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Sample records for cell surface carbohydrates

  1. Cell surface carbohydrates as prognostic markers in human carcinomas

    DEFF Research Database (Denmark)

    Dabelsteen, Erik

    1996-01-01

    Tumour development is usually associated with changes in cell surface carbohydrates. These are often divided into changes related to terminal carbohydrate structures, which include incomplete synthesis and modification of normally existing carbohydrates, and changes in the carbohydrate core...... structure. The latter includes chain elongation of both glycolipids and proteins, increased branching of carbohydrates in N-linked glycoproteins, and blocked synthesis of carbohydrates in O-linked mucin-like glycoproteins. In mature organisms, expression of distinct carbohydrates is restricted to specific...... cell types; within a given tissue, variation in expression may be related to cell maturation. Tumour-associated carbohydrate structures often reflect a certain stage of cellular development; most of these moieties are structures normally found in other adult or embryonic tissues. There is no unique...

  2. Vaccines based on the cell surface carbohydrates of pathogenic bacteria

    Directory of Open Access Journals (Sweden)

    Jones Christopher

    2005-01-01

    Full Text Available Glycoconjugate vaccines, in which a cell surface carbohydrate from a micro-organism is covalently attached to an appropriate carrier protein are proving to be the most effective means to generate protective immune responses to prevent a wide range of diseases. The technology appears to be generic and applicable to a wide range of pathogens, as long as antibodies against surface carbohydrates help protect against infection. Three such vaccines, against Haemophilus influenzae type b, Neisseria meningitidis Group C and seven serotypes of Streptococcus pneumoniae, have already been licensed and many others are in development. This article discusses the rationale for the development and use of glycoconjugate vaccines, the mechanisms by which they elicit T cell-dependent immune responses and the implications of this for vaccine development, the role of physicochemical methods in the characterisation and quality control of these vaccines, and the novel products which are under development.

  3. Cell surface carbohydrate changes during embryonic and fetal skin development

    DEFF Research Database (Denmark)

    Dabelsteen, Erik; Holbrook, K; Clausen, H

    1986-01-01

    Monoclonal antibodies to four type 2 chain carbohydrate antigens were used for immunohistochemical studies of embryonic and fetal skin. The antibodies detected N-acetyllactosamine and 3 fucosyl substitutes of this, blood group antigen H, Lex, and Ley. Periderm consistently stained for N...... expressed at the early stages of development, but may later be modified either by sialylation or fucosylation into blood group H or Lex, or by Ley substances, respectively. The orderly and well-defined changes observed during skin differentiation are in agreement with other studies, which have demonstrated...... and granular cells in the epithelium. Lex stained both basal cells and intermediate cells positively, until keratinization around week 20 EGA. Ley is never expressed on basal cells. It is weakly expressed by intermediate cells from week 14 EGA. Our study demonstrates that N-acetyllactosamine is maximally...

  4. Differential carbohydrate binding and cell surface glycosylation of human cancer cell lines.

    Science.gov (United States)

    Arndt, Nadia X; Tiralongo, Joe; Madge, Paul D; von Itzstein, Mark; Day, Christopher J

    2011-09-01

    Currently there is only a modest level knowledge of the glycosylation status of immortalised cell lines that are commonly used in cancer biology as well as their binding affinities to different glycan structures. Through use of glycan and lectin microarray technology, this study has endeavoured to define the different bindings of cell surface carbohydrate structures to glycan-binding lectins. The screening of breast cancer MDA-MB435 cells, cervical cancer HeLa cells and colon cancer Caco-2, HCT116 and HCT116-FM6 cells was conducted to determine their differential bindings to a variety of glycan and lectin structures printed on the array slides. An inverse relationship between the number of glycan structures recognised and the variety of cell surface glycosylation was observed. Of the cell lines tested, it was found that four bound to sialylated structures in initial screening. Secondary screening in the presence of a neuraminidase inhibitor (4-deoxy-4-guanidino-Neu5Ac2en) significantly reduced sialic acid binding. The array technology has proven to be useful in determining the glycosylation signatures of various cell-lines as well as their glycan binding preferences. The findings of this study provide the groundwork for further investigation into the numerous glycan-lectin interactions that are exhibited by immortalised cell lines.

  5. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation.

    Science.gov (United States)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-08-21

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 10(10). The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.

  6. The cell surface protein Ag43 facilitates phage infection of Escherichia coli in the presence of bile salts and carbohydrates.

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    Gabig, Magdalena; Herman-Antosiewicz, Anna; Kwiatkowska, Marta; Los, Marcin; Thomas, Mark S; Wegrzyn, Grzegorz

    2002-05-01

    It was found that infection of Escherichia coli by bacteriophage lambda is inhibited in the presence of certain bile salts and carbohydrates when cells are in the "OFF" state for production of the phase-variable cell surface protein antigen 43 (Ag43). The inhibition of phage growth was found to be due to a significant impairment in the process of phage adsorption. Expression of the gene encoding Ag43 (agn43) from a plasmid or inactivation of the oxyR gene (encoding an activator of genes important for defence against oxidative stress) suppressed this inhibition. A mutation, rpoA341, in the gene encoding the alpha subunit of RNA polymerase also facilitated phage adsorption in the presence of bile salts and carbohydrates. The rpoA341 mutation promoted efficient production of Ag43 in a genetic background that would otherwise be in the "OFF" phase for expression of the agn43 gene. Analysis of a reporter gene fusion demonstrated that the promoter for the agn43 gene was more active in the rpoA341 mutant than in the otherwise isogenic rpoA(+) strain. The combined inhibitory action of bile salts and carbohydrates on phage adsorption and the abolition of this inhibition by production of Ag43 was not restricted to lambda, as a similar phenomenon was observed for the coliphages P1 and T4.

  7. (A structural assessment of the role of the cell surface carbohydrates of Rhizobium in the Rhizobium/legume symbiosis)

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, R.I.

    1991-01-01

    Research continued on the study of cell surface carbohydrates of Rhizobium. Objectives include: To characterize, at a structural level, the differences between the lipopolysaccharides of a representative number of strains from different Rhizobium species to determine which features of LPS structure are species-specific and might, therefore, be determinants of host specificity. Determine the effect(s) of nod gene induction on the structure of Rhizobium lipopolysaccharides and determine whether synthesis of a modified LPS molecule or a new surface glycoconjugate is initiated by nod gene induction. Develop a non-chemical means for rapidly screening large numbers of bacterial strains in order to determine which glycoconjugate structural features are conserved between strains of the same species. Provide the necessary structural information which, when coupled with developments in the rapidly expanding field of Rhizobium genetics, should lead to a clear understanding of the role of Rhizobium surface glycoconjugates in host/symbiont interactions. Progress is discussed.

  8. Surface characterization of carbohydrate microarrays.

    Science.gov (United States)

    Scurr, David J; Horlacher, Tim; Oberli, Matthias A; Werz, Daniel B; Kroeck, Lenz; Bufali, Simone; Seeberger, Peter H; Shard, Alexander G; Alexander, Morgan R

    2010-11-16

    Carbohydrate microarrays are essential tools to determine the biological function of glycans. Here, we analyze a glycan array by time-of-flight secondary ion mass spectrometry (ToF-SIMS) to gain a better understanding of the physicochemical properties of the individual spots and to improve carbohydrate microarray quality. The carbohydrate microarray is prepared by piezo printing of thiol-terminated sugars onto a maleimide functionalized glass slide. The hyperspectral ToF-SIMS imaging data are analyzed by multivariate curve resolution (MCR) to discern secondary ions from regions of the array containing saccharide, linker, salts from the printing buffer, and the background linker chemistry. Analysis of secondary ions from the linker common to all of the sugar molecules employed reveals a relatively uniform distribution of the sugars within the spots formed from solutions with saccharide concentration of 0.4 mM and less, whereas a doughnut shape is often formed at higher-concentration solutions. A detailed analysis of individual spots reveals that in the larger spots the phosphate buffered saline (PBS) salts are heterogeneously distributed, apparently resulting in saccharide concentrated at the rim of the spots. A model of spot formation from the evaporating sessile drop is proposed to explain these observations. Saccharide spot diameters increase with saccharide concentration due to a reduction in surface tension of the saccharide solution compared to PBS. The multivariate analytical partial least squares (PLS) technique identifies ions from the sugars that in the complex ToF-SIMS spectra correlate with the binding of galectin proteins.

  9. Carbohydrate profiling of fungal cell wall surface glycoconjugates of Trichophyton tonsurans and other keratinophilic filamentous fungi using lectins.

    Science.gov (United States)

    Leal, André Ferraz Goiana; de Lima Neto, Reginaldo Gonçalves; Macêdo, Danielle Patrícia Cerqueira; Beltrão, Eduardo Isidoro Carneiro; Neves, Rejane Pereira

    2011-11-01

    Various researchers have concluded that lectins are useful reagents for the study of fungal cell wall surface glycoconjugates. In this study, we evaluated the expression of N-acetyl-D-glucosamine, L-fucose, D-galactose and glucose/mannose on the cell wall surface of Trichophyton tonsurans and other keratinophilic filamentous fungi, using a simple lectin-binding protocol. The fungal cultures used were isolated from soils obtained from public parks by the hair-bait technique. The lectin assays used concanavalin A (Con A), wheat germ agglutinin (WGA), Ulex europeus agglutinin I (UEA-I) and peanut agglutinin (PNA), all conjugated with horseradish peroxidase. Adhesive tape was placed sticky-side down over the fungal colony, gently pressed and then removed. The fungal-tape samples were incubated with the lectin for 1 h at 4 °C. Lectin binding was visualised using 3,3-diaminobendizine (DAB) and hydrogen peroxidase. There was a high expression of N-acetyl-D-glucosamine on the cell wall surface of all fungi species tested, whereas the expression of L-fucose, D-galactose and glucose/mannose demonstrated inter-specific variations. The lectin-binding assay presented in this article eliminates many of the laborious steps involved in other protocols. The amount and quality of the mycelium and spores immobilised by the adhesive tapes were suitable for obtaining the carbohydrate profile in glycoconjugates of the cell wall surface of filamentous fungi.

  10. PPARγ regulates expression of carbohydrate sulfotransferase 11 (CHST11/C4ST1, a regulator of LPL cell surface binding.

    Directory of Open Access Journals (Sweden)

    Ismayil Tasdelen

    Full Text Available The transcription factor PPARγ is the key regulator of adipocyte differentiation, function and maintenance, and the cellular target of the insulin-sensitizing thiazolidinediones. Identification and functional characterization of genes regulated by PPARγ will therefore lead to a better understanding of adipocyte biology and may also contribute to the development of new anti-diabetic drugs. Here, we report carbohydrate sulfotransferase 11 (Chst11/C4st1 as a novel PPARγ target gene. Chst11 can sulphate chondroitin, a major glycosaminoglycan involved in development and disease. The Chst11 gene contains two functional intronic PPARγ binding sites, and is up-regulated at the mRNA and protein level during 3T3-L1 adipogenesis. Chst11 knockdown reduced intracellular lipid accumulation in mature adipocytes, which is due to a lowered activity of lipoprotein lipase, which may associate with the adipocyte cell surface through Chst11-mediated sulfation of chondroitin, rather than impaired adipogenesis. Besides directly inducing Lpl expression, PPARγ may therefore control lipid accumulation by elevating the levels of Chst11-mediated proteoglycan sulfation and thereby increasing the binding capacity for Lpl on the adipocyte cell surface.

  11. Synthesis and application of water-soluble, photoswitchable cyanine dyes for bioorthogonal labeling of cell-surface carbohydrates.

    Science.gov (United States)

    Mertsch, Alexander; Letschert, Sebastian; Memmel, Elisabeth; Sauer, Markus; Seibel, Jürgen

    2016-09-01

    The synthesis of cyanine dyes addressing absorption wavelengths at 550 and 648 nm is reported. Alkyne functionalized dyes were used for bioorthogonal click reactions by labeling of metabolically incorporated sugar-azides on the surface of living neuroblastoma cells, which were applied to direct stochastic optical reconstruction microscopy (dSTORM) for the visualization of cell-surface glycans in the nm-range.

  12. [A structural assessment of the role of the cell surface carbohydrates of Rhizobium in the Rhizobium/legume symbiosis]. Progress report, June 1989--June 1991

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, R.I.

    1991-12-31

    Research continued on the study of cell surface carbohydrates of Rhizobium. Objectives include: To characterize, at a structural level, the differences between the lipopolysaccharides of a representative number of strains from different Rhizobium species to determine which features of LPS structure are species-specific and might, therefore, be determinants of host specificity. Determine the effect(s) of nod gene induction on the structure of Rhizobium lipopolysaccharides and determine whether synthesis of a modified LPS molecule or a new surface glycoconjugate is initiated by nod gene induction. Develop a non-chemical means for rapidly screening large numbers of bacterial strains in order to determine which glycoconjugate structural features are conserved between strains of the same species. Provide the necessary structural information which, when coupled with developments in the rapidly expanding field of Rhizobium genetics, should lead to a clear understanding of the role of Rhizobium surface glycoconjugates in host/symbiont interactions. Progress is discussed.

  13. An investigation of the fine structure, cell surface carbohydrates, and appeal of the diatom Extubocellulus sp. as prey for small flagellates.

    Science.gov (United States)

    Martin-Cereceda, M; Williams, R; Guinea, A; Novarino, G

    2007-01-01

    The fine structure and surface exopolymers of a coastal planktonic nanodiatom of the sparsely reported genus Extubocellulus were studied respectively by scanning electron microscopy and confocal microscopy in conjunction with fluorescent lectins. Monitoring the suitability of the species as prey food for other protists was also investigated by video microscopy coupled with digital film. Cells are rectangular in girdle view, with a pervalvar axis longer than the apical axis. Valves are almost circular with a diameter of 2.8 to 3.6 microm. The valve face bears randomly distributed areolae (ca. 50 in 10 microm), which may be either open or occluded. Two small raised ocelluli occur at the apices, with a rim devoid of perforations and about 6-7 porelli. Glucose and N-acetyl-glucosamine moieties present on the surface of the live diatom were labelled with fluorescent lectins, and a differential pattern of distribution for both carbohydrates was observed. The potential role of fluorescent lectins as cellular probes of taxonomic value in small diatoms is compared with that of nucleotide and antibody probes. We provide the first illustrative evidence of the presence of Extubocellulus sp. in the cytoplasm of the nanoflagellate Goniomonas amphinema and of the egestion of diatom frustules. Results obtained are discussed in the light of the present knowledge of the role of carbohydrate-protein interactions in phagocytosis of prey by free-living protozoa.

  14. Carbohydrates and T cells: a sweet twosome.

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    Avci, Fikri Y; Li, Xiangming; Tsuji, Moriya; Kasper, Dennis L

    2013-04-01

    Carbohydrates as T cell-activating antigens have been generating significant interest. For many years, carbohydrates were thought of as T-independent antigens, however, more recent research had demonstrated that mono- or oligosaccharides glycosidically linked to peptides can be recognized by T cells. T cell recognition of these glycopeptides depends on the structure of both peptide and glycan portions of the antigen. Subsequently, it was discovered that natural killer T cells recognized glycolipids when presented by the antigen presenting molecule CD1d. A transformative insight into glycan-recognition by T cells occurred when zwitterionic polysaccharides were discovered to bind to and be presented by MHCII to CD4+ T cells. Based on this latter observation, the role that carbohydrate epitopes generated from glycoconjugate vaccines had in activating helper T cells was explored and it was found that these epitopes are presented to specific carbohydrate recognizing T cells through a unique mechanism. Here we review the key interactions between carbohydrate antigens and the adaptive immune system at the molecular, cellular and systems levels exploring the significant biological implications in health and disease.

  15. Carbohydrates

    Science.gov (United States)

    Carbohydrates are one of the main types of nutrients. They are the most important source of energy for your body. Your digestive system changes carbohydrates into glucose (blood sugar). Your body uses this ...

  16. Systemic localization of seven major types of carbohydrates on cell membranes by dSTORM imaging

    OpenAIRE

    Junling Chen; Jing Gao; Min Zhang; Mingjun Cai; Haijiao Xu; Junguang Jiang; Zhiyuan Tian; Hongda Wang

    2016-01-01

    Carbohydrates on the cell surface control intercellular interactions and play a vital role in various physiological processes. However, their systemic distribution patterns are poorly understood. Through the direct stochastic optical reconstruction microscopy (dSTORM) strategy, we systematically revealed that several types of representative carbohydrates are found in clustered states. Interestingly, the results from dual-color dSTORM imaging indicate that these carbohydrate clusters are prone...

  17. A high-power carbohydrate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Ragnar [SuFuCell AB, Bytaregatan 23, SE 222 21 Lund (Sweden); Folkesson, Boerje [Bronsaaldersvaegen 21, SE-226 54 Lund (Sweden); Spaziante, Placido M. [Cellennium Co., Ltd., 14th Floor Gypsum Metropolitan Tower, 539 Sri Ayudhaya Rd., Bangkok 10400 (Thailand); Veerasai, Waret [Chemistry Department, Faculty of Science, Mahidol University, Bangkok 10400 (Thailand); Exell, Robert H.B. [Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology Thonburi, 91 Prachauthit Rd., Bangmod, Tungkru, Bangkok 10140 (Thailand)

    2006-04-01

    This paper reports the development of a fuel cell consisting of a vanadium flow battery in which the vanadium ions are reduced by sugar (from a carbohydrate) to oxidation state +3 on one side of a membrane, and are oxidized to state +5 on the other side by oxygen. The theoretical upper limit to the conversion efficiency of the energy in sugar by this method under standard conditions is 54%. We have obtained efficiencies up to 45% in our laboratory tests. This way of using biomass for electricity production avoids the Carnot cycle losses in heat engines. (author)

  18. Sensitive carbohydrate detection using surface enhanced Raman tagging.

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    Vangala, Karthikeshwar; Yanney, Michael; Hsiao, Cheng-Te; Wu, Wells W; Shen, Rong-Fong; Zou, Sige; Sygula, Andrzej; Zhang, Dongmao

    2010-12-15

    Glycomic analysis is an increasingly important field in biological and biomedical research as glycosylation is one of the most important protein post-translational modifications. We have developed a new technique to detect carbohydrates using surface enhanced Raman spectroscopy (SERS) by designing and applying a Rhodamine B derivative as the SERS tag. Using a reductive amination reaction, the Rhodamine-based tag (RT) was successfully conjugated to three model carbohydrates (glucose, lactose, and glucuronic acid). SERS detection limits obtained with a 633 nm HeNe laser were ∼1 nM in concentration for all the RT-carbohydrate conjugates and ∼10 fmol in total sample consumption. The dynamic range of the SERS method is about 4 orders of magnitude, spanning from 1 nM to 5 μM. Ratiometric SERS quantification using isotope-substituted SERS internal references allows comparative quantifications of carbohydrates labeled with RT and deuterium/hydrogen substituted RT tags, respectively. In addition to enhancing the SERS detection of the tagged carbohydrates, the Rhodamine tagging facilitates fluorescence and mass spectrometric detection of carbohydrates. Current fluorescence sensitivity of RT-carbohydrates is ∼3 nM in concentration while the mass spectrometry (MS) sensitivity is about 1 fmol, achieved with a linear ion trap electrospray ionization (ESI)-MS instrument. Potential applications that take advantage of the high SERS, fluorescence, and MS sensitivity of this SERS tagging strategy are discussed for practical glycomic analysis where carbohydrates may be quantified with a fluorescence and SERS technique and then identified with ESI-MS techniques.

  19. Mechanistic insights into the distribution of carbohydrate clusters on cell membranes revealed by dSTORM imaging

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    Chen, Junling; Gao, Jing; Cai, Mingjun; Xu, Haijiao; Jiang, Junguang; Tian, Zhiyuan; Wang, Hongda

    2016-07-01

    Cell surface carbohydrates play significant roles in many physiological processes and act as primary markers to indicate various cellular physiological states. The functions of carbohydrates are always associated with their expression and distribution on cell membranes. Based on our previous work, we found that carbohydrates tend to form clusters; however, the underlying mechanism of these clusters remains unknown. Through the direct stochastic optical reconstruction microscopy (dSTORM) strategy, we found that with the contributions of lipid raft as a stable factor and actin cytoskeleton as a restrictive factor, carbohydrate clusters can stably exist with restricted size. Additionally, we revealed that the formation of most carbohydrate clusters (Gal and GlcANc clusters) depended on the carbohydrate-binding proteins (i.e., galectins) cross-linking their specific carbohydrate ligands. Our results clarify the organizational mechanism of carbohydrates on cell surfaces from their formation, stable existence and size-restriction, which promotes a better understanding of the relationship between the function and distribution of carbohydrates, as well as the structure of cell membranes.Cell surface carbohydrates play significant roles in many physiological processes and act as primary markers to indicate various cellular physiological states. The functions of carbohydrates are always associated with their expression and distribution on cell membranes. Based on our previous work, we found that carbohydrates tend to form clusters; however, the underlying mechanism of these clusters remains unknown. Through the direct stochastic optical reconstruction microscopy (dSTORM) strategy, we found that with the contributions of lipid raft as a stable factor and actin cytoskeleton as a restrictive factor, carbohydrate clusters can stably exist with restricted size. Additionally, we revealed that the formation of most carbohydrate clusters (Gal and GlcANc clusters) depended on the

  20. Lactobacillus plantarum gene clusters encoding putative cell-surface protein complexes for carbohydrate utilization are conserved in specific gram-positive bacteria

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    Muscariello Lidia

    2006-05-01

    Full Text Available Abstract Background Genomes of gram-positive bacteria encode many putative cell-surface proteins, of which the majority has no known function. From the rapidly increasing number of available genome sequences it has become apparent that many cell-surface proteins are conserved, and frequently encoded in gene clusters or operons, suggesting common functions, and interactions of multiple components. Results A novel gene cluster encoding exclusively cell-surface proteins was identified, which is conserved in a subgroup of gram-positive bacteria. Each gene cluster generally has one copy of four new gene families called cscA, cscB, cscC and cscD. Clusters encoding these cell-surface proteins were found only in complete genomes of Lactobacillus plantarum, Lactobacillus sakei, Enterococcus faecalis, Listeria innocua, Listeria monocytogenes, Lactococcus lactis ssp lactis and Bacillus cereus and in incomplete genomes of L. lactis ssp cremoris, Lactobacillus casei, Enterococcus faecium, Pediococcus pentosaceus, Lactobacillius brevis, Oenococcus oeni, Leuconostoc mesenteroides, and Bacillus thuringiensis. These genes are neither present in the genomes of streptococci, staphylococci and clostridia, nor in the Lactobacillus acidophilus group, suggesting a niche-specific distribution, possibly relating to association with plants. All encoded proteins have a signal peptide for secretion by the Sec-dependent pathway, while some have cell-surface anchors, novel WxL domains, and putative domains for sugar binding and degradation. Transcriptome analysis in L. plantarum shows that the cscA-D genes are co-expressed, supporting their operon organization. Many gene clusters are significantly up-regulated in a glucose-grown, ccpA-mutant derivative of L. plantarum, suggesting catabolite control. This is supported by the presence of predicted CRE-sites upstream or inside the up-regulated cscA-D gene clusters. Conclusion We propose that the CscA, CscB, CscC and Csc

  1. Interleukin-2 carbohydrate recognition modulates CTLL-2 cell proliferation.

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    Fukushima, K; Yamashita, K

    2001-03-01

    Interleukin-2 (IL-2) specifically recognizes high-mannose type glycans with five or six mannosyl residues. To determine whether the carbohydrate recognition activity of IL-2 contributes to its physiological activity, the inhibitory effects of high-mannose type glycans on IL-2-dependent CTLL-2 cell proliferation were investigated. Man(5)GlcNAc(2)Asn added to CTLL-2 cell cultures inhibited not only phosphorylation of tyrosine kinases but also IL-2-dependent cell proliferation. We found that a complex of IL-2, IL-2 receptor alpha, beta, gamma subunits, and tyrosine kinases was formed in rhIL-2-stimulated CTLL-2 cells. Among the components of this complex, only the IL-2 receptor alpha subunit was stained with Galanthus nivalis agglutinin which specifically recognizes high-mannose type glycans. This staining was diminished after digestion of the glycans with endo-beta-N-acetylglucosaminidase H or D, suggesting that at least a N-glycan containing Man(5)GlcNAc(2) is linked to the extracellular portion of the IL-2 receptor alpha subunit. Our findings indicate that IL-2 binds the IL-2 receptor alpha subunit through Man(5)GlcNAc(2) and a specific peptide sequence on the surface of CTLL-2 cells. When IL-2 binds to the IL-2Ralpha subunit, this may trigger formation of the high affinity complex of IL-2-IL-2Ralpha, -beta, and -gamma subunits, leading to cellular signaling.

