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Sample records for acidic protein-positive cells

  1. Kidney specific protein-positive cells derived from embryonic stem cells reproduce tubular structures in vitro and differentiate into renal tubular cells.

    PubMed

    Morizane, Ryuji; Monkawa, Toshiaki; Fujii, Shizuka; Yamaguchi, Shintaro; Homma, Koichiro; Matsuzaki, Yumi; Okano, Hideyuki; Itoh, Hiroshi

    2014-01-01

    Embryonic stem cells and induced pluripotent stem cells have the ability to differentiate into various organs and tissues, and are regarded as new tools for the elucidation of disease mechanisms as well as sources for regenerative therapies. However, a method of inducing organ-specific cells from pluripotent stem cells is urgently needed. Although many scientists have been developing methods to induce various organ-specific cells from pluripotent stem cells, renal lineage cells have yet to be induced in vitro because of the complexity of kidney structures and the diversity of kidney-component cells. Here, we describe a method of inducing renal tubular cells from mouse embryonic stem cells via the cell purification of kidney specific protein (KSP)-positive cells using an anti-KSP antibody. The global gene expression profiles of KSP-positive cells derived from ES cells exhibited characteristics similar to those of cells in the developing kidney, and KSP-positive cells had the capacity to form tubular structures resembling renal tubular cells when grown in a 3D culture in Matrigel. Moreover, our results indicated that KSP-positive cells acquired the characteristics of each segment of renal tubular cells through tubular formation when stimulated with Wnt4. This method is an important step toward kidney disease research using pluripotent stem cells, and the development of kidney regeneration therapies.

  2. The Zebrafish Period2 Protein Positively Regulates the Circadian Clock through Mediation of Retinoic Acid Receptor (RAR)-related Orphan Receptor α (Rorα)*

    PubMed Central

    Wang, Mingyong; Zhong, Zhaomin; Zhong, Yingbin; Zhang, Wei; Wang, Han

    2015-01-01

    We report the characterization of a null mutant for zebrafish circadian clock gene period2 (per2) generated by transcription activator-like effector nuclease and a positive role of PER2 in vertebrate circadian regulation. Locomotor experiments showed that per2 mutant zebrafish display reduced activities under light-dark and 2-h phase delay under constant darkness, and quantitative real time PCR analyses showed up-regulation of cry1aa, cry1ba, cry1bb, and aanat2 but down-regulation of per1b, per3, and bmal1b in per2 mutant zebrafish, suggesting that Per2 is essential for the zebrafish circadian clock. Luciferase reporter assays demonstrated that Per2 represses aanat2 expression through E-box and enhances bmal1b expression through the Ror/Rev-erb response element, implicating that Per2 plays dual roles in the zebrafish circadian clock. Cell transfection and co-immunoprecipitation assays revealed that Per2 enhances bmal1b expression through binding to orphan nuclear receptor Rorα. The enhancing effect of mouse PER2 on Bmal1 transcription is also mediated by RORα even though it binds to REV-ERBα. Moreover, zebrafish Per2 also appears to have tissue-specific regulatory roles in numerous peripheral organs. These findings help define the essential functions of Per2 in the zebrafish circadian clock and in particular provide strong evidence for a positive role of PER2 in the vertebrate circadian system. PMID:25544291

  3. Carboxyl-Terminal Modulator Protein Positively Acts as an Oncogenic Driver in Head and Neck Squamous Cell Carcinoma via Regulating Akt phosphorylation

    PubMed Central

    Chang, Jae Won; Jung, Seung-Nam; Kim, Ju-Hee; Shim, Geun-Ae; Park, Hee Sung; Liu, Lihua; Kim, Jin Man; Park, Jongsun; Koo, Bon Seok

    2016-01-01

    The exact regulatory mechanisms of carboxyl-terminal modulator protein (CTMP) and its downstream pathways in cancer have been controversial and are not completely understood. Here, we report a new mechanism of regulation of Akt serine/threonine kinase, one of the most important dysregulated signals in head and neck squamous cell carcinoma (HNSCC) by the CTMP pathway and its clinical implications. We find that HNSCC tumor tissues and cell lines had relatively high levels of CTMP expression. Clinical data indicate that CTMP expression was significantly associated with positive lymph node metastasis (OR = 3.8, P = 0.033) and correlated with poor prognosis in patients with HNSCC. CTMP was also positively correlated with Akt/GSK-3β phosphorylation, Snail up-regulation and E-cadherin down-regulation, which lead to increased proliferation and epithelial-to-mesenchymal transition, suggesting that CTMP expression results in enhanced tumorigenic and metastatic properties of HNSCC cells. Moreover, CTMP suppression restores sensitivity to cisplatin chemotherapy. Intriguingly, all the molecular responses to CTMP regulation are identical regardless of p53 status in HNSCC cells. We conclude that CTMP promotes Akt phosphorylation and functions as an oncogenic driver and prognostic marker in HNSCC irrespective of p53. PMID:27328758

  4. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

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

    1996-12-31

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

  5. Biotransformation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid by plant cell cultures of Eucalyptus perriniana.

    PubMed

    Katsuragi, Hisashi; Shimoda, Kei; Kubota, Naoji; Nakajima, Nobuyoshi; Hamada, Hatsuyuki; Hamada, Hiroki

    2010-01-01

    Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.

  6. Ascorbic acid transport into cultured pituitary cells

    SciTech Connect

    Cullen, E.I.; May, V.; Eipper, R.A.

    1986-05-01

    An amidating enzyme designated peptidyl-glycine ..cap alpha..-amidating monooxygenase (PAM) has been studied in a variety of tissues and is dependent on molecular oxygen and stimulated by copper and ascorbic acid. To continue investigating the relationship among cellular ascorbic acid concentrations, amidating ability, and PAM activity, the authors studied ascorbic acid transport in three cell preparations that contain PAM and produce amidated peptides: primary cultures of rat anterior and intermediate pituitary and mouse AtT-20 tumor cells. When incubated in 50 ..mu..M (/sup 14/C)ascorbic acid all three cell preparations concentrated ascorbic acid 20- to 40-fold, producing intracellular ascorbate concentrations of 1 to 2 mM, based on experimentally determined cell volumes. All three cell preparations displayed saturable ascorbic acid uptake with half-maximal initial rates occurring between 9 and 18 ..mu..M ascorbate. Replacing NaCl in the uptake buffer with choline chloride significantly diminished ascorbate uptake in all three preparations. Ascorbic acid efflux from these cells was slow, displaying half-lives of 7 hours. Unlike systems that transport dehydroascorbic acid, the transport system for ascorbic acid in these cells was not inhibited by glucose. Thus, ascorbate is transported into pituitary cells by a sodium-dependent, active transport system.

  7. Stabilizing platinum in phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Remick, R. J.

    1982-01-01

    Platinum sintering on phosphoric acid fuel cell cathodes is discussed. The cathode of the phosphoric acid fuel cell uses a high surface area platinum catalyst dispersed on a conductive carbon support to minimize both cathode polarization and fabrication costs. During operation, however, the active surface area of these electrodes decreases, which in turn leads to decreased cell performance. This loss of active surface area is a major factor in the degradation of fuel cell performance over time.

  8. Dendritic Cells: A Spot on Sialic Acid

    PubMed Central

    Crespo, Hélio J.; Lau, Joseph T. Y.; Videira, Paula A.

    2013-01-01

    Glycans decorating cell surface and secreted proteins and lipids occupy the juncture where critical host–host and host-pathogen interactions occur. The role of glycan epitopes in cell–cell and cell-pathogen adhesive events is already well-established, and cell surface glycan structures change rapidly in response to stimulus and inflammatory cues. Despite the wide acceptance that glycans are centrally implicated in immunity, exactly how glycans and their changes contribute to the overall immune response remains poorly defined. Sialic acids are unique sugars that usually occupy the terminal position of the glycan chains and may be modified by external factors, such as pathogens, or upon specific physiological cellular events. At cell surface, sialic acid-modified structures form the key fundamental determinants for a number of receptors with known involvement in cellular adhesiveness and cell trafficking, such as the Selectins and the Siglec families of carbohydrate recognizing receptors. Dendritic cells (DCs) preside over the transition from innate to the adaptive immune repertoires, and no other cell has such relevant role in antigen screening, uptake, and its presentation to lymphocytes, ultimately triggering the adaptive immune response. Interestingly, sialic acid-modified structures are involved in all DC functions, such as antigen uptake, DC migration, and capacity to prime T cell responses. Sialic acid content changes along DC differentiation and activation and, while, not yet fully understood, these changes have important implications in DC functions. This review focuses on the developmental regulation of DC surface sialic acids and how manipulation of DC surface sialic acids can affect immune-critical DC functions by altering antigen endocytosis, pathogen and tumor cell recognition, cell recruitment, and capacity for T cell priming. The existing evidence points to a potential of DC surface sialylation as a therapeutic target to improve and diversify DC

  9. Anacardic Acid, Salicylic Acid, and Oleic Acid Differentially Alter Cellular Bioenergetic Function in Breast Cancer Cells.

    PubMed

    Radde, Brandie N; Alizadeh-Rad, Negin; Price, Stephanie M; Schultz, David J; Klinge, Carolyn M

    2016-11-01

    Anacardic acid is a dietary and medicinal phytochemical that inhibits breast cancer cell proliferation and uncouples oxidative phosphorylation (OXPHOS) in isolated rat liver mitochondria. Since mitochondrial-targeted anticancer therapy (mitocans) may be useful in breast cancer, we examined the effect of anacardic acid on cellular bioenergetics and OXPHOS pathway proteins in breast cancer cells modeling progression to endocrine-independence: MCF-7 estrogen receptor α (ERα)+ endocrine-sensitive; LCC9 and LY2 ERα+, endocrine-resistant, and MDA-MB-231 triple negative breast cancer (TNBC) cells. At concentrations similar to cell proliferation IC50 s, anacardic acid reduced ATP-linked oxygen consumption rate (OCR), mitochondrial reserve capacity, and coupling efficiency while increasing proton leak, reflecting mitochondrial toxicity which was greater in MCF-7 compared to endocrine-resistant and TNBC cells. These results suggest tolerance in endocrine-resistant and TNBC cells to mitochondrial stress induced by anacardic acid. Since anacardic acid is an alkylated 2-hydroxybenzoic acid, the effects of salicylic acid (SA, 2-hydroxybenzoic acid moiety) and oleic acid (OA, monounsaturated alkyl moiety) were tested. SA inhibited whereas OA stimulated cell viability. In contrast to stimulation of basal OCR by anacardic acid (uncoupling effect), neither SA nor OA altered basal OCR- except OA inhibited basal and ATP-linked OCR, and increased ECAR, in MDA-MB-231 cells. Changes in OXPHOS proteins correlated with changes in OCR. Overall, neither the 2-hydroxybenzoic acid moiety nor the monounsaturated alky moiety of anacardic acid is solely responsible for the observed mitochondria-targeted anticancer activity in breast cancer cells and hence both moieties are required in the same molecule for the observed effects. J. Cell. Biochem. 117: 2521-2532, 2016. © 2016 Wiley Periodicals, Inc. PMID:26990649

  10. Corrosion free phosphoric acid fuel cell

    DOEpatents

    Wright, Maynard K.

    1990-01-01

    A phosphoric acid fuel cell with an electrolyte fuel system which supplies electrolyte via a wick disposed adjacent a cathode to an absorbent matrix which transports the electrolyte to portions of the cathode and an anode which overlaps the cathode on all sides to prevent corrosion within the cell.

  11. Nucleic Acid Aptamers for Living Cell Analysis

    NASA Astrophysics Data System (ADS)

    Xiong, Xiangling; Lv, Yifan; Chen, Tao; Zhang, Xiaobing; Wang, Kemin; Tan, Weihong

    2014-06-01

    Cells as the building blocks of life determine the basic functions and properties of a living organism. Understanding the structure and components of a cell aids in the elucidation of its biological functions. Moreover, knowledge of the similarities and differences between diseased and healthy cells is essential to understanding pathological mechanisms, identifying diagnostic markers, and designing therapeutic molecules. However, monitoring the structures and activities of a living cell remains a challenging task in bioanalytical and life science research. To meet the requirements of this task, aptamers, as “chemical antibodies,” have become increasingly powerful tools for cellular analysis. This article reviews recent advances in the development of nucleic acid aptamers in the areas of cell membrane analysis, cell detection and isolation, real-time monitoring of cell secretion, and intracellular delivery and analysis with living cell models. Limitations of aptamers and possible solutions are also discussed.

  12. Micro-electro-mechanical systems phosphoric acid fuel cell

    DOEpatents

    Sopchak, David A.; Morse, Jeffrey D.; Upadhye, Ravindra S.; Kotovsky, Jack; Graff, Robert T.

    2010-08-17

    A phosphoric acid fuel cell system comprising a porous electrolyte support, a phosphoric acid electrolyte in the porous electrolyte support, a cathode electrode contacting the phosphoric acid electrolyte, and an anode electrode contacting the phosphoric acid electrolyte.

  13. Micro-electro-mechanical systems phosphoric acid fuel cell

    DOEpatents

    Sopchak, David A.; Morse, Jeffrey D.; Upadhye, Ravindra S.; Kotovsky, Jack; Graff, Robert T.

    2010-12-21

    A phosphoric acid fuel cell system comprising a porous electrolyte support, a phosphoric acid electrolyte in the porous electrolyte support, a cathode electrode contacting the phosphoric acid electrolyte, and an anode electrode contacting the phosphoric acid electrolyte.

  14. Formic acid fuel cells and catalysts

    DOEpatents

    Masel, Richard I.; Larsen, Robert; Ha, Su Yun

    2010-06-22

    An exemplary fuel cell of the invention includes a formic acid fuel solution in communication with an anode (12, 134), an oxidizer in communication with a cathode (16, 135) electrically linked to the anode, and an anode catalyst that includes Pd. An exemplary formic acid fuel cell membrane electrode assembly (130) includes a proton-conducting membrane (131) having opposing first (132) and second surfaces (133), a cathode catalyst on the second membrane surface, and an anode catalyst including Pd on the first surface.

  15. Phosphoric Acid Fuel Cell Technology Status

    NASA Technical Reports Server (NTRS)

    Simons, S. N.; King, R. B.; Prokopius, P. R.

    1981-01-01

    A review of the current phosphoric acid fuel cell system technology development efforts is presented both for multimegawatt systems for electric utility applications and for multikilowatt systems for on-site integrated energy system applications. Improving fuel cell performance, reducing cost, and increasing durability are the technology drivers at this time. Electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, and fuel selection are discussed.

  16. Solid acids as fuel cell electrolytes.

    PubMed

    Haile, S M; Boysen, D A; Chisholm, C R; Merle, R B

    2001-04-19

    Fuel cells are attractive alternatives to combustion engines for electrical power generation because of their very high efficiencies and low pollution levels. Polymer electrolyte membrane fuel cells are generally considered to be the most viable approach for mobile applications. However, these membranes require humid operating conditions, which limit the temperature of operation to less than 100 degrees C; they are also permeable to methanol and hydrogen, which lowers fuel efficiency. Solid, inorganic, acid compounds (or simply, solid acids) such as CsHSO4 and Rb3H(SeO4)2 have been widely studied because of their high proton conductivities and phase-transition behaviour. For fuel-cell applications they offer the advantages of anhydrous proton transport and high-temperature stability (up to 250 degrees C). Until now, however, solid acids have not been considered viable fuel-cell electrolyte alternatives owing to their solubility in water and extreme ductility at raised temperatures (above approximately 125 degrees C). Here we show that a cell made of a CsHSO4 electrolyte membrane (about 1.5 mm thick) operating at 150-160 degrees C in a H2/O2 configuration exhibits promising electrochemical performances: open circuit voltages of 1.11 V and current densities of 44 mA cm-2 at short circuit. Moreover, the solid-acid properties were not affected by exposure to humid atmospheres. Although these initial results show promise for applications, the use of solid acids in fuel cells will require the development of fabrication techniques to reduce electrolyte thickness, and an assessment of possible sulphur reduction following prolonged exposure to hydrogen.

  17. Acetylsalicylic acid induces programmed cell death in Arabidopsis cell cultures.

    PubMed

    García-Heredia, José M; Hervás, Manuel; De la Rosa, Miguel A; Navarro, José A

    2008-06-01

    Acetylsalicylic acid (ASA), a derivative from the plant hormone salicylic acid (SA), is a commonly used drug that has a dual role in animal organisms as an anti-inflammatory and anticancer agent. It acts as an inhibitor of cyclooxygenases (COXs), which catalyze prostaglandins production. It is known that ASA serves as an apoptotic agent on cancer cells through the inhibition of the COX-2 enzyme. Here, we provide evidences that ASA also behaves as an agent inducing programmed cell death (PCD) in cell cultures of the model plant Arabidopsis thaliana, in a similar way than the well-established PCD-inducing agent H(2)O(2), although the induction of PCD by ASA requires much lower inducer concentrations. Moreover, ASA is herein shown to be a more efficient PCD-inducing agent than salicylic acid. ASA treatment of Arabidopsis cells induces typical PCD-linked morphological and biochemical changes, namely cell shrinkage, nuclear DNA degradation, loss of mitochondrial membrane potential, cytochrome c release from mitochondria and induction of caspase-like activity. However, the ASA effect can be partially reverted by jasmonic acid. Taking together, these results reveal the existence of common features in ASA-induced animal apoptosis and plant PCD, and also suggest that there are similarities between the pathways of synthesis and function of prostanoid-like lipid mediators in animal and plant organisms.

  18. Stabilizing platinum in phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Remick, R. J.

    1981-01-01

    The cathode of the phosphoric acid fuel cell uses a high surface area platinum catalyst supported on a carbon substrate. During operation, the small platinum crystallites sinter, causing loss in cell performance. A support was developed that stabilizes platinum in the high surface area condition by retarding or preventing the sintering process. The approach is to form etch pits in the carbon by oxidizing the carbon in the presence of a metal oxide catalyst, remove the metal oxide by an acid wash, and then deposit platinum in these pits. Results confirm the formation of etch pits in each of the three supports chosen for investigation: Vulcan XC-72R, Vulcan XC-72 that was graphized at 2500 C, and Shawinigan Acetylene Black.

  19. World wide IFC phosphoric acid fuel cell implementation

    SciTech Connect

    King, J.M. Jr

    1996-04-01

    International Fuel Cells, a subsidary of United technologies Corporation, is engaged in research and development of all types of fuel cell technologies and currently manufactures alkaline fuel cell power plants for the U.S. manned space flight program and natural gas fueled stationary power plants using phosphoric acid fuel cells. This paper describes the phosphoric acid fuel cell power plants.

  20. Hsp70 protein positively regulates rabies virus infection.

    PubMed

    Lahaye, Xavier; Vidy, Aurore; Fouquet, Baptiste; Blondel, Danielle

    2012-05-01

    The Hsp70 chaperone plays a central role in multiple processes within cells, including protein translation, folding, intracellular trafficking, and degradation. This protein is implicated in the replication of numerous viruses. We have shown that rabies virus infection induced the cellular expression of Hsp70, which accumulated in Negri body-like structures, where viral transcription and replication take place. In addition, Hsp70 is present in both nucleocapsids purified from infected cells and in purified virions. Hsp70 has been shown to interact with the nucleoprotein N. The downregulation of Hsp70, using specific chaperone inhibitors, such as quercetin or RNA interference, resulted in a significant decrease of the amount of viral mRNAs, viral proteins, and virus particles. These results indicate that Hsp70 has a proviral function during rabies virus infection and suggest that Hsp70 is involved in at least one stage(s) of the viral life cycle, such as viral transcription, translation, and/or production. The mechanism by which Hsp70 controls viral infection will be discussed.

  1. Lactic acid bacterial cell factories for gamma-aminobutyric acid.

    PubMed

    Li, Haixing; Cao, Yusheng

    2010-11-01

    Gamma-aminobutyric acid is a non-protein amino acid that is widely present in organisms. Several important physiological functions of gamma-aminobutyric acid have been characterized, such as neurotransmission, induction of hypotension, diuretic effects, and tranquilizer effects. Many microorganisms can produce gamma-aminobutyric acid including bacteria, fungi and yeasts. Among them, gamma-aminobutyric acid-producing lactic acid bacteria have been a focus of research in recent years, because lactic acid bacteria possess special physiological activities and are generally regarded as safe. They have been extensively used in food industry. The production of lactic acid bacterial gamma-aminobutyric acid is safe and eco-friendly, and this provides the possibility of production of new naturally fermented health-oriented products enriched in gamma-aminobutyric acid. The gamma-aminobutyric acid-producing species of lactic acid bacteria and their isolation sources, the methods for screening of the strains and increasing their production, the enzymatic properties of glutamate decarboxylases and the relative fundamental research are reviewed in this article. And the potential applications of gamma-aminobutyric acid-producing lactic acid bacteria were also referred to.

  2. New applications for phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Stickles, R. P.; Breuer, C. T.

    1983-01-01

    New applications for phosphoric acid fuel cells were identified and evaluated. Candidates considered included all possibilities except grid connected electric utility applications, on site total energy systems, industrial cogeneration, opportunistic use of waste hydrogen, space and military applications, and applications smaller than 10 kW. Applications identified were screened, with the most promising subjected to technical and economic evaluation using a fuel cell and conventional power system data base developed in the study. The most promising applications appear to be the underground mine locomotive and the railroad locomotive. Also interesting are power for robotic submersibles and Arctic villages. The mine locomotive is particularly attractive since it is expected that the fuel cell could command a very high price and still be competitive with the conventionally used battery system. The railroad locomotive's attractiveness results from the (smaller) premium price which the fuel cell could command over the conventional diesel electric system based on its superior fuel efficiency, and on the large size of this market and the accompanying opportunities for manufacturing economy.

  3. New applications for phosphoric acid fuel cells

    SciTech Connect

    Stickles, R.P.; Breuer, C.T.

    1983-11-01

    New applications for phosphoric acid fuel cells were identified and evaluated. Candidates considered included all possibilities except grid connected electric utility applications, on-site total energy systems, industrial co-generation, opportunistic use of waste hydrogen, space and military applications, and applications smaller than 10 kW. Applications identified were screened, with the most promising subjected to technical and economic evaluation using a fuel cell and conventional power system data base developed in the study. The most promising applications appear to be the underground mine locomotive and the railroad locomotive. Also interesting is power for robotic submersibles and Arctic villages. The mine locomotive is particularly attractive since it is expected that the fuel cell could command a very high price and still be competitive with the conventionally used battery system. The railroad locomotive's attractiveness results from the (smaller) premium price which the fuel cell could command over the conventional diesel electric system based on its superior fuel efficiency, and on the large size of this market and the accompanying opportunities for manufacturing economy.

  4. Lactobionic and cellobionic acid production profiles of the resting cells of acetic acid bacteria.

    PubMed

    Kiryu, Takaaki; Kiso, Taro; Nakano, Hirofumi; Murakami, Hiromi

    2015-01-01

    Lactobionic acid was produced by acetic acid bacteria to oxidize lactose. Gluconobacter spp. and Gluconacetobacter spp. showed higher lactose-oxidizing activities than Acetobacter spp. Gluconobacter frateurii NBRC3285 produced the highest amount of lactobionic acid per cell, among the strains tested. This bacterium assimilated neither lactose nor lactobionic acid. At high lactose concentration (30%), resting cells of the bacterium showed sufficient oxidizing activity for efficient production of lactobionic acid. These properties may contribute to industrial production of lactobionic acid by the bacterium. The bacterium showed higher oxidizing activity on cellobiose than that on lactose and produced cellobionic acid. PMID:25965080

  5. Induced accumulation of oleanolic acid and ursolic acid in cell suspension cultures of Uncaria tomentosa.

    PubMed

    Feria-Romero, Iris; Lazo, Elizabeth; Ponce-Noyola, Teresa; Cerda-García-Rojas, Carlos M; Ramos-Valdivia, Ana C

    2005-06-01

    Increasing sucrose from 20 to 50 g l(-1) in Uncaria tomentosa cell suspension cultures enhanced ursolic acid and oleanolic acid production from 129 +/- 61 to 553 +/- 193 microg g(-1) cell dry wt. The maximal concentration of both triterpenes (1680 +/- 39 microg g(-1) cell dry wt) was 8 days after elicitation by jasmonic acid, while yeast extract or citrus pectin treatments produced 1189 +/- 20 or 1120 +/- 26 microg g(-1) cell dry wt, respectively. The ratio of ursolic acid:oleanolic acid was constant at 70:30.

  6. Lactobacillus casei combats acid stress by maintaining cell membrane functionality.

    PubMed

    Wu, Chongde; Zhang, Juan; Wang, Miao; Du, Guocheng; Chen, Jian

    2012-07-01

    Lactobacillus casei strains have traditionally been recognized as probiotics and frequently used as adjunct culture in fermented dairy products where lactic acid stress is a frequently encountered environmental condition. We have investigated the effect of lactic acid stress on the cell membrane of L. casei Zhang [wild type (WT)] and its acid-resistant mutant Lbz-2. Both strains were grown under glucose-limiting conditions in chemostats; following challenge by low pH, the cell membrane stress responses were investigated. In response to acid stress, cell membrane fluidity decreased and its fatty acid composition changed to reduce the damage caused by lactic acid. Compared with the WT, the acid-resistant mutant exhibited numerous survival advantages, such as higher membrane fluidity, higher proportions of unsaturated fatty acids, and higher mean chain length. In addition, cell integrity analysis showed that the mutant maintained a more intact cellular structure and lower membrane permeability after environmental acidification. These results indicate that alteration in membrane fluidity, fatty acid distribution, and cell integrity are common mechanisms utilized by L. casei to withstand severe acidification and to reduce the deleterious effect of lactic acid on the cell membrane. This detailed comparison of cell membrane responses between the WT and mutant add to our knowledge of the acid stress adaptation and thus enable new strategies to be developed aimed at improving the industrial performance of this species under acid stress. PMID:22366811

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

    PubMed

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

    2016-09-01

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

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

    PubMed Central

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

    2016-01-01

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

  9. Cell cycle nucleic acids, polypeptides and uses thereof

    DOEpatents

    Gordon-Kamm, William J.; Lowe, Keith S.; Larkins, Brian A.; Dilkes, Brian R.; Sun, Yuejin

    2007-08-14

    The invention provides isolated nucleic acids and their encoded proteins that are involved in cell cycle regulation. The invention further provides recombinant expression cassettes, host cells, transgenic plants, and antibody compositions. The present invention provides methods and compositions relating to altering cell cycle protein content, cell cycle progression, cell number and/or composition of plants.

  10. Electrochemical characteristics of acid electrolytes for fuel cells

    NASA Astrophysics Data System (ADS)

    Adzic, R.; Gervasio, D.; Kanamura, K.; Razaq, A.; Razaq, M.; Yeager, Ernest B.

    1990-01-01

    Five topics investigated by the Gas Research Institute (GRI) contractors at Case Western Reserve University (CWRU) during the past year included: (1) electrochemical evaluation of perfluorinated electrolyte, (2) the Nafion solid polymer electrolyte (SPE) fuel cell, (3) electrochemistry of single crystal Pt electrodes in acid solution, (4) catalytic effects of adatoms entrapped on electrode surfaces by bipolar or monopolar ion exchange membrane layers, (5) investigations of the Fleischmann-Pons phenomenon. The principal objective of the project is to evaluate new acid electrolytes. Electrochemical evaluation was made for two bisphosphonic acids as a replacement for phosphoric acid as a fuel cell electrolyte, and also a bis-sulfonyl carbon acid as an additive to concentrated phosphoric acid electrolyte for acid H2-O2 fuel cells. Electrochemical characteristics were found for these new perfluorinated acids.

  11. Growth modulating effects of chlorinated oleic acid in cell cultures.

    PubMed

    Høstmark, A T; Lystad, E; Jebens, E; Skramstad, J; Frøyen, P

    1998-07-01

    Chlorinated fatty acids represent a major fraction of extractable, organically bound chlorine in fish. After dietary intake such fatty acids may be transferred from the mother to the foetus through the placenta, and via breast milk to the child. In the present work we have studied the effect of chlorinated oleic acid on the growth of three widely differing types of cells in culture. Chlorinated oleic acid inhibited growth of Human Microvascular Endothelial Cells (HMVEC), Immortilized Human Kidney Epithelial (IHKE) cells, and human Hepatoma cells (HepG2). The order of potency was: HMVEC > IHKE > HepG2. Vitamin E counteracted the inhibitory effect of chlorinated oleic acid on HepG2 cells, but did not significantly affect the fatty acid effect on HMVEC or IHKE. Defatted serum albumin stimulated the growth of HMVEC and IHKE. With HMVEC there was no major interaction between the effect of albumin and chlorinated oleic acid on cell growth. In contrast, with IHKE albumin at low concentration abolished the growth inhibiting effect of chlorinated oleic acid and appreciably counteracted growth inhibition by the fatty acid of HepG2. We conclude that the growth modulation by chlorinated oleic acid and its interaction with vitamin E and albumin are cell specific.

  12. Amino acids in the cultivation of mammalian cells.

    PubMed

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

    2016-05-01

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

  13. Amino acids in the cultivation of mammalian cells.

    PubMed

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

    2016-05-01

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

  14. Transepithelial transport of ferulic acid by monocarboxylic acid transporter in Caco-2 cell monolayers.

    PubMed

    Konishi, Yutaka; Shimizu, Makoto

    2003-04-01

    Our previous study (Biosci. Biotechnol. Biochem., 66, 2449-2457 (2002)), suggested that ferulic acid was transported via a monocarboxylic acid transporter (MCT). Transepithelial transport of ferulic acid was examined in this study by directly measuring the rate of its transport across Caco-2 cell monolayers. Ferulic acid transport was dependent on pH, and in a vectorical way in the apical-basolateral direction. The permeation of ferulic acid was concentration-dependent and saturable; the Michaelis constant was 16.2 mM and the maximum velocity was 220.4 nmol min-1 (mg protein)-1. Various substrates for MCTs, such as benzoic acid and acetic acid, strongly inhibited the permeation of ferulic acid, demonstrating that ferulic acid is obviously transported by MCT. Antioxidative phenolic acid compounds from dietary sources like ferulic acid would be recognized and transported by MCT by intestinal absorption.

  15. Formic acid and acetic acid induce a programmed cell death in pathogenic Candida species.

    PubMed

    Lastauskienė, Eglė; Zinkevičienė, Auksė; Girkontaitė, Irutė; Kaunietis, Arnoldas; Kvedarienė, Violeta

    2014-09-01

    Cutaneous fungal infections are common and widespread. Antifungal agents used for the treatment of these infections often have undesirable side effects. Furthermore, increased resistance of the microorganisms to the antifungal drugs becomes the growing problem. Accordingly, the search for natural antifungal compounds continues to receive attention. Apoptosis is highly regulated programmed cell death. During yeast cell apoptosis, amino acids and peptides are released and can stimulate regeneration of human epithelium cells. Thus, detection of chemical compounds inducing apoptosis in yeast and nontoxic for humans is of great medical relevance. The aim of this study was to detect chemical compound inducing apoptosis in pathogenic Candida species with the lowest toxicity to the mammalian cells. Five chemical compounds--acetic acid, sodium bicarbonate, potassium carbonate, lithium acetate, and formic acid--were tested for evaluation of antifungal activity on C. albicans, C. guilliermondii, and C. lusitaniae. The results showed that acetic acid and formic acid at the lowest concentrations induced yeast cells death. Apoptosis analysis revealed that cells death was accompanied by activation of caspase. Minimal inhibitory concentrations of potassium carbonate and sodium bicarbonate induced Candida cells necrosis. Toxicity test with mammalian cell cultures showed that formic acid has the lowest effect on the growth of Jurkat and NIH 3T3 cells. In conclusion, our results show that a low concentration of formic acid induces apoptosis-like programmed cell death in the Candida yeast and has a minimal effect on the survivability of mammalian cells, suggesting potential applications in the treatment of these infections. PMID:24752490

  16. Targeting cancer cells with folic acid-iminoboronate fluorescent conjugates.

    PubMed

    Cal, Pedro M S D; Frade, Raquel F M; Chudasama, Vijay; Cordeiro, Carlos; Caddick, Stephen; Gois, Pedro M P

    2014-05-25

    Herein we present the synthesis of fluorescent 2-acetylbenzeneboronic acids that undergo B-N promoted conjugation with lysozyme and N-(2-aminoethyl) folic acid (EDA-FA), generating conjugates that are selectively recognized and internalized by cancer cells that over-express folic acid receptors.

  17. Retinol oxidation to retinoic acid in human thyroid glandular cells.

    PubMed

    Taibi, Gennaro; Gueli, Maria Concetta; Nicotra, Concetta M A; Cocciadiferro, Letizia; Carruba, Giuseppe

    2014-12-01

    Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its ability to oxidize xanthine to uric acid and its sensitivity to the inhibitory effect of oxypurinol. The evidence of XDH-driven formation of retinoic acid in HTGC cultures further corroborates the potential role of XDH in retinoic acid biosynthesis in the epithelia. PMID:24506204

  18. Chrysophanic Acid Induces Necrosis but not Necroptosis in Human Renal Cell Carcinoma Caki-2 Cells

    PubMed Central

    Choi, Joon-Seok

    2016-01-01

    Background: Chrysophanic acid, also known as chrysophanol, has a number of biological activities. It enhances memory and learning abilities, raises superoxide dismutase activity, and has anti-cancer effects in several model systems. According to previous reports, chrysophanic acid-induced cell death shares features of necrotic cell death. However, the molecular and cellular processes underlying chrysophanic acid-induced cell death remain poorly understood. Methods: Chrysophanic acid-induced cell death was monitored by cell viability assay and Annexin V-propidium iodide (PI) staining of renal cell carcinoma Caki-2 cells. The induction of intracellular reactive oxygen species (ROS) by chrysophanic acid and the suppression of ROS by anti-oxidants were evaluated by 2′,7′-dichlorofluorescin diacetate staining. The expression and phosphorylation of proteins that are involved in apoptosis and necroptosis were detected by immunoblotting. Results: The extent of chrysophanic acid-induced cell death was concentration and time dependent, and dead cells mainly appeared in the PI-positive population, which is a major feature of necrosis, upon fluorescence-activated cell sorting analysis. Chrysophanic acid-induced cell death was associated with the generation of intracellular ROS, and this effect was reversed by pretreatment with N-acetyl cysteine. Chrysophanic acid-induced cell death was not associated with changes in apoptotic or necroptotic marker proteins. Conclusions: The cell death induced by chrysophanic acid resembled neither apoptotic nor necroptotic cell death in human renal cell carcinoma Caki-2 cells. PMID:27390736

  19. Colorimetric determination of phosphoric acid leakage for phosphoric acid-doped polybenzimidazole membrane fuel cell applications

    NASA Astrophysics Data System (ADS)

    Jeong, Yeon Hun; Jung, Ju Hae; Choi, Euiji; Han, Seungyoon; Begley, Alina Irene; Yoo, Sung Jong; Jang, Jong Hyun; Kim, Hyoung-Juhn; Nam, Suk Woo; Lee, Kwan-Young; Kim, Jin Young

    2015-12-01

    A simple and precise colorimetric method for analyzing phosphoric acid leakage in phosphoric acid-doped polybenzimidazole membrane fuel cells is described. The developed method is based on the colorimetric determination from a rapid formation of molybdenum blue color by the reduction reaction of molybdate ions in the presence of phosphoric acid in the acidic medium. The color is stable up to a few months and can be used for the sensitive and accurate detection of phosphoric acid electrolyte which is discharged from the fuel cell during operation. Tests with a wide concentration range of phosphate compounds showed that it permits determination of phosphoric acid up to nanogram quantities. The developed detection method assists monitoring the phosphoric acid contents and developing stable operation strategies of fuel cells.

  20. Phosphoric acid fuel cell platinum use study

    NASA Technical Reports Server (NTRS)

    Lundblad, H. L.

    1983-01-01

    The U.S. Department of Energy is promoting the private development of phosphoric acid fuel cell (PAFC) power plants for terrestrial applications. Current PAFC technology utilizes platinum as catalysts in the power electrodes. The possible repercussions that the platinum demand of PAFC power plant commercialization will have on the worldwide supply and price of platinum from the outset of commercialization to the year 2000 are investigated. The platinum demand of PAFC commercialization is estimated by developing forecasts of platinum use per unit of generating capacity and penetration of PAFC power plants into the electric generation market. The ability of the platinum supply market to meet future demands is gauged by assessing the size of platinum reserves and the capability of platinum producers to extract, refine and market sufficient quantities of these reserves. The size and timing of platinum price shifts induced by the added demand of PAFC commercialization are investigated by several analytical methods. Estimates of these price shifts are then used to calculate the subsequent effects on PAFC power plant capital costs.

  1. Phosphoric acid fuel cell platinum use study

    NASA Astrophysics Data System (ADS)

    Lundblad, H. L.

    1983-05-01

    The U.S. Department of Energy is promoting the private development of phosphoric acid fuel cell (PAFC) power plants for terrestrial applications. Current PAFC technology utilizes platinum as catalysts in the power electrodes. The possible repercussions that the platinum demand of PAFC power plant commercialization will have on the worldwide supply and price of platinum from the outset of commercialization to the year 2000 are investigated. The platinum demand of PAFC commercialization is estimated by developing forecasts of platinum use per unit of generating capacity and penetration of PAFC power plants into the electric generation market. The ability of the platinum supply market to meet future demands is gauged by assessing the size of platinum reserves and the capability of platinum producers to extract, refine and market sufficient quantities of these reserves. The size and timing of platinum price shifts induced by the added demand of PAFC commercialization are investigated by several analytical methods. Estimates of these price shifts are then used to calculate the subsequent effects on PAFC power plant capital costs.

  2. Designer nucleic acids to probe and program the cell.

    PubMed

    Krishnan, Yamuna; Bathe, Mark

    2012-12-01

    Recent advances in nucleic acid sequencing, structural, and computational technologies have resulted in dramatic progress in our understanding of nucleic acid structure and function in the cell. This knowledge, together with the predictable base-pairing of nucleic acids and powerful synthesis and expression capabilities now offers the unique ability to program nucleic acids to form precise 3D architectures with diverse applications in synthetic and cell biology. The unique modularity of structural motifs that include aptamers, DNAzymes, and ribozymes, together with their well-defined construction rules, enables the synthesis of functional higher-order nucleic acid complexes from these subcomponents. As we illustrate here, these highly programmable, smart complexes are increasingly enabling researchers to probe and program the cell in a sophisticated manner that moves well beyond the use of nucleic acids for conventional genetic manipulation alone.

  3. Intercellular communications within the rat anterior pituitary. XVI: postnatal changes of distribution of S-100 protein positive cells, connexin 43 and LH-RH positive sites in the pars tuberalis of the rat pituitary gland. An immunohistochemical and electron microscopic study.

    PubMed

    Wada, Ikuo; Sakuma, Eisuke; Shirasawa, Nobuyuki; Wakabayashi, Kenjiro; Otsuka, Takanobu; Hattori, Kazuki; Yashiro, Takashi; Herbert, Damon C; Soji, Tsuyoshi

    2014-02-01

    The architecture of luteinizing hormone-releasing hormone (LH-RH) nerve ends and the S-100 protein containing folliculo-stellate cells forming gap junctions in the pars tuberalis is basically important in understanding the regulation of the hormone producing mechanism of anterior pituitary glands. In this study, intact male rats 5-60 days old were prepared for immunohistochemistry and electron microscopy. From immunostained sections, the S-100 containing cells in pars tuberalis were first detected on day 30 and increased in number to day 60; this was parallel to the immunohistochemical staining of gap junction protein, connexin 43. LH-RH positive sites were clearly observed on just behind the optic chiasm and on the root of pituitary stalk on day 30. On day 60, the width of layer increased, while follicles and gap junctions were frequently observed between agranular cells in 10 or more layers of pars tuberalis. In the present study, we investigated the sexual maturation of the anterior pituitary glands through the postnatal development of S-100 positive cells, connexin 43 and LH-RH nerves. It is suggested that the folliculo-stellate cell system including the LH-RH neurons in the pars tuberalis participates in the control of LH secretion along with the portal vein system. PMID:24216131

  4. Gallic acid reduces cell viability, proliferation, invasion and angiogenesis in human cervical cancer cells

    PubMed Central

    ZHAO, BING; HU, MENGCAI

    2013-01-01

    Gallic acid is a trihydroxybenzoic acid, also known as 3,4,5-trihydroxybenzoic acid, which is present in plants worldwide, including Chinese medicinal herbs. Gallic acid has been shown to have cytotoxic effects in certain cancer cells, without damaging normal cells. The objective of the present study was to determine whether gallic acid is able to inhibit human cervical cancer cell viability, proliferation and invasion and suppress cervical cancer cell-mediated angiogenesis. Treatment of HeLa and HTB-35 human cancer cells with gallic acid decreased cell viability in a dose-dependent manner. BrdU proliferation and tube formation assays indicated that gallic acid significantly decreased human cervical cancer cell proliferation and tube formation in human umbilical vein endothelial cells, respectively. Additionally, gallic acid decreased HeLa and HTB-35 cell invasion in vitro. Western blot analysis demonstrated that the expression of ADAM17, EGFR, p-Akt and p-Erk was suppressed by gallic acid in the HeLa and HTB-35 cell lines. These data indicate that the suppression of ADAM17 and the downregulation of the EGFR, Akt/p-Akt and Erk/p-Erk signaling pathways may contribute to the suppression of cancer progression by Gallic acid. Gallic acid may be a valuable candidate for the treatment of cervical cancer. PMID:24843386

  5. Lactic acid fermentation in cell-recycle membrane bioreactor.

    PubMed

    Choudhury, B; Swaminathan, T

    2006-02-01

    Traditional lactic acid fermentation suffers from low productivity and low product purity. Cell-recycle fermentation has become one of the methods to obtain high cell density, which results in higher productivity. Lactic acid fermentation was investigated in a cell-recycle membrane bioreactor at higher substrate concentrations of 100 and 120 g/dm3. A maximum cell density of 145 g/dm3 and a maximum productivity of 34 g/(dm3.h) were achieved in cell-recycle fermentation. In spite of complete consumption of substrate, there was a continuous increase in cell density in cell-recycle fermentation. Control of cell density in cell-recycle fermentation was attempted by cell bleeding and reduction in yeast extract concentration.

  6. Chlorogenic Acids Biosynthesis in Centella asiatica Cells Is not Stimulated by Salicylic Acid Manipulation.

    PubMed

    Ncube, E N; Steenkamp, P A; Madala, N E; Dubery, I A

    2016-07-01

    Exogenous application of synthetic and natural elicitors of plant defence has been shown to result in mass production of secondary metabolites with nutraceuticals properties in cultured cells. In particular, salicylic acid (SA) treatment has been reported to induce the production of phenylpropanoids, including cinnamic acid derivatives bound to quinic acid (chlorogenic acids). Centella asiatica is an important medicinal plant with several therapeutic properties owing to its wide spectrum of secondary metabolites. We investigated the effect of SA on C. asiatica cells by monitoring perturbation of chlorogenic acids in particular. Different concentrations of SA were used to treat C. asiatica cells, and extracts from both treated and untreated cells were analysed using an optimised UHPLC-QTOF-MS/MS method. Semi-targeted multivariate data analyses with the aid of principal component analysis (PCA) and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) revealed a concentration-dependent metabolic response. Surprisingly, a range of chlorogenic acid derivatives were found to be downregulated as a consequence of SA treatment. Moreover, irbic acid (3,5-O-dicaffeoyl-4-O-malonilquinic acid) was found to be a dominant CGA in C. asiatica cells, although the SA treatment also had a negative effect on its concentration. Overall SA treatment was found to be an ineffective elicitor of CGA production in cultured C. asiatica cells.

  7. Synthesis of novel acid electrolytes for phosphoric acid fuel cells

    NASA Astrophysics Data System (ADS)

    Adcock, James L.

    1988-11-01

    A 40 millimole per hour scale aerosol direct fluorination reactor was constructed. F-Methyl F-4-methoxybutanoate and F-4-methoxybutanoyl fluoride were synthesized by aerosol direct fluorination of methyl 4-methoxybutanoate. Basic hydrolysis of the perfluorinated derivatives produce sodium F-4 methoxybutanoate which was pyrolyzed to F-3-methoxy-1-propene. Purification and shipment of 33 grams of F-3-methoxy-1-propene followed. Syntheses by analogous methods allowed production and shipment of 5 grams of F-3-ethoxy 1-propene, 18 grams of F-3-(2-methoxy.ethoxy) 1-propene, and 37 grams of F-3,3-dimethyl 1-butene. Eighteen grams of F-2,2-dimethyl 1-chloropropane was produced directly and shipped. As suggested by other contractors, 5 grams of F-3-methoxy 1-iodopropane, and 5 grams of F-3-(2-methoxy.ethoxy) 1-iodopropane were produced by converting the respective precursor acid sodium salts produced for olefin synthesis to the silver salts and pyrolyzing them with iodine. Each of these compounds was prepared for the first time by the aerosol fluorination process during the course of the contract. These samples were provided to other Gas Research Institute (GRI) contractors for synthesis of perfluorinated sulfur (VI) and phosphorous (V) acids.

  8. Influence of decenylsuccinic Acid on water permeability of plant cells.

    PubMed

    Lee, O Y; Stadelmann, E J; Weiser, C J

    1972-11-01

    Decenylsuccinic acid altered permeability to water of epidermal cells of bulb scales of Allium cepa and of the leaf midrib of Rhoeo discolor. Water permeability, as determined by deplasmolysis time measurements, was related to the dose of undissociated decenylsuccinic acid (mm undissociated decenylsuccinic acid x minute). No relationship was found between permeability and total dose of decenylsuccinic acid, or dose of dissociated decenylsuccinic acid, suggesting that the undissociated molecule was the active factor in permeability changes and injury.At doses which did not damage cells (0.0008 to 0.6 [mm of the undissociated molecule x minute]) decenylsuccinic acid decreased water permeability. At higher doses (e.g., 4 to 8 [mm x minute]) injury to cells was common and decenylsuccinic acid increased permeability. Doses above the 10 to 20 (mm x minute) range were generally lethal. The plasmolysis form of uninjured cells was altered and protoplasmic swelling occasionally was observed. The dose-dependent reversal of water permeability changes (decreased to increased permeability) may reflect decenylsuccinic acid-induced changes in membrane structure. Reported effects of decenylsuccinic acid on temperature dependence of permeability and frost resistance were not verified. PMID:16658227

  9. The Polyunsaturated Fatty Acids Arachidonic Acid and Docosahexaenoic Acid Induce Mouse Dendritic Cells Maturation but Reduce T-Cell Responses In Vitro

    PubMed Central

    Carlsson, Johan A.; Wold, Agnes E.; Sandberg, Ann-Sofie; Östman, Sofia M.

    2015-01-01

    Long-chain polyunsaturated fatty acids (PUFAs) might regulate T-cell activation and lineage commitment. Here, we measured the effects of omega-3 (n-3), n-6 and n-9 fatty acids on the interaction between dendritic cells (DCs) and naïve T cells. Spleen DCs from BALB/c mice were cultured in vitro with ovalbumin (OVA) with 50 μM fatty acids; α-linolenic acid, arachidonic acid (AA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid or oleic acid and thereafter OVA-specific DO11.10 T cells were added to the cultures. Fatty acids were taken up by the DCs, as shown by gas chromatography analysis. After culture with arachidonic acid or DHA CD11c+ CD11b+ and CD11c+ CD11bneg DCs expressed more CD40, CD80, CD83, CD86 and PDL-1, while IAd remained unchanged. However, fewer T cells co-cultured with these DCs proliferated (CellTrace Violetlow) and expressed CD69 or CD25, while more were necrotic (7AAD+). We noted an increased proportion of T cells with a regulatory T cell (Treg) phenotype, i.e., when gating on CD4+ FoxP3+ CTLA-4+, CD4+ FoxP3+ Helios+ or CD4+ FoxP3+ PD-1+, in co-cultures with arachidonic acid- or DHA-primed DCs relative to control cultures. The proportion of putative Tregs was inversely correlated to T-cell proliferation, indicating a suppressive function of these cells. With arachidonic acid DCs produced higher levels of prostaglandin E2 while T cells produced lower amounts of IL-10 and IFNγ. In conclusion arachidonic acid and DHA induced up-regulation of activation markers on DCs. However arachidonic acid- and DHA-primed DCs reduced T-cell proliferation and increased the proportion of T cells expressing FoxP3, indicating that these fatty acids can promote induction of regulatory T cells. PMID:26619195

  10. Retinoic acid stimulate differentiation of hippocampal stem cells into opsin expressing cells in vitro.

    PubMed

    Safari, M; Nobakht, M; Roshandel, N Rahbar; Ghazi, F; Joghataee, M T

    2009-09-01

    The results of several studies have demonstrated that cell differentiation influenced by derivatives of retinoic acid. To determine whether retinoic acid mediate the differentiation of neural stem cells we treated dissociated hippocampal stem cells with different concentrations of all trans or 9-cis retinoic acid and analyzed the effects on cell fate by specific monoclonal antibody for photoreceptors. Addition of exogenous retinoic acid caused a dose dependent specific in the elevation of the cell number that developed as photoreceptors in culture. Also results ofimmunohistochemical studies using monoclonal antibody demonstrated that the primary effect ofretinoic acid was to influence progenitor cells the developed as mature and immature photoreceptors. These results suggest that retinoic acid may play an important effect in the normal development of photoreceptor cells in vitro.

  11. Gallic acid suppresses cell viability, proliferation, invasion and angiogenesis in human glioma cells

    PubMed Central

    Lu, Yong; Jiang, Feng; Jiang, Hao; Wu, Kalina; Zheng, Xuguang; Cai, Yizhong; Katakowski, Mark; Chopp, Michael; To, Shing-Shun Tony

    2010-01-01

    Gallic acid, an organic acid, also known as 3,4,5-trihydroxybenzoic acid, is cytotoxic against certain cancer cells, without harming normal cells. The objective of this study is to evaluate whether gallic acid can inhibit glioma cell viability, proliferation, invasion and reduce glioma cell mediated angiogenesis. Treatment of U87 and U251n glioma cells with gallic acid inhibited cell viability in a dose- and time-dependent manner. BrdU and tube formation assays indicated that gallic acid significantly decreased glioma cell proliferation and tube formation in mouse brain endothelial cells, respectively. In addition, gallic acid decreased U87 cell invasion in vitro. Western blot analysis showed that expression of ADAM17, p-Akt and p-Erk was suppressed by gallic acid in both U87 and U251n cell lines. These data suggest that suppression of ADAM17 and downregulation of PI3K/Akt and Ras/MAPK signaling pathways may contribute to gallic acid-induced decrease of invasiveness. Gallic acid may be a valuable candidate for treatment of brain tumor. PMID:20553913

  12. Retinoic Acid Stimulates Regeneration of Mammalian Auditory Hair Cells

    NASA Astrophysics Data System (ADS)

    Lefebvre, Philippe P.; Malgrange, Brigitte; Staecker, Hinrich; Moonen, Gustave; van de Water, Thomas R.

    1993-04-01

    Sensorineural hearing loss resulting from the loss of auditory hair cells is thought to be irreversible in mammals. This study provides evidence that retinoic acid can stimulate the regeneration in vitro of mammalian auditory hair cells in ototoxic-poisoned organ of Corti explants in the rat. In contrast, treatment with retinoic acid does not stimulate the formation of extra hair cells in control cultures of Corti's organ. Retinoic acid-stimulated hair cell regeneration can be blocked by cytosine arabinoside, which suggests that a period of mitosis is required for the regeneration of auditory hair cells in this system. These results provide hope for a recovery of hearing function in mammals after auditory hair cell damage.

  13. Direct acid methylation for extraction of fatty acid content from microalgae cells.

    PubMed

    Frigo-Vaz, Benjamin D; Wang, Ping

    2014-08-01

    Direct acid methylation was examined as a means for both analysis of fatty acid content in microalgal cells and biodiesel production without pretreatment. Microalgal cells of Chlamydomonas reinhardtii and Dunaliella tertiolecta were prepared and examined. It appeared that direct acid methylation extracted higher fatty acid content than the solvent-based Soxhlet extraction process. It also revealed that the latter was prone to extract a significant amount of nonlipid hydrophobic impurities, including hydrophobic proteins and phytol-type compounds, while direct methylation produces essentially pure ester product. This work demonstrates that direct acid methylation provides superior fatty acid extraction, promising an efficient process for either quantification of lipid content or production of biodiesel. PMID:24838798

  14. Full scale phosphoric acid fuel cell stack technology development

    NASA Technical Reports Server (NTRS)

    Christner, L.; Faroque, M.

    1984-01-01

    The technology development for phosphoric acid fuel cells is summarized. The preparation, heat treatment, and characterization of carbon composites used as bipolar separator plates are described. Characterization included resistivity, porosity, and electrochemical corrosion. High density glassy carbon/graphite composites performed well in long-term fuel cell endurance tests. Platinum alloy cathode catalysts and low-loaded platinum electrodes were evaluated in 25 sq cm cells. Although the alloys displayed an initial improvement, some of this improvement diminished after a few thousand hours of testing. Low platinum loading (0.12 mg/sq cm anodes and 0.3 mg/sq cm cathodes) performed nearly as well as twice this loading. A selectively wetproofed anode backing paper was tested in a 5 by 15 inch three-cell stack. This material may provide for acid volume expansion, acid storage, and acid lateral distribution.

  15. Technology development for phosphoric acid fuel cell powerplant (phase 2)

    NASA Technical Reports Server (NTRS)

    Christner, L.

    1979-01-01

    The status of technology for the manufacturing and testing of 1200 sq. cm cell materials, components, and stacks for on-site integrated energy systems is assessed. Topics covered include: (1) preparation of thin layers of silicon carbide; (2) definition and control schemes for volume changes in phosphoric acid fuel cells; (3) preparation of low resin content graphite phenolic resin composites; (4) chemical corrosion of graphite-phenolic resin composites in hot phosphoric acid; (5) analysis of electrical resistance of composite materials for fuel cells; and (6) fuel cell performance and testing.

  16. Effects of oral eicosapentaenoic acid versus docosahexaenoic acid on human peripheral blood mononuclear cell gene expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have beneficial effects on inflammation and cardiovascular disease (CVD). Our aim was to assess the effect of a six-week supplementation with either olive oil, EPA, or DHA on gene expression in peripheral blood mononuclear cells (...

  17. The effect of propionic acid and valeric acid on the cell cycle in root meristems of Pisum sativum

    SciTech Connect

    Tramontano, W.A.; Yang, Shauyu; Delillo, A.R. )

    1990-01-01

    Propionic acid and valeric acid at 1mM reduced the mitotic index of root meristem cells of Pisum sativum to < 1% after 12 hr in aerated White's medium. This effect varied with different acid concentrations. After a 12 hr exposure to either acid, seedlings transferred to fresh medium without either acid, resumed their normal mitotic index after 12 hr, with a burst of mitosis 8 hr post-transfer. Exposure of root meristem cells to either acid also inhibited ({sup 3}H)-TdR incorporation. Neither acid significantly altered the distribution of meristematic cells in G1 and G2 after 12 hr. The incorporation of ({sup 3}H) - uridine was also unaltered by the addition of either acid. This information suggests that propionic acid and valeric acid, limit progression through the cell cycle by inhibiting DNA synthesis and arresting cells in G1 and G2. These results were consistent with previous data which utilized butyric acid.

  18. Expanding the diversity of unnatural cell surface sialic acids

    SciTech Connect

    Luchansky, Sarah J.; Goon, Scarlett; Bertozzi, Carolyn R.

    2003-10-30

    Novel chemical reactivity can be introduced onto cell surfaces through metabolic oligosaccharide engineering. This technique exploits the substrate promiscuity of cellular biosynthetic enzymes to deliver unnatural monosaccharides bearing bioorthogonal functional groups into cellular glycans. For example, derivatives of N-acetylmannosamine (ManNAc) are converted by the cellular biosynthetic machinery into the corresponding sialic acids and subsequently delivered to the cell surface in the form of sialoglycoconjugates. Analogs of N-acetylglucosamine (GlcNAc) and N-acetylgalactosamine (GalNAc) are also metabolized and incorporated into cell surface glycans, likely through the sialic acid and GalNAc salvage pathways, respectively. Furthermore, GlcNAc analogs can be incorporated into nucleocytoplasmic proteins in place of {beta}-O-GlcNAc residues. These pathways have been exploited to integrate unique electrophiles such as ketones and azides into the target glycoconjugate class. These functional groups can be further elaborated in a chemoselective fashion by condensation with hydrazides and by Staudinger ligation, respectively, thereby introducing detectable probes onto the cell. In conclusion, sialic acid derivatives are efficient vehicles for delivery of bulky functional groups to cell surfaces and masking of their hydroxyl groups improves their cellular uptake and utilization. Furthermore, the successful introduction of photoactivatable aryl azides into cell surface glycans opens up new avenues for studying sialic acid-binding proteins and elucidating the role of sialic acid in essential processes such as signaling and cell adhesion.

  19. Technology Development for Phosphoric Acid Fuel Cell Powerplant, Phase 2

    NASA Technical Reports Server (NTRS)

    Christner, L.

    1980-01-01

    The technology development for materials, cells, and reformers for on site integrated energy systems is described. The carbonization of 25 cu cm, 350 cu cm, and 1200 cu cm cell test hardware was accomplished and the performance of 25 cu cm fuel cells was improved. Electrochemical corrosion rates of graphite/phenolic resin composites in phosphoric acid were determined. Three cells (5 in by 15 in stacks) were operated for longer than 7000 hours. Specified endurance stacks completed a total of 4000 hours. An electrically heated reformer was tested and is to provide hydrogen for 23 cell fuel cell stack.

  20. Bile acids induce hepatic differentiation of mesenchymal stem cells

    PubMed Central

    Sawitza, Iris; Kordes, Claus; Götze, Silke; Herebian, Diran; Häussinger, Dieter

    2015-01-01

    Mesenchymal stem cells (MSC) have the potential to differentiate into multiple cell lineages and their therapeutic potential has become obvious. In the liver, MSC are represented by stellate cells which have the potential to differentiate into hepatocytes after stimulation with growth factors. Since bile acids can promote liver regeneration, their influence on liver-resident and bone marrow-derived MSC was investigated. Physiological concentrations of bile acids such as tauroursodeoxycholic acid were able to initiate hepatic differentiation of MSC via the farnesoid X receptor and transmembrane G-protein-coupled bile acid receptor 5 as investigated with knockout mice. Notch, hedgehog, transforming growth factor-β/bone morphogenic protein family and non-canonical Wnt signalling were also essential for bile acid-mediated differentiation, whereas β-catenin-dependent Wnt signalling was able to attenuate this process. Our findings reveal bile acid-mediated signalling as an alternative way to induce hepatic differentiaion of stem cells and highlight bile acids as important signalling molecules during liver regeneration. PMID:26304833

  1. Low contaminant formic acid fuel for direct liquid fuel cell

    DOEpatents

    Masel, Richard I.; Zhu, Yimin; Kahn, Zakia; Man, Malcolm

    2009-11-17

    A low contaminant formic acid fuel is especially suited toward use in a direct organic liquid fuel cell. A fuel of the invention provides high power output that is maintained for a substantial time and the fuel is substantially non-flammable. Specific contaminants and contaminant levels have been identified as being deleterious to the performance of a formic acid fuel in a fuel cell, and embodiments of the invention provide low contaminant fuels that have improved performance compared to known commercial bulk grade and commercial purified grade formic acid fuels. Preferred embodiment fuels (and fuel cells containing such fuels) including low levels of a combination of key contaminants, including acetic acid, methyl formate, and methanol.

  2. Corrosion of graphite composites in phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Christner, L. G.; Dhar, H. P.; Farooque, M.; Kush, A. K.

    1986-01-01

    Polymers, polymer-graphite composites and different carbon materials are being considered for many of the fuel cell stack components. Exposure to concentrated phosphoric acid in the fuel cell environment and to high anodic potential results in corrosion. Relative corrosion rates of these materials, failure modes, plausible mechanisms of corrosion and methods for improvement of these materials are investigated.

  3. Amino acid transporters: roles in amino acid sensing and signalling in animal cells.

    PubMed Central

    Hyde, Russell; Taylor, Peter M; Hundal, Harinder S

    2003-01-01

    Amino acid availability regulates cellular physiology by modulating gene expression and signal transduction pathways. However, although the signalling intermediates between nutrient availability and altered gene expression have become increasingly well documented, how eukaryotic cells sense the presence of either a nutritionally rich or deprived medium is still uncertain. From recent studies it appears that the intracellular amino acid pool size is particularly important in regulating translational effectors, thus, regulated transport of amino acids across the plasma membrane represents a means by which the cellular response to amino acids could be controlled. Furthermore, evidence from studies with transportable amino acid analogues has demonstrated that flux through amino acid transporters may act as an initiator of nutritional signalling. This evidence, coupled with the substrate selectivity and sensitivity to nutrient availability classically associated with amino acid transporters, plus the recent discovery of transporter-associated signalling proteins, demonstrates a potential role for nutrient transporters as initiators of cellular nutrient signalling. Here, we review the evidence supporting the idea that distinct amino acid "receptors" function to detect and transmit certain nutrient stimuli in higher eukaryotes. In particular, we focus on the role that amino acid transporters may play in the sensing of amino acid levels, both directly as initiators of nutrient signalling and indirectly as regulators of external amino acid access to intracellular receptor/signalling mechanisms. PMID:12879880

  4. Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats.

    PubMed Central

    Zhou, A; Nielsen, J H; Farver, O; Thorn, N A

    1991-01-01

    Several amidated biologically active peptides such as pancreastatin, thyrotropin-releasing hormone, pancreatic polypeptide and amylin are produced in endocrine pancreatic tissue which contains the enzyme necessary for their final processing, i.e. peptidylglycine alpha-amidating mono-oxygenase (EC 1.14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which involves a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on concentration. Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. The uptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules contained a fairly low concentration of iron but a high concentration of copper. Images Fig. 6. PMID:2012602

  5. Plasma and red blood cell fatty acids in peroxisomal disorders.

    PubMed

    Moser, A B; Jones, D S; Raymond, G V; Moser, H W

    1999-02-01

    The demonstration of abnormal levels of fatty acids or plasmalogens in plasma or red blood cells is key to the diagnosis of peroxisomal disorders. We report the levels of 62 fatty acids and plasmalogens in patients with X-linked adrenoleukodystrophy (X-ALD), Zellweger syndrome (ZS), neonatal adrenoleukodystrophy (NALD), and infantile Refsum disease (IRD), both at baseline and after dietary interventions. "Lorenzo's Oil" therapy in X-ALD normalizes the levels of saturated very long chain fatty acids in plasma, but leads to reduced levels of omega 6 and other omega 3 fatty acids, and requires monitoring and appropriate dietary supplements. Patients with ZS, NALD and IRD have reduced levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) which can be normalized by the oral administration of microencapsulated DHA and AA.

  6. Solid Acid Fuel Cell Stack for APU Applications

    SciTech Connect

    Duong, Hau H.

    2011-04-15

    Solid acid fuel cell technology affords the opportunity to operate at the 200-300 degree centigrade regime that would allow for more fuel flexibility, compared to polymer electrode membrane fuel cell, while avoiding the relatively more expensive and complex system components required by solid oxide fuel cell. This project addresses many factors such as MEA size scalability, fuel robustness, stability, etc., that are essential for successful commercialization of the technology.

  7. Silicon dioxide thin film mediated single cell nucleic acid isolation.

    PubMed

    Bogdanov, Evgeny; Dominova, Irina; Shusharina, Natalia; Botman, Stepan; Kasymov, Vitaliy; Patrushev, Maksim

    2013-01-01

    A limited amount of DNA extracted from single cells, and the development of single cell diagnostics make it necessary to create a new highly effective method for the single cells nucleic acids isolation. In this paper, we propose the DNA isolation method from biomaterials with limited DNA quantity in sample, and from samples with degradable DNA based on the use of solid-phase adsorbent silicon dioxide nanofilm deposited on the inner surface of PCR tube.

  8. Silicon Dioxide Thin Film Mediated Single Cell Nucleic Acid Isolation

    PubMed Central

    Bogdanov, Evgeny; Dominova, Irina; Shusharina, Natalia; Botman, Stepan; Kasymov, Vitaliy; Patrushev, Maksim

    2013-01-01

    A limited amount of DNA extracted from single cells, and the development of single cell diagnostics make it necessary to create a new highly effective method for the single cells nucleic acids isolation. In this paper, we propose the DNA isolation method from biomaterials with limited DNA quantity in sample, and from samples with degradable DNA based on the use of solid-phase adsorbent silicon dioxide nanofilm deposited on the inner surface of PCR tube. PMID:23874571

  9. Characterization of ascorbic acid uptake by isolated rat kidney cells

    SciTech Connect

    Bowers-Komro, D.M.; McCormick, D.B. )

    1991-01-01

    Isolated kidney cells accumulated L(1-14C)ascorbic acid in a time-dependent manner and reached a steady state after 15 min at 37 degrees C. Initial velocity for uptake was over 300 pmol/mg protein per min when cells were separated from the bathing solution using a density gradient established during centrifugation. The uptake process was saturable with an apparent concentration at half maximal uptake of 36 mumols/L. Ascorbate uptake was reduced by metabolic inhibitors and was temperature dependent. Although ascorbic acid is an acid anion at pH 7.4, uptake did not appear to be inhibited by other acid anions such as p-aminohippurate and probenecid; however, involvement of the ion gradient established by Na+, H(+)-adenosine triphosphatase could not be confirmed. Replacing the sodium ion with other monovalent ions reduced the accumulation of ascorbate significantly. Isoascorbic and dehydroascorbic acids inhibited ascorbate uptake (34 and 13 mmol/L, respectively), whereas high concentrations of glucose showed some stimulation. These findings indicated that ascorbic acid is reabsorbed by the kidney in a sodium-dependent active transport process that is not common to other acid anions and has some specificity for the ascorbic acid structure.

  10. The effect of ascetic acid on mammalian cells

    SciTech Connect

    Mariana, Oana C; Trujillo, Antoinette; Sanders, Claire K; Burnett, Kassidy S; Freyer, James P; Mourant, Judith R

    2010-01-01

    Effects of the contrast agent, acetic acid, on mammalian cells are studied using light scattering measurements, viability and fluorescence pH assays. Results depend on whether cells are in PBS or are live and metabolizing. Acetic acid is a contrast agent used to aid the detection of cancerous and precancerous lesions of the uterine cervix. Typically 3% or 5% acetic acid is applied to the swface of the cervix and areas of the tissue that turn 'acetowhite' are considered more likely to be precancerous. The mechanism of action of acetic acid has never been understood in detail, although there are several hypotheses. One is that a decrease in pH causes cytokeratins in epithelial cells to polymerize. We will present data demonstrating that this is not the sole mechanism of acetowhitening. Another hypothesis is that a decrease in pH in the nucleus causes deacetylation of the histones which in turn results in a dense chromatin structure. Relevant to this hypothesis we have measured the internal pH of cells. Additional goals of this work are to understand what physical changes result in acetowhitening, to understand why there is variation in how cells respond to acetic acid, and to investigate how acetowhitening affects the light scatter properties measured by a fiber-optic probe we have developed for cervical cancer diagnostics.

  11. High cell density propionic acid fermentation with an acid tolerant strain of Propionibacterium acidipropionici.

    PubMed

    Wang, Zhongqiang; Jin, Ying; Yang, Shang-Tian

    2015-03-01

    Propionic acid is an important chemical with wide applications and its production via fermentation is of great interest. However, economic production of bio-based propionic acid requires high product titer, yield, and productivity in the fermentation. A highly efficient and stable high cell density (HCD) fermentation process with cell recycle by centrifugation was developed for propionic acid production from glucose using an acid-tolerant strain of Propionibacterium acidipropionici, which had a higher specific growth rate, productivity, and acid tolerance compared to the wild type ATCC 4875. The sequential batch HCD fermentation at pH 6.5 produced propionic acid at a high titer of ∼40 g/L and productivity of 2.98 g/L h, with a yield of ∼0.44 g/g. The product yield increased to 0.53-0.62 g/g at a lower pH of 5.0-5.5, which, however, decreased the productivity to 1.28 g/L h. A higher final propionic acid titer of >55 g/L with a productivity of 2.23 g/L h was obtained in fed-batch HCD fermentation at pH 6.5. A 3-stage simulated fed-batch process in serum bottles produced 49.2 g/L propionic acid with a yield of 0.53 g/g and productivity of 0.66 g/L h. These productivities, yields and propionic acid titers were among the highest ever obtained in free-cell propionic acid fermentation.

  12. Lactic Acid Bacteria Convert Human Fibroblasts to Multipotent Cells

    PubMed Central

    Ohta, Kunimasa; Kawano, Rie; Ito, Naofumi

    2012-01-01

    The human gastrointestinal tract is colonized by a vast community of symbionts and commensals. Lactic acid bacteria (LAB) form a group of related, low-GC-content, gram-positive bacteria that are considered to offer a number of probiotic benefits to general health. While the role of LAB in gastrointestinal microecology has been the subject of extensive study, little is known about how commensal prokaryotic organisms directly influence eukaryotic cells. Here, we demonstrate the generation of multipotential cells from adult human dermal fibroblast cells by incorporating LAB. LAB-incorporated cell clusters are similar to embryoid bodies derived from embryonic stem cells and can differentiate into endodermal, mesodermal, and ectodermal cells in vivo and in vitro. LAB-incorporated cell clusters express a set of genes associated with multipotency, and microarray analysis indicates a remarkable increase of NANOG, a multipotency marker, and a notable decrease in HOX gene expression in LAB-incorporated cells. During the cell culture, the LAB-incorporated cell clusters stop cell division and start to express early senescence markers without cell death. Thus, LAB-incorporated cell clusters have potentially wide-ranging implications for cell generation, reprogramming, and cell-based therapy. PMID:23300571

  13. Materials characterization of phosphoric acid fuel cell system

    NASA Technical Reports Server (NTRS)

    Venkatesh, Srinivasan

    1986-01-01

    The component materials used in the fabrication of phosphoric acid fuel cells (PAFC) must have mechanical, chemical, and electrochemical stability to withstand the moderately high temperature (200 C) and pressure (500 kPa) and highly oxidizing nature of phosphoric acid. This study discusses the chemical and structural stability, performance and corrosion data on certain catalysts, catalyst supports, and electrode support materials used in PAFC applications.

