects of omega-3 and -6 polyunsaturated fatty acids on ovine follicular cell steroidogenesis, embryo development and molecular markers of fatty acid metabolism.

    PubMed

    Hughes, Jaime; Kwong, Wing Yee; Li, Dongfang; Salter, Andrew M; Lea, Richard G; Sinclair, Kevin D

    2011-01-01

    We previously reported increased follicular fluid progesterone (P(4)) concentrations in ewes fed an n-3 compared to an n-6 polyunsaturated fatty acid (PUFA)-enriched diet, but detected no differential effect of n-3 and n-6 PUFA-enriched high-density lipoproteins (HDL) on granulosa cell (GC) steroidogenesis in vitro. Moreover, net n-6 PUFA-enriched HDL reduced early embryo development, but in the absence of a net uptake of FA. Consequently, we hypothesised that a) effects of n-3 PUFA on ovarian steroidogenesis are mediated by theca rather than GCs and b) during embryo culture lipids are acquired solely from the albumin fraction of serum, so that albumin-delivered n-3 and n-6 PUFA exert a greater differential effect on embryo development than either low-density lipoprotein (LDL)- or HDL-delivered PUFA. Data confirmed that n-3 PUFA increases P(4) production solely in theca cells and that this is associated with an increase in STAR transcript expression. Furthermore, LDL- and HDL-delivered n-3 PUFA are equally efficacious in this regard during the first 96 h of culture, but thereafter only HDL-delivered n-3 PUFA induces this effect in partially luteinised theca cells. We also demonstrate that albumin is the sole serum fraction that leads to a net uptake of FA during embryo culture. PUFA-enriched serum and albumin increased the yield of morphologically poorer quality blastocysts with increased transcript expression for the antioxidant enzyme SOD1. Important differential effects of n-3 and n-6 PUFA on ovarian steroidogenesis acting solely on theca cells are identified, but differential effects of PUFA on embryo development are less apparent. PMID:21045166

  8. Sialic acid metabolism and sialyltransferases: natural functions and applications

    PubMed Central

    Li, Yanhong

    2012-01-01

    Sialic acids are a family of negatively charged monosaccharides which are commonly presented as the terminal residues in glycans of the glycoconjugates on eukaryotic cell surface or as components of capsular polysaccharides or lipooligosaccharides of some pathogenic bacteria. Due to their important biological and pathological functions, the biosynthesis, activation, transfer, breaking down, and recycle of sialic acids are attracting increasing attention. The understanding of the sialic acid metabolism in eukaryotes and bacteria leads to the development of metabolic engineering approaches for elucidating the important functions of sialic acid in mammalian systems and for large-scale production of sialosides using engineered bacterial cells. As the key enzymes in biosynthesis of sialylated structures, sialyltransferases have been continuously identified from various sources and characterized. Protein crystal structures of seven sialyltransferases have been reported. Wild-type sialyltransferases and their mutants have been applied with or without other sialoside biosynthetic enzymes for producing complex sialic acid-containing oligosaccharides and glycoconjugates. This mini-review focuses on current understanding and applications of sialic acid metabolism and sialyltransferases. PMID:22526796

  9. Branched Tricarboxylic Acid Metabolism in Plasmodium falciparum

    PubMed Central

    Olszewski, Kellen L.; Mather, Michael W.; Morrisey, Joanne M.; Garcia, Benjamin A.; Vaidya, Akhil B.; Rabinowitz, Joshua D.; Llinás, Manuel

    2010-01-01

    A central hub of carbon metabolism is the tricarboxylic acid (TCA) cycle1, which serves to connect the processes of glycolysis, gluconeogenesis, respiration, amino acid synthesis and other biosynthetic pathways. The protozoan intracellular malaria parasites (Plasmodium spp.), however, have long been suspected of possessing a significantly streamlined carbon metabolic network in which TCA metabolism plays a minor role2. Blood-stage Plasmodium parasites rely almost entirely on glucose fermentation for energy and consume minimal amounts of oxygen3, yet the parasite genome encodes all of the enzymes necessary for a complete TCA cycle4. By tracing 13C-labeled compounds using mass spectrometry5 we show that TCA metabolism in the human malaria parasite P. falciparum is largely disconnected from glycolysis and is organized along a fundamentally different architecture than the canonical textbook pathway. We find that this pathway is not cyclic but rather a branched structure in which the major carbon sources are the amino acids glutamate and glutamine. As a consequence of this branched architecture, several reactions must run in the reverse of the standard direction thereby generating two-carbon units in the form of acetyl-coenzyme A (acetyl-CoA). We further show that glutamine-derived acetyl-CoA is used for histone acetylation while glucose-derived acetyl-CoA is used to acetylate aminosugars. Thus the parasite has evolved two independent acetyl-CoA-production mechanisms with different biological functions. These results significantly clarify our understanding of the Plasmodium metabolic network and highlight the ability of altered variants of central carbon metabolism to arise in response to unique environments. PMID:20686576

  10. Mitochondrial Dynamics Controls T Cell Fate through Metabolic Programming.

    PubMed

    Buck, Michael D; O'Sullivan, David; Klein Geltink, Ramon I; Curtis, Jonathan D; Chang, Chih-Hao; Sanin, David E; Qiu, Jing; Kretz, Oliver; Braas, Daniel; van der Windt, Gerritje J W; Chen, Qiongyu; Huang, Stanley Ching-Cheng; O'Neill, Christina M; Edelson, Brian T; Pearce, Edward J; Sesaki, Hiromi; Huber, Tobias B; Rambold, Angelika S; Pearce, Erika L

    2016-06-30

    Activated effector T (TE) cells augment anabolic pathways of metabolism, such as aerobic glycolysis, while memory T (TM) cells engage catabolic pathways, like fatty acid oxidation (FAO). However, signals that drive these differences remain unclear. Mitochondria are metabolic organelles that actively transform their ultrastructure. Therefore, we questioned whether mitochondrial dynamics controls T cell metabolism. We show that TE cells have punctate mitochondria, while TM cells maintain fused networks. The fusion protein Opa1 is required for TM, but not TE cells after infection, and enforcing fusion in TE cells imposes TM cell characteristics and enhances antitumor function. Our data suggest that, by altering cristae morphology, fusion in TM cells configures electron transport chain (ETC) complex associations favoring oxidative phosphorylation (OXPHOS) and FAO, while fission in TE cells leads to cristae expansion, reducing ETC efficiency and promoting aerobic glycolysis. Thus, mitochondrial remodeling is a signaling mechanism that instructs T cell metabolic programming.

  11. Mitochondrial Dynamics Controls T Cell Fate through Metabolic Programming.

    PubMed

    Buck, Michael D; O'Sullivan, David; Klein Geltink, Ramon I; Curtis, Jonathan D; Chang, Chih-Hao; Sanin, David E; Qiu, Jing; Kretz, Oliver; Braas, Daniel; van der Windt, Gerritje J W; Chen, Qiongyu; Huang, Stanley Ching-Cheng; O'Neill, Christina M; Edelson, Brian T; Pearce, Edward J; Sesaki, Hiromi; Huber, Tobias B; Rambold, Angelika S; Pearce, Erika L

    2016-06-30

    Activated effector T (TE) cells augment anabolic pathways of metabolism, such as aerobic glycolysis, while memory T (TM) cells engage catabolic pathways, like fatty acid oxidation (FAO). However, signals that drive these differences remain unclear. Mitochondria are metabolic organelles that actively transform their ultrastructure. Therefore, we questioned whether mitochondrial dynamics controls T cell metabolism. We show that TE cells have punctate mitochondria, while TM cells maintain fused networks. The fusion protein Opa1 is required for TM, but not TE cells after infection, and enforcing fusion in TE cells imposes TM cell characteristics and enhances antitumor function. Our data suggest that, by altering cristae morphology, fusion in TM cells configures electron transport chain (ETC) complex associations favoring oxidative phosphorylation (OXPHOS) and FAO, while fission in TE cells leads to cristae expansion, reducing ETC efficiency and promoting aerobic glycolysis. Thus, mitochondrial remodeling is a signaling mechanism that instructs T cell metabolic programming. PMID:27293185

  12. Bile acid metabolism and signaling in cholestasis, inflammation and cancer

    PubMed Central

    Apte, Udayan

    2015-01-01

    Bile acids are synthesized from cholesterol in the liver. Some cytochrome P450 (CYP) enzymes play key roles in bile acid synthesis. Bile acids are physiological detergent molecules, so are highly cytotoxic. They undergo enterohepatic circulation and play important roles in generating bile flow and facilitating biliary secretion of endogenous metabolites and xenobiotics and intestinal absorption of dietary fats and lipid soluble vitamins. Bile acid synthesis, transport and pool size are therefore tightly regulated under physiological conditions. In cholestasis, impaired bile flow leads to accumulation of bile acids in the liver, causing hepatocyte and biliary injury and inflammation. Chronic cholestasis is associated with fibrosis, cirrhosis and eventually liver failure. Chronic cholestasis also increases the risk of developing hepatocellular or cholangiocellular carcinomas. Extensive research in the last two decades has shown that bile acids act as signaling molecules that regulate various cellular processes. The bile acid-activated nuclear receptors are ligand-activated transcriptional factors that play critical roles in the regulation of bile acid, drug and xenobiotic metabolism. In cholestasis, these bile acid-activated receptors regulate a network of genes involved in bile acid synthesis, conjugation, transport and metabolism to alleviate bile acid-induced inflammation and injury. Additionally, bile acids are known to regulate cell growth and proliferation, and altered bile acid levels in diseased conditions have been implicated in liver injury/regeneration and tumorigenesis. We will cover the mechanisms that regulate bile acid homeostasis and detoxification during cholestasis, and the roles of bile acids in the initiation and regulation of hepatic inflammation, regeneration and carcinogenesis. PMID:26233910

  13. Metabolic annotation of 2-ethylhydracrylic acid.

    PubMed

    Ryan, Robert O

    2015-08-25

    Increased levels of the organic acid, 2-ethylhydracrylic acid (2-EHA) occur in urine of subjects with impaired L(+)-isoleucine metabolism. Chiral intermediates formed during isoleucine degradation are (S) enantiomers. Blockage of (S) pathway flux drives racemization of (2S, 3S) L(+)-isoleucine and its (2S, 3R) stereoisomer, L(+)-alloisoleucine. This non-protein amino acid is metabolized to (R)-2-methylbutyryl CoA via enzymes common to branched chain amino acid degradation. Subsequently, (R) intermediates serve as alternate substrates for three valine metabolic enzymes, generating 2-EHA. Once formed, 2-EHA accumulates because it is poorly recognized by distal valine pathway enzymes. Thus, urinary 2-EHA represents a biomarker of isoleucine pathway defects. 2-EHA levels are also increased in rats exposed to the industrial solvent, ethylene glycol monomethyl ether or the neurotoxin precursor, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. In these cases, a block in (S) pathway isoleucine catabolism occurs at the level of (S)-2-methylbutyryl CoA conversion to tiglyl CoA via inhibition of electron transferring flavoprotein/ubiquinone oxidoreductase dependent reactions. Elevated urinary 2-EHA in propionyl CoA carboxylase deficiency and methylmalonic aciduria results from a buildup of distal intermediates in the (S) pathway of isoleucine degradation. In Barth syndrome and dilated cardiomyopathy with ataxia syndrome, 2-EHA is a byproduct of impeded propionyl CoA entry into the Krebs cycle.

  14. Metabolic annotation of 2-ethylhydracrylic acid

    PubMed Central

    Ryan, Robert O.

    2015-01-01

    Summary Increased levels of the organic acid, 2-ethylhydracrylic acid (2-EHA) occur in urine of subjects with impaired L(+)-isoleucine metabolism. Chiral intermediates formed during isoleucine degradation are (S) enantiomers. Blockage of (S) pathway flux drives racemization of (2S, 3S) L(+)-isoleucine and its (2S, 3R) stereoisomer, L(+)-alloisoleucine. This non-protein amino acid is metabolized to (R)-2-methylbutyryl CoA via enzymes common to branched chain amino acid degradation. Subsequently, (R) intermediates serve as alternate substrates for three valine metabolic enzymes, generating 2-EHA. Once formed, 2-EHA accumulates because it is poorly recognized by distal valine pathway enzymes. Thus, urinary 2-EHA represents a biomarker of isoleucine pathway defects. 2-EHA levels are also increased in rats exposed to the industrial solvent, ethylene glycol monomethyl ether or the neurotoxin precursor, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. In these cases, a block in (S) pathway isoleucine catabolism occurs at the level of (S)-2-methylbutyryl CoA conversion to tiglyl CoA via inhibition of electron transferring flavoprotein / ubiquinone oxidoreductase dependent reactions. Elevated urinary 2-EHA in propionyl CoA carboxylase deficiency and methylmalonic aciduria results from a buildup of distal intermediates in the (S) pathway of isoleucine degradation. In Barth syndrome and dilated cardiomyopathy with ataxia syndrome, 2-EHA is a byproduct of impeded propionyl CoA entry into the Krebs cycle. PMID:26115894

  15. Ecophysiology of Crassulacean Acid Metabolism (CAM)

    PubMed Central

    LÜTTGE, ULRICH

    2004-01-01

    • Background and Scope Crassulacean Acid Metabolism (CAM) as an ecophysiological modification of photosynthetic carbon acquisition has been reviewed extensively before. Cell biology, enzymology and the flow of carbon along various pathways and through various cellular compartments have been well documented and discussed. The present attempt at reviewing CAM once again tries to use a different approach, considering a wide range of inputs, receivers and outputs. • Input Input is given by a network of environmental parameters. Six major ones, CO2, H2O, light, temperature, nutrients and salinity, are considered in detail, which allows discussion of the effects of these factors, and combinations thereof, at the individual plant level (‘physiological aut‐ecology’). • Receivers Receivers of the environmental cues are the plant types genotypes and phenotypes, the latter including morphotypes and physiotypes. CAM genotypes largely remain ‘black boxes’, and research endeavours of genomics, producing mutants and following molecular phylogeny, are just beginning. There is no special development of CAM morphotypes except for a strong tendency for leaf or stem succulence with large cells with big vacuoles and often, but not always, special water storage tissues. Various CAM physiotypes with differing degrees of CAM expression are well characterized. • Output Output is the shaping of habitats, ecosystems and communities by CAM. A number of systems are briefly surveyed, namely aquatic systems, deserts, salinas, savannas, restingas, various types of forests, inselbergs and paramós. • Conclusions While quantitative census data for CAM diversity and biomass are largely missing, intuition suggests that the larger CAM domains are those systems which are governed by a network of interacting stress factors requiring versatile responses and not systems where a single stress factor strongly prevails. CAM is noted to be a strategy for variable, flexible and plastic

  16. Water-relation Parameters of Individual Mesophyll Cells of the Crassulacean Acid Metabolism Plant Kalanchoë daigremontiana1

    PubMed Central

    Steudle, Ernst; Smith, J. Andrew C.; Lüttge, Ulrich

    1980-01-01

    Water-relation parameters of leaf mesophyll cells of the CAM plant Kalanchoë daigremontiana have been determined directly in cells of tissue slices using the pressure-probe technique. Turgor pressures measured in cells of the second to fourth layer from the cut surface showed an average of 1.82 ± 0.62 bar (mean ± sd; n = 157 cells). This was lower than expected from measurements of the osmotic pressure of the cell sap. The half-time (T1/2) for water-flux equilibration of individual cells was 2.5 to 8.8 seconds. This is the fastest T1/2 found so far for higher-plant cells. The calculated values of the hydraulic conductivity were in the range of 0.20 to 1.6 × 10−5 centimeters second−1 bar−1, with an average of (0.69 ± 0.46) × 10−5 centimeters second−1 bar−1 (mean ± sd; n = 8 cells). The T1/2 values of water exchange of individual cells are consistent with the overall rates of water-flux equilibration measured for tissue slices. The volumetric elastic moduli (∈) of individual cells were in the range 13 to 128 bar for turgor pressures between 0.0 and 3.4 bar; the average ∈ value was 42.4 ± 27.7 bar (mean ± sd; n = 21 cells). This ∈ value is similar to that observed for other higher-plant cells. The water-storage capacity of individual cells, calculated as Cc = V/(∈ + πi) (where V = cell volume and πi = internal osmotic pressure) was 9.1 × 10−9 cubic centimeters bar−1 per cell, and the capacity for the tissue was 2.2 × 10−2 cubic centimeters bar−1 gram−1 fresh weight. The significance of the water-relation parameters determined at the cellular level is discussed in terms of the water relations of whole leaves and the high water-use efficiency characteristic of CAM plants. Images PMID:16661595

  17. Dual role of fatty acid-binding protein 5 on endothelial cell fate: a potential link between lipid metabolism and angiogenic responses.

    PubMed

    Yu, Chen-Wei; Liang, Xiaoliang; Lipsky, Samantha; Karaaslan, Cagatay; Kozakewich, Harry; Hotamisligil, Gokhan S; Bischoff, Joyce; Cataltepe, Sule

    2016-01-01

    Fatty acid-binding proteins (FABP) are small molecular mass intracellular lipid chaperones that are expressed in a tissue-specific manner with some overlaps. FABP4 and FABP5 share ~55 % amino acid sequence homology and demonstrate synergistic effects in regulation of metabolic and inflammatory responses in adipocytes and macrophages. Recent studies have shown that FABP4 and FABP5 are also co-expressed in a subset of endothelial cells (EC). FABP4, which has a primarily microvascular distribution, enhances angiogenic responses of ECs, including proliferation, migration, and survival. However, the vascular expression of FABP5 has not been well characterized, and the role of FABP5 in regulation of angiogenic responses in ECs has not been studied to date. Herein we report that while FABP4 and FABP5 are co-expressed in microvascular ECs in several tissues, FABP5 expression is also detected in ECs of larger blood vessels. In contrast to FABP4, EC-FABP5 levels are not induced by VEGF-A or bFGF. FABP5 deficiency leads to a profound impairment in EC proliferation and chemotactic migration. These effects are recapitulated in an ex vivo assay of angiogenesis, the aortic ring assay. Interestingly, in contrast to FABP4-deficient ECs, FABP5-deficient ECs are significantly more resistant to apoptotic cell death. The effect of FABP5 on EC proliferation and survival is mediated, only in part, by PPARδ-dependent pathways. Collectively, these findings demonstrate that EC-FABP5, similar to EC-FABP4, promotes angiogenic responses under certain conditions, but it can also exert opposing effects on EC survival as compared to EC-FABP4. Thus, the balance between FABP4 and FABP5 in ECs may be important in regulation of angiogenic versus quiescent phenotypes in blood vessels.

  18. Targeting amino acid metabolism in cancer growth and anti-tumor immune response

    PubMed Central

    Ananieva, Elitsa

    2015-01-01

    Recent advances in amino acid metabolism have revealed that targeting amino acid metabolic enzymes in cancer therapy is a promising strategy for the development of novel therapeutic agents. There are currently several drugs in clinical trials that specifically target amino acid metabolic pathways in tumor cells. In the context of the tumor microenvironment, however, tumor cells form metabolic relationships with immune cells, and they often compete for common nutrients. Many tumors evolved to escape immune surveillance by taking advantage of their metabolic flexibility and redirecting nutrients for their own advantage. This review outlines the most recent advances in targeting amino acid metabolic pathways in cancer therapy while giving consideration to the impact these pathways may have on the anti-tumor immune response. PMID:26629311

  19. Retinoic acid: its biosynthesis and metabolism.

    PubMed

    Napoli, J L

    1999-01-01

    This article presents a model that integrates the functions of retinoid-binding proteins with retinoid metabolism. One of these proteins, the widely expressed (throughout retinoid target tissues and in all vertebrates) and highly conserved cellular retinol-binding protein (CRBP), sequesters retinol in an internal binding pocket that segregates it from the intracellular milieu. The CRBP-retinol complex appears to be the quantitatively major form of retinol in vivo, and may protect the promiscuous substrate from nonenzymatic degradation and/or non-specific enzymes. For example, at least seven types of dehydrogenases catalyze retinal synthesis from unbound retinol in vitro (NAD+ vs. NADP+ dependent, cytosolic vs. microsomal, short-chain dehydrogenases/reductases vs. medium-chain alcohol dehydrogenases). But only a fraction of these (some of the short-chain de-hydrogenases/reductases) have the fascinating additional ability of catalyzing retinal synthesis from CRBP-bound retinol as well. Similarly, CRBP and/or other retinoid-binding proteins function in the synthesis of retinal esters, the reduction of retinal generated from intestinal beta-carotene metabolism, and retinoic acid metabolism. The discussion details the evidence supporting an integrated model of retinoid-binding protein/metabolism. Also addressed are retinoid-androgen interactions and evidence incompatible with ethanol causing fetal alcohol syndrome by competing directly with retinol dehydrogenation to impair retinoic acid biosynthesis. PMID:10506831

  20. Intermediaries of branched chain amino acid metabolism induce fetal hemoglobin, and repress SOX6 and BCL11A, in definitive erythroid cells.

    PubMed

    Karkashon, Shay; Raghupathy, Radha; Bhatia, Himanshu; Dutta, Amrita; Hess, Sonja; Higgs, Jaimie; Tifft, Cynthia J; Little, Jane A

    2015-08-01

    High levels of fetal hemoglobin (HbF) can ameliorate human β-globin gene disorders. The short chain fatty acid butyrate is the paradigmatic metabolic intermediary that induces HbF. Inherited disorders of branched-chain amino acid (BCAA) metabolism have been associated with supranormal HbF levels beyond infancy, e.g., propionic acidemia (PA) and methylmalonic acidemia (MMA). We tested intermediaries of BCAA metabolism for their effects on definitive erythropoiesis. Like butyrate, the elevated BCAA intermediaries isovalerate, isobutyrate, and propionate, induce fetal globin gene expression in murine EryD in vitro, are associated with bulk histone H3 hyperacylation, and repress the transcription of key gamma globin regulatory factors, notably BCL11A and SOX6. Metabolic intermediaries that are elevated in Maple Syrup Urine Disease (MSUD) affect none of these processes. Percent HbF and gamma (γ) chain isoforms were also measured in non-anemic, therapeutically optimized subjects with MSUD (Group I, n=6) or with Isovaleric Acidemia (IVA), MMA, or PA (Group II, n=5). Mean HbF was 0.24 ± 0.15% in Group I and 0.87 ± 0.13% in Group II (p=.01); only the Gγ isoform was detected. We conclude that a family of biochemically related intermediaries of branched chain amino acid metabolism induces fetal hemoglobin during definitive erythropoiesis, with mechanisms that mirror those so far identified for butyrate. PMID:26142333

  1. Carbohydrate and amino acid metabolism of Spironucleus vortens.

    PubMed

    Millet, Coralie O M; Lloyd, David; Coogan, Michael P; Rumsey, Joanna; Cable, Joanne

    2011-09-01

    The metabolism of Spironucleus vortens, a parasitic, diplomonad flagellate related to Giardia intestinalis, was investigated using a combination of membrane inlet mass spectrometry, (1)H NMR, (13)C NMR, bioscreen continuous growth monitoring, and ion exchange chromatography. The products of glucose-fuelled and endogenous metabolism were identified by (1)H NMR and (13)C NMR as ethanol, acetate, alanine and lactate. Mass spectrometric monitoring of gas metabolism in buffered cell suspensions showed that glucose and ethanol could be used by S. vortens as energy-generating substrates, but bioscreen automated monitoring of growth in culture medium, as well as NMR analyses, suggested that neither of these compounds are the substrates of choice for this organism. Ion-exchange chromatographic analyses of free amino-acid and amino-acid hydrolysate of growth medium revealed that, despite the availability of large pools of free amino-acids in the medium, S. vortens hydrolysed large amounts of proteins during growth. The organism produced alanine and aspartate, and utilised lysine, arginine, leucine, cysteine and urea. However, mass spectrometric and bioscreen investigations showed that addition of the utilised amino acids to diluted culture medium did not induce any significant increase in metabolic or growth rates. Moreover, as no significant amounts of ornithine were produced, and addition of arginine under aerobic conditions did not generate NO production, there was no evidence of the presence of an energy-generating, arginine dihydrolase pathway in S. vortens under in vitro conditions.

  2. Regulation of intestinal protein metabolism by amino acids.

    PubMed

    Bertrand, Julien; Goichon, Alexis; Déchelotte, Pierre; Coëffier, Moïse

    2013-09-01

    Gut homeostasis plays a major role in health and may be regulated by quantitative and qualitative food intake. In the intestinal mucosa, an intense renewal of proteins occurs, at approximately 50% per day in humans. In some pathophysiological conditions, protein turnover is altered and may contribute to intestinal or systemic diseases. Amino acids are key effectors of gut protein turnover, both as constituents of proteins and as regulatory molecules limiting intestinal injury and maintaining intestinal functions. Many studies have focused on two amino acids: glutamine, known as the preferential substrate of rapidly dividing cells, and arginine, another conditionally essential amino acid. The effects of glutamine and arginine on protein synthesis appear to be model and condition dependent, as are the involved signaling pathways. The regulation of gut protein degradation by amino acids has been minimally documented until now. This review will examine recent data, helping to better understand how amino acids regulate intestinal protein metabolism, and will explore perspectives for future studies.

  3. Interaction of functionally bound vitamins in the distribution and metabolism of (/sup 14/C)nicotinic acid in tissues and blood cells

    SciTech Connect

    Rozanov, A.Ya.; Yakubik, E.Yu.

    1986-03-10

    Leukocytes absorb two orders of magnitude more of labeled nicotinic acid ((/sup 14/C)NA) than erythrocytes (recalculated per cell). The dynamics of the binding of the labeled vitamin by leukocytes is biphasic, with the formation chiefly of (/sup 14/C)-nicotinic coenzymes in the shortest periods after its injection into rats. At the same time, injected thiamine, riboflavin, lipoate, and pantothenate increase the accumulation of labeled metabolites of nicotinate in the blood and leukocytes of rats by a factor of 2.1 and 4.1, respectively. The metabolism of subcutaneously injected (/sup 14/C)NA occurs chiefly in the digestive system, with a pronounced biphasic dynamics of the changes in the content of labeled metabolites in the liver and small intestine, with secretion of substantial amounts of them with the digestive juices. At the same time, functionally bound vitamins introduced increase the incorporation of the total label into liver tissue (to 45% of the introduced dose, versus 33% in the control) and the rise in the content of (/sup 14/C)-pyridine nucleotides. Analogous effects were also observed in the accumulation of labeled metabolites of (/sup 14/C)NA in the membranes of the small intestine.

  4. Effect of cell hydration on metabolism.

    PubMed

    Lang, Florian

    2011-01-01

    Prerequisites for cell survival include avoidance of excessive cell volume alterations. Cell membranes are highly permeable to water, which follows osmotic gradients. Thus, cell volume constancy requires osmotic equilibrium across cell membranes. Cells accumulate osmotically active organic substances and compensate their osmolarity by lowering cytosolic Cl(-) concentrations. Following cell shrinkage, regulatory cell volume increase is accomplished by ion uptake (activation of Na(+), K(+), 2Cl(-) cotransport, Na(+)/H(+) exchange in - parallel to Cl(-)/HCO(-)(3) exchange and Na(+) channels), by cellular accumulation of organic osmolytes (e.g. myoinositol, betaine, phosphorylcholine, taurine) as well as by proteolysis leading to generation of amino acids and glycogenolysis generating glucose phosphate. Following cell swelling, cell volume is restored by ion exit (activation of K(+) channels and/ - or anion channels, KCl cotransport, parallel activation of K(+)/H(+) exchange and Cl(-)/HCO(-)(3) exchange), release or degradation of organic osmolytes as well as stimulation of protein synthesis and of glycogen synthesis. The activity of cell volume regulatory mechanisms is modified by hormones, transmitters and drugs, which thus influence protein and glycogen metabolism. Moreover, alterations of cell volume modify generation of oxidants and the sensitivity to oxidative stress. Deranged cell volume regulation significantly contributes to the pathophysiology of several disorders such as liver insufficiency, diabetic ketoacidosis, hypercatabolism, ischemia, and fibrosing disease. PMID:22301839

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

    PubMed

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

    2014-10-01

    In the luteal phase, human endometrial stromal cells (HESCs) undergo proliferation, migration and differentiation during the decidualization process under the control of the ovarian steroids progesterone and estrogen. Proper decidualization of stromal cells is required for blastocyst implantation and the development of pregnancy. The proliferation, migration and differentiation of HESCs in decidualization do not require the presence of a blastocyst but are greatly accelerated during implantation. Lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are potent bioactive lysophospholipids that have critical roles in various physiological and pathophysiological processes, including inflammation, angiogenesis and cancer. The expression of the enzymes involved in LPA and S1P turnover and their receptors in HESCs during decidualization has not been characterized yet. We found that the LPAR1 and LPAR6 and S1PR3 receptors are highly expressed in HESCs. LPAR1, autotaxin (ATX), an LPA producing enzyme and lipid phosphate phosphatase 3 were up-regulated during decidualization. Interestingly, the expression of all S1P receptor subtypes and LPA receptors (LPAR2-6) mRNA was down-regulated after decidualization. We found that SPHK1 is highly expressed in HESCs, and is up-regulated during decidualization. S1P phosphatase SGPP1 and S1P lyase SGPL1 are highly expressed in HESCs. SGPP1 mRNA expression was significantly up-regulated in decidualized HESCs. In conclusion, this study shows the first time that specific LPA and S1P receptors and their metabolizing enzymes are highly regulated in HESCs during decidualization. Furthermore, we suggest that LPAR1 receptor-mediated signaling in HESCs may be crucial in decidualization process. SPHK1 activity and high turnover of S1P and LPA might be essential for precise regulation of their signaling during decidualization of human endometrium and implantation. PMID:24994816

  6. Metabolic selection of glycosylation defects in human cells

    SciTech Connect

    Yarema, Kevin J.; Goon, Scarlett; Bertozzi, Carolyn R.

    2000-08-01

    Changes in glycosylation are often associated with disease progression, but the genetic and metabolic basis of these events is rarely understood in detail at a molecular level. This report describes a novel metabolism-based approach to the selection of mutants in glycoconjugate biosynthesis that has provided insight into regulatory mechanisms for oligosaccharide expression and metabolic flux. Unnatural intermediates are used to challenge a specific pathway and cell-surface expression of their metabolic products provides a readout of flux in that pathway and a basis for selecting genetic mutants. The approach was applied to the sialic acid metabolic pathway in human cells, yielding novel mutants with phenotypes related to the inborn metabolic defect sialuria and metastatic tumor cells.

  7. Omeprazole induces altered bile acid metabolism

    PubMed Central

    Shindo, K; Machida, M; Fukumura, M; Koide, K; Yamazaki, R

    1998-01-01

    Background—It has been reported that the acidity of gastric contents could be an important factor in regulating jejunal flora. 
Aims—To investigate the effects of omeprazole induced changes in gastric pH on jejunal flora and bile acid metabolism. 
Methods—Twenty one patients with gastric ulcer and 19 healthy volunteers were studied. Deconjugation of bile acids was detected using a bile acid breath test. Jejunal fluid was aspirated using a double lumen tube with a rubber cover on the tip and deconjugation was examined using thin layer chromatography. Fat malabsorption was detected by a triolein breath test. 
Results—In the bile acid breath test, expired breath samples from all patients and healthy volunteers showed significantly greater 14CO2 specific activity after omeprazole treatment (20 mg/day) than before treatment. Bacterial overgrowth was found in the jejunal fluid and gastric juice of both ulcer patients and healthy volunteers after omeprazole treatment. The following species were identified: Escherichia coli, Candida albicans, enterococcus, Lactobacillus bifidus, Bacteroides vulgatus, B uniformis, Eubacterium lentum, Eu parvum, and Corynebacterium granulosum. All of these species, except E coli and C albicans, deconjugate bile acids. There was a significant correlation between 14CO2 activity and gastric pH, both before and after omeprazole treatment in both groups. The triolein breath test revealed impaired fat absorption in both groups after omeprazole treatment. 
Conclusions—Both patients with gastric ulcer and healthy volunteers exhibited increased deconjugation of bile acids caused by bacterial overgrowth in the jejunum and fat malabsorption after omeprazole treatment. The bacterial overgrowth consisted of both anaerobes and aerobes with deconjugation ability and was probably associated with an omeprazole induced shift to neutral pH in the gastric juice. 

 Keywords: omeprazole; bacterial overgrowth; deconjugation; bile acid breath

  8. Rewired Metabolism in Drug-resistant Leukemia Cells

    PubMed Central

    Stäubert, Claudia; Bhuiyan, Hasanuzzaman; Lindahl, Anna; Broom, Oliver Jay; Zhu, Yafeng; Islam, Saiful; Linnarsson, Sten; Lehtiö, Janne; Nordström, Anders

    2015-01-01

    Cancer cells that escape induction therapy are a major cause of relapse. Understanding metabolic alterations associated with drug resistance opens up unexplored opportunities for the development of new therapeutic strategies. Here, we applied a broad spectrum of technologies including RNA sequencing, global untargeted metabolomics, and stable isotope labeling mass spectrometry to identify metabolic changes in P-glycoprotein overexpressing T-cell acute lymphoblastic leukemia (ALL) cells, which escaped a therapeutically relevant daunorubicin treatment. We show that compared with sensitive ALL cells, resistant leukemia cells possess a fundamentally rewired central metabolism characterized by reduced dependence on glutamine despite a lack of expression of glutamate-ammonia ligase (GLUL), a higher demand for glucose and an altered rate of fatty acid β-oxidation, accompanied by a decreased pantothenic acid uptake capacity. We experimentally validate our findings by selectively targeting components of this metabolic switch, using approved drugs and starvation approaches followed by cell viability analyses in both the ALL cells and in an acute myeloid leukemia (AML) sensitive/resistant cell line pair. We demonstrate how comparative metabolomics and RNA expression profiling of drug-sensitive and -resistant cells expose targetable metabolic changes and potential resistance markers. Our results show that drug resistance is associated with significant metabolic costs in cancer cells, which could be exploited using new therapeutic strategies. PMID:25697355

  9. Comparative Metabolic Flux Profiling of Melanoma Cell Lines

    PubMed Central

    Scott, David A.; Richardson, Adam D.; Filipp, Fabian V.; Knutzen, Christine A.; Chiang, Gary G.; Ronai, Ze'ev A.; Osterman, Andrei L.; Smith, Jeffrey W.

    2011-01-01

    Metabolic rewiring is an established hallmark of cancer, but the details of this rewiring at a systems level are not well characterized. Here we acquire this insight in a melanoma cell line panel by tracking metabolic flux using isotopically labeled nutrients. Metabolic profiling and flux balance analysis were used to compare normal melanocytes to melanoma cell lines in both normoxic and hypoxic conditions. All melanoma cells exhibited the Warburg phenomenon; they used more glucose and produced more lactate than melanocytes. Other changes were observed in melanoma cells that are not described by the Warburg phenomenon. Hypoxic conditions increased fermentation of glucose to lactate in both melanocytes and melanoma cells (the Pasteur effect). However, metabolism was not strictly glycolytic, as the tricarboxylic acid (TCA) cycle was functional in all melanoma lines, even under hypoxia. Furthermore, glutamine was also a key nutrient providing a substantial anaplerotic contribution to the TCA cycle. In the WM35 melanoma line glutamine was metabolized in the “reverse” (reductive) direction in the TCA cycle, particularly under hypoxia. This reverse flux allowed the melanoma cells to synthesize fatty acids from glutamine while glucose was primarily converted to lactate. Altogether, this study, which is the first comprehensive comparative analysis of metabolism in melanoma cells, provides a foundation for targeting metabolism for therapeutic benefit in melanoma. PMID:21998308

  10. Metabolism Is Central to Tolerogenic Dendritic Cell Function

    PubMed Central

    Sim, Wen Jing; Ahl, Patricia Jennifer; Connolly, John Edward

    2016-01-01

    Immunological tolerance is a fundamental tenant of immune homeostasis and overall health. Self-tolerance is a critical component of the immune system that allows for the recognition of self, resulting in hyporeactivity instead of immunogenicity. Dendritic cells are central to the establishment of dominant immune tolerance through the secretion of immunosuppressive cytokines and regulatory polarization of T cells. Cellular metabolism holds the key to determining DC immunogenic or tolerogenic cell fate. Recent studies have demonstrated that dendritic cell maturation leads to a shift toward a glycolytic metabolic state and preferred use of glucose as a carbon source. In contrast, tolerogenic dendritic cells favor oxidative phosphorylation and fatty acid oxidation. This dichotomous metabolic reprogramming of dendritic cells drives differential cellular function and plays a role in pathologies, such as autoimmune disease. Pharmacological alterations in metabolism have promising therapeutic potential. PMID:26980944

  11. Adaptive changes in fatty acid profile of erythrocyte membrane in relation to plasma and red cell metabolic changes in chronic alcoholic men.

    PubMed

    Maturu, Paramahamsa; Varadacharyulu, Nallanchakravarthula

    2012-07-01

    Chronic alcohol consumption is a major reason for several human diseases, and alcoholism has been associated with a variety of societal problems. Changes in fatty acid metabolism in alcoholics and its effects leading to membrane damage are largely unknown. Therefore, we aimed to investigate the fatty acid composition of erythrocyte membrane phospholipids in relation with plasma lipid profile and other plasma metabolites in chronic alcoholics in comparison with controls. We systematically measured the levels of glucose, lactate and pyruvate in the blood and free amino acids, free fatty acids, mucoproteins and glycolipids, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very-low-density lipoprotein (VLDL) cholesterol and triglycerides (TG) in plasma of chronic alcoholics and controls. Furthermore, we measured fatty acid composition by gas chromatographic analysis. The fatty acid composition clearly revealed certain changes in chronic alcoholic erythrocyte membrane, chiefly increments in C16:0 and a decrease in C22:4 and C22:6 fatty acids besides the presence of unidentified fatty acids, probably C-24 or C-26 fatty acids. In addition, a significant increase in blood lactate, decrease in blood pyruvate and increased levels of free amino acids and free fatty acids, mucoproteins, VLDL cholesterol, TG and HDL-C in chronic alcoholics were observed with no significant change in plasma TC, LDL-C and glycolipids when compared with controls. Alcohol-induced alterations in plasma and erythrocyte membranes of chronic alcoholics in the present study might be an adaptive response to counteract the deleterious effects of alcohol. The implications of our findings warrant further investigation and needs further in-depth study to explore the mechanisms of alcohol-induced membrane changes.

  12. Intestinal amino acid metabolism in neonates.

    PubMed

    van Goudoever, Johannes B; van der Schoor, Sophie R D; Stoll, Barbara; Burrin, Douglas G; Wattimena, Darcos; Schierbeek, Henk; Schaart, Maaike W; Riedijk, Maaike A; van der Lugt, Jasper

    2006-01-01

    The portal-drained viscera (stomach, intestine, pancreas and spleen) have a much higher rate of both energy expenditure and protein synthesis than can be estimated on the basis of their weight. A high utilization rate of dietary nutrients by the portal-drained viscera might result in a low systemic availability which determines whole-body growth. From studies in our multiple catheterized piglet model, we conclude that more than half of the dietary protein intake is utilized within the portal-drained viscera and that amino acids are a major fuel source for the visceral organs. Specific stable isotope studies reveal that there are large differences in the utilization rate amongst the different amino acids. The majority of the results obtained from the piglet studies can be extrapolated to the human (preterm) infant. First-pass, splanchnic uptake of lysine and threonine differ substantially, while non-essential amino acids are oxidized to a great extend in the human gut. Overall, these studies indicate that gut amino acid metabolism has a great impact on systemic availability and hence growth in the neonate.

  13. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  14. Linking vitamin B1 with cancer cell metabolism

    PubMed Central

    2013-01-01

    The resurgence of interest in cancer metabolism has linked alterations in the regulation and exploitation of metabolic pathways with an anabolic phenotype that increases biomass production for the replication of new daughter cells. To support the increase in the metabolic rate of cancer cells, a coordinated increase in the supply of nutrients, such as glucose and micronutrients functioning as enzyme cofactors is required. The majority of co-enzymes are water-soluble vitamins such as niacin, folic acid, pantothenic acid, pyridoxine, biotin, riboflavin and thiamine (Vitamin B1). Continuous dietary intake of these micronutrients is essential for maintaining normal health. How cancer cells adaptively regulate cellular homeostasis of cofactors and how they can regulate expression and function of metabolic enzymes in cancer is underappreciated. Exploitation of cofactor-dependent metabolic pathways with the advent of anti-folates highlights the potential vulnerabilities and importance of vitamins in cancer biology. Vitamin supplementation products are easily accessible and patients often perceive them as safe and beneficial without full knowledge of their effects. Thus, understanding the significance of enzyme cofactors in cancer cell metabolism will provide for important dietary strategies and new molecular targets to reduce disease progression. Recent studies have demonstrated the significance of thiamine-dependent enzymes in cancer cell metabolism. Therefore, this review discusses the current knowledge in the alterations in thiamine availability, homeostasis, and exploitation of thiamine-dependent pathways by cancer cells. PMID:24280319

  15. Metabolic control of the cell cycle

    PubMed Central

    Kalucka, Joanna; Missiaen, Rindert; Georgiadou, Maria; Schoors, Sandra; Lange, Christian; De Bock, Katrien; Dewerchin, Mieke; Carmeliet, Peter

    2015-01-01

    Cell division is a metabolically demanding process, requiring the production of large amounts of energy and biomass. Not surprisingly therefore, a cell's decision to initiate division is co-determined by its metabolic status and the availability of nutrients. Emerging evidence reveals that metabolism is not only undergoing substantial changes during the cell cycle, but it is becoming equally clear that metabolism regulates cell cycle progression. Here, we overview the emerging role of those metabolic pathways that have been best characterized to change during or influence cell cycle progression. We then studied how Notch signaling, a key angiogenic pathway that inhibits endothelial cell (EC) proliferation, controls EC metabolism (glycolysis) during the cell cycle. PMID:26431254

  16. How does metabolism affect cell death in cancer?

    PubMed

    Villa, Elodie; Ricci, Jean-Ehrland

    2016-07-01

    In cancer research, identifying a specificity of tumor cells compared with 'normal' proliferating cells for targeted therapy is often considered the Holy Grail for researchers and clinicians. Although diverse in origin, most cancer cells share characteristics including the ability to escape cell death mechanisms and the utilization of different methods of energy production. In the current paradigm, aerobic glycolysis is considered the central metabolic characteristic of cancer cells (Warburg effect). However, recent data indicate that cancer cells also show significant changes in other metabolic pathways. Indeed, it was recently suggested that Kreb's cycle, pentose phosphate pathway intermediates, and essential and nonessential amino acids have key roles. Renewed interest in the fact that cancer cells have to reprogram their metabolism in order to proliferate or resist treatment must take into consideration the ability of tumor cells to adapt their metabolism to the local microenvironment (low oxygen, low nutrients). This variety of metabolic sources might be either a strength, resulting in infinite possibilities for adaptation and increased ability to resist chemotherapy-induced death, or a weakness that could be targeted to kill cancer cells. Here, we discuss recent insights showing how energetic metabolism may regulate cell death and how this might be relevant for cancer treatment.

  17. Cadmium Induces Retinoic Acid Signaling by Regulating Retinoic Acid Metabolic Gene Expression*

    PubMed Central

    Cui, Yuxia; Freedman, Jonathan H.

    2009-01-01

    The transition metal cadmium is an environmental teratogen. In addition, cadmium and retinoic acid can act synergistically to induce forelimb malformations. The molecular mechanism underlying the teratogenicity of cadmium and the synergistic effect with retinoic acid has not been addressed. An evolutionarily conserved gene, β,β-carotene 15,15′-monooxygenase (BCMO), which is involved in retinoic acid biosynthesis, was studied in both Caenorhabditis elegans and murine Hepa 1–6 cells. In C. elegans, bcmo-1 was expressed in the intestine and was cadmium inducible. Similarly, in Hepa 1–6 cells, Bcmo1 was induced by cadmium. Retinoic acid-mediated signaling increased after 24-h exposures to 5 and 10 μm cadmium in Hepa 1–6 cells. Examination of gene expression demonstrated that the induction of retinoic acid signaling by cadmium may be mediated by overexpression of Bcmo1. Furthermore, cadmium inhibited the expression of Cyp26a1 and Cyp26b1, which are involved in retinoic acid degradation. These results indicate that cadmium-induced teratogenicity may be due to the ability of the metal to increase the levels of retinoic acid by disrupting the expression of retinoic acid-metabolizing genes. PMID:19556237

  18. Bile Acid Alters Male Mouse Fertility in Metabolic Syndrome Context

    PubMed Central

    Baptissart, Marine; De Haze, Angélique; Vaz, Frederic; Kulik, Wim; Damon-Soubeyrand, Christelle; Baron, Silvère; Caira, Françoise; Volle, David H.

    2015-01-01

    Bile acids have recently been demonstrated as molecules with endocrine activities controlling several physiological functions such as immunity and glucose homeostases. They act mainly through two receptors, the nuclear receptor Farnesol-X-Receptor alpha (FXRα) and the G-protein coupled receptor (TGR5). These recent studies have led to the idea that molecules derived from bile acids (BAs) and targeting their receptors must be good targets for treatment of metabolic diseases such as obesity or diabetes. Thus it might be important to decipher the potential long term impact of such treatment on different physiological functions. Indeed, BAs have recently been demonstrated to alter male fertility. Here we demonstrate that in mice with overweight induced by high fat diet, BA exposure leads to increased rate of male infertility. This is associated with the altered germ cell proliferation, default of testicular endocrine function and abnormalities in cell-cell interaction within the seminiferous epithelium. Even if the identification of the exact molecular mechanisms will need more studies, the present results suggest that both FXRα and TGR5 might be involved. We believed that this work is of particular interest regarding the potential consequences on future approaches for the treatment of metabolic diseases. PMID:26439743

  19. Cell signalling and phospholipid metabolism

    SciTech Connect

    Boss, W.F.

    1989-01-01

    Our research for the past two years has involved the study of phosphoinositides and their potential role in regulating plant growth and development. Our initial goal was to document the sequence of events involved in inositol phospholipid metabolism in response to external stimuli. Our working hypothesis was that phosphatidylinositol bisphosphate (PIP/sub 2/) was in the plasma membrane of plants cells and would be hydrolyzed by phospholipase C to yield the second messengers inositol triphosphate (IP/sub 3/) and diacyglycerol (DAG) and that IP/sub 3/ would mobilize intracellular calcium as has been shown for animal cells. Our results with both carrot suspension culture cells and sunflower hypocotyl indicate that this paradigm is not the primary mechanism of signal transduction in these systems. We have observed very rapid, within 5 sec, stimulation of phosphatidylinositol monophosphate (PIP) kinase which resulted in an increase in PIP/sub 2/. However, there was no evidence for activation of phospholipase C. In addition, we have shown that PIP and PIP/sub 2/ can activate the plasma membrane ATPase. The results of these studies are described briefly in the paragraphs below. Inositol phospholipids are localized in distinct membrane fractions. If PIP and PIP/sub 2/ play a role in the transduction of external signals, they should be present in the plasma membrane. We used the fusogenic carrot suspension culture cells as a model system to study the distribution of inositol phospholipids in various membrane fractions and organelles. Cells were labeled 12 to 18 h with myo(2-/sup 3/H) inositol and the membranes were isolated by aqueous two-phase partitioning. The plasma membrane was enriched in PIP and PIP/sub 2/ compared to the intracellular membranes.

  20. Absorption and metabolism of the food contaminant 3-chloro-1,2-propanediol (3-MCPD) and its fatty acid esters by human intestinal Caco-2 cells.

    PubMed

    Buhrke, Thorsten; Weisshaar, Rüdiger; Lampen, Alfonso

    2011-10-01

    3-Chloro-1,2-propanediol (3-MCPD) fatty acid esters are formed upon thermal processing of fat-containing foods in the presence of chloride ions. Upon hydrolytic cleavage, these substances could release free 3-MCPD. This compound is toxicologically well characterised and displayed cancerogenic potential in rodent models. Recently, serious contaminations of different food products with 3-MCPD fatty acid esters have been reported. In regard to a risk assessment, the key question is to which degree these 3-MCPD fatty acid esters are hydrolysed in the human gut. Therefore, the aim of the present project was to examine the hydrolysis of 3-MCPD fatty acid esters and the resulting release of free 3-MCPD by using differentiated Caco-2 cells, a cellular in vitro model for the human intestinal barrier. Here, we show that 3-MCPD fatty acid esters at a concentration of 100 μM were neither absorbed by the cells nor the esters were transported via a Caco-2 monolayer. 3-MCPD-1-monoesters were hydrolysed in the presence of Caco-2 cells. In contrast, a 3-MCPD-1,2-diester used in this study was obviously absorbed and metabolised by the cells. Free 3-MCPD was not absorbed by the cells, but the substance migrated through a Caco-2 monolayer by paracellular diffusion. From these in vitro studies, we conclude that 3-MCPD-1-monoesters are likely to be hydrolysed in the human intestine, thereby increasing the burden with free 3-MCPD. In contrast, intestinal cells seem to have the capacity to metabolise 3-MCPD diesters, thereby detoxifying the 3-MCPD moiety.

  1. The Role of Glucose and Lipid Metabolism in Growth and Survival of Cancer Cells.

    PubMed

    Brault, Charlene; Schulze, Almut

    2016-01-01

    One of the prerequisites for cell growth and proliferation is the synthesis of macromolecules, including proteins, nucleic acids and lipids. Cells have to alter their metabolism to allow the production of metabolic intermediates that are the precursors for biomass production. It is now evident that oncogenic signalling pathways target metabolic processes on several levels and metabolic reprogramming has emerged as a hallmark of cancer. The increased metabolic demand of cancer cells also produces selective dependencies that could be targeted for therapeutic intervention. Understanding the role of glucose and lipid metabolism in supporting cancer cell growth and survival is crucial to identify essential processes that could provide therapeutic windows for cancer therapy. PMID:27557532

  2. Folic Acid-Metabolizing Enzymes Regulate the Antitumor Effect of 5-Fluoro-2′-Deoxyuridine in Colorectal Cancer Cell Lines

    PubMed Central

    Tsukihara, Hiroshi; Tsunekuni, Kenta; Takechi, Teiji

    2016-01-01

    In colorectal cancer chemotherapy, the current standard of care includes combination therapy with 5-fluorouracil (5-FU) and leucovorin (LV). However, the factors that determine the LV-mediated enhancement of 5-FU antitumor activity are not fully understood. Therefore, we investigated the roles of thymidine synthase (TYMS), folate receptor 1 (FOLR1), dihydrofolate reductase (DHFR), phosphoribosylglycinamide formyltransferase (GART), methylenetetrahydrofolate dehydrogenase (MTHFD1), and methylenetetrahydrofolate reductase (MTHFR) in LV-mediated enhancement of 5-fluoro-2′-deoxyuridine (FdUrd) cytotoxicity in vitro as a model of 5-FU antitumor activity. These genes were downregulated in DLD-1 and HCT116 human colorectal cancer cells by using small-interfering RNA. Reduced expression of TYMS mRNA significantly increased FdUrd cytotoxicity by 100- and 8.3-fold in DLD-1 and HCT116 cells, respectively. In contrast, reducing the expression of FOLR1, DHFR, GART, MTHFD1, and MTHFR decreased FdUrd cytotoxicity by 2.13- to 12.91-fold in DLD-1 cells and by 3.52- to 10.36-fold in HCT116 cells. These results demonstrate that folate metabolism is important for the efficacy of FdUrd. Overall, the results indicate that it is important to clarify the relationship between folate metabolism-related molecules and 5-FU treatment in order to improve predictions of the effectiveness of 5-FU and LV combination therapy. PMID:27685866

  3. Bile Acid Signaling in Metabolic Disease and Drug Therapy

    PubMed Central

    Li, Tiangang

    2014-01-01

    Bile acids are the end products of cholesterol catabolism. Hepatic bile acid synthesis accounts for a major fraction of daily cholesterol turnover in humans. Biliary secretion of bile acids generates bile flow and facilitates hepatobiliary secretion of lipids, lipophilic metabolites, and xenobiotics. In the intestine, bile acids are essential for the absorption, transport, and metabolism of dietary fats and lipid-soluble vitamins. Extensive research in the last 2 decades has unveiled new functions of bile acids as signaling molecules and metabolic integrators. The bile acid–activated nuclear receptors farnesoid X receptor, pregnane X receptor, constitutive androstane receptor, vitamin D receptor, and G protein–coupled bile acid receptor play critical roles in the regulation of lipid, glucose, and energy metabolism, inflammation, and drug metabolism and detoxification. Bile acid synthesis exhibits a strong diurnal rhythm, which is entrained by fasting and refeeding as well as nutrient status and plays an important role for maintaining metabolic homeostasis. Recent research revealed an interaction of liver bile acids and gut microbiota in the regulation of liver metabolism. Circadian disturbance and altered gut microbiota contribute to the pathogenesis of liver diseases, inflammatory bowel diseases, nonalcoholic fatty liver disease, diabetes, and obesity. Bile acids and their derivatives are potential therapeutic agents for treating metabolic diseases of the liver. PMID:25073467

  4. Investigational cancer drugs targeting cell metabolism in clinical development

    PubMed Central

    Sborov, Douglas W; Haverkos, Bradley M; Harris, Pamela J

    2015-01-01

    Introduction Malignant cell transformation and tumor progression are associated with alterations in glycolysis, fatty acid synthesis, amino acid delivery and production of reactive oxygen species. With increased understanding of the role of metabolism in tumors, there has been interest in developing agents that target tumor specific metabolic pathways. Numerous promising agents targeting altered metabolic pathways are currently in Phase I – III clinical trials. Areas covered This paper reviews the early phase clinical trial development of these agents and provides perspective on the future direction of this emerging field. Specifically, the authors describe novel and repurposed therapies, focusing on the effects of each agent on tumor metabolism and results from relevant Phase I and II clinical trials. Expert opinion Metabolism modulating agents, alone and in combinations with other classes of agents, have shown efficacy in the treatment of neoplasm, which, the authors believe, will bear positive results in future studies. Because of the significant crosstalk between metabolic pathways and oncogenic signaling pathways, the authors also believe that combining metabolic modifiers with targeted agents will be an important strategy. An increased understanding of cancer metabolism, in addition to the continued study of metabolic modulators, should lead to further advances in this nascent therapeutic field in the future. PMID:25224845

  5. Metabolic regulation of natural killer cells.

    PubMed

    Finlay, David K

    2015-08-01

    Natural killer (NK) cells have key roles in anti-viral and anti-tumour immune responses. Recent research demonstrates that cellular metabolism is an important determinant for the function of pro-inflammatory immune cells, including activated NK cells. The mammalian target of rapamcyin (mTOR) complex 1 (mTORC1) has been identified as a key metabolic regulator that promotes glycolytic metabolism in multiple immune cell subsets. Glycolysis is integrally linked to pro-inflammatory immune responses such that activated NK cells and effector T-cell subsets are reliant on sufficient glucose availability for maximal effector function. This article will discuss the regulation of cellular metabolism in NK cells as compared with that of T lymphocytes and discuss the implications for NK cell responses to viral infection and cancer.