  2. The cell surface of Trypanosoma cruzi

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    Wanderley de Souza

    1984-01-01

    Full Text Available The cell surface of trypanosomatids is formed by the plasma membrane and a layer of sub-pellicular microtubules which are connected to the plasma membrane. The plasma membrane is composed by proteins, lipids and carbohydrates which form the glycocalix. In this paper we will review briefly aspects related to the organization of the cell surface of Trypanosoma cruzi.

  3. Sulfated polysaccharides from marine sponges (Porifera): an ancestor cell-cell adhesion event based on the carbohydrate-carbohydrate interaction.

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    Vilanova, Eduardo; Coutinho, Cristiano C; Mourão, Paulo A S

    2009-08-01

    Marine sponges (Porifera) are ancient and simple eumetazoans. They constitute key organisms in the evolution from unicellular to multicellular animals. We now demonstrated that pure sulfated polysaccharides from marine sponges are responsible for the species-specific cell-cell interaction in these invertebrates. This conclusion was based on the following observations: (1) each species of marine sponge has a single population of sulfated polysaccharide, which differ among the species in their sugar composition and sulfate content; (2) sulfated polysaccharides from sponge interact with each other in a species-specific way, as indicated by an affinity chromatography assay, and this interaction requires calcium; (3) homologous, but not heterologous, sulfated polysaccharide inhibits aggregation of dissociated sponge cells; (4) we also observed a parallel between synthesis of the sulfated polysaccharide and formation of large aggregates of sponge cells, known as primmorphs. Once aggregation reached a plateau, the demand for the de novo synthesis of sulfated polysaccharides ceased. Heparin can mimic the homologous sulfated polysaccharide on the in vitro interaction and also as an inhibitor of aggregation of the dissociated sponge cells. However, this observation is not relevant for the biology of the sponge since heparin is not found in the invertebrate. In conclusion, marine sponges display an ancestor event of cell-cell adhesion, based on the calcium-dependent carbohydrate-carbohydrate interaction.

  4. Differences in carbohydrate profiles in batch culture grown planktonic and biofilm cells of Amphora rostrata Wm. Sm

    Digital Repository Service at National Institute of Oceanography (India)

    Khodse, V.B.; Bhosle, N.B.

    modes of growth, the concentration of total carbohydrates, carbohydrate fractions, neutral carbohydrates, uronic acids and amino sugars in planktonic and biofilm cells of Amphora rostrata were measured. The results showed that the distribution...

  5. The interaction between Histoplasma capsulatum cell wall carbohydrates and host components: relevance in the immunomodulatory role of histoplasmosis

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    Patricia Gorocica

    2009-05-01

    Full Text Available Histoplasma capsulatum is an intracellular fungal pathogen that causes respiratory and systemic disease by proliferating within phagocytic cells. The binding of H. capsulatum to phagocytes may be mediated by the pathogen's cell wall carbohydrates, glucans, which consist of glucose homo and hetero-polymers and whose glycosydic linkage types differ between the yeast and mycelial phases. The ±-1,3-glucan is considered relevant for H. capsulatum virulence, whereas the ²-1,3-glucan is antigenic and participates in the modulation of the host immune response. H. capsulatum cell wall components with lectin-like activity seem to interact with the host cell surface, while host membrane lectin-like receptors can recognize a particular fungal carbohydrate ligand. This review emphasizes the relevance of the main H. capsulatum and host carbohydrate-driven interactions that allow for binding and internalization of the fungal cell into phagocytes and its subsequent avoidance of intracellular elimination.

  6. Continuous microbial fuel cells convert carbohydrates to electricity

    Energy Technology Data Exchange (ETDEWEB)

    Rabaey, K.; Ossieur, W.; Verstraete, W. [Ghent Univ., Ghent (Belgium). Laboratory for Microbial Ecology and Technology; Verhaege, M. [Ghent Univ., Ghent (Belgium). Laboratory for Non-ferrous Metallurgy

    2004-07-01

    Microbial fuel cells (MFCs) are considered to be a potential new source of renewable energy for power applications. This study examined the electrochemistry of MFCs with particular reference to the problem of overpotential at the electrodes and the high internal resistance. The objective was to optimize the anodes of the biofuel cell using biological and chemical approaches. The fundamentals of electron transfer were studied along with the microbial ecology of the MFC. The problem of inserting redox mediators in the electrode mix was examined. A continuous microbial fuel cell was developed that is capable of efficiently biodegrading carbohydrates (glucose), and thereby produce electricity continuously. This study is a first step towards treating liquid waste streams in the future. 16 refs., 2 tabs., 2 figs.

  7. Study of surface carbohydrates in Galba truncatula tissues before and after infection with Fasciola hepatica

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    Georgieva, Katya; Georgieva, Liliya; Mizinska-Boevska, Yana; Stoitsova, Stoyanka R

    2016-01-01

    The presence and distribution of surface carbohydrates in the tissues of Galba truncatula snails uninfected or after infection with Fasciola hepatica as well as on the surface of the snail-pathogenic larval stages of the parasite were studied by lectin labelling assay. This is an attempt to find similarities that indicate possible mimicry, utilised by the parasite as an evasion strategy in this snail-trematode system. Different binding patterns were identified on head-foot-mantle, hepatopancreas, genital glands, renopericardial complex of the host as well as of the snail-pathogenic larval stages of F. hepatica. The infection with F. hepatica leads to changes of labelling with Glycine max in the head-mantle cells and Arachis hypogaea in the tubular epithelium of the hepatopancreas. The lectin binding on the other snail tissues is not changed by the development of the larvae. Our data clearly demonstrated the similarity in labelling of G. truncatula tissues and the surface of the snail-pathogenic larval stages of F. hepatica. The role of glycosylation of the contact surfaces of both organisms in relation to the host-parasite interactions is also discussed. PMID:27384082

  8. Study of surface carbohydrates in Galba truncatula tissues before and after infection with Fasciola hepatica.

    Science.gov (United States)

    Georgieva, Katya; Georgieva, Liliya; Mizinska-Boevska, Yana; Stoitsova, Stoyanka R

    2016-07-01

    The presence and distribution of surface carbohydrates in the tissues of Galba truncatula snails uninfected or after infection with Fasciola hepatica as well as on the surface of the snail-pathogenic larval stages of the parasite were studied by lectin labelling assay. This is an attempt to find similarities that indicate possible mimicry, utilised by the parasite as an evasion strategy in this snail-trematode system. Different binding patterns were identified on head-foot-mantle, hepatopancreas, genital glands, renopericardial complex of the host as well as of the snail-pathogenic larval stages of F. hepatica. The infection with F. hepatica leads to changes of labelling with Glycine max in the head-mantle cells and Arachis hypogaea in the tubular epithelium of the hepatopancreas. The lectin binding on the other snail tissues is not changed by the development of the larvae. Our data clearly demonstrated the similarity in labelling of G. truncatula tissues and the surface of the snail-pathogenic larval stages of F. hepatica. The role of glycosylation of the contact surfaces of both organisms in relation to the host-parasite interactions is also discussed.

  9. Carbohydrate specificity of the recognition of diverse glycolipids by natural killer T cells.

    Science.gov (United States)

    Zajonc, Dirk M; Kronenberg, Mitchell

    2009-07-01

    Most T lymphocytes recognize peptide antigens bound to or presented by molecules encoded in the major histocompatibility complex (MHC). The CD1 family of antigen-presenting molecules is related to the MHC-encoded molecules, but CD1 proteins present lipid antigens, mostly glycolipids. Here we review T-lymphocyte recognition of glycolipids, with particular emphasis on the subpopulation known as natural killer T (NKT) cells. NKT cells influence many immune responses, they have a T-cell antigen receptor (TCR) that is restricted in diversity, and they share properties with cells of the innate immune system. NKT cells recognize antigens presented by CD1d with hexose sugars in alpha-linkage to lipids, although other, related antigens are known. The hydrophobic alkyl chains are buried in the CD1d groove, with the carbohydrate exposed for TCR recognition, together with the surface of the CD1d molecule. Therefore, understanding the biochemical basis for antigen recognition by NKT cells requires an understanding of how the trimolecular complex of CD1d, glycolipid, and the TCR is formed, which is in part a problem of carbohydrate recognition by the TCR. Recent investigations from our laboratories as well as studies from other groups have provided important information on the structural basis for NKT-cell specificity.

  10. Syntheses of alkenylated carbohydrate derivatives toward the preparation of monolayers on silicon surfaces

    NARCIS (Netherlands)

    Smet, de L.C.P.M.; Pukin, A.V.; Stork, G.A.; Vos, de C.H.; Visser, G.M.; Zuilhof, H.; Sudhölter, E.J.R.

    2004-01-01

    This note describes the synthesis of different alkenylated carbohydrate derivatives suitable for direct attachment to hydrogen-terminated silicon surfaces. The derivatives were alkenylated at the C-1 position, while the remaining hydroxyl groups were protected. The development of such new carbohydra

  11. A model system for carbohydrates interactions on single-crystalline Ru surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thanh Nam

    2015-07-01

    In this thesis, I present a model system for carbohydrate interactions with single-crystalline Ru surfaces. Geometric and electronic properties of copper phthalocyanine (CuPc) on top of graphene on hexagonal Ru(0001), rectangular Ru(10 anti 10) and vicinal Ru(1,1, anti 2,10) surfaces have been studied. First, the Fermi surfaces and band structures of the three Ru surfaces were investigated by high-resolution angle-resolved photoemission spectroscopy. The experimental data and theoretical calculations allow to derive detailed information about the momentum-resolved electronic structure. The results can be used as a reference to understand the chemical and catalytic properties of Ru surfaces. Second, graphene layers were prepared on the three different Ru surfaces. Using low-energy electron diffraction and scanning tunneling microscopy, it was found that graphene can be grown in well-ordered structures on all three surfaces, hexagonal Ru(0001), rectangular Ru(10 anti 10) and vicinal Ru(1,1, anti 2,10), although they have different surface symmetries. Evidence for a strong interaction between graphene and Ru surfaces is a 1.3-1.7 eV increase in the graphene π-bands binding energy with respect to free-standing graphene sheets. This energy variation is due to the hybridization between the graphene pi bands and the Ru 4d electrons, while the lattice mismatch does not play an important role in the bonding between graphene and Ru surfaces. Finally, the geometric and electronic structures of CuPc on Ru(10 anti 10), graphene/Ru(10 anti 10), and graphene/Ru(0001) have been studied in detail. CuPc molecules can be grown well-ordered on Ru(10 anti 10) but not on Ru(0001). The growth of CuPc on graphene/Ru(10 anti 10) and Ru(0001) is dominated by the Moire pattern of graphene. CuPc molecules form well-ordered structures with rectangular unit cells on graphene/Ru(10 anti 10) and Ru(0001). The distance of adjacent CuPc molecules is 15±0.5 Aa and 13±0.5 Aa on graphene/Ru(0001

  12. COUPLING OF LIPOPOLYSACCHARIDE-DERIVED CARBOHYDRATES ONTO SOLID SURFACES

    DEFF Research Database (Denmark)

    2000-01-01

    The present invention provides a method for immobilising a polysaccharide (PS) to a solid surface, said polysaccharide having a keto-carboxy group (-C(=O)-COOH) or a ketal or hemiketal group corresponding thereto, e.g. derived from KDO (2-keto-3-deoxy-D-mannooctonic acid), the method comprising...... the steps of: (a) forming a covalent bond between the carboxy group of the polysaccharide and a reporter molecule (RM). Comprising a recognition/substrate site (e.g. biotin or an anthraquinone); and (b) immobilising for diagnostic purposes, e.g. for the detection of bacterial infections from Gram...

  13. Chemical synthesis of carbohydrates and their surface immobilization: a brief introduction.

    Science.gov (United States)

    Werz, Daniel B

    2012-01-01

    For all carbohydrate microarrays, two important prerequisites are necessary: the carbohydrate of interest has to be obtained either by isolation from natural sources, enzymatic or chemical synthesis; an immobilization of the carbohydrate at the surface of the chip has to be achieved. This chapter provides a very brief overview of the chemical synthesis of carbohydrates (creation of building blocks, assembly, and deprotection) and of immobilization techniques. Numerous methods are known to construct oligosaccharides by chemical methods. A typical monosaccharide building block, used in oligosaccharide assembly, is equipped with different protecting groups that mask the hydroxyl and amine groups. In general, a good leaving group at the anomeric center that can easily be activated is mandatory; especially trichloroacetimidates, phosphates, and thioethers have been widely used for the creation of glycosidic bonds. After the complete assembly of the oligosaccharide, a global deprotection of all permanent protecting groups affords the desired target structure with free hydroxyl groups. Linkers, which were introduced during the synthesis, must often be modified at the end to create appropriate functionalities for surface immobilization.

  14. Fiber Type-Specific Satellite Cell Content in Cyclists Following Heavy Training with Carbohydrate and Carbohydrate-Protein Supplementation

    Science.gov (United States)

    McKenzie, Alec I.; D'Lugos, Andrew C.; Saunders, Michael J.; Gworek, Keith D.; Luden, Nicholas D.

    2016-01-01

    The central purpose of this study was to evaluate the fiber type-specific satellite cell and myonuclear responses of endurance-trained cyclists to a block of intensified training, when supplementing with carbohydrate (CHO) vs. carbohydrate-protein (PRO). In a crossover design, endurance-trained cyclists (n = 8) performed two consecutive training periods, once supplementing with CHO (de facto “control” condition) and the other with PRO. Each training period consisted of 10 days of intensified cycle training (ICT–120% increase in average training duration) followed by 10 days of recovery (RVT–reduced volume training; 33% volume reduction vs. normal training). Skeletal muscle biopsies were obtained from the vastus lateralis before and after ICT and again following RVT. Immunofluorescent microscopy was used to quantify SCs (Pax7+), myonuclei (DAPI+), and myosin heavy chain I (MyHC I). Data are expressed as percent change ± 90% confidence limits. The 10-day block of ICTCHO increased MyHC I SC content (35 ± 28%) and myonuclear density (16 ± 6%), which remained elevated following RVTCHO (SC = 69 ± 50% vs. PRE; Nuclei = 17 ± 15% vs. PRE). MyHC II SC and myonuclei were not different following ICTCHO, but were higher following RVTCHO (SC = +33 ± 31% vs. PRE; Nuclei = 15 ± 14% vs. PRE), indicating a delayed response compared to MyHC I fibers. The MyHC I SC pool increased following ICTPRO (37 ± 37%), but without a concomitant increase in myonuclei. There were no changes in MyHC II SC or myonuclei following ICTPRO. Collectively, these trained endurance cyclists possessed a relatively large pool of SCs that facilitated rapid (MyHC I) and delayed (MyHC II) satellite cell proliferation and myonuclear accretion under carbohydrate conditions. The current findings strengthen the growing body of evidence demonstrating alterations in satellite cell number in the absence of hypertrophy. Satellite cell pool expansion is typically viewed as an advantageous response to

  15. Glycosynapses: microdomains controlling carbohydrate-dependent cell adhesion and signaling

    Directory of Open Access Journals (Sweden)

    Senitiroh Hakomori

    2004-09-01

    Full Text Available The concept of microdomains in plasma membranes was developed over two decades, following observation of polarity of membrane based on clustering of specific membrane components. Microdomains involved in carbohydrate-dependent cell adhesion with concurrent signal transduction that affect cellular phenotype are termed "glycosynapse". Three types of glycosynapse have been distinguished: "type 1" having glycosphingolipid associated with signal transducers (small G-proteins, cSrc, Src family kinases and proteolipids; "type 2" having O-linked mucin-type glycoprotein associated with Src family kinases; and "type 3" having N-linked integrin receptor complexed with tetraspanin and ganglioside. Different cell types are characterized by presence of specific types of glycosynapse or their combinations, whose adhesion induces signal transduction to either facilitate or inhibit signaling. E.g., signaling through type 3 glycosynapse inhibits cell motility and differentiation. Glycosynapses are distinct from classically-known microdomains termed "caveolae", "caveolar membrane", or more recently "lipid raft", which are not involved in carbohydrate-dependent cell adhesion. Type 1 and type 3 glycosynapses are resistant to cholesterol-binding reagents, whereas structure and function of "caveolar membrane" or "lipid raft" are disrupted by these reagents. Various data indicate a functional role of glycosynapses during differentiation, development, and oncogenic transformation.O conceito de microdomínios em membrana plasmática foi desenvolvido há mais de duas décadas, após a observação da polaridade da membrana baseada no agrupamento de componentes específicos da membrana. Microdomínios envolvidos na adesão celular dependente de carboidrato, com transdução de sinal que afeta o fenótipo celular são denominados ''glicosinapses''. Três tipos de glicosinapse foram observados: ''tipo 1'' que possue glicoesfingolipídio associado com transdutores de sinal

  16. Carbohydrate microarrays

    DEFF Research Database (Denmark)

    Park, Sungjin; Gildersleeve, Jeffrey C; Blixt, Klas Ola;

    2012-01-01

    In the last decade, carbohydrate microarrays have been core technologies for analyzing carbohydrate-mediated recognition events in a high-throughput fashion. A number of methods have been exploited for immobilizing glycans on the solid surface in a microarray format. This microarray-based technol...

  17. Analysis of surface binding sites (SBSs) in carbohydrate active enzymes with focus on glycoside hydrolase families 13 and 77

    DEFF Research Database (Denmark)

    Cockburn, Darrell; Wilkens, Casper; Ruzanski, Christian

    2014-01-01

    Surface binding sites (SBSs) interact with carbohydrates outside of the enzyme active site. They are frequently situated on catalytic domains and are distinct from carbohydrate binding modules (CBMs). SBSs are found in a variety of enzymes and often seen in crystal structures. Notably about half ...

  18. Biophysical studies on calcium and carbohydrate binding to carbohydrate recognition domain of Gal/GalNAc lectin from Entamoeba histolytica: insights into host cell adhesion.

    Science.gov (United States)

    Yadav, Rupali; Verma, Kuldeep; Chandra, Mintu; Mukherjee, Madhumita; Datta, Sunando

    2016-09-01

    Entamoeba histolytica, an enteric parasite expresses a Gal/GalNAc-specific lectin that contributes to its virulence by establishing adhesion to host cell. In this study, carbohydrate recognition domain of Hgl (EhCRD) was purified and biophysical studies were conducted to understand the thermodynamic basis of its binding to carbohydrate and Ca(++) Here, we show that carbohydrate recognition domain (CRD) of the lectin binds to calcium through DPN motif. To decipher the role of calcium in carbohydrate binding and host cell adhesion, biophysical and cell-based studies were carried out. We demonstrated that the presence of the cation neither change the affinity of the lectin for carbohydrates nor alters its conformation. Mutation of the calcium-binding motif in EhCRD resulted in complete loss of ability to bind calcium but retained its affinity for carbohydrates. Purified EhCRD significantly diminished adhesion of the amebic trophozoites to Chinese Hamster Ovary (CHO) cells as well as triggered red blood cell agglutination. The calcium-binding defective mutant abrogated amebic adhesion to CHO cells similar to the wild-type protein, but it failed to agglutinate RBCs suggesting a differential role of the cation in these two processes. This study provides the first molecular description of the role of calcium in Gal/GalNAc mediated host cell adhesion.

  19. Application of surface plasmon resonance for the detection of carbohydrates, glycoconjugates, and measurement of the carbohydrate-specific interactions: a comparison with conventional analytical techniques. A critical review.

    Science.gov (United States)

    Safina, Gulnara

    2012-01-27

    Carbohydrates (glycans) and their conjugates with proteins and lipids contribute significantly to many biological processes. That makes these compounds important targets to be detected, monitored and identified. The identification of the carbohydrate content in their conjugates with proteins and lipids (glycoforms) is often a challenging task. Most of the conventional instrumental analytical techniques are time-consuming and require tedious sample pretreatment and utilising various labeling agents. Surface plasmon resonance (SPR) has been intensively developed during last two decades and has received the increasing attention for different applications, from the real-time monitoring of affinity bindings to biosensors. SPR does not require any labels and is capable of direct measurement of biospecific interaction occurring on the sensing surface. This review provides a critical comparison of modern analytical instrumental techniques with SPR in terms of their analytical capabilities to detect carbohydrates, their conjugates with proteins and lipids and to study the carbohydrate-specific bindings. A few selected examples of the SPR approaches developed during 2004-2011 for the biosensing of glycoforms and for glycan-protein affinity studies are comprehensively discussed.

  20. Effect of anti-carbohydrate antibodies on HIV infection in a monocytic cell line (U937)

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Clausen, H;

    1991-01-01

    . This study therefore investigated the neutralization of HIV in a monocytic cell line (U937) using mAbs against these carbohydrate gp120-epitopes. While antibodies against one of the epitopes (AI) neutralized infection of U937 cells despite binding to the Fc-receptor, one mAb against the sialosyl-Tn epitope...... enhanced infection. This enhancement was independent of complement and could be blocked by mAb Leu3a against the CD4-receptor. The study indicated that enhancement of infection in monocytic cells can occur by the same anti-carbohydrate antibodies that neutralize infection in lymphocytes, and that antibody...

