WorldWideScience

Sample records for cell metabolism growth

  1. Metabolic pathways promoting cancer cell survival and growth.

    Science.gov (United States)

    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.

  2. GROWTH AND METABOLISM OF INDIVIDUAL BACTERIAL CELLS UTILIZING NANOSIMS

    Energy Technology Data Exchange (ETDEWEB)

    NEALSON, H. K.

    2007-08-03

    This work involved the use of the Nano-SIMS Instrument at Lawrence Livermore Laboratory, in an effort to utilize this unique tool for experiments in Biology. The work consisted primarily of experiments to measure in real time, C and N fixation in cyanobacteria. The work revealed a number of the difficulties in using the nano-SIMS approach with biological material, but with collaboration from a number of individuals at USC and LLNL, major progress was made. The collaborators from LLNL were from the Chemistry Group (Dr. Peter Weber), and the Biology Group (Dr. Jennifer Pett-Ridge). In addition, there were a number of other scientists involved from LLNL. The USC group consisted of Dr. K.H. Nealson, the PI on the grant, Dr. R. Popa, a postdoctoral fellow and research associate at USC, Professor Douglas Capone, and Juliet Finze, a graduate student in biology. Two major experiments were done, both of which yielded new and exciting data. (1) We studied nitrogen and carbon fixation in Anabaena, demonstrating that fixation ofN occurred rapidly in the heterocysts, and that the fixed N was transported rapidly and completely to the vegetative cells. C fixation occurred in the vegetative cells, with labeled C remaining in these cells in support of their growth and metabolism. This work was accepted in the ISME Journal (Nature Publication), and published last month. (2) We studied nitrogen and carbon fixation in Trichodesmium, a non-heterocystous cyanobacterium that also fixes nitrogen. Interestingly, the nitrogen fixation was confined to regions within the filaments that seem to be identical to the so-called cyanophycaen granules. The fixed N is then transported to other parts of the cyanobacterium, as judged by movement of the heavy N throughout the filaments. On the basis of these very exciting results, we have applied for funding from the NSF to continue the collaboration with LLNL. The results of both studies were presented in the summer of 2007 at the Gordon Research

  3. Bioactive food components, cancer cell growth limitation and reversal of glycolytic metabolism.

    Science.gov (United States)

    Keijer, Jaap; Bekkenkamp-Grovenstein, Melissa; Venema, Dini; Dommels, Yvonne E M

    2011-06-01

    Cancer cells are resistant to apoptosis and show a shift in energy production from mitochondrial oxidative phosphorylation to cytosolic glycolysis. Apoptosis resistance and metabolic reprogramming are linked in many cancer cells and both processes center on mitochondria. Clearly, mutated cancer cells escape surveillance and turn into selfish cells. However, many of the mechanisms that operate cellular metabolic control still function in cancer cells. This review describes the metabolic importance of glucose and glutamine, glycolytic enzymes, oxygen, growth cofactors and mitochondria and focuses on the potential role of bioactive food components, including micronutrients. The role of B- and A-vitamin cofactors in (mitochondrial) metabolism is highlighted and the cancer protective potential of omega-3 fatty acids and several polyphenols is discussed in relation to metabolic reprogramming, including the mechanisms that may be involved. Furthermore, it is shown that cancer cell growth reduction by limiting the growth cofactor folic acid seems to be associated with reversal of metabolic reprogramming. Altogether, reversal of metabolic reprogramming may be an attractive strategy to increase susceptibility to apoptotic surveillance. Food bioactive components that affect various aspects of metabolism may be important tools to reverse glycolytic to oxidative metabolism and enhance sensitivity to apoptosis. The success of such a strategy may depend on several actors, acting in concert. Growth cofactors may be one of these, which call for careful (re)evaluation of their function in normal and in cancer metabolism.

  4. Anammox--growth physiology, cell biology, and metabolism.

    Science.gov (United States)

    Kartal, Boran; van Niftrik, Laura; Keltjens, Jan T; Op den Camp, Huub J M; Jetten, Mike S M

    2012-01-01

    Anaerobic ammonium-oxidizing (anammox) bacteria are the last major addition to the nitrogen-cycle (N-cycle). Because of the presumed inert nature of ammonium under anoxic conditions, the organisms were deemed to be nonexistent until about 15 years ago. They, however, appear to be present in virtually any anoxic place where fixed nitrogen (ammonium, nitrate, nitrite) is found. In various mar`ine ecosystems, anammox bacteria are a major or even the only sink for fixed nitrogen. According to current estimates, about 50% of all nitrogen gas released into the atmosphere is made by these bacteria. Besides this, the microorganisms may be very well suited to be applied as an efficient, cost-effective, and environmental-friendly alternative to conventional wastewater treatment for the removal of nitrogen. So far, nine different anammox species divided over five genera have been enriched, but none of these are in pure culture. This number is only a modest reflection of a continuum of species that is suggested by 16S rRNA analyses of environmental samples. In their environments, anammox bacteria thrive not just by competition, but rather by delicate metabolic interactions with other N-cycle organisms. Anammox bacteria owe their position in the N-cycle to their unique property to oxidize ammonium in the absence of oxygen. Recent research established that they do so by activating the compound into hydrazine (N(2)H(4)), using the oxidizing power of nitric oxide (NO). NO is produced by the reduction of nitrite, the terminal electron acceptor of the process. The forging of the N-N bond in hydrazine is catalyzed by hydrazine synthase, a fairly slow enzyme and its low activity possibly explaining the slow growth rates and long doubling times of the organisms. The oxidation of hydrazine results in the formation of the end product (N(2)), and electrons that are invested both in electron-transport phosphorylation and in the regeneration of the catabolic intermediates (N(2)H(4), NO

  5. Identifying anti-growth factors for human cancer cell lines through genome-scale metabolic modeling

    DEFF Research Database (Denmark)

    Ghaffari, Pouyan; Mardinoglu, Adil; Asplund, Anna

    2015-01-01

    Human cancer cell lines are used as important model systems to study molecular mechanisms associated with tumor growth, hereunder how genomic and biological heterogeneity found in primary tumors affect cellular phenotypes. We reconstructed Genome scale metabolic models (GEMs) for eleven cell lines...... based on RNA-Seq data and validated the functionality of these models with data from metabolite profiling. We used cell line-specific GEMs to analyze the differences in the metabolism of cancer cell lines, and to explore the heterogeneous expression of the metabolic subsystems. Furthermore, we predicted...... antimetabolites using two cell lines with different phenotypic origins, and found that it is effective in inhibiting the growth of these cell lines. Using immunohistochemistry, we also showed high or moderate expression levels of proteins targeted by the validated antimetabolite. Identified anti-growth factors...

  6. 293SF metabolic flux analysis during cell growth and infection with an adenoviral vector.

    Science.gov (United States)

    Nadeau, I; Jacob, D; Perrier, M; Kamen, A

    2000-01-01

    Metabolic flux quantification of cell culture is becoming a crucial means to improve cell growth as well as protein and vector productions. The technique allows rapid determination of cell culture status, thus providing a tool for further feeding improvements. Herein, we report on key results of a metabolic investigation using 293 cells adapted to suspension and serum-free medium (293SF) during growth and infection with an adenoviral vector encoding the green fluorescence protein (GFP). The model developed contains 35 fluxes, which include the main fluxes of glycolysis, glutaminolysis, and amino acids pathways. It requires specific consumption and production rate measurements of amino acids, glucose, lactate, NH(3), and O(2), as well as DNA and total proteins biosynthesis rate measurements. Also, it was found that extracellular protein concentration measurement is important for flux calculation accuracy. With this model, we are able to describe the 293SF cell metabolism, grown under different culture conditions in a 3-L controlled bioreactor for batch and fed-batch with low glucose. The metabolism is also investigated during infection under two different feeding strategies: a fed-batch starting at the end of the growth phase and extending during infection without medium change and a fed-batch after infection following medium renewal. Differences in metabolism are observed between growth and infection, as well as between the different feeding strategies, thus providing a better understanding of the general metabolism.

  7. Metabolic flux analysis of CHO cells at growth and non-growth phases using isotopic tracers and mass spectrometry.

    Science.gov (United States)

    Ahn, Woo Suk; Antoniewicz, Maciek R

    2011-09-01

    Chinese hamster ovary (CHO) cells are the main platform for production of biotherapeutics in the biopharmaceutical industry. However, relatively little is known about the metabolism of CHO cells in cell culture. In this work, metabolism of CHO cells was studied at the growth phase and early stationary phase using isotopic tracers and mass spectrometry. CHO cells were grown in fed-batch culture over a period of six days. On days 2 and 4, [1,2-(13)C] glucose was introduced and the labeling of intracellular metabolites was measured by gas chromatography-mass spectrometry (GC-MS) at 6, 12 and 24h following the introduction of tracer. Intracellular metabolic fluxes were quantified from measured extracellular rates and (13)C-labeling dynamics of intracellular metabolites using non-stationary (13)C-metabolic flux analysis ((13)C-MFA). The flux results revealed significant rewiring of intracellular metabolic fluxes in the transition from growth to non-growth, including changes in energy metabolism, redox metabolism, oxidative pentose phosphate pathway and anaplerosis. At the exponential phase, CHO cell metabolism was characterized by a high flux of glycolysis from glucose to lactate, anaplerosis from pyruvate to oxaloacetate and from glutamate to α-ketoglutarate, and cataplerosis though malic enzyme. At the stationary phase, the flux map was characterized by a reduced flux of glycolysis, net lactate uptake, oxidative pentose phosphate pathway flux, and reduced rate of anaplerosis. The fluxes of pyruvate dehydrogenase and TCA cycle were similar at the exponential and stationary phase. The results presented here provide a solid foundation for future studies of CHO cell metabolism for applications such as cell line development and medium optimization for high-titer production of recombinant proteins.

  8. Metabolism and growth inhibitory activity of cranberry derived flavonoids in bladder cancer cells.

    Science.gov (United States)

    Prasain, Jeevan K; Rajbhandari, Rajani; Keeton, Adam B; Piazza, Gary A; Barnes, Stephen

    2016-09-14

    In the present study, anti-proliferative activities of cranberry derived flavonoids and some of their in vivo metabolites were evaluated using a panel of human bladder tumor cell lines (RT4, SCABER, and SW-780) and non-tumorigenic immortalized human uroepithelial cells (SV-HUC). Among the compounds tested, quercetin 3-O-glucoside, isorhamnetin (3'-O-methylquercetin), myricetin and quercetin showed strong concentration-dependent cell growth inhibitory activities in bladder cancer cells with IC50 values in a range of 8-92 μM. Furthermore, isorhamnetin and myricetin had very low inhibitory activity against SV-HUC even at very high concentrations (>200 μM) compared to bladder cancer cells, indicating that their cytotoxicity is selective for cancer cells. To determine whether the differential cell growth inhibitory effects of isomeric flavonoids quercetin 3-O-glucoside (active) and hyperoside (quercetin 3-O-galactoside) (inactive) are related to their metabolism by the cancer cells, SW-780 cells were incubated with these compounds and their metabolism was examined by LC-MS/MS. Compared to quercetin 3-O-glucoside, hyperoside undergoes relatively less metabolic biotransformation (methylation, glucuronidation and quinone formation). These data suggest that isorhamnetin and quercetin 3-O-glucoside may be the active forms of quercetin in prevention of bladder cancer in vivo and emphasize the importance of metabolism for the prevention of bladder cancer by diets rich in cranberries.

  9. Expansion of mesenchymal stem cells using a microcarrier-based cultivation system: growth and metabolism

    NARCIS (Netherlands)

    Schop, D.; Janssen, F.W.; Borgart, E.; Bruijn, de J.D.; Dijkhuizen-Radersma, van R.

    2008-01-01

    For the continuous and fast expansion of mesenchymal stem cells (MSCs), microcarriers have gained increasing interest. The aim of this study was to evaluate the growth and metabolism profiles of MSCs, expanded in a microcarrier-based cultivation system. We investigated various cultivation conditions

  10. Growth and metabolism of mesenchymal stem cells cultivated on microcarriers

    NARCIS (Netherlands)

    Schop, Deborah

    2010-01-01

    Mesenchymal stem cells, MSCs, are a great potential source for clinical applications in the field of tissue regeneration. Although MSCs can be isolated from several tissues of the human body, e.g. the bone marrow, the tissues does not contain clinically relevant amounts of MSCs for cell therapeutic

  11. Polyamine metabolism during exponential growth transition in Scots pine embryogenic cell culture.

    Science.gov (United States)

    Vuosku, Jaana; Suorsa, Marja; Ruottinen, Maria; Sutela, Suvi; Muilu-Mäkelä, Riina; Julkunen-Tiitto, Riitta; Sarjala, Tytti; Neubauer, Peter; Häggman, Hely

    2012-10-01

    Polyamine (PA) metabolism was studied in liquid cultures of Scots pine (Pinus sylvestris L.) embryogenic cells. The focus of the study was on the metabolic changes at the interphase between the initial lag phase and the exponential growth phase. PA concentrations fluctuated in the liquid cultures as follows. Putrescine (Put) concentrations increased, whereas spermidine (Spd) concentrations decreased in both free and soluble conjugated PA fractions. The concentrations of free and soluble conjugated spermine (Spm) remained low, and small amounts of excreted PAs were also found in the culture medium. The minor production of secondary metabolites reflected the undifferentiated stage of the embryogenic cell culture. Put was produced via the arginine decarboxylase (ADC) pathway. Futhermore, the gene expression data suggested that the accumulation of Put was caused neither by an increase in Put biosynthesis nor by a decrease in Put catabolism, but resulted mainly from the decrease in the biosynthesis of Spd and Spm. Put seemed to play an important role in cell proliferation in Scots pine embryogenic cells, but the low pH of the culture medium could also, at least partially, be the reason for the accumulation of endogenous Put. High Spd concentrations at the initiation of the culture, when cells were exposed to stress and cell death, suggested that Spd may act not only as a protector against stress but also as a growth suppressor, when proliferative growth is not promoted. All in all, Scots pine embryogenic cell culture was proved to be a favourable experimental platform to study PA metabolism and, furthermore, the developed system may also be beneficial in experiments where, e.g., the effect of specific stressors on PA metabolism is addressed.

  12. Bladder cancer cell growth and motility implicate cannabinoid 2 receptor-mediated modifications of sphingolipids metabolism

    Science.gov (United States)

    Bettiga, Arianna; Aureli, Massimo; Colciago, Giorgia; Murdica, Valentina; Moschini, Marco; Lucianò, Roberta; Canals, Daniel; Hannun, Yusuf; Hedlund, Petter; Lavorgna, Giovanni; Colombo, Renzo; Bassi, Rosaria; Samarani, Maura; Montorsi, Francesco; Salonia, Andrea; Benigni, Fabio

    2017-01-01

    The inhibitory effects demonstrated by activation of cannabinoid receptors (CB) on cancer proliferation and migration may also play critical roles in controlling bladder cancer (BC). CB expression on human normal and BC specimens was tested by immunohistochemistry. Human BC cells RT4 and RT112 were challenged with CB agonists and assessed for proliferation, apoptosis, and motility. Cellular sphingolipids (SL) constitution and metabolism were evaluated after metabolic labelling. CB1-2 were detected in BC specimens, but only CB2 was more expressed in the tumour. Both cell lines expressed similar CB2. Exposure to CB2 agonists inhibited BC growth, down-modulated Akt, induced caspase 3-activation and modified SL metabolism. Baseline SL analysis in cell lines showed differences linked to unique migratory behaviours and cytoskeletal re-arrangements. CB2 activation changed the SL composition of more aggressive RT112 cells by reducing (p < 0.01) Gb3 ganglioside (−50 ± 3%) and sphingosine 1-phosphate (S1P, −40 ± 4%), which ended up to reduction in cell motility (−46 ± 5%) with inhibition of p-SRC. CB2-selective antagonists, gene silencing and an inhibitor of SL biosynthesis partially prevented CB2 agonist-induced effects on cell viability and motility. CB2 activation led to ceramide-mediated BC cell apoptosis independently of SL constitutive composition, which instead was modulated by CB2 agonists to reduce cell motility. PMID:28191815

  13. Lin28: Primal Regulator of Growth and Metabolism in Stem Cells

    Science.gov (United States)

    Shyh-Chang, Ng; Daley, George Q.

    2013-01-01

    In recent years, the highly conserved Lin28 RNA-binding proteins have emerged as factors that define stemness in several tissue lineages. Lin28 proteins repress let-7 microRNAs and influence mRNA translation, thereby regulating the self-renewal of mammalian embryonic stem cells. Subsequent discoveries revealed that Lin28a and Lin28b are also important in organismal growth and metabolism, tissue development, somatic reprogramming and cancer. In this Review, we discuss the Lin28 pathway and its regulation, outline its roles in stem cells, tissue development, and pathogenesis, and examine the ramifications for re-engineering mammalian physiology. PMID:23561442

  14. Regulation of prostaglandin metabolism by calcitriol attenuates growth stimulation in prostate cancer cells.

    Science.gov (United States)

    Moreno, Jacqueline; Krishnan, Aruna V; Swami, Srilatha; Nonn, Larisa; Peehl, Donna M; Feldman, David

    2005-09-01

    Calcitriol exhibits antiproliferative and pro-differentiation effects in prostate cancer. Our goal is to further define the mechanisms underlying these actions. We studied established human prostate cancer cell lines and primary prostatic epithelial cells and showed that calcitriol regulated the expression of genes involved in the metabolism of prostaglandins (PGs), known stimulators of prostate cell growth. Calcitriol significantly repressed the mRNA and protein expression of prostaglandin endoperoxide synthase/cyclooxygenase-2 (COX-2), the key PG synthesis enzyme. Calcitriol also up-regulated the expression of 15-hydroxyprostaglandin dehydrogenase, the enzyme initiating PG catabolism. This dual action was associated with decreased prostaglandin E2 secretion into the conditioned media of prostate cancer cells exposed to calcitriol. Calcitriol also repressed the mRNA expression of the PG receptors EP2 and FP, providing a potential additional mechanism of suppression of the biological activity of PGs. Calcitriol treatment attenuated PG-mediated functional responses, including the stimulation of prostate cancer cell growth. The combination of calcitriol with nonsteroidal anti-inflammatory drugs (NSAIDs) synergistically acted to achieve significant prostate cancer cell growth inhibition at approximately 2 to 10 times lower concentrations of the drugs than when used alone. In conclusion, the regulation of PG metabolism and biological actions constitutes a novel pathway of calcitriol action that may contribute to its antiproliferative effects in prostate cells. We propose that a combination of calcitriol and nonselective NSAIDs might be a useful chemopreventive and/or therapeutic strategy in men with prostate cancer, as it would allow the use of lower concentrations of both drugs, thereby reducing their toxic side effects.

  15. Optimization of the cell seeding density and modeling of cell growth and metabolism using the modified Gompertz model for microencapsulated animal cell culture.

    Science.gov (United States)

    Wen-tao, Qi; Ying, Zhang; Juan, Ma; Xin, Guo; Yu-bing, Xie; Wei, Wang; Xiaojun, Ma

    2006-04-01

    Cell microencapsulation is one of the promising strategies for the in vitro production of proteins or in vivo delivery of therapeutic products. In order to design and fabricate the optimized microencapsulated cell system, the Gompertz model was applied and modified to describe the growth and metabolism of microencapsulated cell, including substrate consumption and product formation. The Gompertz model successfully described the cell growth kinetics and the modified Gompertz models fitted the substrate consumption and product formation well. It was demonstrated that the optimal initial cell seeding density was about 4-5 x 10(6) cells/mL of microcapsule, in terms of the maximum specific growth rate, the glucose consumption potential and the product formation potential calculated by the Gompertz and modified Gompertz models. Modeling of cell growth and metabolism in microcapsules provides a guideline for optimizing the culture of microencapsulated cells.

  16. PUTATIVE ROLE OF ADIPOSE TISSUE IN GROWTH AND METABOLISM OF COLON CANCER CELLS

    Directory of Open Access Journals (Sweden)

    Betty eSchwartz

    2014-06-01

    Full Text Available Newly emerging data highlight obesity as an important risk factor for developing certain types of cancer, including colorectal cancer. Although evidence supports a link between the two, the mechanisms responsible for this relationship have not yet been fully elucidated. Hypertrophied and dysfunctional adipose tissue of the obese state is characterized by low-grade inflammation. Adipokines and cytokines secreted from adipocytes, together with the abundant availability of lipids from adipocytes in the tumor microenvironment, promote adhesion, migration, and invasion of tumor cells and support tumor progression and uncontrolled growth. One of the predisposed targets of the deleterious effects exerted by secretions from adipose tissue in obesity are the activities associated with the cellular mitochondria. Mitochondrial oxidative metabolism plays a key role in meeting cells' energetic demands by oxidative phosphorylation (OxPhos. Here we discuss: (a the dynamic relationship between glycolysis, the tricarboxylic acid (TCA cycle, and OxPhos; (b the evidence for impaired OxPhos (i.e. mitochondrial dysfunction in colon cancer; (c the mechanisms by which mitochondrial dysfunction can predispose to cancer. We propose that impaired OxPhos increases susceptibility to colon cancer since OxPhos is sensitive to a large number of factors that are intrinsic to the host (e.g. inflammation.Given that adipocytes are a major source of adipokines and energy for the cancer cell, understanding the mechanisms of metabolic symbiosis between cancer cells and adipocytes should reveal new therapeutic possibilities.

  17. Growth regulation mechanisms in higher plants under microgravity conditions - changes in cell wall metabolism.

    Science.gov (United States)

    Hoson, T; Kamisaka, S; Wakabayashi, K; Soga, K; Tabuchi, A; Tokumoto, H; Okamura, K; Nakamura, Y; Mori, R; Tanimoto, E; Takeba, G; Nishitani, K; Izumi, R; Ishioka, N; Kamigaichi, S; Aizawa, S; Yoshizaki, I; Shimazu, T; Fukui, K

    2000-06-01

    During Space Shuttle STS-95 mission, we cultivated seedlings of rice (Oryza sativa L. cv. Koshihikari and cv. Tan-ginbozu) and Arabidopsis (Arabidopsis thaliana L. cv. Columbia and cv. etr1-1) for 68.5, 91.5, and 136 hr on board, and then analyzed changes in the nature of their cell walls, growth, and morphogenesis under microgravity conditions. In space, elongation growth of both rice coleoptiles and Arabidopsis hypocotyls was stimulated. Also, the increase in the cell wall extensibility, especially that in the irreversible extensibility, was observed for such materials. The analyses of the amounts, the structure, and the physicochemical properties of the cell wall constituents indicated that the decreases in levels and molecular masses of cell wall polysaccharides were induced under microgravity conditions, which appeared to contribute to the increase in the wall extensibility. The activity of certain wall enzymes responsible for the metabolic turnover of the wall polysaccharides was increased in space. By the space flight, we also confirmed the occurrence of automorphogenesis of both seedlings under microgravity conditions; rice coleoptiles showed an adaxial bending, whereas Arabidopsis hypocotyls elongated in random directions. Furthermore, it was shown that spontaneous curvatures of rice coleoptiles in space were brought about uneven modifications of cell wall properties between the convex and the concave sides.

  18. Effect of CO2 on uninfected Sf-9 cell growth and metabolism.

    Science.gov (United States)

    Vajrala, Sucheta G; Murhammer, David W

    2016-03-01

    A problem in the mass production of recombinant proteins and biopesticides using insect cell culture is CO2 accumulation. This research investigated the effect of elevated CO2 concentration on insect cell growth and metabolism. Spodoptera frugiperda Sf-9 insect cells were grown at 20% air saturation, 27(°) C, and a pH of 6.2. The cells were exposed to a constant CO2 concentration by purging the medium with CO2 and the headspace with air. The population doubling time (PDT) of Sf-9 cells increased with increasing CO2 concentration. Specifically, the PDT for 0-37, 73, 147, 183, and 220 mm Hg CO2 concentrations were 23.2 ± 6.7, 32.4 ± 7.2, 38.1 ± 13.3, 42.9 ± 5.4, and 69.3 ± 35.9 h (n = 3 or 4, 95% confidence level), respectively. The viability of cells in all experiments was above 90%, i.e., while increased CO2 concentrations inhibited cell growth, it did not affect cell viability. The osmolality for all bioreactor experiments was observed to be 300-360 mOsm/kg, a range that is known to have a negligible effect on insect cell culture. Elevated CO2 concentration did not significantly alter the cell specific glucose consumption rate (2.5-3.2 × 10(-17) mol/cell s), but slightly increased the specific lactate production rate from -3.0 × 10(-19) to 10.2 × 10(-19) mol/cell s. Oxidative stress did not contribute to CO2 inhibition in uninfected Sf-9 cells as no significant increase in the levels of lipid hydroperoxide and protein carbonyl concentrations was discovered at elevated CO2 concentration. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:465-469, 2016.

  19. Shigella reroutes host cell central metabolism to obtain high-flux nutrient supply for vigorous intracellular growth.

    Science.gov (United States)

    Kentner, David; Martano, Giuseppe; Callon, Morgane; Chiquet, Petra; Brodmann, Maj; Burton, Olga; Wahlander, Asa; Nanni, Paolo; Delmotte, Nathanaël; Grossmann, Jonas; Limenitakis, Julien; Schlapbach, Ralph; Kiefer, Patrick; Vorholt, Julia A; Hiller, Sebastian; Bumann, Dirk

    2014-07-08

    Shigella flexneri proliferate in infected human epithelial cells at exceptionally high rates. This vigorous growth has important consequences for rapid progression to life-threatening bloody diarrhea, but the underlying metabolic mechanisms remain poorly understood. Here, we used metabolomics, proteomics, and genetic experiments to determine host and Shigella metabolism during infection in a cell culture model. The data suggest that infected host cells maintain largely normal fluxes through glycolytic pathways, but the entire output of these pathways is captured by Shigella, most likely in the form of pyruvate. This striking strategy provides Shigella with an abundant favorable energy source, while preserving host cell ATP generation, energy charge maintenance, and survival, despite ongoing vigorous exploitation. Shigella uses a simple three-step pathway to metabolize pyruvate at high rates with acetate as an excreted waste product. The crucial role of this pathway for Shigella intracellular growth suggests targets for antimicrobial chemotherapy of this devastating disease.

  20. The phosphorylation-dependent regulation of nuclear SREBP1 during mitosis links lipid metabolism and cell growth

    Science.gov (United States)

    Bengoechea-Alonso, Maria Teresa; Ericsson, Johan

    2016-01-01

    ABSTRACT The SREBP transcription factors are major regulators of lipid metabolism. Disturbances in lipid metabolism are at the core of several health issues facing modern society, including cardiovascular disease, obesity and diabetes. In addition, the role of lipid metabolism in cancer cell growth is receiving increased attention. Transcriptionally active SREBP molecules are unstable and rapidly degraded in a phosphorylation-dependent manner by Fbw7, a ubiquitin ligase that targets several cell cycle regulatory proteins for degradation. We have previously demonstrated that active SREBP1 is stabilized during mitosis. We have now delineated the mechanisms involved in the stabilization of SREBP1 in mitotic cells. This process is initiated by the phosphorylation of a specific serine residue in nuclear SREBP1 by the mitotic kinase Cdk1. The phosphorylation of this residue creates a docking site for a separate mitotic kinase, Plk1. Plk1 interacts with nuclear SREBP1 in mitotic cells and phosphorylates a number of residues in the C-terminal domain of the protein, including a threonine residue in close proximity of the Fbw7 docking site in SREBP1. The phosphorylation of these residues by Plk1 blocks the interaction between SREBP1 and Fbw7 and attenuates the Fbw7-dependent degradation of nuclear SREBP1 during cell division. Inactivation of SREBP1 results in a mitotic defect, suggesting that SREBP1 could regulate cell division. We propose that the mitotic phosphorylation and stabilization of nuclear SREBP1 during cell division provides a link between lipid metabolism and cell proliferation. Thus, the current study provides additional support for the emerging hypothesis that SREBP-dependent lipid metabolism may be important for cell growth. PMID:27579997

  1. Evidence for a transketolase-mediated metabolic checkpoint governing biotrophic growth in rice cells by the blast fungus Magnaporthe oryzae.

    Directory of Open Access Journals (Sweden)

    Jessie Fernandez

    2014-09-01

    Full Text Available The blast fungus Magnaporthe oryzae threatens global food security through the widespread destruction of cultivated rice. Foliar infection requires a specialized cell called an appressorium that generates turgor to force a thin penetration hypha through the rice cuticle and into the underlying epidermal cells, where the fungus grows for the first days of infection as a symptomless biotroph. Understanding what controls biotrophic growth could open new avenues for developing sustainable blast intervention programs. Here, using molecular genetics and live-cell imaging, we dismantled M. oryzae glucose-metabolizing pathways to reveal that the transketolase enzyme, encoded by TKL1, plays an essential role in facilitating host colonization during rice blast disease. In the absence of transketolase, Δtkl1 mutant strains formed functional appressoria that penetrated rice cuticles successfully and developed invasive hyphae (IH in rice cells from primary hyphae. However, Δtkl1 could not undertake sustained biotrophic growth or cell-to-cell movement. Transcript data and observations using fluorescently labeled histone H1:RFP fusion proteins indicated Δtkl1 mutant strains were alive in host cells but were delayed in mitosis. Mitotic delay could be reversed and IH growth restored by the addition of exogenous ATP, a metabolite depleted in Δtkl1 mutant strains. We show that ATP might act via the TOR signaling pathway, and TOR is likely a downstream target of activation for TKL1. TKL1 is also involved in controlling the migration of appressorial nuclei into primary hyphae in host cells. When taken together, our results indicate transketolase has a novel role in mediating--via ATP and TOR signaling--an in planta-specific metabolic checkpoint that controls nuclear migration from appressoria into primary hyphae, prevents mitotic delay in early IH and promotes biotrophic growth. This work thus provides new information about the metabolic strategies employed by M

  2. The biology of cancer: metabolic reprogramming fuels cell growth and proliferation.

    Science.gov (United States)

    DeBerardinis, Ralph J; Lum, Julian J; Hatzivassiliou, Georgia; Thompson, Craig B

    2008-01-01

    Cell proliferation requires nutrients, energy, and biosynthetic activity to duplicate all macromolecular components during each passage through the cell cycle. It is therefore not surprising that metabolic activities in proliferating cells are fundamentally different from those in nonproliferating cells. This review examines the idea that several core fluxes, including aerobic glycolysis, de novo lipid biosynthesis, and glutamine-dependent anaplerosis, form a stereotyped platform supporting proliferation of diverse cell types. We also consider regulation of these fluxes by cellular mediators of signal transduction and gene expression, including the phosphatidylinositol 3-kinase (PI3K)/Akt/mTOR system, hypoxia-inducible factor 1 (HIF-1), and Myc, during physiologic cell proliferation and tumorigenesis.

  3. Cancer stem cell metabolism

    National Research Council Canada - National Science Library

    Peiris-Pagès, Maria; Martinez-Outschoorn, Ubaldo E; Pestell, Richard G; Sotgia, Federica; Lisanti, Michael P

    2016-01-01

    .... Cancer stem cells also seem to adapt their metabolism to microenvironmental changes by conveniently shifting energy production from one pathway to another, or by acquiring intermediate metabolic phenotypes...

  4. Acetyl-CoA Synthetase 2 Promotes Acetate Utilization and Maintains Cancer Cell Growth under Metabolic Stress

    Science.gov (United States)

    Schug, Zachary T.; Peck, Barrie; Jones, Dylan T.; Zhang, Qifeng; Grosskurth, Shaun; Alam, Israt S.; Goodwin, Louise M.; Smethurst, Elizabeth; Mason, Susan; Blyth, Karen; McGarry, Lynn; James, Daniel; Shanks, Emma; Kalna, Gabriela; Saunders, Rebecca E.; Jiang, Ming; Howell, Michael; Lassailly, Francois; Thin, May Zaw; Spencer-Dene, Bradley; Stamp, Gordon; van den Broek, Niels J.F.; Mackay, Gillian; Bulusu, Vinay; Kamphorst, Jurre J.; Tardito, Saverio; Strachan, David; Harris, Adrian L.; Aboagye, Eric O.; Critchlow, Susan E.; Wakelam, Michael J.O.; Schulze, Almut; Gottlieb, Eyal

    2015-01-01

    Summary A functional genomics study revealed that the activity of acetyl-CoA synthetase 2 (ACSS2) contributes to cancer cell growth under low-oxygen and lipid-depleted conditions. Comparative metabolomics and lipidomics demonstrated that acetate is used as a nutritional source by cancer cells in an ACSS2-dependent manner, and supplied a significant fraction of the carbon within the fatty acid and phospholipid pools. ACSS2 expression is upregulated under metabolically stressed conditions and ACSS2 silencing reduced the growth of tumor xenografts. ACSS2 exhibits copy-number gain in human breast tumors, and ACSS2 expression correlates with disease progression. These results signify a critical role for acetate consumption in the production of lipid biomass within the harsh tumor microenvironment. PMID:25584894

  5. Analysis of metabolic pathways by the growth of cells in the presence of organic solvents.

    Science.gov (United States)

    Spinnler, H E; Ginies, C; Khan, J A; Vulfson, E N

    1996-01-01

    A new approach to the analysis of metabolic pathways involving poorly water-soluble intermediates is proposed. It relies upon the ability of the hydrophobic intermediates formed by a sequence of intracellular reactions to cross the membrane(s) and partition between aqueous and organic phases, when cells are incubated in the presence of a nonpolar and nontoxic organic solvent. As a result of this thermodynamically driven efflux of the formed intermediates from the cell, they accumulate in the organic medium in sufficient quantities for GC-MS analysis and identification. This enables direct determination of the sequence of chemical reactions involved with no requirement for the isolation of each individual metabolite from a cell-free extract. The feasibility of the proposed methodology has been demonstrated by the elucidation of the biosynthesis of (R)-gamma-decalactone from (R)-ricinoleic acid catalyzed by the yeast Sporidiobolus ruinenii grown in the presence of decane. The corresponding 4-hydroxy-acid intermediates, formed in the course of beta-oxidation of (R)-ricinoleic acid, were simultaneously observed in a single experiment on the same chromatogram. Potential applications of this proposed methodology are briefly discussed. Images Fig. 1 PMID:11607651

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

    Science.gov (United States)

    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. Flavonoids suppress human glioblastoma cell growth by inhibiting cell metabolism, migration, and by regulating extracellular matrix proteins and metalloproteinases expression.

    Science.gov (United States)

    Santos, Balbino L; Oliveira, Mona N; Coelho, Paulo L C; Pitanga, Bruno P S; da Silva, Alessandra B; Adelita, Taís; Silva, Victor Diógenes A; Costa, Maria de F D; El-Bachá, Ramon S; Tardy, Marcienne; Chneiweiss, Hervé; Junier, Marie-Pierre; Moura-Neto, Vivaldo; Costa, Silvia L

    2015-12-01

    The malignant gliomas are very common primary brain tumors with poor prognosis, which require more effective therapies than the current used, such as with chemotherapy drugs. In this work, we investigated the effects of several polyhydroxylated flavonoids namely, rutin, quercetin (F7), apigenin (F32), chrysin (F11), kaempferol (F12), and 3',4'-dihydroxyflavone (F2) in human GL-15 glioblastoma cells. We observed that all flavonoids decreased the number of viable cells and the mitochondrial metabolism. Furthermore, they damaged mitochondria and rough endoplasmic reticulum, inducing apoptosis. Flavonoids also induced a delay in cell migration, related to a reduction in filopodia-like structures on the cell surface, reduction on metalloproteinase (MMP-2) expression and activity, as well as an increase in intra- and extracellular expression of fibronectin, and intracellular expression of laminin. Morphological changes were also evident in adherent cells characterized by the presence of a condensed cell body with thin and long cellular processes, expressing glial fibrillary acidic protein (GFAP). Therefore, these flavonoids should be tested as potential antitumor agents in vitro and in vivo in other malignant glioma models.

  8. Polyamine metabolism in prostate cancer : studies on localization, cell growth and apoptosis

    NARCIS (Netherlands)

    Schipper, Raymond Godfried

    2000-01-01

    The involvement of polyamines in cellular growth and differentiation has prompted many studies of their possible role in cellular neoplasia, including prostatic carcinoma and benign hyperplasia, which represent increasingly important pathologies in men. The precise role of the

  9. Effects of HIF-1 and HIF2 on Growth and Metabolism of Clear-Cell Renal Cell Carcinoma 786-0 Xenografts

    Directory of Open Access Journals (Sweden)

    Swethajit Biswas

    2010-01-01

    Full Text Available In cultured clear-cell renal carcinoma (CCRCC 786-0 cells transfected with HIF1 (HIF-1+, HIF-2 (HIF-2+, or empty vector (EV, no significant differences were observed in the growth rates in vitro, but when grown in vivo as xenografts HIF-2 significantly increased, and HIF-1 significantly decreased growth rates, compared to EV tumors. Factors associated with proliferation were increased and factors associated with cell death were decreased in HIF-2+ tumors. Metabolite profiles showed higher glucose and lower lactate and alanine levels in the HIF-2+ tumors whilst immunostaining demonstrated higher pyruvate dehydrogenase and lower pyruvate dehydrogenase kinase 1, compared to control tumors. Taken together, these results suggest that overexpression of HIF-2 in CCRCC 786-0 tumors regulated growth both by maintaining a low level of glycolysis and by allowing more mitochondrial metabolism and tolerance to ROS induced DNA damage. The growth profiles observed may be mediated by adaptive changes to a more oxidative phenotype.

  10. Tumor cell metabolism

    Science.gov (United States)

    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

  11. Novel electrochemical sensor system for monitoring metabolic activity during the growth and cultivation of prokaryotic and eukaryotic cells.

    Science.gov (United States)

    Pescheck, M; Schrader, J; Sell, D

    2005-09-01

    A novel amperometric sensor system is presented which directly reflects the metabolic activity of prokaryotic and eukaryotic cells during cultivation. The principle of an externally mounted sensor is current measurement using a three-electrode system. Only living cells are detected since the current signal is based on a redox mediator. Added to a culture sample in its oxidized form, the mediator is reduced by cellular metabolism and subsequently re-oxidized at the anode. The spontaneous immobilisation of the cells in the reaction vessel of the sensor by swelling dextrane polymers (Sephadex) prior to measurement is the key to a fast, consistent signal. Even metabolically less active mammalian cells produce a reliable signal within a few minutes; this may open up future applications of the electrochemical sensor in closed loop process control not only for bacterial and fungal bioprocesses, but also in cell culture technology.

  12. Metabolic profiling and flux analysis of MEL-2 human embryonic stem cells during exponential growth at physiological and atmospheric oxygen concentrations.

    Science.gov (United States)

    Turner, Jennifer; Quek, Lake-Ee; Titmarsh, Drew; Krömer, Jens O; Kao, Li-Pin; Nielsen, Lars; Wolvetang, Ernst; Cooper-White, Justin

    2014-01-01

    As human embryonic stem cells (hESCs) steadily progress towards regenerative medicine applications there is an increasing emphasis on the development of bioreactor platforms that enable expansion of these cells to clinically relevant numbers. Surprisingly little is known about the metabolic requirements of hESCs, precluding the rational design and optimisation of such platforms. In this study, we undertook an in-depth characterisation of MEL-2 hESC metabolic behaviour during the exponential growth phase, combining metabolic profiling and flux analysis tools at physiological (hypoxic) and atmospheric (normoxic) oxygen concentrations. To overcome variability in growth profiles and the problem of closing mass balances in a complex environment, we developed protocols to accurately measure uptake and production rates of metabolites, cell density, growth rate and biomass composition, and designed a metabolic flux analysis model for estimating internal rates. hESCs are commonly considered to be highly glycolytic with inactive or immature mitochondria, however, whilst the results of this study confirmed that glycolysis is indeed highly active, we show that at least in MEL-2 hESC, it is supported by the use of oxidative phosphorylation within the mitochondria utilising carbon sources, such as glutamine to maximise ATP production. Under both conditions, glycolysis was disconnected from the mitochondria with all of the glucose being converted to lactate. No difference in the growth rates of cells cultured under physiological or atmospheric oxygen concentrations was observed nor did this cause differences in fluxes through the majority of the internal metabolic pathways associated with biogenesis. These results suggest that hESCs display the conventional Warburg effect, with high aerobic activity despite high lactate production, challenging the idea of an anaerobic metabolism with low mitochondrial activity. The results of this study provide new insight that can be used in

  13. CDP-Diacylglycerol Synthetase Coordinates Cell Growth and Fat Storage through Phosphatidylinositol Metabolism and the Insulin Pathway

    Science.gov (United States)

    Liu, Yuan; Wang, Wei; Shui, Guanghou; Huang, Xun

    2014-01-01

    During development, animals usually undergo a rapid growth phase followed by a homeostatic stage when growth has ceased. The increase in cell size and number during the growth phase requires a large amount of lipids; while in the static state, excess lipids are usually stored in adipose tissues in preparation for nutrient-limited conditions. How cells coordinate growth and fat storage is not fully understood. Through a genetic screen we identified Drosophila melanogaster CDP-diacylglycerol synthetase (CDS/CdsA), which diverts phosphatidic acid from triacylglycerol synthesis to phosphatidylinositol (PI) synthesis and coordinates cell growth and fat storage. Loss of CdsA function causes significant accumulation of neutral lipids in many tissues along with reduced cell/organ size. These phenotypes can be traced back to reduced PI levels and, subsequently, low insulin pathway activity. Overexpressing CdsA rescues the fat storage and cell growth phenotypes of insulin pathway mutants, suggesting that CdsA coordinates cell/tissue growth and lipid storage through the insulin pathway. We also revealed that a DAG-to-PE route mediated by the choline/ethanolamine phosphotransferase Bbc may contribute to the growth of fat cells in CdsA RNAi. PMID:24603715

  14. Single-cell genomics reveal metabolic strategies for microbial growth and survival in an oligotrophic aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; Kennedy, David W.; Castelle, Cindy; Field, Erin; Stepanauskas, Ramunas; Fredrickson, Jim K.; Konopka, Allan

    2014-02-09

    Bacteria from the genus Pedobacter are a major component of microbial assemblages at Hanford Site and have been shown to significantly change in abundance in response to the subsurface intrusion of Columbia River water. Here we employed single cell genomics techniques to shed light on the physiological niche of these microorganisms. Analysis of four Pedobacter single amplified genomes (SAGs) from Hanford Site sediments revealed a chemoheterotrophic lifestyle, with the potential to exist under both aerobic and microaerophilic conditions via expression of both aa3­-type and cbb3-type cytochrome c oxidases. These SAGs encoded a wide-range of both intra-and extra­-cellular carbohydrate-active enzymes, potentially enabling the degradation of recalcitrant substrates such as xylan and chitin, and the utilization of more labile sugars such as mannose and fucose. Coupled to these enzymes, a diversity of transporters and sugar-binding molecules were involved in the uptake of carbon from the extracellular local environment. The SAGs were enriched in TonB-dependent receptors (TBDRs), which play a key role in uptake of substrates resulting from degradation of recalcitrant carbon. CRISPR-Cas mechanisms for resisting viral infections were identified in all SAGs. These data demonstrate the potential mechanisms utilized for persistence by heterotrophic microorganisms in a carbon-limited aquifer, and hint at potential linkages between observed Pedobacter abundance shifts within the 300 Area subsurface and biogeochemical shifts associated with Columbia River water intrusion.

  15. Rethinking Guard Cell Metabolism.

    Science.gov (United States)

    Santelia, Diana; Lawson, Tracy

    2016-11-01

    Stomata control gaseous fluxes between the internal leaf air spaces and the external atmosphere and, therefore, play a pivotal role in regulating CO2 uptake for photosynthesis as well as water loss through transpiration. Guard cells, which flank the stomata, undergo adjustments in volume, resulting in changes in pore aperture. Stomatal opening is mediated by the complex regulation of ion transport and solute biosynthesis. Ion transport is exceptionally well understood, whereas our knowledge of guard cell metabolism remains limited, despite several decades of research. In this review, we evaluate the current literature on metabolism in guard cells, particularly the roles of starch, sucrose, and malate. We explore the possible origins of sucrose, including guard cell photosynthesis, and discuss new evidence that points to multiple processes and plasticity in guard cell metabolism that enable these cells to function effectively to maintain optimal stomatal aperture. We also discuss the new tools, techniques, and approaches available for further exploring and potentially manipulating guard cell metabolism to improve plant water use and productivity. © 2016 American Society of Plant Biologists. All Rights Reserved.

  16. Life Functions and Cells: Level II, Unit 7, Lesson 1; Cell Structure: Lesson 2; Tissues, Organs, Systems: Lesson 3; Growth and Nutrition: Lesson 4; Metabolism: Lesson 5. Advanced General Education Program. A High School Self-Study Program.

    Science.gov (United States)

    Manpower Administration (DOL), Washington, DC. Job Corps.

    This self-study program for high-school level contains lessons on: Life Functions and Cells; Cell Structure; Tissues, Organs, Systems; Growth and Nutrition; and Metabolism. Each of the lessons concludes with a Mastery Test to be completed by the student. (DB)

  17. Metabolic and growth inhibitory effects of conjugated fatty acids in the cell line HT-29 with special regard to the conversion of t11,t13-CLA.

    Science.gov (United States)

    Degen, Christian; Ecker, Josef; Piegholdt, Stefanie; Liebisch, Gerhard; Schmitz, Gerd; Jahreis, Gerhard

    2011-12-01

    Conjugated fatty acids (CFAs) exhibit growth inhibitory effects on colon cancer in vitro and in vivo. To investigate whether the anticancerogenic potency depends on number or configuration of the conjugated double bonds, the effect of conjugated linoleic acid (CLA; C18:2) isomers and conjugated linolenic acid (CLnA; C18:3) isomers on viability and growth of HT-29 cells were compared. Low concentrations of CLnAs (t11,t13-CLA≥t9,t11-CLA>c9,t11-CLA. The mRNA expression analysis of important genes associated with fatty acid metabolism showed an absence of ∆5-/∆6-desaturases and elongases in HT-29 cells, which was confirmed by fatty acid analysis. Using time- and dose-dependent stimulation experiments several metabolites were determined. Low concentrations of all trans-CFAs (5-20μM) led to dose-dependent increase of conjugated t/t-C16:2 formed by β-oxidation of C18 CFAs, ranging from 1-5% of total FAME. Importantly, it was found that CLnA is converted to CLA and that CLA is inter-converted (t11,t13-CLA is metabolized to c9,t11-CLA) by HT-29 cells. In summary, our study shows that growth inhibition of human cancer cells is associated with a specific cellular transcriptomic and metabolic profile of fatty acid metabolism, which might contribute to the diversified ability of CFAs as anti-cancer compounds.

  18. Reprogrammed metabolism of cancer cells as a potential therapeutic target

    NARCIS (Netherlands)

    Keijer, J.; Dartel, van D.A.M.

    2014-01-01

    Metabolism in cancer cells is reprogrammed. Cancer cells largely depend on glycolysis for ATP production. The metabolic alterations in cancer cells facilitate resistance to cell death as well as biosynthesis of nucleotides and lipids, building blocks for growth. The reprogrammed metabolism is

  19. Metabolic regulator betaKlotho interacts with fibroblast growth factor receptor 4 (FGFR4) to induce apoptosis and inhibit tumor cell proliferation.

    Science.gov (United States)

    Luo, Yongde; Yang, Chaofeng; Lu, Weiqin; Xie, Rui; Jin, Chengliu; Huang, Peng; Wang, Fen; McKeehan, Wallace L

    2010-09-24

    In organs involved in metabolic homeostasis, transmembrane α and βklothos direct FGFR signaling to control of metabolic pathways. Coordinate expression of βklotho and FGFR4 is a property of mature hepatocytes. Genetic deletion of FGFR4 or βklotho in mice disrupts hepatic cholesterol/bile acid and lipid metabolism. The deletion of FGFR4 has no effect on the proliferative response of hepatocytes after liver injury. However, its absence results in accelerated progression of dimethynitrosamine-initiated hepatocellular carcinomas, indicating that FGFR4 suppresses hepatoma proliferation. The mechanism underlying the FGFR4-mediated hepatoma suppression has not been addressed. Here we show that βklotho expression is more consistently down-regulated in human and mouse hepatomas than FGFR4. Co-expression and activation by either endocrine FGF19 or cellular FGF1 of the FGFR4 kinase in a complex with βklotho restricts cell population growth through induction of apoptotic cell death in both hepatic and nonhepatic cells. The βklotho-FGFR4 partnership caused a depression of activated AKT and mammalian target of rapamycin while activating ERK1/2 that may underlie the pro-apoptotic effect. Our results show that βklotho not only interacts with heparan sulfate-FGFR4 to form a complex with high affinity for endocrine FGF19 but also impacts the quality of downstream signaling and biological end points activated by either FGF19 or canonical FGF1. Thus the same βklotho-heparan sulfate-FGFR4 partnership that mediates endocrine control of hepatic metabolism plays a role in cellular homeostasis and hepatoma suppression through negative control of cell population growth mediated by pro-apoptotic signaling.

  20. Phase transitions in tumor growth: IV relationship between metabolic rate and fractal dimension of human tumor cells

    Science.gov (United States)

    Betancourt-Mar, J. A.; Llanos-Pérez, J. A.; Cocho, G.; Mansilla, R.; Martin, R. R.; Montero, S.; Nieto-Villar, J. M.

    2017-05-01

    By the use of thermodynamics formalism of irreversible processes, complex systems theory and systems biology, it is derived a relationship between the production of entropy per unit time, the fractal dimension and the tumor growth rate for human tumors cells. The thermodynamics framework developed demonstrates that, the dissipation function is a Landau potential and also the Lyapunov function of the dynamical behavior of tumor growth, which indicate the directional character, stability and robustness of the phenomenon. The entropy production rate may be used as a quantitative index of the metastatic potential of tumors. The current theoretical framework will hopefully provide a better understanding of cancer and contribute to improvements in cancer treatment.

  1. One Carbon Metabolism, Fetal Growth and Long Term Consequences

    OpenAIRE

    2013-01-01

    One carbon metabolism, or methyl transfer, is critical for metabolism in all cells, is involved in the synthesis of purines, pyrimidines, in the methylation of numerous substrates, proteins, DNA and RNA, and in the expression of a number of genes. Serine is the primary endogenous methyl donor to the one carbon pool. Perturbations in methyl transfer due to nutrient and hormonal changes can have profound effect on cell function, growth and proliferation. It is postulated that at critical stages...

  2. Metabolic regulation of regulatory T cell development and function

    Directory of Open Access Journals (Sweden)

    David John Coe

    2014-11-01

    Full Text Available It is now well established that the effector T cell (Teff response is regulated by a series of metabolic switches. Quiescent T cells predominantly require ATP-generating processes, whereas proliferating Teff require high metabolic flux through growth-promoting pathways, such as glycolysis. Pathways that control metabolism and immune cell function are intimately linked, and changes in cell metabolism at both the cell and system levels have been shown to enhance or suppress specific T cell effector functions. Furthermore, functionally distinct T cell subsets have been shown to require distinct energetic and biosynthetic pathways to support their specific functional needs. In particular, naturally occurring regulatory T cells (Treg are characterized by a unique metabolic signature distinct to that of conventional Teff cells. We here briefly review the signaling pathways that control Treg metabolism and how this metabolic phenotype integrates their differentiation and function. Ultimately, these metabolic features may provide new opportunities for the therapeutic modulation of unwanted immune responses.

  3. Dependence on glucose limitation of the pCO2 influences on CHO cell growth, metabolism and IgG production.

    Science.gov (United States)

    Takuma, Shinya; Hirashima, Chikashi; Piret, James M

    2007-08-15

    The culture levels of glucose and CO(2) have been reported to independently have important influences on mammalian cell processes. In this work the combined effects of glucose limitation and CO(2) partial pressure (pCO(2)) on monoclonal antibody (IgG) producing Chinese Hamster Ovary cells were investigated in a perfusion reactor operated with controlled cell specific medium feed rate, pH and osmolality. Under high glucose conditions (14.3 +/- 0.8 mM), the apparent growth rate decreased (from 0.021 to 0.009 h(-1)) as the pCO(2) increased to approximately 220 mmHg, while the cell specific IgG productivity was almost unchanged. The lactate yield from glucose was not affected by pCO(2) up to approximately 220 mmHg and glucose was mainly converted to lactate. A feed medium modification from high (33 mM) to low (6 mM) glucose resulted in glucose in the culture. As a result of apparently shifting metabolism towards the conversion of pyruvate to CO(2), both the ratio of lactate to glucose and the alanine production rate were lowered (1.51-1.14 and 17.7-0.56 nmol/10(6) cells h, respectively). Interestingly, when the pCO(2) was increased to approximately 140 mmHg, limiting glucose resulted in 1.7-fold higher growth rates, compared to high glucose conditions. However, at approximately 220 mmHg pCO(2) this beneficial effect of glucose limitation on these CHO cells was lost as the growth rate dropped dramatically to 0.008 h(-1) and the IgG productivity was lowered by 15% (P glucose condition. The IgG galactosylation increased under glucose- limited compared to high-glucose conditions. (c) 2007 Wiley Periodicals, Inc.

  4. Modelling microbial metabolic rewiring during growth in a complex medium.

    Science.gov (United States)

    Fondi, Marco; Bosi, Emanuele; Presta, Luana; Natoli, Diletta; Fani, Renato

    2016-11-24

    In their natural environment, bacteria face a wide range of environmental conditions that change over time and that impose continuous rearrangements at all the cellular levels (e.g. gene expression, metabolism). When facing a nutritionally rich environment, for example, microbes first use the preferred compound(s) and only later start metabolizing the other one(s). A systemic re-organization of the overall microbial metabolic network in response to a variation in the composition/concentration of the surrounding nutrients has been suggested, although the range and the entity of such modifications in organisms other than a few model microbes has been scarcely described up to now. We used multi-step constraint-based metabolic modelling to simulate the growth in a complex medium over several time steps of the Antarctic model organism Pseudoalteromonas haloplanktis TAC125. As each of these phases is characterized by a specific set of amino acids to be used as carbon and energy source our modelling framework describes the major consequences of nutrients switching at the system level. The model predicts that a deep metabolic reprogramming might be required to achieve optimal biomass production in different stages of growth (different medium composition), with at least half of the cellular metabolic network involved (more than 50% of the metabolic genes). Additionally, we show that our modelling framework is able to capture metabolic functional association and/or common regulatory features of the genes embedded in our reconstruction (e.g. the presence of common regulatory motifs). Finally, to explore the possibility of a sub-optimal biomass objective function (i.e. that cells use resources in alternative metabolic processes at the expense of optimal growth) we have implemented a MOMA-based approach (called nutritional-MOMA) and compared the outcomes with those obtained with Flux Balance Analysis (FBA). Growth simulations under this scenario revealed the deep impact of

  5. Carbon monoxide expedites metabolic exhaustion to inhibit tumor growth.

    Science.gov (United States)

    Wegiel, Barbara; Gallo, David; Csizmadia, Eva; Harris, Clair; Belcher, John; Vercellotti, Gregory M; Penacho, Nuno; Seth, Pankaj; Sukhatme, Vikas; Ahmed, Asif; Pandolfi, Pier Paolo; Helczynski, Leszek; Bjartell, Anders; Persson, Jenny Liao; Otterbein, Leo E

    2013-12-01

    One classical feature of cancer cells is their metabolic acquisition of a highly glycolytic phenotype. Carbon monoxide (CO), one of the products of the cytoprotective molecule heme oxygenase-1 (HO-1) in cancer cells, has been implicated in carcinogenesis and therapeutic resistance. However, the functional contributions of CO and HO-1 to these processes are poorly defined. In human prostate cancers, we found that HO-1 was nuclear localized in malignant cells, with low enzymatic activity in moderately differentiated tumors correlating with relatively worse clinical outcomes. Exposure to CO sensitized prostate cancer cells but not normal cells to chemotherapy, with growth arrest and apoptosis induced in vivo in part through mitotic catastrophe. CO targeted mitochondria activity in cancer cells as evidenced by higher oxygen consumption, free radical generation, and mitochondrial collapse. Collectively, our findings indicated that CO transiently induces an anti-Warburg effect by rapidly fueling cancer cell bioenergetics, ultimately resulting in metabolic exhaustion.

  6. Fibroblast growth factor signaling in metabolic regulation

    Directory of Open Access Journals (Sweden)

    Vera eNies

    2016-01-01

    Full Text Available The prevalence of obesity is a growing health problem. Obesity is strongly associated with several comorbidities, such as non-alcoholic fatty liver disease, certain cancers, insulin resistance and type 2 diabetes, which all reduce life expectancy and life quality. Several drugs have been put forward in order to treat these diseases, but many of them have detrimental side effects. The unexpected role of the family of fibroblast growth factors in the regulation of energy metabolism provides new approaches to the treatment of metabolic diseases, and offers a valuable tool to gain more insight into metabolic regulation. The known beneficial effects of FGF19 and FGF21 on metabolism, together with recently discovered similar effects of FGF1 suggest that FGFs and their derivatives carry great potential as novel therapeutics to treat metabolic conditions. To facilitate the development of new therapies with improved targeting and minimal side effects, a better understanding of the molecular mechanism of action of FGFs is needed.In this review we will discuss what is currently known about the physiological roles of FGF signaling in tissues important for metabolic homeostasis. In addition, we will discuss current concepts regarding their pharmacological properties and effector tissues in the context of metabolic disease. Also the recent progress in the development of FGF variants will be reviewed. Our goal is to provide a comprehensive overview of the current concepts and consensuses regarding FGF signaling in metabolic health and disease, and to provide starting points for the development of FGF-based therapies against metabolic conditions.

  7. Asymptotic analysis of noisy fitness maximization, applied to metabolism & growth

    Science.gov (United States)

    De Martino, Daniele; Masoero, Davide

    2016-12-01

    We consider a population dynamics model coupling cell growth to a diffusion in the space of metabolic phenotypes as it can be obtained from realistic constraints-based modeling. In the asymptotic regime of slow diffusion, that coincides with the relevant experimental range, the resulting non-linear Fokker-Planck equation is solved for the steady state in the WKB approximation that maps it into the ground state of a quantum particle in an Airy potential plus a centrifugal term. We retrieve scaling laws for growth rate fluctuations and time response with respect to the distance from the maximum growth rate suggesting that suboptimal populations can have a faster response to perturbations.

  8. Microcalorimetric Studies on Thermochemical Characteristics of Escherichia coli NCTC 10418 Aerobic Growth Metabolism in Basic Media

    Institute of Scientific and Technical Information of China (English)

    刘义; 高振霆; 王宏; 屈松生

    2001-01-01

    By using an LKB-2277 bioactivity monitor, cycle-flow mode,the thermogenic curve of metabolism of Escherichia coli NCTC 10418 growth at 37°C in basic media was determined.The experimental results indicate that the relationship between cell concentration and power output can be characterized by the equations: C=k'P+a dC/dP0 = KCn, n=1 where P is the power output (μW), C is cell concentration (mg/mL), P0 is the power output produced by the metabolism of one unit of cell (P0=P/0.6C),the order of metabolism n is 1, and k′, a and K are constants which depend on the culture condition and phylogenic state of the cells.These equations are different from those of the non-growth metabolism of resting cells and endogenous mtabolism of cells. For different kinds of metabolism of cells, the order of metabolism, n, is different. For endogenous metabolism,n =0, for growth metabolism, n=1, and for non-growth metabolism of resting cells, n = 2.The equations are general thecal equations for the various different kinds of metabolism of cells.

  9. Cell biology. Metabolic control of cell death.

    Science.gov (United States)

    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.

  10. Metabolic effects of discontinuing growth hormone treatment

    OpenAIRE

    Cowan, F; Evans, W.; Gregory, J

    1999-01-01

    AIMS—To evaluate the effects of discontinuing growth hormone (GH) treatment on energy expenditure and body composition, which might help predict those most likely to benefit from early reintroduction of GH treatment in young adult life.
METHODS—Body composition was calculated from skinfold thicknesses and dual energy x ray absorptometry (DXA). Resting metabolic rate (RMR) and whole body bone mineral content (BMC) were also measured. Measurements were made before stoppi...

  11. Growth of Entamoeba invadens in sediments with metabolically repressed bacteria leads to multicellularity and redefinition of the amoebic cell system.

    Science.gov (United States)

    Niculescu, Vladimir F

    2013-01-01

    Extracellular signaling and mechanisms of cell differentiation in Entamoeba are misunderstood. The main reason is the popular use of axenic media, which do not correspond to the natural habitats of Entamoeba. The axenic environment lacks the exogenous activators and repressors provided by natural habitats. Absent bacterial commensals understanding of the development of the amoebic cell system remains deficient. The present Aa(Sm) culture method using mixed sediments of antibiotically repressed Aerobacter aerogens and amoebae was developed to model in vitro extracellular signaling that induce multicellularity in cultures of E. invadens. Repressed oxygen consuming sediment bacteria supply E. invadens the hypoxic environment needed for differentiation and development. The amoebae themselves alter the environment by consuming the bacteria by phagocytosis thus reversing hypoxia. Exogenous activators are in this manner down regulated and suppressed. This feedback effect controls amoebic development and differentiation. Co-existing cell types and cell fractions with different life spans and cell cycle length could be identified. Aa(Sm) long term cultures contain continuous and non-continuous self renewing cell lines producing quiescent and terminally differentiated daughter cells (precysts) by asymmetric division. This culturing method helps to understand the intimate relationship between hypoxic environments and the multicellular behaviour of E. invadens and the interrelations existing between the distinct cell types.

  12. Effect of benzalkonium chloride on viability and energy metabolism in exponential- and stationary-growth-phase cells of Listeria monocytogenes

    NARCIS (Netherlands)

    Luppens, S.B.I.; Abee, T.; Oosterom, J.

    2001-01-01

    The difference in killing exponential- and stationary-phase cells of Listeria monocytogenes by benzalkonium chloride (BAC) was investigated by plate counting and linked to relevant bioenergetic parameters. At a low concentration of BAC (8 mg liter-1), a similar reduction in viable cell numbers was o

  13. Rethinking cell growth models.

    Science.gov (United States)

    Kafri, Moshe; Metzl-Raz, Eyal; Jonas, Felix; Barkai, Naama

    2016-11-01

    The minimal description of a growing cell consists of self-replicating ribosomes translating the cellular proteome. While neglecting all other cellular components, this model provides key insights into the control and limitations of growth rate. It shows, for example, that growth rate is maximized when ribosomes work at full capacity, explains the linear relation between growth rate and the ribosome fraction of the proteome and defines the maximal possible growth rate. This ribosome-centered model also highlights the challenge of coordinating cell growth with related processes such as cell division or nutrient production. Coordination is promoted when ribosomes don't translate at maximal capacity, as it allows escaping strict exponential growth. Recent data support the notion that multiple cellular processes limit growth. In particular, increasing transcriptional demand may be as deleterious as increasing translational demand, depending on growth conditions. Consistent with the idea of trade-off, cells may forgo maximal growth to enable more efficient interprocess coordination and faster adaptation to changing conditions. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Cancer Cells Hijack Gluconeogenic Enzymes to Fuel Cell Growth.

    Science.gov (United States)

    Balsa-Martinez, Eduardo; Puigserver, Pere

    2015-11-19

    In this issue and the October 15th issue of Molecular Cell, studies by Montal et al. (2015) and Vincent et al. (2015) report that certain types of cancer cells utilize the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (PEPCK) and phosphoenolpyruvate carboxykinase 2 (PCK2) to reprogram anabolic metabolism and support cell growth.

  15. Cell signalling and phospholipid metabolism

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Cell Growth Enhancement

    Science.gov (United States)

    1992-01-01

    Exogene Corporation uses advanced technologies to enhance production of bio-processed substances like proteins, antibiotics and amino acids. Among them are genetic modification and a genetic switch. They originated in research for Jet Propulsion Laboratory. Extensive experiments in cell growth through production of hemoglobin to improve oxygen supply to cells were performed. By improving efficiency of oxygen use by cells, major operational expenses can be reduced. Greater product yields result in decreased raw material costs and more efficient use of equipment. A broad range of applications is cited.

  17. The metabolic effects of growth hormone in adipose tissue.

    Science.gov (United States)

    Chaves, Valéria Ernestânia; Júnior, Fernando Mesquita; Bertolini, Gisele Lopes

    2013-10-01

    There is a general consensus that a reduction in growth hormone (GH) secretion results in obesity. However, the pathophysiologic role of GH in the metabolism of lipids is yet to be fully understood. The major somatic targets of GH are bones and muscles, but GH stimulates lipolysis and seems to regulate lipid deposition in adipose tissue. Patients with isolated GH deficiency (GHD) have enlarged fat depots due to higher fat cell volume, but their fat cell numbers are lower than those of matched controls. The treatment of patients with GH results in a relative loss of body fat and shifts both fat cell number and fat cell volume toward normal, indicating an adipogenic effect of GH. Adults with GHD are characterized by perturbations in body composition, lipid metabolism, cardiovascular risk profile, and bone mineral density. It is well established that GHD is usually accompanied by an increase in fat accumulation; GH replacement in GHD results in the reduction of fat mass, particularly abdominal fat mass. In addition, abdominal obesity results in a secondary reduction in GH secretion that is reversible with weight loss. However, whereas GH replacement in patients with GHD leads to specific depletion of intra-abdominal fat, administering GH to obese individuals does not seem to result in a consistent reduction or redistribution of body fat. Although administering GH to obese non-GHD subjects has only led to equivocal results, more recent studies indicate that GH still remains a plausible metabolic candidate.