  6. Metabolic switch during adipogenesis: From branched chain amino acid catabolism to lipid synthesis.

    PubMed

    Halama, Anna; Horsch, Marion; Kastenmüller, Gabriele; Möller, Gabriele; Kumar, Pankaj; Prehn, Cornelia; Laumen, Helmut; Hauner, Hans; Hrabĕ de Angelis, Martin; Beckers, Johannes; Suhre, Karsten; Adamski, Jerzy

    2016-01-01

    Fat cell metabolism has an impact on body homeostasis and its proper function. Nevertheless, the knowledge about simultaneous metabolic processes, which occur during adipogenesis and in mature adipocytes, is limited. Identification of key metabolic events associated with fat cell metabolism could be beneficial in the field of novel drug development, drug repurposing, as well as for the discovery of patterns predicting obesity risk. The main objective of our work was to provide comprehensive characterization of metabolic processes occurring during adipogenesis and in mature adipocytes. In order to globally determine crucial metabolic pathways involved in fat cell metabolism, metabolomics and transcriptomics approaches were applied. We observed significantly regulated metabolites correlating with significantly regulated genes at different stages of adipogenesis. We identified the synthesis of phosphatidylcholines, the metabolism of even and odd chain fatty acids, as well as the catabolism of branched chain amino acids (BCAA; leucine, isoleucine and valine) as key regulated pathways. Our further analysis led to identification of an enzymatic switch comprising the enzymes Hmgcs2 (3-hydroxy-3-methylglutaryl-CoA synthase) and Auh (AU RNA binding protein/enoyl-CoA hydratase) which connects leucine degradation with cholesterol synthesis. In addition, propionyl-CoA, a product of isoleucine degradation, was identified as a putative substrate for odd chain fatty acid synthesis. The uncovered crosstalks between BCAA and lipid metabolism during adipogenesis might contribute to the understanding of molecular mechanisms of obesity and have potential implications in obesity prediction. PMID:26408941

  7. Impulsive mathematical modeling of ascorbic acid metabolism in healthy subjects.

    PubMed

    Bachar, Mostafa; Raimann, Jochen G; Kotanko, Peter

    2016-03-01

    In this work, we develop an impulsive mathematical model of Vitamin C (ascorbic acid) metabolism in healthy subjects for daily intake over a long period of time. The model includes the dynamics of ascorbic acid plasma concentration, the ascorbic acid absorption in the intestines and a novel approach to quantify the glomerular excretion of ascorbic acid. We investigate qualitative and quantitative dynamics. We show the existence and uniqueness of the global asymptotic stability of the periodic solution. We also perform a numerical simulation for the entire time period based on published data reporting parameters reflecting ascorbic acid metabolism at different oral doses of ascorbic acid.

  8. Targeting T cell metabolism for therapy

    PubMed Central

    O’Sullivan, David

    2015-01-01

    In the past several years, a wealth of evidence has emerged illustrating how metabolism supports many aspects of T cell biology, as well as how metabolic changes drive T cell differentiation and fate. Here we outline developing principles in the regulation of T cell metabolism, and discuss how these processes are impacted in settings of inflammation and cancer. In this context we discuss how metabolic pathways might be manipulated for the treatment of human disease, including how metabolism may be targeted to prevent T cell dysfunction in inhospitable microenvironments, to generate more effective adoptive cellular immunotherapies in cancer, and to direct T cell differentiation and function towards non-pathogenic phenotypes in settings of autoimmunity. PMID:25601541

  9. Connecting Mitochondria, Metabolism, and Stem Cell Fate

    PubMed Central

    Wanet, Anaïs; Arnould, Thierry; Najimi, Mustapha

    2015-01-01

    As sites of cellular respiration and energy production, mitochondria play a central role in cell metabolism. Cell differentiation is associated with an increase in mitochondrial content and activity and with a metabolic shift toward increased oxidative phosphorylation activity. The opposite occurs during reprogramming of somatic cells into induced pluripotent stem cells. Studies have provided evidence of mitochondrial and metabolic changes during the differentiation of both embryonic and somatic (or adult) stem cells (SSCs), such as hematopoietic stem cells, mesenchymal stem cells, and tissue-specific progenitor cells. We thus propose to consider those mitochondrial and metabolic changes as hallmarks of differentiation processes. We review how mitochondrial biogenesis, dynamics, and function are directly involved in embryonic and SSC differentiation and how metabolic and sensing pathways connect mitochondria and metabolism with cell fate and pluripotency. Understanding the basis of the crosstalk between mitochondria and cell fate is of critical importance, given the promising application of stem cells in regenerative medicine. In addition to the development of novel strategies to improve the in vitro lineage-directed differentiation of stem cells, understanding the molecular basis of this interplay could lead to the identification of novel targets to improve the treatment of degenerative diseases. PMID:26134242

  10. Connecting Mitochondria, Metabolism, and Stem Cell Fate.

    PubMed

    Wanet, Anaïs; Arnould, Thierry; Najimi, Mustapha; Renard, Patricia

    2015-09-01

    As sites of cellular respiration and energy production, mitochondria play a central role in cell metabolism. Cell differentiation is associated with an increase in mitochondrial content and activity and with a metabolic shift toward increased oxidative phosphorylation activity. The opposite occurs during reprogramming of somatic cells into induced pluripotent stem cells. Studies have provided evidence of mitochondrial and metabolic changes during the differentiation of both embryonic and somatic (or adult) stem cells (SSCs), such as hematopoietic stem cells, mesenchymal stem cells, and tissue-specific progenitor cells. We thus propose to consider those mitochondrial and metabolic changes as hallmarks of differentiation processes. We review how mitochondrial biogenesis, dynamics, and function are directly involved in embryonic and SSC differentiation and how metabolic and sensing pathways connect mitochondria and metabolism with cell fate and pluripotency. Understanding the basis of the crosstalk between mitochondria and cell fate is of critical importance, given the promising application of stem cells in regenerative medicine. In addition to the development of novel strategies to improve the in vitro lineage-directed differentiation of stem cells, understanding the molecular basis of this interplay could lead to the identification of novel targets to improve the treatment of degenerative diseases.

  11. Metabolic engineering as a tool for enhanced lactic acid production.

    PubMed

    Upadhyaya, Bikram P; DeVeaux, Linda C; Christopher, Lew P

    2014-12-01

    Metabolic engineering is a powerful biotechnological tool that finds, among others, increased use in constructing microbial strains for higher lactic acid productivity, lower costs and reduced pollution. Engineering the metabolic pathways has concentrated on improving the lactic acid fermentation parameters, enhancing the acid tolerance of production organisms and their abilities to utilize a broad range of substrates, including fermentable biomass-derived sugars. Recent efforts have focused on metabolic engineering of lactic acid bacteria as they produce high yields and have a small genome size that facilitates their genetic manipulation. We summarize here the current trends in metabolic engineering techniques and strategies for manipulating lactic acid producing organisms developed to address and overcome major challenges in the lactic acid production process.

  12. Absorption and metabolism of cis-9,trans-11-CLA and of its oxidation product 9,11-furan fatty acid by Caco-2 cells.

    PubMed

    Buhrke, Thorsten; Merkel, Roswitha; Lengler, Imme; Lampen, Alfonso

    2012-04-01

    Furan fatty acids (furan-FA) can be formed by auto-oxidation of conjugated linoleic acids (CLA) and may therefore be ingested when CLA-containing foodstuff is consumed. Due to the presence of a furan ring structure, furan-FA may have toxic properties, however, these substances are toxicologically not well characterized so far. Here we show that 9,11-furan-FA, the oxidation product of the major CLA isomer cis-9,trans-11-CLA (c9,t11-CLA), is not toxic to human intestinal Caco-2 cells up to a level of 100 μM. Oil-Red-O staining indicated that 9,11-furan-FA as well as c9,t11-CLA and linoleic acid are taken up by the cells and stored in the form of triglycerides in lipid droplets. Chemical analysis of total cellular lipids revealed that 9,11-furan-FA is partially elongated probably by the enzymatic activity of cellular fatty acid elongases whereas c9,t11-CLA is partially converted to other isomers such as c9,c11-CLA or t9,t11-CLA. In the case of 9,11-furan-FA, there is no indication for any modification or activation of the furan ring system. From these results, we conclude that 9,11-furan-FA has no properties of toxicological relevance at least for Caco-2 cells which serve as a model for enterocytes of the human small intestine.

  13. Effects of Elaidic Acid on Lipid Metabolism in HepG2 Cells, Investigated by an Integrated Approach of Lipidomics, Transcriptomics and Proteomics

    PubMed Central

    Young, Clifford; Ferreri, Carla; Chatgilialoglu, Chryssostomos; Nørregaard Jensen, Ole; Enghild, Jan J.

    2013-01-01

    Trans fatty acid consumption in the human diet can cause adverse health effects, such as cardiovascular disease, which is associated with higher total cholesterol, a higher low density lipoprotein-cholesterol level and a decreased high density lipoprotein-cholesterol level. The aim of the study was to elucidate the hepatic response to the most abundant trans fatty acid in the human diet, elaidic acid, to help explain clinical findings on the relationship between trans fatty acids and cardiovascular disease. The human HepG2 cell line was used as a model to investigate the hepatic response to elaidic acid in a combined proteomic, transcriptomic and lipidomic approach. We found many of the proteins responsible for cholesterol synthesis up-regulated together with several proteins involved in the esterification and hepatic import/export of cholesterol. Furthermore, a profound remodeling of the cellular membrane occurred at the phospholipid level. Our findings contribute to the explanation on how trans fatty acids from the diet can cause modifications in plasma cholesterol levels by inducing abundance changes in several hepatic proteins and the hepatic membrane composition. PMID:24058537

  14. Mitochondria, cholesterol and cancer cell metabolism.

    PubMed

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

    2016-12-01

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

  15. Disturbed Amino Acid Metabolism in HIV: Association with Neuropsychiatric Symptoms

    PubMed Central

    Gostner, Johanna M.; Becker, Kathrin; Kurz, Katharina; Fuchs, Dietmar

    2015-01-01

    Blood levels of the amino acid phenylalanine, as well as of the tryptophan breakdown product kynurenine, are found to be elevated in human immunodeficiency virus type 1 (HIV-1)-infected patients. Both essential amino acids, tryptophan and phenylalanine, are important precursor molecules for neurotransmitter biosynthesis. Thus, dysregulated amino acid metabolism may be related to disease-associated neuropsychiatric symptoms, such as development of depression, fatigue, and cognitive impairment. Increased phenylalanine/tyrosine and kynurenine/tryptophan ratios are associated with immune activation in patients with HIV-1 infection and decrease upon effective antiretroviral therapy. Recent large-scale metabolic studies have confirmed the crucial involvement of tryptophan and phenylalanine metabolism in HIV-associated disease. Herein, we summarize the current status of the role of tryptophan and phenylalanine metabolism in HIV disease and discuss how inflammatory stress-associated dysregulation of amino acid metabolism may be part of the pathophysiology of common HIV-associated neuropsychiatric conditions. PMID:26236243

  16. (1)H NMR metabolomics analysis of renal cell carcinoma cells: Effect of VHL inactivation on metabolism.

    PubMed

    Cuperlovic-Culf, Miroslava; Cormier, Kevin; Touaibia, Mohamed; Reyjal, Julie; Robichaud, Sarah; Belbraouet, Mehdi; Turcotte, Sandra

    2016-05-15

    Von Hippel-Lindau (VHL) is an onco-suppressor involved in oxygen and energy-dependent promotion of protein ubiquitination and proteosomal degradation. Loss of function mutations of VHL (VHL-cells) result in organ specific cancers with the best studied example in renal cell carcinomas. VHL has a well-established role in deactivation of hypoxia-inducible factor (HIF-1) and in regulation of PI3K/AKT/mTOR activity. Cell culture metabolomics analysis was utilized to determined effect of VHL and HIF-1α or HIF-2α on metabolism of renal cell carcinomas (RCC). RCC cells were stably transfected with VHL or shRNA designed to silence HIF-1α or HIF-2α genes. Obtained metabolic data was analysed qualitatively, searching for overall effects on metabolism as well as quantitatively, using methods developed in our group in order to determine specific metabolic changes. Analysis of the effect of VHL and HIF silencing on cellular metabolic footprints and fingerprints provided information about the metabolic pathways affected by VHL through HIF function as well as independently of HIF. Through correlation network analysis as well as statistical analysis of significant metabolic changes we have determined effects of VHL and HIF on energy production, amino acid metabolism, choline metabolism as well as cell regulation and signaling. VHL was shown to influence cellular metabolism through its effect on HIF proteins as well as by affecting activity of other factors.

  17. T cell metabolism drives immunity

    PubMed Central

    Buck, Michael D.; O’Sullivan, David

    2015-01-01

    Lymphocytes must adapt to a wide array of environmental stressors as part of their normal development, during which they undergo a dramatic metabolic remodeling process. Research in this area has yielded surprising findings on the roles of diverse metabolic pathways and metabolites, which have been found to regulate lymphocyte signaling and influence differentiation, function and fate. In this review, we integrate the latest findings in the field to provide an up-to-date resource on lymphocyte metabolism. PMID:26261266

  18. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with "Auxin-Like" Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways.

    PubMed

    Bhat, Supriya V; Booth, Sean C; McGrath, Seamus G K; Dahms, Tanya E S

    2014-01-01

    There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv) as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria. PMID:25919284

  19. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with “Auxin-Like” Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways

    PubMed Central

    Bhat, Supriya V.; Booth, Sean C.; McGrath, Seamus G. K.; Dahms, Tanya E. S.

    2015-01-01

    There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv) as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria. PMID:25919284

  20. Rhizobium leguminosarum bv. viciae 3841 Adapts to 2,4-Dichlorophenoxyacetic Acid with "Auxin-Like" Morphological Changes, Cell Envelope Remodeling and Upregulation of Central Metabolic Pathways.

    PubMed

    Bhat, Supriya V; Booth, Sean C; McGrath, Seamus G K; Dahms, Tanya E S

    2014-01-01

    There is a growing need to characterize the effects of environmental stressors at the molecular level on model organisms with the ever increasing number and variety of anthropogenic chemical pollutants. The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), as one of the most widely applied pesticides in the world, is one such example. This herbicide is known to have non-targeted undesirable effects on humans, animals and soil microbes, but specific molecular targets at sublethal levels are unknown. In this study, we have used Rhizobium leguminosarum bv. viciae 3841 (Rlv) as a nitrogen fixing, beneficial model soil organism to characterize the effects of 2,4-D. Using metabolomics and advanced microscopy we determined specific target pathways in the Rlv metabolic network and consequent changes to its phenotype, surface ultrastructure, and physical properties during sublethal 2,4-D exposure. Auxin and 2,4-D, its structural analogue, showed common morphological changes in vitro which were similar to bacteroids isolated from plant nodules, implying that these changes are related to bacteroid differentiation required for nitrogen fixation. Rlv showed remarkable adaptation capabilities in response to the herbicide, with changes to integral pathways of cellular metabolism and the potential to assimilate 2,4-D with consequent changes to its physical and structural properties. This study identifies biomarkers of 2,4-D in Rlv and offers valuable insights into the mode-of-action of 2,4-D in soil bacteria.

  1. Metabolic profiling of hematopoietic stem and progenitor cells during proliferation and differentiation into red blood cells.

    PubMed

    Daud, Hasbullah; Browne, Susan; Al-Majmaie, Rasoul; Murphy, William; Al-Rubeai, Mohamed

    2016-01-25

    An understanding of the metabolic profile of cell proliferation and differentiation should support the optimization of culture conditions for hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and maturation into red blood cells. We have evaluated the key metabolic parameters during each phase of HSPC culture for red blood cell production in serum-supplemented (SS) and serum-free (SF) conditions. A simultaneous decrease in growth rate, total protein content, cell size, and the percentage of cells in the S/G2 phase of cell cycle, as well as an increase in the percentage of cells with a CD71(-)/GpA(+) surface marker profile, indicates HSPC differentiation into red blood cells. Compared with proliferating HSPCs, differentiating HSPCs showed significantly lower glucose and glutamine consumption rates, lactate and ammonia production rates, and amino acid consumption and production rates in both SS and SF conditions. Furthermore, extracellular acidification was associated with late proliferation phase, suggesting a reduced cellular metabolic rate during the transition from proliferation to differentiation. Under both SS and SF conditions, cells demonstrated a high metabolic rate with a mixed metabolism of both glycolysis and oxidative phosphorylation (OXPHOS) in early and late proliferation, an increased dependence on OXPHOS activity during differentiation, and a shift to glycolytic metabolism only during maturation phase. These changes indicate that cell metabolism may have an important impact on the ability of HSPCs to proliferate and differentiate into red blood cells. PMID:26013297

  2. Metabolic profiling of hematopoietic stem and progenitor cells during proliferation and differentiation into red blood cells.

    PubMed

    Daud, Hasbullah; Browne, Susan; Al-Majmaie, Rasoul; Murphy, William; Al-Rubeai, Mohamed

    2016-01-25

    An understanding of the metabolic profile of cell proliferation and differentiation should support the optimization of culture conditions for hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and maturation into red blood cells. We have evaluated the key metabolic parameters during each phase of HSPC culture for red blood cell production in serum-supplemented (SS) and serum-free (SF) conditions. A simultaneous decrease in growth rate, total protein content, cell size, and the percentage of cells in the S/G2 phase of cell cycle, as well as an increase in the percentage of cells with a CD71(-)/GpA(+) surface marker profile, indicates HSPC differentiation into red blood cells. Compared with proliferating HSPCs, differentiating HSPCs showed significantly lower glucose and glutamine consumption rates, lactate and ammonia production rates, and amino acid consumption and production rates in both SS and SF conditions. Furthermore, extracellular acidification was associated with late proliferation phase, suggesting a reduced cellular metabolic rate during the transition from proliferation to differentiation. Under both SS and SF conditions, cells demonstrated a high metabolic rate with a mixed metabolism of both glycolysis and oxidative phosphorylation (OXPHOS) in early and late proliferation, an increased dependence on OXPHOS activity during differentiation, and a shift to glycolytic metabolism only during maturation phase. These changes indicate that cell metabolism may have an important impact on the ability of HSPCs to proliferate and differentiate into red blood cells.

  3. Dietary fatty acids in metabolic syndrome, diabetes and cardiovascular diseases.

    PubMed

    Cascio, Giuseppe; Schiera, Gabriella; Di Liegro, Italia

    2012-01-01

    In the last few decades, the prevalence of overweight and essential obesity has been undergoing a fast and progressive worldwide increase. Obesity has been in turn linked to type II diabetes, with the total number of diabetic patients worryingly increasing, in the last fifteen years, suggesting a pandemic phenomenon. At the same time, an increase in the prevalence of cardiovascular diseases has been also recorded. Increasing evidence suggests that the diet is involved in such escalation. In particular, the progressive globalization of food industry allowed massive supply, at a relatively low price, of a great variety of pre-packed food and bakery products, with very high energy content. Most of this food contains high amounts of saturated fatty acids (SFA) and of hydrogenated or trans fatty acids (TFA), that probably represent the prominent risk factors in the diet. Herein we will report diffusion and possible impact on health of such molecules, with reference to coronary heart disease, insulin resistance, metabolic syndrome and diabetes. We will also discuss the cellular and molecular mechanisms of action of fatty acids and fatty acid-derivatives which have been involved either in promoting or in preventing human pathologies. Free fatty acids (FFA) are not indeed only essential fuels for the organism. They also act as ligands for both membrane and nuclear receptors involved in different signaling pathways. Notably, some of these pathways can induce cell stress and apoptosis. Most important, FFA can affect glucose-induced insulin secretion and activate β-cell death. These events can be at least in part counteracted by polyunsaturated fatty acids. PMID:22414056

  4. [Pandanus tectorius derived caffeoylquinic acids inhibit lipid accumulation in HepG2 hepatoma cells through regulation of gene expression involved in lipid metabolism].

    PubMed

    Wu, Chong-ming; Luan, Hong; Wang, Shuai; Zhang, Xiao-po; Liu, Hai-tao; Guo, Peng

    2015-03-01

    The fruit of Pandanus tectorius (PTF) has a long history of use as a folk medicine to treat hyperlipidemia in Hainan province, South China. Our previous studies have shown that the n-butanol extract of PTF is rich in caffeoylquinic acids and has an adequate therapeutic effect on dyslipidemic animals induced by high-fat diet. In this work, seven caffeoylquinic acids isolated from PTF were screened for the lipid-lowering activity in HepG2 hepatoma cells. Oil-Red O staining, microscopy and intracellular triglyceride (TG) and total cholesterol (TC) quantification showed that 3-O-caffeoylquinic acid (3-CQA), 3, 5-di-O-caffeoylquinic acid (3,5-CQA), and 3,4,5-tri-O-caffeoylquinic acid (3,4,5-CQA) significantly inhibited lipid accumulation induced by oleic acid and decreased intracellular levels of TC and TG in a dose-dependent manner. These three caffeoylquinic acids showed no significant cytotoxicity at concentrations of 1 -50 μmol x L(-1) as determined by MTT assay. Realtime quantitative PCR revealed that 3-CQA and 3, 5-CQA significantly increased the expression of lipid oxidation-related genes PPARα, CPT-1 and ACOX1 while 3-CQA, 3, 5-CQA and 3,4,5-CQA decreased the expression of lipogenic genes SREBP-1c, SREBP-2, HMGR, ACC, FAS. Overall, 3-CQA, 3, 5-CQA and 3, 4, 5-CQA may be the principal hypolipidemic components in PTF which can decrease intracellular lipid accumulation through up-regulating the expression of lipid oxidative genes and down-regulating the expression of lipogenic genes.

  5. Ovarian tumor-initiating cells display a flexible metabolism

    SciTech Connect

    Anderson, Angela S.; Roberts, Paul C.; Frisard, Madlyn I.; Hulver, Matthew W.; Schmelz, Eva M.

    2014-10-15

    An altered metabolism during ovarian cancer progression allows for increased macromolecular synthesis and unrestrained growth. However, the metabolic phenotype of cancer stem or tumor-initiating cells, small tumor cell populations that are able to recapitulate the original tumor, has not been well characterized. In the present study, we compared the metabolic phenotype of the stem cell enriched cell variant, MOSE-L{sub FFLv} (TIC), derived from mouse ovarian surface epithelial (MOSE) cells, to their parental (MOSE-L) and benign precursor (MOSE-E) cells. TICs exhibit a decrease in glucose and fatty acid oxidation with a concomitant increase in lactate secretion. In contrast to MOSE-L cells, TICs can increase their rate of glycolysis to overcome the inhibition of ATP synthase by oligomycin and can increase their oxygen consumption rate to maintain proton motive force when uncoupled, similar to the benign MOSE-E cells. TICs have an increased survival rate under limiting conditions as well as an increased survival rate when treated with AICAR, but exhibit a higher sensitivity to metformin than MOSE-E and MOSE-L cells. Together, our data show that TICs have a distinct metabolic profile that may render them flexible to adapt to the specific conditions of their microenvironment. By better understanding their metabolic phenotype and external environmental conditions that support their survival, treatment interventions can be designed to extend current therapy regimens to eradicate TICs. - Highlights: • Ovarian cancer TICs exhibit a decreased glucose and fatty acid oxidation. • TICs are more glycolytic and have highly active mitochondria. • TICs are more resistant to AICAR but not metformin. • A flexible metabolism allows TICs to adapt to their microenvironment. • This flexibility requires development of specific drugs targeting TIC-specific changes to prevent recurrent TIC outgrowth.

  6. Targeting cancer cell metabolism in pancreatic adenocarcinoma

    PubMed Central

    Cohen, Romain; Neuzillet, Cindy; Tijeras-Raballand, Annemilaï; Faivre, Sandrine; de Gramont, Armand; Raymond, Eric

    2015-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is expected to become the second leading cause of cancer death by 2030. Current therapeutic options are limited, warranting an urgent need to explore innovative treatment strategies. Due to specific microenvironment constraints including an extensive desmoplastic stroma reaction, PDAC faces major metabolic challenges, principally hypoxia and nutrient deprivation. Their connection with oncogenic alterations such as KRAS mutations has brought metabolic reprogramming to the forefront of PDAC therapeutic research. The Warburg effect, glutamine addiction, and autophagy stand as the most important adaptive metabolic mechanisms of cancer cells themselves, however metabolic reprogramming is also an important feature of the tumor microenvironment, having a major impact on epigenetic reprogramming and tumor cell interactions with its complex stroma. We present a comprehensive overview of the main metabolic adaptations contributing to PDAC development and progression. A review of current and future therapies targeting this range of metabolic pathways is provided. PMID:26164081

  7. Metabolic flux rewiring in mammalian cell cultures

    PubMed Central

    Young, Jamey D.

    2013-01-01

    Continuous cell lines (CCLs) engage in “wasteful” glucose and glutamine metabolism that leads to accumulation of inhibitory byproducts, primarily lactate and ammonium. Advances in techniques for mapping intracellular carbon fluxes and profiling global changes in enzyme expression have led to a deeper understanding of the molecular drivers underlying these metabolic alterations. However, recent studies have revealed that CCLs are not necessarily entrenched in a glycolytic or glutaminolytic phenotype, but instead can shift their metabolism toward increased oxidative metabolism as nutrients become depleted and/or growth rate slows. Progress to understand dynamic flux regulation in CCLs has enabled the development of novel strategies to force cultures into desirable metabolic phenotypes, by combining fed-batch feeding strategies with direct metabolic engineering of host cells. PMID:23726154

  8. Correlated FLIM and PLIM for cell metabolism

    NASA Astrophysics Data System (ADS)

    Rück, A.; Breymayer, J.; Kalinina, S.

    2016-03-01

    Correlated imaging of phosphorescence and fluorescence lifetime parameters of metabolic markers is a challenge for direct investigating mechanisms related to cell metabolism and oxygen tension. A large variety of clinical phenotypes is associated with mitochondrial defects accomplished with changes in cell metabolism. In many cases the hypoxic microenvironment of cancer cells shifts metabolism from oxidative phosphorylation (OXPHOS) to anaerobic or aerobic glycolysis, a process known as "Warburg" effect. Also during stem cell differentiation a switch in cell metabolism is observed. A defective mitochondrial function associated with hypoxia has been invoked in many complex disorders such as type 2 diabetes, Alzheimers disease, cardiac ischemia/reperfusion injury, tissue inflammation and cancer. Cellular responses to oxygen tension have been studied extensively, optical imaging techniques based on time correlated single photon counting (TCSPC) to detect the underlying metabolic mechanisms are therefore of prominent interest. They offer the possibility by inspecting fluorescence decay characteristics of intrinsic coenzymes to directly image metabolic pathways. Moreover oxygen tension can be determined by considering the phosphorescence lifetime of a phosphorescent probe. The combination of both fluorescence lifetime imaging (FLIM) of coenzymes like NADH and FAD and phosphorescence lifetime (PLIM) of phosphorescent dyes could provide valuable information about correlation of metabolic pathways and oxygen tension.

  9. In vivo metabolism of 2,2 prime -diaminopimelic acid from gram-positive and gram-negative bacterial cells by ruminal microorganisms and ruminants and its use as a marker of bacterial biomass

    SciTech Connect

    Masson, H.A.; Denholm, A.M.; Ling, J.R. )

    1991-06-01

    Cells of Bacillus megaterium GW1 and Escherichia coli W7-M5 were specifically radiolabeled with 2,2{prime}-diamino (G-{sup 3}H) pimelic acid (({sup 3}H)DAP) as models of gram-positive and gram-negative bacteria, respectively. Two experiments were conducted to study the in vivo metabolism of 2,2{prime}-diaminopimelic acid (DAP) in sheep. In experiment 1, cells of ({sup 3}H)DAP-labeled B. megaterium GW1 were infused into the rumen of one sheep and the radiolabel was traced within microbial samples, digesta, and the whole animal. Bacterially bound ({sup 3}H)DAP was extensively metabolized, primarily (up to 70% after 8 h) via decarboxylation to ({sup 3}H)lysine by both ruminal protozoa and ruminal bacteria. Recovery of infused radiolabel in urine and feces was low (42% after 96 h) and perhaps indicative of further metabolism by the host animal. In experiment 2, ({sup 3}H)DAP-labeled B. megaterium GW1 was infused into the rumens of three sheep and ({sup 3}H)DAP-labeled E. coli W7-W5 was infused into the rumen of another sheep. The radioactivity contents of these mutant bacteria were insufficient to use as tracers, but the metabolism of DAP was monitored in the total, free, and peptidyl forms. Free DAP, as a proportion of total DPA in duodenal digesta, varied from 0 to 9.5%, whereas peptidyl DAP accounted for 8.3 to 99.2%.

  10. Crassulacean acid metabolism photosynthesis: ;working the night shift'.

    PubMed

    Black, Clanton C; Osmond, C Barry

    2003-01-01

    Crassulacean acid metabolism (CAM) can be traced from Roman times through persons who noted a morning acid taste of some common house plants. From India in 1815, Benjamin-Heyne described a 'daily acid taste cycle' with some succulent garden plants. Recent work has shown that the nocturnally formed acid is decarboxylated during the day to become the CO(2) for photosynthesis. Thus, CAM photosynthesis extends over a 24-hour day using several daily interlocking cycles. To understand CAM photosynthesis, several landmark discoveries were made at the following times: daily reciprocal acid and carbohydrate cycles were found during 1870 to 1887; their precise identification, as malic acid and starch, and accurate quantification occurred from 1940 to 1954; diffusive gas resistance methods were introduced in the early 1960s that led to understanding the powerful stomatal control of daily gas exchanges; C(4) photosynthesis in two different types of cells was discovered from 1965 to approximately 1974 and the resultant information was used to elucidate the day and night portions of CAM photosynthesis in one cell; and exceptionally high internal green tissue CO(2) levels, 0.2 to 2.5%, upon the daytime decarboxylation of malic acid, were discovered in 1979. These discoveries then were combined with related information from C(3) and C(4) photosynthesis, carbon biochemistry, cellular anatomy, and ecological physiology. Therefore by approximately 1980, CAM photosynthesis finally was rigorously outlined. In a nutshell, 24-hour CAM occurs by phosphoenol pyruvate (PEP) carboxylase fixing CO(2)(HCO(3) (-)) over the night to form malic acid that is stored in plant cell vacuoles. While stomata are tightly closed the following day, malic acid is decarboxylated releasing CO(2) for C(3) photosynthesis via ribulose bisphosphate carboxylase oxygenase (Rubisco). The CO(2) acceptor, PEP, is formed via glycolysis at night from starch or other stored carbohydrates and after decarboxylation the

  11. Metabolic circuits in neural stem cells

    PubMed Central

    Kim, Do-Yeon; Rhee, Inmoo

    2015-01-01

    Metabolic activity indicative of cellular demand is emerging as a key player in cell fate decision. Numerous studies have demonstrated that diverse metabolic pathways have a critical role in the control of the proliferation, differentiation and quiescence of stem cells. The identification of neural stem/progenitor cells (NSPCs) and the characterization of their development and fate decision process have provided insight into the regenerative potential of the adult brain. As a result, the potential of NSPCs in cell replacement therapies for neurological diseases is rapidly growing. The aim of this review is to discuss the recent findings on the crosstalk among key regulators of NSPC development and the metabolic regulation crucial for the function and cell fate decisions of NSPCs. Fundamental understanding of the metabolic circuits in NSPCs may help to provide novel approaches for reactivating neurogenesis to treat degenerative brain conditions and cognitive decline. PMID:25037158

  12. Metabolic strategies of beer spoilage lactic acid bacteria in beer.

    PubMed

    Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

    2016-01-01

    Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.

  13. Metabolic strategies of beer spoilage lactic acid bacteria in beer.

    PubMed

    Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

    2016-01-01

    Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis. PMID:26398285

  14. Metabolic carbon fluxes and biosynthesis of polyhydroxyalkanoates in Ralstonia eutropha on short chain fatty acids.

    PubMed

    Yu, Jian; Si, Yingtao

    2004-01-01

    Short chain fatty acids such as acetic, propionic, and butyric acids can be synthesized into polyhydroxyalkanoates (PHAs) by Ralstonia eutropha. Metabolic carbon fluxes of the acids in living cells have significant effect on the yield, composition, and thermomechanical properties of PHA bioplastics. Based on the general knowledge of central metabolism pathways and the unusual metabolic pathways in R. eutropha, a metabolic network of 41 bioreactions is constructed to analyze the carbon fluxes on utilization of the short chain fatty acids. In fed-batch cultures with constant feeding of acid media, carbon metabolism and distribution in R. eutropha were measured involving CO2, PHA biopolymers, and residual cell mass. As the cells underwent unsteady state metabolism and PHA biosynthesis under nitrogen-limited conditions, accumulative carbon balance was applied for pseudo-steady-state analysis of the metabolic carbon fluxes. Cofactor NADP/NADPH balanced between PHA synthesis and the C3/C4 pathway provided an independent constraint for solution of the underdetermined metabolic network. A major portion of propionyl-CoA was directed to pyruvate via the 2-methylcitrate cycle and further decarboxylated to acetyl-CoA. Only a small amount of propionate carbon (<15% carbon) was directly condensed with acetyl-CoA for 3-hydroxyvalerate. The ratio of glyoxylate shunt to TCA cycle varies from 0 to 0.25, depending on the intracellular acetyl-CoA level and acetic acid in the medium. Malate is the node of the C3/C4 pathway and TCA cycle and its decarboxylation to dehydrogenation ranges from 0.33 to 1.28 in response to the demands on NADPH and oxaloacetate for short chain fatty acids utilization. PMID:15296425

  15. The ins and outs of maternal-fetal fatty acid metabolism.

    PubMed

    Bobiński, Rafał; Mikulska, Monika

    2015-01-01

    Fatty acids (FAs) are one the most essential substances in intrauterine human growth. They are involved in a number of energetic and metabolic processes, including the growth of cell membranes, the retina and the nervous system. Fatty acid deficiency and disruptions in the maternal-placental fetal metabolism of FAs lead to malnutrition of the fetus, hypotrophy and preterm birth. What is more, metabolic diseases and cardiovascular conditions may appear later in life. Meeting a fetus' need for FAs is dependent on maternal diet and on the efficiency of the placenta in transporting FAs to fetal circulation. "Essential fatty acids" are among the most important FAs during the intrauterine growth period. These are α-linolenic acid, which is a precursor of the n-3 series, linoleic acid, which is a precursor of the n-6 series and their derivatives, represented by docosahexaenoic acid and arachidonic acid. The latest studies have shown that medium-chain fatty acids also play a significant role in maternal-fetal metabolism. These FAs have significant effect on the transformation of the precursors into DHA, which may contribute to a relatively stable supply of DHA - even in pregnant women whose diet is low in FAs. The review discusses the problem of fatty acid metabolism at the intersection between a pregnant woman and her child with reference to physiological pregnancy, giving birth to a healthy child, intrauterine growth restriction, preterm birth and giving birth to a small for gestational age child. PMID:26345097

  16. Textbook Errors & Misconceptions in Biology: Cell Metabolism.

    ERIC Educational Resources Information Center

    Storey, Richard D.

    1991-01-01

    The idea that errors and misconceptions in biology textbooks are often slow to be discovered and corrected is discussed. Selected errors, misconceptions, and topics of confusion about cell metabolism are described. Fermentation, respiration, Krebs cycle, pentose phosphate pathway, uniformity of catabolism, and metabolic pathways as models are…

  17. Amino acid composition and amino acid-metabolic network in supragingival plaque.

    PubMed

    Washio, Jumpei; Ogawa, Tamaki; Suzuki, Keisuke; Tsukiboshi, Yosuke; Watanabe, Motohiro; Takahashi, Nobuhiro

    2016-01-01

    Dental plaque metabolizes both carbohydrates and amino acids. The former can be degraded to acids mainly, while the latter can be degraded to various metabolites, including ammonia, acids and amines, and associated with acid-neutralization, oral malodor and tissue inflammation. However, amino acid metabolism in dental plaque is still unclear. This study aimed to elucidate what kinds of amino acids are available as metabolic substrates and how the amino acids are metabolized in supragingival plaque, by a metabolome analysis. Amino acids and the related metabolites in supragingival plaque were extracted and quantified comprehensively by CE-TOFMS. Plaque samples were also incubated with amino acids, and the amounts of ammonia and amino acid-related metabolites were measured. The concentration of glutamate was the highest in supragingival plaque, while the ammonia-production was the highest from glutamine. The obtained metabolome profile revealed that amino acids are degraded through various metabolic pathways, including deamination, decarboxylation and transamination and that these metabolic systems may link each other, as well as with carbohydrate metabolic pathways in dental plaque ecosystem. Moreover, glutamine and glutamate might be the main source of ammonia production, as well as arginine, and contribute to pH-homeostasis and counteraction to acid-induced demineralization in supragingival plaque. PMID:27545001

  18. Fatty acid metabolism: Implications for diet, genetic variation, and disease

    PubMed Central

    Suburu, Janel; Gu, Zhennan; Chen, Haiqin; Chen, Wei; Zhang, Hao; Chen, Yong Q.

    2014-01-01

    Cultures across the globe, especially Western societies, are burdened by chronic diseases such as obesity, metabolic syndrome, cardiovascular disease, and cancer. Several factors, including diet, genetics, and sedentary lifestyle, are suspected culprits to the development and progression of these health maladies. Fatty acids are primary constituents of cellular physiology. Humans can acquire fatty acids by de novo synthesis from carbohydrate or protein sources or by dietary consumption. Importantly, regulation of their metabolism is critical to sustain balanced homeostasis, and perturbations of such can lead to the development of disease. Here, we review de novo and dietary fatty acid metabolism and highlight recent advances in our understanding of the relationship between dietary influences and genetic variation in fatty acid metabolism and their role in chronic diseases. PMID:24511462

  19. Metabolism and transport of gamma-carboxyglutamic acid.

    PubMed

    Shah, D V; Tews, J K; Harper, A E; Suttie, J W

    1978-03-01

    gamma-Carboxyglutamic acid residues have beeh shown to be present in prothrombin, the other vitamin K-dependent clotting factors, and more recently in bone and kidney proteins. This amino acid is formed by a posttranslational vitamin K-dependent carboxylation of glutamyl residues in polypeptide precursors of these protens. It has now been demonstrated that this amino acid, either in the free or peptide-bound form, is not metabolically degraded by the rat, but is quantitatively excreted in the urine. In nephrectomized rats, the tissue concentration of intravenously administered gamma-carboxyglutamic acid is increased, but there is still no evidence of any oxidative metabolism of this amino acid. These amino acid is transported by kidney slices against a concentration gradient, but does not accumulate in liver, intestinal or brain tissues. Preliminary data suggest that gamma-carboxyglutamic acid may be concentrated by a carrier system different from that utilized by other amino acids. PMID:629998

  20. C19 odd-chain polyunsaturated fatty acids (PUfas) are metabolized to C21-PUfas in a rat liver cell line, and curcumin, gallic acid, and their related compounds inhibit their desaturation.

    PubMed

    Nakano, N; Shirasaka, N; Koyama, H; Hino, M; Murakami, T; Shimizu, S; Yoshizumi, H

    2000-08-01

    It was demonstrated that the rat liver cell line BRL-3A converted exogenous C19 odd chain-polyunsaturated fatty acids (PUFAs) into the corresponding C21- and C23-PUFAs as follows: 21:3n-8, 21:4n-8, 23:3n-8, and 23:4n-8 (from 19:3n-8); 21:4n-5, 21:5n-5, 23:4n-5, and 23:5n-5 (from 19:4n-5); 21:5n-2, 21:6n-2, 23:5n-2, and 23:6n-2 (from 19:5n-2). It presumed that these C19 PUFAs were converted through the mimic route to docosahexaenoic acid (22:6n-3) from eicosapentaenoic acid (20:5n-3). In addition, the characterization of the change of fatty acid composition of cellular lipids in rat liver cells were examined, using 19:4n-5 and several fatty acid desaturation inhibitors. Curcumin related compounds, curcumin, capsaicin, isoeugenol, 4-(4-hydroxy-3-methoxyphenyl)-3-buten-2-one, and gallic acid esters with near five carbon numbered alcohol had great changes of fatty acid composition of cellular lipids based on inhibition of the A6 desaturation of C24-PUFAs in rat liver cells.

  1. Citric acid cycle and role of its intermediates in metabolism.

    PubMed

    Akram, Muhammad

    2014-04-01

    The citric acid cycle is the final common oxidative pathway for carbohydrates, fats and amino acids. It is the most important metabolic pathway for the energy supply to the body. TCA is the most important central pathway connecting almost all the individual metabolic pathways. In this review article, introduction, regulation and energetics of TCA cycle have been discussed. The present study was carried out to review literature on TCA cycle.

  2. Systems metabolic engineering design: Fatty acid production as an emerging case study

    PubMed Central

    Tee, Ting Wei; Chowdhury, Anupam; Maranas, Costas D; Shanks, Jacqueline V

    2014-01-01

    Increasing demand for petroleum has stimulated industry to develop sustainable production of chemicals and biofuels using microbial cell factories. Fatty acids of chain lengths from C6 to C16 are propitious intermediates for the catalytic synthesis of industrial chemicals and diesel-like biofuels. The abundance of genetic information available for Escherichia coli and specifically, fatty acid metabolism in E. coli, supports this bacterium as a promising host for engineering a biocatalyst for the microbial production of fatty acids. Recent successes rooted in different features of systems metabolic engineering in the strain design of high-yielding medium chain fatty acid producing E. coli strains provide an emerging case study of design methods for effective strain design. Classical metabolic engineering and synthetic biology approaches enabled different and distinct design paths towards a high-yielding strain. Here we highlight a rational strain design process in systems biology, an integrated computational and experimental approach for carboxylic acid production, as an alternative method. Additional challenges inherent in achieving an optimal strain for commercialization of medium chain-length fatty acids will likely require a collection of strategies from systems metabolic engineering. Not only will the continued advancement in systems metabolic engineering result in these highly productive strains more quickly, this knowledge will extend more rapidly the carboxylic acid platform to the microbial production of carboxylic acids with alternate chain-lengths and functionalities. PMID:24481660

  3. Metabolic pathway alterations that support cell proliferation.

    PubMed

    Vander Heiden, M G; Lunt, S Y; Dayton, T L; Fiske, B P; Israelsen, W J; Mattaini, K R; Vokes, N I; Stephanopoulos, G; Cantley, L C; Metallo, C M; Locasale, J W

    2011-01-01

    Proliferating cells adapt metabolism to support the conversion of available nutrients into biomass. How cell metabolism is regulated to balance the production of ATP, metabolite building blocks, and reducing equivalents remains uncertain. Proliferative metabolism often involves an increased rate of glycolysis. A key regulated step in glycolysis is catalyzed by pyruvate kinase to convert phosphoenolpyruvate (PEP) to pyruvate. Surprisingly, there is strong selection for expression of the less active M2 isoform of pyruvate kinase (PKM2) in tumors and other proliferative tissues. Cell growth signals further decrease PKM2 activity, and cells with less active PKM2 use another pathway with separate regulatory properties to convert PEP to pyruvate. One consequence of using this alternative pathway is an accumulation of 3-phosphoglycerate (3PG) that leads to the diversion of 3PG into the serine biosynthesis pathway. In fact, in some cancers a substantial portion of the total glucose flux is directed toward serine synthesis, and genetic evidence suggests that glucose flux into this pathway can promote cell transformation. Environmental conditions can also influence the pathways that cells use to generate biomass with the source of carbon for lipid synthesis changing based on oxygen availability. Together, these findings argue that distinct metabolic phenotypes exist among proliferating cells, and both genetic and environmental factors influence how metabolism is regulated to support cell growth.

  4. Pancreatic stellate cells support tumour metabolism through autophagic alanine secretion.

    PubMed

    Sousa, Cristovão M; Biancur, Douglas E; Wang, Xiaoxu; Halbrook, Christopher J; Sherman, Mara H; Zhang, Li; Kremer, Daniel; Hwang, Rosa F; Witkiewicz, Agnes K; Ying, Haoqiang; Asara, John M; Evans, Ronald M; Cantley, Lewis C; Lyssiotis, Costas A; Kimmelman, Alec C

    2016-08-25

    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by an intense fibrotic stromal response and deregulated metabolism. The role of the stroma in PDAC biology is complex and it has been shown to play critical roles that differ depending on the biological context. The stromal reaction also impairs the vasculature, leading to a highly hypoxic, nutrient-poor environment. As such, these tumours must alter how they capture and use nutrients to support their metabolic needs. Here we show that stroma-associated pancreatic stellate cells (PSCs) are critical for PDAC metabolism through the secretion of non-essential amino acids (NEAA). Specifically, we uncover a previously undescribed role for alanine, which outcompetes glucose and glutamine-derived carbon in PDAC to fuel the tricarboxylic acid (TCA) cycle, and thus NEAA and lipid biosynthesis. This shift in fuel source decreases the tumour’s dependence on glucose and serum-derived nutrients, which are limited in the pancreatic tumour microenvironment. Moreover, we demonstrate that alanine secretion by PSCs is dependent on PSC autophagy, a process that is stimulated by cancer cells. Thus, our results demonstrate a novel metabolic interaction between PSCs and cancer cells, in which PSC-derived alanine acts as an alternative carbon source. This finding highlights a previously unappreciated metabolic network within pancreatic tumours in which diverse fuel sources are used to promote growth in an austere tumour microenvironment. PMID:27509858

  5. Pancreatic stellate cells support tumour metabolism through autophagic alanine secretion.

    PubMed

    Sousa, Cristovão M; Biancur, Douglas E; Wang, Xiaoxu; Halbrook, Christopher J; Sherman, Mara H; Zhang, Li; Kremer, Daniel; Hwang, Rosa F; Witkiewicz, Agnes K; Ying, Haoqiang; Asara, John M; Evans, Ronald M; Cantley, Lewis C; Lyssiotis, Costas A; Kimmelman, Alec C

    2016-08-25

    Pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease characterized by an intense fibrotic stromal response and deregulated metabolism. The role of the stroma in PDAC biology is complex and it has been shown to play critical roles that differ depending on the biological context. The stromal reaction also impairs the vasculature, leading to a highly hypoxic, nutrient-poor environment. As such, these tumours must alter how they capture and use nutrients to support their metabolic needs. Here we show that stroma-associated pancreatic stellate cells (PSCs) are critical for PDAC metabolism through the secretion of non-essential amino acids (NEAA). Specifically, we uncover a previously undescribed role for alanine, which outcompetes glucose and glutamine-derived carbon in PDAC to fuel the tricarboxylic acid (TCA) cycle, and thus NEAA and lipid biosynthesis. This shift in fuel source decreases the tumour’s dependence on glucose and serum-derived nutrients, which are limited in the pancreatic tumour microenvironment. Moreover, we demonstrate that alanine secretion by PSCs is dependent on PSC autophagy, a process that is stimulated by cancer cells. Thus, our results demonstrate a novel metabolic interaction between PSCs and cancer cells, in which PSC-derived alanine acts as an alternative carbon source. This finding highlights a previously unappreciated metabolic network within pancreatic tumours in which diverse fuel sources are used to promote growth in an austere tumour microenvironment.

  6. Rewired metabolism in drug-resistant leukemia cells: a metabolic switch hallmarked by reduced dependence on exogenous glutamine.

    PubMed

    Stäubert, Claudia; Bhuiyan, Hasanuzzaman; Lindahl, Anna; Broom, Oliver Jay; Zhu, Yafeng; Islam, Saiful; Linnarsson, Sten; Lehtiö, Janne; Nordström, Anders

    2015-03-27

    Cancer cells that escape induction therapy are a major cause of relapse. Understanding metabolic alterations associated with drug resistance opens up unexplored opportunities for the development of new therapeutic strategies. Here, we applied a broad spectrum of technologies including RNA sequencing, global untargeted metabolomics, and stable isotope labeling mass spectrometry to identify metabolic changes in P-glycoprotein overexpressing T-cell acute lymphoblastic leukemia (ALL) cells, which escaped a therapeutically relevant daunorubicin treatment. We show that compared with sensitive ALL cells, resistant leukemia cells possess a fundamentally rewired central metabolism characterized by reduced dependence on glutamine despite a lack of expression of glutamate-ammonia ligase (GLUL), a higher demand for glucose and an altered rate of fatty acid β-oxidation, accompanied by a decreased pantothenic acid uptake capacity. We experimentally validate our findings by selectively targeting components of this metabolic switch, using approved drugs and starvation approaches followed by cell viability analyses in both the ALL cells and in an acute myeloid leukemia (AML) sensitive/resistant cell line pair. We demonstrate how comparative metabolomics and RNA expression profiling of drug-sensitive and -resistant cells expose targetable metabolic changes and potential resistance markers. Our results show that drug resistance is associated with significant metabolic costs in cancer cells, which could be exploited using new therapeutic strategies.

  7. Rewired metabolism in drug-resistant leukemia cells: a metabolic switch hallmarked by reduced dependence on exogenous glutamine.

    PubMed

    Stäubert, Claudia; Bhuiyan, Hasanuzzaman; Lindahl, Anna; Broom, Oliver Jay; Zhu, Yafeng; Islam, Saiful; Linnarsson, Sten; Lehtiö, Janne; Nordström, Anders

    2015-03-27

    Cancer cells that escape induction therapy are a major cause of relapse. Understanding metabolic alterations associated with drug resistance opens up unexplored opportunities for the development of new therapeutic strategies. Here, we applied a broad spectrum of technologies including RNA sequencing, global untargeted metabolomics, and stable isotope labeling mass spectrometry to identify metabolic changes in P-glycoprotein overexpressing T-cell acute lymphoblastic leukemia (ALL) cells, which escaped a therapeutically relevant daunorubicin treatment. We show that compared with sensitive ALL cells, resistant leukemia cells possess a fundamentally rewired central metabolism characterized by reduced dependence on glutamine despite a lack of expression of glutamate-ammonia ligase (GLUL), a higher demand for glucose and an altered rate of fatty acid β-oxidation, accompanied by a decreased pantothenic acid uptake capacity. We experimentally validate our findings by selectively targeting components of this metabolic switch, using approved drugs and starvation approaches followed by cell viability analyses in both the ALL cells and in an acute myeloid leukemia (AML) sensitive/resistant cell line pair. We demonstrate how comparative metabolomics and RNA expression profiling of drug-sensitive and -resistant cells expose targetable metabolic changes and potential resistance markers. Our results show that drug resistance is associated with significant metabolic costs in cancer cells, which could be exploited using new therapeutic strategies. PMID:25697355

  8. Aspects of astrocyte energy metabolism, amino acid neurotransmitter homoeostasis and metabolic compartmentation.

    PubMed

    Kreft, Marko; Bak, Lasse K; Waagepetersen, Helle S; Schousboe, Arne

    2012-04-27

    Astrocytes are key players in brain function; they are intimately involved in neuronal signalling processes and their metabolism is tightly coupled to that of neurons. In the present review, we will be concerned with a discussion of aspects of astrocyte metabolism, including energy-generating pathways and amino acid homoeostasis. A discussion of the impact that uptake of neurotransmitter glutamate may have on these pathways is included along with a section on metabolic compartmentation.