  14. Cinnamic acid induces apoptotic cell death and cytoskeleton disruption in human melanoma cells.

    PubMed

    Niero, Evandro Luís de Oliveira; Machado-Santelli, Gláucia Maria

    2013-05-23

    Anticancer activities of cinnamic acid derivatives include induction of apoptosis by irreversible DNA damage leading to cell death. The present work aimed to compare the cytotoxic and genotoxic potential of cinnamic acid in human melanoma cell line (HT-144) and human melanocyte cell line derived from blue nevus (NGM). Viability assay showed that the IC50 for HT-144 cells was 2.4 mM, while NGM cells were more resistant to the treatment. The growth inhibition was probably associated with DNA damage leading to DNA synthesis inhibition, as shown by BrdU incorporation assay, induction of nuclear aberrations and then apoptosis. The frequency of cell death caused by cinnamic acid was higher in HT-144 cells. Activated-caspase 3 staining showed apoptosis after 24 hours of treatment with cinnamic acid 3.2 mM in HT-144 cells, but not in NGM. We observed microtubules disorganization after cinnamic acid exposure, but this event and cell death seem to be independent according to M30 and tubulin labeling. The frequency of micronucleated HT-144 cells was higher after treatment with cinnamic acid (0.4 and 3.2 mM) when compared to the controls. Cinnamic acid 3.2 mM also increased the frequency of micronucleated NGM cells indicating genotoxic activity of the compound, but the effects were milder. Binucleation and multinucleation counting showed similar results. We conclude that cinnamic acid has effective antiproliferative activity against melanoma cells. However, the increased frequency of micronucleation in NGM cells warrants the possibility of genotoxicity and needs further investigation.

  15. Cinnamic acid induces apoptotic cell death and cytoskeleton disruption in human melanoma cells

    PubMed Central

    2013-01-01

    Anticancer activities of cinnamic acid derivatives include induction of apoptosis by irreversible DNA damage leading to cell death. The present work aimed to compare the cytotoxic and genotoxic potential of cinnamic acid in human melanoma cell line (HT-144) and human melanocyte cell line derived from blue nevus (NGM). Viability assay showed that the IC50 for HT-144 cells was 2.4 mM, while NGM cells were more resistant to the treatment. The growth inhibition was probably associated with DNA damage leading to DNA synthesis inhibition, as shown by BrdU incorporation assay, induction of nuclear aberrations and then apoptosis. The frequency of cell death caused by cinnamic acid was higher in HT-144 cells. Activated-caspase 3 staining showed apoptosis after 24 hours of treatment with cinnamic acid 3.2 mM in HT-144 cells, but not in NGM. We observed microtubules disorganization after cinnamic acid exposure, but this event and cell death seem to be independent according to M30 and tubulin labeling. The frequency of micronucleated HT-144 cells was higher after treatment with cinnamic acid (0.4 and 3.2 mM) when compared to the controls. Cinnamic acid 3.2 mM also increased the frequency of micronucleated NGM cells indicating genotoxic activity of the compound, but the effects were milder. Binucleation and multinucleation counting showed similar results. We conclude that cinnamic acid has effective antiproliferative activity against melanoma cells. However, the increased frequency of micronucleation in NGM cells warrants the possibility of genotoxicity and needs further investigation. PMID:23701745

  16. T cells cooperate with palmitic acid in induction of beta cell apoptosis

    PubMed Central

    Cvjetićanin, Tamara; Stojanović, Ivana; Timotijević, Gordana; Stošić-Grujičić, Stanislava; Miljković, Djordje

    2009-01-01

    Background Diabetes is characterized by progressive failure of insulin producing beta cells. It is well known that both saturated fatty acids and various products of immune cells can contribute to the reduction of beta cell viability and functionality during diabetes pathogenesis. However, their joint action on beta cells has not been investigated, so far. Therefore, we explored the possibility that leukocytes and saturated fatty acids cooperate in beta cell destruction. Results Rat pancreatic islets or insulinoma cells (RIN) were co-cultivated with concanavalin A (ConA)-stimulated rat lymph node cells (LNC), or they were treated with cell-free supernatants (Sn) obtained from ConA-stimulated spleen cells or from activated CD3+ cells, in the absence or presence of palmitic acid (PA). ConA-stimulated LNC or Sn and PA cooperated in inducing caspase-3-dependent RIN cell apoptosis. The observed effect of PA and Sn on RIN cell viability was mediated by p38 mitogen-activated protein kinase (MAPK)-signaling and was achieved through auto-destructive nitric oxide (NO) production. The cooperative effect of Sn was mimicked with the combination of interleukin-1β, interleukin-2, interleukin-6, interleukin-17, interferon-γ and tumor necrosis factor-α. Conclusion These results imply that stimulated T cells produce cytokines that cooperate with saturated free fatty acids in beta cell destruction during diabetes pathogenesis. PMID:19463182

  17. Genetic Code Expansion of Mammalian Cells with Unnatural Amino Acids.

    PubMed

    Brown, Kalyn A; Deiters, Alexander

    2015-09-01

    The expansion of the genetic code of mammalian cells enables the incorporation of unnatural amino acids into proteins. This is achieved by adding components to the protein biosynthetic machinery, specifically an engineered aminoacyl-tRNA synthetase/tRNA pair. The unnatural amino acids are chemically synthesized and supplemented to the growth medium. Using this methodology, fundamental new chemistries can be added to the functional repertoire of the genetic code of mammalian cells. This protocol outlines the steps necessary to incorporate a photocaged lysine into proteins and showcases its application in the optical triggering of protein translocation to the nucleus.

  18. Acid treatment of melanoma cells selects for invasive phenotypes.

    PubMed

    Moellering, Raymond E; Black, Kvar C; Krishnamurty, Chetan; Baggett, Brenda K; Stafford, Phillip; Rain, Matthew; Gatenby, Robert A; Gillies, Robert J

    2008-01-01

    Solid tumors become acidic due to hypoxia and upregulated glycolysis. We have hypothesized that this acidosis leads to more aggressive invasive behavior during carcinogenesis (Nature Reviews Cancer 4:891-899, 2004). Previous work on this subject has shown mixed results. While some have observed an induction of metastasis and invasion with acid treatments, others have not. To investigate this, human melanoma cells were acclimated to low pH growth conditions. Significant cell mortality occurred during acclimation, suggesting that acidosis selected for resistant phenotypes. Cells maintained under acidic conditions exhibited a greater range of motility, a reduced capacity to form flank tumors in SCID mice and did not invade more rapidly in vitro, compared to non-selected control cells. However, re-acclimation of these selected cells to physiological pH gave rise to stable populations with significantly higher in vitro invasion. These re-acclimated cells maintained higher invasion and higher motility for multiple generations. Transcriptomic analyses of these three phenotypes revealed significant differences, including upregulation of relevant pathways important for tissue remodeling, cell cycle control and proliferation. These results reinforce the hypothesis that acidosis promotes selection of stable, more invasive phenotypes, rather than inductive changes, which would be reversible.

  19. Folic Acid Supplementation Stimulates Notch Signaling and Cell Proliferation in Embryonic Neural Stem Cells

    PubMed Central

    Liu, Huan; Huang, Guo-wei; Zhang, Xu-mei; Ren, Da-lin; X. Wilson, John

    2010-01-01

    The present study investigated the effect of folic acid supplementation on the Notch signaling pathway and cell proliferation in rat embryonic neural stem cells (NSCs). The NSCs were isolated from E14–16 rat brain and grown as neurospheres in serum-free suspension culture. Individual cultures were assigned to one of 3 treatment groups that differed according to the concentration of folic acid in the medium: Control (baseline folic acid concentration of 4 mg/l), low folic acid supplementation (4 mg/l above baseline, Folate-L) and high folic acid supplementation (40 mg/l above baseline, Folate-H). NSCs were identified by their expression of immunoreactive nestin and proliferating cells by incorporation of 5'bromo-2'deoxyuridine. Cell proliferation was also assessed by methyl thiazolyl tetrazolium assay. Notch signaling was analyzed by real-time PCR and western blot analyses of the expression of Notch1 and hairy and enhancer of split 5 (Hes5). Supplementation of NSCs with folic acid increased the mRNA and protein expression levels of Notch1 and Hes5. Folic acid supplementation also stimulated NSC proliferation dose-dependently. Embryonic NSCs respond to folic acid supplementation with increased Notch signaling and cell proliferation. This mechanism may mediate the effects of folic acid supplementation on neurogenesis in the embryonic nervous system. PMID:20838574

  20. Inhibitory Activity of (+)-Usnic Acid against Non-Small Cell Lung Cancer Cell Motility

    PubMed Central

    Yang, Yi; Nguyen, Thanh Thi; Jeong, Min-Hye; Crişan, Florin; Yu, Young Hyun; Ha, Hyung-Ho; Choi, Kyung Hee; Jeong, Hye Gwang; Jeong, Tae Cheon; Lee, Kwang Youl; Kim, Kyung Keun; Hur, Jae-Seoun; Kim, Hangun

    2016-01-01

    Lichens are symbiotic organisms that produce various unique chemicals that can be used for pharmaceutical purposes. With the aim of screening new anti-cancer agents that inhibit cancer cell motility, we tested the inhibitory activity of seven lichen species collected from the Romanian Carpathian Mountains against migration and invasion of human lung cancer cells and further investigated the molecular mechanisms underlying their anti-metastatic activity. Among them, Alectoria samentosa, Flavocetraria nivalis, Alectoria ochroleuca, and Usnea florida showed significant inhibitory activity against motility of human lung cancer cells. HPLC results showed that usnic acid is the main compound in these lichens, and (+)-usnic acid showed similar inhibitory activity that crude extract have. Mechanistically, β-catenin-mediated TOPFLASH activity and KITENIN-mediated AP-1 activity were decreased by (+)-usnic acid treatment in a dose-dependent manner. The quantitative real-time PCR data showed that (+)-usnic acid decreased the mRNA level of CD44, Cyclin D1 and c-myc, which are the downstream target genes of both β-catenin/LEF and c-jun/AP-1. Also, Rac1 and RhoA activities were decreased by treatment with (+)-usnic acid. Interestingly, higher inhibitory activity for cell invasion was observed when cells were treated with (+)-usnic acid and cetuximab. These results implied that (+)-usnic acid might have potential activity in inhibition of cancer cell metastasis, and (+)-usnic acid could be used for anti-cancer therapy with a distinct mechanisms of action. PMID:26751081

  1. Effects of citric acid on cultured human osteoblastic cells.

    PubMed

    Guimarães, Lizandra Ferrari; Fidalgo, Tatiana Kelly da Silva; Menezes, Gustavo Conde; Primo, Laura Guimarães; Costa e Silva-Filho, Fernando

    2010-11-01

    We investigated the effects of citric acid (CA) on cultured human osteoblastic (HOB) cells by evaluating cell adhesion, proliferation, and cytotoxicity. (3)H-Thymidine-labeled HOB cells were incubated in culture medium supplemented or not with 4%, 6%, 8%, or 10% CA for 1 minute. After incubation, cell morphology was evaluated by Nomarski interferential light microscopy, cell proliferation was accessed by measurements of (3)H-thymidine associated to the cells, and cell lysis was monitored by measuring the amount of (3)H-thymidine released by cells. We observed that most of the CA-treated cells presented numerous atypical vacuoles, and such cells were also highly polymorphic, exhibiting round-shaped cells. Nonetheless, CA at all concentrations assayed did not yield cytotoxicity as measured by (3)H-containing DNA release, although significant decrease in cell proliferation was observed (P > .05). Furthermore, cells which were treated with CA at the lowest concentration assayed (4%) restored normal proliferation rates 3 days after treatment.

  2. Integral edge seals for phosphoric acid fuel cells

    DOEpatents

    Granata, Jr., Samuel J.; Woodle, Boyd M.; Dunyak, Thomas J.

    1992-01-01

    A phosphoric acid fuel cell having integral edge seals formed by an elastomer permeating an outer peripheral band contiguous with the outer peripheral edges of the cathode and anode assemblies and the matrix to form an integral edge seal which is reliable, easy to manufacture and has creep characteristics similar to the anode, cathode and matrix assemblies inboard of the seals to assure good electrical contact throughout the life of the fuel cell.

  3. Ursolic acid and oleanolic acid from Eriobotrya fragrans inhibited the viability of A549 cells.

    PubMed

    Yuan, Yuan; Gao, Yongshun; Song, Gang; Lin, Shunquan

    2015-02-01

    Loquat {Eriobotrya japonica (Lindl.)}, a kind of Chinese herb, has many efficacies such as anti-inflammatory, antimicrobial and curing chronic bronchitis. However, reports on the pharmacological action of wild loquat extract are limited. In this work, the A549 cell line was selected to study the inhibitory effect of ursolic acid and oleanolic acid (UA, OA) from the leaves of E. fragrans. Results showed that UA/OA inhibited A549 cell viability and induced apoptosis in a dose and time dependent manner. The cell fraction in the G0/G1 phase dramatically increased under treatment with UA/OA. Data showed that UA activated the expression of PARP. UA and OA down-regulated MMP-2 and Bcl-2; on the contrary, they up-regulated Bid. This work demonstrated that UA/OA extracted from wild loquat leaves can significantly inhibit the viability of A549 cells.

  4. Growth-modulating effects of dichloro myristic and dichloro stearic acid in cell cultures.

    PubMed

    Høstmark, A T; Lystad, E; Jebens, E; Skramstad, J; Frøyen, P

    1999-10-01

    Chloro-containing fatty acids are a major fraction of extractable, organically bound chlorine in fish. It has been suggested that dichloro stearic acid (9,10-dichlorooctadecanoic acid) (C18) is metabolized to dichloro myristic acid (5,6-dichlorotetradecanoic acid) (C14) which accumulates in tissues. Hence, the biological effects of the C18 dichloro fatty acid could be due to formation of the C14 dichloro fatty acid. In this study we have compared the effects of dichloro stearic and dichloro myristic acid on growth of three widely differing cell lines. Both fatty acids inhibited cell growth; however, dichloro myristic acid had a weaker growth inhibitory effect than dichloro stearic acid. Dichloro myristic acid had a biphasic effect (i.e. growth was stimulated at low concentrations, followed by inhibition at higher concentrations) on the growth of human hepatoma cells and immortalized human kidney epithelial cells, but no such effect on human microvascular endothelial cells. The order of potency for growth inhibition by dichloro myristic acid was consistently human hepatoma cells>immortalized human kidney epithelial cells >human microvascular endothelial cells, whereas the relative potency of dichloro stearic acid was variable. Albumin alone stimulated cell growth and had a stronger protective effect against growth inhibition by dichloro myristic acid than against that of dichloro stearic acid. It seems unlikely that a major part of the effect of dichloro stearic acid on cell growth is caused by conversion to dichloro myristic acid.

  5. Enhanced Production of Docosahexaenoic Acid in Mammalian Cells

    PubMed Central

    Zhu, Guiming; Jiang, Xudong; Ou, Qin; Zhang, Tao; Wang, Mingfu; Sun, Guozhi; Wang, Zhao; Sun, Jie; Ge, Tangdong

    2014-01-01

    Docosahexaenoic acid (DHA), one of the important polyunsaturated fatty acids (PUFA) with pharmaceutical and nutraceutical effects, may be obtained through diet or synthesized in vivo from dietary a-linolenic acid (ALA). However, the acumulation of DHA in human body or other mammals relies on the intake of high dose of DHA for a certain period of time, and the bioconversion of dietary ALA to DHA is very limited. Therefore the mammalian cells are not rich in DHA. Here, we report a new technology for increased prodution of DHA in mammalian cells. By using transient transfection method, Siganus canaliculatus Δ4 desaturase was heterologously expressed in chinese hamster ovary (CHO) cells, and simultaneously, mouse Δ6-desaturase and Δ5-desaturase were overexpressed. The results demonstrated that the overexpression of Δ6/Δ5-desaturases significantly enhanced the ability of transfected cells to convert the added ALA to docosapentaenoic acid (DPA) which in turn get converted into DHA directly and efficiently by the heterologously expressed Δ4 desaturase. This technology provides the basis for potential utility of these gene constructs in the creation of transgenic livestock for increased production of DHA/related products to meet the growing demand of this important PUFA. PMID:24788769

  6. Rosmarinic Acid and Melissa officinalis Extracts Differently Affect Glioblastoma Cells

    PubMed Central

    Ramanauskiene, Kristina; Raudonis, Raimondas

    2016-01-01

    Lemon balm (Melissa officinalis L.) has many biological effects but especially important is its neuroprotective activity. The aim of the study is to produce different extracts of Melissa officinalis and analyse their chemical composition and biological properties on rat glioblastoma C6 cells. Results revealed that rosmarinic acid (RA) is the predominant compound of lemon balm extracts. RA has cytotoxic effect on glioblastoma cells (LC50 290.5 μM after the incubation of 24 h and LC50 171.3 μM after 48 h). RA at concentration 80–130 μM suppresses the cell proliferation and has an antioxidant effect. 200 μM and higher concentrations of RA have a prooxidant effect and initiate cell death through necrosis. The aqueous extract of lemon balm is also enriched in phenolic compounds: protocatechuic, caftaric, caffeic, ferulic, and cichoric acids and flavonoid luteolin-7-glucoside. This extract at concentrations 50 μM–200 μM RA has cytotoxic activity and initiates cell death through apoptosis. Extracts prepared with 70% ethanol contain the biggest amount of active compounds. These extracts have the highest cytotoxic activity on glioblastoma cells. They initiate generation of intracellular ROS and cell death through apoptosis and necrosis. Our data suggest that differently prepared lemon balm extracts differently affect glioblastoma cells and can be used as neuroprotective agents in several therapeutic strategies.

  7. Rosmarinic Acid and Melissa officinalis Extracts Differently Affect Glioblastoma Cells

    PubMed Central

    Ramanauskiene, Kristina; Raudonis, Raimondas

    2016-01-01

    Lemon balm (Melissa officinalis L.) has many biological effects but especially important is its neuroprotective activity. The aim of the study is to produce different extracts of Melissa officinalis and analyse their chemical composition and biological properties on rat glioblastoma C6 cells. Results revealed that rosmarinic acid (RA) is the predominant compound of lemon balm extracts. RA has cytotoxic effect on glioblastoma cells (LC50 290.5 μM after the incubation of 24 h and LC50 171.3 μM after 48 h). RA at concentration 80–130 μM suppresses the cell proliferation and has an antioxidant effect. 200 μM and higher concentrations of RA have a prooxidant effect and initiate cell death through necrosis. The aqueous extract of lemon balm is also enriched in phenolic compounds: protocatechuic, caftaric, caffeic, ferulic, and cichoric acids and flavonoid luteolin-7-glucoside. This extract at concentrations 50 μM–200 μM RA has cytotoxic activity and initiates cell death through apoptosis. Extracts prepared with 70% ethanol contain the biggest amount of active compounds. These extracts have the highest cytotoxic activity on glioblastoma cells. They initiate generation of intracellular ROS and cell death through apoptosis and necrosis. Our data suggest that differently prepared lemon balm extracts differently affect glioblastoma cells and can be used as neuroprotective agents in several therapeutic strategies. PMID:27688825

  8. Cystine and dibasic amino acid uptake by opossum kidney cells

    SciTech Connect

    States, B.; Segal, S. )

    1990-06-01

    The characteristics of the uptake of L-cystine by the continuous opossum kidney cell line, OK, were examined. Uptake of cystine is rapid and, in contrast to other continuous cultured cell lines, these cells retain the cystine/dibasic amino acid transport system which is found in vivo and in freshly isolated kidney tissue. Confluent monolayers of cells also fail to show the presence of the cystine/glutamate transport system present in LLC-PK1 cells, fibroblasts, and cultured hepatocytes. Uptake of cystine occurs via a high-affinity saturable process which is independent of medium sodium concentration. The predominant site of cystine transport is across the apical cell membrane. The intracellular concentration of GSH far exceeds that of cystine with a ratio greater than 100:1 for GSH:cysteine. Incubation of cells for 5 minutes with a physiological level of labelled cystine resulted in the labelling of 66% and 5% of the total intracellular cysteine and glutathione, respectively. The ability of these cells to reflect the shared cystine/dibasic amino acid transport system makes them a suitable model for investigation of the cystine carrier which is altered in human cystinuria.

  9. Technology development for phosphoric acid fuel cell powerplant, phase 2

    NASA Technical Reports Server (NTRS)

    Christner, L.

    1981-01-01

    The development of materials, cell components, and reformers for on site integrated energy systems is described. Progress includes: (1) heat-treatment of 25 sq cm, 350 sq cm and 1200 sq cm cell test hardware was accomplished. Performance of fuel cells is improved by using this material; (2) electrochemical and chemical corrosion rates of heat-treated and as-molded graphite/phenolic resin composites in phosphoric acid were determined; (3) three cell, 5 in. x 15 in. stacks operated for up to 10,000 hours and 12 in. x 17 in. five cell stacks were tested for 5,000 hours; (4) a three cell 5 in. x 15 in. stack with 0.12 mg Pt/sq cm anodes and 0.25 mg Pt/sq cm cathodes was operated for 4,500 hours; and (5) an ERC proprietary high bubble pressure matrix, MAT-1, was tested for up to 10,000 hours.

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

    PubMed

    Lochner, Matthias; Berod, Luciana; Sparwasser, Tim

    2015-02-01

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

  11. Acid-induced secretory cell metaplasia in hamster bronchi

    SciTech Connect

    Christensen, T.G.; Lucey, E.C.; Breuer, R.; Snider, G.L.

    1988-02-01

    Hamsters were exposed to an intratracheal instillation of 0.5 ml of 0.08 N nitric, hydrochloric, or sulfuric acid to determine their airway epithelial response. Three weeks after exposure, the left intrapulmonary bronchi in Alcian blue/PAS-strained paraffin sections were evaluated for the amount of secretory product in the airway epithelium as a measure of secretory cell metaplasia (SCM). Compared to saline-treated control animals, all three acids caused statistically significant SCM. In addition to the bronchial lesion, all three acids caused similar interstitial fibrosis, bronchiolectasis, and bronchiolization of alveoli that varied in individual animals from mild to severe. In a separate experiment to study the persistence of the SCM, hamsters treated with a single instillation of 0.1 N nitric acid showed significant SCM 3, 7, and 17 weeks after exposure. There was a high correlation (r = 0.96) between a subjective assessment of SCM and objective assessment using a digital image-analysis system. We conclude that protons induce SCM independently of the associated anion; the SCM persists at least 17 weeks. Sulfuric acid is an atmospheric pollutant and nitric acid may form locally on the mucosa of lungs exposed to nitrogen dioxide. These acids may contribute to the development of maintenance of the SCM seen in the conducting airways of humans with chronic obstructive pulmonary disease.

  12. Aminomethylphosphonic acid and methoxyacetic acid induce apoptosis in prostate cancer cells.

    PubMed

    Parajuli, Keshab R; Zhang, Qiuyang; Liu, Sen; You, Zongbing

    2015-01-01

    Aminomethylphosphonic acid (AMPA) and its parent compound herbicide glyphosate are analogs to glycine, which have been reported to inhibit proliferation and promote apoptosis of cancer cells, but not normal cells. Methoxyacetic acid (MAA) is the active metabolite of ester phthalates widely used in industry as gelling, viscosity and stabilizer; its exposure is associated with developmental and reproductive toxicities in both rodents and humans. MAA has been reported to suppress prostate cancer cell growth by inducing growth arrest and apoptosis. However, it is unknown whether AMPA and MAA can inhibit cancer cell growth. In this study, we found that AMPA and MAA inhibited cell growth in prostate cancer cell lines (LNCaP, C4-2B, PC-3 and DU-145) through induction of apoptosis and cell cycle arrest at the G1 phase. Importantly, the AMPA-induced apoptosis was potentiated with the addition of MAA, which was due to downregulation of the anti-apoptotic gene baculoviral inhibitor of apoptosis protein repeat containing 2 (BIRC2), leading to activation of caspases 7 and 3. These results demonstrate that the combination of AMPA and MAA can promote the apoptosis of prostate cancer cells, suggesting that they can be used as potential therapeutic drugs in the treatment of prostate cancer.

  13. Cell nucleus directed 2,3,5-triiodobenzoic acid conjugates.

    PubMed

    Sturzu, Alexander; Vogel, Ulrich; Gharabaghi, Alireza; Beck, Alexander; Kalbacher, Hubert; Echner, Hartmut; Heckl, Stefan

    2009-07-01

    Triiodobenzoic acid (TIBA) represents the core structure of most clinically used contrast agents for computed tomography and other X-ray procedures. To construct an intracellular radiopaque contrast agent, TIBA was coupled to various different positively and negatively charged fluorescein iothiocyanate (FITC)-labelled peptides. TIBA coupled to the SV40 T Antigen nuclear localization sequence (NLS) stained 80% of human glioma cells and caused cell death. This occurred with C- or N-terminal binding of TIBA and with the correct or mutant NLS. No cell death and only small numbers of stained cells (below 3 %) were observed after incubation with NLS conjugates lacking TIBA or after incubation with TIBA-conjugates containing a negatively charged polyglutamic acid stretch. TIBA-conjugates containing the Antennapedia-derived cell-penetrating peptide penetratin were only nuclearly taken up when TIBA and FITC were coupled to lysines outside the 16-amino acid peptide sequence. The study shows that intracellular TIBA may have potential as a chemotherapeutic agent rather than a contrast agent.

  14. Ferulic acid is esterified to glucuronoarabinoxylans in pineapple cell walls.

    PubMed

    Smith, B G; Harris, P J

    2001-03-01

    The ester-linkage of ferulic acid (mainly E) to polysaccharides in primary cell walls of pineapple fruit (Ananas comosus) (Bromeliaceae) was investigated by treating a cell-wall preparation with 'Driselase' which contains a mixture of endo- and exo-glycanases, but no hydroxycinnamoyl esterase activity. The most abundant feruloyl oligosaccharide released was O-[5-O-(E-feruloyl)-alpha-L-arabinofuranosyl](1-->3)-O-beta-D-xylopyranosyl-(1-->4)-D-xylopyranose (FAXX). This indicated that the ferulic acid is ester-linked to glucuronoarabinoxylans in the same way as in the primary walls of grasses and cereals (Poaceae). Glucuronoarabinoxylans are the major non-cellulosic polysaccharides in the pineapple cell walls.

  15. Retinoic acid-induced neural differentiation of embryonal carcinoma cells.

    PubMed Central

    Jones-Villeneuve, E M; Rudnicki, M A; Harris, J F; McBurney, M W

    1983-01-01

    We have previously shown that the P19 line of embryonal carcinoma cells develops into neurons, astroglia, and fibroblasts after aggregation and exposure to retinoic acid. The neurons were initially identified by their morphology and by the presence of neurofilaments within their cytoplasm. We have more fully documented the neuronal nature of these cells by showing that their cell surfaces display tetanus toxin receptors, a neuronal cell marker, and that choline acetyl-transferase and acetyl cholinesterase activities appear coordinately in neuron-containing cultures. Several days before the appearance of neurons, there is a marked decrease in the amount of an embryonal carcinoma surface antigen, and at the same time there is a substantial decrease in the volumes of individual cells. Various retinoids were able to induce the development of neurons in cultures of aggregated P19 cells, but it did not appear that polyamine metabolism was involved in the effect. We have isolated a mutant clone which does not differentiate in the presence of any of the drugs which are normally effective in inducing differentiation of P19 cells. This mutant and others may help to elucidate the chain of events triggered by retinoic acid and other differentiation-inducing drugs. Images PMID:6656766

  16. Bile-acid-induced cell injury and protection

    PubMed Central

    Perez, Maria J; Briz, Oscar

    2009-01-01

    Several studies have characterized the cellular and molecular mechanisms of hepatocyte injury caused by the retention of hydrophobic bile acids (BAs) in cholestatic diseases. BAs may disrupt cell membranes through their detergent action on lipid components and can promote the generation of reactive oxygen species that, in turn, oxidatively modify lipids, proteins, and nucleic acids, and eventually cause hepatocyte necrosis and apoptosis. Several pathways are involved in triggering hepatocyte apoptosis. Toxic BAs can activate hepatocyte death receptors directly and induce oxidative damage, thereby causing mitochondrial dysfunction, and induce endoplasmic reticulum stress. When these compounds are taken up and accumulate inside biliary cells, they can also cause apoptosis. Regarding extrahepatic tissues, the accumulation of BAs in the systemic circulation may contribute to endothelial injury in the kidney and lungs. In gastrointestinal cells, BAs may behave as cancer promoters through an indirect mechanism involving oxidative stress and DNA damage, as well as acting as selection agents for apoptosis-resistant cells. The accumulation of BAs may have also deleterious effects on placental and fetal cells. However, other BAs, such as ursodeoxycholic acid, have been shown to modulate BA-induced injury in hepatocytes. The major beneficial effects of treatment with ursodeoxycholic acid are protection against cytotoxicity due to more toxic BAs; the stimulation of hepatobiliary secretion; antioxidant activity, due in part to an enhancement in glutathione levels; and the inhibition of liver cell apoptosis. Other natural BAs or their derivatives, such as cholyl-N-methylglycine or cholylsarcosine, have also aroused pharmacological interest owing to their protective properties. PMID:19360911

  17. Intertissue signal transfer of abscisic acid from vascular cells to guard cells.

    PubMed

    Kuromori, Takashi; Sugimoto, Eriko; Shinozaki, Kazuo

    2014-04-01

    Abscisic acid (ABA) is a phytohormone that responds to environmental stresses, such as water deficiency. Recent studies have shown that ABA biosynthetic enzymes are expressed in the vascular area under both nonstressed and water-stressed growth conditions. However, specific cells in the vasculature involved in ABA biosynthesis have not been identified. Here, we detected the expression of two genes encoding ABA biosynthetic enzymes, ABSCISIC ACID DEFICIENT2 and ABSCISIC ALDEHYDE OXIDASE3, in phloem companion cells in vascular tissues. Furthermore, we identified an ATP-binding cassette transporter, Arabidopsis thaliana ABCG25 (AtABCG25), expressed in the same cells. Additionally, AtABCG25-expressing Spodoptera frugiperda9 culture cells showed an ABA efflux function. Finally, we observed that enhancement of ABA biosynthesis in phloem companion cells induced guard cell responses, even under normal growth conditions. These results show that ABA is synthesized in specific cells and can be transported to target cells in different tissues.

  18. Cryptococcal 3-Hydroxy Fatty Acids Protect Cells Against Amoebal Phagocytosis.

    PubMed

    Madu, Uju L; Ogundeji, Adepemi O; Mochochoko, Bonang M; Pohl, Carolina H; Albertyn, Jacobus; Swart, Chantel W; Allwood, J William; Southam, Andrew D; Dunn, Warwick B; May, Robin C; Sebolai, Olihile M

    2015-01-01

    We previously reported on a 3-hydroxy fatty acid that is secreted via cryptococcal capsular protuberances - possibly to promote pathogenesis and survival. Thus, we investigated the role of this molecule in mediating the fate of Cryptococcus (C.) neoformans and the related species C. gattii when predated upon by amoebae. We show that this molecule protects cells against the phagocytic effects of amoebae. C. neoformans UOFS Y-1378 (which produces 3-hydroxy fatty acids) was less sensitive toward amoebae compared to C. neoformans LMPE 046 and C. gattii R265 (both do not produce 3-hydroxy fatty acids) and addition of 3-hydroxy fatty acids to C. neoformans LMPE 046 and C. gattii R265 culture media, causes these strains to become more resistant to amoebal predation. Conversely, addition of aspirin (a 3-hydroxy fatty acid inhibitor) to C. neoformans UOFS Y-1378 culture media made cells more susceptible to amoebae. Our data suggest that this molecule is secreted at a high enough concentration to effect intracellular signaling within amoeba, which in turn, promotes fungal survival. PMID:26696972

  19. Characteristics of neutralization of acids by newly isolated fungal cells.

    PubMed

    Shiomi, Naofumi; Yasuda, Takako; Inoue, Yoko; Kusumoto, Noriko; Iwasaki, Saori; Katsuda, Tomohisa; Katoh, Shigeo

    2004-01-01

    Soil microorganisms play an important role in maintaining soil pH at levels suitable for other soil organisms. To clarify the biological neutralization mechanism in soil, we isolated soil microorganisms showing a high ability to neutralize acids and studied their characteristics. From our taxonomic study, three isolated strains were identified as filamentous fungi, namely Mucor sp., Aspergillus fumigatus, and Aureobasidium pullulans. These strains could secrete basic materials, such as ammonia, for neutralization, grow in the medium at pH 4.0 and increase the pH of the medium to approximately 8.0. These microbial cells could neutralize not only nitric acid but also sulfuric and hydrochloric acids. The strains could also grow by utilizing nitric acid as a sole nitrogen source. In the soil containing these organisms, the pH was maintained in the neutral range by the buffering action of basic materials that they secrete. These results suggest that these fungal cells are useful for protecting the soil from acidification by acid rain.

  20. Cryptococcal 3-Hydroxy Fatty Acids Protect Cells Against Amoebal Phagocytosis

    PubMed Central

    Madu, Uju L.; Ogundeji, Adepemi O.; Mochochoko, Bonang M.; Pohl, Carolina H.; Albertyn, Jacobus; Swart, Chantel W.; Allwood, J. William; Southam, Andrew D.; Dunn, Warwick B.; May, Robin C.; Sebolai, Olihile M.

    2015-01-01

    We previously reported on a 3-hydroxy fatty acid that is secreted via cryptococcal capsular protuberances - possibly to promote pathogenesis and survival. Thus, we investigated the role of this molecule in mediating the fate of Cryptococcus (C.) neoformans and the related species C. gattii when predated upon by amoebae. We show that this molecule protects cells against the phagocytic effects of amoebae. C. neoformans UOFS Y-1378 (which produces 3-hydroxy fatty acids) was less sensitive toward amoebae compared to C. neoformans LMPE 046 and C. gattii R265 (both do not produce 3-hydroxy fatty acids) and addition of 3-hydroxy fatty acids to C. neoformans LMPE 046 and C. gattii R265 culture media, causes these strains to become more resistant to amoebal predation. Conversely, addition of aspirin (a 3-hydroxy fatty acid inhibitor) to C. neoformans UOFS Y-1378 culture media made cells more susceptible to amoebae. Our data suggest that this molecule is secreted at a high enough concentration to effect intracellular signaling within amoeba, which in turn, promotes fungal survival. PMID:26696972

  1. Cryptococcal 3-Hydroxy Fatty Acids Protect Cells Against Amoebal Phagocytosis.

    PubMed

    Madu, Uju L; Ogundeji, Adepemi O; Mochochoko, Bonang M; Pohl, Carolina H; Albertyn, Jacobus; Swart, Chantel W; Allwood, J William; Southam, Andrew D; Dunn, Warwick B; May, Robin C; Sebolai, Olihile M

    2015-01-01

    We previously reported on a 3-hydroxy fatty acid that is secreted via cryptococcal capsular protuberances - possibly to promote pathogenesis and survival. Thus, we investigated the role of this molecule in mediating the fate of Cryptococcus (C.) neoformans and the related species C. gattii when predated upon by amoebae. We show that this molecule protects cells against the phagocytic effects of amoebae. C. neoformans UOFS Y-1378 (which produces 3-hydroxy fatty acids) was less sensitive toward amoebae compared to C. neoformans LMPE 046 and C. gattii R265 (both do not produce 3-hydroxy fatty acids) and addition of 3-hydroxy fatty acids to C. neoformans LMPE 046 and C. gattii R265 culture media, causes these strains to become more resistant to amoebal predation. Conversely, addition of aspirin (a 3-hydroxy fatty acid inhibitor) to C. neoformans UOFS Y-1378 culture media made cells more susceptible to amoebae. Our data suggest that this molecule is secreted at a high enough concentration to effect intracellular signaling within amoeba, which in turn, promotes fungal survival.

  2. A nucleic acid dependent chemical photocatalysis in live human cells.

    PubMed

    Arian, Dumitru; Cló, Emiliano; Gothelf, Kurt V; Mokhir, Andriy

    2010-01-01

    Only two nucleic acid directed chemical reactions that are compatible with live cells have been reported to date. Neither of these processes generate toxic species from nontoxic starting materials. Reactions of the latter type could be applied as gene-specific drugs, for example, in the treatment of cancer. We report here the first example of a chemical reaction that generates a cytotoxic drug from a nontoxic prodrug in the presence of a specific endogeneous ribonucleic acid in live mammalian cells. In this case, the prodrug is triplet oxygen and the drug is singlet oxygen. The key component of this reaction is an inert molecule (InP-2'-OMe-RNA/Q-2'-OMe-RNA; P: photosensitizer; Q: quencher), which becomes an active photosensitizer (InP-2'-OMe-RNA) in the presence of single-stranded nucleic acid targets. Upon irradiation with red light, the photosensitizer produces over 6000 equivalents of toxic singlet oxygen per nucleic acid target. This reaction is highly sequence specific. To detect the generation of singlet oxygen in live cells, we prepared a membrane-permeable and water-soluble fluorescent scavenger, a derivative of 2,5-diphenylisobenzofurane. The scavenger decomposes upon reaction with singlet oxygen and this is manifested in a decrease in the fluorescence intensity. This effect can be conveniently monitored by flow cytometry.

  3. Opposing effects of bile acids deoxycholic acid and ursodeoxycholic acid on signal transduction pathways in oesophageal cancer cells.

    PubMed

    Abdel-Latif, Mohamed M; Inoue, Hiroyasu; Reynolds, John V

    2016-09-01

    Ursodeoxycholic acid (UDCA) was reported to reduce bile acid toxicity, but the mechanisms underlying its cytoprotective effects are not fully understood. The aim of the present study was to examine the effects of UDCA on the modulation of deoxycholic acid (DCA)-induced signal transduction in oesophageal cancer cells. Nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) activity was assessed using a gel shift assay. NF-κB activation and translocation was performed using an ELISA-based assay and immunofluorescence analysis. COX-2 expression was analysed by western blotting and COX-2 promoter activity was assessed by luciferase assay. DCA induced NF-κB and AP-1 DNA-binding activities in SKGT-4 and OE33 cells. UDCA pretreatment inhibited DCA-induced NF-κB and AP-1 activation and NF-κB translocation. This inhibitory effect was coupled with a blockade of IκB-α degradation and inhibition of phosphorylation of IKK-α/β and ERK1/2. Moreover, UDCA pretreatment inhibited COX-2 upregulation. Using transient transfection of the COX-2 promoter, UDCA pretreatment abrogated DCA-induced COX-2 promoter activation. In addition, UDCA protected oesophageal cells from the apoptotic effects of deoxycholate. Our findings indicate that UDCA inhibits DCA-induced signalling pathways in oesophageal cancer cells. These data indicate a possible mechanistic role for the chemopreventive actions of UDCA in oesophageal carcinogenesis.

  4. Cathode catalysts for primary phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Alkylation or carbon Vulcan XC-72, the support carbon, was shown to provide the most stable bond type for linking cobalt dehydrodibenzo tetraazannulene (CoTAA) to the surface of the carbon; this result is based on data obtained by cyclic voltammetry, pulse voltammetry and by release of 14C from bonded CoTAA. Half-cell tests at 100 C in 85% phosphoric acid showed that CoTAA bonded to the surface of carbon (Vulcan XC-72) via an alkylation procedure is a more active catalyst than is platinum based on a factor of two improvement in Tafel slope; dimeric CoTAA had catalytic activity equal to platinum. Half-cell tests also showed that bonded CoTAA catalysts do not suffer a loss in potential when air is used as a fuel rather than oxygen. Commercially available polytetrafluroethylene (PTFE) was shown to be unstable in the fuel cell environment with degradation occurring in 2000 hours or less. The PTFE was stressed at 200 C in concentrated phosphoric acid as well as electrochemically stressed in 150 C concentrated phosphoric acid; the surface chemistry of PTFE was observed to change significantly. Radiolabeled PTFE was prepared and used to verify that such chemical changes also occur in the primary fuel cell environment.

  5. Oxidation of L-ascorbic acid to dehydroascorbic acid on the surface of the red blood cell

    SciTech Connect

    Wagner, E.; Jennings, M.; Bennett, K.

    1986-05-01

    L-ascorbic acid-1-/sup 14/C when incubated with human blood did not bind irreversibly to any of the protein components of plasma but did migrate irreversibly into erythrocytes. Isolation and characterization via IR of the moiety trapped within the cell established its identity as apparently, unchanged L-ascorbic acid. When dehydroascorbic acid-1-/sup 14/C was incubated with human blood, the results were identical including the identity of the entrapped moiety, L-ascorbic acid. It was found that L-ascorbic acid was enzymatically oxidized on the surface of the red blood cell to dehydroascorbic acid which diffused through the lipid soluble portion of the cell membrane and was enzymatically reduced back to ascorbic acid within the cell.

  6. Production of arachidonic and linoleic acid metabolites by guinea pig tracheal epithelial cells

    SciTech Connect

    Oosthuizen, M.J.; Engels, F.; Van Esch, B.; Henricks, P.A.; Nijkamp, F.P. )

    1990-08-01

    Pulmonary epithelial cells may be responsible for regulating airway smooth muscle function, in part by release of fatty acid-derived mediators. Incubation of isolated guinea pig tracheal epithelial cells with radiolabeled arachidonic acid (AA) leads to the production of 5- and 15-hydroxyeicosatetraenoic acid (5- and 15-HETE) and smaller amounts of leukotriene (LT) B4 and C4 and 12-hydroxyheptadecatrienoic acid (HHT). Epithelial cells also are able to release linoleic acid (LA) metabolites. Incubation with radiolabeled linoleic acid leads to the formation of 9- and 13-hydroxyoctadecadienoic acid (9- and 13-HODE). The biological significance of these mediators produced by epithelial cells is discussed.

  7. Hydrochloric acid alters the effect of L-glutamic acid on cell viability in human neuroblastoma cell cultures.

    PubMed

    Croce, Nicoletta; Bernardini, Sergio; Di Cecca, Stefano; Caltagirone, Carlo; Angelucci, Francesco

    2013-07-15

    l-Glutamic acid (l-glutamate) is used to induce excitotoxicity and test neuroprotective compounds in cell cultures. However, because l-glutamate powder is nearly insoluble in water, many manufacturers recommend reconstituting l-glutamate in hydrochloric acid (HCl) prior to successive dilutions. Nevertheless, HCl, even at low concentrations, may alter the pH of the cell culture medium and interfere with cell activity. Thus, the aim of this study was to evaluate whether the reconstitution of l-glutamate powder in HCl alters its capacity to induce neurotoxicity in different human neuroblastoma cell lines. SH-SY5Y, IMR-32 and SK-N-BE(2) cells were exposed to various concentrations of l-glutamate, which was either reconstituted in HCl (1M) or post re-equilibrated to the pH of the culture medium (7.5). After 24 and 48h of incubation, changes in the cell viability of treated versus untreated cells were evaluated. The effect of an identical amount of HCl present in the l-glutamate dilutions on neuroblastoma cell survival was also investigated. Our data showed that the neurotoxicity of glutamate reconstituted in HCl was comparable to that of HCl alone. Moreover, the pH variations induced by glutamate or HCl in the culture medium were similar. When the pH of the glutamate stock solution was re-equilibrated, l-glutamate induced variation in cell viability to a lower extent and after a longer incubation time. This study demonstrated that HCl used to reconstitute l-glutamate powder might alter the effect of glutamate itself in neuroblastoma cell cultures. Thus, this information might be useful to scientists who use l-glutamate to induce excitotoxicity or to test neuroprotective agents.

  8. Cell wall structure and function in lactic acid bacteria

    PubMed Central

    2014-01-01

    The cell wall of Gram-positive bacteria is a complex assemblage of glycopolymers and proteins. It consists of a thick peptidoglycan sacculus that surrounds the cytoplasmic membrane and that is decorated with teichoic acids, polysaccharides, and proteins. It plays a major role in bacterial physiology since it maintains cell shape and integrity during growth and division; in addition, it acts as the interface between the bacterium and its environment. Lactic acid bacteria (LAB) are traditionally and widely used to ferment food, and they are also the subject of more and more research because of their potential health-related benefits. It is now recognized that understanding the composition, structure, and properties of LAB cell walls is a crucial part of developing technological and health applications using these bacteria. In this review, we examine the different components of the Gram-positive cell wall: peptidoglycan, teichoic acids, polysaccharides, and proteins. We present recent findings regarding the structure and function of these complex compounds, results that have emerged thanks to the tandem development of structural analysis and whole genome sequencing. Although general structures and biosynthesis pathways are conserved among Gram-positive bacteria, studies have revealed that LAB cell walls demonstrate unique properties; these studies have yielded some notable, fundamental, and novel findings. Given the potential of this research to contribute to future applied strategies, in our discussion of the role played by cell wall components in LAB physiology, we pay special attention to the mechanisms controlling bacterial autolysis, bacterial sensitivity to bacteriophages and the mechanisms underlying interactions between probiotic bacteria and their hosts. PMID:25186919

  9. Cell membrane fatty acid composition differs between normal and malignant cell lines.

    PubMed

    Meng, Xialong; Riordan, Neil H; Riordan, Hugh D; Mikirova, Nina; Jackson, James; González, Michael J; Miranda-Massari, Jorge R; Mora, Edna; Trinidad Castillo, Waleska

    2004-06-01

    Twenty-eight fatty acids (C8:0 to C24:l n-9) were measured by gas chromatography in four normal cell lines (C3H / 10T1 / 2, CCD-18Co, CCD-25SK and CCD-37Lu) and seven cancer cell lines (C-41, Caov-3, LS-180, PC-3, SK-MEL-28, SK-MES-1 and U-87 MG). Results show differences in the content and proportions of fatty acids when comparing cancer cell lines with their normal counterparts. Cancer cell lines showed lower C20: 4 n-6, C24:1 n-9, polyunsaturated fatty acids (PUFA's) and ratios of C20:4 n-6 to C20:5 n-3 and C16:0 to C18:1 n-9 and stearic to oleic (SA/OA) than their normal counterparts. All cancer cell lines had SA/OA ratios lower than 7.0 while normal cell lines had ratios greater than 0.7 (p<0.05). In addition, the ratios of total saturated fatty acids (SFA) to PUFA'S and the concentration of C18:1 n-9, C18:2 n-6, C20:5 n-3 were higher in cancer cell lines as compared to normal cell lines. A positive correlation was detected between C16:0 and longer SFA'S (r = +0.511, p<0.05) in normal cell lines whereas a negative correlation (r=0.608, p<0.05) was obtained for malignant cell lines. Moreover, cancerous cell lines exhibited a particular desaturation defect and an abnormal incorporation of C18:2 n-6 and C20-4 n-6 fatty acids. PMID:15377057

  10. Okadaic acid inhibits cell multiplication and induces apoptosis in a549 cells, a human lung adenocarcinoma cell line

    PubMed Central

    Wang, Renjun; Lv, Lili; Zhao, Yunfeng; Yang, Nana

    2014-01-01

    This essay aims to research the effect of okadaic acid (OA) on A549 cell multiplication, and cell apoptosis induced by OA was observed by cell morphology. MTT assay, trypan blue exclusion test (TBET), Giemsa staining method and acridine orange (AO) fluorescence staining assay were applied. The results of cell survival evaluated by TBET and colorimetric assay with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) showed: The number of A549 cells was decreased in a dose-dependent manner. Cytomorphology observation of okadaic acid-treated cells showed that cells became shrinkage and turned round, some cells floated in the nutrient medium with nucleus agglutination broken, resulting in apoptotic bodies. Above-mentioned results indicated that OA exerted significantly inhibitory effect on A549 cell multiplication due to the apoptosis induced by OA. PMID:25232383

  11. Catalyst and electrode research for phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Antoine, A. C.; King, R. B.

    1987-01-01

    An account is given of the development status of phosphoric acid fuel cells' high performance catalyst and electrode materials. Binary alloys have been identified which outperform the baseline platinum catalyst; it has also become apparent that pressurized operation is required to reach the desired efficiencies, calling in turn for the use of graphitized carbon blacks in the role of catalyst supports. Efforts to improve cell performance and reduce catalyst costs have led to the investigation of a class of organometallic cathode catalysts represented by the tetraazaannulenes, and a mixed catalyst which is a mixture of carbons catalyzed with an organometallic and a noble metal.

  12. Omega-3 fatty acids, lipid rafts, and T cell signaling.

    PubMed

    Hou, Tim Y; McMurray, David N; Chapkin, Robert S

    2016-08-15

    n-3 polyunsaturated fatty acids (PUFA) have been shown in many clinical studies to attenuate inflammatory responses. Although inflammatory responses are orchestrated by a wide spectrum of cells, CD4(+) T cells play an important role in the etiology of many chronic inflammatory diseases such as inflammatory bowel disease and obesity. In light of recent concerns over the safety profiles of non-steroidal anti-inflammatory drugs (NSAIDs), alternatives such as bioactive nutraceuticals are becoming more attractive. In order for these agents to be accepted into mainstream medicine, however, the mechanisms by which nutraceuticals such as n-3 PUFA exert their anti-inflammatory effects must be fully elucidated. Lipid rafts are nanoscale, dynamic domains in the plasma membrane that are formed through favorable lipid-lipid (cholesterol, sphingolipids, and saturated fatty acids) and lipid-protein (membrane-actin cytoskeleton) interactions. These domains optimize the clustering of signaling proteins at the membrane to facilitate efficient cell signaling which is required for CD4(+) T cell activation and differentiation. This review summarizes novel emerging data documenting the ability of n-3 PUFA to perturb membrane-cytoskeletal structure and function in CD4(+) T cells. An understanding of these underlying mechanisms will provide a rationale for the use of n-3 PUFA in the treatment of chronic inflammation.

  13. Cell density-dependent linoleic acid toxicity to Saccharomyces cerevisiae.

    PubMed

    Ferreira, Túlio César; de Moraes, Lídia Maria Pepe; Campos, Elida Geralda

    2011-08-01

    Since the discovery of the apoptotic pathway in Saccharomyces cerevisiae, several compounds have been shown to cause apoptosis in this organism. While the toxicity of polyunsaturated fatty acids (PUFA) peroxides towards S. cerevisiae has been known for a long time, studies on the effect of nonoxidized PUFA are scarce. The present study deals specifically with linoleic acid (LA) in its nonoxidized form and investigates its toxicity to yeast. Saccharomyces cerevisiae is unable to synthesize PUFA, but can take up and incorporate them into its membranes. Reports from the literature indicate that LA is not toxic to yeast cells. However, we demonstrated that yeast cell growth decreased in cultures treated with 0.1 mM LA for 4 h, and 3-(4,5 dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide reduction (a measure of respiratory activity) decreased by 47%. This toxicity was dependent on the number of cells used in the experiment. We show apoptosis induction by LA concomitant with increases in malondialdehyde, glutathione content, activities of catalase and cytochrome c peroxidase, and decreases in two metabolic enzyme activities. While the main purpose of this study was to show that LA causes cell death in yeast, our results indicate some of the molecular mechanisms of the cell toxicity of PUFA. PMID:21457450

  14. Cell patterning on polylactic acid through surface-tethered oligonucleotides.

    PubMed

    Matsui, Toshiki; Arima, Yusuke; Takemoto, Naohiro; Iwata, Hiroo

    2015-02-01

    Polylactic acid (PLA) is a candidate material to prepare scaffolds for 3-D tissue regeneration. However, cells do not adhere or proliferate well on the surface of PLA because it is hydrophobic. We report a simple and rapid method for inducing cell adhesion to PLA through DNA hybridization. Single-stranded DNA (ssDNA) conjugated to poly(ethylene glycol) (PEG) and to a terminal phospholipid (ssDNA-PEG-lipid) was used for cell surface modification. Through DNA hybridization, modified cells were able to attach to PLA surfaces modified with complementary sequence (ssDNA'). Different cell types can be attached to PLA fibers and films in a spatially controlled manner by using ssDNAs with different sequences. In addition, they proliferate well in a culture medium supplemented with fetal bovine serum. The coexisting modes of cell adhesion through DNA hybridization and natural cytoskeletal adhesion machinery revealed no serious effects on cell growth. The combination of a 3-D scaffold made of PLA and cell immobilization on the PLA scaffold through DNA hybridization will be useful for the preparation of 3-D tissue and organs.

  15. Boswellic acid activity against glioblastoma stem-like cells

    PubMed Central

    SCHNEIDER, HANNAH; WELLER, MICHAEL

    2016-01-01

    Boswellic acids (BAs) have long been considered as useful adjunct pharmacological agents for the treatment of patients with malignant brain tumors, notably glioblastoma. Two principal modes of action associated with BAs have been postulated: i) Anti-inflammatory properties, which are useful for containing edema formation, and ii) intrinsic antitumor cell properties, with a hitherto ill-defined mode of action. The present study assessed the effects of various BA derivatives on the viability and clonogenicity of a panel of nine long-term glioma cell lines and five glioma-initiating cell lines, studied cell cycle progression and the mode of cell death induction, and explored potential synergy with temozolomide (TMZ) or irradiation. BA induced the concentration-dependent loss of viability and clonogenicity that was independent of tumor protein 53 status and O6-methylguanine DNA methyltransferase expression. The treatment of glioma cells with BA resulted in cell death induction, prior to or upon S phase entry, and exhibited features of apoptotic cell death. Synergy with irradiation or TMZ was detected at certain concentrations; however, the inhibitory effects were mostly additive, and never antagonistic. While the intrinsic cytotoxic properties of BA at low micromolecular concentrations were confirmed and the potential synergy with irradiation and TMZ was identified, the proximate pharmacodynamic target of BA remains to be identified. PMID:27313764

  16. Status of commercial phosphoric acid fuel cell system development

    NASA Technical Reports Server (NTRS)

    Warshay, M.; Prokopius, P. R.; Simons, S. N.; King, R. B.

    1981-01-01

    A review of the current commercial phosphoric acid fuel cell system development efforts is presented. In both the electric utility and on-site integrated energy system applications, reducing cost and increasing reliability are important. The barrier to the attainment of these goals has been materials. The differences in approach among the three major participants are their technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy.

  17. Fatty acid profile and proliferation of bovine blood mononuclear cells after conjugated linoleic acid supplementation

    PubMed Central

    2012-01-01

    Background Conjugated linoleic acids (CLA) are in focus of dairy cattle research because of its milk fat reducing effects. Little is known about the impact of CLA on immune function in dairy cows. Therefore, in the present study we investigated the effects of a long term supplementation of dairy cows with CLA on the fatty acid profile of peripheral blood mononuclear cells (PBMC) and their proliferation ex vivo. Results The supplementation of dairy cows with either 100 g/d of a control fat preparation (CON, n = 15), 50 g/d of the control fat preparation and 50 g/d CLA supplement – containing 12.0% cis-9, trans-11 and 11.9% trans-10, cis-12 CLA of total fatty acid methyl esters – (CLA-50, n = 15) or 100 g/d of the CLA supplement (CLA-100, n = 16) did not influence the major fatty acids (C18:0, C16:0, cis-9 C18:1, cis-9, cis-12 C18:2, cis-5, cis-8, cis-11, cis-14 C20:4) in the lipid fraction of PBMC. The proportion of trans-10, cis-12 CLA of total fatty acids was increased in both CLA supplemented groups, but there was no effect on the cis-9, trans-11 isomer. Furthermore, the proportion of trans-9 C18:1 and cis-12 C24:1 was reduced in the CLA-100 group. The mitogen stimulated cell proliferation was not influenced by CLA feeding. Conclusion CLA supplementation influenced the FA profile of some minor FA in PBMC, but these changes did not lead to differences in the mitogen induced activation of the cells. PMID:22668674

  18. Cinnamic acid derivatives induce cell cycle arrest in carcinoma cell lines.

    PubMed

    Sova, Matej; Žižak, Željko; Stanković, Jelena A Antic; Prijatelj, Matevž; Turk, Samo; Juranić, Zorica D; Mlinarič-Raščan, Irena; Gobec, Stanislav

    2013-08-01

    Cinnamic acid derivatives can be found in plant material, and they possess a remarkable variety of biological effects. In the present study, we have investigated the cytotoxic effects of representative cinnamic acid esters and amides. The cytotoxicity was determined by MTT test on human cervix adenocarcinoma (HeLa), myelogenous leukemia (K562), malignant melanoma (Fem-x), and estrogen-receptor-positive breast cancer (MCF-7) cells, versus peripheral blood mononuclear cells (PBMCs) without or with the addition of the plant lectin phytohemaglutinin (PHA). The compounds tested showed significant cytotoxicity (IC50s between 42 and 166 µM) and furthermore selectivity of these cytotoxic effects on the malignant cell lines versus the PBMCs was also seen, especially when electron-withdrawing groups, such as a cyano group (compound 5), were present on the aromatic rings of the alcohol or amine parts of the cinnamic acid derivatives. The additional study on cell cycle phase distribution indicated that novel cinnamic acid derivatives inhibit cell growth by induction of cell death. Thus, cinnamic acids derivatives represent important lead compounds for further development of antineoplastic agents.

  19. Analysis of Cell Wall Teichoic Acids in Staphylococcus aureus.

    PubMed

    Covas, Gonçalo; Vaz, Filipa; Henriques, Gabriela; Pinho, Mariana G; Filipe, Sérgio R

    2016-01-01

    Most bacterial cells are surrounded by a surface composed mainly of peptidoglycan (PGN), a glycopolymer responsible for ensuring the bacterial shape and a telltale molecule that betrays the presence of bacteria to the host immune system. In Staphylococcus aureus, as in most gram-positive bacteria, peptidoglycan is concealed by covalently linked molecules of wall teichoic acids (WTA)-phosphate rich molecules made of glycerol and ribitol phosphates which may be tailored by different amino acids and sugars.In order to analyze and compare the composition of WTA produced by different S. aureus strains, we describe methods to: (1) quantify the total amount of WTA present at the bacterial cell surface, through the determination of the inorganic phosphate present in phosphodiester linkages of WTA; (2) identify which sugar constituents are present in the assembled WTA molecules, by detecting the monosaccharides, released by acid hydrolysis, through an high-performance anion exchange chromatography analysis coupled with pulsed amperometric detection (HPAEC-PAD) and (3) compare the polymerization degree of WTA found at the cell surface of different S. aureus strains, through their different migration in a polyacrylamide gel electrophoresis (PAGE). PMID:27311674

  20. Effects of acetic acid on light scattering from cells

    NASA Astrophysics Data System (ADS)

    Marina, Oana C.; Sanders, Claire K.; Mourant, Judith R.

    2012-08-01

    Acetic acid has been used for decades as an aid for the detection of precancerous cervical lesions, and the use of acetic acid is being investigated in several other tissues. Nonetheless, the mechanism of acetowhitening is unclear. This work tests some of the hypotheses in the literature and measures changes in light scattering specific to the nucleus and the cytoplasm. Wide angle side scattering from both the nucleus and the cytoplasm increases with acetic application to tumorigenic cells, with the increase in nuclear scattering being greater. In one cell line, the changes in nuclear scattering are likely due to an increase in number or scattering efficiency of scattering centers smaller than the wavelength of excitation light. There are likely several cellular changes that cause acetowhitening and the cellular changes may differ with cell type. These results should lead to a better understanding of acetowhitening and potentially the development of adjunct techniques to improve the utility of acetic acid application. For the well-studied case of cervical tissue, acetowhitening has been shown to be sensitive, but not specific for oncogenic changes needing treatment.

  1. Effects of elaidic acid, a predominant industrial trans fatty acid, on bacterial growth and cell surface hydrophobicity of lactobacilli.

    PubMed

    Wu, Qinglong; Shah, Nagendra P

    2014-12-01

    The consumption of trans fatty acids (TFAs) increases the risk of cardiovascular diseases and coronary heart disease in human, and there are no effective ways to remove TFAs after consumption. The aim of this study was to investigate the effects of elaidic acid on bacterial growth, cell surface hydrophobicity of lactobacilli, and metabolism of elaidic acid by lactobacilli. Lactobacilli were inoculated in MRS broth containing 0, 100, 200, and 500 mg/L of elaidic acid. Viable cell counts of lactobacilli were enumerated, concentrations of elaidic acid were determined, and cell surface hydrophobicity of lactobacilli was measured. The results showed that the growth of lactobacilli was significantly inhibited by 500 mg/L of elaidic acid, however, a cell count of 8.50 log10 CFU/mL was still reached for tested lactobacilli after 24-h incubation. In particular, a reduction of elaidic acid was found for tested lactobacilli after 24-h incubation as compared to its initial concentration of 200 mg/L. However, cell surface hydrophobicity showed no correlations with the metabolism of elaidic acid by lactobacilli. Moreover, elaidic acid was able to influence cell surface hydrophobicity, and the decrease in hydrophobicity was more obvious in Lactobacillus paracasei and Lactobacillus casei compared with that in other tested lactobacilli. This study suggests that elaidic acid could change physiochemical surface properties of lactobacilli and the lactobacilli have the potential to reduce TFAs.

  2. Macronutrients, fatty acids, cholesterol and renal cell cancer risk.

    PubMed

    Bidoli, Ettore; Talamini, Renato; Zucchetto, Antonella; Polesel, Jerry; Bosetti, Cristina; Negri, Eva; Maruzzi, Daniele; Montella, Maurizio; Franceschi, Silvia; La Vecchia, Carlo

    2008-06-01

    The role of selected macronutrients, fatty acids and cholesterol in the etiology of renal cell carcinoma (RCC) was analyzed using data from a case-control study conducted in 4 Italian areas between 1992 and 2004. Cases were 767 patients with incident, histologically confirmed RCC, admitted to major teaching and general hospitals of the study areas. Controls were 1,534 subjects admitted for acute, nonneoplastic conditions to the same hospitals. Information on dietary habits and nutrient intake was elicited using a validated food frequency questionnaire including 78 food groups and recipes. Odds ratios (OR) and 95% confidence intervals (CI) for increasing levels of nutrient intake were estimated after allowance for total energy intake and other potential confounding factors. A direct association with RCC was found for starch intake (OR = 1.9 for highest versus lowest quintile of intake; 95% CI: 1.4-2.6, p-value for trend = 0.001), while an inverse association was found for fats from vegetable sources (OR = 0.6; 95% CI: 0.5-0.8; p-value for trend = 0.002), unsaturated fatty acids (OR = 0.5; 95% CI: 0.4-0.7; p-value for trend = 0.0002), and polyunsaturated fatty acids (OR = 0.5; 95% CI: 0.4-0.7; p-value for trend = 0.001). Among polyunsaturated fatty acids, linoleic acid (OR = 0.5; 95% CI: 0.4-0.7; p-value for trend = 0.0001) and linolenic acid (OR = 0.7; 95% CI: 0.5-1.0; p-value for trend = 0.01) were inversely related to RCC. When 6 major macronutrients were included in the same model, the adverse effect of high intake of starch remained statistically significant, together with the protective effect of polyunsaturated fatty acids. Results were consistent in strata of age, body mass index, treated hypertension, energy intake, stage and family history of RCC. PMID:18224688

  3. Orexin A attenuates palmitic acid-induced hypothalamic cell death.

    PubMed

    Duffy, Cayla M; Nixon, Joshua P; Butterick, Tammy A

    2016-09-01

    Palmitic acid (PA), an abundant dietary saturated fatty acid, contributes to obesity and hypothalamic dysregulation in part through increase in oxidative stress, insulin resistance, and neuroinflammation. Increased production of reactive oxygen species (ROS) as a result of PA exposure contributes to the onset of neuronal apoptosis. Additionally, high fat diets lead to changes in hypothalamic gene expression profiles including suppression of the anti-apoptotic protein B cell lymphoma 2 (Bcl-2) and upregulation of the pro-apoptotic protein B cell lymphoma 2 associated X protein (Bax). Orexin A (OXA), a hypothalamic peptide important in obesity resistance, also contributes to neuroprotection. Prior studies have demonstrated that OXA attenuates oxidative stress induced cell death. We hypothesized that OXA would be neuroprotective against PA induced cell death. To test this, we treated an immortalized hypothalamic cell line (designated mHypoA-1/2) with OXA and PA. We demonstrate that OXA attenuates PA-induced hypothalamic cell death via reduced caspase-3/7 apoptosis, stabilization of Bcl-2 gene expression, and reduced Bax/Bcl-2 gene expression ratio. We also found that OXA inhibits ROS production after PA exposure. Finally, we show that PA exposure in mHypoA-1/2 cells significantly reduces basal respiration, maximum respiration, ATP production, and reserve capacity. However, OXA treatment reverses PA-induced changes in intracellular metabolism, increasing basal respiration, maximum respiration, ATP production, and reserve capacity. Collectively, these results support that OXA protects against PA-induced hypothalamic dysregulation, and may represent one mechanism through which OXA can ameliorate effects of obesogenic diet on brain health. PMID:27449757

  4. Zoledronic acid induces apoptosis and autophagy in cervical cancer cells.

    PubMed

    Wang, I-Te; Chou, Shou-Chu; Lin, Ying-Chin

    2014-12-01

    Cervical cancer is one of the most common gynecological cancers in association with high mortality and morbidity. The present study was aimed to investigate the in vitro effects of zoledronic acid (ZA) on viability and induction of apoptosis and autophagy as well as inflammatory effects in three human cervical cancer cell lines (HeLa, SiHa, and CaSki). Cell viability was measured by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay. Induction of apoptosis was determined by quantitation of expression level of B cell lymphoma 2 (Bcl-2) and Bax messenger RNA (mRNA) and identification of the proteolytic cleavage of poly (ADP)-ribose polymerase (PARP) and caspase-3. Autophagic effects were examined by quantitation of mRNA expression of autophagy protein 5 (ATG5) and beclin1 and identifying accumulation of microtubule-associated protein 1 light chain 3 (LC3)-II. Inflammatory effect was determined by measuring expression and production of IL-6 and cyclooxygenase-2 (Cox-2). The results showed ZA significantly inhibited cell viability of cervical cancer cells. ZA-induced cell death displayed features characteristic to both apoptosis and autophagy and was associated with different changes in the levels of Bcl-2 and Bax in the various cervical cancer lines. Expression of metastatic cytokines, IL-6 and Cox-2, was upregulated in the presence of ZA at low concentration. Our data revealed that ZA inhibits cervical cancer cells through the synergistic effect of apoptosis induction and autophagy activation.

  5. Lysophosphatidic acid mediates pleiotropic responses in skeletal muscle cells

    SciTech Connect

    Jean-Baptiste, Gael; Yang Zhao; Khoury, Chamel; Greenwood, Michael T.; E-mail: michael.greenwood@mcgill.ca

    2005-10-07

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

  6. Retinoic Acid as a Modulator of T Cell Immunity

    PubMed Central

    Bono, Maria Rosa; Tejon, Gabriela; Flores-Santibañez, Felipe; Fernandez, Dominique; Rosemblatt, Mario; Sauma, Daniela

    2016-01-01

    Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity. PMID:27304965

  7. Monomethylarsonous acid induces transformation of human bladder cells

    SciTech Connect

    Bredfeldt, Tiffany G.; Jagadish, Bhumasamudram; Eblin, Kylee E.; Mash, Eugene A.; Gandolfi, A. Jay . E-mail: gandolfi@pharmacy.arizona.edu

    2006-10-01

    Arsenic is a human bladder carcinogen. Arsenic is methylated to both monomethyl and dimethyl metabolites which have been detected in human urine. The trivalent methylated arsenicals are more toxic than inorganic arsenic. It is unknown if these trivalent methylated metabolites can directly cause malignant transformation in human cells. The goal of this study is determine if monomethylarsonous acid (MMA{sup III}) can induce malignant transformation in a human bladder urothelial cell line. To address this goal, a non-tumorigenic human urothelial cell line (UROtsa) was continuously exposed to 0.05 {mu}M MMA{sup III} for 52 weeks. Hyperproliferation was the first phenotypic change observed in exposed UROtsa (URO-MSC). After 12 weeks of exposure, doubling time had decreased from 42 h in unexposed control cells to 27 h in URO-MSC. Hyperproliferation continued to be a quality possessed by the URO-MSC cells after both 24 and 52 weeks of exposure to MMA{sup III}, which had a 40-50% reduction in doubling time. Throughout the 52-week exposure, URO-MSC cells retained an epithelial morphology with subtle morphological differences from control cells. 24 weeks of MMA{sup III} exposure was required to induce anchorage-independent growth as detected by colony formation in soft agar, a characteristic not found in UROtsa cells. To further substantiate that malignant transformation had occurred, URO-MSC cells were tested after 24 and 52 weeks of exposure to MMA{sup III} for the ability to form tumors in SCID mice. Enhanced tumorigenicity in SCID mouse xenografts was observed after 52 weeks of treatment with MMA{sup III}. These observations are the first demonstration of MMA{sup III}-induced malignant transformation in a human bladder urothelial cell line and provide important evidence that MMA{sup III} may be carcinogenic in human tissues.

  8. Changes in Dehydrodiferulic Acids and Peroxidase Activity against Ferulic Acid Associated with Cell Walls during Growth of Pinus pinaster Hypocotyl.

    PubMed Central

    Sanchez, M.; Pena, M. J.; Revilla, G.; Zarra, I.