  1. Fermentable carbohydrate stimulates FFAR2-dependent colonic PYY cell expansion to increase satiety

    Directory of Open Access Journals (Sweden)

    Lucy Brooks

    2017-01-01

    Conclusion: Our results demonstrate that FFAR2 is predominantly involved in regulating the effects of fermentable carbohydrate on metabolism and does so, in part, by enhancing PYY cell density and release. This highlights the potential for targeting enteroendocrine cell differentiation to treat obesity.

  2. Hydration Repulsion between Carbohydrate Surfaces Mediated by Temperature and Specific Ions

    Science.gov (United States)

    Chen, Hsieh; Cox, Jason R.; Ow, Hooisweng; Shi, Rena; Panagiotopoulos, Athanassios Z.

    2016-06-01

    Stabilizing colloids or nanoparticles in solution involves a fine balance between surface charges, steric repulsion of coating molecules, and hydration forces against van der Waals attractions. At high temperature and electrolyte concentrations, the colloidal stability of suspensions usually decreases rapidly. Here, we report a new experimental and simulation discovery that the polysaccharide (dextran) coated nanoparticles show ion-specific colloidal stability at high temperature, where we observed enhanced colloidal stability of nanoparticles in CaCl2 solution but rapid nanoparticle-nanoparticle aggregation in MgCl2 solution. The microscopic mechanism was unveiled in atomistic simulations. The presence of surface bound Ca2+ ions increases the carbohydrate hydration and induces strongly polarized repulsive water structures beyond at least three hydration shells which is farther-reaching than previously assumed. We believe leveraging the binding of strongly hydrated ions to macromolecular surfaces represents a new paradigm in achieving absolute hydration and colloidal stability for a variety of materials, particularly under extreme conditions.

  3. Chinese hamster ovary cell mutants with multiple glycosylation defects for production of glycoproteins with minimal carbohydrate heterogeneity.

    OpenAIRE

    Stanley, P.

    1989-01-01

    The production of glycoproteins with carbohydrates of defined structure and minimal heterogeneity is important for functional studies of mammalian carbohydrates. To facilitate such studies, several Chinese hamster ovary mutants that carry between two and four glycosylation mutations were developed. All of the lines grew readily in culture despite the drastic simplification of their surface carbohydrates. Therefore, both endogenous glycoproteins and those introduced by transfection can be obta...

  4. Expression of blood group I and i active carbohydrate sequences on cultured human and animal cell lines assessed by radioimmunoassays with monoclonal cold agglutinins

    Energy Technology Data Exchange (ETDEWEB)

    Childs, R.A.; Kapadia, A.; Feizi, T. (Clinical Research Centre, Harrow (UK))

    1980-05-01

    Human monoclonal anti-I und anti-i antibodies, reactive with known carbohydrate sequences, have been used as reagents to quantitate (by radioimmunoassay) and visualize (by immunofluorscence) the expression of the various blood group I and i antigenic determinants in a variety of cultured cell lines commonly used in laboratory investigations. It has been shown that the antigens they recognize are widely distributed on the surface of human and animal cell lines, expressed in varying amounts in different cell lines and on individual cells within a given cell line. In two cell lines, a transformation-associated increase in the expression of I antigen was observed. Because of their precise specificity for defined carbohydrate chain domains, these autoantibodies have become valuable reagents in biological chemistry.

  5. Expression of blood group I and I active carbohydrate sequences on cultured human and animal cell lines assessed by radioimmunoassays with monoclonal cold agglutinins

    Energy Technology Data Exchange (ETDEWEB)

    Childs, R.A.; Kapadia, A.; Feizi, T.

    1980-05-01

    Human monoclonal anti-I and anti-i, reactive with known carbohydrate sequences, have been used as reagents to quantitate (by radioimmunoassay) and visualize (by immunofluorescence) the expression of the various blood group I and i antigenic determinants in a variety of cultured cell lines commonly used in laboratory investigations. It has been shown that the antigens they recognize are widely distributed on the surface of human and animal cell lines, expressed in varying amounts in different cell lines and on individual cells within a given cell line. In two cell lines, a transformation-associated increase in the expression of I antigen was observed. Because of their precise specificity for defined carbohydrate chain domains, these autoantibodies have become valuable reagents in biological chemistry.

  6. Structural Studies of Complex Carbohydrates of Plant Cell Walls

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, Alan [Univ. of Georgia, Athens, GA (United States); Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States); O' Neill, Malcolm A. [Univ. of Georgia, Athens, GA (United States); York, William S. [Univ. of Georgia, Athens, GA (United States)

    2015-02-17

    Most of the solar energy captured by land plants is converted into the polysaccharides (cellulose, hemicellulose, and pectin) that are the predominant components of the cell wall. These walls, which account for the bulk of plant biomass, have numerous roles in the growth and development of plants. Moreover, these walls have a major impact on human life as they are a renewable source of biomass, a source of diverse commercially useful polymers, a major component of wood, and a source of nutrition for humans and livestock. Thus, understanding the molecular mechanisms that lead to wall assembly and how cell walls and their component polysaccharides contribute to plant growth and development is essential to improve and extend the productivity and value of plant materials. The proposed research will develop and apply advanced analytical and immunological techniques to study specific changes in the structures and interactions of the hemicellulosic and pectic polysaccharides that occur during differentiation and in response to genetic modification and chemical treatments that affect wall biosynthesis. These new techniques will make it possible to accurately characterize minute amounts of cell wall polysaccharides so that subtle changes in structure that occur in individual cell types can be identified and correlated to the physiological or developmental state of the plant. Successful implementation of this research will reveal fundamental relationships between polysaccharide structure, cell wall architecture, and cell wall functions.

  7. Synthesis of the Oligosaccharide Fragment of the Surface of TumorCell and Its Analogue

    Institute of Scientific and Technical Information of China (English)

    QinZhihui; ZhangLihe; LiZhongjun

    2001-01-01

    Selectins are a new class of carbohydrate-binding glycoproteins which have been identified on the surface ofspecific cell types, such as leukocytes,platelets and vascular endothelium.It is now known that the selectin-carbohydrate recognition not only play key roles at early stage of the inflammatory reaction,but also are very important for the invasion and metastasis of tumors.

  8. Human antimicrobial peptide LL-37 inhibits adhesion of Candida albicans by interacting with yeast cell-wall carbohydrates.

    Directory of Open Access Journals (Sweden)

    Pei-Wen Tsai

    Full Text Available Candida albicans is the major fungal pathogen of humans. Fungal adhesion to host cells is the first step of mucosal infiltration. Antimicrobial peptides play important roles in the initial mucosal defense against C. albicans infection. LL-37 is the only member of the human cathelicidin family of antimicrobial peptides and is commonly expressed in various tissues and cells, including epithelial cells of both the oral cavity and urogenital tract. We found that, at sufficiently low concentrations that do not kill the fungus, LL-37 was still able to reduce C. albicans infectivity by inhibiting C. albicans adhesion to plastic surfaces, oral epidermoid OECM-1 cells, and urinary bladders of female BALB/c mice. Moreover, LL-37-treated C. albicans floating cells that did not adhere to the underlying substratum aggregated as a consequence of LL-37 bound to the cell surfaces. According to the results of a competition assay, the inhibitory effects of LL-37 on cell adhesion and aggregation were mediated by its preferential binding to mannan, the main component of the C. albicans cell wall, and partially by its ability to bind chitin or glucan, which underlie the mannan layer. Therefore, targeting of cell-wall carbohydrates by LL-37 provides a new strategy to prevent C. albicans infection, and LL-37 is a useful, new tool to screen for other C. albicans components involved in adhesion.

  9. Rapid analysis of Listeria monocytogenes cell wall teichoic acid carbohydrates by ESI-MS/MS.

    Science.gov (United States)

    Eugster, Marcel R; Loessner, Martin J

    2011-01-01

    We report the application of electrospray ionization (ESI) mass spectrometry for compositional characterization of wall teichoic acids (WTA), a major component of gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS) of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria.

  10. Rapid analysis of Listeria monocytogenes cell wall teichoic acid carbohydrates by ESI-MS/MS.

    Directory of Open Access Journals (Sweden)

    Marcel R Eugster

    Full Text Available We report the application of electrospray ionization (ESI mass spectrometry for compositional characterization of wall teichoic acids (WTA, a major component of gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria.

  11. Intraspecific epitopic variation in a carbohydrate antigen exposed on the surface of Trichostrongylus colubriformis infective L3 larvae.

    Directory of Open Access Journals (Sweden)

    David R Maass

    2009-09-01

    Full Text Available The carbohydrate larval antigen, CarLA, is present on the exposed surface of all strongylid nematode infective L3 larvae tested, and antibodies against CarLA can promote rapid immune rejection of incoming Trichostrongylus colubriformis larvae in sheep. A library of ovine recombinant single chain Fv (scFv antibody fragments, displayed on phage, was prepared from B cell mRNA of field-immune sheep. Phage displaying scFvs that bind to the surface of living exsheathed T. colubriformis L3 larvae were identified, and the majority of worm-binding scFvs recognized CarLA. Characterization of greater than 500 worm surface binding phage resulted in the identification of nine different anti-CarLA scFvs that recognized three distinct T. colubriformis CarLA epitopes based on blocking and additive ELISA. All anti-CarLA scFvs were specific to the T. colubriformis species of nematode. Each of the three scFv epitope classes displayed identical Western blot recognition patterns and recognized the exposed surface of living T. colubriformis exsheathed L3 larvae. Surprisingly, each of the anti-CarLA scFvs was able to bind to only a subset of worms. Double-labelling indirect immunofluorescence revealed that the three classes of anti-CarLA scFvs recognize distinct, non-overlapping, T. colubriformis sub-populations. These results demonstrate that individual T. colubriformis L3 larvae display only one of at least three distinct antigenic forms of CarLA on their surface at any given time, and suggest that antigenic variation within CarLA is likely a mechanism of immune evasion in strongylid nematodes.

  12. Molecular recognition of surface-immobilized carbohydrates by a synthetic lectin

    Directory of Open Access Journals (Sweden)

    Melanie Rauschenberg

    2014-06-01

    Full Text Available The molecular recognition of carbohydrates and proteins mediates a wide range of physiological processes and the development of synthetic carbohydrate receptors (“synthetic lectins” constitutes a key advance in biomedical technology. In this article we report a synthetic lectin that selectively binds to carbohydrates immobilized in a molecular monolayer. Inspired by our previous work, we prepared a fluorescently labeled synthetic lectin consisting of a cyclic dimer of the tripeptide Cys-His-Cys, which forms spontaneously by air oxidation of the monomer. Amine-tethered derivatives of N-acetylneuraminic acid (NANA, β-D-galactose, β-D-glucose and α-D-mannose were microcontact printed on epoxide-terminated self-assembled monolayers. Successive prints resulted in simple microarrays of two carbohydrates. The selectivity of the synthetic lectin was investigated by incubation on the immobilized carbohydrates. Selective binding of the synthetic lectin to immobilized NANA and β-D-galactose was observed by fluorescence microscopy. The selectivity and affinity of the synthetic lectin was screened in competition experiments. In addition, the carbohydrate binding of the synthetic lectin was compared with the carbohydrate binding of the lectins concanavalin A and peanut agglutinin. It was found that the printed carbohydrates retain their characteristic selectivity towards the synthetic and natural lectins and that the recognition of synthetic and natural lectins is strictly orthogonal.

  13. Surface binding sites in carbohydrate active enzymes: An emerging picture of structural and functional diversity

    DEFF Research Database (Denmark)

    Svensson, Birte; Cockburn, Darrell

    2013-01-01

    Carbohydrate active enzymes, particularly those that are active on polysaccharides, are often found associated with carbohydrate binding modules (CBMs), which can play several roles in supporting enzyme function, such as localizing the enzyme to the substrate. However, the presence of CBMs...

  14. Flow cytometric analysis of lectin binding to in vitro-cultured Perkinsus marinus surface carbohydrates

    Science.gov (United States)

    Gauthier, J.D.; Jenkins, J.A.; La Peyre, Jerome F.

    2004-01-01

    Parasite surface glycoconjugates are frequently involved in cellular recognition and colonization of the host. This study reports on the identification of Perkinsus marinus surface carbohydrates by flow cytometric analyses of fluorescein isothiocyanate-conjugated lectin binding. Lectin-binding specificity was confirmed by sugar inhibition and Kolmogorov-Smirnov statistics. Clear, measurable fluorescence peaks were discriminated, and no parasite autofluorescence was observed. Parasites (GTLA-5 and Perkinsus-1 strains) harvested during log and stationary phases of growth in a protein-free medium reacted strongly with concanavalin A and wheat germ agglutinin, which bind to glucose-mannose and N-acetyl-D-glucosamine (GlcNAc) moieties, respectively. Both P. marinus strains bound with lower intensity to Maclura pomifera agglutinin, Bauhinia purpurea agglutinin, soybean agglutinin (N-acetyl-D-galactosamine-specific lectins), peanut agglutinin (PNA) (terminal galactose specific), and Griffonia simplicifolia II (GlcNAc specific). Only background fluorescence levels were detected with Ulex europaeus agglutinin I (L-fucose specific) and Limulus polyphemus agglutinin (sialic acid specific). The lectin-binding profiles were similar for the 2 strains except for a greater relative binding intensity of PNA for Perkinsus-1 and an overall greater lectin-binding capacity of Perkinsus-1 compared with GTLA-5. Growth stage comparisons revealed increased lectin-binding intensities during stationary phase compared with log phase of growth. This is the first report of the identification of surface glycoconjugates on a Perkinsus spp. by flow cytometry and the first to demonstrate that differential surface sugar expression is growth phase and strain dependent. ?? American Society of Parasitologists 2004.

  15. Detection of opsonic antibodies against Enterococcus faecalis cell wall carbohydrates in immune globulin preparations.

    Science.gov (United States)

    Hufnagel, M; Sixel, K; Hammer, F; Kropec, A; Sava, I G; Theilacker, C; Berner, R; Huebner, J

    2014-08-01

    Three different commercially available polyvalent immune globulins (IG) were investigated for the existence of antibodies against cell wall carbohydrates of four different E. faecalis serotypes (using a cell wall carbohydrate-enzyme-linked immunosorbent assay), and whether these antibodies mediated opsonic killing (using an opsonic-killing assay). All three IG preparations contained antibodies against all four serotypes (CPS-A to CPS-D). However, only one of the three IG preparations showed opsonic killing against all four serotypes. Average killing was higher against serotypes A and B (72 and 79 %, respectively) than against serotypes C and D (30 and 37 %, respectively). Such IG preparations could play a role as an adjuvant therapeutic option in life-threatening infections with E. faecalis, particularly when resistant strains are involved.

  16. A new human cholangiocellular carcinoma cell line (HuCC-T1) producing carbohydrate antigen 19/9 in serum-free medium.

    Science.gov (United States)

    Miyagiwa, M; Ichida, T; Tokiwa, T; Sato, J; Sasaki, H

    1989-06-01

    A human cholangiocellular carcinoma cell line, HuCC-T1, was established in vitro from the malignant cells of ascites of a 56-yr-old patient. Histologic findings of the primary liver tumor revealed a moderately differentiated adenocarcinoma. Tumor cells from the ascites have been cultured with RPMI 1640 medium containing 0.2% lactalbumin hydrolysate and the cultured cells grew as monolayers with a population doubling time of 74 h during exponential growth at Passage 25. They had an epithelial-like morphology and were positive for mucine staining. Ultrastructural studies revealed the presence of microvilli on the cell surface and poorly developed organelles in the cytoplasm. The HuCC-T1 cell was tumorigenic in nude mice. The number of chromosomes in HuCC-T1 ranged from 61 to 80. These human cholangiocellular carcinoma cells in serum-free medium secreted several tumor markers, including carbohydrate antigen 19/9, carbohydrate antigen 125, carcinoembryonic antigen, and tissue polypeptide antigen. The carbohydrate antigen 19/9 secretion level of HuCC-T1 cells cultured in RPMI 1640 medium with 1% fetal bovine serum was sixfold higher than that with 0.2% lactalbumin hydrolysate. These findings suggest that HuCC-T1 will provide useful information to clarify the mechanism of tumor marker secretion and tumor cell growth in the human cholangiocellular carcinoma.

  17. Fabrication of hydrophobic polymer foams with double acid sites on surface of macropore for conversion of carbohydrate.

    Science.gov (United States)

    Pan, Jianming; Mao, Yanli; Gao, Heping; Xiong, Qingang; Qiu, Fengxian; Zhang, Tao; Niu, Xiangheng

    2016-06-05

    Herein we reported a simple and novel synthetic strategy for the fabrication of two kinds of hydrophobic polymer foam catalysts (i.e. Cr(3+)-HPFs-1-H(+) and HPFs-1-H(+)) with hierarchical porous structure, inhomogeneous acidic composition and Lewis-Brønsted double acid sites distributed on the surface, which was used to one-pot conversion of carbohydrate (such as cellulose, glucose and fructose) to a key chemical platform (i.e. 5-hydroxymethylfurfural, HMF). The water-in-oil (W/O) high internal phase emulsions (HIPEs), stabilized by both Span 80 and acidic prepolymers as analogous particles offered the acidic actives, were used as the template for simultaneous polymerization of oil phase in the presence of divinylbenzene (DVB) and styrene (St). After subsequent ion-exchange process, Lewis and Brønsted acid sites derived from exchanged Cr(3+) and H(+) ion were both fixed on the surface of cell of the catalysts. The HPFs-1-H(+) and Cr(3+)-HPFs-1-H(+) had similar hierarchical porous, hydrophobic surface and acid sites (HPFs-1-H(+) with macropores ranging from 0.1 μm to 20 μm, uniform mesopores in 14.4 nm, water contact angle of 122° and 0.614 mmolg(-1) of Brønsted acid sites, as well as Cr(3+)-HPFs-1-H(+) with macropores ranging from 0.1 μm to 20 μm, uniform mesopores in 13.3 nm, water contact angle of 136° and 0.638 mmolg(-1) of Lewis-Brønsted acid sites). It was confirmed that Lewis acid sites of catalyst had a slight influence on the HMF yield of fructose came from the function of Brønsted acid sites, and Lewis acid sites were in favor of improving the HMF yield from cellulose and glucose. This work opens up a simple and novel route to synthesize multifunctional polymeric catalysts for efficient one-pot conversion of carbohydrate to HMF.

  18. Protein-carbohydrate complex reveals circulating metastatic cells in a microfluidic assay

    KAUST Repository

    Simone, Giuseppina

    2013-02-11

    Advances in carbohydrate sequencing technologies reveal the tremendous complexity of the glycome and the role that glycomics might have to bring insight into the biological functions. Carbohydrate-protein interactions, in particular, are known to be crucial to most mammalian physiological processes as mediators of cell adhesion and metastasis, signal transducers, and organizers of protein interactions. An assay is developed here to mimic the multivalency of biological complexes that selectively and sensitively detect carbohydrate-protein interactions. The binding of β-galactosides and galectin-3 - a protein that is correlated to the progress of tumor and metastasis - is examined. The efficiency of the assay is related to the expression of the receptor while anchoring to the interaction\\'s strength. Comparative binding experiments reveal molecular binding preferences. This study establishes that the assay is robust to isolate metastatic cells from colon affected patients and paves the way to personalized medicine. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Single-cell genomics reveals complex carbohydrate degradation patterns in poribacterial symbionts of marine sponges

    Science.gov (United States)

    Kamke, Janine; Sczyrba, Alexander; Ivanova, Natalia; Schwientek, Patrick; Rinke, Christian; Mavromatis, Kostas; Woyke, Tanja; Hentschel, Ute

    2013-01-01

    Many marine sponges are hosts to dense and phylogenetically diverse microbial communities that are located in the extracellular matrix of the animal. The candidate phylum Poribacteria is a predominant member of the sponge microbiome and its representatives are nearly exclusively found in sponges. Here we used single-cell genomics to obtain comprehensive insights into the metabolic potential of individual poribacterial cells representing three distinct phylogenetic groups within Poribacteria. Genome sizes were up to 5.4 Mbp and genome coverage was as high as 98.5%. Common features of the poribacterial genomes indicated that heterotrophy is likely to be of importance for this bacterial candidate phylum. Carbohydrate-active enzyme database screening and further detailed analysis of carbohydrate metabolism suggested the ability to degrade diverse carbohydrate sources likely originating from seawater and from the host itself. The presence of uronic acid degradation pathways as well as several specific sulfatases provides strong support that Poribacteria degrade glycosaminoglycan chains of proteoglycans, which are important components of the sponge host matrix. Dominant glycoside hydrolase families further suggest degradation of other glycoproteins in the host matrix. We therefore propose that Poribacteria are well adapted to an existence in the sponge extracellular matrix. Poribacteria may be viewed as efficient scavengers and recyclers of a particular suite of carbon compounds that are unique to sponges as microbial ecosystems. PMID:23842652

  20. Single-cell genomics reveals complex carbohydrate degradation patterns in poribacterial symbionts of marine sponges.

    Science.gov (United States)

    Kamke, Janine; Sczyrba, Alexander; Ivanova, Natalia; Schwientek, Patrick; Rinke, Christian; Mavromatis, Kostas; Woyke, Tanja; Hentschel, Ute

    2013-12-01

    Many marine sponges are hosts to dense and phylogenetically diverse microbial communities that are located in the extracellular matrix of the animal. The candidate phylum Poribacteria is a predominant member of the sponge microbiome and its representatives are nearly exclusively found in sponges. Here we used single-cell genomics to obtain comprehensive insights into the metabolic potential of individual poribacterial cells representing three distinct phylogenetic groups within Poribacteria. Genome sizes were up to 5.4 Mbp and genome coverage was as high as 98.5%. Common features of the poribacterial genomes indicated that heterotrophy is likely to be of importance for this bacterial candidate phylum. Carbohydrate-active enzyme database screening and further detailed analysis of carbohydrate metabolism suggested the ability to degrade diverse carbohydrate sources likely originating from seawater and from the host itself. The presence of uronic acid degradation pathways as well as several specific sulfatases provides strong support that Poribacteria degrade glycosaminoglycan chains of proteoglycans, which are important components of the sponge host matrix. Dominant glycoside hydrolase families further suggest degradation of other glycoproteins in the host matrix. We therefore propose that Poribacteria are well adapted to an existence in the sponge extracellular matrix. Poribacteria may be viewed as efficient scavengers and recyclers of a particular suite of carbon compounds that are unique to sponges as microbial ecosystems.