  18. The metabolic switch and its regulation in cancer cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The primary features of cancer are maintained via intrinsically modified metabolic activity, which is characterized by enhanced nutrient supply, energy production, and biosynthetic activity to synthesize a variety of macromolecular components during each passage through the cell cycle. This metabolic shift in transformed cells, as compared with non-proliferating cells, in-volves aberrant activation of aerobic glycolysis, de novo lipid biosynthesis and glutamine-dependent anaplerosis to fuel robust cell growth and proliferation. Here, we discuss the unique metabolic characteristics of cancer, the constitutive regulation of metabolism through a variety of signal transduction pathways and/or enzymes involved in metabolic reprogramming in cancer cells, and their implications in cancer diagnosis and therapy.

  19. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    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

  20. Cysteine catabolism: a novel metabolic pathway contributing to glioblastoma growth.

    Science.gov (United States)

    Prabhu, Antony; Sarcar, Bhaswati; Kahali, Soumen; Yuan, Zhigang; Johnson, Joseph J; Adam, Klaus-Peter; Kensicki, Elizabeth; Chinnaiyan, Prakash

    2014-02-01

    The relevance of cysteine metabolism in cancer has gained considerable interest in recent years, largely focusing on its role in generating the antioxidant glutathione. Through metabolomic profiling using a combination of high-throughput liquid and gas chromatography-based mass spectrometry on a total of 69 patient-derived glioma specimens, this report documents the discovery of a parallel pathway involving cysteine catabolism that results in the accumulation of cysteine sulfinic acid (CSA) in glioblastoma. These studies identified CSA to rank as one of the top metabolites differentiating glioblastoma from low-grade glioma. There was strong intratumoral concordance of CSA levels with expression of its biosynthetic enzyme cysteine dioxygenase 1 (CDO1). Studies designed to determine the biologic consequence of this metabolic pathway identified its capacity to inhibit oxidative phosphorylation in glioblastoma cells, which was determined by decreased cellular respiration, decreased ATP production, and increased mitochondrial membrane potential following pathway activation. CSA-induced attenuation of oxidative phosphorylation was attributed to inhibition of the regulatory enzyme pyruvate dehydrogenase. Studies performed in vivo abrogating the CDO1/CSA axis using a lentiviral-mediated short hairpin RNA approach resulted in significant tumor growth inhibition in a glioblastoma mouse model, supporting the potential for this metabolic pathway to serve as a therapeutic target. Collectively, we identified a novel, targetable metabolic pathway involving cysteine catabolism contributing to the growth of aggressive high-grade gliomas. These findings serve as a framework for future investigations designed to more comprehensively determine the clinical application of this metabolic pathway and its contributory role in tumorigenesis.

  1. Metabolism of growth hormone releasing peptides.

    Science.gov (United States)

    Thomas, Andreas; Delahaut, Philippe; Krug, Oliver; Schänzer, Wilhelm; Thevis, Mario

    2012-12-04

    New, potentially performance enhancing compounds have frequently been introduced to licit and illicit markets and rapidly distributed via worldwide operating Internet platforms. Developing fast analytical strategies to follow these new trends is one the most challenging issues for modern doping control analysis. Even if reference compounds for the active drugs are readily obtained, their unknown metabolism complicates effective testing strategies. Recently, a new class of small C-terminally amidated peptides comprising four to seven amino acid residues received considerable attention of sports drug testing authorities due to their ability to stimulate growth hormone release from the pituitary. The most promising candidates are the growth hormone releasing peptide (GHRP)-1, -2, -4, -5, -6, hexarelin, alexamorelin, and ipamorelin. With the exemption of GHRP-2, the entity of these peptides represents nonapproved pharmaceuticals; however, via Internet providers, all compounds are readily available. To date, only limited information on the metabolism of these substances is available and merely one metabolite for GHRP-2 is established. Therefore, a comprehensive in vivo (po and iv administration in rats) and in vitro (with human serum and recombinant amidase) study was performed in order to generate information on urinary metabolites potentially useful for routine doping controls. The urine samples from the in vivo experiments were purified by mixed-mode cation-exchange solid-phase extraction and analyzed by ultrahigh-performance liquid chromatography (UHPLC) separation followed by high-resolution/high-accuracy mass spectrometry. Combining the high resolution power of a benchtop Orbitrap mass analyzer for the first metabolite screening and the speed of a quadrupole/time-of-flight (Q-TOF) instrument for identification, urinary metabolites were screened by means of a sensitive full scan analysis and subsequently confirmed by high-accuracy product ion scan experiments. Two

  2. The LKB1-AMPK pathway: metabolism and growth control in tumor suppression

    Science.gov (United States)

    Shackelford, David B.; Shaw, Reuben J.

    2009-01-01

    In the past decade, studies of the human tumor suppressor LKB1 have uncovered a novel signaling pathway that links cell metabolism to growth control and cell polarity. LKB1 encodes a serine/threonine kinase that directly phosphorylates and activates AMPK, a central metabolic sensor. AMPK regulates lipid, cholesterol and glucose metabolism in specialized metabolic tissues such as liver, muscle, and adipose, a function that has made it a key therapeutic target in patients with diabetes. The connection of AMPK with several tumor suppressors suggests that therapeutic manipulation of this pathway with established diabetes drugs warrants further investigation in patients with cancer. PMID:19629071

  3. The LKB1-AMPK pathway: metabolism and growth control in tumour suppression.

    Science.gov (United States)

    Shackelford, David B; Shaw, Reuben J

    2009-08-01

    In the past decade, studies of the human tumour suppressor LKB1 have uncovered a novel signalling pathway that links cell metabolism to growth control and cell polarity. LKB1 encodes a serine-threonine kinase that directly phosphorylates and activates AMPK, a central metabolic sensor. AMPK regulates lipid, cholesterol and glucose metabolism in specialized metabolic tissues, such as liver, muscle and adipose tissue. This function has made AMPK a key therapeutic target in patients with diabetes. The connection of AMPK with several tumour suppressors suggests that therapeutic manipulation of this pathway using established diabetes drugs warrants further investigation in patients with cancer.

  4. Vero细胞在不同微载体固定化培养中的生长和代谢%Growth and Metabolism of Vero Cells Immobilized Cultured on Various Microcarriers

    Institute of Scientific and Technical Information of China (English)

    刘红; 叶玲玲; 李世崇; 王启伟; 刘兴茂; 陈昭烈

    2012-01-01

    Objective: To investigate the growth and metabolism of Vero cells immobilized cultured on various microcarriers. Methods: Cell viability and cell morphology of the Vero cells cultured in 1% (v/v) newborn bovine serum DMEM/F12, the growth of the Vero cells cultured on 2D MicroHex, Biosilon, Cytodex 1 and Cytopore 1 was evaluated on the viable cell density; The specific consumption rate of glucose (qglc), the specific production rate of lactate (qlac), the specific consumption rate of glutamine (qgln), and the specific consumption rate of glutamate (qglu) were used as the evaluation indexes, the metabolism of the Vero cells cultured on various microcarriers was determined. Results: After 7 d in culture the viable cell density of the Vero cells cultured on 2D MicroHex, Biosilon, Cytodex 1 and Cytopore 1 was 18.4x 105 cells/ml, 21.9×105 cells/ml, 23.9× 105 cells/ml and 16.2× 105 cells/ml, respectively. And, the Vero cells growth on Cytodex 1 formed compact cell layers with distinct cell morphology; Metabolic indexes of the Vero cells cultured on various microcarriers were basically the same. Conclusion: Among these microcarriers, Cytodex 1 is comparatively good for the growth of Vero cells, and could be used as the favor choice of microcarrier for the large-scale cultivation of Vero cells for viral vaccine production.%目的:比较Vero细胞在不同的商品化微载体中固定化培养的生长和代谢.方法:以Vero细胞在含1%新生牛血清的DMEM/F12中培养的细胞形态、活细胞密度和细胞活力为指标,考察Vero细胞在2D MicroHex、Biosilon、Cytodex 1和Cytopore 1微载体固定化培养的细胞生长;以葡萄糖比消耗速率(qglc)、乳酸比生产速率(qlac)、谷氨酰胺比消耗速率(qgln)和谷氨酸比生产速率(qglu)为指标,考察Vero细胞在不同微载体固定化培养的细胞代谢.结果:Vero细胞在2D MicroHex、Biosilon、Cytodex 1和Cytopore 1微载体固定化培养7d的活细胞密度分别为18.4×105

  5. Growth phase of the diatom Skeletonema marinoi influences the metabolic profile of the cells and the selective feeding of the copepod Calanus spp

    DEFF Research Database (Denmark)

    Barofsky, A.; Simonelli, P.; Vidoudez, V.

    2010-01-01

    of a bloom and a culture. Quantitative PCR gut content assessment revealed that the food uptake of the copepod Calanus spp. on mixed diets and on artificially induced mesocosm blooms was selective. Uptake of S. marinoi was highest during the post-bloom phase in the mesocosms even if the abundance...... in both laboratory and field settings. In parallel, we monitored cellular metabolites of the diatom using a metabolomic approach. Complex changes in the metabolic profile occur during development of a culture. Since no obvious effect of nutrient quality and cell size was involved, we suggest that changes...

  6. An Integrated Metabolic Atlas of Clear Cell Renal Cell Carcinoma

    National Research Council Canada - National Science Library

    Hakimi, A Ari; Reznik, Ed; Lee, Chung-Han; Creighton, Chad J; Brannon, A Rose; Luna, Augustin; Aksoy, B Arman; Liu, Eric Minwei; Shen, Ronglai; Lee, William; Chen, Yang; Stirdivant, Steve M; Russo, Paul; Chen, Ying-Bei; Tickoo, Satish K; Reuter, Victor E; Cheng, Emily H; Sander, Chris; Hsieh, James J

    2016-01-01

    .... We performed metabolomic profiling on 138 matched clear cell renal cell carcinoma (ccRCC)/normal tissue pairs and found that ccRCC is characterized by broad shifts in central carbon metabolism, one-carbon metabolism, and antioxidant response...

  7. Modulation of fructose-2,6-bisphosphate metabolism by components of the extracellular matrix in cultured cells. Interaction with epidermal growth factor.

    Science.gov (United States)

    Baulida, J; Onetti, R; Bassols, A

    1997-11-24

    The use of NIH3T3 fibroblasts overexpressing different mutations of the EGF receptor shows that regulation of fructose-2,6-bisphosphate (Fru-2,6-P2) metabolism by EGF is mediated by the kinase activity of the EGF receptor and suggests a PLCgamma1-mediated mechanism. The effect of several extracellular matrix components on glucose metabolism was assessed by incubating A431 cells and NIH3T3 fibroblasts with heparin, laminin, fibronectin, collagen and PG-I and PG-II proteoglycans and measuring the levels of Fru-2,6-P2. Laminin increased the levels of Fru-2,6-P2 and heparin decreased the levels of the metabolite, whereas the other molecules did not have any effect. No effect of laminin or heparin in glucose uptake by the cell was observed. Laminin was able to modulate the effects of EGF on Fru-2,6-P2 concentration, suggesting cross-talk between these agents.

  8. AtPME3, a ubiquitous cell wall pectin methylesterase of Arabidopsis thaliana, alters the metabolism of cruciferin seed storage proteins during post-germinative growth of seedlings.

    Science.gov (United States)

    Guénin, Stéphanie; Hardouin, Julie; Paynel, Florence; Müller, Kerstin; Mongelard, Gaëlle; Driouich, Azeddine; Lerouge, Patrice; Kermode, Allison R; Lehner, Arnaud; Mollet, Jean-Claude; Pelloux, Jérôme; Gutierrez, Laurent; Mareck, Alain

    2017-02-01

    AtPME3 (At3g14310) is a ubiquitous cell wall pectin methylesterase. Atpme3-1 loss-of-function mutants exhibited distinct phenotypes from the wild type (WT), and were characterized by earlier germination and reduction of root hair production. These phenotypical traits were correlated with the accumulation of a 21.5-kDa protein in the different organs of 4-day-old Atpme3-1 seedlings grown in the dark, as well as in 6-week-old mutant plants. Microarray analysis showed significant down-regulation of the genes encoding several pectin-degrading enzymes and enzymes involved in lipid and protein metabolism in the hypocotyl of 4-day-old dark grown mutant seedlings. Accordingly, there was a decrease in proteolytic activity of the mutant as compared with the WT. Among the genes specifying seed storage proteins, two encoding CRUCIFERINS were up-regulated. Additional analysis by RT-qPCR showed an overexpression of four CRUCIFERIN genes in the mutant Atpme3-1, in which precursors of the α- and β-subunits of CRUCIFERIN accumulated. Together, these results provide evidence for a link between AtPME3, present in the cell wall, and CRUCIFERIN metabolism that occurs in vacuoles.

  9. 诱导表达p27对HEK293细胞生长代谢的影响%Effects of p27 Inducible-Expression on the Growth and Metabolism of HEK293 cells

    Institute of Scientific and Technical Information of China (English)

    叶玲玲; 刘红; 李世崇; 刘兴茂; 陈昭烈

    2011-01-01

    Objective: To investigate the effect of p27 inducible-expression on the growth and metabolism of HEK293 cells. Methods: The vector pTet-on and Dox-responsive p27-expressing vector were co-transfected into HEK293 cells and individual clones were isolated randomly. Cell growth and metabolism were assessed by cell-cycle distribution and viable cell density, Qglc, Qlac and Qgln as indexes, respectively. Results: The expression of p27 increased percentage of G1 cells, reduced consumption of glucose and production of lactate of HEK293 cells. Conclusions: The inducible-expression of p27 is an effective strategy for G1-phase arrest of HEK293 cells.%目的:研究诱导表达p27对HEK293细胞生长和代谢的影响.方法:将pTet-on载体和响应于Dox的p27诱导表达载体共转染HEK293细胞,随机挑选单克隆细胞株.以细胞周期分布和活细胞密度为主要观察指标,考察稳定转染的细胞在Dox诱导下的细胞生长;以Qglc、Qlac和Qgln为主要观察指标,考察转染细胞在Dox诱导下的细胞代谢.结果:p27基因的表达使HEK293细胞的增殖速度显著降低,G1期细胞比例显著升高,葡萄糖消耗和乳酸生产减少.结论:诱导表达p27基因是对HEK293细胞进行G1期阻滞的一种有效策略.

  10. Growth Plate Flow and Metabolism Screening Using MR: A New Application for Specialized MR Sequences

    DEFF Research Database (Denmark)

    Shiguetomi Medina, Juan Manuel; Stødkilde-Jørgensen, Hans; Rahbek, Ole

    Summary MR Apparent Diffusion Constant and Surface Tension Images can provide an overview of the cell metabolism and flow of the bone growth plate. This is a new application for specialized MR sequences. Introduction Magnetic Resonance imaging (MRI) can be used for studies of joint cartilage...... sequences can be applied to cartilage-like tissue such as growth plate. These sequences provide images that correspond to flow and cell-metabolism. MR imaging provides enough evidence and information about the structure and behavior of the growth plate to propose a standardized protocol for MRI ADC...... as well as bone growth plates. A number of MR derived parameters presents aspects of viability and growth patterns: the apparent diffusion constant (ADC) is dependent on intracellular as well as extracellular water movements and as such related to cell viability and cell apoptosis. The ADC provides early...

  11. Effect of feed and bleed rate on hybridoma cells in an acoustic perfusion bioreactor: Metabolic analysis

    NARCIS (Netherlands)

    Dalm, M.C.F.; Lamers, P.P.; Cuijten, S.M.R.; Tjeerdsma, A.M.; Grunsven, van W.M.J.; Tramper, J.; Martens, D.E.

    2007-01-01

    For the development of optimal perfusion processes, insight into the effect of feed and bleed rate on cell growth, productivity, and metabolism is essential. In the here presented study the effect of the feed and bleed rate on cell metabolism was investigated using metabolic flux analysis. Under all

  12. Metabolic network reconstruction, growth characterization and 13C-metabolic flux analysis of the extremophile Thermus thermophilus HB8.

    Science.gov (United States)

    Swarup, Aditi; Lu, Jing; DeWoody, Kathleen C; Antoniewicz, Maciek R

    2014-07-01

    Thermus thermophilus is an extremely thermophilic bacterium with significant biotechnological potential. In this work, we have characterized aerobic growth characteristics of T. thermophilus HB8 at temperatures between 50 and 85°C, constructed a metabolic network model of its central carbon metabolism and validated the model using (13)C-metabolic flux analysis ((13)C-MFA). First, cells were grown in batch cultures in custom constructed mini-bioreactors at different temperatures to determine optimal growth conditions. The optimal temperature for T. thermophilus grown on defined medium with glucose was 81°C. The maximum growth rate was 0.25h(-1). Between 50 and 81°C the growth rate increased by 7-fold and the temperature dependence was described well by an Arrhenius model with an activation energy of 47kJ/mol. Next, we performed a (13)C-labeling experiment with [1,2-(13)C] glucose as the tracer and calculated intracellular metabolic fluxes using (13)C-MFA. The results provided support for the constructed network model and highlighted several interesting characteristics of T. thermophilus metabolism. We found that T. thermophilus largely uses glycolysis and TCA cycle to produce biosynthetic precursors, ATP and reducing equivalents needed for cells growth. Consistent with its proposed metabolic network model, we did not detect any oxidative pentose phosphate pathway flux or Entner-Doudoroff pathway activity. The biomass precursors erythrose-4-phosphate and ribose-5-phosphate were produced via the non-oxidative pentose phosphate pathway, and largely via transketolase, with little contribution from transaldolase. The high biomass yield on glucose that was measured experimentally was also confirmed independently by (13)C-MFA. The results presented here provide a solid foundation for future studies of T. thermophilus and its metabolic engineering applications.

  13. Beyond Warburg effect – dual metabolic nature of cancer cells

    Science.gov (United States)

    Xie, Jiansheng; Wu, Hao; Dai, Chunyan; Pan, Qiangrong; Ding, Zonghui; Hu, Danqing; Ji, Bingyan; Luo, Yan; Hu, Xun

    2014-01-01

    Warburg effect is a dominant phenotype of most cancer cells. Here we show that this phenotype depends on its environment. When cancer cells are under regular culture condition, they show Warburg effect; whereas under lactic acidosis, they show a nonglycolytic phenotype, characterized by a high ratio of oxygen consumption rate over glycolytic rate, negligible lactate production and efficient incorporation of glucose carbon(s) into cellular mass. These two metabolic modes are intimately interrelated, for Warburg effect generates lactic acidosis that promotes a transition to a nonglycolytic mode. This dual metabolic nature confers growth advantage to cancer cells adapting to ever changing microenvironment. PMID:24820099

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

    Science.gov (United States)

    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.

  15. Metabolic reprogramming towards aerobic glycolysis correlates with greater proliferative ability and resistance to metabolic inhibition in CD8 versus CD4 T cells.

    Directory of Open Access Journals (Sweden)

    Yilin Cao

    Full Text Available T lymphocytes (T cells undergo metabolic reprogramming after activation to provide energy and biosynthetic materials for growth, proliferation and differentiation. Distinct T cell subsets, however, adopt metabolic programs specific to support their needs. As CD4 T cells coordinate adaptive immune responses while CD8 T cells become cytotoxic effectors, we compared activation-induced proliferation and metabolic reprogramming of these subsets. Resting CD4 and CD8 T cells were metabolically similar and used a predominantly oxidative metabolism. Following activation CD8 T cells proliferated more rapidly. Stimulation led both CD4 and CD8 T cells to sharply increase glucose metabolism and adopt aerobic glycolysis as a primary metabolic program. Activated CD4 T cells, however, remained more oxidative and had greater maximal respiratory capacity than activated CD8 T cells. CD4 T cells were also associated with greater levels of ROS and increased mitochondrial content, irrespective of the activation context. CD8 cells were better able, however, to oxidize glutamine as an alternative fuel source. The more glycolytic metabolism of activated CD8 T cells correlated with increased capacity for growth and proliferation, along with reduced sensitivity of cell growth to metabolic inhibition. These specific metabolic programs may promote greater growth and proliferation of CD8 T cells and enhance survival in diverse nutrient conditions.

  16. The pituitary growth hormone cell in space

    Science.gov (United States)

    Hymer, Wesley C.; Grindeland, R.

    1989-01-01

    Growth hormone (GH), produced and secreted from specialized cells in the pituitary gland, controls the metabolism of protein, fat, and carbohydrate. It is also probably involved in the regulation of proper function of bone, muscle and immune systems. The behavior of the GH cell system was studied by flying either isolated pituitary cells or live rats. In the latter case, pituitary GH cells are prepared on return to earth and then either transplanted into hypophysectomized rats or placed into cell culture so that function of GH cells in-vivo vs. in-vitro can be compared. The results from three flights to date (STS-8, 1983; SL-3, 1985; Cosmos 1887, 1987) established that the ability of GH cells to release hormone, on return to earth, is compromised. The mechanism(s) responsible for this attenuation response is unknown. However, the data are sufficiently positive to indicate that the nature of the secretory defect resides directly within the GH cells.

  17. T-cell Metabolism as a Target to Control Autoreactive T Cells in β-Cell Autoimmunity.

    Science.gov (United States)

    Bordignon, Carlotta; Canu, Adriana; Dyczko, Aleksandra; Leone, Serena; Monti, Paolo

    2017-05-01

    An increasing body of evidence indicates that bio-energetic metabolism of activated T cells is a potential target to control the autoimmune response in type 1 diabetes (T1D). T-cell activation and proliferation is linked to the cell capacity to provide sufficient energy and biosynthesis molecules to support T-cell growth and division. This makes T cells susceptible to metabolic inhibition for the control of the T-cell response. There is a wide therapeutic arsenal of metabolic inhibitors, including novel classes of drugs that have become recently available. With the current knowledge and availability of metabolic inhibitors, we are now in the position to design a metabolic inhibition strategy to determine whether targeting of autoreactive T cells is an effective strategy to control the process of β-cell destruction in T1D.

  18. Role of bentonite clays on cell growth.

    Science.gov (United States)

    Cervini-Silva, Javiera; Ramírez-Apan, María Teresa; Kaufhold, Stephan; Ufer, Kristian; Palacios, Eduardo; Montoya, Ascención

    2016-04-01

    Bentonites, naturally occurring clays, are produced industrially because of their adsorbent capacity but little is known about their effects on human health. This manuscript reports on the effect of bentonites on cell growth behaviour. Bentonites collected from India (Bent-India), Hungary (Bent-Hungary), Argentina (Bent-Argentina), and Indonesia (Bent-Indonesia) were studied. All four bentonites were screened in-vitro against two human cancer cell lines [U251 (central nervous system, glioblastoma) and SKLU-1 (lung adenocarcinoma)] supplied by the National Cancer Institute (USA). Bentonites induced growth inhibition in the presence of U251 cells, and growth increment in the presence of SKLU-1 cells, showing that interactions between bentonite and cell surfaces were highly specific. The proliferation response for U251 cells was explained because clay surfaces controlled the levels of metabolic growth components, thereby inhibiting the development of high-grade gliomas, particularly primary glioblastomas. On the other hand, the proliferation response for SKLU-1 was explained by an exacerbated growth favoured by swelling, and concomitant accumulation of solutes, and their hydration and transformation via clay-surface mediated reactions.

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

    Science.gov (United States)

    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.

  20. Correlated FLIM and PLIM for cell metabolism

    Science.gov (United States)

    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.

  1. Metabolism of dinosaurs as determined from their growth

    Science.gov (United States)

    Lee, Scott A.

    2015-09-01

    A model based on cellular properties is used to analyze the mass growth curves of 20 dinosaurs. This analysis yields the first measurement of the average cellular metabolism of dinosaurs. The organismal metabolism is also determined. The cellular metabolism of dinosaurs is found to decrease with mass at a slower rate than is observed in extant animals. The organismal metabolism increases with the mass of the dinosaur. These results come from both the Saurischia and Ornithischia branches of Dinosauria, suggesting that the observed metabolic features were common to all dinosaurs. The results from dinosaurs are compared to data from extant placental and marsupial mammals, a monotreme, and altricial and precocial birds, reptiles, and fish. Dinosaurs had cellular and organismal metabolisms in the range observed in extant mesotherms.

  2. Metabolic Reprogramming of Stem Cell Epigenetics

    Science.gov (United States)

    Ryall, James G.; Cliff, Tim; Dalton, Stephen; Sartorelli, Vittorio

    2015-01-01

    Summary For many years, stem cell metabolism was viewed as a by product of cell fate status rather than an active regulatory mechanism, however there is now a growing appreciation that metabolic pathways influence epigenetic changes associated with lineage commitment, specification, and self-renewal. Here we review how metabolites generated during glycolytic and oxidative processes are utilized in enzymatic reactions leading to epigenetic modifications and transcriptional regulation. We discuss how “metabolic reprogramming” contributes to global epigenetic changes in the context of naïve and primed pluripotent states, somatic reprogramming, and hematopoietic and skeletal muscle tissue stem cells, and the implications for regenerative medicine. PMID:26637942

  3. Aerobic glucose metabolism of Saccharomyces kluyveri: Growth, metabolite production, and quantification of metabolic fluxes

    DEFF Research Database (Denmark)

    Møller, Kasper; Christensen, B.; Förster, Jochen

    2002-01-01

    The growth and product formation of Saccharomyces kluyveri was characterized in aerobic batch cultivation on glucose. At these conditions it was found that ethyl acetate was a major overflow metabolite in S. kluyveri. During the exponential-growth phase on glucose ethyl acetate was produced.......29 +/- 0.01 g/g). The glucose metabolism of S. kluyveri was further characterized by the new and powerful techniques of metabolic network analysis. Flux distributions in the central carbon metabolism were estimated for respiro-fermentative growth in aerobic batch cultivation on glucose and respiratory...... growth in aerobic glucose-limited continuous cultivation. It was found that in S. kluyveri the flux into the pentose phosphate pathway was 18.8 mmole per 100 mmole glucose consumed during respiratory growth in aerobic glucose-limited continuous cultivation. Such a low flux into the pentose phosphate...

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  6. Effect of moderate static electric field on the growth and metabolism of Chlorella vulgaris.

    Science.gov (United States)

    Nezammahalleh, Hassan; Ghanati, Faezeh; Adams, Thomas A; Nosrati, Mohsen; Shojaosadati, Seyed Abbas

    2016-10-01

    An electric field (EF) generator device was fabricated and applied to the treatment of Chlorella vulgaris ISC33 at three distinct concentrations before cultivation. The EF of moderate intensity (2.7kVcm(-1)) has a hormetic effect on algal growth. The highest growth stimulation of 51% was observed after 50min treatment of 0.4gL(-1) algal suspension. The influence of EF on the system was then studied from both theoretical and experimental perspectives. The growth rate increased with treatment time up to a maximum because of improved membrane permeability, and then declined afterwards due to peroxide accumulation in the medium. The contents of chlorophylls, carotenoids, soluble carbohydrates, lipids, and proteins were also measured to understand possible changes on algal metabolism. The EF treatment of algal suspension has no observable effect on the cell metabolism while both algal growth and metabolism was significantly affected by the inoculum size.

  7. Dissecting Germ Cell Metabolism through Network Modeling.

    Directory of Open Access Journals (Sweden)

    Leanne S Whitmore

    Full Text Available 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.

  8. Silibinin-mediated metabolic reprogramming attenuates pancreatic cancer-induced cachexia and tumor growth.

    Science.gov (United States)

    Shukla, Surendra K; Dasgupta, Aneesha; Mehla, Kamiya; Gunda, Venugopal; Vernucci, Enza; Souchek, Joshua; Goode, Gennifer; King, Ryan; Mishra, Anusha; Rai, Ibha; Nagarajan, Sangeetha; Chaika, Nina V; Yu, Fang; Singh, Pankaj K

    2015-12-01

    Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths in the US. Cancer-associated cachexia is present in up to 80% of PDAC patients and is associated with aggressive disease and poor prognosis. In the present studies we evaluated an anti-cancer natural product silibinin for its effectiveness in targeting pancreatic cancer aggressiveness and the cachectic properties of pancreatic cancer cells and tumors. Our results demonstrate that silibinin inhibits pancreatic cancer cell growth in a dose-dependent manner and reduces glycolytic activity of cancer cells. Our LC-MS/MS based metabolomics data demonstrates that silibinin treatment induces global metabolic reprogramming in pancreatic cancer cells. Silibinin treatment diminishes c-MYC expression, a key regulator of cancer metabolism. Furthermore, we observed reduced STAT3 signaling in silibinin-treated cancer cells. Overexpression of constitutively active STAT3 was sufficient to substantially revert the silibinin-induced downregulation of c-MYC and the metabolic phenotype. Our in vivo investigations demonstrate that silibinin reduces tumor growth and proliferation in an orthotopic mouse model of pancreatic cancer and prevents the loss of body weight and muscle. It also improves physical activity including grip strength and latency to fall in tumor-bearing mice. In conclusion, silibinin-induced metabolic reprogramming diminishes cell growth and cachectic properties of pancreatic cancer cells and animal models.

  9. Pluripotent Stem Cell Metabolism and Mitochondria: Beyond ATP

    Directory of Open Access Journals (Sweden)

    Jarmon G. Lees

    2017-01-01

    Full Text Available Metabolism is central to embryonic stem cell (ESC pluripotency and differentiation, with distinct profiles apparent under different nutrient milieu, and conditions that maintain alternate cell states. The significance of altered nutrient availability, particularly oxygen, and metabolic pathway activity has been highlighted by extensive studies of their impact on preimplantation embryo development, physiology, and viability. ESC similarly modulate their metabolism in response to altered metabolite levels, with changes in nutrient availability shown to have a lasting impact on derived cell identity through the regulation of the epigenetic landscape. Further, the preferential use of glucose and anaplerotic glutamine metabolism serves to not only support cell growth and proliferation but also minimise reactive oxygen species production. However, the perinuclear localisation of spherical, electron-poor mitochondria in ESC is proposed to sustain ESC nuclear-mitochondrial crosstalk and a mitochondrial-H2O2 presence, to facilitate signalling to support self-renewal through the stabilisation of HIFα, a process that may be favoured under physiological oxygen. The environment in which a cell is grown is therefore a critical regulator and determinant of cell fate, with metabolism, and particularly mitochondria, acting as an interface between the environment and the epigenome.

  10. FXR: a metabolic regulator and cell protector

    Institute of Scientific and Technical Information of China (English)

    Yan-Dong Wang; Wei-Dong Chen; David D Moore; Wendong Huang

    2008-01-01

    Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of ligand-activated transcription fac-tors. As a metabolic regulator, FXR plays key roles in bile acid, cholesterol, lipid, and glucose metabolism. Therefore, FXR is a potential drug target for a number of metabolic disorders, especially those related to the metabolic syn-drome. More recently, our group and others have extended the functions of FXR to more than metabolic regulation, which include anti-bacterial growth in intestine, liver regeneration, and hepatocarcinogenesis. These new findings suggest that FXR has much broader roles than previously thought, and also higl light FXR as a drug target for mul-tiple diseases. This review summarizes the basic information of FXR but focuses on its new functions.

  11. Red cell metabolism studies on Skylab

    Science.gov (United States)

    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. Red cell metabolism studies on Skylab

    Science.gov (United States)

    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.

  13. Metabolic regulation of suppressive myeloid cells in cancer.

    Science.gov (United States)

    Sica, Antonio; Strauss, Laura; Consonni, Francesca Maria; Travelli, Cristina; Genazzani, Armando; Porta, Chiara

    2017-06-01

    Cancer cells rewire their metabolism to promote growth, survival, proliferation and long-term maintenance. The common feature of this altered metabolism is the increased glucose uptake and fermentation of glucose to lactate, which is observed even in the presence of completely functioning mitochondria. This effect is known as the 'Warburg Effect' and its intensive investigation in the last decade has partially established either its causes or its functions. It is now emerging that a major side effect of the Warburg Effect is immunosuppression, which limits the immunogenicity of cancer cells and therefore restricts the therapeutic efficacy of anticancer immunotherapy. Here we discuss how the metabolic communication between cancer and infiltrating myeloid cells contributes to cancer immune evasion and how the understanding of these mechanisms may improve current immunotherapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. A transcription factor links growth rate and metabolism in the hypersaline adapted archaeon Halobacterium salinarum.

    Science.gov (United States)

    Todor, Horia; Dulmage, Keely; Gillum, Nicholas; Bain, James R; Muehlbauer, Michael J; Schmid, Amy K

    2014-09-01

    Co-ordinating metabolism and growth is a key challenge for all organisms. Despite fluctuating environments, cells must produce the same metabolic outputs to thrive. The mechanisms underlying this 'growth homeostasis' are known in bacteria and eukaryotes, but remain unexplored in archaea. In the model archaeon Halobacterium salinarum, the transcription factor TrmB regulates enzyme-coding genes in diverse metabolic pathways in response to glucose. However, H. salinarum is thought not to catabolize glucose. To resolve this discrepancy, we demonstrate that TrmB regulates the gluconeogenic production of sugars incorporated into the cell surface S-layer glycoprotein. Additionally, we show that TrmB-DNA binding correlates with instantaneous growth rate, likely because S-layer glycosylation is proportional to growth. This suggests that TrmB transduces a growth rate signal to co-regulated metabolic pathways including amino acid, purine, and cobalamin biosynthesis. Remarkably, the topology and function of this growth homeostatic network appear conserved across domains despite extensive alterations in protein components.

  15. Early growth and development of later life metabolic disorders.

    Science.gov (United States)

    Foo, Joo-Pin; Mantzoros, Christos

    2013-01-01

    Growth is effected via a complex interaction of genetic, nutritional, environmental and growth factors. Hormonal factors such as the growth hormone (GH) and insulin-like growth factor (IGF) signaling system, the human placental lactogen, and insulin play an integral role in early growth. Genetic factors affecting the GH-IGF system and insulin secretion and actions, and epigenetic mechanisms including DNA methylation have been further implicated as contributory factors. These hormonal systems, on a background of genetic susceptibility, together with other factors including maternal nutrition, placental and environmental factors, regulate not only early growth but also development. These interactions may impact on later health consequences in adult life. Accumulating data in the last few decades on developmental programming and later life metabolic disorders has provided a novel perspective on the possible pathogenesis of metabolic dysregulation. Despite postulations put forward to elucidate the mechanism underlying the association between early growth and later life metabolic disorders, it remains unclear what the dominant factor(s) would be, how any underlying mechanisms interact, or whether these mechanisms are truly causal.

  16. Ovarian tumor-initiating cells display a flexible metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Angela S. [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States); Roberts, Paul C. [Biomedical Science and Pathobiology, Virginia Tech, Blacksburg, VA (United States); Frisard, Madlyn I. [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States); Hulver, Matthew W., E-mail: hulvermw@vt.edu [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States); Schmelz, Eva M., E-mail: eschmelz@vt.edu [Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA (United States)

    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.

  17. Bounds on bacterial cell growth rates

    CERN Document Server

    Landy, Jonathan

    2013-01-01

    Recent experiments have shown that rod-like bacteria in nutrient-rich media grow in length at an exponential rate. Here, I point out that it is the elongated shape of these bacteria that allows for this behavior. Further, I show that when a bacterium's growth is limited by some nutrient -- taken in by the cell through a diffusion-to-capture process -- its growth is suppressed: In three-dimensional geometries, the length $L$ is bounded by $\\log L \\lesssim t^{1/2}$, while in two dimensions the length is bounded by a power-law form. Fits of experimental growth curves to these predicted, sub-exponential forms could allow for direct measures of quantities relating to cellular metabolic rates.

  18. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  19. Glutathione Primes T Cell Metabolism for Inflammation

    DEFF Research Database (Denmark)

    Mak, Tak W.; Grusdat, Melanie; Duncan, Gordon S.

    2017-01-01

    Activated T cells produce reactive oxygen species (ROS), which trigger the antioxidative glutathione (GSH) response necessary to buffer rising ROS and prevent cellular damage. We report that GSH is essential for T cell effector functions through its regulation of metabolic activity. Conditional g...

  20. Circadian rhythm and cell population growth

    CERN Document Server

    Clairambault, Jean; Lepoutre, Thomas

    2010-01-01

    Molecular circadian clocks, that are found in all nucleated cells of mammals, are known to dictate rhythms of approximately 24 hours (circa diem) to many physiological processes. This includes metabolism (e.g., temperature, hormonal blood levels) and cell proliferation. It has been observed in tumor-bearing laboratory rodents that a severe disruption of these physiological rhythms results in accelerated tumor growth. The question of accurately representing the control exerted by circadian clocks on healthy and tumour tissue proliferation to explain this phenomenon has given rise to mathematical developments, which we review. The main goal of these previous works was to examine the influence of a periodic control on the cell division cycle in physiologically structured cell populations, comparing the effects of periodic control with no control, and of different periodic controls between them. We state here a general convexity result that may give a theoretical justification to the concept of cancer chronothera...

  1. Methionine, homocysteine, one carbon metabolism and fetal growth.

    Science.gov (United States)

    Kalhan, Satish C; Marczewski, Susan E

    2012-06-01

    Methionine and folate are the key components of one carbon metabolism, providing the methyl groups for numerous methyl transferase reactions via the ubiquitous methyl donor, s-adenosyl methionine. Methionine metabolism is responsive to nutrient intake, is regulated by several hormones and requires a number of vitamins (B12, pyridoxine, riboflavin) as co-factors. The critical relationship between perturbations in the mother's methionine metabolism and its impact on fetal growth and development is now becoming evident. The relation of folate intake to fetal teratogenesis has been known for some time. Studies in human pregnancy show a continuous decrease in plasma homocysteine, and an increase in plasma choline concentrations with advancing gestation. A higher rate of transsulfuration of methionine in early gestation and of transmethylation in the 3rd trimester was seen in healthy pregnant women. How these processes are impacted by nutritional, hormonal and other influences in human pregnancy and their effect on fetal growth has not been examined. Isocaloric protein restriction in pregnant rats, resulted in fetal growth restriction and metabolic reprogramming. Isocaloric protein restriction in the non-pregnant rat, resulted in differential expression of a number of genes in the liver, a 50% increase in whole body serine biosynthesis and high rate of transmethylation, suggesting high methylation demands. These responses were associated with a significant decrease in intracellular taurine levels in the liver suggesting a role of cellular osmolarity in the observed metabolic responses. These unique changes in methionine and one carbon metabolism in response to physiological, nutritional and hormonal influences make these processes critical for cellular and organ function and growth.

  2. Horizontal and vertical growth of S. cerevisiae metabolic network.

    KAUST Repository

    Grassi, Luigi

    2011-10-14

    BACKGROUND: The growth and development of a biological organism is reflected by its metabolic network, the evolution of which relies on the essential gene duplication mechanism. There are two current views about the evolution of metabolic networks. The retrograde model hypothesizes that a pathway evolves by recruiting novel enzymes in a direction opposite to the metabolic flow. The patchwork model is instead based on the assumption that the evolution is based on the exploitation of broad-specificity enzymes capable of catalysing a variety of metabolic reactions. RESULTS: We analysed a well-studied unicellular eukaryotic organism, S. cerevisiae, and studied the effect of the removal of paralogous gene products on its metabolic network. Our results, obtained using different paralog and network definitions, show that, after an initial period when gene duplication was indeed instrumental in expanding the metabolic space, the latter reached an equilibrium and subsequent gene duplications were used as a source of more specialized enzymes rather than as a source of novel reactions. We also show that the switch between the two evolutionary strategies in S. cerevisiae can be dated to about 350 million years ago. CONCLUSIONS: Our data, obtained through a novel analysis methodology, strongly supports the hypothesis that the patchwork model better explains the more recent evolution of the S. cerevisiae metabolic network. Interestingly, the effects of a patchwork strategy acting before the Euascomycete-Hemiascomycete divergence are still detectable today.

  3. Horizontal and vertical growth of S. cerevisiae metabolic network

    Directory of Open Access Journals (Sweden)

    Tramontano Anna

    2011-10-01

    Full Text Available Abstract Background The growth and development of a biological organism is reflected by its metabolic network, the evolution of which relies on the essential gene duplication mechanism. There are two current views about the evolution of metabolic networks. The retrograde model hypothesizes that a pathway evolves by recruiting novel enzymes in a direction opposite to the metabolic flow. The patchwork model is instead based on the assumption that the evolution is based on the exploitation of broad-specificity enzymes capable of catalysing a variety of metabolic reactions. Results We analysed a well-studied unicellular eukaryotic organism, S. cerevisiae, and studied the effect of the removal of paralogous gene products on its metabolic network. Our results, obtained using different paralog and network definitions, show that, after an initial period when gene duplication was indeed instrumental in expanding the metabolic space, the latter reached an equilibrium and subsequent gene duplications were used as a source of more specialized enzymes rather than as a source of novel reactions. We also show that the switch between the two evolutionary strategies in S. cerevisiae can be dated to about 350 million years ago. Conclusions Our data, obtained through a novel analysis methodology, strongly supports the hypothesis that the patchwork model better explains the more recent evolution of the S. cerevisiae metabolic network. Interestingly, the effects of a patchwork strategy acting before the Euascomycete-Hemiascomycete divergence are still detectable today.

  4. The Metabolism and Growth of Web Forums

    CERN Document Server

    Wu, Lingfei; Zhao, Min

    2013-01-01

    We view web forums as virtual living organisms feeding on user's attention and investigate how these organisms grow at the expense of collective attention. We find that the "body mass" ($PV$) and "energy consumption" ($UV$) of the studied forums exhibits the allometric growth property, i.e., $PV_t \\sim UV_t ^ \\theta$. This implies that within a forum, the network transporting attention flow between threads has a structure invariant of time, despite of the continuously changing of the nodes (threads) and edges (clickstreams). The observed time-invariant topology allows us to explain the dynamics of networks by the behavior of threads. In particular, we describe the clickstream dissipation on threads using the function $D_i \\sim T_i ^ \\gamma$, in which $T_i$ is the clickstreams to node $i$ and $D_i$ is the clickstream dissipated from $i$. It turns out that $\\gamma$, an indicator for dissipation efficiency, is negatively correlated with $\\theta$ and $1/\\gamma$ sets the lower boundary for $\\theta$. Our findings h...

  5. Triiodothyronine regulates cell growth and survival in renal cell cancer.

    Science.gov (United States)

    Czarnecka, Anna M; Matak, Damian; Szymanski, Lukasz; Czarnecka, Karolina H; Lewicki, Slawomir; Zdanowski, Robert; Brzezianska-Lasota, Ewa; Szczylik, Cezary

    2016-10-01

    Triiodothyronine plays an important role in the regulation of kidney cell growth, differentiation and metabolism. Patients with renal cell cancer who develop hypothyreosis during tyrosine kinase inhibitor (TKI) treatment have statistically longer survival. In this study, we developed cell based model of triiodothyronine (T3) analysis in RCC and we show the different effects of T3 on renal cell cancer (RCC) cell growth response and expression of the thyroid hormone receptor in human renal cell cancer cell lines from primary and metastatic tumors along with human kidney cancer stem cells. Wild-type thyroid hormone receptor is ubiquitously expressed in human renal cancer cell lines, but normalized against healthy renal proximal tube cell expression its level is upregulated in Caki-2, RCC6, SKRC-42, SKRC-45 cell lines. On the contrary the mRNA level in the 769-P, ACHN, HKCSC, and HEK293 cells is significantly decreased. The TRβ protein was abundant in the cytoplasm of the 786-O, Caki-2, RCC6, and SKRC-45 cells and in the nucleus of SKRC-42, ACHN, 769-P and cancer stem cells. T3 has promoting effect on the cell proliferation of HKCSC, Caki-2, ASE, ACHN, SK-RC-42, SMKT-R2, Caki-1, 786-0, and SK-RC-45 cells. Tyrosine kinase inhibitor, sunitinib, directly inhibits proliferation of RCC cells, while thyroid hormone receptor antagonist 1-850 (CAS 251310‑57-3) has less significant inhibitory impact. T3 stimulation does not abrogate inhibitory effect of sunitinib. Renal cancer tumor cells hypostimulated with T3 may be more responsive to tyrosine kinase inhibition. Moreover, some tumors may be considered as T3-independent and present aggressive phenotype with thyroid hormone receptor activated independently from the ligand. On the contrary proliferation induced by deregulated VHL and or c-Met pathways may transgress normal T3 mediated regulation of the cell cycle.

  6. OP449 inhibits breast cancer growth without adverse metabolic effects.

    Science.gov (United States)

    Shlomai, Gadi; Zelenko, Zara; Antoniou, Irini Markella; Stasinopoulos, Marilyn; Tobin-Hess, Aviva; Vitek, Michael P; LeRoith, Derek; Gallagher, Emily Jane

    2017-10-01

    Hyperinsulinemia is associated with a decrease in breast cancer recurrence-free survival and overall survival. Inhibition of insulin receptor signaling is associated with glycemic dysregulation. SET is a direct modulator of PP2A, which negatively regulates the PI3K/AKT/mTOR pathway. OP449, a SET inhibitor, decreases AKT/mTOR activation. The effects of OP449 treatment on breast cancer growth in the setting of pre-diabetes, and its metabolic implications are currently unknown. We found that the volumes and weights of human MDA-MB-231 breast cancer xenografts were greater in hyperinsulinemic mice compared with controls (P < 0.05), and IR phosphorylation was 4.5-fold higher in these mice (P < 0.05). Human and murine breast cancer tumors treated with OP449 were 47% and 39% smaller than controls (P < 0.05, for both, respectively). AKT and S6RP phosphorylation were 82% and 34% lower in OP449-treated tumors compared with controls (P < 0.05, P = 0.06, respectively). AKT and S6RP phosphorylation in response to insulin was 30% and 12% lower in cells, pre-treated with OP449, compared with control cells (P < 0.01, P < 0.05, respectively). However, even with decreased AKT/mTOR activation, body weights and composition, blood glucose and plasma insulin, glucose tolerance, serum triglyceride and cholesterol levels were similar between OP449-treated mice and controls. Xenografts and liver tissue from OP449-treated mice showed a 64% and 70% reduction in STAT5 activation, compared with controls (P < 0.01 and P = 0.06, respectively). Our data support an anti-neoplastic effect of OP449 on human breast cancer cells in vitro and in xenografts in the setting of hyperinsulinemia. OP449 led to the inhibition of AKT/mTOR signaling, albeit, not leading to metabolic derangements. © 2017 Society for Endocrinology.

  7. Growth against entropy in bacterial metabolism: the phenotypic trade-off behind empirical growth rate distributions in E. coli

    Science.gov (United States)

    De Martino, Daniele; Capuani, Fabrizio; De Martino, Andrea

    2016-06-01

    The solution space of genome-scale models of cellular metabolism provides a map between physically viable flux configurations and cellular metabolic phenotypes described, at the most basic level, by the corresponding growth rates. By sampling the solution space of E. coli's metabolic network, we show that empirical growth rate distributions recently obtained in experiments at single-cell resolution can be explained in terms of a trade-off between the higher fitness of fast-growing phenotypes and the higher entropy of slow-growing ones. Based on this, we propose a minimal model for the evolution of a large bacterial population that captures this trade-off. The scaling relationships observed in experiments encode, in such frameworks, for the same distance from the maximum achievable growth rate, the same degree of growth rate maximization, and/or the same rate of phenotypic change. Being grounded on genome-scale metabolic network reconstructions, these results allow for multiple implications and extensions in spite of the underlying conceptual simplicity.

  8. Effect of captopril on collagen metabolisms in keloid fibroblast cells.

    Science.gov (United States)

    Chen, Junjie; Zhao, Sha; Liu, Yong; Cen, Ying; Nicolas, Crook

    2016-12-01

    Keloid is a proliferative disease of fibrous tissues. The mechanism and consistently effective treatments of keloid remained unknown. Although there was a report about treating keloid with topical captopril, the further investigation about captopril affecting keloid has not been performed so far. The aim of this study was to analyse the effect of captopril on collagen metabolisms in keloid fibroblast cells, and to provide information for the mechanism and therapy of keloid. To investigate the effects and relative mechanism of captopril on keloid fibroblast cells, we examined the changes of collagen metabolism, expression of angiotensin, transforming growth factor (TGF)-β1, platelet-derived growth factor (PDGF)-BB and heat shock protein 47 (HSP47), and cellular proliferation in keloid fibroblast cells. We found that all collagen metabolisms, expression of TGF-β1, PDGF-BB and HSP47, and cellular proliferation decreased significantly with effective captopril concentrations in keloid fibroblast cells. With a comprehensive analysis of test results, we proposed that captopril may decrease the expression of angiotensin, PDGF-BB, TGF-β1 and HSP47, and further inhibit proliferation and collagen synthesis of keloid fibroblast cells, which were the key in keloid formation. © 2014 Royal Australasian College of Surgeons.

  9. THE ROLE OF GROWTH HORMONE IN LIPID METABOLISM

    Directory of Open Access Journals (Sweden)

    I Gusti Ayu Dewi Ratnayanti

    2013-04-01

    Full Text Available Growth hormone (GH is one of the hormones that regulate metabolism, including lipid metabolism. GH can regulate the amount of fat in the tissue and also the level of lipid profile. Growth hormone affects the lipid in the tissue and blood by modulating the lipid metabolism, especially through the regulation of synthesis, excretion and breakdown of internal lipids. Research showed that GH could consistently lower the level of total cholesterol and LDL, whereas its effect on triglyceride and HDL level showed varying results. Growth hormone induces lypolisis by stimulating the activity of HSL and LPL and thereby influenced the triglyceride level and tissue fat storage. Cholesterol and lipoprotein levels are controlled by regulating the synthesis of cholesterol by lowering the activity of HMGCoA reductase. The excretion of cholesterol through the bile is also enhanced by stimulating the activity of enzymes C7?OH. The breakdown of VLDL and LDL are enhanced by increasing the expression of LDL receptor and ApoE as well as affecting the editing of mRNA ApoB100. Increase activity of LPL is also known to be the important factor in the HDL metabolism

  10. The thrifty phenotype: An adaptation in growth or metabolism?

    Science.gov (United States)

    Wells, Jonathan C K

    2011-01-01

    The thrifty phenotype hypothesis is widely used to interpret associations between early nutritional experience and degenerative disease risks. However, it remains unclear what is adaptive about early life thrift, and biomedical approaches struggle to explain why associations between early growth and later disease hold across the entire range of birth size. This issue can be addressed using a simple model, attributing disease to a high metabolic load (large tissue masses, rich diet, and sedentary lifestyle) relative to metabolic capacity (physiological traits contingent on fetal/infant development). In this context, different hypotheses regarding the long-term functions of thrift can be examined. The "predictive adaptive response" hypothesis considers thrift to involve metabolic adaptations (insulin resistance and central adiposity) that emerge in anticipation of a poor quality adult breeding environment. The competing "maternal capital" hypothesis considers thrift to involve reductions in lean mass and organ phenotype arising through constraints on maternal phenotype, reflecting both maternal developmental experience and current ecological conditions. This hypothesis assumes offspring developmental responses to stresses such as temperature, altitude, and nutritional ecology occur under the influence of maternal capital indices, including size, physiology, reproductive history and social status. I argue that insulin resistance only emerges after infancy, and far from being anticipatory of a low nutritional plane, indicates perturbations of metabolism. Following exposure of early thrifty growth to the obesogenic niche. Thrift as early growth variability represents a plausible profile of developmental plasticity for human evolutionary history, aiding understand how the modern obesogenic environment interacts with physiological variability to induce disease.

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

    Science.gov (United States)

    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.

  12. Metabolic alterations in renal cell carcinoma.

    Science.gov (United States)

    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.

  13. Growth Plate Flow and Metabolism Screening Using MR: A New Application for Specialized MR Sequences

    DEFF Research Database (Denmark)

    Shiguetomi Medina, Juan Manuel; Stødkilde-Jørgensen, Hans; Rahbek, Ole

    Introduction Magnetic Resonance imaging (MRI) can be used for studies of joint cartilage as well as bone growth plates. A number of MR derived parameters present aspects of viability and growth patterns: the apparent diffusion constant (ADC) is dependent on intracellular as well as extracellular...... resolution MR images resemble those seen in histological sections. Discussion A number of MR derived sequences can be applied to cartilage-like tissue such as growth plate. These sequences provide images that correspond to flow and cell-metabolism. MR imaging provides enough evidence and information about...... the structure and behavior of the growth plate to propose a standardized protocol for MRI ADC and Tension Surface Images. This should provide more information about growth disturbances causes and characteristics. MR Apparent Diffusion Constant and Surface Tension Images can provide an overview of the cell...

  14. Compartment-specific activation of PPARγ governs breast cancer tumor growth, via metabolic reprogramming and symbiosis.

    Science.gov (United States)

    Avena, Paola; Anselmo, Wanda; Whitaker-Menezes, Diana; Wang, Chenguang; Pestell, Richard G; Lamb, Rebecca S; Hulit, James; Casaburi, Ivan; Andò, Sebastiano; Martinez-Outschoorn, Ubaldo E; Lisanti, Michael P; Sotgia, Federica

    2013-05-01

    The role of PPARγ in cancer therapy is controversial, with studies showing either pro-tumorigenic or antineoplastic effects. This debate is very clinically relevant, because PPARγ agonists are used as antidiabetic drugs. Here, we evaluated if the effects of PPARγ on tumorigenesis are determined by the cell type in which PPARγ is activated. Second, we examined if the metabolic changes induced by PPARγ, such as glycolysis and autophagy, play any role in the tumorigenic process. To this end, PPARγ was overexpressed in breast cancer cells or in stromal cells. PPARγ-overexpressing cells were examined with respect to (1) their tumorigenic potential, using xenograft models, and (2) regarding their metabolic features. In xenograft models, we show that when PPARγ is activated in cancer cells, tumor growth is inhibited by 40%. However, when PPARγ is activated in stromal cells, the growth of co-injected breast cancer cells is enhanced by 60%. Thus, the effect(s) of PPARγ on tumorigenesis are dependent on the cell compartment in which PPARγ is activated. Mechanistically, stromal cells with activated PPARγ display metabolic features of cancer-associated fibroblasts, with increased autophagy, glycolysis and senescence. Indeed, fibroblasts overexpressing PPARγ show increased expression of autophagic markers, increased numbers of acidic autophagic vacuoles, increased production of L-lactate, cell hypertrophy and mitochondrial dysfunction. In addition, PPARγ fibroblasts show increased expression of CDKs (p16/p21) and β-galactosidase, which are markers of cell cycle arrest and senescence. Finally, PPARγ induces the activation of the two major transcription factors that promote autophagy and glycolysis, i.e., HIF-1α and NFκB, in stromal cells. Thus, PPARγ activation in stromal cells results in the formation of a catabolic pro-inflammatory microenvironment that metabolically supports cancer growth. Interestingly, the tumor inhibition observed when PPARγ is

  15. Lactococcus lactis metabolism and gene expression during growth on plant tissues.

    Science.gov (United States)

    Golomb, Benjamin L; Marco, Maria L

    2015-01-01

    Lactic acid bacteria have been isolated from living, harvested, and fermented plant materials; however, the adaptations these bacteria possess for growth on plant tissues are largely unknown. In this study, we investigated plant habitat-specific traits of Lactococcus lactis during growth in an Arabidopsis thaliana leaf tissue lysate (ATL). L. lactis KF147, a strain originally isolated from plants, exhibited a higher growth rate and reached 7.9-fold-greater cell densities during growth in ATL than the dairy-associated strain L. lactis IL1403. Transcriptome profiling (RNA-seq) of KF147 identified 853 induced and 264 repressed genes during growth in ATL compared to that in GM17 laboratory culture medium. Genes induced in ATL included those involved in the arginine deiminase pathway and a total of 140 carbohydrate transport and metabolism genes, many of which are involved in xylose, arabinose, cellobiose, and hemicellulose metabolism. The induction of those genes corresponded with L. lactis KF147 nutrient consumption and production of metabolic end products in ATL as measured by gas chromatography-time of flight mass spectrometry (GC-TOF/MS) untargeted metabolomic profiling. To assess the importance of specific plant-inducible genes for L. lactis growth in ATL, xylose metabolism was targeted for gene knockout mutagenesis. Wild-type L. lactis strain KF147 but not an xylA deletion mutant was able to grow using xylose as the sole carbon source. However, both strains grew to similarly high levels in ATL, indicating redundancy in L. lactis carbohydrate metabolism on plant tissues. These findings show that certain strains of L. lactis are well adapted for growth on plants and possess specific traits relevant for plant-based food, fuel, and feed fermentations.

  16. Metabolic acidosis increases fibroblast growth factor 23 in neonatal mouse bone.

    Science.gov (United States)

    Krieger, Nancy S; Culbertson, Christopher D; Kyker-Snowman, Kelly; Bushinsky, David A

    2012-08-01

    Fibroblast growth factor 23 (FGF23) significantly increases with declining renal function, leading to reduced renal tubular phosphate reabsorption, decreased 1,25-dihydroxyvitamin D, and increased left ventricular hypertrophy. Elevated FGF23 is associated with increased mortality. FGF23 is synthesized in osteoblasts and osteocytes; however, the mechanisms by which it is regulated are not clear. Patients with chronic kidney disease have decreased renal acid excretion leading to metabolic acidosis, which has a direct effect on bone cell activity. We hypothesized that metabolic acidosis would directly increase bone cell FGF23 production. Using cultured neonatal mouse calvariae, we found that metabolic acidosis increased medium FGF23 protein levels as well as FGF23 RNA expression at 24 h and 48 h compared with incubation in neutral pH medium. To exclude that the increased FGF23 was secondary to metabolic acidosis-induced release of bone mineral phosphate, we cultured primary calvarial osteoblasts. In these cells, metabolic acidosis increased FGF23 RNA expression at 6 h compared with incubation in neutral pH medium. Thus metabolic acidosis directly increases FGF23 mRNA and protein in mouse bone. If these results are confirmed in humans with chronic kidney disease, therapeutic interventions to mitigate acidosis, such as bicarbonate administration, may also lower levels of FGF23, decrease left ventricular hypertrophy, and perhaps even decrease mortality.

  17. An Integrated Metabolic Atlas of Clear Cell Renal Cell Carcinoma.

    Science.gov (United States)

    Hakimi, A Ari; Reznik, Ed; Lee, Chung-Han; Creighton, Chad J; Brannon, A Rose; Luna, Augustin; Aksoy, B Arman; Liu, Eric Minwei; Shen, Ronglai; Lee, William; Chen, Yang; Stirdivant, Steve M; Russo, Paul; Chen, Ying Bei; Tickoo, Satish K; Reuter, Victor E; Cheng, Emily H; Sander, Chris; Hsieh, James J

    2016-01-11

    Dysregulated metabolism is a hallmark of cancer, manifested through alterations in metabolites. We performed metabolomic profiling on 138 matched clear cell renal cell carcinoma (ccRCC)/normal tissue pairs and found that ccRCC is characterized by broad shifts in central carbon metabolism, one-carbon metabolism, and antioxidant response. Tumor progression and metastasis were associated with metabolite increases in glutathione and cysteine/methionine metabolism pathways. We develop an analytic pipeline and visualization tool (metabolograms) to bridge the gap between TCGA transcriptomic profiling and our metabolomic data, which enables us to assemble an integrated pathway-level metabolic atlas and to demonstrate discordance between transcriptome and metabolome. Lastly, expression profiling was performed on a high-glutathione cluster, which corresponds to a poor-survival subgroup in the ccRCC TCGA cohort. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Metabolic properties of chicken embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Cellular energy metabolism correlates with cell fate,but the metabolic properties of chicken embryonic stem (chES) cells are poorly understood.Using a previously established chES cell model and electron microscopy (EM),we found that undifferentiated chES cells stored glycogen.Additionally,undifferentiated chES cells expressed lower levels of glucose transporter 1 (GLUT1) and phosphofructokinase (PFK) mRNAs but higher levels of hexokinase 1 (HK1) and glycogen synthase (GYS) mRNAs compared with control primary chicken embryonic fibroblast (CEF) cells,suggesting that chES cells direct glucose flux towards the glycogenic pathway.Moreover,we demonstrated that undifferentiated chES cells block gluconeogenic outflow and impede the accumulation of glucose-6-phosphate (G6P) from this pathway,as evidenced by the barely detectable levels of pyruvate carboxylase (PCX) and mitochondrial phosphoenolpyruvate carboxykinase (PCK2) mRNAs.Additionally,cell death occurred in undifferentiated chES cells as shown by Hoechst 33342 and propidium iodide (PI) double staining,but it could be rescued by exogenous G6P.However,we found that differentiated chES cells decreased the glycogen reserve through the use of PAS staining.Moreover,differentiated chES cells expressed higher levels of GLUT1,HK1 and PFK mRNAs,while the level of GYS mRNA remained similar in control CEF cells.These data indicate that undifferentiated chES cells continue to synthesize glycogen from glucose at the expense of G6P,while differentiated chES cells have a decreased glycogen reserve,which suggests that the amount of glycogen is indicative of the chES cell state.

  19. Metabolism Kinetics of Glucose in Anchorage-dependent Cell Cultures

    Institute of Scientific and Technical Information of China (English)

    孙祥明; 张元兴

    2001-01-01

    The kinetic model of glucose metabolism was established and successfully applied to batchcultures of rCHO and rBHK cells. It was found that a large amount of glucose was utilized for cellmaintenance, and the overwhelming majority of maintenance energy from glucose was by its anaerobicmetabolism in both rBHK and rCHO cell cultures. The overall maintenance coefficients from aerobicmetabolism were 1.9×10-13 mmol/(cell.h) for rCHO cells and 7×10-13 mmol/(cell.h) for rBHK cells. Inaddition, all Go/T and Eo/T gradually increased with the same trend as the cell growth in the culture ofboth rCHO and rBHK cells. The overall molecule yield coefficients of lactate to glucose were 1.61 for rCHO cells and 1.38 for rBHK cells. The yield coefficients of cell to glucose were 4.5×108 cells/mmol for rCHO cells and 1.9 × 108 cells/mmol for rBHK cells, respectively.

  20. A Consensus Genome-scale Reconstruction of Chinese Hamster Ovary Cell Metabolism

    DEFF Research Database (Denmark)

    Hefzi, Hooman; Ang, Kok Siong; Hanscho, Michael

    2016-01-01

    in CHO and associated them with >1,700 genes in the Cricetulus griseus genome. The genome-scale metabolic model based on this reconstruction, iCHO1766, and cell-line-specific models for CHO-K1, CHO-S, and CHO-DG44 cells provide the biochemical basis of growth and recombinant protein production......Chinese hamster ovary (CHO) cells dominate biotherapeutic protein production and are widely used in mammalian cell line engineering research. To elucidate metabolic bottlenecks in protein production and to guide cell engineering and bioprocess optimization, we reconstructed the metabolic pathways...... simulations show that the metabolic resources in CHO are more than three times more efficiently utilized for growth or recombinant protein synthesis following targeted efforts to engineer the CHO secretory pathway. This model will further accelerate CHO cell engineering and help optimize bioprocesses....

  1. Myristica fragrans Suppresses Tumor Growth and Metabolism by Inhibiting Lactate Dehydrogenase A.

    Science.gov (United States)

    Kim, Eun-Yeong; Choi, Hee-Jung; Park, Mi-Ju; Jung, Yeon-Seop; Lee, Syng-Ook; Kim, Keuk-Jun; Choi, Jung-Hye; Chung, Tae-Wook; Ha, Ki-Tae

    2016-01-01

    Most cancer cells predominantly produce ATP by maintaining a high rate of lactate fermentation, rather than by maintaining a comparatively low rate of tricarboxylic acid cycle, i.e., Warburg's effect. In the pathway, the pyruvate produced by glycolysis is converted to lactic acid by lactate dehydrogenase (LDH). Here, we demonstrated that water extracts from the seeds of Myristica fragrans Houtt. (MF) inhibit the in vitro enzymatic activity of LDH. MF effectively suppressed cell growth and the overall Warburg effect in HT29 human colon cancer cells. Although the expression of LDH-A was not changed by MF, both lactate production and LDH activity were decreased in MF-treated cells under both normoxic and hypoxic conditions. In addition, intracellular ATP levels were also decreased by MF treatment, and the uptake of glucose was also reduced by MF treatment. Furthermore, the experiment on tumor growth in the in vivo mice model revealed that MF effectively reduced the growth of allotransplanted Lewis lung carcinoma cells. Taken together, these results suggest that MF effectively inhibits cancer growth and metabolism by inhibiting the activity of LDH, a major enzyme responsible for regulating cancer metabolism. These results implicate MF as a potential candidate for development into a novel drug against cancer through inhibition of LDH activity.

  2. Catecholamines promote Actinobacillus pleuropneumoniae growth by regulating iron metabolism.

    Directory of Open Access Journals (Sweden)

    Lu Li

    Full Text Available Catecholamines are host stress hormones that can induce the growth of many bacteria by facilitating iron utilization and/or regulate the expression of virulence genes through specific hormone receptors. Whether these two responsive pathways are interconnected is unknown. In our previous study, it was found that catecholamines can regulate the expression of a great number of genes of Actinobacillus pleuropneumoniae, an important swine respiratory pathogen. However, bacterial growth was not affected by catecholamines in rich medium. In this study, it was discovered that catecholamines affected A. pleuropneumoniae growth in chemically defined medium (CDM. We found that serum inhibited A. pleuropneumoniae growth in CDM, while epinephrine, norepinephrine and dopamine promoted A. pleuropneumoniae growth in the CDM containing serum. The known bacterial hormone receptor QseC didn't play roles in this process. Ion-supplementation and transcriptome analysis indicated that serum addition resulted in iron-restricted conditions which were alleviated by the addition of catecholamines. Transferrin, one of the components in serum, inhibited the growth of A. pleuropneumoniae in CDM, an effect reversed by addition of catecholamines in a TonB2-dependent manner. Our data demonstrate that catecholamines promote A. pleuropneumoniae growth by regulating iron-acquisition and metabolism, which is independent of the adrenergic receptor QseC.