  9. Metabolic profiling of breast cancer: Differences in central metabolism between subtypes of breast cancer cell lines.

    PubMed

    Willmann, Lucas; Schlimpert, Manuel; Halbach, Sebastian; Erbes, Thalia; Stickeler, Elmar; Kammerer, Bernd

    2015-09-01

    Although the concept of aerobic glycolysis in cancer was already reported in the 1930s by Otto Warburg, the understanding of metabolic pathways remains challenging especially due to the heterogeneity of cancer. In consideration of four different time points (1, 2, 4, and 7 days of incubation), GC-MS profiling of metabolites was performed on cell extracts and supernatants of breast cancer cell lines (MDA-MB-231, -453, BT-474) with different sub classification and the breast epithelial cell line MCF-10A. To the exclusion of trypsinization, direct methanolic extraction, cell scraping and cell disruption was executed to obtain central metabolites. Major differences in biochemical pathways have been observed in the breast cancer cell lines compared to the breast epithelial cell line, as well as between the breast cancer cell lines themselves. Characteristics of breast cancer subtypes could be correlated to their individual metabolic profiles. PLS-DA revealed the discrimination of breast cancer cell lines from MCF-10A based on elevated amino acid levels. The observed metabolic signatures have great potential as biomarker for breast cancer as well as an improved understanding of subtype specific phenomenons of breast cancer. PMID:26218769

  10. Decreased consumption of branched chain amino acids improves metabolic health

    PubMed Central

    Arriola Apelo, Sebastian I.; Neuman, Joshua C.; Kasza, Ildiko; Schmidt, Brian A.; Cava, Edda; Spelta, Francesco; Tosti, Valeria; Syed, Faizan A.; Baar, Emma L.; Veronese, Nicola; Cottrell, Sara E.; Fenske, Rachel J.; Bertozzi, Beatrice; Brar, Harpreet K.; Pietka, Terri; Bullock, Arnold D.; Figenshau, Robert S.; Andriole, Gerald L.; Merrins, Matthew J.; Alexander, Caroline M.; Kimple, Michelle E.; Lamming, Dudley W.

    2016-01-01

    Protein restricted, high carbohydrate diets improve metabolic health in rodents, yet the precise dietary components that are responsible for these effects have not been identified. Further, the applicability of these studies to humans is unclear. Here, we demonstrate in a randomized controlled trial that a moderately protein restricted (PR) diet also improves markers of metabolic health in humans. Intriguingly, we find that feeding mice a diet specifically reduced in branched chain amino acids (BCAAs) is sufficient to improve glucose tolerance and body composition equivalently to a PR diet, via metabolically distinct pathways. Our results highlight a critical role for dietary quality at the level of amino acids in the maintenance of metabolic health, and suggest that diets specifically reduced in BCAAs, or pharmacological interventions in this pathway, may offer a translatable way to achieve many of the metabolic benefits of a PR diet. PMID:27346343

  11. DNA Tumor Viruses and Cell Metabolism

    PubMed Central

    Mushtaq, Muhammad; Darekar, Suhas

    2016-01-01

    Viruses play an important role in cancerogenesis. It is estimated that approximately 20% of all cancers are linked to infectious agents. The viral genes modulate the physiological machinery of infected cells that lead to cell transformation and development of cancer. One of the important adoptive responses by the cancer cells is their metabolic change to cope up with continuous requirement of cell survival and proliferation. In this review we will focus on how DNA viruses alter the glucose metabolism of transformed cells. Tumor DNA viruses enhance “aerobic” glycolysis upon virus-induced cell transformation, supporting rapid cell proliferation and showing the Warburg effect. Moreover, viral proteins enhance glucose uptake and controls tumor microenvironment, promoting metastasizing of the tumor cells. PMID:27034740

  12. An integrated metabonomics and transcriptomics approach to understanding metabolic pathway disturbance induced by perfluorooctanoic acid.

    PubMed

    Peng, Siyuan; Yan, Lijuan; Zhang, Jie; Wang, Zhanlin; Tian, Meiping; Shen, Heqing

    2013-12-01

    Perfluorooctanoic acid (PFOA) is one of the most representative perfluorinated compounds and liver is the major organ where PFOA is accumulated. Although the multiple toxicities had been reported, its toxicological profile remained unclear. In this study, a systems toxicology strategy integrating liquid chromatography/mass spectrometry-based metabonomics and transcriptomics analyses was applied for the first time to investigate the effects of PFOA on a representative Chinese normal human liver cell line L-02, with focusing on the metabolic disturbance. Fifteen potential biomarkers were identified on metabolic level and most observations were consistent with the altered levels of gene expression. Our results showed that PFOA induced the perturbations in various metabolic processes in L-02 cells, especially lipid metabolism-related pathways. The up-stream mitochondrial carnitine metabolism was proved to be influenced by PFOA treatment. The specific transformation from carnitine to acylcarnitines, which showed a dose-dependent effect, and the expression level of key genes involved in this pathway were observed to be altered correspondingly. Furthermore, the down-stream cholesterol biosynthesis was directly confirmed to be up-regulated by both increased cholesterol content and elevated expression level of key genes. The PFOA-induced lipid metabolism-related effects in L-02 cells started from the fatty acid catabolism in cytosol, fluctuated to the processes in mitochondria, extended to the cholesterol biosynthesis. Many other metabolic pathways like amino acid metabolism and tricarboxylic acid cycle might also be disturbed. The findings obtained from the systems biological research provide more details about metabolic disorders induced by PFOA in human liver.

  13. Natural toxins that affect plant amino acid metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A diverse range of natural compounds interfere with the synthesis and other aspects of amino acid metabolism. Some are amino acid analogues, but most are not. This review covers a number of specific natural phytotoxic compounds by molecular target site. Inhibition of glutamine synthetase is of part...

  14. Protein and amino acid metabolism in the human newborn.

    PubMed

    Kalhan, Satish C; Bier, Dennis M

    2008-01-01

    Birth and adaptation to extrauterine life involve major shifts in the protein and energy metabolism of the human newborn. These include a shift from a state of continuous supply of nutrients including amino acids from the mother to cyclic periodic oral intake, a change in the redox state of organs, thermogenesis, and a significant change in the mobilization and use of oxidative substrates. The development of safe, stable isotopic tracer methods has allowed the study of protein and amino acid metabolism not only in the healthy newborn but also in those born prematurely and of low birth weight. These studies have identified the unique and quantitative aspects of amino acid/protein metabolism in the neonate, thus contributing to rational nutritional care of these babies. The present review summarizes the contemporary data on some of the significant developments in essential and dispensable amino acids and their relationship to overall protein metabolism. Specifically, the recent data of kinetics of leucine, phenylalanine, glutamine, sulfur amino acid, and threonine and their relation to whole-body protein turnover are presented. Finally, the physiological rationale and the impact of nutrient (amino acids) interventions on the dynamics of protein metabolism are discussed.

  15. Phytanic acid metabolism in health and disease.

    PubMed

    Wanders, Ronald J A; Komen, Jasper; Ferdinandusse, Sacha

    2011-09-01

    Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) is a branched-chain fatty acid which cannot be beta-oxidized due to the presence of the first methyl group at the 3-position. Instead, phytanic acid undergoes alpha-oxidation to produce pristanic acid (2,6,10,14-tetramethylpentadecanoic acid) plus CO(2). Pristanic acid is a 2-methyl branched-chain fatty acid which can undergo beta-oxidation via sequential cycles of beta-oxidation in peroxisomes and mitochondria. The mechanism of alpha-oxidation has been resolved in recent years as reviewed in this paper, although some of the individual enzymatic steps remain to be identified. Furthermore, much has been learned in recent years about the permeability properties of the peroxisomal membrane with important consequences for the alpha-oxidation process. Finally, we present new data on the omega-oxidation of phytanic acid making use of a recently generated mouse model for Refsum disease in which the gene encoding phytanoyl-CoA 2-hydroxylase has been disrupted.

  16. Macromolecular crowding explains overflow metabolism in cells

    PubMed Central

    Vazquez, Alexei; Oltvai, Zoltán N.

    2016-01-01

    Overflow metabolism is a metabolic phenotype of cells characterized by mixed oxidative phosphorylation (OxPhos) and fermentative glycolysis in the presence of oxygen. Recently, it was proposed that a combination of a protein allocation constraint and a higher proteome fraction cost of energy generation by OxPhos relative to fermentation form the basis of overflow metabolism in the bacterium, Escherichia coli. However, we argue that the existence of a maximum or optimal macromolecular density is another essential requirement. Here we re-evaluate our previous theory of overflow metabolism based on molecular crowding following the proteomic fractions formulation. We show that molecular crowding is a key factor in explaining the switch from OxPhos to overflow metabolism. PMID:27484619

  17. Metabolic engineering of carbon and redox flow in the production of small organic acids.

    PubMed

    Thakker, Chandresh; Martínez, Irene; Li, Wei; San, Ka-Yiu; Bennett, George N

    2015-03-01

    The review describes efforts toward metabolic engineering of production of organic acids. One aspect of the strategy involves the generation of an appropriate amount and type of reduced cofactor needed for the designed pathway. The ability to capture reducing power in the proper form, NADH or NADPH for the biosynthetic reactions leading to the organic acid, requires specific attention in designing the host and also depends on the feedstock used and cell energetic requirements for efficient metabolism during production. Recent work on the formation and commercial uses of a number of small mono- and diacids is discussed with redox differences, major biosynthetic precursors and engineering strategies outlined. Specific attention is given to those acids that are used in balancing cell redox or providing reduction equivalents for the cell, such as formate, which can be used in conjunction with metabolic engineering of other products to improve yields. Since a number of widely studied acids derived from oxaloacetate as an important precursor, several of these acids are covered with the general strategies and particular components summarized, including succinate, fumarate and malate. Since malate and fumarate are less reduced than succinate, the availability of reduction equivalents and level of aerobiosis are important parameters in optimizing production of these compounds in various hosts. Several other more oxidized acids are also discussed as in some cases, they may be desired products or their formation is minimized to afford higher yields of more reduced products. The placement and connections among acids in the typical central metabolic network are presented along with the use of a number of specific non-native enzymes to enhance routes to high production, where available alternative pathways and strategies are discussed. While many organic acids are derived from a few precursors within central metabolism, each organic acid has its own special requirements for high

  18. Regulatory mechanism of protein metabolic pathway during the differentiation process of chicken male germ cell.

    PubMed

    Li, Dong; Zuo, Qisheng; Lian, Chao; Zhang, Lei; Shi, Qingqing; Zhang, Zhentao; Wang, Yingjie; Ahmed, Mahmoud F; Tang, Beibei; Xiao, Tianrong; Zhang, Yani; Li, Bichun

    2015-08-01

    We explored the regulatory mechanism of protein metabolism during the differentiation process of chicken male germ cells and provide a basis for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro. We sequenced the transcriptome of embryonic stem cells, primordial germ cells, and spermatogonial stem cells with RNA sequencing (RNA-Seq), bioinformatics analysis methods, and detection of the key genes by quantitative reverse transcription PCR (qRT-PCR). Finally, we found 16 amino acid metabolic pathways enriched in the biological metabolism during the differentiation process of embryonic stem cells to primordial germ cells and 15 amino acid metabolic pathways enriched in the differentiation stage of primordial germ cells to spermatogonial stem cells. We found three pathways, arginine-proline metabolic pathway, tyrosine metabolic pathway, and tryptophan metabolic pathway, significantly enriched in the whole differentiation process of embryonic stem cells to spermatogonial stem cells. Moreover, for these three pathways, we screened key genes such as NOS2, ADC, FAH, and IDO. qRT-PCR results showed that the expression trend of these genes were the same to RNA-Seq. Our findings showed that the three pathways and these key genes play an important role in the differentiation process of embryonic stem cells to male germ cells. These results provide basic information for improving the induction system of embryonic stem cell differentiation to male germ cells in vitro.

  19. Therapeutic strategies impacting cancer cell glutamine metabolism

    PubMed Central

    Lukey, Michael J; Wilson, Kristin F; Cerione, Richard A

    2014-01-01

    The metabolic adaptations that support oncogenic growth can also render cancer cells dependent on certain nutrients. Along with the Warburg effect, increased utilization of glutamine is one of the metabolic hallmarks of the transformed state. Glutamine catabolism is positively regulated by multiple oncogenic signals, including those transmitted by the Rho family of GTPases and by c-Myc. The recent identification of mechanistically distinct inhibitors of glutaminase, which can selectively block cellular transformation, has revived interest in the possibility of targeting glutamine metabolism in cancer therapy. Here, we outline the regulation and roles of glutamine metabolism within cancer cells and discuss possible strategies for, and the consequences of, impacting these processes therapeutically. PMID:24047273

  20. Drosophila melanogaster as a model system to study long-chain fatty acid amide metabolism

    PubMed Central

    Jeffries, Kristen A.; Dempsey, Daniel R.; Behari, Anita L.; Anderson, Ryan L.; Merkler, David J.

    2014-01-01

    Long-chain fatty acid amides are cell-signaling lipids identified in mammals and, recently, in invertebrates, as well. Many details regarding fatty acid amide metabolism remain unclear. Herein, we demonstrate that Drosophila melanogaster is an excellent model system for the study long-chain fatty acid amide metabolism as we have quantified the endogenous levels of N-acylglycines, N-acyldopamines, N-acylethanolamines, and primary fatty acid amides by LC/QTOF-MS. Growth of Drosophila melanogaster on media supplemented with [1-13C]-palmitate lead to a family of 13C-palmitate-labeled fatty acid amides in the fly heads. The [1-13C]-palmitate feeding studies provide insight into the biosynthesis of the fatty acid amides. PMID:24650760

  1. Metabolic reprogramming in macrophages and dendritic cells in innate immunity

    PubMed Central

    Kelly, Beth; O'Neill, Luke AJ

    2015-01-01

    Activation of macrophages and dendritic cells (DCs) by pro-inflammatory stimuli causes them to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS), similar to the Warburg effect in tumors. However, it is only recently that the mechanisms responsible for this metabolic reprogramming have been elucidated in more detail. The transcription factor hypoxia-inducible factor-1α (HIF-1α) plays an important role under conditions of both hypoxia and normoxia. The withdrawal of citrate from the tricarboxylic acid (TCA) cycle has been shown to be critical for lipid biosynthesis in both macrophages and DCs. Interference with this process actually abolishes the ability of DCs to activate T cells. Another TCA cycle intermediate, succinate, activates HIF-1α and promotes inflammatory gene expression. These new insights are providing us with a deeper understanding of the role of metabolic reprogramming in innate immunity. PMID:26045163

  2. Metabolism of sulfur amino acids in Saccharomyces cerevisiae.

    PubMed Central

    Thomas, D; Surdin-Kerjan, Y

    1997-01-01

    , the transcription activation function of Met4 is prevented by Met30p, which binds to the Met4 inhibitory region. In addition to the Cbf1p-Met4p-Met28p complex, transcriptional regulation involves two zinc finger-containing proteins, Met31p and Met32p. The AdoMet-mediated control of the sulfur amino acid pathway illustrates the molecular strategies used by eucaryotic cells to couple gene expression to metabolic changes. PMID:9409150

  3. ERK2 mediates metabolic stress response to regulate cell fate

    PubMed Central

    Shin, Sejeong; Buel, Gwen R.; Wolgamott, Laura; Plas, David R.; Asara, John M.; Blenis, John; Yoon, Sang-Oh

    2015-01-01

    Insufficient nutrients disrupt physiological homeostasis resulting in diseases and even death. Considering the physiological and pathological consequences of this metabolic stress, the adaptive responses that cells utilize under this condition are of great interest. We show that under low glucose conditions, cells initiate adaptation followed by apoptosis responses using PERK/Akt and MEK1/ERK2 signaling, respectively. For adaptation, cells engage the endoplasmic reticulum stress-induced unfolded protein response, which results in PERK/Akt activation and cell survival. Sustained and extreme energetic stress promotes a switch to isoform-specific MEK1/ERK2 signaling, induction of GCN2/eIF2α phosphorylation and ATF4 expression, which overrides PERK/Akt-mediated adaptation and induces apoptosis through ATF4-dependent expression of pro-apoptotic factors including Bid and Trb3. ERK2 activation during metabolic stress contributes to changes in TCA cycle and amino acid metabolism, and cell death, which is suppressed by glutamate and α-ketoglutarate supplementation. Taken together, our results reveal promising targets to protect cells or tissues from metabolic stress. PMID:26190261

  4. Phasor FLIM metabolic mapping of stem cells and cancer cells in live tissues

    NASA Astrophysics Data System (ADS)

    Stringari, Chiara; Donovan, Peter; Gratton, Enrico

    2012-03-01

    We use the phasor approach to fluorescence lifetime imaging and intrinsic biochemical fluorescence biomarkers in conjunction with image segmentation and the concept of cell phasor for deriving metabolic maps of cells and living tissues in vivo. In issues we identify and separate intrinsic fluorophores such as collagen, retinol, retinoic acid, porphyrin, flavins, free and bound nicotinamide adenine dinucleotide (NADH). Metabolic signatures of tissues are obtained by calculating the phasor fingerprint of single cells and by mapping the relative concentration of metabolites. This method detects small changes in metabolic signatures and redox states of cells. Phasor fingerprints of stem cells cluster according to their differentiation state in a living tissue such as the C. elegans germ line and the crypt base of small intestine and colon. Phasor FLIM provides a label-free and fit-free sensitive method to identify metabolic states of cells and to classify stem cells, normal differentiated cells and cancer cells both in vitro and in a live tissue. Our method could identify symmetric and asymmetric divisions, predict cell fate and identify pre-cancer stages in vivo. This method is a promising non-invasive optical tool for monitoring metabolic pathways during differentiation and carcinogenesis, for cell sorting and high throughput screening.

  5. Gallic acid and gallic acid derivatives: effects on drug metabolizing enzymes.

    PubMed

    Ow, Yin-Yin; Stupans, Ieva

    2003-06-01

    Gallic acid and its structurally related compounds are found widely distributed in fruits and plants. Gallic acid, and its catechin derivatives are also present as one of the main phenolic components of both black and green tea. Esters of gallic acid have a diverse range of industrial uses, as antioxidants in food, in cosmetics and in the pharmaceutical industry. In addition, gallic acid is employed as a source material for inks, paints and colour developers. Studies utilising these compounds have found them to possess many potential therapeutic properties including anti-cancer and antimicrobial properties. In this review, studies of the effects of gallic acid, its esters, and gallic acid catechin derivatives on Phase I and Phase II enzymes are examined. Many published reports of the effects of the in vitro effects of gallic acid and its derivatives on drug metabolising enzymes concern effects directly on substrate (generally drug or mutagen) metabolism or indirectly through observed effects in Ames tests. In the case of the Ames test an antimutagenic effect may be observed through inhibition of CYP activation of indirectly acting mutagens and/or by scavenging of metabolically generated mutagenic electrophiles. There has been considerable interest in the in vivo effects of the gallate esters because of their incorporation into foodstuffs as antioxidants and in the catechin gallates with their potential role as chemoprotective agents. Principally an induction of Phase II enzymes has been observed however more recent studies using HepG2 cells and primary cultures of human hepatocytes provide evidence for the overall complexity of actions of individual components versus complex mixtures, such as those in food. Further systematic studies of mechanisms of induction and inhibition of drug metabolising enzymes by this group of compounds are warranted in the light of their distribution and consequent ingestion, current uses and suggested therapeutic potential. However, it

  6. Effect of pentoxifylline on arachidonic acid metabolism, neutral lipid synthesis and accumulation during induction of the lipocyte phenotype by retinol in murine hepatic stellate cell.

    PubMed

    Cardoso, Carla C A; Paviani, Ernani R; Cruz, Lavínia A; Guma, Fátima C R; Borojevic, Radovan; Guaragna, Regina M

    2003-12-01

    In liver fibrosis, the quiescent hepatic stellate cells (HSC) are activated to proliferate and express the activated myofibroblast phenotype, losing fat droplets and the stored vitamin A, and depositing more extracellular matrix. Therapeutic strategies for liver fibrosis are focused on HSC. Pentoxifylline (PTF), an analog of the methylxanthine, prevents the biochemical and histological changes associated with animal liver fibrosis. The aim of the present study was to investigate the phenotypic change of myofibroblasts into quiescent lipocytes by PTF and/or retinol, using a permanent cell line GRX that represents murine HSC. We studied the action of both drugs on the synthesis of neutral lipids, activity of phospholipase A2 (PLA2), release of arachidonic acid (AA) and prostaglandins synthesis. Accumulation and synthesis of neutral lipids was dependent upon association of retinol with PTF. PTF (0.5 mg/mL) alone did not induce lipid accumulation and synthesis, but in cells induced by physiologic concentration of retinol (1-2.5 microM), it increased the quantity of stored lipids. Retinol and PTF (5 microM and 0.1 mg/mL, respectively) had a synergistic effect on neutral lipid synthesis and accumulation. In higher PTF concentrations (0.5 and 0.7 mg/ml), the synthesis was stimulated but accumulation decreased. Membrane-associated PLA2 activity decreased after PTF treatment, which increased the AA release 8 fold, and significantly increased the production of PGE2, but not of PGF2. However, when in presence of retinol, we observed a slightly higher increase in PGE2 and PGF2a production. In conclusion, PTF treatment generated an excess of free AA. We propose that retinol counteracts the action of PTF on the AA release and PGs production, even though both drugs stimulated the lipocyte induction in the HSC. PMID:14674680

  7. Cell signalling and phospholipid metabolism

    SciTech Connect

    Boss, W.F.

    1990-01-01

    These studies explored whether phosphoinositide (PI) has a role in plants analogous to its role in animal cells. Although no parallel activity of PI in signal transduction was found in plant cells, activity of inositol phospholipid kinase was found to be modulated by light and by cell wall degrading enzymes. These studies indicate a major role for inositol phospholipids in plant growth and development as membrane effectors but not as a source of second messengers.

  8. Deficits in docosahexaenoic acid and associated elevations in the metabolism of arachidonic acid and saturated fatty acids in the postmortem orbitofrontal cortex of patients with bipolar disorder

    PubMed Central

    McNamara, Robert K.; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Stanford, Kevin E.; Hahn, Chang-Gyu; Richtand, Neil M.

    2008-01-01

    Previous antemortem and postmortem tissue fatty acid composition studies have observed significant deficits in the omega-3 fatty acid docosahexaenoic acid (DHA, 22:6n-3) in red blood cell (RBC) and postmortem cortical membranes of patients with unipolar depression. In the present we determined the fatty acid composition of postmortem orbitofrontal cortex (OFC, Brodmann area 10) of patients with bipolar disorder (n=18) and age-matched normal controls (n=19) by gas chromatography. After correction for multiple comparisons, DHA (-24%), arachidonic acid (-14%), and stearic acid (C18:0)(-4.5%) compositions were significantly lower, and cis-vaccenic acid (18:1n-7)(+12.5%) composition significantly higher, in the OFC of bipolar patients relative to normal controls. Based on metabolite:precursor ratios, significant elevations in arachidonic acid, stearic acid, and palmitic acid conversion/metabolism were observed in the OFC of bipolar patients, and were inversely correlated with DHA composition. Deficits in OFC DHA and arachidonic acid composition, and elevations in arachidonic acid metabolism, were numerically (but not significantly) greater in drug-free bipolar patients relative to patients treated with mood-stabilizer or antipsychotic medications. OFC DHA and arachidonic acid deficits were greater in patients plus normal controls with high versus low alcohol abuse severity. These results add to a growing body of evidence implicating omega-3 fatty acid deficiency as well as the OFC in the pathoaetiology of bipolar disorder. PMID:18715653

  9. Volatile profiling reveals intracellular metabolic changes in Aspergillus parasiticus: veA regulates branched chain amino acid and ethanol metabolism

    PubMed Central

    2010-01-01

    Background Filamentous fungi in the genus Aspergillus produce a variety of natural products, including aflatoxin, the most potent naturally occurring carcinogen known. Aflatoxin biosynthesis, one of the most highly characterized secondary metabolic pathways, offers a model system to study secondary metabolism in eukaryotes. To control or customize biosynthesis of natural products we must understand how secondary metabolism integrates into the overall cellular metabolic network. By applying a metabolomics approach we analyzed volatile compounds synthesized by Aspergillus parasiticus in an attempt to define the association of secondary metabolism with other metabolic and cellular processes. Results Volatile compounds were examined using solid phase microextraction - gas chromatography/mass spectrometry. In the wild type strain Aspergillus parasiticus SU-1, the largest group of volatiles included compounds derived from catabolism of branched chain amino acids (leucine, isoleucine, and valine); we also identified alcohols, esters, aldehydes, and lipid-derived volatiles. The number and quantity of the volatiles produced depended on media composition, time of incubation, and light-dark status. A block in aflatoxin biosynthesis or disruption of the global regulator veA affected the volatile profile. In addition to its multiple functions in secondary metabolism and development, VeA negatively regulated catabolism of branched chain amino acids and synthesis of ethanol at the transcriptional level thus playing a role in controlling carbon flow within the cell. Finally, we demonstrated that volatiles generated by a veA disruption mutant are part of the complex regulatory machinery that mediates the effects of VeA on asexual conidiation and sclerotia formation. Conclusions 1) Volatile profiling provides a rapid, effective, and powerful approach to identify changes in intracellular metabolic networks in filamentous fungi. 2) VeA coordinates the biosynthesis of secondary

  10. Tumor microenvironment derived exosomes pleiotropically modulate cancer cell metabolism

    PubMed Central

    Zhao, Hongyun; Yang, Lifeng; Baddour, Joelle; Achreja, Abhinav; Bernard, Vincent; Moss, Tyler; Marini, Juan C; Tudawe, Thavisha; Seviour, Elena G; San Lucas, F Anthony; Alvarez, Hector; Gupta, Sonal; Maiti, Sourindra N; Cooper, Laurence; Peehl, Donna; Ram, Prahlad T; Maitra, Anirban; Nagrath, Deepak

    2016-01-01

    Cancer-associated fibroblasts (CAFs) are a major cellular component of tumor microenvironment in most solid cancers. Altered cellular metabolism is a hallmark of cancer, and much of the published literature has focused on neoplastic cell-autonomous processes for these adaptations. We demonstrate that exosomes secreted by patient-derived CAFs can strikingly reprogram the metabolic machinery following their uptake by cancer cells. We find that CAF-derived exosomes (CDEs) inhibit mitochondrial oxidative phosphorylation, thereby increasing glycolysis and glutamine-dependent reductive carboxylation in cancer cells. Through 13C-labeled isotope labeling experiments we elucidate that exosomes supply amino acids to nutrient-deprived cancer cells in a mechanism similar to macropinocytosis, albeit without the previously described dependence on oncogenic-Kras signaling. Using intra-exosomal metabolomics, we provide compelling evidence that CDEs contain intact metabolites, including amino acids, lipids, and TCA-cycle intermediates that are avidly utilized by cancer cells for central carbon metabolism and promoting tumor growth under nutrient deprivation or nutrient stressed conditions. DOI: http://dx.doi.org/10.7554/eLife.10250.001 PMID:26920219

  11. Tumor microenvironment derived exosomes pleiotropically modulate cancer cell metabolism.

    PubMed

    Zhao, Hongyun; Yang, Lifeng; Baddour, Joelle; Achreja, Abhinav; Bernard, Vincent; Moss, Tyler; Marini, Juan C; Tudawe, Thavisha; Seviour, Elena G; San Lucas, F Anthony; Alvarez, Hector; Gupta, Sonal; Maiti, Sourindra N; Cooper, Laurence; Peehl, Donna; Ram, Prahlad T; Maitra, Anirban; Nagrath, Deepak

    2016-01-01

    Cancer-associated fibroblasts (CAFs) are a major cellular component of tumor microenvironment in most solid cancers. Altered cellular metabolism is a hallmark of cancer, and much of the published literature has focused on neoplastic cell-autonomous processes for these adaptations. We demonstrate that exosomes secreted by patient-derived CAFs can strikingly reprogram the metabolic machinery following their uptake by cancer cells. We find that CAF-derived exosomes (CDEs) inhibit mitochondrial oxidative phosphorylation, thereby increasing glycolysis and glutamine-dependent reductive carboxylation in cancer cells. Through 13C-labeled isotope labeling experiments we elucidate that exosomes supply amino acids to nutrient-deprived cancer cells in a mechanism similar to macropinocytosis, albeit without the previously described dependence on oncogenic-Kras signaling. Using intra-exosomal metabolomics, we provide compelling evidence that CDEs contain intact metabolites, including amino acids, lipids, and TCA-cycle intermediates that are avidly utilized by cancer cells for central carbon metabolism and promoting tumor growth under nutrient deprivation or nutrient stressed conditions. PMID:26920219

  12. Biobased organic acids production by metabolically engineered microorganisms.

    PubMed

    Chen, Yun; Nielsen, Jens

    2016-02-01

    Bio-based production of organic acids via microbial fermentation has been traditionally used in food industry. With the recent desire to develop more sustainable bioprocesses for production of fuels, chemicals and materials, the market for microbial production of organic acids has been further expanded as organic acids constitute a key group among top building block chemicals that can be produced from renewable resources. Here we review the current status for production of citric acid and lactic acid, and we highlight the use of modern metabolic engineering technologies to develop high performance microbes for production of succinic acid and 3-hydroxypropionic acid. Also, the key limitations and challenges in microbial organic acids production are discussed. PMID:26748037

  13. Cytochrome P450 epoxygenase pathway of polyunsaturated fatty acid metabolism

    PubMed Central

    Spector, Arthur A.; Kim, Hee-Yong

    2014-01-01

    Polyunsaturated fatty acids (PUFA) are oxidized by cytochrome P450 epoxygenases to PUFA epoxides which function as potent lipid mediators. The major metabolic pathways of PUFA epoxides are incorporation into phospholipids and hydrolysis to the corresponding PUFA diols by soluble epoxide hydrolase. Inhibitors of soluble epoxide hydrolase stabilize PUFA epoxides and potentiate their functional effects. The epoxyeicosatrienoic acids (EETs) synthesized from arachidonic acid produce vasodilation, stimulate angiogenesis, have anti-inflammatory actions, and protect the heart against ischemia-reperfusion injury. EETs produce these functional effects by activating receptor-mediated signaling pathways and ion channels. The epoxyeicosatetraenoic acids synthesized from eicosapentaenoic acid and epoxydocosapentaenoic acids synthesized from docosahexaenoic acid are potent inhibitors of cardiac arrhythmias. Epoxydocosapentaenoic acids also inhibit angiogenesis, decrease inflammatory and neuropathic pain, and reduce tumor metastasis. These findings indicate that a number of the beneficial functions of PUFA may be due to their conversion to PUFA epoxides. PMID:25093613

  14. Epicatechin gallate impairs colon cancer cell metabolic productivity.

    PubMed

    Sánchez-Tena, Susana; Alcarraz-Vizán, Gema; Marín, Silvia; Torres, Josep Lluís; Cascante, Marta

    2013-05-01

    Green tea and grape phenolics inhibit cancer growth and modulate cellular metabolism. Targeting the tumor metabolic profile is a novel therapeutic approach to inhibit cancer cell proliferation. Therefore, we treated human colon adenocarcinoma HT29 cells with the phenolic compound epicatechin gallate (ECG), one of the main catechins in green tea and the most important catechin in grape extracts, and evaluated its antiproliferation effects. ECG reduced tumor viability and induced apoptosis, necrosis, and S phase arrest in HT29 cells. Later, biochemical determinations combined with mass isotopomer distribution analysis using [1,2-(13)C2]-D-glucose as a tracer were used to characterize the metabolic network of HT29 cells in response to different concentrations of ECG. Glucose consumption was importantly decreased after ECG treatment. Moreover, metabolization of [1,2-(13)C2]-D-glucose indicated that the de novo synthesis of fatty acids and the pentose phosphate pathway were reduced in ECG-treated cells. Interestingly, ECG inhibited the activity of transketolase and glucose-6-phosphate dehydrogenase, the key enzymes of the pentose phosphate pathway. Our data point to ECG as a promising chemotherapeutic agent for the treatment of colon cancer.

  15. Metabolism of gambogic acid in rats: a rare intestinal metabolic pathway responsible for its final disposition.

    PubMed

    Yang, Jing; Ding, Li; Hu, Linlin; Qian, Wenjuan; Jin, Shaohong; Sun, Xiaoping; Wang, Zhenzhong; Xiao, Wei

    2011-04-01

    Gambogic acid (GA) is a promising natural anticancer candidate. Although the anticancer activity of GA has been well demonstrated, information regarding the metabolic fate of GA is limited. Previous studies suggested that GA is mainly excreted into intestinal tract in rats through bile after intravenous administration, whereas only traces appeared in the feces, suggesting that GA is metabolized extensively in the intestine. However, there has been no report about the intestinal metabolism of GA either in animals or humans. In this study, large amounts of two sulfonic acid metabolites of GA were found in the feces samples of rats after intravenous administration, and their structures were identified as 10-α sulfonic acid GA and 10-β sulfonic acid GA by comparison of the retention times and spectral data with those of synthesized reference substances using liquid chromatography-diode array detector-tandem mass spectrometry. This rare intestinal metabolic pathway mainly involves Michael addition of the sulfite ion to the 9,10 carbon-carbon double bond of α,β-unsaturated ketone. In addition, a more detailed metabolic profile in rats is proposed, according to the results of in vitro and in vivo studies. It was found that GA can be metabolized by a variety of routes, including monooxidation, hydration, glutathionylation, glucuronidation, and glucosidation in the liver of rats. These findings provide information on the major metabolic soft spot of GA in the intestine and liver of rats, which is not only useful in the future human metabolic study of this compound but also of value in the metabolic studies of GA analogs.

  16. Leptin regulates energy metabolism in MCF-7 breast cancer cells.

    PubMed

    Blanquer-Rosselló, Maria del Mar; Oliver, Jordi; Sastre-Serra, Jorge; Valle, Adamo; Roca, Pilar

    2016-03-01

    Obesity is known to be a poorer prognosis factor for breast cancer in postmenopausal women. Among the diverse endocrine factors associated to obesity, leptin has received special attention since it promotes breast cancer cell growth and invasiveness, processes which force cells to adapt their metabolism to satisfy the increased demands of energy and biosynthetic intermediates. Taking this into account, our aim was to explore the effects of leptin in the metabolism of MCF-7 breast cancer cells. Polarographic analysis revealed that leptin increased oxygen consumption rate and cellular ATP levels were more dependent on mitochondrial oxidative metabolism in leptin-treated cells compared to the more glycolytic control cells. Experiments with selective inhibitors of glycolysis (2-DG), fatty acid oxidation (etomoxir) or aminoacid deprivation showed that ATP levels were more reliant on fatty acid oxidation. In agreement, levels of key proteins involved in lipid catabolism (FAT/CD36, CPT1, PPARα) and phosphorylation of the energy sensor AMPK were increased by leptin. Regarding glucose, cellular uptake was not affected by leptin, but lactate release was deeply repressed. Analysis of pyruvate dehydrogenase (PDH), lactate dehydrogenase (LDH) and pyruvate carboxylase (PC) together with the pentose-phosphate pathway enzyme glucose-6 phosphate dehydrogenase (G6PDH) revealed that leptin favors the use of glucose for biosynthesis. These results point towards a role of leptin in metabolic reprogramming, consisting of an enhanced use of glucose for biosynthesis and lipids for energy production. This metabolic adaptations induced by leptin may provide benefits for MCF-7 growth and give support to the reverse Warburg effect described in breast cancer. PMID:26772821

  17. Leptin regulates energy metabolism in MCF-7 breast cancer cells.

    PubMed

    Blanquer-Rosselló, Maria del Mar; Oliver, Jordi; Sastre-Serra, Jorge; Valle, Adamo; Roca, Pilar

    2016-03-01

    Obesity is known to be a poorer prognosis factor for breast cancer in postmenopausal women. Among the diverse endocrine factors associated to obesity, leptin has received special attention since it promotes breast cancer cell growth and invasiveness, processes which force cells to adapt their metabolism to satisfy the increased demands of energy and biosynthetic intermediates. Taking this into account, our aim was to explore the effects of leptin in the metabolism of MCF-7 breast cancer cells. Polarographic analysis revealed that leptin increased oxygen consumption rate and cellular ATP levels were more dependent on mitochondrial oxidative metabolism in leptin-treated cells compared to the more glycolytic control cells. Experiments with selective inhibitors of glycolysis (2-DG), fatty acid oxidation (etomoxir) or aminoacid deprivation showed that ATP levels were more reliant on fatty acid oxidation. In agreement, levels of key proteins involved in lipid catabolism (FAT/CD36, CPT1, PPARα) and phosphorylation of the energy sensor AMPK were increased by leptin. Regarding glucose, cellular uptake was not affected by leptin, but lactate release was deeply repressed. Analysis of pyruvate dehydrogenase (PDH), lactate dehydrogenase (LDH) and pyruvate carboxylase (PC) together with the pentose-phosphate pathway enzyme glucose-6 phosphate dehydrogenase (G6PDH) revealed that leptin favors the use of glucose for biosynthesis. These results point towards a role of leptin in metabolic reprogramming, consisting of an enhanced use of glucose for biosynthesis and lipids for energy production. This metabolic adaptations induced by leptin may provide benefits for MCF-7 growth and give support to the reverse Warburg effect described in breast cancer.

  18. CLOCK genetic variation and metabolic syndrome risk: modulation by monounsaturated fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Disruption of the circadian system may be causal for manifestations of Metabolic Syndrome (MetS). Objective: To study the associations of five CLOCK polymorphisms with MetS features considering fatty acid (FA) composition, from dietary and red-blood-cells (RBC) membrane sources. Design: ...

  19. Amino acid metabolism during prolonged starvation

    PubMed Central

    Felig, Philip; Owen, Oliver E.; Wahren, John; Cahill, George F.

    1969-01-01

    Plasma concentration, splanchnic and renal exchange, and urinary excretion of 20 amino acids were studied in obese subjects during prolonged (5-6 wk) starvation. Splanchnic amino acid uptake was also investigated in postabsorptive and briefly (36-48 hr) fasted subjects. A transient increase in plasma valine, leucine, isoleucine, methionine, and α-aminobutyrate was noted during the 1st wk of starvation. A delayed, progressive increase in glycine, threonine, and serine occurred after the 1st 5 days. 13 of the amino acids ultimately decreased in starvation, but the magnitude of this diminution was greatest for alanine which decreased most rapidly during the 1st week of fasting. In all subjects alanine was extracted by the splanchnic circulation to a greater extent than all other amino acids combined. Brief fasting resulted in an increased arterio-hepatic venous difference for alanine due to increased fractional extraction. After 5-6 wk of starvation, a marked falloff in splanchnic alanine uptake was attributable to the decreased arterial concentration. Prolonged fasting resulted in increased glycine utilization by the kidney and in net renal uptake of alanine. It is concluded that the marked decrease in plasma alanine is due to augmented and preferential splanchnic utilization of this amino acid in early starvation resulting in substrate depletion. Maintenance of the hypoalaninemia ultimately serves to diminish splanchnic uptake of this key glycogenic amino acid and is thus an important component of the regulatory mechanism whereby hepatic gluconeogenesis is diminished and protein catabolism is minimized in prolonged fasting. The altered renal extraction of glycine and alanine is not due to increased urinary excretion but may be secondary to the increased rate of renal gluconeogenesis observed in prolonged starvation. PMID:5773094

  20. Fatty acids from diet and microbiota regulate energy metabolism

    PubMed Central

    Alcock, Joe; Lin, Henry C.

    2015-01-01

    A high-fat diet and elevated levels of free fatty acids are known risk factors for metabolic syndrome, insulin resistance, and visceral obesity. Although these disease associations are well established, it is unclear how different dietary fats change the risk of insulin resistance and metabolic syndrome. Here, we review emerging evidence that insulin resistance and fat storage are linked to changes in the gut microbiota. The gut microbiota and intestinal barrier function, in turn, are highly influenced by the composition of fat in the diet. We review findings that certain fats (for example, long-chain saturated fatty acids) are associated with dysbiosis, impairment of intestinal barrier function, and metabolic endotoxemia. In contrast, other fatty acids, including short-chain and certain unsaturated fatty acids, protect against dysbiosis and impairment of barrier function caused by other dietary fats. These fats may promote insulin sensitivity by inhibiting metabolic endotoxemia and dysbiosis-driven inflammation. During dysbiosis, the modulation of metabolism by diet and microbiota may represent an adaptive process that compensates for the increased fuel demands of an activated immune system. PMID:27006755

  1. Metabolic alterations in renal cell carcinoma.

    PubMed

    Massari, Francesco; Ciccarese, Chiara; Santoni, Matteo; Brunelli, Matteo; Piva, Francesco; Modena, Alessandra; Bimbatti, Davide; Fantinel, Emanuela; Santini, Daniele; Cheng, Liang; Cascinu, Stefano; Montironi, Rodolfo; Tortora, Giampaolo

    2015-11-01

    Renal cell carcinoma (RCC) is a metabolic disease, being characterized by the dysregulation of metabolic pathways involved in oxygen sensing (VHL/HIF pathway alterations and the subsequent up-regulation of HIF-responsive genes such as VEGF, PDGF, EGF, and glucose transporters GLUT1 and GLUT4, which justify the RCC reliance on aerobic glycolysis), energy sensing (fumarate hydratase-deficient, succinate dehydrogenase-deficient RCC, mutations of HGF/MET pathway resulting in the metabolic Warburg shift marked by RCC increased dependence on aerobic glycolysis and the pentose phosphate shunt, augmented lipogenesis, and reduced AMPK and Krebs cycle activity) and/or nutrient sensing cascade (deregulation of AMPK-TSC1/2-mTOR and PI3K-Akt-mTOR pathways). We analyzed the key metabolic abnormalities underlying RCC carcinogenesis, highlighting those altered pathways that may represent potential targets for the development of more effective therapeutic strategies.

  2. Identification of the phytosphingosine metabolic pathway leading to odd-numbered fatty acids.

    PubMed

    Kondo, Natsuki; Ohno, Yusuke; Yamagata, Maki; Obara, Takashi; Seki, Naoya; Kitamura, Takuya; Naganuma, Tatsuro; Kihara, Akio

    2014-01-01

    The long-chain base phytosphingosine is a component of sphingolipids and exists in yeast, plants and some mammalian tissues. Phytosphingosine is unique in that it possesses an additional hydroxyl group compared with other long-chain bases. However, its metabolism is unknown. Here we show that phytosphingosine is metabolized to odd-numbered fatty acids and is incorporated into glycerophospholipids both in yeast and mammalian cells. Disruption of the yeast gene encoding long-chain base 1-phosphate lyase, which catalyzes the committed step in the metabolism of phytosphingosine to glycerophospholipids, causes an ~40% reduction in the level of phosphatidylcholines that contain a C15 fatty acid. We also find that 2-hydroxypalmitic acid is an intermediate of the phytosphingosine metabolic pathway. Furthermore, we show that the yeast MPO1 gene, whose product belongs to a large, conserved protein family of unknown function, is involved in phytosphingosine metabolism. Our findings provide insights into fatty acid diversity and identify a pathway by which hydroxyl group-containing lipids are metabolized. PMID:25345524

  3. Identification of the phytosphingosine metabolic pathway leading to odd-numbered fatty acids.

    PubMed

    Kondo, Natsuki; Ohno, Yusuke; Yamagata, Maki; Obara, Takashi; Seki, Naoya; Kitamura, Takuya; Naganuma, Tatsuro; Kihara, Akio

    2014-10-27

    The long-chain base phytosphingosine is a component of sphingolipids and exists in yeast, plants and some mammalian tissues. Phytosphingosine is unique in that it possesses an additional hydroxyl group compared with other long-chain bases. However, its metabolism is unknown. Here we show that phytosphingosine is metabolized to odd-numbered fatty acids and is incorporated into glycerophospholipids both in yeast and mammalian cells. Disruption of the yeast gene encoding long-chain base 1-phosphate lyase, which catalyzes the committed step in the metabolism of phytosphingosine to glycerophospholipids, causes an ~40% reduction in the level of phosphatidylcholines that contain a C15 fatty acid. We also find that 2-hydroxypalmitic acid is an intermediate of the phytosphingosine metabolic pathway. Furthermore, we show that the yeast MPO1 gene, whose product belongs to a large, conserved protein family of unknown function, is involved in phytosphingosine metabolism. Our findings provide insights into fatty acid diversity and identify a pathway by which hydroxyl group-containing lipids are metabolized.

  4. Metabolism of hydroxycinnamic acids and their tartaric acid esters by Brettanomyces and Pediococcus in red wines.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caffeic, p-coumaric, and ferulic acids and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric, respectively) are found in wines in varying concentrations. While Brettanomyces and Pediococcus can utilize the free acids, it is not known whether they can metabolize the correspon...

  5. Systematic identification of genes involved in metabolic acid stress resistance in yeast and their potential as cancer targets.

    PubMed

    Shin, John J; Aftab, Qurratulain; Austin, Pamela; McQueen, Jennifer A; Poon, Tak; Li, Shu Chen; Young, Barry P; Roskelley, Calvin D; Loewen, Christopher J R

    2016-09-01

    A hallmark of all primary and metastatic tumours is their high rate of glucose uptake and glycolysis. A consequence of the glycolytic phenotype is the accumulation of metabolic acid; hence, tumour cells experience considerable intracellular acid stress. To compensate, tumour cells upregulate acid pumps, which expel the metabolic acid into the surrounding tumour environment, resulting in alkalization of intracellular pH and acidification of the tumour microenvironment. Nevertheless, we have only a limited understanding of the consequences of altered intracellular pH on cell physiology, or of the genes and pathways that respond to metabolic acid stress. We have used yeast as a genetic model for metabolic acid stress with the rationale that the metabolic changes that occur in cancer that lead to intracellular acid stress are likely fundamental. Using a quantitative systems biology approach we identified 129 genes required for optimal growth under conditions of metabolic acid stress. We identified six highly conserved protein complexes with functions related to oxidative phosphorylation (mitochondrial respiratory chain complex III and IV), mitochondrial tRNA biosynthesis [glutamyl-tRNA(Gln) amidotransferase complex], histone methylation (Set1C-COMPASS), lysosome biogenesis (AP-3 adapter complex), and mRNA processing and P-body formation (PAN complex). We tested roles for two of these, AP-3 adapter complex and PAN deadenylase complex, in resistance to acid stress using a myeloid leukaemia-derived human cell line that we determined to be acid stress resistant. Loss of either complex inhibited growth of Hap1 cells at neutral pH and caused sensitivity to acid stress, indicating that AP-3 and PAN complexes are promising new targets in the treatment of cancer. Additionally, our data suggests that tumours may be genetically sensitized to acid stress and hence susceptible to acid stress-directed therapies, as many tumours accumulate mutations in mitochondrial respiratory chain

  6. Systematic identification of genes involved in metabolic acid stress resistance in yeast and their potential as cancer targets

    PubMed Central

    Shin, John J.; Aftab, Qurratulain; Austin, Pamela; McQueen, Jennifer A.; Poon, Tak; Li, Shu Chen; Young, Barry P.; Roskelley, Calvin D.

    2016-01-01

    ABSTRACT A hallmark of all primary and metastatic tumours is their high rate of glucose uptake and glycolysis. A consequence of the glycolytic phenotype is the accumulation of metabolic acid; hence, tumour cells experience considerable intracellular acid stress. To compensate, tumour cells upregulate acid pumps, which expel the metabolic acid into the surrounding tumour environment, resulting in alkalization of intracellular pH and acidification of the tumour microenvironment. Nevertheless, we have only a limited understanding of the consequences of altered intracellular pH on cell physiology, or of the genes and pathways that respond to metabolic acid stress. We have used yeast as a genetic model for metabolic acid stress with the rationale that the metabolic changes that occur in cancer that lead to intracellular acid stress are likely fundamental. Using a quantitative systems biology approach we identified 129 genes required for optimal growth under conditions of metabolic acid stress. We identified six highly conserved protein complexes with functions related to oxidative phosphorylation (mitochondrial respiratory chain complex III and IV), mitochondrial tRNA biosynthesis [glutamyl-tRNA(Gln) amidotransferase complex], histone methylation (Set1C–COMPASS), lysosome biogenesis (AP-3 adapter complex), and mRNA processing and P-body formation (PAN complex). We tested roles for two of these, AP-3 adapter complex and PAN deadenylase complex, in resistance to acid stress using a myeloid leukaemia-derived human cell line that we determined to be acid stress resistant. Loss of either complex inhibited growth of Hap1 cells at neutral pH and caused sensitivity to acid stress, indicating that AP-3 and PAN complexes are promising new targets in the treatment of cancer. Additionally, our data suggests that tumours may be genetically sensitized to acid stress and hence susceptible to acid stress-directed therapies, as many tumours accumulate mutations in mitochondrial

  7. Amino acid metabolism of Lemna minor L

    SciTech Connect

    Rhodes, D.; Rich, P.J.; Brunk, D.G. )

    1989-04-01

    A serious limitation to the use of N(O,S)-heptafluorobutyryl isobutyl amino acid derivatives in the analysis of {sup 15}N-labeling kinetics of amino acids in plant tissues, is that the amides glutamine and asparagine undergo acid hydrolysis to glutamate and aspartate, respectively, during derivatization. This led us to consider an alternative procedure for derivatization of glutamine and asparagine with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide in pyridine. Gas chromatography-mass spectrometry yielded fragment ions (M-57) of mass 417 and 431 for the ({sup 14}N)asparagine and ({sup 14}N)glutamine derivatives, respectively, suitable for monitoring unlabeled, single-{sup 15}N- and double-{sup 15}N-labeled amide species from the ion clusters at mass to charge ratio (m/z) 415 to 423 for asparagine, and m/z 429 to 437 for glutamine. From separate analyses of the specific isotope abundance of the amino-N groups of asparagine and glutamine as their N-heptafluorobutyryl isobutyl derivatives, the specific amide-({sup 15}N) abundance of these amino acids was determined.

  8. Post-uptake metabolism affects quantification of amino acid uptake.

    PubMed

    Warren, Charles R

    2012-01-01

    • The quantitative significance of amino acids to plant nutrition remains controversial. This experiment determined whether post-uptake metabolism and root to shoot export differ between glycine and glutamine, and examined implications for estimation of amino acid uptake. • Field soil containing a Eucalyptus pauciflora seedling was injected with uniformly (13)C- and (15)N-labelled glycine or glutamine. I quantified (15)N and (13)C excess in leaves and roots and intact labelled amino acids in leaves, roots and stem xylem sap. A tunable diode laser quantified fluxes of (12)CO(2) and (13)CO(2) from leaves and soil. • 60-360 min after addition of amino acid, intact molecules of U-(13)C,(15)N glutamine were < 5% of (15)N excess in roots, whereas U-(13)C,(15)N glycine was 30-100% of (15)N excess in roots. Intact molecules of glutamine, but not glycine, were exported from roots to shoots. • Post-uptake metabolism and transport complicate interpretation of isotope labelling such that root and shoot contents of intact amino acid, (13)C and (15)N may not reflect rates of uptake. Future experiments should focus on reconciling discrepancies between intact amino acid, (13)C and (15)N by determining the turnover of amino acids within roots. Alternatively, post-uptake metabolism and transport could be minimized by harvesting plants within minutes of isotope addition.

  9. Omega 3 fatty acids and inborn errors of metabolism.

    PubMed

    Gil-Campos, Mercedes; Sanjurjo Crespo, Pablo

    2012-06-01

    A number of studies are investigating the role of n-3 polyunsaturated fatty acids in children with metabolic inborn errors, while the effects on visual and brain development in premature infants and neonates are well known. However, their function incertain chronic neurological, inflammatory and metabolic disorders is still under study. Standards should be established to help identify the need of docosahexaenoic acid supplementation in conditions requiring a restricted diet resulting in an altered metabolism system, and find scientific evidence on the effects of such supplementation. This study reviews relevant published literature to propose adequate n-3 intake or supplementation doses for different ages and pathologies. The aim of this review is to examine the effects of long chain polyunsaturated fatty acids supplementation in preventing cognitive impairment or in retarding its progress, and to identify nutritional deficiencies, in children with inborn errors of metabolism. Trials were identified from a search of the Cochrane and MEDLINE databases in 2011. These databases include all major completed and ongoing double-blind, placebo-controlled, randomized trials, as well as all studies in which omega-3 supplementation was administered to children with inborn errors, and studies assessing omega-3 fatty acids status in plasma in these pathologies. Although few randomized controlled trials met the inclusion criteria of this review, some evidenced that most of children with inborn errors are deficient in omega-3 fatty acids, and demonstrated that supplementation might improve their neural function, or prevent the progression of neurological impairment. Nontheless, further investigations are needed on this issue.

  10. Myocardial imaging and metabolic studies with (17-/sup 123/I)iodoheptadecanoic acid

    SciTech Connect

    Freundlieb, C.; Hoeck, A.; Vyska, K.; Feinendegen, L.E.; Machulla, H.J.; Stoecklin, G.

    1980-11-01

    After intravenous administration of the stearic acid analogue (17-/sup 123/I)iodoheptadecanoic acid (I-123 HA), myocardial metabolism was studied in ten normal individuals, eight patients with coronary artery disease and three patients with congestive heart failure. High-quality images were obtained in sequential scintigraphy of I-123 metabolically bound in myocardial tissue. Infarcted zones as well as ischemic regions are indicated by reduced tracer uptake. Iodine-123 in the blood pool and interstitial space consists mainly of radioiodide that is liberated by fatty-acid metabolism and was corrected for. Using the proposed correction not only are the images improved but the uptake and elimination of the I-123 in the myocardial cells can be followed. The average disappearance half-time of I-123 HA from the myocardium of normal persons was 24 +- 4.7 min. In patients with coronary artery disease significant differences between myocardial regions were observed.