    1996-01-01

    Hydroxycinnamic acids associated with hypocotyl cell walls of dark-grown seedlings of Pinus pinaster Aiton were extracted with 1 N NaOH and identified by gas chromatography-mass spectrometry. The main hydroxycinnamic acid found was ferulic acid. Diferulic acid dehydrodimers were also found, with the 8,8-coupled isomer (compound 11) being the dehydrodiferulate present in the highest amount. However, the 5,5-coupled isomer, commonly referred to referred to as diferulic acid, was not detected. Two truxillic acids, 4-4[prime]-dihydroxy-3-3[prime]-dimethoxy-[alpha]-truxillic acids I and II, were tentatively identified. The 8,8-coupled dehydrodiferulic acid (compound 11) was the phenolic acid that showed the most conspicuous changes with hypocotyl age as well as along the hypocotyl axis. Peroxidase activity against ferulic acid was found in the apoplastic fluid as well as being ionically and covalently bound to the cell walls. The peroxidase activity increased with hypocotyl age as well as from the subapical toward the basal region of the hypocotyls. A key role in the cell-wall stiffening of 8,8 but not 5,5 dimerization of ferulic acid catalyzed by cell-wall peroxidases is proposed. PMID:12226339

  9. Endothelial Differentiation of Human Adipose-Derived Stem Cells on Polyglycolic Acid/Polylactic Acid Mesh.

    PubMed

    Deng, Meng; Gu, Yunpeng; Liu, Zhenjun; Qi, Yue; Ma, Gui E; Kang, Ning

    2015-01-01

    Adipose-derived stem cell (ADSC) is considered as a cell source potentially useful for angiogenesis in tissue engineering and regenerative medicine. This study investigated the growth and endothelial differentiation of human ADSCs on polyglycolic acid/polylactic acid (PGA/PLA) mesh compared to 2D plastic. Cell adhesion, viability, and distribution of hADSCs on PGA/PLA mesh were observed by CM-Dil labeling, live/dead staining, and SEM examination while endothelial differentiation was evaluated by flow cytometry, Ac-LDL/UEA-1 uptake assay, immunofluorescence stainings, and gene expression analysis of endothelial related markers. Results showed hADSCs gained a mature endothelial phenotype with a positive ratio of 21.4 ± 3.7% for CD31+/CD34- when induced in 3D mesh after 21 days, which was further verified by the expressions of a comprehensive range of endothelial related markers, whereas hADSCs in 2D induced and 2D/3D noninduced groups all failed to differentiate into endothelial cells. Moreover, compared to 2D groups, the expression for α-SMA was markedly suppressed in 3D cultured hADSCs. This study first demonstrated the endothelial differentiation of hADSCs on the PGA/PLA mesh and pointed out the synergistic effect of PGA/PLA 3D culture and growth factors on the acquisition of mature characteristic endothelial phenotype. We believed this study would be the initial step towards the generation of prevascularized tissue engineered constructs.

  10. Requirement of Phosphoinositides Containing Stearic Acid To Control Cell Polarity.

    PubMed

    Doignon, François; Laquel, Patricia; Testet, Eric; Tuphile, Karine; Fouillen, Laetitia; Bessoule, Jean-Jacques

    2016-03-01

    Phosphoinositides (PIPs) are present in very small amounts but are essential for cell signaling, morphogenesis, and polarity. By mass spectrometry, we demonstrated that some PIPs with stearic acyl chains were strongly disturbed in a psi1Δ Saccharomyces cerevisiae yeast strain deficient in the specific incorporation of a stearoyl chain at the sn-1 position of phosphatidylinositol. The absence of PIPs containing stearic acid induced disturbances in intracellular trafficking, although the total amount of PIPs was not diminished. Changes in PIPs also induced alterations in the budding pattern and defects in actin cytoskeleton organization (cables and patches). Moreover, when the PSI1 gene was impaired, a high proportion of cells with bipolar cortical actin patches that occurred concomitantly with the bipolar localization of Cdc42p was specifically found among diploid cells. This bipolar cortical actin phenotype, never previously described, was also detected in a bud9Δ/bud9Δ strain. Very interestingly, overexpression of PSI1 reversed this phenotype.

  11. Organometallic catalysts for primary phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Walsh, Fraser

    1987-01-01

    A continuing effort by the U.S. Department of Energy to improve the competitiveness of the phosphoric acid fuel cell by improving cell performance and/or reducing cell cost is discussed. Cathode improvement, both in performance and cost, available through the use of a class of organometallic cathode catalysts, the tetraazaannulenes (TAAs), was investigated. A new mixed catalyst was identified which provides improved cathode performance without the need for the use of a noble metal. This mixed catalyst was tested under load for 1000 hr. in full cell at 160 to 200 C in phosphoric acid H3PO4, and was shown to provide stable performance. The mixed catalyst contains an organometallic to catalyze electroreduction of oxygen to hydrogen peroxide and a metal to catalyze further electroreduction of the hydrogen peroxide to water. Cathodes containing an exemplar mixed catalyst (e.g., Co bisphenyl TAA/Mn) operate at approximately 650 mV vs DHE in 160 C, 85% H3PO4 with oxygen as reactant. In developing this mixed catalyst, a broad spectrum of TAAs were prepared, tested in half-cell and in a rotating ring-disk electrode system. TAAs found to facilitate the production of hydrogen peroxide in electroreduction were shown to be preferred TAAs for use in the mixed catalyst. Manganese (Mn) was identified as a preferred metal because it is capable of catalyzing hydrogen peroxide electroreduction, is lower in cost and is of less strategic importance than platinum, the cathode catalyst normally used in the fuel cell.

  12. Direct formic acid microfluidic fuel cell design and performance evolution

    NASA Astrophysics Data System (ADS)

    Moreno-Zuria, A.; Dector, A.; Cuevas-Muñiz, F. M.; Esquivel, J. P.; Sabaté, N.; Ledesma-García, J.; Arriaga, L. G.; Chávez-Ramírez, A. U.

    2014-12-01

    This work reports the evolution of design, fabrication and testing of direct formic acid microfluidic fuel cells (DFAμFFC), the architecture and channel dimensions are miniaturized from a thousand to few cents of micrometers. Three generations of DFAμFFCs are presented, from the initial Y-shape configuration made by a hot pressing technique; evolving into a novel miniaturized fuel cell based on microfabrication technology using SU-8 photoresist as core material; to the last air-breathing μFFC with enhanced performance and built with low cost materials and processes. The three devices were evaluated in acidic media in the presence of formic acid as fuel and oxygen/air as oxidant. Commercial Pt/C (30 wt. % E-TEK) and Pd/C XC-72 (20 wt. %, E-TEK) were used as cathode and anode electrodes respectively. The air-breathing μFFC generation, delivered up to 27.3 mW cm-2 for at least 30 min, which is a competitive power density value at the lowest fuel flow of 200 μL min-1 reported to date.

  13. Mechanisms of 5-aminolevulic acid ester uptake in mammalian cells

    PubMed Central

    Rodriguez, Lorena; Batlle, Alcira; Di Venosa, Gabriela; Battah, Sinan; Dobbin, Paul; MacRobert, Alexander J; Casas, Adriana

    2006-01-01

    The porphyrin precursor 5-aminolevulinic acid (ALA) is being widely used in photodynamic therapy of cancer. Improvement in ALA delivery has been sought through the use of ALA derivatives, in particular the esterification of ALA with aliphatic alcohols, which in certain cases can improve cellular penetration and selectivity. ALA uptake systems appear to be distinctive for each cell type. The LM3 mammary adenocarcinoma cell line takes ALA up by BETA transporters. In this work, we investigated ALA derivative transport systems through the inhibition of radiolabelled ALA uptake in the LM3 cells. We also performed inhibition studies of γ-aminobutyric acid (GABA) uptake. The more lipohilic ALA derivatives hexyl-ALA and undecanoyl-ALA inhibit ALA uptake, whereas methyl-ALA, R, S-ALA-2-(hydroxymethyl)tetrahydropyranyl ester and the dendron aminomethane tris methyl 5-ALA does not inhibit ALA uptake. A similar pattern was found for GABA, except that the dendron inhibited GABA uptake. However, hexyl-ALA and undecanoyl-ALA are not taken up by BETA transporters, but by simple diffusion, although they still inhibit ALA uptake by binding to the cell membrane. These results show that different modifications to the ALA molecule lead to different uptake mechanisms. Whereas ALA is taken up by BETA transporters, none of the ALA derivatives shares the same mechanism. Knowledge of the mechanisms of ALA derivatives entry into the cells is essential to understand and improve ALA-mediated PDT and to the design of new ALA derivatives that may be taken up at a higher rate than ALA. PMID:16432502

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

    PubMed

    Lampen, A; Meyer, S; Nau, H

    2001-10-31

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

  15. Fatty acid double bond orientation alters interaction with L-cell fibroblasts.

    PubMed

    Heyliger, C E; Kheshgi, T J; Murphy, E J; Myers-Payne, S; Schroeder, F

    1996-02-23

    Relatively little is known of fatty acid specificity in cellular fatty acid uptake. In this study L-cells, a fibroblastic cell line with very low levels of endogenous cytosolic fatty acid binding protein, were used to examine the role of cis and trans unsaturation on fatty acid uptake. The fluorescent fatty acids, trans-parinaric acid and cis-parinaric acid, were used as analogs of straight-chain saturated, and kinked-chain unsaturated fatty acids, respectively, in order to evaluate the fatty acid specificity of the uptake system. Parinaric acid is poorly metabolizable; greater than 97% was unesterified while 3H-oleic acid was almost totally metabolized after 30 min uptake. Cis- and trans-parinaric acid uptake was saturable and dependent on the concentration of fatty acid. However, the initial rate and maximal amount of trans-parinaric acid taken up by the L-cells was greater than for cis-parinaric acid under the same conditions. The affinity of L-cell uptake for trans-parinaric acid (Km = 0.12 uM) was 35-fold higher than that for cis-parinaric acid (Km = 4.17 uM). Based on competition studies with oleic and stearic acids, it was concluded that the cis- and trans-parinaric acid were taken up by the same L-cell fatty acid uptake system. The results suggest that the L-cell fatty acid uptake system has selectivity for straight chain rather than kinked chain unsaturated fatty acids.

  16. Fatty acid double bond orientation alters interaction with L-cell fibroblasts.

    PubMed

    Heyliger, C E; Kheshgi, T J; Murphy, E J; Myers-Payne, S; Schroeder, F

    1996-02-23

    Relatively little is known of fatty acid specificity in cellular fatty acid uptake. In this study L-cells, a fibroblastic cell line with very low levels of endogenous cytosolic fatty acid binding protein, were used to examine the role of cis and trans unsaturation on fatty acid uptake. The fluorescent fatty acids, trans-parinaric acid and cis-parinaric acid, were used as analogs of straight-chain saturated, and kinked-chain unsaturated fatty acids, respectively, in order to evaluate the fatty acid specificity of the uptake system. Parinaric acid is poorly metabolizable; greater than 97% was unesterified while 3H-oleic acid was almost totally metabolized after 30 min uptake. Cis- and trans-parinaric acid uptake was saturable and dependent on the concentration of fatty acid. However, the initial rate and maximal amount of trans-parinaric acid taken up by the L-cells was greater than for cis-parinaric acid under the same conditions. The affinity of L-cell uptake for trans-parinaric acid (Km = 0.12 uM) was 35-fold higher than that for cis-parinaric acid (Km = 4.17 uM). Based on competition studies with oleic and stearic acids, it was concluded that the cis- and trans-parinaric acid were taken up by the same L-cell fatty acid uptake system. The results suggest that the L-cell fatty acid uptake system has selectivity for straight chain rather than kinked chain unsaturated fatty acids. PMID:8700156

  17. Lysophosphatidic acid-induced chemotaxis of bone cells.

    SciTech Connect

    Karagiosis, Sue A.; Masiello, Lisa M.; Bollinger, Nikki; Karin, Norm J.

    2006-07-01

    Lysophosphatidic acid (LPA) is a platelet-derived bioactive lipid that is postulated to regulate wound healing. LPA activates G protein-coupled receptors to induce Ca2+ signaling in MC3T3-E1 pre-osteoblasts, and is a potent chemotactic stimulus for these cells. Since bone fracture healing requires the migration of osteoblast progenitors, we postulate that LPA is among the factors that stimulate bone repair. UMR 106-01 cells, which express a more mature osteoblastic phenotype than MC3T3-E1 cells, did not migrate in response to LPA, although they express LPA receptors and exhibit LPA-induced Ca2+ signals. This suggests that LPA differentially induces pre-osteoblast chemotaxis, consistent with our hypothesis that LPA stimulates the motility of osteoblast progenitors during bone healing. LPA-stimulated MC3T3-E1 cells exhibit striking changes in morphology and F-actin architecture, and phosphatidylinositol-3 kinase (PI3K) is required for motility-associated cytoskeletal rearrangements in many cell types. We found a dose-dependent reduction in LPA-induced osteoblast migration when cells also were treated with the PI3K inhibitor, LY294002. Treatment of many cell types with LPA is associated with an autocrine/paracrine transactivation of the EGF receptor (EGFR) via shedding of surface-tethered EGFR ligands, a phenomenon often required for LPA-induced chemotaxis. MC3T3-E1 cells express multiple EGFR ligands (epigen, epiregulin, HB-EGF and amphiregulin) and migrated in response to EGF. However, while EGF-stimulated motility in MC3T3-E1 cells was blocked by an EGFR inhibitor, there was no significant effect on LPA-induced chemotaxis. Activation of MAP kinases is a hallmark of EGFR-mediated signaling, and EGF treatment of MC3T3-E1 cells led to a strong stimulation of ERK1/2 kinase. In contrast, LPA induced only a minor elevation in ERK activity. Thus, it is likely that the increase in ERK activity by LPA is related to cell proliferation associated with lipid treatment. We

  18. Fate of retinoic acid-activated embryonic cell lineages.

    PubMed

    Dollé, Pascal; Fraulob, Valérie; Gallego-Llamas, Jabier; Vermot, Julien; Niederreither, Karen

    2010-12-01

    Retinoic acid (RA), a vitamin A derivative, is synthesized by specific cell populations and acts as a diffusible embryonic signal activating ligand-inducible transcription factors, the RA receptors (RARs). RA-activatable transgenic systems have revealed many discrete, transient sites of RA action during development. However, there has been no attempt to permanently label the RA-activated cell lineages during mouse ontogenesis. We describe the characterization of a RA-activatable Cre transgene, which through crosses with a conditional reporter strain (the ROSA26R lacZ reporter), leads to a stable labeling of the cell populations experiencing RA signaling during embryogenesis. RA response-element (RARE)-driven Cre activity mimics at early stages the known activity of the corresponding RARE-lacZ transgene (Rossant et al.,1991). Stable labeling of the Cre-excised cell populations allows to trace the distribution of the RA-activated cell lineages at later stages. These are described in relationship with current models of RA activity in various developmental systems, including the embryonic caudal region, limb buds, hindbrain, sensory organs, and heart. PMID:21046629

  19. Dry compliant seal for phosphoric acid fuel cell

    DOEpatents

    Granata, Jr., Samuel J.; Woodle, Boyd M.

    1990-01-01

    A dry compliant overlapping seal for a phosphoric acid fuel cell preformed f non-compliant Teflon to make an anode seal frame that encircles an anode assembly, a cathode seal frame that encircles a cathode assembly and a compliant seal frame made of expanded Teflon, generally encircling a matrix assembly. Each frame has a thickness selected to accommodate various tolerances of the fuel cell elements and are either bonded to one of the other frames or to a bipolar or end plate. One of the non-compliant frames is wider than the other frames forming an overlap of the matrix over the wider seal frame, which cooperates with electrolyte permeating the matrix to form a wet seal within the fuel cell that prevents process gases from intermixing at the periphery of the fuel cell and a dry seal surrounding the cell to keep electrolyte from the periphery thereof. The frames may be made in one piece, in L-shaped portions or in strips and have an outer perimeter which registers with the outer perimeter of bipolar or end plates to form surfaces upon which flanges of pan shaped, gas manifolds can be sealed.

  20. Induction of autophagy by amino acid starvation in fish cells.

    PubMed

    Yabu, Takeshi; Imamura, Shintaro; Mizusawa, Nanami; Touhata, Ken; Yamashita, Michiaki

    2012-08-01

    Autophagy is well established as a starvation-induced process in yeast and mammalian cells and tissues. To elucidate the cellular mechanisms induced by starvation in fish, we characterized the induction of autophagy in cultured zebrafish cells under starvation conditions. As an autophagic marker protein, the microtubule-associated protein 1-light chain 3B protein (MAP1-LC3B) was cloned from the fish cells, and its expression and localization were characterized. In zebrafish embryonic (ZE) cells, posttranslational modifications produced two distinct forms of MAP1-LC3B, i.e., a cytosolic form and a membrane-bound form (types I and II, respectively). Immunofluorescence microscopy revealed fluorescently labeled autophagosomes in cells stably transfected with a green fluorescent protein (GFP)–MAP1-LC3B fusion protein and showed that this protein accumulated in punctate dots in a time-dependent manner in response to amino acid starvation. Starvation also induced the degradation of long-lived proteins. Treatment with 3-methyladenine and wortmannin, two class-III inhibitors of phosphoinositide 3-kinase (PI3K), repressed autophagy under starvation conditions, indicating that the PI3K class-III pathway regulates starvation-induced autophagy in fish.

  1. Commercial phosphoric acid fuel cell system technology development

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.; Warshay, M.; Simons, S. N.; King, R. B.

    1979-01-01

    A review of the current commercial phosphoric acid fuel cell system technology development efforts is presented. In both the electric utility and on-site integrated energy system applications, reducing cost and increasing reliability are the technology drivers at this time. The longstanding barrier to the attainment of these goals, which manifests itself in a number of ways, has been materials. The differences in approach among the three major participants (United Technologies Corporation (UTC), Westinghouse Electric Corporation/Energy Research Corporation (ERC), and Engelhard Industries) and their unique technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy are discussed.

  2. Effects of omega-3 fatty acids on vascular smooth muscle cells: reduction in arachidonic acid incorporation into inositol phospholipids.

    PubMed

    Yerram, N R; Spector, A A

    1989-07-01

    A rapid increase in arachidonic acid incorporation into phosphatidylinositol (PI) occurred following exposure of cultured porcine pulmonary artery smooth muscle cells to calcium ionophore A23187. This response was specific for PI and phosphatidic acid; none of the other phosphoglycerides showed any increase in arachidonic acid incorporation. The incorporation of [3H]inositol also was increased, indicating that complete synthesis of PI rather than only fatty acylation occurred in response to the ionophore. The presence of omega-3 fatty acids, especially eicosapentaenoic acid (EPA), reduced arachidonic acid but not inositol incorporation into PI. Stimulated incorporation of EPA also occurred under these conditions, suggesting that EPA replaces arachidonic acid in the newly synthesized pool of PI. Although much less arachidonic acid was incorporated into the polyphosphoinositides following exposure to the ionophore, arachidonic acid incorporation into these phosphorylated derivatives also decreased when EPA was present. These findings suggest that when omega-3 fatty acids are available, less arachidonic acid is channeled into the inositol phospholipids of activated smooth muscle cells because of replacement by EPA. This may represent a mechanism whereby omega-3 fatty acids, especially EPA, can accumulate in the metabolically active pools of inositol phospholipids and thereby possibly influence the properties or responsiveness of vascular smooth muscle.

  3. Molten Carbonate and Phosphoric Acid Stationary Fuel Cells: Overview and Gap Analysis

    SciTech Connect

    Remick, R.; Wheeler, D.

    2010-09-01

    This report describes the technical and cost gap analysis performed to identify pathways for reducing the costs of molten carbonate fuel cell (MCFC) and phosphoric acid fuel cell (PAFC) stationary fuel cell power plants.

  4. Pulse charging of lead-acid traction cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1980-01-01

    Pulse charging, as a method of rapidly and efficiently charging 300 amp-hour lead-acid traction cells for an electric vehicle application was investigated. A wide range of charge pulse current square waveforms were investigated and the results were compared to constant current charging at the time averaged pulse current values. Representative pulse current waveforms were: (1) positive waveform-peak charge pulse current of 300 amperes (amps), discharge pulse-current of zero amps, and a duty cycle of about 50%; (2) Romanov waveform-peak charge pulse current of 300 amps, peak discharge pulse current of 15 amps, and a duty of 50%; and (3) McCulloch waveform peak charge pulse current of 193 amps, peak discharge pulse current of about 575 amps, and a duty cycle of 94%. Experimental results indicate that on the basis of amp-hour efficiency, pulse charging offered no significant advantage as a method of rapidly charging 300 amp-hour lead-acid traction cells when compared to constant current charging at the time average pulse current value. There were, however, some disadvantages of pulse charging in particular a decrease in charge amp-hour and energy efficiencies and an increase in cell electrolyte temperature. The constant current charge method resulted in the best energy efficiency with no significant sacrifice of charge time or amp-hour output. Whether or not pulse charging offers an advantage over constant current charging with regard to the cell charge/discharge cycle life is unknown at this time.

  5. Combined staurosporine and retinoic acid induces differentiation in retinoic acid resistant acute promyelocytic leukemia cell lines

    PubMed Central

    Ge, Dong-zheng; Sheng, Yan; Cai, Xun

    2014-01-01

    All-trans retinoic acid (ATRA) resistance has been a critical problem in acute promyelocytic leukemia (APL) relapsed patients. In ATRA resistant APL cell lines NB4-R1 and NB4-R2, the combination of staurosporine and ATRA synergized to trigger differentiation accompanied by significantly enhanced protein level of CCAAT/enhancer binding protein ε (C/EBPε) and C/EBPβ as well as the phosphorylation of mitogen-activated protein (MEK) and extracellular signal-regulated kinase (ERK). Furthermore, attenuation of the MEK activation blocked not only the differentiation but also the increased protein level of C/EBPε and C/EBPβ. Taken together, we concluded that the combination of ATRA and staurosporine could overcome differentiation block via MEK/ERK signaling pathway in ATRA-resistant APL cell lines. PMID:24769642

  6. Breakdown of Cell Wall Nanostructure in Dilute Acid Pretreated Biomass

    SciTech Connect

    Pingali, Sai Venkatesh; Urban, Volker S; Heller, William T; McGaughey, Joseph; O'Neill, Hugh Michael; Foston, Marcus B; Myles, Dean A A; Ragauskas, Arthur J; Evans, Barbara R

    2010-01-01

    The generation of bioethanol from lignocellulosic biomass holds great promise for renewable and clean energy production. A better understanding of the complex mechanisms of lignocellulose breakdown during various pretreatment methods is needed to realize this potential in a cost and energy efficient way. Here, we use small-angle neutron scattering (SANS) to characterize morphological changes in switchgrass lignocellulose across molecular to sub-micron length scales resulting from the industrially-relevant dilute acid pretreatment method. Our results demonstrate that dilute acid pretreatment increases the cross-sectional radius of the crystalline cellulose fibril. This change is accompanied by removal of hemicellulose and the formation of Rg ~ 135 lignin aggregates. The structural signature of smooth cell wall surfaces is observed at length scales larger than 1000 , and it remains remarkably invariable during pretreatment. This study elucidates the interplay of the different biomolecular components in the break down process of switchgrass by dilute acid pretreatment. The results are important for the development of efficient strategies of biomass to biofuel conversion.

  7. Fibroblastic reticular cell-derived lysophosphatidic acid regulates confined intranodal T-cell motility

    PubMed Central

    Takeda, Akira; Kobayashi, Daichi; Aoi, Keita; Sasaki, Naoko; Sugiura, Yuki; Igarashi, Hidemitsu; Tohya, Kazuo; Inoue, Asuka; Hata, Erina; Akahoshi, Noriyuki; Hayasaka, Haruko; Kikuta, Junichi; Scandella, Elke; Ludewig, Burkhard; Ishii, Satoshi; Aoki, Junken; Suematsu, Makoto; Ishii, Masaru; Takeda, Kiyoshi; Jalkanen, Sirpa; Miyasaka, Masayuki; Umemoto, Eiji

    2016-01-01

    Lymph nodes (LNs) are highly confined environments with a cell-dense three-dimensional meshwork, in which lymphocyte migration is regulated by intracellular contractile proteins. However, the molecular cues directing intranodal cell migration remain poorly characterized. Here we demonstrate that lysophosphatidic acid (LPA) produced by LN fibroblastic reticular cells (FRCs) acts locally to LPA2 to induce T-cell motility. In vivo, either specific ablation of LPA-producing ectoenzyme autotaxin in FRCs or LPA2 deficiency in T cells markedly decreased intranodal T cell motility, and FRC-derived LPA critically affected the LPA2-dependent T-cell motility. In vitro, LPA activated the small GTPase RhoA in T cells and limited T-cell adhesion to the underlying substrate via LPA2. The LPA-LPA2 axis also enhanced T-cell migration through narrow pores in a three-dimensional environment, in a ROCK-myosin II-dependent manner. These results strongly suggest that FRC-derived LPA serves as a cell-extrinsic factor that optimizes T-cell movement through the densely packed LN reticular network. DOI: http://dx.doi.org/10.7554/eLife.10561.001 PMID:26830463

  8. Endothelial Differentiation of Human Adipose-Derived Stem Cells on Polyglycolic Acid/Polylactic Acid Mesh

    PubMed Central

    Deng, Meng; Gu, Yunpeng; Liu, Zhenjun; Qi, Yue; Ma, Gui E.; Kang, Ning

    2015-01-01

    Adipose-derived stem cell (ADSC) is considered as a cell source potentially useful for angiogenesis in tissue engineering and regenerative medicine. This study investigated the growth and endothelial differentiation of human ADSCs on polyglycolic acid/polylactic acid (PGA/PLA) mesh compared to 2D plastic. Cell adhesion, viability, and distribution of hADSCs on PGA/PLA mesh were observed by CM-Dil labeling, live/dead staining, and SEM examination while endothelial differentiation was evaluated by flow cytometry, Ac-LDL/UEA-1 uptake assay, immunofluorescence stainings, and gene expression analysis of endothelial related markers. Results showed hADSCs gained a mature endothelial phenotype with a positive ratio of 21.4 ± 3.7% for CD31+/CD34− when induced in 3D mesh after 21 days, which was further verified by the expressions of a comprehensive range of endothelial related markers, whereas hADSCs in 2D induced and 2D/3D noninduced groups all failed to differentiate into endothelial cells. Moreover, compared to 2D groups, the expression for α-SMA was markedly suppressed in 3D cultured hADSCs. This study first demonstrated the endothelial differentiation of hADSCs on the PGA/PLA mesh and pointed out the synergistic effect of PGA/PLA 3D culture and growth factors on the acquisition of mature characteristic endothelial phenotype. We believed this study would be the initial step towards the generation of prevascularized tissue engineered constructs. PMID:26106426

  9. Universal nucleic acids sample preparation method for cells, spores and their mixture

    DOEpatents

    Bavykin, Sergei

    2011-01-18

    The present invention relates to a method for extracting nucleic acids from biological samples. More specifically the invention relates to a universal method for extracting nucleic acids from unidentified biological samples. An advantage of the presently invented method is its ability to effectively and efficiently extract nucleic acids from a variety of different cell types including but not limited to prokaryotic or eukaryotic cells and/or recalcitrant organisms (i.e. spores). Unlike prior art methods which are focused on extracting nucleic acids from vegetative cell or spores, the present invention effectively extracts nucleic acids from spores, multiple cell types or mixtures thereof using a single method. Important that the invented method has demonstrated an ability to extract nucleic acids from spores and vegetative bacterial cells with similar levels effectiveness. The invented method employs a multi-step protocol which erodes the cell structure of the biological sample, isolates, labels, fragments nucleic acids and purifies labeled samples from the excess of dye.

  10. Shedding light on proteins, nucleic acids, cells, humans and fish

    NASA Technical Reports Server (NTRS)

    Setlow, Richard B.

    2002-01-01

    I was trained as a physicist in graduate school. Hence, when I decided to go into the field of biophysics, it was natural that I concentrated on the effects of light on relatively simple biological systems, such as proteins. The wavelengths absorbed by the amino acid subunits of proteins are in the ultraviolet (UV). The wavelengths that affect the biological activities, the action spectra, also are in the UV, but are not necessarily parallel to the absorption spectra. Understanding these differences led me to investigate the action spectra for affecting nucleic acids, and the effects of UV on viruses and cells. The latter studies led me to the discovery of the important molecular nature of the damages affecting DNA (cyclobutane pyrimidine dimers) and to the discovery of nucleotide excision repair. Individuals with the genetic disease xeroderma pigmentosum (XP) are extraordinarily sensitive to sunlight-induced skin cancer. The finding, by James Cleaver, that their skin cells were defective in DNA repair strongly suggested that DNA damage was a key step in carcinogenesis. Such information was important for estimating the wavelengths in sunlight responsible for human skin cancer and for predicting the effects of ozone depletion on the incidence of non-melanoma skin cancer. It took experiments with backcross hybrid fish to call attention to the probable role of the longer UV wavelengths not absorbed by DNA in the induction of melanoma. These reflections trace the biophysicist's path from molecules to melanoma.

  11. Shedding light on proteins, nucleic acids, cells, humans and fish.

    PubMed

    Setlow, Richard B

    2002-03-01

    I was trained as a physicist in graduate school. Hence, when I decided to go into the field of biophysics, it was natural that I concentrated on the effects of light on relatively simple biological systems, such as proteins. The wavelengths absorbed by the amino acid subunits of proteins are in the ultraviolet (UV). The wavelengths that affect the biological activities, the action spectra, also are in the UV, but are not necessarily parallel to the absorption spectra. Understanding these differences led me to investigate the action spectra for affecting nucleic acids, and the effects of UV on viruses and cells. The latter studies led me to the discovery of the important molecular nature of the damages affecting DNA (cyclobutane pyrimidine dimers) and to the discovery of nucleotide excision repair. Individuals with the genetic disease xeroderma pigmentosum (XP) are extraordinarily sensitive to sunlight-induced skin cancer. The finding, by James Cleaver, that their skin cells were defective in DNA repair strongly suggested that DNA damage was a key step in carcinogenesis. Such information was important for estimating the wavelengths in sunlight responsible for human skin cancer and for predicting the effects of ozone depletion on the incidence of non-melanoma skin cancer. It took experiments with backcross hybrid fish to call attention to the probable role of the longer UV wavelengths not absorbed by DNA in the induction of melanoma. These reflections trace the biophysicist's path from molecules to melanoma.

  12. Enhancement of cell viability after treatment with polyunsaturated fatty acids.

    PubMed

    Bartl, J; Walitza, S; Grünblatt, E

    2014-01-24

    Attention-deficit/hyperactivity disorder (ADHD) is highly prevalent in children and adolescents and both environmental and genetic factors play major roles. Polyunsaturated fatty acids (PUFAs) are postulated to contribute to the development of the infant brain and an imbalance in these may increase the risk of ADHD. In recent clinical studies, supplementation with PUFAs improved symptoms of ADHD in some cases. Similarly, some beneficial effects were observed with PUFA treatment in neuronal cell cultures. Therefore, in this study, we hypothesized that a specific PUFA combination (available on the market as Equazen™ [Vifor Pharma, Switzerland]) along with iron, zinc, or vitamin B5 (vitB5) would produce an additive beneficial effect on the viability of rat pheochromocytoma-12 dopaminergic cells. The specific PUFA combination alone, as well as added to each of the three nutrients, was tested in a dose-response manner. The specific PUFAs significantly improved cell viability, starting at very low doses (100pM) from 60h up to 90h; while the combined treatment with vitB5 and minerals did not provide additional benefit. Our results confirmed the beneficial effect of the specific PUFAs on neuronal cell viability; although supplementation with minerals and vitB5 did not enhance this effect.

  13. Advanced water-cooled phosphoric acid fuel cell development

    SciTech Connect

    Not Available

    1992-09-01

    This program was conducted to improve the performance and minimize the cost of existing water-cooled phosphoric acid fuel cell stacks for electric utility and on-site applications. The goals for the electric utility stack technology were a power density of at least 175 watts per square foot over a 40,000-hour useful life and a projected one-of-a-kind, full-scale manufactured cost of less than $400 per kilowatt. The program adapted the existing on-site Configuration-B cell design to electric utility operating conditions and introduced additional new design features. Task 1 consisted of the conceptual design of a full-scale electric utility cell stack that meets program objectives. The conceptual design was updated to incorporate the results of material and process developments in Tasks 2 and 3, as well as results of stack tests conducted in Task 6. Tasks 2 and 3 developed the materials and processes required to fabricate the components that meet the program objectives. The design of the small area and 10-ft{sup 2} stacks was conducted in Task 4. Fabrication and assembly of the short stacks were conducted in Task 5 and subsequent tests were conducted in Task 6. The management and reporting functions of Task 7 provided DOE/METC with program visibility through required documentation and program reviews. This report describes the cell design and development effort that was conducted to demonstrate, by subscale stack test, the technical achievements made toward the above program objectives.

  14. Gambogic acid induces apoptosis in diffuse large B-cell lymphoma cells via inducing proteasome inhibition

    PubMed Central

    Shi, Xianping; Lan, Xiaoying; Chen, Xin; Zhao, Chong; Li, Xiaofen; Liu, Shouting; Huang, Hongbiao; Liu, Ningning; Zang, Dan; Liao, Yuning; Zhang, Peiquan; Wang, Xuejun; Liu, Jinbao

    2015-01-01

    Resistance to chemotherapy is a great challenge to improving the survival of patients with diffuse large B-cell lymphoma (DLBCL), especially those with activated B-cell-like DLBCL (ABC-DLBCL). Therefore it is urgent to search for novel agents for the treatment of DLBCL. Gambogic acid (GA), a small molecule derived from Chinese herb gamboges, has been approved for Phase II clinical trial for cancer therapy by Chinese FDA. In the present study, we investigated the effect of GA on cell survival and apoptosis in DLBCL cells including both GCB- and ABC-DLBCL cells. We found that GA induced growth inhibition and apoptosis of both GCB- and ABC-DLBCL cells in vitro and in vivo, which is associated with proteasome malfunction. These findings provide significant pre-clinical evidence for potential usage of GA in DLBCL therapy particularly in ABC-DLBCL treatment. PMID:25853502

  15. Gambogic acid induces apoptotic cell death in T98G glioma cells.

    PubMed

    Thida, Mya; Kim, Dae Won; Tran, Thi Thu Thuy; Pham, Minh Quan; Lee, Heesu; Kim, Inki; Lee, Jae Wook

    2016-02-01

    Gambogic acid (GA), a natural product with a xanthone structure, has a broad range of anti-proliferative effects on cancer cell lines. We evaluated GA for its cytotoxic effects on T98G glioblastoma cells. GA exhibited potent anti-proliferative activity and induced apoptosis in T98G glioblastoma cells in a dose-dependent manner. Incubation of cells with GA revealed apoptotic features including increased Bax and AIF expression, cytochrome c release, and cleavage of caspase-3, -8, -9, and PARP, while Bcl-2 expression was downregulated. Furthermore, GA induced reactive oxygen species (ROS) generation in T98G cells. Our results indicate that GA increases Bax- and AIF-associated apoptotic signaling in glioblastoma cells. PMID:26631318

  16. Uric acid: a modulator of prostate cells and activin sensitivity.

    PubMed

    Sangkop, Febbie; Singh, Geeta; Rodrigues, Ely; Gold, Elspeth; Bahn, Andrew

    2016-03-01

    Elevated serum uric acid (SUA) or urate is associated with inflammation and gout. Recent evidence has linked urate to cancers, but little is known about urate effects in prostate cancer. Activins are inflammatory cytokines and negative growth regulators in the prostate. A hallmark of prostate cancer progression is activin insensitivity; however, mechanisms underlying this are unclear. We propose that elevated SUA is associated with prostate cancer counteracting the growth inhibitory effects of activins. The expression of activins A and B, urate transporter GLUT9 and tissue urate levels were examined in human prostate disease. Intracellular and secreted urate and GLUT9 expression were assessed in human prostate cancer cell lines. Furthermore, the effects of urate and probenecid, a known urate transport inhibitor, were determined in combination with activin A. Activin A expression was increased in low-grade prostate cancer, whereas activin B expression was reduced in high-grade prostate cancer. Intracellular urate levels decreased in all prostate pathologies, while GLUT9 expression decreased in benign prostatic hyperplasia, prostatitis and high-grade prostate cancer. Activin responsive LNCaP cells had higher intracellular and lower secreted urate levels than activin-insensitive PC3 cells. GLUT9 expression in prostate cancer cells was progressively lower than in prostate epithelial cells. Elevated extracellular urate was growth promoting in vitro, which was abolished by the gout medication probenecid, and it antagonized the growth inhibitory effects of activins. This study shows for the first time that a change in plasma or intracellular urate levels, possibly involving GLUT9 and a urate efflux transporter, has an impact on prostate cancer cell growth, and that lowering SUA levels in prostate cancer is likely to be therapeutically beneficial. PMID:26910779

  17. Salicylic acid antagonizes abscisic acid inhibition of shoot growth and cell cycle progression in rice

    NASA Astrophysics Data System (ADS)

    Meguro, Ayano; Sato, Yutaka

    2014-04-01

    We analysed effects of abscisic acid (ABA, a negative regulatory hormone), alone and in combination with positive or neutral hormones, including salicylic acid (SA), on rice growth and expression of cell cycle-related genes. ABA significantly inhibited shoot growth and induced expression of OsKRP4, OsKRP5, and OsKRP6. A yeast two-hybrid assay showed that OsKRP4, OsKRP5, and OsKRP6 interacted with OsCDKA;1 and/or OsCDKA;2. When SA was simultaneously supplied with ABA, the antagonistic effect of SA completely blocked ABA inhibition. SA also blocked ABA inhibition of DNA replication and thymidine incorporation in the shoot apical meristem. These results suggest that ABA arrests cell cycle progression by inducing expression of OsKRP4, OsKRP5, and OsKRP6, which inhibit the G1/S transition, and that SA antagonizes ABA by blocking expression of OsKRP genes.

  18. Induction of cellular deoxyribonucleic acid synthesis in butyrate-treated cells by simian virus 40 deoxyribonucleic acid

    SciTech Connect

    Kawasaki, S.; Diamond, L.; Baserga, R.

    1981-11-01

    Sodium butyrate (3mM) inhibited the entry into the S phase of quiescent 3T3 cells stimulated by serum, but had no effect on the accumulation of cellular ribonucleic acid. Simian virus 40 infection or manual microinjection of cloned fragments from the simian virus 40 A gene caused quiescent 3T3 cells to enter the S phase even in the presence of butyrate. NGI cells, a line of 3T3 cells transformed by simian virus 40, grew vigorously in 3 mM butyrate. Homokaryons were formed between G/sub 1/ and S-phase 3T3 cells. Butyrate inhibited the induction of deoxyribonucleic acid synthesis that usually occurs in G/sub 1/ nuclei when G/sub 1/ cells are fused with S-phase cells. However, when G/sub 1/ 3T3 cells were fused with exponentially growing NGI cells, the 3T3 nuclei were induced to enter deoxyribonucleic acid synthesis. In tsAF8 cells, a ribonucleic acid polymerase II mutant that stops in the G/sub 1/ phase of the cell cycle, no temporal sequence was demonstrated between the butyrate block and the temperature-sensitive block. These results confirm previous reports that certain virally coded proteins can induce cell deoxyribonucleic acid synthesis in the absence of cellular functions that are required by serum-stimulated cells. The author's interpretation of these data is that butyrate inhibited cell growth by inhibiting the expression of genes required for the G/sub o/ ..-->.. G/sub 1/ ..-->.. S transition and that the product of the simian virus 40 A gene overrode this inhibition by providing all of the necessary functions for the entry into the S phase.

  19. cAMP-response-element-binding protein positively regulates breast cancer metastasis and subsequent bone destruction

    SciTech Connect

    Son, Jieun; Lee, Jong-Ho; Kim, Ha-Neui; Ha, Hyunil Lee, Zang Hee

    2010-07-23

    Research highlights: {yields} CREB is highly expressed in advanced breast cancer cells. {yields} Tumor-related factors such as TGF-{beta} further elevate CREB expression. {yields} CREB upregulation stimulates metastatic potential of breast cancer cells. {yields} CREB signaling is required for breast cancer-induced bone destruction. -- Abstract: cAMP-response-element-binding protein (CREB) signaling has been reported to be associated with cancer development and poor clinical outcome in various types of cancer. However, it remains to be elucidated whether CREB is involved in breast cancer development and osteotropism. Here, we found that metastatic MDA-MB-231 breast cancer cells exhibited higher CREB expression than did non-metastatic MCF-7 cells and that CREB expression was further increased by several soluble factors linked to cancer progression, such as IL-1, IGF-1, and TGF-{beta}. Using wild-type CREB and a dominant-negative form (K-CREB), we found that CREB signaling positively regulated the proliferation, migration, and invasion of MDA-MB-231 cells. In addition, K-CREB prevented MDA-MB-231 cell-induced osteolytic lesions in a mouse model of cancer metastasis. Furthermore, CREB signaling in cancer cells regulated the gene expression of PTHrP, MMPs, and OPG, which are closely involved in cancer metastasis and bone destruction. These results indicate that breast cancer cells acquire CREB overexpression during their development and that this CREB upregulation plays an important role in multiple steps of breast cancer bone metastasis.

  20. [Alpha-lipoic acid triggers elimination of cells with abnormal nuclei in human carcinoma epidermoid cell line].

    PubMed

    Kisurina-Evgen'eva, O P; Onishchenko, G E

    2010-01-01

    The skin is usually exposed to adverse environmental conditions that may cause pathological cell proliferation and cellular transformations leading to the formation of malignant cells. Antioxidants may affect these processes and induce the elimination of transformed cell. The purpose of this work was to investigate the effect of alfa-lipoic acid on human carcinoma epidermoid cell line A431. Our results showed that alfa-lipoic acid induced inhibition of cell proliferation or stimulated apoptotic cell death. Cells with abnormal nuclei were eliminated by apoptosis. Electron microscopy showed that survived cells had typical for control cells shape and organization of the nuclei, organization of the cytoplasm and organelles. Thus, alfa-lipoic acid not only triggered apoptosis of carcinoma cells, but it may also activate the mechanism of elimination of cells with abnormal chromosome number.

  1. Ribonucleic Acid Regulation in Permeabilized Cells of Escherichia coli Capable of Ribonucleic Acid and Protein Synthesis1

    PubMed Central

    Atherly, Alan G.

    1974-01-01

    A cell permeabilization procedure is described that reduces viability less than 10% and does not significantly reduce the rates of ribonucleic acid and protein synthesis when appropriately supplemented. Permeabilization abolishes the normal stringent coupling of protein and ribonucleic acid synthesis. PMID:4364330

  2. Physiological responses to acid stress by Saccharomyces cerevisiae when applying high initial cell density

    PubMed Central

    Guo, Zhong-peng; Olsson, Lisbeth

    2016-01-01

    High initial cell density is used to increase volumetric productivity and shorten production time in lignocellulosic hydrolysate fermentation. Comparison of physiological parameters in high initial cell density cultivation of Saccharomyces cerevisiae in the presence of acetic, formic, levulinic and cinnamic acids demonstrated general and acid-specific responses of cells. All the acids studied impaired growth and inhibited glycolytic flux, and caused oxidative stress and accumulation of trehalose. However, trehalose may play a role other than protecting yeast cells from acid-induced oxidative stress. Unlike the other acids, cinnamic acid did not cause depletion of cellular ATP, but abolished the growth of yeast on ethanol. Compared with low initial cell density, increasing initial cell density reduced the lag phase and improved the bioconversion yield of cinnamic acid during acid adaptation. In addition, yeast cells were able to grow at elevated concentrations of acid, probable due to the increase in phenotypic cell-to-cell heterogeneity in large inoculum size. Furthermore, the specific growth rate and the specific rates of glucose consumption and metabolite production were significantly lower than at low initial cell density, which was a result of the accumulation of a large fraction of cells that persisted in a viable but non-proliferating state. PMID:27620460

  3. Eicosopentaneoic Acid and Other Free Fatty Acid Receptor Agonists Inhibit Lysophosphatidic Acid- and Epidermal Growth Factor-Induced Proliferation of Human Breast Cancer Cells

    PubMed Central

    Hopkins, Mandi M.; Zhang, Zhihong; Liu, Ze; Meier, Kathryn E.

    2016-01-01

    Many key actions of ω-3 (n-3) fatty acids have recently been shown to be mediated by two G protein-coupled receptors (GPCRs) in the free fatty acid receptor (FFAR) family, FFA1 (GPR40) and FFA4 (GPR120). n-3 Fatty acids inhibit proliferation of human breast cancer cells in culture and in animals. In the current study, the roles of FFA1 and FFA4 were investigated. In addition, the role of cross-talk between GPCRs activated by lysophosphatidic acid (LPA), and the tyrosine kinase receptor activated by epidermal growth factor (EGF), was examined. In MCF-7 and MDA-MB-231 human breast cancer cell lines, both LPA and EGF stimulated proliferation, Erk activation, Akt activation, and CCN1 induction. LPA antagonists blocked effects of LPA and EGF on proliferation in MCF-7 and MDA-MB-231, and on cell migration in MCF-7. The n-3 fatty acid eicosopentaneoic acid inhibited LPA- and EGF-induced proliferation in both cell lines. Two synthetic FFAR agonists, GW9508 and TUG-891, likewise inhibited LPA- and EGF-induced proliferation. The data suggest a major role for FFA1, which was expressed by both cell lines. The results indicate that n-3 fatty acids inhibit breast cancer cell proliferation via FFARs, and suggest a mechanism involving negative cross-talk between FFARS, LPA receptors, and EGF receptor. PMID:26821052

  4. Loss of lysophosphatidic acid receptor-3 enhances cell migration in rat lung tumor cells

    SciTech Connect

    Hayashi, Mai; Okabe, Kyoko; Yamawaki, Yasuna; Teranishi, Miki; Honoki, Kanya; Mori, Toshio; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2011-02-18

    Research highlights: {yields} Loss of the Lpar3 expression due to aberrant DNA methylation occurred in rat lung tumor cells. {yields} The Lpar3 inhibited cell migration of rat lung tumor cells. {yields} The Lpar3 may act as a negative regulator of rat lung tumor cells. -- Abstract: Lysophosphatidic acid (LPA) indicates several biological effects, such as cell proliferation, differentiation and migration. LPA interacts with G protein-coupled transmembrane LPA receptors. In our previous report, we detected that loss of the LPA receptor-1 (Lpar1) expression is due to its aberrant DNA methylation in rat tumor cell lines. In this study, to assess an involvement of the other LPA receptor, Lpar3, in the pathogenesis of rat lung tumor cells, we measured the expression levels of the Lpar3 gene and its DNA methylation status by reverse transcription (RT)-polymerase chain reaction (PCR) and bisulfite sequencing analyses, respectively. RLCNR lung adenocarcinoma cells showed reduced expression of the Lpar3, compared with normal lung tissues. In the 5' upstream region of the Lpar3, normal lung tissues were unmethylated. By contrast, RLCNR cells were highly methylated, correlating with reduced expressions of the Lpar3. Based on these results, we generated the Lpar3-expressing RLCNR-a3 cells and measured the cell migration ability. Interestingly, the cell migration of RLCNR-a3 cells was significantly lower than that of RLCNR cells. This study suggests that loss of the Lpar3 due to aberrant DNA methylation may be involved in the progression of rat lung tumor cells.

  5. Folic acid-CdTe quantum dot conjugates and their applications for cancer cell targeting

    SciTech Connect

    Suriamoorthy, Preethi; Zhang, Xing; Hao, Guiyang; Joly, Alan G.; Singh, S.; Hossu, Marius; Sun, Xiankai; Chen, Wei

    2010-12-01

    In this study, we report the preparation,luminescence, and targeting properties of folic acid- CdTe quantum dot conjugates. Water-soluble CdTe quantum dots were synthesized and conjugated with folic acid using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-N-hydroxysuccinimide chemistry. The in-fluence of folic acid on the luminescence properties of CdTe quantum dots was investigated, and no energy transfer between them was observed. To investigate the efficiency of folic acid-CdTe nanoconjugates for tumor targeting, pure CdTe quantum dots and folic acid-coated CdTe quantum dots were incubated with human naso- pharyngeal epidermal carcinoma cell line with positive expressing folic acid receptors (KB cells) and lung cancer cells without expression of folic acid receptors (A549 cells). For the cancer cells with positive folate receptors (KB cells), the uptake for CdTe quantum dots is very low, but for folic acid-CdTe nanoconjugates, the uptake is very high. For the lung cancer cells without folate receptors (A549 cells), the uptake for folic acid- CdTe nanoconjugates is also very low. The results indicate that folic acid is an effective targeting molecule for tumor cells with overexpressed folate receptors.

  6. Cytotoxicity and immunotoxicity of cyclopiazonic acid on human cells.

    PubMed

    Hymery, Nolwenn; Masson, Floriane; Barbier, Georges; Coton, Emmanuel

    2014-08-01

    In this study, in vitro cytotoxicity and immunotoxicity of the mycotoxin cyclopiazonic acid (CPA) was evaluated on human cells. To evaluate cytoxicity, several cellular targets were used (CD34+, monocytes, THP-1 and Caco-2). Monocytes were more sensitive to CPA than the THP-1 monocytic cell line after 48h of incubation in the tested conditions. Half maximal inhibitory concentration (IC50) were determined to be 8.5 × 10(-8) and 1.75 × 10(-7)M for monocytes and THP1, respectively, while IC50>1.25 × 10(-7)M was observed for Caco-2 and CD34+ cells. The CPA effect on macrophage differentiation was also examined at non-cytotoxic concentrations. The monocyte differentiation process was markedly disturbed in the presence of CPA. After 6 days of culture, CD71 expression was downregulated, while CD14 and CD11a expressions did not change. Moreover, activated macrophages showed a raised burst activity and TNF-α secretion. Overall, the results indicated that CPA exhibited toxicity on various human cellular models. Moreover, at non-cytotoxic concentrations, CPA disturbed human monocytes differentiation into macrophages. This work contributes to understanding the immunosuppressive properties of this food-related toxin. PMID:24747294

  7. Cytotoxicity and immunotoxicity of cyclopiazonic acid on human cells.

    PubMed

    Hymery, Nolwenn; Masson, Floriane; Barbier, Georges; Coton, Emmanuel

    2014-08-01

    In this study, in vitro cytotoxicity and immunotoxicity of the mycotoxin cyclopiazonic acid (CPA) was evaluated on human cells. To evaluate cytoxicity, several cellular targets were used (CD34+, monocytes, THP-1 and Caco-2). Monocytes were more sensitive to CPA than the THP-1 monocytic cell line after 48h of incubation in the tested conditions. Half maximal inhibitory concentration (IC50) were determined to be 8.5 × 10(-8) and 1.75 × 10(-7)M for monocytes and THP1, respectively, while IC50>1.25 × 10(-7)M was observed for Caco-2 and CD34+ cells. The CPA effect on macrophage differentiation was also examined at non-cytotoxic concentrations. The monocyte differentiation process was markedly disturbed in the presence of CPA. After 6 days of culture, CD71 expression was downregulated, while CD14 and CD11a expressions did not change. Moreover, activated macrophages showed a raised burst activity and TNF-α secretion. Overall, the results indicated that CPA exhibited toxicity on various human cellular models. Moreover, at non-cytotoxic concentrations, CPA disturbed human monocytes differentiation into macrophages. This work contributes to understanding the immunosuppressive properties of this food-related toxin.

  8. Proposed Ancestors of Phage Nucleic Acid Packaging Motors (and Cells)

    PubMed Central

    Serwer, Philip

    2011-01-01

    I present a hypothesis that begins with the proposal that abiotic ancestors of phage RNA and DNA packaging systems (and cells) include mobile shells with an internal, molecule-transporting cavity. The foundations of this hypothesis include the conjecture that current nucleic acid packaging systems have imprints from abiotic ancestors. The abiotic shells (1) initially imbibe and later also bind and transport organic molecules, thereby providing a means for producing molecular interactions that are links in the chain of events that produces ancestors to the first molecules that are both information carrying and enzymatically active, and (2) are subsequently scaffolds on which proteins assemble to form ancestors common to both shells of viral capsids and cell membranes. Emergence of cells occurs via aggregation and merger of shells and internal contents. The hypothesis continues by using proposed imprints of abiotic and biotic ancestors to deduce an ancestral thermal ratchet-based DNA packaging motor that subsequently evolves to integrate a DNA packaging ATPase that provides a power stroke. PMID:21994778

  9. Requirement of Phosphoinositides Containing Stearic Acid To Control Cell Polarity

    PubMed Central

    Laquel, Patricia; Testet, Eric; Tuphile, Karine; Fouillen, Laetitia; Bessoule, Jean-Jacques

    2015-01-01

    Phosphoinositides (PIPs) are present in very small amounts but are essential for cell signaling, morphogenesis, and polarity. By mass spectrometry, we demonstrated that some PIPs with stearic acyl chains were strongly disturbed in a psi1Δ Saccharomyces cerevisiae yeast strain deficient in the specific incorporation of a stearoyl chain at the sn-1 position of phosphatidylinositol. The absence of PIPs containing stearic acid induced disturbances in intracellular trafficking, although the total amount of PIPs was not diminished. Changes in PIPs also induced alterations in the budding pattern and defects in actin cytoskeleton organization (cables and patches). Moreover, when the PSI1 gene was impaired, a high proportion of cells with bipolar cortical actin patches that occurred concomitantly with the bipolar localization of Cdc42p was specifically found among diploid cells. This bipolar cortical actin phenotype, never previously described, was also detected in a bud9Δ/bud9Δ strain. Very interestingly, overexpression of PSI1 reversed this phenotype. PMID:26711260

  10. Depigmenting Effect of Kojic Acid Esters in Hyperpigmented B16F1 Melanoma Cells

    PubMed Central

    Lajis, Ahmad Firdaus B.; Hamid, Muhajir; Ariff, Arbakariya B.

    2012-01-01

    The depigmenting effect of kojic acid esters synthesized by the esterification of kojic acid using Rhizomucor miehei immobilized lipase was investigated in B16F1 melanoma cells. The depigmenting effect of kojic acid and kojic acid esters was evaluated by the inhibitory effect of melanin formation and tyrosinase activity on alpha-stimulating hormone- (α-MSH-) induced melanin synthesis in B16F1 melanoma cells. The cellular tyrosinase inhibitory effect of kojic acid monooleate, kojic acid monolaurate, and kojic acid monopalmitate was found similar to kojic acid at nontoxic doses ranging from 1.95 to 62.5 μg/mL. However, kojic acid monopalmitate gave slightly higher inhibition to melanin formation compared to other inhibitors at doses ranging from 15.63 to 62.5 μg/mL. Kojic acid and kojic acid esters also show antioxidant activity that will enhance the depigmenting effect. The cytotoxicity of kojic acid esters in B16F1 melanoma cells was significantly lower than kojic acid at high doses, ranging from 125 and 500 μg/mL. Since kojic acid esters have lower cytotoxic effect than kojic acid, it is suggested that kojic acid esters can be used as alternatives for a safe skin whitening agent and potential depigmenting agents to treat hyperpigmentation. PMID:23091364

  11. The fatty acid desaturase 2 (FADS2) gene product catalyzes Δ4 desaturation to yield n-3 docosahexaenoic acid and n-6 docosapentaenoic acid in human cells

    PubMed Central

    Park, Hui Gyu; Park, Woo Jung; Kothapalli, Kumar S. D.; Brenna, J. Thomas

    2015-01-01

    Docosahexaenoic acid (DHA) is a Δ4-desaturated C22 fatty acid and the limiting highly unsaturated fatty acid (HUFA) in neural tissue. The biosynthesis of Δ4-desaturated docosanoid fatty acids 22:6n-3 and 22:5n-6 are believed to proceed via a circuitous biochemical pathway requiring repeated use of a fatty acid desaturase 2 (FADS2) protein to perform Δ6 desaturation on C24 fatty acids in the endoplasmic reticulum followed by 1 round of β-oxidation in the peroxisomes. We demonstrate here that the FADS2 gene product can directly Δ4-desaturate 22:5n-3→22:6n-3 (DHA) and 22:4n-6→22:5n-6. Human MCF-7 cells lacking functional FADS2-mediated Δ6-desaturase were stably transformed with FADS2, FADS1, or empty vector. When incubated with 22:5n-3 or 22:4n-6, FADS2 stable cells produce 22:6n-3 or 22:5n-6, respectively. Similarly, FADS2 stable cells when incubated with d5-18:3n-3 show synthesis of d5-22:6n-3 with no labeling of 24:5n-3 or 24:6n-3 at 24 h. Further, both C24 fatty acids are shown to be products of the respective C22 fatty acids via elongation. Our results demonstrate that the FADS2 classical transcript mediates direct Δ4 desaturation to yield 22:6n-3 and 22:5n-6 in human cells, as has been widely shown previously for desaturation by fish and many other organisms.—Park, H. G., Park, W. J., Kothapalli, K. S. D., Brenna, J. T. The fatty acid desaturase 2 (FADS2) gene product catalyzes Δ4 desaturation to yield n-3 docosahexaenoic acid and n-6 docosapentaenoic acid in human cells. PMID:26065859

  12. Variable responses of different human cancer cells to the lichen compounds parietin, atranorin, usnic acid and gyrophoric acid.

    PubMed

    Bačkorová, M; Bačkor, M; Mikeš, J; Jendželovský, R; Fedoročko, P

    2011-02-01

    One of the ways for searching for potentially new anti-cancer drugs is the testing of various naturally synthesized compounds. Lichens are a source of unique chemical agents of which some have already been proved to be effective against various cancer in vitro models. Our study reports on the sensitivity of up to nine human cancer cell lines (A2780, HeLa, MCF-7, SK-BR-3, HT-29, HCT-116 p53(+/+), HCT-116 p53(-/-), HL-60 and Jurkat) to the anti-proliferative/cytotoxic effects of four typical secondary metabolites of lichens (parietin, atranorin, usnic acid and gyrophoric acid). Variations in the dynamics of tumour cell line populations were evaluated by the MTT, clonogenic and viability assays, cell proliferation and detachment, cell cycle transition and apoptotic nuclear morphology, thereby confirming their concentration- and time-dependent cytotoxicity. However, in comparison with parietin and gyrophoric acid, the suppression of viability and cell proliferation by usnic acid or atranorin was found to be more efficient at equitoxic doses and correlated more strongly with an increased number of floating cells or a higher apoptotic index. Moreover, the analysis of cell cycle distribution also revealed an accumulation of cells in S-phase. This study has confirmed a differential sensitivity of cancer cell lines to lichen secondary metabolites. PMID:20837130

  13. Lactic acid-producing yeast cells having nonfunctional L- or D-lactate:ferricytochrome C oxidoreductase cells

    DOEpatents

    Miller, Matthew; Suominen, Pirkko; Aristidou, Aristos; Hause, Benjamin Matthew; Van Hoek, Pim; Dundon, Catherine Asleson

    2012-03-20

    Yeast cells having an exogenous lactate dehydrogenase gene ae modified by reducing L- or D-lactate:ferricytochrome c oxidoreductase activity in the cell. This leads to reduced consumption of lactate by the cell and can increase overall lactate yields in a fermentation process. Cells having the reduced L- or D-lactate:ferricytochrome c oxidoreductase activity can be screened for by resistance to organic acids such as lactic or glycolic acid.

  14. Delta-6 desaturase from borage converts linoleic acid to gamma-linolenic acid in HEK293 cells.

    PubMed

    Chen, Qing; Nimal, Jonathan; Li, Wanli; Liu, Xia; Cao, Wenguang

    2011-07-01

    Gamma-linolenic acid (GLA, 18:3 n6) is an essential polyunsaturated fatty acid of the omega-6 family and is found to be effective in prevention and/or treatment of various health problems. In this study, we evaluated the possibility of increasing γ-linolenic acid contents in mammalian cells using the delta-6 gene from Borago officinalis. The borage Δ6-desaturase gene (sDelta-6) was codon-optimized and introduced into HEK293 cells by lipofectin transfection. Co-expression of GFP with sDelta-6 and RT-PCR analysis indicated that sDelta-6 could be expressed in mammalian cells. Subsequently, the heterologous expression of borage Δ6-desaturase was evaluated by fatty acid analysis. Total cellular lipid analysis of transformed cells fed with linoleic acid (LA 18:2 n6) as a substrate showed that the expression of sDelta-6 resulted in an 228-483% (p<0.05) increase of GLA when compared with that in the control cells. The highest conversion efficiency of LA into GLA in sDelta-6(+) cells was 6.9 times higher than that in the control group (11.59% vs. 1.69%; p<0.05). Our present work demonstrated that the sDelta-6 gene from borage could be functionally expressed in mammalian cells, and could convert LA into GLA. Furthermore, this study may pave the way to generate transgenic livestock that can synthesise GLA.

  15. Uptake mechanism of valproic acid in human placental choriocarcinoma cell line (BeWo).

    PubMed

    Ushigome, F; Takanaga, H; Matsuo, H; Tsukimori, K; Nakano, H; Ohtani, H; Sawada, Y

    2001-04-13

    Valproic acid is an anticonvulsant widely used for the treatment of epilepsy. However, valproic acid is known to show fetal toxicity, including teratogenicity. In the present study, to elucidate the mechanisms of valproic acid transport across the blood-placental barrier, we carried out transcellular transport and uptake experiments with human placental choriocarcinoma epithelial cells (BeWo cells) in culture. The permeability coefficient of [3H]valproic acid in BeWo cells for the apical-to-basolateral flux was greater than that for the opposite flux, suggesting a higher unidirectional transport in the fetal direction. The uptake of [3H]valproic acid from the apical side was temperature-dependent and enhanced under acidic pH. In the presence of 50 microM carbonyl cyanide p-trifluoromethoxylhydrazone, the uptake of [3H]valproic acid was significantly reduced. A metabolic inhibitor, 10 mM sodium azide, also significantly reduced the uptake of [3H]valproic acid. Therefore, valproic acid is actively transported in a pH-dependent manner on the brush-border membrane of BeWo cells. Kinetic analysis of valproic acid uptake revealed the involvement of a non-saturable component and a saturable component. The Michaelis constant for the saturable transport (K(t)) was smaller under acidic pH, suggesting a proton-linked active transport mechanism for valproic acid in BeWo cells. In the inhibitory experiments, some short-chain fatty acids, such as acetic acid, lactic acid, propanoic acid and butyric acid, and medium-chain fatty acids, such as hexanoic acid and octanoic acid, inhibited the uptake of [3H]valproic acid. The uptake of [3H]valproic acid was also significantly decreased in the presence of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid, salicylic acid and furosemide, which are well-known inhibitors of the anion exchange system. Moreover, p-aminohippuric acid significantly reduced the uptake of [3H]valproic acid. These results suggest that an active transport

  16. Synthesis and release of fatty acids by human trophoblast cells in culture

    SciTech Connect

    Coleman, R.A.; Haynes, E.B.

    1987-11-01

    In order to determine whether placental cells can synthesize and release fatty acids, trophoblast cells from term human placentas were established in monolayer culture. The cells continued to secrete placental lactogen and progesterone and maintained specific activities of critical enzymes of triacylglycerol and phosphatidylcholine biosynthesis for 24 to 72 hr in culture. Fatty acid was rapidly synthesized from (/sup 14/C)acetate and released by the cells. Palmitoleic, palmitic, and oleic acids were the major fatty acids synthesized from (/sup 14/C)acetate and released. Small amounts of lauric, myristic, and stearic acids were also identified. (/sup 14/C)acetate was also incorporated into cellular triacylglycerol, phospholipid, and cholesterol, but radiolabeled free fatty acid did not accumulate intracellularly. In a pulse-chase experiment, cellular glycerolipids were labeled with (1-/sup 14/C)oleate; trophoblast cells then released /sup 14/C-labeled fatty acid into the media as the cellular content of labeled phospholipid and triacylglycerol decreased without intracellular accumulation of free fatty acid. Twenty percent of the /sup 14/C-label lost from cellular glycerolipid could not be recovered as a chloroform-extractable product, suggesting that some of the hydrolyzed fatty acid had been oxidized. These data indicate that cultured placenta trophoblast cells can release fatty acids that have either been synthesized de novo or that have been hydrolyzed from cellular glycerolipids. Trophoblast cells in monolayer culture should provide an excellent model for molecular studies of placental fatty acid metabolism and release.

  17. Transmission electron microscopic examination of phosphoric acid fuel cell components

    NASA Technical Reports Server (NTRS)

    Pebler, A.

    1986-01-01

    Transmission electron microscopy (TEM) was used to physically characterize tested and untested phosphoric acid fuel cell (PAFC) components. Those examined included carbon-supported platinum catalysts, carbon backing paper, and Teflon-bonded catalyst layers at various stages of fabrication and after testing in pressurized PAFC's. Applicability of electron diffraction and electron energy loss spectroscopy for identifying the various phases was explored. The discussion focuses on the morphology and size distribution of platinum, the morphology and structural aspects of Teflon in catalyst layers, and the structural evidence of carbon corrosion. Reference is made to other physical characterization techniques where appropriate. A qualitative model of the catalyst layer that emerged from the TEM studies is presented.

  18. Corrosion-resistant catalyst supports for phosphoric acid fuel cells

    SciTech Connect

    Kosek, J.A.; Cropley, C.C.; LaConti, A.B.

    1990-01-01

    High-surface-area carbon blacks such as Vulcan XC-72 (Cabot Corp.) and graphitized carbon blacks such as 2700{degree}C heat-treated Black Pearls 2000 (HTBP) (Cabot Corp.) have found widespread applications as catalyst supports in phosphoric acid fuel cells (PAFCs). However, due to the operating temperatures and pressures being utilized in PAFCs currently under development, the carbon-based cathode catalyst supports suffer from corrosion, which decreases the performance and life span of a PAFC stack. The feasibility of using alternative, low-cost, corrosion-resistant catalyst support (CRCS) materials as replacements for the cathode carbon support materials was investigated. The objectives of the program were to prepare high-surface-area alternative supports and to evaluate the physical characteristics and the electrochemical stability of these materials. The O{sub 2} reduction activity of the platinized CRCS materials was also evaluated. 2 refs., 3 figs.

  19. PANTOTHENIC ACID AND THE UTILIZATION OF GLUCOSE BY LIVING AND CELL-FREE SYSTEMS.

    PubMed

    Teague, P C; Williams, R J

    1942-07-20

    1. Added pantothenic acid was found to have no appreciable effect on the fermentation of glucose when used in conjunction with preparations of dialyzed yeast maceration juice or acetone-precipitated yeast maceration juice. 2. Addition of pantothenic acid failed to affect the rate of phosphorylation of glucose or the rate of decarboxylation of pyruvic acid by yeast maceration juice. 3. Pantothenic acid showed no effect on the rate of glycolysis by homogenized deficient chick tissues. 4. The accelerating effect of pantothenic acid on fermentation by deficient yeast cells was found to be accompanied by a "binding" of pantothenic acid by the yeast cells.

  20. Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells.

    PubMed

    Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

    2015-01-09

    To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting.