  3. Catecholamines promote Actinobacillus pleuropneumoniae growth by regulating iron metabolism.

    Science.gov (United States)

    Li, Lu; Chen, Zhaohui; Bei, Weicheng; Su, Zhipeng; Huang, Qi; Zhang, Liang; Chen, Huanchun; Zhou, Rui

    2015-01-01

    Catecholamines are host stress hormones that can induce the growth of many bacteria by facilitating iron utilization and/or regulate the expression of virulence genes through specific hormone receptors. Whether these two responsive pathways are interconnected is unknown. In our previous study, it was found that catecholamines can regulate the expression of a great number of genes of Actinobacillus pleuropneumoniae, an important swine respiratory pathogen. However, bacterial growth was not affected by catecholamines in rich medium. In this study, it was discovered that catecholamines affected A. pleuropneumoniae growth in chemically defined medium (CDM). We found that serum inhibited A. pleuropneumoniae growth in CDM, while epinephrine, norepinephrine and dopamine promoted A. pleuropneumoniae growth in the CDM containing serum. The known bacterial hormone receptor QseC didn't play roles in this process. Ion-supplementation and transcriptome analysis indicated that serum addition resulted in iron-restricted conditions which were alleviated by the addition of catecholamines. Transferrin, one of the components in serum, inhibited the growth of A. pleuropneumoniae in CDM, an effect reversed by addition of catecholamines in a TonB2-dependent manner. Our data demonstrate that catecholamines promote A. pleuropneumoniae growth by regulating iron-acquisition and metabolism, which is independent of the adrenergic receptor QseC.

  4. The metabolic landscape of cancer stem cells.

    Science.gov (United States)

    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.

  5. Re-thinking cell cycle regulators : the cross-talk with metabolism.

    Directory of Open Access Journals (Sweden)

    Lluis eFajas

    2013-01-01

    Full Text Available Analyses of genetically engineered mice deficient for cell cycle regulators, including E2F1, cdk4, or, pRB showed that the major phenotypes are metabolic perturbations. These key cell cycle regulators contribute to lipid synthesis, glucose production, insulin secretion, and glycolytic metabolism and it has been shown how deregulation of those pathways can lead to metabolic perturbations and related metabolic diseases, such as obesity and type II diabetes. The cyclin-cdk-Rb-E2F1 pathway regulates adipogenesis in addition to its well-described roles in cell cycle regulation and cancer. It was also proved that E2F1 directly participates in the regulation of pancreatic growth and function. Similarly, cyclin D3, cdk4, and cdk9 are also adipogenic factors with strong effects on whole organism metabolism. These examples illustrate the growing notion that cell cycle regulatory proteins can also modulate metabolic processes. Cell cycle regulators are activated by insulin and glucose, even in non-proliferating cells. Most importantly cell cycle regulators trigger the adaptive metabolic switch that normal and cancer cells require in order to proliferate. These changes include increased lipid synthesis, decreased oxidative, and increased glycolytic metabolism. In summary, cell cycle regulators are essential in the control of anabolic, biosynthetic processes, and block at the same time oxidative and catabolic pathways, which are the metabolic hallmarks of cancer.

  6. Cell signalling and phospholipid metabolism. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boss, W.F.

    1990-12-31

    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.

  7. Comparative metabolic pathway analysis with special reference to nucleotide metabolism-related genes in chicken primordial germ cells.

    Science.gov (United States)

    Rengaraj, Deivendran; Lee, Bo Ram; Jang, Hyun-Jun; Kim, Young Min; Han, Jae Yong

    2013-01-01

    Metabolism provides energy and nutrients required for the cellular growth, maintenance, and reproduction. When compared with genomics and proteomics, metabolism studies provide novel findings in terms of cellular functions. In this study, we examined significant and differentially expressed genes in primordial germ cells (PGCs), gonadal stromal cells, and chicken embryonic fibroblasts compared with blastoderms using microarray. All upregulated genes (1001, 1118, and 974, respectively) and downregulated genes (504, 627, and 1317, respectively) in three test samples were categorized into functional groups according to gene ontology. Then all selected genes were tested to examine their involvement in metabolic pathways through Kyoto Encyclopedia of Genes and Genomes pathway database using overrepresentation analysis. In our results, most of the upregulated and downregulated genes were involved in at least one subcategory of seven major metabolic pathways. The main objective of this study is to compare the PGC expressed genes and their metabolic pathways with blastoderms, gonadal stromal cells, and chicken embryonic fibroblasts. Among the genes involved in metabolic pathways, a higher number of PGC upregulated genes were identified in retinol metabolism, and a higher number of PGC downregulated genes were identified in sphingolipid metabolism. In terms of the fold change, acyl-CoA synthetase medium-chain family member 3 (ACSM3), which is involved in butanoate metabolism, and N-acetyltransferase, pineal gland isozyme NAT-10 (PNAT10), which is involved in energy metabolism, showed higher expression in PGCs. To validate these gene changes, the expression of 12 nucleotide metabolism-related genes in chicken PGCs was examined by real-time polymerase chain reaction. The results of this study provide new information on the expression of genes associated with metabolism function of PGCs and will facilitate more basic research on animal PGC differentiation and function

  8. Dynamic Metabolic Modeling of Denitrifying Bacterial Growth: The Cybernetic Approach

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hyun-Seob; Liu, Chongxuan

    2015-06-29

    Denitrification is a multistage reduction process converting nitrate ultimately to nitrogen gas, carried out mostly by facultative bacteria. Modeling of the denitrification process is challenging due to the complex metabolic regulation that modulates sequential formation and consumption of a series of nitrogen oxide intermediates, which serve as the final electron acceptors for denitrifying bacteria. In this work, we examined the effectiveness and accuracy of the cybernetic modeling framework in simulating the growth dynamics of denitrifying bacteria in comparison with kinetic models. In four different case studies using the literature data, we successfully simulated diauxic and triauxic growth patterns observed in anoxic and aerobic conditions, only by tuning two or three parameters. In order to understand the regulatory structure of the cybernetic model, we systematically analyzed the effect of cybernetic control variables on simulation accuracy. The results showed that the consideration of both enzyme synthesis and activity control through u- and v-variables is necessary and relevant and that uvariables are of greater importance in comparison to v-variables. In contrast, simple kinetic models were unable to accurately capture dynamic metabolic shifts across alternative electron acceptors, unless an inhibition term was additionally incorporated. Therefore, the denitrification process represents a reasonable example highlighting the criticality of considering dynamic regulation for successful metabolic modeling.

  9. Studies on growth, nitrogen and energy metabolism in rats

    DEFF Research Database (Denmark)

    Thorbek, G; Chwalibog, André; Eggum, B O

    1982-01-01

    Feed intake, growth, nitrogen retention and energy metabolism were measured in 12 male Wistar rats fed ad lib. for 14 weeks with non-purified diets. The feed intake increased rapidly in 4 weeks time from 16 g/d to 25 g/d, and then it was constant in the following 10 weeks. In relation to metabolic...... live weight the energy intake decreased from about 1400 to 800 kJ GE/kg0.75. With the high intake of energy the growth curve obtained is assumed to be near maximum level. The curve can be transformed to a linear one based on log days expressed as y, LW, g = -836 + 594 X log days with CV = 7.5% and r2...... = 0.968. The nitrogen retention increased from 200 to 300 mg N/d in period III when the rats 60 days old, and then it decreased in the following 10 weeks to about 100 mg N/d. In relation to metabolic live weight nitrogen retention is assumed to be near maximum level, decreasing from 1100 to 200 mg N...

  10. Metabolic effects of growth hormone administered subcutaneously once or twice daily to growth hormone deficient adults

    DEFF Research Database (Denmark)

    Laursen, Torben; Jørgensen, Jens Otto Lunde; Christiansen, Jens Sandahl

    1994-01-01

    -term metabolic effects in GH deficient patients. An improved growth response is obtained in GH deficient children when a fixed weekly GH dose is administered by daily subcutaneous injections instead of twice or thrice-weekly intramuscular injections. A more pulsatile pattern and serum GH levels above zero might...

  11. Two-compartment tumor metabolism: autophagy in the tumor microenvironment and oxidative mitochondrial metabolism (OXPHOS) in cancer cells.

    Science.gov (United States)

    Salem, Ahmed F; Whitaker-Menezes, Diana; Lin, Zhao; Martinez-Outschoorn, Ubaldo E; Tanowitz, Herbert B; Al-Zoubi, Mazhar Salim; Howell, Anthony; Pestell, Richard G; Sotgia, Federica; Lisanti, Michael P

    2012-07-01

    Previously, we proposed a new paradigm to explain the compartment-specific role of autophagy in tumor metabolism. In this model, autophagy and mitochondrial dysfunction in the tumor stroma promotes cellular catabolism, which results in the production of recycled nutrients. These chemical building blocks and high-energy "fuels" would then drive the anabolic growth of tumors, via autophagy resistance and oxidative mitochondrial metabolism in cancer cells. We have termed this new form of stromal-epithelial metabolic coupling: "two-compartment tumor metabolism." Here, we stringently tested this energy-transfer hypothesis, by genetically creating (1) constitutively autophagic fibroblasts, with mitochondrial dysfunction or (2) autophagy-resistant cancer cells, with increased mitochondrial function. Autophagic fibroblasts were generated by stably overexpressing key target genes that lead to AMP-kinase activation, such as DRAM and LKB1. Autophagy-resistant cancer cells were derived by overexpressing GOLPH3, which functionally promotes mitochondrial biogenesis. As predicted, DRAM and LKB1 overexpressing fibroblasts were constitutively autophagic and effectively promoted tumor growth. We validated that autophagic fibroblasts showed mitochondrial dysfunction, with increased production of mitochondrial fuels (L-lactate and ketone body accumulation). Conversely, GOLPH3 overexpressing breast cancer cells were autophagy-resistant, and showed signs of increased mitochondrial biogenesis and function, which resulted in increased tumor growth. Thus, autophagy in the tumor stroma and oxidative mitochondrial metabolism (OXPHOS) in cancer cells can both dramatically promote tumor growth, independently of tumor angiogenesis. For the first time, our current studies also link the DNA damage response in the tumor microenvironment with "Warburg-like" cancer metabolism, as DRAM is a DNA damage/repair target gene.

  12. Metabolic pathways in immune cell activation and quiescence.

    Science.gov (United States)

    Pearce, Erika L; Pearce, Edward J

    2013-04-18

    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, therefore, cells face choices as to 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, given that 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. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Hepatic growth hormone and glucocorticoid receptor signaling in body growth, steatosis and metabolic liver cancer development.

    Science.gov (United States)

    Mueller, Kristina M; Themanns, Madeleine; Friedbichler, Katrin; Kornfeld, Jan-Wilhelm; Esterbauer, Harald; Tuckermann, Jan P; Moriggl, Richard

    2012-09-25

    Growth hormone (GH) and glucocorticoids (GCs) are involved in the control of processes that are essential for the maintenance of vital body functions including energy supply and growth control. GH and GCs have been well characterized to regulate systemic energy homeostasis, particular during certain conditions of physical stress. However, dysfunctional signaling in both pathways is linked to various metabolic disorders associated with aberrant carbohydrate and lipid metabolism. In liver, GH-dependent activation of the transcription factor signal transducer and activator of transcription (STAT) 5 controls a variety of physiologic functions within hepatocytes. Similarly, GCs, through activation of the glucocorticoid receptor (GR), influence many important liver functions such as gluconeogenesis. Studies in hepatic Stat5 or GR knockout mice have revealed that they similarly control liver function on their target gene level and indeed, the GR functions often as a cofactor of STAT5 for GH-induced genes. Gene sets, which require physical STAT5-GR interaction, include those controlling body growth and maturation. More recently, it has become evident that impairment of GH-STAT5 signaling in different experimental models correlates with metabolic liver disease, ranging from hepatic steatosis to hepatocellular carcinoma (HCC). While GH-activated STAT5 has a protective role in chronic liver disease, experimental disruption of GC-GR signaling rather seems to ameliorate metabolic disorders under metabolic challenge. In this review, we focus on the current knowledge about hepatic GH-STAT5 and GC-GR signaling in body growth, metabolism, and protection from fatty liver disease and HCC development.

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

    Science.gov (United States)

    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.

  15. Growth kinetics of Thiobacillus ferrooxidans in bioelectrochemical cell

    Institute of Scientific and Technical Information of China (English)

    李宏煦; 王淀佐; 邱冠周; 胡岳华

    2004-01-01

    Thiobacillus ferrooxidans might be the most important bacteria used in biometallurgy. The foundation way of its growth process is oxidizing ferrous in order to obtain energy needed for metabolism, but the variation of ferrous concentration and mixed potential of the culture media would have crucial effect on the bacteria growth.Based on the characteristics of Thiobacillus ferrooxidans growth and redox potential of ferric and ferrous, an electrochemical cell was designed conventionally to study growth rule and the relationship between redox potential and bacteria growth was built up, and some growth kinetics of Thiobacillus ferrooxidans were elucidated. It demonstrates that the variation of open potential of electrochemical cell △E shows the growth tendency of Thiobacillus ferrooxidans, at the initial growth stage, the value of △E increases slowly, when at logistic growth stage, it increases drastically, and the growth rate of bacteria is linear with the oxidation rate of ferrous. The bacteria growth kinetics model is proposed using Monod and Michealis-Menten equation, and the kinetics parameters are got. The consistence of the measured and the calculated results proves that it is proper to use the proposed kinetics model and the electrochemical cell method to describe the growth rule of Thiobacillus ferrooxidans.

  16. Minimal sulfur requirement for growth and sulfur-dependent metabolism of the hyperthermophilic archaeon Staphylothermus marinus

    Directory of Open Access Journals (Sweden)

    Xiaolei Hao

    2003-01-01

    Full Text Available Staphylothermus marinus is an anaerobic hyperthermophilic archaeon that uses peptides as carbon and energy sources. Elemental sulfur (S° is obligately required for its growth and is reduced to H2S. The metabolic functions and mechanisms of S° reduction were explored by examining S°-dependent growth and activities of key enzymes present in this organism. All three forms of S° tested—sublimed S°, colloidal S° and polysulfide—were used by S. marinus, and no other sulfur-containing compounds could replace S°. Elemental sulfur did not serve as physical support but appeared to function as an electron acceptor. The minimal S° concentration required for optimal growth was 0.05% (w/v. At this concentration, there appeared to be a metabolic transition from H2 production to S° reduction. Some enzymatic activities related to S°-dependent metabolism, including sulfur reductase, hydrogenase, glutamate dehydrogenase and electron transfer activities, were detected in cell-free extracts of S. marinus. These results indicate that S° plays an essential role in the heterotrophic metabolism of S. marinus. Reducing equivalents generated by the oxidation of amino acids from peptidolysis may be transferred to sulfur reductase and hydrogenase, which then catalyze the production of H2S and H2, respectively.

  17. Effects of acetate on Kluyveromyces marxianus DSM 5422 growth and metabolism.

    Science.gov (United States)

    Martynova, Jekaterina; Kokina, Agnese; Kibilds, Juris; Liepins, Janis; Scerbaka, Rita; Vigants, Armands

    2016-05-01

    Metabolically active cells produce a wide array of metabolites that can inhibit their growth. Acetate is a widely known preservative, and it is also produced by yeast cells during their growth. Kluyveromyces marxianus DSM 5422 is a promising yeast strain that could be employed in biotechnological processes, but the knowledge of its stress physiology is scarce. Here, we investigate the effects of acetate on growth and changes in cell population structure during adaptation to elevated concentrations of acetate in K. marxianus DSM 5422. Our results indicate that acetate inhibits growth in a pH-dependent manner and has pronounced effects if yeast is grown on lactose or galactose. When challenged with acetate, culture extends lag phase, during which cells adapt to elevated acetate concentrations, and growth reoccurs, albeit at a slower rate, when majority of the population is acetate resistant. Acetate resistance is maintained only if acetate is present in the media or if the culture has reached end of active growth phase. This study shows possible caveats in lactose fermentation with K. marxianus and gives a further perspective in non-conventional yeast applications in biotechnology.

  18. Tumor metabolism: cancer cells give and take lactate.

    Science.gov (United States)

    Semenza, Gregg L

    2008-12-01

    Tumors contain well-oxygenated (aerobic) and poorly oxygenated (hypoxic) regions, which were thought to utilize glucose for oxidative and glycolytic metabolism, respectively. In this issue of the JCI, Sonveaux et al. show that human cancer cells cultured under hypoxic conditions convert glucose to lactate and extrude it, whereas aerobic cancer cells take up lactate via monocarboxylate transporter 1 (MCT1) and utilize it for oxidative phosphorylation (see the related article beginning on page 3930). When MCT1 is inhibited, aerobic cancer cells take up glucose rather than lactate, and hypoxic cancer cells die due to glucose deprivation. Treatment of tumor-bearing mice with an inhibitor of MCT1 retarded tumor growth. MCT1 expression was detected exclusively in nonhypoxic regions of human cancer biopsy samples, and in combination, these data suggest that MCT1 inhibition holds potential as a novel cancer therapy.

  19. Maximal sum of metabolic exchange fluxes outperforms biomass yield as a predictor of growth rate of microorganisms.

    Directory of Open Access Journals (Sweden)

    Raphy Zarecki

    Full Text Available Growth rate has long been considered one of the most valuable phenotypes that can be measured in cells. Aside from being highly accessible and informative in laboratory cultures, maximal growth rate is often a prime determinant of cellular fitness, and predicting phenotypes that underlie fitness is key to both understanding and manipulating life. Despite this, current methods for predicting microbial fitness typically focus on yields [e.g., predictions of biomass yield using GEnome-scale metabolic Models (GEMs] or notably require many empirical kinetic constants or substrate uptake rates, which render these methods ineffective in cases where fitness derives most directly from growth rate. Here we present a new method for predicting cellular growth rate, termed SUMEX, which does not require any empirical variables apart from a metabolic network (i.e., a GEM and the growth medium. SUMEX is calculated by maximizing the SUM of molar EXchange fluxes (hence SUMEX in a genome-scale metabolic model. SUMEX successfully predicts relative microbial growth rates across species, environments, and genetic conditions, outperforming traditional cellular objectives (most notably, the convention assuming biomass maximization. The success of SUMEX suggests that the ability of a cell to catabolize substrates and produce a strong proton gradient enables fast cell growth. Easily applicable heuristics for predicting growth rate, such as what we demonstrate with SUMEX, may contribute to numerous medical and biotechnological goals, ranging from the engineering of faster-growing industrial strains, modeling of mixed ecological communities, and the inhibition of cancer growth.

  20. Maximal sum of metabolic exchange fluxes outperforms biomass yield as a predictor of growth rate of microorganisms.

    Science.gov (United States)

    Zarecki, Raphy; Oberhardt, Matthew A; Yizhak, Keren; Wagner, Allon; Shtifman Segal, Ella; Freilich, Shiri; Henry, Christopher S; Gophna, Uri; Ruppin, Eytan

    2014-01-01

    Growth rate has long been considered one of the most valuable phenotypes that can be measured in cells. Aside from being highly accessible and informative in laboratory cultures, maximal growth rate is often a prime determinant of cellular fitness, and predicting phenotypes that underlie fitness is key to both understanding and manipulating life. Despite this, current methods for predicting microbial fitness typically focus on yields [e.g., predictions of biomass yield using GEnome-scale metabolic Models (GEMs)] or notably require many empirical kinetic constants or substrate uptake rates, which render these methods ineffective in cases where fitness derives most directly from growth rate. Here we present a new method for predicting cellular growth rate, termed SUMEX, which does not require any empirical variables apart from a metabolic network (i.e., a GEM) and the growth medium. SUMEX is calculated by maximizing the SUM of molar EXchange fluxes (hence SUMEX) in a genome-scale metabolic model. SUMEX successfully predicts relative microbial growth rates across species, environments, and genetic conditions, outperforming traditional cellular objectives (most notably, the convention assuming biomass maximization). The success of SUMEX suggests that the ability of a cell to catabolize substrates and produce a strong proton gradient enables fast cell growth. Easily applicable heuristics for predicting growth rate, such as what we demonstrate with SUMEX, may contribute to numerous medical and biotechnological goals, ranging from the engineering of faster-growing industrial strains, modeling of mixed ecological communities, and the inhibition of cancer growth.

  1. Tumor cell metabolism: the marriage of molecular genetics and proteomics with cellular intermediary metabolism; proceed with caution!

    Directory of Open Access Journals (Sweden)

    Franklin Renty B

    2006-11-01

    Full Text Available Abstract Metabolic transformations of malignant cells are essential to the development and progression of all cancers. The understanding of the pathogenesis and progression of cancer requires the establishment of the altered genetic/metabolic factors that are essential to the development, growth, and proliferation of the malignant cells. Recognition of this important relationship has resulted in a resurgence of interest in the intermediary metabolism of tumor cells. The role of molecular genetics and proteomics and the application of molecular technology in assessing altered cellular metabolism has become a major area of biomedical research. The contemporary generation of biomedical scientists is exceptionally well trained in all areas of molecular biology and molecular technology, which are now important tools to be applied to the regulation of cellular intermediary metabolism. Simultaneously, the didactic and methodological training associated with the principles and operation of metabolic pathways, enzymology, cellular enzyme activity, and associated biochemical implications has been diminished and often eliminated from the pre- and post-doctoral programs. Interpretations and conclusions of alterations in cellular enzyme activity and associated metabolic pathways based on genetic/proteomic changes can and will result in misrepresentation of important metabolic implications in malignancy and other diseases. It is essential that the genetic/proteomic studies be coupled to biochemical/metabolic cellular events to satisfy the axiom: "genetic transformations and proteomic alterations will have little relevancy to disease processes if the genetic/proteomic alterations are not manifested in altered and impaired cellular and metabolic function". The appropriate marriage of molecular genetics/proteomics with the regulation of cellular intermediary metabolism will provide new revelations and understanding of malignancy that could not be achieved in

  2. Metabolic features of the cell danger response.

    Science.gov (United States)

    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

  3. Effects of aluminum on organic acid metabolism and secretion by red spruce cell suspension cultures and the reversal of Al effects on growth and polyamine metabolism by exogenous organic acids

    Science.gov (United States)

    Rakesh Minocha; Stephanie Long

    2004-01-01

    In the absence of added Al, the concentration of succinate in cultured red spruce (Picea rubens Sarg.) cells was 15-20 times higher (> 600 nmol g-1FW) than that of citrate or oxalate and 4-6 times higher than that of malate. Addition of AICIJ (effective monomeric Al concentrations of 0.23 and 0.48...

  4. Docosahexaenoic acid attenuates breast cancer cell metabolism and the Warburg phenotype by targeting bioenergetic function.

    Science.gov (United States)

    Mouradian, Michael; Kikawa, Keith D; Dranka, Brian P; Komas, Steven M; Kalyanaraman, Balaraman; Pardini, Ronald S

    2015-09-01

    Docosahexaenoic acid (DHA; C22:6n-3) depresses mammary carcinoma proliferation and growth in cell culture and in animal models. The current study explored the role of interrupting bioenergetic pathways in BT-474 and MDA-MB-231 breast cancer cell lines representing respiratory and glycolytic phenotypes, respectively and comparing the impacts of DHA with a non-transformed cell line, MCF-10A. Metabolic investigation revealed that DHA supplementation significantly diminished the bioenergetic profile of the malignant cell lines in a dose-dependent manner. DHA enrichment also resulted in decreases in hypoxia-inducible factor (HIF-1α) total protein level and transcriptional activity in the malignant cell lines but not in the non-transformed cell line. Downstream targets of HIF-1α, including glucose transporter 1 (GLUT 1) and lactate dehydrogenase (LDH), were decreased by DHA treatment in the BT-474 cell line, as well as decreases in LDH protein level in the MDA-MB-231 cell line. Glucose uptake, total glucose oxidation, glycolytic metabolism, and lactate production were significantly decreased in response to DHA supplementation; thereby enhancing metabolic injury and decreasing oxidative metabolism. The DHA-induced metabolic changes led to a marked decrease of intracellular ATP levels by 50% in both cancer cell lines, which mediated phosphorylation of metabolic stress marker, AMPK, at Thr172. These findings show that DHA contributes to impaired cancer cell growth and survival by altering cancer cell metabolism, increasing metabolic stress and altering HIF-1α-associated metabolism, while not affecting non-transformed MCF-10A cells. This study provides rationale for enhancement of current cancer prevention models and current therapies by combining them with dietary sources, like DHA.

  5. Modeling core metabolism in cancer cells: surveying the topology underlying the Warburg effect.

    Directory of Open Access Journals (Sweden)

    Osbaldo Resendis-Antonio

    Full Text Available BACKGROUND: Alterations on glucose consumption and biosynthetic activity of amino acids, lipids and nucleotides are metabolic changes for sustaining cell proliferation in cancer cells. Irrevocable evidence of this fact is the Warburg effect which establishes that cancer cells prefers glycolysis over oxidative phosphorylation to generate ATP. Regulatory action over metabolic enzymes has opened a new window for designing more effective anti-cancer treatments. This enterprise is not trivial and the development of computational models that contribute to identifying potential enzymes for breaking the robustness of cancer cells is a priority. METHODOLOGY/PRINCIPAL FINDINGS: This work presents a constraint-base modeling of the most experimentally studied metabolic pathways supporting cancer cells: glycolysis, TCA cycle, pentose phosphate, glutaminolysis and oxidative phosphorylation. To evaluate its predictive capacities, a growth kinetics study for Hela cell lines was accomplished and qualitatively compared with in silico predictions. Furthermore, based on pure computational criteria, we concluded that a set of enzymes (such as lactate dehydrogenase and pyruvate dehydrogenase perform a pivotal role in cancer cell growth, findings supported by an experimental counterpart. CONCLUSIONS/SIGNIFICANCE: Alterations on metabolic activity are crucial to initiate and sustain cancer phenotype. In this work, we analyzed the phenotype capacities emerged from a constructed metabolic network conformed by the most experimentally studied pathways sustaining cancer cell growth. Remarkably, in silico model was able to resemble the physiological conditions in cancer cells and successfully identified some enzymes currently studied by its therapeutic effect. Overall, we supplied evidence that constraint-based modeling constitutes a promising computational platform to: 1 integrate high throughput technology and establish a crosstalk between experimental validation and in

  6. Influence of carbon and nitrogen sources on growth, nitrogenase activity, and carbon metabolism of Gluconacetobacter diazotrophicus.

    Science.gov (United States)

    Tejera, Noel A; Ortega, Eduardo; Rodés, Rosa; Lluch, Carmen

    2004-09-01

    The effects of different carbon and nitrogen sources on the growth, nitrogenase activity, and carbon metabolism of Gluconacetobacter diazotrophicus were investigated. The amino acids asparagine, aspartic acid, and glutamic acid affected microbial growth and nitrogenase activity. Several enzymatic activities involved in the tricarboxylic acid cycle were affected by the carbon source used. In addition, glucose and gluconate significantly increased the oxygen consumption (respiration rate) of whole cells of G. diazotrophicus grown under aerobic conditions. Enzymes responsible for direct oxidation of glucose and gluconate were especially active in cells grown with sucrose and gluconate. The presence of amino acids in the apoplastic and symplastic sap of sugarcane stems suggests that these compounds might be of importance in the regulation of growth and nitrogenase activity during the symbiotic association. The information obtained from the plant-bacterium association together with the results of other biochemical studies could contribute to the development of biotechnological applications of G. diazotrophicus.

  7. Growth signals, inflammation, and vascular perturbations: mechanistic links between obesity, metabolic syndrome, and cancer.

    Science.gov (United States)

    Hursting, Stephen D; Hursting, Marcie J

    2012-08-01

    Nearly 35% of adults and 20% of children in the United States are obese, defined as a body mass index ≥ 30 kg/m(2). Obesity, which is accompanied by metabolic dysregulation often manifesting in the metabolic syndrome, is an established risk factor for many cancers. Within the growth-promoting, proinflammatory environment of the obese state, cross talk between macrophages, adipocytes, and epithelial cells occurs via obesity-associated hormones, cytokines, and other mediators that may enhance cancer risk and progression. This review synthesizes the evidence on key biological mechanisms underlying the obesity-cancer link, with particular emphasis on obesity-associated enhancements in growth factor signaling, inflammation, and vascular integrity processes. These interrelated pathways represent possible mechanistic targets for disrupting the obesity-cancer link.

  8. Metabolic alterations in cancer cells and therapeutic implications

    Institute of Scientific and Technical Information of China (English)

    Naima Hammoudi; Kausar Begam Riaz Ahmed; Celia Garcia-Prieto; Peng Huang

    2011-01-01

    Cancer metabolism has emerged as an important area of research in recent years. Elucidation of the metabolic differences between cancer and normal cells and the underlying mechanisms will not only advance our understanding of fundamental cancer cell biology but also provide an important basis for the development of new therapeutic strategies and novel compounds to selectively eliminate cancer cells by targeting their unique metabolism. This article reviews several important metabolic alterations in cancer cells, with an emphasis on increased aerobic glycolysis (the Warburg effect) and glutamine addiction, and discusses the mechanisms that may contribute to such metabolic changes. In addition, metabolic alterations in cancer stem cells, mitochondrial metabolism and its influence on drug sensitivity, and potential therapeutic strategies and agents that target cancer metabolism are also discussed.

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

    Science.gov (United States)

    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. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Analysis of CHO cells metabolic redistribution in a glutamate-based defined medium in continuous culture.

    Science.gov (United States)

    Altamirano, C; Illanes, A; Casablancas, A; Gámez, X; Cairó, J J; Gòdia, C

    2001-01-01

    The effect of glutamine replacement by glutamate and the balance between glutamate and glucose metabolism on the redistribution of t-PA-producing recombinant CHO cells metabolism is studied in a series of glucose shift down and shift up experiments in continuous culture. These experiments reveal the existence of multiple steady states, and experimental data are used to perform metabolic flux analysis to gain a better insight into cellular metabolism and its redistribution. Regulation of glucose feed rate promotes a higher efficiency of glucose and nitrogen source utilization, with lower production of metabolic byproducts, but this reduces t-PA specific production rate. This reduction under glucose limitation can be attributed to the fact that the cells are forced to efficiently utilize the carbon and energy source for growth, impairing the production of dispensable metabolites. It is, therefore, the combination of growth rate and carbon and energy source availability that determines the level of t-PA production in continuous culture.

  11. Metabolism

    Science.gov (United States)

    ... a particular food provides to the body. A chocolate bar has more calories than an apple, so ... acid phenylalanine, needed for normal growth and protein production). Inborn errors of metabolism can sometimes lead to ...

  12. Ets-1 regulates energy metabolism in cancer cells.

    Directory of Open Access Journals (Sweden)

    Meghan L Verschoor

    Full Text Available Cancer cells predominantly utilize glycolysis for ATP production even in the presence of abundant oxygen, an environment that would normally result in energy production through oxidative phosphorylation. Although the molecular mechanism for this metabolic switch to aerobic glycolysis has not been fully elucidated, it is likely that mitochondrial damage to the electron transport chain and the resulting increased production of reactive oxygen species are significant driving forces. In this study, we have investigated the role of the transcription factor Ets-1 in the regulation of mitochondrial function and metabolism. Ets-1 was over-expressed using a stably-incorporated tetracycline-inducible expression vector in the ovarian cancer cell line 2008, which does not express detectable basal levels of Ets-1 protein. Microarray analysis of the effects of Ets-1 over-expression in these ovarian cancer cells shows that Ets-1 up-regulates key enzymes involved in glycolysis and associated feeder pathways, fatty acid metabolism, and antioxidant defense. In contrast, Ets-1 down-regulates genes involved in the citric acid cycle, electron transport chain, and mitochondrial proteins. At the functional level, we have found that Ets-1 expression is directly correlated with cellular oxygen consumption whereby increased expression causes decreased oxygen consumption. Ets-1 over-expression also caused increased sensitivity to glycolytic inhibitors, as well as growth inhibition in a glucose-depleted culture environment. Collectively our findings demonstrate that Ets-1 is involved in the regulation of cellular metabolism and response to oxidative stress in ovarian cancer cells.

  13. Metabolic Regulation and Coordination of the Metabolism in Bacteria in Response to a Variety of Growth Conditions.

    Science.gov (United States)

    Shimizu, Kazuyuki

    2016-01-01

    Living organisms have sophisticated but well-organized regulation system. It is important to understand the metabolic regulation mechanisms in relation to growth environment for the efficient design of cell factories for biofuels and biochemicals production. Here, an overview is given for carbon catabolite regulation, nitrogen regulation, ion, sulfur, and phosphate regulations, stringent response under nutrient starvation as well as oxidative stress regulation, redox state regulation, acid-shock, heat- and cold-shock regulations, solvent stress regulation, osmoregulation, and biofilm formation, and quorum sensing focusing on Escherichia coli metabolism and others. The coordinated regulation mechanisms are of particular interest in getting insight into the principle which governs the cell metabolism. The metabolism is controlled by both enzyme-level regulation and transcriptional regulation via transcription factors such as cAMP-Crp, Cra, Csr, Fis, P(II)(GlnB), NtrBC, CysB, PhoR/B, SoxR/S, Fur, MarR, ArcA/B, Fnr, NarX/L, RpoS, and (p)ppGpp for stringent response, where the timescales for enzyme-level and gene-level regulations are different. Moreover, multiple regulations are coordinated by the intracellular metabolites, where fructose 1,6-bisphosphate (FBP), phosphoenolpyruvate (PEP), and acetyl-CoA (AcCoA) play important roles for enzyme-level regulation as well as transcriptional control, while α-ketoacids such as α-ketoglutaric acid (αKG), pyruvate (PYR), and oxaloacetate (OAA) play important roles for the coordinated regulation between carbon source uptake rate and other nutrient uptake rate such as nitrogen or sulfur uptake rate by modulation of cAMP via Cya.

  14. Influence of long noncoding RNA HOTAIR on human glioma cell metabolism and growth%长链非编码RNA HOTAIR对人胶质瘤细胞代谢和生长的影响

    Institute of Scientific and Technical Information of China (English)

    魏文金; 韩东风; 李海林; 张军霞; 张雅旋; 胡奇; 李文涛; 俞天赋; 尤永平

    2015-01-01

    目的 探讨长链非编码RNA HOX转录反义RNA (HOX transcript antisense RNA,HOTAIR)对人脑胶质瘤细胞代谢和生长的影响.方法 采用荧光标记的小干扰HOTAIR (si-HOTAIR)转染胶质瘤U87和U251细胞株,通过实时定量荧光聚合酶链式反应(RT-PCR)检测HOTAIR在胶质瘤细胞中的表达水平;利用CCK8实验和克隆形成实验检测细胞的生长变化;采用海马生物公司糖酵解应激实验和线粒体应激实验试剂盒检测细胞有氧糖酵解和线粒体功能.通过Western blot检测有氧糖酵解相关酶[包括葡萄糖-6-磷酸异构酶(GPI)、丙酮酸激酶M2(PKM2)及乳酸脱氢酶A(LDHA)]的表达水平.结果 荧光显微镜下观察U87和U251细胞中si-HOTAIR转染效率均>90%.与阴性对照(NC)组比较,si-HOTAIR组细胞中HOTAIR的表达均明显下调(P<0.01);si-HOTAIR组U87和U251胶质瘤细胞的增殖能力和克隆形成能力明显低于NC组(P<0.01);下调HOTAIR后,胶质瘤细胞有氧糖酵解能力减弱,表现为基础糖酵解水平降低(P<0.05)、最大糖酵解能力减弱(P<0.01)及糖酵解剩储备量下降(P<0.01);si-HOTAIR组GPI、PKM2和LDHA表达水平较NC组降低(P<0.01).下调HOTAIR后,胶质瘤细胞线粒体功能受损,与NC组比较,表现为基础呼吸水平下降(其中U87细胞P<0.01)、线粒体偶联效率降低及剩余呼吸能力减弱(U87和U251组均P<0.05).结论 下调HOTAIR表达可以使人胶质瘤细胞糖酵解能力和线粒体功能受损,同时影响胶质瘤细胞的生长能力.%Objective To investigate the influence of long noncoding RNA HOX transcript antisense RNA (HOTAIR) on human glioma cell metabolism and growth.Methods The fluorescently labeled small interfering (si-HOTAIR) was used to transfect glioma U87 and U251 cell lines.The real-time polymerase chain reaction (RT-PCR) was used to detect the expression level of HOTAIR in glioma cells.CCK8 test and colony formation assay were used to detect the growth changes of

  15. Metabolic Hallmarks of Tumor and Immune Cells in the Tumor Microenvironment

    Science.gov (United States)

    Renner, Kathrin; Singer, Katrin; Koehl, Gudrun E.; Geissler, Edward K.; Peter, Katrin; Siska, Peter J.; Kreutz, Marina

    2017-01-01

    Cytotoxic T lymphocytes and NK cells play an important role in eliminating malignant tumor cells and the number and activity of tumor-infiltrating T cells represent a good marker for tumor prognosis. Based on these findings, immunotherapy, e.g., checkpoint blockade, has received considerable attention during the last couple of years. However, for the majority of patients, immune control of their tumors is gray theory as malignant cells use effective mechanisms to outsmart the immune system. Increasing evidence suggests that changes in tumor metabolism not only ensure an effective energy supply and generation of building blocks for tumor growth but also contribute to inhibition of the antitumor response. Immunosuppression in the tumor microenvironment is often based on the mutual metabolic requirements of immune cells and tumor cells. Cytotoxic T and NK cell activation leads to an increased demand for glucose and amino acids, a well-known feature shown by tumor cells. These close metabolic interdependencies result in metabolic competition, limiting the proliferation, and effector functions of tumor-specific immune cells. Moreover, not only nutrient restriction but also tumor-driven shifts in metabolite abundance and accumulation of metabolic waste products (e.g., lactate) lead to local immunosuppression, thereby facilitating tumor progression and metastasis. In this review, we describe the metabolic interplay between immune cells and tumor cells and discuss tumor cell metabolism as a target structure for cancer therapy. Metabolic (re)education of tumor cells is not only an approach to kill tumor cells directly but could overcome metabolic immunosuppression in the tumor microenvironment and thereby facilitate immunotherapy. PMID:28337200

  16. Metabolic Hallmarks of Tumor and Immune Cells in the Tumor Microenvironment.

    Science.gov (United States)

    Renner, Kathrin; Singer, Katrin; Koehl, Gudrun E; Geissler, Edward K; Peter, Katrin; Siska, Peter J; Kreutz, Marina

    2017-01-01

    Cytotoxic T lymphocytes and NK cells play an important role in eliminating malignant tumor cells and the number and activity of tumor-infiltrating T cells represent a good marker for tumor prognosis. Based on these findings, immunotherapy, e.g., checkpoint blockade, has received considerable attention during the last couple of years. However, for the majority of patients, immune control of their tumors is gray theory as malignant cells use effective mechanisms to outsmart the immune system. Increasing evidence suggests that changes in tumor metabolism not only ensure an effective energy supply and generation of building blocks for tumor growth but also contribute to inhibition of the antitumor response. Immunosuppression in the tumor microenvironment is often based on the mutual metabolic requirements of immune cells and tumor cells. Cytotoxic T and NK cell activation leads to an increased demand for glucose and amino acids, a well-known feature shown by tumor cells. These close metabolic interdependencies result in metabolic competition, limiting the proliferation, and effector functions of tumor-specific immune cells. Moreover, not only nutrient restriction but also tumor-driven shifts in metabolite abundance and accumulation of metabolic waste products (e.g., lactate) lead to local immunosuppression, thereby facilitating tumor progression and metastasis. In this review, we describe the metabolic interplay between immune cells and tumor cells and discuss tumor cell metabolism as a target structure for cancer therapy. Metabolic (re)education of tumor cells is not only an approach to kill tumor cells directly but could overcome metabolic immunosuppression in the tumor microenvironment and thereby facilitate immunotherapy.

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

    Science.gov (United States)

    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.

  18. Distinct metabolic responses of an ovarian cancer stem cell line.

    Science.gov (United States)

    Vermeersch, Kathleen A; Wang, Lijuan; McDonald, John F; Styczynski, Mark P

    2014-12-18

    Cancer metabolism is emerging as an important focus area in cancer research. However, the in vitro cell culture conditions under which much cellular metabolism research is performed differ drastically from in vivo tumor conditions, which are characterized by variations in the levels of oxygen, nutrients like glucose, and other molecules like chemotherapeutics. Moreover, it is important to know how the diverse cell types in a tumor, including cancer stem cells that are believed to be a major cause of cancer recurrence, respond to these variations. Here, in vitro environmental perturbations designed to mimic different aspects of the in vivo environment were used to characterize how an ovarian cancer cell line and its derived, isogenic cancer stem cells metabolically respond to environmental cues. Mass spectrometry was used to profile metabolite levels in response to in vitro environmental perturbations. Docetaxel, the chemotherapeutic used for this experiment, caused significant metabolic changes in amino acid and carbohydrate metabolism in ovarian cancer cells, but had virtually no metabolic effect on isogenic ovarian cancer stem cells. Glucose deprivation, hypoxia, and the combination thereof altered ovarian cancer cell and cancer stem cell metabolism to varying extents for the two cell types. Hypoxia had a much larger effect on ovarian cancer cell metabolism, while glucose deprivation had a greater effect on ovarian cancer stem cell metabolism. Core metabolites and pathways affected by these perturbations were identified, along with pathways that were unique to cell types or perturbations. The metabolic responses of an ovarian cancer cell line and its derived isogenic cancer stem cells differ greatly under most conditions, suggesting that these two cell types may behave quite differently in an in vivo tumor microenvironment. While cancer metabolism and cancer stem cells are each promising potential therapeutic targets, such varied behaviors in vivo would need to

  19. Cell longevity and sustained primary growth in palm stems.

    Science.gov (United States)

    Tomlinson, P Barry; Huggett, Brett A

    2012-12-01

    Longevity, or organismal life span, is determined largely by the period over which constituent cells can function metabolically. Plants, with modular organization (the ability continually to develop new organs and tissues) differ from animals, with unitary organization (a fixed body plan), and this difference is reflected in their respective life spans, potentially much longer in plants than animals. We draw attention to the observation that palm trees, as a group of monocotyledons without secondary growth comparable to that of lignophytes (plants with secondary growth from a bifacial cambium), retain by means of sustained primary growth living cells in their trunks throughout their organismal life span. Does this make palms the longest-lived trees because they can grow as individuals for several centuries? No conventional lignophyte retains living metabolically active differentiated cell types in its trunk for this length of time, even though the tree as a whole can exist for millennia. Does this contrast also imply that the long-lived cells in a palm trunk have exceptional properties, which allows this seeming immortality? We document the long-life of many tall palm species and their inherent long-lived stem cell properties, comparing such plants to conventional trees. We provide a summary of aspects of cell age and life span in animals and plants. Cell replacement is a feature of animal function, whereas conventional trees rely on active growth centers (meristems) to sustain organismal development. However, the long persistence of living cells in palm trunks is seen not as evidence for unique metabolic processes that sustain longevity, but is a consequence of unique constructional features. This conclusion suggests that the life span of plant cells is not necessarily genetically determined.

  20. Insights into the regulation of muscle metabolism and growth in mice and hibernating grizzly bears

    OpenAIRE

    Mugahid (Megahed), Douaa (Doaa)

    2015-01-01

    Mechanotransduction plays an important role in the regulation of muscle growth and metabolic signalling in striated muscle. Muscle disuse reduces mechanical input to the muscle, which results in a loss of muscle mass. Here I describe how titin's mechanically activated kinase domain affects muscle growth and metabolism via p62 and Akt signalling. I also demonstrate how changes in metabolic and growth signalling in hibernating grizzly bear help maintain muscle mass under conditio...

  1. Temperature dependence of metabolic rates for microbial growth, maintenance, and survival.

    Science.gov (United States)

    Price, P Buford; Sowers, Todd

    2004-03-30

    Our work was motivated by discoveries of prokaryotic communities that survive with little nutrient in ice and permafrost, with implications for past or present microbial life in Martian permafrost and Europan ice. We compared the temperature dependence of metabolic rates of microbial communities in permafrost, ice, snow, clouds, oceans, lakes, marine and freshwater sediments, and subsurface aquifer sediments. Metabolic rates per cell fall into three groupings: (i) a rate, microg(T), for growth, measured in the laboratory at in situ temperatures with minimal disturbance of the medium; (ii) a rate, microm(T), sufficient for maintenance of functions but for a nutrient level too low for growth; and (iii) a rate, micros(T), for survival of communities imprisoned in deep glacial ice, subsurface sediment, or ocean sediment, in which they can repair macromolecular damage but are probably largely dormant. The three groups have metabolic rates consistent with a single activation energy of approximately 110 kJ and that scale as microg(T):microm(T):micros(T) approximately 10(6):10(3):1. There is no evidence of a minimum temperature for metabolism. The rate at -40 degrees C in ice corresponds to approximately 10 turnovers of cellular carbon per billion years. Microbes in ice and permafrost have metabolic rates similar to those in water, soil, and sediment at the same temperature. This finding supports the view that, far below the freezing point, liquid water inside ice and permafrost is available for metabolism. The rate micros(T) for repairing molecular damage by means of DNA-repair enzymes and protein-repair enzymes such as methyltransferase is found to be comparable to the rate of spontaneous molecular damage.

  2. Sulfur amino acid metabolism limits the growth of children living in environments of poor sanitation.

    Science.gov (United States)

    Bickler, Stephen W; Ring, Jason; De Maio, Antonio

    2011-09-01

    Environmental enteropathy has been identified as a cause of poor growth in children living in low-income countries, but a mechanism has not been well defined. We suggest changes in sulfur amino acid metabolism can in part explain the poor growth and possibly the histological changes in the small bowel, which is the hallmark of environmental enteropathy. In environments of poor sanitation, where infection is common, we propose increased oxidative stress drives methionine metabolism toward cystathionine synthesis. This "cystathionine siphon" limits sulfur amino acids from participating in critical protein synthesis pathways. Increased expression of cystathionine β-synthase (CBS) could be one mechanism, as lipopolysaccharide and TNFα increase activity of this enzyme in vivo. CBS catalyzes the first of two steps in the transsulfuration pathway that converts homocysteine to cysteine. As enterocytes are one of the most rapidly proliferating cells in the body, we suggest diminished translation might also be important in the barrier failure observed in environmental enteropathy. Identifying sulfur amino acid metabolism as a mechanism leading to poor growth provides a new testable hypothesis for the undernutrition observed in children living in settings of poor sanitation.

  3. Growth control of the eukaryote cell: a systems biology study in yeast

    Directory of Open Access Journals (Sweden)

    Castrillo Juan I

    2007-04-01

    Full Text Available Abstract Background Cell growth underlies many key cellular and developmental processes, yet a limited number of studies have been carried out on cell-growth regulation. Comprehensive studies at the transcriptional, proteomic and metabolic levels under defined controlled conditions are currently lacking. Results Metabolic control analysis is being exploited in a systems biology study of the eukaryotic cell. Using chemostat culture, we have measured the impact of changes in flux (growth rate on the transcriptome, proteome, endometabolome and exometabolome of the yeast Saccharomyces cerevisiae. Each functional genomic level shows clear growth-rate-associated trends and discriminates between carbon-sufficient and carbon-limited conditions. Genes consistently and significantly upregulated with increasing growth rate are frequently essential and encode evolutionarily conserved proteins of known function that participate in many protein-protein interactions. In contrast, more unknown, and fewer essential, genes are downregulated with increasing growth rate; their protein products rarely interact with one another. A large proportion of yeast genes under positive growth-rate control share orthologs with other eukaryotes, including humans. Significantly, transcription of genes encoding components of the TOR complex (a major controller of eukaryotic cell growth is not subject to growth-rate regulation. Moreover, integrative studies reveal the extent and importance of post-transcriptional control, patterns of control of metabolic fluxes at the level of enzyme synthesis, and the relevance of specific enzymatic reactions in the control of metabolic fluxes during cell growth. Conclusion This work constitutes a first comprehensive systems biology study on growth-rate control in the eukaryotic cell. The results have direct implications for advanced studies on cell growth, in vivo regulation of metabolic fluxes for comprehensive metabolic engineering, and for

  4. Systems biology analysis of drivers underlying hallmarks of cancer cell metabolism

    Science.gov (United States)

    Zielinski, Daniel C.; Jamshidi, Neema; Corbett, Austin J.; Bordbar, Aarash; Thomas, Alex; Palsson, Bernhard O.

    2017-01-01

    Malignant transformation is often accompanied by significant metabolic changes. To identify drivers underlying these changes, we calculated metabolic flux states for the NCI60 cell line collection and correlated the variance between metabolic states of these lines with their other properties. The analysis revealed a remarkably consistent structure underlying high flux metabolism. The three primary uptake pathways, glucose, glutamine and serine, are each characterized by three features: (1) metabolite uptake sufficient for the stoichiometric requirement to sustain observed growth, (2) overflow metabolism, which scales with excess nutrient uptake over the basal growth requirement, and (3) redox production, which also scales with nutrient uptake but greatly exceeds the requirement for growth. We discovered that resistance to chemotherapeutic drugs in these lines broadly correlates with the amount of glucose uptake. These results support an interpretation of the Warburg effect and glutamine addiction as features of a growth state that provides resistance to metabolic stress through excess redox and energy production. Furthermore, overflow metabolism observed may indicate that mitochondrial catabolic capacity is a key constraint setting an upper limit on the rate of cofactor production possible. These results provide a greater context within which the metabolic alterations in cancer can be understood.

  5. Re-programming tumour cell metabolism to treat cancer: no lone target for lonidamine

    Science.gov (United States)

    Bhutia, Yangzom D.; Babu, Ellappan; Ganapathy, Vadivel

    2016-01-01

    Tumour cell metabolism is very different from normal cell metabolism; cancer cells re-programme the metabolic pathways that occur in normal cells in such a manner that it optimizes their proliferation, growth and survival. Although this metabolic re-programming obviously operates to the advantage of the tumour, it also offers unique opportunities for effective cancer therapy. Molecules that target the tumour cell-specific metabolic pathways have potential as novel anti-cancer drugs. Lonidamine belongs to this group of molecules and is already in use in some countries for cancer treatment. It has been known for a long time that lonidamine interferes with energy production in tumour cells by inhibiting hexokinase II (HKII), a glycolytic enzyme. However, subsequent studies have uncovered additional pharmacological targets for the drug, which include the electron transport chain and the mitochondrial permeability transition pore, thus expanding the pharmacological effects of the drug on tumour cell metabolism. A study by Nancolas et al. in a recent issue of the Biochemical Journal identifies two additional new targets for lonidamine: the pyruvate transporter in the mitochondria and the H+-coupled monocarboxylate transporters in the plasma membrane (PM). It is thus becoming increasingly apparent that the anti-cancer effects of lonidamine do not occur through a single target; the drug works at multiple sites. Irrespective of the molecular targets, what lonidamine does in the end is to undo what the tumour cells have done in terms of re-programming cellular metabolism and mitochondrial function. PMID:27234586

  6. Re-programming tumour cell metabolism to treat cancer: no lone target for lonidamine.

    Science.gov (United States)

    Bhutia, Yangzom D; Babu, Ellappan; Ganapathy, Vadivel

    2016-06-01

    Tumour cell metabolism is very different from normal cell metabolism; cancer cells re-programme the metabolic pathways that occur in normal cells in such a manner that it optimizes their proliferation, growth and survival. Although this metabolic re-programming obviously operates to the advantage of the tumour, it also offers unique opportunities for effective cancer therapy. Molecules that target the tumour cell-specific metabolic pathways have potential as novel anti-cancer drugs. Lonidamine belongs to this group of molecules and is already in use in some countries for cancer treatment. It has been known for a long time that lonidamine interferes with energy production in tumour cells by inhibiting hexokinase II (HKII), a glycolytic enzyme. However, subsequent studies have uncovered additional pharmacological targets for the drug, which include the electron transport chain and the mitochondrial permeability transition pore, thus expanding the pharmacological effects of the drug on tumour cell metabolism. A study by Nancolas et al. in a recent issue of the Biochemical Journal identifies two additional new targets for lonidamine: the pyruvate transporter in the mitochondria and the H(+)-coupled monocarboxylate transporters in the plasma membrane (PM). It is thus becoming increasingly apparent that the anti-cancer effects of lonidamine do not occur through a single target; the drug works at multiple sites. Irrespective of the molecular targets, what lonidamine does in the end is to undo what the tumour cells have done in terms of re-programming cellular metabolism and mitochondrial function.

  7. The cultural divide: exponential growth in classical 2D and metabolic equilibrium in 3D environments.

    Directory of Open Access Journals (Sweden)

    Krzysztof Wrzesinski

    Full Text Available INTRODUCTION: Cellular metabolism can be considered to have two extremes: one is characterized by exponential growth (in 2D cultures and the other by a dynamic equilibrium (in 3D cultures. We have analyzed the proteome and cellular architecture at these two extremes and found that they are dramatically different. RESULTS: Structurally, actin organization is changed, microtubules are increased and keratins 8 and 18 decreased. Metabolically, glycolysis, fatty acid metabolism and the pentose phosphate shunt are increased while TCA cycle and oxidative phosphorylation is unchanged. Enzymes involved in cholesterol and urea synthesis are increased consistent with the attainment of cholesterol and urea production rates seen in vivo. DNA repair enzymes are increased even though cells are predominantly in Go. Transport around the cell--along the microtubules, through the nuclear pore and in various types of vesicles has been prioritized. There are numerous coherent changes in transcription, splicing, translation, protein folding and degradation. The amount of individual proteins within complexes is shown to be highly coordinated. Typically subunits which initiate a particular function are present in increased amounts compared to other subunits of the same complex. SUMMARY: We have previously demonstrated that cells at dynamic equilibrium can match the physiological performance of cells in tissues in vivo. Here we describe the multitude of protein changes necessary to achieve this performance.

  8. Growth-related Metabolism of the Carbon Storage Poly-3-hydroxybutyrate in Legionella pneumophila.

    Science.gov (United States)

    Gillmaier, Nadine; Schunder, Eva; Kutzner, Erika; Tlapák, Hana; Rydzewski, Kerstin; Herrmann, Vroni; Stämmler, Maren; Lasch, Peter; Eisenreich, Wolfgang; Heuner, Klaus

    2016-03-18

    Legionella pneumophila, the causative agent of Legionnaires disease, has a biphasic life cycle with a switch from a replicative to a transmissive phenotype. During the replicative phase, the bacteria grow within host cells in Legionella-containing vacuoles. During the transmissive phenotype and the postexponential (PE) growth phase, the pathogens express virulence factors, become flagellated, and leave the Legionella-containing vacuoles. Using (13)C labeling experiments, we now show that, under in vitro conditions, serine is mainly metabolized during the replicative phase for the biosynthesis of some amino acids and for energy generation. During the PE phase, these carbon fluxes are reduced, and glucose also serves as an additional carbon substrate to feed the biosynthesis of poly-3-hydroxybuyrate (PHB), an essential carbon source for transmissive L. pneumophila. Whole-cell FTIR analysis and comparative isotopologue profiling further reveal that a putative 3-ketothiolase (Lpp1788) and a PHB polymerase (Lpp0650), but not enzymes of the crotonyl-CoA pathway (Lpp0931-0933) are involved in PHB metabolism during the PE phase. However, the data also reflect that additional bypassing reactions for PHB synthesis exist in agreement with in vivo competition assays using Acanthamoeba castellannii or human macrophage-like U937 cells as host cells. The data suggest that substrate usage and PHB metabolism are coordinated during the life cycle of the pathogen.

  9. Effect of Growth factors, estradiol 17-ß, and short chain fatty acids on the intestinal HT29-MTX cells

    DEFF Research Database (Denmark)

    Giromini, Carlotta; Baldi, Antonella; Fusi, Eleonora

    2015-01-01

    studies. The effect of insulin-like growth factors (IGF)-I, epidermal growth factors (EGF), transforming growth factor alpha (TGF-α), transforming growth factor beta (TGF-β), estradiol 17-β and butyrate, propionate, and acetate was assessed on metabolic activity and proliferation of E12 cells using Alamar...... of the cells. Further, a dose-dependent inhibition of cell metabolic activity was detected in the presence of all SCFAs tested. Butyrate showed to be the most active in the inhibition of E12 metabolic activity and its effect was enhanced by the presence of propionate and acetate. E12 cells, in undifferentiated...

  10. Approaches to Optimizing Animal Cell Culture Process: Substrate Metabolism Regulation and Protein Expression Improvement

    Science.gov (United States)

    Zhang, Yuanxing

    Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.

  11. Approaches to optimizing animal cell culture process: substrate metabolism regulation and protein expression improvement.

    Science.gov (United States)

    Zhang, Yuanxing

    2009-01-01

    Some high value proteins and vaccines for medical and veterinary applications by animal cell culture have an increasing market in China. In order to meet the demands of large-scale productions of proteins and vaccines, animal cell culture technology has been widely developed. In general, an animal cell culture process can be divided into two stages in a batch culture. In cell growth stage a high specific growth rate is expected to achieve a high cell density. In production stage a high specific production rate is stressed for the expression and secretion of qualified protein or replication of virus. It is always critical to maintain high cell viability in fed-batch and perfusion cultures. More concern has been focused on two points by the researchers in China. First, the cell metabolism of substrates is analyzed and the accumulation of toxic by-products is decreased through regulating cell metabolism in the culture process. Second, some important factors effecting protein expression are understood at the molecular level and the production ability of protein is improved. In pace with the rapid development of large-scale cell culture for the production of vaccines, antibodies and other recombinant proteins in China, the medium design and process optimization based on cell metabolism regulation and protein expression improvement will play an important role. The chapter outlines the main advances in metabolic regulation of cell and expression improvement of protein in animal cell culture in recent years.

  12. Metabolic changes associated with methionine stress sensitivity in MDA-MB-468 breast cancer cells.

    Science.gov (United States)

    Borrego, Stacey L; Fahrmann, Johannes; Datta, Rupsa; Stringari, Chiara; Grapov, Dmitry; Zeller, Michael; Chen, Yumay; Wang, Ping; Baldi, Pierre; Gratton, Enrico; Fiehn, Oliver; Kaiser, Peter

    2016-01-01

    The majority of cancer cells have a unique metabolic requirement for methionine that is not observed in normal, non-tumorigenic cells. This phenotype is described as "methionine dependence" or "methionine stress sensitivity" in which cancer cells are unable to proliferate when methionine has been replaced with its metabolic precursor, homocysteine, in cell culture growth media. We focus on the metabolic response to methionine stress in the triple negative breast cancer cell line MDA-MB-468 and its methionine insensitive derivative cell line MDA-MB-468res-R8. Using a variety of techniques including fluorescence lifetime imaging microscopy (FLIM) and extracellular flux assays, we identified a metabolic down-regulation of oxidative phosphorylation in both MDA-MB-468 and MDA-MB-468res-R8 cell types when cultured in homocysteine media. Untargeted metabolomics was performed by way of gas chromatography/time-of-flight mass spectrometry on both cell types cultured in homocysteine media over a period of 2 to 24 h. We determined unique metabolic responses between the two cell lines in specific pathways including methionine salvage, purine/pyrimidine synthesis, and the tricarboxylic acid cycle. Stable isotope tracer studies using deuterium-labeled homocysteine indicated a redirection of homocysteine metabolism toward the transsulfuration pathway and glutathione synthesis. This data corroborates with increased glutathione levels concomitant with increased levels of oxidized glutathione. Redirection of homocysteine flux resulted in reduced generation of methionine from homocysteine particularly in MDA-MB-468 cells. Consequently, synthesis of the important one-carbon donor S-adenosylmethionine (SAM) was decreased, perturbing the SAM to S-adenosylhomocysteine ratio in MDA-MB-468 cells, which is an indicator of the cellular methylation potential. This study indicates a differential metabolic response between the methionine sensitive MDA-MB-468 cells and the methionine insensitive

  13. Toxicity of graphene oxide on growth and metabolism of Pseudomonas putida.

    Science.gov (United States)

    Combarros, R G; Collado, S; Díaz, M

    2016-06-05

    The increasing consumption of graphene derivatives leads to greater presence of these materials in wastewater treatment plants and ecological systems. The toxicity effect of graphene oxide (GO) on the microbial functions involved in the biological wastewater treatment process is studied, using Pseudomonas putida and salicylic acid (SA) as bacterial and pollutant models. A multiparametric flow cytometry (FC) method has been developed to measure the metabolic activity and viability of P. putida in contact with GO. A continuous reduction in the percentages of viable cells and a slight increase, lower than 5%, in the percentages of damaged and dead cells, suggest that P. putida in contact with GO loses the membrane integrity but preserves metabolic activity. The growth of P. putida was strongly inhibited by GO, since 0.05mgmL(-1) of GO reduced the maximum growth by a third, and the inhibition was considerably greater for GO concentrations higher than 0.1mgmL(-1). The specific SA removal rate decreased with GO concentration up to 0.1mgmL(-1) indicating that while GO always reduces the growth of P. putida, for concentrations higher than 0.1mgmL(-1), it also reduces its activity. Similar behaviour is observed using simulated urban and industrial wastewaters, the observed effects being more acute in the industrial wastewaters.

  14. On size and growth of cells

    CERN Document Server

    Boudaoud, A

    2002-01-01

    Understanding how growth induces form is a longstanding biological question. Many studies concentrated on the shapes of plant cells, fungi or bacteria. Some others have shown the importance of the mechanical properties of bacterial walls and plant tissues in pattern formation. Here I sketch a simple physical picture of cell growth. The study is focussed on isolated cells that have walls. They are modeled as thin elastic shells containing a liquid, which pressure drives the growth as generally admitted for bacteria or plant cells. Requiring mechanical equilibrium leads to estimations of typical cell sizes, in quantitative agreement with compiled data including bacteria, cochlear outer hair, fungi, yeast, root hair and giant alga cells.

  15. A dynamic model of tomato fruit growth integrating cell division, cell growth and endoreduplication

    NARCIS (Netherlands)

    Fanwoua, J.; Visser, de P.H.B.; Heuvelink, E.; Yin, X.; Struik, P.C.; Marcelis, L.F.M.

    2013-01-01

    In this study, we developed a model of tomato (Solanum lycopersicum L.) fruit growth integrating cell division, cell growth and endoreduplication. The fruit was considered as a population of cells grouped in cell classes differing in their initial cell age and cell mass. The model describes fruit gr

  16. [Metabolic characterization of rat sertoli cell in vitro culture].

    Science.gov (United States)

    Shi, Bingyang; Zhang, Shuxiang; Guo, Meijin; Wang, Yonghong; Zhang, Siliang; Shi, Xiaolin

    2009-05-01

    Sertoli cell (SC) is intrinsic to the testis and provides an appropriate growth environment for the germ cells. It was separated from rat's testis and identified by hematoxylin and eosin staining(HE) and immunocytochemical reaction, then cultivated in vitro. Culture conditions such as pH, osmotic pressure and metabolic parameters that include consumption rates of glucose, glutamine, amino acids and formation rates of lactic acid, ammonium ion were investigated. It was showed that adhesion process of SCs was accomplished within 2-4 hours after inoculation. It was also observed that the SCs entered into the decline phase when the concentration of ammonium ion and lactic acid were above 2.3 mmol/L and 14 mmol/L, respectively, which caused osmotic pressure above 326 mosm/kg and pH below 6.8 in the medium. As the changes of amino acids during culture were concerned, Glu and Ala accumulated rapidly, while Val, Leu, Ile reduced slightly and at the same time Ser, Arg, and Gly were stable. The restrict factors for SCs grown in static culture might be high osmotic pressure and low pH, which were generated when glutamine and glucose were metabolized into lactic acid. The findings could be fundamental in the process optimization of large scale Sertoli cells in vitro culture.

  17. Growth and Metabolism of the Green Alga, Chlorella Pyrenoidosa, in Simulated Microgravity

    Science.gov (United States)

    Mills, W. Ronald

    2003-01-01

    The effect of microgravity on living organisms during space flight has been a topic of interest for some time, and a substantial body of knowledge on the subject has accumulated. Despite this, comparatively little information is available regarding the influence of microgravity on algae, even though it has been suggested for long duration flight or occupancy in space that plant growth systems, including both higher plants and algae, are likely to be necessary for bioregenerative life support systems. High-Aspect-Ratio Rotating-Wall Vessel or HARV bioreactors developed at Johnson Space Center provide a laboratory-based approach to investigating the effects of microgravity on cellular reactions. In this study, the HARV bioreactor was used to examine the influence of simulated microgravity on the growth and metabolism of the green alga, Chlorella pyrenoidosa. After the first 2 days of culture, cell numbers increased more slowly in simulated microgravity than in the HARV gravity control; after 7 days, growth in simulated microgravity was just over half (58%) that of the gravity control and at 14 days it was less than half (42%). Chlorophyll and protein were also followed as indices of cell competence and function; as with growth, after 2-3 days, protein and chlorophyll levels were reduced in modeled microgravity compared to gravity controls. Photosynthesis is a sensitive biochemical index of the fitness of photosynthetic organisms; thus, CO2-dependent O2 evolution was tested as a measure of photosynthetic capacity of cells grown in simulated microgravity. When data were expressed with respect to cell number, modeled microgravity appeared to have little effect on CO2 fixation. Thus, even though the overall growth rate was lower for cells cultured in microgravity, the photosynthetic capacity of the cells appears to be unaffected. Cells grown in simulated microgravity formed loose clumps or aggregates within about 2 days of culture, with aggregation increasing over time

  18. Skeletal and metabolic complications of testicular germ cell tumours.

    NARCIS (Netherlands)

    Willemse, Peter-Paul Michiel

    2014-01-01

    The studies described in this thesis were performed to investigate the short and long-term effects of chemotherapy on bone metabolism, fat metabolism and cardiovascular risk in testicular germ cell tumour (GCT) patients. We report a twofold increased prevalence of Metabolic Syndrome (MetS) in GCT

  19. OVCAR-3 spheroid-derived cells display distinct metabolic profiles.

    Directory of Open Access Journals (Sweden)

    Kathleen A Vermeersch

    Full Text Available 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.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.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.Overall, we demonstrate for the first time that metabolism

  20. Metabolism correlates with variation in post-natal growth rate among songbirds at three latitudes

    Science.gov (United States)

    Ton, Riccardo; Martin, Thomas E.