  11. Analytical strategies for studying stem cell metabolism

    PubMed Central

    Arnold, James M.; Choi, William T.; Sreekumar, Arun

    2015-01-01

    Owing to their capacity for self-renewal and pluripotency, stem cells possess untold potential for revolutionizing the field of regenerative medicine through the development of novel therapeutic strategies for treating cancer, diabetes, cardiovascular and neurodegenerative diseases. Central to developing these strategies is improving our understanding of biological mechanisms responsible for governing stem cell fate and self-renewal. Increasing attention is being given to the significance of metabolism, through the production of energy and generation of small molecules, as a critical regulator of stem cell functioning. Rapid advances in the field of metabolomics now allow for in-depth profiling of stem cells both in vitro and in vivo, providing a systems perspective on key metabolic and molecular pathways which influence stem cell biology. Understanding the analytical platforms and techniques that are currently used to study stem cell metabolomics, as well as how new insights can be derived from this knowledge, will accelerate new research in the field and improve future efforts to expand our understanding of the interplay between metabolism and stem cell biology. PMID:26213533

  12. Hallmarks of cancer stem cell metabolism

    PubMed Central

    Sancho, Patricia; Barneda, David; Heeschen, Christopher

    2016-01-01

    Cancer cells adapt cellular metabolism to cope with their high proliferation rate. Instead of primarily using oxidative phosphorylation (OXPHOS), cancer cells use less efficient glycolysis for the production of ATP and building blocks (Warburg effect). However, tumours are not uniform, but rather functionally heterogeneous and harbour a subset of cancer cells with stemness features. Such cancer cells have the ability to repopulate the entire tumour and thus have been termed cancer stem cells (CSCs) or tumour-initiating cells (TICs). As opposed to differentiated bulk tumour cells relying on glycolysis, CSCs show a distinct metabolic phenotype that, depending on the cancer type, can be highly glycolytic or OXPHOS dependent. In either case, mitochondrial function is critical and takes centre stage in CSC functionality. Remaining controversies in this young and emerging research field may be related to CSC isolation techniques and/or the use of less suitable model systems. Still, the apparent dependence of CSCs on mitochondrial function, regardless of their primary metabolic phenotype, represents a previously unrecognised Achilles heel amendable for therapeutic intervention. Elimination of highly chemoresistant CSCs as the root of many cancers via inhibition of mitochondrial function bears the potential to prevent relapse from disease and thus improve patients' long-term outcome. PMID:27219018

  13. Hallmarks of cancer stem cell metabolism.

    PubMed

    Sancho, Patricia; Barneda, David; Heeschen, Christopher

    2016-06-14

    Cancer cells adapt cellular metabolism to cope with their high proliferation rate. Instead of primarily using oxidative phosphorylation (OXPHOS), cancer cells use less efficient glycolysis for the production of ATP and building blocks (Warburg effect). However, tumours are not uniform, but rather functionally heterogeneous and harbour a subset of cancer cells with stemness features. Such cancer cells have the ability to repopulate the entire tumour and thus have been termed cancer stem cells (CSCs) or tumour-initiating cells (TICs). As opposed to differentiated bulk tumour cells relying on glycolysis, CSCs show a distinct metabolic phenotype that, depending on the cancer type, can be highly glycolytic or OXPHOS dependent. In either case, mitochondrial function is critical and takes centre stage in CSC functionality. Remaining controversies in this young and emerging research field may be related to CSC isolation techniques and/or the use of less suitable model systems. Still, the apparent dependence of CSCs on mitochondrial function, regardless of their primary metabolic phenotype, represents a previously unrecognised Achilles heel amendable for therapeutic intervention. Elimination of highly chemoresistant CSCs as the root of many cancers via inhibition of mitochondrial function bears the potential to prevent relapse from disease and thus improve patients' long-term outcome. PMID:27219018

  14. Lipid metabolic reprogramming in cancer cells

    PubMed Central

    Beloribi-Djefaflia, S; Vasseur, S; Guillaumond, F

    2016-01-01

    Many human diseases, including metabolic, immune and central nervous system disorders, as well as cancer, are the consequence of an alteration in lipid metabolic enzymes and their pathways. This illustrates the fundamental role played by lipids in maintaining membrane homeostasis and normal function in healthy cells. We reviewed the major lipid dysfunctions occurring during tumor development, as determined using systems biology approaches. In it, we provide detailed insight into the essential roles exerted by specific lipids in mediating intracellular oncogenic signaling, endoplasmic reticulum stress and bidirectional crosstalk between cells of the tumor microenvironment and cancer cells. Finally, we summarize the advances in ongoing research aimed at exploiting the dependency of cancer cells on lipids to abolish tumor progression. PMID:26807644

  15. Amino acid metabolism in tumour-bearing mice.

    PubMed Central

    Rivera, S; Azcón-Bieto, J; López-Soriano, F J; Miralpeix, M; Argilés, J M

    1988-01-01

    Mice bearing the Lewis lung carcinoma showed a high tumour glutaminase activity and significantly higher concentrations of most amino acids than in both the liver and the skeletal muscle of the host. Tumour tissue slices showed a marked preference for glutamine, especially for oxidation of its skeleton to CO2. It is proposed that the metabolism of this particular carcinoma is focused on amino acid degradation, glutamine being its preferred substrate. PMID:3342022

  16. Functional analysis of protein N-myristoylation: Metabolic labeling studies using three oxygen-substituted analogs of myristic acid and cultured mammalian cells provide evidence for protein-sequence-specific incorporation and analog-specific redistribution

    SciTech Connect

    Johnson, D.R.; Heuckeroth, R.O.; Gordon, J.I. ); Cox, A.D.; Solski, P.A.; Buss, J.E. ); Devadas, B.; Adams, S.P.; Leimgruber, R.M. )

    1990-11-01

    Covalent attachment of myristic acid (C14:0) to the NH{sub 2}-terminal glycine residue of a number of cellular, viral, and oncogene-encoded proteins is essential for full expression of their biological function. Substitution of oxygen for methylene groups in this fatty acid does not produce a significant change in chain length or stereochemistry but does result in a reduction in hydrophobicity. These heteroatom-containing analogs serve as alternative substrates for mammalian myristoyl-CoA: protein N-myristoyltransferase and offer the opportunity to explore structure/function relationships of myristate in N-myristoyltransferase proteins. The authors have synthesized three tritiated analogs of myristate with oxygen substituted for methylene groups at C6, C11, and C13. Metabolic labeling studies were performed with these compounds and (i) a murine myocyte cell line (BC{sub 3}H1), (ii) a rat fibroblast cell that produces p60{sup v-src} (3Xsrc), or (iii) NIH 3T3 cells that have been engineered to express a fusion protein consisting of an 11-residue myristoylation signal from the Rasheed sarcoma virus (RaSV) gag protein linked to c-Ha-ras with a Cys {yields} Ser-186 mutation. Two-dimensional gel electrophoresis of membrane and soluble fractions prepared from cell lysates revealed different patterns of incorporation of the analogs into cellular N-myristoyl proteins. The demonstration that these analogs differ in the extent to which they are incorporated and in their ability to cause redistribution of any single protein suggests that they may also have sufficient selectivity to be of potential therapeutic value.

  17. Transport and metabolism of fumaric acid in Saccharomyces cerevisiae in aerobic glucose-limited chemostat culture.

    PubMed

    Shah, Mihir V; van Mastrigt, Oscar; Heijnen, Joseph J; van Gulik, Walter M

    2016-04-01

    Currently, research is being focused on the industrial-scale production of fumaric acid and other relevant organic acids from renewable feedstocks via fermentation, preferably at low pH for better product recovery. However, at low pH a large fraction of the extracellular acid is present in the undissociated form, which is lipophilic and can diffuse into the cell. There have been no studies done on the impact of high extracellular concentrations of fumaric acid under aerobic conditions in S. cerevisiae, which is a relevant issue to study for industrial-scale production. In this work we studied the uptake and metabolism of fumaric acid in S. cerevisiae in glucose-limited chemostat cultures at a cultivation pH of 3.0 (pH < pK). Steady states were achieved with different extracellular levels of fumaric acid, obtained by adding different amounts of fumaric acid to the feed medium. The experiments were carried out with the wild-type S. cerevisiae CEN.PK 113-7D and an engineered S. cerevisiae ADIS 244 expressing a heterologous dicarboxylic acid transporter (DCT-02) from Aspergillus niger, to examine whether it would be capable of exporting fumaric acid. We observed that fumaric acid entered the cells most likely via passive diffusion of the undissociated form. Approximately two-thirds of the fumaric acid in the feed was metabolized together with glucose. From metabolic flux analysis, an increased ATP dissipation was observed only at high intracellular concentrations of fumarate, possibly due to the export of fumarate via an ABC transporter. The implications of our results for the industrial-scale production of fumaric acid are discussed. PMID:26683700

  18. Dynamic modeling of lactic acid fermentation metabolism with Lactococcus lactis.

    PubMed

    Oh, Euhlim; Lu, Mingshou; Park, Changhun; Park, Changhun; Oh, Han Bin; Lee, Sang Yup; Lee, Jinwon

    2011-02-01

    A dynamic model of lactic acid fermentation using Lactococcus lactis was constructed, and a metabolic flux analysis (MFA) and metabolic control analysis (MCA) were performed to reveal an intensive metabolic understanding of lactic acid bacteria (LAB). The parameter estimation was conducted with COPASI software to construct a more accurate metabolic model. The experimental data used in the parameter estimation were obtained from an LC-MS/ MS analysis and time-course simulation study. The MFA results were a reasonable explanation of the experimental data. Through the parameter estimation, the metabolic system of lactic acid bacteria can be thoroughly understood through comparisons with the original parameters. The coefficients derived from the MCA indicated that the reaction rate of L-lactate dehydrogenase was activated by fructose 1,6-bisphosphate and pyruvate, and pyruvate appeared to be a stronger activator of L-lactate dehydrogenase than fructose 1,6-bisphosphate. Additionally, pyruvate acted as an inhibitor to pyruvate kinase and the phosphotransferase system. Glucose 6-phosphate and phosphoenolpyruvate showed activation effects on pyruvate kinase. Hexose transporter was the strongest effector on the flux through L-lactate dehydrogenase. The concentration control coefficient (CCC) showed similar results to the flux control coefficient (FCC).

  19. Carnitine is associated with fatty acid metabolism in plants.

    PubMed

    Bourdin, Benoîte; Adenier, Hervé; Perrin, Yolande

    2007-12-01

    The finding of acylcarnitines alongside free carnitine in Arabidopsis thaliana and other plant species, using tandem mass spectrometry coupled to liquid chromatography shows a link between carnitine and plant fatty acid metabolism. Moreover the occurrence of both medium- and long-chain acylcarnitines suggests that carnitine is connected to diverse fatty acid metabolic pathways in plant tissues. The carnitine and acylcarnitine contents in plant tissues are respectively a hundred and a thousand times lower than in animal tissues, and acylcarnitines represent less than 2% of the total carnitine pool whereas this percentage reaches 30% in animal tissues. These results suggest that carnitine plays a lesser role in lipid metabolism in plants than it does in animals.

  20. Unraveling the mystery of cancer metabolism in the genesis of tumor-initiating cells and development of cancer.

    PubMed

    Zhang, Gaochuan; Yang, Ping; Guo, Pengda; Miele, Lucio; Sarkar, Fazlul H; Wang, Zhiwei; Zhou, Quansheng

    2013-08-01

    Robust anaerobic metabolism plays a causative role in the origin of cancer cells; however, the oncogenic metabolic genes, factors, pathways, and networks in genesis of tumor-initiating cells (TICs) have not yet been systematically summarized. In addition, the mechanisms of oncogenic metabolism in the genesis of TICs are enigmatic. In this review, we discussed multiple cancer metabolism-related genes (MRGs) that are overexpressed in TICs and are responsible for inducing pluripotent stem cells. Moreover, we summarized that oncogenic metabolic genes and onco-metabolites induce metabolic reprogramming, which switches normal mitochondrial oxidative phosphorylation to cancer anaerobic metabolism, triggers epigenetic, genetic, and environmental alterations, drives the generation of TICs, and boosts the development of cancer. Importantly, cancer metabolism is controlled by positive and negative metabolic regulators. Positive oncogenic metabolic regulators, including key oncogenic metabolic genes, onco-metabolites, hypoxia, and an acidic environment, promote oncogenic metabolic reprogramming and anaerobic metabolism. However, dysfunction of negative metabolic regulators, including defects in p53, PTEN, and LKB1-AMPK-mTOR pathways, enhances cancer metabolism. Loss of the metabolic balance results in oncogenic metabolic reprogramming, genesis of TICs, and tumorigenesis. Collectively, this review provides new insight into the role and mechanism of these oncogenic metabolisms in the genesis of TICs and tumorigenesis. Accordingly, targeting key oncogenic genes, onco-metabolites, pathways, networks, and the acidic cancer microenvironment appears to be an attractive strategy for novel anti-tumor treatment.

  1. Nicotinamide metabolism in ferns: formation of nicotinic acid glucoside.

    PubMed

    Ashihara, Hiroshi; Yin, Yuling; Watanabe, Shin

    2011-03-01

    The metabolic fate of [carbonyl-(14)C]nicotinamide was investigated in 9 fern species, Psilotum nudum, Angiopteris evecta, Lygodium japonicum, Acrostichum aureum, Asplenium antiquum, Diplazium subsinuatum, Thelypteris acuminate, Blechnum orientale and Crytomium fortune. All fern species produce a large quantity of nicotinic acid glucoside from [(14)C]nicotinamide, but trigonelline formation is very low. Increases in the release of (14)CO(2) with incubation time was accompanied by decreases in [carboxyl-(14)C]nicotinic acid glucoside. There was slight stimulation of nicotinic acid glucoside formation by 250 mM NaCl in mature leaves of the mangrove fern, Acrostichum aureum, but it is unlikely that this compound acts as a compatible solute. Nicotinamide and nicotinic acid salvage for pyridine nucleotide synthesis was detected in all fern species, although this activity was always less than nicotinic acid glucoside synthesis. Predominant formation of nicotinic acid glucoside is characteristic of nicotinic acid metabolism in ferns. This reaction appears to act as a detoxication mechanism, removing excess nicotinic acid.

  2. Protein and amino acid metabolism and requirements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteins are the major structural and functional components of all cells of the body. Enzymes, membrane carriers, blood transport molecules, intracellular matrix, and even hair and fingernails are proteins, as are many hormones. Proteins also constitute a major portion of all membranes, and the cons...

  3. Stromal uptake and transmission of acid is a pathway for venting cancer cell-generated acid.

    PubMed

    Hulikova, Alzbeta; Black, Nicholas; Hsia, Lin-Ting; Wilding, Jennifer; Bodmer, Walter F; Swietach, Pawel

    2016-09-01

    Proliferation and invasion of cancer cells require favorable pH, yet potentially toxic quantities of acid are produced metabolically. Membrane-bound transporters extrude acid from cancer cells, but little is known about the mechanisms that handle acid once it is released into the poorly perfused extracellular space. Here, we studied acid handling by myofibroblasts (colon cancer-derived Hs675.T, intestinal InMyoFib, embryonic colon-derived CCD-112-CoN), skin fibroblasts (NHDF-Ad), and colorectal cancer (CRC) cells (HCT116, HT29) grown in monoculture or coculture. Expression of the acid-loading transporter anion exchanger 2 (AE2) (SLC4A2 product) was detected in myofibroblasts and fibroblasts, but not in CRC cells. Compared with CRC cells, Hs675.T and InMyoFib myofibroblasts had very high capacity to absorb extracellular acid. Acid uptake into CCD-112-CoN and NHDF-Ad cells was slower and comparable to levels in CRC cells, but increased alongside SLC4A2 expression under stimulation with transforming growth factor β1 (TGFβ1), a cytokine involved in cancer-stroma interplay. Myofibroblasts and fibroblasts are connected by gap junctions formed by proteins such as connexin-43, which allows the absorbed acid load to be transmitted across the stromal syncytium. To match the stimulatory effect on acid uptake, cell-to-cell coupling in NHDF-Ad and CCD-112-CoN cells was strengthened with TGFβ1. In contrast, acid transmission was absent between CRC cells, even after treatment with TGFβ1. Thus, stromal cells have the necessary molecular apparatus for assembling an acid-venting route that can improve the flow of metabolic acid through tumors. Importantly, the activities of stromal AE2 and connexin-43 do not place an energetic burden on cancer cells, allowing resources to be diverted for other activities. PMID:27543333

  4. Stromal uptake and transmission of acid is a pathway for venting cancer cell-generated acid

    PubMed Central

    Hulikova, Alzbeta; Black, Nicholas; Hsia, Lin-Ting; Wilding, Jennifer; Bodmer, Walter F.; Swietach, Pawel

    2016-01-01

    Proliferation and invasion of cancer cells require favorable pH, yet potentially toxic quantities of acid are produced metabolically. Membrane-bound transporters extrude acid from cancer cells, but little is known about the mechanisms that handle acid once it is released into the poorly perfused extracellular space. Here, we studied acid handling by myofibroblasts (colon cancer-derived Hs675.T, intestinal InMyoFib, embryonic colon-derived CCD-112-CoN), skin fibroblasts (NHDF-Ad), and colorectal cancer (CRC) cells (HCT116, HT29) grown in monoculture or coculture. Expression of the acid-loading transporter anion exchanger 2 (AE2) (SLC4A2 product) was detected in myofibroblasts and fibroblasts, but not in CRC cells. Compared with CRC cells, Hs675.T and InMyoFib myofibroblasts had very high capacity to absorb extracellular acid. Acid uptake into CCD-112-CoN and NHDF-Ad cells was slower and comparable to levels in CRC cells, but increased alongside SLC4A2 expression under stimulation with transforming growth factor β1 (TGFβ1), a cytokine involved in cancer–stroma interplay. Myofibroblasts and fibroblasts are connected by gap junctions formed by proteins such as connexin-43, which allows the absorbed acid load to be transmitted across the stromal syncytium. To match the stimulatory effect on acid uptake, cell-to-cell coupling in NHDF-Ad and CCD-112-CoN cells was strengthened with TGFβ1. In contrast, acid transmission was absent between CRC cells, even after treatment with TGFβ1. Thus, stromal cells have the necessary molecular apparatus for assembling an acid-venting route that can improve the flow of metabolic acid through tumors. Importantly, the activities of stromal AE2 and connexin-43 do not place an energetic burden on cancer cells, allowing resources to be diverted for other activities. PMID:27543333

  5. Metabolic measurements in cell culture and tissue constructs

    NASA Astrophysics Data System (ADS)

    Rolfe, P.

    2008-10-01

    This paper concerns the study and use of biological cells in which there is a need for sensors and assemblies for the measurement of a diverse range of physical and chemical variables. In this field cell culture is used for basic research and for applications such as protein and drug synthesis, and in cell, tissue and organ engineering. Metabolic processes are fundamental to cell behaviour and must therefore be monitored reliably. Basic metabolic studies measure the transport of oxygen, glucose, carbon dioxide, lactic acid to, from, or within cells, whilst more advanced research requires examination of energy storage and utilisation. Assemblies are designed to incorporate bioreactor functions for cell culture together with appropriate sensing devices. Oxygen consumption by populations of cells is achieved in a flowthrough assembly that incorporates O2 micro-sensors based on either amperometry or fluorescence. Measurements in single cell are possible with intra-cellular fluorophores acting as biosensors together with optical stimulation and detection. Near infra-red spectroscopy (NIRS) is used for analysis within culture fluid, for example for estimation of glucose levels, as well as within cell populations, for example to study the respiratory enzymes.Â#

  6. Role of mitochondrial transamination in branched chain amino acid metabolism

    SciTech Connect

    Hutson, S.M.; Fenstermacher, D.; Mahar, C.

    1988-03-15

    Oxidative decarboxylation and transamination of 1-/sup 14/C-branched chain amino and alpha-keto acids were examined in mitochondria isolated from rat heart. Transamination was inhibited by aminooxyacetate, but not by L-cycloserine. At equimolar concentrations of alpha-ketoiso(1-/sup 14/C)valerate (KIV) and isoleucine, transamination was increased by disrupting the mitochondria with detergent which suggests transport may be one factor affecting the rate of transamination. Next, the subcellular distribution of the aminotransferase(s) was determined. Branched chain aminotransferase activity was measured using two concentrations of isoleucine as amino donor and (1-/sup 14/C)KIV as amino acceptor. The data show that branched chain aminotransferase activity is located exclusively in the mitochondria in rat heart. Metabolism of extramitochondrial branched chain alpha-keto acids was examined using 20 microM (1-/sup 14/C)KIV and alpha-ketoiso(1-/sup 14/C)caproate (KIC). There was rapid uptake and oxidation of labeled branched chain alpha-keto acid, and, regardless of the experimental condition, greater than 90% of the labeled keto acid substrate was metabolized during the 20-min incubation. When a branched chain amino acid (200 microM) or glutamate (5 mM) was present, 30-40% of the labeled keto acid was transaminated while the remainder was oxidized. Provision of an alternate amino acceptor in the form of alpha-keto-glutarate (0.5 mM) decreased transamination of the labeled KIV or KIC and increased oxidation. Metabolism of intramitochondrially generated branched chain alpha-keto acids was studied using (1-/sup 14/C)leucine and (1-/sup 14/C)valine. Essentially all of the labeled branched chain alpha-keto acid produced by transamination of (1-/sup 14/C)leucine or (1-/sup 14/C)valine with a low concentration of unlabeled branched chain alpha-keto acid (20 microM) was oxidized.

  7. The metabolic landscape of cancer stem cells.

    PubMed

    Dando, Ilaria; Dalla Pozza, Elisa; Biondani, Giulia; Cordani, Marco; Palmieri, Marta; Donadelli, Massimo

    2015-09-01

    Cancer stem cells (CSCs) are a sub-population of quiescent cells endowed with self-renewal properties that can sustain the malignant behavior of the tumor mass giving rise to more differentiated cancer cells. For this reason, the specific killing of CSCs represents one of the most important challenges of the modern molecular oncology. However, their particular resistance to traditional chemotherapy and radiotherapy imposes a thorough understanding of their biological and biochemical features. The metabolic peculiarities of CSCs may be a therapeutic and diagnostic opportunity in cancer research. In this review, we summarize the most significant discoveries on the metabolism of CSCs describing and critically analyzing the studies supporting either glycolysis or mitochondrial oxidative phosphorylation as a primary source of energy for CSCs.

  8. Evolution of amino acid metabolism inferred through cladistic analysis.

    PubMed

    Cunchillos, Chomin; Lecointre, Guillaume

    2003-11-28

    Because free amino acids were most probably available in primitive abiotic environments, their metabolism is likely to have provided some of the very first metabolic pathways of life. What were the first enzymatic reactions to emerge? A cladistic analysis of metabolic pathways of the 16 aliphatic amino acids and 2 portions of the Krebs cycle was performed using four criteria of homology. The analysis is not based on sequence comparisons but, rather, on coding similarities in enzyme properties. The properties used are shared specific enzymatic activity, shared enzymatic function without substrate specificity, shared coenzymes, and shared functional family. The tree shows that the earliest pathways to emerge are not portions of the Krebs cycle but metabolisms of aspartate, asparagine, glutamate, and glutamine. The views of Horowitz (Horowitz, N. H. (1945) Proc. Natl. Acad. Sci. U. S. A. 31, 153-157) and Cordón (Cordón, F. (1990) Tratado Evolucionista de Biologia, Aguilar, Madrid, Spain), according to which the upstream reactions in the catabolic pathways and the downstream reactions in the anabolic pathways are the earliest in evolution, are globally corroborated; however, with some exceptions. These are due to later opportunistic connections of pathways (actually already suggested by these authors). Earliest enzymatic functions are mostly catabolic; they were deaminations, transaminations, and decarboxylations. From the consensus tree we extracted four time spans for amino acid metabolism development. For some amino acids catabolism and biosynthesis occurred at the same time (Asp, Glu, Lys, Leu, Ala, Val, Ile, Pro, Arg). For others ultimate reactions that use amino acids as a substrate or as a product are distinct in time, with catabolism preceding anabolism for Asn, Gln, and Cys and anabolism preceding catabolism for Ser, Met, and Thr. Cladistic analysis of the structure of biochemical pathways makes hypotheses in biochemical evolution explicit and parsimonious.

  9. PGC-1α-Mediated Branched-Chain Amino Acid Metabolism in the Skeletal Muscle

    PubMed Central

    Nagaike, Yuta; Morita, Akihito; Ogawa, Yoshihiro; Ezaki, Osamu; Takai-Igarashi, Takako; Kitaura, Yasuyuki; Shimomura, Yoshiharu; Kamei, Yasutomi; Miura, Shinji

    2014-01-01

    Peroxisome proliferator-activated receptor (PPAR) γ coactivator 1α (PGC-1α) is a coactivator of various nuclear receptors and other transcription factors, which is involved in the regulation of energy metabolism, thermogenesis, and other biological processes that control phenotypic characteristics of various organ systems including skeletal muscle. PGC-1α in skeletal muscle is considered to be involved in contractile protein function, mitochondrial function, metabolic regulation, intracellular signaling, and transcriptional responses. Branched-chain amino acid (BCAA) metabolism mainly occurs in skeletal muscle mitochondria, and enzymes related to BCAA metabolism are increased by exercise. Using murine skeletal muscle overexpressing PGC-1α and cultured cells, we investigated whether PGC-1α stimulates BCAA metabolism by increasing the expression of enzymes involved in BCAA metabolism. Transgenic mice overexpressing PGC-1α specifically in the skeletal muscle had increased the expression of branched-chain aminotransferase (BCAT) 2, branched-chain α-keto acid dehydrogenase (BCKDH), which catabolize BCAA. The expression of BCKDH kinase (BCKDK), which phosphorylates BCKDH and suppresses its enzymatic activity, was unchanged. The amount of BCAA in the skeletal muscle was significantly decreased in the transgenic mice compared with that in the wild-type mice. The amount of glutamic acid, a metabolite of BCAA catabolism, was increased in the transgenic mice, suggesting the activation of muscle BCAA metabolism by PGC-1α. In C2C12 cells, the overexpression of PGC-1α significantly increased the expression of BCAT2 and BCKDH but not BCKDK. Thus, PGC-1α in the skeletal muscle is considered to significantly contribute to BCAA metabolism. PMID:24638054

  10. Regulation of amino acid metabolic enzymes and transporters in plants.

    PubMed

    Pratelli, Réjane; Pilot, Guillaume

    2014-10-01

    Amino acids play several critical roles in plants, from providing the building blocks of proteins to being essential metabolites interacting with many branches of metabolism. They are also important molecules that shuttle organic nitrogen through the plant. Because of this central role in nitrogen metabolism, amino acid biosynthesis, degradation, and transport are tightly regulated to meet demand in response to nitrogen and carbon availability. While much is known about the feedback regulation of the branched biosynthesis pathways by the amino acids themselves, the regulation mechanisms at the transcriptional, post-transcriptional, and protein levels remain to be identified. This review focuses mainly on the current state of our understanding of the regulation of the enzymes and transporters at the transcript level. Current results describing the effect of transcription factors and protein modifications lead to a fragmental picture that hints at multiple, complex levels of regulation that control and coordinate transport and enzyme activities. It also appears that amino acid metabolism, amino acid transport, and stress signal integration can influence each other in a so-far unpredictable fashion.

  11. Metformin Decouples Phospholipid Metabolism in Breast Cancer Cells

    PubMed Central

    Smith, Tim A. D.; Phyu, Su M.

    2016-01-01

    Introduction The antidiabetic drug metformin, currently undergoing trials for cancer treatment, modulates lipid and glucose metabolism both crucial in phospholipid synthesis. Here the effect of treatment of breast tumour cells with metformin on phosphatidylcholine (PtdCho) metabolism which plays a key role in membrane synthesis and intracellular signalling has been examined. Methods MDA-MB-468, BT474 and SKBr3 breast cancer cell lines were treated with metformin and [3H-methyl]choline and [14C(U)]glucose incorporation and lipid accumulation determined in the presence and absence of lipase inhibitors. Activities of choline kinase (CK), CTP:phosphocholine cytidylyl transferase (CCT) and PtdCho-phospholipase C (PLC) were also measured. [3H] Radiolabelled metabolites were determined using thin layer chromatography. Results Metformin-treated cells exhibited decreased formation of [3H]phosphocholine but increased accumulation of [3H]choline by PtdCho. CK and PLC activities were decreased and CCT activity increased by metformin-treatment. [14C] incorporation into fatty acids was decreased and into glycerol was increased in breast cancer cells treated with metformin incubated with [14C(U)]glucose. Conclusion This is the first study to show that treatment of breast cancer cells with metformin induces profound changes in phospholipid metabolism. PMID:26959405

  12. Cell metabolism, FLIM and PLIM and applications

    NASA Astrophysics Data System (ADS)

    Kalinina, S.; Bisinger, D.; Breymayer, J.; Ruck, A.

    2015-03-01

    Methods of time resolved spectroscopy are applied in biomedicine during diagnosis of various malignant and nonmalignant diseases. Fluorescence lifetime measurement provides monitoring of intracellular metabolic enzymes like NADH and FAD, controlling the balance between oxidative phosphorylation and glycolysis. The simultaneous monitoring of the different metabolic parameters is still a challenge. Here we present a setup, which is based on two-photon microscopy and multi-dimensional time-correlated single-photoncounting (TCSPC). The presented method allows consecutive NADH and FAD imaging with high specificity and minimal side effects. In addition the setup is useful for simultaneous monitoring of NADH FLIM and intracellular oxygen partial pressure (pO2). With the two-channel FLIM/PLIM system we could show that pO2 is investigated simultaneously with different metabolic parameters in living cells.

  13. Metabolic evolution of Escherichia coli strains that produce organic acids

    SciTech Connect

    Grabar, Tammy; Gong, Wei; Yocum, R Rogers

    2014-10-28

    This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

  14. Metabolism of lithocholic and chenodeoxycholic acids in the squirrel monkey

    SciTech Connect

    Suzuki, H.; Hamada, M.; Kato, F.

    1985-09-01

    Metabolism of lithocholic acid (LCA) and chenodeoxycholic acid (CDCA) was studied in the squirrel monkey to clarify the mechanism of the lack of toxicity of CDCA in this animal. Radioactive LCA was administered to squirrel monkeys with biliary fistula. Most radioactivity was excreted in the bile in the form of unsulfated lithocholyltaurine. The squirrel monkey thus differs from humans and chimpanzees, which efficiently sulfate LCA, and is similar to the rhesus monkey and baboon in that LCA is poorly sulfated. When labeled CDCA was orally administered to squirrel monkeys, less than 20% of the dosed radioactivity was recovered as LCA and its further metabolites in feces over 3 days, indicating that bacterial metabolism of CDCA into LCA is strikingly less than in other animals and in humans. It therefore appears that LCA, known as a hepatotoxic secondary bile acid, is not accumulated in the squirrel monkey, not because of its rapid turnover through sulfation, but because of the low order of its production.

  15. Human embryonic stem cells and embryonal carcinoma cells have overlapping and distinct metabolic signatures.

    PubMed

    Abu Dawud, Raed; Schreiber, Kerstin; Schomburg, Dietmar; Adjaye, James

    2012-01-01

    While human embryonic stem cells (hESCs) and human embryonal carcinoma cells (hECCs) have been studied extensively at the levels of the genome, transcriptome, proteome and epigenome our knowledge of their corresponding metabolomes is limited. Here, we present the metabolic signatures of hESCs and hESCs obtained by untargeted gas chromatography coupled to mass spectrometry (GC-MS). Whilst some metabolites are common to both cell types, representing the self-renewal and house-keeping signatures, others were either higher (e.g., octadecenoic acid, glycerol-3-phosphate, 4-hydroxyproline) or lower (e.g., glutamic acid, mannitol, malic acid, GABA) in hESCs (H9) compared to hECCs (NTERA2), these represent cell type specific signatures. Further, our combined results of GC-MS and microarray based gene expression profiling of undifferentiated and OCT4-depleted hESCs are consistent with the Warburg effect which is increased glycolysis in embryonic cells and tumor cells in the presence of O(2) while oxidative phosphorylation (OXPHOS) is impaired or even shut down. RNAi-based OCT4 knock down mediated differentiation resulted in the activation of the poised OXPHOS machinery by expressing missing key proteins such as NDUFC1, UQCRB and COX, increase in TCA cycle activity and decreased lactate metabolism. These results shed light on the metabolite layer of pluripotent stem cells and could potentially establish novel metabolic markers of self renewal and pluripotency. PMID:22768158

  16. Human embryonic stem cells and embryonal carcinoma cells have overlapping and distinct metabolic signatures.

    PubMed

    Abu Dawud, Raed; Schreiber, Kerstin; Schomburg, Dietmar; Adjaye, James

    2012-01-01

    While human embryonic stem cells (hESCs) and human embryonal carcinoma cells (hECCs) have been studied extensively at the levels of the genome, transcriptome, proteome and epigenome our knowledge of their corresponding metabolomes is limited. Here, we present the metabolic signatures of hESCs and hESCs obtained by untargeted gas chromatography coupled to mass spectrometry (GC-MS). Whilst some metabolites are common to both cell types, representing the self-renewal and house-keeping signatures, others were either higher (e.g., octadecenoic acid, glycerol-3-phosphate, 4-hydroxyproline) or lower (e.g., glutamic acid, mannitol, malic acid, GABA) in hESCs (H9) compared to hECCs (NTERA2), these represent cell type specific signatures. Further, our combined results of GC-MS and microarray based gene expression profiling of undifferentiated and OCT4-depleted hESCs are consistent with the Warburg effect which is increased glycolysis in embryonic cells and tumor cells in the presence of O(2) while oxidative phosphorylation (OXPHOS) is impaired or even shut down. RNAi-based OCT4 knock down mediated differentiation resulted in the activation of the poised OXPHOS machinery by expressing missing key proteins such as NDUFC1, UQCRB and COX, increase in TCA cycle activity and decreased lactate metabolism. These results shed light on the metabolite layer of pluripotent stem cells and could potentially establish novel metabolic markers of self renewal and pluripotency.

  17. Rh2E2, a novel metabolic suppressor, specifically inhibits energy-based metabolism of tumor cells

    PubMed Central

    Bai, Li-Ping; Jiang, Zhi-Hong; Guo, Yue; Kong, Ah-Ng Tony; Wang, Rui; Kam, Richard Kin Ting; Law, Betty Yuen Kwan; Hsiao, Wendy Wen Luen; Chan, Ka Man; Wang, Jingrong; Chan, Rick Wai Kit; Guo, Jianru; Zhang, Wei; Yen, Feng Gen; Zhou, Hua; Leung, Elaine Lai Han; Yu, Zhiling; Liu, Liang

    2016-01-01

    Energy metabolism in cancer cells is often increased to meet their higher proliferative rate and biosynthesis demands. Suppressing cancer cell metabolism using agents like metformin has become an attractive strategy for treating cancer patients. We showed that a novel ginsenoside derivative, Rh2E2, is as effective as aspirin in preventing the development of AOM/DSS-induced colorectal cancer and suppresses tumor growth and metastasis in a LLC-1 xenograft. A sub-chronic and acute toxicity LD50 test of Rh2E2 showed no harmful reactions at the maximum oral dosage of 5000 mg/kg body weight in mice. Proteomic profiling revealed that Rh2E2 specifically inhibited ATP production in cancer cells via down-regulation of metabolic enzymes involving glycolysis, fatty acid β-oxidation and the tricarboxylic acid cycle, leading to specific cytotoxicity and S-phase cell cycle arrest in cancer cells. Those findings suggest that Rh2E2 possesses a novel and safe anti-metabolic agent for cancer patients by specific reduction of energy-based metabolism in cancer cells. PMID:26799418

  18. Nickel deficiency disrupts metabolism of ureides, amino acids, and organic acids of young pecan foliage.

    PubMed

    Bai, Cheng; Reilly, Charles C; Wood, Bruce W

    2006-02-01

    The existence of nickel (Ni) deficiency is becoming increasingly apparent in crops, especially for ureide-transporting woody perennials, but its physiological role is poorly understood. We evaluated the concentrations of ureides, amino acids, and organic acids in photosynthetic foliar tissue from Ni-sufficient (Ni-S) versus Ni-deficient (Ni-D) pecan (Carya illinoinensis [Wangenh.] K. Koch). Foliage of Ni-D pecan seedlings exhibited metabolic disruption of nitrogen metabolism via ureide catabolism, amino acid metabolism, and ornithine cycle intermediates. Disruption of ureide catabolism in Ni-D foliage resulted in accumulation of xanthine, allantoic acid, ureidoglycolate, and citrulline, but total ureides, urea concentration, and urease activity were reduced. Disruption of amino acid metabolism in Ni-D foliage resulted in accumulation of glycine, valine, isoleucine, tyrosine, tryptophan, arginine, and total free amino acids, and lower concentrations of histidine and glutamic acid. Ni deficiency also disrupted the citric acid cycle, the second stage of respiration, where Ni-D foliage contained very low levels of citrate compared to Ni-S foliage. Disruption of carbon metabolism was also via accumulation of lactic and oxalic acids. The results indicate that mouse-ear, a key morphological symptom, is likely linked to the toxic accumulation of oxalic and lactic acids in the rapidly growing tips and margins of leaflets. Our results support the role of Ni as an essential plant nutrient element. The magnitude of metabolic disruption exhibited in Ni-D pecan is evidence of the existence of unidentified physiological roles for Ni in pecan. PMID:16415214

  19. Unified Theory of Bacterial Sialometabolism: How and Why Bacteria Metabolize Host Sialic Acids

    PubMed Central

    Vimr, Eric R.

    2013-01-01

    Sialic acids are structurally diverse nine-carbon ketosugars found mostly in humans and other animals as the terminal units on carbohydrate chains linked to proteins or lipids. The sialic acids function in cell-cell and cell-molecule interactions necessary for organismic development and homeostasis. They not only pose a barrier to microorganisms inhabiting or invading an animal mucosal surface, but also present a source of potential carbon, nitrogen, and cell wall metabolites necessary for bacterial colonization, persistence, growth, and, occasionally, disease. The explosion of microbial genomic sequencing projects reveals remarkable diversity in bacterial sialic acid metabolic potential. How bacteria exploit host sialic acids includes a surprisingly complex array of metabolic and regulatory capabilities that is just now entering a mature research stage. This paper attempts to describe the variety of bacterial sialometabolic systems by focusing on recent advances at the molecular and host-microbe-interaction levels. The hope is that this focus will provide a framework for further research that holds promise for better understanding of the metabolic interplay between bacterial growth and the host environment. An ability to modify or block this interplay has already yielded important new insights into potentially new therapeutic approaches for modifying or blocking bacterial colonization or infection. PMID:23724337

  20. Metabolism, cell growth and the bacterial cell cycle.

    PubMed

    Wang, Jue D; Levin, Petra A

    2009-11-01

    Adaptation to fluctuations in nutrient availability is a fact of life for single-celled organisms in the 'wild'. A decade ago our understanding of how bacteria adjust cell cycle parameters to accommodate changes in nutrient availability stemmed almost entirely from elegant physiological studies completed in the 1960s. In this Opinion article we summarize recent groundbreaking work in this area and discuss potential mechanisms by which nutrient availability and metabolic status are coordinated with cell growth, chromosome replication and cell division.

  1. Reliable Metabolic Flux Estimation in Escherichia coli Central Carbon Metabolism Using Intracellular Free Amino Acids

    PubMed Central

    Okahashi, Nobuyuki; Kajihata, Shuichi; Furusawa, Chikara; Shimizu, Hiroshi

    2014-01-01

    13C metabolic flux analysis (MFA) is a tool of metabolic engineering for investigation of in vivo flux distribution. A direct 13C enrichment analysis of intracellular free amino acids (FAAs) is expected to reduce time for labeling experiments of the MFA. Measurable FAAs should, however, vary among the MFA experiments since the pool sizes of intracellular free metabolites depend on cellular metabolic conditions. In this study, minimal 13C enrichment data of FAAs was investigated to perform the FAAs-based MFA. An examination of a continuous culture of Escherichia coli using 13C-labeled glucose showed that the time required to reach an isotopically steady state for FAAs is rather faster than that for conventional method using proteinogenic amino acids (PAAs). Considering 95% confidence intervals, it was found that the metabolic flux distribution estimated using FAAs has a similar reliability to that of the PAAs-based method. The comparative analysis identified glutamate, aspartate, alanine and phenylalanine as the common amino acids observed in E. coli under different culture conditions. The results of MFA also demonstrated that the 13C enrichment data of the four amino acids is required for a reliable analysis of the flux distribution. PMID:24957033

  2. Metabolic engineering of Yarrowia lipolytica for itaconic acid production.

    PubMed

    Blazeck, John; Hill, Andrew; Jamoussi, Mariam; Pan, Anny; Miller, Jarrett; Alper, Hal S

    2015-11-01

    Itaconic acid is a naturally produced organic acid with diverse applications as a replacement for petroleum derived products. However, its industrial viability as a bio-replacement has been restricted due to limitations with native producers. In this light, Yarrowia lipolytica is an excellent potential candidate for itaconic acid production due to its innate capacity to accumulate citric acid cycle intermediates and tolerance to lower pH. Here, we demonstrate the capacity to produce itaconic acid in Y. lipolytica through heterologous expression of the itaconic acid synthesis enzyme, resulting in an initial titer of 33 mg/L. Further optimizations of this strain via metabolic pathway engineering, enzyme localization, and media optimization strategies enabled 4.6g/L of itaconic acid to be produced in bioreactors, representing a 140-fold improvement over initial titer. Moreover, these fermentation conditions did not require additional nutrient supplementation and utilized a low pH condition that enabled the acid form of itaconic acid to be produced. Overall yields (0.058 g/g yield from glucose) and maximum productivity of 0.045 g/L/h still provide areas for future strain improvement. Nevertheless, this work demonstrates that Y. lipolytica has the potential to serve as an industrially relevant platform for itaconic acid production.

  3. Taurocholic acid metabolism by gut microbes and colon cancer.

    PubMed

    Ridlon, Jason M; Wolf, Patricia G; Gaskins, H Rex

    2016-05-01

    Colorectal cancer (CRC) is one of the most frequent causes of cancer death worldwide and is associated with adoption of a diet high in animal protein and saturated fat. Saturated fat induces increased bile secretion into the intestine. Increased bile secretion selects for populations of gut microbes capable of altering the bile acid pool, generating tumor-promoting secondary bile acids such as deoxycholic acid and lithocholic acid. Epidemiological evidence suggests CRC is associated with increased levels of DCA in serum, bile, and stool. Mechanisms by which secondary bile acids promote CRC are explored. Furthermore, in humans bile acid conjugation can vary by diet. Vegetarian diets favor glycine conjugation while diets high in animal protein favor taurine conjugation. Metabolism of taurine conjugated bile acids by gut microbes generates hydrogen sulfide, a genotoxic compound. Thus, taurocholic acid has the potential to stimulate intestinal bacteria capable of converting taurine and cholic acid to hydrogen sulfide and deoxycholic acid, a genotoxin and tumor-promoter, respectively. PMID:27003186

  4. An enhanced in vivo stable isotope labeling by amino acids in cell culture (SILAC) model for quantification of drug metabolism enzymes.

    PubMed

    MacLeod, A Kenneth; Fallon, Padraic G; Sharp, Sheila; Henderson, Colin J; Wolf, C Roland; Huang, Jeffrey T-J

    2015-03-01

    Many of the enzymes involved in xenobiotic metabolism are maintained at a low basal level and are only synthesized in response to activation of upstream sensor/effector proteins. This induction can have implications in a variety of contexts, particularly during the study of the pharmacokinetics, pharmacodynamics, and drug-drug interaction profile of a candidate therapeutic compound. Previously, we combined in vivo SILAC material with a targeted high resolution single ion monitoring (tHR/SIM) LC-MS/MS approach for quantification of 197 peptide pairs, representing 51 drug metabolism enzymes (DME), in mouse liver. However, as important enzymes (for example, cytochromes P450 (Cyp) of the 1a and 2b subfamilies) are maintained at low or undetectable levels in the liver of unstimulated metabolically labeled mice, quantification of these proteins was unreliable. In the present study, we induced DME expression in labeled mice through synchronous ligand-mediated activation of multiple upstream nuclear receptors, thereby enhancing signals for proteins including Cyps 1a, 2a, 2b, 2c, and 3a. With this enhancement, 115 unique, lysine-containing, Cyp-derived peptides were detected in the liver of a single animal, as opposed to 56 in a pooled sample from three uninduced animals. A total of 386 peptide pairs were quantified by tHR/SIM, representing 68 Phase I, 30 Phase II, and eight control proteins. This method was employed to quantify changes in DME expression in the hepatic cytochrome P450 reductase null (HRN) mouse. We observed compensatory induction of several enzymes, including Cyps 2b10, 2c29, 2c37, 2c54, 2c55, 2e1, 3a11, and 3a13, carboxylesterase (Ces) 2a, and glutathione S-transferases (Gst) m2 and m3, along with down-regulation of hydroxysteroid dehydrogenases (Hsd) 11b1 and 17b6. Using DME-enhanced in vivo SILAC material with tHR/SIM, therefore, permits the robust analysis of multiple DME of importance to xenobiotic metabolism, with improved utility for the study of

  5. Metabolic Pathways In Immune Cell Activation And Quiescence

    PubMed Central

    Pearce, Erika L.; Pearce, Edward J.

    2013-01-01

    Studies of immune system metabolism (“immunometabolism”) segregate along two paths. The first investigates the effects of immune cells on organs that regulate whole body metabolism, such as adipose tissue and liver. The second explores the role of metabolic pathways within immune cells and how this regulates immune response outcome. Distinct metabolic pathways diverge and converge at many levels and cells therefore face choices in how to achieve their metabolic goals. There is interest in fully understanding how and why immune cells commit to particular metabolic fates, and in elucidating the immunologic consequences of reaching a metabolic endpoint by one pathway versus another. This is particularly intriguing since metabolic commitment is influenced not only by substrate availability, but also by signaling pathways elicited by metabolites. Thus metabolic choices in cells enforce fate and function and this area will be the subject of this review. PMID:23601682

  6. Structurally modified fatty acids - clinical potential as tracers of metabolism

    SciTech Connect

    Dudczak, R.; Schmoliner, R.; Angelberger, P.; Knapp, F.F.; Goodman, M.M.

    1985-01-01

    Recently 15-p-iodophenyl-betamethyl-pentadecanoic acid (BMPPA) was proposed for myocardial scintigraphy, as possible probe of metabolic processes other than ..beta..-oxidation. In 19 patients myocardial scintigraphy was done after i.v. BMPPA (2 to 4 mCi). Data were collected (LAO 45/sup 0//14; anterior/5) for 100 minutes in the fasted patients. From heart (H) and liver (L) organ to background (BG) ratios were calculated, and the elimination (E) behavior was analyzed from BG (V. cava region) corrected time activity curves. In 10 patients plasma and urine were examined. By CHCl/sub 3//MeOH extraction of plasma samples (90 min. pi) both in water and in organic medium soluble catabolites were found. TLC fractionation showed that those were co-migrating, compared to standards, with benzoic acid, BMPPA and triglycerides. In urine (0 to 2h pi: 4.1% dose) hippuric acid was found. It is concluded that BMPPA is a useful agent for myocardial scintigraphy. Its longer retention in the heart compared to unbranched radioiodinated fatty acids may facilitate SPECT studies. Rate of elimination and plasma analysis indicate the metabolic breakdown of BMPPA. Yet, the complexity of the supposed mechanism may impede curve interpretation in terms of specific metabolic pathways. 19 refs., 5 tabs.

  7. Acid-base metabolism: implications for kidney stones formation.

    PubMed

    Hess, Bernhard

    2006-04-01

    The physiology and pathophysiology of renal H+ ion excretion and urinary buffer systems are reviewed. The main focus is on the two major conditions related to acid-base metabolism that cause kidney stone formation, i.e., distal renal tubular acidosis (dRTA) and abnormally low urine pH with subsequent uric acid stone formation. Both the entities can be seen on the background of disturbances of the major urinary buffer system, NH3+ <--> NH4+. On the one hand, reduced distal tubular secretion of H+ ions results in an abnormally high urinary pH and either incomplete or complete dRTA. On the other hand, reduced production/availability of NH4+ is the cause of an abnormally low urinary pH, which predisposes to uric acid stone formation. Most recent research indicates that the latter abnormality may be a renal manifestation of the increasingly prevalent metabolic syndrome. Despite opposite deviations from normal urinary pH values, both the dRTA and uric acid stone formation due to low urinary pH require the same treatment, i.e., alkali. In the dRTA, alkali is needed for improving the body's buffer capacity, whereas the goal of alkali treatment in uric acid stone formers is to increase the urinary pH to 6.2-6.8 in order to minimize uric acid crystallization.

  8. Metabolic Responses of Bacterial Cells to Immobilization.

    PubMed

    Żur, Joanna; Wojcieszyńska, Danuta; Guzik, Urszula

    2016-01-01

    In recent years immobilized cells have commonly been used for various biotechnological applications, e.g., antibiotic production, soil bioremediation, biodegradation and biotransformation of xenobiotics in wastewater treatment plants. Although the literature data on the physiological changes and behaviour of cells in the immobilized state remain fragmentary, it is well documented that in natural settings microorganisms are mainly found in association with surfaces, which results in biofilm formation. Biofilms are characterized by genetic and physiological heterogeneity and the occurrence of altered microenvironments within the matrix. Microbial cells in communities display a variety of metabolic differences as compared to their free-living counterparts. Immobilization of bacteria can occur either as a natural phenomenon or as an artificial process. The majority of changes observed in immobilized cells result from protection provided by the supports. Knowledge about the main physiological responses occurring in immobilized cells may contribute to improving the efficiency of immobilization techniques. This paper reviews the main metabolic changes exhibited by immobilized bacterial cells, including growth rate, biodegradation capabilities, biocatalytic efficiency and plasmid stability. PMID:27455220

  9. Nitrogen metabolism in Lignifying Pinus taeda cell cultures

    NASA Technical Reports Server (NTRS)

    van Heerden, P. S.; Towers, G. H.; Lewis, N. G.

    1996-01-01

    The primary metabolic fate of phyenylalanine, following its deamination in plants, is conscription of its carbon skeleton for lignin, suberin, flavonoid, and related metabolite formation. Since this accounts for approximately 30-40% of all organic carbon, an effective means of recycling the liberated ammonium ion must be operative. In order to establish how this occurs, the uptake and metabolism of various 15N-labeled precursors (15N-Phe, 15NH4Cl, 15N-Gln, and 15N-Glu) in lignifying Pinus taeda cell cultures was investigated, using a combination of high performance liquid chromatography, 15N NMR, and gas chromatograph-mass spectrometry analyses. It was found that the ammonium ion released during active phenylpropanoid metabolism was not made available for general amino acid/protein synthesis. Rather it was rapidly recycled back to regenerate phenylalanine, thereby providing an effective means of maintaining active phenylpropanoid metabolism with no additional nitrogen requirement. These results strongly suggest that, in lignifying cells, ammonium ion reassimilation is tightly compartmentalized.

  10. Increased Brain Fatty Acid Uptake in Metabolic Syndrome

    PubMed Central

    Karmi, Anna; Iozzo, Patricia; Viljanen, Antti; Hirvonen, Jussi; Fielding, Barbara A.; Virtanen, Kirsi; Oikonen, Vesa; Kemppainen, Jukka; Viljanen, Tapio; Guiducci, Letizia; Haaparanta-Solin, Merja; Någren, Kjell; Solin, Olof; Nuutila, Pirjo

    2010-01-01

    OBJECTIVE To test whether brain fatty acid uptake is enhanced in obese subjects with metabolic syndrome (MS) and whether weight reduction modifies it. RESEARCH DESIGN AND METHODS We measured brain fatty acid uptake in a group of 23 patients with MS and 7 age-matched healthy control subjects during fasting conditions using positron emission tomography (PET) with [11C]-palmitate and [18F]fluoro-6-thia-heptadecanoic acid ([18F]-FTHA). Sixteen MS subjects were restudied after 6 weeks of very low calorie diet intervention. RESULTS At baseline, brain global fatty acid uptake derived from [18F]-FTHA was 50% higher in patients with MS compared with control subjects. The mean percentage increment was 130% in the white matter, 47% in the gray matter, and uniform across brain regions. In the MS group, the nonoxidized fraction measured using [11C]-palmitate was 86% higher. Brain fatty acid uptake measured with [18F]-FTHA-PET was associated with age, fasting serum insulin, and homeostasis model assessment (HOMA) index. Both total and nonoxidized fractions of fatty acid uptake were associated with BMI. Rapid weight reduction decreased brain fatty acid uptake by 17%. CONCLUSIONS To our knowledge, this is the first study on humans to observe enhanced brain fatty acid uptake in patients with MS. Both fatty acid uptake and accumulation appear to be increased in MS patients and reversed by weight reduction. PMID:20566663

  11. Arachidonic acid metabolism in fibroblasts derived from canine myocardium

    SciTech Connect

    Weber, D.R.; Prescott, S.M.