  1. Lectin binding patterns and carbohydrate mediation of sperm binding to llama oviductal cells in vitro.

    Science.gov (United States)

    Apichela, Silvana A; Valz-Gianinet, Jorge N; Schuster, Stefanie; Jiménez-Díaz, María A; Roldán-Olarte, Eugenia M; Miceli, Dora C

    2010-04-01

    Sperm binding to oviductal epithelium would be involved in sperm reservoir formation in the utero tubal junction (UTJ). Although in other mammals sperm-oviduct interaction has been proved to be mediated by carbohydrate-recognition mechanisms, the factors implicated in the sperm adhesion to oviductal epithelium of llama are still unknown. In order to assess the role of carbohydrates present in the mucosa surface, we examined the distribution of glycoconjugates in the llama oviduct by confocal lectin-histochemistry. Mannosyl, glucosyl, N-acetylglucosaminyl, galactosyl, N-acetylgalactosaminyl and sialic acid residues were detected in the oviductal mucose glycocalyx. By incubation of UTJ oviductal explants with LCA, DBA, UEA-1 or PNA lectin previous to co-culture with sperm, we observed a significant decrease in sperm binding only with LCA lectin. In the mucosa surface there were numerous d-glucosyl and D-manosyl residues, which were spotted by this lectin. Probably, this fact promotes the whole covering of the oviduct luminal surface by the sugar-lectin complex, preventing sperm access and adhesion of further residues. However, sperm incubation with mannose or glucose does not significantly prevent binding, which means that glucose and mannose would not be involved in a specific sperm-oviduct interaction. On the other hand, we observed a high reduction in sperm binding to UTJ explants with N-acetylgalactosamine and galactose (pllama sperm have lectin-like molecules in their surface, as is the case in other mammals. Probably, these lectin-like molecules, by means of N-acetylgalactosamine and galactose recognition, could link the sperm to the oviductal mucosa with the purpose of forming storing sites in the UTJ. Our results support the idea that more than one carbohydrate could participate in sperm reservoir formation in the llama UTJ oviductal segment.

  2. Bacterial Adhesion of Streptococcus suis to Host Cells and Its Inhibition by Carbohydrate Ligands

    Directory of Open Access Journals (Sweden)

    Sauli Haataja

    2013-07-01

    Full Text Available Streptococcus suis is a Gram-positive bacterium, which causes sepsis and meningitis in pigs and humans. This review examines the role of known S. suis virulence factors in adhesion and S. suis carbohydrate-based adhesion mechanisms, as well as the inhibition of S. suis adhesion by anti-adhesion compounds in in vitro assays. Carbohydrate-binding specificities of S. suis have been identified, and these studies have shown that many strains recognize Galα1-4Gal-containing oligosaccharides present in host glycolipids. In the era of increasing antibiotic resistance, new means to treat infections are needed. Since microbial adhesion to carbohydrates is important to establish disease, compounds blocking adhesion could be an alternative to antibiotics. The use of oligosaccharides as drugs is generally hampered by their relatively low affinity (micromolar to compete with multivalent binding to host receptors. However, screening of a library of chemically modified Galα1-4Gal derivatives has identified compounds that inhibit S. suis adhesion in nanomolar range. Also, design of multivalent Galα1-4Gal-containing dendrimers has resulted in a significant increase of the inhibitory potency of the disaccharide. The S. suis adhesin binding to Galα1-4Gal-oligosaccharides, Streptococcal adhesin P (SadP, was recently identified. It has a Galα1-4Gal-binding N-terminal domain and a C-terminal LPNTG-motif for cell wall anchoring. The carbohydrate-binding domain has no homology to E. coli P fimbrial adhesin, which suggests that these Gram-positive and Gram-negative bacterial adhesins recognizing the same receptor have evolved by convergent evolution. SadP adhesin may represent a promising target for the design of anti-adhesion ligands for the prevention and treatment of S. suis infections.

  3. Counting carbohydrates

    Science.gov (United States)

    Carb counting; Carbohydrate-controlled diet; Diabetic diet; Diabetes-counting carbohydrates ... Many foods contain carbohydrates (carbs), including: Fruit and fruit juice Cereal, bread, pasta, and rice Milk and milk products, soy milk Beans, legumes, ...

  4. Selenium Protects Retinal Cells from Cisplatin-Induced Alterations in Carbohydrate Residues

    Science.gov (United States)

    Akşit, Dilek; Yazıcı, Alper; Akşit, Hasan; Sarı, Esin S.; Yay, Arzu; Yıldız, Onur; Kılıç, Adil; Ermiş, Sıtkı S.; Seyrek, Kamil

    2016-01-01

    Background: Investigate alterations in the expression and localization of carbohydrate units in rat retinal cells exposed to cisplatin toxicity. Aims: The aim of the study was to evaluate putative protective effects of selenium on retinal cells subjected to cisplatin. Study Design: Animal experiment. Methods: Eighteen healthy Wistar rats were divided into three equal groups: 1. Control, 2. Cisplatin and 3. Cisplatin+selenium groups. After anesthesia, the right eye of each rat was enucleated. Results: Histochemically, retinal cells of control groups reacted with α-2,3-bound sialic acid-specific Maackia amurensis lectin (MAA) strongly, while cisplatin reduced the staining intensity for MAA. However, selenium administration alleviated the reducing effect of cisplatin on the binding sites for MAA in retinal cells. The staining intensity for N-acetylgalactosamine (GalNAc residues) specific Griffonia simplicifolia-1 (GSL–1) was relatively slight in control animals and cisplatin reduced this slight staining for GSL-1 further. Selenium administration mitigated the reducing effect of cisplatin on the binding sites for GSL-1. A diffuse staining for N-acetylglucosamine (GlcNAc) specific wheat germ agglutinin (WGA) was observed throughout the retina of the control animals. In particular, cells localized in the inner plexiform and photoreceptor layers are reacted strongly with WGA. Compared to the control animals, binding sites for WGA in the retina of rats given cisplatin were remarkably decreased. However, the retinal cells of rats given selenium reacted strongly with WGA. Conclusion: Cisplatin reduces α-2,3-bound sialic acid, GlcNAc and GalNAc residues in certain retinal cells. However, selenium alleviates the reducing effect of cisplatin on carbohydrate residues in retinal cells. PMID:27606141

  5. CELL WALL CARBOHYDRATE EPITOPES IN THE GREEN ALGA OEDOGONIUM BHARUCHAE F. MINOR (OEDOGONIALES, CHLOROPHYTA)(1).

    Science.gov (United States)

    Estevez, José M; Leonardi, Patricia I; Alberghina, Josefina S

    2008-10-01

    Cell wall changes in vegetative and suffultory cells (SCs) and in oogonial structures from Oedogonium bharuchae N. D. Kamat f. minor Vélez were characterized using monoclonal antibodies against several carbohydrate epitopes. Vegetative cells and SCs develop only a primary cell wall (PCW), whereas mature oogonial cells secrete a second wall, the oogonium cell wall (OCW). Based on histochemical and immunolabeling results, (1→4)-β-glucans in the form of crystalline cellulose together with a variable degree of Me-esterified homogalacturonans (HGs) and hydroxyproline-rich glycoprotein (HRGP) epitopes were detected in the PCW. The OCW showed arabinosides of the extensin type and low levels of arabinogalactan-protein (AGP) glycans but lacked cellulose, at least in its crystalline form. Surprisingly, strong colabeling in the cytoplasm of mature oogonia cells with three different antibodies (LM-5, LM-6, and CCRC-M2) was found, suggesting the presence of rhamnogalacturonan I (RG-I)-like structures. Our results are discussed relating the possible functions of these cell wall epitopes with polysaccharides and O-glycoproteins during oogonium differentiation. This study represents the first attempt to characterize these two types of cell walls in O. bharuchae, comparing their similarities and differences with those from other green algae and land plants. This work represents a contribution to the understanding of how cell walls have evolved from simple few-celled to complex multicelled organisms.

  6. Sugar-Decorated Sugar Vesicles : Lectin-Carbohydrate Recognition at the Surface of Cyclodextrin Vesicles

    NARCIS (Netherlands)

    Voskuhl, Jens; Stuart, Marc C. A.; Ravoo, Bart Jan

    2010-01-01

    An artificial glycocalix self-assembles when unilamellar bilayer vesicles of amphiphilic beta-cyclodextrins are decorated with maltose and lactose by host-guest interactions. To this end, maltose and lactose were conjugated with adamantane through a tetra(ethyleneglycol) spacer. Both carbohydrate-ad

  7. Binding Preferences, Surface Attachment, Diffusivity, and Orientation of a Family 1 Carbohydrate-Binding Module on Cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Nimlos, M. R.; Beckham, G. T.; Matthews, J. F.; Bu, L.; Himmel, M. E.; Crowley, M. F.

    2012-06-08

    Cellulase enzymes often contain carbohydrate-binding modules (CBMs) for binding to cellulose. The mechanisms by which CBMs recognize specific surfaces of cellulose and aid in deconstruction are essential to understand cellulase action. The Family 1 CBM from the Trichoderma reesei Family 7 cellobiohydrolase, Cel7A, is known to selectively bind to hydrophobic surfaces of native cellulose. It is most commonly suggested that three aromatic residues identify the planar binding face of this CBM, but several recent studies have challenged this hypothesis. Here, we use molecular simulation to study the CBM binding orientation and affinity on hydrophilic and hydrophobic cellulose surfaces. Roughly 43 {mu}s of molecular dynamics simulations were conducted, which enables statistically significant observations. We quantify the fractions of the CBMs that detach from crystal surfaces or diffuse to other surfaces, the diffusivity along the hydrophobic surface, and the overall orientation of the CBM on both hydrophobic and hydrophilic faces. The simulations demonstrate that there is a thermodynamic driving force for the Cel7A CBM to bind preferentially to the hydrophobic surface of cellulose relative to hydrophilic surfaces. In addition, the simulations demonstrate that the CBM can diffuse from hydrophilic surfaces to the hydrophobic surface, whereas the reverse transition is not observed. Lastly, our simulations suggest that the flat faces of Family 1 CBMs are the preferred binding surfaces. These results enhance our understanding of how Family 1 CBMs interact with and recognize specific cellulose surfaces and provide insights into the initial events of cellulase adsorption and diffusion on cellulose.

  8. Structural studies of complex carbohydrates of plant cell walls. Progress report, June 15, 1992--June 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Darvill, A.G.

    1994-10-01

    This report contains the abstracts of fourteen papers published, in press, or in preparation reporting on research activities to investigate the structure, as well as the function of cell walls in plants. This document also contains research on methods to determine the structure of complex carbohydrates of the cell walls.

  9. Effect of sucrose starvation on sycamore (Acer pseudoplatanus) cell carbohydrate and Pi status.

    Science.gov (United States)

    Rébeillé, F; Bligny, R; Martin, J B; Douce, R

    1985-03-15

    The mobilization of stored carbohydrates during sucrose starvation was studied with sycamore (Acer pseudoplatanus) cells. When sucrose was omitted from the nutrient medium, the intracellular sucrose pool decreased rapidly during the first hours of the experiment, whereas the starch content remained practically unchanged. After 10h of sucrose starvation, starch hydrolysis replaced sucrose breakdown. From this moment, the phosphate-ester pool and respiration rate decreased with time. Conversely, the intracellular Pi concentration increased. 31P n.m.r. of intact sycamore cells indicated that, under these conditions, most of the Pi accumulated in the vacuole. These results strongly suggest that starch breakdown, in contrast with sucrose hydrolysis, is not rapid enough to maintain a high cellular metabolism.

  10. A cytochemical study of acid carbohydrates on the surface of Candida lipolytica grown in tween 80-containing medium

    OpenAIRE

    Nascimento Aline E.; Shariá Allana E. do Nascimento; Lima Marco Antonio Barbosa de; Campos-Takaki Galba Maria de

    2000-01-01

    Carbohydrate-containing molecules were located on the surface of Candida lipolytica by using ruthenium red in a cytochemical study. The yeast was grown in media containing Tween 80. The surfactant, at 1.0% and 0.5%, was added to the culture medium in different intervals of time, correspondent to the beginning of exponential growth phase, mid of logarithimic phase and beginning of stationary growth phase. Control cultures were grown in a medium containing glucose. The growth of the yeast in me...

  11. Influences of Plant Growth Regulators,Basal Media and Carbohydrate Levels on Cell Suspension Culture of Panax ginseng

    Institute of Scientific and Technical Information of China (English)

    TangWei; WuJiongyuan; 等

    1995-01-01

    A cell suspension culture of Panax ginseng which may be continuously subcultured has been established.Embryogenic callus derived from clutured young leaves was used to initiate the culture,Plant growth regulators,basal medium formula and carbohydrate levels were examined to determine their various effects on suspension culture cell growth and development ,The best selection of plant growth regulator,basal medium and carbohydrate level is 2mg/L 2,4-D:0.5mg/L KT,MS and 3% sucrose respectively.

  12. Glyco-gold nanoparticle shapes enhance carbohydrate-protein interactions in mammalian cells

    Science.gov (United States)

    Sangabathuni, Sivakoti; Vasudeva Murthy, Raghavendra; Chaudhary, Preeti Madhukar; Surve, Manalee; Banerjee, Anirban; Kikkeri, Raghavendra

    2016-06-01

    Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions.Advances in shape-dependent nanoparticle (NP) research have prompted a close scrutiny of the behaviour of nanostructures in vitro and in vivo. Data pertaining to cellular uptake and site specific sequestration of different shapes of NPs will undoubtedly assist researchers to design better nano-probes for therapeutic and imaging purposes. Herein, we investigated the shape dependent uptake of glyco-gold nanoparticles (G-AuNPs) in different cancer cell lines. Specifically, we have compared the behaviour of spherical, rod and star AuNPs with mannose and galactose conjugations. In vitro experiments showed that the rod-AuNPs exhibited the highest uptake over that of the star and spherical counterparts. Further, an investigation of the mechanism of the uptake clearly demonstrated clathrin mediated endocytosis of the specific G-AuNPs. These results reveal the benefits of different G-AuNP shapes in carbohydrate-mediated interactions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03008d

  13. Reconstituted B cell receptor signaling reveals carbohydrate-dependent mode of activation

    OpenAIRE

    2016-01-01

    Activation of immune cells (but not B cells) with lectins is widely known. We used the structurally defined interaction between influenza hemagglutinin (HA) and its cell surface receptor sialic acid (SA) to identify a B cell receptor (BCR) activation modality that proceeded through non-cognate interactions with antigen. Using a new approach to reconstitute antigen-receptor interactions in a human reporter B cell line, we found that sequence-defined BCRs from the human germline repertoire coul...

  14. Carbohydrate-binding specificities of potential probiotic Lactobacillus strains in porcine jejunal (IPEC-J2) cells and porcine mucin.

    Science.gov (United States)

    Valeriano, Valerie Diane; Bagon, Bernadette B; Balolong, Marilen P; Kang, Dae-Kyung

    2016-07-01

    Bacterial lectins are carbohydrate-binding adhesins that recognize glycoreceptors in the gut mucus and epithelium of hosts. In this study, the contribution of lectin-like activities to adhesion of Lactobacillus mucosae LM1 and Lactobacillus johnsonii PF01, which were isolated from swine intestine, were compared to those of the commercial probiotic Lactobacillus rhamnosus GG. Both LM1 and PF01 strains have been reported to have good adhesion ability to crude intestinal mucus of pigs. To confirm this, we quantified their adhesion to porcine gastric mucin and intestinal porcine enterocytes isolated from the jejunum of piglets (IPEC-J2). In addition, we examined their carbohydrate-binding specificities by suspending bacterial cells in carbohydrate solutions prior to adhesion assays. We found that the selected carbohydrates affected the adherences of LM1 to IPEC-J2 cells and of LGG to mucin. In addition, compared to adhesion to IPEC-J2 cells, adhesion to mucin by both LM1 and LGG was characterized by enhanced specific recognition of glycoreceptor components such as galactose, mannose, and N-acetylglucosamine. Hydrophobic interactions might make a greater contribution to adhesion of PF01. A similar adhesin profile between a probiotic and a pathogen, suggest a correlation between shared pathogen-probiotic glycoreceptor recognition and the ability to exclude enteropathogens such as Escherichia coli K88 and Salmonella Typhimurium KCCM 40253. These findings extend our understanding of the mechanisms of the intestinal adhesion and pathogen-inhibition abilities of probiotic Lactobacillus strains.

  15. Interplay between carbohydrate and lipid in recognition of glycolipid antigens by natural killer T cells.

    Science.gov (United States)

    Pei, Bo; Vela, Jose Luis; Zajonc, Dirk; Kronenberg, Mitchell

    2012-04-01

    Natural killer T (NKT) cells are a T cell subpopulation that were named originally based on coexpression of receptors found on natural killer (NK) cells, cells of the innate immune system, and by T lymphocytes. The maturation and activation of NKT cells requires presentation of glycolipid antigens by CD1d, a cell surface protein distantly related to the major histocompatibility complex (MHC)-encoded antigen presenting molecules. This specificity distinguishes NKT cells from most CD4(+) and CD8(+) T cells that recognize peptides presented by MHC class I and class II molecules. The rapid secretion of a large amount of both Th1 and Th2 cytokines by activated NKT cells endows them with the ability to play a vital role in the host immune defense against various microbial infections. In this review, we summarize progress on identifying the sources of microbe-derived glycolipid antigens recognized by NKT cells and the biochemical basis for their recognition.

  16. Monocatenary, branched, double-headed, and bolaform surface active carbohydrate esters via photochemical thiol-ene/-yne reactions.

    Science.gov (United States)

    Boyère, Cédric; Broze, Guy; Blecker, Christophe; Jérôme, Christine; Debuigne, Antoine

    2013-10-18

    An original and versatile method for the synthesis of a range of novel mannose-based surfactants was developed via metal-free photo-induced thiol-ene/-yne 'click' reactions. This light-mediated hydrothiolation reaction involving a thiolated mannose was successfully applied to terminal and internal alkenes, dienes, and alkynes, leading to monocatenary, branched, double-headed, and bolaform amphiphilic carbohydrate esters, respectively. A surface activity study showed that these new compounds possess valuable properties and display specific behavior at the air-water interface. It also demonstrated the greater flexibility of the thioether moiety in the spacer of the surfactants produced via a thiol-ene reaction in comparison with the triazole heterocyclic rings in similar glucose-based surfactants synthesized elsewhere by the alkyne-azide 1,3-dipolar addition.

  17. Cell surface differences of Naegleria fowleri and Naegleria lovaniensis exposed with surface markers.

    Science.gov (United States)

    González-Robles, Arturo; Castañón, Guadalupe; Cristóbal-Ramos, Ana Ruth; Hernández-Ramírez, Verónica Ivonne; Omaña-Molina, Maritza; Martínez-Palomo, Adolfo

    2007-12-01

    Differences in the distribution of diverse cell surface coat markers were found between Naegleria fowleri and Naegleria lovaniensis. The presence of carbohydrate-containing components in the cell coat of the two species was detected by selective staining with ruthenium red and alcian blue. Using both markers, N. fowleri presented a thicker deposit than N. lovaniensis. The existence of exposed mannose or glucose residues was revealed by discriminatory agglutination with the plant lectin Concanavalin A. These sugar residues were also visualized at the cell surface of these parasites either by transmission electron microscopy or by fluorescein-tagged Concanavalin A. Using this lectin cap formation was induced only in N. fowleri. The anionic sites on the cell surface detected by means of cationized ferritin were more apparent in N. fowleri. Biotinylation assays confirmed that even though the two amoebae species have some analogous plasma membrane proteins, there is a clear difference in their composition.

  18. Surface functionalization of liposomes with proteins and carbohydrates for use in anti-cancer applications

    Science.gov (United States)

    Platt, Virginia M.

    Liposomes can be used to exploit the altered biology of cancer thereby increasing delivery of liposome-associated anti-cancer drugs. In this dissertation, I explore methods that utilize the unique cancer expression of the polymeric glycosaminoglycan hyaluronan (HA) and the HA receptor CD44 to target liposomes to tumors, using liposomes functionalized with proteins or oligosaccharides on their surface. To make it easier to prepare protein-functionalized liposomes, a non-covalent protein/liposome association method based upon metal chelation/his 6 interaction was devised and characterized. I evaluated non-covalent attachment of the prodrug converting enzyme yeast cytosine deaminase, the far-red fluorescent protein mKate, two antigens ovalbumin and the membrane proximal region of an HIV GAG and hyaluronidase, a HA-degrading enzyme. In Chapter 2, I describe the synthesis of hyaluronan-oligosaccharide (HA-O) lipid conjugates and their incorporation into liposomes to target CD44-overexpressing cancer cells. HA-O ligands of defined-length, up to 10 monosaccharides, were attached to lipids via various linkers by reductive amination. The HA-lipids were easily incorporated into liposomes but did not mediate binding of liposomes to CD44 overexpressing cells. In Chapter 3, I evaluate the capacity of tris-NTA-Ni-lipids incorporated within a liposome bilayer to associate with his6-tagged proteins. Tris-NTA-lipids of differing structures and avidities were used to associate yeast cytosine deaminase and mKate to the surface of liposomes. Two tris-NTA-lipids and a mono-NTA lipid associated his-tagged proteins to a 1:1 molar ratio in solution. The proteins remained active while associated with the liposome surface. When challenged in vitro with fetal calf serum, tris-NTA-containing liposomes retained his-tagged proteins longer than mono-NTA. However, the tris-NTA/his6 interaction was found to be in a dynamic state; free yeast cytosine deaminase rapidly competed with pre-bound m

  19. Carbohydrate Analysis

    Science.gov (United States)

    Bemiller, James N.

    Carbohydrates are important in foods as a major source of energy, to impart crucial textural properties, and as dietary fiber which influences physiological processes. Digestible carbohydrates, which are converted into monosaccharides, which are absorbed, provide metabolic energy. Worldwide, carbohydrates account for more than 70% of the caloric value of the human diet. It is recommended that all persons should limit calories from fat (the other significant source) to not more than 30% and that most of the carbohydrate calories should come from starch. Nondigestible polysaccharides (all those other than starch) comprise the major portion of dietary fiber (Sect. 10.5). Carbohydrates also contribute other attributes, including bulk, body, viscosity, stability to emulsions and foams, water-holding capacity, freeze-thaw stability, browning, flavors, aromas, and a range of desirable textures (from crispness to smooth, soft gels). They also provide satiety. Basic carbohydrate structures, chemistry, and terminology can be found in references (1, 2).

  20. [Disorders of carbohydrate metabolism, dyslipidemia, and bone metabolic disease after hematopoietic stem cell transplantation].