    2016-01-01

    1. Variation in post-natal growth rates is substantial among organisms and especially strong among latitudes because tropical and south temperate species typically have slower growth than north temperate relatives. Metabolic rate is thought to be a critical mechanism underlying growth rates after accounting for allometric effects of body mass. However, comparative tests on a large spatial scale are lacking, and the importance of metabolism for growth rates remains unclear both within and particularly across latitudes.

  1. Energy metabolism and metabolic sensors in stem cells: the metabostem crossroads of aging and cancer.

    Science.gov (United States)

    Menendez, Javier A; Joven, Jorge

    2014-01-01

    We are as old as our adult stem cells are; therefore, stem cell exhaustion is considered a hallmark of aging. Our tumors are as aggressive as the number of cancer stem cells (CSCs) they bear because CSCs can survive treatments with hormones, radiation, chemotherapy, and molecularly targeted drugs, thus increasing the difficulty of curing cancer. Not surprisingly, interest in stem cell research has never been greater among members of the public, politicians, and scientists. But how can we slow the rate at which our adult stem cells decline over our lifetime, reducing the regenerative potential of tissues, while efficiently eliminating the aberrant, life-threatening activity of "selfish", immortal, and migrating CSCs? Frustrated by the gene-centric limitations of conventional approaches to aging diseases, our group and other groups have begun to appreciate that bioenergetic metabolism, i.e., the production of fuel & building blocks for growth and division, and autophagy/mitophagy, i.e., the quality-control, self-cannibalistic system responsible for "cleaning house" and "recycling the trash", can govern the genetic and epigenetic networks that facilitate stem cell behaviors. Indeed, it is reasonable to suggest the existence of a "metabostem" infrastructure that operates as a shared hallmark of aging and cancer, thus making it physiologically plausible to maintain or even increase the functionality of adult stem cells while reducing the incidence of cancer and extending the lifespan. This "metabostemness" property could lead to the discovery of new drugs that reprogram cell metabotypes to increase the structural and functional integrity of adult stem cells and positively influence their lineage determination, while preventing the development and aberrant function of stem cells in cancer tissues. While it is obvious that the antifungal antibiotic rapamycin, the polyphenol resveratrol, and the biguanide metformin already belong to this new family of metabostemness

  2. Nucleoside transporters and liver cell growth

    National Research Council Canada - National Science Library

    Valdés, Raquel; Mata, João F; Del Santo, Belén; Pastor-Anglada, Marçal; Felipe, Antonio; Casado, F Javier

    1998-01-01

    .... This review summarizes work performed in our laboratory on these transport systems, particularly nucleoside transporters, which are up-regulated in physiological situations associated with liver cell growth...

  3. A Consensus Genome-scale Reconstruction of Chinese Hamster Ovary Cell Metabolism

    KAUST Repository

    Hefzi, Hooman

    2016-11-23

    Chinese hamster ovary (CHO) cells dominate biotherapeutic protein production and are widely used in mammalian cell line engineering research. To elucidate metabolic bottlenecks in protein production and to guide cell engineering and bioprocess optimization, we reconstructed the metabolic pathways in CHO and associated them with >1,700 genes in the Cricetulus griseus genome. The genome-scale metabolic model based on this reconstruction, iCHO1766, and cell-line-specific models for CHO-K1, CHO-S, and CHO-DG44 cells provide the biochemical basis of growth and recombinant protein production. The models accurately predict growth phenotypes and known auxotrophies in CHO cells. With the models, we quantify the protein synthesis capacity of CHO cells and demonstrate that common bioprocess treatments, such as histone deacetylase inhibitors, inefficiently increase product yield. However, our simulations show that the metabolic resources in CHO are more than three times more efficiently utilized for growth or recombinant protein synthesis following targeted efforts to engineer the CHO secretory pathway. This model will further accelerate CHO cell engineering and help optimize bioprocesses.

  4. From Ancient Pathways to Aging Cells-Connecting Metabolism and Cellular Senescence.

    Science.gov (United States)

    Wiley, Christopher D; Campisi, Judith

    2016-06-14

    Cellular senescence is a complex stress response that permanently arrests the proliferation of cells at risk for oncogenic transformation. However, senescent cells can also drive phenotypes associated with aging. Although the senescence-associated growth arrest prevents the development of cancer, and the metabolism of cancer cells has been studied in depth, the metabolic causes and consequences of cellular senescence were largely unexplored until recently. New findings reveal key roles for several aspects of cellular metabolism in the establishment and control of senescent phenotypes. These discoveries have important implications for both cancer and aging. In this review, we highlight some of the recent links between metabolism and phenotypes that are commonly associated with senescent cells.

  5. Alterations in cancer cell metabolism: the Warburg effect and metabolic adaptation.

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Aerobic degradation of trichloroethylene by co-metabolism using phenol and gasoline as growth substrates.

    Science.gov (United States)

    Li, Yan; Li, Bing; Wang, Cui-Ping; Fan, Jun-Zhao; Sun, Hong-Wen

    2014-05-22

    Trichloroethylene (TCE) is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26×10⁷ cell/mL), initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE)/mg (biomass) and 5.1 μg (TCE)/mg (phenol), respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%). When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively). This study provides a promising approach for the removal of combined pollution of TCE and gasoline.

  7. Aerobic Degradation of Trichloroethylene by Co-Metabolism Using Phenol and Gasoline as Growth Substrates

    Directory of Open Access Journals (Sweden)

    Yan Li

    2014-05-01

    Full Text Available Trichloroethylene (TCE is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26 × 107 cell/mL, initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE/mg (biomass and 5.1 μg (TCE/mg (phenol, respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%. When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively. This study provides a promising approach for the removal of combined pollution of TCE and gasoline.

  8. Rapid increase in fibroblast growth factor 21 in protein malnutrition and its impact on growth and lipid metabolism.

    Science.gov (United States)

    Ozaki, Yori; Saito, Kenji; Nakazawa, Kyoko; Konishi, Morichika; Itoh, Nobuyuki; Hakuno, Fumihiko; Takahashi, Shin-Ichiro; Kato, Hisanori; Takenaka, Asako

    2015-11-14

    Protein malnutrition promotes hepatic steatosis, decreases insulin-like growth factor (IGF)-I production and retards growth. To identify new molecules involved in such changes, we conducted DNA microarray analysis on liver samples from rats fed an isoenergetic low-protein diet for 8 h. We identified the fibroblast growth factor 21 gene (Fgf21) as one of the most strongly up-regulated genes under conditions of acute protein malnutrition (P<0·05, false-discovery rate<0·001). In addition, amino acid deprivation increased Fgf21 mRNA levels in rat liver-derived RL-34 cells (P<0·01). These results suggested that amino acid limitation directly increases Fgf21 expression. FGF21 is a polypeptide hormone that regulates glucose and lipid metabolism. FGF21 also promotes a growth hormone-resistance state and suppresses IGF-I in transgenic mice. Therefore, to determine further whether Fgf21 up-regulation causes hepatic steatosis and growth retardation after IGF-I decrease in protein malnutrition, we fed an isoenergetic low-protein diet to Fgf21-knockout (KO) mice. Fgf21-KO did not rescue growth retardation and reduced plasma IGF-I concentration in these mice. Fgf21-KO mice showed greater epididymal white adipose tissue weight and increased hepatic TAG and cholesterol levels under protein malnutrition conditions (P<0·05). Overall, the results showed that protein deprivation directly increased Fgf21 expression. However, growth retardation and decreased IGF-I were not mediated by increased FGF21 expression in protein malnutrition. Furthermore, FGF21 up-regulation rather appears to have a protective effect against obesity and hepatic steatosis in protein-malnourished animals.

  9. From gametogenesis and stem cells to cancer: common metabolic themes.

    Science.gov (United States)

    Pereira, Sandro L; Rodrigues, Ana Sofia; Sousa, Maria Inês; Correia, Marcelo; Perestrelo, Tânia; Ramalho-Santos, João

    2014-01-01

    Both pluripotent stem cells (PSCs) and cancer cells have been described as having similar metabolic pathways, most notably a penchant for favoring glycolysis even under aerobiosis, suggesting common themes that might be explored for both stem cell differentiation and anti-oncogenic purposes. A search of the scientific literature available in the PubMed/Medline was conducted for studies on metabolism and mitochondrial function related to gametogenesis, early development, stem cells and cancers in the reproductive system, notably breast, prostate, ovarian and testicular cancers. Both PSCs and some types of cancer cells, particularly reproductive cancers, were found to obtain energy mostly by glycolysis, often reducing mitochondrial activity and oxidative phosphorylation. This strategy links proliferating cells, allowing for the biosynthesis reactions necessary for cell division. Interventions that affect metabolic pathways, and force cells to change their preferences, can lead to shifts in cell status, increasing either pluripotency or differentiation of stem cells, and causing cancer cells to become more or less aggressive. Interestingly metabolic changes in many cases seemed to lead to cell transformation, not necessarily follow it, suggesting a direct role of metabolic choices in influencing the (epi)genetic program of different cell types. There are uncanny similarities between PSCs and cancer cells at the metabolic level. Furthermore, metabolism may also play a direct role in cell status and targeting metabolic pathways could therefore be a promising strategy for both the control of cancer cell proliferation and the regulation of stem cell physiology, in terms of manipulating stem cells toward relevant phenotypes that may be important for tissue engineering, or making cancer cells become less tumorigenic. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For

  10. GROWTH DIFFERENTIATION FACTOR-5 STIMULATES THE GROWTH AND ANABOLIC METABOLISM OF ARTICULAR CHONDROCYTES

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective To observe the effect of growth differentiation factor-5 (GDF-5) on the growth and anabolic metabolism of articular chondrocytes. Methods The articular chondrocytes isolated from rats were treated with various concentrations of rmGDF-5, and the growth of chondrocytes measured by MTT assay, the cellular cartilage matrices formation detected sulfated glycosaminoglycan by Alcian blue staining and type Ⅱcollagen by RT-PCR. Results After 7 days culture, MTT assay showed that GDF-5 enhanced the growth of chondrocytes in a dose-dependent manner, RT-PCR showed that GDF-5 clearly induced the synthesis of type Ⅱ collagen because of the col2a1 mRNA band more and more strong in a dose-dependent. Chondrocytes were cultured with GDF-5 for 14 days, the intensity of Alcian blue staining was greatly enhanced, especially, at a high concentration of blue-stainable material in a concentration-dependent manner and in a does-dependent manner. Conclusion GDF-5 enhanced the growth of mature articular chondrocytes, and stimulated the cellular cartilage matrices formation in mono-layer culture.

  11. Growth differentiation factor-5 stimulates the growth and anabolic metabolism of articular chondrocytes

    Institute of Scientific and Technical Information of China (English)

    Xu Peng; Guo Xiong; Yao Jianfeng; Zhang Yingang; Klaus von der Mark

    2005-01-01

    Objective: To observe the effect of growth differentiation factor-5 (GDF-5) on the growth and anabolic metabolism of articular chondrocytes. Methods: The articular chondrocytes isolated from rats were treated with various concentrations of rmGDF-5, and the growth of chondrocytes measured by MTT assay, the cellular cartilage matrices formation detected sulfated glycosaminoglycan by Alcian blue staining and type Ⅱ collagen by RT-PCR,the collagen phenotypic expression of chondrocytes detected by immunofluorescence. Results: After 7 days culture,MTT assay showed that GDF-5 enhanced the growth of chondrocytes in a dose-dependent manner, RT-PCR showed that GDF-5 clearly induced the synthesis of type Ⅱ collagen because of the col2a1 mRNA band more and more strong in a dose-dependent. Chondrocytes were cultured with GDF-5 for 14 days, the intensity of Alcian blue staining was greatly enhanced, especially, at a high concentration of 1000ng/ml, and GDF-5 enhanced the accumulation of the Alcian blue-stainable material in a concentration-dependent manner and in a does-dependent manner. Chondrocytes were cultured with GDF-5 for 21 days, immunofluorescent staining of type Ⅱ collagen was clear, the type Ⅰ and X collagen were negative. Conclusion: GDF-5 enhanced the growth of mature articular chondrocytes, and stimulated the cellular cartilage matrices formation, but did not change the collagen phenotypic expression of chondrocytes in mono-layer culture.

  12. Growth Differentiation Factor-5 Stimulates the Growth and Anabolic Metabolism of Articular Chondrocytes

    Institute of Scientific and Technical Information of China (English)

    Xu Peng; Yao Jianfeng; Guo Xiong; Zhang Yingang; Klaus von der Mark

    2009-01-01

    Objective: To observe the effect of growth differentiation factor-5 (GDF-5) on the growth and anabolic metabolism of articular chondrocytes. Methods: The articular chondrocytes isolated from rats were treated with various concentrations of rmGDF-5, and the growth of chondrocytes measured by MTr assay, the cellular cartilage matrices formation detected sulfated glycosaminoglycan by Alcian blue staining and type 11 collagen by RT-PCR, the collagen phenotypic expression of chondrocytes detected by immunofluorescence. Results: After 7 days culture, MTF assay showed that GDF-5 enhanced the growth of ehondrocytes in a dose-dependent manner, RT-PCR showed that GDF-5 clearly induced the synthesis of type Ⅱ collagen because of the colal mRNA band more and more strong in a dose-dependent. Chondrocytes were cultured with GDF-5 for 14 days, the intensity of Alcian blue staining was gready enhanced, especially, at a high concentration of 1000ng/ml, and GDF-5 enhanced the accumulation of the Alcian blue-stainable material in a concentration-dependent manner and in a does-dependent manner. Chondrocytes were cultured with GDF-5 for 21 days, immunofluorescent staining of type Ⅱ collagen was clear, the type Ⅰ and Ⅹ collagen were negative. Conclusion: GDF-5 enhanced the growth of mature articular chon-drocytes, and stimulated the cellular cartilage matrices formation, but did not change the collagen phenotypic ex-pression of chondrocytes in mono-layer culture.

  13. Stochastic Gompertz model of tumour cell growth.

    Science.gov (United States)

    Lo, C F

    2007-09-21

    In this communication, based upon the deterministic Gompertz law of cell growth, a stochastic model in tumour growth is proposed. This model takes account of both cell fission and mortality too. The corresponding density function of the size of the tumour cells obeys a functional Fokker--Planck equation which can be solved analytically. It is found that the density function exhibits an interesting "multi-peak" structure generated by cell fission as time evolves. Within this framework the action of therapy is also examined by simply incorporating a therapy term into the deterministic cell growth term.

  14. Effects of subacute hypothyroidism on metabolism and growth-related molecules.

    Science.gov (United States)

    Chang, Yen-Jui; Hwu, Chii-Min; Yeh, Chii-Chang; Wang, Paulus S; Wang, Shyi-Wu

    2014-07-30

    Thyroid hormones are crucial hormones that primarily regulate the metabolism of entire body cells. In this study, Sprague-Dawley rats were grouped into sham thyroidectomy (Sham Tx), thyroidectomy (Tx), Tx with thyroxine replacement (Tx + T4), and PTU injection (PTU) groups. Metabolic parameters were measured by means of metabolic cages for 14 days. After 14 days, the rats were sacrificed while the levels of plasma or serum TSH and growth-related molecules, such as active and total ghrelin, GH, and IGF-1, were assayed. The results revealed that hypothyroid rats tended to eat less food and experienced substantial body weight gain, whereas the rats with T4 replacement tended to eat more food while continuing to lose weight. In hypothyroid rats, the growth-related molecules, such as active ghrelin and total ghrelin secretion, were enhanced, and the ghrelin receptors were also up-regulated. However, circulating GH levels were not elevated and IGF-1 secretion was inhibited in hypothyroid rats. In the Tx + T4 group, the changes of active ghrelin, total ghrelin, GHS-R expression, and IGF-1 were reversed, whereas the GH secretion was higher than that of the Sham Tx group and hypothyroid groups. This study resulted in the novel finding that the ghrelin/GHS-R axis and GH/IGF-1 axis are interrupted in hypothyroid rats.

  15. Effects of Subacute Hypothyroidism on Metabolism and Growth-Related Molecules

    Directory of Open Access Journals (Sweden)

    Yen-Jui Chang

    2014-07-01

    Full Text Available Thyroid hormones are crucial hormones that primarily regulate the metabolism of entire body cells. In this study, Sprague-Dawley rats were grouped into sham thyroidectomy (Sham Tx, thyroidectomy (Tx, Tx with thyroxine replacement (Tx + T4, and PTU injection (PTU groups. Metabolic parameters were measured by means of metabolic cages for 14 days. After 14 days, the rats were sacrificed while the levels of plasma or serum TSH and growth-related molecules, such as active and total ghrelin, GH, and IGF-1, were assayed. The results revealed that hypothyroid rats tended to eat less food and experienced substantial body weight gain, whereas the rats with T4 replacement tended to eat more food while continuing to lose weight. In hypothyroid rats, the growth-related molecules, such as active ghrelin and total ghrelin secretion, were enhanced, and the ghrelin receptors were also up-regulated. However, circulating GH levels were not elevated and IGF-1 secretion was inhibited in hypothyroid rats. In the Tx + T4 group, the changes of active ghrelin, total ghrelin, GHS-R expression, and IGF-1 were reversed, whereas the GH secretion was higher than that of the Sham Tx group and hypothyroid groups. This study resulted in the novel finding that the ghrelin/GHS-R axis and GH/IGF-1 axis are interrupted in hypothyroid rats.

  16. Relationship between photosynthetic metabolism and cell cycle in a synchronized culture of the marine alga Cylindrotheca fusiformis (Bacillariophyceae)

    NARCIS (Netherlands)

    Claquin, P.; Kromkamp, J.C.; Martin-Jezequel, V.

    2004-01-01

    The aim of this study was to characterize the variation and regulation of photosynthetic carbon metabolism in Cylindrotheca fusiformis during the cell cycle. The cells were synchronized using two cell cycle inhibitors: one for cells grown under light:dark cycles and one for growth in continuous

  17. Relationship between photosynthetic metabolism and cell cycle in a synchronized culture of the marine alga Cylindrotheca fusiformis (Bacillariophyceae)

    NARCIS (Netherlands)

    Claquin, P.; Kromkamp, J.C.; Martin-Jezequel, V.

    2004-01-01

    The aim of this study was to characterize the variation and regulation of photosynthetic carbon metabolism in Cylindrotheca fusiformis during the cell cycle. The cells were synchronized using two cell cycle inhibitors: one for cells grown under light:dark cycles and one for growth in continuous ligh

  18. Kaposi's sarcoma herpesvirus microRNAs induce metabolic transformation of infected cells.

    Directory of Open Access Journals (Sweden)

    Ohad Yogev

    2014-09-01

    Full Text Available Altered cell metabolism is inherently connected with pathological conditions including cancer and viral infections. Kaposi's sarcoma-associated herpesvirus (KSHV is the etiological agent of Kaposi's sarcoma (KS. KS tumour cells display features of lymphatic endothelial differentiation and in their vast majority are latently infected with KSHV, while a small number are lytically infected, producing virions. Latently infected cells express only a subset of viral genes, mainly located within the latency-associated region, among them 12 microRNAs. Notably, the metabolic properties of KSHV-infected cells closely resemble the metabolic hallmarks of cancer cells. However, how and why KSHV alters host cell metabolism remains poorly understood. Here, we investigated the effect of KSHV infection on the metabolic profile of primary dermal microvascular lymphatic endothelial cells (LEC and the functional relevance of this effect. We found that the KSHV microRNAs within the oncogenic cluster collaborate to decrease mitochondria biogenesis and to induce aerobic glycolysis in infected cells. KSHV microRNAs expression decreases oxygen consumption, increase lactate secretion and glucose uptake, stabilize HIF1α and decreases mitochondria copy number. Importantly this metabolic shift is important for latency maintenance and provides a growth advantage. Mechanistically we show that KSHV alters host cell energy metabolism through microRNA-mediated down regulation of EGLN2 and HSPA9. Our data suggest that the KSHV microRNAs induce a metabolic transformation by concurrent regulation of two independent pathways; transcriptional reprograming via HIF1 activation and reduction of mitochondria biogenesis through down regulation of the mitochondrial import machinery. These findings implicate viral microRNAs in the regulation of the cellular metabolism and highlight new potential avenues to inhibit viral latency.

  19. Cell-selective metabolic labeling of biomolecules with bioorthogonal functionalities.

    Science.gov (United States)

    Xie, Ran; Hong, Senlian; Chen, Xing

    2013-10-01

    Metabolic labeling of biomolecules with bioorthogonal functionalities enables visualization, enrichment, and analysis of the biomolecules of interest in their physiological environments. This versatile strategy has found utility in probing various classes of biomolecules in a broad range of biological processes. On the other hand, metabolic labeling is nonselective with respect to cell type, which imposes limitations for studies performed in complex biological systems. Herein, we review the recent methodological developments aiming to endow metabolic labeling strategies with cell-type selectivity. The cell-selective metabolic labeling strategies have emerged from protein and glycan labeling. We envision that these strategies can be readily extended to labeling of other classes of biomolecules.

  20. Growth of Yersinia pseudotuberculosis in human plasma: impacts on virulence and metabolic gene expression

    Directory of Open Access Journals (Sweden)

    Coppée Jean-Yves

    2008-12-01

    Full Text Available Abstract Background In man, infection by the Gram-negative enteropathogen Yersinia pseudotuberculosis is usually limited to the terminal ileum. However, in immunocompromised patients, the microorganism may disseminate from the digestive tract and thus cause a systemic infection with septicemia. Results To gain insight into the metabolic pathways and virulence factors expressed by the bacterium at the blood stage of pseudotuberculosis, we compared the overall gene transcription patterns (the transcriptome of bacterial cells cultured in either human plasma or Luria-Bertani medium. The most marked plasma-triggered metabolic consequence in Y. pseudotuberculosis was the switch to high glucose consumption, which is reminiscent of the acetogenic pathway (known as "glucose overflow" in Escherichia coli. However, upregulation of the glyoxylate shunt enzymes suggests that (in contrast to E. coli acetate may be further metabolized in Y. pseudotuberculosis. Our data also indicate that the bloodstream environment can regulate major virulence genes (positively or negatively; the yadA adhesin gene and most of the transcriptional units of the pYV-encoded type III secretion apparatus were found to be upregulated, whereas transcription of the pH6 antigen locus was strongly repressed. Conclusion Our results suggest that plasma growth of Y. pseudotuberculosis is responsible for major transcriptional regulatory events and prompts key metabolic reorientations within the bacterium, which may in turn have an impact on virulence.

  1. Lactate promotes glutamine uptake and metabolism in oxidative cancer cells

    OpenAIRE

    Pérez-Escuredo, Jhudit; Dadhich, Rajesh K.; Dhup, Suveera; Cacace, Andrea; Van Hée, Vincent F.; De Saedeleer, Christophe J; Sboarina, Martina; Rodriguez, Fabien; Fontenille, Marie-Joséphine; Brisson, Lucie; Porporato, Paolo E.; Sonveaux, Pierre

    2015-01-01

    Oxygenated cancer cells have a high metabolic plasticity as they can use glucose, glutamine and lactate as main substrates to support their bioenergetic and biosynthetic activities. Metabolic optimization requires integration. While glycolysis and glutaminolysis can cooperate to support cellular proliferation, oxidative lactate metabolism opposes glycolysis in oxidative cancer cells engaged in a symbiotic relation with their hypoxic/glycolytic neighbors. However, little is known concerning th...

  2. Effects of Growth Hormone and Insulin-Like Growth Factor-1 on Postoperative Muscle and Substrate Metabolism

    Directory of Open Access Journals (Sweden)

    Folke Hammarqvist

    2010-01-01

    To conclude, growth factors influences urea metabolism, protein degradation and protein synthesis. There was no clearcut additional effect when combining GH and IGF-1 but the study was probably underpowered to outrule this and effects on nitrogen balance.

  3. DRUM: a new framework for metabolic modeling under non-balanced growth. Application to the carbon metabolism of unicellular microalgae.

    Directory of Open Access Journals (Sweden)

    Caroline Baroukh

    Full Text Available Metabolic modeling is a powerful tool to understand, predict and optimize bioprocesses, particularly when they imply intracellular molecules of interest. Unfortunately, the use of metabolic models for time varying metabolic fluxes is hampered by the lack of experimental data required to define and calibrate the kinetic reaction rates of the metabolic pathways. For this reason, metabolic models are often used under the balanced growth hypothesis. However, for some processes such as the photoautotrophic metabolism of microalgae, the balanced-growth assumption appears to be unreasonable because of the synchronization of their circadian cycle on the daily light. Yet, understanding microalgae metabolism is necessary to optimize the production yield of bioprocesses based on this microorganism, as for example production of third-generation biofuels. In this paper, we propose DRUM, a new dynamic metabolic modeling framework that handles the non-balanced growth condition and hence accumulation of intracellular metabolites. The first stage of the approach consists in splitting the metabolic network into sub-networks describing reactions which are spatially close, and which are assumed to satisfy balanced growth condition. The left metabolites interconnecting the sub-networks behave dynamically. Then, thanks to Elementary Flux Mode analysis, each sub-network is reduced to macroscopic reactions, for which simple kinetics are assumed. Finally, an Ordinary Differential Equation system is obtained to describe substrate consumption, biomass production, products excretion and accumulation of some internal metabolites. DRUM was applied to the accumulation of lipids and carbohydrates of the microalgae Tisochrysis lutea under day/night cycles. The resulting model describes accurately experimental data obtained in day/night conditions. It efficiently predicts the accumulation and consumption of lipids and carbohydrates.

  4. DRUM: A New Framework for Metabolic Modeling under Non-Balanced Growth. Application to the Carbon Metabolism of Unicellular Microalgae

    Science.gov (United States)

    Baroukh, Caroline; Muñoz-Tamayo, Rafael; Steyer, Jean-Philippe; Bernard, Olivier

    2014-01-01

    Metabolic modeling is a powerful tool to understand, predict and optimize bioprocesses, particularly when they imply intracellular molecules of interest. Unfortunately, the use of metabolic models for time varying metabolic fluxes is hampered by the lack of experimental data required to define and calibrate the kinetic reaction rates of the metabolic pathways. For this reason, metabolic models are often used under the balanced growth hypothesis. However, for some processes such as the photoautotrophic metabolism of microalgae, the balanced-growth assumption appears to be unreasonable because of the synchronization of their circadian cycle on the daily light. Yet, understanding microalgae metabolism is necessary to optimize the production yield of bioprocesses based on this microorganism, as for example production of third-generation biofuels. In this paper, we propose DRUM, a new dynamic metabolic modeling framework that handles the non-balanced growth condition and hence accumulation of intracellular metabolites. The first stage of the approach consists in splitting the metabolic network into sub-networks describing reactions which are spatially close, and which are assumed to satisfy balanced growth condition. The left metabolites interconnecting the sub-networks behave dynamically. Then, thanks to Elementary Flux Mode analysis, each sub-network is reduced to macroscopic reactions, for which simple kinetics are assumed. Finally, an Ordinary Differential Equation system is obtained to describe substrate consumption, biomass production, products excretion and accumulation of some internal metabolites. DRUM was applied to the accumulation of lipids and carbohydrates of the microalgae Tisochrysis lutea under day/night cycles. The resulting model describes accurately experimental data obtained in day/night conditions. It efficiently predicts the accumulation and consumption of lipids and carbohydrates. PMID:25105494

  5. A high-throughput method for quantifying metabolically active yeast cells

    DEFF Research Database (Denmark)

    Nandy, Subir Kumar; Knudsen, Peter Boldsen; Rosenkjær, Alexander

    2015-01-01

    By redesigning the established methylene blue reduction test for bacteria and yeast, we present a cheap and efficient methodology for quantitative physiology of eukaryotic cells applicable for high-throughput systems. Validation of themethod in fermenters and highthroughput systems proved...... equivalent, displaying reduction curves that interrelated directly with CFU counts. For growth rate estimation, the methylene blue reduction test (MBRT) proved superior, since the discriminatory nature of the method allowed for the quantification of metabolically active cells only, excluding dead cells...

  6. Cell energy budget platform for assessment of cell metabolism.

    Science.gov (United States)

    Papkovsky, Dmitri B; Zhdanov, Alexander V

    2015-01-01

    Changes in bioenergetic parameters report on metabolic rearrangement, dysfunction of major pathways, and regulatory processes within the cell, adaptation to energy stress, or new physiological condition. A combined measurement of oxidative phosphorylation, glycolytic flux, the Krebs cycle activity, ATP levels, and total biomass allows detailed metabolic assessment. We describe a simple methodology for high-throughput multiparametric assessment of cell bioenergetics, called cell energy budget (CEB) platform, and demonstrate its practical use with cell models. The CEB relies on a standard multi-label reader with time-resolved fluorescence capabilities, the lanthanide probe pH-Xtra™ to measure extracellular acidification (ECA) associated with lactate (L-ECA) and combined lactate/CO2 (T-ECA) extrusion, the phosphorescent probe MitoXpress®-Xtra to measure oxygen consumption rate (OCR), the bioluminescent total ATP assay, and absorbance-based total protein assay. This approach can be further extended with the measurement of other cellular parameters, such as NAD(P)H, Ca(2+), mitochondrial pH, membrane potential, and redox state, using the corresponding fluorescent or luminescent probes.

  7. Loss of the tumor suppressor LKB1 promotes metabolic reprogramming of cancer cells via HIF-1α.

    Science.gov (United States)

    Faubert, Brandon; Vincent, Emma E; Griss, Takla; Samborska, Bozena; Izreig, Said; Svensson, Robert U; Mamer, Orval A; Avizonis, Daina; Shackelford, David B; Shaw, Reuben J; Jones, Russell G

    2014-02-18

    One of the major metabolic changes associated with cellular transformation is enhanced nutrient utilization, which supports tumor progression by fueling both energy production and providing biosynthetic intermediates for growth. The liver kinase B1 (LKB1) is a serine/threonine kinase and tumor suppressor that couples bioenergetics to cell-growth control through regulation of mammalian target of rapamycin (mTOR) activity; however, the influence of LKB1 on tumor metabolism is not well defined. Here, we show that loss of LKB1 induces a progrowth metabolic program in proliferating cells. Cells lacking LKB1 display increased glucose and glutamine uptake and utilization, which support both cellular ATP levels and increased macromolecular biosynthesis. This LKB1-dependent reprogramming of cell metabolism is dependent on the hypoxia-inducible factor-1α (HIF-1α), which accumulates under normoxia in LKB1-deficient cells and is antagonized by inhibition of mTOR complex I signaling. Silencing HIF-1α reverses the metabolic advantages conferred by reduced LKB1 signaling and impairs the growth and survival of LKB1-deficient tumor cells under low-nutrient conditions. Together, our data implicate the tumor suppressor LKB1 as a central regulator of tumor metabolism and growth control through the regulation of HIF-1α-dependent metabolic reprogramming.

  8. AspC-mediated aspartate metabolism coordinates the Escherichia coli cell cycle.

    Directory of Open Access Journals (Sweden)

    Feng Liu

    Full Text Available The fast-growing bacterial cell cycle consists of at least two independent cycles of chromosome replication and cell division. To ensure proper cell cycles and viability, chromosome replication and cell division must be coordinated. It has been suggested that metabolism could affect the Escherichia coli cell cycle, but the idea is still lacking solid evidences.We found that absence of AspC, an aminotransferase that catalyzes synthesis of aspartate, led to generation of small cells with less origins and slow growth. In contrast, excess AspC was found to exert the opposite effect. Further analysis showed that AspC-mediated aspartate metabolism had a specific effect in the cell cycle, as only extra aspartate of the 20 amino acids triggered production of bigger cells with more origins per cell and faster growth. The amount of DnaA protein per cell was found to be changed in response to the availability of AspC. Depletion of (pppGpp by ΔrelAΔspoT led to a slight delay in initiation of replication, but did not change the replication pattern found in the ΔaspC mutant.The results suggest that AspC-mediated metabolism of aspartate coordinates the E. coli cell cycle through altering the amount of the initiator protein DnaA per cell and the division signal UDP-glucose. Furthermore, AspC sequence conservation suggests similar functions in other organisms.

  9. Impact of Stroma on the Growth, Microcirculation, Metabolism of Experimental Prostate Tumors

    Directory of Open Access Journals (Sweden)

    Christian M. Zechmann

    2007-01-01

    Full Text Available In prostate cancers (PCa, the formation of malignant stroma may substantially influence tumor phenotype and aggressiveness. Thus, the impact of the orthotopic and subcutaneous implantations of hormone-sensitive (H, hormone-insensitive (HI, anaplastic (AT1 Dunning PCa in rats on growth, microcirculation, metabolism was investigated. For this purpose, dynamic contrast-enhanced magnetic resonance imaging and 1H magnetic resonance spectroscopy ([1H]MRS were applied in combination with histology. Consistent observations revealed that orthotopic H tumors grew significantly slower compared to subcutaneous ones, whereas the growth of HI and AT1 tumors was comparable at both locations. Histologic analysis indicated that glandular differentiation and a close interaction of tumor cells and smooth muscle cells (SMC were associated with slow tumor growth. Furthermore, there was a significantly lower SMC density in subcutaneous H tumors than in orthotopic H tumors. Perfusion was observed to be significantly lower in orthotopic H tumors than in subcutaneous H tumors. Regional blood volume and permeability-surface area product showed no significant differences between tumor models and their implantation sites. Differences in growth between subcutaneous and orthotopic H tumors can be attributed to tumor-stroma interaction and perfusion. Here, SMC, may stabilize glandular structures and contribute to the maintenance of differentiated phenotype.

  10. Metabolic profiles of planktonic and biofilm cells of Candida orthopsilosis.

    Science.gov (United States)

    Pires, Regina Helena; Cataldi, Thaís Regiani; Franceschini, Livia Maria; Labate, Mônica Veneziano; Fusco-Almeida, Ana Marisa; Labate, Carlos Alberto; Palma, Mario Sérgio; Soares Mendes-Giannini, Maria José

    2016-10-01

    This study aims to understand which Candida orthopsilosis protein aids fungus adaptation upon its switching from planktonic growth to biofilm. Ion mobility separation within mass spectrometry analysis combination were used. Proteins mapped for different biosynthetic pathways showed that selective ribosome autophagy might occur in biofilms. Glucose, used as a carbon source in the glycolytic flux, changed to glycogen and trehalose. Candida orthopsilosis expresses proteins that combine a variety of mechanisms to provide yeasts with the means to adjust the catalytic properties of enzymes. Adjustment of the enzymes helps modulate the biosynthesis/degradation rates of the available nutrients, in order to control and coordinate the metabolic pathways that enable cells to express an adequate response to nutrient availability.

  11. Effect of arginase II on L-arginine depletion and cell growth in murine cell lines of renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Patterson John R

    2008-09-01

    Full Text Available Abstract Background L-arginine is the common substrate for the two isoforms of arginase. Arginase I, highly expressed in the liver and arginase II mainly expressed in the kidney. Arginase I-producing myeloid derived suppressor cells have been shown to inhibit T-cell function by the depletion of L-arginine. On the other hand, arginase II has been detected in patients with cancer and is thought to metabolize L-arginine to L-ornithine needed to sustain rapid tumor growth; however its role in L-arginine depletion is unclear. Thus, in tumor biology, L-arginine metabolism may play a dual role in tumor growth and in the induction of T cell dysfunction. Therefore, we studied in murine renal cell carcinoma (RCC cell lines, the effect of arginase II on tumor cell proliferation and L-arginine depletion. The effect of arginase inhibitors on cell proliferation was also tested. Methods Three murine renal cell carcinoma (mRCC cell lines were tested for the presence of arginase. nor-NOHA, an arginase inhibitor was used to substantiate the effect of arginase on cell growth and L-arginine depletion. Amino acid levels were tested by HPLC. Results Our results show that mRCC cell lines express only arginase II and were able to deplete L-arginine from the medium. Cell growth was independent of the amount of arginase activity expressed by the cells. nor-NOHA significantly (P = 0.01 reduced arginase II activity and suppressed cell growth in cells exhibiting high arginase activity. The depletion of L-arginine by mRCC induced the decrease expression of CD3ζ a key element for T-cell function. Conclusion The results of this study show for the first time that arginase II produced by RCC cell lines depletes L-arginine resulting in decreased expression of CD3ζ. These results indicate that RCC cell lines expressing arginase II can modulate the L-arginine metabolic pathway to regulate both cell growth and T-cell function. Blocking arginase may lead to a decrease in RCC cell

  12. Optimal design of metabolic flux analysis experiments for anchorage-dependent mammalian cells using a cellular automaton model.

    Science.gov (United States)

    Meadows, Adam L; Roy, Siddhartha; Clark, Douglas S; Blanch, Harvey W

    2007-09-01

    Metabolic flux analysis (MFA) is widely used to quantify metabolic pathway activity. Typical applications involve isotopically labeled substrates, which require both metabolic and isotopic steady states for simplified data analysis. For bacterial systems, these steady states are readily achieved in chemostat cultures. However, mammalian cells are often anchorage dependent and experiments are typically conducted in batch or fed-batch systems, such as tissue culture dishes or microcarrier-containing bioreactors. Surface adherence may cause deviations from exponential growth, resulting in metabolically heterogeneous populations and a varying number of cellular "nearest neighbors" that may affect the observed metabolism. Here, we discuss different growth models suitable for deconvoluting these effects and their application to the design and optimization of MFA experiments employing surface-adherent mammalian cells. We describe a stochastic two-dimensional (2D) cellular automaton model, with empirical descriptions of cell number and non-growing cell fraction, suitable for easy application to most anchorage-dependent mammalian cell cultures. Model utility was verified by studying the impact of contact inhibition on the growth rate, specific extracellular flux rates, and isotopic labeling in lactate for MCF7 cells, a commonly studied breast cancer cell line. The model successfully defined the time over which exponential growth and a metabolically homogeneous growing cell population could be assumed. The cellular automaton model developed is shown to be a useful tool in designing optimal MFA experiments.

  13. Gravitational force regulates elongation growth of Arabidopsis hypocotyls by modifying xyloglucan metabolism.

    Science.gov (United States)

    Soga, K; Wakabayashi, K; Hoson, T; Kamisaka, S

    2001-01-01

    Growth of dark-grown Arabidopsis hypocotyls was suppressed under hypergravity conditions (300 g), or was stimulated under microgravity conditions in space (Space Shuttle STS-95). The mechanical extensibility of cell walls decreased and increased under hypergravity and microgravity conditions, respectively. The amounts of cell wall polysaccharides (pectin, hemicellulose-I, hemicellulose-II and cellulose) per unit length of hypocotyls increased under hypergravity conditions, and decreased under microgravity conditions. The amount and the molecular mass of xyloglucans also increased under the hypergravity conditions, while those decreased under microgravity conditions. The activity of xyloglucan-degrading enzymes extracted from hypocotyl cell walls decreased and increased under hypergravity and microgravity conditions, respectively. These results indicate that the amount and the molecular mass of xyloglucans are affected by the magnitude of gravity and that such changes are caused by changes in xyloglucan-degrading activity. Modifications of xyloglucan metabolism as well as the thickness of cell walls by gravity stimulus may be the primary event determining the cell wall extensibility, thereby regulating the growth rate of Arabidopsis hypocotyls.

  14. Gravitational force regulates elongation growth of arabidopsis hypocotyls by modifying xyloglucan metabolism

    Science.gov (United States)

    Soga, K.; Wakabayashi, K.; Hoson, T.; Kamisaka, S.

    Growth of dark-grown Arabidopsis hypocotyls was suppressed under hypergravity conditions (300 g), or was stimulated under microgravity conditions in space (Space Shuttle STS-95). The mechanical extensibility of cell walls decreased and increased under hypergravity and microgravity conditions, respectively. The amounts of cell wall polysaccharides (pectin, hemicellulose-I, hemicellulose-II and cellulose) per unit length of hypocotyls increased under hypergravity conditions, and decreased under microgravity conditions. The amount and the molecular mass of xyloglucans also increased under the hypergravity conditions, while those decreased under microgravity conditions. The activity of xyloglucan-degrading enzymes extracted from hypocotyl cell walls decreased and increased under hypergravity and microgravity conditions, respectively. These results indicate that the amount and the molecular mass of xyloglucans are affected by the magnitude of gravity and that such changes are caused by changes in xyloglucan-degrading activity. Modifications of xyloglucan metabolism as well as the thickness of cell walls by gravity stimulus may be the primary event determining the cell wall extensibility, thereby regulating the growth rate of Arabidopsis hypocotyls.

  15. Energy transfer in "parasitic" cancer metabolism: mitochondria are the powerhouse and Achilles' heel of tumor cells.

    Science.gov (United States)

    Martinez-Outschoorn, Ubaldo E; Pestell, Richard G; Howell, Anthony; Tykocinski, Mark L; Nagajyothi, Fnu; Machado, Fabiana S; Tanowitz, Herbert B; Sotgia, Federica; Lisanti, Michael P

    2011-12-15

    It is now widely recognized that the tumor microenvironment promotes cancer cell growth and metastasis via changes in cytokine secretion and extracellular matrix remodeling. However, the role of tumor stromal cells in providing energy for epithelial cancer cell growth is a newly emerging paradigm. For example, we and others have recently proposed that tumor growth and metastasis is related to an energy imbalance. Host cells produce energy-rich nutrients via catabolism (through autophagy, mitophagy, and aerobic glycolysis), which are then transferred to cancer cells to fuel anabolic tumor growth. Stromal cell-derived L-lactate is taken up by cancer cells and is used for mitochondrial oxidative phosphorylation (OXPHOS) to produce ATP efficiently. However, "parasitic" energy transfer may be a more generalized mechanism in cancer biology than previously appreciated. Two recent papers in Science and Nature Medicine now show that lipolysis in host tissues also fuels tumor growth. These studies demonstrate that free fatty acids produced by host cell lipolysis are re-used via beta-oxidation (beta-OX) in cancer cell mitochondria. Thus, stromal catabolites (such as lactate, ketones, glutamine and free fatty acids) promote tumor growth by acting as high-energy onco-metabolites. As such, host catabolism, via autophagy, mitophagy and lipolysis, may explain the pathogenesis of cancer-associated cachexia and provides exciting new druggable targets for novel therapeutic interventions. Taken together, these findings also suggest that tumor cells promote their own growth and survival by behaving as a "parasitic organism." Hence, we propose the term "Parasitic Cancer Metabolism" to describe this type of metabolic coupling in tumors. Targeting tumor cell mitochondria (OXPHOS and beta-OX) would effectively uncouple tumor cells from their hosts, leading to their acute starvation. In this context, we discuss new evidence that high-energy onco-metabolites (produced by the stroma) can

  16. Cell differentiation within a yeast colony: metabolic and regulatory parallels with a tumor-affected organism.

    Science.gov (United States)

    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. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Cybernetic modeling and regulation of metabolic pathways in multiple steady states of hybridoma cells.

    Science.gov (United States)

    Guardia, M J; Gambhir, A; Europa, A F; Ramkrishna, D; Hu, W S

    2000-01-01

    Hybridoma cells utilize a pair of complementary and partially substitutable substrates, glucose and glutamine, for growth. It has been shown that cellular metabolism shifts under different culture conditions. When those cultures at different metabolic states are switched to a continuous mode, they reach different steady states under the same operating conditions. A cybernetic model was constructed to describe the complementary and partial substitutable nature of substrate utilization. The model successfully predicted the metabolic shift and multiple steady-state behavior. The results are consistent with the experimental observation that the history of the culture affects the resulting steady state.

  18. Target of rapamycin signaling regulates metabolism, growth, and life span in Arabidopsis.

    Science.gov (United States)

    Ren, Maozhi; Venglat, Prakash; Qiu, Shuqing; Feng, Li; Cao, Yongguo; Wang, Edwin; Xiang, Daoquan; Wang, Jinghe; Alexander, Danny; Chalivendra, Subbaiah; Logan, David; Mattoo, Autar; Selvaraj, Gopalan; Datla, Raju

    2012-12-01

    Target of Rapamycin (TOR) is a major nutrition and energy sensor that regulates growth and life span in yeast and animals. In plants, growth and life span are intertwined not only with nutrient acquisition from the soil and nutrition generation via photosynthesis but also with their unique modes of development and differentiation. How TOR functions in these processes has not yet been determined. To gain further insights, rapamycin-sensitive transgenic Arabidopsis thaliana lines (BP12) expressing yeast FK506 Binding Protein12 were developed. Inhibition of TOR in BP12 plants by rapamycin resulted in slower overall root, leaf, and shoot growth and development leading to poor nutrient uptake and light energy utilization. Experimental limitation of nutrient availability and light energy supply in wild-type Arabidopsis produced phenotypes observed with TOR knockdown plants, indicating a link between TOR signaling and nutrition/light energy status. Genetic and physiological studies together with RNA sequencing and metabolite analysis of TOR-suppressed lines revealed that TOR regulates development and life span in Arabidopsis by restructuring cell growth, carbon and nitrogen metabolism, gene expression, and rRNA and protein synthesis. Gain- and loss-of-function Ribosomal Protein S6 (RPS6) mutants additionally show that TOR function involves RPS6-mediated nutrition and light-dependent growth and life span in Arabidopsis.

  19. Inhibition of fatty acid metabolism reduces human myeloma cells proliferation.

    Directory of Open Access Journals (Sweden)

    José Manuel Tirado-Vélez

    Full Text Available Multiple myeloma is a haematological malignancy characterized by the clonal proliferation of plasma cells. It has been proposed that targeting cancer cell metabolism would provide a new selective anticancer therapeutic strategy. In this work, we tested the hypothesis that inhibition of β-oxidation and de novo fatty acid synthesis would reduce cell proliferation in human myeloma cells. We evaluated the effect of etomoxir and orlistat on fatty acid metabolism, glucose metabolism, cell cycle distribution, proliferation, cell death and expression of G1/S phase regulatory proteins in myeloma cells. Etomoxir and orlistat inhibited β-oxidation and de novo fatty acid synthesis respectively in myeloma cells, without altering significantly glucose metabolism. These effects were associated with reduced cell viability and cell cycle arrest in G0/G1. Specifically, etomoxir and orlistat reduced by 40-70% myeloma cells proliferation. The combination of etomoxir and orlistat resulted in an additive inhibitory effect on cell proliferation. Orlistat induced apoptosis and sensitized RPMI-8226 cells to apoptosis induction by bortezomib, whereas apoptosis was not altered by etomoxir. Finally, the inhibitory effect of both drugs on cell proliferation was associated with reduced p21 protein levels and phosphorylation levels of retinoblastoma protein. In conclusion, inhibition of fatty acid metabolism represents a potential therapeutic approach to treat human multiple myeloma.

  20. Superoxide and its metabolism during germination and axis growth of Vigna radiata (L.) Wilczek seeds.

    Science.gov (United States)

    Singh, Khangembam Lenin; Chaudhuri, Abira; Kar, Rup Kumar

    2014-01-01

    Involvement of reactive oxygen species in regulation of plant growth and development is recently being demonstrated with various results depending on the experimental system and plant species. Role of superoxide and its metabolism in germination and axis growth was investigated in case of Vigna radiata seeds, a non-endospermous leguminous species having epigeal germination, by studying the effect of different reactive oxygen species (ROS) inhibitors, distribution of O2(•)- and H2O2 and ROS enzyme profile in axes. Germination percentage and axis growth were determined under treatment with ROS inhibitors and scavengers. Localization of O2(•)- and H2O2 was done using nitroblue tetrazolium (NBT) and 3,3',5,5'-tetramethyl benzidine dihydrochloride hydrate (TMB), respectively. Apoplastic level of O2(•)- was monitored by spectrophotometric analysis of bathing medium of axes. Profiles of NADPH oxidase and superoxide dismutase (SOD) were studied by in-gel assay. Germination was retarded by treatments affecting ROS level except H2O2 scavengers, while axis growth was retarded by all. Superoxide synthesis inhibitor and scavenger prevented H2O2 accumulation in axes in later phase as revealed from TMB staining. Activity of Cu/Zn SOD1 was initially high and declined thereafter. Superoxide being produced in apoplast possibly by NADPH oxidase activity is further metabolized to (•)OH via H2O2. Germination process depends possibly on (•)OH production in the axes. Post-germinative axis growth requires O2(•)- while the differentiating zone of axis (radicle) requires H2O2 for cell wall stiffening.

  1. Dynamic metabolic flux analysis using B-splines to study the effects of temperature shift on CHO cell metabolism

    Directory of Open Access Journals (Sweden)

    Verónica S. Martínez

    2015-12-01

    Full Text Available Metabolic flux analysis (MFA is widely used to estimate intracellular fluxes. Conventional MFA, however, is limited to continuous cultures and the mid-exponential growth phase of batch cultures. Dynamic MFA (DMFA has emerged to characterize time-resolved metabolic fluxes for the entire culture period. Here, the linear DMFA approach was extended using B-spline fitting (B-DMFA to estimate mass balanced fluxes. Smoother fits were achieved using reduced number of knots and parameters. Additionally, computation time was greatly reduced using a new heuristic algorithm for knot placement. B-DMFA revealed that Chinese hamster ovary cells shifted from 37 °C to 32 °C maintained a constant IgG volume-specific productivity, whereas the productivity for the controls peaked during mid-exponential growth phase and declined afterward. The observed 42% increase in product titer at 32 °C was explained by a prolonged cell growth with high cell viability, a larger cell volume and a more stable volume-specific productivity.

  2. Development of a screening approach for exploring cell factory potential through metabolic flux analysis and physiology

    DEFF Research Database (Denmark)

    Knudsen, Peter Boldsen; Nielsen, Kristian Fog; Thykær, Jette

    2012-01-01

    The recent developments within the field of metabolic engineering have significantly increased the speed by which fungal recombinant strains are being constructed, pushing focus towards physiological characterisation and analysis. This raises demand for a tool for diligent analysis of the recombi...... and work-load connected with screening and selection of potential cell factories with attractive properties, compared with more “traditional” methodologies where metabolic flux analysis is applied at a much later state in the characterisation process.......The recent developments within the field of metabolic engineering have significantly increased the speed by which fungal recombinant strains are being constructed, pushing focus towards physiological characterisation and analysis. This raises demand for a tool for diligent analysis...... on a Hamilton robotic system. This method aimed at characterising physiology at two levels: (1) An approach focusing on the traditional growth related parameters, i.e. growth rate, yield coefficients and extracellular metabolites. (2) 13C-labelling experiments, where metabolic fluxes are quantified...

  3. c-Myc activates multiple metabolic networks to generate substrates for cell-cycle entry.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. c-Myc activates multiple metabolic networks to generate substrates for cell-cycle entry.

    Science.gov (United States)

    Morrish, F; Isern, N; Sadilek, M; Jeffrey, M; Hockenbery, D M

    2009-07-09

    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.

  5. Metabolism Is Central to Tolerogenic Dendritic Cell Function

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    Wen Jing Sim

    2016-01-01

    Full Text Available 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.

  6. Rewired Metabolism in Drug-resistant Leukemia Cells

    Science.gov (United States)

    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

  7. Is cancer a metabolic rebellion against host aging? In the quest for immortality, tumor cells try to save themselves by boosting mitochondrial metabolism.

    Science.gov (United States)

    Ertel, Adam; Tsirigos, Aristotelis; Whitaker-Menezes, Diana; Birbe, Ruth C; Pavlides, Stephanos; Martinez-Outschoorn, Ubaldo E; Pestell, Richard G; Howell, Anthony; Sotgia, Federica; Lisanti, Michael P

    2012-01-15

    Aging drives large systemic reductions in oxidative mitochondrial function, shifting the entire body metabolically towards aerobic glycolysis, a.k.a, the Warburg effect. Aging is also one of the most significant risk factors for the development of human cancers, including breast tumors. How are these two findings connected? One simplistic idea is that cancer cells rebel against the aging process by increasing their capacity for oxidative mitochondrial metabolism (OXPHOS). Then, local and systemic aerobic glycolysis in the aging host would provide energy-rich mitochondrial fuels (such as L-lactate and ketones) to directly "fuel" tumor cell growth and metastasis. This would establish a type of parasite-host relationship or "two-compartment tumor metabolism", with glycolytic/oxidative metabolic-coupling. The cancer cells ("the seeds") would flourish in this nutrient-rich microenvironment ("the soil"), which has been fertilized by host aging. In this scenario, cancer cells are only trying to save themselves from the consequences of aging, by engineering a metabolic mutiny, through the amplification of mitochondrial metabolism. We discuss the recent findings of Drs. Ron DePinho (MD Anderson) and Craig Thomspson (Sloan-Kettering) that are also consistent with this new hypothesis, linking cancer progression with metabolic aging. Using data mining and bioinformatics approaches, we also provide key evidence of a role for PGC1a/NRF1 signaling in the pathogenesis of (1) two-compartment tumor metabolism, and (2) mitochondrial biogenesis in human breast cancer cells.

  8. Gluconeogenesis and amino acids metabolism in ovarian clear cell carcinoma

    OpenAIRE

    2013-01-01

    Dissertação de mestrado, Ciências Biomédicas, Departamento de Ciências Biomédicas e Medicina, Universidade do Algarve, 2013 Tumor cells may exhibit different metabolic profiles compared to normal tissues from which they are derived. Those observations gave rise to the new concept that tumorigenesis requires metabolic alterations to sustain cell proliferation. Several studies reveal that increased cell proliferation is accompanied by increased glucose consumption. In OCCC, a typical morphol...

  9. Comparative Metabolic Flux Profiling of Melanoma Cell Lines

    Science.gov (United States)

    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. Comparison of growth and metabolic regulation between wild, domesticated and transgenic salmonids.

    Science.gov (United States)

    To gain a better understanding of the aspects underlying normal and growth hormone enhanced growth in salmonids, quantitative expression analysis was performed for a number of genes related to muscle growth, metabolism, immunology and energy regulation. This analysis was performed in liver and musc...

  11. Lactate promotes glutamine uptake and metabolism in oxidative cancer cells.

    Science.gov (United States)

    Pérez-Escuredo, Jhudit; Dadhich, Rajesh K; Dhup, Suveera; Cacace, Andrea; Van Hée, Vincent F; De Saedeleer, Christophe J; Sboarina, Martina; Rodriguez, Fabien; Fontenille, Marie-Joséphine; Brisson, Lucie; Porporato, Paolo E; Sonveaux, Pierre

    2016-01-01

    Oxygenated cancer cells have a high metabolic plasticity as they can use glucose, glutamine and lactate as main substrates to support their bioenergetic and biosynthetic activities. Metabolic optimization requires integration. While glycolysis and glutaminolysis can cooperate to support cellular proliferation, oxidative lactate metabolism opposes glycolysis in oxidative cancer cells engaged in a symbiotic relation with their hypoxic/glycolytic neighbors. However, little is known concerning the relationship between oxidative lactate metabolism and glutamine metabolism. Using SiHa and HeLa human cancer cells, this study reports that intracellular lactate signaling promotes glutamine uptake and metabolism in oxidative cancer cells. It depends on the uptake of extracellular lactate by monocarboxylate transporter 1 (MCT1). Lactate first stabilizes hypoxia-inducible factor-2α (HIF-2α), and HIF-2α then transactivates c-Myc in a pathway that mimics a response to hypoxia. Consequently, lactate-induced c-Myc activation triggers the expression of glutamine transporter ASCT2 and of glutaminase 1 (GLS1), resulting in improved glutamine uptake and catabolism. Elucidation of this metabolic dependence could be of therapeutic interest. First, inhibitors of lactate uptake targeting MCT1 are currently entering clinical trials. They have the potential to indirectly repress glutaminolysis. Second, in oxidative cancer cells, resistance to glutaminolysis inhibition could arise from compensation by oxidative lactate metabolism and increased lactate signaling.

  12. Nerve growth factor metabolic dysfunction in Down's syndrome brains.

    Science.gov (United States)

    Iulita, M Florencia; Do Carmo, Sonia; Ower, Alison K; Fortress, Ashley M; Flores Aguilar, Lisi; Hanna, Michael; Wisniewski, Thomas; Granholm, Ann-Charlotte; Buhusi, Mona; Busciglio, Jorge; Cuello, A Claudio

    2014-03-01

    Basal forebrain cholinergic neurons play a key role in cognition. This neuronal system is highly dependent on NGF for its synaptic integrity and the phenotypic maintenance of its cell bodies. Basal forebrain cholinergic neurons progressively degenerate in Alzheimer's disease and Down's syndrome, and their atrophy contributes to the manifestation of dementia. Paradoxically, in Alzheimer's disease brains, the synthesis of NGF is not affected and there is abundance of the NGF precursor, proNGF. We have shown that this phenomenon is the result of a deficit in NGF's extracellular metabolism that compromises proNGF maturation and exacerbates its subsequent degradation. We hypothesized that a similar imbalance should be present in Down's syndrome. Using a combination of quantitative reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, western blotting and zymography, we investigated signs of NGF metabolic dysfunction in post-mortem brains from the temporal (n = 14), frontal (n = 34) and parietal (n = 20) cortex obtained from subjects with Down's syndrome and age-matched controls (age range 31-68 years). We further examined primary cultures of human foetal Down's syndrome cortex (17-21 gestational age weeks) and brains from Ts65Dn mice (12-22 months), a widely used animal model of Down's syndrome. We report a significant increase in proNGF levels in human and mouse Down's syndrome brains, with a concomitant reduction in the levels of plasminogen and tissue plasminogen activator messenger RNA as well as an increment in neuroserpin expression; enzymes that partake in proNGF maturation. Human Down's syndrome brains also exhibited elevated zymogenic activity of MMP9, the major NGF-degrading protease. Our results indicate a failure in NGF precursor maturation in Down's syndrome brains and a likely enhanced proteolytic degradation of NGF, changes which can compromise the trophic support of basal forebrain cholinergic neurons. The alterations in pro

  13. The metabolic advantage of tumor cells

    Directory of Open Access Journals (Sweden)

    Schwartz Laurent

    2011-06-01

    Full Text Available Abstract 1- Oncogenes express proteins of "Tyrosine kinase receptor pathways", a receptor family including insulin or IGF-Growth Hormone receptors. Other oncogenes alter the PP2A phosphatase brake over these kinases. 2- Experiments on pancreatectomized animals; treated with pure insulin or total pancreatic extracts, showed that choline in the extract, preserved them from hepatomas. Since choline is a methyle donor, and since methylation regulates PP2A, the choline protection may result from PP2A methylation, which then attenuates kinases. 3- Moreover, kinases activated by the boosted signaling pathway inactivate pyruvate kinase and pyruvate dehydrogenase. In addition, demethylated PP2A would no longer dephosphorylate these enzymes. A "bottleneck" between glycolysis and the oxidative-citrate cycle interrupts the glycolytic pyruvate supply now provided via proteolysis and alanine transamination. This pyruvate forms lactate (Warburg effect and NAD+ for glycolysis. Lipolysis and fatty acids provide acetyl CoA; the citrate condensation increases, unusual oxaloacetate sources are available. ATP citrate lyase follows, supporting aberrant transaminations with glutaminolysis and tumor lipogenesis. Truncated urea cycles, increased polyamine synthesis, consume the methyl donor SAM favoring carcinogenesis. 4- The decrease of butyrate, a histone deacetylase inhibitor, elicits epigenic changes (PETEN, P53, IGFBP decrease; hexokinase, fetal-genes-M2, increase 5- IGFBP stops binding the IGF - IGFR complex, it is perhaps no longer inherited by a single mitotic daughter cell; leading to two daughter cells with a mitotic capability. 6- An excess of IGF induces a decrease of the major histocompatibility complex MHC1, Natural killer lymphocytes should eliminate such cells that start the tumor, unless the fever prostaglandin PGE2 or inflammation, inhibit them...

  14. Salmonella Modulates Metabolism During Growth under Conditions that Induce Expression of Virulence Genes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young-Mo; Schmidt, Brian; Kidwai, Afshan S.; Jones, Marcus B.; Deatherage, Brooke L.; Brewer, Heather M.; Mitchell, Hugh D.; Palsson, Bernhard O.; McDermott, Jason E.; Heffron, Fred; Smith, Richard D.; Peterson, Scott N.; Ansong, Charles; Hyduke, Daniel R.; Metz, Thomas O.; Adkins, Joshua N.

    2013-04-05

    Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative pathogen that uses complex mechanisms to invade and proliferate within mammalian host cells. To investigate possible contributions of metabolic processes in S. Typhimurium grown under conditions known to induce expression of virulence genes, we used a metabolomics-driven systems biology approach coupled with genome scale modeling. First, we identified distinct metabolite profiles associated with bacteria grown in either rich or virulence-inducing media and report the most comprehensive coverage of the S. Typhimurium metabolome to date. Second, we applied an omics-informed genome scale modeling analysis of the functional consequences of adaptive alterations in S. Typhimurium metabolism during growth under our conditions. Excitingly, we observed possible sequestration of metabolites recently suggested to have immune modulating roles. Modeling efforts highlighted a decreased cellular capability to both produce and utilize intracellular amino acids during stationary phase culture in virulence conditions, despite significant abundance increases for these molecules as observed by our metabolomics measurements. Model-guided analysis suggested that alterations in metabolism prioritized other activities necessary for pathogenesis instead, such as lipopolysaccharide biosynthesis.

  15. Experimental and Computational Investigation of Biofilm Formation by Rhodopseudomonas palustris Growth under Two Metabolic Modes.

    Directory of Open Access Journals (Sweden)

    Chase Kernan

    Full Text Available We examined biofilms formed by the metabolically versatile bacterium Rhodopseudomonas palustris grown via different metabolic modes. R. palustris was grown in flow cell chambers with identical medium conditions either in the presence or absence of light and oxygen. In the absence of oxygen and the presence of light, R. palustris grew and formed biofilms photoheterotrophically, and in the presence of oxygen and the absence of light, R. palustris grew and formed biofilms heterotrophically. We used confocal laser scanning microscopy and image analysis software to quantitatively analyze and compare R. palustris biofilm formation over time in these two metabolic modes. We describe quantifiable differences in structure between the biofilms formed by the bacterium grown heterotrophically and those grown photoheterotrophically. We developed a computational model to explore ways in which biotic and abiotic parameters could drive the observed biofilm architectures, as well as a random-forest machine-learning algorithm based on structural differences that was able to identify growth conditions from the confocal imaging of the biofilms with 87% accuracy. Insight into the structure of phototrophic biofilms and conditions that influence biofilm formation is relevant for understanding the generation of biofilm structures with different properties, and for optimizing applications with phototrophic bacteria growing in the biofilm state.

  16. Growth hormone dose regimens in adult GH deficiency: effects on biochemical growth markers and metabolic parameters

    DEFF Research Database (Denmark)

    Møller, Jens; Jørgensen, Jens Otto Lunde; Laursen, Torben;

    1993-01-01

    Abstract OBJECTIVE: We examined the effects of different doses of GH on insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), body composition, energy expenditure, and various metabolites in GH deficient adults, in order to approach a metabolically appropriate GH dosage in young GH...... deficient adults. DESIGN: Ten GH deficient patients (age 21-43) were studied after 4 weeks without GH followed by three consecutive 4-week periods, where the patients received in a fixed order GH 1, 2 and 4 IU/m2 s.c. per day. At the end of each period the patients were hospitalized for a 24-hour...... examination. RESULTS: Mean 24-hour levels of GH (mIU/l) were 2.7 +/- 0.3 (0 GH), 7.2 +/- 0.9 (1), 10.8 +/- 1.5 (2) and 18.9 +/- 2.7 (4 IU/m2) (mean +/- SEM) (P

  17. Synergism between Inositol Polyphosphates and TOR Kinase Signaling in Nutrient Sensing, Growth Control, and Lipid Metabolism in Chlamydomonas[OPEN

    Science.gov (United States)

    Evans, Bradley S.; Li, Jia; Liu, Yu; Diamond, Spencer

    2016-01-01

    The networks that govern carbon metabolism and control intracellular carbon partitioning in photosynthetic cells are poorly understood. Target of Rapamycin (TOR) kinase is a conserved growth regulator that integrates nutrient signals and modulates cell growth in eukaryotes, though the TOR signaling pathway in plants and algae has yet to be completely elucidated. We screened the unicellular green alga Chlamydomonas reinhardtii using insertional mutagenesis to find mutants that conferred hypersensitivity to the TOR inhibitor rapamycin. We characterized one mutant, vip1-1, that is predicted to encode a conserved inositol hexakisphosphate kinase from the VIP family that pyrophosphorylates phytic acid (InsP6) to produce the low abundance signaling molecules InsP7 and InsP8. Unexpectedly, the rapamycin hypersensitive growth arrest of vip1-1 cells was dependent on the presence of external acetate, which normally has a growth-stimulatory effect on Chlamydomonas. vip1-1 mutants also constitutively overaccumulated triacylglycerols (TAGs) in a manner that was synergistic with other TAG inducing stimuli such as starvation. vip1-1 cells had reduced InsP7 and InsP8, both of which are dynamically modulated in wild-type cells by TOR kinase activity and the presence of acetate. Our data uncover an interaction between the TOR kinase and inositol polyphosphate signaling systems that we propose governs carbon metabolism and intracellular pathways that lead to storage lipid accumulation. PMID:27600537

  18. Energy metabolism characterization of a novel cancer stem cell-like line 3AB-OS.

    Science.gov (United States)

    Palorini, Roberta; Votta, Giuseppina; Balestrieri, Chiara; Monestiroli, Andrea; Olivieri, Sandro; Vento, Renza; Chiaradonna, Ferdinando

    2014-02-01

    Cancer stem cells (CSC) have a central role in driving tumor growth. Since metabolism is becoming an important diagnostic and therapeutic target, characterization of CSC line energetic properties is an emerging need. Embryonic and adult stem cells, compared to differentiated cells, exhibit a reduced mitochondrial activity and a stronger dependence on aerobic glycolysis. Here, we aimed to comparatively analyze bioenergetics features of the human osteosarcoma 3AB-OS CSC-like line, and the parental osteosarcoma MG63 cells, from which 3AB-OS cells have been previously selected. Our results suggest that 3AB-OS cells depend on glycolytic metabolism more strongly than MG63 cells. Indeed, growth in glucose shortage or in presence of galactose or pyruvate (mitochondrial specific substrates) leads to a significant reduction of their proliferation compared to MG63 cells. Accordingly, 3AB-OS cells show an increased expression of lactate dehydrogenase A (LDHA) and a larger accumulation of lactate in the culture medium. In line with these findings 3AB-OS cells as compared to MG63 cells present a reduced mitochondrial respiration, a stronger sensitivity to glucose depletion or glycolysis inhibition and a lessened sensitivity to oxidative phosphorylation inhibitors. Additionally, in contrast to MG63 cells, 3AB-OS display fragmented mitochondria, which become networked as they grow in glucose-rich medium, while almost entirely loose these structures growing in low glucose. Overall, our findings suggest that 3AB-OS CSC energy metabolism is more similar to normal stem cells and to cancer cells characterized by a glycolytic anaerobic metabolism.