  1. Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells

    PubMed Central

    Yang, Jianhong; Zhou, Yongzhao; Cheng, Xia; Fan, Yi; He, Shichao; Li, Shucai; Ye, Haoyu; Xie, Caifeng; Wu, Wenshuang; Li, Chunyan; Pei, Heying; Li, Luyuan; Wei, Zhe; Peng, Aihua; Wei, Yuquan; Li, Weimin; Chen, Lijuan

    2015-01-01

    To overcome drug resistance caused by apoptosis deficiency in patients with non-small cell lung carcinoma (NSCLC), there is a need to identify other means of triggering apoptosis-independent cancer cell death. We are the first to report that isogambogenic acid (iso-GNA) can induce apoptosis-independent autophagic cell death in human NSCLC cells. Several features of the iso-GNA-treated NSCLC cells indicated that iso-GNA induced autophagic cell death. First, there was no evidence of apoptosis or cleaved caspase 3 accumulation and activation. Second, iso-GNA treatment induced the formation of autophagic vacuoles, increased LC3 conversion, caused the appearance of autophagosomes and increased the expression of autophagy-related proteins. These findings provide evidence that iso-GNA induces autophagy in NSCLC cells. Third, iso-GNA-induced cell death was inhibited by autophagic inhibitors or by selective ablation of Atg7 and Beclin 1 genes. Furthermore, the mTOR inhibitor rapamycin increased iso-GNA-induced cell death by enhancing autophagy. Finally, a xenograft model provided additional evidence that iso-GNA exhibited anticancer effect through inducing autophagy-dependent cell death in NSCLC cells. Taken together, our results demonstrated that iso-GNA exhibited an anticancer effect by inducing autophagy-dependent cell death in NSCLC cells, which may be an effective chemotherapeutic agent that can be used against NSCLC in a clinical setting. PMID:25571970

  2. Smoking and red blood cell phospholipid membrane fatty acids.

    PubMed

    Murff, H J; Tindle, H A; Shrubsole, M J; Cai, Q; Smalley, W; Milne, G L; Swift, L L; Ness, R M; Zheng, W

    2016-09-01

    Smoking is associated with lower n-3 long chain polyunsaturated fatty acids (LCPUFA) concentrations; however, limited studies have accounted for dietary PUFA intake or whether tobacco dose or smoking duration influences this association. We measured red blood cell phospholipid (RBC) membrane concentrations of fatty acids in 126 current smokers, 311 former smokers, and 461 never smokers using gas liquid chromatography and tandem mass spectrometry. Smokers had lower RBC membrane percentages of total n-3 LCPUFAs compared to former smokers or never smokers (median percent: 5.46, [interquartile range (IQR) 4.52, 6.28] versus 6.39; [IQR: 5.18, 7.85] versus 6.59; [IQR 5.34, 8.01]) (p<0.001) and this association remained after adjusting for dietary PUFA intake. Duration of smoking and cigarettes per day were not associated with RBC membrane n-3 LCPUFA differences. Smoking is associated with lower n-3 LCPUFA RBC membrane percentages and this association was not influenced by diet or smoking dose or duration. PMID:27637337

  3. Engineering a cyanobacterial cell factory for production of lactic acid.

    PubMed

    Angermayr, S Andreas; Paszota, Michal; Hellingwerf, Klaas J

    2012-10-01

    Metabolic engineering of microorganisms has become a versatile tool to facilitate production of bulk chemicals, fuels, etc. Accordingly, CO(2) has been exploited via cyanobacterial metabolism as a sustainable carbon source of biofuel and bioplastic precursors. Here we extended these observations by showing that integration of an ldh gene from Bacillus subtilis (encoding an l-lactate dehydrogenase) into the genome of Synechocystis sp. strain PCC6803 leads to l-lactic acid production, a phenotype which is shown to be stable for prolonged batch culturing. Coexpression of a heterologous soluble transhydrogenase leads to an even higher lactate production rate and yield (lactic acid accumulating up to a several-millimolar concentration in the extracellular medium) than those for the single ldh mutant. The expression of a transhydrogenase alone, however, appears to be harmful to the cells, and a mutant carrying such a gene is rapidly outcompeted by a revertant(s) with a wild-type growth phenotype. Furthermore, our results indicate that the introduction of a lactate dehydrogenase rescues this phenotype by preventing the reversion. PMID:22865063

  4. Polysialic Acid Directs Tumor Cell Growth by Controlling Heterophilic Neural Cell Adhesion Molecule Interactions

    PubMed Central

    Seidenfaden, Ralph; Krauter, Andrea; Schertzinger, Frank; Gerardy-Schahn, Rita; Hildebrandt, Herbert

    2003-01-01

    Polysialic acid (PSA), a carbohydrate polymer attached to the neural cell adhesion molecule (NCAM), promotes neural plasticity and tumor malignancy, but its mode of action is controversial. Here we establish that PSA controls tumor cell growth and differentiation by interfering with NCAM signaling at cell-cell contacts. Interactions between cells with different PSA and NCAM expression profiles were initiated by enzymatic removal of PSA and by ectopic expression of NCAM or PSA-NCAM. Removal of PSA from the cell surface led to reduced proliferation and activated extracellular signal-regulated kinase (ERK), inducing enhanced survival and neuronal differentiation of neuroblastoma cells. Blocking with an NCAM-specific peptide prevented these effects. Combinatorial transinteraction studies with cells and membranes with different PSA and NCAM phenotypes revealed that heterophilic NCAM binding mimics the cellular responses to PSA removal. In conclusion, our data demonstrate that PSA masks heterophilic NCAM signals, having a direct impact on tumor cell growth. This provides a mechanism for how PSA may promote the genesis and progression of highly aggressive PSA-NCAM-positive tumors. PMID:12897159

  5. High folic acid increases cell turnover and lowers differentiation and iron content in human HT29 colon cancer cells.

    PubMed

    Pellis, Linette; Dommels, Yvonne; Venema, Dini; Polanen, Ab van; Lips, Esther; Baykus, Hakan; Kok, Frans; Kampman, Ellen; Keijer, Jaap

    2008-04-01

    Folate, a water-soluble B vitamin, is a cofactor in one-carbon metabolism and is essential for DNA synthesis, amino acid interconversion, methylation and, consequently, normal cell growth. In animals with existing pre-neoplastic and neoplastic lesions, folic acid supplementation increases the tumour burden. To identify processes that are affected by increased folic acid levels, we compared HT29 human colon cancer cells exposed to a chronic supplemental (100 ng/ml) level of folic acid to cells exposed to a normal (10 ng/ml) level of folic acid, in the presence of vitamin B12 and other micronutrients involved in the folate-methionine cycle. In addition to higher intracellular folate levels, HT29 cells at 100 ng folic acid/ml displayed faster growth and higher metabolic activity. cDNA microarray analysis indicated an effect on cell turnover and Fe metabolism. We fully confirmed these effects at the physiological level. At 100 ng/ml, cell assays showed higher proliferation and apoptosis, while gene expression analysis and a lower E-cadherin protein expression indicated decreased differentiation. These results are in agreement with the promoting effect of folic acid supplementation on established colorectal neoplasms. The lower expression of genes related to Fe metabolism at 100 ng folic acid/ml was confirmed by lower intracellular Fe levels in the cells exposed to folic acid at 100 ng/ml. This suggests an effect of folate on Fe metabolism.

  6. Stimulation of phosphatidic acid of calcium influx and cyclic GMP synthesis in neuroblastoma cells.

    PubMed

    Ohsako, S; Deguchi, T

    1981-11-10

    Phosphatidic acid added to the medium markedly elevated intracellular cyclic GMP content in cultured neuroblastoma N1E 115 cells. There was a significant elevation of cyclic GMP with 1 micrograms/ml and a maximum (70-fold) elevation with 100 micrograms/ml of phosphatidic acid. Other natural phospholipids did not increase, or increased only slightly, the cyclic GMP content in the cells. The elevation of cyclic GMP content by phosphatidic acid was absolutely dependent on extracellular calcium. Phosphatidic acid stimulated the influx of calcium into neuroblastoma cells 2- to 5-fold. The pattern of the calcium influx induced by phosphatidic acid was comparable to that of cyclic GMP elevation. The stimulation of calcium influx by phosphatidic acid was also observed in cultured heart cells, indicating that phosphatidic acid acts as a calcium ionophore or opens a specific calcium-gate in a variety of cell membranes. Treatment of neuroblastoma cells with phospholipase C increased 32Pi labeling of phosphatidic acid, stimulated the influx of calcium, and elevated the cyclic GMP content in the cells. Thus exogenous as well as endogenous phosphatidic acid stimulates the translocation of calcium across cell membranes and, as a consequence, induces the synthesis of cyclic GMP in the neuroblastoma cells.

  7. Salicylic acid induces apoptosis in colon carcinoma cells grown in-vitro: Influence of oxygen and salicylic acid concentration

    SciTech Connect

    Zitta, Karina; Meybohm, Patrick; Bein, Berthold; Huang, Ying; Heinrich, Christin; Scholz, Jens; Steinfath, Markus; Albrecht, Martin

    2012-04-15

    In solid tumors the hypoxic environment can promote tumor progression and resistance to therapy. Recently, acetylsalicylic acid a major component of analgesic drugs and its metabolite salicylic acid (SA) have been shown to reduce the risk of colon cancer, but the mechanisms of action remain still unclear. Here we elucidate the effects of physiologically relevant concentrations of SA on colon carcinoma cells (CaCo-2) grown under normoxic and hypoxic conditions. Western blotting, caspase-3/7 apoptosis assays, MTS cell-proliferation assays, LDH cytotoxicity assays and hydrogen peroxide measurements were performed to investigate the effects of 1 and 10 {mu}M SA on CaCo-2 cells grown under normoxic conditions and cells exposed to hypoxia. Under normoxic conditions, SA did not influence cell proliferation or LDH release of CaCo-2 cells. However, caspase-3/7 activity was significantly increased. Under hypoxia, cell proliferation was reduced and LDH release and caspase-3/7 activities were increased. None of these parameters was altered by the addition of SA under hypoxic conditions. Hypoxia increased hydrogen peroxide concentrations 300-fold and SA significantly augmented the release of hydrogen peroxide under normoxic, but not under hypoxic conditions. Phosphorylation of the pro-survival kinases akt and erk1/2 was not changed by SA under hypoxic conditions, whereas under normoxia SA reduced phosphorylation of erk1/2 after 2 hours. We conclude that in colon carcinoma cells effects of SA on apoptosis and cellular signaling are dependent on the availability of oxygen. -- Highlights: Black-Right-Pointing-Pointer Effects of salicylic acid on colon carcinoma cells grown under normoxic and hypoxic conditions Black-Right-Pointing-Pointer Salicylic acid increases caspase-3/7 activity and hydrogen peroxide release under normoxia Black-Right-Pointing-Pointer Salicylic acid decreases pro-survival erk-1/2 phosphorylation under normoxia Black-Right-Pointing-Pointer Salicylic acid does

  8. Proteomic analysis of the molecular response of Raji cells to maslinic acid treatment.

    PubMed

    Yap, W H; Khoo, K S; Lim, S H; Yeo, C C; Lim, Y M

    2012-01-15

    Maslinic acid, a natural pentacyclic triterpene has been shown to inhibit growth and induce apoptosis in some tumour cell lines. We studied the molecular response of Raji cells towards maslinic acid treatment. A proteomics approach was employed to identify the target proteins. Seventeen differentially expressed proteins including those involved in DNA replication, microtubule filament assembly, nucleo-cytoplasmic trafficking, cell signaling, energy metabolism and cytoskeletal organization were identified by MALDI TOF-TOF MS. The down-regulation of stathmin, Ran GTPase activating protein-1 (RanBP1), and microtubule associated protein RP/EB family member 1 (EB1) were confirmed by Western blotting. The study of the effect of maslinic acid on Raji cell cycle regulation showed that it induced a G1 cell cycle arrest. The differential proteomic changes in maslinic acid-treated Raji cells demonstrated that it also inhibited expression of dUTPase and stathmin which are known to induce early S and G2 cell cycle arrests. The mechanism of maslinic acid-induced cell cycle arrest may be mediated by inhibiting cyclin D1 expression and enhancing the levels of cell cycle-dependent kinase (CDK) inhibitor p21 protein. Maslinic acid suppressed nuclear factor-kappa B (NF-κB) activity which is known to stimulate expression of anti-apoptotic and cell cycle regulatory gene products. These results suggest that maslinic acid affects multiple signaling molecules and inhibits fundamental pathways regulating cell growth and survival in Raji cells. PMID:21893403

  9. Effect of salicylic acid on invasion of human vascular endothelial cells by Staphylococcus aureus.

    PubMed

    Park, Wan Beom; Kim, Sung-Han; Cho, Jae Hyun; Bang, Ji Hwan; Kim, Hong Bin; Kim, Nam Joong; Oh, Myoung-don; Choe, Kang Won

    2007-02-01

    Invasion of vascular endothelial cells by Staphylococcus aureus is associated with diverse complications and recurrent infection. Little is known about the effect of salicylic acid, the major metabolite of aspirin, on the interaction between S. aureus and vascular endothelial cells. We examined the adhesion of S. aureus strain 8325-4 cultured with or without salicylic acid to human umbilical vein endothelial cells (HUVECs), and the ability of the strain to invade these cells. Strain 8325-4 cells grown in salicylic acid were significantly less adherent to and invasive in HUVECs. Production of cytokine interleukin (IL)-6 was lower from the HUVECs infected with clinical isolates of S. aureus cultured in salicylic acid compared with those unexposed to salicylic acid. This study raises the possibility of using salicylic acid as an adjuvant therapeutic agent in the treatment of S. aureus bacteremia to prevent its complications or recurrence.

  10. The Comparative Performance of Batteries: The Lead-Acid and the Aluminum-Air Cells

    NASA Astrophysics Data System (ADS)

    Leroux, Xavier; Ottewill, Gerry A.; Walsh, Frank C.

    1996-08-01

    An experimental program designed to convey, to students aged 16 through undergraduate, the principles of battery electrochemistry through a comparative study of two different systems, the lead acid cell and aluminum air cell, is described.

  11. Myelin basic protein-positive nerve fibres in human Meissner corpuscles.

    PubMed

    García-Suárez, O; Montaño, J A; Esteban, I; González-Martínez, T; Alvarez-Abad, C; López-Arranz, E; Cobo, J; Vega, J A

    2009-06-01

    Myelinated nerve fibres forming sensory corpuscles become amyelinic before entering the corpuscle. Interestingly, in Meissner corpuscles from monkey myelin basic protein (MBP), a specific component of myelin sheath co-localized with neuronal markers. To investigate whether or not this also occurs in human digital Meissner corpuscles, we used single and double immunohistochemistry to detect MBP associated with axonic (protein gene product (PGP) 9.5) or Schwann and Schwann-related cell (S100 protein) markers. We also studied these markers in Pacinian corpuscles. Nerve fibres immunoreactive for MBP were detected in about 25% of the Meissner corpuscles examined; however, MBP never co-localized with PGP 9.5 and MBP occasionally co-localized with S100 protein. MBP-immunoreactive fibres associated with Meissner corpuscles were observed at the periphery of the lamellar cells or within the corpuscle between the lamellar cells. These results describe the distribution of myelinated nerve fibres expressing MBP in human Meissner corpuscles, which is important when studying Meissner corpuscles in cutaneous biopsies used for the diagnosis of peripheral and degenerative neuropathies.

  12. Myelin basic protein-positive nerve fibres in human Meissner corpuscles

    PubMed Central

    García-Suárez, O; Montaño, J A; Esteban, I; González-Martínez, T; Alvarez-Abad, C; López-Arranz, E; Cobo, J; Vega, J A

    2009-01-01

    Myelinated nerve fibres forming sensory corpuscles become amyelinic before entering the corpuscle. Interestingly, in Meissner corpuscles from monkey myelin basic protein (MBP), a specific component of myelin sheath co-localized with neuronal markers. To investigate whether or not this also occurs in human digital Meissner corpuscles, we used single and double immunohistochemistry to detect MBP associated with axonic (protein gene product (PGP) 9.5) or Schwann and Schwann-related cell (S100 protein) markers. We also studied these markers in Pacinian corpuscles. Nerve fibres immunoreactive for MBP were detected in about 25% of the Meissner corpuscles examined; however, MBP never co-localized with PGP 9.5 and MBP occasionally co-localized with S100 protein. MBP-immunoreactive fibres associated with Meissner corpuscles were observed at the periphery of the lamellar cells or within the corpuscle between the lamellar cells. These results describe the distribution of myelinated nerve fibres expressing MBP in human Meissner corpuscles, which is important when studying Meissner corpuscles in cutaneous biopsies used for the diagnosis of peripheral and degenerative neuropathies. PMID:19538632

  13. Differential Utilization of Dietary Fatty Acids in Benign and Malignant Cells of the Prostate.

    PubMed

    Dueregger, Andrea; Schöpf, Bernd; Eder, Theresa; Höfer, Julia; Gnaiger, Erich; Aufinger, Astrid; Kenner, Lukas; Perktold, Bernhard; Ramoner, Reinhold; Klocker, Helmut; Eder, Iris E

    2015-01-01

    Tumor cells adapt via metabolic reprogramming to meet elevated energy demands due to continuous proliferation, for example by switching to alternative energy sources. Nutrients such as glucose, fatty acids, ketone bodies and amino acids may be utilized as preferred substrates to fulfill increased energy requirements. In this study we investigated the metabolic characteristics of benign and cancer cells of the prostate with respect to their utilization of medium chain (MCTs) and long chain triglycerides (LCTs) under standard and glucose-starved culture conditions by assessing cell viability, glycolytic activity, mitochondrial respiration, the expression of genes encoding key metabolic enzymes as well as mitochondrial mass and mtDNA content. We report that BE prostate cells (RWPE-1) have a higher competence to utilize fatty acids as energy source than PCa cells (LNCaP, ABL, PC3) as shown not only by increased cell viability upon fatty acid supplementation but also by an increased ß-oxidation of fatty acids, although the base-line respiration was 2-fold higher in prostate cancer cells. Moreover, BE RWPE-1 cells were found to compensate for glucose starvation in the presence of fatty acids. Of notice, these findings were confirmed in vivo by showing that PCa tissue has a lower capacity in oxidizing fatty acids than benign prostate. Collectively, these metabolic differences between benign and prostate cancer cells and especially their differential utilization of fatty acids could be exploited to establish novel diagnostic and therapeutic strategies. PMID:26285134

  14. Ferulic acid reverses ABCB1-mediated paclitaxel resistance in MDR cell lines.

    PubMed

    Muthusamy, Ganesan; Balupillai, Agilan; Ramasamy, Karthikeyan; Shanmugam, Mohana; Gunaseelan, Srithar; Mary, Beaulah; Prasad, N Rajendra

    2016-09-01

    Multidrug resistance (MDR) remains a major obstacle in cancer chemotherapy. The use of the dietary phytochemicals as chemosensitizing agents to enhance the efficacy of conventional cytostatic drugs has recently gained the attention as a plausible approach for overcoming the drug resistance. The aim of this study was to investigate whether a naturally occurring diet-based phenolic acid, ferulic acid, could sensitize paclitaxel efficacy in ABCB1 overexpressing (P-glycoprotein) colchicine selected KB Ch(R)8-5 cell line. In vitro drug efflux assays demonstrated that ferulic acid inhibits P-glycoprotein transport function in drug resistant KB Ch(R)8-5 cell lines. However, ferulic acid significantly downregulates ABCB1 expression in a concentration dependent manner. Cytotoxicity assay reveals that ferulic acid decreased paclitaxel resistance in KBCh(R)8-5 and HEK293/ABCB1 cells, which indicates its chemosensitizing potential. Clonogenic cell survival assay and apoptotic morphological staining further confirm the chemosensitizing potential of ferulic acid in drug resistant KB Ch(R)8-5 cell lines. Ferulic acid treatment enhances paclitaxel mediated cell cycle arrest and upregulates paclitaxel-induced apoptotic signaling in KB resistant cells. Hence, it has been concluded that downregulation of ABCB1 and subsequent induction of paclitaxel-mediated cell cycle arrest and apoptotic signaling may be the cause for the chemosensitizing potential of ferulic acid in P-gp overexpressing cell lines. PMID:27262378

  15. Differential Utilization of Dietary Fatty Acids in Benign and Malignant Cells of the Prostate.

    PubMed

    Dueregger, Andrea; Schöpf, Bernd; Eder, Theresa; Höfer, Julia; Gnaiger, Erich; Aufinger, Astrid; Kenner, Lukas; Perktold, Bernhard; Ramoner, Reinhold; Klocker, Helmut; Eder, Iris E

    2015-01-01

    Tumor cells adapt via metabolic reprogramming to meet elevated energy demands due to continuous proliferation, for example by switching to alternative energy sources. Nutrients such as glucose, fatty acids, ketone bodies and amino acids may be utilized as preferred substrates to fulfill increased energy requirements. In this study we investigated the metabolic characteristics of benign and cancer cells of the prostate with respect to their utilization of medium chain (MCTs) and long chain triglycerides (LCTs) under standard and glucose-starved culture conditions by assessing cell viability, glycolytic activity, mitochondrial respiration, the expression of genes encoding key metabolic enzymes as well as mitochondrial mass and mtDNA content. We report that BE prostate cells (RWPE-1) have a higher competence to utilize fatty acids as energy source than PCa cells (LNCaP, ABL, PC3) as shown not only by increased cell viability upon fatty acid supplementation but also by an increased ß-oxidation of fatty acids, although the base-line respiration was 2-fold higher in prostate cancer cells. Moreover, BE RWPE-1 cells were found to compensate for glucose starvation in the presence of fatty acids. Of notice, these findings were confirmed in vivo by showing that PCa tissue has a lower capacity in oxidizing fatty acids than benign prostate. Collectively, these metabolic differences between benign and prostate cancer cells and especially their differential utilization of fatty acids could be exploited to establish novel diagnostic and therapeutic strategies.

  16. Differential Utilization of Dietary Fatty Acids in Benign and Malignant Cells of the Prostate

    PubMed Central

    Eder, Theresa; Höfer, Julia; Gnaiger, Erich; Aufinger, Astrid; Kenner, Lukas; Perktold, Bernhard; Ramoner, Reinhold; Klocker, Helmut; Eder, Iris E.

    2015-01-01

    Tumor cells adapt via metabolic reprogramming to meet elevated energy demands due to continuous proliferation, for example by switching to alternative energy sources. Nutrients such as glucose, fatty acids, ketone bodies and amino acids may be utilized as preferred substrates to fulfill increased energy requirements. In this study we investigated the metabolic characteristics of benign and cancer cells of the prostate with respect to their utilization of medium chain (MCTs) and long chain triglycerides (LCTs) under standard and glucose-starved culture conditions by assessing cell viability, glycolytic activity, mitochondrial respiration, the expression of genes encoding key metabolic enzymes as well as mitochondrial mass and mtDNA content. We report that BE prostate cells (RWPE-1) have a higher competence to utilize fatty acids as energy source than PCa cells (LNCaP, ABL, PC3) as shown not only by increased cell viability upon fatty acid supplementation but also by an increased ß-oxidation of fatty acids, although the base-line respiration was 2-fold higher in prostate cancer cells. Moreover, BE RWPE-1 cells were found to compensate for glucose starvation in the presence of fatty acids. Of notice, these findings were confirmed in vivo by showing that PCa tissue has a lower capacity in oxidizing fatty acids than benign prostate. Collectively, these metabolic differences between benign and prostate cancer cells and especially their differential utilization of fatty acids could be exploited to establish novel diagnostic and therapeutic strategies. PMID:26285134

  17. Histone Deacetylase Inhibitor Valproic Acid Promotes the Differentiation of Human Induced Pluripotent Stem Cells into Hepatocyte-Like Cells

    PubMed Central

    Kondo, Yuki; Iwao, Takahiro; Yoshihashi, Sachimi; Mimori, Kayo; Ogihara, Ruri; Nagata, Kiyoshi; Kurose, Kouichi; Saito, Masayoshi; Niwa, Takuro; Suzuki, Takayoshi; Miyata, Naoki; Ohmori, Shigeru; Nakamura, Katsunori; Matsunaga, Tamihide

    2014-01-01

    In this study, we aimed to elucidate the effects and mechanism of action of valproic acid on hepatic differentiation from human induced pluripotent stem cell-derived hepatic progenitor cells. Human induced pluripotent stem cells were differentiated into endodermal cells in the presence of activin A and then into hepatic progenitor cells using dimethyl sulfoxide. Hepatic progenitor cells were matured in the presence of hepatocyte growth factor, oncostatin M, and dexamethasone with valproic acid that was added during the maturation process. After 25 days of differentiation, cells expressed hepatic marker genes and drug-metabolizing enzymes and exhibited drug-metabolizing enzyme activities. These expression levels and activities were increased by treatment with valproic acid, the timing and duration of which were important parameters to promote differentiation from human induced pluripotent stem cell-derived hepatic progenitor cells into hepatocytes. Valproic acid inhibited histone deacetylase activity during differentiation of human induced pluripotent stem cells, and other histone deacetylase inhibitors also enhanced differentiation into hepatocytes. In conclusion, histone deacetylase inhibitors such as valproic acid can be used to promote hepatic differentiation from human induced pluripotent stem cell-derived hepatic progenitor cells. PMID:25084468

  18. The importance of 1,2-dithiolane structure in α-lipoic acid for the downregulation of cell surface β1-integrin expression of human bladder cancer cells.

    PubMed

    Yamasaki, Masao; Soda, Shozen; Sakakibara, Yoichi; Suiko, Masahito; Nishiyama, Kazuo

    2014-01-01

    Here, we show that cell surface β1-integrin expression, cell adhesion to fibronectin, migration, and invasion were all significantly inhibited by α-lipoic acid. These effects were not observed when cells were treated with dihydrolipoic acid or caprylic acid. These data reveal that the 1,2-dithiolane structure plays an important role in the action of α-lipoic acid.

  19. Fusaric acid induction of programmed cell death modulated through nitric oxide signalling in tobacco suspension cells.

    PubMed

    Jiao, Jiao; Zhou, Benguo; Zhu, Xiaoping; Gao, Zhengliang; Liang, Yuancun

    2013-10-01

    Fusaric acid (FA) is a nonhost-selective toxin mainly produced by Fusarium oxysporum, the causal agent of plant wilt diseases. We demonstrate that FA can induce programmed cell death (PCD) in tobacco suspension cells and the FA-induced PCD is modulated by nitric oxide (NO) signalling. Cells undergoing cell death induced by FA treatment exhibited typical characteristics of PCD including cytoplasmic shrinkage, chromatin condensation, DNA fragmentation, membrane plasmolysis, and formation of small cytoplasmic vacuoles. In addition, caspase-3-like activity was activated upon the FA treatment. The process of FA-induced PCD was accompanied by a rapid accumulation of NO in a FA dose-dependent manner. Pre-treatment of cells with NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) or NO synthase inhibitor N(G)-monomethyl-arginine monoacetate (L-NMMA) significantly reduced the rate of FA-induced cell death. Furthermore, the caspase-3-like activity and the expression of PAL and Hsr203J genes were alleviated by application of cPTIO or L-NMMA to FA-treated tobacco cells. This indicates that NO is an important factor involved in the FA-induced PCD. Our results also show that pre-treatment of tobacco cells with a caspase-3-specific inhibitor, Ac-DEVD-CHO, can reduce the rate of FA-induced cell death. These results demonstrate that the FA-induced cell death is a PCD and is modulated by NO signalling through caspase-3-like activation. PMID:23838885

  20. Proliferation-dependent changes in release of arachidonic acid from endothelial cells.

    PubMed Central

    Whatley, R E; Satoh, K; Zimmerman, G A; McIntyre, T M; Prescott, S M

    1994-01-01

    Stimulation of endothelial cells resulted in release of arachidonic acid from phospholipids. The magnitude of this response decreased as the cells became confluent and the change coincided with a decrease in the percentage of cells in growth phases (G2+M); this was not a consequence of time in culture or a factor in the growth medium. Preconfluent cells released approximately 30% of arachidonic acid; confluent cells released only 6%. The decreasing release of arachidonic acid was demonstrated using metabolic labeling, mass measurements of arachidonic acid, and measurement of PGI2. The decrease was not due to a changing pool of arachidonic acid, and mass measurements showed no depletion of arachidonic acid. Release from each phospholipid and from each phospholipid class decreased with confluence. Conversion of confluent cells to the proliferative phenotype by mechanical wounding of the monolayer caused increased release of arachidonic acid. Potential mechanisms for these changes were investigated using assays of phospholipase activity. Phospholipase A2 activity changed in concert with the alteration in release, a consequence of changes in phosphorylation of the enzyme. The increased release of arachidonic acid from preconfluent, actively dividing cells may have important physiologic implications and may help elucidate mechanisms regulating release of arachidonic acid. Images PMID:7962534

  1. Essential role for retinoic acid in the promotion of CD4+ T cell effector responses via retinoic acid receptor alpha

    PubMed Central

    Hall, J.A.; Cannons, J.L.; Grainger, J.R.; Santos, L.M. Dos; Hand, T.W.; Naik, S.; Wohlfert, E.A.; Chou, D.B.; Oldenhove, G.; Robinson, M.; Grigg, M.E.; Kastenmayer, R.; Schwartzberg, P.L.; Belkaid, Y.

    2012-01-01

    SUMMARY Vitamin A and its metabolite, retinoic acid (RA), have recently been implicated in the regulation of immune homeostasis via the peripheral induction of regulatory T cells. Here we show that RA is also required to elicit proinflammatory CD4+ helper T cell responses to infection and mucosal vaccination. Retinoic acid receptor alpha (RARα) is the critical mediator of these effects. Strikingly, antagonism of RAR signaling and deficiency in RARα(Rara−/−) results in a cell autonomous CD4+ T cell activation defect. Altogether, these findings reveal a fundamental role for the RA/RARα axis in the development of both regulatory and inflammatory arms of adaptive immunity and establish nutritional status as a broad regulator of adaptive T cell responses. PMID:21419664

  2. Whole-cell bioconversion of vanillin to vanillic acid by Streptomyces viridosporus

    SciTech Connect

    Pometto, A.L. III; Crawford, D.L.

    1983-05-01

    A two-step batch fermentation-bioconversion of vanillin (4-hydroxy-3-methoxybenzaldehyde) to vanillic acid (4-hydroxy-3-methoxybenzoic acid) was developed, utilizing whole cells of Streptomyces viridosporus T7A. In the first step, cells were grown in a yeast extract-vanillin medium under conditions where cells produced an aromatic aldehyde oxidase. In the second step, vanillin was incubated with the active cells and was quantitatively oxidized to vanillic acid which accumulated in the growth medium. Vanillic acid was readily recovered from the spent medium by a combination of acid precipitation and ether extraction at greater than or equal to96% molar yield and upon recrystallization from glacial acetic acid was obtained in greater than or equal to99% purity.

  3. Whole-cell bioconversion of vanillin to vanillic acid by Streptomyces viridosporus.

    PubMed Central

    Pometto, A L; Crawford, D L

    1983-01-01

    A two-step batch fermentation-bioconversion of vanillin (4-hydroxy-3-methoxybenzaldehyde) to vanillic acid (4-hydroxy-3-methoxybenzoic acid) was developed, utilizing whole cells of Streptomyces viridosporus T7A. In the first step, cells were grown in a yeast extract-vanillin medium under conditions where cells produced an aromatic aldehyde oxidase. In the second step, vanillin was incubated with the active cells and was quantitatively oxidized to vanillic acid which accumulated in the growth medium. Vanillic acid was readily recovered from the spent medium by a combination of acid precipitation and ether extraction at greater than or equal to 96% molar yield and upon recrystallization from glacial acetic acid was obtained in greater than or equal to 99% purity. PMID:6870241

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-08-14

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

  6. Structure-activity relationship between carboxylic acids and T cell cycle blockade.

    PubMed

    Gilbert, Kathleen M; DeLoose, Annick; Valentine, Jimmie L; Fifer, E Kim

    2006-04-01

    This study was designed to examine the potential structure-activity relationship between carboxylic acids, histone acetylation and T cell cycle blockade. Toward this goal a series of structural homologues of the short-chain carboxylic acid n-butyrate were studied for their ability to block the IL-2-stimulated proliferation of cloned CD4+ T cells. The carboxylic acids were also tested for their ability to inhibit histone deacetylation. In addition, Western blotting was used to examine the relative capacity of the carboxlic acids to upregulate the cyclin kinase-dependent inhibitor p21cip1 in T cells. As shown earlier n-butyrate effectively inhibited histone deacetylation. The increased acetylation induced by n-butyrate was associated with the upregulation of the cyclin-dependent kinase inhibitor p21cip1 and the cell cycle blockade of CD4+ T cells. Of the other carboxylic acids studied, the short chain acids, C3-C5, without branching were the best inhibitors of histone deacetylase. This inhibition correlated with increased expression of the cell cycle blocker p21cip1, and the associated suppression of CD4+ T cell proliferation. The branched-chain carboxylic acids tested were ineffective in all the assays. These results underline the relationship between the ability of a carboxylic acid to inhibit histone deacetylation, and their ability to block T cell proliferation, and suggests that branching inhibits these effects.

  7. Asiatic Acid Prevents the Deleterious Effects of Valproic Acid on Cognition and Hippocampal Cell Proliferation and Survival

    PubMed Central

    Umka Welbat, Jariya; Sirichoat, Apiwat; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanun; Pakdeechote, Poungrat; Sripanidkulchai, Bungorn; Wigmore, Peter

    2016-01-01

    Valproic acid (VPA) is commonly prescribed as an anticonvulsant and mood stabilizer used in the treatment of epilepsy and bipolar disorder. A recent study has demonstrated that VPA reduces histone deacetylase (HDAC) activity, an action which is believed to contribute to the effects of VPA on neural stem cell proliferation and differentiation which may explain the cognitive impairments produced in rodents and patients. Asiatic acid is a triterpenoid derived from the medicinal plant Centella asiatica. Our previous study has shown that Asiatic acid improves working spatial memory and increases cell proliferation in the sub granular zone of the hippocampal dentate gyrus. In the present study we investigate the effects of Asiatic acid in preventing the memory and cellular effects of VPA. Male Spraque-Dawley rats were orally administered Asiatic acid (30 mg/kg/day) for 28 days, while VPA-treated animals received injections of VPA (300 mg/kg) twice a day from Day 15 to Day 28 for 14 days. Spatial memory was determined using the novel object location (NOL) test and hippocampal cell proliferation and survival was quantified by immuostaining for Ki-67 and Bromodeoxyuridine (BrdU), respectively. The results showed that VPA-treated animals were unable to discriminate between objects in familiar and novel locations. Moreover, VPA significantly reduced numbers of Ki-67 and BrdU positive cells. These results indicate that VPA treatment caused impairments of spatial working memory, cell proliferation and survival in the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG). However, these abnormalities were restored to control levels by co-treatment with Asiatic acid. These data demonstrate that Asiatic acid could prevent the spatial memory and neurogenesis impairments caused by VPA. PMID:27213437

  8. Asiatic Acid Prevents the Deleterious Effects of Valproic Acid on Cognition and Hippocampal Cell Proliferation and Survival.

    PubMed

    Umka Welbat, Jariya; Sirichoat, Apiwat; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanun; Pakdeechote, Poungrat; Sripanidkulchai, Bungorn; Wigmore, Peter

    2016-01-01

    Valproic acid (VPA) is commonly prescribed as an anticonvulsant and mood stabilizer used in the treatment of epilepsy and bipolar disorder. A recent study has demonstrated that VPA reduces histone deacetylase (HDAC) activity, an action which is believed to contribute to the effects of VPA on neural stem cell proliferation and differentiation which may explain the cognitive impairments produced in rodents and patients. Asiatic acid is a triterpenoid derived from the medicinal plant Centella asiatica. Our previous study has shown that Asiatic acid improves working spatial memory and increases cell proliferation in the sub granular zone of the hippocampal dentate gyrus. In the present study we investigate the effects of Asiatic acid in preventing the memory and cellular effects of VPA. Male Spraque-Dawley rats were orally administered Asiatic acid (30 mg/kg/day) for 28 days, while VPA-treated animals received injections of VPA (300 mg/kg) twice a day from Day 15 to Day 28 for 14 days. Spatial memory was determined using the novel object location (NOL) test and hippocampal cell proliferation and survival was quantified by immuostaining for Ki-67 and Bromodeoxyuridine (BrdU), respectively. The results showed that VPA-treated animals were unable to discriminate between objects in familiar and novel locations. Moreover, VPA significantly reduced numbers of Ki-67 and BrdU positive cells. These results indicate that VPA treatment caused impairments of spatial working memory, cell proliferation and survival in the subgranular zone (SGZ) of the hippocampal dentate gyrus (DG). However, these abnormalities were restored to control levels by co-treatment with Asiatic acid. These data demonstrate that Asiatic acid could prevent the spatial memory and neurogenesis impairments caused by VPA. PMID:27213437

  9. Tranexamic Acid and Hyaluronate/Carboxymethylcellulose Create Cell Injury

    PubMed Central

    Yılmaz, Bayram; Dilbaz, Serdar; Üstün, Yusuf; Kumru, Selahattin

    2014-01-01

    Background and Objectives: Postoperative pelvic adhesions are associated with chronic pelvic pain, dyspareunia, and infertility. The aim of this study was to evaluate the adhesion prevention effects of tranexamic acid (TA) and hyaluronate/carboxymethylcellulose (HA/CMC) barrier in the rat uterine horn models on the basis of macroscopic and microscopic adhesion scores and histopathological as well as biochemical parameters of inflammation. Methods: Twenty-one Wistar rats were randomly divided into 3 groups. Ten lesions were created on the antimesenteric surface of both uterine horns by bipolar cautery. Three milliliters of 0.9% sodium chloride solution were administered in the control group. A single layer of 2 × 2 cm HA/CMC was plated in group 2. Two milliliters of TA was applied in the last group. All rats were sacrificed at postoperative day 21. Results: No significant difference was found among the control group, the HA/CMC group, and the TA group in terms of macro-adhesion score (P = .206) and microadhesion score (P = .056). No significant difference was found among the 3 groups in terms of inflammation score (P = .815) and inflammatory cell activity (P = .835). Malondialdehyde levels were significantly lower in the control group than in the TA group and HA/CMC group (P = .028). Superoxide dismutase and glutathione S-transferase activities were found to be higher in the control group than in the TA group (P = .005) and HA/CMC group (P = .009). Conclusions: TA and HA/CMC had no efficacy in preventing macroscopic or microscopic adhesion formation and decreasing inflammatory cell activity or inflammation score in our rat models. TA and HA/CMC increased the levels of free radicals and reduced the activities of superoxide dismutase and glutathione S-transferase enzymes, which act to reduce tissue injury. PMID:25392658

  10. Gibberellic acid production by free and immobilized cells in different culture systems.

    PubMed

    Durán-Páramo, Enrique; Molina-Jiménez, Héctor; Brito-Arias, Marco A; Robles-Martínez, Fabián

    2004-01-01

    Gibberellic acid production was studied in different fermentation systems. Free and immobilized cells of Gibberella fujikuroi cultures in shake-flask, stirred and fixed-bed reactors were evaluated for the production of gibberellic acid (GA3). Gibberellic acid production with free cells cultured in a stirred reactor reached 0.206 g/L and a yield of 0.078 g of GA3/g biomass.

  11. Bioavailability of hydroxycinnamic acids from Crepidiastrum denticulatum using simulated digestion and Caco-2 intestinal cells.

    PubMed

    Lee, Hee Ju; Cha, Kwang Hyun; Kim, Chul Young; Nho, Chu Won; Pan, Cheol-Ho

    2014-06-11

    Hydroxycinnamic acids have antioxidant properties and potentially beneficial effects on human health. This study investigated the digestive stability, bioaccessibility, and permeability of hydroxycinnamic acids from Crepidiastrum denticulatum using simulated digestion and Caco-2 intestinal cells. The major compounds of C. denticulatum were determined to be four hydroxycinnamic acids [caftaric acid, chlorogenic acid, chicoric acid, and 3,5-di-O-caffeoylquinic acid (3,5-DCQA)] and one flavonoid (luteolin-7-O-glucuronide) by high-performance liquid chromatography and electrospray ionization mass spectrometry. Hydroxycinnamic acids from C. denticulatum were rapidly released in the stomach and duodenum phase, maximizing the possibility of absorption in the intestinal Caco-2 cells. The digestive stability and bioaccessibility of hydroxycinnamic acids from C. denticulatum were markedly low after simulated digestion and remained minimal in the soluble fraction of the ileum phase. Unlike the four hydroxycinnamic acids, luteolin-7-O-glucuronide was stable in terms of digestive stability and bioaccessibility during simulated digestion. The cell permeabilities (P(app A to B)/P(app B to A)) of caftaric acid (0.054) and chlorogenic acid (0.055) were higher than those of chicoric acid (0.011) and 3,5-DCQA (0.006) in general. That of luteolin-7-O-glucuronide was not detectable, showing its low absorption in Caco-2 cells. These results indicate that the rapid release of hydroxycinnamic acids in the stomach and duodenum phase may increase the potential for absorption in Caco-2 cells, and that luteolin-7-O-glucuronide, which was stable in terms of digestive stability and bioaccessibility, has relatively low absorption compared with hydroxycinnamic acids.

  12. Smac mimetic and oleanolic acid synergize to induce cell death in human hepatocellular carcinoma cells.

    PubMed

    Liese, Juliane; Abhari, Behnaz Ahangarian; Fulda, Simone

    2015-08-28

    Chemotherapy resistance of hepatocellular carcinoma (HCC) is still a major unsolved problem highlighting the need to develop novel therapeutic strategies. Here, we identify a novel synergistic induction of cell death by the combination of the Smac mimetic BV6, which antagonizes Inhibitor of apoptosis (IAP) proteins, and the triterpenoid oleanolic acid (OA) in human HCC cells. Importantly, BV6 and OA also cooperate to suppress long-term clonogenic survival as well as tumor growth in a preclinical in vivo model of HCC underscoring the clinical relevance of our findings. In contrast, BV6/OA cotreatment does not exert cytotoxic effects against normal primary hepatocytes, pointing to some tumor selectivity. Mechanistic studies show that BV6/OA cotreatment leads to DNA fragmentation and caspase-3 cleavage, while supply of the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) revealed a cell type-dependent requirement of caspases for BV6/OA-induced cell death. The receptor interacting protein (RIP)1 kinase Inhibitor Necrostatin-1 (Nec-1) or genetic knockdown of RIP1 fails to rescue BV6/OA-mediated cell death, indicating that BV6/OA cotreatment does not primarily engage necroptotic cell death. Notably, the addition of several reactive oxygen species (ROS) scavengers significantly decreases BV6/OA-triggered cell death, indicating that ROS production contributes to BV6/OA-induced cell death. In conclusion, cotreatment of Smac mimetic and OA represents a novel approach for the induction of cell death in HCC and implicates further studies.

  13. Smac mimetic and oleanolic acid synergize to induce cell death in human hepatocellular carcinoma cells.

    PubMed

    Liese, Juliane; Abhari, Behnaz Ahangarian; Fulda, Simone

    2015-08-28

    Chemotherapy resistance of hepatocellular carcinoma (HCC) is still a major unsolved problem highlighting the need to develop novel therapeutic strategies. Here, we identify a novel synergistic induction of cell death by the combination of the Smac mimetic BV6, which antagonizes Inhibitor of apoptosis (IAP) proteins, and the triterpenoid oleanolic acid (OA) in human HCC cells. Importantly, BV6 and OA also cooperate to suppress long-term clonogenic survival as well as tumor growth in a preclinical in vivo model of HCC underscoring the clinical relevance of our findings. In contrast, BV6/OA cotreatment does not exert cytotoxic effects against normal primary hepatocytes, pointing to some tumor selectivity. Mechanistic studies show that BV6/OA cotreatment leads to DNA fragmentation and caspase-3 cleavage, while supply of the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) revealed a cell type-dependent requirement of caspases for BV6/OA-induced cell death. The receptor interacting protein (RIP)1 kinase Inhibitor Necrostatin-1 (Nec-1) or genetic knockdown of RIP1 fails to rescue BV6/OA-mediated cell death, indicating that BV6/OA cotreatment does not primarily engage necroptotic cell death. Notably, the addition of several reactive oxygen species (ROS) scavengers significantly decreases BV6/OA-triggered cell death, indicating that ROS production contributes to BV6/OA-induced cell death. In conclusion, cotreatment of Smac mimetic and OA represents a novel approach for the induction of cell death in HCC and implicates further studies. PMID:25917078

  14. Combined cycle phosphoric acid fuel cell electric power system

    SciTech Connect

    Mollot, D.J.; Micheli, P.L.

    1995-12-31

    By arranging two or more electric power generation cycles in series, combined cycle systems are able to produce electric power more efficiently than conventional single cycle plants. The high fuel to electricity conversion efficiency results in lower plant operating costs, better environmental performance, and in some cases even lower capital costs. Despite these advantages, combined cycle systems for the 1 - 10 megawatt (MW) industrial market are rare. This paper presents a low noise, low (oxides of nitrogen) NOx, combined cycle alternative for the small industrial user. By combining a commercially available phosphoric acid fuel cell (PAFC) with a low-temperature Rankine cycle (similar to those used in geothermal applications), electric conversion efficiencies between 45 and 47 percent are predicted. While the simple cycle PAFC is competitive on a cost of energy basis with gas turbines and diesel generators in the 1 to 2 MW market, the combined cycle PAFC is competitive, on a cost of energy basis, with simple cycle diesel generators in the 4 to 25 MW market. In addition, the efficiency and low-temperature operation of the combined cycle PAFC results in a significant reduction in carbon dioxide emissions with NO{sub x} concentration on the order of 1 parts per million (per weight) (ppmw).

  15. Vascular smooth muscle cells preloaded with eicosapentaenoic acid and docosahexaenoic acid fail to respond to serotonin stimulation.

    PubMed

    Pakala, R; Pakala, R; Sheng, W L; Benedict, C R

    2000-11-01

    Epidemiological, animal and clinical studies indicate that n-3 fatty acids may benefit individuals with known history of cardiovascular disease or at risk of developing it. Though there is indirect evidence to suggest that the beneficial effects of n-3 fatty acids may be because of their ability to inhibit smooth muscle cell (SMC) proliferation, there are no studies that have examined this hypothesis. In this study, the mitogenic effect of serotonin (5HT) and platelet derived growth factor (PDGF), known mitogens for vascular SMC, on aortic SMCs preloaded with eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) is examined. 5HT and PDGF could only partially stimulate proliferation of SMC that were preloaded with EPA or DHA as compared to the control cells. gamma-Linolenic acid (LA) and oleic acid (OA) did not block the 5HT or PDGF induced 3[H]thymidine incorporation suggesting that the anti-proliferative effect was specific to n-3 fatty acids only. Further, when EPA and DHA were combined in the ratio they are present in fishoils, there was a synergistic interaction in inhibiting the proliferation of SMC. Further, SMC grown in the presence of EPA or DHA, when stimulated with 5HT, failed to show an increase in 5HT(2) receptor mRNA. One of the potential mechanism by which fish oils may prevent the development of atherosclerosis or restenosis could be inhibition of the mitogen induced SMC proliferation. Combination of EPA with DHA is likely to be more beneficial.

  16. Limiting amino acid for protein synthesis with mammary cells in tissue culture.

    PubMed

    Park, C S; Chandler, P T; Norman, A W

    1976-05-01

    To identify the limiting amino acid in the minimal essential medium as published by Eagle (Science 130:432, 1959) for milk protein synthesis in rat mammary cells in tissue culture, two different experimental approaches were used. The first study involved the reduction of amino acids singly from the total amino acid complement of the medium for milk protein synthesis. The second study was to investigate the effect on milk protein synthesis of single amino acid addition to the basic complement of amino acids. Order of limiting amino acids was lysine (first) and possible methionine, valine, or arginine (second).

  17. Isolation of fatty acids and aromatics from cell suspension cultures of Lavandula angustifolia.

    PubMed

    Topçu, Gülaçti; Herrmann, Gabriele; Kolak, Ufuk; Gören, C; Porzel, Andrea; Kutchan, Toni M

    2007-02-01

    Cell suspension cultures of Lavandula angustifolia Mill. ssp. angustifolia (syn.: L. officinalis Chaix.) afforded a fatty acid composition, cis and trans p-coumaric acids (=p-hydroxy cinnamic acids), and beta-sitosterol. The fatty acid composition was analyzed by GC-MS, and the structures of the isolated three compounds were determined by 1H- and 13C-NMR, and MS spectroscopic techniques.

  18. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells.

    PubMed

    da Silva, E P; Nachbar, R T; Levada-Pires, A C; Hirabara, S M; Lambertucci, R H

    2016-01-01

    During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual's performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be beneficial to the anti-oxidant system in cultured skeletal muscle cells. C2C12 myocytes were differentiated and treated with either eicosapentaenoic acid or docosahexaenoic acid for 24 h. Superoxide content was quantified using the dihydroethidine oxidation method and superoxide dismutase, catalase, and glutathione peroxidase activity, and expression was quantified. We observed that the docosahexaenoic fatty acids caused an increase in superoxide production. Eicosapentaenoic acid induced catalase activity, while docosahexaenoic acid suppressed superoxide dismutase activity. In addition, we found an increased protein expression of the total manganese superoxide dismutase and catalase enzymes when cells were treated with eicosapentaenoic acid. Taken together, these data indicate that the use of eicosapentaenoic acid may present both acute and chronic benefits; however, the treatment with DHA may not be beneficial to muscle cells.

  19. Omega-3 fatty acids differentially modulate enzymatic anti-oxidant systems in skeletal muscle cells.

    PubMed

    da Silva, E P; Nachbar, R T; Levada-Pires, A C; Hirabara, S M; Lambertucci, R H

    2016-01-01

    During physical activity, increased reactive oxygen species production occurs, which can lead to cell damage and in a decline of individual's performance and health. The use of omega-3 polyunsaturated fatty acids as a supplement to protect the immune system has been increasing; however, their possible benefit to the anti-oxidant system is not well described. Thus, the aim of this study was to evaluate whether the omega-3 fatty acids (docosahexaenoic acid and eicosapentaenoic acid) can be beneficial to the anti-oxidant system in cultured skeletal muscle cells. C2C12 myocytes were differentiated and treated with either eicosapentaenoic acid or docosahexaenoic acid for 24 h. Superoxide content was quantified using the dihydroethidine oxidation method and superoxide dismutase, catalase, and glutathione peroxidase activity, and expression was quantified. We observed that the docosahexaenoic fatty acids caused an increase in superoxide production. Eicosapentaenoic acid induced catalase activity, while docosahexaenoic acid suppressed superoxide dismutase activity. In addition, we found an increased protein expression of the total manganese superoxide dismutase and catalase enzymes when cells were treated with eicosapentaenoic acid. Taken together, these data indicate that the use of eicosapentaenoic acid may present both acute and chronic benefits; however, the treatment with DHA may not be beneficial to muscle cells. PMID:26386577

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

    PubMed

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

    1976-08-01

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

  1. Gibberellic acid controls specific acid-phosphatase isozymes in aleurone cells and protoplasts of Avena fatua L.

    PubMed

    Hooley, R

    1984-06-01

    In the presence of gibberellic acid (GA3) aleurone layers and isolated aleurone protoplasts of Avena fatua accumulate specific isozymes of acid phosphatase (EC 3.1.3.2). Some of these may be involved in mobilizing aleurone-grain phosphate reserves during germination. The hormone also controls secretion of other specific molecular forms of the enzyme that probably assist in endosperm hydrolysis. The accumulation and secretion of putative cell-wall-associated isozymes are stimulated by the action of GA3 in isolated protoplasts. This effect however, is apparently over-ridden in the intact tissue, possibly by a cell-wall-based feedback mechanism.

  2. 3,4,5-tricaffeoylquinic acid attenuates proteasome inhibition-mediated programmed cell death in differentiated PC12 cells.

    PubMed

    Nam, Yoon Jeong; Lee, Da Hee; Kim, Yun Jeong; Shin, Yong Kyoo; Sohn, Dong Suep; Lee, Min Sung; Lee, Chung Soo

    2014-08-01

    The dysfunction of the proteasome system is suggested to be implicated in neuronal degeneration. Caffeoylquinic acid derivatives have demonstrated anti-oxidant and anti-inflammatory effects. However, the effect of 3,4,5-tricaffeoylquinic acid on the neuronal cell death induced by proteasome inhibition has not been studied. Therefore, in the respect of cell death process, we assessed the effect of 3,4,5-tricaffeoylquinic acid on the proteasome inhibition-induced programmed cell death using differentiated PC12 cells. The proteasome inhibitors MG132 and MG115 induced a decrease in Bid, Bcl-2, and survivin protein levels, an increase in Bax, loss of the mitochondrial transmembrane potential, cytochrome c release, activation of caspases (-8, -9 and -3), and an increase in the tumor suppressor p53 levels. Treatment with 3,4,5-tricaffeoylquinic acid attenuated the proteasome inhibitor-induced changes in the programmed cell death-related protein levels, formation of reactive oxygen species, GSH depletion and cell death. The results show that 3,4,5-tricaffeoylquinic acid may attenuate the proteasome inhibitor-induced programmed cell death in PC12 cells by suppressing the activation of the mitochondrial pathway and the caspase-8- and Bid-dependent pathways. The preventive effect of 3,4,5-tricaffeoylquinic acid appears to be attributed to its inhibitory effect on the formation of reactive oxygen species and depletion of GSH.

  3. Polyunsaturated fatty acids trigger apoptosis of colon cancer cells through a mitochondrial pathway

    PubMed Central

    Zhang, Chengcheng; Yu, Haining; Shen, Yuzhen; Ni, Xiaofeng; Das, Undurti N.

    2015-01-01

    Introduction Colorectal cancer is common in developed countries. Polyunsaturated fatty acids (PUFAs) have been reported to possess tumoricidal action, but the exact mechanism of their action is not clear. Material and methods In the present study, we studied the effect of various n-6 and n-3 fatty acids on the survival of the colon cancer cells LoVo and RKO and evaluated the possible involvement of a mitochondrial pathway in their ability to induce apoptosis. Results It was observed that n-3 α-linolenic acid, eicosapentaenoic acid and docosahexaenoic acid (ALA, EPA and DHA respectively) and n-6 linoleic acid, gamma-linolenic acid and arachidonic acid (LA, GLA and AA respectively) induced apoptosis of the colon cancer cells LoVo and RKO at concentrations above 120 μM (p < 0.01 compared to control). The semi-differentiated colon cancer cell line RKO was more sensitive to the cytotoxic action of PUFAs compared to the undifferentiated colon cancer cell line LoVo. PUFA-treated cells showed an increased number of lipid droplets in their cytoplasm. PUFA-induced apoptosis of LoVo and RKO cells is mediated through a mitochondria-mediated pathway as evidenced by loss of mitochondrial membrane potential, generation of ROS, accumulation of intracellular Ca2+, activation of caspase-9 and caspase-3, decreased ATP level and increase in the Bax/Bcl2 expression ratio. Conclusions PUFAs induced apoptosis of colon cancer cells through a mitochondrial dependent pathway. PMID:26528354

  4. Complexing of amino acids to DNA by chromate in intact cells.

    PubMed Central

    Voitkun, V; Zhitkovich, A; Costa, M

    1994-01-01

    Using o-pthaldialdehyde (OPT) fluorescence, the amino acids associated with DNA were studied following exposure of intact Chinese hamster ovary cells to chromate. Rigorous extraction with EDTA, acid, or base was required to release the amino acids cross-linked to the DNA isolated from control or chromate-treated cells by standard procedures (i.e., proteinase K, phenol, etc.). Amino acids resisting extraction from DNA were not studied since analysis was limited to those that could be released by these procedures. There was a chromate dose-dependent increase in amino acids complexed with the DNA that could be released by EDTA, acid, and base, and these amino acids were separated by HPLC and identified. Substantial increases in cysteine, glutamine, glutamic acid, histidine, threonine, and tyrosine were found as a function of increasing concentrations of chromate. There was also a time-dependent increase in complexing of these amino acids to the DNA by chromate. The amino acids found complexed to DNA in intact cells by chromate were thought to originate from reactions of free amino acids or small peptides with the DNA rather than being proteolytic products derived from larger proteins that were cross-linked to the DNA. This was supported by a number of experiments: a) free amino acids or bovine serum albumin (BSA) were cross-linked by chromium to DNA in vitro and the DNA was isolated by standard procedures.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7843108

  5. Delta-6 desaturase from borage converts linoleic acid to gamma-linolenic acid in HEK293 cells.

    PubMed

    Chen, Qing; Nimal, Jonathan; Li, Wanli; Liu, Xia; Cao, Wenguang

    2011-07-01

    Gamma-linolenic acid (GLA, 18:3 n6) is an essential polyunsaturated fatty acid of the omega-6 family and is found to be effective in prevention and/or treatment of various health problems. In this study, we evaluated the possibility of increasing γ-linolenic acid contents in mammalian cells using the delta-6 gene from Borago officinalis. The borage Δ6-desaturase gene (sDelta-6) was codon-optimized and introduced into HEK293 cells by lipofectin transfection. Co-expression of GFP with sDelta-6 and RT-PCR analysis indicated that sDelta-6 could be expressed in mammalian cells. Subsequently, the heterologous expression of borage Δ6-desaturase was evaluated by fatty acid analysis. Total cellular lipid analysis of transformed cells fed with linoleic acid (LA 18:2 n6) as a substrate showed that the expression of sDelta-6 resulted in an 228-483% (p<0.05) increase of GLA when compared with that in the control cells. The highest conversion efficiency of LA into GLA in sDelta-6(+) cells was 6.9 times higher than that in the control group (11.59% vs. 1.69%; p<0.05). Our present work demonstrated that the sDelta-6 gene from borage could be functionally expressed in mammalian cells, and could convert LA into GLA. Furthermore, this study may pave the way to generate transgenic livestock that can synthesise GLA. PMID:21679695

  6. Cell proliferation, apoptosis and accumulation of lipid droplets in U937-1 cells incubated with eicosapentaenoic acid.

    PubMed Central

    Finstad, H S; Drevon, C A; Kulseth, M A; Synstad, A V; Knudsen, E; Kolset, S O

    1998-01-01

    The monocytic cell line U937-1 was cultured in the presence of eicosapentaenoic acid (20:5, n-3) (EPA) or oleic acid (18:1, n-9) (OA). EPA caused a dose-dependent inhibition of cell proliferation, whereas OA had no effect. At the highest EPA concentrations, 120 and 240 microM, inhibition of cell proliferation was accompanied by initiation of apoptosis. A concentration of 60 microM EPA caused a 35% reduction in cell proliferation without inducing apoptosis, and was therefore used for further studies. Addition of antioxidants or inhibitors of eicosanoid synthesis had no influence on the reduced cell proliferation after EPA treatment. The inhibition required continuous presence of EPA in the incubation medium as the cells resumed a normal proliferation rate when they were placed in EPA-free medium. The inhibition of proliferation was not accompanied by differentiation into macrophage-like cells, as expression of serglycin and the ability to perform respiratory burst was unaffected by EPA. Expression of CD23 mRNA increased when the cells were incubated with EPA, but to a smaller extent than after retinoic acid (RA) or PMA treatment. Furthermore, expression of the monocytic differentiation markers CD36 and CD68 was lower in cells treated with EPA or OA when compared with untreated cells. The cell cycle distribution of U937-1 cells was similar in cells incubated with EPA or PMA, whereas RA-treated cells accumulated in the G1 phase. Side scatter increased in cells incubated with EPA and OA, which was ascribed to an accumulation of lipid droplets after examination of the cells by electron microscopy. The number of droplets per cell was higher in cells exposed to EPA than OA. The cellular triacylglycerol (TAG) increased 5.5- and 15.5-fold after incubation with OA and EPA respectively. No difference in the cellular content of cholesterol compared with untreated cells was observed. The TAG fraction in EPA-treated cells contained high amounts of EPA and docosapentaenoic acid

  7. Sialic Acids on Varicella-Zoster Virus Glycoprotein B Are Required for Cell-Cell Fusion.

    PubMed

    Suenaga, Tadahiro; Matsumoto, Maki; Arisawa, Fuminori; Kohyama, Masako; Hirayasu, Kouyuki; Mori, Yasuko; Arase, Hisashi

    2015-08-01

    Varicella-zoster virus (VZV) is a member of the human Herpesvirus family that causes varicella (chicken pox) and zoster (shingles). VZV latently infects sensory ganglia and is also responsible for encephalomyelitis. Myelin-associated glycoprotein (MAG), a member of the sialic acid (SA)-binding immunoglobulin-like lectin family, is mainly expressed in neural tissues. VZV glycoprotein B (gB) associates with MAG and mediates membrane fusion during VZV entry into host cells. The SA requirements of MAG when associating with its ligands vary depending on the specific ligand, but it is unclear whether the SAs on gB are involved in the association with MAG. In this study, we found that SAs on gB are essential for the association with MAG as well as for membrane fusion during VZV infection. MAG with a point mutation in the SA-binding site did not bind to gB and did not mediate cell-cell fusion or VZV entry. Cell-cell fusion and VZV entry mediated by the gB-MAG interaction were blocked by sialidase treatment. N-glycosylation or O-glycosylation inhibitors also inhibited the fusion and entry mediated by gB-MAG interaction. Furthermore, gB with mutations in N-glycosylation sites, i.e. asparagine residues 557 and 686, did not associate with MAG, and the cell-cell fusion efficiency was low. Fusion between the viral envelope and cellular membrane is essential for host cell entry by herpesviruses. Therefore, these results suggest that SAs on gB play important roles in MAG-mediated VZV infection.

  8. Pseudolaric acid B activates autophagy in MCF-7 human breast cancer cells to prevent cell death

    PubMed Central

    YU, JINGHUA; CHEN, CHUNHAI; XU, TIANYANG; YAN, MINGHUI; XUE, BIANBIAN; WANG, YING; LIU, CHUNYU; ZHONG, TING; WANG, ZENGYAN; MENG, XIANYING; HU, DONGHUA; YU, XIAOFANG

    2016-01-01

    Pseudolaric acid B (PAB) has been demonstrated to exert antitumor effects in MCF-7 human breast cancer cells. The present study aimed to investigate the mechanism of resistance to PAB-induced cell death. Following incubation with 4 µM of PAB for 3 days, the majority of MCF-7 cells became senescent, while some retained the same morphology as control cells, as assessed using a senescence detection kit. Additionally, 36 h of treatment with 4 µM of PAB increased the positive staining of autophagy markers, as shown by monodansylcadaverine and acridine orange staining. Western blot analysis indicated that this treatment also increased expression of the autophagy-related proteins Beclin-1 and microtubule-associated protein 1 light chain 3. Furthermore, treatment with PAB and the autophagy inhibitor 3-methyl adenine significantly decreased the ratio of autophagy, as assessed by flow cytometric analysis of monodansylcadaverine staining density (P<0.001), and increased the ratio of cell death, as assessed by MTT analysis (P<0.001). This indicated that autophagy promotes cell survival as a resistance mechanism to PAB treatment. Additionally, the present study demonstrated that PAB treatment did not affect the mitochondrial membrane potential, which may be related to autophagy. Increased Bcl-2 expression may explain why PAB did not affect the mitochondrial membrane potential. A Bcl-2 binding test demonstrated that PAB treatment inhibits the binding of Bcl-2 and Beclin-1, which may free Beclin-1 to participate in autophagy. Therefore, the present study demonstrated that autophagy may be activated by PAB treatment in human breast cancer MCF-7 cells, contributing to resistance to cell death. PMID:26998069

  9. Docosahexaenoic acid and other fatty acids induce a decrease in pHi in Jurkat T-cells

    PubMed Central

    Aires, Virginie; Hichami, Aziz; Moutairou, Kabirou; Khan, Naim Akhtar

    2003-01-01

    Docosahexaenoic acid (DHA) induced rapid (t1/2=33 s) and dose-dependent decreases in pHi in BCECF-loaded human (Jurkat) T-cells. Addition of 5-(N,N-dimethyl)-amiloride, an inhibitor of Na+/H+ exchanger, prolonged DHA-induced acidification as a function of time, indicating that the exchanger is implicated in pHi recovery. Other fatty acids like oleic acid, arachidonic acid, eicosapentaenoic acid, but not palmitic acid, also induced a fall in pHi in these cells. To assess the role of calcium in the DHA-induced acidification, we conducted experiments in Ca2+-free (0% Ca2+) and Ca2+-containing (100% Ca2+) buffer. We observed that there was no difference in the degree of DHA-induced transient acidification in both the experimental conditions, though pHi recovery was faster in 0% Ca2+ medium than that in 100% Ca2+ medium. In the presence of BAPTA, a calcium chelator, a rapid recovery of DHA-induced acidosis was observed. Furthermore, addition of CaCl2 into 0% Ca2+ medium curtailed DHA-evoked rapid pHi recovery. In 0% Ca2+ medium, containing BAPTA, DHA did not evoke increases in [Ca2+]i, though this fatty acid still induced a rapid acidification in these cells. These observations suggest that calcium is implicated in the long-lasting DHA-induced acidosis. DHA-induced rapid acidification may be due to its deprotonation in the plasma membrane (flip-flop model), as suggested by the following observations: (1) DHA with a –COOH group induced intracellular acidification, but this fatty acid with a –COOCH3 group failed to do so, and (2) DHA, but not propionic acid, -induced acidification was completely reversed by addition of fatty acid-free bovine serum albumin in these cells. These results suggest that DHA induces acidosis via deprotonation and Ca2+ mobilization in human T-cells. PMID:14645139

  10. Short Chain Fatty Acids (SCFA) Reprogram Gene Expression in Human Malignant Epithelial and Lymphoid Cells

    PubMed Central

    Astakhova, Lidiia; Ngara, Mtakai; Babich, Olga; Prosekov, Aleksandr; Asyakina, Lyudmila; Dyshlyuk, Lyubov; Midtvedt, Tore; Zhou, Xiaoying; Ernberg, Ingemar; Matskova, Liudmila

    2016-01-01

    The effect of short chain fatty acids (SCFAs) on gene expression in human, malignant cell lines was investigated, with a focus on signaling pathways. The commensal microbial flora produce high levels of SCFAs with established physiologic effects in humans. The most abundant SCFA metabolite in the human microflora is n-butyric acid. It is well known to activate endogenous latent Epstein-Barr virus (EBV), that was used as a reference read out system and extended to EBV+ epithelial cancer cell lines. N-butyric acid and its salt induced inflammatory and apoptotic responses in tumor cells of epithelial and lymphoid origin. Epithelial cell migration was inhibited. The n-butyric gene activation was reduced by knock-down of the cell membrane transporters MCT-1 and -4 by siRNA. N-butyric acid show biologically significant effects on several important cellular functions, also with relevance for tumor cell phenotype. PMID:27441625

  11. Short Chain Fatty Acids (SCFA) Reprogram Gene Expression in Human Malignant Epithelial and Lymphoid Cells.

    PubMed

    Astakhova, Lidiia; Ngara, Mtakai; Babich, Olga; Prosekov, Aleksandr; Asyakina, Lyudmila; Dyshlyuk, Lyubov; Midtvedt, Tore; Zhou, Xiaoying; Ernberg, Ingemar; Matskova, Liudmila

    2016-01-01

    The effect of short chain fatty acids (SCFAs) on gene expression in human, malignant cell lines was investigated, with a focus on signaling pathways. The commensal microbial flora produce high levels of SCFAs with established physiologic effects in humans. The most abundant SCFA metabolite in the human microflora is n-butyric acid. It is well known to activate endogenous latent Epstein-Barr virus (EBV), that was used as a reference read out system and extended to EBV+ epithelial cancer cell lines. N-butyric acid and its salt induced inflammatory and apoptotic responses in tumor cells of epithelial and lymphoid origin. Epithelial cell migration was inhibited. The n-butyric gene activation was reduced by knock-down of the cell membrane transporters MCT-1 and -4 by siRNA. N-butyric acid show biologically significant effects on several important cellular functions, also with relevance for tumor cell phenotype. PMID:27441625

  12. Effect of nerve growth factor on the synthesis of amino acids in PC12 cells

    SciTech Connect

    Zielke, H.R.; Tildon, J.T.; Kauffman, F.C.; Baab, P.J. )

    1989-04-01

    Radioactive short-chain fatty acids preferentially label glutamine relative to glutamate in brain due to compartmentation of glutamine and glutamate. To determine whether this phenomenon occurs in a single cell culture model, we examined the effect of fatty acid chain length on the synthesis as well as pool size of selected amino acids in rat pheochromocytoma PC12 cells, a cell culture model of the large glutamate compartment in neurons. Intracellular 14C-amino acids were quantitated by HPLC, and the incorporation of (U-14C)-glucose, (1-14C)-butyrate, (1-14C)-octanoate, and (1-14C)-palmitate into five amino acids was measured in native and NGF-treated PC12 cells. NGF pretreatment decreased the intracellular concentration of amino acids as did addition of fatty acids but these effects were not additive. Specific activities of amino acids in native cells labelled by 14C-octanoate were 1,300 DPM/nmol, 490 DPM/nmol, 200 DPM/nmol, and 110 DPM/nmol for glutamate, aspartate, glutamine, and serine, respectively. No radioactivity was detected in alanine. Similar specific activities were noted when 14C-butyrate was the precursor; however, there was at least 5-fold less if 14C-palmitate was the precursor. Pretreatment of cells with NGF decreased the specific activity of amino acids by 25-65%. Specific activities of amino acids synthesized from 14C-glucose decreased in the following order: glutamate, 1,640 DPM/nmol; aspartate, 1,210 DPM/nmol; alanine, 580 DPM/nmol; glutamine, 275 DPM/nmol; and serine, 80 DPM/nmol for native cells. NGF pretreatment decreased the specific activities of glutamate and glutamine, but not of the other 3 amino acids. The preferred precursor for glutamate synthesis in native PC12 cells was glucose followed by octanoate, butyrate and palmitate (16:6:3:1).

  13. Oleic acid stimulates system A amino acid transport in primary human trophoblast cells mediated by toll-like receptor 4.

    PubMed

    Lager, Susanne; Gaccioli, Francesca; Ramirez, Vanessa I; Jones, Helen N; Jansson, Thomas; Powell, Theresa L

    2013-03-01

    Obese women have an increased risk to deliver large babies. However, the mechanisms underlying fetal overgrowth in these pregnancies are not well understood. Obese pregnant women typically have elevated circulating lipid levels. We tested the hypothesis that fatty acids stimulate placental amino acid transport, mediated via toll-like receptor 4 (TLR4) and mammalian target of rapamycin (mTOR) signaling pathways. Circulating NEFA levels and placental TLR4 expression were assessed in women with varying prepregnancy body mass index (BMI). The effects of oleic acid on system A and system L amino acid transport, and on the activation of the mTOR (4EBP1, S6K1, rpS6), TLR4 (IĸB, JNK, p38 MAPK), and STAT3 signaling pathways were determined in cultured primary human trophoblast cells. Maternal circulating NEFAs (n = 33), but not placental TLR4 mRNA expression (n = 16), correlated positively with BMI (P < 0.05). Oleic acid increased trophoblast JNK and STAT3 phosphorylation (P < 0.05), whereas mTOR activity was unaffected. Furthermore, oleic acid doubled trophoblast system A activity (P < 0.05), without affecting system L activity. siRNA-mediated silencing of TLR4 expression prevented the stimulatory effect of oleic acid on system A activity. Our data suggest that maternal fatty acids can increase placental nutrient transport via TLR4, thereby potentially affecting fetal growth.

  14. Alginate immobilization of Escherichia coli MTCC 1652 whole cells for bioconversion of glycyrrhizinic acid and into 18-beta glycyrrhetinic acid.

    PubMed

    Ahmad, M; Panda, B P

    2013-12-15

    Microbial biotransformation of Glycyrrhizinic acid (GL) into 18-beta Glycyrrhetinic Acid (GA) was achieved using Escherichia coli MTCC 1652 whole cell. The E. coli whole cell was immobilized by entrapment method within calcium alginate beads using cell suspension of equal volume with sodium alginate 8%. The pH of solution, reaction volume and % of GL were optimized during the immobilization procedure and optimum pH 6.5, reaction volume of 4 mL and at 3% GL concentration for 12 h of incubation time showed highest concentration of GA (72.649 microg mL(-1)) with 76% bioconversion of GL to GA. Under optimized condition the immobilized cell produces 58.663 microg per mL of GA in licorice root extract containing 95.118 microg of GL per mL of the extract with 61% conversion at 12 h.

  15. Stimulation of proliferation of an essential fatty acid-deficient fish cell line by C20 and C22 polyunsaturated fatty acids and effects on fatty acid composition.