    Science.gov (United States)

    Wędrychowicz, Anna; Starzykk, Jerzy

    2013-01-01

    Among long-term survivors after hematopoietic stem cell transplantation (HSCT) late endocrine complications are observed in 20-50%. Very often these complications influence significantly the patient´s life and have to be treated till the end of life. Their proper prevention and monitoring are extremely important in patients who underwent HSCT during childhood. Since the 90s of the last millennium/century, thyroid dysfunction, disorders of somatic and sexual development, and disturbances of fertility have been presented in several publications. In the paper, less known endocrine complications after HSCT published in the last years are discussed. Disorders of carbohydrate metabolism, post-transplant diabetes and insulin resistance are presented. Moreover, dyslipidemia, hypertension, and post-transplant bone metabolic disease are demonstrated/shown. The paper describes the etiopathogenesis, methods of prevention as well as treatment and the results of the treatment of these endocrine complications after HSCT. Moreover, actual recommendations for screening and prevention of endocrine complications in long-term HCT survivors are presented.

  1. Antiviral activity of carbohydrate-binding agents against Nidovirales in cell culture.

    Science.gov (United States)

    van der Meer, F J U M; de Haan, C A M; Schuurman, N M P; Haijema, B J; Peumans, W J; Van Damme, E J M; Delputte, P L; Balzarini, J; Egberink, H F

    2007-10-01

    Coronaviruses are important human and animal pathogens, the relevance of which increased due to the emergence of new human coronaviruses like SARS-CoV, HKU1 and NL63. Together with toroviruses, arteriviruses, and roniviruses the coronaviruses belong to the order Nidovirales. So far antivirals are hardly available to combat infections with viruses of this order. Therefore, various antiviral strategies to counter nidoviral infections are under evaluation. Lectins, which bind to N-linked oligosaccharide elements of enveloped viruses, can be considered as a conceptionally new class of virus inhibitors. These agents were recently evaluated for their antiviral activity towards a variety of enveloped viruses and were shown in most cases to inhibit virus infection at low concentrations. However, limited knowledge is available for their efficacy towards nidoviruses. In this article the application of the plant lectins Hippeastrum hybrid agglutinin (HHA), Galanthus nivalis agglutinin (GNA), Cymbidium sp. agglutinin (CA) and Urtica dioica agglutinin (UDA) as well as non-plant derived pradimicin-A (PRM-A) and cyanovirin-N (CV-N) as potential antiviral agents was evaluated. Three antiviral tests were compared based on different evaluation principles: cell viability (MTT-based colorimetric assay), number of infected cells (immunoperoxidase assay) and amount of viral protein expression (luciferase-based assay). The presence of carbohydrate-binding agents strongly inhibited coronaviruses (transmissible gastroenteritis virus, infectious bronchitis virus, feline coronaviruses serotypes I and II, mouse hepatitis virus), arteriviruses (equine arteritis virus and porcine respiratory and reproductive syndrome virus) and torovirus (equine Berne virus). Remarkably, serotype II feline coronaviruses and arteriviruses were not inhibited by PRM-A, in contrast to the other viruses tested.

  2. Carbohydrate Loading.

    Science.gov (United States)

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  3. The Plant Cell Surface

    Institute of Scientific and Technical Information of China (English)

    Anne-Mie C.Emons; Kurt V.Fagerstedt

    2010-01-01

    @@ Multicellular organization and tissue construction has evolved along essentially different lines in plants and animals. Since plants do not run away, but are anchored in the soil, their tissues are more or less firm and stiff. This strength stems from the cell walls, which encase the fragile cytoplasm, and protect it.

  4. Carbohydrate-active enzymes in pythium and their role in plant cell wall and storage polysaccharide degradation.

    Directory of Open Access Journals (Sweden)

    Marcelo M Zerillo

    Full Text Available Carbohydrate-active enzymes (CAZymes are involved in the metabolism of glycoconjugates, oligosaccharides, and polysaccharides and, in the case of plant pathogens, in the degradation of the host cell wall and storage compounds. We performed an in silico analysis of CAZymes predicted from the genomes of seven Pythium species (Py. aphanidermatum, Py. arrhenomanes, Py. irregulare, Py. iwayamai, Py. ultimum var. ultimum, Py. ultimum var. sporangiiferum and Py. vexans using the "CAZymes Analysis Toolkit" and "Database for Automated Carbohydrate-active Enzyme Annotation" and compared them to previously published oomycete genomes. Growth of Pythium spp. was assessed in a minimal medium containing selected carbon sources that are usually present in plants. The in silico analyses, coupled with our in vitro growth assays, suggest that most of the predicted CAZymes are involved in the metabolism of the oomycete cell wall with starch and sucrose serving as the main carbohydrate sources for growth of these plant pathogens. The genomes of Pythium spp. also encode pectinases and cellulases that facilitate degradation of the plant cell wall and are important in hyphal penetration; however, the species examined in this study lack the requisite genes for the complete saccharification of these carbohydrates for use as a carbon source. Genes encoding for xylan, xyloglucan, (galacto(glucomannan and cutin degradation were absent or infrequent in Pythium spp.. Comparative analyses of predicted CAZymes in oomycetes indicated distinct evolutionary histories. Furthermore, CAZyme gene families among Pythium spp. were not uniformly distributed in the genomes, suggesting independent gene loss events, reflective of the polyphyletic relationships among some of the species.

  5. Structural motif screening reveals a novel, conserved carbohydrate-binding surface in the pathogenesis-related protein PR-5d

    Directory of Open Access Journals (Sweden)

    Moffatt Barbara A

    2010-08-01

    Full Text Available Abstract Background Aromatic amino acids play a critical role in protein-glycan interactions. Clusters of surface aromatic residues and their features may therefore be useful in distinguishing glycan-binding sites as well as predicting novel glycan-binding proteins. In this work, a structural bioinformatics approach was used to screen the Protein Data Bank (PDB for coplanar aromatic motifs similar to those found in known glycan-binding proteins. Results The proteins identified in the screen were significantly associated with carbohydrate-related functions according to gene ontology (GO enrichment analysis, and predicted motifs were found frequently within novel folds and glycan-binding sites not included in the training set. In addition to numerous binding sites predicted in structural genomics proteins of unknown function, one novel prediction was a surface motif (W34/W36/W192 in the tobacco pathogenesis-related protein, PR-5d. Phylogenetic analysis revealed that the surface motif is exclusive to a subfamily of PR-5 proteins from the Solanaceae family of plants, and is absent completely in more distant homologs. To confirm PR-5d's insoluble-polysaccharide binding activity, a cellulose-pulldown assay of tobacco proteins was performed and PR-5d was identified in the cellulose-binding fraction by mass spectrometry. Conclusions Based on the combined results, we propose that the putative binding site in PR-5d may be an evolutionary adaptation of Solanaceae plants including potato, tomato, and tobacco, towards defense against cellulose-containing pathogens such as species of the deadly oomycete genus, Phytophthora. More generally, the results demonstrate that coplanar aromatic clusters on protein surfaces are a structural signature of glycan-binding proteins, and can be used to computationally predict novel glycan-binding proteins from 3 D structure.

  6. The ligand-binding domain of the cell surface receptor for urokinase-type plasminogen activator

    DEFF Research Database (Denmark)

    Behrendt, N; Ploug, M; Patthy, L;

    1991-01-01

    part of the intact receptor, probably including the whole sequence 1-87, and contained N-linked carbohydrate. After detergent phase separation in the Triton X-114 system, the fragment was present in the water phase where its binding activity could be demonstrated in the absence of the rest...... applications in interfering with cell-surface plasmin-mediated proteolysis....

  7. Defined presentation of carbohydrates on a duplex DNA scaffold.

    Science.gov (United States)

    Schlegel, Mark K; Hütter, Julia; Eriksson, Magdalena; Lepenies, Bernd; Seeberger, Peter H

    2011-12-16

    A new method for the spatially defined alignment of carbohydrates on a duplex DNA scaffold is presented. The use of an N-hydroxysuccinimide (NHS)-ester phosphoramidite along with carbohydrates containing an alkylamine linker allows for on-column labeling during solid-phase oligonucleotide synthesis. This modification method during solid-phase synthesis only requires the use of minimal amounts of complex carbohydrates. The covalently attached carbohydrates are presented in the major groove of the B-form duplex DNA as potential substrates for murine type II C-type lectin receptors mMGL1 and mMGL2. CD spectroscopy and thermal melting revealed only minimal disturbance of the overall helical structure. Surface plasmon resonance and cellular uptake studies with bone-marrow-derived dendritic cells were used to assess the capability of these carbohydrate-modified duplexes to bind to mMGL receptors.

  8. Effect of anti-carbohydrate antibodies on HIV infection in a monocytic cell line (U937)

    DEFF Research Database (Denmark)

    Hansen, J E; Nielsen, C; Clausen, H

    1991-01-01

    Monoclonal antibodies (mAbs) against carbohydrate epitopes of gp120 have recently been found to inhibit HIV infection of lymphocytes in vitro thereby opening new possibilities for vaccine considerations. Antibody-dependent enhancement of infection has however come increasingly into focus. This st......Monoclonal antibodies (mAbs) against carbohydrate epitopes of gp120 have recently been found to inhibit HIV infection of lymphocytes in vitro thereby opening new possibilities for vaccine considerations. Antibody-dependent enhancement of infection has however come increasingly into focus...

  9. Entirely Carbohydrate-Based Vaccines: An Emerging Field for Specific and Selective Immune Responses

    Directory of Open Access Journals (Sweden)

    Sharmeen Nishat

    2016-05-01

    Full Text Available Carbohydrates are regarded as promising targets for vaccine development against infectious disease because cell surface glycans on many infectious agents are attributed to playing an important role in pathogenesis. In addition, oncogenic transformation of normal cells, in many cases, is associated with aberrant glycosylation of the cell surface glycan generating tumor associated carbohydrate antigens (TACAs. Technological advances in glycobiology have added a new dimension to immunotherapy when considering carbohydrates as key targets in developing safe and effective vaccines to combat cancer, bacterial infections, viral infections, etc. Many consider effective vaccines induce T-cell dependent immunity with satisfactory levels of immunological memory that preclude recurrence. Unfortunately, carbohydrates alone are poorly immunogenic as they do not bind strongly to the MHCII complex and thus fail to elicit T-cell immunity. To increase immunogenicity, carbohydrates have been conjugated to carrier proteins, which sometimes can impede carbohydrate specific immunity as peptide-based immune responses can negate antibodies directed at the targeted carbohydrate antigens. To overcome many challenges in using carbohydrate-based vaccine design and development approaches targeting cancer and other diseases, zwitterionic polysaccharides (ZPSs, isolated from the capsule of commensal anaerobic bacteria, will be discussed as promising carriers of carbohydrate antigens to achieve desired immunological responses.

  10. Understanding plant cell-wall remodelling during the symbiotic interaction between Tuber melanosporum and Corylus avellana using a carbohydrate microarray

    DEFF Research Database (Denmark)

    Sillo, Fabiano; Fangel, Jonatan Ulrik; Henrissat, Bernard;

    2016-01-01

    MAIN CONCLUSION: A combined approach, using a carbohydrate microarray as a support for genomic data, has revealed subtle plant cell-wall remodelling during Tuber melanosporum and Corylus avellana interaction. Cell walls are involved, to a great extent, in mediating plant-microbe interactions....... An important feature of these interactions concerns changes in the cell-wall composition during interaction with other organisms. In ectomycorrhizae, plant and fungal cell walls come into direct contact, and represent the interface between the two partners. However, very little information is available...... on the re-arrangement that could occur within the plant and fungal cell walls during ectomycorrhizal symbiosis. Taking advantage of the Comprehensive Microarray Polymer Profiling (CoMPP) technology, the current study has had the aim of monitoring the changes that take place in the plant cell wall in Corylus...

  11. Cell-surface changes in cadmium-resistant Euglena: Studies using lectin-binding techniques and flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Bonaly, J.; Brochiero, E. [Faculte de Pharmacie, Chatenay-Malabry (France)

    1994-01-01

    Most in vitro studies on contaminants focus on the short-term effects of pollutants on cells, without regard to long-term effects and the ability of cells or microorganisms to develop a specific resistance to a pollutant. Cadmium is ubiquitous environmental contaminant. This heavy metal enters the aquatic environment mainly through vapor emissions and fallout during smelting operations. Diverse mechanisms of algal resistance to toxic metals are known. Among these, the most general mechanism is the development of metal-binding proteins. In cadmium-resistant unicellular Euglena gracilis Z algae cells, the metal did not appear to be sequestered on soluble metal-binding ligands. Previous experiments have shown that resistance development is related to a diminution of cadmium penetration into cells, implicating cell surface or membrane alteration. This research investigates the mechanisms of development of cadmium resistance in Euglena cells at the cell-surface level. Sugar chains of glycoproteins and glycolipids are a predominant feature of the surface of cells. Moreover, the cell-response to environmental changes is often orchestrated through surface macromolecules such as glycoproteins. In this study, we applied this lectin method to investigate surface carbohydrate expression during and after resistance development. Our interest was twofold: (1) to learn more about the carbohydrate composition of the cell-surface of Euglena; and (2) to determine whether transition from wild cells to Cd-resistant cells changes the expression of cell-surface carbohydrates. 13 refs., 2 figs., 1 tab.

  12. Protein and carbohydrate exopolymer particles in the sea surface microlayer (SML

    Directory of Open Access Journals (Sweden)

    Daniel Conrad Ogilvie Thornton

    2016-08-01

    Full Text Available Exchanges of matter and energy between ocean and atmosphere occur through the sea surface microlayer (SML. The SML is the thin surface layer of the ocean at the ocean-atmosphere interface that has distinctive physical, chemical and biological properties compared with the underlying water. We measured the concentration of two types of exopolymer particles in the SML and underlying water in the Pacific Ocean off the coast of Oregon (United States during July 2011. Transparent exopolymer particles (TEP are defined by their acidic polysaccharide content, whereas Coomassie staining particles (CSP are composed of protein. TEP and CSP were ubiquitous in the SML. TEP were not significantly enriched in the SML compared with the underlying water. CSP were significantly enriched in the SML, with an enrichment factor (EF of 1.4 to 2.4. The distribution of exopolymer particles in the water and microscopic imaging indicated that TEP and CSP are distinct populations of particles rather than different chemical components of the same particles. Dissolved polysaccharides were not enriched in the SML, whereas monosaccharides had an EF of 1.2 to 1.8. Sampling occurred during the collapse of a diatom bloom, and diatoms were found both in the water column and SML. While there were living diatoms in the samples, most of the diatoms were dead and there were abundant empty frustules covered in layer of TEP. The collapsing diatom bloom was probably the source of exopolymer particles to both the SML and underlying water. Exopolymer particles are a component of the SML that may play a significant role in the marine carbon and nitrogen cycles, and the exchange of material between ocean and atmosphere.

  13. Carbohydrate malabsorption

    DEFF Research Database (Denmark)

    Rumessen, J J; Nordgaard-Andersen, I; Gudmand-Høyer, E

    1994-01-01

    Previous studies in small series of healthy adults have suggested that parallel measurement of hydrogen and methane resulting from gut fermentation may improve the precision of quantitative estimates of carbohydrate malabsorption. Systematic, controlled studies of the role of simultaneous hydrogen...

  14. Single Cell Synchrotron FT-IR Microspectroscopy Reveals a Link between Neutral Lipid and Storage Carbohydrate Fluxes in S. cerevisiae

    Science.gov (United States)

    Jamme, Frédéric; Vindigni, Jean-David; Méchin, Valérie; Cherifi, Tamazight; Chardot, Thierry; Froissard, Marine

    2013-01-01

    In most organisms, storage lipids are packaged into specialized structures called lipid droplets. These contain a core of neutral lipids surrounded by a monolayer of phospholipids, and various proteins which vary depending on the species. Hydrophobic structural proteins stabilize the interface between the lipid core and aqueous cellular environment (perilipin family of proteins, apolipoproteins, oleosins). We developed a genetic approach using heterologous expression in Saccharomyces cerevisiae of the Arabidopsis thaliana lipid droplet oleosin and caleosin proteins AtOle1 and AtClo1. These transformed yeasts overaccumulate lipid droplets, leading to a specific increase in storage lipids. The phenotype of these cells was explored using synchrotron FT-IR microspectroscopy to investigate the dynamics of lipid storage and cellular carbon fluxes reflected as changes in spectral fingerprints. Multivariate statistical analysis of the data showed a clear effect on storage carbohydrates and more specifically, a decrease in glycogen in our modified strains. These observations were confirmed by biochemical quantification of the storage carbohydrates glycogen and trehalose. Our results demonstrate that neutral lipid and storage carbohydrate fluxes are tightly connected and co-regulated. PMID:24040242

  15. Single cell synchrotron FT-IR microspectroscopy reveals a link between neutral lipid and storage carbohydrate fluxes in S. cerevisiae.

    Directory of Open Access Journals (Sweden)

    Frédéric Jamme

    Full Text Available In most organisms, storage lipids are packaged into specialized structures called lipid droplets. These contain a core of neutral lipids surrounded by a monolayer of phospholipids, and various proteins which vary depending on the species. Hydrophobic structural proteins stabilize the interface between the lipid core and aqueous cellular environment (perilipin family of proteins, apolipoproteins, oleosins. We developed a genetic approach using heterologous expression in Saccharomyces cerevisiae of the Arabidopsis thaliana lipid droplet oleosin and caleosin proteins AtOle1 and AtClo1. These transformed yeasts overaccumulate lipid droplets, leading to a specific increase in storage lipids. The phenotype of these cells was explored using synchrotron FT-IR microspectroscopy to investigate the dynamics of lipid storage and cellular carbon fluxes reflected as changes in spectral fingerprints. Multivariate statistical analysis of the data showed a clear effect on storage carbohydrates and more specifically, a decrease in glycogen in our modified strains. These observations were confirmed by biochemical quantification of the storage carbohydrates glycogen and trehalose. Our results demonstrate that neutral lipid and storage carbohydrate fluxes are tightly connected and co-regulated.

  16. Yield of Fumaric Acid from Different Carbohydrates by Stationary Surface Culture Method

    Directory of Open Access Journals (Sweden)

    Km. Maya Saijwani

    1968-07-01

    Full Text Available Studies on the yield of fumaric acid by Rhizopus arrhizus and Bhizopus nigricans using glucose, sucrose, xylose,cane molassess and bagasse hydrolysate either alone or in combination with glucose were undertaken. Thirty three and 26 per cently yield of fumaric acid were obtained from 12 and 10 per cent glucose media respectively, in 15 days at 33 degree calcius by stationary surface culture method. Higher yields of fumaric acid were obtained from glucose using R. arrhizus. Ability of this organism to produce fumaric acid from media containing (i 50:50 glucose and deionized bagasse,hydrolysate (ii deionized bagasse hydrolysate, and (iii clarified cane molasses was investigated. A 7 per cent yield of fumaric acid was obtained from 50:50 glucose and deionized bagasse hydrolysate medium. In the case of xylose good growth of the fungus was obtained but no fumaric acid was produced. These studies have indicated that R. arrhizus is not able to utilize pentose sugars.

  17. Biosynthesis of intestinal microvillar proteins. Processing of N-linked carbohydrate is not required for surface expression

    DEFF Research Database (Denmark)

    Danielsen, Erik Michael; Cowell, G M

    1986-01-01

    . The proteinase inhibitor leupeptin partially restored the suppressed synthesis, indicating that the majority of the wrongly processed enzymes, probably because of conformational instability, become degraded soon after synthesis rather than being transported to the microvillar membrane.......Castanospermine, an inhibitor of glucosidase I, the initial enzyme in the trimming of N-linked carbohydrate, was used to study the importance of carbohydrate processing in the biosynthesis of microvillar enzymes in organ-cultured pig intestinal explants. For aminopeptidase N (EC 3...

  18. Hemiuroid trematode sporocysts are undetected by hemocytes of their intermediate host, the ark cockle Anadara trapezia: potential role of surface carbohydrates in successful parasitism.

    Science.gov (United States)

    Kawasaki, Minami; Delamare-Deboutteville, Jerome; Dang, Cecile; Barnes, Andrew C

    2013-12-01

    In order to establish a successful relationship with their hosts, parasites must subvert or evade immune defences. Cockle Anadara trapezia and Sydney Rock oyster (SRO) Saccostrea glomerata live in the same location but only ark cockles are infected by sporocysts of hemiuroid trematode. This provides an opportunity to explore differing interactions between the parasite and the immune system of susceptible and refractive hosts. Rapid migration and encapsulation of sporocysts was observed by SRO hemocytes but not by cockle hemocytes. This migration/encapsulation was inhibited by N-acetylglucosamine or N-acetylgalactosamine but not by the other sugars, implicating specific surface carbohydrates in immune detection. Effector responses of hemocytes were investigated in vitro in terms of production of reactive oxygen production (ROS). Hemocytes of both species strongly reacted to Zymosan, but only SRO hemocytes responded to live sporocysts. Neither species' hemocytes produced ROS in the presence of dead/fixed sporocysts, and there was no suppression of Zymosan-induced respiratory burst by sporocysts. This suggests that immune escape is mediated by avoiding encapsulation, perhaps through molecular mimicry. Membrane-shaving with proteases indicated that sporocyst surface proteins are not a key factors in hemocytic detection. Surface carbohydrates of SRO and cockle hemocytes and of sporocysts were profiled with a panel of biotinylated lectins. This revealed substantial differences between cockle and SRO hemocytes, but greater similarity between cockle hemocytes and sporocysts. Results suggest that surface carbohydrates play an integral role in hemocyte immunorecognition and that surface carbohydrate molecular mimicry is a potential strategy for immune evasion in cockles by hemiuroid trematode sporocysts.

  19. Altered expression of epithelial cell surface glycoconjugates and intermediate filaments at the margins of mucosal wounds

    DEFF Research Database (Denmark)

    Dabelsteen, Erik; Grøn, B; Mandel, U

    1998-01-01

    Alterations in cell to cell adhesion are necessary to enable the type of cell movements that are associated with epithelial wound healing and malignant invasion. Several studies of transformed cells have related epithelial cell movement to changes in the cell surface expression of the carbohydrate......-T antigen. The changes induced by wounding in the expression of collagen IV, laminin gamma2-chain (laminin-5), and laminin alpha5-chain were similar to those found in skin wounds and served to define the region of epithelial movement. This region was found to show a marked increase in staining for both...... epithelium, a pattern of expression similar to K16, which was also strongly upregulated in both the outgrowth and the adjacent nonwounded epithelium. These findings provide further support for an influence of such carbohydrate structures on the migratory behavior of epithelial cells....

  20. Rapid Conversion from Carbohydrates to Large-Scale Carbon Quantum Dots for All-Weather Solar Cells.

    Science.gov (United States)

    Tang, Qunwei; Zhu, Wanlu; He, Benlin; Yang, Peizhi

    2017-02-28

    A great challenge for state-of-the-art solar cells is to generate electricity in all weather. We present here the rapid conversion of carbon quantum dots (CQDs) from carbohydrates (including glucose, maltol, sucrose) for an all-weather solar cell, which comprises a CQD-sensitized mesoscopic titanium dioxide/long-persistence phosphor (m-TiO2/LPP) photoanode, a I(-)/I3(-) redox electrolyte, and a platinum counter electrode. In virtue of the light storing and luminescent behaviors of LPP phosphors, the generated all-weather solar cells can not only convert sunlight into electricity on sunny days but persistently realize electricity output in all dark-light conditions. The maximized photoelectric conversion efficiency is as high as 15.1% for so-called all-weather CQD solar cells in dark conditions.