  19. Quantification of Metabolic Rearrangements During Neural Stem Cells Differentiation into Astrocytes by Metabolic Flux Analysis.

    Science.gov (United States)

    Sá, João V; Kleiderman, Susanne; Brito, Catarina; Sonnewald, Ursula; Leist, Marcel; Teixeira, Ana P; Alves, Paula M

    2017-01-01

    Proliferation and differentiation of neural stem cells (NSCs) have a crucial role to ensure neurogenesis and gliogenesis in the mammalian brain throughout life. As there is growing evidence for the significance of metabolism in regulating cell fate, knowledge on the metabolic programs in NSCs and how they evolve during differentiation into somatic cells may provide novel therapeutic approaches to address brain diseases. In this work, we applied a quantitative analysis to assess how the central carbon metabolism evolves upon differentiation of NSCs into astrocytes. Murine embryonic stem cell (mESC)-derived NSCs and astrocytes were incubated with labelled [1-(13)C]glucose and the label incorporation into intracellular metabolites was followed by GC-MS. The obtained (13)C labelling patterns, together with uptake/secretion rates determined from supernatant analysis, were integrated into an isotopic non-stationary metabolic flux analysis ((13)C-MFA) model to estimate intracellular flux maps. Significant metabolic differences between NSCs and astrocytes were identified, with a general downregulation of central carbon metabolism during astrocytic differentiation. While glucose uptake was 1.7-fold higher in NSCs (on a per cell basis), a high lactate-secreting phenotype was common to both cell types. Furthermore, NSCs consumed glutamine from the medium; the highly active reductive carboxylation of alpha-ketoglutarate indicates that this was converted to citrate and used for biosynthetic purposes. In astrocytes, pyruvate entered the TCA cycle mostly through pyruvate carboxylase (81%). This pathway supported glutamine and citrate secretion, recapitulating well described metabolic features of these cells in vivo. Overall, this fluxomics study allowed us to quantify the metabolic rewiring accompanying astrocytic lineage specification from NSCs.

  20. Transgenic manipulation of the metabolism of polyamines in poplar cells

    Science.gov (United States)

    Pratiksha Bhatnagar; Bernadette M. Glasheen; Suneet K. Bains; Stephanie L. Long; Rakesh Minocha; Christian Walter; Subhash C. Minocha

    2001-01-01

    The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra 3 maximowiczii) expressing a...

  1. 13C metabolic flux analysis in Clostridium acetobutylicum during growth on L-arabinose

    Science.gov (United States)

    Hurley, Margaret; Sund, Christian; Liu, Sanchao; Germane, Katherine; Servinsky, Matthew; Gerlach, Elliot

    2015-03-01

    Clostridium acetobutylicum's metabolic pathways have been studied for decades due to its metabolic diversity and industrial value, yet many details of its metabolism are continuing to emerge. To elucidate the role of xylulose-5-P/fructose-6-P phosphoketolase (XFP), and the recently discovered Pentose Phosphate Pathway (PKP) in C. acetobutylicum, experimental and computational metabolic isotope analysis was performed under growth on glucose, xylose, and arabinose. Results indicate that PKP utilization increased with increasing xylose concentration and this trend was further pronounced during growth on arabinose. This was confirmed by mutation of the gene encoding XFP, which almost completely abolished flux through the PKP during growth on arabinose and resulted in decreased acetate:butyrate ratios. We discuss these experimental and computational results here, and the implications for our understanding of sugar metabolism in C. acetobutylicum.

  2. Ptpmt1 induced by HIF-2α regulates the proliferation and glucose metabolism in erythroleukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qin-Qin [High Altitude Medicine of Ministry of Chinese Education and Research Center for High Altitude Medicine, Qinghai University, Xining, 810001 (China); Qinghai Provincial People' s Hospital, Xining (China); Xiao, Feng-Jun; Sun, Hui-Yan [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, 100850 (China); Shi, Xue-Feng [High Altitude Medicine of Ministry of Chinese Education and Research Center for High Altitude Medicine, Qinghai University, Xining, 810001 (China); Qinghai Provincial People' s Hospital, Xining (China); Wang, Hua; Yang, Yue-Feng; Li, Yu-Xiang [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, 100850 (China); Wang, Li-Sheng, E-mail: wangls@bmi.ac.cn [Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing, 100850 (China); Ge, Ri-Li, E-mail: geriligao@hotmail.com [High Altitude Medicine of Ministry of Chinese Education and Research Center for High Altitude Medicine, Qinghai University, Xining, 810001 (China)

    2016-03-18

    Hypoxia provokes metabolism misbalance, mitochondrial dysfunction and oxidative stress in both human and animal cells. However, the mechanisms which hypoxia causes mitochondrial dysfunction and energy metabolism misbalance still remain unclear. In this study, we presented evidence that mitochondrial phosphatase Ptpmt1 is a hypoxia response molecule that regulates cell proliferation, survival and glucose metabolism in human erythroleukemia TF-1 cells. Exposure to hypoxia or DFO treatment results in upregulation of HIF1-α, HIF-2α and Ptpmt1. Only inhibition of HIF-2α by shRNA transduction reduces Ptpmt1 expression in TF-1 cells under hypoxia. Ptpmt1 inhibitor suppresses the growth and induces apoptosis of TF-1 cells. Furthermore, we demonstrated that Ptpmt1 inhibition reduces the Glut1 and Glut3 expression and decreases the glucose consumption in TF-1 cells. In additional, Ptpmt1 knockdown also results in the mitochondrial dysfunction determined by JC1 staining. These results delineate a key role for HIF-2α-induced Ptpmt1 upregulation in proliferation, survival and glucose metabolism of erythroleukemia cells. It is indicated that Ptpmt1 plays important roles in hypoxia-induced cell metabolism and mitochondrial dysfunction. - Highlights: • Hypoxia induces upregulation of HIF-1α, HIF-2α and Ptpmt1; HIF-2a induces Ptpmt1 upregulation in TF-1 cells. • PTPMT-1 inhibition reduces growth and induces apoptosis of TF-1 cells. • PTPMT1 inhibition downregulates Glut-1, Glut-3 expression and reduces glucose consumption.

  3. Tomato fruit growth : integrating cell division, cell growth and endoreduplication by experimentation and modelling

    NARCIS (Netherlands)

    Fanwoua, J.

    2012-01-01

    Keywords: cell division, cell growth, cell endoreduplication, fruit growth, genotype, G×E interaction, model, tomato. Fruit size is a major component of fruit yield and quality of many crops. Variations in fruit size can be tremendous due to genotypic and environmental factors. The mechanisms

  4. Altered metabolism of growth hormone receptor mutant mice: a combined NMR metabonomics and microarray study.

    Directory of Open Access Journals (Sweden)

    Horst Joachim Schirra

    Full Text Available BACKGROUND: Growth hormone is an important regulator of post-natal growth and metabolism. We have investigated the metabolic consequences of altered growth hormone signalling in mutant mice that have truncations at position 569 and 391 of the intracellular domain of the growth hormone receptor, and thus exhibit either low (around 30% maximum or no growth hormone-dependent STAT5 signalling respectively. These mutations result in altered liver metabolism, obesity and insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS: The analysis of metabolic changes was performed using microarray analysis of liver tissue and NMR metabonomics of urine and liver tissue. Data were analyzed using multivariate statistics and Gene Ontology tools. The metabolic profiles characteristic for each of the two mutant groups and wild-type mice were identified with NMR metabonomics. We found decreased urinary levels of taurine, citrate and 2-oxoglutarate, and increased levels of trimethylamine, creatine and creatinine when compared to wild-type mice. These results indicate significant changes in lipid and choline metabolism, and were coupled with increased fat deposition, leading to obesity. The microarray analysis identified changes in expression of metabolic enzymes correlating with alterations in metabolite concentration both in urine and liver. Similarity of mutant 569 to the wild-type was seen in young mice, but the pattern of metabolites shifted to that of the 391 mutant as the 569 mice became obese after six months age. CONCLUSIONS/SIGNIFICANCE: The metabonomic observations were consistent with the parallel analysis of gene expression and pathway mapping using microarray data, identifying metabolites and gene transcripts involved in hepatic metabolism, especially for taurine, choline and creatinine metabolism. The systems biology approach applied in this study provides a coherent picture of metabolic changes resulting from impaired STAT5 signalling by the growth hormone

  5. Metabolic Adaptations of Azospirillum brasilense to Oxygen Stress by Cell-to-Cell Clumping and Flocculation

    Science.gov (United States)

    Bible, Amber N.; Khalsa-Moyers, Gurusahai K.; Mukherjee, Tanmoy; Green, Calvin S.; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B.

    2015-01-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists. PMID:26407887

  6. Metabolic adaptations of Azospirillum brasilense to oxygen stress by cell-to-cell clumping and flocculation.

    Science.gov (United States)

    Bible, Amber N; Khalsa-Moyers, Gurusahai K; Mukherjee, Tanmoy; Green, Calvin S; Mishra, Priyanka; Purcell, Alicia; Aksenova, Anastasia; Hurst, Gregory B; Alexandre, Gladys

    2015-12-01

    The ability of bacteria to monitor their metabolism and adjust their behavior accordingly is critical to maintain competitiveness in the environment. The motile microaerophilic bacterium Azospirillum brasilense navigates oxygen gradients by aerotaxis in order to locate low oxygen concentrations that can support metabolism. When cells are exposed to elevated levels of oxygen in their surroundings, motile A. brasilense cells implement an alternative response to aerotaxis and form transient clumps by cell-to-cell interactions. Clumping was suggested to represent a behavior protecting motile cells from transiently elevated levels of aeration. Using the proteomics of wild-type and mutant strains affected in the extent of their clumping abilities, we show that cell-to-cell clumping represents a metabolic scavenging strategy that likely prepares the cells for further metabolic stresses. Analysis of mutants affected in carbon or nitrogen metabolism confirmed this assumption. The metabolic changes experienced as clumping progresses prime cells for flocculation, a morphological and metabolic shift of cells triggered under elevated-aeration conditions and nitrogen limitation. The analysis of various mutants during clumping and flocculation characterized an ordered set of changes in cell envelope properties accompanying the metabolic changes. These data also identify clumping and early flocculation to be behaviors compatible with the expression of nitrogen fixation genes, despite the elevated-aeration conditions. Cell-to-cell clumping may thus license diazotrophy to microaerophilic A. brasilense cells under elevated oxygen conditions and prime them for long-term survival via flocculation if metabolic stress persists.

  7. Metabolic characterization of a CHO cell size increase phase in fed-batch cultures.

    Science.gov (United States)

    Pan, Xiao; Dalm, Ciska; Wijffels, René H; Martens, Dirk E

    2017-09-26

    Normally, the growth profile of a CHO cell fed-batch process can be divided into two main phases based on changes in cell concentration, being an exponential growth phase and a stationary (non-growth) phase. In this study, an additional phase is observed during which the cell division comes to a halt but the cell growth continues in the form of an increase in cell size. The cell size increase (SI) phase occurs between the exponential proliferation phase (also called the number increase or NI phase) and the stationary phase. During the SI phase, the average volume and dry weight per cell increase threefold linearly with time. The average mAb specific productivity per cell increases linearly with the cell volume and therefore is on average two times higher in the SI phase than in the NI phase. The specific essential amino acids consumption rates per cell remain fairly constant between the NI and the SI phase, which agrees with the similar biomass production rate per cell between these two phases. Accumulation of fatty acids and formation of lipid droplets in the cells are observed during the SI phase, indicating that the fatty acids synthesis rate exceeds the demand for the synthesis of membrane lipids. A metabolic comparison between NI and SI phase shows that the cells with a larger size produce more mAb per unit of O2 and nutrient consumed, which can be used for further process optimization.

  8. Body shape shifting during growth permits tests that distinguish between competing geometric theories of metabolic scaling

    DEFF Research Database (Denmark)

    Hirst, Andrew G.; Glazier, Douglas S.; Atkinson, David

    2014-01-01

    the size dependence of metabolism is derived from material transport across external surfaces, or through internal resource-transport networks. We show that when body shape changes during growth, these models make opposing predictions. These models are tested using pelagic invertebrates, because...... these animals exhibit highly variable intraspecific scaling relationships for metabolic rate and body shape. Metabolic scaling slopes of diverse integument-breathing species were significantly positively correlated with degree of body flattening or elongation during ontogeny, as expected from surface area...

  9. Horizontal and vertical growth of S. cerevisiae metabolic network

    OpenAIRE

    Tramontano Anna; Grassi Luigi

    2011-01-01

    Abstract Background The growth and development of a biological organism is reflected by its metabolic network, the evolution of which relies on the essential gene duplication mechanism. There are two current views about the evolution of metabolic networks. The retrograde model hypothesizes that a pathway evolves by recruiting novel enzymes in a direction opposite to the metabolic flow. The patchwork model is instead based on the assumption that the evolution is based on the exploitation of br...

  10. Exometabolom analysis of breast cancer cell lines: Metabolic signature.

    Science.gov (United States)

    Willmann, Lucas; Erbes, Thalia; Halbach, Sebastian; Brummer, Tilman; Jäger, Markus; Hirschfeld, Marc; Fehm, Tanja; Neubauer, Hans; Stickeler, Elmar; Kammerer, Bernd

    2015-08-21

    Cancer cells show characteristic effects on cellular turnover and DNA/RNA modifications leading to elevated levels of excreted modified nucleosides. We investigated the molecular signature of different subtypes of breast cancer cell lines and the breast epithelial cell line MCF-10A. Prepurification of cell culture supernatants was performed by cis-diol specific affinity chromatography using boronate-derivatized polyacrylamide gel. Samples were analyzed by application of reversed phase chromatography coupled to a triple quadrupole mass spectrometer. Collectively, we determined 23 compounds from RNA metabolism, two from purine metabolism, five from polyamine/methionine cycle, one from histidine metabolism and two from nicotinate and nicotinamide metabolism. We observed major differences of metabolite excretion pattern between the breast cancer cell lines and MCF-10A, just as well as between the different breast cancer cell lines themselves. Differences in metabolite excretion resulting from cancerous metabolism can be integrated into altered processes on the cellular level. Modified nucleosides have great potential as biomarkers in due consideration of the heterogeneity of breast cancer that is reflected by the different molecular subtypes of breast cancer. Our data suggests that the metabolic signature of breast cancer cell lines might be a more subtype-specific tool to predict breast cancer, rather than a universal approach.

  11. Integrated metabolic modelling reveals cell-type specific epigenetic control points of the macrophage metabolic network.

    Science.gov (United States)

    Pacheco, Maria Pires; John, Elisabeth; Kaoma, Tony; Heinäniemi, Merja; Nicot, Nathalie; Vallar, Laurent; Bueb, Jean-Luc; Sinkkonen, Lasse; Sauter, Thomas

    2015-10-19

    The reconstruction of context-specific metabolic models from easily and reliably measurable features such as transcriptomics data will be increasingly important in research and medicine. Current reconstruction methods suffer from high computational effort and arbitrary threshold setting. Moreover, understanding the underlying epigenetic regulation might allow the identification of putative intervention points within metabolic networks. Genes under high regulatory load from multiple enhancers or super-enhancers are known key genes for disease and cell identity. However, their role in regulation of metabolism and their placement within the metabolic networks has not been studied. Here we present FASTCORMICS, a fast and robust workflow for the creation of high-quality metabolic models from transcriptomics data. FASTCORMICS is devoid of arbitrary parameter settings and due to its low computational demand allows cross-validation assays. Applying FASTCORMICS, we have generated models for 63 primary human cell types from microarray data, revealing significant differences in their metabolic networks. To understand the cell type-specific regulation of the alternative metabolic pathways we built multiple models during differentiation of primary human monocytes to macrophages and performed ChIP-Seq experiments for histone H3 K27 acetylation (H3K27ac) to map the active enhancers in macrophages. Focusing on the metabolic genes under high regulatory load from multiple enhancers or super-enhancers, we found these genes to show the most cell type-restricted and abundant expression profiles within their respective pathways. Importantly, the high regulatory load genes are associated to reactions enriched for transport reactions and other pathway entry points, suggesting that they are critical regulatory control points for cell type-specific metabolism. By integrating metabolic modelling and epigenomic analysis we have identified high regulatory load as a common feature of metabolic

  12. Metabolic and Epigenetic Coordination of T Cell and Macrophage Immunity.

    Science.gov (United States)

    Phan, Anthony T; Goldrath, Ananda W; Glass, Christopher K

    2017-05-16

    Recognition of pathogens by innate and adaptive immune cells instructs rapid alterations of cellular processes to promote effective resolution of infection. To accommodate increased bioenergetic and biosynthetic demands, metabolic pathways are harnessed to maximize proliferation and effector molecule production. In parallel, activation initiates context-specific gene-expression programs that drive effector functions and cell fates that correlate with changes in epigenetic landscapes. Many chromatin- and DNA-modifying enzymes make use of substrates and cofactors that are intermediates of metabolic pathways, providing potential cross talk between metabolism and epigenetic regulation of gene expression. In this review, we discuss recent studies of T cells and macrophages supporting a role for metabolic activity in integrating environmental signals with activation-induced gene-expression programs through modulation of the epigenome and speculate as to how this may influence context-specific macrophage and T cell responses to infection. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Prediction of Microbial Growth Rate versus Biomass Yield by a Metabolic Network with Kinetic Parameters

    NARCIS (Netherlands)

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    2012-01-01

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal bio

  14. Prediction of Microbial Growth Rate versus Biomass Yield by a Metabolic Network with Kinetic Parameters

    NARCIS (Netherlands)

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal

  15. Induction of mitochondrial dysfunction as a strategy for targeting tumour cells in metabolically compromised microenvironments.

    Science.gov (United States)

    Zhang, Xiaonan; Fryknäs, Mårten; Hernlund, Emma; Fayad, Walid; De Milito, Angelo; Olofsson, Maria Hägg; Gogvadze, Vladimir; Dang, Long; Påhlman, Sven; Schughart, Leoni A Kunz; Rickardson, Linda; D'Arcy, Padraig; Gullbo, Joachim; Nygren, Peter; Larsson, Rolf; Linder, Stig

    2014-01-01

    Abnormal vascularization of solid tumours results in the development of microenvironments deprived of oxygen and nutrients that harbour slowly growing and metabolically stressed cells. Such cells display enhanced resistance to standard chemotherapeutic agents and repopulate tumours after therapy. Here we identify the small molecule VLX600 as a drug that is preferentially active against quiescent cells in colon cancer 3-D microtissues. The anticancer activity is associated with reduced mitochondrial respiration, leading to bioenergetic catastrophe and tumour cell death. VLX600 shows enhanced cytotoxic activity under conditions of nutrient starvation. Importantly, VLX600 displays tumour growth inhibition in vivo. Our findings suggest that tumour cells in metabolically compromised microenvironments have a limited ability to respond to decreased mitochondrial function, and suggest a strategy for targeting the quiescent populations of tumour cells for improved cancer treatment.

  16. Self-induced metabolic state switching by a tunable cell density sensor for microbial isopropanol production.

    Science.gov (United States)

    Soma, Yuki; Hanai, Taizo

    2015-07-01

    Chemicals production by engineered microorganisms often requires induction of target gene expression at an appropriate cell density to reduce conflict with cell growth. The lux system in Vibrio fischeri is a well-characterized model for cell density-dependent regulation of gene expression termed quorum sensing (QS). However, there are currently no reports for application of the lux system to microbial chemical production. Here, we constructed a synthetic lux system as a tunable cell density sensor-regulator using a synthetic lux promoter and a positive feedback loop in Escherichia coli. In this system, self-induction of a target gene expression is driven by QS-signal, and its threshold cell density can be changed depending on the concentration of a chemical inducer. We demonstrate auto-redirection of metabolic flux from central metabolic pathways toward a synthetic isopropanol pathway at a desired cell density resulting in a significant increase in isopropanol production.

  17. Kinetic characterization of vero cell metabolism in a serum-free batch culture process.

    Science.gov (United States)

    Petiot, Emma; Guedon, Emmanuel; Blanchard, Fabrice; Gény, Cécile; Pinton, Hervé; Marc, Annie

    2010-09-01

    A global kinetic study of the central metabolism of Vero cells cultivated in a serum-free medium is proposed in the present work. Central metabolism including glycolysis, glutaminolysis, and tricarboxylic acid cycle (TCA) was demonstrated to be saturated by high flow rates of consumption of the two major substrates, glucose, and glutamine. Saturation was reavealed by an accumulation of metabolic intermediates and amino acids, by a high production of lactate needed to balance the redox pathway, and by a low participation of the carbon flow to the TCA cycle supply. Different culture conditions were set up to reduce the central metabolism saturation and to better balance the metabolic flow rates between lactate production and energetic pathways. From these culture conditions, substitutions of glutamine by other carbon sources, which have lower transport rates such as asparagine, or pyruvate in order to shunt the glycolysis pathway, were successful to better balance the central metabolism. As a result, an increase of the cell growth with a concomitant decrease of cell death and a better distribution of the carbon flow between TCA cycle and lactate production occurred. We also demonstrated that glutamine was a major carbon source to supply the TCA cycle in Vero cells and that a reduction of lactate production did not necessary improve the efficiency of the Vero cell metabolism. Thus, to adapt the formulation of the medium to the Vero cell needs, it is important to provide carbon substrates inducing a regulated supply of carbon in the TCA cycle either through the glycolysis or through other pathways such as glutaminolysis. Finally, this study allowed to better understand the Vero cell behavior in serum-free medium which is a valuable help for the implementation of this cell line in serum-free industrial production processes. 2010 Wiley Periodicals, Inc.

  18. Dynamic metabolic flux analysis of plant cell wall synthesis.

    Science.gov (United States)

    Chen, Xuewen; Alonso, Ana P; Shachar-Hill, Yair

    2013-07-01

    The regulation of plant cell wall synthesis pathways remains poorly understood. This has become a bottleneck in designing bioenergy crops. The goal of this study was to analyze the regulation of plant cell wall precursor metabolism using metabolic flux analysis based on dynamic labeling experiments. Arabidopsis T87 cells were cultured heterotrophically with (13)C labeled sucrose. The time course of ¹³C labeling patterns in cell wall precursors and related sugar phosphates was monitored using liquid chromatography tandem mass spectrometry until steady state labeling was reached. A kinetic model based on mass action reaction mechanisms was developed to simulate the carbon flow in the cell wall synthesis network. The kinetic parameters of the model were determined by fitting the model to the labeling time course data, cell wall composition, and synthesis rates. A metabolic control analysis was performed to predict metabolic regulations that may improve plant biomass composition for biofuel production. Our results describe the routes and rates of carbon flow from sucrose to cell wall precursors. We found that sucrose invertase is responsible for the entry of sucrose into metabolism and UDP-glucose-4-epimerase plays a dominant role in UDP-Gal synthesis in heterotrophic Aradidopsis cells under aerobic conditions. We also predicted reactions that exert strong regulatory influence over carbon flow to cell wall synthesis and its composition.

  19. Yearly growth and metabolic changes in earthen pond-cultured meagre Argyrosomus regius

    Directory of Open Access Journals (Sweden)

    Luis Vargas-Chacoff

    2014-06-01

    Full Text Available Metabolic modifications associated with natural environmental conditions were assessed in the meagre Argyrosomus regius cultured in earthen ponds under natural photoperiod and temperature. Juvenile specimens (90-100 g initial weight were sampled (plasma, liver and muscle every two months for 18 months (between December 2004 and May 2006. Specimens showed seasonal variations in growth rate, with the highest values in spring and summer. Plasmatic, hepatic and muscular metabolite levels and hepatic and muscular metabolic enzymes also showed significant variations throughout the year. Enzymatic activity related to carbohydrate metabolism in the liver (HK, FBPase and G6PDH showed great modifications in summer, increasing glycogenogenic pathways, while amino acid metabolism (GDH and GOT activity was enhanced in spring and summer. However lipid-related (G3PDH activity metabolic enzymes did not show a clear seasonal pattern. In muscle, enzymatic activity related to amino acid, lipid and lactate metabolism (LDH-O activity, but not carbohydrate metabolism, showed seasonal changes in parallel with changes in growth rate. Thus A. regius specimens showed a trend to grow in summer months and mobilize their energy reserves in winter. Differences in the hepatic level were observed between the first and the second year of the study, suggesting the possible existence of metabolic changes related to specimen age or size. Our results indicate that growth and metabolic responses in A. regius are environmentally dependent and that this species is a very good candidate for diversification in aquaculture.

  20. Mapping cancer cell metabolism with 13 C flux analysis: Recent progress and future challenges

    Directory of Open Access Journals (Sweden)

    Casey Scott Duckwall

    2013-01-01

    Full Text Available The reprogramming of energy metabolism is emerging as an important molecular hallmark of cancer cells. Recent discoveries linking specific metabolic alterations to cancer development have strengthened the idea that altered metabolism is more than a side effect of malignant transformation, but may in fact be a functional driver of tumor growth and progression in some cancers. As a result, dysregulated metabolic pathways have become attractive targets for cancer therapeutics. This review highlights the application of 13 C metabolic flux analysis (MFA to map the flow of carbon through intracellular biochemical pathways of cancer cells. We summarize several recent applications of MFA that have identified novel biosynthetic pathways involved in cancer cell proliferation and shed light on the role of specific oncogenes in regulating these pathways. Through such studies, it has become apparent that the metabolic phenotypes of cancer cells are not as homogeneous as once thought, but instead depend strongly on the molecular alterations and environmental factors at play in each case.

  1. Toxic effects of linear alkylbenzene sulfonate on metabolic activity, growth rate, and microcolony formation of Nitrosomonas and Nitrosospira strains.

    Science.gov (United States)

    Brandt, K K; Hesselsøe, M; Roslev, P; Henriksen, K; Sørensen, J

    2001-06-01

    Strong inhibitory effects of the anionic surfactant linear alkylbenzene sulfonate (LAS) on four strains of autotrophic ammonia-oxidizing bacteria (AOB) are reported. Two Nitrosospira strains were considerably more sensitive to LAS than two Nitrosomonas strains were. Interestingly, the two Nitrosospira strains showed a weak capacity to remove LAS from the medium. This could not be attributed to adsorption or any other known physical or chemical process, suggesting that biodegradation of LAS took place. In each strain, the metabolic activity (50% effective concentration [EC(50)], 6 to 38 mg liter(-1)) was affected much less by LAS than the growth rate and viability (EC(50), 3 to 14 mg liter(-1)) were. However, at LAS levels that inhibited growth, metabolic activity took place only for 1 to 5 days, after which metabolic activity also ceased. The potential for adaptation to LAS exposure was investigated with Nitrosomonas europaea grown at a sublethal LAS level (10 mg liter(-1)); compared to control cells, preexposed cells showed severely affected cell functions (cessation of growth, loss of viability, and reduced NH(4)(+) oxidation activity), demonstrating that long-term incubation at sublethal LAS levels was also detrimental. Our data strongly suggest that AOB are more sensitive to LAS than most heterotrophic bacteria are, and we hypothesize that thermodynamic constraints make AOB more susceptible to surfactant-induced stress than heterotrophic bacteria are. We further suggest that AOB may comprise a sensitive indicator group which can be used to determine the impact of LAS on microbial communities.

  2. Lin28 and let-7 in cell metabolism and cancer.

    Science.gov (United States)

    Nguyen, Liem H; Zhu, Hao

    2015-01-01

    Malignant cells exhibit major metabolic alterations. The regulatory gene networks that regulate metabolism and the impact of these alterations on overall cellular fitness deserve further exploration. The let-7 microRNAs and their antagonists, the Lin28 RNA-binding proteins, are well-known for controlling the timing of embryonic development. This pathway has recently been shown to regulate glucose metabolism in adult mice and to reprogram metabolism during tissue injury and repair. In addition, many lines of evidence have established that Lin28 is an oncogene that drives tumorigenesis in part by suppressing let-7. The metabolic underpinnings of this oncogenic program are just beginning to be uncovered. Here, we will review the current understanding of how Lin28 exerts regenerative and oncogenic effects through metabolic mechanisms.

  3. Synergizing metabolic flux analysis and nucleotide sugar metabolism to understand the control of glycosylation of recombinant protein in CHO cells

    LENUS (Irish Health Repository)

    Burleigh, Susan C

    2011-10-18

    Abstract Background The glycosylation of recombinant proteins can be altered by a range of parameters including cellular metabolism, metabolic flux and the efficiency of the glycosylation process. We present an experimental set-up that allows determination of these key processes associated with the control of N-linked glycosylation of recombinant proteins. Results Chinese hamster ovary cells (CHO) were cultivated in shake flasks at 0 mM glutamine and displayed a reduced growth rate, glucose metabolism and a slower decrease in pH, when compared to other glutamine-supplemented cultures. The N-linked glycosylation of recombinant human chorionic gonadotrophin (HCG) was also altered under these conditions; the sialylation, fucosylation and antennarity decreased, while the proportion of neutral structures increased. A continuous culture set-up was subsequently used to understand the control of HCG glycosylation in the presence of varied glutamine concentrations; when glycolytic flux was reduced in the absence of glutamine, the glycosylation changes that were observed in shake flask culture were similarly detected. The intracellular content of UDP-GlcNAc was also reduced, which correlated with a decrease in sialylation and antennarity of the N-linked glycans attached to HCG. Conclusions The use of metabolic flux analysis illustrated a case of steady state multiplicity, where use of the same operating conditions at each steady state resulted in altered flux through glycolysis and the TCA cycle. This study clearly demonstrated that the control of glycoprotein microheterogeneity may be examined by use of a continuous culture system, metabolic flux analysis and assay of intracellular nucleotides. This system advances our knowledge of the relationship between metabolic flux and the glycosylation of biotherapeutics in CHO cells and will be of benefit to the bioprocessing industry.

  4. Synergizing metabolic flux analysis and nucleotide sugar metabolism to understand the control of glycosylation of recombinant protein in CHO cells

    Directory of Open Access Journals (Sweden)

    Rudd Pauline M

    2011-10-01

    Full Text Available Abstract Background The glycosylation of recombinant proteins can be altered by a range of parameters including cellular metabolism, metabolic flux and the efficiency of the glycosylation process. We present an experimental set-up that allows determination of these key processes associated with the control of N-linked glycosylation of recombinant proteins. Results Chinese hamster ovary cells (CHO were cultivated in shake flasks at 0 mM glutamine and displayed a reduced growth rate, glucose metabolism and a slower decrease in pH, when compared to other glutamine-supplemented cultures. The N-linked glycosylation of recombinant human chorionic gonadotrophin (HCG was also altered under these conditions; the sialylation, fucosylation and antennarity decreased, while the proportion of neutral structures increased. A continuous culture set-up was subsequently used to understand the control of HCG glycosylation in the presence of varied glutamine concentrations; when glycolytic flux was reduced in the absence of glutamine, the glycosylation changes that were observed in shake flask culture were similarly detected. The intracellular content of UDP-GlcNAc was also reduced, which correlated with a decrease in sialylation and antennarity of the N-linked glycans attached to HCG. Conclusions The use of metabolic flux analysis illustrated a case of steady state multiplicity, where use of the same operating conditions at each steady state resulted in altered flux through glycolysis and the TCA cycle. This study clearly demonstrated that the control of glycoprotein microheterogeneity may be examined by use of a continuous culture system, metabolic flux analysis and assay of intracellular nucleotides. This system advances our knowledge of the relationship between metabolic flux and the glycosylation of biotherapeutics in CHO cells and will be of benefit to the bioprocessing industry.

  5. Integrated metabolomics and transcriptomics reveal enhanced specialized metabolism in Medicago truncatula root border cells.

    Science.gov (United States)

    Watson, Bonnie S; Bedair, Mohamed F; Urbanczyk-Wochniak, Ewa; Huhman, David V; Yang, Dong Sik; Allen, Stacy N; Li, Wensheng; Tang, Yuhong; Sumner, Lloyd W

    2015-04-01

    Integrated metabolomics and transcriptomics of Medicago truncatula seedling border cells and root tips revealed substantial metabolic differences between these distinct and spatially segregated root regions. Large differential increases in oxylipin-pathway lipoxygenases and auxin-responsive transcript levels in border cells corresponded to differences in phytohormone and volatile levels compared with adjacent root tips. Morphological examinations of border cells revealed the presence of significant starch deposits that serve as critical energy and carbon reserves, as documented through increased β-amylase transcript levels and associated starch hydrolysis metabolites. A substantial proportion of primary metabolism transcripts were decreased in border cells, while many flavonoid- and triterpenoid-related metabolite and transcript levels were increased dramatically. The cumulative data provide compounding evidence that primary and secondary metabolism are differentially programmed in border cells relative to root tips. Metabolic resources normally destined for growth and development are redirected toward elevated accumulation of specialized metabolites in border cells, resulting in constitutively elevated defense and signaling compounds needed to protect the delicate root cap and signal motile rhizobia required for symbiotic nitrogen fixation. Elevated levels of 7,4'-dihydroxyflavone were further increased in border cells of roots exposed to cotton root rot (Phymatotrichopsis omnivora), and the value of 7,4'-dihydroxyflavone as an antimicrobial compound was demonstrated using in vitro growth inhibition assays. The cumulative and pathway-specific data provide key insights into the metabolic programming of border cells that strongly implicate a more prominent mechanistic role for border cells in plant-microbe signaling, defense, and interactions than envisioned previously.

  6. Unique growth pattern of human mammary epithelial cells induced by polymeric nanoparticles.

    Science.gov (United States)

    Hussien, Rajaa; Rihn, Bertrand H; Eidi, Housam; Ronzani, Carole; Joubert, Olivier; Ferrari, Luc; Vazquez, Oscar; Kaufer, Daniela; Brooks, George A

    2013-09-01

    Due to their unique properties, engineered nanoparticles (NPs) have found broad use in industry, technology, and medicine, including as a vehicle for drug delivery. However, the understanding of NPs' interaction with different types of mammalian cells lags significantly behind their increasing adoption in drug delivery. In this study, we show unique responses of human epithelial breast cells when exposed to polymeric Eudragit® RS NPs (ENPs) for 1-3 days. Cells displayed dose-dependent increases in metabolic activity and growth, but lower proliferation rates, than control cells, as evidenced in tetrazolium salt (WST-1) and 5-bromo-2'-deoxyuridine (BrdU) assays, respectively. Those effects did not affect cell death or mitochondrial fragmentation. We attribute the increase in metabolic activity and growth of cells culture with ENPs to three factors: (1) high affinity of proteins present in the serum for ENPs, (2) adhesion of ENPs to cells, and (3) activation of proliferation and growth pathways. The proteins and genes responsible for stimulating cell adhesion and growth were identified by mass spectrometry and Microarray analyses. We demonstrate a novel property of ENPs, which act to increase cell metabolic activity and growth and organize epithelial cells in the epithelium as determined by Microarray analysis.

  7. Metabolic Effects of Cobalt Ferrite Nanoparticles on Cervical Carcinoma Cells and Nontumorigenic Keratinocytes.

    Science.gov (United States)

    Oliveira, Ana Beatriz Bortolozo; de Moraes, Fabio Rogério; Candido, Natalia Maria; Sampaio, Isabella; Paula, Alex Silva; de Vasconcellos, Adriano; Silva, Thais Cerqueira; Miller, Alex Henrique; Rahal, Paula; Nery, Jose Geraldo; Calmon, Marilia Freitas

    2016-12-02

    The cytotoxic response, cellular uptake, and metabolomic profile of HeLa and HaCaT cell lines treated with cobalt ferrite nanoparticles (CoFe2O4 NPs) were investigated in this study. Cell viability assays showed low cytotoxicity caused by the uptake of the nanoparticles at 2 mg/mL. However, metabolomics revealed that these nanoparticles impacted cell metabolism even when tested at a concentration that presented low cytotoxicity according to the cell viability assay. The two cell lines shared stress-related metabolic changes such as increase in alanine and creatine levels. A reduced level of fumarate was also observed in HeLa cells after treatment with the nanoparticles, and this alteration can inhibit tumorigenesis. Fumarate is considered to be an oncometabolite that can inhibit prolyl hydroxylase, and this inhibition stabilizes HIF1α, one of the master regulators of tumorigenesis that promotes tumor growth and development. In summary, this study showed that nanoparticle-treated HeLa cells demonstrated decreased concentrations of metabolites associated with cell proliferation and tumor growth. The results clearly indicated that treatment with these nanoparticles might cause a perturbation in cellular metabolism.

  8. The effect of metformin in growth and energy metabolism of follicular thyroid cancer cell%二甲双胍对人滤泡状甲状腺癌细胞生长和能量代谢的影响

    Institute of Scientific and Technical Information of China (English)

    张斯亮; 郭慧玲; 王红; 关海霞; 单忠艳; 滕卫平

    2016-01-01

    Objective:To investigate the effects of different concentration metformin on proliferation,apoptosis and energy metabolism of follicular thyroid cancer(FTC). Methods:After treating with metformin(0,1,3,10mmol/ L), the viability of FTC cell line(FTC - 133)was analyzed by 3 -(4,5 - dimethyl - thiazol - 2 - yl)- 2,5 - dipheny-ltetrazoliumbromide(MTT). Cell cycle analysis was performed by AnnexinV - FITC/ PI flow cytometry,the energy metabolism of FTC - 133 was tested by Seahorse. Results:Compared with control group,MTT assays showed that the proliferation of FTC - 133 was inhibited in a dose - time dependent manner after treating with metformin(P < 0. 05). Moreover,metformin induced the late apoptosis of FTC - 133(P < 0. 05). Metformin changed the pattern of cell ener-gy metabolism,manifested with a significant decrease in glycolysis and mitochondrial respiration of FTC - 133 in a dose - time dependent manner(P < 0. 05). Conclusion:Metformin provided an anti - tumor effect in FTC - 133 which may be mediated by decreasing the energy supply of cancer cells.%目的:观察不同浓度二甲双胍对人滤泡状甲状腺癌(follicular thyroid cancer,FTC)细胞增殖、凋亡及能量代谢的影响。方法:体外培养人 FTC 细胞(FTC -133),分为对照组和不同浓度二甲双胍处理组(1、3和10mmol/ L),分别培养24h、48h 和72h。四甲基偶氮唑蓝(MTT)法检测细胞增殖,Annexin V - FITC/ PI 流式细胞术检测细胞凋亡,Seahorse 能量代谢分析仪检测细胞糖酵解及线粒体呼吸的变化。结果:与对照组相比,二甲双胍抑制 FTC -133增殖,随浓度及处理时间的增加,抑制效应加大,呈剂量-时间依赖性(P <0.05)。二甲双胍诱导 FTC -133凋亡,随浓度及处理时间的增加,其中晚期凋亡率明显增加,呈剂量-时间依赖性(P <0.05)。二甲双胍可影响 FTC -133糖代谢,与对照组相比,随二甲双胍浓度增加,糖酵解和线粒

  9. [Biological activities of exogenous polysaccharides via controlling endogenous proteoglycan metabolism in vascular endothelial cells].

    Science.gov (United States)

    Sato, Tomoko; Yamamoto, Chika; Fujiwara, Yasuyuki; Kaji, Toshiyuki

    2008-05-01

    Proteoglycan contains glycosmainoglycans, which are endogenous sulfated polysaccharides, in the molecule. The metabolism of proteoglycans regulates cell behavior and cellular events. It is possible that exogenous polysaccharide-related molecules exhibit their biological activities by two mechanisms. One is the interaction with cells and the other is the interaction with growth factors/cytokines that regulate proteoglycans. In this review, we describe sodium spirulan, a sulfated polysaccharide obtained from a hot-water extract of the blue-green alga Spirulina platensis, as an exogenous polysaccharide that stimulates the release of proteoglycans from vascular endothelial cells. Factors that regulate endothelial proteoglycan metabolism are also being described as possible target molecules of exogenous polysaccharides. Further research is required to obtain exogenous polysaccharide-related molecules that exhibit useful biological activities through controlling endothelial proteoglycan metabolism for protection against vascular lesions such as atheroslcerosis.

  10. Shape of growth cells in directional solidification.

    Science.gov (United States)

    Pocheau, A; Georgelin, M

    2006-01-01

    The purpose of this study is to characterize experimentally the whole shape of the growth cells displayed in directional solidification and its evolution with respect to control parameters. A library of cells is first built up from observation of directional solidification of a succinonitrile alloy in a large range of pulling velocity, cell spacing, and thermal gradient. Cell boundaries are then extracted from these images and fitted by trial functions on their whole profile, from cell tip to cell grooves. A coherent evolution of the fit parameters with the control parameters is evidenced. It enables us to characterize the whole cell shape by a single function involving only two parameters which vary smoothly in the control parameter space. This, in particular, evidences a continuous evolution of the cell geometry at the cell to dendrite transition which denies the existence of a change of branch of solutions at the occurrence of sidebranching. More generally, this global determination of cell shape complemented with a previous determination of the position of cells in the thermal field (the cell tip undercooling) provides a complete characterization of growth solutions and of their evolutions in this system. It thus brings about a relevant framework for testing and improving theoretical and numerical understanding of cell shapes and cell stability in directional solidification.

  11. Elucidating the role of copper in CHO cell energy metabolism using (13)C metabolic flux analysis.

    Science.gov (United States)

    Nargund, Shilpa; Qiu, Jinshu; Goudar, Chetan T

    2015-01-01

    (13)C-metabolic flux analysis was used to understand copper deficiency-related restructuring of energy metabolism, which leads to excessive lactate production in recombinant protein-producing CHO cells. Stationary-phase labeling experiments with U-(13)C glucose were conducted on CHO cells grown under high and limiting copper in 3 L fed-batch bioreactors. The resultant labeling patterns of soluble metabolites were measured by GC-MS and used to estimate metabolic fluxes in the central carbon metabolism pathways using OpenFlux. Fluxes were evaluated 300 times from stoichiometrically feasible random guess values and their confidence intervals calculated by Monte Carlo simulations. Results from metabolic flux analysis exhibited significant carbon redistribution throughout the metabolic network in cells under Cu deficiency. Specifically, glycolytic fluxes increased (25%-79% relative to glucose uptake) whereas fluxes through the TCA and pentose phosphate pathway (PPP) were lower (15%-23% and 74%, respectively) compared with the Cu-containing condition. Furthermore, under Cu deficiency, 33% of the flux entering TCA via the pyruvate node was redirected to lactate and malate production. Based on these results, we hypothesize that Cu deficiency disrupts the electron transport chain causing ATP deficiency, redox imbalance, and oxidative stress, which in turn drive copper-deficient CHO cells to produce energy via aerobic glycolysis, which is associated with excessive lactate production, rather than the more efficient route of oxidative phosphorylation.

  12. Arginine Metabolism in Myeloid Cells Shapes Innate and Adaptive Immunity

    Science.gov (United States)

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

    2017-01-01

    Arginine metabolism has been a key catabolic and anabolic process throughout the evolution of the immune response. Accruing evidence indicates that arginine-catabolizing enzymes, mainly nitric oxide synthases and arginases, are closely integrated with the control of immune response under physiological and pathological conditions. Myeloid cells are major players that exploit the regulators of arginine metabolism to mediate diverse, although often opposing, immunological and functional consequences. In this article, we focus on the importance of arginine catabolism by myeloid cells in regulating innate and adaptive immunity. Revisiting this matter could result in novel therapeutic approaches by which the immunoregulatory nodes instructed by arginine metabolism can be targeted.

  13. Metabolic fingerprints of altered brain growth, osmoregulation and neurotransmission in a Rett syndrome model.

    Directory of Open Access Journals (Sweden)

    Angèle Viola

    Full Text Available BACKGROUND: Rett syndrome (RS is the leading cause of profound mental retardation of genetic origin in girls. Since RS is mostly caused by mutations in the MECP2 gene, transgenic animal models such as the Mecp2-deleted ("Mecp2-null" mouse have been employed to study neurological symptoms and brain function. However, an interdisciplinary approach drawing from chemistry, biology and neuroscience is needed to elucidate the mechanistic links between the genotype and phenotype of this genetic disorder. METHODOLOGY/PRINCIPAL FINDINGS: We performed, for the first time, a metabolomic study of brain extracts from Mecp2-null mice by using high-resolution magnetic resonance spectroscopy. A large number of individual water-soluble metabolites and phospholipids were quantified without prior selection for specific metabolic pathways. Results were interpreted in terms of Mecp2 gene deletion, brain cell function and brain morphology. This approach provided a "metabolic window" to brain characteristics in Mecp2-null mice (n = 4, revealing (i the first metabolic evidence of astrocyte involvement in RS (decreased levels of the astrocyte marker, myo-inositol, vs. wild-type mice; p = 0.034; (ii reduced choline phospholipid turnover in Mecp2-null vs. wild-type mice, implying a diminished potential of cells to grow, paralleled by globally reduced brain size and perturbed osmoregulation; (iii alterations of the platelet activating factor (PAF cycle in Mecp2-null mouse brains, where PAF is a bioactive lipid acting on neuronal growth, glutamate exocytosis and other processes; and (iv changes in glutamine/glutamate ratios (p = 0.034 in Mecp2-null mouse brains potentially indicating altered neurotransmitter recycling. CONCLUSIONS/SIGNIFICANCE: This study establishes, for the first time, detailed metabolic fingerprints of perturbed brain growth, osmoregulation and neurotransmission in a mouse model of Rett syndrome. Combined with morphological and neurological findings

  14. Segregated mathematical model for growth of anchorage-dependent MDCK cells in microcarrier culture.

    Science.gov (United States)

    Möhler, Lars; Bock, Andreas; Reichl, Udo

    2008-01-01

    To describe the growth behavior of anchorage-dependent mammalian cells in microcarrier systems, various approaches comprising deterministic and stochastic single cell models as well as automaton-based models have been presented in the past. The growth restriction of these often contact-inhibited cells by spatial effects is described at levels with different complexity but for the most part not taking into account their metabolic background. Compared to suspension cell lines these cells have a comparatively long lag phase required for attachment and start of proliferation on the microcarrier. After an initial phase of exponential growth only a moderate specific growth rate is achieved due to restrictions in space available for cell growth, limiting medium components, and accumulation of growth inhibitors. Here, a basic deterministic unstructured segregated cell model for growth of Madin Darby Canine Kidney (MDCK) cells used in influenza vaccine production is described. Four classes of cells are considered: cells on microcarriers, cells in suspension, dead cells, and lysed cells. Based on experimental data, cell attachment and detachment is taken explicitly into account. The model allows simulation of the overall growth behavior in microcarrier culture, including the lag phase. In addition, it describes the time course of uptake and release of key metabolites and the identification of parameters relevant for the design and optimization of vaccine manufacturing processes.

  15. Prediction of microbial growth rate versus biomass yield by a metabolic network with kinetic parameters.

    Science.gov (United States)

    Adadi, Roi; Volkmer, Benjamin; Milo, Ron; Heinemann, Matthias; Shlomi, Tomer

    2012-01-01

    Identifying the factors that determine microbial growth rate under various environmental and genetic conditions is a major challenge of systems biology. While current genome-scale metabolic modeling approaches enable us to successfully predict a variety of metabolic phenotypes, including maximal biomass yield, the prediction of actual growth rate is a long standing goal. This gap stems from strictly relying on data regarding reaction stoichiometry and directionality, without accounting for enzyme kinetic considerations. Here we present a novel metabolic network-based approach, MetabOlic Modeling with ENzyme kineTics (MOMENT), which predicts metabolic flux rate and growth rate by utilizing prior data on enzyme turnover rates and enzyme molecular weights, without requiring measurements of nutrient uptake rates. The method is based on an identified design principle of metabolism in which enzymes catalyzing high flux reactions across different media tend to be more efficient in terms of having higher turnover numbers. Extending upon previous attempts to utilize kinetic data in genome-scale metabolic modeling, our approach takes into account the requirement for specific enzyme concentrations for catalyzing predicted metabolic flux rates, considering isozymes, protein complexes, and multi-functional enzymes. MOMENT is shown to significantly improve the prediction accuracy of various metabolic phenotypes in E. coli, including intracellular flux rates and changes in gene expression levels under different growth rates. Most importantly, MOMENT is shown to predict growth rates of E. coli under a diverse set of media that are correlated with experimental measurements, markedly improving upon existing state-of-the art stoichiometric modeling approaches. These results support the view that a physiological bound on cellular enzyme concentrations is a key factor that determines microbial growth rate.

  16. Metabolic and protein interaction sub-networks controlling the proliferation rate of cancer cells and their impact on patient survival.

    Science.gov (United States)

    Feizi, Amir; Bordel, Sergio

    2013-10-24

    Cancer cells can have a broad scope of proliferation rates. Here we aim to identify the molecular mechanisms that allow some cancer cell lines to grow up to 4 times faster than other cell lines. The correlation of gene expression profiles with the growth rate in 60 different cell lines has been analyzed using several genome-scale biological networks and new algorithms. New possible regulatory feedback loops have been suggested and the known roles of several cell cycle related transcription factors have been confirmed. Over 100 growth-correlated metabolic sub-networks have been identified, suggesting a key role of simultaneous lipid synthesis and degradation in the energy supply of the cancer cells growth. Many metabolic sub-networks involved in cell line proliferation appeared also to correlate negatively with the survival expectancy of colon cancer patients.

  17. Targeted killing of a mammalian cell based upon its specialized metabolic state.

    Science.gov (United States)

    Alexander, Peter B; Wang, Jian; McKnight, Steven L

    2011-09-20

    Mouse ES cells use a mitochondrial threonine dehydrogenase (TDH) enzyme to catabolize threonine into glycine and acetyl-CoA. Measurements of mRNA abundance have given evidence that ES cells express upwards of 1,000-fold higher levels of TDH mRNA than any of seven other mouse tissues tested. When cell culture medium is deprived of threonine, ES cells rapidly discontinue DNA synthesis, arrest cell division, and eventually die. Such studies led to the conclusion that mouse ES cells exist in a threonine-dependent metabolic state. Proceeding with the assumption that the active TDH enzyme should be essential for the growth and viability of mouse ES cells, we performed a drug screen in search of specific inhibitors of the purified TDH enzyme. Such efforts led to the discovery of a class of quinazolinecarboxamide (Qc) compounds that inhibit the ability of the TDH enzyme to catabolize threonine into glycine and acetyl-CoA. Administration of Qc inhibitors of TDH to mouse ES cells impeded cell growth and resulted in the induction of autophagy. By contrast, the same chemicals failed to affect the growth of HeLa cells at concentrations 300-fold higher than that required to kill mouse ES cells. It was likewise observed that the Qc class of TDH inhibitors failed to affect the growth or viability of ES cell-derived embryoid body cells known to have extinguished TDH expression. These studies demonstrate how it is possible to kill a specific mammalian cell type on the basis of its specialized metabolic state.

  18. Two-dimensional diffusion limited system for cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Hlatky, L.

    1985-11-01

    A new cell system, the ''sandwich'' system, was developed to supplement multicellular spheroids as tumor analogues. Sandwiches allow new experimental approaches to questions of diffusion, cell cycle effects and radiation resistance in tumors. In this thesis the method for setting up sandwiches is described both theoretically and experimentally followed by its use in x-ray irradiation studies. In the sandwich system, cells are grown in a narrow gap between two glass slides. Where nutrients and waste products can move into or out of the local environment of the cells only by diffusing through the narrow gap between the slides. Due to the competition between cells, self-created gradients of nutrients and metabolic products are set up resulting in a layer of cells which resembles a living spheroid cross section. Unlike the cells of the spheroid, however, cells in all regions of the sandwich are visible. Therefore, the relative sizes of the regions and their time-dependent growth can be monitored visually without fixation or sectioning. The oxygen and nutrient gradients can be ''turned off'' at any time without disrupting the spatial arrangement of the cells by removing the top slide of the assembly and subsequently turned back on if desired. Removal of the top slide also provides access to all the cells, including those near the necrotic center, of the sandwich. The cells can then be removed for analysis outside the sandwich system. 61 refs., 17 figs.

  19. Evidence for a metabolic shift of arginine metabolism in sickle cell disease

    NARCIS (Netherlands)

    Schnog, JJB; Jager, EH; van der Dijs, FPL; Duits, AJ; Moshage, H; Muskiet, FD; Muskiet, FAJ

    2004-01-01

    Over the last few years, a pivotal role has been ascribed to reduced nitric oxide (NO) availability as a contributing factor to the vaso-occlusive process of sickle cell disease. We investigated whether arginine metabolism in sickle cell patients is different from healthy controls. Blood samples wer

  20. Evidence for a metabolic shift of arginine metabolism in sickle cell disease

    NARCIS (Netherlands)

    Schnog, JJB; Jager, EH; van der Dijs, FPL; Duits, AJ; Moshage, H; Muskiet, FD; Muskiet, FAJ

    2004-01-01

    Over the last few years, a pivotal role has been ascribed to reduced nitric oxide (NO) availability as a contributing factor to the vaso-occlusive process of sickle cell disease. We investigated whether arginine metabolism in sickle cell patients is different from healthy controls. Blood samples wer

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

    Institute of Scientific and Technical Information of China (English)

    Elitsa; Ananieva

    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 oftencompete 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.

  2. Effect of Organic Solvents on Microalgae Growth, Metabolism and Industrial Bioproduct Extraction: A Review

    Science.gov (United States)

    Miazek, Krystian; Sulc, Radek; Jirout, Tomas; Aguedo, Mario; Goffin, Dorothee

    2017-01-01

    In this review, the effect of organic solvents on microalgae cultures from molecular to industrial scale is presented. Traditional organic solvents and solvents of new generation-ionic liquids (ILs), are considered. Alterations in microalgal cell metabolism and synthesis of target products (pigments, proteins, lipids), as a result of exposure to organic solvents, are summarized. Applications of organic solvents as a carbon source for microalgal growth and production of target molecules are discussed. Possible implementation of various industrial effluents containing organic solvents into microalgal cultivation media, is evaluated. The effect of organic solvents on extraction of target compounds from microalgae is also considered. Techniques for lipid and carotenoid extraction from viable microalgal biomass (milking methods) and dead microalgal biomass (classical methods) are depicted. Moreover, the economic survey of lipid and carotenoid extraction from microalgae biomass, by means of different techniques and solvents, is conducted. PMID:28677659

  3. Growth and by-product profiles of Kluyveromyces marxianus cells immobilized in foamed alginate.

    Science.gov (United States)

    Wilkowska, Agnieszka; Kregiel, Dorota; Guneser, Onur; Karagul Yuceer, Yonca

    2015-01-01

    The aim of this research was to study how the yeast cell immobilization technique influences the growth and fermentation profiles of Kluyveromyces marxianus cultivated on apple/chokeberry and apple/cranberry pomaces. Encapsulation of the cells was performed by droplet formation from a foamed alginate solution. The growth and metabolic profiles were evaluated for both free and immobilized cells. Culture media with fruit waste produced good growth of free as well as immobilized yeast cells. The fermentation profiles of K. marxianus were different with each waste material. The most varied aroma profiles were noted for immobilized yeast cultivated on apple/chokeberry pomace.

  4. Different functions of AKT1 and AKT2 in molecular pathways, cell migration and metabolism in colon cancer cells.

    Science.gov (United States)

    Häggblad Sahlberg, Sara; Mortensen, Anja C; Haglöf, Jakob; Engskog, Mikael K R; Arvidsson, Torbjörn; Pettersson, Curt; Glimelius, Bengt; Stenerlöw, Bo; Nestor, Marika

    2017-01-01

    AKT is a central protein in many cellular pathways such as cell survival, proliferation, glucose uptake, metabolism, angiogenesis, as well as radiation and drug response. The three isoforms of AKT (AKT1, AKT2 and AKT3) are proposed to have different physiological functions, properties and expression patterns in a cell type-dependent manner. As of yet, not much is known about the influence of the different AKT isoforms in the genome and their effects in the metabolism of colorectal cancer cells. In the present study, DLD-1 isogenic AKT1, AKT2 and AKT1/2 knockout colon cancer cell lines were used as a model system in conjunction with the parental cell line in order to further elucidate the differences between the AKT isoforms and how they are involved in various cellular pathways. This was done using genome wide expression analyses, metabolic profiling and cell migration assays. In conclusion, downregulation of genes in the cell adhesion, extracellular matrix and Notch-pathways and upregulation of apoptosis and metastasis inhibitory genes in the p53-pathway, confirm that the knockout of both AKT1 and AKT2 will attenuate metastasis and tumor cell growth. This was verified with a reduction in migration rate in the AKT1 KO and AKT2 KO and most explicitly in the AKT1/2 KO. Furthermore, the knockout of AKT1, AKT2 or both, resulted in a reduction in lactate and alanine, suggesting that the metabolism of carbohydrates and glutathione was impaired. This was further verified in gene expression analyses, showing downregulation of genes involved in glucose metabolism. Additionally, both AKT1 KO and AKT2 KO demonstrated an impaired fatty acid metabolism. However, genes were upregulated in the Wnt and cell proliferation pathways, which could oppose this effect. AKT inhibition should therefore be combined with other effectors to attain the best effect.

  5. New paradigms for metabolic modeling of human cells

    DEFF Research Database (Denmark)

    Mardinoglu, Adil; Nielsen, Jens

    2015-01-01

    Abnormalities in cellular functions are associated with the progression of human diseases, often resulting in metabolic reprogramming. GEnome-scale metabolic Models (GEMs) have enabled studying global metabolic reprogramming in connection with disease development in a systematic manner. Here we......, challenges in integration of cell/tissue models for simulation of whole body functions as well as integration of GEMs with other biological networks for generating complete cell/tissue models are presented....... review recent work on reconstruction of GEMs for human cell/tissue types and cancer, and the use of GEMs for identification of metabolic changes occurring in response to disease development. We further discuss how GEMs can be used for the development of efficient therapeutic strategies. Finally...

  6. Developmental role for endocannabinoid signaling in regulating glucose metabolism and growth.

    Science.gov (United States)

    Li, Zhiying; Schmidt, Sarah F; Friedman, Jeffrey M

    2013-07-01

    Treatment of ob/ob (obese) mice with a cannabinoid receptor 1 (Cnr1) antagonist reduces food intake, suggesting a role for endocannabinoid signaling in leptin action. We further evaluated the role of endocannabinoid signaling by analyzing the phenotype of Cnr1 knockout ob/ob mice. Double mutant animals show a more severe growth retardation than ob/ob mice with similar levels of adiposity and reduced IGF-I levels without alterations of growth hormone (GH) levels. The double mutant mice are also significantly more glucose intolerant than ob/ob mice. This is in contrast to treatment of ob/ob mice with a Cnr1 antagonist that had no effect on glucose metabolism, suggesting a possible requirement for endocannabinoid signaling during development for normal glucose homeostasis. Double mutant animals also showed similar leptin sensitivity as ob/ob mice, suggesting that there are developmental changes that compensate for the loss of Cnr1 signaling. These data establish a role for Cnr1 during development and suggest that compensatory changes during development may mitigate the requirement for Cnr1 in mediating the effects of leptin. The data also suggest a developmental role for Cnr1 to promote growth, regulate the GH/IGF-I axis, and improve β-cell function and glucose homeostasis in the setting of leptin deficiency.

  7. Effect of moderate electric field frequency on growth kinetics and metabolic activity of Lactobacillus acidophilus.

    Science.gov (United States)

    Loghavi, Laleh; Sastry, Sudhir K; Yousef, Ahmed E

    2008-01-01

    Moderate electric fields (MEF) have been previously shown to alter the metabolic activity of microbial cells; thus, the effect of frequency and electric field would be of considerable interest. We investigated herein the effects of MEF frequency on microbial growth kinetics and bacteriocin (Lacidin A) production of Lactobacillus acidophilus OSU 133 during fermentation. The following fermentation treatments were compared: conventional (for 40 h), MEF (1 V cm(-1), for 40 h), combination of MEF (1 V cm(-1), for the first 5 h) and conventional (for 35 h) at various frequency levels (45, 60, and 90 Hz) all at 30 degrees C, and control (conventional) fermentation at 37 degrees C. MEF treatments with purely sinusoidal waveforms at all frequencies at 30 degrees C produced a shorter lag phase than conventional fermentation. However, no lag phase reduction was found for a 60 Hz waveform that contained high-frequency harmonics. There was, however, a significant increase in the bacteriocin production under early MEF treatment at 60 Hz with high-frequency harmonics. On the basis of these observations, the fermentation process is accelerated by applying pure sinusoidal MEF at the early stage of growth while a significant increase in the bacteriocin production occurs when sinusoidal field at 60 Hz with harmonics is applied at the early stage of the growth.

  8. Achieving optimal growth through product feedback inhibition in metabolism.

    Directory of Open Access Journals (Sweden)

    Sidhartha Goyal

    2010-06-01

    Full Text Available Recent evidence suggests that the metabolism of some organisms, such as Escherichia coli, is remarkably efficient, producing close to the maximum amount of biomass per unit of nutrient consumed. This observation raises the question of what regulatory mechanisms enable such efficiency. Here, we propose that simple product-feedback inhibition by itself is capable of leading to such optimality. We analyze several representative metabolic modules--starting from a linear pathway and advancing to a bidirectional pathway and metabolic cycle, and finally to integration of two different nutrient inputs. In each case, our mathematical analysis shows that product-feedback inhibition is not only homeostatic but also, with appropriate feedback connections, can minimize futile cycling and optimize fluxes. However, the effectiveness of simple product-feedback inhibition comes at the cost of high levels of some metabolite pools, potentially associated with toxicity and osmotic imbalance. These large metabolite pool sizes can be restricted if feedback inhibition is ultrasensitive. Indeed, the multi-layer regulation of metabolism by control of enzyme expression, enzyme covalent modification, and allostery is expected to result in such ultrasensitive feedbacks. To experimentally test whether the qualitative predictions from our analysis of feedback inhibition apply to metabolic modules beyond linear pathways, we examine the case of nitrogen assimilation in E. coli, which involves both nutrient integration and a metabolic cycle. We find that the feedback regulation scheme suggested by our mathematical analysis closely aligns with the actual regulation of the network and is sufficient to explain much of the dynamical behavior of relevant metabolite pool sizes in nutrient-switching experiments.

  9. Effects of growth hormone transgenesis on metabolic rate, exercise performance and hypoxia tolerance in tilapia hybrids

    DEFF Research Database (Denmark)

    McKenzie, DJ; Martinez, R; Morales, A

    2003-01-01

    Swimming respirometry was employed to compare inactive metabolic rate (Rr), maximum metabolic rate (Rmax), resultant aerobic scope and maximum sustainable (critical) swimming speed (Ucrit), in growth hormone transgenic (GHT) and wild-type (W) tilapia Oreochromis sp. hybrids. Although the Rr of GHT...... tilapia also exhibited the same capacity to regulate oxygen uptake during progressive hypoxia, despite the fact that the GHT fish were defending a higher demand for O2. The results indicate that ectopic expression of GH raises metabolic rate in tilapia, but the fish compensate for this metabolic load...

  10. Temperature dependences of growth rates and carrying capacities of marine bacteria depart from metabolic theoretical predictions

    KAUST Repository

    Huete-Stauffer, Tamara Megan

    2015-09-11

    Using the metabolic theory of ecology (MTE) framework, we evaluated over a whole annual cycle the monthly responses to temperature of the growth rates (μ) and carrying capacities (K) of heterotrophic bacterioplankton at a temperate coastal site. We used experimental incubations spanning 6oC with bacterial physiological groups identified by flow cytometry according to membrane integrity (live), nucleic acid content (HNA and LNA) and respiratory activity (CTC+). The temperature dependence of μat the exponential phase of growth was summarized by the activation energy (E), which was variable (-0.52 to 0.72 eV) but followed a seasonal pattern, only reaching the hypothesized value for aerobic heterotrophs of 0.65 eV during the spring bloom for the most active bacterial groups (live, HNA, CTC+). K (i.e. maximum experimental abundance) peaked at 4 × 106 cells mL-1 and generally covaried with μbut, contrary to MTE predictions, it did not decrease consistently with temperature. In the case of live cells, the responses of μand K to temperature were positively correlated and related to seasonal changes in substrate availability, indicating that the responses of bacteria to warming are far from homogeneous and poorly explained by MTE at our site. © FEMS 2015.