    PubMed

    Tocher, D R; Dick, J R; Sargent, J R

    1996-11-01

    Recently we reported the development of a fish cell line, EPC-EFAD, derived from the carp (Cyprinus carpio) epithelial papilloma line, EPC, that could survive and proliferate in essential fatty acid-deficient (EFAD) medium. The EPC-EFAD cell line may be a useful model system in which to study the cellular biochemical effects of EFA deficiency and has advantages in studies of polyunsaturated fatty acid (PUFA) and eicosanoid metabolism in fish in that the complications introduced by culture in relatively n-6 PUFA-rich mammalian sera are removed. In the present study, the effects on cell proliferation rate of supplementing EPC-EFAD cells with various n-3 and n-6 PUFA were investigated to determine the possible role(s) of PUFA in cell growth and division. The selectivity of incorporation of specific PUFA into individual glycerophospholipid classes and the feasibility of reproducing in vivo fatty acid compositions in vitro were also investigated. Proliferation of the EPC-EFAD cell line was stimulated by arachidonic (20:4 n-6), eicosapentaenoic (20:5 n-3) and docosahexaenoic (22:6 n-3) fatty acids but not by 18:2 n-6 or 18:3 n-3. The differential effects of PUFA on cellular proliferation may be related to the lack of significant delta 5 desaturase activity in the cells at 22 degrees C and may implicate a role for eicosanoids in the mechanism of stimulation of proliferation. PUFA supplementation increased the cytotoxic effects of longer term culture, an effect that was partly alleviated by inclusion of vitamin E in the culture medium. The cells could generally be supplemented with PUFA to produce cellular fatty acid compositions in vitro that were similar to in vivo compositions. PMID:8981632

  16. An Analysis of Lipoproteins, Bile Acids, and Red Cell Membranes Associated with Target Cells and Spur Cells in Patients with Liver Disease

    PubMed Central

    Cooper, Richard A.; Diloy-Puray, Milagros; Lando, Patricia; Greenberg, Mortimer S.

    1972-01-01

    Most patients with stable cirrhosis of the alcoholic have “target” red cells; however, a minority have “spur” cells and severe hemolytic anemia. These two syndromes were studied in 27 patients with target cells and 17 patients with spur cells, all of whom had advanced cirrhosis. The cholesterol and phospholipid content of red cell membranes effectively distinguished target cells from spur cells. Target cells alone were rich in lecithin, and both the cholesterol/phospholipid and cholesterol/lecithin mole ratios were greater in spur cells. The cholesterol/phospholipid mole ratio of both types of red cells correlated closely with the free cholesterol saturation of serum lipoproteins, as defined by the amount of free cholesterol relative to phospholipid and protein in these lipoproteins. Lecithin: cholesterol acyltransferase (LCAT) activity was decreased in most patients with target cells and spur cells; however, the relationship between this activity and the lipid abnormalities observed was weak. Serum bile acid levels also correlated poorly with serum and cell lipids. However, in patients with target cells the amount of cholic and deoxycholic acids in serum was approximately equal to the amount of chenodeoxycholic acid, whereas in patients with spur cells chenodeoxycholic acid (the precursor of lithocholic acid) predominated. PMID:4640953

  17. Okadaic Acid Toxin at Sublethal Dose Produced Cell Proliferation in Gastric and Colon Epithelial Cell Lines

    PubMed Central

    del Campo, Miguel; Toledo, Héctor; Lagos, Néstor

    2013-01-01

    The aim of this study was to analyze the effect of Okadaic Acid (OA) on the proliferation of gastric and colon epithelial cells, the main target tissues of the toxin. We hypothesized that OA, at sublethal doses, activates multiple signaling pathways, such as Erk and Akt, through the inhibition of PP2A. To demonstrate this, we carried out curves of doses and time response against OA in AGS, MKN-45 and Caco 2 cell lines, and found an increase in the cell proliferation at sublethal doses, at 24 h or 48 h exposure. Indeed, cells can withstand high concentrations of the toxin at 4 h exposure, the time chosen considering the maximum time before total gastric emptying. We have proved that this increased proliferation is due to an overexpression of Cyclin B, a cyclin that promotes the passage from G2 to mitosis. In addition, we have demonstrated that OA induces activation of Akt and Erk in the three cells lines, showing that OA can activate pathways involved in oncogenesis. In conclusion, this study contributes to the knowledge about the possible effects of chronic OA consumption. PMID:24317467

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

    PubMed

    Napoli, J L

    1986-10-15

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

  19. Luteolin prevents uric acid-induced pancreatic β-cell dysfunction

    PubMed Central

    Ding, Ying; Shi, Xuhui; Shuai, Xuanyu; Xu, Yuemei; Liu, Yun; Liang, Xiubin; Wei, Dong; Su, Dongming

    2014-01-01

    Abstract Elevated uric acid causes direct injury to pancreatic β-cells. In this study, we examined the effects of luteolin, an important antioxidant, on uric acid-induced β-cell dysfunction. We first evaluated the effect of luteolin on nitric oxide (NO) formation in uric acid-stimulated Min6 cells using the Griess method. Next, we performed transient transfection and reporter assays to measure transcriptional activity of nuclear factor (NF)-κB. Western blotting assays were also performed to assess the effect of luteolin on the expression of MafA and inducible NO synthase (iNOS) in uric acid-treated cells. Finally, we evaluated the effect of luteolin on uric acid-induced inhibition of glucose-stimulated insulin secretion (GSIS) in Min6 cells and freshly isolated mouse pancreatic islets. We found that luteolin significantly inhibited uric acid-induced NO production, which was well correlated with reduced expression of iNOS mRNA and protein. Furthermore, decreased activity of NF-κB was implicated in inhibition by luteolin of increased iNOS expression induced by uric acid. Besides, luteolin significantly increased MafA expression in Min6 cells exposed to uric acid, which was reversed by overexpression of iNOS. Moreover, luteolin prevented uric acid-induced inhibition of GSIS in both Min6 cells and mouse islets. In conclusion, luteolin protects pancreatic β-cells from uric acid-induced dysfunction and may confer benefit on the protection of pancreatic β-cells in hyperuricemia-associated diabetes. PMID:25050113

  20. Induction of apoptosis by a potent caffeic acid derivative, caffeic acid undecyl ester, is mediated by mitochondrial damage in NALM-6 human B cell leukemia cells

    PubMed Central

    TOMIZAWA, AYAKO; KANNO, SYU-ICHI; OSANAI, YUU; GOTO, AKANE; SATO, CHIZURU; YOMOGIDA, SHIN; ISHIKAWA, MASAAKI

    2013-01-01

    Caffeic acid esters have various biological activities, and we previously reported that undecyl caffeate (caffeic acid undecyl ester, CAUE), a new caffeic acid derivative, has strong pharmacological activity. The present study investigated the cytotoxicity of both CAUE and its parent compound, caffeic acid phenethyl ester (CAPE), and characterized the mechanisms by which they induce apoptosis in the human B cell leukemia cell line NALM-6. Treatment with CAUE reduced cell survival in NALM-6 cells but had no significant effect on the survival of normal lymphocytes. When assessing the 50% inhibitory concentration (IC50) for cytotoxicity, CAUE had 10-fold higher activity than CAPE in NALM-6 cells. CAUE treatment resulted in induction of apoptotic features in NALM-6 cells, including cleaved poly (ADP-ribose) polymerase and activated caspase-3. A caspase inhibitor completely blocked CAUE-induced apoptosis. CAUE treatment resulted in a concentration- and time-dependent decrease in both mitochondrial membrane potential and downregulation of Bcl-2 expression. Moreover, CAUE-induced apoptosis was enhanced in the Bcl-2 knockdown condition induced by small interfering RNA. These data suggest that CAUE-induced apoptosis was mediated via an apoptotic intrinsic pathway including mitochondrial damage and was caspase-dependent. These data also suggest that CAUE is a powerful anti-leukemic agent that acts via induction of apoptosis by mitochondrial damage and selective action in leukemia cells. PMID:23229564

  1. Epoxyeicosatrienoic Acids Affect Electrolyte Transport in Renal Tubular Epithelial Cells: Dependence on Cyclooxygenase and Cell Polarity

    PubMed Central

    Nüsing, Rolf M.; Schweer, Horst; Fleming, Ingrid; Zeldin, Darryl C.; Wegmann, Markus

    2007-01-01

    We investigated the effects of epoxyeicosatrienoic acids (EETs) on ion transport in the polarized renal distal tubular cell line, MDCK C7. Of the four EET regioisomers (5,6-EET, 8,9-EET, 11,12-EET, and 14,15-EET) studied, only apical, but not basolateral, application of 5,6-EET increased short circuit current (Isc) with kinetics similar to those of arachidonic acid. The ion transport was blocked by preincubation with the cyclooxygenase inhibitor indomethacin or with the chloride channel blocker NPPB. Further, both a Cl−-free bath solution and the Ca2+ antagonist verapamil blocked 5,6-EET-induced ion transport. Although the presence of the PGE2 receptors EP2, EP3, and EP4 was demonstrated, apically added PGE2 was ineffective and basolaterally added PGE2 caused a different kinetics in ion transport compared to 5,6-EET. Moreover, PGE2 sythesis in MDCK C7 cells was unaffected by 5,6-EET treatment. GC/MS/MS analysis of cell supernatants revealed the presence of the biologically inactive 5,6-dihydroxy-PGE1 in 5,6-EET-treated cells, but not in control cells. Indomethacin suppressed the formation of 5,6-dihydroxy-PGE1. 5,6-epoxy-PGE1 the precursor of 5,6-dihydroxy-PGE1, caused a similar ion transport as 5,6-EET. Cytochrome P450 enzymes homolog to human CYP2C8, CYP2C9, and CYP2J2 protein were detected immunologically in the MDCK C7 cells. Our findings suggest that 5,6-EET affects Cl-transport in renal distal tubular cells independent of PGE2 but by a mechanism, dependent on its conversion to 5,6-epoxy-PGE1 by cyclooxygenase. We suggest a role for this P450 epoxygenase product in the regulation of electrolyte transport, especially as a saluretic compound acting from the luminal side of tubular cells in the mammalian kidney. PMID:17494091

  2. Asparagine promotes cancer cell proliferation through use as an amino acid exchange factor.

    PubMed

    Krall, Abigail S; Xu, Shili; Graeber, Thomas G; Braas, Daniel; Christofk, Heather R

    2016-01-01

    Cellular amino acid uptake is critical for mTOR complex 1 (mTORC1) activation and cell proliferation. However, the regulation of amino acid uptake is not well-understood. Here we describe a role for asparagine as an amino acid exchange factor: intracellular asparagine exchanges with extracellular amino acids. Through asparagine synthetase knockdown and altering of media asparagine concentrations, we show that intracellular asparagine levels regulate uptake of amino acids, especially serine, arginine and histidine. Through its exchange factor role, asparagine regulates mTORC1 activity and protein synthesis. In addition, we show that asparagine regulation of serine uptake influences serine metabolism and nucleotide synthesis, suggesting that asparagine is involved in coordinating protein and nucleotide synthesis. Finally, we show that maintenance of intracellular asparagine levels is critical for cancer cell growth. Collectively, our results indicate that asparagine is an important regulator of cancer cell amino acid homeostasis, anabolic metabolism and proliferation. PMID:27126896

  3. Dietary Phenolic Acids Act as Effective Antioxidants in Membrane Models and in Cultured Cells, Exhibiting Proapoptotic Effects in Leukaemia Cells

    PubMed Central

    Zambonin, Laura; Caliceti, Cristiana; Vieceli Dalla Sega, Francesco; Fiorentini, Diana; Hrelia, Silvana; Landi, Laura; Prata, Cecilia

    2012-01-01

    Caffeic, syringic, and protocatechuic acids are phenolic acids derived directly from food intake or come from the gut metabolism of polyphenols. In this study, the antioxidant activity of these compounds was at first evaluated in membrane models, where caffeic acid behaved as a very effective chain-breaking antioxidant, whereas syringic and protocatechuic acids were only retardants of lipid peroxidation. However, all three compounds acted as good scavengers of reactive species in cultured cells subjected to exogenous oxidative stress produced by low level of H2O2. Many tumour cells are characterised by increased ROS levels compared with their noncancerous counterparts. Therefore, we investigated whether phenolic acids, at low concentrations, comparable to those present in human plasma, were able to decrease basal reactive species. Results show that phenolic acids reduced ROS in a leukaemia cell line (HEL), whereas no effect was observed in normal cells, such as HUVEC. The compounds exhibited no toxicity to normal cells while they decreased proliferation in leukaemia cells, inducing apoptosis. In the debate on optimal ROS-manipulating strategies in cancer therapy, our work in leukaemia cells supports the antioxidant ROS-depleting approach. PMID:22792417

  4. Intracellular boron accumulation in CHO-K1 cells using amino acid transport control.

    PubMed

    Sato, Eisuke; Yamamoto, Tetsuya; Shikano, Naoto; Ogura, Masato; Nakai, Kei; Yoshida, Fumiyo; Uemae, Yoji; Takada, Tomoya; Isobe, Tomonori; Matsumura, Akira

    2014-06-01

    BPA used in BNCT has a similar structure to some essential amino acids and is transported into tumor cells by amino acid transport systems. Previous study groups have tried various techniques of loading BPA to increase intracellular boron concentration. CHO-K1 cells demonstrate system L (LAT1) activity and are suitable for specifying the transport system of a neutral amino acid. In this study, we examined the intracellular accumulation of boron in CHO-K1 cells by amino acid transport control, which involves co-loading with L-type amino acid esters. Intracellular boron accumulation in CHO-K1 cells showed the greatest increased upon co-loading 1.0mM BPA, with 1.0mM l-Tyr-O-Et and incubating for 60min. This increase is caused by activation of a system L amino acid exchanger between BPA and l-Tyr. The amino acid esters are metabolized to amino acids by intracellular hydrolytic enzymes that increase the concentrations of intracellular amino acids and stimulate exchange transportation. We expect that this amino acid transport control will be useful for enhancing intracellular boron accumulation.

  5. Inhibition of Fatty Acid Synthesis Induces Apoptosis of Human Pancreatic Cancer Cells.

    PubMed

    Nishi, Koji; Suzuki, Kenta; Sawamoto, Junpei; Tokizawa, Yuma; Iwase, Yumiko; Yumita, Nagahiko; Ikeda, Toshihiko

    2016-09-01

    Cancer cells tend to have a high requirement for lipids, including fatty acids, cholesterol and triglyceride, because of their rapid proliferative rate compared to normal cells. In this study, we investigated the effects of inhibition of lipid synthesis on the proliferation and viability of human pancreatic cancer cells. Of the inhibitors of lipid synthesis that were tested, 5-(tetradecyloxy)-2-furoic acid (TOFA), which is an inhibitor of acetyl-CoA carboxylase, and the fatty acid synthase (FAS) inhibitors cerulenin and irgasan, significantly suppressed the proliferation of MiaPaCa-2 and AsPC-1 cells. Treatment of MiaPaCa-2 cells with these inhibitors significantly increased the number of apoptotic cells. In addition, TOFA increased caspase-3 activity and induced cleavage of poly (ADP-ribose) polymerase in MiaPaCa-2 cells. Moreover, addition of palmitate to MiaPaCa-2 cells treated with TOFA rescued cells from apoptotic cell death. These results suggest that TOFA induces apoptosis via depletion of fatty acids and that, among the various aspects of lipid metabolism, inhibition of fatty acid synthesis may be a notable target for the treatment of human pancreatic cancer cells. PMID:27630308

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

    PubMed

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

    2015-01-01

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

  7. Potential Role of Omega-3 Fatty Acids on the Myogenic Program of Satellite Cells

    PubMed Central

    Bhullar, Amritpal S.; Putman, Charles T.; Mazurak, Vera C.

    2016-01-01

    Skeletal muscle loss is associated with aging as well as pathological conditions. Satellite cells (SCs) play an important role in muscle regeneration. Omega-3 fatty acids are widely studied in a variety of muscle wasting diseases; however, little is known about their impact on skeletal muscle regeneration. The aim of this review is to evaluate studies examining the effect of omega-3 fatty acids, α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid on the regulation of SC proliferation and differentiation. This review highlights mechanisms by which omega-3 fatty acids may modulate the myogenic program of the stem cell population within skeletal muscles and identifies considerations for future studies. It is proposed that minimally three myogenic transcriptional regulatory factors, paired box 7 (Pax7), myogenic differentiation 1 protein, and myogenin, should be measured to confirm the stage of SCs within the myogenic program affected by omega-3 fatty acids. PMID:26884682

  8. Potential Role of Omega-3 Fatty Acids on the Myogenic Program of Satellite Cells.

    PubMed

    Bhullar, Amritpal S; Putman, Charles T; Mazurak, Vera C

    2016-01-01

    Skeletal muscle loss is associated with aging as well as pathological conditions. Satellite cells (SCs) play an important role in muscle regeneration. Omega-3 fatty acids are widely studied in a variety of muscle wasting diseases; however, little is known about their impact on skeletal muscle regeneration. The aim of this review is to evaluate studies examining the effect of omega-3 fatty acids, α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid on the regulation of SC proliferation and differentiation. This review highlights mechanisms by which omega-3 fatty acids may modulate the myogenic program of the stem cell population within skeletal muscles and identifies considerations for future studies. It is proposed that minimally three myogenic transcriptional regulatory factors, paired box 7 (Pax7), myogenic differentiation 1 protein, and myogenin, should be measured to confirm the stage of SCs within the myogenic program affected by omega-3 fatty acids.

  9. Chemical remodeling of cell-surface sialic acids through a palladium-triggered bioorthogonal elimination reaction.

    PubMed

    Wang, Jie; Cheng, Bo; Li, Jie; Zhang, Zhaoyue; Hong, Weiyao; Chen, Xing; Chen, Peng R

    2015-04-27

    We herein report a chemical decaging strategy for the in situ generation of neuramic acid (Neu), a unique type of sialic acid, on live cells by the use of a palladium-mediated bioorthogonal elimination reaction. Palladium nanoparticles (Pd NPs) were found to be a highly efficient and biocompatible depropargylation catalyst for the direct conversion of metabolically incorporated N-(propargyloxycarbonyl)neuramic acid (Neu5Proc) into Neu on cell-surface glycans. This conversion chemically mimics the enzymatic de-N-acetylation of N-acetylneuramic acid (Neu5Ac), a proposed mechanism for the natural occurrence of Neu on cell-surface glycans. The bioorthogonal elimination was also exploited for the manipulation of cell-surface charge by unmasking the free amine at C5 to neutralize the negatively charged carboxyl group at C1 of sialic acids.

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

    PubMed

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

    2012-02-01

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

  11. Acid stress suggests different determinants for polystyrene and HeLa cell adhesion in Lactobacillus casei.

    PubMed

    Haddaji, N; Khouadja, S; Fdhila, K; Krifi, B; Ben Ismail, M; Lagha, R; Bakir, K; Bakhrouf, A

    2015-07-01

    Adhesion has been regarded as one of the basic features of probiotics. The aim of this study was to investigate the influence of acid stress on the functional properties, such as hydrophobicity, adhesion to HeLa cells, and composition of membrane fatty acids, of Lactobacillus probiotics strains. Two strains of Lactobacillus casei were used. Adhesion on polystyrene, hydrophobicity, epithelial cells adhesion, and fatty acids analysis were evaluated. Our results showed that the membrane properties such as hydrophobicity and fatty acid composition of stressed strains were significantly changed with different pH values. However, we found that acid stress caused a change in the proportions of unsaturated and saturated fatty acid. The ratio of saturated fatty acid to unsaturated fatty acids observed in acid-stressed Lactobacillus casei cells was significantly higher than the ration in control cells. In addition, we observed a significant decrease in the adhesion ability of these strains to HeLa cells and to a polystyrene surface at low pH. The present finding could first add new insight about the acid stress adaptation and, thus, enable new strategies to be developed aimed at improving the industrial performance of this species under acid stress. Second, no relationship was observed between changes in membrane composition and fluidity induced by acid treatment and adhesion to biotic and abiotic surfaces. In fact, the decrease of cell surface hydrophobicity and the adhesion ability to abiotic surface and the increase of the capacity of adhesion to biotic surface demonstrate that adhesive characteristics will have little relevance in probiotic strain-screening procedures.

  12. GSH-dependent antioxidant defense contributes to the acclimation of colon cancer cells to acidic microenvironment

    PubMed Central

    Zhao, Minnan; Liu, Qiao; Gong, Yanchao; Xu, Xiuhua; Zhang, Chen; Liu, Xiaojie; Zhang, Caibo; Guo, Haiyang; Zhang, Xiyu; Gong, Yaoqin; Shao, Changshun

    2016-01-01

    ABSTRACT Due to increased glycolysis and poor local perfusion, solid tumors are usually immersed in an acidic microenvironment. While extracellular acidosis is cytotoxic, cancer cells eventually become acclimated to it. While previous studies have addressed the acute effect of acidosis on cancer cells, little is known about how cancer cells survive chronic acidosis. In this study we exposed colorectal cancer (CRC) cells (HCT15, HCT116 and LoVo) to acidic pH (pH 6.5) continuously for over three months and obtained CRC cells that become acclimated to acidic pH, designated as CRC-acidosis-acclimated or CRC-AA. We unexpectedly found that while acute exposure to low pH resulted in an increase in the level of intracellular reactive oxygen species (ROS), CRC-AA cells exhibited a significantly reduced level of ROS when compared to ancestor cells. CRC-AA cells were found to maintain a higher level of reduced glutathione, via the upregulation of CD44 and glutathione reductase (GSR), among others, than their ancestor cells. Importantly, CRC-AA cells were more sensitive to agents that deplete GSH. Moreover, downregulation of GSR by RNA interference was more deleterious to CRC-AA cells than to control cells. Together, our results demonstrate a critical role of glutathione-dependent antioxidant defense in acclimation of CRC cells to acidic extracellular pH. PMID:26950675

  13. The role of the neutral amino acid transporter SNAT2 in cell volume regulation.

    PubMed

    Franchi-Gazzola, R; Dall'Asta, V; Sala, R; Visigalli, R; Bevilacqua, E; Gaccioli, F; Gazzola, G C; Bussolati, O

    2006-01-01

    Sodium-dependent neutral amino acid transporter-2 (SNAT2), the ubiquitous member of SLC38 family, accounts for the activity of transport system A for neutral amino acids in most mammalian tissues. As the transport process performed by SNAT2 is highly energized, system A substrates, such as glutamine, glycine, proline and alanine, reach high transmembrane gradients and constitute major components of the intracellular amino acid pool. Moreover, through a complex array of exchange fluxes, involving other amino acid transporters, and of metabolic reactions, such as the synthesis of glutamate from glutamine, SNAT2 activity influences the cell content of most amino acids, thus determining the overall size and the composition of the intracellular amino acid pool. As amino acids represent a large fraction of cell organic osmolytes, changes of SNAT2 activity are followed by modifications in both cell amino acids and cell volume. This mechanism is utilized by many cell types to perform an effective regulatory volume increase (RVI) upon hypertonic exposure. Under these conditions, the expression of SNAT2 gene is induced and newly synthesized SNAT2 proteins are preferentially targeted to the cell membrane, leading to a significant increase of system A transport Vmax. In cultured human fibroblasts incubated under hypertonic conditions, the specific silencing of SNAT2 expression, obtained with anti-SNAT2 siRNAs, prevents the increase in system A transport activity, hinders the expansion of intracellular amino acid pool, and significantly delays cell volume recovery. These results demonstrate the pivotal role played by SNAT2 induction in the short-term hypertonic RVI and suggest that neutral amino acids behave as compatible osmolytes in hypertonically stressed cells.

  14. Induction of carnitine palmitoyl transferase 1 and fatty acid oxidation by retinoic acid in HepG2 cells.

    PubMed

    Amengual, Jaume; Petrov, Petar; Bonet, M Luisa; Ribot, Joan; Palou, Andreu

    2012-11-01

    The vitamin A derivative retinoic acid (RA) is an important regulator of mammalian adiposity and lipid metabolism, primarily acting at the gene expression level through nuclear receptors of the RA receptor (RAR) and retinoid X receptor (RXR) subfamilies. Here, we studied cell-autonomous effects of RA on fatty acid metabolism, particularly fatty acid oxidation, in human hepatoma HepG2 cells. Exposure to all-trans RA (ATRA) up-regulated the expression of carnitine palmitoyl transferase-1 (CPT1-L) in HepG2 cells in a dose- and time-dependent manner, and increased cellular oxidation rate of exogenously added radiolabeled palmitate. The effect of ATRA on gene expression of CPT1-L was: dependent on ongoing transcription, reproduced by both 9-cis RA and a pan-RXR agonist (but not a pan-RAR agonist) and abolished following RXRα partial siRNA-mediated silencing. CPT1-L gene expression was synergistically induced in HepG2 cells simultaneously exposed to ATRA and a selective peroxisome proliferator-activated receptor α agonist. We conclude that ATRA treatment enhances fatty acid catabolism in hepatocytes through RXR-mediated mechanisms that likely involve the transactivation of the PPARα:RXR heterodimer. Knowledge of agents and nutrient-derivatives capable of enhancing substrate oxidation systemically and specifically in liver, and their mechanisms of action, may contribute to new avenues of prevention and treatment of fatty liver, obesity and other metabolic syndrome-related disorders. PMID:22871568

  15. Compartmentation of hepatic fatty-acid-binding protein in liver cells and its effect on microsomal phosphatidic acid biosynthesis.

    PubMed

    Bordewick, U; Heese, M; Börchers, T; Robenek, H; Spener, F

    1989-03-01

    Fatty-acid-binding proteins are known to occur in the cytosol of mammalian cells and to bind fatty acids and their CoA-esters. Application of the postembedding protein A-gold labeling method with antibody against the hepatic type fatty-acid-binding protein (hFABP) to cross-sections of liver cells and a newly developed gel-chromatographic immunofluorescence assay established qualitatively (1) that hFABP in mitochondria was confined to outer mitochondrial membranes, (2) the presence of this protein in microsomes and (3) that nuclei were also filled with hFABP. Quantitative data elaborated with a non-competitive ELISA confirmed these results. A significant difference to the distribution of cardiac FABP in heart muscle cells, where this type of protein was found in cytosol, matrix and nuclei, was observed (Börchers et al. (1989) Biochim. Biophys. Acta, in the press). hFABP-containing rat liver microsomes were incubated with long-chain acyl-CoAs in the presence of hFABP (isolated from rat liver cytosol) in a study on the acylation of sn-glycerol-3-phosphate and lysophosphatidic acid. Both acyltransferases were stimulated by addition of hFABP to the incubation medium. The morphological, immunochemical as well as kinetic data infer a direct interaction of hFABP with microsomal membranes in liver cells.

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

    PubMed Central

    Schornack, Paul A; Gillies, Robert J

    2003-01-01

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

  17. Production of Cell Wall Hydrolyzing Enzymes by Barley Aleurone Layers in Response to Gibberellic Acid 1

    PubMed Central

    Taiz, Lincoln; Honigman, William A.

    1976-01-01

    The cell walls of barley (Hordeum vulgare var. Himalaya) aleurone layers undergo extensive degradation during the tissue's response to gibberellic acid. Previous work had shown that these cell walls consist almost entirely of arabinoxylan. In this study we show that gibberellic acid stimulates endo-β-1,4-xylanase activity in isolated aleurone layers. In addition, gibberellic acid enhances the activity of two glycosidases: β-xylopyranosidase and α-arabinofuranosidase. No gibberellic acid-stimulated cellulase activity was detected. Germination studies showed a similar pattern of enzyme development in intact seeds. Images PMID:16659683

  18. Reduced Endoplasmic Reticulum Luminal Calcium Links Saturated Fatty Acid-Mediated Endoplasmic Reticulum Stress and Cell Death in Liver Cells

    PubMed Central

    Wei, Yuren; Wang, Dong; Gentile, Christopher L.; Pagliassotti, Michael J.

    2010-01-01

    Chronic exposure to elevated free fatty acids, in particular long chain saturated fatty acids, provokes endoplasmic reticulum (ER) stress and cell death in a number of cell types. The perturbations to the ER that instigate ER stress and activation of the unfolded protein in response to fatty acids in hepatocytes have not been identified. The present study employed H4IIE liver cells and primary rat hepatocytes to examine the hypothesis that saturated fatty acids induce ER stress via effects on ER luminal calcium stores. Exposure of H4IIE liver cells and primary hepatocytes to palmitate and stearate reduced thapsigargin-sensitive calcium stores and biochemical markers of ER stress over similar time courses (6h). These changes preceded cell death, which was only observed at later time points (16h). Co-incubation with oleate prevented the reduction in calcium stores, induction of ER stress markers and cell death observed in response to palmitate. Inclusion of calcium chelators, BAPTA-AM or EGTA, reduced palmitate- and stearate-mediated enrichment of cytochrome c in post-mitochondrial supernatant fractions and cell death. These data suggest that redistribution of ER luminal calcium contributes to long chain saturated fatty acid-mediated ER stress and cell death. PMID:19444596

  19. Imaging Cancer Cells Expressing the Folate Receptor with Carbon Dots Produced from Folic Acid.

    PubMed

    Bhunia, Susanta Kumar; Maity, Amit Ranjan; Nandi, Sukhendu; Stepensky, David; Jelinek, Raz

    2016-04-01

    Development of new imaging tools for cancer cells in vitro and in vitro is important for advancing cancer research, elucidating drug effects upon cancer cells, and studying cellular processes. We showed that fluorescent carbon dots (C-dots) synthesized from folic acid can serve as an effective vehicle for imaging cancer cells expressing the folate receptor on their surface. The C-dots, synthesized through a simple one-step process from folic acid as the carbon source, exhibited selectivity towards cancer cells displaying the folate receptor, making such cells easily distinguishable in fluorescence microscopy imaging. Biophysical measurements and competition experiments both confirmed the specific targeting and enhanced uptake of C-dots by the folate receptor-expressing cells. The folic acid-derived C-dots were not cytotoxic, and their use in bioimaging applications could aid biological studies of cancer cells, identification of agonists/antagonists, and cancer diagnostics.

  20. High folic acid intake reduces natural killer cell cytotoxicity in aged mice.

    PubMed

    Sawaengsri, Hathairat; Wang, Junpeng; Reginaldo, Christina; Steluti, Josiane; Wu, Dayong; Meydani, Simin Nikbin; Selhub, Jacob; Paul, Ligi

    2016-04-01

    Presence of unmetabolized folic acid in plasma, which is indicative of folic acid intake beyond the metabolic capacity of the body, is associated with reduced natural killer (NK) cell cytotoxicity in postmenopausal women ≥50years. NK cells are cytotoxic lymphocytes that are part of the innate immune system critical for surveillance and defense against virus-infected and cancer cells. We determined if a high folic acid diet can result in reduced NK cell cytotoxicity in an aged mouse model. Female C57BL/6 mice (16-month-old) were fed an AIN-93M diet with the recommended daily allowance (1× RDA, control) or 20× RDA (high) folic acid for 3months. NK cytotoxicity was lower in splenocytes from mice fed a high folic acid diet when compared to mice on control diet (P<.04). The lower NK cell cytotoxicity in high folic acid fed mice could be due to their lower mature cytotoxic/naïve NK cell ratio (P=.03) when compared to the control mice. Splenocytes from mice on high folic acid diet produced less interleukin (IL)-10 when stimulated with lipopolysaccharide (P<.05). The difference in NK cell cytotoxicity between dietary groups was abolished when the splenocytes were supplemented with exogenous IL-10 prior to assessment of the NK cytotoxicity, suggesting that the reduced NK cell cytotoxicity of the high folic acid group was at least partially due to reduced IL-10 production. This study demonstrates a causal relationship between high folic acid intake and reduced NK cell cytotoxicity and provides some insights into the potential mechanisms behind this relationship.

  1. Lipopolysaccharide Stimulates Butyric Acid-Induced Apoptosis in Human Peripheral Blood Mononuclear Cells

    PubMed Central

    Kurita-Ochiai, Tomoko; Fukushima, Kazuo; Ochiai, Kuniyasu

    1999-01-01

    We previously reported that butyric acid, an extracellular metabolite from periodontopathic bacteria, induced apoptosis in murine thymocytes, splenic T cells, and human Jurkat T cells. In this study, we examined the ability of butyric acid to induce apoptosis in peripheral blood mononuclear cells (PBMC) and the effect of bacterial lipopolysaccharide (LPS) on this apoptosis. Butyric acid significantly inhibited the anti-CD3 monoclonal antibody- and concanavalin A-induced proliferative responses in a dose-dependent fashion. This inhibition of PBMC growth by butyric acid depended on apoptosis in vitro. It was characterized by internucleosomal DNA digestion and revealed by gel electrophoresis followed by a colorimetric DNA fragmentation assay to occur in a concentration-dependent fashion. Butyric acid-induced PBMC apoptosis was accompanied by caspase-3 protease activity but not by caspase-1 protease activity. LPS potentiated butyric acid-induced PBMC apoptosis in a dose-dependent manner. Flow-cytometric analysis revealed that LPS increased the proportion of sub-G1 cells and the number of late-stage apoptotic cells induced by butyric acid. Annexin V binding experiments with fractionated subpopulations of PBMC in flow cytometory revealed that LPS accelerated the butyric acid-induced CD3+-T-cell apoptosis followed by similar levels of both CD4+- and CD8+-T-cell apoptosis. The addition of LPS to PBMC cultures did not cause DNA fragmentation, suggesting that LPS was unable to induce PBMC apoptosis directly. These data suggest that LPS, in combination with butyric acid, potentiates CD3+ PBMC T-cell apoptosis and plays a role in the apoptotic depletion of CD4+ and CD8+ cells. PMID:9864191

  2. The Comparative Performance of Batteries: The Lead-Acid and the Aluminum-Air Cells.

    ERIC Educational Resources Information Center

    LeRoux, Xavier; And Others

    1996-01-01

    Describes a teaching program that shows how electrochemical principles can be conveyed by means of hands-on experiences of student-centered teaching experiments. Employs the readily available lead-acid cell and the simple aluminum-air cell. Discusses the batteries, equilibrium cell potential, performance comparison, current, electrode separation,…

  3. Redox control of retinoic acid receptor activity: a novel mechanism for retinoic acid resistance in melanoma cells.

    PubMed

    Demary, K; Wong, L; Liou, J S; Faller, D V; Spanjaard, R A

    2001-06-01

    Retinoic acid (RA) slows growth and induces differentiation of tumor cells through activation of RA receptors (RARs). However, melanoma cell lines display highly variable responsiveness to RA, which is a poorly understood phenomenon. By using Northern and Western blot analyses, we show that RA-resistant A375 and RA-responsive S91 melanoma cells express comparable levels of major components of RAR-signaling pathways. However, A375 cells have substantially higher intracellular reactive oxygen species (ROS) levels than S91 cells. Lowering ROS levels in A375 cells through hypoxic culture conditions restores RAR-dependent trans-activity, which could be further enhanced by addition of the antioxidant N-acetyl-cysteine. Hypoxia also enhances RAR activity in the moderately RA-responsive C32 cells, which have intermediate ROS levels. Conversely, increasing oxidative stress in highly RA-responsive S91 and B16 cells, which have low ROS levels, by treatment with H(2)O(2) impairs RAR activity. Consistent with these observations, RA more potently inhibited the proliferation of hypoxic A375 cells than that of normoxic cells. Oxidative states diminish, whereas reducing conditions enhance, DNA binding of retinoid X receptor/RAR heterodimers in vitro, providing a molecular basis for the observed inverse correlation between RAR activity and ROS levels. The redox state of melanoma cells provides a novel, epigenetic control mechanism of RAR activity and RA resistance. PMID:11356710

  4. Design of Cell-Matrix Interactions in Hyaluronic Acid Hydrogel Scaffolds

    PubMed Central

    Segura, Tatiana

    2013-01-01

    The design of hyaluronic acid-based hydrogel scaffolds to elicit highly controlled and tunable cell response and behavior is a major field of interest in developing tissue engineering and regenerative medicine applications. This review will begin with an overview of the biological context of hyaluronic acid, knowledge needed to better understand how to engineer cell-matrix interactions in the scaffolds via the incorporation of different types of signals in order to direct and control cell behavior. Specifically, recent methods of incorporating various bioactive, mechanical, and spatial signals are reviewed, as well as novel hyaluronic acid modifications and crosslinking schemes with a focus on specificity. PMID:23899481

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

    PubMed Central

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

    2012-01-01

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

  6. Omega 3 but not omega 6 fatty acids inhibit AP-1 activity and cell transformation in JB6 cells

    PubMed Central

    Liu, Guangming; Bibus, Douglas M.; Bode, Ann M.; Ma, Wei-Ya; Holman, Ralph T.; Dong, Zigang

    2001-01-01

    Epidemiological and animal-based investigations have indicated that the development of skin cancer is in part associated with poor dietary practices. Lipid content and subsequently the derived fatty acid composition of the diet are believed to play a major role in the development of tumorigenesis. Omega 3 (ω3) fatty acids, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), can effectively reduce the risk of skin cancer whereas omega 6 (ω6) fatty acids such as arachidonic acid (AA) reportedly promote risk. To investigate the effects of fatty acids on tumorigenesis, we performed experiments to examine the effects of the ω3 fatty acids EPA and DHA and of the ω6 fatty acid AA on phorbol 12-tetradecanoate 13-acetate (TPA)-induced or epidermal growth factor (EGF)-induced transcription activator protein 1 (AP-1) transactivation and on the subsequent cellular transformation in a mouse epidermal JB6 cell model. DHA treatment resulted in marked inhibition of TPA- and EGF-induced cell transformation by inhibiting AP-1 transactivation. EPA treatment also inhibited TPA-induced AP-1 transactivation and cell transformation but had no effect on EGF-induced transformation. AA treatment had no effect on either TPA- or EGF-induced AP-1 transactivation or transformation, but did abrogate the inhibitory effects of DHA on TPA- or EGF-induced AP-1 transactivation and cell transformation in a dose-dependent manner. The results of this study demonstrate that the inhibitory effects of ω3 fatty acids on tumorigenesis are more significant for DHA than for EPA and are related to an inhibition of AP-1. Similarly, because AA abrogates the beneficial effects of DHA, the dietary ratio of ω6 to ω3 fatty acids may be a significant factor in mediating tumor development. PMID:11416221

  7. Single-Cell Protein Production by the Acid-Tolerant Fungus Scytalidium acidophilum from Acid Hydrolysates of Waste Paper †

    PubMed Central

    Ivarson, K. C.; Morita, H.

    1982-01-01

    The bioconversion of waste paper to single-cell protein at pH <1 by Scytalidium acidophilum is described. Waste paper pretreated with 72% H2SO4 at 4°C was diluted with water to a pH of <0.1 and hydrolyzed. This yielded an adequate sugar-containing substrate for the growth of the fungus. A total of 97% of the sugars (glucose, galactose, mannose, xylose, arabinose) in the hydrolysates were converted to cell biomass. Microbial contamination was not observed. Based on the sugars consumed, S. acidophilum produced higher yields in shake cultures than many other Fungi Imperfecti. In aerated cultures, productivity increased, and yields of 43 to 46% containing 44 to 47% crude protein were obtained. This compares favorably with Candida utilis, a yeast used commercially to produce single-cell protein. The chemical constituents and the essential amino acids of the fungal cells were similar to those of other fungi. The nucleic acid content was characteristic of microbes containing low levels of nucleic acid. The advantages of using S. acidophilum for single-cell protein production are discussed. PMID:16345970

  8. Anti-inflammatory drugs and uterine cervical cancer cells: Antineoplastic effect of meclofenamic acid

    PubMed Central

    SORIANO-HERNANDEZ, ALEJANDRO D.; MADRIGAL-PÉREZ, DANIELA; GALVAN-SALAZAR, HECTOR R.; MARTINEZ-FIERRO, MARGARITA L.; VALDEZ-VELAZQUEZ, LAURA L.; ESPINOZA-GÓMEZ, FRANCISCO; VAZQUEZ-VUELVAS, OSCAR F.; OLMEDO-BUENROSTRO, BERTHA A.; GUZMAN-ESQUIVEL, JOSE; RODRIGUEZ-SANCHEZ, IRAM P.; LARA-ESQUEDA, AGUSTIN; MONTES-GALINDO, DANIEL A.; DELGADO-ENCISO, IVAN

    2015-01-01

    Uterine cervical cancer (UCC) is one of the main causes of cancer-associated mortality in women. Inflammation has been identified as an important component of this neoplasia; in this context, anti-inflammatory drugs represent possible prophylactic and/or therapeutic alternatives that require further investigation. Anti-inflammatory drugs are common and each one may exhibit a different antineoplastic effect. As a result, the present study investigated different anti-inflammatory models of UCC in vitro and in vivo. Celecoxib, sulindac, nimesulide, dexamethasone, meclofenamic acid, flufenamic acid and mefenamic acid were tested in UCC HeLa, VIPA, INBL and SiHa cell lines. The cytotoxicity of the drugs was evaluated in vitro. Celecoxib, sulindac, nimesulide, mefenamic acid and flufenamic acid presented with slight to moderate toxicity (10–40% of cell death corresponding to 100 µM) in certain cell lines, while meclofenamic acid exhibited significant cytotoxicity in all essayed cell lines (50–90% of cell death corresponding to 100 µM). The meclofenamic acid was tested in murine models (immunodeficient and immunocompetent) of UCC, which manifested a significant reduction in tumor growth and increased mouse survival. It was demonstrated that of the evaluated anti-inflammatory drugs, meclofenamic acid was the most cytotoxic, with a significant antitumor effect in murine models. Subsequent studies are necessary to evaluate the clinical utility of this drug. PMID:26622892

  9. Granulosa cells and retinoic acid co-treatment enrich potential germ cells from manually selected Oct4-EGFP expressing human embryonic stem cells.

    PubMed

    Chen, Hsin-Fu; Jan, Pey-Shynan; Kuo, Hung-Chih; Wu, Fang-Chun; Lan, Chen-Wei; Huang, Mei-Chi; Chien, Chung-Liang; Ho, Hong-Nerng

    2014-09-01

    Differentiation of human embryonic stem (HES) cells to germ cells may become clinically useful in overcoming diseases related to germ-cell development. Niches were used to differentiate HES cell lines, NTU1 and H9 Oct4-enhanced green fluorescence protein (EGFP), including laminin, granulosa cell co-culture or conditioned medium, ovarian stromal cell co-culture or conditioned medium, retinoic acid, stem cell factor (SCF) and BMP4-BMP7-BMP8b treatment. Flow cytometry showed that granulosa cell co-culture (P < 0.001) or conditioned medium (P = 0.007) treatment for 14 days significantly increased the percentages of differentiated H9 Oct4-EGFP cells expressing early germ cell marker stage-specific embryonic antigen 1(SSEA1); sorted SSEA1[+] cells did not express higher levels of germ cell gene VASA and GDF9. Manually collected H9 Oct4-EGFP[+] cells expressed significantly higher levels of VASA (P = 0.005) and GDF9 (P = 0.001). H9 Oct4-EGFP[+] cells developed to ovarian follicle-like structures after culture for 28 days but with low efficiency. Unlike SCF and BMP4, retinoic acid co-treatment enhanced VASA, GDF9 and SCP3 expression. A protocol is recommended to enrich differentiated HES cells with germ-cell potential by culture with granulosa cells, conditioned medium or retinoic acid, manual selection of Oct4-EGFP[+] cells, and analysis of VASA, GDF9 expression, or both.

  10. Ribonucleic Acid, Deoxyribonucleic Acid, and Protein Content of Cells of Different Ages of Mycobacterium tuberculosis and the Relationship to Immunogenicity

    PubMed Central

    Youmans, Anne S.; Youmans, Guy P.

    1968-01-01

    The amount of ribonucleic acid (RNA), protein, and deoxyribonucleic acid (DNA) was determined in pellicle cultures of different ages of the H37Ra strain of Mycobacterium tuberculosis, grown on a synthetic medium. We found that the highest content of RNA and protein was present in 2-week-old cultures, indicating that these cells were in the logarithmic phase of growth. DNA content was highest at 1 and 2 weeks. The amount of all three compounds then decreased about 50% during the following 6 weeks. Two-week-old cells should therefore be used for preparation of the immunogenic ribosomal fraction. The optimal concentration of zinc chloride increased RNA and protein synthesis, and also improved the appearance of the pellicle growth. Two-week-old cells, which contained the largest amount of RNA and protein, immunized mice significantly better than older cells. Since protein and DNA are not involved in the production of immunity, a correlation could be made between amount of RNA and the capacity of viable H37Ra cells to immunize mice. The immunizing capacity of these cells was not affected by ribonuclease, probably because the ribonuclease did not penetrate into the whole cells. PMID:4966539

  11. Release of endothelial cell lipoprotein lipase by plasma lipoproteins and free fatty acids

    SciTech Connect

    Saxena, U.; Witte, L.D.; Goldberg, I.J.

    1989-03-15

    Lipoprotein lipase (LPL) bound to the lumenal surface of vascular endothelial cells is responsible for the hydrolysis of triglycerides in plasma lipoproteins. Studies were performed to investigate whether human plasma lipoproteins and/or free fatty acids would release LPL which was bound to endothelial cells. Purified bovine milk LPL was incubated with cultured porcine aortic endothelial cells resulting in the association of enzyme activity with the cells. When the cells were then incubated with media containing chylomicrons or very low density lipoproteins (VLDL), a concentration-dependent decrease in the cell-associated LPL enzymatic activity was observed. In contrast, incubation with media containing low density lipoproteins or high density lipoproteins produced a much smaller decrease in the cell-associated enzymatic activity. The addition of increasing molar ratios of oleic acid:bovine serum albumin to the media also reduced enzyme activity associated with the endothelial cells. To determine whether the decrease in LPL activity was due to release of the enzyme from the cells or inactivation of the enzyme, studies were performed utilizing radioiodinated bovine LPL. Radiolabeled LPL protein was released from endothelial cells by chylomicrons, VLDL, and by free fatty acids (i.e. oleic acid bound to bovine serum albumin). The release of radiolabeled LPL by VLDL correlated with the generation of free fatty acids from the hydrolysis of VLDL triglyceride by LPL bound to the cells. Inhibition of LPL enzymatic activity by use of a specific monoclonal antibody, reduced the extent of release of /sup 125/I-LPL from the endothelial cells by the added VLDL. These results demonstrated that LPL enzymatic activity and protein were removed from endothelial cells by triglyceride-rich lipoproteins (chylomicrons and VLDL) and oleic acid.

  12. Effect of palmitic acid and linoleic acid on expression of ICAM-1 and VCAM-1 in human bone marrow endothelial cells (HBMECs)

    PubMed Central

    Sanadgol, Nima; Mansouri, Kamran; Bahrami, Gholamreza

    2012-01-01

    Introduction The amount and type of fatty acids (FAs) in the diet influence the risk of atherosclerosis. Palmitic acid and linoleic acid exist at high levels in Iranian edible oils. In this study, we investigated the effect of palmitic acid and linoleic acid on expression of soluble and cell-associated forms of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human bone marrow endothelial cells (HBMECs). Material and methods The endothelial cells were induced with bacterial lipopolysaccharide (LPS) or tumor necrosis factor α (TNF-α), and thereafter incubated with palmitic or linoleic acid. The level of soluble and cell-associated VCAM-1 and ICAM-1 were analyzed using ELISA and western blot. Results Our findings indicated that palmitic acid up-regulates the expression of ICAM-1 and VCAM-1 in HBMECs when these cells are induced with TNF-α or LPS. In addition, the results suggest that linoleic acid could sustain up-regulated ICAM-1 and VCAM-1 in activated endothelial cells. Conclusions Chronic activation of endothelial cells in the presence of palmitic and linoleic may account for pathogenesis of cardiovascular events. These findings provide further support for the detrimental effects of these fatty acids, especially palmitic acid, in promotion and induction of cardiovascular diseases which are prevalent in the Iranian population. PMID:22661989

  13. Brown but not white adipose cells synthesize omega-3 docosahexaenoic acid in culture.

    PubMed

    Qin, Xia; Park, Hui Gyu; Zhang, Ji Yao; Lawrence, Peter; Liu, Guowen; Subramanian, Nivetha; Kothapalli, Kumar S D; Brenna, J Thomas

    2016-01-01

    Adipose tissue is a complex endocrine organ which coordinates several crucial biological functions including fatty acid metabolism, glucose metabolism, energy homeostasis, and immune function. Brown adipose tissue (BAT) is most abundant in young infants during the brain growth spurt when demands for omega-3 docosahexaenoic acid (DHA, 22:6n-3) is greatest for brain structure. Our aim was to characterize relative biosynthesis of omega-3 long chain polyunsaturated fatty acids (LCPUFA) from precursors in cultured white (WAT) and brown (BAT) cells and study relevant gene expression. Mouse WAT and BAT cells were grown in regular DMEM media to confluence, and differentiation was induced. At days 0 and 8 cells were treated with albumin bound d5-18:3n-3 (d5-ALA) and analyzed 24h later. d5-ALA increased cellular eicosapentaenoic acid (EPA, 20:5n-3) and docosapentaenoic acid (DPA, 22:5n-3) in undifferentiated BAT cells, whereas differentiated BAT cells accumulated 20:4n-3, EPA and DPA. DHA as a fraction of total omega-3 LCPUFA was greatest in differentiated BAT cells compared to undifferentiated cells. Undifferentiated WAT cells accumulated EPA, whereas differentiated cells accumulated DPA. WAT accumulated trace newly synthesized DHA. Zic1 a classical brown marker and Prdm16 a key driver of brown fat cell fate are expressed only in BAT cells. Ppargc1a is 15 fold higher in differentiated BAT cells. We conclude that in differentiated adipose cells accumulating fat, BAT cells but not WAT cells synthesize DHA, supporting the hypothesis that BAT is a net producer of DHA.

  14. Reconstitution of bile acid transport in the rat hepatoma McArdle RH-7777 cell line.

    PubMed

    Torchia, E C; Shapiro, R J; Agellon, L B

    1996-07-01

    The liver recovers bile acids from the portal circulation primarily via an active process that is dependent on sodium ions. Hepatocytes lose the ability to transport bile acids in culture, and, in liver-derived permanent cell lines, this ability is severely reduced or absent. To study the importance of bile acids in regulating liver-specific functions (e.g., cellular bile acid and cholesterol metabolism), we have re-established active bile acid transport in cultured cells. The complementary DNA (cDNA) encoding the rat sodium/taurocholate cotransporting polypeptide (ntcp) was placed under the control of a cytomegalovirus promoter and transfected into the rat hepatoma cell line, McArdle RH-7777. Transfected cells were screened for the ability to take up [3H]-taurocholate. Clones that displayed the ability to take up taurocholate were expanded (designated McNtcp) and further characterized. The apparent Michaelis constant (Km) for taurocholate uptake was similar among the different clones. The observed maximum velocity (Vmax), however, differed and was positively correlated with the abundance of recombinant ntcp messenger RNA (mRNA). The highest level of taurocholate uptake activity observed in McNtcp cells was comparable with that of freshly isolated hepatocytes. Efflux of accumulated taurocholate from McNtcp cells proceeded in a manner similar to primary hepatocytes, indicating that McArdle RH-7777 cells have retained the ability to secrete bile acids. Moreover, taurocholate uptake in McNtcp cells was inhibited by other bile acid species. Based on the observed kinetic parameters, the reconstituted McArdle RH-7777 cells mimic the ability of primary hepatocytes to transport bile acids.

  15. Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells.

    PubMed

    Göttlicher, M; Minucci, S; Zhu, P; Krämer, O H; Schimpf, A; Giavara, S; Sleeman, J P; Lo Coco, F; Nervi, C; Pelicci, P G; Heinzel, T

    2001-12-17

    Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy. PMID:11742974

  16. Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells

    PubMed Central

    Göttlicher, Martin; Minucci, Saverio; Zhu, Ping; Krämer, Oliver H.; Schimpf, Annemarie; Giavara, Sabrina; Sleeman, Jonathan P.; Lo Coco, Francesco; Nervi, Clara; Pelicci, Pier Giuseppe; Heinzel, Thorsten

    2001-01-01

    Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy. PMID:11742974

  17. A review on synthesis and characterization of solid acid materials for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Mohammad, Norsyahida; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Loh, Kee Shyuan

    2016-08-01

    Solid acids emerged as an electrolyte material for application in fuel cells due to their high protonic conductivity and stability at high temperatures between 100 °C and 250 °C. This paper gives an overview of the different solid acid materials and their properties, such as high protonic conductivity and thermal stability, in relation to phase transitions and mechanisms of proton transport. Various solid acid synthesis methods including aqueous and dry mixing, electrospinning, sol-gel, impregnation and thin-film casting will be discussed, and the impact of synthesis methods on the properties of solid acids will be highlighted. The properties of solid acids synthesized as either single crystals and or polycrystalline powders were identified via X-ray diffraction, nuclear magnetic resonance, thermal analyses, optical microscopy and infrared spectroscopy. A selection of electrolyte-electrode assembly methods and the performance of solid acid fuel cell prototypes are also reviewed.

  18. Succinic acid production by Actinobacillus succinogenes using hydrolysates of spent yeast cells and corn fiber.

    PubMed

    Chen, Ke-Quan; Li, Jian; Ma, Jiang-Feng; Jiang, Min; Wei, Ping; Liu, Zhong-Min; Ying, Han-Jie

    2011-01-01

    The enzymatic hydrolysate of spent yeast cells was evaluated as a nitrogen source for succinic acid production by Actinobacillus succinogenes NJ113, using corn fiber hydrolysate as a carbon source. When spent yeast cell hydrolysate was used directly as a nitrogen source, a maximum succinic acid concentration of 35.5 g/l was obtained from a glucose concentration of 50 g/l, with a glucose utilization of 95.2%. Supplementation with individual vitamins showed that biotin was the most likely factor to be limiting for succinic acid production with spent yeast cell hydrolysate. After supplementing spent yeast cell hydrolysate and 90 g/l of glucose with 150 μg/l of biotin, cell growth increased 32.5%, glucose utilization increased 37.6%, and succinic acid concentration was enhanced 49.0%. As a result, when biotin-supplemented spent yeast cell hydrolysate was used with corn fiber hydrolysate, a succinic acid yield of 67.7% was obtained from 70.3 g/l of total sugar concentration, with a productivity of 0.63 g/(l h). Our results suggest that biotin-supplemented spent yeast cell hydrolysate may be an alternative nitrogen source for the efficient production of succinic acid by A. succinogenes NJ113, using renewable resources. PMID:20801644

  19. Valproic Acid Increases the Hepatic Differentiation Potential of Salivary Gland Cells.

    PubMed

    Petrakova, O S; Ashapkin, V V; Shtratnikova, V Y; Kutueva, L I; Vorotelyak, E A; Borisov, M A; Terskikh, V V; Gvazava, I G; Vasiliev, A V

    2015-01-01

    The studies of cell plasticity and differentiation abilities are important problems in modern cellular biology. The use of histone deacetylase inhibitor - valproic acid is a promising approach to increasing the differentiation efficiency of various cell types. In this paper we investigate the ability of mouse submandibular salivary gland cells to differentiate into the hepatic direction and the effect of valproic acid on the efficiency of this differentiation. It was shown that the gene expression levels of hepatocyte markers (Aat, Afp, G6p, Pepck, Tat, Cyp3a13) and liver-enriched transcription factors (Hnf-3α, Hnf-3β, Hnf-4α, Hnf-6) were increased after differentiation in salivary gland cells. Valproic acid increases the specificity of hepatic differentiation, reducing the expression levels of the ductal (Krt19, Hhex1, Cyp7a1) and acinar (Ptf1a) markers. After valproic acid exposure, the efficiency of hepatic differentiation also increases, as evidenced by the increase in the gene expression level of Alb and Tdo, and increase in urea production by differentiated cells. No change was found in DNA methylation of the promoter regions of the genes; however, valproic acid treatment and subsequent hepatic differentiation largely affected the histone H3 methylation of liver-enriched genes. Thus, mouse submandibular salivary gland cells are capable of effective differentiation in the hepatic direction. Valproic acid increases the specificity and efficiency of the hepatic differentiation of these cells.

  20. Recent advances in lead-acid cell research and development

    SciTech Connect

    Voss, E.

    1980-01-01

    During the last decade it was demonstate that the lead-acid system is capable of proving an attractive energy source of sufficient energy and power per unit weight and volume which allows its sucessful application for electric vehicle propulsion. This is shown by a number of typical examples, such as the relationship between active material properties and capacity at high rates of discharge the effect of acid stratification and others. Simultaneously, the expenditure for the maintenance of lead-acid batteries was minimized by the development of peripheric equipment, as there are means for central-automatic water refill and recombination devices. It is shown that there is still a considerable potential for further improvement which might again strengthen the unique position of the lead-acid system in the market in comparison to competitive systems.

  1. Plasmonic coupling of dual gold nanoprobes for SERS imaging of sialic acids on living cells.

    PubMed

    Song, Wanyao; Ding, Lin; Chen, Yunlong; Ju, Huangxian

    2016-08-23

    This work reports a benzoic group functionalized gold nanoflower as a bridge probe for both recognition of target sialic acids and assembly of poly(N-acetylneuraminic acid) modified gold nanoparticles, which leads to plasmonic coupling of two kinds of gold nanoprobes in a single-core-multi-satellite nanostructure to produce a sensitive surface-enhanced Raman scattering (SERS) signal for the imaging of sialic acids on living cells. PMID:27500291

  2. [Gene therapy: nucleic acids as drugs. Action mechanisms and delivery into the cell].

    PubMed

    Cavagnari, Brian M

    2011-06-01

    Gene therapy involves the transference of new genetic material to the cell in order to obtain a therapeutic benefit, offering a new option for the treatment of various diseases. In this article, some of these nucleic acid-based drugs, such as plasmids, aptamers, oligonucleotides, ribozymes and small interfering ribonucleic acid, are presented. Their mechanism and level of action is commented and several delivery systems, such as liposomes, cationic polymers, direct nucleic acid transfer and viral vectors, are also discussed.

  3. Listeria monocytogenes wall teichoic acid decoration in virulence and cell-to-cell spread.

    PubMed

    Spears, Patricia A; Havell, Edward A; Hamrick, Terri S; Goforth, John B; Levine, Alexandra L; Abraham, S Thomas; Heiss, Christian; Azadi, Parastoo; Orndorff, Paul E

    2016-09-01

    Wall teichoic acid (WTA) comprises a class of glycopolymers covalently attached to the peptidoglycan of gram positive bacteria. In Listeria monocytogenes, mutations that prevent addition of certain WTA decorating sugars are attenuating. However, the steps required for decoration and the pathogenic process interrupted are not well described. We systematically examined the requirement for WTA galactosylation in a mouse oral-virulent strain by first creating mutations in four genes whose products conferred resistance to a WTA-binding bacteriophage. WTA biochemical and structural studies indicated that galactosylated WTA was directly required for bacteriophage adsorption and that mutant WTA lacked appreciable galactose in all except one mutant - which retained a level ca. 7% of the parent. All mutants were profoundly attenuated in orally infected mice and were impaired in cell-to-cell spread in vitro. Confocal microscopy of cytosolic mutants revealed that all expressed ActA on their cell surface and formed actin tails with a frequency similar to the parent. However, the mutant tails were significantly shorter - suggesting a defect in actin based motility. Roles for the gene products in WTA galactosylation are proposed. Identification and interruption of WTA decoration pathways may provide a general strategy to discover non-antibiotic therapeutics for gram positive infections. © 2016 John Wiley & Sons Ltd. PMID:26871418

  4. Proteomic investigation into betulinic acid-induced apoptosis of human cervical cancer HeLa cells.

    PubMed

    Xu, Tao; Pang, Qiuying; Zhou, Dong; Zhang, Aiqin; Luo, Shaman; Wang, Yang; Yan, Xiufeng

    2014-01-01

    Betulinic acid is a pentacyclic triterpenoid that exhibits anticancer functions in human cancer cells. This study provides evidence that betulinic acid is highly effective against the human cervical cancer cell line HeLa by inducing dose- and time-dependent apoptosis. The apoptotic process was further investigated using a proteomics approach to reveal protein expression changes in HeLa cells following betulinic acid treatment. Proteomic analysis revealed that there were six up- and thirty down-regulated proteins in betulinic acid-induced HeLa cells, and these proteins were then subjected to functional pathway analysis using multiple analysis software. UDP-glucose 6-dehydrogenase, 6-phosphogluconate dehydrogenase decarboxylating, chain A Horf6-a novel human peroxidase enzyme that involved in redox process, was found to be down-regulated during the apoptosis process of the oxidative stress response pathway. Consistent with our results at the protein level, an increase in intracellular reactive oxygen species was observed in betulinic acid-treated cells. The proteins glucose-regulated protein and cargo-selection protein TIP47, which are involved in the endoplasmic reticulum pathway, were up-regulated by betulinic acid treatment. Meanwhile, 14-3-3 family proteins, including 14-3-3β and 14-3-3ε, were down-regulated in response to betulinic acid treatment, which is consistent with the decrease in expression of the target genes 14-3-3β and 14-3-3ε. Furthermore, it was found that the antiapoptotic bcl-2 gene was down-regulated while the proapoptotic bax gene was up-regulated after betulinic acid treatment in HeLa cells. These results suggest that betulinic acid induces apoptosis of HeLa cells by triggering both the endoplasmic reticulum pathway and the ROS-mediated mitochondrial pathway.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  6. Production of vanillic acid from vanillin by resting cells of Serratia marcescens.

    PubMed Central

    Perestelo, F; Dalcón, M A; de la Fuente, G

    1989-01-01

    Resting-cell suspensions of Serratia marcescens were able to convert, quantitatively, 0.3% vanillin to vanillic acid. The vanillic acid-producing activity reached a maximum after 28 h of incubation with 0.01% vanillin as an inducer. PMID:2669632

  7. What controls fleshy fruit acidity? A review of malate and citrate accumulation in fruit cells.

    PubMed

    Etienne, A; Génard, M; Lobit, P; Mbeguié-A-Mbéguié, D; Bugaud, C

    2013-04-01

    Fleshy fruit acidity is an important component of fruit organoleptic quality and is mainly due to the presence of malic and citric acids, the main organic acids found in most ripe fruits. The accumulation of these two acids in fruit cells is the result of several interlinked processes that take place in different compartments of the cell and appear to be under the control of many factors. This review combines analyses of transcriptomic, metabolomic, and proteomic data, and fruit process-based simulation models of the accumulation of citric and malic acids, to further our understanding of the physiological mechanisms likely to control the accumulation of these two acids during fruit development. The effects of agro-environmental factors, such as the source:sink ratio, water supply, mineral nutrition, and temperature, on citric and malic acid accumulation in fruit cells have been reported in several agronomic studies. This review sheds light on the interactions between these factors and the metabolism and storage of organic acids in the cell.

  8. Membrane lipid composition of pancreatic AR42J cells: modification by exposure to different fatty acids.

    PubMed

    Audi, Nama'a; Mesa, María D; Martínez, María A; Martínez-Victoria, Emilio; Mañas, Mariano; Yago, María D

    2007-04-01

    Dietary fat type influences fatty acids in rat pancreatic membranes, in association with modulation of secretory activity and cell signalling in viable acini. We aimed to confirm whether AR42J cells are a valid model to study the interactions between lipids and pancreatic acinar cell function. For this purpose we have (i) compared the baseline fatty acid composition of AR42J cells with that of pancreatic membranes from rats fed a standard chow; (ii) investigated if fatty acids in AR42J membranes can be modified in culture; and (iii) studied if similar compositional variations that can be evoked in rats when dietary fat type is altered occur in AR42J cells. Weaning Wistar rats were fed for 8 weeks either a commercial chow (C) or semi-purified diets containing virgin olive oil (VOO) or sunflower oil (SO) as fat source. AR42J cells were incubated for 72 hrs in medium containing unmodified fetal calf serum (FCS, AR42J-C cells), FCS enriched with 18:1 n-9 (AR42J-O cells), or FCS enriched with 18:2 n-6 (AR42J-L cells). Fatty acids in crude membranes from rat pancreas and AR42J cells were determined by gas-liquid chromatography. Differences in membrane fatty acids between C rats and AR42J-C cells can be explained in part by variations in the amount of fatty acids in the extracellular environment. Supplementation of FCS with 18:1 n-9 or 18:2 n-6 changed the fatty acid spectrum of AR42J cells in a manner that resembles the pattern found, respectively, in VOO and SO rats, although AR42J-L cells were unable to accumulate 20:4 n-6. The AR42J cell line can be a useful tool to assess the effect of membrane compositional changes on acinar cell function. However, differences in baseline characteristics, and perhaps fatty acid metabolism, indicate that results obtained in AR42J cells should be confirmed with experiments in the whole animal.

  9. Circulating tumour cells and circulating free nucleic acid as prognostic and predictive biomarkers in colorectal cancer.

    PubMed

    Lim, S H; Becker, T M; Chua, W; Caixeiro, N J; Ng, W L; Kienzle, N; Tognela, A; Lumba, S; Rasko, J E J; de Souza, P; Spring, K J

    2014-04-28

    The detection of circulating tumour cells or circulating free tumour nucleic acids can potentially guide treatment and inform prognosis in colorectal cancer using minimally invasive "liquid biopsies". Current literature supports the notion that high circulating tumour cell counts or presence of tumour nucleic acid correlate with inferior clinical outcomes for patients, but they are not yet part of routine clinical care. Future research evolves around the examination of the molecular phenotype of circulating tumour cells. The key unanswered areas include differentiating between circulating tumour cell presence and their proliferative capacity and dormancy, identifying tumour heterogeneity and understanding the epithelial-mesenchymal transition.

  10. Degradation of h-acid by free and immobilized cells of Alcaligenes latus

    PubMed Central

    Usha, M.S.; Sanjay, M.K.; Gaddad, S.M.; Shivannavar, C.T.

    2010-01-01

    Alcaligenes latus, isolated from industrial effluent, was able to grow in mineral salts medium with 50 ppm (0.15 mM) of H-acid as a sole source of carbon. Immobilization of Alcaligenes latus in Ca-alginate and polyurethane foam resulted in cells embedded in the matrices. When free cells and immobilized cells were used for biodegradation studies at concentration ranging from 100 ppm (0.3 mM) to 500 ppm (1.15 mM) degradation rate was enhanced with immobilized cells. Cells immobilized in polyurethane foam showed 100% degradation up to 350 ppm (1.05 mM) and 57% degradation at 500 ppm (1.5 mM). Degradation rate of Ca-alginate immobilized cells was less as compared to that of polyurethane foam immobilized cells. With Ca-alginate immobilized cells 100% degradation was recorded up to 200 ppm (0.6 mM) of H-acid and only 33% degradation was recorded at 500 ppm (1.5 mM) of H-acid. Spectral analysis of the products after H-acid utilization showed that the spent medium did not contain any aromatic compounds indicating H-acid degradation by A. latus. PMID:24031573

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

    PubMed

    Koontongkaew, Sittichai; Monthanapisut, Paopanga; Saensuk, Theeranuch

    2010-11-01

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

  12. Clavulanic acid inhibits MPP⁺-induced ROS generation and subsequent loss of dopaminergic cells.

    PubMed

    Kost, Gina Chun; Selvaraj, Senthil; Lee, Young Bok; Kim, Deog Joong; Ahn, Chang-Ho; Singh, Brij B

    2012-08-21

    Clavulanic acid is a psychoactive compound that has been shown to modulate central nervous system activity. Importantly, in neurotoxin-induced animal models, clavulanic acid has been shown to improve motor function (Huh et al., 2010) suggesting that it can be neuroprotective; however, the mechanism as how clavulanic acid can induce neuroprotection is not known. We demonstrate here that clavulanic acid abrogates the effects of the neurotoxin 1-methyl-4-phenylpyridinium (MPP(+)) which mimics Parkinson's disease (PD) by inducing neurodegeneration. To further establish the mechanism we identified that clavulanic acid inhibits neurotoxin-induced loss of mitochondrial membrane potential and ROS production. Consistent with these results, neurotoxin-induced increase in Bax levels was also decreased in clavulanic acid treated cells. Importantly, neurotoxin-induced release of cytochrome c levels as well as caspase activation was also inhibited in clavulanic acid treated cells. In addition, Bcl-xl levels were also restored and the Bcl-xl/Bax ratio that is critical for inducing apoptosis was increased in clavulanic acid treated cells. Overall, these results suggest that clavulanic acid is intimately involved in inhibiting neurotoxin-induced loss of mitochondrial function and induction of apoptosis that contributes towards neuronal survival.

  13. Steric hindrance of 2,6-disubstituted benzoic acid derivatives on the uptake via monocarboxylic acid transporters from the apical membranes of Caco-2 cells.

    PubMed

    Tsukagoshi, Kensuke; Kimura, Osamu; Endo, Tetsuya

    2014-05-01

    Benzoic acid is a typical substrate for monocarboxylic acid transporters (MCTs), and easily taken up from the apical membranes of Caco-2 cells by MCTs. However, some benzoic acid derivatives were sparingly taken up by Caco-2 cells. To elucidate the mechanism of lower uptake of the derivatives, we investigated the effect of substitution of benzene ring on the uptake by MCTs using Caco-2 cells. Among the benzoic acid derivatives tested, the uptake of 2,6-disubstituted benzoic acids was markedly lower than that of other benzoic acids. Co-incubation of the 2,6-disubstituted derivatives with benzoic acid did not decrease the uptake of benzoic acid, while co-incubation with other derivatives significantly decreased the uptake of benzoic acid. Kinetic analyses elucidated that the uptake of 2,6-dichlorobenzoic acid and 2,3,6-trichlorobenzoic acid did not involve the carrier-mediated process. The 2,6-disubstitution of benzoic acid may prevent the access of carboxylic acid group to MCTs expressed on the apical membranes of Caco-2 cells. PMID:24861932

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

    PubMed Central

    Nurse, P.; Wiemken, A.