    1986-03-05

    Canine fibroblasts from normal or healing infarcted myocardium were grown in culture. The cells were morphologically indistinguishable, but the doubling time of cells from healing myocardium was 39.6 +/- 3.5 hr whereas that of normals was 24 +/- 3.7 (n=5, p < .025). Fibroblasts incorporated (/sup 3/H)arachidonate (AA) into phospholipids. Calcium ionophore A23187 (10 ..mu..M) caused release and metabolism of (/sup 3/H) AA. A23187 or AA (10..mu..M) induced production of 6-keto PGF1..cap alpha.., PGE2, and a hydroxy metabolite of AA. RIA of 6-keto PGF1..cap alpha.. showed that subconfluent cells from healing myocardium produced 1202 +/- 354 pg/mg protein whereas that of normals was 551 +/- 222 (n=7, p < .025). Histamine and bradykinin also induced AA metabolism but were less potent. They examined the effect of AA released from deteriorating myocytes on AA metabolism by cultured fibroblasts. They confirmed that isolated myocytes labelled with (/sup 3/H)AA released but did not metabolize (/sup 3/H)AA. In coincubations, fibroblasts incorporated myocyte-derived AA. Subsequent stimulation of the fibroblasts with A23187 induced the synthesis of 6-keto PGF1..cap alpha.., PGE2 and a hydroxy metabolite. The fibroblast content of healing myocardium was 35-1000 times that of normal tissue (n=7). Thus even a moderate change in AA metabolism, amplified by the AA released from deteriorating myocytes, may be a significant physiologic or pathologic event.

  12. KDM4C and ATF4 Cooperate in Transcriptional Control of Amino Acid Metabolism

    PubMed Central

    Xia, Yingfeng; Liu, Mengling; Ye, Bingwei; Choi, Jeong-Hyeon; Yan, Chunhong; Dong, Zheng; Huang, Shuang; Zha, Yunhong; Yang, Liqun; Cui, Hongjuan; Ding, Han-Fei

    2015-01-01

    SUMMARY The histone lysine demethylase KDM4C is often overexpressed in cancers primarily through gene amplification. The molecular mechanisms of KDM4C action in tumorigenesis are not well defined. Here we report that KDM4C transcriptionally activates amino acid biosynthesis and transport, leading to a significant increase in intracellular amino acid levels. Examination of the serine-glycine synthesis pathway reveals that KDM4C epigenetically activates the pathway genes under steady-state and serine deprivation conditions by removing the repressive histone modification H3 lysine 9 (H3K9) trimethylation. This action of KDM4C requires ATF4, a transcriptional master regulator of amino acid metabolism and stress responses. KDM4C activates ATF4 transcription and interacts with ATF4 to target serine pathway genes for transcriptional activation. We further present evidence for KDM4C in transcriptional coordination of amino acid metabolism and cell proliferation. These findings suggest a molecular mechanism linking KDM4C-mediated H3K9 demethylation and ATF4-mediated transactivation in reprogramming amino acid metabolism for cancer cell proliferation. PMID:26774480

  13. Bile Acids, FXR, and Metabolic Effects of Bariatric Surgery

    PubMed Central

    Noel, Olivier F.; Still, Christopher D.; Argyropoulos, George; Edwards, Michael; Gerhard, Glenn S.

    2016-01-01

    Overweight and obesity represent major risk factors for diabetes and related metabolic diseases. Obesity is associated with a chronic and progressive inflammatory response leading to the development of insulin resistance and type 2 diabetes (T2D) mellitus, although the precise mechanism mediating this inflammatory process remains poorly understood. The most effective intervention for the treatment of obesity, bariatric surgery, leads to glucose normalization and remission of T2D. Recent work in both clinical studies and animal models supports bile acids (BAs) as key mediators of these effects. BAs are involved in lipid and glucose homeostasis primarily via the farnesoid X receptor (FXR) transcription factor. BAs are also involved in regulating genes involved in inflammation, obesity, and lipid metabolism. Here, we review the novel role of BAs in bariatric surgery and the intersection between BAs and immune, obesity, weight loss, and lipid metabolism genes. PMID:27006824

  14. Red cell metabolism studies on Skylab

    NASA Technical Reports Server (NTRS)

    Mengel, C. E.

    1974-01-01

    On the basis of these background data, metabolic studies were performed on humans involved in space flight. These studies included the Skylab experiences. The primary purpose of the investigations was to study red cells for: (1) evidences of lipid peroxidation, or (2) changes at various points in the glycolytic pathway. The Skylab missions were an opportunity to study blood samples before, during, and after flight and to compare results with simultaneous controls. No direct evidence that lipid peroxidation had occurred in the red blood cells was apparent in the studies.

  15. Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance.

    PubMed

    Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

    2015-11-01

    Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a "push" (synthesis) and "pull" (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses.

  16. Metabolic features of the cell danger response.

    PubMed

    Naviaux, Robert K

    2014-05-01

    The cell danger response (CDR) is the evolutionarily conserved metabolic response that protects cells and hosts from harm. It is triggered by encounters with chemical, physical, or biological threats that exceed the cellular capacity for homeostasis. The resulting metabolic mismatch between available resources and functional capacity produces a cascade of changes in cellular electron flow, oxygen consumption, redox, membrane fluidity, lipid dynamics, bioenergetics, carbon and sulfur resource allocation, protein folding and aggregation, vitamin availability, metal homeostasis, indole, pterin, 1-carbon and polyamine metabolism, and polymer formation. The first wave of danger signals consists of the release of metabolic intermediates like ATP and ADP, Krebs cycle intermediates, oxygen, and reactive oxygen species (ROS), and is sustained by purinergic signaling. After the danger has been eliminated or neutralized, a choreographed sequence of anti-inflammatory and regenerative pathways is activated to reverse the CDR and to heal. When the CDR persists abnormally, whole body metabolism and the gut microbiome are disturbed, the collective performance of multiple organ systems is impaired, behavior is changed, and chronic disease results. Metabolic memory of past stress encounters is stored in the form of altered mitochondrial and cellular macromolecule content, resulting in an increase in functional reserve capacity through a process known as mitocellular hormesis. The systemic form of the CDR, and its magnified form, the purinergic life-threat response (PLTR), are under direct control by ancient pathways in the brain that are ultimately coordinated by centers in the brainstem. Chemosensory integration of whole body metabolism occurs in the brainstem and is a prerequisite for normal brain, motor, vestibular, sensory, social, and speech development. An understanding of the CDR permits us to reframe old concepts of pathogenesis for a broad array of chronic, developmental

  17. Metabolic features of the cell danger response.

    PubMed

    Naviaux, Robert K

    2014-05-01

    The cell danger response (CDR) is the evolutionarily conserved metabolic response that protects cells and hosts from harm. It is triggered by encounters with chemical, physical, or biological threats that exceed the cellular capacity for homeostasis. The resulting metabolic mismatch between available resources and functional capacity produces a cascade of changes in cellular electron flow, oxygen consumption, redox, membrane fluidity, lipid dynamics, bioenergetics, carbon and sulfur resource allocation, protein folding and aggregation, vitamin availability, metal homeostasis, indole, pterin, 1-carbon and polyamine metabolism, and polymer formation. The first wave of danger signals consists of the release of metabolic intermediates like ATP and ADP, Krebs cycle intermediates, oxygen, and reactive oxygen species (ROS), and is sustained by purinergic signaling. After the danger has been eliminated or neutralized, a choreographed sequence of anti-inflammatory and regenerative pathways is activated to reverse the CDR and to heal. When the CDR persists abnormally, whole body metabolism and the gut microbiome are disturbed, the collective performance of multiple organ systems is impaired, behavior is changed, and chronic disease results. Metabolic memory of past stress encounters is stored in the form of altered mitochondrial and cellular macromolecule content, resulting in an increase in functional reserve capacity through a process known as mitocellular hormesis. The systemic form of the CDR, and its magnified form, the purinergic life-threat response (PLTR), are under direct control by ancient pathways in the brain that are ultimately coordinated by centers in the brainstem. Chemosensory integration of whole body metabolism occurs in the brainstem and is a prerequisite for normal brain, motor, vestibular, sensory, social, and speech development. An understanding of the CDR permits us to reframe old concepts of pathogenesis for a broad array of chronic, developmental

  18. Fatty Acids in Energy Metabolism of the Central Nervous System

    PubMed Central

    Orynbayeva, Zulfiya; Vavilin, Valentin; Lyakhovich, Vyacheslav

    2014-01-01

    In this review, we analyze the current hypotheses regarding energy metabolism in the neurons and astroglia. Recently, it was shown that up to 20% of the total brain's energy is provided by mitochondrial oxidation of fatty acids. However, the existing hypotheses consider glucose, or its derivative lactate, as the only main energy substrate for the brain. Astroglia metabolically supports the neurons by providing lactate as a substrate for neuronal mitochondria. In addition, a significant amount of neuromediators, glutamate and GABA, is transported into neurons and also serves as substrates for mitochondria. Thus, neuronal mitochondria may simultaneously oxidize several substrates. Astrocytes have to replenish the pool of neuromediators by synthesis de novo, which requires large amounts of energy. In this review, we made an attempt to reconcile β-oxidation of fatty acids by astrocytic mitochondria with the existing hypothesis on regulation of aerobic glycolysis. We suggest that, under condition of neuronal excitation, both metabolic pathways may exist simultaneously. We provide experimental evidence that isolated neuronal mitochondria may oxidize palmitoyl carnitine in the presence of other mitochondrial substrates. We also suggest that variations in the brain mitochondrial metabolic phenotype may be associated with different mtDNA haplogroups. PMID:24883315

  19. Age dependency of the metabolic conversion of polyamines into amino acids in IMR-90 human embryonic lung diploid fibroblasts

    SciTech Connect

    Chen, K.Y.; Chang, Z.

    1986-07-01

    When radioactive polyamines (putrescine or spermidine) were incubated with mammalian cells in tissue culture, the radioactivity was incorporated into cellular proteins via two different metabolic pathways; one is metabolic labeling of an 18,000-dalton protein via hypusine formation, and the other is general protein synthesis employing radioactive amino acids derived from biodegradation of polyamines via GABA shunt and Krebs cycle. Aminoguanidine, a potent inhibitor of diamine oxidase, blocked the metabolic conversion of polyamines to amino acids but had no effect on the metabolic labeling of the 18,000-dalton protein. The authors have investigated these two polyamine-associated biochemical events in IMR-90 human diploid fibroblasts as a function of their population doubling level (PDL). They found that (1) the metabolic labeling of the 18,000-dalton protein was about two-fold greater in young cells (PDL = 22) than that in old cells (PDL = 48), and (2) the metabolic labeling of other cellular proteins, employing amino acids derived from putrescine via polyamine catabolic pathway, was more than six-fold greater in the old cells (PDL = 48) than in the young cells (PDL = 22). Since the rate of protein synthesis was about 1.4-fold higher in the young cells as compared to the old cells, their data indicated that the activity of catabolic conversion of putrescine (or spermidine) to amino acids in old IMR-90 cells was about eight-fold greater than that in young cells. This remarkable increase of polyamine catabolism and the slight decrease of metabolic labeling of the 18,000-dalton protein were also observed in cell strains derived from patients with premature aging disease.

  20. Pyroglutamic acid-induced metabolic acidosis: a case report.

    PubMed

    Luyasu, S; Wamelink, M M C; Galanti, L; Dive, A

    2014-06-01

    High anion gap metabolic acidosis due to pyroglutamic acid (5-oxoproline) is a rare complication of acetaminophen treatment (which depletes glutathione stores) and is often associated with clinically moderate to severe encephalopathy. Acquired 5-oxoprolinase deficiency (penicillins) or the presence of other risk factors of glutathione depletion such as malnutrition or sepsis seems to be necessary for symptoms development. We report the case of a 55-year-old women who developed a symptomatic overproduction of 5-oxoproline during flucloxacillin treatment for severe sepsis while receiving acetaminophen for fever control. Hemodialysis accelerated the clearance of the accumulated organic acid, and was followed by a sustained clinical improvement.

  1. Metabolic engineering of lactic acid bacteria for the production of industrially important compounds

    PubMed Central

    Papagianni, Maria

    2012-01-01

    Lactic acid bacteria (LAB) are receiving increased attention for use as cell factories for the production of metabolites with wide use by the food and pharmaceutical industries. The availability of efficient tools for genetic modification of LAB during the past decade permitted the application of metabolic engineering strategies at the levels of both the primary and the more complex secondary metabolism. The recent developments in the area with a focus on the production of industrially important metabolites will be discussed in this review. PMID:24688663

  2. Neutrophil chemotaxis and arachidonic acid metabolism are not linked: evidence from metal ion probe studies

    SciTech Connect

    Turner, S.R.; Turner, R.A.; Smith, D.M.; Johnson, J.A.

    1986-03-05

    Heavy metal ions can inhibit arachidonic acid (AA) metabolism protect against ionophore cytotoxicity (ibid) and inhibit neutrophil chemotaxis. In this study they used Au/sup 3 +/, Zn/sup 2 +/, Cr/sup 3 +/, Mn/sup 2 +/ and Cu/sup 2 +/ as probes of the interrelationships among AA metabolism, ionophore-mediated cytotoxicity, and chemotaxis. Phospholipid deacylation was measured in ionophore-treated cells prelabeled with /sup 3/H-AA. Eicosanoid release from ionophore-treated cells was monitored by radioimmunoassay. Cytoprotection was quantitated as ability to exclude trypan blue. Chemotaxis toward f-met-leu-phe was measured by leading front analysis. The results imply that metal ions attenuate ionophore cytotoxicity by blocking phospholipid deacylation and eicosanoid release. In contrast to previous reports, no correlation between AA metabolism and chemotaxis was demonstrated, suggesting that these 2 processes are not linked.

  3. Tissue of origin dictates branched-chain amino acid metabolism in mutant Kras-driven cancers.

    PubMed

    Mayers, Jared R; Torrence, Margaret E; Danai, Laura V; Papagiannakopoulos, Thales; Davidson, Shawn M; Bauer, Matthew R; Lau, Allison N; Ji, Brian W; Dixit, Purushottam D; Hosios, Aaron M; Muir, Alexander; Chin, Christopher R; Freinkman, Elizaveta; Jacks, Tyler; Wolpin, Brian M; Vitkup, Dennis; Vander Heiden, Matthew G

    2016-09-01

    Tumor genetics guides patient selection for many new therapies, and cell culture studies have demonstrated that specific mutations can promote metabolic phenotypes. However, whether tissue context defines cancer dependence on specific metabolic pathways is unknown. Kras activation and Trp53 deletion in the pancreas or the lung result in pancreatic ductal adenocarinoma (PDAC) or non-small cell lung carcinoma (NSCLC), respectively, but despite the same initiating events, these tumors use branched-chain amino acids (BCAAs) differently. NSCLC tumors incorporate free BCAAs into tissue protein and use BCAAs as a nitrogen source, whereas PDAC tumors have decreased BCAA uptake. These differences are reflected in expression levels of BCAA catabolic enzymes in both mice and humans. Loss of Bcat1 and Bcat2, the enzymes responsible for BCAA use, impairs NSCLC tumor formation, but these enzymes are not required for PDAC tumor formation, arguing that tissue of origin is an important determinant of how cancers satisfy their metabolic requirements. PMID:27609895

  4. Tissue of origin dictates branched-chain amino acid metabolism in mutant Kras-driven cancers.

    PubMed

    Mayers, Jared R; Torrence, Margaret E; Danai, Laura V; Papagiannakopoulos, Thales; Davidson, Shawn M; Bauer, Matthew R; Lau, Allison N; Ji, Brian W; Dixit, Purushottam D; Hosios, Aaron M; Muir, Alexander; Chin, Christopher R; Freinkman, Elizaveta; Jacks, Tyler; Wolpin, Brian M; Vitkup, Dennis; Vander Heiden, Matthew G

    2016-09-01

    Tumor genetics guides patient selection for many new therapies, and cell culture studies have demonstrated that specific mutations can promote metabolic phenotypes. However, whether tissue context defines cancer dependence on specific metabolic pathways is unknown. Kras activation and Trp53 deletion in the pancreas or the lung result in pancreatic ductal adenocarinoma (PDAC) or non-small cell lung carcinoma (NSCLC), respectively, but despite the same initiating events, these tumors use branched-chain amino acids (BCAAs) differently. NSCLC tumors incorporate free BCAAs into tissue protein and use BCAAs as a nitrogen source, whereas PDAC tumors have decreased BCAA uptake. These differences are reflected in expression levels of BCAA catabolic enzymes in both mice and humans. Loss of Bcat1 and Bcat2, the enzymes responsible for BCAA use, impairs NSCLC tumor formation, but these enzymes are not required for PDAC tumor formation, arguing that tissue of origin is an important determinant of how cancers satisfy their metabolic requirements.

  5. Maintenance Carbon Cycle in Crassulacean Acid Metabolism Plant Leaves 1

    PubMed Central

    Kenyon, William H.; Severson, Ray F.; Black, Clanton C.

    1985-01-01

    The reciprocal relationship between diurnal changes in organic acid and storage carbohydrate was examined in the leaves of three Crassulacean acid metabolism plants. It was found that depletion of leaf hexoses at night was sufficient to account quantitatively for increase in malate in Ananas comosus but not in Sedum telephium or Kalanchoë daigremontiana. Fructose and to a lesser extent glucose underwent the largest changes. Glucose levels in S. telephium leaves oscillated diurnally but were not reciprocally related to malate fluctuations. Analysis of isolated protoplasts and vacuoles from leaves of A. comosus and S. telephium revealed that vacuoles contain a large percentage (>50%) of the protoplast glucose, fructose and malate, citrate, isocitrate, ascorbate and succinate. Sucrose, a major constituent of intact leaves, was not detectable or was at extremely low levels in protoplasts and vacuoles from both plants. In isolated vacuoles from both A. comosus and S. telephium, hexose levels decreased at night at the same time malate increased. Only in A. comosus, however, could hexose metabolism account for a significant amount of the nocturnal increase in malate. We conclude that, in A. comosus, soluble sugars are part of the daily maintenance carbon cycle and that the vacuole plays a dynamic role in the diurnal carbon assimilation cycle of this Crassulacean acid metabolism plant. PMID:16664005

  6. Mechanisms of triglyceride metabolism in patients with bile acid diarrhea

    PubMed Central

    Sagar, Nidhi Midhu; McFarlane, Michael; Nwokolo, Chuka; Bardhan, Karna Dev; Arasaradnam, Ramesh Pulendran

    2016-01-01

    Bile acids (BAs) are essential for the absorption of lipids. BA synthesis is inhibited through intestinal farnesoid X receptor (FXR) activity. BA sequestration is known to influence BA metabolism and control serum lipid concentrations. Animal data has demonstrated a regulatory role for the FXR in triglyceride metabolism. FXR inhibits hepatic lipogenesis by inhibiting the expression of sterol regulatory element binding protein 1c via small heterodimer primer activity. Conversely, FXR promotes free fatty acids oxidation by inducing the expression of peroxisome proliferator-activated receptor α. FXR can reduce the expression of microsomal triglyceride transfer protein, which regulates the assembly of very low-density lipoproteins (VLDL). FXR activation in turn promotes the clearance of circulating triglycerides by inducing apolipoprotein C-II, very low-density lipoproteins receptor (VLDL-R) and the expression of Syndecan-1 together with the repression of apolipoprotein C-III, which increases lipoprotein lipase activity. There is currently minimal clinical data on triglyceride metabolism in patients with bile acid diarrhoea (BAD). Emerging data suggests that a third of patients with BAD have hypertriglyceridemia. Further research is required to establish the risk of hypertriglyceridaemia in patients with BAD and elicit the mechanisms behind this, allowing for targeted treatment. PMID:27570415

  7. Mechanisms of triglyceride metabolism in patients with bile acid diarrhea.

    PubMed

    Sagar, Nidhi Midhu; McFarlane, Michael; Nwokolo, Chuka; Bardhan, Karna Dev; Arasaradnam, Ramesh Pulendran

    2016-08-14

    Bile acids (BAs) are essential for the absorption of lipids. BA synthesis is inhibited through intestinal farnesoid X receptor (FXR) activity. BA sequestration is known to influence BA metabolism and control serum lipid concentrations. Animal data has demonstrated a regulatory role for the FXR in triglyceride metabolism. FXR inhibits hepatic lipogenesis by inhibiting the expression of sterol regulatory element binding protein 1c via small heterodimer primer activity. Conversely, FXR promotes free fatty acids oxidation by inducing the expression of peroxisome proliferator-activated receptor α. FXR can reduce the expression of microsomal triglyceride transfer protein, which regulates the assembly of very low-density lipoproteins (VLDL). FXR activation in turn promotes the clearance of circulating triglycerides by inducing apolipoprotein C-II, very low-density lipoproteins receptor (VLDL-R) and the expression of Syndecan-1 together with the repression of apolipoprotein C-III, which increases lipoprotein lipase activity. There is currently minimal clinical data on triglyceride metabolism in patients with bile acid diarrhoea (BAD). Emerging data suggests that a third of patients with BAD have hypertriglyceridemia. Further research is required to establish the risk of hypertriglyceridaemia in patients with BAD and elicit the mechanisms behind this, allowing for targeted treatment. PMID:27570415

  8. Ancestral genetic complexity of arachidonic acid metabolism in Metazoa.

    PubMed

    Yuan, Dongjuan; Zou, Qiuqiong; Yu, Ting; Song, Cuikai; Huang, Shengfeng; Chen, Shangwu; Ren, Zhenghua; Xu, Anlong

    2014-09-01

    Eicosanoids play an important role in inducing complex and crucial physiological processes in animals. Eicosanoid biosynthesis in animals is widely reported; however, eicosanoid production in invertebrate tissue is remarkably different to vertebrates and in certain respects remains elusive. We, for the first time, compared the orthologs involved in arachidonic acid (AA) metabolism in 14 species of invertebrates and 3 species of vertebrates. Based on parsimony, a complex AA-metabolic system may have existed in the common ancestor of the Metazoa, and then expanded and diversified through invertebrate lineages. A primary vertebrate-like AA-metabolic system via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways was further identified in the basal chordate, amphioxus. The expression profiling of AA-metabolic enzymes and lipidomic analysis of eicosanoid production in the tissues of amphioxus supported our supposition. Thus, we proposed that the ancestral complexity of AA-metabolic network diversified with the different lineages of invertebrates, adapting with the diversity of body plans and ecological opportunity, and arriving at the vertebrate-like pattern in the basal chordate, amphioxus.

  9. Ancestral genetic complexity of arachidonic acid metabolism in Metazoa.

    PubMed

    Yuan, Dongjuan; Zou, Qiuqiong; Yu, Ting; Song, Cuikai; Huang, Shengfeng; Chen, Shangwu; Ren, Zhenghua; Xu, Anlong

    2014-09-01

    Eicosanoids play an important role in inducing complex and crucial physiological processes in animals. Eicosanoid biosynthesis in animals is widely reported; however, eicosanoid production in invertebrate tissue is remarkably different to vertebrates and in certain respects remains elusive. We, for the first time, compared the orthologs involved in arachidonic acid (AA) metabolism in 14 species of invertebrates and 3 species of vertebrates. Based on parsimony, a complex AA-metabolic system may have existed in the common ancestor of the Metazoa, and then expanded and diversified through invertebrate lineages. A primary vertebrate-like AA-metabolic system via cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome P450 (CYP) pathways was further identified in the basal chordate, amphioxus. The expression profiling of AA-metabolic enzymes and lipidomic analysis of eicosanoid production in the tissues of amphioxus supported our supposition. Thus, we proposed that the ancestral complexity of AA-metabolic network diversified with the different lineages of invertebrates, adapting with the diversity of body plans and ecological opportunity, and arriving at the vertebrate-like pattern in the basal chordate, amphioxus. PMID:24801744

  10. Metabolic regulation of T cell differentiation and function

    PubMed Central

    Park, Benjamin V.; Pan, Fan

    2016-01-01

    Upon encountering pathogens, T cells mount immune responses by proliferating, increasing cellular mass and differentiating. These cellular changes impose significant energetic challenges on T cells. It was believed that TCR and cytokine-mediated signaling are dominant dictators of T cell-mediated immune responses. Recently, it was recognized that T cells utilize metabolic transporters and metabolic sensors that allow them to rapidly respond to nutrient-limiting inflammatory environments. Metabolic sensors allow T cells to find a balance between energy consumption (anabolic metabolism) and production (catabolic metabolism) in order to mount effective immune responses. Also, metabolic regulators interact with cytokine-dependent transcriptional regulators, suggesting a more integrative and advanced model of T cell activation and differentiation. In this review, we will discuss recent discoveries regarding the roles of metabolic regulators in effector and memory T cell development and their interaction with canonical transcription factors. PMID:26277275

  11. Organic Acid Metabolism by Isolated Rhizobium japonicum Bacteroids

    PubMed Central

    Stovall, Iris; Cole, Michael

    1978-01-01

    Rhizobium japonicum bacteroids isolated from soybean (Glycine max L.) nodules oxidized 14C-labeled succinate, pyruvate, and acetate in a manner consistent with operation of the tricarboxylic acid cycle and a partial glyoxylate cycle. Substrate carbon was incorporated into all major cellular components (cell wall + membrane, nucleic acids, and protein). PMID:16660386

  12. Metabolic reprogramming of myeloid-derived suppressor cells (MDSC) in cancer.

    PubMed

    Al-Khami, Amir A; Rodriguez, Paulo C; Ochoa, Augusto C

    2016-08-01

    MDSC undergo metabolic reprogramming in the tumor resulting in an increased fatty acid β oxidation that supports their immunosuppressive functions. Fatty acid oxidation inhibitors, used to treat coronary disease, significantly delayed tumor growth and had a significantly increased antitumor effect when combined with adoptive cell therapy or low dose chemotherapy. PMID:27622069

  13. D-Serine metabolism in C6 glioma cells: Involvement of alanine-serine-cysteine transporter (ASCT2) and serine racemase (SRR) but not D-amino acid oxidase (DAO)

    PubMed Central

    Sikka, Pilleriin; Walker, Rosie; Cockayne, Rebecca; Wood, Matthew JA; Harrison, Paul J; Burnet, Philip WJ

    2010-01-01

    D-serine is an endogenous N-methyl-D-aspartate (NMDA) receptor coagonist. It is synthesized from L-serine by serine racemase (SRR), but many aspects of its metabolism remain unclear, especially in the forebrain, which lacks active D-amino acid oxidase (DAO), the major D-serine degradative enzyme. Candidate mechanisms include SRR operating in α,β-eliminase mode (converting D-serine to pyruvate) and regulation by serine transport, in which the alanine-serine-cysteine transporter ASCT2 is implicated. Here we report studies in C6 glioma cells, which “simulate” the forebrain, in that the cells express SRR and ASCT2 but lack DAO activity. We measured D-serine, ASCT2, SRR, and DAO expression and DAO activity in two situations: after incubation of cells for 48 hr with serine isomers and after increased or decreased SRR expression by transfection and RNA interference, respectively. Incubation with serine enantiomers decreased [3H]D-serine uptake and ASCT2 mRNA and increased SRR immunoreactivity but did not alter DAO immunoreactivity, and DAO activity remained undetectable. SRR overexpression increased D-serine and pyruvate and decreased [3H]D-serine uptake and ASCT2 mRNA but did not affect DAO. SRR knockdown did not alter any of the parameters. Our data suggest that D-serine transport mediated by ASCT2 contributes prominently to D-serine homeostasis when DAO activity is absent. The factors regulating D-serine are important for understanding normal NMDA receptor function and because D-serine, along with DAO and SRR, is implicated in the pathogenesis and treatment of schizophrenia. © 2010 Wiley-Liss, Inc. PMID:20091774

  14. The effect of immunosuppressive molecules on T-cell metabolic reprogramming.

    PubMed

    Fernández-Ramos, Ana A; Poindessous, Virginie; Marchetti-Laurent, Catherine; Pallet, Nicolas; Loriot, Marie-Anne

    2016-08-01

    T lymphocytes undergo metabolic reprogramming to adapt to extracellular and intracellular cues. Specifically, T-cell metabolism results into ATP production, anabolism and catabolism pathways that not only support rapid cell growth and proliferation, but also differentiation and effector functions, recently referred as "immunometabolism". Quiescent naïve T cells rely on oxidative phosphorylation whereas aerobic glycolysis (Warburg effect) occurs in activated T cells (effector CD4(+) and CD8(+)). The molecular mechanisms that sense metabolic status and influence T-cell function require metabolic checkpoints including sensors of metabolic signals and transducers (Myc, HIF-1α, AMPK and mTOR). These metabolic checkpoints represent a novel therapeutic strategy for immune modulation. Interestingly, many immunosuppressive drugs including mTOR inhibitors (rapamycin), calcineurin inhibitors (tacrolimus, cyclosporine A) and inhibitors of de novo purine synthesis (6-mercaptopurine, mycophenolic acid and methotrexate) provide examples into how modulating these metabolic checkpoints can regulate T-cell activation, differentiation and function. In this Review we highlight emerging concepts about metabolic reprogramming in T-cell responses and we discuss the potential therapeutic interventions to influence T-cell fate and effector function. PMID:27126071

  15. The effect of immunosuppressive molecules on T-cell metabolic reprogramming.

    PubMed

    Fernández-Ramos, Ana A; Poindessous, Virginie; Marchetti-Laurent, Catherine; Pallet, Nicolas; Loriot, Marie-Anne

    2016-08-01

    T lymphocytes undergo metabolic reprogramming to adapt to extracellular and intracellular cues. Specifically, T-cell metabolism results into ATP production, anabolism and catabolism pathways that not only support rapid cell growth and proliferation, but also differentiation and effector functions, recently referred as "immunometabolism". Quiescent naïve T cells rely on oxidative phosphorylation whereas aerobic glycolysis (Warburg effect) occurs in activated T cells (effector CD4(+) and CD8(+)). The molecular mechanisms that sense metabolic status and influence T-cell function require metabolic checkpoints including sensors of metabolic signals and transducers (Myc, HIF-1α, AMPK and mTOR). These metabolic checkpoints represent a novel therapeutic strategy for immune modulation. Interestingly, many immunosuppressive drugs including mTOR inhibitors (rapamycin), calcineurin inhibitors (tacrolimus, cyclosporine A) and inhibitors of de novo purine synthesis (6-mercaptopurine, mycophenolic acid and methotrexate) provide examples into how modulating these metabolic checkpoints can regulate T-cell activation, differentiation and function. In this Review we highlight emerging concepts about metabolic reprogramming in T-cell responses and we discuss the potential therapeutic interventions to influence T-cell fate and effector function.

  16. Radiometric measurement of differential metabolism of fatty acid by mycobacteria

    SciTech Connect

    Camargo, E.E.; Kertcher, J.A.; Larson, S.M.; Tepper, B.S.; Wagner, H.N. Jr.

    1982-06-01

    An assay system has been developed based on automated radiometric quantification of /sup 14/CO2 produced through oxidation of (1-/sup 14/C) fatty acids by mycobacteria. Two stains of M. tuberculosis (H37Rv and Erdman) and one of M. bovis (BCG) in 7H9 medium (ADC) with 1.0 microCi of one of the fatty acids (butyric, hexanoic, octanoic, decanoic, lauric, myristic, palmitic, stearic, oleic, linoleic and linolenic) were studied. Results previously published on M. lepraemurium (Hawaiian) were also included for comparison. Both strains of M. tuberculosis had maximum /sup 14/CO2 production from hexanoic acid. Oxidation of butyric and avid oxidation of lauric acids were also found with the H37Rv strain but not with Erdman. In contrast, /sup 14/CO2 production by M. bovis was greatest from lauric and somewhat less from decanoic acid. M. lepraemurium showed increasing oxidation rates from myristic, decanoic and lauric acids. Assimilation studies of M. tuberculosis H37Rv confirmed that most of the oxidized substrates were converted into by-products with no change in those from which no oxidation was found. These data suggest that the radiometric measurement of differential fatty acid metabolism may provide a basis of strain identification of the genus Mycobacterium.

  17. Metabolic engineering of biocatalysts for carboxylic acids production

    PubMed Central

    Liu, Ping; Jarboe, Laura R.

    2012-01-01

    Fermentation of renewable feedstocks by microbes to produce sustainable fuels and chemicals has the potential to replace petrochemical-based production. For example, carboxylic acids produced by microbial fermentation can be used to generate primary building blocks of industrial chemicals by either enzymatic or chemical catalysis. In order to achieve the titer, yield and productivity values required for economically viable processes, the carboxylic acid-producing microbes need to be robust and well-performing. Traditional strain development methods based on mutagenesis have proven useful in the selection of desirable microbial behavior, such as robustness and carboxylic acid production. On the other hand, rationally-based metabolic engineering, like genetic manipulation for pathway design, has becoming increasingly important to this field and has been used for the production of several organic acids, such as succinic acid, malic acid and lactic acid. This review investigates recent works on Saccharomyces cerevisiae and Escherichia coli, as well as the strategies to improve tolerance towards these chemicals. PMID:24688671

  18. Biochemistry and genetics of inherited disorders of peroxisomal fatty acid metabolism[S

    PubMed Central

    Van Veldhoven, Paul P.

    2010-01-01

    In humans, peroxisomes harbor a complex set of enzymes acting on various lipophilic carboxylic acids, organized in two basic pathways, α-oxidation and β-oxidation; the latter pathway can also handle ω-oxidized compounds. Some oxidation products are crucial to human health (primary bile acids and polyunsaturated FAs), whereas other substrates have to be degraded in order to avoid neuropathology at a later age (very long-chain FAs and xenobiotic phytanic acid and pristanic acid). Whereas total absence of peroxisomes is lethal, single peroxisomal protein deficiencies can present with a mild or severe phenotype and are more informative to understand the pathogenic factors. The currently known single protein deficiencies equal about one-fourth of the number of proteins involved in peroxisomal FA metabolism. The biochemical properties of these proteins are highlighted, followed by an overview of the known diseases. PMID:20558530

  19. Production of omega-3 eicosapentaenoic acid by metabolic engineering of Yarrowia lipolytica.

    PubMed

    Xue, Zhixiong; Sharpe, Pamela L; Hong, Seung-Pyo; Yadav, Narendra S; Xie, Dongming; Short, David R; Damude, Howard G; Rupert, Ross A; Seip, John E; Wang, Jamie; Pollak, Dana W; Bostick, Michael W; Bosak, Melissa D; Macool, Daniel J; Hollerbach, Dieter H; Zhang, Hongxiang; Arcilla, Dennis M; Bledsoe, Sidney A; Croker, Kevin; McCord, Elizabeth F; Tyreus, Bjorn D; Jackson, Ethel N; Zhu, Quinn

    2013-08-01

    The availability of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is currently limited because they are produced mainly by marine fisheries that cannot keep pace with the demands of the growing market for these products. A sustainable non-animal source of EPA and DHA is needed. Metabolic engineering of the oleaginous yeast Yarrowia lipolytica resulted in a strain that produced EPA at 15% of dry cell weight. The engineered yeast lipid comprises EPA at 56.6% and saturated fatty acids at less than 5% by weight, which are the highest and the lowest percentages, respectively, among known EPA sources. Inactivation of the peroxisome biogenesis gene PEX10 was crucial in obtaining high EPA yields and may increase the yields of other commercially desirable lipid-related products. This technology platform enables the production of lipids with tailored fatty acid compositions and provides a sustainable source of EPA.

  20. Metabolic requirements for the maintenance of self-renewing stem cells

    PubMed Central

    Ito, Keisuke; Suda, Toshio

    2014-01-01

    A distinctive feature of stem cells is their capacity to self-renew to maintain pluripotency. Studies of genetically-engineered mouse models and recent advances in metabolomic analysis, particularly in haematopoietic stem cells, have deepened our understanding of the contribution made by metabolic cues to the regulation of stem cell self-renewal. Many types of stem cells heavily rely on anaerobic glycolysis, and stem cell function is also regulated by bioenergetic signalling, the AKT–mTOR pathway, Gln metabolism and fatty acid metabolism. As maintenance of a stem cell pool requires a finely-tuned balance between self-renewal and differentiation, investigations into the molecular mechanisms and metabolic pathways underlying these decisions hold great therapeutic promise. PMID:24651542

  1. [Disturbances of folic acid and homocysteine metabolism in alcohol abuse].

    PubMed

    Cylwik, Bogdan; Chrostek, Lech

    2011-04-01

    Chronic alcohol abuse leads to malnutrition, and thus to the deficiency of many nutrients, including vitamins and trace elements. Most often comes to the deficiency of all vitamins, however because the clinical implications, the most important is folic acid (vitamin B9) deficiency. Biochemical effect of folate deficiency is elevated homocysteine concentration in the blood, named "cholesterol of XXI. century". In the paper, the folate and homocysteine metabolism in alcohol abuse was discussed. Mechanisms of alcohol action on folate homeostasis in the human body have been indicated. Chronic alcohol consumption leads to deficiency of this vitamin due to their dietary inadequacy, intestinal malabsorption, decreased hepatic uptake and increased body excretion, mainly via urine. The decreased concentration of serum folic acid may occur in 80% of alcoholics. The cause of elevated concentrations of homocysteine in the serum of alcohol abusers is also a deficiency of vitamins involved such as vitamin B12 and pyridoxal phosphate. Disturbance of folic acid and homocysteine metabolism in alcohol abusers can lead to serious clinical consequences. Folic acid deficiency leads inter alia to macrocytic and megaloblastic anemia and neurological disorders. Megaloblastic anemia occurs in about half of alcohol abusers with chronic liver diseases. In turn, high level of homocysteine in blood is associated with an inreased risk of cardiovascular diseases. Hyperhomocysteinemia is an independent risk factor that favors the occurrence of acute coronary syndromes in patients with coronary heart disease.

  2. Hydroxyoctadecadienoic acids: Oxidised derivatives of linoleic acid and their role in inflammation associated with metabolic syndrome and cancer.

    PubMed

    Vangaveti, Venkat N; Jansen, Holger; Kennedy, Richard Lee; Malabu, Usman H

    2016-08-15

    Linoleic acid (LA) is a major constituent of low-density lipoproteins. An essential fatty acid, LA is a polyunsaturated fatty acid, which is oxidised by endogenous enzymes and reactive oxygen species in the circulation. Increased levels of low-density lipoproteins coupled with oxidative stress and lack of antioxidants drive the oxidative processes. This results in synthesis of a range of oxidised derivatives, which play a vital role in regulation of inflammatory processes. The derivatives of LA include, hydroxyoctadecadienoic acids, oxo-​octadecadienoic acids, epoxy octadecadecenoic acid and epoxy-keto-octadecenoic acids. In this review, we examine the role of LA derivatives and their actions on regulation of inflammation relevant to metabolic processes associated with atherogenesis and cancer. The processes affected by LA derivatives include, alteration of airway smooth muscles and vascular wall, affecting sensitivity to pain, and regulating endogenous steroid hormones associated with metabolic syndrome. LA derivatives alter cell adhesion molecules, this initial step, is pivotal in regulating inflammatory processes involving transcription factor peroxisome proliferator-activated receptor pathways, thus, leading to alteration of metabolic processes. The derivatives are known to elicit pleiotropic effects that are either beneficial or detrimental in nature hence making it difficult to determine the exact role of these derivatives in the progress of an assumed target disorder. The key may lie in understanding the role of these derivatives at various stages of development of a disorder. Novel pharmacological approaches in altering the synthesis or introduction of synthesised LA derivatives could possibly help drive processes that could regulate inflammation in a beneficial manner. Chemical Compounds: Linoleic acid (PubChem CID: 5280450), 9- hydroxyoctadecadienoic acid (PubChem CID: 5312830), 13- hydroxyoctadecadienoic acid (PubChem CID: 6443013), 9-oxo

  3. [Energy metabolism of Ehrlich ascites cancer cells].

    PubMed

    del Pozo, A M; Valladares, Y; Alvarez Rodríguez, Y

    1983-01-01

    Cell respiration (CR) and glycolysis (GL) are the main sources cell energy, since along their metabolic pathways ATP is produced. Expressed as microM/100 mg/h, normal cells produce 63 by CR, 0.2 by aerobic GL, and 9.37 by anaerobic GL, while cancer cells produce 35 by CR, 18 by aerobic GL, and 29 by anaerobic GL. The ascites fluid from EAC increases the anaerobic GL to 38, while it does not change the aerobic GL to 7 and diminishes the CR to 26. Insulin produces a lowering of CR to 26, aerobic GL to 26 and anaerobic GL to 22. Glucose inhibits CR and stimulates GL. Ribose does not modify CR and inhibits GL. Mannose inhibits both CR and GL. Ribonuclease increases GL in the presence of glucose but not of ribose. Glucose-phosphate and ribose-phosphate have no action because they do not enter into the cell. Expressed as QLN2/100 mg, the main localization of GL is the cytosol (480), but it is significant in the nucleus (170), and diminishes in microsomes (100) and mitochondria (52). Mitochondria inhibit the cytosol glycolytic activity when they are either in the usual proportion they have in the cell or in a higher proportion. It is curious the observation that a diminution of the relative concentration of mitochondria with regard to cytosol (1/100 to 1/1000) produces a marked increase of GL. The addition of nuclear fraction stabilizes the cytosol-mitochondria complex and modifies the metabolic pathway of the CO2 that is produced during the GL.

  4. Regulation of inflammatory and lipid metabolism genes by eicosapentaenoic acid-rich oil[S

    PubMed Central

    Gillies, Peter J.; Bhatia, Sujata K.; Belcher, Leigh A; Hannon, Daniel B.; Thompson, Jerry T.; Vanden Heuvel, John P.

    2012-01-01

    Omega-3-PUFAs, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), are associated with prevention of various aspects of metabolic syndrome. In the present studies, the effects of oil rich in EPA on gene expression and activation of nuclear receptors was examined and compared with other ω3-PUFAs. The EPA-rich oil (EO) altered the expression of FA metabolism genes in THP-1 cells, including stearoyl CoA desaturase (SCD) and FA desaturase-1 and -2 (FASDS1 and -2). Other ω3-PUFAs resulted in a similar gene expression response for a subset of genes involved in lipid metabolism and inflammation. In reporter assays, EO activated human peroxisome proliferator-activated receptor α (PPARα) and PPARβ/γ with minimal effects on PPARγ, liver X receptor, retinoid X receptor, farnesoid X receptor, and retinoid acid receptor γ (RARγ); these effects were similar to that observed for purified EPA. When serum from a 6 week clinical intervention with dietary supplements containing olive oil (control), DHA, or two levels of EPA were applied to THP-1 cells, the expression of SCD and FADS2 decreased in the cells treated with serum from the ω3-PUFA-supplemented individuals. Taken together, these studies indicate regulation of gene expression by EO that is consistent with treating aspects of dyslipidemia and inflammation. PMID:22556214

  5. Amino acids in the cultivation of mammalian cells.

    PubMed

    Salazar, Andrew; Keusgen, Michael; von Hagen, Jörg

    2016-05-01

    Amino acids are crucial for the cultivation of mammalian cells. This importance of amino acids was realized soon after the development of the first cell lines, and a solution of a mixture of amino acids has been supplied to cultured cells ever since. The importance of amino acids is further pronounced in chemically defined mammalian cell culture media, making the consideration of their biological and chemical properties necessary. Amino acids concentrations have been traditionally adjusted to their cellular consumption rates. However, since changes in the metabolic equilibrium of amino acids can be caused by changes in extracellular concentrations, metabolomics in conjunction with flux balance analysis is being used in the development of culture media. The study of amino acid transporters is also gaining importance since they control the intracellular concentrations of these molecules and are influenced by conditions in cell culture media. A better understanding of the solubility, stability, dissolution kinetics, and interactions of these molecules is needed for an exploitation of these properties in the development of dry powdered chemically defined media for mammalian cells. Due to the complexity of these mixtures however, this has proven to be challenging. Studying amino acids in mammalian cell culture media will help provide a better understanding of how mammalian cells in culture interact with their environment. It would also provide insight into the chemical behavior of these molecules in solutions of complex mixtures, which is important in the understanding of the contribution of individual amino acids to protein structure. PMID:26832172

  6. Amino acids in the cultivation of mammalian cells.

    PubMed

    Salazar, Andrew; Keusgen, Michael; von Hagen, Jörg

    2016-05-01

    Amino acids are crucial for the cultivation of mammalian cells. This importance of amino acids was realized soon after the development of the first cell lines, and a solution of a mixture of amino acids has been supplied to cultured cells ever since. The importance of amino acids is further pronounced in chemically defined mammalian cell culture media, making the consideration of their biological and chemical properties necessary. Amino acids concentrations have been traditionally adjusted to their cellular consumption rates. However, since changes in the metabolic equilibrium of amino acids can be caused by changes in extracellular concentrations, metabolomics in conjunction with flux balance analysis is being used in the development of culture media. The study of amino acid transporters is also gaining importance since they control the intracellular concentrations of these molecules and are influenced by conditions in cell culture media. A better understanding of the solubility, stability, dissolution kinetics, and interactions of these molecules is needed for an exploitation of these properties in the development of dry powdered chemically defined media for mammalian cells. Due to the complexity of these mixtures however, this has proven to be challenging. Studying amino acids in mammalian cell culture media will help provide a better understanding of how mammalian cells in culture interact with their environment. It would also provide insight into the chemical behavior of these molecules in solutions of complex mixtures, which is important in the understanding of the contribution of individual amino acids to protein structure.

  7. Pyruvate kinase triggers a metabolic feedback loop that controls redox metabolism in respiring cells.

    PubMed

    Grüning, Nana-Maria; Rinnerthaler, Mark; Bluemlein, Katharina; Mülleder, Michael; Wamelink, Mirjam M C; Lehrach, Hans; Jakobs, Cornelis; Breitenbach, Michael; Ralser, Markus

    2011-09-01

    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 when respiration is activated. Low PYK activity activated yeast respiration. However, levels of reactive oxygen species (ROS) did not increase, and cells gained resistance to oxidants. This adaptation was attributable to accumulation of the PYK substrate phosphoenolpyruvate (PEP). PEP acted as feedback inhibitor of the glycolytic enzyme triosephosphate isomerase (TPI). TPI inhibition stimulated the pentose phosphate pathway, increased antioxidative metabolism, and prevented ROS accumulation. Thus, a metabolic feedback loop, initiated by PYK, mediated by its substrate and acting on TPI, stimulates redox metabolism in respiring cells. Originating from a single catalytic step, this autonomous reconfiguration of central carbon metabolism prevents oxidative stress upon shifts between fermentation and respiration.

  8. Deregulation of lipid metabolism pathway genes in nasopharyngeal carcinoma cells.

    PubMed

    Daker, Maelinda; Bhuvanendran, Saatheeyavaane; Ahmad, Munirah; Takada, Kenzo; Khoo, Alan Soo-Beng

    2013-03-01

    Nasopharyngeal carcinoma (NPC) is a unique tumour of epithelial origin with a distinct geographical distribution, closely associated with the Epstein‑Barr virus (EBV). EBV‑encoded RNAs (EBERs) are small non‑polyadenylated RNAs that are abundantly expressed in latent EBV‑infected NPC cells. To study the role of EBERs in NPC, we established stable expression of EBERs in HK1, an EBV‑negative NPC cell line. Cells expressing EBERs consistently exhibited an increased growth rate. However, EBERs did not confer resistance towards cisplatin‑induced apoptosis or promote migration or invasion ability in the cells tested. Using microarray gene expression profiling, we identified potential candidate genes that were deregulated in NPC cells expressing EBERs. Gene Ontology analysis of the data set revealed that EBERs upregulate the cellular lipid metabolic process. Upregulation of low‑density lipoprotein receptor (LDLR) and fatty acid synthase (FASN) was observed in EBER‑expressing cells. NPC cells exhibited LDL‑dependent cell proliferation. In addition, a polyphenolic flavonoid compound, quercetin, known to inhibit FASN, was found to inhibit proliferation of NPC cells.

  9. Adipose tissue n-3 fatty acids and metabolic syndrome

    PubMed Central

    Cespedes, Elizabeth; Baylin, Ana; Campos, Hannia

    2014-01-01

    Background Evidence regarding the relationship of n-3 fatty acids (FA) to type 2 diabetes (T2D) and metabolic syndrome components (MetS) is inconsistent. Objective To examine associations of adipose tissue n-3 FA with MetS. Design We studied 1611 participants without prior history of diabetes or heart disease who were participants in a population-based case-control study of diet and heart disease (The Costa Rica Heart Study). We calculated prevalence ratios (PR) and 95% confidence intervals (CI) for MetS by quartile of n-3 FA in adipose tissue derived mainly from plants [α-Linolenic acid (ALA)], fish [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)], or metabolism [docosapentaenoic acid (DPA), as well as the EPA:ALA ratio, a surrogate marker of delta-6 desaturase activity]. Results N-3 FA levels in adipose tissue were associated with MetS prevalence in opposite directions. The PR (95% CI) for the highest compared to the lowest quartile adjusted for age, sex, BMI, residence, lifestyle, diet and other fatty acids were 0.60 (0.44, 0.81) for ALA, 1.43 (1.12, 1.82) for EPA, 1.63 (1.22, 2.18) for DPA, and 1.47 (1.14, 1.88) for EPA:ALA, all p for trend <0.05. Although these associations were no longer significant (except DPA) after adjustment for BMI, ALA and DPA were associated with lower glucose and higher triglyceride levels, p<0.05 (respectively). Conclusions These results suggest that ALA could exert a modest protective benefit, while EPA and DHA are not implicated in MetS. The positive associations for DPA and MetS could reflect higher delta-6 desaturase activity caused by increased adiposity. PMID:25097001

  10. Metabolic pathways promoting cancer cell survival and growth.

    PubMed

    Boroughs, Lindsey K; DeBerardinis, Ralph J

    2015-04-01

    Activation of oncogenes and loss of tumour suppressors promote metabolic reprogramming in cancer, resulting in enhanced nutrient uptake to supply energetic and biosynthetic pathways. However, nutrient limitations within solid tumours may require that malignant cells exhibit metabolic flexibility to sustain growth and survival. Here, we highlight these adaptive mechanisms and also discuss emerging approaches to probe tumour metabolism in vivo and their potential to expand the metabolic repertoire of malignant cells even further.

  11. Utilization of Lactic Acid by Fusarium oxysporum var. lini: Regulation of Transport and Metabolism

    PubMed Central

    Castro, Ieso M.; Loureiro-Dias, Maria C.

    1994-01-01

    Lactic acid was transported in Fusarium oxysporum var. lini ATCC 10960 by a saturable transport system that had a half-saturation constant of 56.6 ± 7.5 μM and a maximum velocity of 0.61 ± 0.10 mmol h-1 g-1 (dry weight) at 26°C and pH 5.0. This transport system was inducible and was not expressed in the presence of a repressing substrate. Evidence is presented that the anionic form lactate- was taken up by the cells. Propionic, acetic, pyruvic, and bromoacetic acids but not succinic acid competitively inhibited the transport of lactic acid. Bromoacetic acid, which was not metabolized, was taken up to a steady-state level when intracellular and extracellular concentrations were identical, indicating that the transport system was not accumulative. The enzymatic activity that was physiologically more relevant in the metabolism of lactic acid was lactate: ferricytochrome c oxidase. This enzyme did not exhibit stereospecifity and was induced by lactic acid. PMID:16349143

  12. Metabolic control of cell division in α-proteobacteria by a NAD-dependent glutamate dehydrogenase.

    PubMed

    Beaufay, François; De Bolle, Xavier; Hallez, Régis

    2016-01-01

    Prior to initiate energy-consuming processes, such as DNA replication or cell division, cells need to evaluate their metabolic status. We have recently identified and characterized a new connection between metabolism and cell division in the α-proteobacterium Caulobacter crescentus. We showed that an NAD-dependent glutamate dehydrogenase (GdhZ) coordinates growth with cell division according to its enzymatic activity. Here we report the conserved role of GdhZ in controlling cell division in another α-proteobacterium, the facultative intracellular pathogen Brucella abortus. We also discuss the importance of amino acids as a main carbon source for α-proteobacteria.