  11. Single-cell level based approach to investigate acetate metabolism during batch industrial fermentation

    DEFF Research Database (Denmark)

    Nierychlo, Marta; Larsen, Poul; Eriksen, Niels T.

    and control the overflow metabolism phenomenon in E. coli. Even though acetate formation by E. coli have been studied for more than three decades, the literature published presents the results based on the average measurement of the whole population. The averaged data can mask the distribution of the activity......Acetate is a product of Escherichia coli overflow metabolism when the bacteria are grown under aerobic conditions and glucose is present in excessive amount. It is an undesirable byproduct that affects growth, physiology, and performance of E. coli when used in industrial bioprocesses; its...... on the sub-population level. We hypothesized that during the fermentation process, bacterial subpopulation exist, which exhibit different metabolic strategies towards the acetate. In this study, pure culture of Escherichia coli MG1655 was used to investigate in situ acetate metabolism at single-cell level...

  12. Exo-MFA - A 13C metabolic flux analysis framework to dissect tumor microenvironment-secreted exosome contributions towards cancer cell metabolism.

    Science.gov (United States)

    Achreja, Abhinav; Zhao, Hongyun; Yang, Lifeng; Yun, Tae Hyun; Marini, Juan; Nagrath, Deepak

    2017-09-01

    Dissecting the pleiotropic roles of tumor micro-environment (TME) on cancer progression has been brought to the foreground of research on cancer pathology. Extracellular vesicles such as exosomes, transport proteins, lipids, and nucleic acids, to mediate intercellular communication between TME components and have emerged as candidates for anti-cancer therapy. We previously reported that cancer-associated fibroblast (CAF) derived exosomes (CDEs) contain metabolites in their cargo that are utilized by cancer cells for central carbon metabolism and promote cancer growth. However, the metabolic fluxes involved in donor cells towards packaging of metabolites in extracellular vesicles and exosome-mediated metabolite flux upregulation in recipient cells are still not known. Here, we have developed a novel empirical and computational technique, exosome-mediated metabolic flux analysis (Exo-MFA) to quantify flow of cargo from source cells to recipient cells via vesicular transport. Our algorithm, which is based on (13)C metabolic flux analysis, successfully predicts packaging fluxes to metabolite cargo in CAFs, dynamic changes in rate of exosome internalization by cancer cells, and flux of cargo release over time. We find that cancer cells internalize exosomes rapidly leading to depletion of extracellular exosomes within 24h. However, metabolite cargo significantly alters intracellular metabolism over the course of 24h by regulating glycolysis pathway fluxes via lactate supply. Furthermore, it can supply up to 35% of the TCA cycle fluxes by providing TCA intermediates and glutamine. Our algorithm will help gain insight into (i) metabolic interactions in multicellular systems (ii) biogenesis of extracellular vesicles and their differential packaging of cargo under changing environments, and (iii) regulation of cancer cell metabolism by its microenvironment. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  13. Larval developmental rate, metabolic rate and future growth performance in Atlantic salmon

    DEFF Research Database (Denmark)

    Serrano, Jonathan Vaz; Åberg, Madelene; Gjoen, Hans Magnus;

    2009-01-01

    Previous studies in salmonids suggest a link between larval developmental rate, metabolic rate, and future growth. However, the connection between growth during exogenous and endogenous feeding is still debated. In the current study, a positive relationship between larval developmental rate, quan...

  14. The impact of atmospheric ammonia and temperature on growth and nitrogen metabolism of winter wheat

    NARCIS (Netherlands)

    Clement, J.M A M; Loorbach, J; Meijer, J; van Hasselt, P.R; Stulen, G

    The effect of atmospheric ammonia in combination with low and moderate growth temperature on growth and nitrogen metabolism of winter wheat plants (Triticum aestivum L. cv. Urban) was investigated. Plants were exposed to 0, 1000 and 2000 nl l(-1) NH3 for 1 week at moderate day/night temperatures

  15. The Eukaryote-Like Serine/Threonine Kinase STK Regulates the Growth and Metabolism of Zoonotic Streptococcus suis

    Science.gov (United States)

    Zhang, Chunyan; Sun, Wen; Tan, Meifang; Dong, Mengmeng; Liu, Wanquan; Gao, Ting; Li, Lu; Xu, Zhuofei; Zhou, Rui

    2017-01-01

    Like eukaryotes, bacteria express one or more serine/threonine kinases (STKs) that initiate diverse signaling networks. The STK from Streptococcus suis is encoded by a single-copy stk gene, which is crucial in stress response and virulence. To further understand the regulatory mechanism of STK in S. suis, a stk deletion strain (Δstk) and its complementary strain (CΔstk) were constructed to systematically decode STK characteristics by applying whole transcriptome RNA sequencing (RNA-Seq) and phosphoproteomic analysis. Numerous genes were differentially expressed in Δstk compared with the wild-type parental strain SC-19, including 320 up-regulated and 219 down-regulated genes. Particularly, 32 virulence-associated genes (VAGs) were significantly down-regulated in Δstk. Seven metabolic pathways relevant to bacterial central metabolism and translation are significantly repressed in Δstk. Phosphoproteomic analysis further identified 12 phosphoproteins that exhibit differential phosphorylation in Δstk. These proteins are associated with cell growth and division, glycolysis, and translation. Consistently, phenotypic assays confirmed that the Δstk strain displayed deficient growth and attenuated pathogenicity. Thus, STK is a central regulator that plays an important role in cell growth and division, as well as S. suis metabolism. PMID:28326294

  16. [Specific growth rate and the rate of energy metabolism in the ontogenesis of axolotl, Ambystoma mexicanum (Amphibia: Ambystomatidae)].

    Science.gov (United States)

    Vladimirova, I G; Kleĭmenov, S Iu; Alekseeva, T A; Radzinskaia, L I

    2003-01-01

    Concordant changes in the rate of energy metabolism and specific growth rate of axolotls have been revealed. Several periods of ontogeny are distinguished, which differ in the ratio of energy metabolism to body weight and, therefore, are described by different allometric equations. It is suggested that the specific growth rate of an animal determines the type of dependence of energy metabolism on body weight.

  17. Vapor Crystal Growth (VCG) experiment Cell

    Science.gov (United States)

    1992-01-01

    The image shows a test cell of Crystal Growth experiment inside the Vapor Crystal Growth System (VCGS) furnace aboard the STS-42, International Microgravity Laboratory-1 (IML-1), mission. The goal of IML-1, a pressurized marned Spacelab module, was to explore in depth the complex effects of weightlessness of living organisms and materials processing. More than 200 scientists from 16 countires participated in the investigations.

  18. [Advances in studies on growth metabolism and response mechanisms of medicinal plants under drought stress].

    Science.gov (United States)

    Si, Can; Zhang, Jun-Yi; Xu, Hu-Chao

    2014-07-01

    Drought stress exerts a considerable effect on growth, physiology and secondary metabolisms of the medicinal plants. It could inhabit the growth of the medicinal plants but promote secretion of secondary metabolites. Other researches indicated that the medicinal plants could depend on the ABA signaling pathway and secreting osmotic substances to resist the drought stress and reduce the damage by it. The article concludes the changes in growth, physiology, secondary metabolisms and response mechanisms of medicinal plants to drought stress that provides a theoretical basis for exploring the relationship between medicinal plants and drought stress.

  19. Luciferase does not Alter Metabolism in Cancer Cells

    Science.gov (United States)

    Johnson, Caroline H.; Fisher, Timothy S.; Hoang, Linh T.; Felding, Brunhilde H.; Siuzdak, Gary; O’Brien, Peter J.

    2014-01-01

    Luciferase transfected cell lines are used extensively for cancer models, revealing valuable biological information about disease mechanisms. However, these genetically encoded reporters, while useful for monitoring tumor response in cancer models, can impact cell metabolism. Indeed firefly luciferase and fatty acyl-CoA synthetases differ by a single amino acid, raising the possibility that luciferase activity might alter metabolism and introduce experimental artifacts. Therefore knowledge of the metabolic response to luciferase transfection is of significant importance, especially given the thousands of research studies using luciferase as an in vivo bioluminescence imaging (BLI) reporter. Untargeted metabolomics experiments were performed to examine three different types of lymphoblastic leukemia cell lines (Ramos, Raji and SUP T1) commonly used in cancer research, each were analyzed with and without vector transduction. The Raji model was also tested under perturbed starvation conditions to examine potential luciferase-mediated stress responses. The results showed that no significant metabolic differences were observed between parental and luciferase transduced cells for each cell line, and that luciferase overexpression does not alter cell metabolism under basal or perturbed conditions. PMID:24791164

  20. Control of cell cycle and cell growth by molecular chaperones.

    Science.gov (United States)

    Aldea, Martí; Garí, Eloi; Colomina, Neus

    2007-11-01

    Cells adapt their size to both intrinsic and extrinsic demands and, among them, those that stem from growth and proliferation rates are crucial for cell size homeostasis. Here we revisit mechanisms that regulate cell cycle and cell growth in budding yeast. Cyclin Cln3, the most upstream activator of Start, is retained at the endoplasmic reticulum in early G(1) and released by specific chaperones in late G(1) to initiate the cell cycle. On one hand, these chaperones are rate-limiting for release of Cln3 and cell cycle entry and, on the other hand, they are required for key biosynthetic processes. We propose a model whereby the competition for specialized chaperones between growth and cycle machineries could gauge biosynthetic rates and set a critical size threshold at Start.

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

    Science.gov (United States)

    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.

  2. Metabolism

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness Metabolism KidsHealth > For Teens > Metabolism Print A A A ... food through a process called metabolism. What Is Metabolism? Metabolism (pronounced: meh-TAB-uh-lih-zem) is ...

  3. Dehydroascorbate uptake activity correlates with cell growth and cell division of tobacco bright yellow-2 cell cultures.

    Science.gov (United States)

    Horemans, Nele; Potters, Geert; De Wilde, Leen; Caubergs, Roland J

    2003-09-01

    Recently, ascorbate (ASC) concentration and the activity of a number of enzymes from the ASC metabolism have been proven to correlate with differences in growth or cell cycle progression. Here, a possible correlation between growth and the activity of a plasma membrane dehydroascorbate (DHA) transporter was investigated. Protoplasts were isolated from a tobacco (Nicotiana tabacum) Bright Yellow-2 cell culture at different intervals after inoculation and the activity of DHA transport was tested with (14)C-labeled ASC. Ferricyanide (1 mM) or dithiothreitol (1 mM) was included in the test to keep the external (14)C-ASC in its oxidized respectively reduced form. Differential uptake activity was observed, correlating with growth phases of the cell culture. Uptake of DHA in cells showed a peak in exponential growth phase, whereas uptake in the presence of dithiothreitol did not. The enhanced DHA uptake was not due to higher endogenous ASC levels that are normally present in exponential phase because preloading of protoplasts of different ages did not affect DHA uptake. Preloading was achieved by incubating cells before protoplastation for 4 h in a medium supplemented with 1 mM DHA. In addition to testing cells at different growth phases, uptake of DHA into the cells was also followed during the cell cycle. An increase in uptake activity was observed during M phase and the M/G1 transition. These experiments are the first to show that DHA transport activity into plant cells differs with cell growth. The relevance of the data to the action of DHA and ASC in cell growth will be discussed.

  4. NGF, BDNF, leptin, and mast cells in human coronary atherosclerosis and metabolic syndrome.

    Science.gov (United States)

    Chaldakov, G N; Fiore, M; Stankulov, I S; Hristova, M; Antonelli, A; Manni, L; Ghenev, P I; Angelucci, F; Aloe, L

    2001-10-01

    While multiple growth factor, cytokines, and immune cells are identified in atherosclerotic lesions, as well as an essential nonneuronal function of neurotrophins implicated in cardiovascular tissue development and in lipid and glucose metabolism, the role of the neurotrophins NGF and BDNF and also the adipokine leptin in human coronary atherosclerosis and related disorders, such as metabolic syndrome, remains unclear. Here we report that (i) both the amount and the immunoreactivity of NGF was reduced and the expression of p75NGF receptor and the number of mast cell increased in human atherosclerotic coronary arteries (n = 12) compared with control specimens (n = 9) obtained from autopsy cases, and (ii) NGF and BDNF plasma levels were reduced in patients with metabolic syndrome (n = 23) compared with control subjects (n = 10). Also, in metabolic syndrome patients, a positive correlation between the plasma leptin levels and the number of adipose tissue mast cells was found, suggesting that leptin may be a novel adipoimmune mediator. Altogether, the results provide the first correlative evidence for the potential involvement of NGF, BDNF, leptin, and mast cells in human coronary atherosclerosis and metabolic syndrome, implying neuroimmune and adipoimmune pathways in the pathobiology of these cardiovascular disorders.

  5. FACTORS LIMITING BACTERIAL GROWTH : III. CELL SIZE AND "PHYSIOLOGIC YOUTH" IN BACTERIUM COLI CULTURES.

    Science.gov (United States)

    Hershey, A D; Bronfenbrenner, J

    1938-07-20

    1. Measurements of the rate of oxygen uptake per cell in transplants of Bacterium coli from cultures of this organism in different phases of growth have given results in essential agreement with the observations of others. 2. Correlations of viable count, centrifugable nitrogen, and turbidity, with oxygen consumption, indicate that the increased metabolism during the early portion of the growth period is quantitatively referable to increased average size of cells. 3. Indirect evidence has suggested that the initial rate of growth of transplants is not related to the phase of growth of the parent culture.

  6. Redirector: designing cell factories by reconstructing the metabolic objective.

    Directory of Open Access Journals (Sweden)

    Graham Rockwell

    Full Text Available Advances in computational metabolic optimization are required to realize the full potential of new in vivo metabolic engineering technologies by bridging the gap between computational design and strain development. We present Redirector, a new Flux Balance Analysis-based framework for identifying engineering targets to optimize metabolite production in complex pathways. Previous optimization frameworks have modeled metabolic alterations as directly controlling fluxes by setting particular flux bounds. Redirector develops a more biologically relevant approach, modeling metabolic alterations as changes in the balance of metabolic objectives in the system. This framework iteratively selects enzyme targets, adds the associated reaction fluxes to the metabolic objective, thereby incentivizing flux towards the production of a metabolite of interest. These adjustments to the objective act in competition with cellular growth and represent up-regulation and down-regulation of enzyme mediated reactions. Using the iAF1260 E. coli metabolic network model for optimization of fatty acid production as a test case, Redirector generates designs with as many as 39 simultaneous and 111 unique engineering targets. These designs discover proven in vivo targets, novel supporting pathways and relevant interdependencies, many of which cannot be predicted by other methods. Redirector is available as open and free software, scalable to computational resources, and powerful enough to find all known enzyme targets for fatty acid production.

  7. Inhibition of glutamine utilization sensitizes lung cancer cells to apigenin-induced apoptosis resulting from metabolic and oxidative stress.

    Science.gov (United States)

    Lee, Yoon-Mi; Lee, Gibok; Oh, Taek-In; Kim, Byeong Mo; Shim, Do-Wan; Lee, Kwang-Ho; Kim, Young Jun; Lim, Beong Ou; Lim, Ji-Hong

    2016-01-01

    Recent studies have shown anticancer activity of apigenin by suppressing glucose transporter 1 (GLUT1) expression in cultured cancer cells; however, it is not clear whether apigenin can suppress glucose metabolism in lung cancer cells or sensitize them to inhibition of glutamine utilization-mediated apoptosis through metabolic and oxidative stress. We show that apigenin significantly decreases GLUT1 expression in mice. Furthermore, we demonstrate that apigenin induces growth retardation and apoptosis through metabolic and oxidative stress caused by suppression of glucose utilization in lung cancer cells. The underlying mechanisms were defined that the anticancer effects of apigenin were reversed by ectopic GLUT1 overexpression and galactose supplementation, through activation of pentose phosphate pathway-mediated NADPH generation. Importantly, we showed that severe metabolic stress using a glutaminase inhibitor, compound 968, was involved in the mechanism of sensitization by apigenin. Taken together, the combination of apigenin with inhibitors of glutamine metabolism may provide a promising therapeutic strategy for cancer treatment.

  8. Metabolism of Mequindox in Isolated Rat Liver Cells

    Institute of Scientific and Technical Information of China (English)

    LI Guang-hui; SHAN Qi; WANG Jing; LI Ya-fei; GAO Yan; ZENG Zhen-ling

    2014-01-01

    Mequindox (MEQ), 3-methyl-2-quinoxalinacetyl-1,4-dioxide, is widely used in Chinese veterinary medicine as an antimicrobial agent and feed additive. Its toxicity has been reported to be closely related to its metabolism. To understand the pathways underlying MEQ’s metabolism more clearly, we studied its metabolism in isolated rat liver cells by using liquid chromatography coupled with electrospray ionization hybrid linear trap quadrupole orbitrap (LC-LTQ-Orbitrap) mass spectrometry. The structures of MEQ metabolites and their product ions were readily and reliably characterized on the basis of accurate MS2 spectra and known structure of MEQ. Eleven metabolites were detected in isolated rat liver cells, two of which were detected for the ifrst time in vitro. The major metabolic pathways reported previously for in vitro metabolism of MEQ in rat microsomes were conifrmed in this study, including N→O group reduction, carbonyl reduction, and methyl monohydroxylation. In addition, we found that acetyl hydroxylation was an important pathway of MEQ metabolism. The results also demonstrate that cellular systems more closely simulate in vivo conditions than do other in vitro systems such as microsomes. Taken together, these data contribute to our understanding of the in vivo metabolism of MEQ.

  9. Impact of metabolism and growth phase on the hydrogen isotopic composition of microbial fatty acids

    Science.gov (United States)

    Heinzelmann, Sandra M.; Villanueva, Laura; Sinke-Schoen, Danielle; Sinninghe Damsté, Jaap S.; Schouten, Stefan; van der Meer, Marcel T. J.

    2015-01-01

    Microorganisms are involved in all elemental cycles and therefore it is important to study their metabolism in the natural environment. A recent technique to investigate this is the hydrogen isotopic composition of microbial fatty acids, i.e., heterotrophic microorganisms produce fatty acids enriched in deuterium (D) while photoautotrophic and chemoautotrophic microorganisms produce fatty acids depleted in D compared to the water in the culture medium (growth water). However, the impact of factors other than metabolism have not been investigated. Here, we evaluate the impact of growth phase compared to metabolism on the hydrogen isotopic composition of fatty acids of different environmentally relevant microorganisms with heterotrophic, photoautotrophic and chemoautotrophic metabolisms. Fatty acids produced by heterotrophs are enriched in D compared to growth water with εlipid/water between 82 and 359‰ when grown on glucose or acetate, respectively. Photoautotrophs (εlipid/water between −149 and −264‰) and chemoautotrophs (εlipid/water between −217 and −275‰) produce fatty acids depleted in D. Fatty acids become, in general, enriched by between 4 and 46‰ with growth phase which is minor compared to the influence of metabolisms. Therefore, the D/H ratio of fatty acids is a promising tool to investigate community metabolisms in nature. PMID:26005437

  10. Early metabolic defects in dexamethasone-exposed and undernourished intrauterine growth restricted rats.

    Directory of Open Access Journals (Sweden)

    Emmanuel Somm

    Full Text Available Poor fetal growth, also known as intrauterine growth restriction (IUGR, is a worldwide health concern. IUGR is commonly associated with both an increased risk in perinatal mortality and a higher prevalence of developing chronic metabolic diseases later in life. Obesity, type 2 diabetes or metabolic syndrome could result from noxious "metabolic programming." In order to better understand early alterations involved in metabolic programming, we modeled IUGR rat pups through either prenatal exposure to synthetic glucocorticoid (dams infused with dexamethasone 100 µg/kg/day, DEX or prenatal undernutrition (dams feeding restricted to 30% of ad libitum intake, UN. Physiological (glucose and insulin tolerance, morphometric (automated tissue image analysis and transcriptomic (quantitative PCR approaches were combined during early life of these IUGR pups with a special focus on their endocrine pancreas and adipose tissue development. In the absence of catch-up growth before weaning, DEX and UN IUGR pups both presented basal hyperglycaemia, decreased glucose tolerance, and pancreatic islet atrophy. Other early metabolic defects were model-specific: DEX pups presented decreased insulin sensitivity whereas UN pups exhibited lowered glucose-induced insulin secretion and more marked alterations in gene expression of pancreatic islet and adipose tissue development regulators. In conclusion, these results show that before any catch-up growth, IUGR rats present early physiologic, morphologic and transcriptomic defects, which can be considered as initial mechanistic basis of metabolic programming.

  11. Free fatty acids link metabolism and regulation of the insulin-sensitizing fibroblast growth factor-21.

    Science.gov (United States)

    Mai, Knut; Andres, Janin; Biedasek, Katrin; Weicht, Jessica; Bobbert, Thomas; Sabath, Markus; Meinus, Sabine; Reinecke, Franziska; Möhlig, Matthias; Weickert, Martin O; Clemenz, Markus; Pfeiffer, Andreas F H; Kintscher, Ulrich; Spuler, Simone; Spranger, Joachim

    2009-07-01

    Fibroblast growth factor (FGF)-21 improves insulin sensitivity and lipid metabolism in obese or diabetic animal models, while human studies revealed increased FGF-21 levels in obesity and type 2 diabetes. Given that FGF-21 has been suggested to be a peroxisome proliferator-activator receptor (PPAR) alpha-dependent regulator of fasting metabolism, we hypothesized that free fatty acids (FFAs), natural agonists of PPARalpha, might modify FGF-21 levels. The effect of fatty acids on FGF-21 was investigated in vitro in HepG2 cells. Within a randomized controlled trial, the effects of elevated FFAs were studied in 21 healthy subjects (13 women and 8 men). Within a clinical trial including 17 individuals, the effect of insulin was analyzed using an hyperinsulinemic-euglycemic clamp and the effect of PPARgamma activation was studied subsequently in a rosiglitazone treatment trial over 8 weeks. Oleate and linoleate increased FGF-21 expression and secretion in a PPARalpha-dependent fashion, as demonstrated by small-interfering RNA-induced PPARalpha knockdown, while palmitate had no effect. In vivo, lipid infusion induced an increase of circulating FGF-21 in humans, and a strong correlation between the change in FGF-21 levels and the change in FFAs was observed. An artificial hyperinsulinemia, which was induced to delineate the potential interaction between elevated FFAs and hyperinsulinemia, revealed that hyperinsulinemia also increased FGF-21 levels in vivo, while rosiglitazone treatment had no effect. The results presented here offer a mechanism explaining the induction of the metabolic regulator FGF-21 in the fasting situation but also in type 2 diabetes and obesity.

  12. The RNA chaperone Hfq impacts growth, metabolism and production of virulence factors in Yersinia enterocolitica.

    Directory of Open Access Journals (Sweden)

    Tamara Kakoschke

    Full Text Available To adapt to changes in environmental conditions, bacteria regulate their gene expression at the transcriptional but also at the post-transcriptional level, e.g. by small RNAs (sRNAs which modulate mRNA stability and translation. The conserved RNA chaperone Hfq mediates the interaction of many sRNAs with their target mRNAs, thereby playing a global role in fine-tuning protein production. In this study, we investigated the significance of Hfq for the enteropathogen Yersina enterocolitica serotype O:8. Hfq facilitated optimal growth in complex and minimal media. Our comparative protein analysis of parental and hfq-negative strains suggested that Hfq promotes lipid metabolism and transport, cell redox homeostasis, mRNA translation and ATP synthesis, and negatively affects carbon and nitrogen metabolism, transport of siderophore and peptides and tRNA synthesis. Accordingly, biochemical tests indicated that Hfq represses ornithine decarboxylase activity, indole production and utilization of glucose, mannitol, inositol and 1,2-propanediol. Moreover, Hfq repressed production of the siderophore yersiniabactin and its outer membrane receptor FyuA. In contrast, hfq mutants exhibited reduced urease production. Finally, strains lacking hfq were more susceptible to acidic pH and oxidative stress. Unlike previous reports in other Gram-negative bacteria, Hfq was dispensable for type III secretion encoded by the virulence plasmid. Using a chromosomally encoded FLAG-tagged Hfq, we observed increased production of Hfq-FLAG in late exponential and stationary phases. Overall, Hfq has a profound effect on metabolism, resistance to stress and modulates the production of two virulence factors in Y. enterocolitica, namely urease and yersiniabactin.

  13. A moonlighting enzyme links Escherichia coli cell size with central metabolism.

    Directory of Open Access Journals (Sweden)

    Norbert S Hill

    Full Text Available Growth rate and nutrient availability are the primary determinants of size in single-celled organisms: rapidly growing Escherichia coli cells are more than twice as large as their slow growing counterparts. Here we report the identification of the glucosyltransferase OpgH as a nutrient-dependent regulator of E. coli cell size. During growth under nutrient-rich conditions, OpgH localizes to the nascent septal site, where it antagonizes assembly of the tubulin-like cell division protein FtsZ, delaying division and increasing cell size. Biochemical analysis is consistent with OpgH sequestering FtsZ from growing polymers. OpgH is functionally analogous to UgtP, a Bacillus subtilis glucosyltransferase that inhibits cell division in a growth rate-dependent fashion. In a striking example of convergent evolution, OpgH and UgtP share no homology, have distinct enzymatic activities, and appear to inhibit FtsZ assembly through different mechanisms. Comparative analysis of E. coli and B. subtilis reveals conserved aspects of growth rate regulation and cell size control that are likely to be broadly applicable. These include the conservation of uridine diphosphate glucose as a proxy for nutrient status and the use of moonlighting enzymes to couple growth rate-dependent phenomena to central metabolism.

  14. A phenomenological approach to the simulation of metabolism and proliferation dynamics of large tumour cell populations

    CERN Document Server

    Chignola, R; Chignola, Roberto; Milotti, Edoardo

    2005-01-01

    A major goal of modern computational biology is to simulate the collective behaviour of large cell populations starting from the intricate web of molecular interactions occurring at the microscopic level. In this paper we describe a simplified model of cell metabolism, growth and proliferation, suitable for inclusion in a multicell simulator, now under development (Chignola R and Milotti E 2004 Physica A 338 261-6). Nutrients regulate the proliferation dynamics of tumor cells which adapt their behaviour to respond to changes in the biochemical composition of the environment. This modeling of nutrient metabolism and cell cycle at a mesoscopic scale level leads to a continuous flow of information between the two disparate spatiotemporal scales of molecular and cellular dynamics that can be simulated with modern computers and tested experimentally.

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

    Science.gov (United States)

    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.

  16. The timing of "catch-up growth" affects metabolism and appetite regulation in male rats born with intrauterine growth restriction.

    Science.gov (United States)

    Coupé, Bérengère; Grit, Isabelle; Darmaun, Dominique; Parnet, Patricia

    2009-09-01

    Epidemiological studies demonstrated a relationship between low birth weight mainly caused by intrauterine growth restriction (IUGR) and adult metabolic disorders. The concept of metabolic programming centers on the idea that nutritional and hormonal status during the key period of development determines the long-term control of energy balance by programming future feeding behavior and energy expenditure. The present study examined the consequence of early or late "catch-up growth" after IUGR on feeding behavior and metabolic cues of male offspring of rat dams exposed to protein restriction during gestation and/or lactation. Our results suggest that early catch-up growth may be favorable for fasting metabolic parameters at weaning, as no differences were observed on plasma leptin, triglyceride, glucose, and insulin levels compared with controls. In contrast, if pups remained malnourished until weaning, low insulin concentration was detected and was accompanied by hyperphagia associated with a large increase in hypothalamic NPY and AgRP mRNA expression. At adult age, on a regular chow diet, only the meal structure was modified by fetal programming. The two IUGR groups demonstrated a reduced meal duration that enhanced the speed of food ingestion and consequently increased the rest period associated to the satiety state without changes in the hypothalamic expression of appetite neuropeptides. Our findings demonstrate that in IUGR, regardless of postnatal growth magnitude, metabolic programming occurred in utero and was responsible for both feeding behavior alteration and postprandial higher insulin level in adults. Additionally, catch-up growth immediately after early malnutrition could be a key point for the programming of postprandial hyperleptinemia.

  17. Metabolic signalling in pancreatic beta cells

    OpenAIRE

    Piipari, K.

    2011-01-01

    The main function of pancreatic beta cells is to maintain correct glucose homeostasis within the body by secretion of insulin in response to increased blood glucose concentration. Beta cell dysfunction contributes to the pathogenesis of diabetes. Using transgenic mouse models, the work described in this thesis has investigated the role of AMP-activated protein kinase (AMPK) and phosphatidylinositol 3-kinase (PI3K) in beta cell function and their role in the regulation of ...

  18. Polyamines in relation to growth in carrot cell cultures.

    Science.gov (United States)

    Fallon, K M; Phillips, R

    1988-09-01

    Changes in polyamine metabolism were investigated in relation to growth of cell suspension cultures of carrot (Daucus carota, cv Chantenay). Changes in levels of the major amines putrescine and spermidine throughout the culture period correlated poorly with changes in fresh weight, but a closer correlation with the minor component spermine was observed. The arginine decarboxylase (ADC) inhibitor difluoromethylarginine (DFMA) strongly and specifically inhibited ADC activity in the supernatant, reduced the major amine (putrescine) by 95% and the total amine content by 80%. It had no effect on cell number and stimulated fresh weight by over 25% through increased cell expansion. Spermine content, in contrast, increased with DFMA concentration in parallel with fresh weight increases. Difluoromethylornithine strongly inhibited ornithine decarboxylase activity in the pellet, but had little effect on either polyamine levels or culture growth. It was concluded that little evidence for a correlation between free polyamines and cell number in carrot cultures could be detected, but that a possible correlation between spermine content and cell expansion was observed.

  19. Polyamines in Relation to Growth in Carrot Cell Cultures 1

    Science.gov (United States)

    Fallon, Kevin M.; Phillips, Richard

    1988-01-01

    Changes in polyamine metabolism were investigated in relation to growth of cell suspension cultures of carrot (Daucus carota, cv Chantenay). Changes in levels of the major amines putrescine and spermidine throughout the culture period correlated poorly with changes in fresh weight, but a closer correlation with the minor component spermine was observed. The arginine decarboxylase (ADC) inhibitor difluoromethylarginine (DFMA) strongly and specifically inhibited ADC activity in the supernatant, reduced the major amine (putrescine) by 95% and the total amine content by 80%. It had no effect on cell number and stimulated fresh weight by over 25% through increased cell expansion. Spermine content, in contrast, increased with DFMA concentration in parallel with fresh weight increases. Difluoromethylornithine strongly inhibited ornithine decarboxylase activity in the pellet, but had little effect on either polyamine levels or culture growth. It was concluded that little evidence for a correlation between free polyamines and cell number in carrot cultures could be detected, but that a possible correlation between spermine content and cell expansion was observed. PMID:16666271

  20. Modeling of Xanthophyllomyces dendrorhous growth on glucose and overflow metabolism in batch and fed-batch cultures for astaxanthin production.

    Science.gov (United States)

    Liu, Yuan-Shuai; Wu, Jian-Yong

    2008-12-01

    An astaxanthin-producing yeast Xanthophyllomyces dendrorhous ENM5 was cultivated in a liquid medium containing 50 g/L glucose as the major carbon source in stirred fermentors (1.5-L working volume) in fully aerobic conditions. Ethanol was produced during the exponential growth phase as a result of overflow metabolism or fermentative catabolism of glucose by yeast cells. After accumulating to a peak of 3.5 g/L, the ethanol was consumed by yeast cells as a carbon source when glucose in the culture was nearly exhausted. High initial glucose concentrations and ethanol accumulation in the culture had inhibitory effects on cell growth. Astaxanthin production was partially associated with cell growth. Based on these culture characteristics, we constructed a modified Monod kinetic model incorporating substrate (glucose) and product (ethanol) inhibition to describe the relationship of cell growth rate with glucose and ethanol concentrations. This kinetic model, coupled with the Luedeking-Piret equation for the astaxanthin production, gave satisfactory prediction of the biomass production, glucose consumption, ethanol formation and consumption, and astaxanthin production in batch cultures over 25-75 g/L glucose concentration ranges. The model was also applied to fed-batch cultures to predict the optimum feeding scheme (feeding glucose and corn steep liquor) for astaxanthin production, leading to a high volumetric yield (28.6 mg/L) and a high productivity (5.36 mg/L/day).

  1. The Effect of Created Local Hyperosmotic Microenvironment in Microcapsule for the Growth and Metabolism of Osmotolerant Yeast Candida krusei

    Directory of Open Access Journals (Sweden)

    Guo Chen

    2013-01-01

    Full Text Available Candida krusei is osmotolerant yeast used for the production of glycerol. Addition of osmolyte such as NaCl into culture medium can increase the production of glycerol from glucose, but osmolytes may burden the glycerol separation. A coencapsulation method was suggested to create local extracellular hyperosmotic stress for glycerol accumulation. Firstly, the influence of osmotic stress induced by the addition of PEG4000 on growth and metabolism of free cell was studied in detail. Glycerol accumulation could be improved by employing PEG4000 as osmoregulator. Secondly, cells and PEG4000 were coentrapped in NaCS/PDMDAAC capsules to create local hyperosmotic stress. The effects of local hyperosmotic microenvironment on the cell growth and metabolism were studied. The coentrapment method increased the glycerol concentration by 25%, and the glycerol concentration attained 50 gL−1 with productivity of 18.8 gL−1Day−1 in shake flask. More importantly, the glycerol could be directly separated from the encapsulated cells. The entrapped cells containing PEG4000 were also cultivated for 15 days in an airlift reactor. The yield and productivity were ca. 35% and 21 gL−1Day−1, respectively.

  2. The multiple connections between pRB and cell metabolism.

    Science.gov (United States)

    Nicolay, Brandon N; Dyson, Nicholas J

    2013-12-01

    The pRB tumor suppressor is traditionally seen as an important regulator of the cell cycle. pRB represses the transcriptional activation of a diverse set of genes by the E2F transcription factors and prevents inappropriate S-phase entry. Advances in our understanding of pRB have documented roles that extend beyond the cell cycle and this review summarizes recent studies that link pRB to the control of cell metabolism. pRB has been shown to regulate glucose tolerance, mitogenesis, glutathione synthesis, and the expression of genes involved in central carbon metabolism. Several studies have demonstrated that pRB directly targets a set of genes that are crucial for nucleotide metabolism, and this seems likely to represent one of the ways by which pRB influences the G1/S-phase transition and S-phase progression.

  3. Absorption and Metabolism Characteristics of Rutin in Caco-2 Cells

    Directory of Open Access Journals (Sweden)

    Xiaofang Zhang

    2013-01-01

    Full Text Available The intestinal absorption and metabolism characteristics of the potentially beneficial polyphenol rutin were studied by measuring the intracellular accumulation and transport of rutin into Caco-2 cells with the sensitive and reliable analytical method of HPLC-coupled tandem mass spectrometry. Rutin and glucuronidated rutin were absorbed differently by the basolateral and apical membranes, and rutin showed differential permeability through the apical and basolateral sides. Approximately 33% of the rutin was metabolized to glucuronidated rutin, and the intracellular concentration of glucuronidated rutin was much lower than that of parent rutin. P-glycoprotein and multidrug-resistant proteins 2 and 3 were involved in the transmembrane transport and intracellular accumulation of rutin by Caco-2 cells. These results suggest that a specific transport system mediates rutin movement across the apical membrane in Caco-2 cells and that metabolic enzymes are important for this process.

  4. Bacterial Cell Wall Growth, Shape and Division

    NARCIS (Netherlands)

    Derouaux, A.; Terrak, M.; den Blaauwen, T.; Vollmer, W.; Remaut, H.; Fronzes, R.

    2014-01-01

    The shape of a bacterial cell is maintained by its peptidoglycan sacculus that completely surrounds the cytoplasmic membrane. During growth the sacculus is enlarged by peptidoglycan synthesis complexes that are controlled by components linked to the cytoskeleton and, in Gram-negative bacteria, by ou

  5. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette

    1999-01-01

    Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...... increase in the beta cell number seems to occur. In pregnancy, however, a marked hyperplasia of the beta cells is observed both in rodents and man. Increased mitotic activity has been seen both in vivo and in vitro in islets exposed to placental lactogen (PL), prolactin (PRL) and growth hormone (GH......). Receptors for both GH and PRL are expressed in islet cells and are upregulated during pregnancy. By mutational analysis we have identified different functional domains of the cytoplasmic part of the GH receptor. Thus the mitotic signaling only requires the membrane proximal part of the receptor...

  6. Insect growth regulator activity of Cestrum parqui saponins: an interaction with cholesterol metabolism.

    Science.gov (United States)

    Ikbal, C; Ben, Halima-Kamel M; Ben, Hamouda M H

    2006-01-01

    Cestrum parqui is an ornamental shrub known for its insecticidal activity against some insect pests; this activity comes from the crude saponic extract of the leaves of this plant, the saponins cause insect growth regulator symptoms (development and moulting perturbation). In this work we try to demonstrate the hypothesis that saponins interact with ecdysone (moulting hormone) synthesis mechanisms by reducing diet cholesterol absorption (cholesterol forms the skeleton of ecdysone and of other ecdysteroids). To show the cholesterol/saponin interaction we used a stored product pest insect (Tribolium confuisurn), the larva of this insect are affected by saponins added in their diet, but the addition of cholesterol permits to reduce significatively this insecticidal propriety. Using Spodoptera littoralis larva model the tentative to detect a cholesterol rate reduction on the level of hemolymph is also unsuccessful. All these experiments shows that this type of reaction can't occur in the diet or in the digestive system but probably in insect cells. It is clear that Cestrurn parqui saponins affect the cholesterol metabolism but the exactly mechanism is still unknown. More investigations are necessary to develop this hypothesis and to envisage the use of Cestrum saponins as insect growth regulator bioinsecticide.

  7. Metabolic flux prediction in cancer cells with altered substrate uptake.

    Science.gov (United States)

    Schwartz, Jean-Marc; Barber, Michael; Soons, Zita

    2015-12-01

    Proliferating cells, such as cancer cells, are known to have an unusual metabolism, characterized by an increased rate of glycolysis and amino acid metabolism. Our understanding of this phenomenon is limited but could potentially be used in order to develop new therapies. Computational modelling techniques, such as flux balance analysis (FBA), have been used to predict fluxes in various cell types, but remain of limited use to explain the unusual metabolic shifts and altered substrate uptake in human cancer cells. We implemented a new flux prediction method based on elementary modes (EMs) and structural flux (StruF) analysis and tested them against experimentally measured flux data obtained from (13)C-labelling in a cancer cell line. We assessed the quality of predictions using different objective functions along with different techniques in normalizing a metabolic network with more than one substrate input. Results show a good correlation between predicted and experimental values and indicate that the choice of cellular objective critically affects the quality of predictions. In particular, lactate gives an excellent correlation and correctly predicts the high flux through glycolysis, matching the observed characteristics of cancer cells. In contrast with FBA, which requires a priori definition of all uptake rates, often hard to measure, atomic StruFs (aStruFs) are able to predict uptake rates of multiple substrates.

  8. Suppression of PGC-1α is critical for reprogramming oxidative metabolism in renal cell carcinoma

    Science.gov (United States)

    LaGory, Edward L.; Wu, Colleen; Taniguchi, Cullen M.; Ding, Chien-Kuang Cornelia; Chi, Jen-Tsan; von Eyben, Rie; Scott, David A.; Richardson, Adam D.; Giaccia, Amato J.

    2015-01-01

    Summary Long believed to be a byproduct of malignant transformation, reprogramming of cellular metabolism is now recognized as a driving force in tumorigenesis. In clear cell renal cell carcinoma (ccRCC) frequent activation of HIF-signaling induces a metabolic switch that promotes tumorigenesis. Here we demonstrate that PGC-1α, a central regulator of energy metabolism, is suppressed in VHL-deficient ccRCC by a HIF/Dec1-dependent mechanism. In VHL wild type cells, PGC-1α suppression leads to decreased expression of the mitochondrial transcription factor Tfam and impaired mitochondrial respiration. Conversely, PGC-1α expression in VHL-deficient cells restores mitochondrial function and induces oxidative stress. ccRCC cells expressing PGC-1α exhibit impaired tumor growth and enhanced sensitivity to cytotoxic therapies. In patients, low levels of PGC-1α expression are associated with poor outcome. These studies demonstrate that suppression of PGC-1α recapitulates key metabolic phenotypes of ccRCC and highlight the potential of targeting PGC-1α expression as a therapeutic modality for the treatment of ccRCC. PMID:26119730

  9. Suppression of PGC-1α Is Critical for Reprogramming Oxidative Metabolism in Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Edward L. LaGory

    2015-07-01

    Full Text Available Long believed to be a byproduct of malignant transformation, reprogramming of cellular metabolism is now recognized as a driving force in tumorigenesis. In clear cell renal cell carcinoma (ccRCC, frequent activation of HIF signaling induces a metabolic switch that promotes tumorigenesis. Here, we demonstrate that PGC-1α, a central regulator of energy metabolism, is suppressed in VHL-deficient ccRCC by a HIF/Dec1-dependent mechanism. In VHL wild-type cells, PGC-1α suppression leads to decreased expression of the mitochondrial transcription factor Tfam and impaired mitochondrial respiration. Conversely, PGC-1α expression in VHL-deficient cells restores mitochondrial function and induces oxidative stress. ccRCC cells expressing PGC-1α exhibit impaired tumor growth and enhanced sensitivity to cytotoxic therapies. In patients, low levels of PGC-1α expression are associated with poor outcome. These studies demonstrate that suppression of PGC-1α recapitulates key metabolic phenotypes of ccRCC and highlight the potential of targeting PGC-1α expression as a therapeutic modality for the treatment of ccRCC.

  10. Metabolic Control of Avocado Fruit Growth (Isoprenoid Growth Regulators and the Reaction Catalyzed by 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase).

    Science.gov (United States)

    Cowan, A. K.; Moore-Gordon, C. S.; Bertling, I.; Wolstenholme, B. N.

    1997-06-01

    The effect of isoprenoid growth regulators on avocado (Persea americana Mill. cv Hass) fruit growth and mesocarp 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) activity was investigated during the course of fruit ontogeny. Both normal and small-fruit phenotypes were used to probe the interaction between the end products of isoprenoid biosynthesis and the activity of HMGR in the metabolic control of avocado fruit growth. Kinetic analysis of the changes in both cell number and size revealed that growth was limited by cell number in phenotypically small fruit. In small fruit a 70% reduction in microsomal HMGR activity was associated with an increased mesocarp abscisic acid (ABA) concentration. Application of mevastatin, a competitive inhibitor of HMGR, reduced the growth of normal fruit and increased mesocarp ABA concentration. These effects were reversed by co-treatment of fruit with mevalonic acid lactone, isopentenyladenine, or N-(2-chloro-4-pyridyl)-N-phenylurea, but were not significantly affected by either gibberellic acid or stigmasterol. However, stigmasterol appeared to partially restore fruit growth when co-injected with mevastatin in either phase II or III of fruit growth. In vivo application of ABA reduced fruit growth and mesocarp HMGR activity and accelerated fruit abscission, effects that were reversed by co-treatment with isopentenyladenine. Together, these observations indicate that ABA accumulation down-regulates mesocarp HMGR activity and fruit growth, and that in situ cytokinin biosynthesis modulates these effects during phase I of fruit ontogeny, whereas both cytokinins and sterols seem to perform this function during the later phases.

  11. Mitochondrial Dysfunction and Immune Cell Metabolism in Sepsis

    Science.gov (United States)

    2017-01-01

    Sepsis is a life threatening condition mediated by systemic infection, but also triggered by hemorrhage and trauma. These are significant causes of organ injury implicated in morbidity and mortality, as well as post-sepsis complications associated with dysfunction of innate and adaptive immunity. The role of cellular bioenergetics and loss of metabolic plasticity of immune cells is increasingly emerging in the pathogenesis of sepsis. This review describes mitochondrial biology and metabolic alterations of immune cells due to sepsis, as well as indicates plausible therapeutic opportunities.

  12. Effects of pituitary hormone deficiency on growth and glucose metabolism of the sheep fetus.

    Science.gov (United States)

    Fowden, A L; Forhead, A J

    2007-10-01

    Pituitary hormones are essential for normal growth and metabolic responsiveness after birth, but their role before birth remains unclear. This study examined the effects of hypophysectomizing fetal sheep on their growth and glucose metabolism during the late normal and extended periods of gestation, and on their metabolic response to maternal fasting for 48 h near term. Fetal hypophysectomy reduced crown rump length (CRL), limb lengths, and body weight but increased ponderal index relative to controls near normal term. It also lowered the daily rate of crown rump length increment uniformly from 35 d before, to 20 d after normal term. Hypophysectomized (HX) fetuses had normal weight-specific rates of umbilical uptake, utilization, and oxidation of glucose but lower rates of umbilical oxygen uptake than controls near term. All these metabolic rates were significantly less in HX fetuses during the extended period of gestation than in HX and intact fetuses near normal term. In contrast to controls, glucogenesis was negligible in HX fetuses during maternal fasting. Consequently, the rate of glucose utilization decreased significantly in fasted HX but not intact fetuses. Conversely, the rate of CO(2) production from glucose carbon decreased in fasted intact but not HX fetuses. Fetal hypophysectomy also prevented the fasting-induced increases in plasma cortisol and norepinephrine concentrations seen in controls. These findings demonstrate that the pituitary hormones are important in regulating the growth rate and adaptive responses of glucose metabolism to undernutrition in fetal sheep. They also suggest that fetal metabolism is altered when gestational length is extended.

  13. Selection of metastatic breast cancer cells based on adaptability of their metabolic state.

    Directory of Open Access Journals (Sweden)

    Balraj Singh

    Full Text Available A small subpopulation of highly adaptable breast cancer cells within a vastly heterogeneous population drives cancer metastasis. Here we describe a function-based strategy for selecting rare cancer cells that are highly adaptable and drive malignancy. Although cancer cells are dependent on certain nutrients, e.g., glucose and glutamine, we hypothesized that the adaptable cancer cells that drive malignancy must possess an adaptable metabolic state and that such cells could be identified using a robust selection strategy. As expected, more than 99.99% of cells died upon glutamine withdrawal from the aggressive breast cancer cell line SUM149. The rare cells that survived and proliferated without glutamine were highly adaptable, as judged by additional robust adaptability assays involving prolonged cell culture without glucose or serum. We were successful in isolating rare metabolically plastic glutamine-independent (Gln-ind variants from several aggressive breast cancer cell lines that we tested. The Gln-ind cells overexpressed cyclooxygenase-2, an indicator of tumor aggressiveness, and they were able to adjust their glutaminase level to suit glutamine availability. The Gln-ind cells were anchorage-independent, resistant to chemotherapeutic drugs doxorubicin and paclitaxel, and resistant to a high concentration of a COX-2 inhibitor celecoxib. The number of cells being able to adapt to non-availability of glutamine increased upon prior selection of cells for resistance to chemotherapy drugs or resistance to celecoxib, further supporting a linkage between cellular adaptability and therapeutic resistance. Gln-ind cells showed indications of oxidative stress, and they produced cadherin11 and vimentin, indicators of mesenchymal phenotype. Gln-ind cells were more tumorigenic and more metastatic in nude mice than the parental cell line as judged by incidence and time of occurrence. As we decreased the number of cancer cells in xenografts, lung metastasis

  14. Effect of retinoic acid on proliferation and polyamine metabolism in cultured bovine retinal pigment epithelial cells.

    Science.gov (United States)

    Yasunari, T; Yanagihara, N; Komatsu, T; Moriwaki, M; Shiraki, K; Miki, T; Yano, Y; Otani, S

    1999-01-01

    Reports regarding the effect of all-trans-retinoic acid (RA) on the cell growth of retinal pigment epithelial cells (RPE) have been contradictory. The aims of this study are to clarify the in vitro effect of RA on RPE cells and to examine polyamine metabolism after RA stimulation. A 4-day incubation of fetal-calf-serum (FCS)-stimulated RPE cells with 10 or 25 microM RA significantly increased both cell number and [3H]thymidine incorporation. RPE cells grown over an extended period for 8 days also increased in number and reached full confluency. However, if the incubation was further extended to 12 days, no further increase in cell number was detected. RA treatment of FCS-stimulated RPE cells shifted the peak of ornithine decarboxylase (ODC) activity from 16 to 4 h. S-adenosylmethionine decarboxylase (SAMDC) activity and spermidine/spermine N1-acetyltransferase (SAT) activity of RA-treated RPE cells were significantly greater until 8 and 16 h after incubation, respectively. The putrescine content was significantly increased in RA-treated RPE cells up until 24 h, while spermidine, spermine and N1-acetylspermidine contents were significantly increased until 16 h. Our findings suggest that RA treatment increases the intracellular polyamine concentration of RPE cells via activation of ODC, SAMDC and SAT and that this results in the promotion of RPE cell growth until the cells reach full confluency.

  15. Fibroblast growth factor 21 predicts the metabolic syndrome and type 2 diabetes in Caucasians.

    Science.gov (United States)

    Bobbert, Thomas; Schwarz, Franziska; Fischer-Rosinsky, Antje; Pfeiffer, Andreas F H; Möhlig, Matthias; Mai, Knut; Spranger, Joachim

    2013-01-01

    The incidence of the metabolic syndrome and type 2 diabetes mellitus (T2DM) is rising worldwide. Liver-derived fibroblast growth factor (FGF)-21 affects glucose and lipid metabolism. The aim of this study was to analyze the predictive value of FGF-21 on the incidence of T2DM and the metabolic syndrome. The Metabolic Syndrome Berlin Potsdam (MeSyBePo) recall study includes 440 individuals. Glucose metabolism was analyzed using an oral glucose tolerance test, including insulin measurements. FGF-21 was measured using enzyme-linked immunosorbent assay. Primary study outcome was diabetes and the metabolic syndrome incidence and change of glucose subtraits. During a mean follow-up of 5.30 ± 0.1 years, 54 individuals developed the metabolic syndrome, 35 developed T2DM, and 69 with normal glucose tolerance at baseline progressed to impaired glucose metabolism, defined as impaired fasting glucose, impaired glucose tolerance, or T2DM. FGF-21 predicted incident metabolic syndrome (lnFGF-21 odds ratio [OR] 2.6 [95% CI 1.5 - 4.5]; P = 0.001), T2DM (2.4 [1.2-4.7]; P = 0.01), and progression to impaired glucose metabolism (2.2 [1.3 - 3.6]; P = 0.002) after adjustment for age, sex, BMI, and follow-up time. Additional adjustment for waist-to-hip ratio, systolic blood pressure, HDL cholesterol, triglycerides, and fasting glucose did not substantially modify the predictive value of FGF-21. FGF-21 is an independent predictor of the metabolic syndrome and T2DM in apparently healthy Caucasians. These results may indicate FGF-21 resistance precedes the onset of the metabolic syndrome and T2DM.

  16. Modulation of Kupffer cells on hepatic drug metabolism

    Institute of Scientific and Technical Information of China (English)

    Hong Ding; Jing Tong; Shi-Cheng Wu; Deng-Ke Yin; Xian-Fen Yuan; Jian-Yuan Wu; Jun Chen; Gang-Gang Shi

    2004-01-01

    AIM: To observe the effects of Kupffer cells on hepatic drug metabolic enzymes.METHODS: Kunming mice were ip injected with GdCl310,20, 40 mg/kg to decrease the number and block the function of kupffer cells selectively. The contents of drug metabolic enzymes, cytochrome P450, NADPH-cytochrom C redutase (NADPH-C), aniline hydroxylase (ANH), aminopyrine Ndemethylase (AMD), erythromycin N-demethylase (EMD),and glutathione s-transferase (mGST) in hepatic microsome and S9-GSTpi, S9-GST in supernatant of 9 000 g were accessed 1 d after the injection. The time course of alteration of drug metabolic enzymes was observed on d 1, 3, and 6 treated with a single dose GdCl3. Mice were treated with Angelica sinensis polysaccharides (ASP) of 30, 60, 120 mg/kg, ig, qd ×6 d, respectively and the same assays were performed.RESULTS: P450 content and NADPH-C, ANH, AMD, and END activities were obviously reduced 1 d after Kupffer cell blockade. However, mGST and S9-GST activities were significantly increased. But no relationship was observed between GdCl3 dosage and enzyme activities. With single dose GdCl3 treatment, P450 content, NADPH-C, and ANH activities were further decreased following Kupffer cell blockade lasted for 6 d, by 35.7%, 50.3%, 36.5% after 3 d, and 57.9%, 57.9%, 63.2% after 6 d, respectively. On the contrary, AMD, EMD, mGST, and Sg-GST activities were raised by 36.5%, 71.9%, 23.1%, 35.7% after 3 d,and 155%, 182%, 21.5%, 33.7% after 6 d, respectively.Furthermore, the activities of drug metabolic enzymes were markedly increased after 30 mg/kg ASP treatment,and decreased significantly after 120 mg/kg ASP treatment.No change in activity of Sg-GSTpi was observed in the present study.CONCLUSION: Kupffer cells play an important role in the modulation of drug metabolic enzymes. The changes of drug metabolic enzyme activities depend on the time of kupffer cell blockade and on the degree of Kupffer cells activated. A low concentration of ASP increases the activities of drug

  17. Proteomic analysis of Clostridium thermocellum core metabolism: relative protein expression profiles and growth phase-dependent changes in protein expression

    Directory of Open Access Journals (Sweden)

    Rydzak Thomas

    2012-09-01

    Full Text Available Abstract Background Clostridium thermocellum produces H2 and ethanol, as well as CO2, acetate, formate, and lactate, directly from cellulosic biomass. It is therefore an attractive model for biofuel production via consolidated bioprocessing. Optimization of end-product yields and titres is crucial for making biofuel production economically feasible. Relative protein expression profiles may provide targets for metabolic engineering, while understanding changes in protein expression and metabolism in response to carbon limitation, pH, and growth phase may aid in reactor optimization. We performed shotgun 2D-HPLC-MS/MS on closed-batch cellobiose-grown exponential phase C. thermocellum cell-free extracts to determine relative protein expression profiles of core metabolic proteins involved carbohydrate utilization, energy conservation, and end-product synthesis. iTRAQ (isobaric tag for relative and absolute quantitation based protein quantitation was used to determine changes in core metabolic proteins in response to growth phase. Results Relative abundance profiles revealed differential levels of putative enzymes capable of catalyzing parallel pathways. The majority of proteins involved in pyruvate catabolism and end-product synthesis were detected with high abundance, with the exception of aldehyde dehydrogenase, ferredoxin-dependent Ech-type [NiFe]-hydrogenase, and RNF-type NADH:ferredoxin oxidoreductase. Using 4-plex 2D-HPLC-MS/MS, 24% of the 144 core metabolism proteins detected demonstrated moderate changes in expression during transition from exponential to stationary phase. Notably, proteins involved in pyruvate synthesis decreased in stationary phase, whereas proteins involved in glycogen metabolism, pyruvate catabolism, and end-product synthesis increased in stationary phase. Several proteins that may directly dictate end-product synthesis patterns, including pyruvate:ferredoxin oxidoreductases, alcohol dehydrogenases, and a putative

  18. Sexual dimorphism in epigenomicresponses of stem cells to extreme fetal growth

    Science.gov (United States)

    Delahaye, Fabien; Wijetunga, N. Ari; Heo, Hye J.; Tozour, Jessica N.; Zhao, Yong Mei; Greally, John M.; Einstein, Francine H.

    2014-01-01

    Extreme fetal growth is associated with increased susceptibility to a range of adult diseases through an unknown mechanism of cellular memory. We tested whether heritable epigenetic processes in long-lived CD34+ hematopoietic stem/progenitor cells (HSPCs) showed evidence for re-programming associated with the extremes of fetal growth. Here we show that both fetal growth restriction and over-growth are associated with global shifts towards DNA hypermethylation, targeting cis-regulatory elements in proximity to genes involved in glucose homeostasis and stem cell function. We find a sexually dimorphic response; intrauterine growth restriction (IUGR) is associated with substantially greater epigenetic dysregulation in males, whereas large for gestational age (LGA) growth predominantly affects females. The findings are consistent with extreme fetal growth interacting with variable fetal susceptibility to influence cellular aging and metabolic characteristics through epigenetic mechanisms, potentially generating biomarkers that could identify infants at higher risk for chronic disease later in life. PMID:25300954

  19. Sexual dimorphism in epigenomic responses of stem cells to extreme fetal growth.

    Science.gov (United States)

    Delahaye, Fabien; Wijetunga, N Ari; Heo, Hye J; Tozour, Jessica N; Zhao, Yong Mei; Greally, John M; Einstein, Francine H

    2014-10-10

    Extreme fetal growth is associated with increased susceptibility to a range of adult diseases through an unknown mechanism of cellular memory. We tested whether heritable epigenetic processes in long-lived CD34(+) haematopoietic stem/progenitor cells showed evidence for re-programming associated with the extremes of fetal growth. Here we show that both fetal growth restriction and over-growth are associated with global shifts towards DNA hypermethylation, targeting cis-regulatory elements in proximity to genes involved in glucose homeostasis and stem cell function. We find a sexually dimorphic response; intrauterine growth restriction is associated with substantially greater epigenetic dysregulation in males, whereas large for gestational age growth predominantly affects females. The findings are consistent with extreme fetal growth interacting with variable fetal susceptibility to influence cellular ageing and metabolic characteristics through epigenetic mechanisms, potentially generating biomarkers that could identify infants at higher risk for chronic disease later in life.

  20. MicroRNA-144 mediates metabolic shift in ovarian cancer cells by directly targeting Glut1.

    Science.gov (United States)

    Fan, Jia-Ying; Yang, Yan; Xie, Jing-Ying; Lu, Yan-Ling; Shi, Kun; Huang, Yan-Qing

    2016-05-01

    Warburg effect is characterized by an increased utilization of glucose via glycolysis in cancer cells, even when enough oxygen is present to properly respire. Recent studies demonstrate that deregulation of microRNAs contributes to the Warburg effect. In the present study, we show that miR-144 is downregulated while glucose transporter 1 (Glut1) is upregulated in ovarian cancers. In vitro studies further showed that miR-144 inhibits Glut1 expression through targeting its 3'-untranslated region. As a result, cells overexpressing miR-144 exhibited a metabolic shift, including enhanced glucose uptake and lactate production. The altered glucose metabolism induced by miR-144 also leads to a rapid growth of ovarian cancer cells. Taken together, our results indicate that miR-144 may serve as a molecular switch to regulate glycolysis in ovarian cancer by targeting the expression of Glut1.

  1. Fetal deficiency of lin28 programs life-long aberrations in growth and glucose metabolism.

    Science.gov (United States)

    Shinoda, Gen; Shyh-Chang, Ng; Soysa, T Yvanka de; Zhu, Hao; Seligson, Marc T; Shah, Samar P; Abo-Sido, Nora; Yabuuchi, Akiko; Hagan, John P; Gregory, Richard I; Asara, John M; Cantley, Lewis C; Moss, Eric G; Daley, George Q

    2013-08-01

    LIN28A/B are RNA binding proteins implicated by genetic association studies in human growth and glucose metabolism. Mice with ectopic over-expression of Lin28a have shown related phenotypes. Here, we describe the first comprehensive analysis of the physiologic consequences of Lin28a and Lin28b deficiency in knockout (KO) mice. Lin28a/b-deficiency led to dwarfism starting at different ages, and compound gene deletions showed a cumulative dosage effect on organismal growth. Conditional gene deletion at specific developmental stages revealed that fetal but neither neonatal nor adult deficiency resulted in growth defects and aberrations in glucose metabolism. Tissue-specific KO mice implicated skeletal muscle-deficiency in the abnormal programming of adult growth and metabolism. The effects of Lin28b KO could be rescued by Tsc1 haplo-insufficiency in skeletal muscles. Our data implicate fetal expression of Lin28a/b in the regulation of life-long effects on metabolism and growth, and demonstrate that fetal Lin28b acts at least in part via mTORC1 signaling.

  2. Chick metabolic rate and growth in three species of albatross: a comparative study.

    Science.gov (United States)

    Phillips, R A; Green, J A; Phalan, B; Croxall, J P; Butler, P J

    2003-05-01

    The relative importance of genetic vs. environmental factors in determining the pattern of avian post-embryonic development is much debated. Previous cross-fostering of albatrosses suggested that although inter-specific variation in growth rate was determined primarily by differences in dietary energy content, species-specific constraints might have evolved that could limit maximal growth, even in chicks fed at similar rates and on similar diets. This study aimed to determine whether intrinsic differences in resting metabolic rate were apparent during the linear phase of growth in chicks of three species (black-browed, grey-headed and light-mantled sooty albatrosses). There was a gradual increase in absolute, and a reduction in mass-specific metabolic rate from 5.0 W kg(-1) during the earliest part of linear growth, to 3.5 W kg(-1) by the time chicks reached peak mass. These values are considerably higher than in resting adults of comparable or lower mass, presumably reflecting the large size and high metabolic demand of organs involved in rapid nutrient processing and tissue synthesis by chicks. The lack of any detectable inter-specific variation in the pattern of metabolic rate changes casts some doubt on the existence of fundamental differences in growth rate that cannot be attributed simply to differences in dietary energy or nutrient delivery rate.

  3. The nuclear receptor DAF-12 regulates nutrient metabolism and reproductive growth in nematodes.

    Directory of Open Access Journals (Sweden)

    Zhu Wang

    2015-03-01

    Full Text Available Appropriate nutrient response is essential for growth and reproduction. Under favorable nutrient conditions, the C. elegans nuclear receptor DAF-12 is activated by dafachronic acids, hormones that commit larvae to reproductive growth. Here, we report that in addition to its well-studied role in controlling developmental gene expression, the DAF-12 endocrine system governs expression of a gene network that stimulates the aerobic catabolism of fatty acids. Thus, activation of the DAF-12 transcriptome coordinately mobilizes energy stores to permit reproductive growth. DAF-12 regulation of this metabolic gene network is conserved in the human parasite, Strongyloides stercoralis, and inhibition of specific steps in this network blocks reproductive growth in both of the nematodes. Our study provides a molecular understanding for metabolic adaptation of nematodes to their environment, and suggests a new therapeutic strategy for treating parasitic diseases.

  4. A New Extant Respirometric Assay to Estimate Intrinsic Growth Parameters Applied to Study Plasmid Metabolic Burden

    DEFF Research Database (Denmark)

    Seoane, Jose Miguel; Sin, Gürkan; Lardon, Laurent

    2010-01-01

    Start-Lip phenomena in microbial biokinetic assays are not captured by the most commonly used growth-related equations. In this Study we propose a new respirometric experimental design to estimate intrinsic growth parameters that allow us to avoid these limitations without data omission, separate...... mathematical treatment, or wake-up pulses prior to the analysis.. Identifiability and sensitivity analysis were performed to confirm the robustness of the new approach for obtaining unique and accurate estimates of growth kinetic parameters. The new experimental design was applied to establish the. metabolic...... burden caused by the carriage of a pWW0 TOL plasmid in the model organism Pseudomonas putida KT2440; The metabolic,burden associated was manifested as a reduction in the yield and the specific growth rate of the host, with both plasmid maintenance and the over-expression of recombinant proteins from...

  5. Characterization of the metabolic phenotype of rapamycin-treated CD8+ T cells with augmented ability to generate long-lasting memory cells.

    Directory of Open Access Journals (Sweden)

    Shan He

    Full Text Available BACKGROUND: Cellular metabolism plays a critical role in regulating T cell responses and the development of memory T cells with long-term protections. However, the metabolic phenotype of antigen-activated T cells that are responsible for the generation of long-lived memory cells has not been characterized. DESIGN AND METHODS: Using lymphocytic choriomeningitis virus (LCMV peptide gp33-specific CD8(+ T cells derived from T cell receptor transgenic mice, we characterized the metabolic phenotype of proliferating T cells that were activated and expanded in vitro in the presence or absence of rapamycin, and determined the capability of these rapamycin-treated T cells to generate long-lived memory cells in vivo. RESULTS: Antigen-activated CD8(+ T cells treated with rapamycin gave rise to 5-fold more long-lived memory T cells in vivo than untreated control T cells. In contrast to that control T cells only increased glycolysis, rapamycin-treated T cells upregulated both glycolysis and oxidative phosphorylation (OXPHOS. These rapamycin-treated T cells had greater ability than control T cells to survive withdrawal of either glucose or growth factors. Inhibition of OXPHOS by oligomycin significantly reduced the ability of rapamycin-treated T cells to survive growth factor withdrawal. This effect of OXPHOS inhibition was accompanied with mitochondrial hyperpolarization and elevation of reactive oxygen species that are known to be toxic to cells. CONCLUSIONS: Our findings indicate that these rapamycin-treated T cells may represent a unique cell model for identifying nutrients and signals critical to regulating metabolism in both effector and memory T cells, and for the development of new methods to improve the efficacy of adoptive T cell cancer therapy.