    1974-01-01

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

  15. Inhibition of fatty acid desaturation in sycamore cells deprived of iron.

    PubMed

    Pascal, N; Dorne, A J

    1994-10-10

    The growth of isolated sycamore cells in a medium devoid of iron induced a marked reduction of the unsaturation level of fatty acids: the proportion of linolenic acid (C18:3) in polar lipids (phospholipids and galactolipids) decreased whereas a parallel increase in the proportions of oleic (C18:1) and linoleic (C18:2) acid was observed. In our experimental conditions, no direct effect of iron deprivation on fatty acid and glycerolipid biosynthesis could be observed. When sycamore cells were incubated in the presence of [14C]acetate, the level of unsaturation in fatty acids was very strongly reduced: no polyunsaturated fatty acids were synthesized in iron-deprived cells: only [14C]palmitic and [14C]oleic acids accumulated in glycerolipids. In contrast, sycamore cells grown in an iron-containing medium in the presence of [14C]acetate were able to synthesize glycerolipids containing 14C-labelled C18:2 and C18:3. We concluded that, in sycamore cells, iron is essential for C18:1-->C18:2-->C18:3 desaturations. In contrast, C18:0-->C18:1 desaturation is much less sensitive to iron deprivation under our experimental conditions.

  16. Marine- and plant-derived ω-3 fatty acids differentially regulate prostate cancer cell proliferation

    PubMed Central

    ESER, PINAR O.; VANDEN HEUVEL, JOHN P.; ARAUJO, JOHN; THOMPSON, JERRY T.

    2013-01-01

    Fish oil contains the marine ω-3 polyunsaturated fatty acids (ω-3 PUFAs) docosahexaenoic (DHA) and eicosapentaenoic acid (EPA). The consumption of diets rich in these fatty acids is associated with a decreased incidence of prostate cancer. However, there is limited knowledge regarding the non-marine ω-3 PUFA α-linolenic acid (ALA). To study which ω-3 PUFAs are more effective in prostate cancer prevention, and whether the mechanisms of action are conserved between them, we investigated the effect of DHA, EPA and ALA on the human prostate cancer cell lines PC-3 and LNCaP. Different trends of inhibition of PC-3 cell proliferation were observed for the three ω-3 PUFA, with DHA having the most pronounced effects on cell proliferation, while ALA had the minimum effects of the three ω-3 PUFAs. All the ω-3 PUFAs decreased fatty acid synthase (FASN) mRNA. Concerning genes involved in inflammation, cell cycle and apoptosis, DHA regulated the most genes in all categories, followed by EPA and then ALA. In addition, DHA and EPA increased the gene expression of the pro-apoptotic protein activating transcription factor 3 mRNA. Moreover, these two fatty acids significantly induced apoptosis. In conclusion, while some mechanisms of cancer cell inhibition are conserved among ω-3 PUFA, the extent, magnitude, and duration of transcriptional changes vary for each individual fatty acid. PMID:24649190

  17. Measurement of Fatty Acid Oxidation Rates in Animal Tissues and Cell Lines

    PubMed Central

    Huynh, Frank K.; Green, Michelle F.; Koves, Timothy R.; Hirschey, Matthew D.

    2014-01-01

    While much oncological research has focused on metabolic shifts in glucose and amino acid oxidation, recent evidence suggests that fatty acid oxidation (FAO) may also play an important role in the metabolic reprogramming of cancer cells. Here, we present a simple method for measuring FAO rates using radiolabeled palmitate, common laboratory reagents, and standard supplies. This protocol is broadly applicable for measuring FAO rates in cultured cancer cells as well as in both malignant and nontransformed animal tissues. PMID:24862277

  18. Stable isotope labeling by amino acids in cell culture (SILAC) for quantitative proteomics.

    PubMed

    Hoedt, Esthelle; Zhang, Guoan; Neubert, Thomas A

    2014-01-01

    Stable isotope labeling by amino acids in cell culture (SILAC) is a powerful approach for high-throughput quantitative proteomics. SILAC allows highly accurate protein quantitation through metabolic encoding of whole cell proteomes using stable isotope labeled amino acids. Since its introduction in 2002, SILAC has become increasingly popular. In this chapter we review the methodology and application of SILAC, with an emphasis on three research areas: dynamics of posttranslational modifications, protein-protein interactions, and protein turnover. PMID:24952180

  19. Synthesis of milk specific fatty acids and proteins by dispersed goat mammary-gland epithelial cells.

    PubMed Central

    Hansen, H O; Tornehave, D; Knudsen, J

    1986-01-01

    The method now described for preparation of dispersed lactating goat mammary-gland cells gives a high yield of morphologically and functionally normal mammary cells. The cells synthesize specific goat milk fatty acids in the right proportions, and they respond to hormones by increased protein synthesis. The cells can be frozen and thawed without losing the above properties, which makes them an excellent tool for metabolic and hormonal studies. Images Fig. 1. Fig. 2. PMID:3800930

  20. Ellagic Acid and Embelin Affect Key Cellular Components of Pancreatic Adenocarcinoma, Cancer and Stellate Cells

    PubMed Central

    Edderkaoui, Mouad; Lugea, Aurelia; Hui, Hongxiang; Eibl, Guido; Lu, Qing-Yi; Moro, Aune; Lu, Xuyang; Li, Gang; Go, Vay-Liang; Pandol, Stephen J.

    2014-01-01

    Ellagic acid is a polyphenolic phytochemical present in many fruits and nuts with anti-cancer properties demonstrated in experimental tumor studies. Embelin is a benzoquinone phytochemical isolated from the Japanese herb Ardisiae Japonicae and has been shown to induce apoptosis in cancer cells. We found that ellagic acid and embelin each dose-dependently increased apoptosis and inhibited proliferation in human pancreatic cancer cells, MIA PaCa-2 and HPAF-II cells, and in pancreatic stellate cells (PaSCs) which are progenitors of pancreatic cancer desmoplasia. In each of these cell types, combinations of ellagic acid and embelin at low micromolar concentrations (0.5–3 μM) induced synergistic increases in apoptosis and decreases in proliferation. Ellagic acid decreased NF-κB transcriptional activity, whereas embelin decreased STAT-3 phosphorylation and protein expression of its downstream target survivin, in cancer cells. In vivo dietary ellagic acid alone or in combination with embelin decreased tumor size and tumor cellularity in a subcutaneous (s.c.) xenograft mouse model of pancreatic cancer. These results show that ellagic acid and embelin interact with divergent intracellular signaling pathways resulting in augmentation of apoptosis and inhibition of proliferation at low micromolar concentrations for the key cellular components of pancreatic adenocarcinoma. PMID:24127740

  1. Recent advances in lead-acid cell research and development

    SciTech Connect

    Voss, E.

    1980-01-01

    The lead-acid battery still is and will be for the foreseeable future the most widely used secondary energy storage system. It will maintain this predominant role because of its highly developed technology, its low costs as compared to other secondary systems and its high reliability. During the last decade it has been demonstrated that the lead-acid system is capable of providing an attractive energy source of sufficient energy and power per unit weight and volume which allows its successful application for electric vehicle propulsion. Basic research has contributed in a worldwide effort to the improvement of active material utilization and cycle life as well. This is shown by a number of typical examples, such as the relationship between active material properties and capacity at high rates of discharge, the effect of acid stratification and others. Simultaneously, the expenditure for the maintenance of lead-acid batteries has been minimized by the development of peripheric equipment, as there are means for central-automatic water refill and recombination devices. It is shown that there is still a considerable potential for further improvement which might again strengthen the unique position of the lead-acid system in the market in comparison to competitive systems.

  2. Abnormalities in plasma and red blood cell fatty acid profiles of patients with colorectal cancer.

    PubMed Central

    Baró, L.; Hermoso, J. C.; Núñez, M. C.; Jiménez-Rios, J. A.; Gil, A.

    1998-01-01

    We evaluated total plasma fatty acid concentrations and percentages, and the fatty acid profiles for the different plasma lipid fractions and red blood cell lipids, in 17 patients with untreated colorectal cancer and 12 age-matched controls with no malignant diseases, from the same geographical area. Cancer patients had significantly lower total plasma concentrations of saturated, monounsaturated and essential fatty acids and their polyunsaturated derivatives than healthy controls; when the values were expressed as relative percentages, cancer patients had significantly higher proportions of oleic acid and lower levels of linoleic acid than controls. With regard to lipid fractions, cancer patients had higher proportions of oleic acid in plasma phospholipids, triglycerides and cholesterol esters, and lower percentages of linoleic acid and its derivatives. On the other hand, alpha-linolenic acid was significantly lower in triglycerides from cancer patients and tended to be lower in phospholipids. Its derivatives also tended to be lower in phospholipids and triglycerides from cancer patients. Our findings suggest that colorectal cancer patients present abnormalities in plasma and red blood cell fatty acid profiles characterized by lower amounts of most saturated, monounsaturated and essential fatty acids and their polyunsaturated derivatives, especially members of the n-6 series, than their healthy age-matched counterparts. These changes are probably due to metabolic changes caused by the illness per se but not to malnutrition. PMID:9667678

  3. Utilizing cell-matrix interactions to modulate gene transfer to stem cells inside hyaluronic acid hydrogels.

    PubMed

    Gojgini, Shiva; Tokatlian, Talar; Segura, Tatiana

    2011-10-01

    The effective delivery of DNA locally would increase the applicability of gene therapy in tissue regeneration, where diseased tissue is to be repaired in situ. One promising approach is to use hydrogel scaffolds to encapsulate and deliver plasmid DNA in the form of nanoparticles to the diseased tissue, so that cells infiltrating the scaffold are transfected to induce regeneration. This study focuses on the design of a DNA nanoparticle-loaded hydrogel scaffold. In particular, this study focuses on understanding how cell-matrix interactions affect gene transfer to adult stem cells cultured inside matrix metalloproteinase (MMP) degradable hyaluronic acid (HA) hydrogel scaffolds. HA was cross-linked to form a hydrogel material using a MMP degradable peptide and Michael addition chemistry. Gene transfer inside these hydrogel materials was assessed as a function of polyplex nitrogen to phosphate ratio (N/P = 5 to 12), matrix stiffness (100-1700 Pa), RGD (Arg-Gly-Asp) concentration (10-400 μM), and RGD presentation (0.2-4.7 RGDs per HA molecule). All variables were found to affect gene transfer to mouse mensenchymal stem cells culture inside the DNA loaded hydrogels. As expected, higher N/P ratios lead to higher gene transfer efficiency but also higher toxicity; softer hydrogels resulted in higher transgene expression than stiffer hydrogels, and an intermediate RGD concentration and RGD clustering resulted in higher transgene expression. We believe that the knowledge gained through this in vitro model can be utilized to design better scaffold-mediated gene delivery for local gene therapy.

  4. Immunomodulatory activity of mefenamic acid in mice models of cell-mediated and humoral immunity

    PubMed Central

    Shabbir, Arham; Arshad, Hafiza Maida; Shahzad, Muhammad; Shamsi, Sadia; Ashraf, Muhammad Imran

    2016-01-01

    Objectives: Previously, different nonsteroidal anti-inflammatory drugs (NSAIDs) have been evaluated for their potential immunomodulatory activities. Mefenamic acid is a well-known NSAID and is used in the treatment of musculoskeletal disorders, inflammation, fever, and pain. To the best of our knowledge, promising data regarding the immunomodulatory activity of mefenamic acid is scarce. Current study investigates the immunomodulatory activity of mefenamic acid in different models of cell-mediated and humoral immunity. Materials and Methods: Immunomodulatory effects on cell-mediated immunity were evaluated using dinitrochlorobenzene-induced delayed type hypersensitivity (DTH) and cyclophosphamide-induce myelosuppression assays. While effects on humoral immunity were evaluated using hemagglutination assay and mice lethality test. Results: Hematological analysis showed that mefenamic acid significantly reduced white blood cell count, red blood cell (RBC) count, hemoglobin content, lymphocytes levels, and neutrophils levels in healthy mice as compared with control, suggesting the immunosuppressive activity of mefenamic acid. Treatment with mefenamic acid also significantly reduced all the hematological parameters in cyclophosphamide-induced neutropenic mice, as compared with positive control group. We found that treatment with mefenamic acid significantly suppressed DTH after 24 h, 48 h, and 72 h, as compared with positive control group. Mefenamic acid treated groups showed a significant reduction in antibody titer against sheep RBCs as compared to control group, similar to the effect of cyclophosphamide. We also found increased mice lethality rate in mefenamic acid treated groups, as compared with positive control group. Conclusions: The results provided basic information of immunosuppression of mefenamic acid on both cell-mediated and humoral immunity. PMID:27127320

  5. Bioconversion of l-glutamic acid to α-ketoglutaric acid by an immobilized whole-cell biocatalyst expressing l-amino acid deaminase from Proteus mirabilis.

    PubMed

    Hossain, Gazi Sakir; Li, Jianghua; Shin, Hyun-dong; Chen, Rachel R; Du, Guocheng; Liu, Long; Chen, Jian

    2014-01-01

    The goal of this work was to develop an immobilized whole-cell biocatalytic process for the environment-friendly synthesis of α-ketoglutaric acid (α-KG) from l-glutamic acid. We compared the suitability of Escherichia coli and Bacillus subtilis strains overexpressing Proteus mirabilisl-amino acid deaminase (l-AAD) as potential biocatalysts. Although both recombinant strains were biocatalytically active, the performance of B. subtilis was superior to that of E. coli. With l-glutamic acid as the substrate, α-KG production levels by membranes isolated from B. subtilis and E. coli were 55.3±1.73 and 21.7±0.39μg/mg protein/min, respectively. The maximal conversion ratio of l-glutamic acid to α-KG was 31% (w/w) under the following optimal conditions: 15g/L l-glutamic acid, 20g/L whole-cell biocatalyst, 5mM MgCl2, 40°C, pH 8.0, and 24-h incubation. Immobilization of whole cells with alginate increased the recyclability by an average of 23.33% per cycle. This work established an efficient one-step biotransformation process for the production of α-KG using immobilized whole B. subtilis overexpressing P. mirabilisl-AAD. Compared with traditional multistep chemical synthesis, the biocatalytic process described here has the advantage of reducing environmental pollution and thus has great potential for the large-scale production of α-KG.

  6. Lactic acid bacteria as a cell factory for riboflavin production.

    PubMed

    Thakur, Kiran; Tomar, Sudhir Kumar; De, Sachinandan

    2016-07-01

    Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin-enriched functional foods, proper selection and exploitation of riboflavin-producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production.

  7. Technology development for phosphoric acid fuel cell powerplant, phase 2

    NASA Technical Reports Server (NTRS)

    Christner, L.

    1979-01-01

    Component development has resulted in routine molding of 12 in. by 17 in. bipolar plates with 80 percent acceptance. A 5 C per hour post-cure heating cycle for these plates was found to give blister free materials. Lowering the resin in a bipolar plate content from 32 percent to 22 percent decreases the resistivity more than 50 percent. Evaluation of the corrosion resistance of Novolak and Resol resins at 185 C in phosphoric acid indicates a slow etch. aerosol modified phenolics, however, decompose rapidly. Estimates of acid loss by the use of analytical expressions known as Margule, van Laar, and Wilson equations were not satisfactory. Experimental evaluation of the P4O10 vapor concentration of 103 wt percent acid at 191 C provided a value of 2 ppm. This value is based on a single experiment.

  8. Enhanced amino acid utilization sustains growth of cells lacking Snf1/AMPK.

    PubMed

    Nicastro, Raffaele; Tripodi, Farida; Guzzi, Cinzia; Reghellin, Veronica; Khoomrung, Sakda; Capusoni, Claudia; Compagno, Concetta; Airoldi, Cristina; Nielsen, Jens; Alberghina, Lilia; Coccetti, Paola

    2015-07-01

    The metabolism of proliferating cells shows common features even in evolutionary distant organisms such as mammals and yeasts, for example the requirement for anabolic processes under tight control of signaling pathways. Analysis of the rewiring of metabolism, which occurs following the dysregulation of signaling pathways, provides new knowledge about the mechanisms underlying cell proliferation. The key energy regulator in yeast Snf1 and its mammalian ortholog AMPK have earlier been shown to have similar functions at glucose limited conditions and here we show that they also have analogies when grown with glucose excess. We show that loss of Snf1 in cells growing in 2% glucose induces an extensive transcriptional reprogramming, enhances glycolytic activity, fatty acid accumulation and reliance on amino acid utilization for growth. Strikingly, we demonstrate that Snf1/AMPK-deficient cells remodel their metabolism fueling mitochondria and show glucose and amino acids addiction, a typical hallmark of cancer cells.

  9. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid

    PubMed Central

    Giannattasio, Sergio; Guaragnella, Nicoletta; Ždralević, Maša; Marra, Ersilia

    2013-01-01

    Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications. PMID:23430312

  10. Molecular mechanisms of Saccharomyces cerevisiae stress adaptation and programmed cell death in response to acetic acid.

    PubMed

    Giannattasio, Sergio; Guaragnella, Nicoletta; Zdralević, Maša; Marra, Ersilia

    2013-01-01

    Beyond its classical biotechnological applications such as food and beverage production or as a cell factory, the yeast Saccharomyces cerevisiae is a valuable model organism to study fundamental mechanisms of cell response to stressful environmental changes. Acetic acid is a physiological product of yeast fermentation and it is a well-known food preservative due to its antimicrobial action. Acetic acid has recently been shown to cause yeast cell death and aging. Here we shall focus on the molecular mechanisms of S. cerevisiae stress adaptation and programmed cell death in response to acetic acid. We shall elaborate on the intracellular signaling pathways involved in the cross-talk of pro-survival and pro-death pathways underlying the importance of understanding fundamental aspects of yeast cell homeostasis to improve the performance of a given yeast strain in biotechnological applications. PMID:23430312

  11. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    PubMed

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors.

  12. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    PubMed

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. PMID:26367771

  13. Next market opportunities for phosphoric acid fuel cells

    SciTech Connect

    McClelland, R.H.

    1996-03-01

    Key early entry markets for the next step PC25 Model C fuel cell are most likely to include: Premium Quality Power markets such as data centers, communications facilities, and the like; Healthcare Facilities, particularly for nursing homes and hospitals having 300 or more beds, here, the thermal side of a 200 kW fuel cell is an excellent match and some importance is also attached to power quality and reliability; and Auxiliary Electric Power at natural gas compression facilities, such facilities also tend to place a premium on reliability and low maintenance, moreover, the fuel cell`s inherently low emissions can be very important within the northeast Ozone Transport Region. For the fuel cell concept to remain viable, penetration of this class of early entry markets is needed to sustain economic and reliability progress within a goal of moderate production volumes. This can then build the needed bridge to further markets and to other emerging fuel cell technologies.

  14. Inhibitory effect of ursolic acid and oleanolic acid from Eriobotrya fragrans on A549 cell viability in vivo.

    PubMed

    Gao, Y S; Yuan, Y; Song, G; Lin, S Q

    2016-01-01

    Loquat [Eriobotrya japonica (Lindl.)] is a traditional Chinese medicine, which has been used as an anti-inflammatory and for curing chronic bronchitis among other potential applications. Extracted ursolic acid (UA) and oleanolic acid (OA) from wild loquat were previously found capable of suppressing the proliferation of A549 cells in vitro. In the current study, nude mice were used to determine the inhibitory effect of UA and OA on tumor formation in vivo. The results demonstrate that UA and OA reduced the proliferation of A549 cells in nude mice, and increased the expression of Bid while decreasing the protein levels of MMP-2, Ki-67, and CD34. In this study, we identified potential antitumor activity in a wild loquat extract containing UA and OA, which demonstrates that traditional Chinese medicine may have a role in treating certain types of cancer. PMID:27323036

  15. Inhibitory effect of ursolic acid and oleanolic acid from Eriobotrya fragrans on A549 cell viability in vivo.

    PubMed

    Gao, Y S; Yuan, Y; Song, G; Lin, S Q

    2016-05-13

    Loquat [Eriobotrya japonica (Lindl.)] is a traditional Chinese medicine, which has been used as an anti-inflammatory and for curing chronic bronchitis among other potential applications. Extracted ursolic acid (UA) and oleanolic acid (OA) from wild loquat were previously found capable of suppressing the proliferation of A549 cells in vitro. In the current study, nude mice were used to determine the inhibitory effect of UA and OA on tumor formation in vivo. The results demonstrate that UA and OA reduced the proliferation of A549 cells in nude mice, and increased the expression of Bid while decreasing the protein levels of MMP-2, Ki-67, and CD34. In this study, we identified potential antitumor activity in a wild loquat extract containing UA and OA, which demonstrates that traditional Chinese medicine may have a role in treating certain types of cancer.

  16. Technology development for phosphoric acid fuel cell powerplant, phase 2

    NASA Technical Reports Server (NTRS)

    Christner, L.

    1979-01-01

    A technique for producing an acid inventory control member by spraying FEP onto a partially screened carbon paper backing is discussed. Theoretical analysis of the acid management indicates that the vapor composition of 103% H3PO4 is approximately 1.0 ppm P4O10. An SEM evaluation of corrosion resistance of phenolic resins and graphite/phenolic resin composites in H3PO4 at 185 C shows specific surface etching. Carbonization of graphite/phenolic bipolar plates is achieved without blistering.

  17. Sucrose Loading in Isolated Veins of Pisum sativum: Regulation by Abscisic Acid, Gibberellic Acid, and Cell Turgor.

    PubMed

    Estruch, J J; Peretó, J G; Vercher, Y; Beltrán, J P

    1989-09-01

    Enzymatically isolated vein networks from mature pea (Pisum sativum L. cv Alaska) leaves were employed to investigate the properties of sucrose loading and the effect of phytohormones and cell turgor on this process. The sucrose uptake showed two components: a saturable and a first-order kinetics system. The high affinity system (K(m), 3.3 millimolar) was located at the plasmalemma (p-chloromercuriphenylsulfonic acid and orthovanadate sensitivity). Further characterization of this system, including pH dependence and effects of energy metabolism inhibitors, supported the H(+)-sugar symport concept for sucrose loading. Within a physiological range (0.1-100 micromolar) and after 90 min, abscisic acid (ABA) inhibited and gibberellic acid (GA(3)) promoted 1 millimolar sucrose uptake. These responses were partially (ABA) or totally (GA(3)) turgor-dependent. In experiments of combined hormonal treatments, ABA counteracted the GA(3) positive effects on sucrose uptake. The abolishment of these responses by p-chloromercuriphenylsulfonic acid and experiments on proton flux suggest that both factors (cell turgor and hormones) are modulating the H(+) ATPase plasmalemma activity. The results are discussed in terms of their physiological relevance. PMID:16667007

  18. Promise of Retinoic Acid-Triazolyl Derivatives in Promoting Differentiation of Neuroblastoma Cells.

    PubMed

    Lone, Ali Mohd; Dar, Nawab John; Hamid, Abid; Shah, Wajaht Amin; Ahmad, Muzamil; Bhat, Bilal A

    2016-01-20

    Retinoic acid induces differentiation in various types of cells including skeletal myoblasts and neuroblasts and maintains differentiation of epithelial cells. The present study demonstrates synthesis and screening of a library of retinoic acid-triazolyl derivatives for their differentiation potential on neuroblastoma cells. Click chemistry approach using copper(I)-catalyzed azide-alkyne cycloaddition was adopted for the preparation of these derivatives. The neurite outgrowth promoting potential of retinoic acid-triazolyl derivatives was studied on neuroblastoma cells. Morphological examination revealed that compounds 8a, 8e, 8f, and 8k, among the various derivatives screened, exhibited promising neurite-outgrowth inducing activity at a concentration of 10 μM compared to undifferentiated and retinoic acid treated cells. Further on, to confirm this differentiation potential of these compounds, neuroblastoma cells were probed for expression of neuronal markers such as NF-H and NeuN. The results revealed a marked increase in the NF-H and NeuN protein expression when treated with 8a, 8e, 8f, and 8k compared to undifferentiated and retinoic acid treated cells. Thus, these compounds could act as potential leads in inducing neuronal differentiation for future studies.

  19. Retinoic acid modulates rat Ito cell proliferation, collagen, and transforming growth factor beta production.

    PubMed Central

    Davis, B H; Kramer, R T; Davidson, N O

    1990-01-01

    Recent studies suggest that vitamin A plays an inhibitory role with respect to "activation" of the hepatic Ito cell, a likely effector of hepatic fibrogenesis. Ito cell "activation" during fibrogenesis is characterized by a decrease in intracellular vitamin A and an increase in cellular proliferation and collagen production. To explore the hypothesis that retinoids have the capacity to diminish Ito cell activation, cultured Ito cells were exposed to retinoic acid and its effects assessed on three key features: cell proliferation, collagen protein production and mRNA abundance, and transforming growth factor beta protein production. Retinoic acid was 100-1,000X more potent than retinol with respect to inhibition of Ito cell proliferation. Interstitial collagen and transforming growth factor beta production were also reduced by 10(-6) M retinoic acid. The relative abundance of type I collagen mRNA however, was not significantly altered. By contrast, retinoic acid administration to rats caused a marked reduction in the abundance of type I collagen mRNA in both total hepatic and purified Ito cell RNA. The relative abundance of rat hepatic fibronectin or apolipoprotein E mRNA was not significantly altered. These studies demonstrate that retinoic acid can differentially modulate several key features of hepatic fibrogenesis in vitro and in vivo. Images PMID:2254460

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

    PubMed

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

    2009-01-01

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

  1. The fatty acid profile of rainbow trout liver cells modulates their tolerance to methylmercury and cadmium.

    PubMed

    Ferain, Aline; Bonnineau, Chloé; Neefs, Ineke; Rees, Jean François; Larondelle, Yvan; Schamphelaere, Karel A C De; Debier, Cathy

    2016-08-01

    The polyunsaturated fatty acid (PUFA) composition of fish tissues, which generally reflects that of the diet, affects various cellular properties such as membrane structure and fluidity, energy metabolism and susceptibility to oxidative stress. Since these cellular parameters can play an important role in the cellular response to organic and inorganic pollutants, a variation of the PUFA supply might modify the toxicity induced by such xenobiotics. In this work, we investigated whether the cellular fatty acid profile has an impact on the in vitro cell sensitivity to two environmental pollutants: methylmercury and cadmium. Firstly, the fatty acid composition of the rainbow trout liver cell line RTL-W1 was modified by enriching the growth medium with either alpha-linolenic acid (ALA, 18:3n-3), eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), linoleic acid (LA, 18:2n-6), arachidonic acid (AA, 20:4n-6) or docosapentaenoic acid (DPA, 22:5n-6). These modified cells and their control (no PUFA enrichment) were then challenged for 24h with increasing concentrations of methylmercury or cadmium. We observed that (i) the phospholipid composition of the RTL-W1 cells was profoundly modulated by changing the PUFA content of the growth medium: major modifications were a high incorporation of the supplemented PUFA in the cellular phospholipids, the appearance of direct elongation and desaturation metabolites in the cellular phospholipids as well as a change in the gross phospholipid composition (PUFA and monounsaturated fatty acid (MUFA) levels and n-3/n-6 ratio); (ii) ALA, EPA and DPA enrichment significantly protected the RTL-W1 cells against both methylmercury and cadmium; (iv) DHA enrichment significantly protected the cells against cadmium but not methylmercury; (v) AA and LA enrichment had no impact on the cell tolerance to both methylmercury and cadmium; (vi) the abundance of 20:3n-6, a metabolite of the n-6 biotransformation pathway, in

  2. Omega-3 Polyunsaturated Fatty Acids Trigger Cell Cycle Arrest and Induce Apoptosis in Human Neuroblastoma LA-N-1 Cells.

    PubMed

    So, Wai Wing; Liu, Wai Nam; Leung, Kwok Nam

    2015-08-18

    Omega-3 (n-3) fatty acids are dietary long-chain fatty acids with an array of health benefits. Previous research has demonstrated the growth-inhibitory effect of n-3 fatty acids on different cancer cell lines in vitro, yet their anti-tumor effects and underlying action mechanisms on human neuroblastoma LA-N-1 cells have not yet been reported. In this study, we showed that docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) exhibited time- and concentration-dependent anti-proliferative effect on the human neuroblastoma LA-N-1 cells, but had minimal cytotoxicity on the normal or non-tumorigenic cells, as measured by MTT reduction assay. Mechanistic studies indicated that DHA and EPA triggered G0/G1 cell cycle arrest in LA-N-1 cells, as detected by flow cytometry, which was accompanied by a decrease in the expression of CDK2 and cyclin E proteins. Moreover, DHA and EPA could also induce apoptosis in LA-N-1 cells as revealed by an increase in DNA fragmentation, phosphatidylserine externalization and mitochondrial membrane depolarization. Up-regulation of Bax, activated caspase-3 and caspase-9 proteins, and down-regulation of Bcl-XL protein, might account for the occurrence of apoptotic events. Collectively, our results suggest that the growth-inhibitory effect of DHA and EPA on LA-N-1 cells might be mediated, at least in part, via triggering of cell cycle arrest and apoptosis. Therefore, DHA and EPA are potential anti-cancer agents which might be used for the adjuvant therapy or combination therapy with the conventional anti-cancer drugs for the treatment of some forms of human neuroblastoma with minimal toxicity.

  3. Clavulanic acid increases dopamine release in neuronal cells through a mechanism involving enhanced vesicle trafficking.

    PubMed

    Kost, Gina Chun; Selvaraj, Senthil; Lee, Young Bok; Kim, Deog Joong; Ahn, Chang-Ho; Singh, Brij B

    2011-10-24

    Clavulanic acid is a CNS-modulating compound with exceptional blood-brain barrier permeability and safety profile. Clavulanic acid has been proposed to have anti-depressant activity and is currently entering Phase IIb clinical trials for the treatment of Major Depressive Disorder (MDD). Studies have also shown that clavulanic acid suppresses anxiety and enhances sexual functions in rodent and primate models by a mechanism involving central nervous system (CNS) modulation, although its detailed mechanism of action has yet to be elucidated. To further examine its potential as a CNS modulating agent as well as its mechanism of action, we investigated the effects of clavulanic acid in neuronal cells. Our results indicate that clavulanic acid enhances dopamine release in PC12 and SH-SY5Y cells without affecting dopamine synthesis. Furthermore, using affinity chromatography we were able to identify two proteins, Munc18-1 and Rab4 that potentially bind to clavulanic acid and play a critical role in neurosecretion and the vesicle trafficking process. Consistent with this result, an increase in the translocation of Munc18-1 and Rab4 from the cytoplasm to the plasma membrane was observed in clavulanic acid treated cells. Overall, these data suggest that clavulanic acid enhances dopamine release in a mechanism involving Munc18-1 and Rab4 modulation and warrants further investigation of its therapeutic use in CNS disorders, such as depression.

  4. Arachidonic acid stimulates /sup 45/calcium efflux and HPL release in isolated trophoblast cells

    SciTech Connect

    Zeitler, P.; Murphy, E.; Handwerger, S.

    1986-01-13

    Previous investigations from this laboratory have indicated that arachidonic acid stimulates a rapid, dose-dependent and reversible increase in hPL release which is not dependent on cyclooxygenase or lipoxygenase metabolism. To investigate further the mechanism by which arachidonic acid stimulates the release of hPL, the effect of arachidonic acid on the release of /sup 45/Ca from perifused cells prelabelled with /sup 45/Ca was examined in an enriched cell culture population of term human syncytiotrophoblast. Arachidonic acid (10-100 ..mu..M) stimulated a dose-dependent, rapid, and reversible increase in the release of both /sup 45/Ca and hPL from the perifused placental cells. On the other hand, palmitic acid had little effect on either hPL release or /sup 45/Ca release even at concentrations as high as 100 ..mu..M. Ionophore A23187 (1-10..mu..M) also stimulated a dose-dependent and reversible increase in hPL release. Since arachidonic acid increases the mobilization of cellular calcium, as reflected by the increased /sup 45/calcium efflux, and since an increase in the intracellular calcium concentration appears to stimulate an increase in hPL release, these results suggest that the stimulation of hPL release by arachidonic acid may be due, at least in part, to the effects of the fatty acid on cellular calcium mobilization. 26 references, 5 figures.

  5. Clavulanic acid increases dopamine release in neuronal cells through a mechanism involving enhanced vesicle trafficking

    PubMed Central

    Kost, Gina Chun; Selvaraj, Senthil; Lee, Young Bok; Kim, Deog Joong; Ahn, Chang-Ho; Singh, Brij B

    2011-01-01

    Clavulanic acid is a CNS-modulating compound with exceptional blood-brain barrier permeability and safety profile. Clavulanic acid has been proposed to have anti-depressant activity and is currently entering Phase IIb clinical trials for the treatment of Major Depressive Disorder (MDD). Studies have also shown that clavulanic acid suppresses anxiety and enhances sexual functions in rodent and primate models by a mechanism involving central nervous system (CNS) modulation, although its detailed mechanism of action has yet to be elucidated. To further examine its potential as a CNS modulating agent as well as its mechanism of action, we investigated the effects of clavulanic acid in neuronal cells. Our results indicate that clavulanic acid enhances dopamine release in PC12 and SH-SY5Y cells without affecting dopamine synthesis. Furthermore, using affinity chromatography we were able to identify two proteins, Munc18-1 and Rab4 that potentially bind to clavulanic acid and play a critical role in neurosecretion and the vesicle trafficking process. Consistent with this result, an increase in the translocation of Munc18-1 and Rab4 from the cytoplasm to the plasma membrane was observed in clavulanic acid treated cells. Overall, these data suggest that clavulanic acid enhances dopamine release in a mechanism involving Munc18-1 and Rab4 modulation and warrants further investigation of its therapeutic use in CNS disorders, such as depression. PMID:21964384

  6. Linoleic acid supplementation results in increased arachidonic acid and eicosanoid production in CF airway cells and in cftr−/− transgenic mice

    PubMed Central

    Zaman, Munir M.; Martin, Camilia R.; Andersson, Charlotte; Bhutta, Abdul Q.; Cluette-Brown, Joanne E.; Laposata, Michael

    2010-01-01

    Cystic fibrosis (CF) patients display a fatty acid imbalance characterized by low linoleic acid levels and variable changes in arachidonic acid. This led to the recommendation that CF patients consume a high-fat diet containing >6% linoleic acid. We hypothesized that increased conversion of linoleic acid to arachidonic acid in CF leads to increased levels of arachidonate-derived proinflammatory metabolites and that this process is exacerbated by increasing linoleic acid levels in the diet. To test this hypothesis, we determined the effect of linoleic acid supplementation on downstream proinflammatory biomarkers in two CF models: 1) in vitro cell culture model using 16HBE14o− sense [wild-type (WT)] and antisense (CF) human airway epithelial cells; and 2) in an in vivo model using cftr−/− transgenic mice. Fatty acids were analyzed by gas chromatography-mass spectrometry (GC/MS), and IL-8 and eicosanoids were measured by ELISA. Neutrophils were quantified in bronchoalveolar lavage fluid from knockout mice following linoleic acid supplementation and exposure to aerosolized Pseudomonas LPS. Linoleic acid supplementation increased arachidonic acid levels in CF but not WT cells. IL-8, PGE2, and PGF2α secretion were increased in CF compared with WT cells, with a further increase following linoleic acid supplementation. cftr−/− Mice supplemented with 100 mg of linoleic acid had increased arachidonic acid levels in lung tissue associated with increased neutrophil infiltration into the airway compared with control mice. These findings support the hypothesis that increasing linoleic acid levels in the setting of loss of cystic fibrosis transmembrane conductance regulator (CFTR) function leads to increased arachidonic acid levels and proinflammatory mediators. PMID:20656894

  7. Mycolic Acid Cyclopropanation is Essential for Viability, Drug Resistance, and Cell Wall Integrity of Mycobacterium tuberculosis

    SciTech Connect

    Barkan, Daniel; Liu, Zhen; Sacchettini, James C.; Glickman, Michael S.

    2009-12-01

    Mycobacterium tuberculosis infection remains a major global health problem complicated by escalating rates of antibiotic resistance. Despite the established role of mycolic acid cyclopropane modification in pathogenesis, the feasibility of targeting this enzyme family for antibiotic development is unknown. We show through genetics and chemical biology that mycolic acid methyltransferases are essential for M. tuberculosis viability, cell wall structure, and intrinsic resistance to antibiotics. The tool compound dioctylamine, which we show acts as a substrate mimic, directly inhibits the function of multiple mycolic acid methyltransferases, resulting in loss of cyclopropanation, cell death, loss of acid fastness, and synergistic killing with isoniazid and ciprofloxacin. These results demonstrate that mycolic acid methyltransferases are a promising antibiotic target and that a family of virulence factors can be chemically inhibited with effects not anticipated from studies of each individual enzyme.

  8. Molecular Determinants of the Response of Tumor Cells to Boswellic Acids

    PubMed Central

    Eichhorn, Tolga; Greten, Henry Johannes; Efferth, Thomas

    2011-01-01

    Frankincense (Boswellia serrata, B. carterii) is used as traditional remedy to treat inflammatory diseases. The molecular effects of the active ingredients, the boswellic acids, on the immune system have previously been studied and verified in several clinical studies. Boswellic acids also inhibit cancer cell growth in vitro and in vivo. The molecular basis of the cytotoxicity of boswellic acids is, however, not fully understood as yet. By mRNA-based microarray, COMPARE, and hierarchical cluster analyses, we identified a panel of genes from diverse functional groups, which were significantly associated with sensitivity or resistance of α- or β-boswellic acids, such as transcription factors, signal transducers, growth regulating genes, genes involved in RNA and protein metabolism and others. This indicates that boswellic acids exert profound cytotoxicity on cancer cells by a multiplicity of molecular mechanisms.

  9. Liquid biopsy in patients with pancreatic cancer: Circulating tumor cells and cell-free nucleic acids

    PubMed Central

    Imamura, Taisuke; Komatsu, Shuhei; Ichikawa, Daisuke; Kawaguchi, Tsutomu; Miyamae, Mahito; Okajima, Wataru; Ohashi, Takuma; Arita, Tomohiro; Konishi, Hirotaka; Shiozaki, Atsushi; Morimura, Ryo; Ikoma, Hisashi; Okamoto, Kazuma; Otsuji, Eigo

    2016-01-01

    Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer (PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis. In the blood of patients with cancer, circulating tumor cells (CTCs) and cell-free nucleic acids (cfNAs), such as DNA, mRNA, and noncoding RNA have been recognized. In the recent years, their presence in the blood has encouraged researchers to investigate their potential use as novel blood biomarkers, and numerous studies have demonstrated their potential clinical utility as a biomarker for certain types of cancer. This concept, called “liquid biopsy” has been focused on as a less invasive, alternative approach to cancer tissue biopsy for obtaining genetic and epigenetic aberrations that contribute to oncogenesis and cancer progression. In this article, we review the available literature on CTCs and cfNAs in patients with cancer, particularly focusing on PCa, and discuss future perspectives in this field. PMID:27433079

  10. Electric utility acid fuel cell stack technology advancement

    NASA Technical Reports Server (NTRS)

    Congdon, J. V.; Goller, G. J.; Greising, G. J.; Obrien, J. J.; Randall, S. A.; Sandelli, G. J.; Breault, R. D.; Austin, G. W.; Bopse, S.; Coykendall, R. D.

    1984-01-01

    The principal effort under this program was directed at the fuel cell stack technology required to accomplish the initial feasibility demonstrations of increased cell stack operating pressures and temperatures, increased cell active area, incorporation of the ribbed substrate cell configuration at the bove conditions, and the introduction of higher performance electrocatalysts. The program results were successful with the primary accomplishments being: (1) fabrication of 10 sq ft ribbed substrate, cell components including higher performing electrocatalysts; (2) assembly of a 10 sq ft, 30-cell short stack; and (3) initial test of this stack at 120 psia and 405 F. These accomplishments demonstrate the feasibility of fabricating and handling large area cells using materials and processes that are oriented to low cost manufacture. An additional accomplishment under the program was the testing of two 3.7 sq ft short stacks at 12 psia/405 F to 5400 and 4500 hours respectively. These tests demonstrate the durability of the components and the cell stack configuration to a nominal 5000 hours at the higher pressure and temperature condition planned for the next electric utility power plant.

  11. An amino acid depleted cell-free protein synthesis system for the incorporation of non-canonical amino acid analogs into proteins.

    PubMed

    Singh-Blom, Amrita; Hughes, Randall A; Ellington, Andrew D

    2014-05-20

    Residue-specific incorporation of non-canonical amino acids into proteins is usually performed in vivo using amino acid auxotrophic strains and replacing the natural amino acid with an unnatural amino acid analog. Herein, we present an efficient amino acid depleted cell-free protein synthesis system that can be used to study residue-specific replacement of a natural amino acid by an unnatural amino acid analog. This system combines a simple methodology and high protein expression titers with a high-efficiency analog substitution into a target protein. To demonstrate the productivity and efficacy of a cell-free synthesis system for residue-specific incorporation of unnatural amino acids in vitro, we use this system to show that 5-fluorotryptophan and 6-fluorotryptophan substituted streptavidin retain the ability to bind biotin despite protein-wide replacement of a natural amino acid for the amino acid analog. We envisage this amino acid depleted cell-free synthesis system being an economical and convenient format for the high-throughput screening of a myriad of amino acid analogs with a variety of protein targets for the study and functional characterization of proteins substituted with unnatural amino acids when compared to the currently employed in vivo methodologies.

  12. Kinase Signaling in Apoptosis Induced by Saturated Fatty Acids in Pancreatic β-Cells.

    PubMed

    Šrámek, Jan; Němcová-Fürstová, Vlasta; Kovář, Jan

    2016-01-01

    Pancreatic β-cell failure and death is considered to be one of the main factors responsible for type 2 diabetes. It is caused by, in addition to hyperglycemia, chronic exposure to increased concentrations of fatty acids, mainly saturated fatty acids. Molecular mechanisms of apoptosis induction by saturated fatty acids in β-cells are not completely clear. It has been proposed that kinase signaling could be involved, particularly, c-Jun N-terminal kinase (JNK), protein kinase C (PKC), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), and Akt kinases and their pathways. In this review, we discuss these kinases and their signaling pathways with respect to their possible role in apoptosis induction by saturated fatty acids in pancreatic β-cells. PMID:27626409

  13. Kinase Signaling in Apoptosis Induced by Saturated Fatty Acids in Pancreatic β-Cells

    PubMed Central

    Šrámek, Jan; Němcová-Fürstová, Vlasta; Kovář, Jan

    2016-01-01

    Pancreatic β-cell failure and death is considered to be one of the main factors responsible for type 2 diabetes. It is caused by, in addition to hyperglycemia, chronic exposure to increased concentrations of fatty acids, mainly saturated fatty acids. Molecular mechanisms of apoptosis induction by saturated fatty acids in β-cells are not completely clear. It has been proposed that kinase signaling could be involved, particularly, c-Jun N-terminal kinase (JNK), protein kinase C (PKC), p38 mitogen-activated protein kinase (p38 MAPK), extracellular signal-regulated kinase (ERK), and Akt kinases and their pathways. In this review, we discuss these kinases and their signaling pathways with respect to their possible role in apoptosis induction by saturated fatty acids in pancreatic β-cells. PMID:27626409

  14. Phosphatidic acid phosphatase and phospholipdase A activities in plasma membranes from fusing muscle cells.

    PubMed

    Kent, C; Vagelos, P R

    1976-06-17

    Plasma membrane from fusing embryonic muscle cells were assayed for phospholipase A activity to determine if this enzyme plays a role in cell fusion. The membranes were assayed under a variety of conditions with phosphatidylcholine as the substrate and no phospholipase A activity was found. The plasma membranes did contain a phosphatidic acid phosphatase which was optimally active in the presence of Triton X-100 and glycerol. The enzyme activity was constant from pH 5.2 to 7.0, and did not require divalent cations. Over 97% of the phosphatidic acid phosphatase activity was in the particulate fraction. The subcellular distribution of the phosphatidic acid phosphatase was the same as the distributions of the plasma membrane markers, (Na+ + k+)-ATPase and the acetylcholine receptor, which indicates that this phosphatase is located exclusively in the plasma membranes. There was no detectable difference in the phosphatidic acid phosphatase activities of plasma membranes from fusing and non-fusing cells.

  15. Ascorbic acid protects against cadmium-induced endoplasmic reticulum stress and germ cell apoptosis in testes.

    PubMed

    Ji, Yan-Li; Wang, Zhen; Wang, Hua; Zhang, Cheng; Zhang, Ying; Zhao, Mei; Chen, Yuan-Hua; Meng, Xiu-Hong; Xu, De-Xiang

    2012-11-01

    Cadmium (Cd) is a testicular toxicant which induces endoplasmic reticulum (ER) stress and germ cell apoptosis in testes. This study investigated the effects of ascorbic acid on Cd-evoked ER stress and germ cell apoptosis in testes. Male mice were intraperitoneally injected with CdCl(2) (2.0 mg/kg). As expected, a single dose of Cd induced testicular germ cell apoptosis. Interestingly, Cd-triggered testicular germ cell apoptosis was almost completely inhibited in mice treated with ascorbic acid. Interestingly, ascorbic acid significantly attenuated Cd-induced upregulation of GRP78 in testes. In addition, ascorbic acid significantly attenuated Cd-triggered testicular IRE1α and eIF2α phosphorylation and XBP-1 activation, indicating that this antioxidant counteracts Cd-induced unfolded protein response (UPR) in testes. Finally, ascorbic acid significantly attenuated Cd-evoked upregulation of CHOP and JNK phosphorylation, two components in ER stress-mediated apoptotic pathway. In conclusion, ascorbic acid protects mice from Cd-triggered germ cell apoptosis via inhibiting ER stress and UPR in testes. PMID:22569276

  16. Vasopressin induces release of arachidonic acid from vascular smooth muscle cells

    SciTech Connect

    Grillone, L.R.; Clark, M.A.; Heckman, G.; Schmidt, D.; Stassen, F.L.; Crooke, S.T.

    1986-05-01

    Cultured smooth muscle cells (A-10), derived from rat thoracic aorta, have vascular (V/sub 1/) vasopressin receptors. They have previously shown that these receptors mediate phosphatidylinositol turnover, Ca/sup 2 +/ efflux, and inhibition of isoproterenol-induced increases in cAMP. Here they studied the effect of vasopressin on arachidonic acid metabolism of A-10 cells. Cells were incubated for 18-20 hr with (/sup 3/H)-arachidonic acid (80 Ci/mmol). Vasopressin stimulated release of arachidonic acid in a time- and dose-dependent manner. Significant release of arachidonic acid was observed after 4 min with 10/sup -9/ M vasopressin. Maximum release was reached 4 min after addition of 10/sup -7/ M vasopressin (1100 dpm/10/sup 6/ cells). About 800 dmp were released after 1 and 4 min with 10/sup -7/ M and 10/sup -8/ M vasopressin, respectively. The vasopressin-stimulated release of arachidonic acid was blocked by the specific V/sub 1//V/sub 2/ vasopressin antagonist d(CH2)5D-Tyr(Et)VAVP. These data indicate that vascular smooth muscle cells increase arachidonic acid release in response to vasopressin. This response is likely mediated by V/sub 1/ receptors.

  17. Inhibitory effects of lysophosphatidic acid receptor-5 on cellular functions of sarcoma cells.

    PubMed

    Araki, Mutsumi; Kitayoshi, Misaho; Dong, Yan; Hirane, Miku; Ozaki, Shuhei; Mori, Shiori; Fukushima, Nobuyuki; Honoki, Kanya; Tsujiuchi, Toshifumi

    2014-06-01

    Lysophosphatidic acid (LPA) is a bioactive lipid that interacts with G protein-coupled LPA receptors (LPA receptor-1 (LPA1) to LPA6). Here, we investigated the effects of LPA signaling via LPA5 on cellular functions of sarcoma cells by generating Lpar5 overexpressing and Lpar5 knockdown cells from rat osteosarcoma and malignant fibrous histiocytoma cells, respectively. The cell motility activity of Lpar5 overexpressing cells was significantly lower, while Lpar5 knockdown cells showed high cell motility, compared with respective controls. Gelatin zymography showed that LPA5 suppressed the activation of matrix metalloproteinase-2. LPA5 also inhibited the cell motility activity of endothelial cells, correlating with the expression levels of vascular endothelial growth factor genes. These results suggest that LPA signaling via LPA5 negatively regulates the cellular functions of rat sarcoma cells. PMID:24798396

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

    PubMed

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

    1994-01-01

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

  19. Valproic acid sensitizes human glioma cells to gefitinib-induced autophagy.

    PubMed

    Chang, Cheng-Yi; Li, Jian-Ri; Wu, Chih-Cheng; Ou, Yen-Chuan; Chen, Wen-Ying; Kuan, Yu-Hsiang; Wang, Wen-Yi; Chen, Chun-Jung

    2015-11-01

    Autophagy and apoptosis represent important cellular processes involved in cancer cell killing mechanisms. Epidermal growth factor receptor inhibitor gefitinib and valproic acid have been implicated in the treatment of malignancies including glioma involving autophagic and apoptotic mechanisms. Therefore, it is interesting to investigate whether a combination of gefitinib and valproic acid shows better cancer cell killing effect on human glioma cells. We found that a nontoxic concentration of valproic acid sensitized U87 and T98G glioma cells to gefitinib cytotoxicity by inhibiting cell growth and long-term clonogenic survival. The augmented consequences were accompanied by the formation of autophagic vacuoles, conversion of microtubule-associated protein-1 light chain 3-II (LC3-II), and degradation of p62. Autophagy inhibitor 3-methyladenosine and chloroquine and genetic silencing of LC3 but not broad-spectrum caspase inhibitor attenuated gefitinib/valproic acid-induced growth inhibition. Gefitinib/valproic acid-induced autophagy was accompanied by the activation of liver kinase-B1 (LKB1)/AMP-activated protein kinase (AMPK)/ULK1. Silencing of AMPK and ULK1 suppressed gefitinib/valproic acid-induced autophagy and growth inhibition. Mechanistic studies showed that gefitinib/valproic acid increased intracellular reactive oxygen species generation and N-acetyl cysteine attenuated gefitinib/valproic acid-caused autophagy and growth inhibition. In addition to demonstrating the autophagic mechanisms of gefitinib/valproic acid, the results of this study further suggest that intracellular oxidative stress and the LKB1/AMPK signaling might be a potential target for the development of therapeutic strategy against glioma. PMID:26488897

  20. Lauric Acid Stimulates Ketone Body Production in the KT-5 Astrocyte Cell Line.

    PubMed

    Nonaka, Yudai; Takagi, Tetsuo; Inai, Makoto; Nishimura, Shuhei; Urashima, Shogo; Honda, Kazumitsu; Aoyama, Toshiaki; Terada, Shin

    2016-08-01

    Coconut oil has recently attracted considerable attention as a potential Alzheimer's disease therapy because it contains large amounts of medium-chain fatty acids (MCFAs) and its consumption is thought to stimulate hepatic ketogenesis, supplying an alternative energy source for brains with impaired glucose metabolism. In this study, we first reevaluated the responses of plasma ketone bodies to oral administration of coconut oil to rats. We found that the coconut oil-induced increase in plasma ketone body concentration was negligible and did not significantly differ from that observed after high-oleic sunflower oil administration. In contrast, the administration of coconut oil substantially increased the plasma free fatty acid concentration and lauric acid content, which is the major MCFA in coconut oil. Next, to elucidate whether lauric acid can activate ketogenesis in astrocytes with the capacity to generate ketone bodies from fatty acids, we treated the KT-5 astrocyte cell line with 50 and 100 μM lauric acid for 4 h. The lauric acid treatments increased the total ketone body concentration in the cell culture supernatant to a greater extent than oleic acid, suggesting that lauric acid can directly and potently activate ketogenesis in KT-5 astrocytes. These results suggest that coconut oil intake may improve brain health by directly activating ketogenesis in astrocytes and thereby by providing fuel to neighboring neurons.

  1. Lauric Acid Stimulates Ketone Body Production in the KT-5 Astrocyte Cell Line.

    PubMed

    Nonaka, Yudai; Takagi, Tetsuo; Inai, Makoto; Nishimura, Shuhei; Urashima, Shogo; Honda, Kazumitsu; Aoyama, Toshiaki; Terada, Shin

    2016-08-01

    Coconut oil has recently attracted considerable attention as a potential Alzheimer's disease therapy because it contains large amounts of medium-chain fatty acids (MCFAs) and its consumption is thought to stimulate hepatic ketogenesis, supplying an alternative energy source for brains with impaired glucose metabolism. In this study, we first reevaluated the responses of plasma ketone bodies to oral administration of coconut oil to rats. We found that the coconut oil-induced increase in plasma ketone body concentration was negligible and did not significantly differ from that observed after high-oleic sunflower oil administration. In contrast, the administration of coconut oil substantially increased the plasma free fatty acid concentration and lauric acid content, which is the major MCFA in coconut oil. Next, to elucidate whether lauric acid can activate ketogenesis in astrocytes with the capacity to generate ketone bodies from fatty acids, we treated the KT-5 astrocyte cell line with 50 and 100 μM lauric acid for 4 h. The lauric acid treatments increased the total ketone body concentration in the cell culture supernatant to a greater extent than oleic acid, suggesting that lauric acid can directly and potently activate ketogenesis in KT-5 astrocytes. These results suggest that coconut oil intake may improve brain health by directly activating ketogenesis in astrocytes and thereby by providing fuel to neighboring neurons. PMID:27430387

  2. HALOACETIC ACIDS AND KINASE INHIBITORS PERTURB MOUSE NEURAL CREST CELLS IN VITRO

    EPA Science Inventory

    HUNTER, E.S.1, J. SMITH2, J. ANDREWS1. 1 Reproductive Toxicology Division, NHEERL, US EPA, Research Triangle Park and 2 Department of Cell and Developmental Biology, UNC-CH, Chapel Hill, North Carolina. Haloacetic acids and kinase inhibitors perturb mouse neural crest cells in vi...

  3. Mechanical damage to Escherichia coli cells in a model of amino-acid crystal fermentation.

    PubMed

    Okutani, Satoshi; Iwai, Takayoshi; Iwatani, Shintaro; Kondo, Kazuya; Osumi, Tsuyoshi; Tsujimoto, Nobuharu; Matsuno, Kiyoshi

    2012-04-01

    We investigated the mechanical damage to the Escherichia coli cell caused by polyvinyl chloride particles as a model of amino-acid crystal fermentation. Our results indicated that the glucose-consumption rate and the intracellular ATP concentration temporarily increased by the mechanical damage, and decreased after considerable damage had occurred on cell membrane. PMID:22153714

  4. Current legal and institutional issues in the commercialization of phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Nimmons, J. T.; Sheehy, K. D.; Singer, J. R.; Gardner, T. C.

    1982-01-01

    Legal and institutional factors affecting the development and commercial diffusion of phosphoric acid fuel cells are assessed. Issues for future research and action are suggested. Perceived barriers and potential opportunities for fuel cells in central and dispersed utility operations and on-site applications are reviewed, as well as the general concept of commercialization as applied to emerging energy technologies.

  5. Phosphoric acid fuel cell power plant system performance model and computer program

    NASA Technical Reports Server (NTRS)

    Alkasab, K. A.; Lu, C. Y.

    1984-01-01

    A FORTRAN computer program was developed for analyzing the performance of phosphoric acid fuel cell power plant systems. Energy mass and electrochemical analysis in the reformer, the shaft converters, the heat exchangers, and the fuel cell stack were combined to develop a mathematical model for the power plant for both atmospheric and pressurized conditions, and for several commercial fuels.

  6. [The parietal cell mass and acid secretion: Helicobacter pylori does not induce changes in the course of a duodenal ulcer].

    PubMed

    Testino, G; Sumberaz, A; Cornaggia, M

    1995-12-01

    Some studies have postulated that Helicobacter pylori (HP) itself might be responsible for hypergastrinemia and acid secretion in duodenal ulcer (DU). In each DU patient parietal cell mass (expressed by a parietal index) and stimulated acid secretion (expressed by maximal acid output) were evaluated. The study has been conducted grouping DU patients in relation to HP infection in antral mucosa. HP infection does not modify parietal cell mass and stimulated acid secretion. Therefore, mild chronic hypergastrinemia induced by HP infection is not sufficient to justify any increase of parietal index and acid secretion. In fact, parietal cells and acid secretion remain higher in DU subjects independently from HP infection.

  7. Beef conjugated linoleic acid isomers reduce human cancer cell growth even when associated with other beef fatty acids.

    PubMed

    De La Torre, Anne; Debiton, Eric; Juanéda, Pierre; Durand, Denys; Chardigny, Jean-Michel; Barthomeuf, Chantal; Bauchart, Dominique; Gruffat, Dominique

    2006-02-01

    Although many data are available concerning anticarcinogenic effects of industrial conjugated linoleic acid (CLA), few studies have reported the antitumour properties of CLA mixtures originating from ruminant products. The aim of the present study was to investigate the in vitro antiproliferative effects of beef CLA mixtures on breast, lung, colon, melanoma and ovarian human cancer cell lines. For this purpose, four fatty acid (FA) extracts prepared from beef lipid and varying in their CLA composition, their corresponding purified CLA-enriched fractions, and mixtures of pure synthetic CLA, the composition of which reproduced that of the four selected beef samples, were tested on cancer cell lines. Cancer cells were exposed for 48 h to medium containing 100 microm-FA and their proliferation was determined by quantifying cellular DNA content (Hoechst 33342 dye). Compared with cells incubated without FA, the number of cancer cells was reduced from 25 to 67 % (P<0.0001) following FA treatment. Antiproliferative effects of CLA mixtures varied in magnitude according to the source of FA, the CLA composition and the cell lines. CLA mixtures naturally present in beef inhibited the proliferation of human cancer cell lines, a high content in cis-trans isomers allowing the most important antiproliferative effect. Beef total FA exhibited a greater growth-inhibitory activity than their corresponding CLA-enriched fractions. These results suggested that either beef FA other than beef CLA could possess antiproliferative properties and/or the existence of complementary effects of non-conjugated FA and CLA, which could favour the antiproliferative properties of beef total FA. PMID:16469152

  8. Beef conjugated linoleic acid isomers reduce human cancer cell growth even when associated with other beef fatty acids.

    PubMed

    De La Torre, Anne; Debiton, Eric; Juanéda, Pierre; Durand, Denys; Chardigny, Jean-Michel; Barthomeuf, Chantal; Bauchart, Dominique; Gruffat, Dominique

    2006-02-01

    Although many data are available concerning anticarcinogenic effects of industrial conjugated linoleic acid (CLA), few studies have reported the antitumour properties of CLA mixtures originating from ruminant products. The aim of the present study was to investigate the in vitro antiproliferative effects of beef CLA mixtures on breast, lung, colon, melanoma and ovarian human cancer cell lines. For this purpose, four fatty acid (FA) extracts prepared from beef lipid and varying in their CLA composition, their corresponding purified CLA-enriched fractions, and mixtures of pure synthetic CLA, the composition of which reproduced that of the four selected beef samples, were tested on cancer cell lines. Cancer cells were exposed for 48 h to medium containing 100 microm-FA and their proliferation was determined by quantifying cellular DNA content (Hoechst 33342 dye). Compared with cells incubated without FA, the number of cancer cells was reduced from 25 to 67 % (P<0.0001) following FA treatment. Antiproliferative effects of CLA mixtures varied in magnitude according to the source of FA, the CLA composition and the cell lines. CLA mixtures naturally present in beef inhibited the proliferation of human cancer cell lines, a high content in cis-trans isomers allowing the most important antiproliferative effect. Beef total FA exhibited a greater growth-inhibitory activity than their corresponding CLA-enriched fractions. These results suggested that either beef FA other than beef CLA could possess antiproliferative properties and/or the existence of complementary effects of non-conjugated FA and CLA, which could favour the antiproliferative properties of beef total FA.

  9. Omega 3 fatty acids increase spontaneous release of cytosolic components from tumor cells

    SciTech Connect

    Jenski, L.J.; Sturdevant, L.K.; Ehringer, W.D.; Stillwell, W. )

    1991-05-01

    Mice fed menhaden (fish) oil or coconut oil-rich diets were inoculated intraperitoneally with a rapidly growing leukemia, T27A. After one week, the tumor cells were harvested, and 51Cr was used to label intracellular molecules. Spontaneous release of 51Cr was used as a measure of plasma membrane permeability. Compared to cells from mice fed coconut oil (rich in saturated fatty acids), tumor cells from mice fed menhaden oil (rich in long chain polyunsaturated omega 3 fatty acids) showed an increased level of spontaneous 51Cr release, which was exacerbated by increased temperature and reduced by extracellular protein. At physiological salt concentrations, the released 51Cr was detected in particles of approximately 2700 daltons. Enhanced permeability correlated with the incorporation of dietary (fish oil) omega 3 polyunsaturated fatty acids docosahexaenoic and eicosapentaenoic acid into the tumor cells. The results demonstrate that omega 3 fatty acids are incorporated into cellular constituents of tumor cells and change properties associated with the plasma membrane. This result suggests that dietary manipulation may be used to enhance tumor cell permeability and contribute to tumor eradication.

  10. Biodegradation and Osteosarcoma Cell Cultivation on Poly(aspartic acid) Based Hydrogels.

    PubMed

    Juriga, Dávid; Nagy, Krisztina; Jedlovszky-Hajdú, Angéla; Perczel-Kovách, Katalin; Chen, Yong Mei; Varga, Gábor; Zrínyi, Miklós

    2016-09-14

    Development of novel biodegradable and biocompatible scaffold materials with optimal characteristics is important for both preclinical and clinical applications. The aim of the present study was to analyze the biodegradability of poly(aspartic acid)-based hydrogels, and to test their usability as scaffolds for MG-63 osteoblast-like cells. Poly(aspartic acid) was fabricated from poly(succinimide) and hydrogels were prepared using natural amines as cross-linkers (diaminobutane and cystamine). Disulfide bridges were cleaved to thiol groups and the polymer backbone was further modified with RGD sequence. Biodegradability of the hydrogels was evaluated by experiments on the base of enzymes and cell culture medium. Poly(aspartic acid) hydrogels possessing only disulfide bridges as cross-links proved to be degradable by collagenase I. The MG-63 cells showed healthy, fibroblast-like morphology on the double cross-linked and RGD modified hydrogels. Thiolated poly(aspartic acid) based hydrogels provide ideal conditions for adhesion, survival, proliferation, and migration of osteoblast-like cells. The highest viability was found on the thiolated PASP gels while the RGD motif had influence on compacted cluster formation of the cells. These biodegradable and biocompatible poly(aspartic acid)-based hydrogels are promising scaffolds for cell cultivation. PMID:27541725

  11. Tailoring folic acid and methotrexate-attributed quantum dots for integrated cancer cell imaging and therapy

    NASA Astrophysics Data System (ADS)

    Fahmi, Mochamad Zakki; Chang, Jia-Yaw

    2016-03-01

    Potential application of folic acid and methotrexate-attributed AgInS2-ZnS quantum dots on both detection and therapeutic of cancer cell were intensively investigated on this study. In the initial step, the bright luminescent of QDs, with % QY up to 55.3, were synthesized with one-pot two-step process resulting narrow particle distribution and successfully transferred to water phase without significant effect on optical properties. The water-soluble AgInS2-ZnS quantum dots (QDs) encapsulated with oleylamine have been successfully prepared by ultrasonication assisting. Several aspect including QDs characterization, pH stability, ionic strength, and bonding properties were investigated to reach desired condition of water-soluble AgInS2-ZnS QDs. Folic acid was further conjugated to QDs for HeLa and MCF7 cancer cell imaging to performs the targeting capability. Moreover, folic acid is efficiently internalized into cell through the receptor-mediated endocytosis even when conjugated with a wide variety of molecules. Confocal imaging characterization further informs folic acid-conjugated AgInS2-ZnS QDs could most specific targeted to the human cervical (HeLa) cells. The therapeutic feature of QDs on HeLa cancer cell was conjugated by attributing methotrexate on the QDs, instead of folic acid, and the design could improve on inhibiting the cancer cell viability as well as its fluorescent intensity.

  12. Altered sensitivity to ellagic acid in neuroblastoma cells undergoing differentiation with 12-O-tetradecanoylphorbol-13-acetate and all-trans retinoic acid.

    PubMed

    Alfredsson, Christina Fjæraa; Rendel, Filip; Liang, Qui-Li; Sundström, Birgitta E; Nånberg, Eewa

    2015-12-01

    Ellagic acid has previously been reported to induce reduced proliferation and activation of apoptosis in several tumor cell lines including our own previous data from non-differentiated human neuroblastoma SH-SY5Y cells. The aim of this study was now to investigate if in vitro differentiation with the phorbol ester 12-O- tetradecanoylphorbol-13-acetate or the vitamin A derivative all-trans retinoic acid altered the sensitivity to ellagic acid in SH-SY5Y cells. The methods used were cell counting and LDH-assay for evaluation of cell number and cell death, flow cytometric analysis of SubG1- and TUNEL-analysis for apoptosis and western blot for expression of apoptosis-associated proteins. In vitro differentiation was shown to reduce the sensitivity to ellagic acid with respect to cell detachment, loss of viability and activation of apoptosis. The protective effect was phenotype-specific and most prominent in all-trans retinoic acid-differentiated cultures. Differentiation-dependent up-regulation of Bcl-2 and integrin expression is introduced as possible protective mechanisms. The presented data also point to a positive correlation between proliferative activity and sensitivity to ellagic-acid-induced cell detachment. In conclusion, the presented data emphasize the need to consider degree of neuronal differentiation and phenotype of neuroblastoma cells when discussing a potential pharmaceutical application of ellagic acid in tumor treatment.

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

    SciTech Connect

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

    2011-08-15

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

  14. Differential cell fates induced by all-trans retinoic acid-treated HL-60 human leukemia cells.

    PubMed

    Ozeki, Munetaka; Shively, John E

    2008-09-01

    HL-60 human leukemia cells, differentiated into a neutrophil lineage by all-trans retinoic acid (ATRA) treatment, express three members of the carcinoembryonic antigen (CEA) gene family, CEA-related cell adhesion molecule 1 (CEACAM1; CD66a), CEACAM3 (CD66d), and CEACAM6 (CD66c). CD66d is a neutrophil lineage-specific marker, and CD66a and CD66c are found on epithelial and other cells. HL-60 cells continuously treated with ATRA underwent apoptosis, and cells transiently treated for 1 day underwent cell-cycle arrest, entered into senescence, and exhibited reduced apoptosis with CD66-positive cells accounting for the majority of live cells. CD66 antigens were also induced in NB4 leukemic cells upon continuous treatment with ATRA. NB4 cells underwent apoptosis with a higher frequency in transient versus continuous-treated cells (38% vs. 19% at Day 5), in contrast to HL-60 cells that underwent cell-cycle arrest and senescence when transiently treated with ATRA. CD66 antigens were not induced in transient, ATRA-treated NB4 cells compared with HL-60 cells. Cell-cycle arrest in HL-60 cells involved reduction in expression levels of p21, cyclins D and E, while Rb1 exhibited reduction in protein levels without changes in mRNA levels over the time course of ATRA treatment. Analysis of several proapoptotic proteins implicated the activation of calpain and cleavage of Bax in the intrinsic apoptotic pathway, similar to published studies about the apoptosis of neutrophils. CD1d expression was also induced by ATRA in HL-60 cells and ligation with anti-CD1d antibody-induced apoptosis. In contrast, CD1d-positive primary monocytes were protected from spontaneous apoptosis by CD1d ligation. These studies demonstrate distinct cell fates for ATRA-treated HL-60 cells that provide new insights into ATRA-induced cell differentiation.

  15. Docosahexaenoic acid reduces suppressive and migratory functions of CD4CD25 regulatory T-cells

    PubMed Central

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-01-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4+CD25+ regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4+CD25− effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-β, and IL-10; nonetheless, this fatty acid increased the expression of p27KIP1 mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease. PMID:19561360

  16. Docosahexaenoic acid reduces suppressive and migratory functions of CD4+CD25+ regulatory T-cells.

    PubMed

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-12-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4(+)CD25(+) regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4(+)CD25(-) effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-beta, and IL-10; nonetheless, this fatty acid increased the expression of p27(KIP1) mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease.

  17. Plasmacytoid dendritic cells in the skin: to sense or not to sense nucleic acids.

    PubMed

    Conrad, Curdin; Meller, Stephan; Gilliet, Michel

    2009-06-01

    Plasmacytoid dendritic cells (pDCs) are specialized sensors of viral nucleic acids that initiate protective immunity through the production of type I interferons (IFNs). Normally, pDCs fail to sense host-derived self-nucleic acids but do so when self-nucleic acids form complexes with endogenous antimicrobial peptides produced in damaged skin. Whereas regulated expression of antimicrobial peptides may lead to pDC activation and protective immune responses to skin injury, overexpression of antimicrobial peptides in psoriasis drives excessive sensing of self-nucleic acids by pDCs resulting in IFN-driven autoimmunity. In skin tumors, pDCs are unable to sense self-nucleic acids; however, therapeutic activation of pDCs by synthetic nucleic acids or analogues can be exploited to generate antitumor immunity.