  1. Micro-Spectroscopic Imaging of Lignin-Carbohydrate Complexes in Plant Cell Walls and Their Migration During Biomass Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yining; Zhao, Shuai; Wei, Hui; Tucker, Melvin P.; Johnson, David K.; Himmel, Michael E.; Mosier, Nathan S.; Meilan, Richard; Ding, Shi-You

    2015-04-27

    In lignocellulosic biomass, lignin is the second most abundant biopolymer. In plant cell walls, lignin is associated with polysaccharides to form lignin-carbohydrate complexes (LCC). LCC have been considered to be a major factor that negatively affects the process of deconstructing biomass to simple sugars by cellulosic enzymes. Here, we report a micro-spectroscopic approach that combines fluorescence lifetime imaging microscopy and Stimulated Raman Scattering microscopy to probe in situ lignin concentration and conformation at each cell wall layer. This technique does not require extensive sample preparation or any external labels. Using poplar as a feedstock, for example, we observe variation of LCC in untreated tracheid poplar cell walls. The redistribution of LCC at tracheid poplar cell wall layers is also investigated when the chemical linkages between lignin and hemicellulose are cleaved during pretreatment. Our study would provide new insights into further improvement of the biomass pretreatment process.

  2. Carbohydrate nanocarriers in biomedical applications: functionalization and construction.

    Science.gov (United States)

    Kang, Biao; Opatz, Till; Landfester, Katharina; Wurm, Frederik R

    2015-11-21

    The specific targeting of either tumor cells or immune cells in vivo by carefully designed and appropriately surface-functionalized nanocarriers may become an effective therapeutic treatment for a variety of diseases. Carbohydrates, which are prominent biomolecules, have shown their outstanding ability in balancing the biocompatibility, stability, biodegradability, and functionality of nanocarriers. The recent applications of sugar (mono/oligosaccharides and/or polysaccharides) for the development of nanomedicines are summarized in this review, including the application of carbohydrates for the surface-functionalization of various nanocarriers and for the construction of the nanocarrier itself. Current problems and challenges are also addressed.

  3. Fermentable carbohydrates elevate plasma enteroglucagon but high viscosity is also necessary to stimulate small bowel mucosal cell proliferation in rats.

    Science.gov (United States)

    Gee, J M; Lee-Finglas, W; Wortley, G W; Johnson, I T

    1996-02-01

    Enteroglucagon is a collective term for a small family of peptides derived from proglucagon by post-translational processing in the L-cells of the distal small intestine and colon. There is evidence that it inhibits gastric secretion, and high levels of enteroglucagon occur in plasma during intestinal adaptation, which suggests that it may also function as a trophic factor for the intestine. Certain types of soluble non-starch polysaccharide (dietary fiber) stimulate the release of enteroglucagon in rats but the mechanism is unknown. In this study we explored the importance of the viscosity and fermentability of nonabsorbed carbohydrates as determinants of plasma enteroglucagon and mucosal cell proliferation in the distal ileum of rats. Replacement of cellulose (10 g/kg) with guar gum in a semisynthetic diet led to a prompt and sustained rise in plasma enteroglucagon concentrations. Our initial hypothesis that this was a consequence of delayed nutrient absorption was disproven by the fact that hydroxypropylmethylcellulose (HPMC), a viscous but nonfermentable polysaccharide, had no effect on plasma enteroglucagon under the same conditions. In contrast, the nondigestible disaccharide lactitol led to a prolonged rise in plasma enteroglucagon, similar to that observed with guar gum. Lactitol is nonviscous, but highly fermentable, and we conclude that fermentable carbohydrate is an important stimulus for the release of enteroglucagon under our experimental conditions. There was no evidence that enteroglucagon released by this mechanism exerted trophic effects on the distal small intestinal mucosa.

  4. Roles of multiple surface sites, long substrate binding clefts, and carbohydrate binding modules in the action of amylolytic enzymes on polysaccharide substrates

    DEFF Research Database (Denmark)

    Nielsen, Morten Munch; Seo, E.S.; Dilokpimol, Adiphol

    2008-01-01

    with a characteristic subsite binding energy profile around the catalytic site. Furthermore, several amylolytic enzymes that facilitate attack on the natural substrate, i.e. the endosperm starch granules, have secondary sugar binding sites either situated on the surface of the protein domain or structural unit...... that contains the catalytic site or belonging to a separate starch binding domain. The role of surface sites in the function of barley alpha-amylase 1 has been investigated by using mutational analysis in conjunction with carbohydrate binding analyses and crystallography. The ability to bind starch depends...

  5. Learning about Carbohydrates

    Science.gov (United States)

    ... What Happens in the Operating Room? Learning About Carbohydrates KidsHealth > For Kids > Learning About Carbohydrates A A ... of energy for the body. Two Types of Carbohydrates There are two major types of carbohydrates (or ...

  6. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

    Directory of Open Access Journals (Sweden)

    B. He

    2010-04-01

    Full Text Available Organic matter in surface sediments from the upper reach of the Pearl River Estuary and Lingdingyang Bay, as well as the adjacent northern South China Sea shelf was characterized by a variety of techniques, including elemental (C and N, stable carbon isotopic (δ 13C composition, as well as molecular-level analyses. Total organic carbon (TOC content was 1.61±1.20% in the upper reach down to 1.00±0.22% in Lingdingyang Bay and to 0.80±0.10% on the inner shelf and 0.58±0.06% on the outer shelf. δ13C values ranged from −25.11‰ to −21.28‰ across the studied area, with a trend of enrichment seaward. The spatial trend in C/N ratios mirrored that of δ13C, with a substantial decrease in C/N ratio from 10.9±1.3 in the Lingdingyang Bay surface sediments to 6.5±0.09 in the outer shelf surface sediments. Total carbohydrate yields ranged from 22.1 to 26.7 mg (100 mg OC−1, and typically followed TOC concentrations in the estuarine and shelf sediments, suggesting that the relative abundance of total carbohydrate was fairly constant in TOC. Total neutral sugars as detected by the nine major monosaccharides (lyxose, rhamnose, ribose, arabinose, fucose, xylose, galactose, mannose, and glucose yielded between 4.0 and 18.6 mg (100 mg OC−1 in the same sediments, suggesting that a significant amount of carbohydrates were not neutral aldoses. The bulk organic matter properties, isotopic composition and C/N ratios, combined with molecular-level carbohydrate compositions were used to assess the sources and accumulation of terrestrial organic matter in the Pearl River Estuary and the adjacent northern South China Sea shelf. Results showed a mixture of terrestrial riverine organic carbon with in situ phytoplankton organic carbon in the areas studied. Using a two end-member mixing model based on δ13C values and C/N ratios, we estimated that the terrestrial organic carbon contribution to

  7. Analysis of cell surface antigens by Surface Plasmon Resonance imaging

    NARCIS (Netherlands)

    Stojanovic, I.; Schasfoort, R.B.M.; Terstappen, L.W.M.M.

    2013-01-01

    Surface Plasmon Resonance (SPR) is most commonly used to measure bio-molecular interactions. SPR is used significantly less frequent for measuring whole cell interactions. Here we introduce a method to measure whole cells label free using the specific binding of cell surface antigens expressed on th

  8. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

    Science.gov (United States)

    He, B.; Dai, M.; Huang, W.; Liu, Q.; Chen, H.; Xu, L.

    2010-10-01

    Organic matter in surface sediments from the upper reach of the Pearl River Estuary and Lingdingyang Bay, as well as the adjacent northern South China Sea shelf was characterized using a variety of techniques, including elemental (C and N) ratio, bulk stable organic carbon isotopic composition (δ13C), and carbohydrate composition analyses. Total organic carbon (TOC) content was 1.21±0.45% in the upper reach, down to 1.00±0.22% in Lingdingyang Bay and to 0.80±0.10% on the inner shelf and 0.58±0.06% on the outer shelf. δ13C values ranged from -25.1‰ to -21.3‰ in Lingdingyang Bay and the South China Sea shelf, with a trend of enrichment seawards. The spatial trend in C/N ratios mirrored that of δ13C, with a substantial decrease in C/N ratio offshore. Total carbohydrate yields ranged from 22.1 to 26.7 mg (100 mg OC)-1, and typically followed TOC concentrations in the estuarine and shelf sediments. Total neutral sugars, as detected by the nine major monosaccharides (lyxose, rhamnose, ribose, arabinose, fucose, xylose, galactose, mannose, and glucose), were between 4.0 and 18.6 mg (100 mg OC)-1 in the same sediments, suggesting that significant amounts of carbohydrates were not neutral aldoses. Using a two end-member mixing model based on δ13C values and C/N ratios, we estimated that the terrestrial organic carbon contribution to the surface sediment TOC was ca. 78±11% for Lingdingyang Bay, 34±4% for the inner shelf, and 5.5±1% for the outer shelf. The molecular composition of the carbohydrate in the surface sediments also suggested that the inner estuary was rich in terrestrially derived carbohydrates but that their contribution decreased offshore. A relatively high abundance of deoxyhexoses in the estuary and shelf indicated a considerable bacterial source of these carbohydrates, implying that sediment organic matter had undergone extensive degradation and/or transformation during transport. Sediment budget based on calculated regional accumulation rates

  9. Sources and accumulation of organic carbon in the Pearl River Estuary surface sediment as indicated by elemental, stable carbon isotopic, and carbohydrate compositions

    Directory of Open Access Journals (Sweden)

    B. He

    2010-10-01

    Full Text Available Organic matter in surface sediments from the upper reach of the Pearl River Estuary and Lingdingyang Bay, as well as the adjacent northern South China Sea shelf was characterized using a variety of techniques, including elemental (C and N ratio, bulk stable organic carbon isotopic composition (δ13C, and carbohydrate composition analyses. Total organic carbon (TOC content was 1.21±0.45% in the upper reach, down to 1.00±0.22% in Lingdingyang Bay and to 0.80±0.10% on the inner shelf and 0.58±0.06% on the outer shelf. δ13C values ranged from −25.1‰ to −21.3‰ in Lingdingyang Bay and the South China Sea shelf, with a trend of enrichment seawards. The spatial trend in C/N ratios mirrored that of δ13C, with a substantial decrease in C/N ratio offshore. Total carbohydrate yields ranged from 22.1 to 26.7 mg (100 mg OC−1, and typically followed TOC concentrations in the estuarine and shelf sediments. Total neutral sugars, as detected by the nine major monosaccharides (lyxose, rhamnose, ribose, arabinose, fucose, xylose, galactose, mannose, and glucose, were between 4.0 and 18.6 mg (100 mg OC−1 in the same sediments, suggesting that significant amounts of carbohydrates were not neutral aldoses. Using a two end-member mixing model based on δ13C values and C/N ratios, we estimated that the terrestrial organic carbon contribution to the surface sediment TOC was ca. 78±11% for Lingdingyang Bay, 34±4% for the inner shelf, and 5.5±1% for the outer shelf. The molecular composition of the carbohydrate in the surface sediments also suggested that the inner estuary was rich in terrestrially derived carbohydrates but that their contribution decreased offshore. A relatively high abundance of deoxyhexoses in the estuary and shelf indicated a considerable bacterial source of these carbohydrates, implying that sediment organic matter had undergone extensive degradation and

  10. On the use of response surface strategy to elucidate the electrophoretic migration of carbohydrates and optimize their separation.

    Science.gov (United States)

    Sarazin, Cédric; Delaunay, Nathalie; Costanza, Christine; Eudes, Véronique; Gareil, Pierre; Vial, Jérôme

    2012-06-01

    This paper focuses on the optimization with a design of experiments of a new CE method for the simultaneous separation of four carbohydrates of interest (fructose, glucose, lactose, and sucrose) and five potentially interfering carbohydrates (ribose, xylose, maltose, mannose, and galactose) with a highly alkaline separation electrolyte for subsequent applications to food, beverage, forensic, or pharmaceutical samples. First, the factors that potentially affect the carbohydrate migration were identified: NaOH concentration in the separation electrolyte, separation temperature, and separation electrolyte conductivity. A central composite design was then carried out to determine and model the effects of these three factors on normalized migration times and separation efficiency. From the model, an optimization of the separation was carried out using a desirability analysis based on resolutions between adjacent peaks and analysis time. The optimum conditions obtained were a separation electrolyte composed of 98 mM NaOH and 120 mM NaCl to adjust the conductivity at 4.29 S/m and a separation temperature fixed at 26.5°C. Finally, these conditions were experimentally confirmed and the robustness of the obtained separation was checked.

  11. Glycosylated nanoscale surfaces: preparation and applications in medicine and molecular biology.

    Science.gov (United States)

    Kennedy, David C; Grünstein, Dan; Lai, Chian-Hui; Seeberger, Peter H

    2013-03-18

    Carbohydrates on cell surfaces are critical components of the extracellular landscape and contribute to cell signalling, motility, adhesion and recognition. Multivalent effects are essential to these interactions that are inherently weak. Carbohydrate-functionalised surfaces meet an important need for studying the multivalent interactions between carbohydrates and other biomolecules. Innovations in nanomaterials are revolutionising how these carbohydrate interfaces are studied and underscore their importance in the cosmos of biochemical interactions.

  12. Natural Cytotoxicity Receptors: Pattern Recognition and Involvement of Carbohydrates

    Directory of Open Access Journals (Sweden)

    Angel Porgador

    2005-01-01

    Full Text Available Natural cytotoxicity receptors (NCRs, expressed by natural killer (NK cells, trigger NK lysis of tumor and virus-infected cells on interaction with cell-surface ligands of these target cells. We have determined that viral hemagglutinins expressed on the surface of virus-infected cells are involved in the recognition by the NCRs, NKp44 and NKp46. Recognition of tumor cells by the NCRs NKp30 and NKp46 involves heparan sulfate epitopes expressed on the tumor cell membrane. Our studies provide new evidence for the identity of the ligands for NCRs and indicate that a broader definition should be applied to pathological patterns recognized by innate immune receptors. Since nonmicrobial endogenous carbohydrate structures contribute significantly to this recognition, there is an imperative need to develop appropriate tools for the facile sequencing of carbohydrate moieties.

  13. Two Secondary Carbohydrate Binding Sites on the Surface of Barley alpha-Amylase 1 Have Distinct Functions and Display Synergy in Hydrolysis of Starch Granules

    DEFF Research Database (Denmark)

    Nielsen, Morten Munch; Bozonnet, Sophie; Seo, Eun-Seong

    2009-01-01

    Some polysaccharide processing enzymes possess secondary carbohydrate binding sites situated on the surface far from the active site. In barley alpha-amylase 1 (AMY1), two such sites, SBS1 and SBS2, are found on the catalytic (beta/alpha)8-barrel and the noncatalytic C-terminal domain, respective...... to single alpha-glucan chains accessible for hydrolysis, is proposed. SBS1 and SBS2 also influence the kinetics of hydrolysis for amylose and maltooligosaccharides, the degree of multiple attack on amylose, and subsite binding energies....

  14. Targeting the Cryptococcus neoformans var. grubii Cell Wall Using Lectins: Study of the Carbohydrate-Binding Domain

    Directory of Open Access Journals (Sweden)

    Pamella de Brito Ximenes

    2015-02-01

    Full Text Available Cryptococcus neoformans var. grubii is considered to be the major cause of cryptococcosis in immunosuppressed patients. Understanding cell wall glycoproteins using lectins is of medical interest and can contribute to specific therapy. The aim of this study was to evaluate the carbohydrates on the cell wall of Cryptococcus neoformans var. grubii clinical isolates, using a fluorescein isothiocyanate-lectin binding protocol. Thirty yeast strains stocked in the culture collection were cultivated for 2 days at 30 °C with shaking. Cells were obtained by centrifugation, washed in phosphate-buffered saline, and a suspension of 107 cells/mL was obtained. To determine the binding profile of lectins, concanavalin A (Con A, wheat germ agglutinin (WGA, Ulex europaeus agglutinin I (UEA-I, and peanut agglutinin (PNA conjugated to fluorescein were used. All the tested clinical isolates of Cryptococcus neoformans var. grubii were intensely stained by WGA, moderately stained by Con A, and weakly stained by PNA and UEA-I. Thus, Cryptococcus can be detected in clinical specimens such as blood and cerebrospinal fluid using the fluorescent lectin WGA, which may be considered as an option for detection in cases of suspected cryptococcosis with low laboratory sensitivity. Future applications may be developed using this basic tool.

  15. Carbohydrate microarrays in plant science.

    Science.gov (United States)

    Fangel, Jonatan U; Pedersen, Henriette L; Vidal-Melgosa, Silvia; Ahl, Louise I; Salmean, Armando Asuncion; Egelund, Jack; Rydahl, Maja Gro; Clausen, Mads H; Willats, William G T

    2012-01-01

    Almost all plant cells are surrounded by glycan-rich cell walls, which form much of the plant body and collectively are the largest source of biomass on earth. Plants use polysaccharides for support, defense, signaling, cell adhesion, and as energy storage, and many plant glycans are also important industrially and nutritionally. Understanding the biological roles of plant glycans and the effective exploitation of their useful properties requires a detailed understanding of their structures, occurrence, and molecular interactions. Microarray technology has revolutionized the massively high-throughput analysis of nucleotides, proteins, and increasingly carbohydrates. Using microarrays, the abundance of and interactions between hundreds and thousands of molecules can be assessed simultaneously using very small amounts of analytes. Here we show that carbohydrate microarrays are multifunctional tools for plant research and can be used to map glycan populations across large numbers of samples to screen antibodies, carbohydrate binding proteins, and carbohydrate binding modules and to investigate enzyme activities.

  16. A platform to screen for C-type lectin receptor-binding carbohydrates and their potential for cell-specific targeting and immune modulation.

    Science.gov (United States)

    Maglinao, Maha; Eriksson, Magdalena; Schlegel, Mark K; Zimmermann, Stephanie; Johannssen, Timo; Götze, Sebastian; Seeberger, Peter H; Lepenies, Bernd

    2014-02-10

    Myeloid C-type lectin receptors (CLRs) in innate immunity represent a superfamily of pattern recognition receptors that recognize carbohydrate structures on pathogens and self-antigens. The primary interaction of an antigen-presenting cell and a pathogen shapes the following immune response. Therefore, the identification of CLR ligands that can either enhance or modulate the immune response is of interest. We have developed a screening platform based on glycan arrays to identify immune modulatory carbohydrate ligands of CLRs. A comprehensive library of CLRs was expressed by fusing the extracellular part of each respective CLR, the part containing the carbohydrate-recognition domain (CRD), to the Fc fragment of human IgG1 molecules. CLR-Fc fusion proteins display the CRD in a dimeric form, are properly glycosylated, and can be detected by a secondary antibody with a conjugated fluorophore. Thus, they are valuable tools for high-throughput screening. We were able to identify novel carbohydrate binders of CLRs using the glycan array technology. These CLR-binding carbohydrates were then covalently attached to the model antigen ovalbumin. The ovalbumin neoglycoconjugates were used in a dendritic cell/T cell co-culture assay to stimulate transgenic T cells in vitro. In addition, mice were immunized with these conjugates to analyze the immune modulatory properties of the CLR ligands in vivo. The CLR ligands induced an increased Th1 cytokine production in vitro and modulated the humoral response in vivo. The platform described here allows for the identification of CLR ligands, as well as the evaluation of each ligand's cell-specific targeting and immune modulatory properties.

  17. The properties of lectins and cells surface biopolymers of non-pathogenic corynebacteria

    Directory of Open Access Journals (Sweden)

    Sashschuk E. V.

    2011-02-01

    Full Text Available Aim. To study lectin properties of non-pathogenic corynebacteria cells and preparations of their surface biopolymers (SBP, extracted by SDS. Methods. SBP were extracted from intact cells by 0.15 M solution of NaCl contains 1 % SDS. Protein content was determined using Lowry method, carbohydrates – with anthrone method. Electrophoresis was performed in SDS-PAGE according to Lemmli. Hemagglutinating activity (HAA was studied using rabbit erythrocytes. The lectin carbohydrate specificity was determined by reaction of inhibition of hemagglutination. Results. Electrophoretic set of SBP preparations contained the proteins and carbohydrates biopolymers with molecular mass of 10.0–120.0 kDa which did not possess HAA. After extraction of SBP the corynebacteria cells remained viable and have HAA higher than intact cells (64–2048 units. The hemagglutinins of the majority of corynebacteria strains after treatment of cells with SDS exhibited the highest affinity to the bovine submandibular gland mucin and N-acetylneuraminic acid. Conclusions. The examined non-pathogenic strains of corynebacteria were found to contain the lectins, associated with internal layers of a cell wall, which showed a predominant specificity to sialic acids.

  18. Detection of cell type and marker specificity of nuclear binding sites for anionic carbohydrate ligands.

    Science.gov (United States)

    Chovanec, M; Smetana, K; Purkrábková, T; Holíková, Z; Dvoránková, B; André, S; Pytlík, R; Hozák, P; Plzák, J; Sedo, A; Vacík, J; Gabius, H

    2004-01-01

    The emerging functionality of glycosaminoglycan chains engenders interest in localizing specific binding sites using cytochemical tools. We investigated nuclear binding of labeled heparin, heparan sulfate, a sulfated fucan, chondroitin sulfate, and hyaluronic acid in epidermal keratinocytes, bone marrow stromal cells, 3T3 fibroblasts and glioma cells using chemically prepared biotinylated probes. Binding of the markers was cell-type specific and influenced by extraction of histones, but was not markedly affected by degree of proliferation, differentiation or malignancy. Cell uptake of labeled heparin and other selected probes and their transport into the nucleus also was monitored. Differences between keratinocytes and bone marrow stromal cells were found. Preincubation of permeabilized bone marrow stromal cells with label-free heparin reduced the binding of carrier-immobilized hydrocortisone to its nuclear receptors. Thus, these tools enabled binding sites for glycosaminoglycans to be monitored in routine assays.

  19. Validation of extrusion as a killing step for Enterococcus faecium in a balanced carbohydrate-protein meal by using a response surface design.