  6. Effects of salmeterol on skeletal muscle cells: metabolic and proapoptotic features.

    Science.gov (United States)

    Duranti, Guglielmo; La Rosa, Piergiorgio; Dimauro, Ivan; Wannenes, Francesca; Bonini, Sergio; Sabatini, Stefania; Parisi, Paolo; Caporossi, Daniela

    2011-12-01

    Salmeterol is a β2-adrenergic receptor agonist widely used for the treatment of asthma and chronic obstructive pulmonary disease. It has been shown that salmeterol is also used at supratherapeutic doses as performance-enhancing substance in sport practice. Although the abuse of β-agonists might determine some adverse effects, the molecular effects of salmeterol on skeletal muscle cells remain unclear. We evaluated the effects of salmeterol (0.1-10 μM) on both proliferative and differentiated rat L6C5 and mouse C2C12 skeletal muscle cell lines. The metabolic effects were evaluated by glyceraldehyde phosphate dehydrogenase, lactate dehydrogenase, citrate synthase, 3-OH acyl-CoA dehydrogenase, and alanine transglutaminase activities. Cytotoxic and apoptotic effects were analyzed by 3-(4,5-dimethylthiazol-1)-5-(3-carboxymeth-oxyphenyl)-2H-tetrazolium, trypan blue exclusion assay, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, Western blot analysis, and immunofluorescence staining. We showed that salmeterol reduced the growth rate of proliferating cells in a dose- and time-dependent manner (6-48 h). An increase in oxidative metabolism was found after 6 h in C2C12 and L6C5 myoblasts and in C2C12 myotubes with respect to control cells, while in L6C5 myotubes, anaerobic metabolism prevailed. Exposure of myoblasts and myotubes for 48 and 72 h at high salmeterol concentrations induced apoptosis by the activation of the intrinsic apoptotic pathway, as confirmed by the modulation of the apoptotic proteins Bcl-xL, caspase-9, and poly (ADP-ribose) polymerase and by the cytoplasmic release of Smac/DIABLO. Altogether, our results demonstrate that short-term supratherapeutic salmeterol exposure increased oxidative metabolic pathways on skeletal muscle cells, whereas prolonged treatment inhibits cell growth and exerts either a cytostatic or a proapoptotic effect in a time- and dose-dependent way.

  7. Shear stress induced stimulation of mammalian cell metabolism

    Science.gov (United States)

    Mcintire, L. V.; Frangos, J. A.; Eskin, S. G.

    1988-01-01

    A flow apparatus was developed for the study of the metabolic response of anchorage dependent cells to a wide range of steady and pulsatile shear stresses under well controlled conditions. Human umbilical vein endothelial cell monolayers were subjected to steady shear stresses of up to 24 dynes/sq cm, and the production of prostacyclin was determined. The onset of flow led to a burst in prostacyclin production which decayed to a long term steady state rate (SSR). The SSR of cells exposed to flow was greater than the basal release level, and increased linearly with increasing shear stress. It is demonstrated that shear stresses in certain ranges may not be detrimental to mammalian cell metabolism. In fact, throughout the range of shear stresses studied, metabolite production is maximized by maximizing shear stress.

  8. TARGETING CD8 T CELL METABOLISM IN TRANSPLANTATION

    Directory of Open Access Journals (Sweden)

    Michelle eYap

    2015-10-01

    Full Text Available Infiltration of effector CD8 T cells play a major role in allograft rejection, and increases in memory and terminally-differentiated effector memory (TEMRA CD8 T cells are associated with long term allograft dysfunction. Alternatively, CD8 regulatory T (Tregs cells suppress the inflammatory responses of effector lymphocytes and induce allograft tolerance in animal models. Recently, there has been a renewed interest in the field of immunometabolics and its important role in CD8 function and differentiation. The purpose of this review is to highlight the key metabolic pathways involved in CD8 T cells and to discuss how manipulating these metabolic pathways could lead to new immunosuppressive strategies for the transplantation field.

  9. Unveiling the Metabolic Changes on Muscle Cell Metabolism Underlying p-Phenylenediamine Toxicity

    Science.gov (United States)

    Marín de Mas, Igor; Marín, Silvia; Pachón, Gisela; Rodríguez-Prados, Juan C.; Vizán, Pedro; Centelles, Josep J.; Tauler, Romà; Azqueta, Amaya; Selivanov, Vitaly; López de Ceraín, Adela; Cascante, Marta

    2017-01-01

    Rhabdomyolysis is a disorder characterized by acute damage of the sarcolemma of the skeletal muscle leading to release of potentially toxic muscle cell components into the circulation, most notably creatine phosphokinase (CK) and myoglobulin, and is frequently accompanied by myoglobinuria. In the present work, we evaluated the toxicity of p-phenylenediamine (PPD), a main component of hair dyes which is reported to induce rhabdomyolysis. We studied the metabolic effect of this compound in vivo with Wistar rats and in vitro with C2C12 muscle cells. To this aim we have combined multi-omic experimental measurements with computational approaches using model-driven methods. The integrative study presented here has unveiled the metabolic disorders associated to PPD exposure that may underlay the aberrant metabolism observed in rhabdomyolys disease. Animals treated with lower doses of PPD (10 and 20 mg/kg) showed depressed activity and myoglobinuria after 10 h of treatment. We measured the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) in rats after 24, 48, and 72 h of PPD exposure. At all times, treatment with PPD at higher doses (40 and 60 mg/kg) showed an increase of AST and ALT, and also an increase of lactate dehydrogenase (LDH) and CK after 24 h. Blood packed cell volume and hemoglobin levels, as well as organs weight at 48 and 72 h, were also measured. No significant differences were observed in these parameters under any condition. PPD induce cell cycle arrest in S phase and apoptosis (40% or early apoptotic cells) on mus musculus mouse C2C12 cells after 24 h of treatment. Incubation of mus musculus mouse C2C12 cells with [1,2-13C2]-glucose during 24 h, subsequent quantification of 13C isotopologues distribution in key metabolites of glucose metabolic network and a computational fluxomic analysis using in-house developed software (Isodyn) showed that PPD is inhibiting glycolysis, non-oxidative pentose

  10. Tumor microenvironment derived exosomes pleiotropically modulate cancer cell metabolism

    Science.gov (United States)

    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 tha...

  11. METABOLIC CAPACITY REGULATES IRON HOMEOSTATIS IN ENDOTHELIAL CELLS

    Science.gov (United States)

    The sensitivity of endothelial cells to oxidative stress and the high concentrations of iron in mitochondria led us to test the hypotheses that (1) changes in respiratory capacity alter iron homeostasis, and (2) lack of aerobic metabolism decreases labile iron stores and attenuat...

  12. Cancer cell metabolism regulates extracellular matrix degradation by invadopodia

    NARCIS (Netherlands)

    Horssen, R. van; Buccione, R.; Willemse, M.P.; Cingir, S.; Wieringa, B.; Attanasio, F.

    2013-01-01

    Transformed cancer cells have an altered metabolism, characterized by a shift towards aerobic glycolysis, referred to as 'the Warburg phenotype'. A change in flux through mitochondrial OXPHOS and cytosolic pathways for ATP production and a gain of capacity for biomass production in order to sustain

  13. The Mechanism of Action of SOCS2 and its Role in Metabolism and Growth

    OpenAIRE

    Vesterlund, Mattias

    2013-01-01

    A well-known function of Growth Hormone (GH) is the regulation of postnatal longitudinal growth but it also affects other biological processes, for instance metabolism and inflammation. Actions of GH are tightly regulated at several levels and by several different factors and are initiated by GH binding to membrane bound GH receptors (GHR). The intracellular signaling of GH and other related hormones and cytokines is predominately mediated by the JAK-STAT pathway. This pathway is regulated in...

  14. Growth kinetics of hybridoma cells: (2) The effects of varying energy source concentrations.

    Science.gov (United States)

    Low, K; Harbour, C

    1985-01-01

    Commercial media used for the growth of hybridoma cells contain different glucose concentrations. We have attempted to establish the optimal levels of glucose required for maximum hybridoma cell yields by studying the energy source metabolism of two murine hybridoma cell lines in several commercial media in static 25 cm2 flask cultures. The glucose and lactate quotients and growth yields from glucose of the two cell lines were similar in all media. Glucose limited growth in DME containing lg/L. Glucose supplementation to 2g/L in DME significantly increased cell and antibody yields. When fructose was used as a substitute for glucose the fructose quotient of one cell line was found to be similar to its glucose quotient whereas that of the other cell line was significantly reduced compared to its glucose quotient.

  15. Role of platelet-derived enclothelial cell growth factor/thymidine phosphorylase in fluoropyrimidine sensitivity

    NARCIS (Netherlands)

    de Bruin, M; van Capel, T; Van der Born, K; Kruyt, FA; Fukushinna, M; Hoekman, K; Pinedo, HM; Peters, GJ

    2003-01-01

    Platelet-derived endothelial cell growth factor (PD-ECGF)/thymidine phosphorylase (TP) catalyses the reversible phosphorolysis of thymidine to thymine and 2-deoxyribose-1-phosphate and is involved in the metabolism of fluoropyrimidines. It can also activate 5'-deoxyfluorouridine (5'DFUR) and possibl

  16. miR-132 mediates a metabolic shift in prostate cancer cells by targeting Glut1.

    Science.gov (United States)

    Qu, Wei; Ding, Shi-Mei; Cao, Gang; Wang, She-Jiao; Zheng, Xiang-Hong; Li, Guo-Hui

    2016-07-01

    Prostate cancer is the second leading cause of cancer-related deaths among men worldwide. Early diagnosis increases survival rates in patients but the survival rate has remained relatively poor over the past years. Increasing evidence shows that altered metabolism is a critical hallmark in prostate cancer. There is a strong need to explore the molecular mechanisms underlying cancer metabolism for prostate cancer therapy. Whether the aberrant expression of microRNA (miRNA) contributes to cancer metabolism is not fully known. In this study, we found that microRNA-132 (miR-132) expression is reduced and thus leads to a metabolic switch in prostate cancer cells. miR-132 performs this role by increasing Glut1 expression, resulting in the enhanced rate of lactate production and glucose uptake. The altered metabolism induced by decreased miR-132 levels confers the rapid growth of the cancer cells. These data indicate that miR-132 is involved in regulating the Warburg effect in prostate cancer by inhibiting Glut1 expression.

  17. Cesium reversibly suppresses HeLa cell proliferation by inhibiting cellular metabolism.

    Science.gov (United States)

    Kobayashi, Daisuke; Kakinouchi, Kei; Nagae, Tomoki; Nagai, Toshihiko; Shimura, Kiyohito; Hazama, Akihiro

    2017-03-01

    The aim of the present study was to investigate the influence of Cs(+) on cultured human cells. We find that HeLa cell growth is suppressed by the addition of 10 mm CsCl into the culture media. In the Cs(+) -treated cells, the intracellular Cs(+) and K(+) concentrations are increased and decreased, respectively. This leads to a decrease in activity of the glycolytic enzyme pyruvate kinase, which uses K(+) as a cofactor. Cs(+) -treated cells show an intracellular pH shift towards alkalization. Based on these results, CsCl presumably suppresses HeLa cell proliferation by inducing an intracellular cation imbalance that affects cell metabolism. Our findings may have implications for the use of Cs(+) in cancer therapy.

  18. Molecular Imaging Of Metabolic Reprogramming In Mutant IDH Cells

    Directory of Open Access Journals (Sweden)

    Pavithra eViswanath

    2016-03-01

    Full Text Available Mutations in the metabolic enzyme isocitrate dehydrogenase (IDH have recently been identified as drivers in the development of several tumor types. Most notably, cytosolic IDH1 is mutated in 70-90% of low-grade gliomas and upgraded glioblastomas, and mitochondrial IDH2 is mutated in ~20% of acute myeloid leukemia cases. Wild-type IDH catalyzes the interconversion of isocitrate to α-ketoglutarate (α-KG. Mutations in the enzyme lead to loss of wild-type enzymatic activity and a neomorphic activity that converts α-KG to 2-hydroxyglutarate (2-HG. In turn, 2-HG, which has been termed an oncometabolite, inhibits key α-KG- dependent enzymes, resulting in alterations of the cellular epigenetic profile and, subsequently, inhibition of differentiation and initiation of tumorigenesis. In addition, it is now clear that the IDH mutation also induces a broad metabolic reprogramming that extends beyond 2-HG production, and this reprogramming often differs from what has been previously reported in other cancer types. In this review we will discuss in detail what is known to date about the metabolic reprogramming of mutant IDH cells and how this reprogramming has been investigated using molecular metabolic imaging. We will describe how metabolic imaging has helped shed light on the basic biology of mutant IDH cells and how this information can be leveraged to identify new therapeutic targets and to develop new clinically translatable imaging methods to detect and monitor mutant IDH tumors in vivo.

  19. Arctigenin preferentially induces tumor cell death under glucose deprivation by inhibiting cellular energy metabolism.

    Science.gov (United States)

    Gu, Yuan; Qi, Chunting; Sun, Xiaoxiao; Ma, Xiuquan; Zhang, Haohao; Hu, Lihong; Yuan, Junying; Yu, Qiang

    2012-08-15

    Selectively eradicating cancer cells with minimum adverse effects on normal cells is a major challenge in the development of anticancer therapy. We hypothesize that nutrient-limiting conditions frequently encountered by cancer cells in poorly vascularized solid tumors might provide an opportunity for developing selective therapy. In this study, we investigated the function and molecular mechanisms of a natural compound, arctigenin, in regulating tumor cell growth. We demonstrated that arctigenin selectively promoted glucose-starved A549 tumor cells to undergo necrosis by inhibiting mitochondrial respiration. In doing so, arctigenin elevated cellular level of reactive oxygen species (ROS) and blocked cellular energy metabolism in the glucose-starved tumor cells. We also demonstrated that cellular ROS generation was caused by intracellular ATP depletion and played an essential role in the arctigenin-induced tumor cell death under the glucose-limiting condition. Furthermore, we combined arctigenin with the glucose analogue 2-deoxyglucose (2DG) and examined their effects on tumor cell growth. Interestingly, this combination displayed preferential cell-death inducing activity against tumor cells compared to normal cells. Hence, we propose that the combination of arctigenin and 2DG may represent a promising new cancer therapy with minimal normal tissue toxicity.

  20. Effect of growth rate and body mass on resting metabolic rate in galliform chicks

    NARCIS (Netherlands)

    Dietz, MW; Drent, RH

    1997-01-01

    In this study, we asked whether within-species variation in chick resting metabolic rate was related to variation in growth and whether this relationship changed during development in three galliform species (turkey, Meleagris gallopavo, guinea fowl, Numida meleagris, and Japanese quail, Coturnix co

  1. Normal birth weight piglets with impaired preweaning growth utilize alternative metabolic pathways in the liver

    Science.gov (United States)

    The present study was designed to determine if normal weight pigs that grow poorly during the pre-weaning period have altered hepatic metabolism, as reported for intrauterine growth retarded pigs. Eight pairs of average birth weight pigs (1.57 +/- 0.05 kg) were identified that diverged in weight by...

  2. Food composition influences metabolism, heart rate and organ growth during digestion in Python regius.

    Science.gov (United States)

    Henriksen, Poul Secher; Enok, Sanne; Overgaard, Johannes; Wang, Tobias

    2015-05-01

    Digestion in pythons is associated with a large increase in oxygen consumption (SDA), increased cardiac output and growth in visceral organs assisting in digestion. The processes leading to the large postprandial rise in metabolism in snakes is subject to opposing views. Gastric work, protein synthesis and organ growth have each been speculated to be major contributors to the SDA. To investigate the role of food composition on SDA, heart rate (HR) and organ growth, 48 ball pythons (Python regius) were fed meals of either fat, glucose, protein or protein combined with carbonate. Our study shows that protein, in the absence or presence of carbonate causes a large SDA response, while glucose caused a significantly smaller SDA response and digestion of fat failed to affect metabolism. Addition of carbonate to the diet to stimulate gastric acid secretion did not increase the SDA response. These results support protein synthesis as a major contributor to the SDA response and show that increased gastric acid secretion occurs at a low metabolic cost. The increase in metabolism was supported by tachycardia caused by altered autonomic regulation as well as an increased non-adrenergic, non-cholinergic (NANC) tone in response to all diets, except for the lipid meal. Organ growth only occurred in the small intestine and liver in snakes fed on a high protein diet.

  3. Metabolic measurements in cell culture and tissue constructs

    Science.gov (United States)

    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#

  4. TP53-inducible Glycolysis and Apoptosis Regulator (TIGAR) Metabolically Reprograms Carcinoma and Stromal Cells in Breast Cancer.

    Science.gov (United States)

    Ko, Ying-Hui; Domingo-Vidal, Marina; Roche, Megan; Lin, Zhao; Whitaker-Menezes, Diana; Seifert, Erin; Capparelli, Claudia; Tuluc, Madalina; Birbe, Ruth C; Tassone, Patrick; Curry, Joseph M; Navarro-Sabaté, Àurea; Manzano, Anna; Bartrons, Ramon; Caro, Jaime; Martinez-Outschoorn, Ubaldo

    2016-12-16

    A subgroup of breast cancers has several metabolic compartments. The mechanisms by which metabolic compartmentalization develop in tumors are poorly characterized. TP53 inducible glycolysis and apoptosis regulator (TIGAR) is a bisphosphatase that reduces glycolysis and is highly expressed in carcinoma cells in the majority of human breast cancers. Hence we set out to determine the effects of TIGAR expression on breast carcinoma and fibroblast glycolytic phenotype and tumor growth. The overexpression of this bisphosphatase in carcinoma cells induces expression of enzymes and transporters involved in the catabolism of lactate and glutamine. Carcinoma cells overexpressing TIGAR have higher oxygen consumption rates and ATP levels when exposed to glutamine, lactate, or the combination of glutamine and lactate. Coculture of TIGAR overexpressing carcinoma cells and fibroblasts compared with control cocultures induce more pronounced glycolytic differences between carcinoma and fibroblast cells. Carcinoma cells overexpressing TIGAR have reduced glucose uptake and lactate production. Conversely, fibroblasts in coculture with TIGAR overexpressing carcinoma cells induce HIF (hypoxia-inducible factor) activation with increased glucose uptake, increased 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 (PFKFB3), and lactate dehydrogenase-A expression. We also studied the effect of this enzyme on tumor growth. TIGAR overexpression in carcinoma cells increases tumor growth in vivo with increased proliferation rates. However, a catalytically inactive variant of TIGAR did not induce tumor growth. Therefore, TIGAR expression in breast carcinoma cells promotes metabolic compartmentalization and tumor growth with a mitochondrial metabolic phenotype with lactate and glutamine catabolism. Targeting TIGAR warrants consideration as a potential therapy for breast cancer. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Complex Nonlinear Behavior in Metabolic Processes: Global Bifurcation Analysis of Escherichia coli Growth on Multiple Substrates

    Directory of Open Access Journals (Sweden)

    Hyun-Seob Song

    2013-09-01

    Full Text Available The nonlinear behavior of metabolic systems can arise from at least two different sources. One comes from the nonlinear kinetics of chemical reactions in metabolism and the other from nonlinearity associated with regulatory processes. Consequently, organisms at a constant growth rate (as experienced in a chemostat could display multiple metabolic states or display complex oscillatory behavior both with potentially serious implications to process operation. This paper explores the nonlinear behavior of a metabolic model of Escherichia coli growth on mixed substrates with sufficient detail to include regulatory features through the cybernetic postulate that metabolic regulation is the consequence of a dynamic objective function ensuring the organism’s survival. The chief source of nonlinearity arises from the optimal formulation with the metabolic state determined by a convex combination of reactions contributing to the objective function. The model for anaerobic growth of E. coli was previously examined for multiple steady states in a chemostat fed by a mixture of glucose and pyruvate substrates under very specific conditions and experimentally verified. In this article, we explore the foregoing model for nonlinear behavior over the full range of parameters, γ (the fractional concentration of glucose in the feed mixture and D (the dilution rate. The observed multiplicity is in the cybernetic variables combining elementary modes. The results show steady-state multiplicity up to seven. No Hopf bifurcation was encountered, however. Bifurcation analysis of cybernetic models is complicated by the non-differentiability of the cybernetic variables for enzyme activities. A methodology is adopted here to overcome this problem, which is applicable to more complicated metabolic networks.

  6. Metabolic flux rearrangement in the amino acid metabolism reduces ammonia stress in the α1-antitrypsin producing human AGE1.HN cell line.

    Science.gov (United States)

    Priesnitz, Christian; Niklas, Jens; Rose, Thomas; Sandig, Volker; Heinzle, Elmar

    2012-03-01

    This study focused on metabolic changes in the neuronal human cell line AGE1.HN upon increased ammonia stress. Batch cultivations of α(1)-antitrypsin (A1AT) producing AGE1.HN cells were carried out in media with initial ammonia concentrations ranging from 0mM to 5mM. Growth, A1AT production, metabolite dynamics and finally metabolic fluxes calculated by metabolite balancing were compared. Growth and A1AT production decreased with increasing ammonia concentration. The maximum A1AT concentration decreased from 0.63g/l to 0.51g/l. Central energy metabolism remained relatively unaffected exhibiting only slightly increased glycolytic flux at high initial ammonia concentration in the medium. However, the amino acid metabolism was significantly changed. Fluxes through transaminases involved in amino acid degradation were reduced concurrently with a reduced uptake of amino acids. On the other hand fluxes through transaminases working in the direction of amino acid synthesis, i.e., alanine and phosphoserine, were increased leading to increased storage of excess nitrogen in extracellular alanine and serine. Glutamate dehydrogenase flux was reversed increasingly fixing free ammonia with increasing ammonia concentration. Urea production additionally observed was associated with arginine uptake by the cells and did not increase at high ammonia stress. It was therefore not used as nitrogen sink to remove excess ammonia. The results indicate that the AGE1.HN cell line can adapt to ammonia concentrations usually present during the cultivation process to a large extent by changing metabolism but with slightly reduced A1AT production and growth.

  7. The vitamin D receptor inhibits the respiratory chain, contributing to the metabolic switch that is essential for cancer cell proliferation.

    Science.gov (United States)

    Consiglio, Marco; Destefanis, Michele; Morena, Deborah; Foglizzo, Valentina; Forneris, Mattia; Pescarmona, Gianpiero; Silvagno, Francesca

    2014-01-01

    We recently described the mitochondrial localization and import of the vitamin D receptor (VDR) in actively proliferating HaCaT cells for the first time, but its role in the organelle remains unknown. Many metabolic intermediates that support cell growth are provided by the mitochondria; consequently, the identification of proteins that regulate mitochondrial metabolic pathways is of great interest, and we sought to understand whether VDR may modulate these pathways. We genetically silenced VDR in HaCaT cells and studied the effects on cell growth, mitochondrial metabolism and biosynthetic pathways. VDR knockdown resulted in robust growth inhibition, with accumulation in the G0G1 phase of the cell cycle and decreased accumulation in the M phase. The effects of VDR silencing on proliferation were confirmed in several human cancer cell lines. Decreased VDR expression was consistently observed in two different models of cell differentiation. The impairment of silenced HaCaT cell growth was accompanied by sharp increases in the mitochondrial membrane potential, which sensitized the cells to oxidative stress. We found that transcription of the subunits II and IV of cytochrome c oxidase was significantly increased upon VDR silencing. Accordingly, treatment of HaCaT cells with vitamin D downregulated both subunits, suggesting that VDR may inhibit the respiratory chain and redirect TCA intermediates toward biosynthesis, thus contributing to the metabolic switch that is typical of cancer cells. In order to explore this hypothesis, we examined various acetyl-CoA-dependent biosynthetic pathways, such as the mevalonate pathway (measured as cholesterol biosynthesis and prenylation of small GTPases), and histone acetylation levels; all of these pathways were inhibited by VDR silencing. These data provide evidence of the role of VDR as a gatekeeper of mitochondrial respiratory chain activity and a facilitator of the diversion of acetyl-CoA from the energy-producing TCA cycle

  8. Nerve growth factor interactions with mast cells.

    Science.gov (United States)

    Kritas, S K; Caraffa, A; Antinolfi, P; Saggini, A; Pantalone, A; Rosati, M; Tei, M; Speziali, A; Saggini, R; Pandolfi, F; Cerulli, G; Conti, P

    2014-01-01

    Neuropeptides are involved in neurogenic inflammation where there is vasodilation and plasma protein extravasion in response to this stimulus. Nerve growth factor (NGF), identified by Rita Levi Montalcini, is a neurotrophin family compound which is important for survival of nociceptive neurons during their development. Therefore, NGF is an important neuropeptide which mediates the development and functions of the central and peripheral nervous system. It also exerts its proinflammatory action, not only on mast cells but also in B and T cells, neutrophils and eosinophils. Human mast cells can be activated by neuropeptides to release potent mediators of inflammation, and they are found throughout the body, especially near blood vessels, epithelial tissue and nerves. Mast cells generate and release NGF after degranulation and they are involved in iperalgesia, neuroimmune interactions and tissue inflammation. NGF is also a potent degranulation factor for mast cells in vitro and in vivo, promoting differentiation and maturation of these cells and their precursor, acting as a co-factor with interleukin-3. In conclusion, these studies are focused on cross-talk between neuropeptide NGF and inflammatory mast cells.

  9. Metabolic Stress and Compromised Identity of Pancreatic Beta Cells

    Science.gov (United States)

    Swisa, Avital; Glaser, Benjamin; Dor, Yuval

    2017-01-01

    Beta cell failure is a central feature of type 2 diabetes (T2D), but the molecular underpinnings of the process remain only partly understood. It has been suggested that beta cell failure in T2D involves massive cell death. Other studies ascribe beta cell failure to cell exhaustion, due to chronic oxidative or endoplasmic reticulum stress leading to cellular dysfunction. More recently it was proposed that beta cells in T2D may lose their differentiated identity, possibly even gaining features of other islet cell types. The loss of beta cell identity appears to be driven by glucotoxicity inhibiting the activity of key beta cell transcription factors including Pdx1, Nkx6.1, MafA and Pax6, thereby silencing beta cell genes and derepressing alternative islet cell genes. The loss of beta cell identity is at least partly reversible upon normalization of glycemia, with implications for the reversibility of T2D, although it is not known if beta cell failure reaches eventually a point of no return. In this review we discuss current evidence for metabolism-driven compromised beta cell identity, key knowledge gaps and opportunities for utility in the treatment of T2D.

  10. Metformin Decouples Phospholipid Metabolism in Breast Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Tim A D Smith

    Full Text Available 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.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.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.This is the first study to show that treatment of breast cancer cells with metformin induces profound changes in phospholipid metabolism.

  11. Metabolic impact of anti-angiogenic agents on U87 glioma cells.

    Directory of Open Access Journals (Sweden)

    Tanja Mesti

    Full Text Available BACKGROUND: Glioma cells not only secrete high levels of vascular endothelial growth factor (VEGF but also express VEGF receptors (VEGFR, supporting the existence of an autocrine loop. The direct impact on glioma cells metabolism of drugs targeting the VEGF pathway, such as Bevacizumab (Bev or VEGFR Tyrosine Kinase Inhibitor (TKI, is poorly known. MATERIAL AND METHODS: U87 cells were treated with Bev or SU1498, a selective VEGFR2 TKI. VEGFR expression was checked with FACS flow cytometry and Quantitative Real-Time PCR. VEGF secretion into the medium was assessed with an ELISA kit. Metabolomic studies on cells were performed using High Resolution Magic Angle Spinning Spectroscopy (HR-MAS. RESULTS: U87 cells secreted VEGF and expressed low level of VEGFR2, but no detectable VEGFR1. Exposure to SU1498, but not Bev, significantly impacted cell proliferation and apoptosis. Metabolomic studies with HR MAS showed that Bev had no significant effect on cell metabolism, while SU1498 induced a marked increase in lipids and a decrease in glycerophosphocholine. Accordingly, accumulation of lipid droplets was seen in the cytoplasm of SU1498-treated U87 cells. CONCLUSION: Although both drugs target the VEGF pathway, only SU1498 showed a clear impact on cell proliferation, cell morphology and metabolism. Bevacizumab is thus less likely to modify glioma cells phenotype due to a direct therapeutic pressure on the VEGF autocrine loop. In patients treated with VEGFR TKI, monitoring lipids with magnetic resonance spectroscopic (MRS might be a valuable marker to assess drug cytotoxicity.

  12. Cell transformation and mutability of different genetic loci in mammalian cells by metabolically activated carcinogenic polycylic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Huberman, E.

    1977-01-01

    Treatment of experimental animals with chemical carcinogens, including some polycyclic hydrocarbons, can result in the formation of malignant tumors. The process whereby some chemicals induce malignancy is as yet unknown. However, in a model system using mammalian cells in culture, it was possible to show that the chemical carcinogens induce malignant transformation rather than select for pre-existing tumor cells. In the process of the in vitro cell transformation, the normal cells, which have an oriented pattern of cell growth, a limited life-span in vitro, and are not tumorigenic, are converted into cells that have a hereditary random pattern of cell growth, the ability to grow continuously in culture, and the ability to form tumors in vivo. This stable heritable phenotype of the transformed cells is similar to that of cells derived from spontaneous or experimentally induced tumors. Such stable heritable phenotype changes may arise from alteration in gene expression due to a somatic mutation after interaction of the carcinogen with cellular DNA. In the present experiments we have shown that metabolically activated carcinogenic polycyclic hydrocarbons which have been shown to bind to cellular DNA induce somatic mutations at different genetic loci in mammalian cells and that there is a relationship between the degree of mutant induction and the degree of carcinogenicity of the different hydrocarbons tested.

  13. How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox

    DEFF Research Database (Denmark)

    Snoep, Jacky L.; Jensen, Peter Ruhdal; Groeneveld, Philip

    1994-01-01

    how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat. We develop metabolic control analysis for the chemostat. this analysis does not depend on the particular way in which specific growth rate varies with the concentration of the growth...

  14. Markers of bone metabolism are affected by renal function and growth hormone therapy in children with chronic kidney disease

    DEFF Research Database (Denmark)

    Doyon, Anke; Fischer, Dagmar Christiane; Bayazit, Aysun Karabay;

    2015-01-01

    Objectives: The extent and relevance of altered bone metabolism for statural growth in children with chronic kidney disease is controversial. We analyzed the impact of renal dysfunction and recombinant growth hormone therapy on a panel of serum markers of bone metabolism in a large pediatric chro...

  15. Markers of bone metabolism are affected by renal function and growth hormone therapy in children with chronic kidney disease

    DEFF Research Database (Denmark)

    Doyon, Anke; Fischer, Dagmar Christiane; Bayazit, Aysun Karabay

    2015-01-01

    Objectives: The extent and relevance of altered bone metabolism for statural growth in children with chronic kidney disease is controversial. We analyzed the impact of renal dysfunction and recombinant growth hormone therapy on a panel of serum markers of bone metabolism in a large pediatric chro...

  16. Mesenchymal stem cell like (MSCl) cells generated from human embryonic stem cells support pluripotent cell growth

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Nora [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Vereb, Zoltan; Rajnavoelgyi, Eva [Department of Immunology, Medical and Health Science Centre, University of Debrecen, Debrecen (Hungary); Nemet, Katalin; Uher, Ferenc; Sarkadi, Balazs [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary); Apati, Agota, E-mail: apati@kkk.org.hu [Membrane Research Group of the Hungarian Academy of Sciences, Semmelweis University, Budapest (Hungary)

    2011-10-28

    Highlights: Black-Right-Pointing-Pointer MSC like cells were derived from hESC by a simple and reproducible method. Black-Right-Pointing-Pointer Differentiation and immunosuppressive features of MSCl cells were similar to bmMSC. Black-Right-Pointing-Pointer MSCl cells as feeder cells support the undifferentiated growth of hESC. -- Abstract: Mesenchymal stem cell like (MSCl) cells were generated from human embryonic stem cells (hESC) through embryoid body formation, and isolated by adherence to plastic surface. MSCl cell lines could be propagated without changes in morphological or functional characteristics for more than 15 passages. These cells, as well as their fluorescent protein expressing stable derivatives, efficiently supported the growth of undifferentiated human embryonic stem cells as feeder cells. The MSCl cells did not express the embryonic (Oct4, Nanog, ABCG2, PODXL, or SSEA4), or hematopoietic (CD34, CD45, CD14, CD133, HLA-DR) stem cell markers, while were positive for the characteristic cell surface markers of MSCs (CD44, CD73, CD90, CD105). MSCl cells could be differentiated toward osteogenic, chondrogenic or adipogenic directions and exhibited significant inhibition of mitogen-activated lymphocyte proliferation, and thus presented immunosuppressive features. We suggest that cultured MSCl cells can properly model human MSCs and be applied as efficient feeders in hESC cultures.

  17. TMEFF2 AND SARDH COOPERATE TO MODULATE ONE CARBON METABOLISM AND INVASION OF PROSTATE CANCER CELLS

    Science.gov (United States)

    Green, Thomas; Chen, Xiaofei; Ryan, Stephen; Asch, Adam S.; Ruiz-Echevarría, Maria J.

    2013-01-01

    BACKGROUND The transmembrane protein with epidermal growth factor and two follistatin motifs, TMEFF2, has been implicated in prostate cancer but its role in this disease is unclear. We recently demonstrated that the tumor suppressor role of TMEFF2 correlates, in part, with its ability to interact with sarcosine dehydrogenase (SARDH) and modulate sarcosine level. TMEFF2 overexpression inhibits sarcosine-induced invasion. Here, we further characterize the functional interaction between TMEFF2 and SARDH and their link with one-carbon (1-C) metabolism and invasion. METHODS RNA interference was used to study the effect of SARDH and/or TMEFF2 knockdown (KD) in invasion, evaluated using Boyden chambers. The dependence of invasion on 1-C metabolism was determined by examining sensitivity to methotrexate. Real-time PCR and western blot of subcellular fractions were used to study the effect of SARDH KD or TMEFF2 KD on expression of enzymes involved in one carbon (1-C) metabolism and on TMEFF2 expression and localization. Protein interactions were analyzed by mass-spectrometry. Cell viability and proliferation were measured by cell counting and MTT analysis. RESULTS While knocking down SARDH affects TMEFF2 subcellular localization, this effect is not responsible for the increased invasion observed in SARDH KD cells. Importantly, SARDH and/or TMEFF2 KD promote increased cellular invasion, sensitize the cell to methotrexate, render the cell resistant to invasion induced by sarcosine, a metabolite from the folate-mediated 1-C metabolism pathway, and affect the expression level of enzymes involved in that pathway. CONCLUSIONS Our findings define a role for TMEFF2 and the folate-mediated 1-C metabolism pathway in modulating cellular invasion. PMID:23824605

  18. Pancreatic tumor cell metabolism: focus on glycolysis and its connected metabolic pathways.

    Science.gov (United States)

    Guillaumond, Fabienne; Iovanna, Juan Lucio; Vasseur, Sophie

    2014-03-01

    Because of lack of effective treatment, pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of death by cancer in Western countries, with a very weak improvement of survival rate over the last 40years. Defeat of numerous conventional therapies to cure this cancer makes urgent to develop new tools usable by clinicians for a better management of the disease. Aggressiveness of pancreatic cancer relies on its own hallmarks: a low vascular network as well as a prominent stromal compartment (desmoplasia), which creates a severe hypoxic environment impeding correct oxygen and nutrients diffusion to the tumoral cells. To survive and proliferate in those conditions, pancreatic cancer cells set up specific metabolic pathways to meet their tremendous energetic and biomass demands. However, as PDAC is a heterogenous tumor, a complex reprogramming of metabolic processes is engaged by cancer cells according to their level of oxygenation and nutrients supply. In this review, we focus on the glycolytic activity of PDAC and the glucose-connected metabolic pathways which contribute to the progression and dissemination of this disease. We also discuss possible therapeutic strategies targeting these pathways in order to cure this disease which still until now is resistant to numerous conventional treatments.

  19. Oral Gingival Cell Cigarette Smoke Exposure Induces Muscle Cell Metabolic Disruption

    Directory of Open Access Journals (Sweden)

    Andrea C. Baeder

    2016-01-01

    Full Text Available Cigarette smoke exposure compromises health through damaging multiple physiological systems, including disrupting metabolic function. The purpose of this study was to determine the role of oral gingiva in mediating the deleterious metabolic effects of cigarette smoke exposure on skeletal muscle metabolic function. Using an in vitro conditioned medium cell model, skeletal muscle cells were incubated with medium from gingival cells treated with normal medium or medium containing suspended cigarette smoke extract (CSE. Following incubation of muscle cells with gingival cell conditioned medium, muscle cell mitochondrial respiration and insulin signaling and action were determined as an indication of overall muscle metabolic health. Skeletal muscle cells incubated with conditioned medium of CSE-treated gingival cells had a profound reduction in mitochondrial respiration and respiratory control. Furthermore, skeletal muscle cells had a greatly reduced response in insulin-stimulated Akt phosphorylation and glycogen synthesis. Altogether, these results provide a novel perspective on the mechanism whereby cigarette smoke affects systemic metabolic function. In conclusion, we found that oral gingival cells treated with CSE create an altered milieu that is sufficient to both disrupted skeletal muscle cell mitochondrial function and insulin sensitivity.

  20. Effect of silver nanoparticles on growth performance, metabolism and microbial profile of broiler chickens

    DEFF Research Database (Denmark)

    Pineda, Lane; Chwalibog, André; Sawosz, Ewa

    2012-01-01

    (IgG) in the blood plasma of broilers supplemented with AgNano decreased at day 36 (p = 0.012). The results demonstrated that AgNano affects N utilisation and plasma IgG concentration; however, it does not influence the microbial populations in the digestive tract, the energy metabolism and growth......This study evaluated the potential of silver nanoparticles (AgNano) as an antimicrobial growth-promoting supplement for broiler chickens. One hundred forty-four seven-day-old broiler chicks were distributed randomly to AgNano treatments at 0, 10 and 20 mg/kg (Control, Group AgNano10, and Group Ag...... and intestinal content were collected to evaluate the effects of AgNano on plasma concentration of immunoglobulins and the intestinal microflora, repectively. The provision of water solutions containing different concentrations of AgNano had no effect on postnatal growth performance and the energy metabolism...

  1. Genetic, metabolic and endocrine aspect of intrauterine growth restriction: an update.

    Science.gov (United States)

    Sharma, Deepak; Sharma, Pradeep; Shastri, Sweta

    2017-10-01

    Intrauterine growth restriction (IUGR) is defined as growth of fetus below its in-utero growth potential. Small for gestational age (SGA) is defined as newborn with birth weight less than 10th centile as per the gestational age, sex and race. There exists major difference between IUGR and SGA. IUGR infants have multiple short-term and long-term complications and IUGR is a silent cause of various morbidities and mortalities in these infants. IUGR/SGA is usually end results of maternal, placental, fetal and genetic causes. With the advance of molecular biology, the list genetic cause of IUGR is increasing and these genetic causes include maternal, placental and fetal genes. Several metabolic and endocrinal causes are also responsible to cause IUGR. In this review, we will try to cover genetic, metabolic and endocrinal factors that are responsible for IUGR.

  2. Mechanisms of pancreatic beta-cell growth and regeneration

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    1989-01-01

    Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....

  3. Quantitative analysis of energy metabolic pathways in MCF-7 breast cancer cells by selected reaction monitoring assay.

    Science.gov (United States)

    Drabovich, Andrei P; Pavlou, Maria P; Dimitromanolakis, Apostolos; Diamandis, Eleftherios P

    2012-08-01

    To investigate the quantitative response of energy metabolic pathways in human MCF-7 breast cancer cells to hypoxia, glucose deprivation, and estradiol stimulation, we developed a targeted proteomics assay for accurate quantification of protein expression in glycolysis/gluconeogenesis, TCA cycle, and pentose phosphate pathways. Cell growth conditions were selected to roughly mimic the exposure of cells in the cancer tissue to the intermittent hypoxia, glucose deprivation, and hormonal stimulation. Targeted proteomics assay allowed for reproducible quantification of 76 proteins in four different growth conditions after 24 and 48 h of perturbation. Differential expression of a number of control and metabolic pathway proteins in response to the change of growth conditions was found. Elevated expression of the majority of glycolytic enzymes was observed in hypoxia. Cancer cells, as opposed to near-normal MCF-10A cells, exhibited significantly increased expression of key energy metabolic pathway enzymes (FBP1, IDH2, and G6PD) that are known to redirect cellular metabolism and increase carbon flux through the pentose phosphate pathway. Our quantitative proteomic protocol is based on a mass spectrometry-compatible acid-labile detergent and is described in detail. Optimized parameters of a multiplex selected reaction monitoring (SRM) assay for 76 proteins, 134 proteotypic peptides, and 401 transitions are included and can be downloaded and used with any SRM-compatible mass spectrometer. The presented workflow is an integrated tool for hypothesis-driven studies of mammalian cells as well as functional studies of proteins, and can greatly complement experimental methods in systems biology, metabolic engineering, and metabolic transformation of cancer cells.

  4. Predicting growth conditions from internal metabolic fluxes in an in-silico model of E. coli.

    Directory of Open Access Journals (Sweden)

    Viswanadham Sridhara

    Full Text Available A widely studied problem in systems biology is to predict bacterial phenotype from growth conditions, using mechanistic models such as flux balance analysis (FBA. However, the inverse prediction of growth conditions from phenotype is rarely considered. Here we develop a computational framework to carry out this inverse prediction on a computational model of bacterial metabolism. We use FBA to calculate bacterial phenotypes from growth conditions in E. coli, and then we assess how accurately we can predict the original growth conditions from the phenotypes. Prediction is carried out via regularized multinomial regression. Our analysis provides several important physiological and statistical insights. First, we show that by analyzing metabolic end products we can consistently predict growth conditions. Second, prediction is reliable even in the presence of small amounts of impurities. Third, flux through a relatively small number of reactions per growth source (∼10 is sufficient for accurate prediction. Fourth, combining the predictions from two separate models, one trained only on carbon sources and one only on nitrogen sources, performs better than models trained to perform joint prediction. Finally, that separate predictions perform better than a more sophisticated joint prediction scheme suggests that carbon and nitrogen utilization pathways, despite jointly affecting cellular growth, may be fairly decoupled in terms of their dependence on specific assortments of molecular precursors.

  5. Eukaryotic translation initiation factor 5A2 promotes metabolic reprogramming in hepatocellular carcinoma cells.

    Science.gov (United States)

    Cao, Ting-Ting; Lin, Shu-Hai; Fu, Li; Tang, Zhi; Che, Chi-Ming; Zhang, Li-Yi; Ming, Xiao-Yan; Liu, Teng-Fei; Tang, Xu-Ming; Tan, Bin-Bin; Xiang, Di; Li, Feng; Chan, On-Yee; Xie, Dan; Cai, Zongwei; Guan, Xin-Yuan

    2017-01-01

    Reprogramming of intracellular metabolism is common in liver cancer cells. Understanding the mechanisms of cell metabolic reprogramming may present a new basis for liver cancer treatment. In our previous study, we reported that a novel oncogene eukaryotic translation initiation factor 5A2 (EIF5A2) promotes tumorigenesis under hypoxic condition. Here, we aim to investigate the role of EIF5A2 in cell metabolic reprogramming during hepatocellular carcinoma (HCC) development. In this study, we reported that the messenger RNA (mRNA) level of EIF5A2 was upregulated in 59 of 105 (56.2%) HCC clinical samples (P = 0.015), and EIF5A2 overexpression was significantly associated with shorter survival time of patients with HCC (P = 0.021). Ectopic expression of EIF5A2 in HCC cell lines significantly promoted cell growth and accelerated glucose utilization and lipogenesis rates. The high rates of glucose uptake and lactate secretion conferred by EIF5A2 revealed an abnormal activity of aerobic glycolysis in HCC cells. Several key enzymes involved in glycolysis including glucose transporter type 1 and 2, hexokinase 2, phosphofructokinase liver type, glyceraldehyde 3-phosphate dehydrogenase, pyruvate kinase M2 isoform, phosphoglycerate mutase 1 and lactate dehydrogenase A were upregulated by overexpression of EIF5A2. Moreover, EIF5A2 showed positive correlations with FASN and ACSS2, two key enzymes involved in the fatty acid de novo biosynthetic pathway, at both protein and mRNA levels in HCC. These results indicated that EIF5A2 may regulate fatty acid de novo biosynthesis by increasing the uptake of acetate. In conclusion, our findings demonstrate that EIF5A2 has a critical role in HCC cell metabolic reprogramming and may serve as a prominent novel therapeutic target for liver cancer treatment. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. The TOR Signaling Pathway in Spatial and Temporal Control of Cell Size and Growth

    Directory of Open Access Journals (Sweden)

    Suam Gonzalez

    2017-06-01

    Full Text Available Cell size is amenable by genetic and environmental factors. The highly conserved nutrient-responsive Target of Rapamycin (TOR signaling pathway regulates cellular metabolic status and growth in response to numerous inputs. Timing and duration of TOR pathway activity is pivotal for both cell mass built up as well as cell cycle progression and is controlled and fine-tuned by the abundance and quality of nutrients, hormonal signals, growth factors, stress, and oxygen. TOR kinases function within two functionally and structurally discrete multiprotein complexes, TORC1 and TORC2, that are implicated in temporal and spatial control of cell size and growth respectively; however, recent data indicate that such functional distinctions are much more complex. Here, we briefly review roles of the two complexes in cellular growth and cytoarchitecture in various experimental model systems.

  7. Insulin-like growth factor-I in growth and metabolism

    DEFF Research Database (Denmark)

    Backeljauw, P; Bang, P; Dunger, D B;

    2010-01-01

    Deficiency of insulin-like growth factor-I (IGF-I) results in growth failure. A variety of molecular defects have been found to underlie severe primary IGF-I deficiency (IGFD), in which serum IGF-I concentrations are substantially decreased and fail to respond to GH therapy. Identification of mor...

  8. Insulin-like growth factor-I in growth and metabolism

    DEFF Research Database (Denmark)

    Backeljauw, P; Bang, P; Dunger, D B

    2010-01-01

    Deficiency of insulin-like growth factor-I (IGF-I) results in growth failure. A variety of molecular defects have been found to underlie severe primary IGF-I deficiency (IGFD), in which serum IGF-I concentrations are substantially decreased and fail to respond to GH therapy. Identification of more...

  9. Metabolic shift in lung alveolar cell mitochondria following acrolein exposure.

    Science.gov (United States)

    Agarwal, Amit R; Yin, Fei; Cadenas, Enrique

    2013-11-15

    Acrolein, an α,β unsaturated electrophile, is an environmental pollutant released in ambient air from diesel exhausts and cooking oils. This study examines the role of acrolein in altering mitochondrial function and metabolism in lung-specific cells. RLE-6TN, H441, and primary alveolar type II (pAT2) cells were exposed to acrolein for 4 h, and its effect on mitochondrial oxygen consumption rates was studied by XF Extracellular Flux analysis. Low-dose acrolein exposure decreased mitochondrial respiration in a dose-dependent manner because of alteration in the metabolism of glucose in all the three cell types. Acrolein inhibited glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity, leading to decreased substrate availability for mitochondrial respiration in RLE-6TN, H441, and pAT2 cells; the reduced GAPDH activity was compensated in pAT2 cells by an increase in the activity of glucose-6-phosphate dehydrogenase, the regulatory control of the pentose phosphate pathway. The decrease in pyruvate from glucose metabolism resulted in utilization of alternative sources to support mitochondrial energy production: palmitate-BSA complex increased mitochondrial respiration in RLE-6TN and pAT2 cells. The presence of palmitate in alveolar cells for surfactant biosynthesis may prove to be the alternative fuel source for mitochondrial respiration. Accordingly, a decrease in phosphatidylcholine levels and an increase in phospholipase A2 activity were found in the alveolar cells after acrolein exposure. These findings have implications for understanding the decrease in surfactant levels frequently observed in pathophysiological situations with altered lung function following exposure to environmental toxicants.

  10. The growth and survival of Mycobacterium smegmatis is enhanced by co-metabolism of atmospheric H2.

    Directory of Open Access Journals (Sweden)

    Chris Greening

    Full Text Available The soil bacterium Mycobacterium smegmatis is able to scavenge the trace concentrations of H2 present in the atmosphere, but the physiological function and importance of this activity is not understood. We have shown that atmospheric H2 oxidation in this organism depends on two phylogenetically and kinetically distinct high-affinity hydrogenases, Hyd1 (MSMEG_2262-2263 and Hyd2 (MSMEG_2720-2719. In this study, we explored the effect of deleting Hyd2 on cellular physiology by comparing the viability, energetics, transcriptomes, and metabolomes of wild-type vs. Δhyd2 cells. The long-term survival of the Δhyd2 mutant was significantly reduced compared to the wild-type. The mutant additionally grew less efficiently in a range of conditions, most notably during metabolism of short-chain fatty acids; there was a twofold reduction in growth rate and growth yield of the Δhyd2 strain when acetate served as the sole carbon source. Hyd1 compensated for loss of Hyd2 when cells were grown in a high H2 atmosphere. Analysis of cellular parameters showed that Hyd2 was not necessary to generate the membrane potential, maintain intracellular pH homeostasis, or sustain redox balance. However, microarray analysis indicated that Δhyd2 cells were starved for reductant and compensated by rewiring central metabolism; transcripts encoding proteins responsible for oxidative decarboxylation pathways, the urea cycle, and ABC transporter-mediated import were significantly more abundant in the Δhyd2 mutant. Metabolome profiling consistently revealed an increase in intracellular amino acids in the Δhyd2 mutant. We propose that atmospheric H2 oxidation has two major roles in mycobacterial cells: to generate reductant during mixotrophic growth and to sustain the respiratory chain during dormancy.

  11. Microfluidic cell arrays for metabolic monitoring of stimulated cardiomyocytes.

    Science.gov (United States)

    Cheng, Wei; Klauke, Norbert; Smith, Godfrey; Cooper, Jonathan M

    2010-04-01

    An array of PDMS microchambers was aligned to an array of sensor electrodes and stimulating microelectrodes, which was used for the electrochemical monitoring of the metabolic activity of single isolated adult ventricular myocytes inside the chamber array, stimulated within a transient electric field. The effect of the accumulation of metabolic byproducts in the limited extracellular volume of the picolitre chambers was demonstrated by measuring single muscle cell contraction optically, while concomitant changes in intracellular calcium transients and pH were recorded independently using fluorescent indicator dyes. Both the amplitude of the cell shortening and the magnitude of the intracellular calcium transients decreased over time and both nearly ceased after 20 min of continuous stimulation in the limited extracellullar volume. The intracellular pH decreased gradually during 20 min of continuous stimulation after which a dramatic pH drop was observed, indicating the breakdown of the intracellular buffering capacity. After continuous stimulation, intracellular lactate was released into the microchamber through cell electroporation and was detected electrochemically at a lactate microbiosensor, within the chamber. A mitochondrial uncoupler was used to mimic ischaemia and thus to enhance the cellular content of lactate. Under these circumstances, intracellular lactate concentrations were found to have risen to approximately 15 mM. This array system has the potential of simultaneous electrochemical and optical monitoring of extracellular and intracellular metabolites from single beating heart cells at a controlled metabolic state.

  12. Metabolic activity of bacterial cells enumerated by direct viable count

    Energy Technology Data Exchange (ETDEWEB)

    Roszak, D.B.; Colwell, R.R.

    1987-12-01

    The direct viable count (DVC) method was modified by incorporating radiolabeled substrates in microautoradiographic analyses to assess bacterial survival in controlled laboratory microcosms. The DVC method, which permits enumeration of culturable and nonculturable cells, discriminates those cells that are responsive to added nutrients but in which division is inhibited by the addition of nalidixic acid. The resulting elongated cells represent all viable cells; this includes those that are culturable on routine media and those that are not. Escherichia coli and Salmonella enteritidis were employed in the microcosm studies, and radiolabeled substrates included (methyl-tritium thymidine or (Uranium-Carbon 14) glutamic acid. Samples taken at selected intervals during the survival experiments were examined by epifluorescence microscopy to enumerate cells by the DVC and acridine orange direct count methods, as well as by culture methods. Good correlation was obtained for cell-associated metabolic activity, measured by microautoradiography and substrate responsiveness (by the DVC method) at various stages of survival. Of the cells responsive to nutrients by the DVC method, ca 90% were metabolically active by the microautoradiographic method. No significant difference was observed between DVC enumerations with or without added radiolabeled substrate.

  13. Ferric ions accumulate in the walls of metabolically inactivating Saccharomyces cerevisiae cells and are reductively mobilized during reactivation.

    Science.gov (United States)

    Wofford, Joshua D; Park, Jinkyu; McCormick, Sean P; Chakrabarti, Mrinmoy; Lindahl, Paul A

    2016-07-13

    Mössbauer and EPR spectra of fermenting yeast cells before and after cell wall (CW) digestion revealed that CWs accumulated iron as cells transitioned from exponential to post-exponential growth. Most CW iron was mononuclear nonheme high-spin (NHHS) Fe(III), some was diamagnetic and some was superparamagnetic. A significant portion of CW Fe was removable by EDTA. Simulations using an ordinary-differential-equations-based model suggested that cells accumulate Fe as they become metabolically inactive. When dormant Fe-loaded cells were metabolically reactivated in Fe-deficient bathophenanthroline disulfonate (BPS)-treated medium, they grew using Fe that had been mobilized from their CWs AND using trace amounts of Fe in the Fe-deficient medium. When grown in Fe-deficient medium, Fe-starved cells contained the lowest cellular Fe concentrations reported for a eukaryotic cell. During metabolic reactivation of Fe-loaded dormant cells, Fe(III) ions in the CWs of these cells were mobilized by reduction to Fe(II), followed by release from the CW and reimport into the cell. BPS short-circuited this process by chelating mobilized and released Fe(II) ions before reimport; the resulting Fe(II)(BPS)3 complex adsorbed on the cell surface. NHHS Fe(II) ions appeared transiently during mobilization, suggesting that these ions were intermediates in this process. In the presence of chelators and at high pH, metabolically inactive cells leached CW Fe; this phenomenon probably differs from metabolic mobilization. The iron regulon, as reported by Fet3p levels, was not expressed during post-exponential conditions; Fet3p was maximally expressed in exponentially growing cells. Decreased expression of the iron regulon and metabolic decline combine to promote CW Fe accumulation.

  14. Nitrogen metabolism in Lignifying Pinus taeda cell cultures

    Science.gov (United States)

    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.

  15. Steroid receptor coactivator-3 regulates glucose metabolism in bladder cancer cells through coactivation of hypoxia inducible factor 1α.

    Science.gov (United States)

    Zhao, Wei; Chang, Cunjie; Cui, Yangyan; Zhao, Xiaozhi; Yang, Jun; Shen, Lan; Zhou, Ji; Hou, Zhibo; Zhang, Zhen; Ye, Changxiao; Hasenmayer, Donald; Perkins, Robert; Huang, Xiaojing; Yao, Xin; Yu, Like; Huang, Ruimin; Zhang, Dianzheng; Guo, Hongqian; Yan, Jun

    2014-04-18

    Cancer cell proliferation is a metabolically demanding process, requiring high glycolysis, which is known as "Warburg effect," to support anabolic growth. Steroid receptor coactivator-3 (SRC-3), a steroid receptor coactivator, is overexpressed and/or amplified in multiple cancer types, including non-steroid targeted cancers, such as urinary bladder cancer (UBC). However, whether SRC-3 regulates the metabolic reprogramming for cancer cell growth is unknown. Here, we reported that overexpression of SRC-3 accelerated UBC cell growth, accompanied by the increased expression of genes involved in glycolysis. Knockdown of SRC-3 reduced the UBC cell glycolytic rate under hypoxia, decreased tumor growth in nude mice, with reduction of proliferating cell nuclear antigen and lactate dehydrogenase expression levels. We further revealed that SRC-3 could interact with hypoxia inducible factor 1α (HIF1α), which is a key transcription factor required for glycolysis, and coactivate its transcriptional activity. SRC-3 was recruited to the promoters of HIF1α-target genes, such as glut1 and pgk1. The positive correlation of expression levels between SRC-3 and Glut1 proteins was demonstrated in human UBC patient samples. Inhibition of glycolysis through targeting HK2 or LDHA decelerated SRC-3 overexpression-induced cell growth. In summary, overexpression of SRC-3 promoted glycolysis in bladder cancer cells through HIF1α to facilitate tumorigenesis, which may be an intriguing drug target for bladder cancer therapy.

  16. Metabolism of 4-Hydroxy-7-oxo-5-heptenoic Acid (HOHA) Lactone by Retinal Pigmented Epithelial Cells.

    Science.gov (United States)

    Wang, Hua; Linetsky, Mikhail; Guo, Junhong; Yu, Annabelle O; Salomon, Robert G

    2016-07-18

    4-Hydroxy-7-oxo-5-heptenic acid (HOHA)-lactone is a biologically active oxidative truncation product released (t1/2 = 30 min at 37 °C) by nonenzymatic transesterification/deacylation from docosahexaenoate lipids. We now report that HOHA-lactone readily diffuses into retinal pigmented epithelial (RPE) cells where it is metabolized. A reduced glutathione (GSH) Michael adduct of HOHA-lactone is the most prominent metabolite detected by LC-MS in both the extracellular medium and cell lysates. This molecule appeared inside of ARPE-19 cells within seconds after exposure to HOHA-lactone. The intracellular level reached a maximum concentration at 30 min and then decreased with concomitant increases in its level in the extracellular medium, thus revealing a unidirectional export of the reduced GSH-HOHA-lactone adduct from the cytosol to extracellular medium. This metabolism is likely to modulate the involvement of HOHA-lactone in the pathogenesis of human diseases. HOHA-lactone is biologically active, e.g., low concentrations (0.1-1 μM) induce secretion of vascular endothelial growth factor (VEGF) from ARPE-19 cells. HOHA-lactone is also a precursor of 2-(ω-carboxyethyl)pyrrole (CEP) derivatives of primary amino groups in proteins and ethanolamine phospholipids that have significant pathological and physiological relevance to age-related macular degeneration (AMD), cancer, and wound healing. Both HOHA-lactone and the derived CEP can contribute to the angiogenesis that defines the neovascular "wet" form of AMD and that promotes the growth of tumors. While GSH depletion can increase the lethality of radiotherapy, because it will impair the metabolism of HOHA-lactone, the present study suggests that GSH depletion will also increase levels of HOHA-lactone and CEP that may promote recurrence of tumor growth.

  17. Elevated 20-HETE Impairs Coronary Collateral Growth in Metabolic Syndrome Via Endothelial Dysfunction.

    Science.gov (United States)

    Joseph, Gregory; Soler, Amanda; Hutcheson, Rebecca; Hunter, Ian; Bradford, Chastity; Hutcheson, Brenda; Gotlinger, Katherine H; Jiang, Houli; Falck, John R; Proctor, Spencer; Laniado Schwartzman, Michal; Rocic, Petra

    2016-12-23

    Coronary collateral growth (CCG) is impaired in metabolic syndrome (MetS). microRNA-145 (miR-145-Adv) delivery to our rat model of metabolic syndrome (JCR) completely restored and neutrophil depletion significantly improved CCG. We determined whether low endogenous levels of miR-145 in MetS allowed for elevated production of 20-hydroxyeicosatetraenoic acid (20-HETE), which in turn, resulted in excessive neutrophil accumulation and endothelial dysfunction leading to impaired CCG. Rats underwent 0-9 days of repetitive ischemia (RI). RI-induced cardiac CYP4F (neutrophil-specific 20-HETE synthase) expression and 20-HETE levels were increased (4-fold) in JCR vs. normal rats. miR-145-Adv and 20-HETE antagonists abolished, and neutrophil depletion (blocking antibodies) reduced (~60%) RI-induced increases in CYP4F expression and 20-HETE production in JCR rats. Impaired CCG in JCR rats (collateral-dependent blood flow using microspheres) was completely restored by 20-HETE antagonists ((collateral-dependent zone)CZ/(normal zone)NZ flow ratio was 0.76±0.07 in JCR+20-SOLA, 0.84±0.05 in JCR+20-HEDGE vs. 0.11±0.02 in JCR vs. 0.84±0.03 in normal rats). In JCR rats, elevated 20-HETE was associated with excessive expression of endothelial adhesion molecules and neutrophil infiltration which were reversed by miR-145-Adv. Endothelium-dependent vasodilation of coronary arteries, eNOS Ser1179 phosphorylation, eNOS-dependent NO.- production and endothelial cell survival were compromised in JCR rats. These parameters of endothelial dysfunction were completely reversed by 20-HETE antagonism or miR-145-Adv delivery, whereas neutrophil depletion resulted in partial reversal (~70%). We conclude that low miR-145 in MetS allows for increased 20-HETE, mainly from neutrophils, which compromises endothelial cell survival and function leading to impaired CCG. 20-HETE antagonists could provide viable therapy for restoration of CCG in MetS.

  18. Endocrine regulation of fetal skeletal muscle growth: impact on future metabolic health

    Science.gov (United States)

    Brown, Laura D.

    2014-01-01

    Establishing sufficient skeletal muscle mass is essential for lifelong metabolic health. The intrauterine environment is a major determinant of the muscle mass that is present for the life course of an individual, because muscle fiber number is set at the time of birth. Thus, a compromised intrauterine environment from maternal nutrient restriction or placental insufficiency that restricts development of muscle fiber number can have permanent effects on the amount of muscle an individual will live with. Reduced muscle mass due to fewer muscle fibers persists even after compensatory or “catch up” postnatal growth occurs. Furthermore, muscle hypertrophy can only partially compensate for this limitation in fiber number. Compelling associations link low birth weight and decreased muscle mass to future insulin resistance, which can drive the development of the metabolic syndrome and type 2 diabetes, and risk for cardiovascular events later in life. There are gaps in knowledge about the origins of reduced muscle growth at the cellular level and how these patterns are set during fetal development. By understanding the nutrient and endocrine regulation of fetal skeletal muscle growth and development, we can direct research efforts towards improving muscle growth early in life in order to prevent the development of chronic metabolic disease later in life. PMID:24532817

  19. N2-dependent growth and nitrogenase activity in the metal-metabolizing bacteria, Geobacter and Magnetospirillum species

    Science.gov (United States)

    Bazylinski, D.A.; Dean, A.J.; Schuler, D.; Phillips, E.J.P.; Lovley, D.R.

    2000-01-01

    Cells of Geobacter metallireducens, Magnetospirillum strain AMB-1, Magnetospirillum magnetotacticum and Magnetospirillum gryphiswaldense showed N2-dependent growth, the first anaerobically with Fe(lll) as the electron acceptor, and the latter three species micro-aerobically in semi-solid oxygen gradient cultures. Cells of the Magnetospirillum species grown with N2 under microaerobic conditions were magnetotactic and therefore produced magnetosomes. Cells of Geobacter metallireducens reduced acetylene to ethylene (11.5 ?? 5.9nmol C2H4 produced min-1 mg-1 cell protein) while growing with Fe(lll) as the electron acceptor in anaerobic growth medium lacking a fixed nitrogen source. Cells of the Magnetospirillum species, grown in a semi-solid oxygen gradient medium, also reduced acetylene at comparable rates. Uncut chromosomal and fragments from endonuclease-digested chromosomal DNA from these species, as well as Geobacter sulphurreducens organisms, hybridized with a nifHDK probe from Rhodospirillum rubrum, indicating the presence of these nitrogenase structural genes in these organisms. The evidence presented here shows that members of the metal-metabolizing genera, Geobacter and Magnetospirillum, fix atmospheric dinitrogen.

  20. [Stem cells and growth factors in wound healing].

    Science.gov (United States)

    Pikuła, Michał; Langa, Paulina; Kosikowska, Paulina; Trzonkowski, Piotr

    2015-01-02

    Wound healing is a complex process which depends on the presence of various types of cells, growth factors, cytokines and the elements of extracellular matrix. A wound is a portal of entry for numerous pathogens, therefore during the evolution wound healing process has formed very early, being critical for the survival of every individual. Stem cells, which give rise to their early descendants progenitor cells and subsequently differentiated cells, play a specific role in the process of wound healing. Among the most important cells which take part in wound healing the following cells need to be distinguished: epidermal stem cells, dermal precursor of fibroblasts, adipose-derived stem cells as well as bone marrow cells. The activity of these cells is strictly regulated by various growth factors, inter alia epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), transforming growth factor (TGF), vascular endothelial growth factor (VEGF). Any disorders in functioning of stem cells and biological activity of growth factors may lead to the defects in wound healing, for instance delayed wound healing or creation of hypertrophic scars. Therefore, knowledge concerning the mechanisms of wound healing is extremely essential from clinical point of view. In this review the current state of the knowledge of the role of stem cells and growth factors in the process of wound healing has been presented. Moreover, some clinical aspects of wound healing as well as the possibility of the therapy based on stem cells and growth factors have included.

  1. Stem cells and growth factors in wound healing

    Directory of Open Access Journals (Sweden)

    Michał Pikuła

    2015-01-01

    Full Text Available Wound healing is a complex process which depends on the presence of various types of cells, growth factors, cytokines and the elements of extracellular matrix. A wound is a portal of entry for numerous pathogens, therefore during the evolution wound healing process has formed very early, being critical for the survival of every individual. Stem cells, which give rise to their early descendants progenitor cells and subsequently differentiated cells, play a specific role in the process of wound healing. Among the most important cells which take part in wound healing the following cells need to be distinguished: epidermal stem cells, dermal precursor of fibroblasts, adipose-derived stem cells as well as bone marrow cells. The activity of these cells is strictly regulated by various growth factors, inter alia epidermal growth factor (EGF, fibroblast growth factor (FGF, platelet-derived growth factor (PDGF, transforming growth factor (TGF, vascular endothelial growth factor (VEGF. Any disorders in functioning of stem cells and biological activity of growth factors may lead to the defects in wound healing, for instance delayed wound healing or creation of hypertrophic scars. Therefore, knowledge concerning the mechanisms of wound healing is extremely essential from clinical point of view. In this review the current state of the knowledge of the role of stem cells and growth factors in the process of wound healing has been presented. Moreover, some clinical aspects of wound healing as well as the possibility of the therapy based on stem cells and growth factors have included.

  2. Conditioned medium from neural stem cells inhibits glioma cell growth.

    Science.gov (United States)

    Li, Z; Zhong, Q; Liu, H; Liu, P; Wu, J; Ma, D; Chen, X; Yang, X

    2016-10-31

    Malignant glioma is one of the most common brain tumors in the central nervous system. Although the significant progress has been made in recent years, the mortality is still high and 5-year survival rate is still very low. One of the leading causes to the high mortality for glioma patients is metastasis and invasion. An efficient method to control the tumor metastasis is a promising way to treat the glioma. Previous reports indicated that neural stem cells (NSCs) were served as a delivery vector to the anti-glioma therapy. Here, we used the conditioned medium from rat NSCs (NSC-CM) to culture the human glioblastoma cell lines. We found that NSC-CM could inhibit the glioma cell growth, invasion and migration in vitro and attenuate the tumor growth in vivo. Furthermore, this anti-glioma effect was mediated by the inactivation of mitogen activated protein kinase (MAPK) pathway. Above all, this study provided the direct evidence to put forward a simple and efficient method in the inhibition of glioma cells/tumor growth, potentially advancing the anti-glioma therapy.