  18. Induction of apoptosis by gallic acid in human stomach cancer KATO III and colon adenocarcinoma COLO 205 cell lines.

    PubMed

    Yoshioka, K; Kataoka, T; Hayashi, T; Hasegawa, M; Ishi, Y; Hibasami, H

    2000-01-01

    Antitumor effects of gallic acid on human stomach cancer KATO III cells and human colon adenocarcinoma COLO 205 cells were investigated. The exposures of KATO III and COLO 205 cells to gallic acid led to both growth inhibition and induction of apoptosis. Morphological changes showing apoptotic bodies were observed in both the cell lines treated with gallic acid. The fragmentations by gallic acid of DNA to oligonucleosomal-sized fragments, that are characteristics of apoptosis, were observed to be concentration- and time-dependent. These findings suggest that growth inhibitions by gallic acid of KATO III cells and COLO 205 cells result from the apoptosis induced by gallic acid. Thus, gallic acid might be a candidate drug for digestive gut cancer treatment to overcome the resistance to chemotherapeutic drugs. PMID:11032918

  19. Active targeting of cancer cells using folic acid-conjugated platinum nanoparticles

    NASA Astrophysics Data System (ADS)

    Teow, Yiwei; Valiyaveettil, Suresh

    2010-12-01

    Interaction of nanoparticles with human cells is an interesting topic for understanding toxicity and developing potential drug candidates. Water soluble platinum nanoparticles were synthesized viareduction of hexachloroplatinic acid using sodium borohydride in the presence of capping agents. The bioactivity of folic acid and poly(vinyl pyrrolidone) capped platinum nanoparticles (Pt-nps) has been investigated using commercially available cell lines. In the cell viability experiments, PVP-capped nanoparticles were found to be less toxic (>80% viability), whereas, folic acid-capped platinum nanoparticles showed a reduced viability down to 24% after 72 h of exposure at a concentration of 100 μg ml-1 for MCF7 breast cancer cells. Such toxicity, combined with the possibility to incorporate functional organic molecules as capping agents, can be used for developing new drug candidates.

  20. Active targeting of cancer cells using folic acid-conjugated platinum nanoparticles.

    PubMed

    Teow, Yiwei; Valiyaveettil, Suresh

    2010-12-01

    Interaction of nanoparticles with human cells is an interesting topic for understanding toxicity and developing potential drug candidates. Water soluble platinum nanoparticles were synthesized via reduction of hexachloroplatinic acid using sodium borohydride in the presence of capping agents. The bioactivity of folic acid and poly(vinyl pyrrolidone) capped platinum nanoparticles (Pt-nps) has been investigated using commercially available cell lines. In the cell viability experiments, PVP-capped nanoparticles were found to be less toxic (>80% viability), whereas, folic acid-capped platinum nanoparticles showed a reduced viability down to 24% after 72 h of exposure at a concentration of 100 μg ml(-1) for MCF7 breast cancer cells. Such toxicity, combined with the possibility to incorporate functional organic molecules as capping agents, can be used for developing new drug candidates.

  1. Efficient production of propionic acid through high density culture with recycling cells of Propionibacterium acidipropionici.

    PubMed

    Liu, Zhen; Ge, Yongsheng; Xu, Jing; Gao, Chao; Ma, Cuiqing; Xu, Ping

    2016-09-01

    The aim of this study was to explore propionic acid production via high density culture of Propionibacterium acidipropionici and recycling of cells. Results showed that final cells of P. acidipropionici from high density culture still had high metabolic activity for reuse. Using our process, 75.9gl(-1) propionic acid was produced, which was 1.84-fold of that in fed-batch fermentation with low cell density (41.2gl(-1)); the corresponding productivity was 100.0% higher than that in fed-batch fermentation with low cell density (0.16gl(-1)h(-1)). This bioprocess may have potential for the industrial production of propionic acid. PMID:27318164

  2. Canine and feline parvoviruses preferentially recognize the non-human cell surface sialic acid N-glycolylneuraminic acid

    SciTech Connect

    Löfling, Jonas; Michael Lyi, Sangbom; Parrish, Colin R.; Varki, Ajit

    2013-05-25

    Feline panleukopenia virus (FPV) is a pathogen whose canine-adapted form (canine parvovirus (CPV)) emerged in 1978. These viruses infect by binding host transferrin receptor type-1 (TfR), but also hemagglutinate erythrocytes. We show that hemagglutination involves selective recognition of the non-human sialic acid N-glycolylneuraminic acid (Neu5Gc) but not N-acetylneuraminic acid (Neu5Ac), which differs by only one oxygen atom from Neu5Gc. Overexpression of α2-6 sialyltransferase did not change binding, indicating that both α2-3 and α2-6 linkages are recognized. However, Neu5Gc expression on target cells did not enhance CPV or FPV infection in vitro. Thus, the conserved Neu5Gc-binding preference of these viruses likely plays a role in the natural history of the virus in vivo. Further studies must clarify relationships between virus infection and host Neu5Gc expression. As a first step, we show that transcripts of CMAH (which generates Neu5Gc from Neu5Ac) are at very low levels in Western dog breed cells. - Highlights: ► Feline and canine parvoviruses recognize Neu5Gc but not Neu5Ac, which differ by one oxygen atom. ► The underlying linkage of these sialic acids does not affect recognition. ► Induced Neu5Gc expression on target cells that normally express Neu5Ac did not enhance infection. ► Thus, the conserved binding preference plays an important yet unknown role in in vivo infections. ► Population and breed variations in Neu5Gc expression occur, likely by regulating the gene CMAH.

  3. The effects of omega-3 Fatty acids on matrix metalloproteinase-9 production and cell migration in human immune cells: implications for multiple sclerosis.

    PubMed

    Shinto, Lynne; Marracci, Gail; Bumgarner, Lauren; Yadav, Vijayshree

    2011-01-01

    In multiple sclerosis (MS), compromised blood-brain barrier (BBB) integrity contributes to inflammatory T cell migration into the central nervous system. Matrix metalloproteinase-9 (MMP-9) is associated with BBB disruption and subsequent T cell migration into the CNS. The aim of this paper was to evaluate the effects of omega-3 fatty acids on MMP-9 levels and T cell migration. Peripheral blood mononuclear cells (PBMC) from healthy controls were pretreated with two types of omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Cell supernatants were used to determine MMP-9 protein and activity levels. Jurkat cells were pretreated with EPA and DHA and were added to fibronectin-coated transwells to measure T cell migration. EPA and DHA significantly decreased MMP-9 protein levels, MMP-9 activity, and significantly inhibited human T cell migration. The data suggest that omega-3 fatty acids may benefit patients with multiple sclerosis by modulating immune cell production of MMP-9.

  4. Lactic acid bacteria as a cell factory for riboflavin production

    PubMed Central

    Thakur, Kiran; De, Sachinandan

    2015-01-01

    Summary Consumers are increasingly becoming aware of their health and nutritional requirements, and in this context, vitamins produced in situ by microbes may suit their needs and expectations. B groups vitamins are essential components of cellular metabolism and among them riboflavin is one of the vital vitamins required by bacteria, plants, animals and humans. Here, we focus on the importance of microbial production of riboflavin over chemical synthesis. In addition, genetic abilities for riboflavin biosynthesis by lactic acid bacteria are discussed. Genetically modified strains by employing genetic engineering and chemical analogues have been developed to enhance riboflavin production. The present review attempts to collect the currently available information on riboflavin production by microbes in general, while placing greater emphasis on food grade lactic acid bacteria and human gut commensals. For designing riboflavin‐enriched functional foods, proper selection and exploitation of riboflavin‐producing lactic acid bacteria is essential. Moreover, eliminating the in situ vitamin fortification step will decrease the cost of food production. PMID:26686515

  5. Differential infection of polarized epithelial cell lines by sialic acid-dependent and sialic acid-independent rotavirus strains.

    PubMed

    Ciarlet, M; Crawford, S E; Estes, M K

    2001-12-01

    Infection of epithelial cells by some animal rotaviruses, but not human or most animal rotaviruses, requires the presence of N-acetylneuraminic (sialic) acid (SA) on the cell surface for efficient infectivity. To further understand how rotaviruses enter susceptible cells, six different polarized epithelial cell lines, grown on permeable filter membrane supports containing 0.4-microm pores, were infected apically or basolaterally with SA-independent or SA-dependent rotaviruses. SA-independent rotaviruses applied apically or basolaterally were capable of efficiently infecting both sides of the epithelium of all six polarized cell lines tested, while SA-dependent rotaviruses only infected efficiently through the apical surface of five of the polarized cell lines tested. Regardless of the route of virus entry, SA-dependent and SA-independent rotaviruses were released almost exclusively from the apical domain of the plasma membrane of polarized cells before monolayer disruption or cell lysis. The transepithelial electrical resistance (TER) of cells decreased at the same time, irrespective of whether infection with SA-independent rotaviruses occurred apically or basolaterally. The TER of cells infected apically with SA-dependent rotaviruses decreased earlier than that of cells infected basolaterally. Rotavirus infection decreased TER before the appearance of cytopathic effect and cell death and resulted in an increase in the paracellular permeability to [(3)H]inulin as a function of loss of TER. The presence of SA residues on either the apical or basolateral side was determined using a Texas Red-conjugated lectin, wheat germ agglutinin (WGA), which binds SA residues. WGA bound exclusively to SA residues on the apical surface of the cells, confirming the requirement for SA residues on the apical cell membrane for efficient infectivity of SA-dependent rotaviruses. These results indicate that the rotavirus SA-independent cellular receptor is present on both sides of the

  6. Gallic acid induces mitotic catastrophe and inhibits centrosomal clustering in HeLa cells.

    PubMed

    Tan, Si; Guan, Xin; Grün, Christoph; Zhou, Zhiqin; Schepers, Ute; Nick, Peter

    2015-12-25

    Cancer cells divide rapidly, providing medical targets for anticancer agents. The polyphenolic gallic acid (GA) is known to be toxic for certain cancer cells. However, the cellular mode of action has not been elucidated. Therefore, the current study addressed a potential effect of GA on the mitosis of cancer cells. GA inhibited viability of HeLa cells in a dose-dependent and time-dependent manner. We could show, using fluorescence-activated cell sorting (FACS), that this inhibition was accompanied by elevated frequency of cells arrested at the G2/M transition. This cell-cycle arrest was accompanied by mitotic catastrophe, and formation of cells with multiple nuclei. These aberrations were preceded by impaired centrosomal clustering. We arrive at a model of action, where GA inhibits the progression of the cell cycle at the G2/M phase by impairing centrosomal clustering which will stimulate mitotic catastrophe. Thus, GA has potential as compound against cervical cancer.

  7. Gelatin-Hyaluronic Acid Hydrogels with Tuned Stiffness to Counterbalance Cellular Forces and Promote Cell Differentiation.

    PubMed

    Poveda-Reyes, Sara; Moulisova, Vladimira; Sanmartín-Masiá, Esther; Quintanilla-Sierra, Luis; Salmerón-Sánchez, Manuel; Ferrer, Gloria Gallego

    2016-09-01

    Cells interact mechanically with their environment, exerting mechanical forces that probe the extracellular matrix (ECM). The mechanical properties of the ECM determine cell behavior and control cell differentiation both in 2D and 3D environments. Gelatin (Gel) is a soft hydrogel into which cells can be embedded. This study shows significant 3D Gel shrinking due to the high traction cellular forces exerted by the cells on the matrix, which prevents cell differentiation. To modulate this process, Gel with hyaluronic acid (HA) has been combined in an injectable crosslinked hydrogel with controlled Gel-HA ratio. HA increases matrix stiffness. The addition of small amounts of HA leads to a significant reduction in hydrogel shrinking after cell encapsulation (C2C12 myoblasts). We show that hydrogel stiffness counterbalanced traction forces of cells and this was decisive in promoting cell differentiation and myotube formation of C2C12 encapsulated in the hybrid hydrogels.

  8. Assessment of the environmental aspects of the DOE phosphoric acid fuel cell program

    NASA Technical Reports Server (NTRS)

    Lundblad, H. L.; Cavagrotti, R. R.

    1983-01-01

    The likely facets of a nationwide phosphoric acid fuel cell (PAFC) power plant commercial system are described. The beneficial and adverse environmental impacts produced by the system are assessed. Eleven specific system activities are characterized and evaluated. Also included is a review of fuel cell technology and a description of DOE's National Fuel Cell Program. Based on current and reasonably foreseeable PAFC characteristics, no environmental or energy impact factor was identified that would significantly inhibit the commercialization of PAFC power plant technology.

  9. Lipophilic caffeic and ferulic acid derivatives presenting cytotoxicity against human breast cancer cells.

    PubMed

    Serafim, Teresa L; Carvalho, Filipa S; Marques, Maria P M; Calheiros, Rita; Silva, Tiago; Garrido, Jorge; Milhazes, Nuno; Borges, Fernanda; Roleira, Fernanda; Silva, Elisiaario T; Holy, Jon; Oliveira, Paulo J

    2011-05-16

    In the present work, lipophilic caffeic and ferulic acid derivatives were synthesized, and their cytotoxicity on cultured breast cancer cells was compared. A total of six compounds were initially evaluated: caffeic acid (CA), hexyl caffeate (HC), caffeoylhexylamide (HCA), ferulic acid (FA), hexyl ferulate (HF), and feruloylhexylamide (HFA). Cell proliferation, cell cycle progression, and apoptotic signaling were investigated in three human breast cancer cell lines, including estrogen-sensitive (MCF-7) and insensitive (MDA-MB-231 and HS578T). Furthermore, direct mitochondrial effects of parent and modified compounds were investigated by using isolated liver mitochondria. The results indicated that although the parent compounds presented no cytotoxicity, the new compounds inhibited cell proliferation and induced cell cycle alterations and cell death, with a predominant effect on MCF-7 cells. Interestingly, cell cycle data indicates that effects on nontumor BJ fibroblasts were predominantly cytostatic and not cytotoxic. The parent compounds and derivatives also promoted direct alterations on hepatic mitochondrial bioenergetics, although the most unexpected and never before reported one was that FA induces the mitochondrial permeability transition. The results show that the new caffeic and ferulic acid lipophilic derivatives show increased cytotoxicity toward human breast cancer cell lines, although the magnitude and type of effects appear to be dependent on the cell type. Mitochondrial data had no direct correspondence with effects on intact cells suggesting that this organelle may not be a critical component of the cellular effects observed. The data provide a rational approach to the design of effective cytotoxic lipophilic hydroxycinnamic derivatives that in the future could be profitably applied for chemopreventive and/or chemotherapeutic purposes.

  10. Anacardic acid induces apoptosis-like cell death in the rice blast fungus Magnaporthe oryzae.

    PubMed

    Muzaffar, Suhail; Bose, Chinchu; Banerji, Ashok; Nair, Bipin G; Chattoo, Bharat B

    2016-01-01

    Anacardic acid (6-pentadecylsalicylic acid), extracted from cashew nut shell liquid, is a natural phenolic lipid well known for its strong antibacterial, antioxidant, and anticancer activities. Its effect has been well studied in bacterial and mammalian systems but remains largely unexplored in fungi. The present study identifies antifungal, cytotoxic, and antioxidant activities of anacardic acid in the rice blast fungus Magnaporthe oryzae. It was found that anacardic acid causes inhibition of conidial germination and mycelial growth in this ascomycetous fungus. Phosphatidylserine externalization, chromatin condensation, DNA degradation, and loss of mitochondrial membrane potential suggest that growth inhibition of fungus is mainly caused by apoptosis-like cell death. Broad-spectrum caspase inhibitor Z-VAD-FMK treatment indicated that anacardic acid induces caspase-independent apoptosis in M. oryzae. Expression of a predicted ortholog of apoptosis-inducing factor (AIF) was upregulated during the process of apoptosis, suggesting the possibility of mitochondria dependent apoptosis via activation of apoptosis-inducing factor. Anacardic acid treatment leads to decrease in reactive oxygen species rather than increase in reactive oxygen species (ROS) accumulation normally observed during apoptosis, confirming the antioxidant properties of anacardic acid as suggested by earlier reports. Our study also shows that anacardic acid renders the fungus highly sensitive to DNA damaging agents like ethyl methanesulfonate (EMS). Treatment of rice leaves with anacardic acid prevents M. oryzae from infecting the plant without affecting the leaf, suggesting that anacardic acid can be an effective antifungal agent. PMID:26381667

  11. Loss of growth inhibitory effects of retinoic acid in human breast cancer cells following long-term exposure to retinoic acid

    PubMed Central

    Stephen, R; Darbre, P D

    2000-01-01

    Although retinoids are known to be inhibitory to breast cancer cell growth, a key remaining question is whether they would remain effective if administered long-term. We describe here the long-term effects of all-trans retinoic acid on two oestrogen-dependent human breast cancer cell lines MCF7 and ZR-75-1. Although both cell lines were growth inhibited by retinoic acid in the short-term in either the absence or the presence of oestradiol, prolonged culture with 1 μM all-trans retinoic acid resulted in the cells acquiring resistance to the growth inhibitory effects of retinoic acid. Time courses showed that oestrogen deprivation of the cell lines resulted in upregulation of the basal non-oestrogen stimulated growth rate such that cells learned to grow at the same rate without as with oestradiol, but the cells remained growth inhibited by retinoic acid throughout. Addition of 1 μM all-trans retinoic acid to steroid deprivation conditions resulted in reproducible loss of growth response to both retinoic acid and oestradiol, although the time courses were separable in that loss of growth response to retinoic acid preceded that of oestradiol. Loss of growth response to retinoic acid did not involve loss of receptors, ER as measured by steroid binding assay or RARα as measured by Northern blotting. Function of the receptors was retained in terms of the ability of both oestradiol and retinoic acid to upregulate pS2 gene expression, but there was reduced ability to upregulate transiently transfected ERE- and RRE-linked reporter genes. Despite the accepted role of IGFBP3 in retinoic acid-mediated growth inhibition, progression to retinoic acid resistance occurred irrespective of level of IGFBP3, which remained high in the resistant MCF7 cells. Measurement of AP1 activity showed that the two cell lines had markedly different basal AP1 activities, but that progression to resistance was accompanied in both cases by a lost ability of retinoic acid to reduce AP1 activity

  12. Effects of Asiatic Acid on Spatial Working Memory and Cell Proliferation in the Adult Rat Hippocampus.

    PubMed

    Sirichoat, Apiwat; Chaijaroonkhanarak, Wunnee; Prachaney, Parichat; Pannangrong, Wanassanan; Leksomboon, Ratana; Chaichun, Amnart; Wigmore, Peter; Welbat, Jariya Umka

    2015-10-05

    Asiatic acid is a pentacyclic triterpene from Centella asiatica. Previous studies have reported that asiatic acid exhibits antioxidant and neuroprotective activities in cell culture. It also prevents memory deficits in animal models. The objective of this study was to investigate the relationship between spatial working memory and changes in cell proliferation within the hippocampus after administration of asiatic acid to male Spraque-Dawley rats. Control rats received vehicle (propylene glycol) while treated rats received asiatic acid (30 mg/kg) orally for 14 or 28 days. Spatial memory was determined using the novel object location (NOL) test. In animals administered asiatic acid for both 14 and 28 days, the number of Ki-67 positive cells in the subgranular zone of the dentate gyrus was significantly higher than in control animals. This was associated with a significant increase in their ability to discriminate between novel and familiar object locations in a novel object discrimination task, a hippocampus-dependent spatial memory test. Administration of asiatic acid also significantly increased doublecortin (DCX) and Notch1 protein levels in the hippocampus. These findings demonstrate that asiatic acid treatment may be a potent cognitive enhancer which improves hippocampal-dependent spatial memory, likely by increasing hippocampal neurogenesis.

  13. Transgenic manipulation of a single polyamine in poplar cells affects the accumulation of all amino acids.

    PubMed

    Mohapatra, Sridev; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash C

    2010-04-01

    The polyamine metabolic pathway is intricately connected to metabolism of several amino acids. While ornithine and arginine are direct precursors of putrescine, they themselves are synthesized from glutamate in multiple steps involving several enzymes. Additionally, glutamate is an amino group donor for several other amino acids and acts as a substrate for biosynthesis of proline and gamma-aminobutyric acid, metabolites that play important roles in plant development and stress response. Suspension cultures of poplar (Populus nigra x maximowiczii), transformed with a constitutively expressing mouse ornithine decarboxylase gene, were used to study the effect of up-regulation of putrescine biosynthesis (and concomitantly its enhanced catabolism) on cellular contents of various protein and non-protein amino acids. It was observed that up-regulation of putrescine metabolism affected the steady state concentrations of most amino acids in the cells. While there was a decrease in the cellular contents of glutamine, glutamate, ornithine, arginine, histidine, serine, glycine, cysteine, phenylalanine, tryptophan, aspartate, lysine, leucine and methionine, an increase was seen in the contents of alanine, threonine, valine, isoleucine and gamma-aminobutyric acid. An overall increase in percent cellular nitrogen and carbon content was also observed in high putrescine metabolizing cells compared to control cells. It is concluded that genetic manipulation of putrescine biosynthesis affecting ornithine consumption caused a major change in the entire ornithine biosynthetic pathway and had pleiotropic effects on other amino acids and total cellular carbon and nitrogen, as well. We suggest that ornithine plays a key role in regulating this pathway.

  14. Gambogic acid sensitizes ovarian cancer cells to doxorubicin through ROS-mediated apoptosis.

    PubMed

    Wang, Jianxia; Yuan, Zhixiang

    2013-09-01

    Ovarian cancer is one human malignancy which has response portly to doxorubicin. The anti-cancer activity of gambogic acid has been tested in in vitro and in vivo studies. In this study, we showed that gambogic acid, a natural compound, could potentiate the anticancer activity of doxorubicin in ovarian cancer through ROS-mediated apoptosis. Platinum-resistant human ovarian cancer cell line (SKOV-3) was treated with gambogic acid, doxorubicin, or the combination of both to investigate cell proliferation and apoptosis. We found that the combination of gambogic acid and doxorubicin causes synergistic loss of cell viability in SKOV-3 cells and this synergistic effect correlated with increased cellular ROS accumulation. Moreover, in vivo results showed that gambogic acid and doxorubicin combination resulted in a synergistic suppressing effect on tumor growth in ovarian cancer mice model. Taken together, the results suggested that doxorubicin in combination with gambogic acid might provide a promising therapeutic strategy to enhance chemosensitivity of ovarian cancer to doxorubicin.

  15. Effects of omega-3 fatty acids on regulatory T cells in hematologic neoplasms

    PubMed Central

    Betiati, Dayanne da Silva Borges; de Oliveira, Paula Fernanda; Camargo, Carolina de Quadros; Nunes, Everson Araújo; Trindade, Erasmo Benício Santos de Moraes

    2013-01-01

    The development of leukemia and lymphomas is related to the increase in inflammatory process modulators. These, in turn, have divergent actions on the neoplastic process. Populations of T cells have different roles in the neoplastic environment; while interferon-gamma positive T cells have antitumor activity, the FoxP3+interleukin-10 positive population present a pro-tumor activity. Simultaneously, the inflammatory process promotes the mobilization of fatty acids from the cell membrane to produce lipid mediators, which also participate of the inflammatory response. Eicosapentaenoic (EPA) and docosahexaenoic (DHA) omega-3 fatty acids, when incorporated in the plasmatic membrane, decrease the arachidonic acid (AA) metabolism and the production of eicosanoids derived from it. Thus, an alternative family of lipid mediators are produced that are often less inflammatory than those produced from arachidonic acid. Fatty acids can also influence the production of peptide mediators such as cytokines, and the expression of transcription factors, which can determine the production patterns of eicosanoids and cytokines as well as cell differentiation. Due to these properties, the objective of this literature review was to investigate studies published over the last 15 years on the effects of using omega-3 fatty acids on inflammatory markers in leukemia and lymphomas. PMID:23741190

  16. Identification of sialic acids on the cell surface of Candida albicans.

    PubMed

    Soares, R M; de A Soares, R M; Alviano, D S; Angluster, J; Alviano, C S; Travassos, L R

    2000-04-01

    The cell-surface expression of sialic acids in two isolates of Candida albicans was analyzed by thin-layer and gas chromatography, binding of lectins, colorimetry, sialidase treatment and flow cytofluorimetry with fluorescein-labeled lectins. N-acetylneuraminic acid (NANA) was the only derivative found in both strains of C. albicans grown in a chemically defined medium. Its identification was confirmed by mass spectrometry in comparison with an authentic standard. The density of sialic acid residues per cell ranged from 1. 6x10(6) to 2.8x10(6). The surface distribution of sialic acids over the entire C. albicans was inferred from labeling with fluorescein-Limulus polyphemus and Limax flavus agglutinins and directly observed by optical microscopy with (FITC)-Sambucus nigra agglutinin (SNA), abrogated by previous treatment of yeasts with bacterial sialidase. Sialidase-treated yeasts generated beta-galactopyranosyl terminal residues that reacted with peanut agglutinin. In C. albicans N-acetyl-neuraminic acids are alpha2,6- and alpha2,3-linked as indicated by yeast binding to SNA and Maackia amurensis agglutinin. The alpha2,6-linkage clearly predominated in both strains. We also investigated the contribution of sialic acids to the electronegativity of C. albicans, an important factor determining fungal interactions in vivo. Adhesion of yeast cells to a cationic solid phase substrate (poly-L-lysine) was mediated in part by sialic acids, since the number of adherent cells was significantly reduced after treatment with bacterial sialidase. The present evidence adds C. albicans to the list of pathogenic fungi that synthesize sialic acids, which contribute to the negative charge of fungal cells and have a role in their specific interaction with the host tissue.

  17. Effects of multivalent cations on cell wall-associated acid phosphatase activity

    SciTech Connect

    Tu, S.I.; Brouillette, J.N.; Nagahashi, G.; Kumosinski, T.F.

    1988-09-01

    Primary cell walls, free from cytoplasmic contamination were prepared from corn (Zea mays L.) roots and potato (Solanum tuberosum) tubers. After EDTA treatment, the bound acid phosphatase activities were measured in the presence of various multivalent cations. Under the conditions of minimized Donnan effect and at pH 4.2, the bound enzyme activity of potato tuber cell walls (PCW) was stimulated by Cu/sup 2 +/, Mg/sup 2 +/, Za/sup 2 +/, and Mn/sup 2 +/; unaffected by Ba/sup 2 +/, Cd/sup 2 +/, and Pb/sup 2 +/; and inhibited by Al/sup 3 +/. The bound acid phosphatase of PCW was stimulated by a low concentration but inhibited by a higher concentration of Hg/sup 2 +/. On the other hand, in the case of corn root cells walls (CCW), only inhibition of the bound acid phosphatase by Al/sup 3 +/ and Hg/sup 2 +/ was observed. Kinetic analyses revealed that PCW acid phosphatase exhibited a negative cooperativity under all employed experimental conditions except in the presence of Mg/sup 2 +/. In contrast, CCW acid phosphatase showed no cooperative behavior. The presence of Ca/sup 2 +/ significantly reduced the effects of Hg/sup 2 +/ or Al/sup 3 +/, but not Mg/sup 2 +/, to the bound cell wall acid phosphatases. The salt solubilized (free) acid phosphatases from both PCW and CCW were not affected by the presence of tested cations except for Hg/sup 2 +/ or Al/sup 3 +/ which caused a Ca/sup 2 +/-insensitive inhibition of the enzymes. The induced stimulation or inhibition of bound acid phosphatases was quantitatively related to cation binding in the cell wall structure.

  18. Effect of Chicoric Acid on Mast Cell-Mediated Allergic Inflammation in Vitro and in Vivo.

    PubMed

    Lee, Na Young; Chung, Kyung-Sook; Jin, Jong Sik; Bang, Keuk Soo; Eom, Ye-Jin; Hong, Chul-Hee; Nugroho, Agung; Park, Hee-Jun; An, Hyo-Jin

    2015-12-24

    Chicoric acid (dicaffeoyl-tartaric acid), is a natural phenolic compound found in a number of plants, such as chicory (Cichorium intybus) and Echinacea (Echinacea purpurea), which possesses antioxidant, anti-inflammatory, antiviral, and analgesic activities. Although these biological effects of chicoric acid have been investigated, there are no reports of its antiallergic-related anti-inflammatory effects in human mast cells (HMC)-1 or anaphylactic activity in a mouse model. Therefore, we investigated the antiallergic-related anti-inflammatory effect of chicoric acid and its underlying mechanisms of action using phorbol-12-myristate 13-acetate plus calcium ionophore A23187 (PMACI)-stimulated HMC-1 cells. Chicoric acid decreased the mRNA expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. We studied the inhibitory effects of chicoric acid on the nuclear translocation of nuclear factor kappa B (NF-κB) and activation of caspase-1. However, mitogen-activated protein kinase (MAPK) activation was not sufficient to abrogate the stimulus. In addition, we investigated the ability of chicoric acid to inhibit compound 48/80-induced systemic anaphylaxis in vivo. Oral administration of chicoric acid at 20 mg/kg inhibited histamine release and protected mice against compound 48/80-induced anaphylactic mortality. These results suggest that chicoric acid has an antiallergic-related anti-inflammatory effect that involves modulating mast cell-mediated allergic responses. Therefore, chicoric acid could be an efficacious agent for allergy-related inflammatory disorders. PMID:26593037

  19. Ghrelin stimulates gastric emptying but is without effect on acid secretion and gastric endocrine cells.

    PubMed

    Dornonville de la Cour, Charlotta; Lindström, Erik; Norlén, Per; Håkanson, Rolf

    2004-08-15

    Ghrelin, a recently discovered peptide hormone, is produced by endocrine cells in the stomach, the so-called A-like cells. Ghrelin binds to the growth hormone (GH) secretagogue receptor and releases GH. It is claimed to be orexigenic and to control gastric acid secretion and gastric motility. In this study, we examined the effects of ghrelin, des-Gln14-ghrelin, des-octanoyl ghrelin, ghrelin-18, -10 and -5 (and motilin) on gastric emptying in mice and on gastric acid secretion in chronic fistula rats and pylorus-ligated rats. We also examined whether ghrelin affected the activity of the predominant gastric endocrine cell populations, G cells, ECL cells and D cells. Ghrelin and des-Gln14-ghrelin stimulated gastric emptying in a dose-dependent manner while des-octanoyl ghrelin and motilin were without effect. The C-terminally truncated ghrelin fragments were effective but much less potent than ghrelin itself. Ghrelin, des-Gln14-ghrelin and des-octanoyl ghrelin neither stimulated nor inhibited gastric acid secretion, and ghrelin, finally, did not affect secretion from either G cells, ECL cells or D cells.

  20. Omega-3 Fatty Acids and Cancer Cell Cytotoxicity: Implications for Multi-Targeted Cancer Therapy

    PubMed Central

    D’Eliseo, Donatella; Velotti, Francesca

    2016-01-01

    Cancer is a major disease worldwide. Despite progress in cancer therapy, conventional cytotoxic therapies lead to unsatisfactory long-term survival, mainly related to development of drug resistance by tumor cells and toxicity towards normal cells. n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can exert anti-neoplastic activity by inducing apoptotic cell death in human cancer cells either alone or in combination with conventional therapies. Indeed, n-3 PUFAs potentially increase the sensitivity of tumor cells to conventional therapies, possibly improving their efficacy especially against cancers resistant to treatment. Moreover, in contrast to traditional therapies, n-3 PUFAs appear to cause selective cytotoxicity towards cancer cells with little or no toxicity on normal cells. This review focuses on studies investigating the cytotoxic activity of n-3 PUFAs against cancer cells via apoptosis, analyzing the molecular mechanisms underlying this effective and selective activity. Here, we highlight the multiple molecules potentially targeted by n-3 PUFAs to trigger cancer cell apoptosis. This analysis can allow a better comprehension of the potential cytotoxic therapeutic role of n-3 PUFAs against cancer, providing specific information and support to design future pre-clinical and clinical studies for a better use of n-3 PUFAs in cancer therapy, mainly combinational therapy. PMID:26821053

  1. Hypertonic stress regulates amino acid transport and cell cycle proteins in chick embryo hepatocytes.

    PubMed

    Bruscalupi, Giovannella; Massimi, Mara; Spagnuolo, Silvana; Fiore, Anna Maria; Leoni, Silvia

    2012-02-01

    Hyperosmotic stress affects cell growth, decreasing cell volume and increasing the uptake of organic osmolytes. However, the sensitivity of embryonic cells to osmotic treatment remains to be established. We have analysed some aspects of cell-cycle control and amino-acid transport in hypertonic conditions during prenatal life. The effects of hyperosmotic stress on amino-acid uptake mediated by system A, (3)H-thymidine incorporation, and regulation of cell-cycle proteins were analysed in chick embryo hepatocytes. Hypertonic stress increased system A activity and caused cell-cycle delay. Effects on amino-acid transport involved p38 kinase activation and new carrier synthesis. Cyclin D1, cdk4 (cyclin-dependent kinase 4) and PCNA (proliferating-cell nuclear antigen) levels decreased, whereas cyclin E, p21 and p53 levels were unchanged. Incorporation of (3)H-leucine indicated decreased synthesis of cyclin D1. In contrast, analysis of mRNA by qRT-PCR (quantitative real-time PCR) showed a net increase of cyclin D1 transcripts, suggesting post-transcriptional regulation. The data show that chick embryo hepatocytes respond to hyperosmotic conditions by arresting cell growth to prevent DNA damage and increasing osmolyte uptake to regulate cell volume, indicating that the adaptive response to environmental stress exists during prenatal life.

  2. Eicosapentaenoic acid inhibits voltage-gated sodium channels and invasiveness in prostate cancer cells

    PubMed Central

    Nakajima, T; Kubota, N; Tsutsumi, T; Oguri, A; Imuta, H; Jo, T; Oonuma, H; Soma, M; Meguro, K; Takano, H; Nagase, T; Nagata, T

    2009-01-01

    Background and purpose: The voltage-gated Na+ channels (Nav) and their corresponding current (INa) are involved in several cellular processes, crucial to metastasis of cancer cells. We investigated the effects of eicosapentaenoic (EPA), an omega-3 polyunsaturated fatty acid, on INa and metastatic functions (cell proliferation, endocytosis and invasion) in human and rat prostate cancer cell lines (PC-3 and Mat-LyLu cells). Experimental approach: The whole-cell voltage clamp technique and conventional/quantitative real-time reverse transcriptase polymerase chain reaction analysis were used. The presence of Nav proteins was shown by immunohistochemical methods. Alterations in the fatty acid composition of phospholipids after treatment with EPA and metastatic functions were also examined. Key results: A transient inward Na+ current (INa), highly sensitive to tetrodotoxin, and NaV proteins were found in these cells. Expression of NaV1.6 and NaV1.7 transcripts (SCN8A and SCN9A) was predominant in PC-3 cells, while NaV1.7 transcript (SCN9A) was the major component in Mat-LyLu cells. Tetrodotoxin or synthetic small interfering RNA targeted for SCN8A and SCN9A inhibited metastatic functions (endocytosis and invasion), but failed to inhibit proliferation in PC-3 cells. Exposure to EPA produced a rapid and concentration-dependent suppression of INa. In cells chronically treated (up to 72h) with EPA, the EPA content of cell lipids increased time-dependently, while arachidonic acid content decreased. Treatment of PC-3 cells with EPA decreased levels of mRNA for SCN9A and SCN8A, cell proliferation, invasion and endocytosis. Conclusion and implications: Treatment with EPA inhibited INa directly and also indirectly, by down-regulation of Nav mRNA expression in prostate cancer cells, thus inhibiting their metastatic potential. PMID:19154441

  3. Glycosylated carriers for cell-selective and nuclear delivery of nucleic acids.

    PubMed

    Wijagkanalan, Wassana; Kawakami, Shigeru; Hashida, Mitsuru

    2011-06-01

    Targeted gene delivery via selective cellular receptors has been realized as a crucial strategy for successful gene therapy by maximizing therapeutic efficiency in target cells and minimizing systemic toxicity. The membrane carbohydrate-binding proteins (membrane lectins) with different carbohydrate specificities are differentially expressed on the cellular and intracellular membranes of a number of cells. Their multiplicity, high affinity, and effective endocytosis after receptor binding as well as the biocompatibility of carbohydrate ligands endow them as potential ligands for glycosylated carriers in cell-selective delivery of nucleic acids. To achieve the in vivo application, glycosylated carriers/nucleic acid complexes have to fulfill certain conditions, including having a suitable size, minimal nonspecific interactions, low immunogenicity, and high uptake in target cells. Accordingly, the effective nuclear delivery of nucleic acids is the paramount important step for efficient gene transfer. This review summarizes the recent progress regarding application of glycosylated carriers for cell-selective and nuclear delivery of nucleic acids and their critical factors for efficient gene transfer. In addition, the development of new materials, such as carbon nanotubes, carbon nanospheres, and gold nanoparticles, as innovative carriers will be discussed with regards to glycosylation-mediated delivery of nucleic acids.

  4. Bile acids reduce endocytosis of high-density lipoprotein (HDL) in HepG2 cells.

    PubMed

    Röhrl, Clemens; Eigner, Karin; Fruhwürth, Stefanie; Stangl, Herbert

    2014-01-01

    High-density lipoprotein (HDL) transports lipids to hepatic cells and the majority of HDL-associated cholesterol is destined for biliary excretion. Cholesterol is excreted into the bile directly or after conversion to bile acids, which are also present in the plasma as they are effectively reabsorbed through the enterohepatic cycle. Here, we provide evidence that bile acids affect HDL endocytosis. Using fluorescent and radiolabeled HDL, we show that HDL endocytosis was reduced in the presence of high concentrations of taurocholate, a natural non-cell-permeable bile acid, in human hepatic HepG2 and HuH7 cells. In contrast, selective cholesteryl-ester (CE) uptake was increased. Taurocholate exerted these effects extracellularly and independently of HDL modification, cell membrane perturbation or blocking of endocytic trafficking. Instead, this reduction of endocytosis and increase in selective uptake was dependent on SR-BI. In addition, cell-permeable bile acids reduced HDL endocytosis by farnesoid X receptor (FXR) activation: chenodeoxycholate and the non-steroidal FXR agonist GW4064 reduced HDL endocytosis, whereas selective CE uptake was unaltered. Reduced HDL endocytosis by FXR activation was independent of SR-BI and was likely mediated by impaired expression of the scavenger receptor cluster of differentiation 36 (CD36). Taken together we have shown that bile acids reduce HDL endocytosis by transcriptional and non-transcriptional mechanisms. Further, we suggest that HDL endocytosis and selective lipid uptake are not necessarily tightly linked to each other.

  5. Bile acids reduce endocytosis of high-density lipoprotein (HDL) in HepG2 cells.

    PubMed

    Röhrl, Clemens; Eigner, Karin; Fruhwürth, Stefanie; Stangl, Herbert

    2014-01-01

    High-density lipoprotein (HDL) transports lipids to hepatic cells and the majority of HDL-associated cholesterol is destined for biliary excretion. Cholesterol is excreted into the bile directly or after conversion to bile acids, which are also present in the plasma as they are effectively reabsorbed through the enterohepatic cycle. Here, we provide evidence that bile acids affect HDL endocytosis. Using fluorescent and radiolabeled HDL, we show that HDL endocytosis was reduced in the presence of high concentrations of taurocholate, a natural non-cell-permeable bile acid, in human hepatic HepG2 and HuH7 cells. In contrast, selective cholesteryl-ester (CE) uptake was increased. Taurocholate exerted these effects extracellularly and independently of HDL modification, cell membrane perturbation or blocking of endocytic trafficking. Instead, this reduction of endocytosis and increase in selective uptake was dependent on SR-BI. In addition, cell-permeable bile acids reduced HDL endocytosis by farnesoid X receptor (FXR) activation: chenodeoxycholate and the non-steroidal FXR agonist GW4064 reduced HDL endocytosis, whereas selective CE uptake was unaltered. Reduced HDL endocytosis by FXR activation was independent of SR-BI and was likely mediated by impaired expression of the scavenger receptor cluster of differentiation 36 (CD36). Taken together we have shown that bile acids reduce HDL endocytosis by transcriptional and non-transcriptional mechanisms. Further, we suggest that HDL endocytosis and selective lipid uptake are not necessarily tightly linked to each other. PMID:25010412

  6. Relationship between cadmium, zinc, Cd-peptide, and organic acid in tobacco suspension cells

    SciTech Connect

    Krotz, R.M.; Evangelou, B.P.; Wagner, G.J. )

    1989-10-01

    Responses of tobacco (Nicotiana tabacum) suspension cells to Cd and Zn were studied in the presence and absence of ligand of Cd-peptide in order to understand the role of this peptide versus other mechanisms in Cd and Zn accumulation and accommodation in plants. With 45 micromolar Cd and 300 micromolar Zn (non-growth-inhibiting levels), metals appeared rapidly within cells, and intracellular Cd and Zn reached medium concentrations after 6 to 10 hours. Cd-peptide was observed in response to Cd after 2 hours, but this form only accounted for {approximately}30% of soluble Cd after 24 hours. Peptide was not observed in cells exposed to 300 micromolar Zn for up to 7 days. Organic acid-to-metal stoichiometry indicated that endogenous organic acid content of cells was more than sufficient to complex absorbed metals and no evidence was found for stimulation of organic acid biosynthesis by Cd or Zn. Metal-complexing potential of organic acids for Cd and Zn versus endogenous cations is discussed as is vacuolar-extravacuolar distribution of metals. The absence of Cd-peptide does not limit Cd-accumulation in the system studied. Results suggest that tobacco suspension cells accommodte the presence of non-growth-inhibiting and growth-inhibiting levels of Cd and Zn by sequestration in the vacuole as complexes with endogenous organic acids and that this may be a principal means for accommodation of Cd as well as Zn in the presence and absence of Cd-peptide.

  7. Development of an in vitro model of essential fatty acid deficiency in fish cells.

    PubMed

    Tocher, D R; Dick, J R; Sargent, J R

    1995-11-01

    Levels of eicosapentaenoic acid (EPA; 20:5, n-3) greatly exceed those of arachidonic acid (AA; 20:4, n-6) in the tissue phospholipids of most fish species. Despite this, it is 20:4, n-6-derived eicosanoids that are produced predominantly in fish cells. The development of an essential fatty acid (EFA)-deficient fish cell line would greatly assist the study of this selectivity and so several fish cell lines were cultured in EFA-deficient (EFAD) media. All n-3 and n-6 polyunsaturated fatty acids (PUFA) and total PUFA were considerably reduced in all lines, except turbot fin (TF) in which total n-9 PUFA doubled from 13.8% to 27.5% of total fatty acids. In the topminnow hepatocarcinoma cell line (PLHC-1), there was almost complete depletion of both n-3 and n-6 PUFA and in TF cells, no n-3 PUFA were detected. In the carp epithelial papilloma cell line (EPC), both n-6 and n-3 PUFA were reduced by approximately 70%. The reduced PUFA in cells cultured in EFAD media was compensated to a large extent in most cell lines by significantly increased percentages of monounsaturated fatty acids, particularly 18:1, n-9. Total n-9 PUFA were significantly increased in all cell lines by culture in EFAD media, with 20:2, n-9 significantly increased in all cell lines. There were relatively small increases, but often significant, in 20:3, n-9 in all cell lines. Of the cell lines investigated, only EPC and PLHC-1 showed proliferation after four passages in EFAD medium, although the growth rates were reduced in comparison with media supplemented with serum, but EPC was the only cell line able to survive and proliferate in long-term culture on EFAD medium. The EFAD-EPC line is a potentially useful model system for the study of the effects of EFA deficiency on cell structure and function and eicosanoid metabolism in fish. PMID:8596777

  8. Progress and prospects for phosphoric acid fuel cell power plants

    SciTech Connect

    Bonville, L.J.; Scheffler, G.W.; Smith, M.J.

    1996-12-31

    International Fuel Cells (IFC) has developed the fuel cell power plant as a new, on-site power generation source. IFC`s commercial fuel cell product is the 200-kW PC25{trademark} power plant. To date over 100 PC25 units have been manufactured. Fleet operating time is in excess of one million hours. Individual units of the initial power plant model, the PC25 A, have operated for more than 30,000 hours. The first model {open_quotes}C{close_quotes} power plant has over 10,000 hours of operation. The manufacturing, application and operation of this power plant fleet has established a firm base for design and technology development in terms of a clear understanding of the requirements for power plant reliability and durability. This fleet provides the benchmark against which power plant improvements must be measured.

  9. Advanced water-cooled phosphoric acid fuel cell development

    SciTech Connect

    Not Available

    1989-01-01

    Fabrication of repeat parts for small area short stack is underway: 100 electrode substrates and 150 ERP substrates were graphitized, and 30 electrode substrates were run through each manufacturing step. Teflon content and compaction pressure of shop-made electrodes for the small area short stack was optimized based on single cell tests. A single cell with GSB-18P catalyst and 1 mg/cm[sup 2] loading is performing very well; performance is 0.66 V per cell after 1200 h at 300 ASF. 3 integral separator plate configurations have been selected for verification in the upcoming short stack. Bubble pressures over 7 psid have been demonstrated in filler bands applied with a production curtain and coating process. 5 full-size (small area) coolers were molded, and encapsulation development for molded and commercial graphite coolers continued.

  10. Subcellular SIMS imaging of isotopically labeled amino acids in cryogenically prepared cells

    NASA Astrophysics Data System (ADS)

    Chandra, Subhash

    2004-06-01

    Ion microscopy is a potentially powerful technique for localization of isotopically labeled molecules. In this study, L-arginine and phenylalanine amino acids labeled with stable isotopes 13C and 15N were localized in cultured cells with the ion microscope at 500 nm spatial resolution. Cells were exposed to the labeled amino acids and cryogenically prepared. SIMS analyses were made in fractured freeze-dried cells. A dynamic distribution was observed from labeled arginine-treated LLC-PK 1 kidney cells at mass 28 ( 13C15N) in negative secondaries, revealing cell-to-cell heterogeneity and preferential accumulation of the amino acid (or its metabolite) in the nucleus and nucleolus of some cells. The smaller nucleolus inside the nucleus was clearly resolved in SIMS images and confirmed by correlative light microscopy. The distribution of labeled phenylalanine contrasted with arginine as it was rather homogeneously distributed in T98G human glioblastoma cells. Images of 39K, 23Na and 40Ca were also recorded to confirm the reliability of sample preparation and authenticity of the observed amino acid distributions. These observations indicate that SIMS techniques can provide a valuable technology for subcellular localization of nitrogen-containing molecules in proteomics since nitrogen does not have a radionuclide tracer isotope. Amino acids labeled with stable isotopes can be used as tracers for studying their transport and metabolism in distinct subcellular compartments with SIMS. Further studies of phenylalanine uptake in human glioblastoma cells may have special significance in boron neutron capture therapy (BNCT) as a boron analogue of phenylalanine, boronophenylalanine is a clinically approved compound for the treatment of brain tumors.

  11. In Vitro Cytotoxic Effects of Celecoxib, Mefenamic Acid, Aspirin and Indometacin on Several Cells Lines

    PubMed Central

    Hashemipour, Maryam Alsadat; Mehrabizadeh Honarmand, Hoda; Falsafi, Farideh; Tahmasebi Arashlo, Mehrnaz; Rajabalian, Saied; Gandjalikhan Nassab, Sayed Amir Hossein

    2016-01-01

    Statement of the Problem Use of cyclooxygenase inhibitors as chemotherapy agents has attracted the attention of a large number of investigators in recent years. Given the importance of cancer therapy, only a limited number of studies have been carried out to investigate the effects of cyclooxygenase inhibitors on specific cell lines. Purpose This research aimed to determine the in vitro cytotoxic effects of cyclooxygenase inhibitors (COX-1 and COX-2 inhibitors) on KB, Saos-2, 1321N, U-87MG, SFBF-PI 39 cell lines. Materials and Method Powders of celecoxib, mefenamic acid, aspirin and indometacin were dissolved in the appropriate solvent. The viability of cell lines was carried out by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay technique. Data gathered from four separate experiments were expressed as mean±SD. Statistical significance was defined at p< 0.05 by using analysis of variance. Significant treatment mean values were subjected to post-hoc Tukey’s test. Results Celecoxib showed marked cytotoxic effects on KB, Saos-2, and 1321N cells, which was significant in comparison with the control group. Celecoxib was not effective in killing U-87MG cell line. Mefenamic acid exerted cytotoxic effects on KB, Saos-2, and 1321N cells, where the viability was approximately 75%. U-87MG cells were resistant to mefenamic acid. Indometacin had the highest rate of activity on U-87MG cells, which was significant in comparison with the control group. Aspirin did not exhibit any activity on these cell lines and was not effective in killing U-87MG, KB, Saos-2, and 1321N cells. Conclusion This research showed that celecoxib, indometacin, and mefenamic acid have the cytotoxic effects on KB, Saos-2, 1321N and U-87MG cell lines. Therefore, it appears that these drugs can be considered as anti-neoplastic agents in the experimental phase. PMID:27602398

  12. In Vitro Cytotoxic Effects of Celecoxib, Mefenamic Acid, Aspirin and Indometacin on Several Cells Lines

    PubMed Central

    Hashemipour, Maryam Alsadat; Mehrabizadeh Honarmand, Hoda; Falsafi, Farideh; Tahmasebi Arashlo, Mehrnaz; Rajabalian, Saied; Gandjalikhan Nassab, Sayed Amir Hossein

    2016-01-01

    Statement of the Problem Use of cyclooxygenase inhibitors as chemotherapy agents has attracted the attention of a large number of investigators in recent years. Given the importance of cancer therapy, only a limited number of studies have been carried out to investigate the effects of cyclooxygenase inhibitors on specific cell lines. Purpose This research aimed to determine the in vitro cytotoxic effects of cyclooxygenase inhibitors (COX-1 and COX-2 inhibitors) on KB, Saos-2, 1321N, U-87MG, SFBF-PI 39 cell lines. Materials and Method Powders of celecoxib, mefenamic acid, aspirin and indometacin were dissolved in the appropriate solvent. The viability of cell lines was carried out by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay technique. Data gathered from four separate experiments were expressed as mean±SD. Statistical significance was defined at p< 0.05 by using analysis of variance. Significant treatment mean values were subjected to post-hoc Tukey’s test. Results Celecoxib showed marked cytotoxic effects on KB, Saos-2, and 1321N cells, which was significant in comparison with the control group. Celecoxib was not effective in killing U-87MG cell line. Mefenamic acid exerted cytotoxic effects on KB, Saos-2, and 1321N cells, where the viability was approximately 75%. U-87MG cells were resistant to mefenamic acid. Indometacin had the highest rate of activity on U-87MG cells, which was significant in comparison with the control group. Aspirin did not exhibit any activity on these cell lines and was not effective in killing U-87MG, KB, Saos-2, and 1321N cells. Conclusion This research showed that celecoxib, indometacin, and mefenamic acid have the cytotoxic effects on KB, Saos-2, 1321N and U-87MG cell lines. Therefore, it appears that these drugs can be considered as anti-neoplastic agents in the experimental phase.

  13. Mammalian target of rapamycin signalling modulates amino acid uptake by regulating transporter cell surface abundance in primary human trophoblast cells.

    PubMed

    Rosario, Fredrick J; Kanai, Yoshikatsu; Powell, Theresa L; Jansson, Thomas

    2013-02-01

    Abnormal fetal growth increases the risk for perinatal complications and predisposes for the development of obesity, diabetes and cardiovascular disease later in life. Emerging evidence suggests that changes in placental amino acid transport directly contribute to altered fetal growth. However, the molecular mechanisms regulating placental amino acid transport are largely unknown. Here we combined small interfering (si) RNA-mediated silencing approaches with protein expression/localization and functional studies in cultured primary human trophoblast cells to test the hypothesis that mammalian target of rapamycin complex 1 (mTORC1) and 2 (mTORC2) regulate amino acid transporters by post-translational mechanisms. Silencing raptor (inhibits mTORC1) or rictor (inhibits mTORC2) markedly decreased basal System A and System L amino acid transport activity but had no effect on growth factor-stimulated amino acid uptake. Simultaneous inhibition of mTORC1 and 2 completely inhibited both basal and growth factor-stimulated amino acid transport activity. In contrast, mTOR inhibition had no effect on serotonin transport. mTORC1 or mTORC2 silencing markedly decreased the plasma membrane expression of specific System A (SNAT2, SLC38A2) and System L (LAT1, SLC7A5) transporter isoforms without affecting global protein expression. In conclusion, mTORC1 and mTORC2 regulate human trophoblast amino acid transporters by modulating the cell surface abundance of specific transporter isoforms. This is the first report showing regulation of amino acid transport by mTORC2. Because placental mTOR activity and amino acid transport are decreased in human intrauterine growth restriction our data are consistent with the possibility that dysregulation of placental mTOR plays an important role in the development of abnormal fetal growth.

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

    SciTech Connect

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

    2014-04-04

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

  15. Zoledronic acid enhances Vδ2 T-lymphocyte antitumor response to human glioma cell lines.

    PubMed

    Cimini, E; Piacentini, P; Sacchi, A; Gioia, C; Leone, S; Lauro, G M; Martini, F; Agrati, C

    2011-01-01

    Glioblastoma multiforme (GBM), the most frequent and aggressive primary brain tumor in humans, responds modestly to treatment: most patients survive less than one year after diagnosis, despite both classical and innovative treatment approaches. A recent paper focused on γδ T-cell response in GBM patients, suggesting the application of an immunomodulating strategy based on γδ T-cells which is already in clinical trials for other tumors. Human Vγ2 T-cells recognize changes in the mevalonate metabolic pathway of transformed cells by activating cytotoxic response, and by cytokine and chemokine release. Interestingly, this activation may also be induced in vivo by drugs, such as zoledronic acid, that induce the accumulation of Vγ2 T-cell ligand Isopentenyl-pyrophosphate by blocking the farnesyl pyrophosphate synthase enzyme. The aim of our work is to confirm whether bisphosphonate treatment would make glioma cell lines more susceptible to lysis by in vitro expanded γδ T-cells, improving their antitumor activity. We expanded in vitro human Vγ2 T-cells by phosphoantigen stimulation and tested their activity against glioma cell lines. Co-culture with glioma cells induced Vγ2 T-cell differentiation in effector/memory cells, killing glioma cells by the release of perforin. Interestingly, glioma cells were directly affected by zoledronic acid; moreover, treatment increased their activating ability on Vγ2 T-cells, inducing an effective antitumor cytotoxic response. Taken together, our results show that aminobisphosphonate drugs may play a dual role against GBM, by directly affecting tumor cells, and by enhancing the antitumor response of Vγ2 T-cells. Our results confirm the practicability of this approach as a new immunotherapeutic strategy for GBM treatment.

  16. Comparison of fatty acid composition of cell homogenates and isolated chloroplasts in Acetabularia crenulata (Lamouroux).

    PubMed

    Santiago-Vázquez, Lory Z; Jacobs, Robert S

    2005-01-01

    Algal preparations from Acetabularia crenulata were analyzed for their fatty acid composition to establish the suitability of this alga as a model to study fatty acid oxidation and oxylipin biosynthesis. The work was based on two goals. The first goal of this study was to determine the contribution of fatty acids from contaminating bacteria and how this influenced the total fatty acid composition of cell homogenates of A. crenulata collected in the wild as compared to specimens cultured in sterile conditions. The major fatty acids detected for both specimens were palmitic (C16:0), palmitoleic (C16:1n-7), oleic (C18:1n-9), linoleic (C18:2n-6), linolenic (C18:3n-3), and octadecatetraenoic acid (C18:4n-3). Significant amounts of odd-chain fatty acids common to bacteria were not detected in either sample. Furthermore, branched-chain fatty acids, typical bacterial biomarkers, were not detected in either sample. Data suggest that bacteria do not greatly contribute to the total fatty acid pool of A. crenulata. The second goal was to compare the fatty acid composition of cell homogenates with that of isolated chloroplasts. Comparatively speaking palmitoleic and octadecatetraenoic acid were found at significantly lower concentrations in the chloroplast whereas oleic and linolenic acid were found at significantly higher amounts in this organelle. Furthermore, the amount of hexadecatrienoic acid (C16:3), a fatty acid commonly esterified to monogalactosyldiacylglycerol (MGDG; lipid present at high concentrations inside the chloroplasts of algae), was present at very low concentrations in these plastids (0.7%). Typically green algal follow the "prokaryotic pathway" for MGDG biosynthesis where C18:3 is esterified at the sn-1 position of the glycerol backbone and C18:3 or C16:3 at the sn-2 position, making C16:3 a major fatty acid inside chloroplasts. Interestingly, our results suggest that chloroplasts of A. crenulata appear to follow the "eukaryotic pathway" for MGDG

  17. Advanced Water-Cooled Phosphoric Acid Fuel Cell Development

    SciTech Connect

    Not Available

    1988-01-01

    The initial conceptual design configuration was completed. Baseline on-site electrodes were tested at electric utility conditions in 2 x 2 inch cells. GSB-18P cathodes were fabricated. Design of small area development stack was initiated and long lead time items ordered. Molded cooler thermal cycling tests were initiated. Equipment to evaluate alternative manifold coating processes and materials were procured.

  18. Binding of polyphenols to plant cell wall analogues - Part 2: Phenolic acids.

    PubMed

    Padayachee, A; Netzel, G; Netzel, M; Day, L; Zabaras, D; Mikkelsen, D; Gidley, M J

    2012-12-15

    Bacterial cellulose and cellulose-pectin composites were used as well-defined model plant cell wall (PCW) systems to study the interaction between phenolic acids (PA) derived from purple carrot juice concentrate (PCJC) and PCW components. Significant PA depletion from solution occurred, with pure cellulose initially (30s-1h) absorbing more than cellulose-pectin composites in the first hour (ca 20% cf 10-15%), but with all composites absorbing similar levels (ca 30%) after several days. Individual PAs bound to different relative extents with caffeic acid>chlorogenic acid>ferulic acid. Extrapolation of data for these model systems to carrot puree suggests that nutritionally-significant amounts of PAs could bind to cell walls, potentially restricting bioavailability in the small intestine and, as a consequence, delivering PAs to the large intestine for fermentation and metabolism by gut bacteria.

  19. Selective local lysis and sampling of live cells for nucleic acid analysis using a microfluidic probe

    PubMed Central

    Kashyap, Aditya; Autebert, Julien; Delamarche, Emmanuel; Kaigala, Govind V.

    2016-01-01

    Heterogeneity is inherent to biology, thus it is imperative to realize methods capable of obtaining spatially-resolved genomic and transcriptomic profiles of heterogeneous biological samples. Here, we present a new method for local lysis of live adherent cells for nucleic acid analyses. This method addresses bottlenecks in current approaches, such as dilution of analytes, one-sample-one-test, and incompatibility to adherent cells. We make use of a scanning probe technology - a microfluidic probe - and implement hierarchical hydrodynamic flow confinement (hHFC) to localize multiple biochemicals on a biological substrate in a non-contact, non-destructive manner. hHFC enables rapid recovery of nucleic acids by coupling cell lysis and lysate collection. We locally lysed ~300 cells with chemical systems adapted for DNA or RNA and obtained lysates of ~70 cells/μL for DNA analysis and ~15 cells/μL for mRNA analysis. The lysates were introduced into PCR-based workflows for genomic and transcriptomic analysis. This strategy further enabled selective local lysis of subpopulations in a co-culture of MCF7 and MDA-MB-231 cells, validated by characteristic E-cadherin gene expression in individually extracted cell types. The developed strategy can be applied to study cell-cell, cell-matrix interactions locally, with implications in understanding growth, progression and drug response of a tumor. PMID:27411740

  20. Periplasmic Acid Stress Increases Cell Division Asymmetry (Polar Aging) of Escherichia coli.

    PubMed

    Clark, Michelle W; Yie, Anna M; Eder, Elizabeth K; Dennis, Richard G; Basting, Preston J; Martinez, Keith A; Jones, Brian D; Slonczewski, Joan L

    2015-01-01

    Under certain kinds of cytoplasmic stress, Escherichia coli selectively reproduce by distributing the newer cytoplasmic components to new-pole cells while sequestering older, damaged components in cells inheriting the old pole. This phenomenon is termed polar aging or cell division asymmetry. It is unknown whether cell division asymmetry can arise from a periplasmic stress, such as the stress of extracellular acid, which is mediated by the periplasm. We tested the effect of periplasmic acid stress on growth and division of adherent single cells. We tracked individual cell lineages over five or more generations, using fluorescence microscopy with ratiometric pHluorin to measure cytoplasmic pH. Adherent colonies were perfused continually with LBK medium buffered at pH 6.00 or at pH 7.50; the external pH determines periplasmic pH. In each experiment, cell lineages were mapped to correlate division time, pole age and cell generation number. In colonies perfused at pH 6.0, the cells inheriting the oldest pole divided significantly more slowly than the cells inheriting the newest pole. In colonies perfused at pH 7.50 (near or above cytoplasmic pH), no significant cell division asymmetry was observed. Under both conditions (periplasmic pH 6.0 or pH 7.5) the cells maintained cytoplasmic pH values at 7.2-7.3. No evidence of cytoplasmic protein aggregation was seen. Thus, periplasmic acid stress leads to cell division asymmetry with minimal cytoplasmic stress.

  1. Periplasmic Acid Stress Increases Cell Division Asymmetry (Polar Aging) of Escherichia coli

    PubMed Central

    Clark, Michelle W.; Yie, Anna M.; Eder, Elizabeth K.; Dennis, Richard G.; Basting, Preston J.; Martinez, Keith A.; Jones, Brian D.; Slonczewski, Joan L.

    2015-01-01

    Under certain kinds of cytoplasmic stress, Escherichia coli selectively reproduce by distributing the newer cytoplasmic components to new-pole cells while sequestering older, damaged components in cells inheriting the old pole. This phenomenon is termed polar aging or cell division asymmetry. It is unknown whether cell division asymmetry can arise from a periplasmic stress, such as the stress of extracellular acid, which is mediated by the periplasm. We tested the effect of periplasmic acid stress on growth and division of adherent single cells. We tracked individual cell lineages over five or more generations, using fluorescence microscopy with ratiometric pHluorin to measure cytoplasmic pH. Adherent colonies were perfused continually with LBK medium buffered at pH 6.00 or at pH 7.50; the external pH determines periplasmic pH. In each experiment, cell lineages were mapped to correlate division time, pole age and cell generation number. In colonies perfused at pH 6.0, the cells inheriting the oldest pole divided significantly more slowly than the cells inheriting the newest pole. In colonies perfused at pH 7.50 (near or above cytoplasmic pH), no significant cell division asymmetry was observed. Under both conditions (periplasmic pH 6.0 or pH 7.5) the cells maintained cytoplasmic pH values at 7.2–7.3. No evidence of cytoplasmic protein aggregation was seen. Thus, periplasmic acid stress leads to cell division asymmetry with minimal cytoplasmic stress. PMID:26713733

  2. Role of p53 in the cellular response following oleic acid accumulation in Chang liver cells.

    PubMed

    Park, Eun-Jung; Lee, Ah Young; Chang, Seung-Hee; Yu, Kyeong-Nam; Kim, Jae-Ho; Cho, Myung-Haing

    2014-01-01

    Abnormal accumulation of fatty acids triggers the harmful cellular response called lipotoxicity. In this study, we investigated the cellular response following accumulation of oleic acid (OA), a monounsaturated fatty acid, in human Chang liver cells. OA droplets were distributed freely in the cytoplasm and/or degraded within lysosomes. OA exposure increased ATP production and concomitantly dilated mitochondria. At 24h after OA exposure, cell viability decreased slightly and was coupled with a reduction in mitochondrial Ca(2+) concentration, the alteration in cell viability was also associated with the generation of reactive oxygen species and changes in the cell cycle. Moreover, OA treatment increased the expression of autophagy- and apoptotic cell death-related proteins in a dose-dependent manner. Furthermore, we investigated the role of p53, a tumor suppressor protein, in the cellular response elicited by OA accumulation. OA-induced changes in cell viability and ATP production were rescued to control levels when cells were pretreated with pifithrin-alpha (PTA), a p53 inhibitor. By contrast, the expressions of LC3-II and perilipin, proteins required for lipophagy, were down-regulated by PTA pretreatment. Taken together, our results suggest that p53 plays a key role in the cellular response elicited by OA accumulation in Chang liver cells.

  3. A nanocarrier system for the delivery of nucleic acids targeted to a pancreatic beta cell line.

    PubMed

    Yamada, Yuma; Tabata, Mai; Yasuzaki, Yukari; Nomura, Masatoshi; Shibata, Atsushi; Ibayashi, Yuta; Taniguchi, Yosuke; Sasaki, Shigeki; Harashima, Hideyoshi

    2014-08-01

    Pancreatic β cells secrete insulin in response to glucose levels and thus are involved in controlling blood glucose levels. A line of pancreatic β cells "MIN6" has been used in studies related to the function of β cells and diabetes therapy. Regulating gene expression in MIN6 cells could accelerate these studies, but an efficient method for the transfection of nucleic acids targeted to MIN6 cells is required. We report here on a liposome-based carrier targeted to pancreatic β cells (Multifunctional envelope-type nano device for pancreatic β cells, β-MEND). We identified a lipid composition for use in preparing the β-MEND, which permits the particles to be efficiently internalized into MIN6, as evidenced by flow cytometry analyses. Intracellular observation by confocal laser scanning microscopy showed that the β-MEND efficiently delivered the oligo nucleic acids to the cytosol of MIN6 cells. Moreover, using a β-MEND encapsulating a 2'-O-Methyl RNA complementary to a microRNA that suppresses insulin secretion, the knockdown of the targeted microRNA and an up-regulation of insulin secretion were observed in MIN6. Thus, the β-MEND holds promise as an efficient system for delivering nucleic acids targeted to MIN6 and can contribute to research and therapy aimed at diabetes.

  4. The Influence of 13-cis Retinoic Acid on Human Meibomian Gland Epithelial Cells

    PubMed Central

    Ding, Juan; Kam, Wendy R.; Dieckow, Julia; Sullivan, David A.

    2013-01-01

    Purpose. Meibomian gland dysfunction (MGD) is a primary cause of dry eye disease. One of the risk factors for MGD is exposure to 13-cis retinoic acid (13-cis RA), a metabolite of vitamin A. However, the mechanism is not well understood. We hypothesize that 13-cis RA inhibits cell proliferation, promotes cell death, alters gene and protein expressions, and attenuates cell survival pathways in human meibomian gland epithelial cells. Methods. To test our hypotheses, immortalized human meibomian gland epithelial cells were cultured with or without 13-cis RA for varying doses and time. Cell proliferation, cell death, gene expression, and proteins involved in proliferation/survival and inflammation were evaluated. Results. We found that 13-cis RA inhibited cell proliferation, induced cell death, and significantly altered the expression of 6726 genes, including those involved in cell proliferation, cell death, differentiation, keratinization, and inflammation, in human meibomian gland epithelial cells. Further, 13-cis RA also reduced the phosphorylation of Akt and increased the generation of interleukin-1β and matrix metallopeptidase 9. Conclusions. Exposure to 13-cis RA inhibits cell proliferation, increases cell death, alters gene expression, changes signaling pathways, and promotes inflammatory mediator and protease expression in meibomian gland epithelial cells. These effects may be responsible, at least in part, for the 13-cis RA–related induction of MGD. PMID:23722388

  5. Biotechnological production of caffeic acid derivatives from cell and organ cultures of Echinacea species.

    PubMed

    Murthy, Hosakatte Niranjana; Kim, Yun-Soo; Park, So-Young; Paek, Kee-Yoeup

    2014-09-01

    Caffeic acid derivatives (CADs) are a group of bioactive compounds which are produced in Echinacea species especially Echinacea purpurea, Echinacea angustifolia, and Echinacea pallida. Echinacea is a popular herbal medicine used in the treatment of common cold and it is also a prominent dietary supplement used throughout the world. Caffeic acid, chlorogenic acid (5-O-caffeoylquinic acid), caftaric acid (2-O-caffeoyltartaric acid), cichoric acid (2, 3-O-dicaffeoyltartaric acid), cynarin, and echinacoside are some of the important CADs which have varied pharmacological activities. The concentrations of these bioactive compounds are species specific and also they vary considerably with the cultivated Echinacea species due to geographical location, stage of development, time of harvest, and growth conditions. Due to these reasons, plant cell and organ cultures have become attractive alternative for the production of biomass and caffeic acid derivatives. Adventitious and hairy roots have been induced in E. pupurea and E. angustifolia, and suspension cultures have been established from flask to bioreactor scale for the production of biomass and CADs. Tremendous progress has been made in this area; various bioprocess methods and strategies have been developed for constant high-quality productivity of biomass and secondary products. This review is aimed to discuss biotechnological methods and approaches employed for the sustainable production of CADs.

  6. Nature and nurture in atherosclerosis: The roles of acylcarnitine and cell membrane-fatty acid intermediates.

    PubMed

    Blair, Harry C; Sepulveda, Jorge; Papachristou, Dionysios J

    2016-03-01

    Macrophages recycle components of dead cells, including cell membranes. When quantities of lipids from cell membranes of dead cells exceed processing capacity, phospholipid and cholesterol debris accumulate as atheromas. Plasma lipid profiles, particularly HDL and LDL cholesterol, are important tools to monitor atherosclerosis risk. Membrane lipids are exported, as triglycerides or phospholipids, or as cholesterol or cholesterol esters, via lipoproteins for disposal, for re-use in cell membranes, or for fat storage. Alternative assays evaluate other aspects of lipid pathology. A key process underlying atherosclerosis is backup of macrophage fatty acid catabolism. This can be quantified by accumulation of acylcarnitine intermediates in extracellular fluid, a direct assay of adequacy of β-oxidation to deal with membrane fatty acid recycling. Further, membranes of somatic cells, such as red blood cells (RBC), incorporate fatty acids that reflect dietary intake. Changes in RBC lipid composition occur within days of ingesting modified fats. Since diets with high saturated fat content or artificial trans-fatty acids promote atherosclerosis, RBC lipid content shifts occur with atherosclerosis, and can show cellular adaptation to pathologically stiff membranes by increased long-chain doubly unsaturated fatty acid production. Additional metabolic changes with atherosclerosis of potential utility include inflammatory cytokine production, modified macrophage signaling pathways, and altered lipid-handling enzymes. Even after atherosclerotic lesions appear, approaches to minimize macrophage overload by reducing rate of fat metabolism are promising. These include preventive measures, and drugs including statins and the newer PCSK9 inhibitors. New cell-based biochemical and cytokine assays provide data to prevent or monitor atherosclerosis progression. PMID:26133667

  7. Nature and nurture in atherosclerosis: The roles of acylcarnitine and cell membrane-fatty acid intermediates.

    PubMed

    Blair, Harry C; Sepulveda, Jorge; Papachristou, Dionysios J

    2016-03-01

    Macrophages recycle components of dead cells, including cell membranes. When quantities of lipids from cell membranes of dead cells exceed processing capacity, phospholipid and cholesterol debris accumulate as atheromas. Plasma lipid profiles, particularly HDL and LDL cholesterol, are important tools to monitor atherosclerosis risk. Membrane lipids are exported, as triglycerides or phospholipids, or as cholesterol or cholesterol esters, via lipoproteins for disposal, for re-use in cell membranes, or for fat storage. Alternative assays evaluate other aspects of lipid pathology. A key process underlying atherosclerosis is backup of macrophage fatty acid catabolism. This can be quantified by accumulation of acylcarnitine intermediates in extracellular fluid, a direct assay of adequacy of β-oxidation to deal with membrane fatty acid recycling. Further, membranes of somatic cells, such as red blood cells (RBC), incorporate fatty acids that reflect dietary intake. Changes in RBC lipid composition occur within days of ingesting modified fats. Since diets with high saturated fat content or artificial trans-fatty acids promote atherosclerosis, RBC lipid content shifts occur with atherosclerosis, and can show cellular adaptation to pathologically stiff membranes by increased long-chain doubly unsaturated fatty acid production. Additional metabolic changes with atherosclerosis of potential utility include inflammatory cytokine production, modified macrophage signaling pathways, and altered lipid-handling enzymes. Even after atherosclerotic lesions appear, approaches to minimize macrophage overload by reducing rate of fat metabolism are promising. These include preventive measures, and drugs including statins and the newer PCSK9 inhibitors. New cell-based biochemical and cytokine assays provide data to prevent or monitor atherosclerosis progression.