    Science.gov (United States)

    Bianchini, Andreia; Stratton, Jayne; Weier, Steve; Hartter, Timothy; Plattner, Brian; Rokey, Galen; Hertzel, Gerry; Gompa, Lakshmi; Martinez, Bismarck; Eskridge, Andkent M

    2012-09-01

    Outbreaks of salmonellosis and recalls of low-moisture foods including extruded products highlight the need for the food and feed industries to validate their extrusion processes to ensure the destruction of pathogenic microorganisms. Response surface methodology was employed to study the effect of moisture and temperature on inactivation by extrusion of Enterococcus faecium NRRL B-2354 in a carbohydrate-protein mix. A balanced carbohydrate-protein mix was formulated to different combinations of moisture contents, ranging from 24.9 to 31.1%, and each was inoculated with a pure culture of E. faecium to a final level of 5 log CFU/g. Each mix of various moistures was then extruded in a pilot scale extruder at different temperatures (ranging from 67.5 to 85°C). After the extruder was allowed to equilibrate for 10 min, samples were collected in sterile bags, cooled in dry ice, and stored at 4°C prior to analysis. E. faecium was enumerated with tryptic soy agar and membrane Enterococcus media, followed by incubation at 35°C for 48 h. Each extrusion was repeated twice, with the central point of the design being repeated four times. From each extrusion, three subsamples were collected for microbial counts and moisture determination. Based on the results, the response surface model was y = 185.04 - 3.11X(1) - 4.23X(2) + 0.02X(1)(2) - 0.004X(1)X(2) + 0.08X(2)(2), with a good fit (R(2) = 0.92), which demonstrated the effects of moisture and temperature on the inactivation of E. faecium during extrusion. According to the response surface analysis, the greatest reduction of E. faecium for the inoculation levels studied here (about 5 log) in a carbohydrate-protein meal would occur at the temperature of 81.1°C and moisture content of 28.1%. Other temperature and moisture combinations needed to achieve specific log reductions were plotted in a three-dimensional response surface graph.

  20. Regulation of gene expression in Dictyostelium discoideum cells exposed to immobilized carbohydrates.

    Science.gov (United States)

    Bozzaro, S; Perlo, C; Ceccarelli, A; Mangiarotti, G

    1984-01-01

    When amoebae of Dictyostelium discoideum develop on gels of polyacrylamide that are derivatized with glucosides, they become capable of aggregation at the same time as cells not exposed to glucosides. However, the aggregation centers and streams of adherent cells formed on immobilized glucosides suddenly disintegrate. The cells repeatedly re-aggregate, but never form tight aggregates as they do on other substrata. Tight aggregates formed in the absence of glucosides disperse after their transfer to glucoside gels, and the cells undergo aggregation-disaggregation cycles. The formation of tight aggregates is correlated with the expression of specific post-aggregative poly(A) RNAs. These RNAs are not expressed in cells developing on glucoside gels, and the dispersal of tight aggregates on such gels is accompanied by the almost complete loss of these RNAs. A developmentally regulated membrane glycoprotein called contact site A, which is a marker of aggregation-competent cells, is normally expressed on glucoside gels. Cyclic AMP is also produced, indicating that the strong increase of adenylate cyclase activity during the preaggregation phase is not affected. In conclusion, cell contact with immobilized glucosides specifically inhibits postaggregative gene expression and arrests development at the aggregation stage.

  1. Programming Surface Chemistry with Engineered Cells.

    Science.gov (United States)

    Zhang, Ruihua; Heyde, Keith C; Scott, Felicia Y; Paek, Sung-Ho; Ruder, Warren C

    2016-09-16

    We have developed synthetic gene networks that enable engineered cells to selectively program surface chemistry. E. coli were engineered to upregulate biotin synthase, and therefore biotin synthesis, upon biochemical induction. Additionally, two different functionalized surfaces were developed that utilized binding between biotin and streptavidin to regulate enzyme assembly on programmable surfaces. When combined, the interactions between engineered cells and surfaces demonstrated that synthetic biology can be used to engineer cells that selectively control and modify molecular assembly by exploiting surface chemistry. Our system is highly modular and has the potential to influence fields ranging from tissue engineering to drug development and delivery.

  2. Characterization of the carbohydrate components of Taenia solium oncosphere proteins and their role in the antigenicity.

    Science.gov (United States)

    Arana, Yanina; Verastegui, Manuela; Tuero, Iskra; Grandjean, Louis; Garcia, Hector H; Gilman, Robert H

    2013-10-01

    This study examines the carbohydrate composition of Taenia solium whole oncosphere antigens (WOAs), in order to improve the understanding of the antigenicity of the T. solium. Better knowledge of oncosphere antigens is crucial to accurately diagnose previous exposure to T. solium eggs and thus predict the development of neurocysticercosis. A set of seven lectins conjugates with wide carbohydrate specificity were used on parasite fixations and somatic extracts. Lectin fluorescence revealed that D-mannose, D-glucose, D-galactose and N-acetyl-D-galactosamine residues were the most abundant constituents of carbohydrate chains on the surface of T. solium oncosphere. Lectin blotting showed that posttranslational modification with N-glycosylation was abundant while little evidence of O-linked carbohydrates was observed. Chemical oxidation and enzymatic deglycosylation in situ were performed to investigate the immunoreactivity of the carbohydrate moieties. Linearizing or removing the carbohydrate moieties from the protein backbones did not diminish the immunoreactivity of these antigens, suggesting that a substantial part of the host immune response against T. solium oncosphere is directed against the peptide epitopes on the parasite antigens. Finally, using carbohydrate probes, we demonstrated for the first time that the presence of several lectins on the surface of the oncosphere was specific to carbohydrates found in intestinal mucus, suggesting a possible role in initial attachment of the parasite to host cells.

  3. The role of carbohydrates in infection strategies of enteric pathogens.

    Science.gov (United States)

    Kato, Kentaro; Ishiwa, Akiko

    2015-03-01

    Enteric pathogens cause considerable public health concerns worldwide including tropical regions. Here, we review the roles of carbohydrates in the infection strategies of various enteric pathogens including viruses, bacteria and protozoa, which infect the epithelial lining of the human and animal intestine. At host cell entry, enteric viruses, including norovirus, recognize mainly histo-blood group antigens. At the initial step of bacterial infections, carbohydrates also function as receptors for attachment. Here, we describe the function of carbohydrates in infection by Salmonella enterica and several bacterial species that produce a variety of fimbrial adhesions. During invasion by enteropathogenic protozoa, apicomplexan parasites utilize sialic acids or sulfated glycans. Carbohydrates serve as receptors for infection by these microbes; however, their usage of carbohydrates varies depending on the microbe. On the surface of the mucosal tissues of the gastrointestinal tract, various carbohydrate moieties are present and play a crucial role in infection, representing the site of infection or route of access for most microbes. During the infection and/or invasion process of the microbes, carbohydrates function as receptors for various microbes, but they can also function as a barrier to infection. One approach to develop effective prophylactic and therapeutic antimicrobial agents is to modify the drug structure. Another approach is to modify the mode of inhibition of infection depending on the individual pathogen by using and mimicking the interactions with carbohydrates. In addition, similarities in mode of infection may also be utilized. Our findings will be useful in the development of new drugs for the treatment of enteric pathogens.

  4. Cell attachment on ion implanted titanium surface

    Directory of Open Access Journals (Sweden)

    P.S. Sreejith

    2008-12-01

    Full Text Available Purpose: Of outmost importance for the successful use of an implant is a good adhesion of the surrounding tissue to the biomaterial. In addition to the surface composition of the implant, the surface topography also influences the properties of the adherent cells. In the present investigation, ion implanted and untreated surfaces were compared for cell adhesion and spreading.Design/methodology/approach: The surface topography of the surfaces were analyzed using AFM and the cell studies with SEM.Findings: The results of our present investigation is indicative of the fact that ion implanted titanium surface offer better cell binding affinity compared to untreated/polished surface.Practical implications: Success of non-biodegradable implants will first and foremost depend on biocompatibility, followed by the capacity of the surface topography of the implants to evince desired cell matrix, surface cell matrix interactions. In the present study, the cell growth on ion implanted Ti material is analyzed and discussed.Originality/value: In this paper, we have utilized ion implantation technique, which will produce nano-texturing of the surface without producing any detrimental effects to both the dimensions and properties of the implants.

  5. Analyzing Carbohydrate-Based Regenerative Fuel Cells as a Power Source for Unmanned Aerial Vehicles

    Science.gov (United States)

    2008-03-01

    different researchers. As an example, one fuel cell was reported to have a 95% efficiency [ Weibel and Dodge, 1975] however, upon closer inspection...implants, in 19th IEEE International Conference on Mi- cro Electro Mechanical Systems, vol. 2006, pp. 934–937. Weibel , M. K., and C. Dodge (1975

  6. Functions of proteoglycans at the cell surface

    DEFF Research Database (Denmark)

    Höök, M; Woods, A; Johansson, S;

    1986-01-01

    Proteoglycans (primarily heparan sulphate proteoglycans) are found at the surface of most adherent eukaryotic cells. Earlier studies suggest that these molecules can be associated with the cell surface principally by two different mechanisms. Proteoglycans may occur as membrane......-intercalated glycoproteins, where the core protein of the proteoglycan is anchored in the lipid interior of the plasma membrane, or they may be bound via the polysaccharide components of the molecule to specific anchoring proteins present at the cell surface. A number of functions have been proposed for cell surface......-associated proteoglycans, including: regulation of cell-substrate adhesion; regulation of cell proliferation; participation in the binding and uptake of extracellular components; and participation in the regulation of extracellular matrix formation. Evidence is discussed suggesting that the cell-associated heparan...

  7. Controlled surface chemistries and quantitative cell response

    Science.gov (United States)

    Plant, Anne L.

    2002-03-01

    Living cells experience a large number of signaling cues from their extracellular matrix. As a result of these inputs, a variety of intracellular signaling pathways are apparently initiated simultaneously. The vast array of alternative responses that result from the integration of these inputs suggests that it may be reasonable to look for cellular response not as an 'on' or 'off' condition but as a distribution of responses. A difficult challenge is to determine whether variations in responses from individual cells arise from the complexity of intracellular signals or are due to variations in the cell culture environment. By controlling surface chemistry so that every cell 'sees' the same chemical and physical environment, we can begin to assess how the distribution of cell response is affected strictly by changes in the chemistry of the cell culture surface. Using the gene for green fluorescent protein linked to the gene for the promoter of the extracellular matrix protein, tenascin, we can easily probe the end product in a signaling pathway that is purported to be linked to surface protein chemistry and to cell shape. Cell response to well-controlled, well-characterized, and highly reproducible surfaces prepared using soft lithography techniques are compared with more conventional ways of preparing extracellular matrix proteins for cell culture. Using fluorescence microscopy and image analysis of populations of cells on these surfaces, we probe quantitatively the relationship between surface chemistry, cell shape and variations in gene expression endpoint.

  8. A lectin histochemical study on carbohydrate moieties of the gonadotropin-like substance in the epithelial cells of Hatschek's pit of Branchiostoma belcheri

    Science.gov (United States)

    Fang, Y. Q.; Welsch, U.

    1997-03-01

    The present light microscopic lectin, histochemical study suggests for the first time that the vertebrate gonadotropin-like substance in the basal part of the epithelial cells of Hatschek's pit is a sialic acid-containing glycoprotein. The binding intensity of the epithelial cells in Hatschek's pit to 6 lectins ( Limulus polyphemus agglutinin (LPA), Wheat germ agglutinin (WGA), Helix pomatia agglutinin (HPA), Concanavalin A (Con A), Ulex europaeus agglutinin I (UEA I) and Ricinus communis agglutinin I (RCA I)) indicate that the carbohydrate composition of the gonadotrophic glycoprotein is similar to that of mammals and fish, and that N-acetyl-D-galactosamine, sialic acid, glucosamine, D-mannose and L-fucose are components of the carbohydrate portion.

  9. New fabrication and applications of carbohydrate arrays.

    Science.gov (United States)

    Huang, Gangliang; Chen, Xin; Xiao, Feng

    2014-01-01

    Carbohydrate arrays are used as high-throughput screening platforms to study the carbohydrate-mediated recognition events for glycobiology. The polysaccharide arrays are easy to fabricate by non-covalently or covalently immobilizing polysaccharides onto array surfaces because polysaccharides have hydrophobic interactions. Oligosaccharides must be derived and covalently or non-covalently immobilized onto array surfaces to fabricate oligosaccharide arrays because they have hydrophilic interactions. At the moment, carbohydrate arrays are mainly used to study the carbohydrate-protein interactions and carbohydrate-binding lectins or antibodies, which are possible to be applied to clinics and diagnoses. This review mainly summed up the new fabrication strategies of carbohydrate arrays and their applications in recent four years.

  10. Carbohydrates and Diabetes

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Carbohydrates and Diabetes KidsHealth > For Teens > Carbohydrates and Diabetes A A A What's in this ... that you should keep track of how many carbohydrates (carbs) you eat. But what exactly are carbohydrates ...

  11. Cell-surface remodelling during mammalian erythropoiesis.

    Science.gov (United States)

    Wraith, D C; Chesterton, C J

    1982-10-15

    Current evidence suggests that the major cell-surface modification occurring during mammalian erythropoiesis could be generated by two separate mechanisms: either selective loss of membrane proteins during enucleation or endocytosis at the subsequent reticulocyte and erythrocyte stages. The former idea was tested by collecting developing rabbit erythroid cells before and after the enucleation step and comparing their cell-surface protein composition via radiolabelling and electrophoresis. Few changes were observed. Our data thus lend support to the endocytosis mechanism.

  12. Synthesis of the Oligosaccharide Fragment of the Surface of Tumor Cell and Its Analogue

    Institute of Scientific and Technical Information of China (English)

    Qin Zhihui; Zhang Lihe; Li Zhongjun

    2001-01-01

    @@ Selectins are a new class of carbohydrate-binding glycoproteins which have been identified on the surface of specific cell types, such as leukocytes, platelets and vascular endothelium. It is now known that the selectincarbohydrate recognition not only play key roles at early stage of the inflammatory reaction, but also are very important for the invasion and metastasis of rumors. These results suggested that selectin antagonists can be used as anti-adhesive therapeutics to pathological inflammatory conditions, such as reperfusion injury, storke, etc. and will be helpful to the inhibition of the matastasis of tumor cells.

  13. Nanostructuring of Solar Cell Surfaces

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Schmidt, Michael Stenbæk

    Solar energy is by far the most abundant renewable energy source available, but the levelized cost of solar energy is still not competitive with that of fossil fuels. Therefore there is a need to improve the power conversion effciency of solar cells without adding to the production cost. The main...... objective of this PhD thesis is to develop nanostructured silicon (Si) solar cells with higher power conversion efficiency using only scalable and cost-efficient production methods. The nanostructures, known as 'black silicon', are fabricated by single-step, maskless reactive ion etching and used as front...... and characterized for comparison. Power conversion eciency of 16.5% was obtained for this batch of RIE-textured Si solar cells. The eciency of the KOH-textured reference cell was 17.8%. Quantum Efficiency measurements and carrier loss analysis show that the lower eciency of the RIE-textured cells is primarily due...

  14. Cell behaviour on chemically microstructured surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Magnani, Agnese; Priamo, Alfredo; Pasqui, Daniela; Barbucci, Rolando

    2003-03-03

    Micropatterned surfaces with different chemical topographies were synthesised in order to investigate the influence of surface chemistry and topography on cell behaviour. The microstructured materials were synthesised by photoimmobilising natural Hyaluronan (Hyal) and its sulphated derivative (HyalS), both adequately functionalised with a photorective moiety, on glass substrates. Four different grating patterns (10, 25, 50 and 100 {mu}m) were used to pattern the hyaluronan. The micropatterned samples were analysed by Secondary Ions Mass Spectrometry, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy to investigate the chemistry and the topography of the surfaces. The spectroscopic and microscopic analysis of the microstructured surfaces revealed that the photoimmobilisation process was successful, demonstrating that the photomask patterns were well reproduced on the sample surface. The influence of chemical topographies on the cell behaviour was then analysed. Human and 3T3 fibroblasts, bovine aortic and human (HGTFN line) endothelial cells were used and their behaviour on the micropatterned surfaces was analysed in terms of adhesion, proliferation, locomotion and orientation. Both chemical and topographical controls were found to be important for cell guidance. By decreasing the stripe dimensions, a more fusiform shape of cell was observed. At the same time, the cell locomotion and orientation parallel to the structure increased. However, differences in cell behaviour were detected according to both cell type and micropattern dimensions.

  15. Surface plasmon resonance for real-time study of lectin-carbohydrate interactions for the differentiation and identification of glycoproteins.

    Science.gov (United States)

    Safina, Gulnara; Duran, Iu Benet; Alasel, Mohammed; Danielsson, Bengt

    2011-06-15

    A study of specific interactions between lectins and glycoproteins has been carried out using surface plasmon resonance (SPR) in a flow-injection mode. Lectins were covalently immobilised on the surfaces of the microfluidic sensor chip via amine coupling and serum glycoproteins were injected into the flow channels. Specific lectin-glycoprotein interactions caused the shift of refractive index proportional to the mass concentration accumulated on the channel surface. Lectins showed different affinity to the tested glycoproteins and each glycoprotein displayed its own lectin-binding pattern. It is possible to distinguish and identify even glycoproteins with similar sugar structures by simple and quick screening. The working conditions of the assay were optimised. The lectin-based SPR made it possible to carry out the label-free detection of glycoproteins within a broad concentration range with a good linearity. Regeneration conditions for the surface of the sensor chip were found and optimised. Combination of 10mM HCl and 10mM glycine-HCl (pH 2.5) removes the bound glycoproteins from the lectin surface without damaging it. The kinetic and affinity parameters of lectin-glycoprotein binding were evaluated. The proposed method was tested on human glycosylated serum. Combination of the lectin panel with SPR is suitable both for specific screening and for sensitive assay of serum glycoproteins.

  16. The cancer glycome: carbohydrates as mediators of metastasis.

    Science.gov (United States)

    Glavey, Siobhan V; Huynh, Daisy; Reagan, Michaela R; Manier, Salomon; Moschetta, Michele; Kawano, Yawara; Roccaro, Aldo M; Ghobrial, Irene M; Joshi, Lokesh; O'Dwyer, Michael E

    2015-07-01

    Glycosylation is a frequent post-translational modification which results in the addition of carbohydrate determinants, "glycans", to cell surface proteins and lipids. These glycan structures form the "glycome" and play an integral role in cell-cell and cell-matrix interactions through modulation of adhesion and cell trafficking. Glycosylation is increasingly recognized as a modulator of the malignant phenotype of cancer cells, where the interaction between cells and the tumor micro-environment is altered to facilitate processes such as drug resistance and metastasis. Changes in glycosylation of cell surface adhesion molecules such as selectin ligands, integrins and mucins have been implicated in the pathogenesis of several solid and hematological malignancies, often with prognostic implications. In this review we focus on the functional significance of alterations in cancer cell glycosylation, in terms of cell adhesion, trafficking and the metastatic cascade and provide insights into the prognostic and therapeutic implications of recent findings in this fast-evolving niche.

  17. Biosynthesis of silver nanoparticle and its application in cell wall disruption to release carbohydrate and lipid from C. vulgaris for biofuel production

    Directory of Open Access Journals (Sweden)

    Sirajunnisa Abdul Razack

    2016-09-01

    Full Text Available Microalgae are the fledging feedstocks yielding raw materials for the production of third generation biofuel. Assorted and conventional cell wall disruption techniques were helpful in extracting lipids and carbohydrates, nevertheless the disadvantages have led the biotechnologists to explore new process to lyse cell wall in a faster and an economical manner. Silver nanoparticles have the ability to break the cell wall of microalgae and release biomolecules effectively. Green synthesis of silver nanoparticles was performed using a novel bacterial isolate of Bacillus subtilis. Characterisation of nanosilver and its effect on cell wall lysis of microalgae were extensively analysed. Cell wall damage was confirmed by lactate dehydrogenase assay and visually by SEM analysis. This first piece of research work on direct use of nanoparticles for cell wall lysis would potentially be advantageous over its conventional approaches and a greener, cost effective and non laborious method for the production of biodiesel.

  18. Novel eukaryotic enzymes modifying cell-surface biopolymers

    Directory of Open Access Journals (Sweden)

    Aravind L

    2010-01-01

    Full Text Available Abstract Background Eukaryotic extracellular matrices such as proteoglycans, sclerotinized structures, mucus, external tests, capsules, cell walls and waxes contain highly modified proteins, glycans and other composite biopolymers. Using comparative genomics and sequence profile analysis we identify several novel enzymes that could be potentially involved in the modification of cell-surface glycans or glycoproteins. Results Using sequence analysis and conservation we define the acyltransferase domain prototyped by the fungal Cas1p proteins, identify its active site residues and unify them to the superfamily of classical 10TM acyltransferases (e.g. oatA. We also identify a novel family of esterases (prototyped by the previously uncharacterized N-terminal domain of Cas1p that have a similar fold as the SGNH/GDSL esterases but differ from them in their conservation pattern. Conclusions We posit that the combined action of the acyltransferase and esterase domain plays an important role in controlling the acylation levels of glycans and thereby regulates their physico-chemical properties such as hygroscopicity, resistance to enzymatic hydrolysis and physical strength. We present evidence that the action of these novel enzymes on glycans might play an important role in host-pathogen interaction of plants, fungi and metazoans. We present evidence that in plants (e.g. PMR5 and ESK1 the regulation of carbohydrate acylation by these acylesterases might also play an important role in regulation of transpiration and stress resistance. We also identify a subfamily of these esterases in metazoans (e.g. C7orf58, which are fused to an ATP-grasp amino acid ligase domain that is predicted to catalyze, in certain animals, modification of cell surface polymers by amino acid or peptides. Reviewers This article was reviewed by Gaspar Jekely and Frank Eisenhaber

  19. Novel eukaryotic enzymes modifying cell-surface biopolymers

    Science.gov (United States)

    2010-01-01

    Background Eukaryotic extracellular matrices such as proteoglycans, sclerotinized structures, mucus, external tests, capsules, cell walls and waxes contain highly modified proteins, glycans and other composite biopolymers. Using comparative genomics and sequence profile analysis we identify several novel enzymes that could be potentially involved in the modification of cell-surface glycans or glycoproteins. Results Using sequence analysis and conservation we define the acyltransferase domain prototyped by the fungal Cas1p proteins, identify its active site residues and unify them to the superfamily of classical 10TM acyltransferases (e.g. oatA). We also identify a novel family of esterases (prototyped by the previously uncharacterized N-terminal domain of Cas1p) that have a similar fold as the SGNH/GDSL esterases but differ from them in their conservation pattern. Conclusions We posit that the combined action of the acyltransferase and esterase domain plays an important role in controlling the acylation levels of glycans and thereby regulates their physico-chemical properties such as hygroscopicity, resistance to enzymatic hydrolysis and physical strength. We present evidence that the action of these novel enzymes on glycans might play an important role in host-pathogen interaction of plants, fungi and metazoans. We present evidence that in plants (e.g. PMR5 and ESK1) the regulation of carbohydrate acylation by these acylesterases might also play an important role in regulation of transpiration and stress resistance. We also identify a subfamily of these esterases in metazoans (e.g. C7orf58), which are fused to an ATP-grasp amino acid ligase domain that is predicted to catalyze, in certain animals, modification of cell surface polymers by amino acid or peptides. Reviewers This article was reviewed by Gaspar Jekely and Frank Eisenhaber PMID:20056006

  20. Structure and functions of fungal cell surfaces

    Science.gov (United States)

    Nozawa, Y.