  13. In vitro metabolism and metabolic effects of ajulemic acid, a synthetic cannabinoid agonist.

    PubMed

    Burstein, Sumner H; Tepper, Mark A

    2013-12-01

    Ajulemic acid is a synthetic analog of Δ(8)-THC-11-oic acid, the terminal metabolite of Δ(8)-THC. Unlike Δ(9)-THC, the psychoactive principle of Cannabis, it shows potent anti-inflammatory action and has minimal CNS cannabimimetic activity. Its in vitro metabolism by hepatocytes from rats, dogs, cynomolgus monkeys and humans was studied and the results are reported here. Five metabolites, M1 to M5, were observed in human hepatocyte incubations. One metabolite, M5, a glucuronide, was observed in the chromatogram of canine hepatocyte incubations. In monkey hepatocyte incubations, M5 was observed in the chromatograms of both the 120 and 240 min samples, trace metabolite M1 (side-chain hydroxyl) was observed in the 120 min samples, and trace metabolite M4 (side-chain dehydrogenation) was observed in the 240 min samples. No metabolites were found in the rat hepatocyte incubations. Unchanged amounts of ajulemic acid detected after the 2-h incubation were 103%, 90%, 86%, and 83% for rat, dog, monkey, and human hepatocytes, respectively. Additional studies were done to ascertain if ajulemic acid can inhibit the activities of five principal human cytochrome P450 isozymes; CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5. In contrast to the phytocannabinoids Δ(9)-THC and CBD, no significant inhibition of cytochrome activity was observed. These data further support the conclusions reached in earlier reports on ajulemic acid's high margin of safety and suggest that it undergoes minimal metabolism and is not likely to interfere with the normal metabolism of drugs or endogenous substances. PMID:25505570

  14. In vitro metabolism and metabolic effects of ajulemic acid, a synthetic cannabinoid agonist

    PubMed Central

    Burstein, Sumner H; Tepper, Mark A

    2013-01-01

    Ajulemic acid is a synthetic analog of Δ8-THC-11-oic acid, the terminal metabolite of Δ8-THC. Unlike Δ9-THC, the psychoactive principle of Cannabis, it shows potent anti-inflammatory action and has minimal CNS cannabimimetic activity. Its in vitro metabolism by hepatocytes from rats, dogs, cynomolgus monkeys and humans was studied and the results are reported here. Five metabolites, M1 to M5, were observed in human hepatocyte incubations. One metabolite, M5, a glucuronide, was observed in the chromatogram of canine hepatocyte incubations. In monkey hepatocyte incubations, M5 was observed in the chromatograms of both the 120 and 240 min samples, trace metabolite M1 (side-chain hydroxyl) was observed in the 120 min samples, and trace metabolite M4 (side-chain dehydrogenation) was observed in the 240 min samples. No metabolites were found in the rat hepatocyte incubations. Unchanged amounts of ajulemic acid detected after the 2-h incubation were 103%, 90%, 86%, and 83% for rat, dog, monkey, and human hepatocytes, respectively. Additional studies were done to ascertain if ajulemic acid can inhibit the activities of five principal human cytochrome P450 isozymes; CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4/5. In contrast to the phytocannabinoids Δ9-THC and CBD, no significant inhibition of cytochrome activity was observed. These data further support the conclusions reached in earlier reports on ajulemic acid's high margin of safety and suggest that it undergoes minimal metabolism and is not likely to interfere with the normal metabolism of drugs or endogenous substances. PMID:25505570

  15. Effect of inhibitors of arachidonic acid metabolism on alpha-aminoisobutyric acid transport in human lymphocytes.

    PubMed

    Udey, M C; Parker, C W

    1982-02-01

    The role of arachidonic acid metabolism (or metabolites) in the modulation of alpha-aminoisobutyric acid transport in resting and concanavalin A-stimulated human peripheral blood lymphocytes was evaluated using previously characterized inhibitors of arachidonic acid metabolism. Nordihydroguairetic acid (a nonselective antioxidant), 5,8,11,14-eicosatetraynoic acid (an inhibitor of lipoxygenase and cyclooxygenase activities), indomethacin and acetylsalicylic acid (selective cyclooxygenase inhibitors), and 1-benzylimidazole, Ro-22-3581 and Ro-22-3582 (thromboxane synthetase inhibitors) proved to be potent inhibitors of amino acid transport activity in normal resting and lectin-activated lymphocytes at concentrations known to decrease thromboxane A2 production. The rank order of effectiveness of these various inhibitors compared favorably with their relative potencies as inhibitors of thromboxane B2 synthesis under the same conditions, as determined by radioimmunoassay. Inhibitory effects noted were not due to overt cytotoxicity and seemed to involve changes primarily in the Vmax and not the Km of the transport process. Drug-induced alterations in the magnitude of concanavalin A binding were not observed. These results suggest that the activity of amino acid transport systems can be influenced by certain arachidonic acid metabolites, probably thromboxanes, in both stimulated and unstimulated lymphocytes. In addition, these findings may provide a partial explanation for the observation that inhibitors of thromboxane formation prevent lymphocyte mitogenesis.

  16. Beta-cell metabolic alterations under chronic nutrient overload in rat and human islets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to assess multifactorial Beta-cell responses to metabolic perturbations in primary rat and human islets. Treatment of dispersed rat islet cells with elevated glucose and free fatty acids (FFAs, oleate:palmitate = 1:1 v/v) resulted in increases in the size and the number of ...

  17. Effects of ADMA on gene expression and metabolism in serum-starved LoVo cells.

    PubMed

    Zheng, Ningning; Wang, Ke; He, Jiaojiao; Qiu, Yunping; Xie, Guoxiang; Su, Mingming; Jia, Wei; Li, Houkai

    2016-05-16

    Serum starvation is a typical way for inducing tumor cell apoptosis and stress. Asymmetric dimethylarginine (ADMA) is an endogenous metabolite. Our previous study reveals the plasma ADMA level is elevated in colon cancer patients, which can attenuate serum starvation-induced apoptosis in LoVo cells. In current study, we evaluated the effects of ADMA on gene expression and metabolism in serum-starved LoVo cells with gene microarray and metabolomic approaches. Our results indicated that 96 h serum starvation induced comprehensive alterations at transcriptional level, and most of them were restored by ADMA. The main signaling pathways induced by serum starvation included cancers-related pathways, pathways in cell death, apoptosis, and cell cycle etc. Meanwhile, the metabolomic data showed serum-starved cells were clearly separated with control cells, but not with ADMA-treated cells in PCA model. The identified differential metabolites indicated serum starvation significantly suppressed TCA cycle, altered glucose and fatty acids metabolism, as well as nucleic acids metabolism. However, very few differential metabolites were identified between ADMA and serum-starved cells. In summary, our current results indicated serum starvation profoundly altered the gene expression and metabolism of LoVo cells, whereas ADMA could restore most of the changes at transcriptional level, but not at metabolic level.

  18. Effects of ADMA on gene expression and metabolism in serum-starved LoVo cells

    PubMed Central

    Zheng, Ningning; Wang, Ke; He, Jiaojiao; Qiu, Yunping; Xie, Guoxiang; Su, Mingming; Jia, Wei; Li, Houkai

    2016-01-01

    Serum starvation is a typical way for inducing tumor cell apoptosis and stress. Asymmetric dimethylarginine (ADMA) is an endogenous metabolite. Our previous study reveals the plasma ADMA level is elevated in colon cancer patients, which can attenuate serum starvation-induced apoptosis in LoVo cells. In current study, we evaluated the effects of ADMA on gene expression and metabolism in serum-starved LoVo cells with gene microarray and metabolomic approaches. Our results indicated that 96 h serum starvation induced comprehensive alterations at transcriptional level, and most of them were restored by ADMA. The main signaling pathways induced by serum starvation included cancers-related pathways, pathways in cell death, apoptosis, and cell cycle etc. Meanwhile, the metabolomic data showed serum-starved cells were clearly separated with control cells, but not with ADMA-treated cells in PCA model. The identified differential metabolites indicated serum starvation significantly suppressed TCA cycle, altered glucose and fatty acids metabolism, as well as nucleic acids metabolism. However, very few differential metabolites were identified between ADMA and serum-starved cells. In summary, our current results indicated serum starvation profoundly altered the gene expression and metabolism of LoVo cells, whereas ADMA could restore most of the changes at transcriptional level, but not at metabolic level. PMID:27180883

  19. Myogenic and metabolic feedback in cerebral autoregulation: Putative involvement of arachidonic acid-dependent pathways.

    PubMed

    Berg, Ronan M G

    2016-07-01

    The present paper presents a mechanistic model of cerebral autoregulation, in which the dual effects of the arachidonic acid metabolites 20-hydroxyeicosatetraenoic acid (20-HETE) and epoxyeicosatrienoic acids (EETs) on vascular smooth muscle mediate the cerebrovascular adjustments to a change in cerebral perfusion pressure (CPP). 20-HETE signalling in vascular smooth muscle mediates myogenic feedback to changes in vessel wall stretch, which may be modulated by metabolic feedback through EETs released from astrocytes and endothelial cells in response to changes in brain tissue oxygen tension. The metabolic feedback pathway is much faster than 20-HETE-dependent myogenic feedback, and the former thus initiates the cerebral autoregulatory response, while myogenic feedback comprises a relatively slower mechanism that functions to set the basal cerebrovascular tone. Therefore, assessments of dynamic cerebral autoregulation, which may provide information on the response time of the cerebrovasculature, may specifically be used to yield information on metabolic feedback mechanisms, while data based on assessments of static cerebral autoregulation represent the integrated functionality of myogenic and metabolic feedback. PMID:27241246

  20. The bile acid membrane receptor TGR5 as an emerging target in metabolism and inflammation.

    PubMed

    Pols, Thijs W H; Noriega, Lilia G; Nomura, Mitsunori; Auwerx, Johan; Schoonjans, Kristina

    2011-06-01

    Bile acids (BAs) are amphipathic molecules that facilitate the uptake of lipids, and their levels fluctuate in the intestine as well as in the blood circulation depending on food intake. Besides their role in dietary lipid absorption, bile acids function as signaling molecules capable to activate specific receptors. These BA receptors are not only important in the regulation of bile acid synthesis and their metabolism, but also regulate glucose homeostasis, lipid metabolism, and energy expenditure. These processes are important in diabetes and other facets of the metabolic syndrome, which represents a considerable increasing health burden. In addition to the function of the nuclear receptor FXRα in regulating local effects in the organs of the enterohepatic axis, increasing evidence points to a crucial role of the G-protein coupled receptor (GPCR) TGR5 in mediating systemic actions of BAs. Here we discuss the current knowledge on BA receptors, with a strong focus on the cell membrane receptor TGR5, which emerges as a valuable target for intervention in metabolic diseases. PMID:21145931

  1. Metabolic profiling reveals potential metabolic markers associated with Hypoxia Inducible Factor-mediated signalling in hypoxic cancer cells

    PubMed Central

    Armitage, Emily G.; Kotze, Helen L.; Allwood, J. William; Dunn, Warwick B.; Goodacre, Royston; Williams, Kaye J.

    2015-01-01

    Hypoxia inducible factors (HIFs) plays an important role in oxygen compromised environments and therefore in tumour survival. In this research, metabolomics has been applied to study HIFs metabolic function in two cell models: mouse hepatocellular carcinoma and human colon carcinoma, whereby the metabolism has been profiled for a range of oxygen potentials. Wild type cells have been compared to cells deficient in HIF signalling to reveal its effect on cellular metabolism under normal oxygen conditions as well as low oxygen, hypoxic and anoxic environments. Characteristic responses to hypoxia that were conserved across both cell models involved the anti-correlation between 2-hydroxyglutarate, 2-oxoglutarate, fructose, hexadecanoic acid, hypotaurine, pyruvate and octadecenoic acid with 4-hydroxyproline, aspartate, cysteine, glutamine, lysine, malate and pyroglutamate. Further to this, network-based correlation analysis revealed HIF specific pathway responses to each oxygen condition that were also conserved between cell models. From this, 4-hydroxyproline was revealed as a regulating hub in low oxygen survival of WT cells while fructose appeared to be in HIF deficient cells. Pathways surrounding these hubs were built from the direct connections of correlated metabolites that look beyond traditional pathways in order to understand the mechanism of HIF response to low oxygen environments. PMID:26508589

  2. Lysosomal acid lipase: at the crossroads of normal and atherogenic cholesterol metabolism

    PubMed Central

    Dubland, Joshua A.; Francis, Gordon A.

    2015-01-01

    Unregulated cellular uptake of apolipoprotein B-containing lipoproteins in the arterial intima leads to the formation of foam cells in atherosclerosis. Lysosomal acid lipase (LAL) plays a crucial role in both lipoprotein lipid catabolism and excess lipid accumulation as it is the primary enzyme that hydrolyzes cholesteryl esters derived from both low density lipoprotein (LDL) and modified forms of LDL. Evidence suggests that as atherosclerosis progresses, accumulation of excess free cholesterol in lysosomes leads to impairment of LAL activity, resulting in accumulation of cholesteryl esters in the lysosome as well as the cytosol in foam cells. Impaired metabolism and release of cholesterol from lysosomes can lead to downstream defects in ATP-binding cassette transporter A1 regulation, needed to offload excess cholesterol from plaque foam cells. This review focuses on the role LAL plays in normal cholesterol metabolism and how the associated changes in its enzymatic activity may ultimately contribute to atherosclerosis progression. PMID:25699256

  3. Metabolic modeling of fumaric acid production by Rhizopus arrhizus

    SciTech Connect

    Gangl, I.C.; Weigand, W.W.; Keller, F.A.

    1991-12-31

    A metabolic model is developed for fumaric acid production by Rhizopus arrhizus. The model describes the reaction network and the extents of reaction in terms of the concentrations of the measurable species. The proposed pathway consists of the Embden-Meyerhof pathway and two pathways to FA production, both of which require CO{sub 2} fixation (the forward and the reverse TCA cycles). Relationships among the measurable quantities, in addition to those obtainable by a macroscopic mass balance, are found by invoking a pseudo-steady-state assumption on the nonaccumulating species in the pathway. Applications of the metabolic model, such as verifying the proposed pathway, obtaining the theoretical yield and selectivity, and detecting experimental errors, are discussed.

  4. Cell proliferation and progesterone synthesis depend on lipid metabolism in bovine granulosa cells.

    PubMed

    Elis, Sebastien; Desmarchais, Alice; Maillard, Virginie; Uzbekova, Svetlana; Monget, Philippe; Dupont, Joëlle

    2015-03-15

    In dairy cows, lipids are essential to support energy supplies for all biological functions, especially during early lactation. Lipid metabolism is crucial for sustaining proper reproductive function. Alteration of lipid metabolism impacts follicular development and affects oocyte developmental competence. Indeed, nonesterified fatty acids are able to decrease granulosa cell (GC) proliferation and affect estradiol synthesis, thus potentially affecting follicular growth and viability. The objective of this study was to assess the impact of lipid metabolism on bovine GCs, through the use of the lipid metabolism inhibitors etomoxir, an inhibitor of fatty acid (FA) oxidation through inhibition of carnitine palmitoyl transferase 1 (CPT1), and C75, an inhibitor of FA synthesis through inhibition of fatty acid synthase. We showed that etomoxir and C75 significantly inhibited DNA synthesis in vitro; C75 also significantly decreased progesterone synthesis. Both inhibitors significantly reduced AMPK (5' adenosine monophosphate-activated protein kinase) and acetyl-CoA carboxylase phosphorylation. Etomoxir also affected the AKT (protein kinase B) signaling pathway. Combined, these data suggest that both FA oxidation and synthesis are important for the bovine GCs to express a proliferative and steroidogenic phenotype and, thus, for sustaining follicular growth. Despite these findings, it is important to note that the changes caused by the inhibitors of FA metabolism on GCs in vitro are globally mild, suggesting that lipid metabolism is not as critical in GCs as was observed in the oocyte-cumulus complex. Further studies are needed to investigate the detailed mechanisms by which lipid metabolism interacts with GC functions.

  5. Aberrant Lipid Metabolism Promotes Prostate Cancer: Role in Cell Survival under Hypoxia and Extracellular Vesicles Biogenesis

    PubMed Central

    Deep, Gagan; Schlaepfer, Isabel R.

    2016-01-01

    Prostate cancer (PCa) is the leading malignancy among men in United States. Recent studies have focused on the identification of novel metabolic characteristics of PCa, aimed at devising better preventive and therapeutic approaches. PCa cells have revealed unique metabolic features such as higher expression of several enzymes associated with de novo lipogenesis, fatty acid up-take and β-oxidation. This aberrant lipid metabolism has been reported to be important for PCa growth, hormone-refractory progression and treatment resistance. Furthermore, PCa cells effectively use lipid metabolism under adverse environmental conditions for their survival advantage. Specifically, hypoxic cancer cells accumulate higher amount of lipids through a combination of metabolic alterations including high glutamine and fatty acid uptake, as well as decreased fatty acid oxidation. These stored lipids serve to protect cancer cells from oxidative and endoplasmic reticulum stress, and play important roles in fueling cancer cell proliferation following re-oxygenation. Lastly, cellular lipids have also been implicated in extracellular vesicle biogenesis, which play a vital role in intercellular communication. Overall, the new understanding of lipid metabolism in recent years has offered several novel targets to better target and manage clinical PCa. PMID:27384557

  6. Aberrant Lipid Metabolism Promotes Prostate Cancer: Role in Cell Survival under Hypoxia and Extracellular Vesicles Biogenesis.

    PubMed

    Deep, Gagan; Schlaepfer, Isabel R

    2016-01-01

    Prostate cancer (PCa) is the leading malignancy among men in United States. Recent studies have focused on the identification of novel metabolic characteristics of PCa, aimed at devising better preventive and therapeutic approaches. PCa cells have revealed unique metabolic features such as higher expression of several enzymes associated with de novo lipogenesis, fatty acid up-take and β-oxidation. This aberrant lipid metabolism has been reported to be important for PCa growth, hormone-refractory progression and treatment resistance. Furthermore, PCa cells effectively use lipid metabolism under adverse environmental conditions for their survival advantage. Specifically, hypoxic cancer cells accumulate higher amount of lipids through a combination of metabolic alterations including high glutamine and fatty acid uptake, as well as decreased fatty acid oxidation. These stored lipids serve to protect cancer cells from oxidative and endoplasmic reticulum stress, and play important roles in fueling cancer cell proliferation following re-oxygenation. Lastly, cellular lipids have also been implicated in extracellular vesicle biogenesis, which play a vital role in intercellular communication. Overall, the new understanding of lipid metabolism in recent years has offered several novel targets to better target and manage clinical PCa. PMID:27384557

  7. Ceramide metabolism regulates autophagy and apoptotic cell death induced by melatonin in liver cancer cells.

    PubMed

    Ordoñez, Raquel; Fernández, Anna; Prieto-Domínguez, Néstor; Martínez, Laura; García-Ruiz, Carmen; Fernández-Checa, José C; Mauriz, José L; González-Gallego, Javier

    2015-09-01

    Autophagy is a process that maintains homeostasis during stress, although it also contributes to cell death under specific contexts. Ceramides have emerged as important effectors in the regulation of autophagy, mediating the crosstalk with apoptosis. Melatonin induces apoptosis of cancer cells; however, its role in autophagy and ceramide metabolism has yet to be clearly elucidated. This study was aimed to evaluate the effect of melatonin administration on autophagy and ceramide metabolism and its possible link with melatonin-induced apoptotic cell death in hepatocarcinoma (HCC) cells. Melatonin (2 mm) transiently induced autophagy in HepG2 cells through JNK phosphorylation, characterized by increased Beclin-1 expression, p62 degradation, and LC3II and LAMP-2 colocalization, which translated in decreased cell viability. Moreover, ATG5 silencing sensitized HepG2 cells to melatonin-induced apoptosis, suggesting a dual role of autophagy in cell death. Melatonin enhanced ceramide levels through both de novo synthesis and acid sphingomyelinase (ASMase) stimulation. Serine palmitoyltransferase (SPT) inhibition with myriocin prevented melatonin-induced autophagy and ASMase inhibition with imipramine-impaired autophagy flux. However, ASMase inhibition partially protected HepG2 cells against melatonin, while SPT inhibition significantly enhanced cell death. Findings suggest a crosstalk between SPT-mediated ceramide generation and autophagy in protecting against melatonin, while specific ASMase-induced ceramide production participates in melatonin-mediated cell death. Thus, dual blocking of SPT and autophagy emerges as a potential strategy to potentiate the apoptotic effects of melatonin in liver cancer cells.

  8. Omega-3 fatty acids: role in metabolism and cardiovascular disease.

    PubMed

    Gerber, Philipp A; Gouni-Berthold, Ioanna; Berneis, Kaspar

    2013-01-01

    The inverse association of cardiovascular risk with intake of omega-3 polyunsaturated fatty acids was suspected early in populations that are known to have a high consumption of fish and fish oil. Subsequent cohort studies confirmed such associations in other populations. Further evidence of possible beneficial effects on metabolism and cardiovascular health was provided by many studies that were able to show specific mechanisms that may underlie these observations. These include improvement of the function of tissues involved in the alterations occurring during the development of obesity and the metabolic syndrome, as adipose tissue, the liver and skeletal muscle. Direct action on the cardiovascular system was not only shown regarding vascular function and the formation of atherosclerotic plaques, but also by providing antiarrhythmic effects on the heart. Data on these effects come from in vitro as well as in vivo studies that were conducted in animal models of disease, in healthy humans and in humans suffering from cardiovascular disease. To define prophylactic as well as treatment options in primary and secondary prevention, large clinical trial assessed the effect of omega-3 polyunsaturated fatty acids on end points as cardiovascular morbidity and mortality. However, so far these trials provided ambiguous data that do allow recommendations regarding the use of omega-3 polyunsaturated fatty acids in higher dosages and beyond the dietary advice of regular fish intake only in few clinical situations, such as severe hypertriglyceridemia.

  9. Altered cholesterol and fatty acid metabolism in Huntington disease.

    PubMed

    Block, Robert C; Dorsey, E Ray; Beck, Christopher A; Brenna, J Thomas; Shoulson, Ira

    2010-01-01

    Huntington disease is an autosomal dominant neurodegenerative disorder characterized by behavioral abnormalities, cognitive decline, and involuntary movements that lead to a progressive decline in functional capacity, independence, and ultimately death. The pathophysiology of Huntington disease is linked to an expanded trinucleotide repeat of cytosine-adenine-guanine (CAG) in the IT-15 gene on chromosome 4. There is no disease-modifying treatment for Huntington disease, and novel pathophysiological insights and therapeutic strategies are needed. Lipids are vital to the health of the central nervous system, and research in animals and humans has revealed that cholesterol metabolism is disrupted in Huntington disease. This lipid dysregulation has been linked to specific actions of the mutant huntingtin on sterol regulatory element binding proteins. This results in lower cholesterol levels in affected areas of the brain with evidence that this depletion is pathologic. Huntington disease is also associated with a pattern of insulin resistance characterized by a catabolic state resulting in weight loss and a lower body mass index than individuals without Huntington disease. Insulin resistance appears to act as a metabolic stressor attending disease progression. The fish-derived omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, have been examined in clinical trials of Huntington disease patients. Drugs that combat the dysregulated lipid milieu in Huntington disease may help treat this perplexing and catastrophic genetic disease.

  10. Energy metabolism in intestinal epithelial cells during maturation along the crypt-villus axis.

    PubMed

    Yang, Huansheng; Wang, Xiaocheng; Xiong, Xia; Yin, Yulong

    2016-01-01

    Intestinal epithelial cells continuously migrate and mature along crypt-villus axis (CVA), while the changes in energy metabolism during maturation are unclear in neonates. The present study was conducted to test the hypothesis that the energy metabolism in intestinal epithelial cells would be changed during maturation along CVA in neonates. Eight 21-day-old suckling piglets were used. Intestinal epithelial cells were isolated sequentially along CVA, and proteomics was used to analyze the changes in proteins expression in epithelial cells along CVA. The identified differentially expressed proteins were mainly involved in cellular process, metabolic process, biological regulation, pigmentation, multicellular organizational process and so on. The energy metabolism in intestinal epithelial cells of piglets was increased from the bottom of crypt to the top of villi. Moreover, the expression of proteins related to the metabolism of glucose, most of amino acids, and fatty acids was increased in intestinal epithelial cells during maturation along CVA, while the expression of proteins related to glutamine metabolism was decreased from crypt to villus tip. The expression of proteins involved in citrate cycle was also increased intestinal epithelial cells during maturation along CVA. Moreover, dietary supplementation with different energy sources had different effects on intestinal structure of weaned piglets. PMID:27558220

  11. Energy metabolism in intestinal epithelial cells during maturation along the crypt-villus axis

    PubMed Central

    Yang, Huansheng; Wang, Xiaocheng; Xiong, Xia; Yin, Yulong

    2016-01-01

    Intestinal epithelial cells continuously migrate and mature along crypt-villus axis (CVA), while the changes in energy metabolism during maturation are unclear in neonates. The present study was conducted to test the hypothesis that the energy metabolism in intestinal epithelial cells would be changed during maturation along CVA in neonates. Eight 21-day-old suckling piglets were used. Intestinal epithelial cells were isolated sequentially along CVA, and proteomics was used to analyze the changes in proteins expression in epithelial cells along CVA. The identified differentially expressed proteins were mainly involved in cellular process, metabolic process, biological regulation, pigmentation, multicellular organizational process and so on. The energy metabolism in intestinal epithelial cells of piglets was increased from the bottom of crypt to the top of villi. Moreover, the expression of proteins related to the metabolism of glucose, most of amino acids, and fatty acids was increased in intestinal epithelial cells during maturation along CVA, while the expression of proteins related to glutamine metabolism was decreased from crypt to villus tip. The expression of proteins involved in citrate cycle was also increased intestinal epithelial cells during maturation along CVA. Moreover, dietary supplementation with different energy sources had different effects on intestinal structure of weaned piglets. PMID:27558220

  12. Dysregulation of hepatic fatty acid metabolism in chronic kidney disease

    PubMed Central

    Jin, Kyubok; Norris, Keith; Vaziri, Nosratola D.

    2013-01-01

    Background Chronic kidney disease (CKD) results in hypertriglyceridemia which is largely due to impaired clearance of triglyceride-rich lipoproteins occasioned by downregulation of lipoprotein lipase and very low-density lipoprotein (LDL) receptor in the skeletal muscle and adipose tissue and of hepatic lipase and LDL receptor-related protein in the liver. However, data on the effect of CKD on fatty acid metabolism in the liver is limited and was investigated here. Methods Male Sprague-Dawley rats were randomized to undergo 5/6 nephrectomy (CRF) or sham operation (control) and observed for 12 weeks. The animals were then euthanized and their liver tissue tested for nuclear translocation (activation) of carbohydrate-responsive element binding protein (ChREBP) and sterol-responsive element binding protein-1 (SREBP-1) which independently regulate the expression of key enzyme in fatty acid synthesis, i.e. fatty acid synthase (FAS) and acyl-CoA carboxylase (ACC) as well as nuclear Peroxisome proliferator-activated receptor alpha (PPARα) which regulates the expression of enzymes involved in fatty acid oxidation and transport, i.e. L-FABP and CPT1A. In addition, the expression of ATP synthase α, ATP synthase β, glycogen synthase and diglyceride acyltransferase 1 (DGAT1) and DGAT2 were determined. Results Compared with controls, the CKD rats exhibited hypertriglyceridemia, elevated plasma and liver tissue free fatty acids, increased nuclear ChREBP and reduced nuclear SREBP-1 and PPARα, upregulation of ACC and FAS and downregulation of L-FABP, CPT1A, ATP synthase α, glycogen synthase and DGAT in the liver tissue. Conclusion Liver in animals with advanced CKD exhibits ChREBP-mediated upregulation of enzymes involved in fatty acid synthesis, downregulation of PPARα-regulated fatty acid oxidation system and reduction of DGAT resulting in reduced fatty acid incorporation in triglyceride. PMID:23045433

  13. Exploring De Novo metabolic pathways from pyruvate to propionic acid.

    PubMed

    Stine, Andrew; Zhang, Miaomin; Ro, Soo; Clendennen, Stephanie; Shelton, Michael C; Tyo, Keith E J; Broadbelt, Linda J

    2016-03-01

    Industrial biotechnology provides an efficient, sustainable solution for chemical production. However, designing biochemical pathways based solely on known reactions does not exploit its full potential. Enzymes are known to accept non-native substrates, which may allow novel, advantageous reactions. We have previously developed a computational program named Biological Network Integrated Computational Explorer (BNICE) to predict promiscuous enzyme activities and design synthetic pathways, using generalized reaction rules curated from biochemical reaction databases. Here, we use BNICE to design pathways synthesizing propionic acid from pyruvate. The currently known natural pathways produce undesirable by-products lactic acid and succinic acid, reducing their economic viability. BNICE predicted seven pathways containing four reaction steps or less, five of which avoid these by-products. Among the 16 biochemical reactions comprising these pathways, 44% were validated by literature references. More than 28% of these known reactions were not in the BNICE training dataset, showing that BNICE was able to predict novel enzyme substrates. Most of the pathways included the intermediate acrylic acid. As acrylic acid bioproduction has been well advanced, we focused on the critical step of reducing acrylic acid to propionic acid. We experimentally validated that Oye2p from Saccharomyces cerevisiae can catalyze this reaction at a slow turnover rate (10(-3) s(-1) ), which was unknown to occur with this enzyme, and is an important finding for further propionic acid metabolic engineering. These results validate BNICE as a pathway-searching tool that can predict previously unknown promiscuous enzyme activities and show that computational methods can elucidate novel biochemical pathways for industrial applications. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:303-311, 2016. PMID:26821575

  14. [The medium chain fat acids. Content in food. Physiology, characteristics of metabolism and application in clinical practice].

    PubMed

    Arkhipovskiĭ, A V; Titov, V N

    2013-06-01

    It is rational, according to biology laws and purposes for which cells use fatty acids, to distinguish between saturated (without double bonds in chain), monoene (with one bond), unsaturated (with 2 and 3 double bonds) and polyene (with 4, 5 and 6 double bonds) acids. The saturated and monoene fatty acids are mainly the substratum for oxygenation and working out of energy by cells. The unsaturated fatty acids are the substratum for formation of membranes. The polyene fatty acids are the predecessors of synthesis of eicosanoids and aminophosphotides. With subject to characteristics of metabolism and transfer in vivo, the fatty acids are subdivided into short chain C4 - C8 and medium chain C-10 - C-14 fatty acids. The etherification occurs with glycerin into "short" triglycerides which are not bounded with apoproteins. The long chain fatty acids form "long" triglycerides which in enterocytes are structured by apoprotein B-48 into composition of chylomicrons. It is possible to validly consider that difference in outflow from enterocytes to veins of portal system (which includes veins of omentum) of medium chain fatty acids in the form of short triglycerides can directly input into pathogenesis of syndrome of isolated omental obesity and metabolic syndrome. The another input into the mentioned conditions is the secretion through ductus thoracicus into large veins of greater systemic circulation of long chain fatty acids in the form of triglycerides in the content of chylomicrons. The omental obesity is the only specific symptom of metabolic syndrome.

  15. Metabolism of saturated and polyunsaturated fatty acids by normal and Zellweger syndrome skin fibroblasts.

    PubMed Central

    Street, J M; Johnson, D W; Singh, H; Poulos, A

    1989-01-01

    The metabolism of 1-11C-labelled derivatives of palmitic (C16:0), arachidonic (C20:4,n-6) lignoceric (C21:0) and tetracosatetraenoic (C24:4,n-6) acids was studied in normal skin fibroblast cultures and in cultures of fibroblasts from peroxisome-deficient (Zellweger's syndrome) patients. Radiolabelled products of the fatty acids included carbon dioxide. C14-24 saturated and mono-unsaturated fatty acids formed from released acetate either by synthesis de novo or by elongation of endogenous fatty acids, fatty acids formed by 2-6-carbon elongation of added substrates, and a number of water-soluble compounds, some of which were tentatively identified as the amino acids glutamine, glutamic acid and asparagine. The labelled amino acids were found predominantly in the culture medium. Zellweger's syndrome fibroblasts showed a marked decrease in radiolabelled carbon dioxide and water-soluble-product formation from (I-14C)-labelled arachidonic, tetracosatetraenoic and lignoceric acids but not from [I-14C]palmitic acid, and the production of radiolabelled C14-18 fatty acids was also diminished. However, the elongation of individual fatty acids was either normal or above normal. Our data support the view that the oxidation of 20:4, 24:4 and 24:0 fatty acids in cultured skin fibroblasts takes place largely in peroxisomes, and further that the acetyl-CoA released by the beta-oxidation process is available for the synthesis of fatty acids and amino acids. We speculate that the generation of C2 units used for synthesis is a major peroxisomal function and that this function is absent or greatly impaired in Zellweger's syndrome cells. PMID:2504148

  16. Cell metabolism, tumour diagnosis and multispectral FLIM

    NASA Astrophysics Data System (ADS)

    Rück, A.; Hauser, C.; Lorenz, S.; Mosch, S.; Rotte, S.; Kessler, M.; Kalinina, S.

    2013-02-01

    Fluorescence guided diagnosis of tumour tissue is in many cases insufficient, because false positive results are interfering with the outcome. Discrimination between tumour and inflammation could be therefore difficult. Improvement of fluorescence diagnosis through observation of cell metabolism could be the solution, which needs a detailed understanding of the origin of autofluorescence. However, a complex combination of fluorophores give rise to the emission signal. Also in PDD (photodynamic diagnosis) different photosensitizer metabolites contribute to the fluorescence signal. Therefore, the fluorescence decay in many cases does not show a simple monoexponential profile. In those cases a considerable improvement could be achieved when time-resolved and spectral-resolved techniques are simultaneously incorporated. The discussion will focus on the detection of NADH, FAD and 5-ALA induced porphyrins. With respect to NADH and FAD the discrimination between protein bound and free coenzyme was investigated with multispectral FLIM in normal oral keratinocytes and squamous carcinoma cells from different origin. The redox ratio, which can be correlated with the fluorescence lifetimes of NADH and FAD changed depending on the state of the cells. Most of the investigations were done in monolayer cell cultures. However, in order to get information from a more realistic in vivo situation additionally the chorioallantoismembrane (CAM) of fertilized eggs was used where tumour cells or biopsies were allowed to grow. The results of theses measurements will be discussed as well.

  17. High folic acid increases cell turnover and lowers differentiation and iron content in human HT29 colon cancer cells.

    PubMed

    Pellis, Linette; Dommels, Yvonne; Venema, Dini; Polanen, Ab van; Lips, Esther; Baykus, Hakan; Kok, Frans; Kampman, Ellen; Keijer, Jaap

    2008-04-01

    Folate, a water-soluble B vitamin, is a cofactor in one-carbon metabolism and is essential for DNA synthesis, amino acid interconversion, methylation and, consequently, normal cell growth. In animals with existing pre-neoplastic and neoplastic lesions, folic acid supplementation increases the tumour burden. To identify processes that are affected by increased folic acid levels, we compared HT29 human colon cancer cells exposed to a chronic supplemental (100 ng/ml) level of folic acid to cells exposed to a normal (10 ng/ml) level of folic acid, in the presence of vitamin B12 and other micronutrients involved in the folate-methionine cycle. In addition to higher intracellular folate levels, HT29 cells at 100 ng folic acid/ml displayed faster growth and higher metabolic activity. cDNA microarray analysis indicated an effect on cell turnover and Fe metabolism. We fully confirmed these effects at the physiological level. At 100 ng/ml, cell assays showed higher proliferation and apoptosis, while gene expression analysis and a lower E-cadherin protein expression indicated decreased differentiation. These results are in agreement with the promoting effect of folic acid supplementation on established colorectal neoplasms. The lower expression of genes related to Fe metabolism at 100 ng folic acid/ml was confirmed by lower intracellular Fe levels in the cells exposed to folic acid at 100 ng/ml. This suggests an effect of folate on Fe metabolism.

  18. Metabolic supplementation with orotic acid and magnesium orotate.

    PubMed

    Rosenfeldt, F L

    1998-09-01

    Orotic acid (OA), a naturally occurring substance, is a key intermediate in the biosynthetic pathway of pyrimidines. Previous investigations in the heart suggest that orotate can protect recently infarcted hearts against a further ischemic stress and may be beneficial in certain types of experimental cardiomyopathy. At the Hamburg symposium on magnesium orotate, a number of studies of this form of metabolic supplementation were presented that indicate orotic acid and its magnesium salt have a modest beneficial effect on the myocardium under conditions of stress ranging from myocardial infarction to severe physical exercise. The following conclusions can be drawn: (1) Orotic acid can improve the energy status of the recently infarcted myocardium (rat hearts). (2) Orotic acid may improve myocardial purine and pyrimidine levels by stimulating hepatic release of uridine into the bloodstream, which in turn augments depleted myocardial pyrimidines and purines (rat heart). (3) Orotic acid improves the tolerance of the recently infarcted heart to global ischemia (rats). (4) Magnesium orotate may reduce the severity of chronic myocardial dysfunction and structural damage in cardiomyopathy (cardiomyopathic hamsters). (5) Magnesium orotate may improve exercise tolerance in patients with coronary artery disease and in trained athletes (humans). (6) Magnesium orotate has only a weak inotropic effect, if any, on normal hearts (rats). (7) Further clinical testing is indicated to determine if the effects described could be of significant clinical benefit in the treatment of heart disease. PMID:9794088

  19. The altered glucose metabolism in tumor and a tumor acidic microenvironment associated with extracellular matrix metalloproteinase inducer and monocarboxylate transporters

    PubMed Central

    Li, Xiaofeng; Yu, Xiaozhou; Dai, Dong; Song, Xiuyu; Xu, Wengui

    2016-01-01

    Extracellular matrix metalloproteinase inducer, also knowns as cluster of differentiation 147 (CD147) or basigin, is a widely distributed cell surface glycoprotein that is involved in numerous physiological and pathological functions, especially in tumor invasion and metastasis. Monocarboxylate transporters (MCTs) catalyze the proton-linked transport of monocarboxylates such as L-lactate across the plasma membrane to preserve the intracellular pH and maintain cell homeostasis. As a chaperone to some MCT isoforms, CD147 overexpression significantly contributes to the metabolic transformation of tumor. This overexpression is characterized by accelerated aerobic glycolysis and lactate efflux, and it eventually provides the tumor cells with a metabolic advantage and an invasive phenotype in the acidic tumor microenvironment. This review highlights the roles of CD147 and MCTs in tumor cell metabolism and the associated molecular mechanisms. The regulation of CD147 and MCTs may prove to be with a therapeutic potential for tumors through the metabolic modification of the tumor microenvironment. PMID:27009812

  20. Multiple steady states with distinct cellular metabolism in continuous culture of mammalian cells.

    PubMed

    Europa, A F; Gambhir, A; Fu, P C; Hu, W S

    2000-01-01

    Mammalian cells have the ability to proliferate under different nutrient environments by utilizing different combinations of the nutrients, especially glucose and the amino acids. Under the conditions often used in in vitro cultivation, the cells consume glucose and amino acids in great excess of what is needed for making up biomass and products. They also produce large amounts of metabolites with lactate, ammonia, and some non-essential amino acids such as alanine as the most dominant ones. By controlling glucose and glutamine at low levels, cellular metabolism can be altered and can result in reduced glucose and glutamine consumption as well as in reduced metabolite formation. Using a fed-batch reactor to manipulate glucose at a low level (as compared to a typical batch culture), cell metabolism was altered to a state with substantially reduced lactate production. The culture was then switched to a continuous mode and allowed to reach a steady-state. At this steady-state, the concentrations of cells and antibody were substantially higher than a control culture that was initiated from a batch culture without first altering cellular metabolism. The lactate and other metabolite concentrations were also substantially reduced as compared to the control culture. This newly observed steady-state was achieved at the same dilution rate and feed medium as the control culture. The paths leading to the two steady-states, however, were different. These results demonstrate steady-state multiplicity. At this new steady-state, not only was glucose metabolism altered, but the metabolism of amino acids was altered as well. The amino acid metabolism in the new steady-state was more balanced, and the excretion of non-essential amino acids and ammonia was substantially lower. This approach of reaching a more desirable steady-state with higher concentrations of cells and product opens a new avenue for high-density- and high-productivity-cell culture.

  1. Metabolic engineering in the biotechnological production of organic acids in the tricarboxylic acid cycle of microorganisms: Advances and prospects.

    PubMed

    Yin, Xian; Li, Jianghua; Shin, Hyun-Dong; Du, Guocheng; Liu, Long; Chen, Jian

    2015-11-01

    Organic acids, which are chemically synthesized, are also natural intermediates in the metabolic pathways of microorganisms, among which the tricarboxylic acid (TCA) cycle is the most crucial route existing in almost all living organisms. Organic acids in the TCA cycle include citric acid, α-ketoglutaric acid, succinic acid, fumaric acid, l-malic acid, and oxaloacetate, which are building-block chemicals with wide applications and huge markets. In this review, we summarize the synthesis pathways of these organic acids and review recent advances in metabolic engineering strategies that enhance organic acid production. We also propose further improvements for the production of organic acids with systems and synthetic biology-guided metabolic engineering strategies.

  2. Metabolic fate of arachidonic acid in hepatocytes of continuously endotoxemic rats.

    PubMed Central

    Rodriguez de Turco, E B; Spitzer, J A

    1988-01-01

    The present experiments were designed to characterize the kinetics of [1-14C]arachidonic acid (AA) metabolism as a function of time in hepatocytes obtained from rats infused continuously for 30 h with a nonlethal dose of Escherichia coli endotoxin (ET). Chronic endotoxemia greatly reduces the ability of hepatocytes to utilize [1-14C]AA, which is reflected from the earliest times of incubation in very low labeling of intermediates in the biosynthetic pathways of glycerolipids (phosphatidic acid and diacylglycerol) and slower removal of [1-14C]AA from the free fatty acid pool as compared with saline-infused rats. At later times of incubation, the labeling of phospholipids (especially phosphatidylethanolamine and phosphatidylinositol [PI]), but not of triacylglycerides is decreased. Analysis of fatty acid composition of individual phospholipids from cells of ET-infused rats reveals that the content of AA is significantly reduced only in PI. Hence an impairment in activation/acylation enzymatic mechanisms could affect the turnover of metabolically active phospholipid pools, i.e., PI, involved in signal transmission processes, and result in increased availability of 20:4 for eicosanoid synthesis, contributing to cellular metabolic perturbations in endotoxicosis. PMID:3125225

  3. Zonal heterogeneity of the effects of chronic ethanol feeding on hepatic fatty acid metabolism.

    PubMed

    Guzman, M; Castro, J

    1990-11-01

    Periportal and perivenous hepatocytes were isolated from rats fed a high-fat, ethanol-containing diet to investigate the acinar heterogeneity of the effects of prolonged ethanol administration on lipid metabolism. Chronic feeding of ethanol caused a rather selective accumulation of triacylglycerols in the perivenous zone of the liver. In control animals the rate of lipogenesis and the activity of acetyl-CoA carboxylase were higher in perivenous than in periportal hepatocytes, whereas the rate of fatty acid oxidation and the activity of carnitine palmitoyltransferase I were higher in periportal than in perivenous cells; however, no zonation was evident for very-low-density-lipoprotein-lipid secretion. Prolonged ethanol administration abolished the zonal asymmetry of the lipogenic process and inverted the acinar distribution of the fatty acid-oxidative process (i.e., in ethanol-fed animals the rate of fatty acid oxidation and the activity of carnitine palmitoyltransferase I were higher in perivenous than in periportal hepatocytes). Moreover, chronic feeding of ethanol led to a marked and selective inhibition of very-low-density-lipoprotein-triacylglycerol secretion by the perivenous zone of the liver. Nevertheless, no zonal differences were observed between control and ethanol-fed animals with respect to the effects of acute doses of ethanol and acetaldehyde on lipid metabolism. In conclusion, our results show that chronic ethanol intake produces important alterations in the acinar distribution of the different fatty acid-metabolizing pathways.

  4. Metabolic basis of ethanol-induced cytotoxicity in recombinant HepG2 cells: Role of nonoxidative metabolism

    SciTech Connect

    Wu Hai; Cai Ping; Clemens, Dahn L.; Jerrells, Thomas R.; Ansari, G.A. Shakeel; Kaphalia, Bhupendra S. . E-mail: bkaphali@utmb.edu

    2006-10-15

    Chronic alcohol abuse, a major health problem, causes liver and pancreatic diseases and is known to impair hepatic alcohol dehydrogenase (ADH). Hepatic ADH-catalyzed oxidation of ethanol is a major pathway for the ethanol disposition in the body. Hepatic microsomal cytochrome P450 (CYP2E1), induced in chronic alcohol abuse, is also reported to oxidize ethanol. However, impaired hepatic ADH activity in a rat model is known to facilitate a nonoxidative metabolism resulting in formation of nonoxidative metabolites of ethanol such as fatty acid ethyl esters (FAEEs) via a nonoxidative pathway catalyzed by FAEE synthase. Therefore, the metabolic basis of ethanol-induced cytotoxicity was determined in HepG2 cells and recombinant HepG2 cells transfected with ADH (VA-13), CYP2E1 (E47) or ADH + CYP2E1 (VL-17A). Western blot analysis shows ADH deficiency in HepG2 and E47 cells, compared to ADH-overexpressed VA-13 and VL-17A cells. Attached HepG2 cells and the recombinant cells were incubated with ethanol, and nonoxidative metabolism of ethanol was determined by measuring the formation of FAEEs. Significantly higher levels of FAEEs were synthesized in HepG2 and E47 cells than in VA-13 and VL-17A cells at all concentrations of ethanol (100-800 mg%) incubated for 6 h (optimal time for the synthesis of FAEEs) in cell culture. These results suggest that ADH-catalyzed oxidative metabolism of ethanol is the major mechanism of its disposition, regardless of CYP2E1 overexpression. On the other hand, diminished ADH activity facilitates nonoxidative metabolism of ethanol to FAEEs as found in E47 cells, regardless of CYP2E1 overexpression. Therefore, CYP2E1-mediated oxidation of ethanol could be a minor mechanism of ethanol disposition. Further studies conducted only in HepG2 and VA-13 cells showed lower ethanol disposition and ATP concentration and higher accumulation of neutral lipids and cytotoxicity (apoptosis) in HepG2 cells than in VA-13 cells. The apoptosis observed in HepG2 vs

  5. [Succinic acid production from sucrose and sugarcane molasses by metabolically engineered Escherichia coli].

    PubMed

    Li, Feng; Ma, Jiangfeng; Wu, Mingke; Ji, Yaliang; Chen, Wufang; Ren, Xinyi; Jiang, Min

    2015-04-01

    Sugarcane molasses containing large amounts of sucrose is an economical substrate for succinic acid production. However, Escherichia coli AFP111 cannot metabolize sucrose although it is a promising candidate for succinic acid production. To achieve sucrose utilizing ability, we cloned and expressed cscBKA genes encoding sucrose permease, fructokinase and invertase of non-PTS sucrose-utilization system from E. coli W in E. coli AFP111 to generate a recombinant strain AFP111/pMD19T-cscBKA. After 72 h of anaerobic fermentation of the recombinant in serum bottles, 20 g/L sucrose was consumed and 12 g/L succinic acid was produced. During dual-phase fermentation comprised of initial aerobic growth phase followed by anaerobic fermentation phase, the concentration of succinic acid from sucrose and sugarcane molasses was 34 g/L and 30 g/L, respectively, at 30 h of anaerobic phase in a 3 L fermentor. The results show that the introduction of non-PTS sucrose-utilization system has sucrose-metabolizing capability for cell growth and succinic acid production, and can use cheap sugarcane molasses to produce succinic acid.

  6. The bile acid chenodeoxycholic acid directly modulates metabolic pathways in white adipose tissue in vitro: insight into how bile acids decrease obesity.

    PubMed

    Teodoro, João Soeiro; Rolo, Anabela Pinto; Jarak, Ivana; Palmeira, Carlos Marques; Carvalho, Rui Albuquerque

    2016-10-01

    Obesity is a worldwide epidemic, and associated pathologies, including type 2 diabetes and cardiovascular alterations, are increasingly escalating morbidity and mortality. Despite intensive study, no effective simple treatment for these conditions exists. As such, the need for go-to drugs is serious. Bile acids (BAs) present the possibility of reversing these problems, as various in vivo studies and clinical trials have shown significant effects with regard to weight and obesity reduction, insulin sensitivity restoration and cardiovascular improvements. However, the mechanism of action of BA-induced metabolic improvement has yet to be fully established. The currently most accepted model involves non-shivering thermogenesis for energy waste, but this is disputed. As such, we propose to determine whether the BA chenodeoxycholic acid (CDCA) can exert anti-obesogenic effects in vitro, independent of thermogenic brown adipose tissue activation. By exposing differentiated 3 T3-L1 adipocytes to high glucose and CDCA, we demonstrate that this BA has anti-obesity effects in vitro. Nuclear magnetic resonance spectroscopic analysis of metabolic pathways clearly indicates an improvement in metabolic status, as these cells become more oxidative rather than glycolytic, which may be associated with an increase in fatty acid oxidation. Our work demonstrates that CDCA-induced metabolic alterations occur in white and brown adipocytes and are not totally dependent on endocrine/nervous system signaling, as thought until now. Furthermore, future exploration of the mechanisms behind these effects will undoubtedly reveal interesting targets for clinical modulation. PMID:27488269

  7. Metabolic reprogramming of alloantigen-activated T cells after hematopoietic cell transplantation

    PubMed Central

    Nguyen, Hung D.; Chatterjee, Shilpak; Haarberg, Kelley M.K.; Wu, Yongxia; Bastian, David; Heinrichs, Jessica; Fu, Jianing; Daenthanasanmak, Anusara; Schutt, Steven; Shrestha, Sharad; Liu, Chen; Wang, Honglin; Chi, Hongbo; Mehrotra, Shikhar

    2016-01-01

    Alloreactive donor T cells are the driving force in the induction of graft-versus-host disease (GVHD), yet little is known about T cell metabolism in response to alloantigens after hematopoietic cell transplantation (HCT). Here, we have demonstrated that donor T cells undergo metabolic reprograming after allogeneic HCT. Specifically, we employed a murine allogeneic BM transplant model and determined that T cells switch from fatty acid β-oxidation (FAO) and pyruvate oxidation via the tricarboxylic (TCA) cycle to aerobic glycolysis, thereby increasing dependence upon glutaminolysis and the pentose phosphate pathway. Glycolysis was required for optimal function of alloantigen-activated T cells and induction of GVHD, as inhibition of glycolysis by targeting mTORC1 or 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) ameliorated GVHD mortality and morbidity. Together, our results indicate that donor T cells use glycolysis as the predominant metabolic process after allogeneic HCT and suggest that glycolysis has potential as a therapeutic target for the control of GVHD. PMID:26950421

  8. Protein Analysis of Sapienic Acid-Treated Porphyromonas gingivalis Suggests Differential Regulation of Multiple Metabolic Pathways

    PubMed Central

    Dawson, Deborah V.; Blanchette, Derek R.; Drake, David R.; Wertz, Philip W.; Brogden, Kim A.

    2015-01-01

    ABSTRACT Lipids endogenous to skin and mucosal surfaces exhibit potent antimicrobial activity against Porphyromonas gingivalis, an important colonizer of the oral cavity implicated in periodontitis. Our previous work demonstrated the antimicrobial activity of the fatty acid sapienic acid (C16:1Δ6) against P. gingivalis and found that sapienic acid treatment alters both protein and lipid composition from those in controls. In this study, we further examined whole-cell protein differences between sapienic acid-treated bacteria and untreated controls, and we utilized open-source functional association and annotation programs to explore potential mechanisms for the antimicrobial activity of sapienic acid. Our analyses indicated that sapienic acid treatment induces a unique stress response in P. gingivalis resulting in differential expression of proteins involved in a variety of metabolic pathways. This network of differentially regulated proteins was enriched in protein-protein interactions (P = 2.98 × 10−8), including six KEGG pathways (P value ranges, 2.30 × 10−5 to 0.05) and four Gene Ontology (GO) molecular functions (P value ranges, 0.02 to 0.04), with multiple suggestive enriched relationships in KEGG pathways and GO molecular functions. Upregulated metabolic pathways suggest increases in energy production, lipid metabolism, iron acquisition and processing, and respiration. Combined with a suggested preferential metabolism of serine, which is necessary for fatty acid biosynthesis, these data support our previous findings that the site of sapienic acid antimicrobial activity is likely at the bacterial membrane. IMPORTANCE P. gingivalis is an important opportunistic pathogen implicated in periodontitis. Affecting nearly 50% of the population, periodontitis is treatable, but the resulting damage is irreversible and eventually progresses to tooth loss. There is a great need for natural products that can be used to treat and/or prevent the overgrowth of

  9. Iron metabolism in Pseudomonas: salicylic acid, a siderophore of Pseudomonas fluorescens CHAO.

    PubMed

    Meyer, J M; Azelvandre, P; Georges, C

    1992-12-01

    Under iron-starvation conditions of growth, Pseudomonas fluorescens CHA0, a soil isolate involved in phytopathogenic fungi antagonisms, produced, together with pyoverdine, a second iron-chelating compound which was purified and identified by spectroscopy, HPLC and 1H-NMR to be salicylic acid. Mutants unable to synthesize pyoverdine overproduced this compound by a factor of 9-14. The biosynthesis of salicylic acid was under iron control; it was fully inhibited by 5 microM added iron in the growth medium. In contrast, salicylic acid of either bacterial or commercial origin facilitated labeled iron incorporation in iron-starved cells. Based on these two relationships observed with bacterial iron metabolism it is concluded that salicylic acid has a siderophore function for this strain. PMID:1292472

  10. Actions of gallic esters on the arachidonic acid metabolism of human polymorphonuclear leukocytes.

    PubMed

    Christow, S; Luther, H; Ludwig, P; Gruner, S; Schewe, T

    1991-04-01

    Gallic esters with a varying chain length of its alcohol moiety produced strong inhibition of the conversion of [1-14C]-arachidonic acid to 5S-hydroxy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-HETE) by isolated human polymorphonuclear leukocytes. Octyl gallate and decyl gallate were the most powerful inhibitors with a concentration of half-inhibition of about 1 mumol . 1-1. Additionally these compounds caused however at 10 mumol . 1-1 a complete inhibition of the incorporation of arachidonic acid in triacylglycerols and phospholipids which is assumed to be a consequence of the damage to the energy metabolism of the cells. In contrast, the other gallic esters enhance the incorporation of arachidonic acid in the ester lipids in addition to moderate inhibition of the 5-lipoxygenase pathway.

  11. Amino acid supplementation alters bone metabolism during simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Zwart, S. R.; Davis-Street, J. E.; Paddon-Jones, D.; Ferrando, A. A.; Wolfe, R. R.; Smith, S. M.