  3. Genome-wide metabolic model to improve understanding of CD4(+) T cell metabolism, immunometabolism and application in drug design.

    Science.gov (United States)

    Han, Feifei; Li, Gonghua; Dai, Shaoxing; Huang, Jingfei

    2016-02-01

    CD4(+) T cells play a critical role in adaptive immunity and have been well studied in past decades. However, the systematic metabolism features are less clear. Here, we reconstructed the genome-wide metabolic network of naïve CD4(+) T cells, CD4T1670, by integrating transcriptome and metabolism data. We performed simulations for three critical metabolic subsystems (carbohydrate metabolism, fatty acid metabolism and glutaminolysis). The results were consistent with most experimental observations. Furthermore, we found that depletion of either glucose or glutamine did not significantly affect ATP production and biomass, but dramatically unbalanced the metabolic network and increased the release of some inflammation or anti-inflammation related factors, such as lysophosphatidylcholine, leukotriene and hyaluronan. Genome-wide single gene knockout analysis showed that acetyl-CoA carboxylase 1 (ACC1) was essential for T cell activation. We further investigated the role of immunometabolic genes in metabolic network stability, and found that over 25% of them were essential. The results also showed that although PTEN is a well-studied proliferation inhibitor, it was essential for maintaining the stability of CD4 metabolic networks. Finally, we applied CD4T1670 to evaluate the side-effects of certain drugs in preclinical experiments. These results suggested that CD4T1670 would be useful in understanding CD4(+) T cells and drug design systematically.

  4. Fusion and metabolism of plant cells as affected by microgravity.

    Science.gov (United States)

    Hampp, R; Hoffmann, E; Schönherr, K; Johann, P; De Filippis, L

    1997-01-01

    Plant cell protoplasts derived from leaf tissue of two different tobacco species (Nicotiana tabacum., N. rustica L.) were exposed to short-term (sounding rocket experiments) and long-term (spacelab) microgravity environments in order to study both (electro) cell fusion and cell metabolism during early and later stages of tissue regeneration. The period of exposure to microgravity varied from 10 min (sounding rocket) to 10 d (space shuttle). The process of electro fusion of protoplasts was improved under conditions of microgravity: the time needed to establish close membrane contact between protoplasts (alignment time) was reduced (5 as compared to 15 s under 1 g) and numbers of fusion products between protoplasts of different specific density were increased by a factor of about 10. In addition, viability of fusion products, as shown by the ability to form callus, increased from about 60% to more than 90%. Regenerated fusion products obtained from both sounding-rocket and spacelab experiments showed a wide range of intermediate properties between the two parental plants. This was verified by isozyme analysis and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). In order to address potential metabolic responses, more general markers such as the overall energy state (ATP/ADP ratio), the redox charge of the diphosphopyridine nucleotide system (NADH/NAD ratio), and the pool size of fructose-2,6-bisphosphate (Fru 2,6 bisp), a regulator of the balance between glycolysis and gluconeogenesis, were determined. Responses of these parameters were different with regard to short-term and long-term exposure. Shortly after transition to reduced gravitation (sounding rocket) ratios of ATP/ADP exhibited strong fluctuation while the pool size of NAD decreased (indicating an increased NADH/NAD ratio) and that of Fru 2,6 bisp increased. As similar changes can be observed under stress conditions, this response is probably indicative of a metabolic stress

  5. The Interplay between Signaling and Metabolism in Breast Cancer Cell Motility and Metastasis

    Science.gov (United States)

    Tsarfaty, Ilan

    2013-03-01

    The initiation and growth of tumor metastases require tumor cells go through a transition between collective-to-individual cell migration. Understanding the molecular, cellular and physical mechanisms of these different migration modes is limited. We focus on the tumor cell migration induced by Hepatocyte Growth Factor / Scatter Factor (HGF/SF) - Met-signaling, a master regulator of cell motility in normal and malignant processes. Met has been implicated in tumorigenesis and metastasis and several Met targeting agents have been introduced into the clinic, and are currently in all phases of clinical trials Our analysis demonstrates that Met signaling dramatically alter the morpho-kinetic dynamics of collective migration of tumor cells. It induce a ``wave'' of increasing velocities that propagates back from the leading edge, increases cells' orientation and cooperation capabilities. In parallel Met signaling induces amoeboid cell motility that increased cell individuality. The decision making regarding the motility mode is dependent on the extent of activation of unique signal and metabolic cues. We present a combination of molecular imaging, conceptual and modeling framework for the analysis and assessment of the collective mesenchymal to epithelial versus amoeboid motility. Combined together our analysis can contribute to the understanding of metastasis and personalizing anti Met targeted therapy.

  6. Effect of cell cycle arrest on intermediate metabolism in the marine diatom Phaeodactylum tricornutum.

    Science.gov (United States)

    Kim, Joomi; Brown, Christopher M; Kim, Min Kyung; Burrows, Elizabeth H; Bach, Stéphane; Lun, Desmond S; Falkowski, Paul G

    2017-09-05

    The inhibitor NU 2058 [6-(cyclohexylmethoxy)-9H-purin-2-amine] leads to G1-phase cell cycle arrest in the marine diatom, Phaeodactylum tricornutum, by binding to two cyclin-dependent kinases, CDKA1 and CDKA2. NU 2058 has no effect on photosynthetic attributes, such as Fv/Fm, chlorophyll a/cell, levels of D2 PSII subunits, or RbcL; however, cell cycle arrest leads to unbalanced growth whereby photosynthetic products that can no longer be used for cell division are redirected toward carbohydrates and triacylglycerols (TAGs). Arrested cells up-regulate most genes involved in fatty acid synthesis, including acetyl-CoA carboxylase, and three out of five putative type II diglyceride acyltransferases (DGATs), the enzymes that catalyze TAG production. Correlation of transcriptomes in arrested cells with a flux balance model for P. tricornutum predicts that reactions in the mitochondrion that supply glycerate may support TAG synthesis. Our results reveal that sources of intermediate metabolites and macromolecular sinks are tightly coupled to the cell cycle in a marine diatom, and that arresting cells in the G1 phase leads to remodeling of intermediate metabolism and unbalanced growth.

  7. Studies of the metabolism of cell cultures by microspectrofluoroscopy

    Science.gov (United States)

    Hoehne, Wolfgang; Schramm, Werner; Moritzen, V.; Burgmann, U.; Kronfeldt, Heinz D.

    1996-01-01

    The monitoring of the state of cellular energy metabolism and respiratory activity is a necessary procedure in cell biology and pharmacology. One method is the observation of the redox state by NADH and FAD autofluorescence measurements. Using this technique, investigations on endothelial cell cultures were done to study their behavior under pharmacologic influences. One application was the investigation of cytotoxicity of cyanides, blocking the mitochondrial respiratory chain. Further we studied the activation of energy metabolism as a step of the cellular reaction on extracellular impacts. The measurements have been performed with a fluorescence microscope Zei(beta) Axioplan, extended by a PMT and a CCD camera. During examination, the cell cultures were kept under nearly physiological conditions using a specialized perfusion chamber. The measurements took place on cellular monolayers. Different excitation geometries have been studied to overcome the difficulties, which arose from the very weak absorption of the cell monolayer, resulting in a low quantum yield and SNR. In classical cytotoxicity studies, only the statistical long-time effects (e.g. IC50) of cell damages are recorded. By redox microspectrofluorometry it is possible to observe the process of damage in its progress, shown by the presented results. In the second, more complex model, we studied the reaction of cells on ligands like PIA (Phenylisopropyladenosin). In this case, the intracellular reaction is connected with an increased production of cAMP. Again, this requires an increased production of ATP, which leads to an activation of the cellular energy metabolism. The spectroscopic results are interpreted by a first model.

  8. Effects of 3-styrylchromones on metabolic profiles and cell death in oral squamous cell carcinoma cells

    Directory of Open Access Journals (Sweden)

    Hiroshi Sakagami

    2015-01-01

    Full Text Available 4H-1-benzopyran-4-ones (chromones are important naturally-distributing compounds. As compared with flavones, isoflavones and 2-styrylchromones, there are only few papers of 3-styrylchromones that have been published. We have previously reported that among fifteen 3-styrylchromone derivatives, three new synthetic compounds that have OCH3 group at the C-6 position of chromone ring, (E-3-(4-hydroxystyryl-6-methoxy-4H-chromen-4-one (compound 11, (E-6-methoxy-3-(4-methoxystyryl-4H-chromen-4-one (compound 4, (E-6-methoxy-3-(3,4,5-trimethoxystyryl-4H-chromen-4-one (compound 6 showed much higher cytotoxicities against four epithelial human oral squamous cell carcinoma (OSCC lines than human normal oral mesenchymal cells. In order to further confirm the tumor specificities of these compounds, we compared their cytotoxicities against both human epithelial malignant and non-malignant cells, and then investigated their effects on fine cell structures and metabolic profiles and cell death in human OSCC cell line HSC-2. Cytotoxicities of compounds 4, 6, 11 were assayed with MTT method. Fine cell structures were observed under transmission electron microscope. Cellular metabolites were extracted with methanol and subjected to CE-TOFMS analysis. Compounds 4, 6, 11 showed much weaker cytotoxicity against human oral keratinocyte and primary human gingival epithelial cells, as compared with HSC-2, confirming their tumor-specificity, whereas doxorubicin and 5-FU were highly cytotoxic to these normal epithelial cells, giving unexpectedly lower tumor-specificity. The most cytotoxic compound 11, induced the mitochondrial vacuolization, autophagy suppression followed by apoptosis induction, and changes in the metabolites involved in amino acid and glycerophospholipid metabolisms. Chemical modification of lead compound 11 may be a potential choice for designing new type of anticancer drugs.

  9. Spectrally resolved fluorescence lifetime imaging to investigate cell metabolism in malignant and nonmalignant oral mucosa cells.

    Science.gov (United States)

    Rück, Angelika; Hauser, Carmen; Mosch, Simone; Kalinina, Sviatlana

    2014-09-01

    Fluorescence-guided diagnosis of tumor tissue is in many cases insufficient, because false positive results interfere with the outcome. Improvement through observation of cell metabolism might offer the solution, but needs a detailed understanding of the origin of autofluorescence. With respect to this, spectrally resolved multiphoton fluorescence lifetime imaging was investigated to analyze cell metabolism in metabolic phenotypes of malignant and nonmalignant oral mucosa cells. The time-resolved fluorescence characteristics of NADH were measured in cells of different origins. The fluorescence lifetime of bound and free NADH was calculated from biexponential fitting of the fluorescence intensity decay within different spectral regions. The mean lifetime was increased from nonmalignant oral mucosa cells to different squamous carcinoma cells, where the most aggressive cells showed the longest lifetime. In correlation with reports in the literature, the total amount of NADH seemed to be less for the carcinoma cells and the ratio of free/bound NADH was decreased from nonmalignant to squamous carcinoma cells. Moreover for squamous carcinoma cells a high concentration of bound NADH was found in cytoplasmic organelles (mainly mitochondria). This all together indicates that oxidative phosphorylation and a high redox potential play an important role in the energy metabolism of these cells.

  10. Spectrally resolved fluorescence lifetime imaging to investigate cell metabolism in malignant and nonmalignant oral mucosa cells

    Science.gov (United States)

    Rück, Angelika; Hauser, Carmen; Mosch, Simone; Kalinina, Sviatlana

    2014-09-01

    Fluorescence-guided diagnosis of tumor tissue is in many cases insufficient, because false positive results interfere with the outcome. Improvement through observation of cell metabolism might offer the solution, but needs a detailed understanding of the origin of autofluorescence. With respect to this, spectrally resolved multiphoton fluorescence lifetime imaging was investigated to analyze cell metabolism in metabolic phenotypes of malignant and nonmalignant oral mucosa cells. The time-resolved fluorescence characteristics of NADH were measured in cells of different origins. The fluorescence lifetime of bound and free NADH was calculated from biexponential fitting of the fluorescence intensity decay within different spectral regions. The mean lifetime was increased from nonmalignant oral mucosa cells to different squamous carcinoma cells, where the most aggressive cells showed the longest lifetime. In correlation with reports in the literature, the total amount of NADH seemed to be less for the carcinoma cells and the ratio of free/bound NADH was decreased from nonmalignant to squamous carcinoma cells. Moreover for squamous carcinoma cells a high concentration of bound NADH was found in cytoplasmic organelles (mainly mitochondria). This all together indicates that oxidative phosphorylation and a high redox potential play an important role in the energy metabolism of these cells.

  11. Dynamic gene expression for metabolic engineering of mammalian cells in culture.

    Science.gov (United States)

    Le, Huong; Vishwanathan, Nandita; Kantardjieff, Anne; Doo, Inseok; Srienc, Michael; Zheng, Xiaolu; Somia, Nikunj; Hu, Wei-Shou

    2013-11-01

    Recombinant mammalian cells are the major hosts for the production of protein therapeutics. In addition to high expression of the product gene, a hyper-producer must also harbor superior phenotypic traits related to metabolism, protein secretion, and growth control. Introduction of genes endowing the relevant hyper-productivity traits is a strategy frequently used to enhance the productivity. Most of such cell engineering efforts have been performed using constitutive expression systems. However, cells respond to various environmental cues and cellular events dynamically according to cellular needs. The use of inducible systems allows for time dependent expression, but requires external manipulation. Ideally, a transgene's expression should be synchronous to the host cell's own rhythm, and at levels appropriate for the objective. To that end, we identified genes with different expression dynamics and intensity ranges using pooled transcriptome data. Their promoters may be used to drive the expression of the transgenes following the desired dynamics. We isolated the promoter of the Thioredoxin-interacting protein (Txnip) gene and demonstrated its capability to drive transgene expression in concert with cell growth. We further employed this Chinese hamster promoter to engineer dynamic expression of the mouse GLUT5 fructose transporter in Chinese hamster ovary (CHO) cells, enabling them to utilize sugar according to cellular needs rather than in excess as typically seen in culture. Thus, less lactate was produced, resulting in a better growth rate, prolonged culture duration, and higher product titer. This approach illustrates a novel concept in metabolic engineering which can potentially be used to achieve dynamic control of cellular behaviors for enhanced process characteristics.

  12. Metabolic reprogramming for producing energy and reducing power in fumarate hydratase null cells from hereditary leiomyomatosis renal cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Youfeng Yang

    Full Text Available Fumarate hydratase (FH-deficient kidney cancer undergoes metabolic remodeling, with changes in mitochondrial respiration, glucose, and glutamine metabolism. These changes represent multiple biochemical adaptations in glucose and fatty acid metabolism that supports malignant proliferation. However, the metabolic linkages between altered mitochondrial function, nucleotide biosynthesis and NADPH production required for proliferation and survival have not been elucidated. To characterize the alterations in glycolysis, the Krebs cycle and the pentose phosphate pathways (PPP that either generate NADPH (oxidative or do not (non-oxidative, we utilized [U-(13C]-glucose, [U-(13C,(15N]-glutamine, and [1,2- (13C2]-glucose tracers with mass spectrometry and NMR detection to track these pathways, and measured the oxygen consumption rate (OCR and extracellular acidification rate (ECAR of growing cell lines. This metabolic reprogramming in the FH null cells was compared to cells in which FH has been restored. The FH null cells showed a substantial metabolic reorganization of their intracellular metabolic fluxes to fulfill their high ATP demand, as observed by a high rate of glucose uptake, increased glucose turnover via glycolysis, high production of glucose-derived lactate, and low entry of glucose carbon into the Krebs cycle. Despite the truncation of the Krebs cycle associated with inactivation of fumarate hydratase, there was a small but persistent level of mitochondrial respiration, which was coupled to ATP production from oxidation of glutamine-derived α-ketoglutarate through to fumarate. [1,2- (13C2]-glucose tracer experiments demonstrated that the oxidative branch of PPP initiated by glucose-6-phosphate dehydrogenase activity is preferentially utilized for ribose production (56-66% that produces increased amounts of ribose necessary for growth and NADPH. Increased NADPH is required to drive reductive carboxylation of α-ketoglutarate and fatty acid

  13. Metabolic reprogramming for producing energy and reducing power in fumarate hydratase null cells from hereditary leiomyomatosis renal cell carcinoma.

    Science.gov (United States)

    Yang, Youfeng; Lane, Andrew N; Ricketts, Christopher J; Sourbier, Carole; Wei, Ming-Hui; Shuch, Brian; Pike, Lisa; Wu, Min; Rouault, Tracey A; Boros, Laszlo G; Fan, Teresa W-M; Linehan, W Marston

    2013-01-01

    Fumarate hydratase (FH)-deficient kidney cancer undergoes metabolic remodeling, with changes in mitochondrial respiration, glucose, and glutamine metabolism. These changes represent multiple biochemical adaptations in glucose and fatty acid metabolism that supports malignant proliferation. However, the metabolic linkages between altered mitochondrial function, nucleotide biosynthesis and NADPH production required for proliferation and survival have not been elucidated. To characterize the alterations in glycolysis, the Krebs cycle and the pentose phosphate pathways (PPP) that either generate NADPH (oxidative) or do not (non-oxidative), we utilized [U-(13)C]-glucose, [U-(13)C,(15)N]-glutamine, and [1,2- (13)C2]-glucose tracers with mass spectrometry and NMR detection to track these pathways, and measured the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) of growing cell lines. This metabolic reprogramming in the FH null cells was compared to cells in which FH has been restored. The FH null cells showed a substantial metabolic reorganization of their intracellular metabolic fluxes to fulfill their high ATP demand, as observed by a high rate of glucose uptake, increased glucose turnover via glycolysis, high production of glucose-derived lactate, and low entry of glucose carbon into the Krebs cycle. Despite the truncation of the Krebs cycle associated with inactivation of fumarate hydratase, there was a small but persistent level of mitochondrial respiration, which was coupled to ATP production from oxidation of glutamine-derived α-ketoglutarate through to fumarate. [1,2- (13)C2]-glucose tracer experiments demonstrated that the oxidative branch of PPP initiated by glucose-6-phosphate dehydrogenase activity is preferentially utilized for ribose production (56-66%) that produces increased amounts of ribose necessary for growth and NADPH. Increased NADPH is required to drive reductive carboxylation of α-ketoglutarate and fatty acid synthesis

  14. Correlation of cell growth and heterologous protein production by Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Liu, Zihe; Hou, Jin; Martínez, José L.

    2013-01-01

    .g., metabolic and cellular stresses have a strong impact on recombinant protein production. In this work, we investigated the effect of the specific growth rate on the production of two different recombinant proteins. Our results show that human insulin precursor is produced in a growth-associated manner...... turnover, cell cycle, and global stress response. We also found that there is a shift at a specific growth rate of 0.1 h−1 that influences protein production. Thus, for lower specific growth rates, the α-amylase and insulin precursor-producing strains present similar cell responses and phenotypes, whereas......With the increasing demand for biopharmaceutical proteins and industrial enzymes, it is necessary to optimize the production by microbial fermentation or cell cultures. Yeasts are well established for the production of a wide range of recombinant proteins, but there are also some limitations; e...

  15. Diet and cognition: interplay between cell metabolism and neuronal plasticity.

    Science.gov (United States)

    Gomez-Pinilla, Fernando; Tyagi, Ethika

    2013-11-01

    To discuss studies in humans and animals revealing the ability of foods to benefit the brain: new information with regards to mechanisms of action and the treatment of neurological and psychiatric disorders. Dietary factors exert their effects on the brain by affecting molecular events related to the management of energy metabolism and synaptic plasticity. Energy metabolism influences neuronal function, neuronal signaling, and synaptic plasticity, ultimately affecting mental health. Epigenetic regulation of neuronal plasticity appears as an important mechanism by which foods can prolong their effects on long-term neuronal plasticity. The prime focus of the discussion is to emphasize the role of cell metabolism as a mediator for the action of foods on the brain. Oxidative stress promotes damage to phospholipids present in the plasma membrane such as the omega-3 fatty acid docosahexenoic acid, disrupting neuronal signaling. Thus, dietary docosahexenoic acid seems crucial for supporting plasma membrane function, interneuronal signaling, and cognition. The dual action of brain-derived neurotrophic factor in neuronal metabolism and synaptic plasticity is crucial for activating signaling cascades under the action of diet and other environmental factors, using mechanisms of epigenetic regulation.

  16. Mitofusin 2 Deficiency Affects Energy Metabolism and Mitochondrial Biogenesis in MEF Cells.

    Directory of Open Access Journals (Sweden)

    Maria Kawalec

    Full Text Available Mitofusin 2 (Mfn2, mitochondrial outer membrane protein which is involved in rearrangement of these organelles, was first described in pathology of hypertension and diabetes, and more recently much attention is paid to its functions in Charcot-Marie-Tooth type 2A neuropathy (CMT2A. Here, cellular energy metabolism was investigated in mouse embryonic fibroblasts (MEF differing in the presence of the Mfn2 gene; control (MEFwt and with Mfn2 gene depleted MEFMfn2-/-. These two cell lines were compared in terms of various parameters characterizing mitochondrial bioenergetics. Here, we have shown that relative rate of proliferation of MEFMfn2-/- cells versus control fibroblasts depend on serum supplementation of the growth media. Moreover, MEFMfn2-/- cells exhibited significantly increased respiration rate in comparison to MEFwt, regardless of serum supplementation of the medium. This effect was correlated with increased level of mitochondrial markers (TOM20 and NAO as well as mitochondrial transcription factor A (TFAM and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α protein levels and unchanged total ATP content. Interestingly, mitochondrial DNA content in MEFMfn2-/- cells was not reduced. Fundamentally, these results are in contrast to a commonly accepted belief that mitofusin 2 deficiency inevitably results in debilitation of mitochondrial energy metabolism. However, we suggest a balance between negative metabolic consequences of mitofusin 2 deficiency and adaptive processes exemplified by increased level of PGC-1α and TFAM transcription factor which prevent an excessive depletion of mtDNA and severe impairment of cell metabolism.

  17. Relationship between metabolic syndrome and metabolic syndrome score and beta cell function by gender in Korean populations with obesity.

    Science.gov (United States)

    Yoon, Hyun; Jeong, Dae Keun; Lee, Kyu Su; Kim, Han Soo; Moon, Ae Eun; Park, Jong

    2016-09-30

    The present study was conducted to assess the relationships between metabolic syndrome and metabolic syndrome score (MSS) and beta cell function by gender in Korean populations with obesity. This study included 1,686 adults aged 20 or older using the 2010 Korea National Health and Nutrition Examination Survey (KNHANES) data, which represent national data in Korea. The key study results were as follows: First, in men, after adjusting for related variables (including body mass index), metabolic syndrome (p=0.005) and MSS (p=0.018) were inversely associated with the homeostatic model assessment of beta cell function (HOMA-B) values. Second, in women, after adjusting for related variables, metabolic syndrome (p=0.616) and MSS (p=0.929) were not associated with HOMA-B levels. In conclusion, metabolic syndrome and MSS were inversely associated with beta cell function in Korean men with obesity, but not in Korean women with obesity.

  18. Cytokines, macrophage lipid metabolism and foam cells: implications for cardiovascular disease therapy.

    Science.gov (United States)

    McLaren, James E; Michael, Daryn R; Ashlin, Tim G; Ramji, Dipak P

    2011-10-01

    Cardiovascular disease is the biggest killer globally and the principal contributing factor to the pathology is atherosclerosis; a chronic, inflammatory disorder characterized by lipid and cholesterol accumulation and the development of fibrotic plaques within the walls of large and medium arteries. Macrophages are fundamental to the immune response directed to the site of inflammation and their normal, protective function is harnessed, detrimentally, in atherosclerosis. Macrophages contribute to plaque development by internalizing native and modified lipoproteins to convert them into cholesterol-rich foam cells. Foam cells not only help to bridge the innate and adaptive immune response to atherosclerosis but also accumulate to create fatty streaks, which help shape the architecture of advanced plaques. Foam cell formation involves the disruption of normal macrophage cholesterol metabolism, which is governed by a homeostatic mechanism that controls the uptake, intracellular metabolism, and efflux of cholesterol. It has emerged over the last 20 years that an array of cytokines, including interferon-γ, transforming growth factor-β1, interleukin-1β, and interleukin-10, are able to manipulate these processes. Foam cell targeting, anti-inflammatory therapies, such as agonists of nuclear receptors and statins, are known to regulate the actions of pro- and anti-atherogenic cytokines indirectly of their primary pharmacological function. A clear understanding of macrophage foam cell biology will hopefully enable novel foam cell targeting therapies to be developed for use in the clinical intervention of atherosclerosis.

  19. Metabolism of farnesyl diphosphate in tobacco BY-2 cells treated with squalestatin.

    Science.gov (United States)

    Hartmann, M A; Wentzinger, L; Hemmerlin, A; Bach, T J

    2000-12-01

    Plant isoprenoids represent a large group of compounds with a wide range of physiological functions. In the cytosol, isoprenoids are synthesized via the classical acetate/mevalonate pathway. In this pathway, farnesyl diphosphate (FPP) occupies a central position, from which isoprene units are dispatched to the different classes of isoprenoids, with sterols as the major end products. The present work deals with effects of squalestatin (SQ) on the metabolism of FPP in proliferating and synchronized cultured tobacco cv. Bright Yellow-2 cells. SQ is a potent inhibitor of squalene synthase (SQS), the first committed enzyme in the sterol pathway. At nanomolar concentrations, SQ severely impaired cell growth and sterol biosynthesis, as attested by the rapid decrease in SQS activity. At the same time, it triggered a several-fold increase in both the enzymic activity and mRNA levels of 3-hydroxy-3-methylglutaryl CoA reductase. When SQ was added to cells synchronized by aphidicolin treatment, it was found to block the cell cycle at the end of G(1) phase, but no cell death was induced. Tobacco cells were also fed exogenous tritiated trans-trans farnesol, the allylic alcohol derived from FPP, in the presence and absence of SQ. Evidence is presented that this compound was incorporated into sterols and ubiquinone Q(10). In the presence of SQ, the sterol pathway was inhibited, but no increase in the radioactivity of ubiquinone was observed, suggesting that this metabolic channel was already saturated under normal conditions.

  20. Uptake and metabolism of iron oxide nanoparticles in brain cells.

    Science.gov (United States)

    Petters, Charlotte; Irrsack, Ellen; Koch, Michael; Dringen, Ralf

    2014-09-01

    Magnetic iron oxide nanoparticles (IONPs) are used for various applications in biomedicine, for example as contrast agents in magnetic resonance imaging, for cell tracking and for anti-tumor treatment. However, IONPs are also known for their toxic effects on cells and tissues which are at least in part caused by iron-mediated radical formation and oxidative stress. The potential toxicity of IONPs is especially important concerning the use of IONPs for neurobiological applications as alterations in brain iron homeostasis are strongly connected with human neurodegenerative diseases. Since IONPs are able to enter the brain, potential adverse consequences of an exposure of brain cells to IONPs have to be considered. This article describes the pathways that allow IONPs to enter the brain and summarizes the current knowledge on the uptake, the metabolism and the toxicity of IONPs for the different types of brain cells in vitro and in vivo.

  1. Identifying the Metabolic Differences of a Fast-Growth Phenotype in Synechococcus UTEX 2973

    Science.gov (United States)

    Mueller, Thomas J.; Ungerer, Justin L.; Pakrasi, Himadri B.; Maranas, Costas D.

    2017-01-01

    The photosynthetic capabilities of cyanobacteria make them interesting candidates for industrial bioproduction. One obstacle to large-scale implementation of cyanobacteria is their limited growth rates as compared to industrial mainstays. Synechococcus UTEX 2973, a strain closely related to Synechococcus PCC 7942, was recently identified as having the fastest measured growth rate among cyanobacteria. To facilitate the development of 2973 as a model organism we developed in this study the genome-scale metabolic model iSyu683. Experimental data were used to define CO2 uptake rates as well as the biomass compositions for each strain. The inclusion of constraints based on experimental measurements of CO2 uptake resulted in a ratio of the growth rates of Synechococcus 2973 to Synechococcus 7942 of 2.03, which nearly recapitulates the in vivo growth rate ratio of 2.13. This identified the difference in carbon uptake rate as the main factor contributing to the divergent growth rates. Additionally four SNPs were identified as possible contributors to modified kinetic parameters of metabolic enzymes and candidates for further study. Comparisons against more established cyanobacterial strains identified a number of differences between the strains along with a correlation between the number of cytochrome c oxidase operons and heterotrophic or diazotrophic capabilities. PMID:28139686

  2. [Effect of solcoseryl on oxygen metabolism and growth of experimental tumors].

    Science.gov (United States)

    Mosienko, V S; Zagoruĭko, L I; Todor, I N; Khasanova, L T

    1987-01-01

    Antihypoxant and antitumour properties of solcoseryl were studied on intact and tumour-bearing rats and mice. By the polarographic method it is found that solcoseryl increases the oxygen metabolism only in animal hypoxic tissues and improves, probably, energy production of their mitochondria. On many tumour strains it is shown that the injections of solcoseryl decelerate the growth of some tumours, inhibit the metastatic process and produce no toxic effect on the animals.

  3. Low humic acids promote in vitro lily bulblet enlargement by enhancing roots growth and carbohydrate metabolism * #

    Science.gov (United States)

    Wu, Yun; Xia, Yi-ping; Zhang, Jia-ping; Du, Fang; Zhang, Lin; Ma, Yi-di; Zhou, Hong

    2016-01-01

    Bulblet development is a problem in global lily bulb production and carbohydrate metabolism is a crucial factor. Micropropagation acts as an efficient substitute for faster propagation and can provide a controllable condition to explore bulb growth. The present study was conducted to investigate the effects of humic acid (HA) on bulblet swelling and the carbohydrate metabolic pathway in Lilium Oriental Hybrids ‘Sorbonne’ under in vitro conditions. HA greatly promoted bulblet growth at 0.2, 2.0, and 20.0 mg/L, and pronounced increases in bulblet sucrose, total soluble sugar, and starch content were observed for higher HA concentrations (≥2.0 mg/L) within 45 d after transplanting (DAT). The activities of three major starch synthetic enzymes (including adenosine 5'-diphosphate glucose pyrophosphorylase, granule-bound starch synthase, and soluble starch synthase) were enhanced dramatically after HA application especially low concentration HA (LHA), indicating a quick response of starch metabolism. However, higher doses of HA also caused excessive aboveground biomass accumulation and inhibited root growth. Accordingly, an earlier carbon starvation emerged by observing evident starch degradation. Relative bulblet weight gradually decreased with increased HA doses and thereby broke the balance between the source and sink. A low HA concentration at 0.2 mg/L performed best in both root and bulblet growth. The number of roots and root length peaked at 14.5 and 5.75 cm, respectively. The fresh bulblet weight and diameter reached 468 mg (2.9 times that under the control treatment) and 11.68 mm, respectively. Further, sucrose/starch utilization and conversion were accelerated and carbon famine was delayed as a result with an average relative bulblet weight of 80.09%. To our knowledge, this is the first HA application and mechanism research into starch metabolism in both in vitro and in vivo condition in bulbous crops. PMID:27819136

  4. Growth hormone enhances effects of endurance training on oxidative muscle metabolism in elderly women

    DEFF Research Database (Denmark)

    Lange, K H; Isaksson, F; Juul, A;

    2000-01-01

    The present study investigated whether recombinant human (rh) growth hormone (GH) combined with endurance training would have a larger effect on oxidative capacity, metabolism, and body fat than endurance training alone. Sixteen healthy, elderly women, aged 75 yr, performed closely monitored...... in the two subjects receiving rhGH. In conclusion, rhGH adds to the effects of endurance training on muscle oxidative enzymes and causes a reduction in body fat in elderly women....

  5. The impact of atmospheric H2S on growth and sulfur metabolism of Allium cepa L.

    NARCIS (Netherlands)

    Durenkamp, M; De Kok, LJ

    2002-01-01

    The impact of atmospheric H2S deposition on growth and sulfur metabolism has been studied in onion (Allium cepa L.). The H2S Uptake followed saturation kinetics with respect to the H2S concentration. The maximum H2S uptake rate (JH(2)S(max)) was approx. 1 mumol g(-1) FW h(-1) and the KH2S (H2S conce

  6. The impact of atmospheric H2S on growth and sulfur metabolism of Allium cepa L.

    NARCIS (Netherlands)

    Durenkamp, M; De Kok, LJ

    2002-01-01

    The impact of atmospheric H2S deposition on growth and sulfur metabolism has been studied in onion (Allium cepa L.). The H2S Uptake followed saturation kinetics with respect to the H2S concentration. The maximum H2S uptake rate (JH(2)S(max)) was approx. 1 mumol g(-1) FW h(-1) and the KH2S (H2S

  7. Modulation of plant growth and metabolism in cadmium-enriched environments.

    Science.gov (United States)

    Qadir, Shaista; Jamshieed, Sumiya; Rasool, Saiema; Ashraf, Muhammad; Akram, Nudrat Aisha; Ahmad, Parvaiz

    2014-01-01

    Cadmium (Cd) is a water soluble metal pollutant that is not essential to plant growth.It has attracted attention from soil scientists and plant nutritionists in recent years because of its toxicity and mobility in the soil-plant continuum. Even low levels of Cd (0.1-1 J.!M) cause adverse effects on plant growth and metabolism. Cadmium is known to trigger the synthesis of reactive oxygen species, hinder utilization, uptake and transport of essential nutrients and water, and modify photosynthetic machinery,thereby resulting in plant tissue death. Although the effects of Cd are dose- as well as plant species-dependent, some plants show Cd tolerance through a wide range of cellular responses. Such tolerance results from synthesis of osmolytes,generation of enzymatic and non-enzymatic antioxidants and metal-detoxifying peptides, changes in gene expression, and metal ion homeostasis and compartmentalization of ligand-metal complexes. Cd toxicity in plants produces effects on chlorophyllbio synthesis, reduces photosynthesis, and upsets plant water relations and hormonal and/or nutritional balances. All of these effects on plants and on plant metabolism ultimately reduce growth and productivity.In this review, we describe the extent to which Cd affects underlying metabolic processes in plants and how such altered processes affect plant growth. We review the sources of Cd contamination, its uptake, transportation and bioavailability and accumulation in plants, and its antagonistic and synergistic effects with other metals and compounds. We further address the effects of Cd on plant genetics and metabolism,and how plants respond to mitigate the adverse effects of Cd exposure, as well as strategies(e.g., plant breeding) that can reduce the impact of Cd contamination on plants.

  8. In Vivo Single-Cell Detection of Metabolic Oscillations in Stem Cells

    Directory of Open Access Journals (Sweden)

    Chiara Stringari

    2015-01-01

    Full Text Available Through the use of bulk measurements in metabolic organs, the circadian clock was shown to play roles in organismal energy homeostasis. However, the relationship between metabolic and circadian oscillations has not been studied in vivo at a single-cell level. Also, it is unknown whether the circadian clock controls metabolism in stem cells. We used a sensitive, noninvasive method to detect metabolic oscillations and circadian phase within epidermal stem cells in live mice at the single-cell level. We observe a higher NADH/NAD+ ratio, reflecting an increased glycolysis/oxidative phosphorylation ratio during the night compared to the day. Furthermore, we demonstrate that single-cell metabolic heterogeneity within the basal cell layer correlates with the circadian clock and that diurnal fluctuations in NADH/NAD+ ratio are Bmal1 dependent. Our data show that, in proliferating stem cells, the circadian clock coordinates activities of oxidative phosphorylation and glycolysis with DNA synthesis, perhaps as a protective mechanism against genotoxicity.

  9. Effects of prefermented cereals or the end products of fermentation on growth and metabolism of enterocyte-like Caco-2 cells and on intestinal health of restrictedly fed weanling pigs

    NARCIS (Netherlands)

    Bruininx, E.M.A.M.; Koninkx, J.F.J.G.; Binnendijk, G.P.; Zandstra, T.; Heetkamp, M.J.W.; Peet-Schwering, van der C.M.C.; Gerrits, W.J.J.

    2010-01-01

    To unravel the underlying mechanisms that explain the positive effects of prefermented cereals on in vivo gastrointestinal (GI) architecture and function, an in vitro experiment using a human small intestinal epithelial cell model (Caco-2) was performed. A range of dilutions (0% to 10%) of the super

  10. Amino acids and mTOR mediate distinct metabolic checkpoints in mammalian G1 cell cycle.

    Directory of Open Access Journals (Sweden)

    Mahesh Saqcena

    Full Text Available OBJECTIVE: In multicellular organisms, cell division is regulated by growth factors (GFs. In the absence of GFs, cells exit the cell cycle at a site in G1 referred to as the restriction point (R and enter a state of quiescence known as G0. Additionally, nutrient availability impacts on G1 cell cycle progression. While there is a vast literature on G1 cell cycle progression, confusion remains - especially with regard to the temporal location of R relative to nutrient-mediated checkpoints. In this report, we have investigated the relationship between R and a series of metabolic cell cycle checkpoints that regulate passage into S-phase. METHODS: We used double-block experiments to order G1 checkpoints that monitor the presence of GFs, essential amino acids (EEAs, the conditionally essential amino acid glutamine, and inhibition of mTOR. Cell cycle progression was monitored by uptake of [(3H]-thymidine and flow cytometry, and analysis of cell cycle regulatory proteins was by Western-blot. RESULTS: We report here that the GF-mediated R can be temporally distinguished from a series of late G1 metabolic checkpoints mediated by EAAs, glutamine, and mTOR - the mammalian/mechanistic target of rapamycin. R is clearly upstream from an EAA checkpoint, which is upstream from a glutamine checkpoint. mTOR is downstream from both the amino acid checkpoints, close to S-phase. Significantly, in addition to GF autonomy, we find human cancer cells also have dysregulated metabolic checkpoints. CONCLUSION: The data provided here are consistent with a GF-dependent mid-G1 R where cells determine whether it is appropriate to divide, followed by a series of late-G1 metabolic checkpoints mediated by amino acids and mTOR where cells determine whether they have sufficient nutrients to accomplish the task. Since mTOR inhibition arrests cells the latest in G1, it is likely the final arbiter for nutrient sufficiency prior to committing to replicating the genome.

  11. Effects of Nicotinamide N-Methyltransferase on PANC-1 Cells Proliferation, Metastatic Potential and Survival Under Metabolic Stress

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    Tao Yu

    2015-01-01

    Full Text Available Background: Aberrant expression of Nicotinamide N-methyltransferase (NNMT has been reported in pancreatic cancer. However, the role of NNMT in pancreatic cancer development remains elusive. Therefore, the present study was to investigate the impact of NNMT on pancreatic cancer cell proliferation, metastatic potential and survival under metabolic stress. Methods: Pancreatic cancer cell line PANC-1 was transfected with NNMT expression plasmid or small interfering RNA of NNMT to overexpress or knockdown intracellular NNMT expression, respectively. Rate of cell proliferation was monitored. Transwell migration and matrigel invasion assays were conducted to assess cell migration and invasion capacity. Resistance to glucose deprivation, sensitivity to glycolytic inhibition, mitochondrial inhibtion and resistance to rapamycin were examined to evaluate cell survival under metabolic stress. Results: NNMT silencing markedly reduced cell proliferation, whereas NNMT overexpression promoted cell growth moderately. Knocking down NNMT also significantly suppressed the migration and invasion capacities of PANC-1 cells. Conversely, NNMT upregulation enhanced cell migration and invasion capacities. In addition, NNMT knockdown cells were much less resistant to glucose deprivation and rapamycin as well as glycolytic inhibitor 2-deoxyglucose whereas NNMT-expressing cells showed opposite effects although the effects were not so striking. Conclusions: These data sugguest that NNMT plays an important role in PANC-1 cell proliferation, metastatic potential and survival under metabolic stress.

  12. miR-592/WSB1/HIF-1α axis inhibits glycolytic metabolism to decrease hepatocellular carcinoma growth

    Science.gov (United States)

    Song, Ying; Liu, Mei-You; Yang, Xiao-Juan; Xue, Yan; Wen, Ai-Dong; Shi, Lei

    2016-01-01

    Hepatocellular carcinoma (HCC) cells rapidly switch their energy source from oxidative phosphorylation to glycolytic metabolism in order to efficiently proliferate. However, the molecular mechanisms responsible for this switch remain unclear. In this study, we found that miR-592 was frequently downregulated in human HCC tissues and cell lines, and its downregulation was closely correlated with aggressive clinicopathological features and poor prognosis of HCC patients. Overexpression of miR-592 inhibited aerobic glycolysis and proliferation in HCC cells in vitro. Conversely, knockdown of miR-592 promoted HCC growth in both subcutaneous injection and orthotopic liver tumor implantation models in vivo. Mechanistically, miR-592 downregulation in human HCCs was correlated with an upregulation of WD repeat and SOCS box containing 1 (WSB1). We further showed that miR-592 directly binds to the 3′-UTR of the WSB1 gene, thus disrupting hypoxia inducible factor-1α (HIF-1α) protein stabilization. In turn, overexpression of WSB1 in HCC cells rescued decreased HIF-1α expression, glucose uptake, and HCC growth induced by miR-592. Collectively, our clinical data and functional studies suggest that miR-592 is a new robust inhibitor of the Warburg effect and a promising therapeutic target for HCC treatment. PMID:27153552

  13. Transcriptional regulation of metabolic pathways, alternative respiration and enterotoxin genes in anaerobic growth of Bacillus cereus ATCC 14579

    NARCIS (Netherlands)

    Voort, van der M.; Abee, T.

    2009-01-01

    Aims: To assess genes specifically activated during anaerobic growth that are involved in metabolism and pathogenesis of the foodborne pathogen Bacillus cereus. Methods and Results: Growth under anaerobic conditions in Brain Heart Infusion (BHI) broth revealed a reduced growth rate and lower yield a

  14. Keap1/Nrf2 pathway in the frontiers of cancer and non-cancer cell metabolism.

    Science.gov (United States)

    Chartoumpekis, Dionysios V; Wakabayashi, Nobunao; Kensler, Thomas W

    2015-08-01

    Cancer cells adapt their metabolism to their increased needs for energy and substrates for protein, lipid and nucleic acid synthesis. Nuclear erythroid factor 2-like 2 (Nrf2) pathway is usually activated in cancers and has been suggested to promote cancer cell survival mainly by inducing a large battery of cytoprotective genes. This mini review focuses on metabolic pathways, beyond cytoprotection, which can be directly or indirectly regulated by Nrf2 in cancer cells to affect their survival. The pentose phosphate pathway (PPP) is enhanced by Nrf2 in cancers and aids their growth. PPP has also been found to be up-regulated in non-cancer tissues and other pathways, such as de novo lipogenesis, have been found to be repressed after activation of the Nrf2 pathway. The importance of these Nrf2-regulated metabolic pathways in cancer compared with non-cancer state remains to be determined. Last but not least, the importance of context about Nrf2 and cancer is highlighted as the Nrf2 pathway may be activated in cancers but its pharmacological activators are useful in chemoprevention.

  15. Detection of Metabolic Fluxes of O and H Atoms into Intracellular Water in Mammalian Cells

    Science.gov (United States)

    Kreuzer, Helen W.; Quaroni, Luca; Podlesak, David W.; Zlateva, Theodora; Bollinger, Nikki; McAllister, Aaron; Lott, Michael J.; Hegg, Eric L.

    2012-01-01

    Metabolic processes result in the release and exchange of H and O atoms from organic material as well as some inorganic salts and gases. These fluxes of H and O atoms into intracellular water result in an isotopic gradient that can be measured experimentally. Using isotope ratio mass spectroscopy, we revealed that slightly over 50% of the H and O atoms in the intracellular water of exponentially-growing cultured Rat-1 fibroblasts were isotopically distinct from growth medium water. We then employed infrared spectromicroscopy to detect in real time the flux of H atoms in these same cells. Importantly, both of these techniques indicate that the H and O fluxes are dependent on metabolic processes; cells that are in lag phase or are quiescent exhibit a much smaller flux. In addition, water extracted from the muscle tissue of rats contained a population of H and O atoms that were isotopically distinct from body water, consistent with the results obtained using the cultured Rat-1 fibroblasts. Together these data demonstrate that metabolic processes produce fluxes of H and O atoms into intracellular water, and that these fluxes can be detected and measured in both cultured mammalian cells and in mammalian tissue. PMID:22848359

  16. Detection of metabolic fluxes of O and H atoms into intracellular water in mammalian cells.

    Science.gov (United States)

    Kreuzer, Helen W; Quaroni, Luca; Podlesak, David W; Zlateva, Theodora; Bollinger, Nikki; McAllister, Aaron; Lott, Michael J; Hegg, Eric L

    2012-01-01

    Metabolic processes result in the release and exchange of H and O atoms from organic material as well as some inorganic salts and gases. These fluxes of H and O atoms into intracellular water result in an isotopic gradient that can be measured experimentally. Using isotope ratio mass spectroscopy, we revealed that slightly over 50% of the H and O atoms in the intracellular water of exponentially-growing cultured Rat-1 fibroblasts were isotopically distinct from growth medium water. We then employed infrared spectromicroscopy to detect in real time the flux of H atoms in these same cells. Importantly, both of these techniques indicate that the H and O fluxes are dependent on metabolic processes; cells that are in lag phase or are quiescent exhibit a much smaller flux. In addition, water extracted from the muscle tissue of rats contained a population of H and O atoms that were isotopically distinct from body water, consistent with the results obtained using the cultured Rat-1 fibroblasts. Together these data demonstrate that metabolic processes produce fluxes of H and O atoms into intracellular water, and that these fluxes can be detected and measured in both cultured mammalian cells and in mammalian tissue.

  17. Detection of metabolic fluxes of O and H atoms into intracellular water in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Helen W Kreuzer

    Full Text Available Metabolic processes result in the release and exchange of H and O atoms from organic material as well as some inorganic salts and gases. These fluxes of H and O atoms into intracellular water result in an isotopic gradient that can be measured experimentally. Using isotope ratio mass spectroscopy, we revealed that slightly over 50% of the H and O atoms in the intracellular water of exponentially-growing cultured Rat-1 fibroblasts were isotopically distinct from growth medium water. We then employed infrared spectromicroscopy to detect in real time the flux of H atoms in these same cells. Importantly, both of these techniques indicate that the H and O fluxes are dependent on metabolic processes; cells that are in lag phase or are quiescent exhibit a much smaller flux. In addition, water extracted from the muscle tissue of rats contained a population of H and O atoms that were isotopically distinct from body water, consistent with the results obtained using the cultured Rat-1 fibroblasts. Together these data demonstrate that metabolic processes produce fluxes of H and O atoms into intracellular water, and that these fluxes can be detected and measured in both cultured mammalian cells and in mammalian tissue.

  18. Emerging concepts of T cell metabolism as a target of immunotherapy.

    Science.gov (United States)

    Chang, Chih-Hao; Pearce, Erika L

    2016-04-01

    T cells have a pivotal protective role in defense against infection and cancer but also are instrumental in the development of many autoimmune diseases. The regulation of nutrient uptake and utilization in T cells is critically important for the control of their differentiation, and manipulating metabolic pathways in these cells can alter their function and longevity. While the importance of T cell metabolic remodeling in different physiological settings is not fully understood, there is a growing realization that inappropriate metabolic remodeling underlies many aberrant immune responses and that manipulating cellular metabolism can beneficially enhance or temper immunity. Here we comment on the basic metabolic pathways in T cells, followed by a discussion on up-to-date findings about the relationship between metabolism and T cell function and longevity. Furthermore, we expand on potential approaches and applications in which T cells might be manipulated by the reprogramming of metabolic pathways for therapeutic purposes.

  19. Relation between fibroblast growth factor-21, adiposity, metabolism, and weight reduction.

    Science.gov (United States)

    Mai, Knut; Schwarz, Franziska; Bobbert, Thomas; Andres, Janin; Assmann, Anke; Pfeiffer, Andreas F H; Spranger, Joachim

    2011-02-01

    Fibroblast growth factor-21 (FGF-21) has been proposed as a novel metabolic regulator, and animal experiments suggested that FGF-21 may affect energy balance. In humans, FGF-21 was correlated with obesity. Until now, no data exist regarding the relationship of FGF-21 and weight reduction in humans. We therefore investigated whether FGF-21 is modified by a moderate intended weight loss in a human trial. Thirty obese individuals (24 female, 6 male) participated in a weight reduction program for 6 months. In addition to several anthropometric and metabolic parameters, FGF-21 was measured before and after weight loss. Baseline serum FGF-21 was independently associated with markers of lipid metabolism and waist circumference. The multimodal intervention induced a moderate weight loss (97.4 ± 3.1 vs 92.2 ± 3.1 kg, P < .001), which was accompanied by a significant improvement of lipid and glucose metabolism. However, FGF-21 levels were not modified by moderate weight reduction; and FGF-21 levels at baseline were not a predictive marker for subsequent weight loss. The results presented here confirmed that FGF-21 levels are associated with markers of lipid metabolism and an estimate of abdominal adiposity. The finding that moderate weight loss did not induce changes of FGF-21 levels in humans suggests that FGF-21 is not directly regulated by fat mass under those conditions. © 2011 Elsevier Inc. All rights reserved.

  20. Vitamin B-complex initiates growth and development of human embryonic brain cells in vitro.

    Science.gov (United States)

    Danielyan, K E; Abramyan, R A; Galoyan, A A; Kevorkian, G A

    2011-09-01

    We studied a combined effect of subcomponents of vitamin B complex on the growth, development, and death of human embryonic brain-derived cells (E90) cultured using a modified method of Matson. Cell death was detected by trypan blue staining. According to our results, vitamin B-complex in low-doses promote the development, maturation, and enlargement of human embryonic brain cells, on the one hand, and increases the percent of cell death, which attests to accelerated maturation and metabolism, on the other.

  1. Metabolic monosaccharides altered cell responses to anticancer drugs.

    Science.gov (United States)

    Chen, Long; Liang, Jun F

    2012-06-01

    Metabolic glycoengineering has been used to manipulate the glycochemistry of cell surfaces and thus the cell/cell interaction, cell adhesion, and cell migration. However, potential application of glycoengineering in pharmaceutical sciences has not been studied until recently. Here, we reported that Ac(4)ManNAc, an analog of N-acetyl-D-mannosamine (ManNAc), could affect cell responses to anticancer drugs. Although cells from different tissues and organs responded to Ac(4)ManNAc treatment differently, treated cells with increased sialic acid contents showed dramatically reduced sensitivity (up to 130 times) to anti-cancer drugs as tested on various drugs with distinct chemical structures and acting mechanisms. Neither increased P-glycoprotein activity nor decreased drug uptake was observed during the course of Ac(4)ManNAc treatment. However, greatly altered intracellular drug distributions were observed. Most intracellular daunorubicin was found in the perinuclear region, but not the expected nuclei in the Ac(4)ManNAc treated cells. Since sialoglycoproteins and gangliosides were synthesized in the Golgi, intracellular glycans affected intracellular signal transduction and drug distributions seem to be the main reason for Ac(4)ManNAc affected cell sensitivity to anticancer drugs. It was interesting to find that although Ac(4)ManNAc treated breast cancer cells (MDA-MB-231) maintained the same sensitivity to 5-Fluorouracil, the IC(50) value of 5-Fluorouracil to the same Ac(4)ManNAc treated normal cells (MCF-10A) was increased by more than 20 times. Thus, this Ac(4)ManNAc treatment enlarged drug response difference between normal and tumor cells provides a unique opportunity to further improve the selectivity and therapeutic efficiency of anticancer drugs.

  2. Investigation of the selenium metabolism in cancer cell lines.

    Science.gov (United States)

    Lunøe, Kristoffer; Gabel-Jensen, Charlotte; Stürup, Stefan; Andresen, Lars; Skov, Søren; Gammelgaard, Bente

    2011-02-01

    The aim of this work was to compare different selenium species for their ability to induce cell death in different cancer cell lines, while investigating the underlying chemistry by speciation analysis. A prostate cancer cell line (PC-3), a colon cancer cell line (HT-29) and a leukaemia cell line (Jurkat E6-1) were incubated with five selenium compounds representing inorganic as well as organic Se compounds in different oxidation states. Selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), methylseleninic acid (MeSeA), selenite and selenate in the concentration range 5-100 μM were incubated with cells for 24 h and the induction of cell death was measured using flow cytometry. The amounts of total selenium in cell medium, cell lysate and the insoluble fractions was determined by ICP-MS. Speciation analysis of cellular fractions was performed by reversed phase, anion exchange and size exclusion chromatography and ICP-MS detection. The selenium compounds exhibited large differences in their ability to induce cell death in the three cell lines and the susceptibilities of the cell lines were different. Full recovery of selenium in the cellular fractions was observed for all Se compounds except MeSeA. Speciation analysis showed that MeSeA was completely transformed during the incubations, while metabolic conversion of the other Se compounds was limited. Production of volatile dimethyl diselenide was observed for MeSeA and MeSeCys. MeSeA, MeSeCys and selenite showed noticeable protein binding. Correlations between cell death induction and the Se compounds transformations could not be demonstrated.

  3. Metabolism of the EGFR tyrosin kinase inhibitor gefitinib by cytochrome P450 1A1 enzyme in EGFR-wild type non small cell lung cancer cell lines

    Directory of Open Access Journals (Sweden)

    Alfieri Roberta R

    2011-11-01

    Full Text Available Abstract Background Gefitinib is a tyrosine kinase inhibitor (TKI of the epidermal growth factor receptor (EGFR especially effective in tumors with activating EGFR gene mutations while EGFR wild-type non small cell lung cancer (NSCLC patients at present do not benefit from this treatment. The primary site of gefitinib metabolism is the liver, nevertheless tumor cell metabolism can significantly affect treatment effectiveness. Results In this study, we investigated the intracellular metabolism of gefitinib in a panel of EGFR wild-type gefitinib-sensitive and -resistant NSCLC cell lines, assessing the role of cytochrome P450 1A1 (CYP1A1 inhibition on gefitinib efficacy. Our results indicate that there is a significant difference in drug metabolism between gefitinib-sensitive and -resistant cell lines. Unexpectedly, only sensitive cells metabolized gefitinib, producing metabolites which were detected both inside and outside the cells. As a consequence of gefitinib metabolism, the intracellular level of gefitinib was markedly reduced after 12-24 h of treatment. Consistent with this observation, RT-PCR analysis and EROD assay showed that mRNA and activity of CYP1A1 were present at significant levels and were induced by gefitinib only in sensitive cells. Gefitinib metabolism was elevated in crowded cells, stimulated by exposure to cigarette smoke extract and prevented by hypoxic condition. It is worth noting that the metabolism of gefitinib in the sensitive cells is a consequence and not the cause of drug responsiveness, indeed treatment with a CYP1A1 inhibitor increased the efficacy of the drug because it prevented the fall in intracellular gefitinib level and significantly enhanced the inhibition of EGFR autophosphorylation, MAPK and PI3K/AKT/mTOR signalling pathways and cell proliferation. Conclusion Our findings suggest that gefitinib metabolism in lung cancer cells, elicited by CYP1A1 activity, might represent an early assessment of gefitinib

  4. New insights into Escherichia coli metabolism: carbon scavenging, acetate metabolism and carbon recycling responses during growth on glycerol

    Directory of Open Access Journals (Sweden)

    Martínez-Gómez Karla

    2012-07-01

    Full Text Available Abstract Background Glycerol has enhanced its biotechnological importance since it is a byproduct of biodiesel synthesis. A study of Escherichia coli physiology during growth on glycerol was performed combining transcriptional-proteomic analysis as well as kinetic and stoichiometric evaluations in the strain JM101 and certain derivatives with important inactivated genes. Results Transcriptional and proteomic analysis of metabolic central genes of strain JM101 growing on glycerol, revealed important changes not only in the synthesis of MglB, LamB and MalE proteins, but also in the overexpression of carbon scavenging genes: lamB, malE, mglB, mglC, galP and glk and some members of the RpoS regulon (pfkA, pfkB, fbaA, fbaB, pgi, poxB, acs, actP and acnA. Inactivation of rpoS had an important effect on stoichiometric parameters and growth adaptation on glycerol. The observed overexpression of poxB, pta, acs genes, glyoxylate shunt genes (aceA, aceB, glcB and glcC and actP, suggested a possible carbon flux deviation into the PoxB, Acs and glyoxylate shunt. In this scenario acetate synthesized from pyruvate with PoxB was apparently reutilized via Acs and the glyoxylate shunt enzymes. In agreement, no acetate was detected when growing on glycerol, this strain was also capable of glycerol and acetate coutilization when growing in mineral media and derivatives carrying inactivated poxB or pckA genes, accumulated acetate. Tryptophanase A (TnaA was synthesized at high levels and indole was produced by this enzyme, in strain JM101 growing on glycerol. Additionally, in the isogenic derivative with the inactivated tnaA gene, no indole was detected and acetate and lactate were accumulated. A high efficiency aromatic compounds production capability was detected in JM101 carrying pJLBaroGfbrtktA, when growing on glycerol, as compared to glucose. Conclusions The overexpression of several carbon scavenging, acetate metabolism genes and the absence of acetate

  5. BMP signaling regulates satellite cell-dependent postnatal muscle growth.

    Science.gov (United States)

    Stantzou, Amalia; Schirwis, Elija; Swist, Sandra; Alonso-Martin, Sonia; Polydorou, Ioanna; Zarrouki, Faouzi; Mouisel, Etienne; Beley, Cyriaque; Julien, Anaïs; Le Grand, Fabien; Garcia, Luis; Colnot, Céline; Birchmeier, Carmen; Braun, Thomas; Schuelke, Markus; Relaix, Frédéric; Amthor, Helge

    2017-08-01

    Postnatal growth of skeletal muscle largely depends on the expansion and differentiation of resident stem cells, the so-called satellite cells. Here, we demonstrate that postnatal satellite cells express components of the bone morphogenetic protein (BMP) signaling machinery. Overexpression of noggin in postnatal mice (to antagonize BMP ligands), satellite cell-specific knockout of Alk3 (the gene encoding the BMP transmembrane receptor) or overexpression of inhibitory SMAD6 decreased satellite cell proliferation and accretion during myofiber growth, and ultimately retarded muscle growth. Moreover, reduced BMP signaling diminished the adult satellite cell pool. Abrogation of BMP signaling in satellite cell-derived primary myoblasts strongly diminished cell proliferation and upregulated the expression of cell cycle inhibitors p21 and p57 In conclusion, these results show that BMP signaling defines postnatal muscle development by regulating satellite cell-dependent myofiber growth and the generation of the adult muscle stem cell pool. © 2017. Published by The Company of Biologists Ltd.

  6. CCL5 activation of CCR5 regulates cell metabolism to enhance proliferation of breast cancer cells.

    Science.gov (United States)

    Gao, Darrin; Rahbar, Ramtin; Fish, Eleanor N

    2016-06-01

    In earlier studies, we showed that CCL5 enhances proliferation and survival of MCF-7 breast cancer cells in an mTOR-dependent manner and we provided evidence that, for T cells, CCL5 activation of CCR5 results in increased glycolysis and enhanced ATP production. Increases in metabolic activity of cancer cells, specifically increased glycolytic activity and increased expression of glucose transporters, are associated with tumour progression. In this report, we provide evidence that CCL5 enhances the proliferation of human breast cancer cell lines (MDA-MB-231, MCF-7) and mouse mammary tumour cells (MMTV-PyMT), mediated by CCR5 activation. Concomitant with enhanced proliferation we show that CCL5 increases cell surface expression of the glucose transporter GLUT1, and increases glucose uptake and ATP production by these cells. Blocking CCL5-inducible glucose uptake abrogates the enhanced proliferation induced by CCL5. We provide evidence that increased glucose uptake is associated with enhanced glycolysis, as measured by extracellular acidification. Moreover, CCL5 enhances the invasive capacity of these breast cancer cells. Using metabolomics, we demonstrate that the metabolic signature of CCL5-treated primary mouse mammary tumour cells reflects increased anabolic metabolism. The implications are that CCL5-CCR5 interactions in the tumour microenvironment regulate metabolic events, specifically glycolysis, to promote tumour proliferation and invasion.

  7. Roles of the Lipid Metabolism in Hepatic Stellate Cells Activation

    Institute of Scientific and Technical Information of China (English)

    Xin-yan Jing; Xue-feng Yang; Kai Qing; Yan Ou-Yang

    2013-01-01

    The lipids present in hepatic stellate cells (HSCs) lipid droplets include retinyl ester, triglyceride, cholesteryl ester, cholesterol, phospholipids and free fatty acids. Activation of HSCs is crucial to the development of fibrosis in liver disease. During activation, HSCs transform into myofibroblasts with concomitant loss of their lipid droplets and production of excessive extracellular matrix. Release of lipid droplets containing retinyl esters and triglyceride is a defining feature of activated HSCs. Accumulating evidence supports the proposal that recovering the accumulation of lipids would inhibit the activation of HSCs. In healthy liver, quiescent HSCs store 80%of total liver retinols and release them depending on the extracellular retinol status. However, in injured liver activated HSCs lose their retinols and produce a considerable amount of extracellular matrix, subsequently leading to liver fibrosis. Further findings prove that lipid metabolism of HSCs is closely associated with its activation, yet relationship between activated HSCs and the lipid metabolism has remained mysterious.

  8. Hypoxia and oxygenation induce a metabolic switch between pentose phosphate pathway and glycolysis in glioma stem-like cells.

    Science.gov (United States)

    Kathagen, Annegret; Schulte, Alexander; Balcke, Gerd; Phillips, Heidi S; Martens, Tobias; Matschke, Jakob; Günther, Hauke S; Soriano, Robert; Modrusan, Zora; Sandmann, Thomas; Kuhl, Carsten; Tissier, Alain; Holz, Mareike; Krawinkel, Lutz A; Glatzel, Markus; Westphal, Manfred; Lamszus, Katrin

    2013-11-01

    Fluctuations in oxygen tension during tissue remodeling impose a major metabolic challenge in human tumors. Stem-like tumor cells in glioblastoma, the most common malignant brain tumor, possess extraordinary metabolic flexibility, enabling them to initiate growth even under non-permissive conditions. We identified a reciprocal metabolic switch between the pentose phosphate pathway (PPP) and glycolysis in glioblastoma stem-like (GS) cells. Expression of PPP enzymes is upregulated by acute oxygenation but downregulated by hypoxia, whereas glycolysis enzymes, particularly those of the preparatory phase, are regulated inversely. Glucose flux through the PPP is reduced under hypoxia in favor of flux through glycolysis. PPP enzyme expression is elevated in human glioblastomas compared to normal brain, especially in highly proliferative tumor regions, whereas expression of parallel preparatory phase glycolysis enzymes is reduced in glioblastomas, except for strong upregulation in severely hypoxic regions. Hypoxia stimulates GS cell migration but reduces proliferation, whereas oxygenation has opposite effects, linking the metabolic switch to the "go or grow" potential of the cells. Our findings extend Warburg's observation that tumor cells predominantly utilize glycolysis for energy production, by suggesting that PPP activity is elevated in rapidly proliferating tumor cells but suppressed by acute severe hypoxic stress, favoring glycolysis and migration to protect cells against hypoxic cell damage.

  9. Temperature dependent growth, feeding, nutritional condition and aerobic metabolism of juvenile spiny lobster, Sagmariasus verreauxi.

    Science.gov (United States)

    Fitzgibbon, Quinn P; Simon, Cedric J; Smith, Gregory G; Carter, Chris G; Battaglene, Stephen C

    2017-02-05

    We examined the effects of temperature on the growth, feeding, nutritional condition and aerobic metabolism of juvenile spiny lobster, Sagmariasus verreauxi, in order to determine if temperature acclimated aerobic scope correlates with optimum for growth and to establish the thermal tolerance window for this emerging aquaculture species. Juvenile lobsters (initial weight=10.95±0.47g) were reared (n=7) at temperatures from 11.0 to 28.5°C for 145days. All lobsters survived from 14.5 to 25.0°C while survival was reduced at 11.0°C (86%) and all lobsters died at 28.5°C. Lobster specific growth rate and specific feed consumption displayed a unimodal response with temperature, peaking at 21.5°C. Lobster standard, routine and maximum metabolic rates, and aerobic scope all increased exponentially up to maximum non-lethal temperature. Optimum temperature for growth did not correspond to that for maximum aerobic scope suggesting that aerobic scope is not an effective predictor of the thermal optimum of spiny lobsters. Plateauing of specific feed consumption beyond 21.5°C suggests that temperature dependent growth of lobsters is limited by capacity to ingest or digest sufficient food to meet increasing maintenance metabolic demands at high temperatures. The nutritional condition of lobsters was not influenced by temperature and feed conversion ratio was improved at lower temperatures. These findings add to a growing body of evidence questioning the generality of aerobic scope to describe the physiological thermal boundaries of aquatic ectotherms and suggest that feed intake plays a crucial role in regulating performance at thermal extremes.

  10. Sexual dimorphism of growth plate prehypertrophic and hypertrophic chondrocytes in response to testosterone requires metabolism to dihydrotestosterone (DHT) by steroid 5-alpha reductase type 1.

    Science.gov (United States)

    Raz, P; Nasatzky, E; Boyan, B D; Ornoy, A; Schwartz, Z

    2005-05-01

    Rat costochondral growth plate chondrocytes exhibit sex-specific and cell maturation dependent responses to testosterone. Only male cells respond to testosterone, although testosterone receptors are present in both male and female cells, suggesting other mecha