  8. Ca2+/H+ exchange by acidic organelles regulates cell migration in vivo

    PubMed Central

    Melchionda, Manuela; Pittman, Jon K.

    2016-01-01

    Increasing evidence implicates Ca2+ in the control of cell migration. However, the underlying mechanisms are incompletely understood. Acidic Ca2+ stores are fast emerging as signaling centers. But how Ca2+ is taken up by these organelles in metazoans and the physiological relevance for migration is unclear. Here, we identify a vertebrate Ca2+/H+ exchanger (CAX) as part of a widespread family of homologues in animals. CAX is expressed in neural crest cells and required for their migration in vivo. It localizes to acidic organelles, tempers evoked Ca2+ signals, and regulates cell-matrix adhesion during migration. Our data provide new molecular insight into how Ca2+ is handled by acidic organelles and link this to migration, thereby underscoring the role of noncanonical Ca2+ stores in the control of Ca2+-dependent function. PMID:27002171

  9. Ca2+/H+ exchange by acidic organelles regulates cell migration in vivo.

    PubMed

    Melchionda, Manuela; Pittman, Jon K; Mayor, Roberto; Patel, Sandip

    2016-03-28

    Increasing evidence implicates Ca(2+) in the control of cell migration. However, the underlying mechanisms are incompletely understood. Acidic Ca(2+) stores are fast emerging as signaling centers. But how Ca(2+) is taken up by these organelles in metazoans and the physiological relevance for migration is unclear. Here, we identify a vertebrate Ca(2+)/H(+)exchanger (CAX) as part of a widespread family of homologues in animals. CAX is expressed in neural crest cells and required for their migration in vivo. It localizes to acidic organelles, tempers evoked Ca(2+) signals, and regulates cell-matrix adhesion during migration. Our data provide new molecular insight into how Ca(2+) is handled by acidic organelles and link this to migration, thereby underscoring the role of noncanonical Ca(2+) stores in the control of Ca(2+)-dependent function. PMID:27002171

  10. Computing in mammalian cells with nucleic acid strand exchange

    NASA Astrophysics Data System (ADS)

    Groves, Benjamin; Chen, Yuan-Jyue; Zurla, Chiara; Pochekailov, Sergii; Kirschman, Jonathan L.; Santangelo, Philip J.; Seelig, Georg

    2016-03-01

    DNA strand displacement has been widely used for the design of molecular circuits, motors, and sensors in cell-free settings. Recently, it has been shown that this technology can also operate in biological environments, but capabilities remain limited. Here, we look to adapt strand displacement and exchange reactions to mammalian cells and report DNA circuitry that can directly interact with a native mRNA. We began by optimizing the cellular performance of fluorescent reporters based on four-way strand exchange reactions and identified robust design principles by systematically varying the molecular structure, chemistry and delivery method. Next, we developed and tested AND and OR logic gates based on four-way strand exchange, demonstrating the feasibility of multi-input logic. Finally, we established that functional siRNA could be activated through strand exchange, and used native mRNA as programmable scaffolds for co-localizing gates and visualizing their operation with subcellular resolution.

  11. Computing in mammalian cells with nucleic acid strand exchange

    PubMed Central

    Pochekailov, Sergii; Kirschman, Jonathan L.; Santangelo, Philip J.; Seelig, Georg

    2015-01-01

    DNA strand displacement has been widely used for the design of molecular circuits, motors, and sensors in cell-free settings. Recently, it has been shown that this technology can also operate in biological environments, but capabilities remain limited. Here, we look to adapt strand displacement and exchange reactions to mammalian cells and report DNA circuitry that can directly interact with a native mRNA. We began by optimizing the cellular performance of fluorescent reporters based on four-way strand exchange reactions and identified robust design principles by systematically varying the molecular structure, chemistry and delivery method. Next, we developed and tested AND and OR logic gates based on four-way strand exchange, demonstrating the feasibility of multi-input logic. Finally, we established that functional siRNA could be activated through strand exchange, and used native mRNA as programmable scaffolds for co-localizing gates and visualizing their operation with subcellular resolution. PMID:26689378

  12. The enhancement of radiosensitivity in human esophageal squamous cell carcinoma cells by zoledronic acid and its potential mechanism.

    PubMed

    You, Yanjie; Liu, Jianfeng; Wang, Zhizhong; Zhang, Yuan; Ran, Yonggang; Guo, Xu; Liu, Huimin; Wang, Haibo

    2014-01-01

    Esophageal squamous cell carcinoma (ESCC) has a low 5-year patient survival rate. Radiotherapy, as a preoperative or postoperative treatment of surgery, has a crucial role in improving local control and survival of ESCC. Various chemotherapeutic and biologic agents have been used as radio-sensitizers in combination with radiotherapy. Here, we demonstrate that zoledronic acid (ZOL) has a radio-sensitizing effect on ESCC cells. Exposure of ESCC cancer cells to ZOL plus radiation resulted in increased cell death through arresting the cell cycle between S and G2/M phases. ZOL appeared to inhibit proliferation, tube formation and invasion of endothelial cells. These anti-angiogenetic effects were more marked concurrently with irradiation. In addition, synergistic suppressive effects on VEGF expression were observed after combined treatment. Our data suggest that the combination of ZOL and radiation is a promising therapeutic strategy to enhance radiation therapy for ESCC patients.

  13. Stimulation of cysteinyl leukotriene production in mast cells by heat shock and acetylsalicylic acid.

    PubMed

    Mortaz, Esmaeil; Redegeld, Frank A; Dunsmore, Kathy; Odoms, Kelli; Wong, Hector R; Nijkamp, Frans P; Engels, Ferdi

    2007-04-30

    Immunoglobulin (Ig) E-dependent activation of mast cells is central to the allergic response. The engagement of IgE-occupied receptors initiates a series of molecular events that causes the release of preformed, and de novo synthesis of, allergic mediators. Cysteinyl leukotrienes are able to contract airway smooth muscle and increase mucus secretion and vascular permeability and recruit eosinophils. Mast cells have also recently been recognized as active participants in innate immune responses. Heat stress can modulate innate immunity by inducing stress proteins such as heat-shock proteins (HSPs). We previously demonstrated that treatment of mast cells with heat shock or acetylsalicylic acid results in an increase of TNF-alpha and IL-6 release. This effect was paralleled by expression of HSP70. In the current study, we further investigated the effects of heat shock and acetylsalicylic acid on the activation of mast cells and the release of cysteinyl leukotrienes. In mouse mast cells, derived from a culture of bone marrow cells, responsiveness to heat shock, acetylsalicylic acid and exogenous or endogenous HSP70 was monitored by measuring leukotriene C4 release. We show that after heat shock treatment and exposure to acetylsalicylic acid leukotriene production was increased. Moreover, exogenous rHSP70 also induced leukotriene production. Because it has been reported that leukotriene production in mast cells may be mediated by Toll like receptor (TLR) activation, and HSP70 also activates TLRs signaling, we further explored these issues by using mast cells that are not able to produce HSP70, i.e. heat shock factor-1 (HSF-1) knockout cells. We found that in HSF-1 knockout bone marrow derived mast cells, heat shock and acetylsalicylic acid failed to induce release of leukotrienes. Moreover, in wild type cells the surface expression of TLR4 was attenuated, whereas the intracellular expression was up-regulated. We conclude that heat shock and acetylsalicylic acid induce

  14. [The effect of the amino acid combinations on cell proliferation in tissue cultures in old rats].

    PubMed

    Chalisova, N I; Kontsevaia, E A; Zhekalov, A N; Siniachkin, D A

    2012-01-01

    In organotypic tissue culture, the effect of the 20 coded amino acids combinations, in the effective concentration of 0.05 ng/ml, on the cell proliferation development in the spleen, myocardium, pancreas and brain cortex explants in 24 months rats was investigated. The combinations of two amino acids (stimulating and inhibiting proliferation) produced in the tissue culture the stimulating effect, exceeding by 8-10% as compared to the isolating effect of the stimulating amino acid. The results obtained form the base for the further synthesis of new effective dipeptides to be used to increase the regeneration of tissues when aging. PMID:23130534

  15. Cyclosporine A and palmitic acid treatment synergistically induce cytotoxicity in HepG2 cells

    SciTech Connect

    Luo, Yi Rana, Payal; Will, Yvonne

    2012-06-01

    Immunosuppressant cyclosporine A (CsA) treatment can cause severe side effects. Patients taking immunosuppressant after organ transplantation often display hyperlipidemia and obesity. Elevated levels of free fatty acids have been linked to the etiology of metabolic syndromes, nonalcoholic fatty liver and steatohepatitis. The contribution of free fatty acids to CsA-induced toxicity is not known. In this study we explored the effect of palmitic acid on CsA-induced toxicity in HepG2 cells. CsA by itself at therapeutic exposure levels did not induce detectible cytotoxicity in HepG2 cells. Co-treatment of palmitic acid and CsA resulted in a dose dependent increase in cytotoxicity, suggesting that fatty acid could sensitize cells to CsA-induced cytotoxicity at the therapeutic doses of CsA. A synergized induction of caspase-3/7 activity was also observed, indicating that apoptosis may contribute to the cytotoxicity. We demonstrated that CsA reduced cellular oxygen consumption which was further exacerbated by palmitic acid, implicating that impaired mitochondrial respiration might be an underlying mechanism for the enhanced toxicity. Inhibition of c-Jun N-terminal kinase (JNK) attenuated palmitic acid and CsA induced toxicity, suggesting that JNK activation plays an important role in mediating the enhanced palmitic acid/CsA-induced toxicity. Our data suggest that elevated FFA levels, especially saturated FFA such as palmitic acid, may be predisposing factors for CsA toxicity, and patients with underlying diseases that would elevate free fatty acids may be susceptible to CsA-induced toxicity. Furthermore, hyperlipidemia/obesity resulting from immunosuppressive therapy may aggravate CsA-induced toxicity and worsen the outcome in transplant patients. -- Highlights: ► Palmitic acid and cyclosporine (CsA) synergistically increased cytotoxicity. ► The impairment of mitochondrial functions may contribute to the enhanced toxicity. ► Inhibition of JNK activity attenuated

  16. Tannic Acid Inhibits Hepatitis C Virus Entry into Huh7.5 Cells

    PubMed Central

    Hagedorn, Curt H.

    2015-01-01

    Chronic infection with the hepatitis C virus (HCV) is a cause of cirrhosis and hepatocellular carcinoma worldwide. Although antiviral therapy has dramatically improved recently, a number of patients remain untreated and some do not clear infection with treatment. Viral entry is an essential step in initiating and maintaining chronic HCV infections. One dramatic example of this is the nearly 100% infection of newly transplanted livers in patients with chronic hepatitis C. HCV entry inhibitors could play a critical role in preventing HCV infection of newly transplanted livers. Tannic acid, a polymer of gallic acid and glucose molecules, is a plant-derived polyphenol that defends some plants from insects and microbial infections. It has been shown to have a variety of biological effects, including antiviral activity, and is used as a flavoring agent in foods and beverages. In this study, we demonstrate that tannic acid is a potent inhibitor of HCV entry into Huh7.5 cells at low concentrations (IC50 5.8 μM). It also blocks cell-to-cell spread in infectious HCV cell cultures, but does not inhibit HCV replication following infection. Moreover, experimental results indicate that tannic acid inhibits an early step of viral entry, such as the docking of HCV at the cell surface. Gallic acid, tannic acid’s structural component, did not show any anti-HCV activity including inhibition of HCV entry or replication at concentrations up to 25 μM. It is possible the tannin structure is related on the effect on HCV inhibition. Tannic acid, which is widely distributed in plants and foods, has HCV antiviral activity in cell culture at low micromolar concentrations, may provide a relative inexpensive adjuvant to direct-acting HCV antivirals and warrants future investigation. PMID:26186636

  17. Glucose-Regulated Protein 78 (Grp78) Confers Chemoresistance to Tumor Endothelial Cells under Acidic Stress

    PubMed Central

    Visioli, Fernanda; Wang, Yugang; Alam, Goleeta N.; Ning, Yu; Rados, Pantelis V.; Nör, Jacques E.; Polverini, Peter J.

    2014-01-01

    Objectives This study was designed to investigate the activation of the unfolded protein response (UPR) in tumor associated endothelial cells (TECs) and its association with chemoresistance during acidic pH stress. Materials and Methods Endothelial cells from human oral squamous cell carcinomas (OSCC) were excised by laser capture microdissection (LCM) followed by analysis of UPR markers (Grp78, ATF4 and CHOP) using quantitative PCR. Grp78 expression was also determined by immunostaining. Acidic stress was induced in primary human dermal microvascular endothelial cells (HDMECs) by treatment with conditioned medium (CM) from tumor cells grown under hypoxic conditions or by adjusting medium pH to 6.4 or 7.0 using lactic acid or hydrochloric acid (HCl). HDMEC resistance to the anti-angiogenic drug Sunitinib was assessed with SRB assay. Results UPR markers, Grp78, ATF4 and CHOP were significantly upregulated in TECs from OSCC compared to HDMECs. HDMECs cultured in acidic CM (pH 6.0–6.4) showed increased expression of the UPR markers. However, severe acidosis led to marked cell death in HDMECs. Alternatively, HDMECs were able to adapt when exposed to chronic acidosis at pH 7.0 for 7 days, with concomittant increase in Grp78 expression. Chronic acidosis also confers drug resistance to HDMECs against Sunitinib. Knockdown of Grp78 using shRNA resensitizes HDMECs to drug treatment. Conclusions UPR induction in ECs under acidic pH conditions is related to chemoresistance and may contribute to therapeutic failures in response to chemotherapy. Targeting Grp78, the key component of the UPR pathway, may provide a promising approach to overcome ECs resistance in cancer therapy. PMID:24964091

  18. Crocetinic acid inhibits hedgehog signaling to inhibit pancreatic cancer stem cells

    PubMed Central

    Rangarajan, Parthasarathy; Subramaniam, Dharmalingam; Paul, Santanu; Kwatra, Deep; Palaniyandi, Kanagaraj; Islam, Shamima; Harihar, Sitaram; Ramalingam, Satish; Gutheil, William; Putty, Sandeep; Pradhan, Rohan; Padhye, Subhash; Welch, Danny R.; Anant, Shrikant; Dhar, Animesh

    2015-01-01

    Pancreatic cancer is the fourth leading cause of cancer deaths in the US and no significant treatment is currently available. Here, we describe the effect of crocetinic acid, which we purified from commercial saffron compound crocetin using high performance liquid chromatography. Crocetinic acid inhibits proliferation of pancreatic cancer cell lines in a dose- and time-dependent manner. In addition, it induced apoptosis. Moreover, the compound significantly inhibited epidermal growth factor receptor and Akt phosphorylation. Furthermore, crocetinic acid decreased the number and size of the pancospheres in a dose-dependent manner, and suppressed the expression of the marker protein DCLK-1 (Doublecortin Calcium/Calmodulin-Dependent Kinase-1) suggesting that crocetinic acid targets cancer stem cells (CSC). To understand the mechanism of CSC inhibition, the signaling pathways affected by purified crocetinic acid were dissected. Sonic hedgehog (Shh) upon binding to its cognate receptor patched, allows smoothened to accumulate and activate Gli transcription factor. Crocetinic acid inhibited the expression of both Shh and smoothened. Finally, these data were confirmed in vivo where the compound at a dose of 0.5 mg/Kg bw suppressed growth of tumor xenografts. Collectively, these data suggest that purified crocetinic acid inhibits pancreatic CSC, thereby inhibiting pancreatic tumorigenesis. PMID:26317547

  19. Differential cell growth/apoptosis behavior of 13-hydroxyoctadecadienoic acid enantiomers in a colorectal cancer cell line.

    PubMed

    Cabral, Marisol; Martín-Venegas, Raquel; Moreno, Juan José

    2014-09-15

    Cyclooxygenases (COXs) and lipoxygenases (LOXs) are important enzymes that metabolize arachidonic and linoleic acids. Various metabolites generated by the arachidonic acid cascade regulate cell proliferation, apoptosis, differentiation, and senescence. Hydroxyoctadecadienoic acids (HODEs) are synthesized from linoleic acid, giving two enantiomeric forms for each metabolite. The aim was to investigate the effect of 13-HODE enantiomers on nondifferentiated Caco-2 cell growth/apoptosis. Our results indicate that 13(S)-HODE decreases cell growth and DNA synthesis of nondifferentiated Caco-2 cells cultured with 10% fetal bovine serum (FBS). Moreover, 13(S)-HODE showed an apoptotic effect that was reduced in the presence of a specific peroxisome proliferator-activated receptor-γ (PPARγ) antagonist. In addition, we observed that 13(S)-HODE but not 13(R)-HODE is a ligand to PPARγ, confirming the implication of this nuclear receptor in 13(S)-HODE actions. In contrast, 13(R)-HODE increases cell growth and DNA synthesis in the absence of FBS. 13(R)-HODE interaction with BLT receptors activates ERK and CREB signaling pathways, as well as PGE2 synthesis. These results suggest that the proliferative effect of 13(R)-HODE could be due, at least in part, to COX pathway activation. Thus both enantiomers use different receptors and have contrary effects. We also found these differential effects of 9-HODE enantiomers on cell growth/apoptosis. Therefore, the balance between (R)-HODEs and (S)-HODEs in the intestinal epithelium could be important to its cell growth/apoptosis homeostasis.

  20. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration

    PubMed Central

    Fernández-Sánchez, Laura; Rondón, Netxibeth; Esquiva, Gema; Germain, Francisco; de la Villa, Pedro; Cuenca, Nicolás

    2015-01-01

    Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss. PMID:26379056

  1. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration.

    PubMed

    Gómez-Vicente, Violeta; Lax, Pedro; Fernández-Sánchez, Laura; Rondón, Netxibeth; Esquiva, Gema; Germain, Francisco; de la Villa, Pedro; Cuenca, Nicolás

    2015-01-01

    Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss.

  2. Improvement of Liver Cell Therapy in Rats by Dietary Stearic Acid

    PubMed Central

    Goradel, Nasser Hashemi; Eghbal, Mohammad Ali; Darabi, Masoud; Roshangar, Leila; Asadi, Maryam; Zarghami, Nosratollah; Nouri, Mohammad

    2016-01-01

    Background: Stearic acid is known as a potent anti-inflammatory lipid. This fatty acid has profound and diverse effects on liver metabolism. The aim of this study was to investigate the effect of stearic acid on markers of hepatocyte transplantation in rats with acetaminophen (APAP)-induced liver damage. Methods: Wistar rats were randomly assigned to 10-day treatment. Stearic acid was administered to the rats with APAP-induced liver damage. The isolated liver cells were infused intraperitoneally into rats. Blood samples were obtained to evaluate the changes in the serum liver enzymes, including activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) and the level of serum albumin. To assess the engraftment of infused hepatocytes, rats were euthanized, and the liver DNA was used for PCR using sex-determining region Y (SRY) primers. Results: The levels of AST, ALT and ALP in the serum of rats with APAP-induced liver injury were significantly increased and returned to the levels in control group by day six. The APAP-induced decrease in albumin was significantly improved in rats through cell therapy, when compared with that in the APAP-alone treated rats. SRY PCR analysis showed the presence of the transplanted cells in the liver of transplanted rats. Conclusion: Stearic acid-rich diet in combination with cell therapy accelerates the recovering of hepatic dysfunction in a rat model of liver injury. PMID:27090202

  3. The concentration of amino acids by yeast cells depleted of adenosine triphosphate

    PubMed Central

    Eddy, A. A.; Backen, K.; Watson, G.

    1970-01-01

    1. The ATP content of preparations of a strain of Saccharomyces carlsbergensis was lowered below 0.3nmol/mg of yeast by starving the yeast cells in the presence of both antimycin and 5mm-deoxyglucose. 2. When the depleted cells were put at pH4.5 with glycine up to about 20nmol of the amino acid/mg of yeast was absorbed without being chemically modified. The mechanism did not depend on an exchange with endogenous amino acids. 3. The concentration of the absorbed glycine could apparently reach 100–200 times that outside the cells. 4. Replacement of the cellular K+ by Na+ almost stopped amino acid absorption in the presence of antimycin and deoxyglucose, but not in their absence. 5. It is suggested that, when energy metabolism itself had stopped, a purely physical process, namely the movements of H+ and K+ into and out of the yeast respectively, served to concentrate the amino acids in the cells. Both ionic species appear to be co-substrates of the system transporting amino acids. PMID:5495157

  4. Toxic effects of fatty acids on yeast cells: possible mechanisms of action.

    PubMed

    Hunková, Z; Fencl, A

    1978-08-01

    As shown in a previous paper, threshold concentrations of lower and intermediate fatty acids inhibit the uptake of inorganic phosphate, growth, and cell division in yeast cells. This demonstrates that, apart from these effects, the acids cause an increase in the respiration quotient (RQ), inhibition of CO2 fixation, production of ethanol at the expense of anabolic processes, and inhibition of active amino acid transport in the yeast Candida utilis. On the other hand, the threshold concentrations have no effect on intracellular pH. The inhibition of the inorganic phosphate uptake cannot be the sole primary mode of action of fatty acids since the omission of inorganic phosphate in the incubation medium brings about an inhibition of anabolic processes that is lower than that brought about by fatty acids since the omission of inorganic phosphate in the incubation medium brings about an inhibition of anabolic processes that is lower than that brought by fatty acids at concentrations still premitting some phosphate uptake. Although 2,4-dinitrophenol and caproic acid at low concentrations cause an analogous decrease in biomass yield, their combination does not bring about any marked increase in the effect. Considering the physicochemical properties of fatty acids and their preferential action on energy-requiring processes, one of the key sites of action can be assumed to be the mitochondrial membrane. Fatty acids might inhibit the transport of anions, especially phosphate, across the membrane, and disturb the membrane potential by affecting the transport protons. The physiocochemical properties of fatty acids may also give rise to their binding to other intracellular membranes and to a subsequent interference with the function of the corresponding organelles.

  5. Docosahexaenoic Acid Induces Oxidative DNA Damage and Apoptosis, and Enhances the Chemosensitivity of Cancer Cells.

    PubMed

    Song, Eun Ah; Kim, Hyeyoung

    2016-01-01

    The human diet contains low amounts of ω-3 polyunsaturated fatty acids (PUFAs) and high amounts of ω-6 PUFAs, which has been reported to contribute to the incidence of cancer. Epidemiological studies have shown that a high consumption of fish oil or ω-3 PUFAs reduced the risk of colon, pancreatic, and endometrial cancers. The ω-3 PUFA, docosahexaenoic acid (DHA), shows anticancer activity by inducing apoptosis of some human cancer cells without toxicity against normal cells. DHA induces oxidative stress and oxidative DNA adduct formation by depleting intracellular glutathione (GSH) and decreasing the mitochondrial function of cancer cells. Oxidative DNA damage and DNA strand breaks activate DNA damage responses to repair the damaged DNA. However, excessive DNA damage beyond the capacity of the DNA repair processes may initiate apoptotic signaling pathways and cell cycle arrest in cancer cells. DHA shows a variable inhibitory effect on cancer cell growth depending on the cells' molecular properties and degree of malignancy. It has been shown to affect DNA repair processes including DNA-dependent protein kinases and mismatch repair in cancer cells. Moreover, DHA enhanced the efficacy of anticancer drugs by increasing drug uptake and suppressing survival pathways in cancer cells. In this review, DHA-induced oxidative DNA damage, apoptotic signaling, and enhancement of chemosensitivity in cancer cells will be discussed based on recent studies. PMID:27527148

  6. Cross Talk between Cancer and Mesenchymal Stem Cells through Extracellular Vesicles Carrying Nucleic Acids

    PubMed Central

    Lopatina, Tatiana; Gai, Chiara; Deregibus, Maria Chiara; Kholia, Sharad; Camussi, Giovanni

    2016-01-01

    Extracellular vesicles (EVs) are considered to be a novel complex mechanism of cell communication within the tumor microenvironment. EVs may act as vehicles for transcription factors and nucleic acids inducing epigenetic changes in recipient cells. Since tumor EVs may be present in patient biological fluids, it is important to investigate their function and molecular mechanisms of action. It has been shown that tumor cells release EVs, which are capable of regulating cell apoptosis, proliferation, invasion, and epithelial–mesenchymal transition, as well as to suppress activity of immune cells, to enhance angiogenesis, and to prepare a favorable microenvironment for metastasis. On the other hand, EVs derived from stromal cells, such as mesenchymal stem cells (MSCs), may influence the phenotype of tumor cells through reciprocal cross talk greatly influenced by the transcription factors and nucleic acids they carry. In particular, non-coding RNAs (ncRNAs), including microRNAs and long ncRNAs, have recently been identified as the main candidates for the phenotypic changes induced in the recipient cells by EVs. ncRNAs, which are important regulators of mRNA and protein expression, can function either as tumor suppressors or as oncogenes, depending on their targets. Herein, we have attempted to revise actual evidence reported in the literature on the role of EVs in tumor biology with particular regard to the cross talk of ncRNAs between cancer cells and MSCs. PMID:27242964

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

    PubMed

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  10. Lysophosphatidic acid induces cell migration through the selective activation of Akt1

    PubMed Central

    Kim, Eun Kyoung; Yun, Sung Ji; Do, Kee Hun; Kim, Min Sung; Cho, Mong; Suh, Dong-Soo; Kim, Chi Dae; Kim, Jae Ho; Birnbaum, Morris J.

    2008-01-01

    Akt plays pivotal roles in many physiological responses including growth, proliferation, survival, metabolism, and migration. In the current studies, we have evaluated the isoform-specific role of akt in lysophosphatidic acid (LPA)-induced cell migration. Ascites from ovarian cancer patients (AOCP) induced mouse embryo fibroblast (MEF) cell migration in a dose-dependent manner. On the other hand, ascites from liver cirrhosis patients (ALCP) did not induce MEF cell migration. AOCP-induced MEF cell migration was completely blocked by pre-treatment of cells with LPA receptor antagonist, Ki16425. Both LPA- and AOCP-induced MEF cell migration was completely attenuated by PI3K inhibitor, LY294002. Furthermore, cells lacking Akt1 displayed defect in LPA-induced cell migration. Re-expression of Akt1 in DKO (Akt1-/-Akt2-/-) cells restored LPA-induced cell migration, whereas re-expression of Akt2 in DKO cells could not restore the LPA-induced cell migration. Finally, Akt1 was selectively phosphorylated by LPA and AOCP stimulation. These results suggest that LPA is a major factor responsible for AOCP-induced cell migration and signaling specificity of Akt1 may dictate LPA-induced cell migration. PMID:18779657

  11. Acid gradient across plasma membrane can drive phosphate bond synthesis in cancer cells: acidic tumor milieu as a potential energy source.

    PubMed

    Dhar, Gautam; Sen, Suvajit; Chaudhuri, Gautam

    2015-01-01

    Aggressive cancers exhibit an efficient conversion of high amounts of glucose to lactate accompanied by acid secretion, a phenomenon popularly known as the Warburg effect. The acidic microenvironment and the alkaline cytosol create a proton-gradient (acid gradient) across the plasma membrane that represents proton-motive energy. Increasing experimental data from physiological relevant models suggest that acid gradient stimulates tumor proliferation, and can also support its energy needs. However, direct biochemical evidence linking extracellular acid gradient to generation of intracellular ATP are missing. In this work, we demonstrate that cancer cells can synthesize significant amounts of phosphate-bonds from phosphate in response to acid gradient across plasma membrane. The noted phenomenon exists in absence of glycolysis and mitochondrial ATP synthesis, and is unique to cancer. Biochemical assays using viable cancer cells, and purified plasma membrane vesicles utilizing radioactive phosphate, confirmed phosphate-bond synthesis from free phosphate (Pi), and also localization of this activity to the plasma membrane. In addition to ATP, predominant formation of pyrophosphate (PPi) from Pi was also observed when plasma membrane vesicles from cancer cells were subjected to trans-membrane acid gradient. Cancer cytosols were found capable of converting PPi to ATP, and also stimulate ATP synthesis from Pi from the vesicles. Acid gradient created through glucose metabolism by cancer cells, as observed in tumors, also proved critical for phosphate-bond synthesis. In brief, these observations reveal a role of acidic tumor milieu as a potential energy source and may offer a novel therapeutic target.

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

    PubMed Central

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

    2006-01-01

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

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

    PubMed Central

    Byersdorfer, Craig Alan

    2014-01-01

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

  14. Comparison of γδ T cell responses and farnesyl diphosphate synthase inhibition in tumor cells pretreated with zoledronic acid

    PubMed Central

    Idrees, Atif S. M.; Sugie, Tomoharu; Inoue, Chiyomi; Murata-Hirai, Kaoru; Okamura, Haruki; Morita, Craig T.; Minato, Nagahiro; Toi, Masakazu; Tanaka, Yoshimasa

    2013-01-01

    Summary Exposing human tumor cells to nitrogen-containing bisphosphonates (N-BPs), such as zoledronic acid (Zol), greatly increases their susceptibility to killing by γδ T cells. Based on this finding and other studies, cancer immunotherapy using γδ T cells and N-BPs has been studied in pilot clinical trials and has shown benefits. Although Zol treatment can render a wide variety of human tumor cells susceptible to γδ T cell killing, there has not been a systematic investigation to determine which types of tumor cells are the most susceptible to γδ T cell-mediated cytotoxicity. In this study, we determined the Zol concentrations required to stimulate half maximal tumor necrosis factor-α production by γδ T cells cultured with various tumor cell lines pretreated with Zol and compared these concentrations with those required for half maximal inhibition of farnesyl diphosphate synthase (FPPS) in the same tumor cell lines. The inhibition of tumor cell growth by Zol was also assessed. We found that FPPS inhibition strongly correlated with γδ T cell activation, confirming that the mechanism underlying γδ T cell activation by Zol is isopentenyl diphosphate (IPP) accumulation due to FPPS blockade. In addition, we showed that γδ TCR-mediated signaling correlated with γδ T cell tumor necrosis factor-α production and cytotoxicity. Some lymphoma, myeloid leukemia, and mammary carcinoma cell lines were relatively resistant to Zol treatment suggesting that assessing tumor sensitivity to Zol may help select those patients most likely to benefit from immunotherapy with γδ T cells. PMID:23387443

  15. Role of COUP-TFI during retinoic acid-induced differentiation of P19 cells to endodermal cells.

    PubMed

    Pickens, Brandy S; Teets, Bryan W; Soprano, Kenneth J; Soprano, Dianne Robert

    2013-04-01

    Retinoic acid (RA) is a positive regulator of P19 cell differentiation. Silencing of pre-B cell leukemia transcription factors (PBXs) expression in P19 cells (AS cells) results in a failure of these cells to differentiate to endodermal cells upon RA treatment. Chicken Ovalbumin Upstream Promoter Transcription Factor I (COUP-TFI) is an orphan member of the steroid-thyroid hormone superfamily. RA treatment of wild type P19 cells results in a dramatic increase in the expression of COUP-TFI; however, COUP-TFI mRNA levels fail to be elevated upon RA treatment of AS cells indicating that PBX expression is required for elevation in COUP-TFI expression. To study the role of COUP-TFI during RA-dependent differentiation of P19 cells, AS cells that inducibly express various levels of COUP-TFI were prepared. Exogenous expression of COUP-TFI in AS cells, in a dose-dependent fashion, leads to growth inhibition, modest cell cycle disruption, and early apoptosis. Furthermore, AS cells can overcome the blockage in RA-dependent differentiation to endodermal cells when either pharmacological levels of COUP-TFI are expressed or a combination of both the expression of physiological levels of COUP-TFI and RA treatment. Additionally, the mRNA level of several pluripotency associated genes including OCT-4, DAX-1, and SF-1 in the COUP-TFI expressing AS cells are reduced. Moreover, analysis of the expression of primary RA response genes indicates that COUP-TFI is involved in the regulatory modulation of the expression of at least two genes, CYP26A1 and HoxA1. These studies demonstrate that COUP-TFI functions as a physiologically relevant regulator during RA-mediated endodermal differentiation of P19 cells. PMID:23018522

  16. Importance of brain‑type fatty acid binding protein for cell-biological processes in human renal carcinoma cells.

    PubMed

    Tölle, Angelika; Krause, Hans; Miller, Kurt; Jung, Klaus; Stephan, Carsten

    2011-05-01

    The molecular mechanisms underlying renal cell carcinoma (RCC) development and progression are still not completely understood. The importance of fatty acid binding proteins (FABP) for the progression of carcinomas has been shown for several tumors. However, the importance of brain-type FABP (B‑FABP) in cell-biological processes in renal carcinoma cells is unknown. Therefore, it was the aim of this study to evaluate the role of B‑FABP in processes such as proliferation, migration and invasion. By using the approach of down- and up-regulation of B‑FABP in human kidney carcinoma cells Caki‑2 and Caki‑1, the potential participation of B‑FABP in proliferation, migration and invasion was demonstrated. B‑FABP was down-regulated at both mRNA and protein levels following treatment of Caki‑2 cells with B‑FABP siRNA. Down-regulation of B‑FABP decreased cell proliferation and migration but did not affect invasion. The transfection of Caki‑1 cells with human B‑FABP cDNA generated an increment of B‑FABP mRNA but the protein was not detectable. Transfected Caki‑1 cells developed a faster proliferation compared to untreated cells. An effect on the process of invasion was not observed. Our data suggest that B‑FABP is involved in cell proliferation and migration of human renal carcinoma cells. The detailed molecular mechanisms remain to be elucidated.

  17. Expression of retinoic acid receptor alpha mRNA in human leukemia cells.

    PubMed

    Largman, C; Detmer, K; Corral, J C; Hack, F M; Lawrence, H J

    1989-07-01

    The expression of the newly described human retinoic acid receptor alpha (RAR alpha) in six nonlymphoid and six lymphoid leukemia cell lines and nine freshly obtained samples of leukemia cells from patients with acute nonlymphoid leukemia was assessed by Northern blot analysis, using a full length cDNA clone of RAR alpha as probe. RAR alpha was expressed in all 12 cell lines and in all fresh leukemia samples as two major transcripts of 2.6 and 3.5 kb in size. Levels of RAR alpha expression and transcript sizes in retinoid-sensitive cells (such as HL60 or fresh promyelocytic leukemia cells) were not different from those in other samples. Moreover, expression of RAR alpha was not significantly modulated by exposure to cis-retinoic acid (cisRA) in either cisRA-responsive or unresponsive cells. By using a 3' fragment of the RAR alpha gene as a probe, we confirmed that the transcripts visualized did not represent the homologous RAR beta gene. RAR alpha appears to be expressed in most human leukemia cells regardless of the type of biologic response to retinoic acid.

  18. Rapid, efficient charging of lead-acid and nickel-zinc traction cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1978-01-01

    Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate tapered direct current (HRTDC) charge method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, in these preliminary tests, 300 amp-hour nickel-zinc traction cells were given a HRTDC (initial current 500 amps, final current 100 amps) to 78 percent of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92 percent and an energy efficiency of 52 percent. Three hundred amp-hour lead-acid traction cells were charged to 69 percent of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91 percent with an energy efficiency of 64 percent. In order to find ways to further decrease the recharge times, the effect of periodically (0 to 400 Hz) pulse discharging cells during a constant current charging process (94% duty cycle) was investigated. Preliminary data indicate no significant effect of this type of pulse discharging during charge on charge acceptance of lead-acid or nickel-zinc cells.

  19. Ascorbic acid inhibits TPA-induced HL-60 cell differentiation by decreasing cellular H₂O₂ and ERK phosphorylation.

    PubMed

    Yiang, Giou-Teng; Chen, Jen-Ni; Wu, Tsai-Kun; Wang, Hsueh-Fang; Hung, Yu-Ting; Chang, Wei-Jung; Chen, Chinshuh; Wei, Chyou-Wei; Yu, Yung-Luen

    2015-10-01

    Retinoic acid (RA), vitamin D and 12-O‑tetradecanoyl phorbol-13-acetate (TPA) can induce HL-60 cells to differentiate into granulocytes, monocytes and macrophages, respectively. Similar to RA and vitamin D, ascorbic acid also belongs to the vitamin family. High‑dose ascorbic acid (>100 µM) induces HL‑60 cell apoptosis and induces a small fraction of HL‑60 cells to express the granulocyte marker, CD66b. In addition, ascorbic acid exerts an anti‑oxidative stress function. Oxidative stress is required for HL‑60 cell differentiation following treatment with TPA, however, the effect of ascorbic acid on HL‑60 cell differentiation in combination with TPA treatment remains to be fully elucidated. The aim of the present study was to investigate the cellular effects of ascorbic acid treatment on TPA-differentiated HL-60 cells. TPA-differentiated HL-60 cells were used for this investigation, this study and the levels of cellular hydrogen peroxide (H2O2), caspase activity and ERK phosphorylation were determined following combined treatment with TPA and ascorbic acid. The results demonstrated that low‑dose ascorbic acid (5 µM) reduced the cellular levels of H2O2 and inhibited the differentiation of HL‑60 cells into macrophages following treatment with TPA. In addition, the results of the present study further demonstrated that low‑dose ascorbic acid inactivates the ERK phosphorylation pathway, which inhibited HL‑60 cell differentiation following treatment with TPA.

  20. NADPH oxidase-dependent acid production in airway epithelial cells.

    PubMed

    Schwarzer, Christian; Machen, Terry E; Illek, Beate; Fischer, Horst

    2004-08-27

    The purpose of this study was to determine the role of NADPH oxidase in H(+) secretion by airway epithelia. In whole cell patch clamp recordings primary human tracheal epithelial cells (hTE) and the human serous gland cell line Calu-3 expressed a functionally similar zinc-blockable plasma membrane H(+) conductance. However, the rate of H(+) secretion of confluent epithelial monolayers measured in Ussing chambers was 9-fold larger in hTE compared with Calu-3. In hTE H(+) secretion was blocked by mucosal ZnCl(2) and the NADPH oxidase blockers acetovanillone and 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), whereas these same blockers had no effect in Calu-3. We determined levels of transcripts for the NADPH oxidase transmembrane isoforms (Nox1 through -5, Duox1 and -2, and p22(phox)) and found Duox1, -2, and p22(phox) to be highly expressed in hTE, as well as the intracellular subunits p40(phox), p47(phox), and p67(phox). In contrast, Calu-3 lacked transcripts for Duox1, p40(phox), and p47(phox). Anti-Duox antibody staining resulted in prominent apical staining in hTE but no significant staining in Calu-3. When treated with amiloride to block the Na(+)/H(+) exchanger, intracellular pH in hTE acidified at significantly higher rates than in Calu-3, and treatment with AEBSF blocked acidification. These data suggest a role for an apically located Duox-based NADPH oxidase during intracellular H(+) production and H(+) secretion, but not in H(+) conduction.

  1. Electrocatalyst advances for hydrogen oxidation in phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Stonehart, P.

    1984-01-01

    The important considerations that presently exist for achieving commercial acceptance of fuel cells are centered on cost (which translates to efficiency) and lifetime. This paper addresses the questions of electrocatalyst utilization within porous electrode structures and the preparation of low-cost noble metal electrocatalyst combinations with extreme dispersions of the metal. Now that electrocatalyst particles can be prepared with dimensions of 10 A, either singly or in alloy combinations, a very large percentage of the noble metal atoms in a crystallite are available for reaction. The cost savings for such electrocatalysts in the present commercially driven environment are considerable.

  2. Three sesquiterpene compounds biosynthesised from artemisinic acid using suspension-cultured cells of Averrhoa carambola (Oxalidaceae).

    PubMed

    Yang, Li; Zhu, Jianhua; Song, Liyan; Shi, Xiaojian; Li, Xingyi; Yu, Rongmin

    2012-01-01

    A new sesquiterpene glycoside, artemisinic acid 3-β-O-β-D-glucopyranoside (3, 31.24%) and other two biotransformation products, 3-β-hydroxyartemisinic acid (2, 36.69%) and 3-β-hydroxyartemisinic acid β-D-glucopyranosyl ester (4, 7.03%), were biosynthesised after artemisinic acid (1) was administered to the cultured cells of Averrhoa carambola. The three biotransformation products were obtained for the first time by using the suspension-cultured cells of A. carambola as a new biocatalyst system, and their structures were identified on the basis of the physico-chemical properties, NMR and mass spectral analyses. The results indicate that the cultured cells of A. carambola have the abilities to hydroxylate and glycosylate sesquiterpene compounds in a regio- and stereoselective manner. Furthermore, the anti-tumour activity of compounds 3 and 4 was evaluated against K562 and HeLa cell lines. Compound 4 showed strong activity against HeLa cell line, with the IC₅₀ value of 0.56 µmol mL⁻¹.

  3. Polyunsaturated Fatty Acid-Derived Lipid Mediators and T Cell Function

    PubMed Central

    Nicolaou, Anna; Mauro, Claudio; Urquhart, Paula; Marelli-Berg, Federica

    2014-01-01

    Fatty acids are involved in T cell biology both as nutrients important for energy production as well as signaling molecules. In particular, polyunsaturated fatty acids are known to exhibit a range of immunomodulatory properties that progress through T cell mediated events, although the molecular mechanisms of these actions have not yet been fully elucidated. Some of these immune activities are linked to polyunsaturated fatty acid-induced alteration of the composition of cellular membranes and the consequent changes in signaling pathways linked to membrane raft-associated proteins. However, significant aspects of the polyunsaturated fatty acid bioactivities are mediated through their transformation to specific lipid mediators, products of cyclooxygenase, lipoxygenase, or cytochrome P450 enzymatic reactions. Resulting bioactive metabolites including prostaglandins, leukotrienes, and endocannabinoids are produced by and/or act upon T leukocytes through cell surface receptors and have been shown to alter T cell activation and differentiation, proliferation, cytokine production, motility, and homing events. Detailed appreciation of the mode of action of these lipids presents opportunities for the design and development of therapeutic strategies aimed at regulating T cell function. PMID:24611066

  4. Nucleic Acid Encoding A Lectin-Derived Progenitor Cell Preservation Factor

    SciTech Connect

    Colucci, M. Gabriella; Chrispeels, Maarten J.; Moore, Jeffrey G.

    2001-10-30

    The invention relates to an isolated nucleic acid molecule that encodes a protein that is effective to preserve progenitor cells, such as hematopoietic progenitor cells. The nucleic acid comprises a sequence defined by SEQ ID NO:1, a homolog thereof, or a fragment thereof. The encoded protein has an amino acid sequence that comprises a sequence defined by SEQ ID NO:2, a homolog thereof, or a fragment thereof that contains an amino acid sequence TNNVLQVT. Methods of using the encoded protein for preserving progenitor cells in vitro, ex vivo, and in vivo are also described. The invention, therefore, include methods such as myeloablation therapies for cancer treatment wherein myeloid reconstitution is facilitated by means of the specified protein. Other therapeutic utilities are also enabled through the invention, for example, expanding progenitor cell populations ex vivo to increase chances of engraftation, improving conditions for transporting and storing progenitor cells, and facilitating gene therapy to treat and cure a broad range of life-threatening hematologic diseases.

  5. Amino Acid Similarity Accounts for T Cell Cross-Reactivity and for “Holes” in the T Cell Repertoire

    PubMed Central

    Frankild, Sune; de Boer, Rob J.; Lund, Ole; Nielsen, Morten; Kesmir, Can

    2008-01-01

    Background Cytotoxic T cell (CTL) cross-reactivity is believed to play a pivotal role in generating immune responses but the extent and mechanisms of CTL cross-reactivity remain largely unknown. Several studies suggest that CTL clones can recognize highly diverse peptides, some sharing no obvious sequence identity. The emerging realization in the field is that T cell receptors (TcR) recognize multiple distinct ligands. Principal Findings First, we analyzed peptide scans of the HIV epitope SLFNTVATL (SFL9) and found that TCR specificity is position dependent and that biochemically similar amino acid substitutions do not drastically affect recognition. Inspired by this, we developed a general model of TCR peptide recognition using amino acid similarity matrices and found that such a model was able to predict the cross-reactivity of a diverse set of CTL epitopes. With this model, we were able to demonstrate that seemingly distinct T cell epitopes, i.e., ones with low sequence identity, are in fact more biochemically similar than expected. Additionally, an analysis of HIV immunogenicity data with our model showed that CTLs have the tendency to respond mostly to peptides that do not resemble self-antigens. Conclusions T cell cross-reactivity can thus, to an extent greater than earlier appreciated, be explained by amino acid similarity. The results presented in this paper will help resolving some of the long-lasting discussions in the field of T cell cross-reactivity. PMID:18350167

  6. Effect of Ethylene on Cell Division and Deoxyribonucleic Acid Synthesis in Pisum sativum1

    PubMed Central

    Apelbaum, Akiva; Burg, Stanley P.

    1972-01-01

    Ethylene and supraoptimal levels of 2,4-dichlorophenoxyacetic acid inhibit the growth of the apical hook region of etiolated Pisum sativum (var. Alaska) seedlings by stopping almost all cell divisions. Cells are prevented from entering prophase. The hormones also retard cell division in intact root tips and completely stop the process in lateral buds. The latter inhibition is reversed partially by benzyl adenine. In root tips and the stem plumular and subhook regions, ethylene inhibits DNA synthesis. The magnitude of this inhibition is correlated with the degree of repression of cell division in meristematic tissue, suggesting that the effect on cell division results from a lack of DNA synthesis. Ethylene inhibits cell division within a few hours with a dose-response curve similar to that for most other actions of the gas. Experiments with seedlings grown under hypobaric conditions suggest that the gas naturally controls plumular expansion and cell division in the apical region. Images PMID:16658105

  7. Targeting leukemic side population cells by isatin derivatives of nicotinic acid amide.

    PubMed

    Naglah, A M; Shinwari, Z; Bhat, M A; Al-Tahhan, M; Al-Omar, M A; Al-Dhfyan, A

    2016-01-01

    Side population (SP) cells mediate chemoresistance in leukemia. However, chemical inhibition approach to target SP cells has been poorly studied. Herein, we report the discovery of isatin derivatives of nicotinic acid amide as potent side population cell inhibitors. The selected derivatives showed superior potency over the reference drug verapamil. Furthermore, the treatment increased chemosensitivity and inhibited the cell proliferation on three different leukemic cell lines, K562, THP-1 and U937, suggesting that both SP and the bulk of leukemic cells are affected. Moreover, treatment with the most potent compound Nic9 reduced the expression of ABCG2, demonstrating that side population inhibition effect of the target derivatives is at least via ABCG2 inhibition. Importantly, the target derivatives induced erythrocyte/dendritic differentiation to leukemic cells mainly through Musashi/Numb pathway modulation. PMID:27358121

  8. Gut Microbiota-Derived Short-Chain Fatty Acids, T Cells, and Inflammation

    PubMed Central

    Park, Jeongho; Kim, Myunghoo

    2014-01-01

    T cells are central players in the regulation of adaptive immunity and immune tolerance. In the periphery, T cell differentiation for maturation and effector function is regulated by a number of factors. Various factors such as antigens, co-stimulation signals, and cytokines regulate T cell differentiation into functionally specialized effector and regulatory T cells. Other factors such as nutrients, micronutrients, nuclear hormones and microbial products provide important environmental cues for T cell differentiation. A mounting body of evidence indicates that the microbial metabolites short-chain fatty acids (SCFAs) have profound effects on T cells and directly and indirectly regulate their differentiation. We review the current status of our understanding of SCFA functions in regulation of peripheral T cell activity and discuss their impact on tissue inflammation. PMID:25550694

  9. Rapid Formation of Cell Aggregates and Spheroids Induced by a "Smart" Boronic Acid Copolymer.

    PubMed

    Amaral, Adérito J R; Pasparakis, George

    2016-09-01

    Cell surface engineering has emerged as a powerful approach to forming cell aggregates/spheroids and cell-biomaterial ensembles with significant uses in tissue engineering and cell therapeutics. Herein, we demonstrate that cell membrane remodeling with a thermoresponsive boronic acid copolymer induces the rapid formation of spheroids using either cancer or cardiac cell lines under conventional cell culture conditions at minute concentrations. It is shown that the formation of well-defined spheroids is accelerated by at least 24 h compared to non-polymer-treated controls, and, more importantly, the polymer allows for fine control of the aggregation kinetics owing to its stimulus response to temperature and glucose content. On the basis of its simplicity and effectiveness to promote cellular aggregation, this platform holds promise in three-dimensional tissue/tumor modeling and tissue engineering applications. PMID:27571512

  10. Delivery of nucleic acid therapeutics by genetically engineered hematopoietic stem cells

    PubMed Central

    Doering, Christopher B.; Archer, David; Spencer, H. Trent

    2010-01-01

    Several populations of adult human stem cells have been identified, but only a few of these are in routine clinical use. The hematopoietic stem cell (HSC) is arguably the most well characterized and the most routinely transplanted adult stem cell. Although details regarding several aspects of this cell’s phenotype are not well understood, transplant of HSCs has advanced to become the standard of care for the treatment of a range of monogenic diseases and several types of cancer. It has also proven to be an excellent target for genetic manipulation, and clinical trials have already demonstrated the usefulness of targeting this cell as a means of delivering nucleic acid therapeutics for the treatment of several previously incurable diseases. It is anticipated that additional clinical trials will soon follow, such as genetically engineering HSCs with vectors to treat monogenic diseases such as hemophilia A. In addition to the direct targeting of HSCs, induced pluripotent stem (iPS) cells have the potential to replace virtually any engineered stem cell therapeutic, including HSCs. We now know that for the broad use of genetically-modified HSCs for the treatment of non-lethal diseases, e.g. hemophilia A, we must be able to regulate the introduction of nucleic acid sequences into these target cells. We can begin to refine transduction protocols to provide safer approaches to genetically manipulate HSCs and strategies are being developed to improve the overall safety of gene transfer. This review focuses on recent advances in the systemic delivery of nucleic acid therapeutics using genetically-modified stem cells, specifically focusing on i) the use of retroviral vectors to genetically modify HSCs, ii) the expression of fVIII from hematopoietic stem cells for the treatment of hemophilia A, and iii) the use of genetically engineered hematopoietic cells generated from iPS cells as treatment for disorders of hematopoiesis. PMID:20869414

  11. Fatty acid regulates gene expression and growth of human prostate cancer PC-3 cells

    NASA Technical Reports Server (NTRS)

    Hughes-Fulford, M.; Chen, Y.; Tjandrawinata, R. R.

    2001-01-01

    It has been proposed that the omega-6 fatty acids increase the rate of tumor growth. Here we test that hypothesis in the PC-3 human prostate tumor. We found that the essential fatty acids, linoleic acid (LA) and arachidonic acid (AA), and the AA metabolite PGE(2) stimulate tumor growth while oleic acid (OA) and the omega-3 fatty acid, eicosapentaenoic acid (EPA) inhibited growth. In examining the role of AA in growth response, we extended our studies to analyze changes in early gene expression induced by AA. We demonstrate that c-fos expression is increased within minutes of addition in a dose-dependent manner. Moreover, the immediate early gene cox-2 is also increased in the presence of AA in a dose-dependent manner, while the constitutive cox-1 message was not increased. Three hours after exposure to AA, the synthesis of PGE(2) via COX-2 was also increased. Previous studies have demonstrated that AA was primarily delivered by low density lipoprotein (LDL) via its receptor (LDLr). Since it is known that hepatomas, acute myelogenous leukemia and colorectal tumors lack normal cholesterol feedback, we examined the role of the LDLr in growth regulation of the PC-3 prostate cancer cells. Analysis of ldlr mRNA expression and LDLr function demonstrated that human PC-3 prostate cancer cells lack normal feedback regulation. While exogenous LDL caused a significant stimulation of cell growth and PGE(2) synthesis, no change was seen in regulation of the LDLr by LDL. Taken together, these data show that normal cholesterol feedback of ldlr message and protein is lost in prostate cancer. These data suggest that unregulated over-expression of LDLr in tumor cells would permit increased availability of AA, which induces immediate early genes c-fos and cox-2 within minutes of uptake.

  12. Direct hepatic differentiation of mouse embryonic stem cells induced by valproic acid and cytokines

    PubMed Central

    Dong, Xue-Jun; Zhang, Guo-Rong; Zhou, Qing-Jun; Pan, Ruo-Lang; Chen, Ye; Xiang, Li-Xin; Shao, Jian-Zhong

    2009-01-01

    AIM: To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes. METHODS: Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem (ES) cells were obtained in a sequential manner, induced by valproic acid (VPA) and cytokines (hepatocyte growth factor, epidermal growth factor and insulin). Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy. Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression profiles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepatocytes. Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells. Furthermore, FACS and electron microscopy were used for the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells. RESULTS: Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The differentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers, in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by significant cell cycle arrest and selective survival of differentiating cells towards hepatic lineages. CONCLUSION: Hepatic cells

  13. Regulation of the Nucleolar DNA-Dependent RNA Polymerase by Amino Acids in Ehrlich Ascites Tumor Cells

    PubMed Central

    Franze-Fernández, M. T.; Pogo, A. O.

    1971-01-01

    Experiments were performed to ascertain the degree to which the amount of amino acids might be one of the regulatory factors that control the activity of the nucleolar RNA polymerase. Assays of the enzymatic activity were done with isolated nuclei from cells incubated with low and high concentrations of amino acids. Soon after the cells were exposed to a medium enriched in amino acids, a rapid increase of nucleolar RNA polymerase activity occurred. A similar result was obtained in cells incubated with lower concentrations of amino acids. However, the rate of ribosomal RNA synthesized was regularly much higher in cells incubated in a medium enriched with amino acids than in a medium low in amino acids. Apparently, the amino acids only controlled ribosomal RNA synthesis. Thus, neither maturation, processing, and transport of nuclear precursors into cytoplasmic ribosomal RNA, nor the synthesis of rapidly labeled RNA was affected. PMID:4108870

  14. Cell nucleus targeting for living cell extraction of nucleic acid associated proteins with intracellular nanoprobes of magnetic carbon nanotubes.

    PubMed

    Zhang, Yi; Hu, Zhengyan; Qin, Hongqiang; Liu, Fangjie; Cheng, Kai; Wu, Ren'an; Zou, Hanfa

    2013-08-01

    Since nanoparticles could be ingested by cells naturally and target at a specific cellular location as designed, the extraction of intracellular proteins from living cells for large-scale analysis by nanoprobes seems to be ideally possible. Nucleic acid associated proteins (NAaP) take the crucial position during biological processes in maintaining and regulating gene structure and gene related behaviors, yet there are still challenges during the global investigation of intracellular NAaP, especially from living cells. In this work, a strategy to extract intracellular proteins from living cells with the magnetic carbon nanotube (oMWCNT@Fe3O4) as an intracellular probe is developed, to achieve the high throughput analysis of NAaP from living human hepatoma BEL-7402 cells with a mass spectrometry-based proteomic approach. Due to the specific intracellular localization of the magnetic carbon nanotubes around nuclei and its strong interaction with nucleic acids, the highly efficient extraction was realized for cellular NAaP from living cells, with the capability of identifying 2383 intracellular NAaP from only ca. 10,000 living cells. This method exhibited potential applications in dynamic and in situ analysis of intracellular proteins.

  15. Effects of the food additive, citric acid, on kidney cells of mice.

    PubMed

    Chen, Xg; Lv, Qx; Liu, Ym; Deng, W

    2015-01-01

    Citric acid is a food additive that is widely used in the food and drink industry. We investigated the effects of citric acid injection on mouse kidney. Forty healthy mice were divided into four groups of 10 including one control group and three citric acid-treated groups. Low dose, middle dose and high dose groups were given doses of 120, 240 and 480 mg/kg of citric acid, respectively. On day 7, kidney tissues were collected for histological, biochemical and molecular biological examination. We observed shrinkage of glomeruli, widened urinary spaces and capillary congestion, narrowing of the tubule lumen, edema and cytoplasmic vacuolated tubule cells, and appearance of pyknotic nuclei. The relation between histopathological changes and citric acid was dose dependent. Compared to the control, T-SOD and GSH-Px activities in the treated groups decreased with increasing doses of citric acid, NOS activity tended to increase, and H2O2 and MDA contents gradually decreased, but the differences between any treated group and the control were not statistically significant. The apoptosis assay showed a dose-dependent increase of caspase-3 activity after administering citrate that was statistically significant. DNA ladder formation occurred after treatment with any dose of citric acid. We concluded that administration of citric acid may cause renal toxicity in mice.

  16. Expression of a retinoic acid signature in circulating CD34 cells from coronary artery disease patients

    PubMed Central

    2010-01-01

    Background Circulating CD34+ progenitor cells have the potential to differentiate into a variety of cells, including endothelial cells. Knowledge is still scarce about the transcriptional programs used by CD34+ cells from peripheral blood, and how these are affected in coronary artery disease (CAD) patients. Results We performed a whole genome transcriptome analysis of CD34+ cells, CD4+ T cells, CD14+ monocytes, and macrophages from 12 patients with CAD and 11 matched controls. CD34+ cells, compared to other mononuclear cells from the same individuals, showed high levels of KRAB box transcription factors, known to be involved in gene silencing. This correlated with high expression levels in CD34+ cells for the progenitor markers HOXA5 and HOXA9, which are known to control expression of KRAB factor genes. The comparison of expression profiles of CD34+ cells from CAD patients and controls revealed a less naïve phenotype in patients' CD34+ cells, with increased expression of genes from the Mitogen Activated Kinase network and a lowered expression of a panel of histone genes, reaching levels comparable to that in more differentiated circulating cells. Furthermore, we observed a reduced expression of several genes involved in CXCR4-signaling and migration to SDF1/CXCL12. Conclusions The altered gene expression profile of CD34+ cells in CAD patients was related to activation/differentiation by a retinoic acid-induced differentiation program. These results suggest that circulating CD34+ cells in CAD patients are programmed by retinoic acid, leading to a reduced capacity to migrate to ischemic tissues. PMID:20565948

  17. Energization of amino acid transport in energy-depleted Ehrlich cells and plasma membrane vesicles.

    PubMed

    Ohsawa, M; Kilberg, M S; Kimmel, G; Christensen, H N

    1980-06-20

    We redirect attention to contributions to the energization, of the active transport of amino acids in the Ehrlich cell, beyond the known energization, by down-gradient comigration of Na+, beyond possible direct energization by coupling to ATP breakdown, and beyond known energization by exchange with prior accumulations of amino acids. We re-emphasize the uphill operation of System L, and by prior depletion of cellular amino acids show that this system must receive energy beyond that made available by their coupled exodus. After this depletion the Na+-indepdendent accumulation of the norbornane amino acid, 2-aminobicycloheptane-2-carboxylic acid becomes strongly subject to stimulation by incubation with glucose. Energy transfer between Systems A and L through the mutual substrate action of ordinary amino acids was minimized although not entirely avoided by the use of amino acid analogs specific to each system. When 2,4-dinitrophenol was included in the depleting treatment, and pyruvate, phenazine methosulfate, or glucose used for restoration, recovery of uptake of the norbornane amino acid was independent of external Na+ or K+ levels. Restoration or the uptake of 2-(methylamino)isobutyric acid was, however, decreased by omission of external K+. Contrary to an earlier finding, restoration of uptake of each of these amino acids was associated with distinct and usually correlated rises in cellular ATP levels. ATP addition failed to stimulate exodus of the norbornane amino acid from plasma membrane vesicles, although either NADH or phenazine methosulfate did stimulate exodus. ATP production and use is thus associated with transport energization although evidence for a direct role failed to appear.

  18. Co-culture of vascular endothelial cells and smooth muscle cells by hyaluronic acid micro-pattern on titanium surface

    NASA Astrophysics Data System (ADS)

    Li, Jingan; Li, Guicai; Zhang, Kun; Liao, Yuzhen; Yang, Ping; Maitz, Manfred F.; Huang, Nan

    2013-05-01

    Micro-patterning as an effective bio-modification technique is increasingly used in the development of biomaterials with superior mechanical and biological properties. However, as of now, little is known about the simultaneous regulation of endothelial cells (EC) and smooth muscle cells (SMC) by cardiovascular implants. In this study, a co-culture system of EC and SMC was built on titanium surface by the high molecular weight hyaluronic acid (HMW-HA) micro-pattern. Firstly, the micro-pattern sample with a geometry of 25 μm wide HMW-HA ridges, and 25 μm alkali-activated Ti grooves was prepared by microtransfer molding (μTM) for regulating SMC morphology. Secondly, hyaluronidase was used to decompose high molecular weight hyaluronic acid into low molecular weight hyaluronic acid which could promote EC adhesion. Finally, the morphology of the adherent EC was elongated by the SMC micro-pattern. The surface morphology of the patterned Ti was imaged by SEM. The existence of high molecular weight hyaluronic acid on the modified Ti surface was demonstrated by FTIR. The SMC micro-pattern and EC/SMC co-culture system were characterized by immunofluorescence microscopy. The nitric oxide release test and cell retention calculation were used to evaluate EC function on inhibiting hyperplasia and cell shedding, respectively. The results indicate that EC in EC/SMC co-culture system displayed a higher NO release and cell retention compared with EC cultured alone. It can be suggested that the EC/SMC co-culture system possessed superiority to EC cultured alone in inhibiting hyperplasia and cell shedding at least in a short time of 24 h.

  19. Effects of coolant parameters on steady state temperature distribution in phospheric-acid fuel cell electrode

    NASA Technical Reports Server (NTRS)

    Alkasab, K. A.; Abdul-Aziz, A.

    1991-01-01

    The influence of thermophysical properties and flow rate on the steady-state temperature distribution in a phosphoric-acid fuel cell electrode plate was experimentally investigated. An experimental setup that simulates the operating conditions prevailing in a phosphoric-acid fuel cell stack was used. The fuel cell cooling system utilized three types of coolants to remove excess heat generated in the cell electrode and to maintain a reasonably uniform temperature distribution in the electrode plate. The coolants used were water, engine oil, and air. These coolants were circulated at Reynolds number ranging from 1165 to 6165 for water; 3070 to 6864 for air; and 15 to 79 for oil. Experimental results are presented.

  20. Polyunsaturated fatty acids in the modulation of T-cell signalling.

    PubMed

    Akhtar Khan, Naim

    2010-01-01

    n-3 polyunsaturated fatty acids (PUFA) have been shown to modulate immune responses. These agents, being considered as adjuvant immunosuppressants, have been used in the treatment of various inflammatory and autoimmune diseases. However, the molecular mechanisms of action of n-3 PUFA-induced immunosuppressive effects are not well-understood. Since exogenous n-3 PUFA, under in vitro and in vivo conditions, are efficiently incorporated into T-cell plasma membranes, a number of recent studies have demonstrated that these agents may modulate T-cell signalling. In this review, the interactions of n-3 PUFA with the second messenger cascade initiated during early and late events of T-cell activation are discussed. We particularly focus on how these fatty acids can modulate the production of diacylglycerol and the activation of protein kinase C, mitogen activated protein kinase, calcium signalling and translocation of transcriptional factors, implicated in the regulation of gene transcription in T-cells.

  1. Retinoic acid receptor alpha mediates growth inhibition by retinoids in human colon carcinoma HT29 cells.

    PubMed

    Nicke, B; Kaiser, A; Wiedenmann, B; Riecken, E O; Rosewicz, S

    1999-08-11

    Although retinoids have been suggested to inhibit chemically induced colon carcinogenesis, the molecular mechanisms underlying retinoid-mediated growth regulation in colon carcinoma cells are unknown. Therefore, we investigated the biological effects of retinoids on growth in HT29 colon carcinoma cells. All-trans retinoic acid (ATRA) treatment of HT29 cells resulted in a profound inhibition of anchorage-independent growth without biochemical or morphological evidence for induction of differentiation. Treatment with the selective RARalpha agonist Ro 40-6055 completely mimicked the effects of ATRA on growth and transactivation of a betaRAREx2-luciferase reporter construct, while RARbeta- and gamma-specific analogues were ineffective. Furthermore, ATRA-regulated growth and transactivation could be completely blocked by a RARalpha-selective receptor antagonist. Thus, ATRA potently inhibits anchorage-independent growth in HT29 cells and this effect is mainly if not exclusively mediated by the retinoic acid receptor alpha.

  2. Valproic acid improves second-line regimen of small cell lung carcinoma in preclinical models

    PubMed Central

    Hubaux, Roland; Vandermeers, Fabian; Cosse, Jean-Philippe; Crisanti, Cecilia; Kapoor, Veena; Albelda, Steven M.; Mascaux, Céline; Delvenne, Philippe; Hubert, Pascale

    2015-01-01

    With 5-year survival rates below 5%, small cell lung carcinoma (SCLC) has very poor prognosis and requires improved therapies. Despite an excellent overall response to first-line therapy, relapses are frequent and further treatments are disappointing. The goal of the study was to improve second-line therapy of SCLC. The effect of chemotherapeutic agents was evaluated in cell lines (apoptosis, reactive oxygen species, and RNA and protein expression) and in mouse models (tumour development). We demonstrate here that valproic acid, a histone deacetylase inhibitor, improves the efficacy of a second-line regimen (vindesine, doxorubicin and cyclophosphamide) in SCLC cells and in mouse models. Transcriptomic profiling integrating microRNA and mRNA data identifies key signalling pathways in the response of SCLC cells to valproic acid, opening new prospects for improved therapies. PMID:27730151

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

    PubMed

    Leienbach, K W; Barz, W

    1976-08-01

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

  4. Gallic acid induces apoptosis in EGFR-mutant non-small cell lung cancers by accelerating EGFR turnover.

    PubMed

    Nam, Boas; Rho, Jin Kyung; Shin, Dong-Myung; Son, Jaekyoung

    2016-10-01

    Gallic acid is a common botanic phenolic compound, which is present in plants and foods worldwide. Gallic acid is implicated in various biological processes such as cell growth and apoptosis. Indeed, gallic acid has been shown to induce apoptosis in many cancer types. However, the molecular mechanisms of gallic acid-induced apoptosis in cancer, particularly lung cancer, are still unclear. Here, we report that gallic acid induces apoptosis in EGFR-mutant non-small cell lung cancer (NSCLC) cells, but not in EGFR-WT NSCLC cells. Treatment with gallic acid resulted in a significant reduction in proliferation and induction of apoptosis, only in EGFR-mutant NSCLC cells. Interestingly, treatment with gallic acid led to a robust decrease in EGFR levels, which is critical for NSCLC survival. Treatment with gallic acid had no significant effect on transcription, but induced EGFR turnover. Indeed, treatment with a proteasome inhibitor dramatically reversed gallic acid-induced EGFR downregulation. Moreover, treatment with gallic acid induced EGFR turnover leading to apoptosis in EGFR-TKI (tyrosine kinase inhibitor)-resistant cell lines, which are dependent on EGFR signaling for survival. Thus, these studies suggest that gallic acid can induce apoptosis in EGFR-dependent lung cancers that are dependent on EGFR for growth and survival via acceleration of EGFR turnover.

  5. Gallic acid induces apoptosis in EGFR-mutant non-small cell lung cancers by accelerating EGFR turnover.

    PubMed

    Nam, Boas; Rho, Jin Kyung; Shin, Dong-Myung; Son, Jaekyoung

    2016-10-01

    Gallic acid is a common botanic phenolic compound, which is present in plants and foods worldwide. Gallic acid is implicated in various biological processes such as cell growth and apoptosis. Indeed, gallic acid has been shown to induce apoptosis in many cancer types. However, the molecular mechanisms of gallic acid-induced apoptosis in cancer, particularly lung cancer, are still unclear. Here, we report that gallic acid induces apoptosis in EGFR-mutant non-small cell lung cancer (NSCLC) cells, but not in EGFR-WT NSCLC cells. Treatment with gallic acid resulted in a significant reduction in proliferation and induction of apoptosis, only in EGFR-mutant NSCLC cells. Interestingly, treatment with gallic acid led to a robust decrease in EGFR levels, which is critical for NSCLC survival. Treatment with gallic acid had no significant effect on transcription, but induced EGFR turnover. Indeed, treatment with a proteasome inhibitor dramatically reversed gallic acid-induced EGFR downregulation. Moreover, treatment with gallic acid induced EGFR turnover leading to apoptosis in EGFR-TKI (tyrosine kinase inhibitor)-resistant cell lines, which are dependent on EGFR signaling for survival. Thus, these studies suggest that gallic acid can induce apoptosis in EGFR-dependent lung cancers that are dependent on EGFR for growth and survival via acceleration of EGFR turnover. PMID:27597244