    2005-01-01

    High-protein and acidogenic diets induce hypercalciuria. Foods or supplements with excess sulfur-containing amino acids increase endogenous sulfuric acid production and therefore have the potential to increase calcium excretion and alter bone metabolism. In this study, effects of an amino acid/carbohydrate supplement on bone resorption were examined during bed rest. Thirteen subjects were divided at random into two groups: a control group (Con, n = 6) and an amino acid-supplemented group (AA, n = 7) who consumed an extra 49.5 g essential amino acids and 90 g carbohydrate per day for 28 days. Urine was collected for n-telopeptide (NTX), deoxypyridinoline (DPD), calcium, and pH determinations. Bone mineral content was determined and potential renal acid load was calculated. Bone-specific alkaline phosphatase was measured in serum samples collected on day 1 (immediately before bed rest) and on day 28. Potential renal acid load was higher in the AA group than in the Con group during bed rest (P < 0.05). For all subjects, during bed rest urinary NTX and DPD concentrations were greater than pre-bed rest levels (P < 0.05). Urinary NTX and DPD tended to be higher in the AA group (P = 0.073 and P = 0.056, respectively). During bed rest, urinary calcium was greater than baseline levels (P < 0.05) in the AA group but not the Con group. Total bone mineral content was lower after bed rest than before bed rest in the AA group but not the Con group (P < 0.05). During bed rest, urinary pH decreased (P < 0.05), and it was lower in the AA group than the Con group. These data suggest that bone resorption increased, without changes in bone formation, in the AA group.

  12. Nocturnal water storage in plants having Crassulacean acid metabolism.

    PubMed

    Lüttge, U

    1986-06-01

    Measurements of water uptake and transpiration, during the dark period of plants having Crassulacean acid metabolism (CAM) allow calculation of leaf-volume changes (ΔV). Nocturnal leaf-volume changes of CAM plants have also been reported in the literature on the basis of waterdisplacement measurements. A third way of estimation is from measurements of turgor changes and cellular water-storage capacity using the pressure probe, cytomorphometry and the Scholander pressure chamber. An extension of the interpretation of results reported in the literature shows that for leaf succulent CAM plants the three different approaches give similar values of ΔV ranging between 2.3 and 10.7% (v/v). It is evident that nocturnal malic-acid accumulation osmotically drives significant water storage in CAM leaf tissue. PMID:24232034

  13. Modulation of fatty acid metabolism is involved in the alleviation of isoproterenol-induced rat heart failure by fenofibrate.

    PubMed

    Li, Ping; Luo, Shike; Pan, Chunji; Cheng, Xiaoshu

    2015-12-01

    Heart failure is a disease predominantly caused by an energy metabolic disorder in cardiomyocytes. The present study investigated the inhibitory effects of fenofibrate (FF) on isoproterenol (ISO)‑induced hear failure in rats, and examined the underlying mechanisms. The rats were divided into CON, ISO (HF model), FF and FF+ISO (HF animals pretreated with FF) groups. The cardiac structure and function of the rats were assessed, and contents of free fatty acids and glucose metabolic products were determined. In addition, myocardial cells were isolated from neonatal rats and used in vitro to investigate the mechanisms by which FF relieves heart failure. Western blot analysis was performed to quantify the expression levels of peroxisome proliferator‑activated receptor (PPAR)α and uncoupling protein 2 (UCP2). FF effectively alleviated the ISO‑induced cardiac structural damage, functional decline, and fatty acid and carbohydrate metabolic abnormalities. Compared with the ISO group, the serum levels of brain natriuretic peptide (BNP), free fatty acids, lactic acid and pyruvic acid were decreased in the FF animals. In the cultured myocardial cells, lactic acid and pyruvic acid contents were lower in the supernatants obtained from the FF animals, with lower levels of mitochondrial ROS production and cell necrosis, compared with the ISO group, whereas PPARα upregulation and UCP2 downregulation occurred in the FF+ISO group. The results demonstrated that FF efficiently alleviated heart failure in the ISO‑induced rat model, possibly via promoting fatty acid oxidation. PMID:26497978

  14. Modulation of fatty acid metabolism is involved in the alleviation of isoproterenol-induced rat heart failure by fenofibrate

    PubMed Central

    LI, PING; LUO, SHIKE; PAN, CHUNJI; CHENG, XIAOSHU

    2015-01-01

    Heart failure is a disease predominantly caused by an energy metabolic disorder in cardiomyocytes. The present study investigated the inhibitory effects of fenofibrate (FF) on isoproterenol (ISO)-induced hear failure in rats, and examined the underlying mechanisms. The rats were divided into CON, ISO (HF model), FF and FF+ISO (HF animals pretreated with FF) groups. The cardiac structure and function of the rats were assessed, and contents of free fatty acids and glucose metabolic products were determined. In addition, myocardial cells were isolated from neonatal rats and used in vitro to investigate the mechanisms by which FF relieves heart failure. Western blot analysis was performed to quantify the expression levels of peroxisome proliferator-activated receptor (PPAR)α and uncoupling protein 2 (UCP2). FF effectively alleviated the ISO-induced cardiac structural damage, functional decline, and fatty acid and carbohydrate metabolic abnormalities. Compared with the ISO group, the serum levels of brain natriuretic peptide (BNP), free fatty acids, lactic acid and pyruvic acid were decreased in the FF animals. In the cultured myocardial cells, lactic acid and pyruvic acid contents were lower in the supernatants obtained from the FF animals, with lower levels of mitochondrial ROS production and cell necrosis, compared with the ISO group, whereas PPARα upregulation and UCP2 downregulation occurred in the FF+ISO group. The results demonstrated that FF efficiently alleviated heart failure in the ISO-induced rat model, possibly via promoting fatty acid oxidation. PMID:26497978

  15. Expanding the diversity of unnatural cell surface sialic acids

    SciTech Connect

    Luchansky, Sarah J.; Goon, Scarlett; Bertozzi, Carolyn R.

    2003-10-30

    Novel chemical reactivity can be introduced onto cell surfaces through metabolic oligosaccharide engineering. This technique exploits the substrate promiscuity of cellular biosynthetic enzymes to deliver unnatural monosaccharides bearing bioorthogonal functional groups into cellular glycans. For example, derivatives of N-acetylmannosamine (ManNAc) are converted by the cellular biosynthetic machinery into the corresponding sialic acids and subsequently delivered to the cell surface in the form of sialoglycoconjugates. Analogs of N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) are also metabolized and incorporated into cell surface glycans, likely through the sialic acid and GalNAc salvage pathways, respectively. Furthermore, GlcNAc analogs can be incorporated into nucleocytoplasmic proteins in place of {beta}-O-GlcNAc residues. These pathways have been exploited to integrate unique electrophiles such as ketones and azides into the target glycoconjugate class. These functional groups can be further elaborated in a chemoselective fashion by condensation with hydrazides and by Staudinger ligation, respectively, thereby introducing detectable probes onto the cell. In conclusion, sialic acid derivatives are efficient vehicles for delivery of bulky functional groups to cell surfaces and masking of their hydroxyl groups improves their cellular uptake and utilization. Furthermore, the successful introduction of photoactivatable aryl azides into cell surface glycans opens up new avenues for studying sialic acid-binding proteins and elucidating the role of sialic acid in essential processes such as signaling and cell adhesion.

  16. Characterization of glucose-related metabolic pathways in differentiated rat oligodendrocyte lineage cells.

    PubMed

    Amaral, Ana I; Hadera, Mussie G; Tavares, Joana M; Kotter, Mark R N; Sonnewald, Ursula

    2016-01-01

    Although oligodendrocytes constitute a significant proportion of cells in the central nervous system (CNS), little is known about their intermediary metabolism. We have, therefore, characterized metabolic functions of primary oligodendrocyte precursor cell cultures at late stages of differentiation using isotope-labelled metabolites. We report that differentiated oligodendrocyte lineage cells avidly metabolize glucose in the cytosol and pyruvate derived from glucose in the mitochondria. The labelling patterns of metabolites obtained after incubation with [1,2-(13)C]glucose demonstrated that the pentose phosphate pathway (PPP) is highly active in oligodendrocytes (approximately 10% of glucose is metabolized via the PPP as indicated by labelling patterns in phosphoenolpyruvate). Mass spectrometry and magnetic resonance spectroscopy analyses of metabolites after incubation of cells with [1-(13)C]lactate or [1,2-(13)C]glucose, respectively, demonstrated that anaplerotic pyruvate carboxylation, which was thought to be exclusive to astrocytes, is also active in oligodendrocytes. Using [1,2-(13)C]acetate, we show that oligodendrocytes convert acetate into acetyl CoA which is metabolized in the tricarboxylic acid cycle. Analysis of labelling patterns of alanine after incubation of cells with [1,2-(13)C]acetate and [1,2-(13)C]glucose showed catabolic oxidation of malate or oxaloacetate. In conclusion, we report that oligodendrocyte lineage cells at late differentiation stages are metabolically highly active cells that are likely to contribute considerably to the metabolic activity of the CNS.

  17. Metabolic dependence of red cell deformability

    PubMed Central

    Weed, Robert I.; LaCelle, Paul L.; Merrill, Edward W.

    1969-01-01

    The contribution of the metabolic state of human erythrocytes to maintenance of cellular deformability was studied during and after in vitro incubation in serum for periods up to 28 hr. An initial loss of membrane deformability became apparent between 4 and 6 hr when cellular adenosine triphosphate (ATP) levels were approximately 70% of initial values. Membrane deformability then remained stable between 6 and 10 hr. After 10 hr, when cellular ATP had decreased to < 15% of initial values, progressive parallel changes occurred in red cell calcium which increased 400% by 24 hr and in the viscosity of red cell suspensions which had risen 500-750% at 24 hr. A further progressive decrease in membrane deformability also occurred and was reflected by a 1000% increase in negative pressure required to deform the membrane. Red cell filterability decreased to zero as the disc-sphere shape transformation ensued. These changes were accompanied by an increase in ghost residual hemoglobin and nonhemoglobin protein. Regeneration of ATP in depleted cells by incubation with adenosine produced significant reversal of these changes, even in the presence of ouabain. Introduction of calcium into reconstituted ghosts prepared from fresh red cells mimicked the depleted state, and introduction of ATP, ethylenediamine tetraacetate (EDTA), and magnesium into depleted cells mimicked the adenosine effects in intact depleted cells. ATP added externally to 24-hr depleted cells was without effect. Simultaneous introduction of EDTA, ATP, or magnesium along with calcium into reconstituted ghosts prevented the marked decrease in deformability produced by calcium alone. Incorporation of adenosine diphosphate (ADP), nicotinamide adenine dinucleotide (NAD), NAD phosphate (NADP), NADP, reduced form (NADPH), glutatione, reduced form (GSH), inosine triphosphate (ITP), guanosine triphosphate (GTP), and uridine triphosphate (UTP) was without effect. These data suggest that a major role of ATP in maintenance

  18. c-Myc activates multiple metabolic networks to generate substrates for cell-cycle entry.

    PubMed

    Morrish, F; Isern, N; Sadilek, M; Jeffrey, M; Hockenbery, D M

    2009-07-01

    Cell proliferation requires the coordinated activity of cytosolic and mitochondrial metabolic pathways to provide ATP and building blocks for DNA, RNA and protein synthesis. Many metabolic pathway genes are targets of the c-myc oncogene and cell-cycle regulator. However, the contribution of c-Myc to the activation of cytosolic and mitochondrial metabolic networks during cell-cycle entry is unknown. Here, we report the metabolic fates of [U-(13)C] glucose in serum-stimulated myc(-/-) and myc(+/+) fibroblasts by (13)C isotopomer NMR analysis. We demonstrate that endogenous c-myc increased (13)C labeling of ribose sugars, purines and amino acids, indicating partitioning of glucose carbons into C1/folate and pentose phosphate pathways, and increased tricarboxylic acid cycle turnover at the expense of anaplerotic flux. Myc expression also increased global O-linked N-acetylglucosamine protein modification, and inhibition of hexosamine biosynthesis selectively reduced growth of Myc-expressing cells, suggesting its importance in Myc-induced proliferation. These data reveal a central organizing function for the Myc oncogene in the metabolism of cycling cells. The pervasive deregulation of this oncogene in human cancers may be explained by its function in directing metabolic networks required for cell proliferation.

  19. c-Myc activates multiple metabolic networks to generate substrates for cell-cycle entry.

    SciTech Connect

    Morrish, Fionnuala M.; Isern, Nancy; Sadilek, Martin; Jeffrey, Mark; Hockenbery, David M.

    2009-05-18

    Cell proliferation requires the coordinated activity of cytosolic and mitochondrial metabolic pathways to provide ATP and building blocks for DNA, RNA, and protein synthesis. Many metabolic pathway genes are targets of the c-myc oncogene and cell cycle regulator. However, the contribution of c-Myc to the activation of cytosolic and mitochondrial metabolic networks during cell cycle entry is unknown. Here, we report the metabolic fates of [U-13C] glucose in serum-stimulated myc-/- and myc+/+ fibroblasts by 13C isotopomer NMR analysis. We demonstrate that endogenous c-myc increased 13C-labeling of ribose sugars, purines, and amino acids, indicating partitioning of glucose carbons into C1/folate and pentose phosphate pathways, and increased tricarboxylic acid cycle turnover at the expense of anaplerotic flux. Myc expression also increased global O-linked GlcNAc protein modification, and inhibition of hexosamine biosynthesis selectively reduced growth of Myc-expressing cells, suggesting its importance in Myc-induced proliferation. These data reveal a central organizing role for the Myc oncogene in the metabolism of cycling cells. The pervasive deregulation of this oncogene in human cancers may be explained by its role in directing metabolic networks required for cell proliferation.

  20. Metabolic and Transcriptional Analysis of Acid Stress in Lactococcus lactis, with a Focus on the Kinetics of Lactic Acid Pools

    PubMed Central

    Carvalho, Ana Lúcia; Turner, David L.; Fonseca, Luís L.; Solopova, Ana; Catarino, Teresa; Kuipers, Oscar P.; Voit, Eberhard O.; Neves, Ana Rute; Santos, Helena

    2013-01-01

    The effect of pH on the glucose metabolism of non-growing cells of L. lactis MG1363 was studied by in vivo NMR in the range 4.8 to 6.5. Immediate pH effects on glucose transporters and/or enzyme activities were distinguished from transcriptional/translational effects by using cells grown at the optimal pH of 6.5 or pre-adjusted to low pH by growth at 5.1. In cells grown at pH 5.1, glucose metabolism proceeds at a rate 35% higher than in non-adjusted cells at the same pH. Besides the upregulation of stress-related genes (such as dnaK and groEL), cells adjusted to low pH overexpressed H+-ATPase subunits as well as glycolytic genes. At sub-optimal pHs, the total intracellular pool of lactic acid reached approximately 500 mM in cells grown at optimal pH and about 700 mM in cells grown at pH 5.1. These high levels, together with good pH homeostasis (internal pH always above 6), imply intracellular accumulation of the ionized form of lactic acid (lactate anion), and the concomitant export of the equivalent protons. The average number, n, of protons exported with each lactate anion was determined directly from the kinetics of accumulation of intra- and extracellular lactic acid as monitored online by 13C-NMR. In cells non-adjusted to low pH, n varies between 2 and 1 during glucose consumption, suggesting an inhibitory effect of intracellular lactate on proton export. We confirmed that extracellular lactate did not affect the lactate: proton stoichiometry. In adjusted cells, n was lower and varied less, indicating a different mix of lactic acid exporters less affected by the high level of intracellular lactate. A qualitative model for pH effects and acid stress adaptation is proposed on the basis of these results. PMID:23844205

  1. Metabolic and transcriptional analysis of acid stress in Lactococcus lactis, with a focus on the kinetics of lactic acid pools.

    PubMed

    Carvalho, Ana Lúcia; Turner, David L; Fonseca, Luís L; Solopova, Ana; Catarino, Teresa; Kuipers, Oscar P; Voit, Eberhard O; Neves, Ana Rute; Santos, Helena

    2013-01-01

    The effect of pH on the glucose metabolism of non-growing cells of L. lactis MG1363 was studied by in vivo NMR in the range 4.8 to 6.5. Immediate pH effects on glucose transporters and/or enzyme activities were distinguished from transcriptional/translational effects by using cells grown at the optimal pH of 6.5 or pre-adjusted to low pH by growth at 5.1. In cells grown at pH 5.1, glucose metabolism proceeds at a rate 35% higher than in non-adjusted cells at the same pH. Besides the upregulation of stress-related genes (such as dnaK and groEL), cells adjusted to low pH overexpressed H(+)-ATPase subunits as well as glycolytic genes. At sub-optimal pHs, the total intracellular pool of lactic acid reached approximately 500 mM in cells grown at optimal pH and about 700 mM in cells grown at pH 5.1. These high levels, together with good pH homeostasis (internal pH always above 6), imply intracellular accumulation of the ionized form of lactic acid (lactate anion), and the concomitant export of the equivalent protons. The average number, n, of protons exported with each lactate anion was determined directly from the kinetics of accumulation of intra- and extracellular lactic acid as monitored online by (13)C-NMR. In cells non-adjusted to low pH, n varies between 2 and 1 during glucose consumption, suggesting an inhibitory effect of intracellular lactate on proton export. We confirmed that extracellular lactate did not affect the lactate: proton stoichiometry. In adjusted cells, n was lower and varied less, indicating a different mix of lactic acid exporters less affected by the high level of intracellular lactate. A qualitative model for pH effects and acid stress adaptation is proposed on the basis of these results.

  2. Glycerol metabolism and bitterness producing lactic acid bacteria in cidermaking.

    PubMed

    Garai-Ibabe, G; Ibarburu, I; Berregi, I; Claisse, O; Lonvaud-Funel, A; Irastorza, A; Dueñas, M T

    2008-02-10

    Several lactic acid bacteria were isolated from bitter tasting ciders in which glycerol was partially removed. The degradation of glycerol via glycerol dehydratase pathway was found in 22 out of 67 isolates. The confirmation of glycerol degradation by this pathway was twofold: showing their glycerol dehydratase activity and detecting the presence of the corresponding gene by a PCR method. 1,3-propanediol (1,3-PDL) and 3-hydroxypropionic acid (3-HP) were the metabolic end-products of glycerol utilization, and the accumulation of the acrolein precursor 3-hydroxypropionaldehyde (3-HPA) was also detected in most of them. The strain identification by PCR-DGGE rpoB showed that Lactobacillus collinoides was the predominant species and only 2 belonged to Lactobacillus diolivorans. Environmental conditions conducting to 3-HPA accumulation in cidermaking were studied by varying the fructose concentration, pH and incubation temperature in L. collinoides 17. This strain failed to grow with glycerol as sole carbon source and the addition of fructose enhanced both growth and glycerol degradation. Regarding end-products of glycerol metabolism, 1,3-PDL was always the main end-product in all environmental conditions assayed, the only exception being the culture with 5.55 mM fructose, where equimolar amounts of 1,3-PDL and 3-HP were found. The 3-HPA was transitorily accumulated in the culture medium under almost all culture conditions, the degradation rate being notably slower at 15 degrees C. However, no disappearance of 3-HPA was found at pH 3.6, a usual value in cider making. After sugar exhaustion, L. collinoides 17 oxidated lactic acid and/or mannitol to obtain energy and these oxidations were accompanied by the removal of the toxic 3-HPA increasing the 1,3-PDL, 3-HP and acetic acid contents. PMID:18180066

  3. Liquid chromatography – high resolution mass spectrometry analysis of fatty acid metabolism

    PubMed Central

    Kamphorst, Jurre J.; Fan, Jing; Lu, Wenyun; White, Eileen; Rabinowitz, Joshua D.

    2011-01-01

    We present a liquid chromatography – mass spectrometry (LC-MS) method for long-chain and very-long-chain fatty acid analysis, and its application to 13C-tracer studies of fatty acid metabolism. Fatty acids containing 14 to 36 carbon atoms are separated by C8 reversed-phase chromatography using a water-methanol gradient with tributylamine as ion pairing agent, ionized by electrospray, and analyzed by a stand-alone orbitrap mass spectrometer. The median limit of detection is 5 ng/ml with a linear dynamic range of 100-fold. Ratios of unlabeled to 13C-labeled species are quantitated precisely and accurately (average relative standard deviation 3.2% and deviation from expectation 2.3%). In samples consisting of fatty acids saponified from cultured mammalian cells, 45 species are quantified, with average intraday relative standard deviations for independent biological replicates of 11%. The method enables quantitation of molecular ion peaks for all labeled forms of each fatty acid. Different degrees of 13C-labeling from glucose and glutamine correspond to fatty acid uptake from media, de novo synthesis, and elongation. To exemplify the utility of the method, we examined isogenic cell lines with and without activated Ras oncogene expression. Ras increases the abundance and alters the labeling patterns of saturated and monounsaturated very-long-chain fatty acids, with the observed pattern consistent with Ras leading to enhanced activity of ELOVL4 or an enzyme with similar catalytic activity. This LC-MS method and associated isotope tracer techniques should be broadly applicable to investigating fatty acid metabolism. PMID:22004349

  4. Metabolic maintenance of cell asymmetry following division in activated T lymphocytes.

    PubMed

    Verbist, Katherine C; Guy, Cliff S; Milasta, Sandra; Liedmann, Swantje; Kamiński, Marcin M; Wang, Ruoning; Green, Douglas R

    2016-04-21

    Asymmetric cell division, the partitioning of cellular components in response to polarizing cues during mitosis, has roles in differentiation and development. It is important for the self-renewal of fertilized zygotes in Caenorhabditis elegans and neuroblasts in Drosophila, and in the development of mammalian nervous and digestive systems. T lymphocytes, upon activation by antigen-presenting cells (APCs), can undergo asymmetric cell division, wherein the daughter cell proximal to the APC is more likely to differentiate into an effector-like T cell and the distal daughter is more likely to differentiate into a memory-like T cell. Upon activation and before cell division, expression of the transcription factor c-Myc drives metabolic reprogramming, necessary for the subsequent proliferative burst. Here we find that during the first division of an activated T cell in mice, c-Myc can sort asymmetrically. Asymmetric distribution of amino acid transporters, amino acid content, and activity of mammalian target of rapamycin complex 1 (mTORC1) is correlated with c-Myc expression, and both amino acids and mTORC1 activity sustain the differences in c-Myc expression in one daughter cell compared to the other. Asymmetric c-Myc levels in daughter T cells affect proliferation, metabolism, and differentiation, and these effects are altered by experimental manipulation of mTORC1 activity or c-Myc expression. Therefore, metabolic signalling pathways cooperate with transcription programs to maintain differential cell fates following asymmetric T-cell division.

  5. OVCAR-3 Spheroid-Derived Cells Display Distinct Metabolic Profiles

    PubMed Central

    Vermeersch, Kathleen A.; Wang, Lijuan; Mezencev, Roman; McDonald, John F.; Styczynski, Mark P.

    2015-01-01

    Introduction Recently, multicellular spheroids were isolated from a well-established epithelial ovarian cancer cell line, OVCAR-3, and were propagated in vitro. These spheroid-derived cells displayed numerous hallmarks of cancer stem cells, which are chemo- and radioresistant cells thought to be a significant cause of cancer recurrence and resultant mortality. Gene set enrichment analysis of expression data from the OVCAR-3 cells and the spheroid-derived putative cancer stem cells identified several metabolic pathways enriched in differentially expressed genes. Before this, there had been little previous knowledge or investigation of systems-scale metabolic differences between cancer cells and cancer stem cells, and no knowledge of such differences in ovarian cancer stem cells. Methods To determine if there were substantial metabolic changes corresponding with these transcriptional differences, we used two-dimensional gas chromatography coupled to mass spectrometry to measure the metabolite profiles of the two cell lines. Results These two cell lines exhibited significant metabolic differences in both intracellular and extracellular metabolite measurements. Principal components analysis, an unsupervised dimensional reduction technique, showed complete separation between the two cell types based on their metabolite profiles. Pathway analysis of intracellular metabolomics data revealed close overlap with metabolic pathways identified from gene expression data, with four out of six pathways found enriched in gene-level analysis also enriched in metabolite-level analysis. Some of those pathways contained multiple metabolites that were individually statistically significantly different between the two cell lines, with one of the most broadly and consistently different pathways, arginine and proline metabolism, suggesting an interesting hypothesis about cancerous and stem-like metabolic phenotypes in this pair of cell lines. Conclusions Overall, we demonstrate for the

  6. Dietary n-6 polyunsaturated fatty acid deprivation increases docosahexaenoic acid metabolism in rat brain.

    PubMed

    Igarashi, Miki; Kim, Hyung-Wook; Chang, Lisa; Ma, Kaizong; Rapoport, Stanley I

    2012-03-01

    Dietary n-6 polyunsaturated fatty acid (PUFA) deprivation in rodents reduces brain arachidonic acid (20:4n-6) concentration and 20:4n-6-preferring cytosolic phospholipase A(2) (cPLA(2) -IVA) and cyclooxygenase (COX)-2 expression, while increasing brain docosahexaenoic acid (DHA, 22:6n-3) concentration and DHA-selective calcium-independent phospholipase A(2) (iPLA(2) )-VIA expression. We hypothesized that these changes are accompanied by up-regulated brain DHA metabolic rates. Using a fatty acid model, brain DHA concentrations and kinetics were measured in unanesthetized male rats fed, for 15 weeks post-weaning, an n-6 PUFA 'adequate' (31.4 wt% linoleic acid) or 'deficient' (2.7 wt% linoleic acid) diet, each lacking 20:4n-6 and DHA. [1-(14) C]DHA was infused intravenously, arterial blood was sampled, and the brain was microwaved at 5 min and analyzed. Rats fed the n-6 PUFA deficient compared with adequate diet had significantly reduced n-6 PUFA concentrations in brain phospholipids but increased eicosapentaenoic acid (EPA, 20:5n-3), docosapentaenoic acid n-3 (DPAn-3, 22:5n-3), and DHA (by 9.4%) concentrations, particularly in ethanolamine glycerophospholipid (EtnGpl). Incorporation rates of unesterified DHA from plasma, which represent DHA metabolic loss from brain, were increased 45% in brain phospholipids, as was DHA turnover. Increased DHA metabolism following dietary n-6 PUFA deprivation may increase brain concentrations of antiinflammatory DHA metabolites, which with a reduced brain n-6 PUFA content, likely promotes neuroprotection and alters neurotransmission.

  7. Carotenoid and fatty acid metabolism in nitrogen-starved Dunaliella salina, a unicellular green microalga.

    PubMed

    Lamers, Packo P; Janssen, Marcel; De Vos, Ric C H; Bino, Raoul J; Wijffels, René H

    2012-11-30

    Nitrogen availability and light intensity affect β-carotene overproduction in the green alga Dunaliella salina. Following a previous study on high-light stress, we here report on the effect of nitrogen depletion on the growth characteristics and β-carotene as well as fatty acid metabolism of D. salina under a constant light regime in a turbidostat. Upon nitrogen depletion, the biomass yield on absorbed light approximately doubled, due to a transient increase in cell division rate, swelling of the cells and a linear increase of the density of the cells. Simultaneously, β-carotene started to accumulate up to a final intracellular concentration of 14 mg LCV⁻¹ (i.e. 2.7% of AFDW). This β-carotene production accounted for 6% of the increased density of the cells, indicating that other biochemical constituents accumulated as well. Since D. salina accumulates β-carotene in lipid globules, we also determined the fatty acid content and composition of D. salina. The intracellular concentration of the total fatty acid pool did not change significantly during nitrogen starvation, indicating that β-carotene and total fatty acid accumulation were unrelated, similar to what was found previously for high-light treated cells. However, for both high-light and nitrogen stress, β-carotene accumulation negatively correlated with the degree of unsaturation of the total fatty acid pool and, within the individual fatty acids, correlated positively with oleic acid biosynthesis, suggesting that oleic acid may be a key component of the lipid-globule-localized triacylglycerols and thereby in β-carotene accumulation.

  8. Role of Metabolism in the Immunobiology of Regulatory T Cells.

    PubMed

    Galgani, Mario; De Rosa, Veronica; La Cava, Antonio; Matarese, Giuseppe

    2016-10-01

    Intracellular metabolism is central to cell activity and function. CD4(+)CD25(+) regulatory T cells (Tregs) that express the transcription factor FOXP3 play a pivotal role in the maintenance of immune tolerance to self. Recent studies showed that the metabolism and function of Tregs are influenced significantly by local environmental conditions and the availability of certain metabolites. It also was reported that defined metabolic programs associate with Treg differentiation, expression of FOXP3, and phenotype stabilization. This article reviews how metabolism modulates FOXP3 expression and Treg function, what environmental factors are involved, and how metabolic manipulation could alter Treg frequency and function in physiopathologic conditions. PMID:27638939

  9. Tumour-specific metabolic adaptation to acidosis is coupled to epigenetic stability in osteosarcoma cells.

    PubMed

    Chano, Tokuhiro; Avnet, Sofia; Kusuzaki, Katsuyuki; Bonuccelli, Gloria; Sonveaux, Pierre; Rotili, Dante; Mai, Antonello; Baldini, Nicola

    2016-01-01

    The glycolytic-based metabolism of cancers promotes an acidic microenvironment that is responsible for increased aggressiveness. However, the effects of acidosis on tumour metabolism have been almost unexplored. By using capillary electrophoresis with time-of-flight mass spectrometry, we observed a significant metabolic difference associated with glycolysis repression (dihydroxyacetone phosphate), increase of amino acid catabolism (phosphocreatine and glutamate) and urea cycle enhancement (arginino succinic acid) in osteosarcoma (OS) cells compared with normal fibroblasts. Noteworthy, metabolites associated with chromatin modification, like UDP-glucose and N(8)-acetylspermidine, decreased more in OS cells than in fibroblasts. COBRA assay and acetyl-H3 immunoblotting indicated an epigenetic stability in OS cells than in normal cells, and OS cells were more sensitive to an HDAC inhibitor under acidosis than under neutral pH. Since our data suggest that acidosis promotes a metabolic reprogramming that can contribute to the epigenetic maintenance under acidosis only in tumour cells, the acidic microenvironment should be considered for future therapies. PMID:27186436

  10. Tumour-specific metabolic adaptation to acidosis is coupled to epigenetic stability in osteosarcoma cells

    PubMed Central

    Chano, Tokuhiro; Avnet, Sofia; Kusuzaki, Katsuyuki; Bonuccelli, Gloria; Sonveaux, Pierre; Rotili, Dante; Mai, Antonello; Baldini, Nicola

    2016-01-01

    The glycolytic-based metabolism of cancers promotes an acidic microenvironment that is responsible for increased aggressiveness. However, the effects of acidosis on tumour metabolism have been almost unexplored. By using capillary electrophoresis with time-of-flight mass spectrometry, we observed a significant metabolic difference associated with glycolysis repression (dihydroxyacetone phosphate), increase of amino acid catabolism (phosphocreatine and glutamate) and urea cycle enhancement (arginino succinic acid) in osteosarcoma (OS) cells compared with normal fibroblasts. Noteworthy, metabolites associated with chromatin modification, like UDP-glucose and N8-acetylspermidine, decreased more in OS cells than in fibroblasts. COBRA assay and acetyl-H3 immunoblotting indicated an epigenetic stability in OS cells than in normal cells, and OS cells were more sensitive to an HDAC inhibitor under acidosis than under neutral pH. Since our data suggest that acidosis promotes a metabolic reprogramming that can contribute to the epigenetic maintenance under acidosis only in tumour cells, the acidic microenvironment should be considered for future therapies. PMID:27186436

  11. Alterations in cancer cell metabolism: the Warburg effect and metabolic adaptation.

    PubMed

    Asgari, Yazdan; Zabihinpour, Zahra; Salehzadeh-Yazdi, Ali; Schreiber, Falk; Masoudi-Nejad, Ali

    2015-05-01

    The Warburg effect means higher glucose uptake of cancer cells compared to normal tissues, whereas a smaller fraction of this glucose is employed for oxidative phosphorylation. With the advent of high throughput technologies and computational systems biology, cancer cell metabolism has been reinvestigated over the last decades toward identifying various events underlying "how" and "why" a cancer cell employs aerobic glycolysis. Significant progress has been shaped to revise the Warburg effect. In this study, we have integrated the gene expression of 13 different cancer cells with the genome-scale metabolic network of human (Recon1) based on the E-Flux method, and analyzed them based on constraint-based modeling. Results show that regardless of significant up- and down-regulated metabolic genes, the distribution of metabolic changes is similar in different cancer types. These findings support the theory that the Warburg effect is a consequence of metabolic adaptation in cancer cells.

  12. (-)-Hydroxycitric Acid Nourishes Protein Synthesis via Altering Metabolic Directions of Amino Acids in Male Rats.

    PubMed

    Han, Ningning; Li, Longlong; Peng, Mengling; Ma, Haitian

    2016-08-01

    (-)-Hydroxycitric acid (HCA), a major active ingredient of Garcinia Cambogia extracts, had shown to suppress body weight gain and fat accumulation in animals and humans. While, the underlying mechanism of (-)-HCA has not fully understood. Thus, this study was aimed to investigate the effects of long-term supplement with (-)-HCA on body weight gain and variances of amino acid content in rats. Results showed that (-)-HCA treatment reduced body weight gain and increased feed conversion ratio in rats. The content of hepatic glycogen, muscle glycogen, and serum T4 , T3 , insulin, and Leptin were increased in (-)-HCA treatment groups. Protein content in liver and muscle were significantly increased in (-)-HCA treatment groups. Amino acid profile analysis indicated that most of amino acid contents in serum and liver, especially aromatic amino acid and branched amino acid, were higher in (-)-HCA treatment groups. However, most of the amino acid contents in muscle, especially aromatic amino acid and branched amino acid, were reduced in (-)-HCA treatment groups. These results indicated that (-)-HCA treatment could reduce body weight gain through promoting energy expenditure via regulation of thyroid hormone levels. In addition, (-)-HCA treatment could promote protein synthesis by altering the metabolic directions of amino acids. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27145492

  13. Defining meal requirements for protein to optimize metabolic roles of amino acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary protein provides essential amino acids (EAAs) for the synthesis of new proteins plus an array of other metabolic functions; many of these functions are sensitive to postprandial plasma and intracellular amino acid concentrations. Recent research has focused on amino acids as metabolic signal...

  14. Defining meal requirements for protein to optimize metabolic roles of amino acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary protein provides essential amino acids (EAA) for the synthesis of new proteins plus an array of other metabolic functions; many of these functions are sensitive to post-prandial plasma and intracellular amino acid concentrations. Recent research has focused on amino acids as metabolic signal...

  15. Testosterone and prolactin regulation of metabolic genes and citrate metabolism of prostate epithelial cells.

    PubMed

    Costello, L C; Franklin, R B

    2002-08-01

    The control and alteration of key regulatory enzymes is a determinant of the reactions and pathways of intermediary metabolism in mammalian cells. An important mechanism in the metabolic control is the hormonal regulation of the genes associated with the transcription and the biosynthesis of these key enzymes. The secretory epithelial cells of the prostate gland of humans and other animals possess a unique citrate-related metabolic pathway regulated by testosterone and prolactin. This specialized hormone-regulated metabolic activity is responsible for the major prostate function of the production and secretion of extraordinarily high levels of citrate. The key regulatory enzymes directly associated with citrate production in the prostate cells are mitochondrial aspartate aminotransferase, pyruvate dehydrogenase, and mitochondrial aconitase. Testosterone and prolactin are involved in the regulation of the corresponding genes associated with these enzymes (which we refer to as "metabolic genes"). The regulatory regions of these genes contain the necessary response elements that confer the ability of both hormones to control gene transcription. In this report, we describe the role of protein kinase c (PKC) as the signaling pathway for the prolactin regulation of the metabolic genes in prostate cells. Testosterone and prolactin regulation of these metabolic genes (which are constitutively expressed in all mammalian cells) is specific for these citrate-producing cells. We hope that this review will provide a strong basis for future studies regarding the hormonal regulation of citrate-related intermediary metabolism. Most importantly, altered citrate metabolism is a persistent distinguishing characteristic (decreased citrate production) of prostate cancer (PCa) and also (increased citrate production) of benign prostatic hyperplasia (BPH). An understanding of the role of hormonal regulation of metabolism is essential to understanding the pathogenesis of prostate disease

  16. Metabolic shifts induced by human H460 cells in tumor-bearing mice.

    PubMed

    Liu, Linsheng; Wang, Yaqiong; Zheng, Tian; Cao, Bei; Li, Mengjie; Shi, Jian; Aa, Nan; Wang, Xinwen; Zhao, Chunyan; Aa, Jiye; Wang, Guangji

    2016-03-01

    Tumor markers are most popularly used in diagnosis of various cancers clinically. However, the confounding factors of individual background diversities, such as genetics, food preferences, living styles, physical exercises, etc., greatly challenge the identification of tumor markers. Study of the metabolic impact of inoculated tumors on model animals can facilitate the identification of metabolomic markers relevant to tumor insult. In this study, serum metabolites from nude mice (n = 14) inoculated with human H460 cells (human nonsmall cell lung carcinoma) were profiled using gas chromatography time-of-flight mass spectrometry. The mice with inoculated tumors showed an obviously different metabolic pattern from the control; identification of the discriminatory metabolites suggested the metabolic perturbation of free fatty acids, amino acids, glycolysis and tricarboxylic acid (TCA) cycle turnover. The significantly decreased TCA intermediates, free fatty acids, 3-hydroxybutyric acid and fluctuating amino acids (t-test, p < 0.05) in serum of tumor-bearing mice characterized the metabolic impact of local inoculated H460 tumor cells on the whole system. This indicates that they are candidate metabolomic markers for translational study of lung cancer, clinically. PMID:26147780

  17. Isoprenylcysteine carboxylmethyltransferase regulates mitochondrial respiration and cancer cell metabolism.

    PubMed

    Teh, J T; Zhu, W L; Ilkayeva, O R; Li, Y; Gooding, J; Casey, P J; Summers, S A; Newgard, C B; Wang, M

    2015-06-01

    Isoprenylcysteine carboxylmethyltransferase (Icmt) catalyzes the last of the three-step posttranslational protein prenylation process for the so-called CaaX proteins, which includes many signaling proteins, such as most small GTPases. Despite extensive studies on Icmt and its regulation of cell functions, the mechanisms of much of the impact of Icmt on cellular functions remain unclear. Our recent studies demonstrated that suppression of Icmt results in induction of autophagy, inhibition of cell growth and inhibition of proliferation in various cancer cell types, prompting this investigation of potential metabolic regulation by Icmt. We report here the findings that Icmt inhibition reduces the function of mitochondrial oxidative phosphorylation in multiple cancer cell lines. In-depth oximetry analysis demonstrated that functions of mitochondrial complex I, II and III are subject to Icmt regulation. Consistently, Icmt inhibition decreased cellular ATP and depleted critical tricarboxylic acid cycle metabolites, leading to suppression of cell anabolism and growth, and marked autophagy. Several different approaches demonstrated that the impact of Icmt inhibition on cell proliferation and viability was largely mediated by its effect on mitochondrial respiration. This previously unappreciated function of Icmt, which can be therapeutically exploited, likely has a significant role in the impact of Icmt on tumorigenic processes.

  18. Metabolic profiling reveals that PNPLA3 induces widespread effects on metabolism beyond triacylglycerol remodeling in Huh-7 hepatoma cells

    PubMed Central

    Min, Hae-Ki; Sookoian, Silvia; Pirola, Carlos J.; Cheng, Jianfeng; Mirshahi, Faridoddin

    2014-01-01

    PNPLA3 was recently associated with the susceptibility to nonalcoholic fatty liver disease, a common cause of chronic liver disease characterized by abnormal triglyceride accumulation. Although it is established that PNPLA3 has both triacylglycerol lipase and acylglycerol O-acyltransferase activities, is still unknown whether the gene has any additional role in the modulation of the human liver metabolome. To uncover the functional role of PNPLA3 on liver metabolism, we performed high-throughput metabolic profiling of PNPLA3 siRNA-silencing and overexpression of wild-type and mutant Ile148Met variants (isoleucine/methionine substitution at codon 148) in Huh-7 cells. Metabolomic analysis was performed by using GC/MS and LC/MS platforms. Silencing of PNPLA3 was associated with a global perturbation of Huh-7 hepatoma cells that resembled a catabolic response associated with protein breakdown. A significant decrease in amino- and γ-glutamyl-amino acids and dipeptides and a significant increase in cysteine sulfinic acid, myo-inositol, lysolipids, sphingolipids, and polyunsaturated fatty acids were observed. Overexpression of the PNPLA3 Met148 variant mirrored many of the metabolic changes observed during gene silencing, but in the opposite direction. These findings were replicated by the exploration of canonical pathways associated with PNPLA3 silencing and Met148 overexpression. Overexpression of the PNPLA3 Met148 variant was associated with a 1.75-fold increase in lactic acid, suggesting a shift to anaerobic metabolism and mitochondrial dysfunction. Together, these results suggest a critical role of PNPLA3 in the modulation of liver metabolism beyond its classical participation in triacylglycerol remodeling. PMID:24763554

  19. Punicic acid from Trichosanthes kirilowii seed oil is rapidly metabolized to conjugated linoleic acid in rats.

    PubMed

    Yuan, Gao-Feng; Yuan, Jing-Qun; Li, Duo

    2009-04-01

    The incorporation and metabolism of orally administered punicic acid (PA), one isomer of conjugated linolenic acid (CLNA), in rat tissues and plasma were studied over a 24-hour period. The punic acid was derived from Trichosanthes kirilowii Maxim seed oil, a unique PA-containing material, and identified and analyzed by high-performance liquid chromatography and gas chromatography-mass spectrometry. The results show that PA was incorporated and metabolized to 9c,11t-conjugated linoleic acid (CLA) in rat plasma, liver, kidney, heart, brain, and adipose tissue. The level of PA and CLA in liver and plasma was higher than in brain, heart, kidney, and adipose tissue, and the lowest accumulation occurred in the brain. The observation that PA can be converted into 9c,11t-CLA has gained increased importance since it has been demonstrated that 9c,11t-CLA exerts many biological activities. Therefore natural resources containing CLNA, especially edible T. kirilowii seed, could be a potential dietary source of CLA, following PA metabolism. PA is expected to be used as a functional food and nutraceutical.

  20. Metabolism of cyclohexaneacetic acid and cyclohexanebutyric acid by Arthrobacter sp. strain CA1.

    PubMed Central

    Ougham, H J; Trudgill, P W

    1982-01-01

    A strain of Arthrobacter was isolated by enrichment culture with cyclohexaneacetate as the sole source of carbon and grew with a doubling time of 4.2 h. In addition to growing with cyclohexaneacetate, the organism also grew with cyclohexanebutyrate at concentrations not above 0.05%, and with a variety of alicyclic ketones and alcohols. Oxidation of cyclohexaneacetate proceeded through formation of the coenzyme A (CoA) ester followed by initiation of a beta-oxidation cycle. beta-Oxidation was blocked before the second dehydrogenation step due to the formation of a tertiary alcohol, and the side chain was eliminated as acetyl-CoA by the action of (1-hydroxycyclohexan-1-yl)acetyl-CoA lyase. The cyclohexanone thus formed was degraded by a well-described route that involves ring-oxygen insertion by a biological Baeyer-Villiger oxygenase. All enzymes of the proposed metabolic sequence were demonstrated in cell-free extracts. Arthrobacter sp. strain CA1 synthesized constitutive beta-oxidative enzymes, but further induction of enzymes active toward cyclohexaneacetate and its metabolites could occur during growth with the alicyclic acid. Other enzymes of the sequence, (1-hydroxycyclohexan-1-yl)acetyl-CoA lyase and enzymes of cyclohexanone oxidation, were present at negligible levels in succinate-grown cells but induced by growth with cyclohexaneacetate. The oxidation of cyclohexanebutyrate was integrated into the pathway for cyclohexaneacetate oxidation by a single beta-oxidation cycle. Oxidation of the compound could be divided into two phases. Initial oxidation to (1-hydroxycyclohexan-1-yl)acetate could be catalyzed by constitutive enzymes, whereas the further degradation of (1-hydroxycyclohexan-1-yl)acetate was dependent on induced enzyme synthesis which could be inhibited by chloramphenicol with the consequent accumulation of cyclohexaneacetate and (1-hydroxycyclohexan-1-yl)acetate. PMID:7076617

  1. The platelet isoform of phosphofructokinase contributes to metabolic reprogramming and maintains cell proliferation in clear cell renal cell carcinoma

    PubMed Central

    Wang, Jun; Zhang, Ping; Zhong, Jie; Tan, Mingyue; Ge, Jifu; Tao, Le; Li, Yakui; Zhu, Yemin; Wu, Lifang; Qiu, Jianxin; Tong, Xuemei

    2016-01-01

    Metabolic alterations underlying clear cell renal cell carcinoma (ccRCC) progression include aerobic glycolysis, increased pentose phosphate pathway activity and reduced oxidative phosphorylation. Phosphofructokinase (PFK), a key enzyme of the glycolytic pathway, has L, M, and P isoforms with different tissue distributions. The mRNA level of the platelet isoform of phosphofructokinase (PFKP) is reported to be up-regulated in ccRCC patients. However, it remains unclear whether PFKP plays an important role in promoting aerobic glycolysis and macromolecular biosynthesis to support cell proliferation in ccRCC. Here we found that the up-regulated PFKP became the predominant isoform of PFK in human ccRCC. Suppression of PFKP not only impaired cell proliferation by inducing cell cycle arrest and apoptosis, but also led to decreased glycolysis, pentose phosphate pathway and nucleotide biosynthesis, accompanied by activated tricarboxylic acid cycle in ccRCC cells. Moreover, we found that p53 activation contributed to cell proliferation and metabolic defects induced by PFKP knockdown in ccRCC cells. Furthermore, suppression of PFKP led to reduced ccRCC tumor growth in vivo. Our data indicate that PFKP not only is required for metabolic reprogramming and maintaining cell proliferation, but also may provide us with a valid target for anti-renal cancer pharmaceutical agents. PMID:27049827

  2. Chlorogenic Acids Biosynthesis in Centella asiatica Cells Is not Stimulated by Salicylic Acid Manipulation.

    PubMed

    Ncube, E N; Steenkamp, P A; Madala, N E; Dubery, I A

    2016-07-01

    Exogenous application of synthetic and natural elicitors of plant defence has been shown to result in mass production of secondary metabolites with nutraceuticals properties in cultured cells. In particular, salicylic acid (SA) treatment has been reported to induce the production of phenylpropanoids, including cinnamic acid derivatives bound to quinic acid (chlorogenic acids). Centella asiatica is an important medicinal plant with several therapeutic properties owing to its wide spectrum of secondary metabolites. We investigated the effect of SA on C. asiatica cells by monitoring perturbation of chlorogenic acids in particular. Different concentrations of SA were used to treat C. asiatica cells, and extracts from both treated and untreated cells were analysed using an optimised UHPLC-QTOF-MS/MS method. Semi-targeted multivariate data analyses with the aid of principal component analysis (PCA) and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) revealed a concentration-dependent metabolic response. Surprisingly, a range of chlorogenic acid derivatives were found to be downregulated as a consequence of SA treatment. Moreover, irbic acid (3,5-O-dicaffeoyl-4-O-malonilquinic acid) was found to be a dominant CGA in C. asiatica cells, although the SA treatment also had a negative effect on its concentration. Overall SA treatment was found to be an ineffective elicitor of CGA production in cultured C. asiatica cells.

  3. Metabolism of polyunsaturated fatty acids and their toxicity to the microflora of the rumen.

    PubMed

    Maia, Margarida R G; Chaudhary, Lal C; Figueres, Lauren; Wallace, R John

    2007-05-01

    Ruminal microorganisms hydrogenate polyunsaturated fatty acids (PUFA) present in forages and thereby restrict the availability of health-promoting PUFA in meat and milk. The aim of this study was to investigate PUFA metabolism and the influence of PUFA on members of the ruminal microflora. Eleven of 26 predominant species of ruminal bacteria metabolised linoleic acid (LA; cis-9,cis-12-18:2) substantially. The most common product was vaccenic acid (trans-11-18:1), produced by species related to Butyrivibrio fibrisolvens. alpha-Linolenic acid (LNA; cis-9,cis-12,cis-15-18:3) was metabolised mostly by the same species. The fish oil fatty acids, eicosapentaenoic acid (EPA; 20:5(n - 3)) and docosahexaenoic acid (DHA; 22:6(n - 3)) were not metabolised. Cellulolytic bacteria did not grow in the presence of any PUFA at 50 microg ml(-1), nor did some butyrate-producing bacteria, including the stearate producer Clostridium proteoclasticum, Butyrivibrio hungatei and Eubacterium ruminantium. Toxicity to growth was ranked EPA > DHA > LNA > LA. Cell integrity, as measured using propidium iodide, was damaged by LA in all 26 bacteria, but to different extents. Correlations between its effects on growth and apparent effects on cell integrity in different bacteria were low. Combined effects of LA and sodium lactate in E. ruminantium and C. proteoclasticum indicated that LA toxicity is linked to metabolism in butyrate-producing bacteria. PUFA also inhibited the growth of the cellulolytic ruminal fungi, with Neocallimastix frontalis producing small amounts of cis-9,trans-11-18:2 (CLA) from LA. Thus, while dietary PUFA might be useful in suppressing the numbers of biohydrogenating ruminal bacteria, particularly C. proteoclasticum, care should be taken to avoid unwanted effects in suppressing cellulolysis.

  4. Metabolic flux and the regulation of mammalian cell growth

    PubMed Central

    Locasale, Jason W.; Cantley, Lewis C.

    2011-01-01

    The study of normal mammalian cell growth and the defects that contribute to disease pathogenesis constitutes a fundamental avenue of research that links metabolism to cell growth. Here we visit several aspects of this metabolism, emphasizing recent advances in our understanding of how alterations in glucose metabolism affect cytosolic and mitochondrial redox potential and ATP generation. These alterations drive cell growth not only through supporting biosynthesis, energy metabolism, and maintaining redox potential but also through initiating signaling mechanisms that are still poorly characterized. The evolutionary basis of these additional layers of growth control is also discussed. PMID:21982705

  5. Dynamic changes in energy metabolism upon embryonic stem cell differentiation support developmental toxicant identification.

    PubMed

    van Dartel, Dorien A M; Schulpen, Sjors H; Theunissen, Peter T; Bunschoten, Annelies; Piersma, Aldert H; Keijer, Jaap

    2014-10-01

    Embryonic stem cells (ESC) are widely used to study embryonic development and to identify developmental toxicants. Particularly, the embryonic stem cell test (EST) is well known as in vitro model to identify developmental toxicants. Although it is clear that energy metabolism plays a crucial role in embryonic development, the modulation of energy metabolism in in vitro models, such as the EST, is not yet described. The present study is among the first studies that analyses whole genome expression data to specifically characterize metabolic changes upon ESC early differentiation. Our transcriptomic analyses showed activation of glycolysis, truncated activation of the tricarboxylic acid (TCA) cycle, activation of lipid synthesis, as well as activation of glutaminolysis during the early phase of ESC differentiation. Taken together, this energy metabolism profile points towards energy metabolism reprogramming in the provision of metabolites for biosynthesis of cellular constituents. Next, we defined a gene set that describes this energy metabolism profile. We showed that this gene set could be successfully applied in the EST to identify developmental toxicants known to modulate cellular biosynthesis (5-fluorouracil and methoxyacetic acid), while other developmental toxicants or the negative control did not modulate the expression of this gene set. Our description of dynamic changes in energy metabolism during early ESC differentiation, as well as specific identification of developmental toxicants modulating energy metabolism, is an important step forward in the definition of the applicability domain of the EST.

  6. Farnesoid X receptor activation promotes cell proliferation via PDK4-controlled metabolic reprogramming

    PubMed Central

    Xie, Yang; Wang, Hong; Cheng, Xuefang; Wu, Yuzheng; Cao, Lijuan; Wu, Mengqiu; Xie, Wen; Wang, Guangji; Hao, Haiping

    2016-01-01

    Farnesoid X receptor (FXR) plays a pivotal role in the regulation of various metabolic pathways as well as liver regeneration. However, the casual link between cell proliferative effects during liver regeneration and metabolic regulation of FXR was elusive. In this study, we found that FXR activation significantly promotes HepG2 cell proliferation accompanied with metabolic switch towards the excessive accumulation of aerobic glycolytic intermediates including lactic acid, pyruvate and the subsequently increased biosynthesis of glycine. This FXR-induced metabolic switch was found dependent on an up-regulation of pyruvate dehydrogenate kinase 4 (PDK4), a FXR target gene. FXR agonists were found to promote liver regeneration in the murine model of APAP induced liver injury, which was associated with a metabolic switch favoring the accumulation of glycolytic intermediates as precursors for generation of biomass. However, FXR activation has little effect on the glycolytic metabolism in healthy primary hepatocytes in vitro and the liver of healthy mice in vivo. Therefore, we conclude that FXR may promote the proliferation of tumor cells and the hepatocytes in the process of liver regeneration by activating the PDK4-mediated metabolic reprogramming to generate glycolytic intermediates essential for rapid biomass generation, establishing a mechanistic link between cell proliferation and metabolic switch. PMID:26728993

  7. Metabolism of 2-hydroxy-1-naphthoic acid and naphthalene via gentisic acid by distinctly different sets of enzymes in Burkholderia sp. strain BC1.

    PubMed

    Chowdhury, Piyali Pal; Sarkar, Jayita; Basu, Soumik; Dutta, Tapan K

    2014-05-01

    Burkholderia sp. strain BC1, a soil bacterium, isolated from a naphthalene balls manufacturing waste disposal site, is capable of utilizing 2-hydroxy-1-naphthoic acid (2H1NA) and naphthalene individually as the sole source of carbon and energy. To deduce the pathway for degradation of 2H1NA, metabolites isolated from resting cell culture were identified by a combination of chromatographic and spectrometric analyses. Characterization of metabolic intermediates, oxygen uptake studies and enzyme activities revealed that strain BC1 degrades 2H1NA via 2-naphthol, 1,2,6-trihydroxy-1,2-dihydronaphthalene and gentisic acid. In addition, naphthalene was found to be degraded via 1,2-dihydroxy-1,2-dihydronaphthalene, salicylic acid and gentisic acid, with the putative involvement of the classical nag pathway. Unlike most other Gram-negative bacteria, metabolism of salicylic acid in strain BC1 involves a dual pathway, via gentisic acid and catechol, with the latter being metabolized by catechol 1,2-dioxygenase. Involvement of a non-oxidative decarboxylase in the enzymic transformation of 2H1NA to 2-naphthol indicates an alternative catabolic pathway for the bacterial degradation of hydroxynaphthoic acid. Furthermore, the biochemical observations on the metabolism of structurally similar compounds, naphthalene and 2-naphthol, by similar but different sets of enzymes in strain BC1 were validated by real-time PCR analyses.

  8. Metabolism of hydroxycinnamic acids and esters by Brettanomyces in different red wines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Depending on the cultivars and other factors, differing concentrations of hydroxycinnamic acids (caffeic, p-coumaric, and ferulic acids) and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric acid, respectively) are found in red wines. Hydroxycinnamic acids are metabolized by...

  9. Identification of differences in human and great ape phytanic acid metabolism that could influence gene expression profiles and physiological functions

    PubMed Central

    2010-01-01

    Background It has been proposed that anatomical differences in human and great ape guts arose in response to species-specific diets and energy demands. To investigate functional genomic consequences of these differences, we compared their physiological levels of phytanic acid, a branched chain fatty acid that can be derived from the microbial degradation of chlorophyll in ruminant guts. Humans who accumulate large stores of phytanic acid commonly develop cerebellar ataxia, peripheral polyneuropathy, and retinitis pigmentosa in addition to other medical conditions. Furthermore, phytanic acid is an activator of the PPAR-alpha transcription factor that influences the expression of genes relevant to lipid metabolism. Results Despite their trace dietary phytanic acid intake, all great ape species had elevated red blood cell (RBC) phytanic acid levels relative to humans on diverse diets. Unlike humans, chimpanzees showed sexual dimorphism in RBC phytanic acid levels, which were higher in males relative to females. Cultured skin fibroblasts from all species had a robust capacity to degrade phytanic acid. We provide indirect evidence that great apes, in contrast to humans, derive significant amounts of phytanic acid from the hindgut fermentation of plant materials. This would represent a novel reduction of metabolic activity in humans relative to the great apes. Conclusion We identified differences in the physiological levels of phytanic acid in humans and great apes and propose this is causally related to their gut anatomies and microbiomes. Phytanic acid levels could contribute to cross-species and sex-specific differences in human and great ape transcriptomes, especially those related to lipid metabolism. Based on the medical conditions caused by phytanic acid accumulation, we suggest that differences in phytanic acid metabolism could influence the functions of human and great ape nervous, cardiovascular, and skeletal systems. PMID:20932325

  10. Mitochondrial transporters involved in oleic acid utilization and glutamate metabolism in yeast.

    PubMed

    Trotter, Pamela J; Adamson, Amy L; Ghrist, Angela C; Rowe, Lindsay; Scott, Lori R; Sherman, Matthew P; Stites, Nicole C; Sun, Yue; Tawiah-Boateng, Mary Anne; Tibbetts, Anne S; Wadington, Megan C; West, Aaron C

    2005-10-01

    Utilization of fatty acids such as oleic acid as sole carbon source by the yeast Saccharomyces cerevisiae requires coordinated function of peroxisomes, where the fatty acids are degraded, and the mitochondria, where oxidation is completed. We identified two mitochondrial oxodicarboxylate transporters, Odc1p and Odc2p, as important in efficient utilization of oleic acid in yeast [Tibbetts et al., Arch. Biochem. Biophys. 406 (2002) 96-104]. Yet, the growth phenotype of odc1delta odc2delta strains indicated that additional transporter(s) were also involved. Here, we identify two putative transporter genes, YMC1 and YMC2, as able to suppress the odc1delta odc2delta growth phenotype. The mRNA levels for both are elevated in the presence of glycerol or oleic acid, as compared to glucose. Ymc1p and Ymc2p are localized to the mitochondria in oleic acid-grown cells. Deletion of all four transporters (quad mutant) prevents growth on oleic acid as sole carbon source, while growth on acetate is retained. It is known that the glutamate-sensitive retrograde signaling pathway is important for upregulation of peroxisomal function in response to oleic acid and the oxodicarboxylate alpha-ketoglutarate is transported out of the mitochondria for synthesis of glutamate. So, citric acid cycle function and glutamate synthesis were examined in transporter mutants. The quad mutant has significantly decreased citrate synthase activity and whole cell alpha-ketoglutarate levels, while isocitrate dehydrogenase activity is unaffected and glutamate dehydrogenase activity is increased 10-fold. Strains carrying only two or three transporter deletions exhibit intermediate affects. 13C NMR metabolic enrichment experiments confirm a defect in glutamate biosynthesis in the quad mutant and, in double and triple mutants, suggest increased cycling of the glutamate backbone in the mitochondria before export. Taken together these studies indicate that these four transporters have overlapping activity, and

  11. Metabolic Plasticity of Metastatic Breast Cancer Cells: Adaptation to Changes in the Microenvironment1

    PubMed Central

    Simões, Rui V.; Serganova, Inna S.; Kruchevsky, Natalia; Leftin, Avigdor; Shestov, Alexander A.; Thaler, Howard T.; Sukenick, George; Locasale, Jason W.; Blasberg, Ronald G.; Koutcher, Jason A.; Ackerstaff, Ellen

    2015-01-01

    Cancer cells adapt their metabolism during tumorigenesis. We studied two isogenic breast cancer cells lines (highly metastatic 4T1; nonmetastatic 67NR) to identify differences in their glucose and glutamine metabolism in response to metabolic and environmental stress. Dynamic magnetic resonance spectroscopy of 13C-isotopomers showed that 4T1 cells have higher glycolytic and tricarboxylic acid (TCA) cycle flux than 67NR cells and readily switch between glycolysis and oxidative phosphorylation (OXPHOS) in response to different extracellular environments. OXPHOS activity increased with metastatic potential in isogenic cell lines derived from the same primary breast cancer: 4T1 > 4T07 and 168FARN (local micrometastasis only) > 67NR. We observed a restricted TCA cycle flux at the succinate dehydrogenase step in 67NR cells (but not in 4T1 cells), leading to succinate accumulation and hindering OXPHOS. In the four isogenic cell lines, environmental stresses modulated succinate dehydrogenase subunit A expression according to metastatic potential. Moreover, glucose-derived lactate production was more glutamine dependent in cell lines with higher metastatic potential. These studies show clear differences in TCA cycle metabolism between 4T1 and 67NR breast cancer cells. They indicate that metastases-forming 4T1 cells are more adept at adjusting their metabolism in response to environmental stress than isogenic, nonmetastatic 67NR cells. We suggest that the metabolic plasticity and adaptability are more important to the metastatic breast cancer phenotype than rapid cell proliferation alone, which could 1) provide a new biomarker for early detection of this phenotype, possibly at the time of diagnosis, and 2) lead to new treatment strategies of metastatic breast cancer by targeting mitochondrial metabolism. PMID:26408259

  12. Growth-modulating effects of dichloro myristic and dichloro stearic acid in cell cultures.

    PubMed

    Høstmark, A T; Lystad, E; Jebens, E; Skramstad, J; Frøyen, P

    1999-10-01

    Chloro-containing fatty acids are a major fraction of extractable, organically bound chlorine in fish. It has been suggested that dichloro stearic acid (9,10-dichlorooctadecanoic acid) (C18) is metabolized to dichloro myristic acid (5,6-dichlorotetradecanoic acid) (C14) which accumulates in tissues. Hence, the biological effects of the C18 dichloro fatty acid could be due to formation of the C14 dichloro fatty acid. In this study we have compared the effects of dichloro stearic and dichloro myristic acid on growth of three widely differing cell lines. Both fatty acids inhibited cell growth; however, dichloro myristic acid had a weaker growth inhibitory effect than dichloro stearic acid. Dichloro myristic acid had a biphasic effect (i.e. growth was stimulated at low concentrations, followed by inhibition at higher concentrations) on the growth of human hepatoma cells and immortalized human kidney epithelial cells, but no such effect on human microvascular endothelial cells. The order of potency for growth inhibition by dichloro myristic acid was consistently human hepatoma cells>immortalized human kidney epithelial cells >human microvascular endothelial cells, whereas the relative potency of dichloro stearic acid was variable. Albumin alone stimulated cell growth and had a stronger protective effect against growth inhibition by dichloro myristic acid than against that of dichloro stearic acid. It seems unlikely that a major part of the effect of dichloro stearic acid on cell growth is caused by conversion to dichloro myristic acid.

  13. Effect of heavy metal ions on neutrophil arachidonic acid metabolism and chemotaxis

    SciTech Connect

    Smith, D.M.; Turner, S.R.; Johnson, J.A.; Turner, R.A.

    1986-05-01

    Heavy metal ions can inhibit arachidonic acid (AA) metabolism, protect against ionophore cytotoxicity (ibid) and inhibit neutrophil chemotaxis. In this study they used Au/sup +3/, Zn/sup +2/, Cr/sup +3/, Mn/sup +2/, and Cu/sup +2/ as probes of the interrelationships among AA metabolism, ionophore-mediated cytotoxicity, and chemotaxis. Phospholipid deacylation was measured in ionophore-treated cells prelabeled with /sup 3/H-AA. Eicosanoid release from ionophore-treated cells was monitored both qualitatively by thin-layer chromatography of /sup 3/H-AA metabolities and quantitatively by radioimmunoassay. Cytoprotection was quantitated as ability to exclude trypan blue. Chemotaxis toward f-Met-Leu-Phe was measured by leading front analysis. The results imply that metal ions attenuate ionophore cytotoxicity by blocking phospholipid deacylation and eicosanoid production. In contrast to previous reports, the data obtained using Au/sup +3/ and Cu/sup +2/ demonstrates no correlation between AA metabolism and chemotaxis, suggesting that these 2 processes are not linked.

  14. Metabolomic analysis of amino acid and energy metabolism in rats supplemented with chlorogenic acid

    PubMed Central

    Ruan, Zheng; Yang, Yuhui; Zhou, Yan; Wen, Yanmei; Ding, Sheng; Liu, Gang; Wu, Xin; Deng, Zeyuan; Assaad, Houssein; Wu, Guoyao

    2016-01-01

    This study was conducted to investigate effects of chlorogenic acid (CGA) supplementation on serum and hepatic metabolomes in rats. Rats received daily intragastric administration of either CGA (60 mg/kg body weight) or distilled water (control) for 4 weeks. Growth performance, serum biochemical profiles, and hepatic morphology were measured. Additionally, serum and liver tissue extracts were analyzed for metabolomes by high-resolution 1H nuclear magnetic resonance-based metabolomics and multivariate statistics. CGA did not affect rat growth performance, serum biochemical profiles, or hepatic morphology. However, supplementation with CGA decreased serum concentrations of lactate, pyruvate, succinate, citrate, β-hydroxybutyrate and acetoacetate, while increasing serum concentrations of glycine and hepatic concentrations of glutathione. These results suggest that CGA supplementation results in perturbation of energy and amino acid metabolism in rats. We suggest that glycine and glutathione in serum may be useful biomarkers for biological properties of CGA on nitrogen metabolism in vivo. PMID:24927697

  15. Principal transcriptional regulation and genome-wide system interactions of the Asp-family and aromatic amino acid networks of amino acid metabolism in plants.

    PubMed

    Less, Hadar; Angelovici, Ruthie; Tzin, Vered; Galili, Gad

    2010-10-01

    Amino acid metabolism is among the most important and best recognized networks within biological systems. In plants, amino acids serve multiple functions associated with growth. Besides their function in protein synthesis, the amino acids are also catabolized into energy-associated metabolites as well we into numerous secondary metabolites, which are essential for plant growth and response to various stresses. Despite the central importance of amino acids in plants growth, elucidation of the regulation of amino acid metabolism within the context of the entire system, particularly transcriptional regulation, is still in its infancy. The different amino acids are synthesized by a number of distinct metabolic networks, which are expected to possess regulatory cross interactions between them for proper coordination of their interactive functions, such as incorporation into proteins. Yet, individual amino acid metabolic networks are also expected to differentially cross interact with various genome-wide gene expression programs and metabolic networks, in respect to their functions as precursors for various metabolites with distinct functions. In the present review, we discuss our recent genomics, metabolic and bioinformatics studies, which were aimed at addressing these questions, focusing mainly on the Asp-family metabolic network as the main example and also comparing it to the aromatic amino acids metabolic network as a second example (Angelovici et al. in Plant Physiol 151:2058-2072, 2009; Less and Galili in BMC Syst Biol 3:14, 2009; Tzin et al. in Plant J 60:156-167, 2009). Our focus on these two networks is because of the followings: (i) both networks are central to plant metabolism and growth and are also precursors for a wide range of primary and secondary metabolites that are indispensable to plant growth; (ii) the amino acids produced by these two networks are also essential to the nutrition and health of human and farm animals; and (iii) both networks contain

  16. Metabolic Engineering of a Novel Muconic Acid Biosynthesis Pathway via 4-Hydroxybenzoic Acid in Escherichia coli

    PubMed Central

    Sengupta, Sudeshna; Goonewardena, Lakshani; Juturu, Veeresh

    2015-01-01

    cis,cis-Muconic acid (MA) is a commercially important raw material used in pharmaceuticals, functional resins, and agrochemicals. MA is also a potential platform chemical for the production of adipic acid (AA), terephthalic acid, caprolactam, and 1,6-hexanediol. A strain of Escherichia coli K-12, BW25113, was genetically modified, and a novel nonnative metabolic pathway was introduced for the synthesis of MA from glucose. The proposed pathway converted chorismate from the aromatic amino acid pathway to MA via 4-hydroxybenzoic acid (PHB). Three nonnative genes, pobA, aroY, and catA, coding for 4-hydroxybenzoate hydrolyase, protocatechuate decarboxylase, and catechol 1,2-dioxygenase, respectively, were functionally expressed in E. coli to establish the MA biosynthetic pathway. E. coli native genes ubiC, aroFFBR, aroE, and aroL were overexpressed and the genes ptsH, ptsI, crr, and pykF were deleted from the E. coli genome in order to increase the precursors of the proposed MA pathway. The final engineered E. coli strain produced nearly 170 mg/liter of MA from simple carbon sources in shake flask experiments. The proposed pathway was proved to be functionally active, and the strategy can be used for future metabolic engineering efforts for production of MA from renewable sugars. PMID:26362984

  17. Metabolic engineering of a novel muconic acid biosynthesis pathway via 4-hydroxybenzoic acid in Escherichia coli.

    PubMed

    Sengupta, Sudeshna; Jonnalagadda, Sudhakar; Goonewardena, Lakshani; Juturu, Veeresh

    2015-12-01

    cis,cis-Muconic acid (MA) is a commercially important raw material used in pharmaceuticals, functional resins, and agrochemicals. MA is also a potential platform chemical for the production of adipic acid (AA), terephthalic acid, caprolactam, and 1,6-hexanediol. A strain of Escherichia coli K-12, BW25113, was genetically modified, and a novel nonnative metabolic pathway was introduced for the synthesis of MA from glucose. The proposed pathway converted chorismate from the aromatic amino acid pathway to MA via 4-hydroxybenzoic acid (PHB). Three nonnative genes, pobA, aroY, and catA, coding for 4-hydroxybenzoate hydrolyase, protocatechuate decarboxylase, and catechol 1,2-dioxygenase, respectively, were functionally expressed in E. coli to establish the MA biosynthetic pathway. E. coli native genes ubiC, aroF(FBR), aroE, and aroL were overexpressed and the genes ptsH, ptsI, crr, and pykF were deleted from the E. coli genome in order to increase the precursors of the proposed MA pathway. The final engineered E. coli strain produced nearly 170 mg/liter of MA from simple carbon sources in shake flask experiments. The proposed pathway was proved to be functionally active, and the strategy can be used for future metabolic engineering efforts for production of MA from renewable sugars. PMID:26362984

  18. Positron Emission Tomography Imaging of Tumor Cell Metabolism and Application to Therapy Response Monitoring

    PubMed Central

    Challapalli, Amarnath; Aboagye, Eric O.

    2016-01-01

    Cancer cells do reprogram their energy metabolism to enable several functions, such as generation of biomass including membrane biosynthesis, and overcoming bioenergetic and redox stress. In this article, we review both established and evolving radioprobes developed in association with positron emission tomography (PET) to detect tumor cell metabolism and effect of treatment. Measurement of enhanced tumor cell glycolysis using 2-deoxy-2-[18F]fluoro-D-glucose is well established in the clinic. Analogs of choline, including [11C]choline and various fluorinated derivatives are being tested in several cancer types clinically with PET. In addition to these, there is an evolving array of metabolic tracers for measuring intracellular transport of glutamine and other amino acids or for measuring glycogenesis, as well as probes used as surrogates for fatty acid synthesis or precursors for fatty acid oxidation. In addition to providing us with opportunities for examining the complex regulation of reprogramed energy metabolism in living subjects, the PET methods open up opportunities for monitoring pharmacological activity of new therapies that directly or indirectly inhibit tumor cell metabolism. PMID:26973812

  19. Engineering crassulacean acid metabolism to improve water-use efficiency

    PubMed Central

    Borland, Anne M.; Hartwell, James; Weston, David J.; Schlauch, Karen A.; Tschaplinski, Timothy J.; Tuskan, Gerald A.; Yang, Xiaohan; Cushman, John C.

    2014-01-01

    Climatic extremes threaten agricultural sustainability worldwide. One approach to increase plant water-use efficiency is to introduce crassulacean acid metabolism (CAM) into C3 crops. Such a task requires comprehensive systems-level understanding of the enzymatic and regulatory pathways underpinning this temporal CO2 pump. Here, we review the progress that has been made in achieving this goal. Given that CAM arose through multiple independent evolutionary origins, comparative transcriptomics and genomics of taxonomically diverse CAM species are being used to define the genetic ‘parts list’ required to operate the core CAM functional modules of nocturnal carboxylation, daytime decarboxylation, and inverse stomatal regulation. Engineered CAM offers the potential to sustain plant productivity for food, feed, fiber, and biofuel production in hotter and drier climates. PMID:24559590

  20. Differential Utilization of Dietary Fatty Acids in Benign and Malignant Cells of the Prostate.

    PubMed

    Dueregger, Andrea; Schöpf, Bernd; Eder, Theresa; Höfer, Julia; Gnaiger, Erich; Aufinger, Astrid; Kenner, Lukas; Perktold, Bernhard; Ramoner, Reinhold; Klocker, Helmut; Eder, Iris E

    2015-01-01

    Tumor cells adapt via metabolic reprogramming to meet elevated energy demands due to continuous proliferation, for example by switching to alternative energy sources. Nutrients such as glucose, fatty acids, ketone bodies and amino acids may be utilized as preferred substrates to fulfill increased energy requirements. In this study we investigated the metabolic characteristics of benign and cancer cells of the prostate with respect to their utilization of medium chain (MCTs) and long chain triglycerides (LCTs) under standard and glucose-starved culture conditions by assessing cell viability, glycolytic activity, mitochondrial respiration, the expression of genes encoding key metabolic enzymes as well as mitochondrial mass and mtDNA content. We report that BE prostate cells (RWPE-1) have a higher competence to utilize fatty acids as energy source than PCa cells (LNCaP, ABL, PC3) as shown not only by increased cell viability upon fatty acid supplementation but also by an increased ß-oxidation of fatty acids, although the base-line respiration was 2-fold higher in prostate cancer cells. Moreover, BE RWPE-1 cells were found to compensate for glucose starvation in the presence of fatty acids. Of notice, these findings were confirmed in vivo by showing that PCa tissue has a lower capacity in oxidizing fatty acids than benign prostate. Collectively, these metabolic differences between benign and prostate cancer cells and especially their differential utilization of fatty acids could be exploited to establish novel diagnostic and therapeutic strategies. PMID:26285134

  1. Differential Utilization of Dietary Fatty Acids in Benign and Malignant Cells of the Prostate.

    PubMed

    Dueregger, Andrea; Schöpf, Bernd; Eder, Theresa; Höfer, Julia; Gnaiger, Erich; Aufinger, Astrid; Kenner, Lukas; Perktold, Bernhard; Ramoner, Reinhold; Klocker, Helmut; Eder, Iris E

    2015-01-01

    Tumor cells adapt via metabolic reprogramming to meet elevated energy demands due to continuous proliferation, for example by switching to alternative energy sources. Nutrients such as glucose, fatty acids, ketone bodies and amino acids may be utilized as preferred substrates to fulfill increased energy requirements. In this study we investigated the metabolic characteristics of benign and cancer cells of the prostate with respect to their utilization of medium chain (MCTs) and long chain triglycerides (LCTs) under standard and glucose-starved culture conditions by assessing cell viability, glycolytic activity, mitochondrial respiration, the expression of genes encoding key metabolic enzymes as well as mitochondrial mass and mtDNA content. We report that BE prostate cells (RWPE-1) have a higher competence to utilize fatty acids as energy source than PCa cells (LNCaP, ABL, PC3) as shown not only by increased cell viability upon fatty acid supplementation but also by an increased ß-oxidation of fatty acids, although the base-line respiration was 2-fold higher in prostate cancer cells. Moreover, BE RWPE-1 cells were found to compensate for glucose starvation in the presence of fatty acids. Of notice, these findings were confirmed in vivo by showing that PCa tissue has a lower capacity in oxidizing fatty acids than benign prostate. Collectively, these metabolic differences between benign and prostate cancer cells and especially their differential utilization of fatty acids could be exploited to establish novel diagnostic and therapeutic strategies.

  2. Differential Utilization of Dietary Fatty Acids in Benign and Malignant Cells of the Prostate

    PubMed Central

    Eder, Theresa; Höfer, Julia; Gnaiger, Erich; Aufinger, Astrid; Kenner, Lukas; Perktold, Bernhard; Ramoner, Reinhold; Klocker, Helmut; Eder, Iris E.

    2015-01-01

    Tumor cells adapt via metabolic reprogramming to meet elevated energy demands due to continuous proliferation, for example by switching to alternative energy sources. Nutrients such as glucose, fatty acids, ketone bodies and amino acids may be utilized as preferred substrates to fulfill increased energy requirements. In this study we investigated the metabolic characteristics of benign and cancer cells of the prostate with respect to their utilization of medium chain (MCTs) and long chain triglycerides (LCTs) under standard and glucose-starved culture conditions by assessing cell viability, glycolytic activity, mitochondrial respiration, the expression of genes encoding key metabolic enzymes as well as mitochondrial mass and mtDNA content. We report that BE prostate cells (RWPE-1) have a higher competence to utilize fatty acids as energy source than PCa cells (LNCaP, ABL, PC3) as shown not only by increased cell viability upon fatty acid supplementation but also by an increased ß-oxidation of fatty acids, although the base-line respiration was 2-fold higher in prostate cancer cells. Moreover, BE RWPE-1 cells were found to compensate for glucose starvation in the presence of fatty acids. Of notice, these findings were confirmed in vivo by showing that PCa tissue has a lower capacity in oxidizing fatty acids than benign prostate. Collectively, these metabolic differences between benign and prostate cancer cells and especially their differential utilization of fatty acids could be exploited to establish novel diagnostic and therapeutic strategies. PMID:26285134

  3. Microbial diversity and metabolic networks in acid mine drainage habitats

    PubMed Central

    Méndez-García, Celia; Peláez, Ana I.; Mesa, Victoria; Sánchez, Jesús; Golyshina, Olga V.; Ferrer, Manuel

    2015-01-01

    Acid mine drainage (AMD) emplacements are low-complexity natural systems. Low-pH conditions appear to be the main factor underlying the limited diversity of the microbial populations thriving in these environments, although temperature, ionic composition, total organic carbon, and dissolved oxygen are also considered to significantly influence their microbial life. This natural reduction in diversity driven by extreme conditions was reflected in several studies on the microbial populations inhabiting the various micro-environments present in such ecosystems. Early studies based on the physiology of the autochthonous microbiota and the growing success of omics-based methodologies have enabled a better understanding of microbial ecology and function in low-pH mine outflows; however, complementary omics-derived data should be included to completely describe their microbial ecology. Furthermore, recent updates on the distribution of eukaryotes and archaea recovered through sterile filtering (herein referred to as filterable fraction) in these environments demand their inclusion in the microbial characterization of AMD systems. In this review, we present a complete overview of the bacterial, archaeal (including filterable fraction), and eukaryotic diversity in these ecosystems, and include a thorough depiction of the metabolism and element cycling in AMD habitats. We also review different metabolic network structures at the organismal level, which is necessary to disentangle the role of each member of the AMD communities described thus far. PMID:26074887

  4. Ursodeoxycholic Acid Ameliorates Fructose-Induced Metabolic Syndrome in Rats

    PubMed Central

    2014-01-01

    The metabolic syndrome (MS) is characterized by insulin resistance, dyslipidemia and hypertension. It is associated with increased risk of cardiovascular diseases and type-2 diabetes. Consumption of fructose is linked to increased prevalence of MS. Ursodeoxycholic acid (UDCA) is a steroid bile acid with antioxidant, anti-inflammatory activities and has been shown to improve insulin resistance. The current study aims to investigate the effect of UDCA (150 mg/kg) on MS induced in rats by fructose administration (10%) in drinking water for 12 weeks. The effects of UDCA were compared to fenofibrate (100 mg/kg), an agonist of PPAR-α receptors. Treatment with UDCA or fenofibrate started from the 6th week after fructose administration once daily. Fructose administration resulted in significant increase in body weight, elevations of blood glucose, serum insulin, cholesterol, triglycerides, advanced glycation end products (AGEs), uric acid levels, insulin resistance index and blood pressure compared to control rats. Moreover, fructose increased oxidative stress in aortic tissues indicated by significant increases of malondialdehyde (MDA), expression of iNOS and reduction of reduced glutathione (GSH) content. These disturbances were associated with decreased eNOS expression, increased infiltration of leukocytes and loss of aortic vascular elasticity. Treatment with UDCA successfully ameliorated the deleterious effects of fructose. The protective effect of UDCA could be attributed to its ability to decrease uric acid level, improve insulin resistance and diminish oxidative stress in vascular tissues. These results might support possible clinical application of UDCA in MS patients especially those present with liver diseases, taking into account its tolerability and safety. However, further investigations on human subjects are needed before the clinical application of UDCA for this indication. PMID:25202970

  5. Cell differentiation within a yeast colony: metabolic and regulatory parallels with a tumor-affected organism.

    PubMed

    Cáp, Michal; Stěpánek, Luděk; Harant, Karel; Váchová, Libuše; Palková, Zdena

    2012-05-25

    Nutrient sensing and metabolic reprogramming are crucial for metazoan cell aging and tumor growth. Here, we identify metabolic and regulatory parallels between a layered, multicellular yeast colony and a tumor-affected organism. During development, a yeast colony stratifies into U and L cells occupying the upper and lower colony regions, respectively. U cells activate a unique metabolism controlled by the glutamine-induced TOR pathway, amino acid-sensing systems (SPS and Gcn4p) and signaling from mitochondria with lowered respiration. These systems jointly modulate U cell physiology, which adapts to nutrient limitations and utilize the nutrients released from L cells. Stress-resistant U cells share metabolic pathways and other similar characteristics with tumor cells, including the ability to proliferate. L cells behave similarly to stressed and starving cells, which activate degradative mechanisms to provide nutrients to U cells. Our data suggest a nutrient flow between both cell types, resembling the Cori cycle and glutamine-NH(4)(+) shuttle between tumor and healthy metazoan cells.

  6. Characterization of lipid metabolism in a novel immortalized human hepatocyte cell line.

    PubMed

    Green, Charlotte J; Johnson, Deborah; Amin, Harsh D; Sivathondan, Pamela; Silva, Michael A; Wang, Lai Mun; Stevanato, Lara; McNeil, Catriona A; Miljan, Erik A; Sinden, John D; Morten, Karl J; Hodson, Leanne

    2015-09-15

    The development of hepatocyte cell models that represent fatty acid partitioning within the human liver would be beneficial for the study of the development and progression of nonalcoholic fatty liver disease (NAFLD). We sought to develop and characterize a novel human liver cell line (LIV0APOLY) to establish a model of lipid accumulation using a physiological mixture of fatty acids under low- and high-glucose conditions. LIV0APOLY cells were compared with a well-established cell line (HepG2) and, where possible, primary human hepatocytes. LIV0APOLY cells were found to proliferate and express some mature liver markers and were wild type for the PNPLA3 (rs738409) gene, whereas HepG2 cells carried the Ile(148)Met variant that is positively associated with liver fat content. Intracellular triglyceride content was higher in HepG2 than in LIV0APOLY cells; exposure to high glucose and/or exogenous fatty acids increased intracellular triglyceride in both cell lines. Triglyceride concentrations in media were higher from LIV0APOLY compared with HepG2 cells. Culturing LIV0APOLY cells in high glucose increased a marker of endoplasmic reticulum stress and attenuated insulin-stimulated Akt phosphorylation whereas low glucose and exogenous fatty acids increased AMPK phosphorylation. Although LIV0APOLY cells and primary hepatocytes stored similar amounts of exogenous fatty acids as triglyceride, more exogenous fatty acids were partitioned toward oxidation in the LIV0APOLY cells than in primary hepatocytes. LIV0APOLY cells offer the potential to be a renewable cellular model for studying the effects of exogenous metabolic substrates on fatty acid partitioning; however, their usefulness as a model of lipoprotein metabolism needs to be further explored.

  7. Characterization of lipid metabolism in a novel immortalized human hepatocyte cell line

    PubMed Central

    Green, Charlotte J.; Johnson, Deborah; Amin, Harsh D.; Sivathondan, Pamela; Silva, Michael A.; Wang, Lai Mun; Stevanato, Lara; McNeil, Catriona A.; Miljan, Erik A.; Sinden, John D.; Morten, Karl J.

    2015-01-01

    The development of hepatocyte cell models that represent fatty acid partitioning within the human liver would be beneficial for the study of the development and progression of nonalcoholic fatty liver disease (NAFLD). We sought to develop and characterize a novel human liver cell line (LIV0APOLY) to establish a model of lipid accumulation using a physiological mixture of fatty acids under low- and high-glucose conditions. LIV0APOLY cells were compared with a well-established cell line (HepG2) and, where possible, primary human hepatocytes. LIV0APOLY cells were found to proliferate and express some mature liver markers and were wild type for the PNPLA3 (rs738409) gene, whereas HepG2 cells carried the Ile148Met variant that is positively associated with liver fat content. Intracellular triglyceride content was higher in HepG2 than in LIV0APOLY cells; exposure to high glucose and/or exogenous fatty acids increased intracellular triglyceride in both cell lines. Triglyceride concentrations in media were higher from LIV0APOLY compared with HepG2 cells. Culturing LIV0APOLY cells in high glucose increased a marker of endoplasmic reticulum stress and attenuated insulin-stimulated Akt phosphorylation whereas low glucose and exogenous fatty acids increased AMPK phosphorylation. Although LIV0APOLY cells and primary hepatocytes stored similar amounts of exogenous fatty acids as triglyceride, more exogenous fatty acids were partitioned toward oxidation in the LIV0APOLY cells than in primary hepatocytes. LIV0APOLY cells offer the potential to be a renewable cellular model for studying the effects of exogenous metabolic substrates on fatty acid partitioning; however, their usefulness as a model of lipoprotein metabolism needs to be further explored. PMID:26126685

  8. Measurement of Fatty Acid Oxidation Rates in Animal Tissues and Cell Lines

    PubMed Central

    Huynh, Frank K.; Green, Michelle F.; Koves, Timothy R.; Hirschey, Matthew D.

    2014-01-01

    While much oncological research has focused on metabolic shifts in glucose and amino acid oxidation, recent evidence suggests that fatty acid oxidation (FAO) may also play an important role in the metabolic reprogramming of cancer cells. Here, we present a simple method for measuring FAO rates using radiolabeled palmitate, common laboratory reagents, and standard supplies. This protocol is broadly applicable for measuring FAO rates in cultured cancer cells as well as in both malignant and nontransformed animal tissues. PMID:24862277

  9. Acid rain: effects on arachidonic acid metabolism in perfused and ventilated guinea-pig lung.

    PubMed

    Preziosi, P; Ciabattoni, G

    1987-11-01

    Isolated, perfused and ventilated guinea-pig lungs were exposed for 10 min to acid (sulphuric + nitric acid) aerosol mimicking acid rain at pH 4.5 or 2.5, as well as to a control distilled water aerosol (pH 6.0-6.5). Lung perfusing solution was recovered and thromboxane (TX) B2 and leukotriene (LT) B4 were measured by radioimmunoassay (RIA) techniques. In a series of experiments TXB2 release averaged 0.43 +/- 0.18 (+/- SD) ng/min during exposure to distilled water aerosol and increased to 0.70 +/- 0.30 ng/min during exposure to acid aerosol at pH 4.5 (P less than 0.05). In a second series of experiments TXB2 release was 0.46 +/- 0.18 ng/min and increased to 1.07 +/- 0.51 ng/min (P less than 0.01) after acid aerosol at pH 2.5. In both cases LTB4 release, reflecting lipoxygenase activity, was unchanged. LTC4 levels were not measurable under basal conditions as well as after exposure to acid aerosol. A pneumoconstriction was also observed, being more pronounced after acid aerosol at pH 2.5. Individual sulphuric and nitric acid aerosol component solutions at pH 2.5 evoked TXB2 and airway resistance changes corresponding to those observed with the mixed acid aerosol. LTB4 was not modified. Acid rain inhalation may directly stimulate pathways leading to the bronchoconstrictor and pro-aggregating TXA2 synthesis in isolated guinea-pig lung, without affecting the lipoxygenase pathway of arachidonic acid metabolism.

  10. Metabolic and Signaling Functions of Cancer Cell-Derived Extracellular Vesicles.

    PubMed

    Fonseca, P; Vardaki, I; Occhionero, A; Panaretakis, T

    2016-01-01

    Extracellular vesicles have gained tremendous attention in the recent years as a novel mechanism of cell to cell communication. There are several types of extracellular vesicles, including exosomes, microvesicles, exosome, like vesicles, apoptotic bodies that differ mainly in the mechanism of biogenesis and secretion. The most well studied type of extracellular vesicles are the exosomes which are endosome-derived vesicles with a diameter of 50-150nm and enriched in ESCRT proteins including Alix, TSG101, Hsp70, and tetraspanins. It is now well established that exosomes promote tumor growth, alter the tumor microenvironment, facilitate the dissemination of cancer cells in an organotropic manner, modulate immune responses, and mediate resistance to therapy. Exosomes have also been recently implicated in an emerging hallmark of cancer, the cancer cell metabolism. The metabolic state of the cell defines, to a certain extent, both the rate of secretion and the molecular content of tumor-derived exosomes. Furthermore, exosomes have been shown to possess intrinsic metabolic activity since they can synthesize ATP by glycolysis. It follows that exosomes carry a number of metabolic enzymes and metabolites, including lactate, PGE, LDH isoforms, pyruvate, and monocarboxylate transporters. Last but not the least, exosomes are implicated in fatty acid synthesis and cholesterol metabolism and are thought to be crucial for the transcellular metabolism procedure. Uptake of exosomes is thought to alter the intracellular metabolic state of the cell. In summary, we describe the state of the art on the role of metabolism in the secretion, uptake, and the biological effects of exosomes in the metabolism of recipient cells. PMID:27572129

  11. Reconstruction of a generic metabolic network model of cancer cells.

    PubMed

    Hadi, Mahdieh; Marashi, Sayed-Amir

    2014-11-01

    A promising strategy for finding new cancer drugs is to use metabolic network models to investigate the essential reactions or genes in cancer cells. In this study, we present a generic constraint-based model of cancer metabolism, which is able to successfully predict the metabolic phenotypes of cancer cells. This model is reconstructed by collecting the available data on tumor suppressor genes. Notably, we show that the activation of oncogene related reactions can be explained by the inactivation of tumor suppressor genes. We show that in a simulated growth medium similar to the body fluids, our model outperforms the previously proposed model of cancer metabolism in predicting expressed genes.

  12. Potential of nor-Ursodeoxycholic Acid in Cholestatic and Metabolic Disorders.

    PubMed

    Trauner, Michael; Halilbasic, Emina; Claudel, Thierry; Steinacher, Daniel; Fuchs, Claudia; Moustafa, Tarek; Pollheimer, Marion; Krones, Elisabeth; Kienbacher, Christian; Traussnigg, Stefan; Kazemi-Shirazi, Lili; Munda, Petra; Hofer, Harald; Fickert, Peter; Paumgartner, Gustav

    2015-01-01

    24-nor-ursodeoxycholic acid (norUDCA) is a side-chain shortened derivate of ursodeoxycholic acid (UDCA). Since norUDCA is only ineffectively conjugated with glycine or taurine, it has specific physicochemical and therapeutic properties distinct from UDCA. Nonamidated norUDCA undergoes cholehepatic shunting enabling 'ductular targeting' and inducing a bicarbonate-rich hypercholeresis, with cholangioprotective effects. At the same time it has direct anti-inflammatory, antilipotoxic, anti fibrotic, and antiproliferative properties targeting various liver cell populations. norUDCA appears to be one of the most promising novel treatment approaches targeting the liver and the bile duct system at multifactorial and multicellular levels. This review article is a summary of a lecture given at the XXIII International Bile Acid Meeting (Falk Symposium 194) on 'Bile Acids as Signal Integrators and Metabolic Modulators' held in Freiburg, October 8-9, 2014, and summarizes the recent progress with norUDCA as a novel therapeutic approach in cholestatic and metabolic (liver) disorders.

  13. The effect of ozone exposure on rat alveolar macrophage arachidonic acid metabolism

    SciTech Connect

    Madden, M.C.; Eling, T.E.; Dailey, L.A.; Friedman, M. )

    1991-01-01

    Rat alveolar macrophages were prelabeled with {sup 3}H-arachidonic acid ({sup 3}H-AA) and exposed to air or O3 (0.1-1.0 ppm) in vitro for 2 h. Alveolar macrophages released 3.6-fold more tritium at the 1.0 ppm exposure concentration compared with air-exposed macrophages. A significantly increased production of several {sup 3}H-AA metabolites, including 6-keto-PGF1 alpha, thromboxane B2, 12-hydroxy-5,8,10-heptadecatrienoic acid, prostaglandins E2 and D2, leukotrienes B4 and D4, and 15-hydroxyeicosatetraenoic acid was formed by macrophages exposed to 1.0 ppm O3 compared with air-exposed macrophages as determined by high performance liquid chromatography (HPLC) analysis. O3 exposure did not alter macrophage {sup 3}H-AA metabolism in response to calcium ionophore A23187. The largest tritiated peak observed in the HPLC chromatograms of O{sub 3}-exposed cells was a polar complex of products that contained various phospholipids and neutral lipids (including diacylglycerol) and possibly degradation products of {sup 3}H-AA and some of its metabolites. These changes in macrophage arachidonic acid metabolism may play an important role in the lung response to O{sub 3} exposure in vivo.

  14. Cell-Free Metabolic Engineering: Biomanufacturing beyond the cell

    PubMed Central

    Dudley, Quentin M.; Karim, Ashty S.; Jewett, Michael C.

    2014-01-01

    Industrial biotechnology and microbial metabolic engineering are poised to help meet the growing demand for sustainable, low-cost commodity chemicals and natural products, yet the fraction of biochemicals amenable to commercial production remains limited. Common problems afflicting the current state-of-the-art include low volumetric productivities, build-up of toxic intermediates or products, and byproduct losses via competing pathways. To overcome these limitations, cell-free metabolic engineering (CFME) is expanding the scope of the traditional bioengineering model by using in vitro ensembles of catalytic proteins prepared from purified enzymes or crude lysates of cells for the production of target products. In recent years, the unprecedented level of control and freedom of design, relative to in vivo systems, has inspired the development of engineering foundations for cell-free systems. These efforts have led to activation of long enzymatic pathways (>8 enzymes), near theoretical conversion yields, productivities greater than 100 mg L−1 hr−1, reaction scales of >100L, and new directions in protein purification, spatial organization and enzyme stability. In the coming years, CFME will offer exciting opportunities to (i) debug and optimize biosynthetic pathways, (ii) carry out design-build-test iterations without re-engineering organisms, and (iii) perform molecular transformations when bioconversion yields, productivities, or cellular toxicity limit commercial feasibility. PMID:25319678

  15. Cell-free metabolic engineering: Biomanufacturing beyond the cell

    SciTech Connect

    Dudley, QM; Karim, AS; Jewett, MC

    2014-10-15

    Industrial biotechnology and microbial metabolic engineering are poised to help meet the growing demand for sustainable, low-cost commodity chemicals and natural products, yet the fraction of biochemicals amenable to commercial production remains limited. Common problems afflicting the current state-of-the-art include low volumetric productivities, build-up of toxic intermediates or products, and byproduct losses via competing pathways. To overcome these limitations, cell-free metabolic engineering (CFME) is expanding the scope of the traditional bioengineering model by using in vitro ensembles of catalytic proteins prepared from purified enzymes or crude lysates of cells for the production of target products. In recent years, the unprecedented level of control and freedom of design, relative to in vivo systems, has inspired the development of engineering foundations for cell-free systems. These efforts have led to activation of long enzymatic pathways (>8 enzymes), near theoretical conversion yields, productivities greater than 100 mg L-1 h(-1), reaction scales of >100 L, and new directions in protein purification, spatial organization, and enzyme stability. In the coming years, CFME will offer exciting opportunities to: (i) debug and optimize biosynthetic pathways; (ii) carry out design-build-test iterations without re-engineering organisms; and (iii) perform molecular transformations when bioconversion yields, productivities, or cellular toxicity limit commercial feasibility.

  16. Uric acid in metabolic syndrome: From an innocent bystander to a central player

    PubMed Central

    Kanbay, Mehmet; Jensen, Thomas; Solak, Yalcin; Le, Myphuong; Roncal-Jimenez, Carlos; Rivard, Chris; Lanaspa, Miguel A.; Nakagawa, Takahiko; Johnson, Richard J.

    2016-01-01

    Uric acid, once viewed as an inert metabolic end-product of purine metabolism, has been recently incriminated in a number of chronic disease states, including hypertension, metabolic syndrome, diabetes, non-alcoholic fatty liver disease, and chronic kidney disease. Several experimental and clinical studies support a role for uric acid as a contributory causal factor in these conditions. Here we discuss some of the major mechanisms linking uric acid to metabolic and cardiovascular diseases. At this time the key to understanding the importance of uric acid in these diseases will be the conduct of large clinical trials in which the effect of lowering uric acid on hard clinical outcomes is assessed. Elevated uric acid may turn out to be one of the more important remediable risk factors for metabolic and cardiovascular diseases. PMID:26703429

  17. Nutritional status, metabolic changes and white blood cells in adolescents☆

    PubMed Central

    Oliveira, Thatianne Moreira Silva; de Faria, Franciane Rocha; de Faria, Eliane Rodrigues; Pereira, Patrícia Feliciano; Franceschini, Sylvia C.C.; Priore, Silvia Eloiza

    2014-01-01

    OBJECTIVE: To analyze the relationship between the peripheral blood white cells, metabolic changes, and nutritional status of adolescents with and without excess weight and body fat. METHODS: This cross-sectional study evaluated the body mass index (BMI) and percentage body fat (%BF) in 362 adolescents from 15 to 19 years of age, of both sexes. White blood cell count, platelet count, uric acid, fasting glucose, insulin, and lipid profile were measured. The inclusion criteria were agreement to participate in the study and signature of the informed consent. Exclusion criteria were: presence of chronic or infectious disease; use of medications that could cause changes in biochemical tests; pregnancy; participation in weight reduction and weight control programs; use of diuretics and laxatives; or the presence of a pacemaker. The following statistical tests were applied: Kolmogorov-Smirnov test, Student's t or Mann-Whitney test, Pearson or Spearman correlation tests, and chi-squared test, considering p<0.05. RESULTS: Overweight was observed in 20.7% of adolescents. The total cholesterol (TC) had a higher percentage of inadequacy (52.2%), followed by high-density lipoprotein (HDL) (38.4%). There was a positive correlation between white cells and serum lipids, insulin, body fat, and BMI. Monocytes were negatively correlated with BMI, and rods with BMI, body fat, and insulin. CONCLUSIONS: Nutritional status is related to an inflammatory process, and adolescents with excess weight or body fat presented higher amounts of white blood cells. PMID:25510999

  18. T Cell Metabolic Fitness in Anti-Tumor Immunity

    PubMed Central

    Siska, Peter J.; Rathmell, Jeffrey C.

    2015-01-01

    SUMMARY T cell metabolism plays a central role to support and shape immune responses and may play a key role in anti-tumor immunity. T cell metabolism is normally held under tight regulation in an immune response of glycolysis to promote effector T cell expansion and function. However, tumors may deplete nutrients, generate toxic products, or stimulate conserved negative feedback mechanisms, such as through PD-1, to impair effector T cell nutrient uptake and metabolic fitness. In addition, regulatory T cells are favored in low glucose conditions and may inhibit anti-tumor immune responses. Here we review how the tumor microenvironment modifies metabolic and functional pathways in T cells and how these changes may uncover new targets and challenges for cancer immunotherapy and treatment. PMID:25773310

  19. How does cancer cell metabolism affect tumor migration and invasion?

    PubMed

    Han, Tianyu; Kang, De; Ji, Daokun; Wang, Xiaoyu; Zhan, Weihua; Fu, Minggui; Xin, Hong-Bo; Wang, Jian-Bin

    2013-01-01

    Cancer metastasis is the major cause of cancer-associated death. Accordingly, identification of the regulatory mechanisms that control whether or not tumor cells become "directed walkers" is a crucial issue of cancer research. The deregulation of cell migration during cancer progression determines the capacity of tumor cells to escape from the primary tumors and invade adjacent tissues to finally form metastases. The ability to switch from a predominantly oxidative metabolism to glycolysis and the production of lactate even when oxygen is plentiful is a key characteristic of cancer cells. This metabolic switch, known as the Warburg effect, was first described in 1920s, and affected not only tumor cell growth but also tumor cell migration. In this review, we will focus on the recent studies on how cancer cell metabolism affects tumor cell migration and invasion. Understanding the new aspects on molecular mechanisms and signaling pathways controlling tumor cell migration is critical for development of therapeutic strategies for cancer patients.

  20. Fatty acid metabolism in lambs fed citrus pulp.

    PubMed

    Lanza, M; Scerra, M; Bognanno, M; Buccioni, A; Cilione, C; Biondi, L; Priolo, A; Luciano, G

    2015-06-01

    (P = 0.09) with increasing level of citrus pulp in the diets. Furthermore, the SA/(SA + VA) ratio tended to be lower (P = 0.10) in the ruminal fluid from lambs fed the CIT35 diet compared with that of the CON group. In conclusion, our results support the hypothesis that replacing barley with citrus pulp in the diet of growing lambs improves intramuscular fatty acid composition and underline the need for specific studies to clarify the mechanisms by which feeding citrus pulp affects the fatty acid metabolism in ruminants.

  1. Omega-3 polyunsaturated fatty acids and oxygenated metabolism in atherothrombosis.

    PubMed

    Guichardant, Michel; Calzada, Catherine; Bernoud-Hubac, Nathalie; Lagarde, Michel; Véricel, Evelyne

    2015-04-01

    Numerous epidemiological studies and clinical trials have reported the health benefits of omega-3 polyunsaturated fatty acids (PUFA), including a lower risk of coronary heart diseases. This review mainly focuses on the effects of alpha-linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on some risk factors associated with atherothrombosis, including platelet activation, plasma lipid concentrations and oxidative modification of low-density lipoproteins (LDL). Special focus is given to the effects of marine PUFA on the formation of eicosanoids and docosanoids, and to the bioactive properties of some oxygenated metabolites of omega-3 PUFA produced by cyclooxygenases and lipoxygenases. The antioxidant effects of marine omega-3 PUFA at low concentrations and the pro-oxidant effects of DHA at high concentrations on the redox status of platelets and LDL are highlighted. Non enzymatic peroxidation end-products deriving from omega-3 PUFA such as hydroxy-hexenals, neuroketals and EPA-derived isoprostanes are also considered in relation to atherosclerosis. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance". PMID:25263947

  2. Omega-3 polyunsaturated fatty acids and oxygenated metabolism in atherothrombosis.

    PubMed

    Guichardant, Michel; Calzada, Catherine; Bernoud-Hubac, Nathalie; Lagarde, Michel; Véricel, Evelyne

    2015-04-01

    Numerous epidemiological studies and clinical trials have reported the health benefits of omega-3 polyunsaturated fatty acids (PUFA), including a lower risk of coronary heart diseases. This review mainly focuses on the effects of alpha-linolenic (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on some risk factors associated with atherothrombosis, including platelet activation, plasma lipid concentrations and oxidative modification of low-density lipoproteins (LDL). Special focus is given to the effects of marine PUFA on the formation of eicosanoids and docosanoids, and to the bioactive properties of some oxygenated metabolites of omega-3 PUFA produced by cyclooxygenases and lipoxygenases. The antioxidant effects of marine omega-3 PUFA at low concentrations and the pro-oxidant effects of DHA at high concentrations on the redox status of platelets and LDL are highlighted. Non enzymatic peroxidation end-products deriving from omega-3 PUFA such as hydroxy-hexenals, neuroketals and EPA-derived isoprostanes are also considered in relation to atherosclerosis. This article is part of a Special Issue entitled "Oxygenated metabolism of PUFA: analysis and biological relevance".

  3. Metabolism of [6]-Shogaol in Mice and in Cancer Cells

    PubMed Central

    Chen, Huadong; Lv, Lishuang; Soroka, Dominique; Warin, Renaud F.; Parks, Tiffany A.; Hu, Yuhui; Zhu, Yingdong; Chen, Xiaoxin

    2012-01-01

    Ginger has received extensive attention because of its antioxidant, anti-inflammatory, and antitumor activities. However, the metabolic fate of its major components is still unclear. In the present study, the metabolism of [6]-shogaol, one of the major active components in ginger, was examined for the first time in mice and in cancer cells. Thirteen metabolites were detected and identified, seven of which were purified from fecal samples collected from [6]-shogaol-treated mice. Their structures were elucidated as 1-(4′-hydroxy-3′-methoxyphenyl)-4-decen-3-ol (M6), 5-methoxy-1-(4′-hydroxy-3′-methoxyphenyl)-decan-3-one (M7), 3′,4′-dihydroxyphenyl-decan-3-one (M8), 1-(4′-hydroxy-3′-methoxyphenyl)-decan-3-ol (M9), 5-methylthio-1-(4′-hydroxy-3′-methoxyphenyl)-decan-3-one (M10), 1-(4′-hydroxy-3′-methoxyphenyl)-decan-3-one (M11), and 5-methylthio-1-(4′-hydroxy-3′-methoxyphenyl)-decan-3-ol (M12) on the basis of detailed analysis of their 1H, 13C, and two-dimensional NMR data. The rest of the metabolites were identified as 5-cysteinyl-M6 (M1), 5-cysteinyl-[6]-shogaol (M2), 5-cysteinylglycinyl-M6 (M3), 5-N-acetylcysteinyl-M6 (M4), 5-N-acetylcysteinyl-[6]-shogaol (M5), and 5-glutathiol-[6]-shogaol (M13) by analysis of the MSn (n = 1–3) spectra and comparison to authentic standards. Among the metabolites, M1 through M5, M10, M12, and M13 were identified as the thiol conjugates of [6]-shogaol and its metabolite M6. M9 and M11 were identified as the major metabolites in four different cancer cell lines (HCT-116, HT-29, H-1299, and CL-13), and M13 was detected as a major metabolite in HCT-116 human colon cancer cells. We further showed that M9 and M11 are bioactive compounds that can inhibit cancer cell growth and induce apoptosis in human cancer cells. Our results suggest that 1) [6]-shogaol is extensively metabolized in these two models, 2) its metabolites are bioactive compounds, and 3) the mercapturic acid pathway is one of the major

  4. Mutation assays involving blood cells that metabolize toxic substances

    DOEpatents

    Crespi, Charles L.; Thilly, William G.

    1985-01-01

    A line of human blood cells which have high levels of oxidative activity (such as oxygenase, oxidase, peroxidase, and hydroxylase activity) is disclosed. Such cells grow in suspension culture, and are useful to determine the mutagenicity of xenobiotic substances that are metabolized into toxic or mutagenic substances. Mutation assays using these cells, and other cells with similar characteristics, are also disclosed.

  5. The metabolism of aromatic acids by micro-organisms. Metabolic pathways in the fungi

    PubMed Central

    Cain, R. B.; Bilton, R. F.; Darrah, Josephine A.

    1968-01-01

    1. The metabolic pathways of aromatic-ring fission were examined in a range of fungal genera that utilize several compounds related to lignin. 2. Most of the genera, after growth on p-hydroxybenzoate, protocatechuate or compounds that are degraded to the latter (e.g. caffeate, ferulate or vanillate), rapidly oxidized these compounds, but not catechol. 3. Such genera possessed a protocatechuate 3,4-oxyg