    1984-01-01

    A review with 24 references on the biochemistry, molecular structure, and function of cell surfaces of fungi, especially dermatophytes: the chemistry and structure of the cell wall, the effect of polyene antibiotics on the morphology and function of cytoplasmic membranes, and the chemical structure and function of pigments produced by various fungi are discussed.

  1. In silico analysis of molecular mechanisms of Galanthus nivalis agglutinin-related lectin-induced cancer cell death from carbohydrate-binding motif evolution hypothesis.

    Science.gov (United States)

    Yu, Qi-Jia; Li, Zi-Yue; Yao, Shun; Ming, Miao; Wang, Shu-Ya; Liu, Bo; Bao, Jin-Ku

    2011-10-01

    Galanthus nivalis agglutinin-related lectins, a superfamily of strictly mannose-binding-specific lectins widespread amongst monotyledonous plants, have drawn a rising attention for their remarkable anti-proliferative and apoptosis-inducing activities toward various types of cancer cells; however, the precise molecular mechanisms by which they induce tumor cell apoptosis are still only rudimentarily understood. Herein, we found that the three conserved motifs "QXDXNXVXY," the mannose-specific binding sites, could mutate at one or more amino acid sites, which might be a driving force for the sequential evolution and thus ultimately leading to the complete disappearance of the three conserved motifs. In addition, we found that the motif evolution could result in the diversification of sugar-binding types that G. nivalis agglutinin-related lectins could bind from specific mannose receptors to more types of sugar-containing receptors in cancer cells. Subsequently, we indicated that some sugar-containing receptors such as TNFR1, EGFR, Hsp90, and Hsp70 could block downstream anti-apoptotic or survival signaling pathways, which, in turn, resulted in tumor cell apoptosis. Taken together, our hypothesis that carbohydrate-binding motif evolution may impact the G. nivalis agglutinin-related lectin-induced survival or anti-apoptotic pathways would provide a new perspective for further elucidating the intricate relationships between the carbohydrate-binding specificities and complex molecular mechanisms by which G. nivalis agglutinin-related lectins induce cancer cell death.

  2. Regional variations of cell surface carbohydrates in human oral stratified epithelium

    DEFF Research Database (Denmark)

    Vedtofte, P; Dabelsteen, Erik; Hakomori, S

    1984-01-01

    such as non-keratinized, parakeratinized, and orthokeratinized stratified squamous epithelium. The material included buccal and palatal epithelium from 20 persons with blood group A or O, gingival, and alveolar epithelium from 10 persons with blood group A or B, and buccal metaplastically keratinized......-acetyllactosamine by murine monoclonal antibodies. Each antigen showed a similar staining pattern in buccal and alveolar epithelium (non-keratinized) which differed considerably from that seen in palatal and gingival epithelium (ortho- and parakeratinized). The expression of blood group antigens A or B and the precursor...

  3. Probes for anionic cell surface detection

    Science.gov (United States)

    Smith, Bradley D.

    2013-03-05

    Embodiments of the present invention are generally directed to compositions comprising a class of molecular probes for detecting the presence of anionic cell surfaces. Embodiments include compositions that are enriched for these compositions and preparations, particularly preparations suitable for use as laboratory/clinical reagents and diagnostic indicators, either alone or as part of a kit. An embodiment of the invention provides for a highly selective agent useful in the discernment and identification of dead or dying cells, such as apoptotic cells, in a relatively calcium-free environment. An embodiment of the invention provides a selective agent for the identification of bacteria in a mixed population of bacterial cells and nonbacterial cells.

  4. Nanotomography of Cell Surfaces with Evanescent Fields

    Directory of Open Access Journals (Sweden)

    Michael Wagner

    2008-01-01

    Full Text Available The technique of variable-angle total internal reflection fluorescence microscopy (TIRFM and its application to nanotomography of cell surfaces are described. Present applications include (1 3D imaging of chromosomes in their metaphase to demonstrate axial resolution in the nanometre range, (2 measurements of cell-substrate topology, which upon cholesterol depletion shows some loosening of cell-substrate contacts, and (3 measurements of cell topology upon photodynamic therapy (PDT, which demonstrate cell swelling and maintenance of focal contacts. The potential of the method for in vitro diagnostics, but also some requirements and limitations are discussed.

  5. Carbohydrate clearance receptors in transfusion medicine

    DEFF Research Database (Denmark)

    Sørensen, Anne Louise Tølbøll; Clausen, Henrik; Wandall, Hans H

    2012-01-01

    Complex carbohydrates play important functions for circulation of proteins and cells. They provide protective shields and refraction from non-specific interactions with negative charges from sialic acids to enhance circulatory half-life. For recombinant protein therapeutics carbohydrates are espe...

  6. Role of pathogen-derived cell wall carbohydrates and prostaglandin E2 in immune response and suppression of fish immunity by the oomycete Saprolegnia parasitica.

    Science.gov (United States)

    Belmonte, Rodrigo; Wang, Tiehui; Duncan, Gary J; Skaar, Ida; Mélida, Hugo; Bulone, Vincent; van West, Pieter; Secombes, Christopher J

    2014-11-01

    Saprolegnia parasitica is a freshwater oomycete that is capable of infecting several species of fin fish. Saprolegniosis, the disease caused by this microbe, has a substantial impact on Atlantic salmon aquaculture. No sustainable treatment against saprolegniosis is available, and little is known regarding the host response. In this study, we examined the immune response of Atlantic salmon to S. parasitica infection and to its cell wall carbohydrates. Saprolegnia triggers a strong inflammatory response in its host (i.e., induction of interleukin-1β1 [IL-1β1], IL-6, and tumor necrosis factor alpha), while severely suppressing the expression of genes associated with adaptive immunity in fish, through downregulation of T-helper cell cytokines, antigen presentation machinery, and immunoglobulins. Oomycete cell wall carbohydrates were recognized by fish leukocytes, triggering upregulation of genes involved in the inflammatory response, similar to what is observed during infection. Our data suggest that S. parasitica is capable of producing prostaglandin [corrected] E2 (PGE2) in vitro, a metabolite not previously shown to be produced by oomycetes, and two proteins with homology to vertebrate enzymes known to play a role in prostaglandin biosynthesis have been identified in the oomycete genome. Exogenous PGE2 was shown to increase the inflammatory response in fish leukocytes incubated with cell wall carbohydrates while suppressing genes involved in cellular immunity (gamma interferon [IFN-γ] and the IFN-γ-inducible protein [γ-IP]). Inhibition of S. parasitica zoospore germination and mycelial growth by two cyclooxygenase inhibitors (aspirin and indomethacin) also suggests that prostaglandins may be involved in oomycete development.

  7. Carbohydrate restriction and dietary cholesterol modulate the expression of HMG-CoA reductase and the LDL receptor in mononuclear cells from adult men

    Directory of Open Access Journals (Sweden)

    Volek Jeff S

    2007-11-01

    Full Text Available Abstract The liver is responsible for controlling cholesterol homeostasis in the body. HMG-CoA reductase and the LDL receptor (LDL-r are involved in this regulation and are also ubiquitously expressed in all major tissues. We have previously shown in guinea pigs that there is a correlation in gene expression of HMG-CoA reductase and the LDL-r between liver and mononuclear cells. The present study evaluated human mononuclear cells as a surrogate for hepatic expression of these genes. The purpose was to evaluate the effect of dietary carbohydrate restriction with low and high cholesterol content on HMG-CoA reductase and LDL-r mRNA expression in mononuclear cells. All subjects were counseled to consume a carbohydrate restricted diet with 10–15% energy from carbohydrate, 30–35% energy from protein and 55–60% energy from fat. Subjects were randomly assigned to either EGG (640 mg/d additional dietary cholesterol or SUB groups [equivalent amount of egg substitute (0 dietary cholesterol contributions per day] for 12 weeks. At the end of the intervention, there were no changes in plasma total or LDL cholesterol (LDL-C compared to baseline (P > 0.10 or differences in plasma total or LDL-C between groups. The mRNA abundance for HMG-CoA reductase and LDL-r were measured in mononuclear cells using real time PCR. The EGG group showed a significant decrease in HMG-CoA reductase mRNA (1.98 ± 1.26 to 1.32 ± 0.92 arbitrary units P

  8. [Carbohydrate absorption and malabsorption (author's transl)].

    Science.gov (United States)

    Caspary, W F

    1977-06-01

    Starch is digested intraluminally by alpha-amylase to maltose, maltotriose, and alpha-limit dextrins. These products, as well as the disaccharides sucrose and lactose, undergo enzymatic hydrolysis to monosaccharides at the brush border surface. The monosaccharides enter the absorbing cell by specific transport mechanisms ("carriers"). Primary carbohydrate (CH) intolerance is characterized by the congenital or acquired absence of individual brush border enzymes or of monosaccharide "carriers" without morphologic abnormalities of the intestinal villus: lactose, sucrose and trehalose intolerance and glucose-galactose malabsorption (brush border diseases). Secondary CH intolerance arises when surface digestion and absorption are reduced due to structural changes of the intestinal mucosa: e.g., decrease or absence of villi with sprue and reduction of the absorbing surface with intestinal resection. Watery diarrhea is the lead symptom. Many drugs delay or interfere with CH absorption. This action may be viewed either as an unwanted side effect or as a welcome therapeutic principle.

  9. Carbohydrate Metabolism Disorders

    Science.gov (United States)

    ... you eat. Food is made up of proteins, carbohydrates, and fats. Chemicals in your digestive system (enzymes) ... metabolic disorder, something goes wrong with this process. Carbohydrate metabolism disorders are a group of metabolic disorders. ...

  10. The effect of dietary carbohydrates and Trichuris suis infection on pig large intestine tissue structure, epithelial cell proliferation and mucin characteristics.

    Science.gov (United States)

    Thomsen, L E; Knudsen, K E Bach; Hedemann, M S; Roepstorff, A

    2006-11-30

    Two experiments (Exps. 1 and 2) were performed to study the influence of Trichuris suis infection and type of dietary carbohydrates on large intestine morphology, epithelial cell proliferation and mucin characteristics. Two experimental diets based on barley flour were used; Diet 1 was supplemented with resistant carbohydrates from oat hull meal, while Diet 2 was supplemented with fermentable carbohydrates from sugar beet fibre and inulin. In Experiment 1, 32 pigs were allocated randomly into four groups. Two groups were fed Diet 1 and two groups Diet 2. Pigs from one of each diet group were inoculated with a single dose of 2000 infective T. suis eggs and the other two groups remained uninfected controls. In Experiment 2, 12 pigs were allocated randomly into two groups and fed Diet 1 or Diet 2, respectively, and inoculated with a single dose of 2000 infective T. suis eggs. All the pigs were slaughtered 8 weeks post inoculation (p.i.). The worm counts were lower in pigs fed Diet 2 in both experiments, but not significantly so. Both diet and infection status significantly influenced the tissue weight of the large intestine. In both experiments, pigs fed Diet 2 had heavier large intestines than pigs fed Diet 1 and in Experiment1 the infected pigs of both diets had heavier large intestines than their respective control groups. Diet and infection also significantly affected the morphological architecture and mucin production in both experiments. Pigs fed Diet 1 had larger crypts both in terms of area and height than pigs fed Diet 2 and T. suis infected pigs on both diets in Experiment 1 had larger crypts than their respective control groups. The area of the mucin granules in the crypts constituted 22-53% of the total crypt area and was greatest in the T. suis infected pigs fed Diet 1. Epithelial cell proliferation was affected neither by diet nor infection in any of the experiments. The study showed that both T. suis infection and dietary carbohydrates significantly

  11. Blood-group-related carbohydrates are expressed in organotypic cultures of human skin and oral mucosa

    DEFF Research Database (Denmark)

    Grøn, B; Andersson, A; Dabelsteen, Erik

    1999-01-01

    -group-related carbohydrate structures, including Lewis x, sialylated Lewis x, Lewis y, Lewis a, and Lewis b, on the surface of epithelial cells in the cultures. We compared the results with the expression of more well-established markers, including cytokeratins, integrins, bullous pemphigoid antigen and laminin, in the same...... cultures. The organotypic skin and oral mucosa cultures showed a histological differentiation pattern analogous to that of normal skin and buccal mucosa, and a tissue-specific expression of carbohydrate structures and cytokeratins. However, both types of organotypic cultures also expressed markers which......Cellular maturation and migration are usually associated with changes in cell-surface carbohydrates, but the relationship between these changes and cell behaviour is at present largely unknown. To investigate whether an organotypic culture system can be used as an in vitro model to study...

  12. Arabinogalactan proteins: focus on carbohydrate active enzymes

    Directory of Open Access Journals (Sweden)

    Eva eKnoch

    2014-06-01

    Full Text Available Arabinogalactan proteins (AGPs are a highly diverse class of cell surface proteoglycans that are commonly found in most plant species. AGPs play important roles in many cellular processes during plant development, such as reproduction, cell proliferation, pattern formation and growth, and in plant-microbe interaction. However, little is known about the molecular mechanisms of their function. Numerous studies using monoclonal antibodies that recognize different AGP glycan epitopes have shown the appearance of a slightly altered AGP glycan in a specific stage of development in plant cells. Therefore, it is anticipated that the biosynthesis and degradation of AGP glycan is tightly regulated during development. Until recently, however, little was known about the enzymes involved in the metabolism of AGP glycans. In this review, we summarize recent discoveries of carbohydrate active enzymes (CAZy; http://www.cazy.org/ involved in the biosynthesis and degradation of AGP glycans, and we discuss the biological role of these enzymes in plant development.

  13. Surface cell immobilization within perfluoroalkoxy microchannels

    Science.gov (United States)

    Stojkovič, Gorazd; Krivec, Matic; Vesel, Alenka; Marinšek, Marjan; Žnidaršič-Plazl, Polona

    2014-11-01

    Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor® and Topas®.

  14. Surface cell immobilization within perfluoroalkoxy microchannels

    Energy Technology Data Exchange (ETDEWEB)

    Stojkovič, Gorazd; Krivec, Matic [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Vesel, Alenka [Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana (Slovenia); Marinšek, Marjan [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia); Žnidaršič-Plazl, Polona, E-mail: polona.znidarsic@fkkt.uni-lj.si [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana (Slovenia)

    2014-11-30

    Graphical abstract: - Highlights: • A very efficient approach for immobilization of cells into microreactors is presented. • It is applicable to various materials, including PFA and cyclic olefin (co)polymers. • It was used to immobilize different prokaryotic and eukaryotic microbes. • Cells were immobilized on the surface in high density and showed good stability. • Mechanisms of APTES interactions with target materials are proposed. - Abstract: Perfluoroalkoxy (PFA) is one of the most promising materials for the fabrication of cheap, solvent resistant and reusable microfluidic chips, which have been recently recognized as effective tools for biocatalytic process development. The application of biocatalysts significantly depends on efficient immobilization of enzymes or cells within the reactor enabling long-term biocatalyst use. Functionalization of PFA microchannels by 3-aminopropyltriethoxysilane (ATPES) and glutaraldehyde was used for rapid preparation of microbioreactors with surface-immobilized cells. X-ray photoelectron spectroscopy and scanning electron microscopy were used to accurately monitor individual treatment steps and to select conditions for cell immobilization. The optimized protocol for Saccharomyces cerevisiae immobilization on PFA microchannel walls comprised ethanol surface pretreatment, 4 h contacting with 10% APTES aqueous solution, 10 min treatment with 1% glutaraldehyde and 20 min contacting with cells in deionized water. The same protocol enabled also immobilization of Escherichia coli, Pseudomonas putida and Bacillus subtilis cells on PFA surface in high densities. Furthermore, the developed procedure has been proved to be very efficient also for surface immobilization of tested cells on other materials that are used for microreactor fabrication, including glass, polystyrene, poly (methyl methacrylate), polycarbonate, and two olefin-based polymers, namely Zeonor{sup ®} and Topas{sup ®}.

  15. Application of an enzyme-labeled antigen method for visualizing plasma cells producing antibodies against Strep A, a carbohydrate antigen of Streptococcus pyogenes, in recurrent tonsillitis.

    Science.gov (United States)

    Onouchi, Takanori; Mizutani, Yasuyoshi; Shiogama, Kazuya; Inada, Ken-ichi; Okada, Tatsuyoshi; Naito, Kensei; Tsutsumi, Yutaka

    2015-01-01

    Streptococcus pyogenes is the main causative pathogen of recurrent tonsillitis. Histologically, lesions of recurrent tonsillitis contain numerous plasma cells. Strep A is an antigenic carbohydrate molecule on the cell wall of S. pyogenes. As expected, plasma cells in subjects with recurrent tonsillitis secrete antibodies against Strep A. The enzyme-labeled antigen method is a novel histochemical technique that visualizes specific antibody-producing cells in tissue sections by employing a biotin-labeled antigen as a probe. The purpose of the present study was to visualize plasma cells producing antibodies reactive with Strep A in recurrent tonsillitis. Firstly, the lymph nodes of rats immunized with boiled S. pyogenes were paraformaldehyde-fixed and specific plasma cells localized in frozen sections with biotinylated Strep A. Secondly, an enzyme-labeled antigen method was used on human tonsil surgically removed from 12 patients with recurrent tonsillitis. S. pyogenes genomes were PCR-detected in all 12 specimens. The emm genotypes belonged to emm12 in nine specimens and emm1 in three. Plasma cells producing anti-Strep A antibodies were demonstrated in prefixed frozen sections of rat lymph nodes, 8/12 human specimens from patients with recurrent tonsillitis but not in two control tonsils. In human tonsils, Strep A-reactive plasma cells were observed within the reticular squamous mucosa and just below the mucosa, and the specific antibodies belonged to either IgA or IgG classes. Our technique is effective in visualizing immunocytes producing specific antibodies against the bacterial carbohydrate antigen, and is thus a novel histochemical tool for analyzing immune reactions in infectious disorders.

  16. Cell surface engineering with edible protein nanoshells.

    Science.gov (United States)

    Drachuk, Irina; Shchepelina, Olga; Harbaugh, Svetlana; Kelley-Loughnane, Nancy; Stone, Morley; Tsukruk, Vladimir V

    2013-09-23

    Natural protein (silk fibroin) nanoshells are assembled on the surface of Saccharomyces cerevisiae yeast cells without compromising their viability. The nanoshells facilitate initial protection of the cells and allow them to function in encapsulated state for some time period, afterwards being completely biodegraded and consumed by the cells. In contrast to a traditional methanol treatment, the gentle ionic treatment suggested here stabilizes the shell silk fibroin structure but does not compromise the viability of the cells, as indicated by the fast response of the encapsulated cells, with an immediate activation by the inducer molecules. Extremely high viability rates (up to 97%) and preserved activity of encapsulated cells are facilitated by cytocompatibility of the natural proteins and the formation of highly porous shells in contrast to traditional polyelectrolyte-based materials. Moreover, in a high contrast to traditional synthetic shells, the silk proteins are biodegradable and can be consumed by cells at a later stage of growth, thus releasing the cells from their temporary protective capsules. These on-demand encapsulated cells can be considered a valuable platform for biocompatible and biodegradable cell encapsulation, controlled cell protection in a synthetic environment, transfer to a device environment, and cell implantation followed by biodegradation and consumption of protective protein shells.

  17. Developmentally regulated epitopes of cell surface arabinogalactan proteins and their relation to root tissue pattern formation.

    Science.gov (United States)

    Knox, J P; Linstead, P J; Peart, J; Cooper, C; Roberts, K

    1991-11-01

    Two polymorphic forms of an extracellular arabinogalactan protein (AGP1 and AGP2), obtained from the conditioned media of two carrot suspension-cultured cell lines, have been identified in terms of binding of the anti-plasma membrane antibodies JIM4 and MAC207. AGP1 and AGP2 have been used as immunogens to generate further anti-AGP monoclonal antibodies. JIM14 identified an epitope carried by AGP2 and also by glycoproteins of low molecular weight localized to the plant cell wall. In addition, further antibodies (JIM13 and JIM15) identified carbohydrate epitopes of the AGPs that also occur on plasma membrane glycoproteins and are expressed by patterns of cells that reflect cell position at the carrot root apex. Indirect immunofluorescence microscopy indicated that JIM13 recognized the surface of cells forming the epidermis and cells marking the region and axis of the future xylem. JIM15 recognized a pattern of cells directly complementary to the JIM13 pattern. The panel of anti-AGP monoclonal antibodies now available indicates groups of cells within the root meristem that may reflect an early pre-pattern of the tissues of the mature root structure and suggests extensive modulation of cell surface AGPs during cell development and the positioning of cells within the apex.

  18. Potential of Peptides as Inhibitors and Mimotopes: Selection of Carbohydrate-Mimetic Peptides from Phage Display Libraries

    Directory of Open Access Journals (Sweden)

    Teruhiko Matsubara

    2012-01-01

    Full Text Available Glycoconjugates play various roles in biological processes. In particular, oligosaccharides on the surface of animal cells are involved in virus infection and cell-cell communication. Inhibitors of carbohydrate-protein interactions are potential antiviral drugs. Several anti-influenza drugs such as oseltamivir and zanamivir are derivatives of sialic acid, which inhibits neuraminidase. However, it is very difficult to prepare a diverse range of sugar derivatives by chemical synthesis or by the isolation of natural products. In addition, the pathogenic capsular polysaccharides of bacteria are carbohydrate antigens, for which a safe and efficacious method of vaccination is required. Phage-display technology has been improved to enable the identification of peptides that bind to carbohydrate-binding proteins, such as lectins and antibodies, from a large repertoire of peptide sequences. These peptides are known as “carbohydrate-mimetic peptides (CMPs” because they mimic carbohydrate structures. Compared to carbohydrate derivatives, it is easy to prepare mono- and multivalent peptides and then to modify them to create various derivatives. Such mimetic peptides are available as peptide inhibitors of carbohydrate-protein interactions and peptide mimotopes that are conjugated with adjuvant for vaccination.

  19. The cell surface proteome of Entamoeba histolytica.

    Science.gov (United States)

    Biller, Laura; Matthiesen, Jenny; Kühne, Vera; Lotter, Hannelore; Handal, Ghassan; Nozaki, Tomoyoshi; Saito-Nakano, Yumiko; Schümann, Michael; Roeder, Thomas; Tannich, Egbert; Krause, Eberhard; Bruchhaus, Iris

    2014-01-01

    Surface molecules are of major importance for host-parasite interactions. During Entamoeba histolytica infections, these interactions are predicted to be of prime importance for tissue invasion, induction of colitis and liver abscess formation. To date, however, little is known about the molecules involved in these processes, with only about 20 proteins or protein families found exposed on the E. histolytica surface. We have therefore analyzed the complete surface proteome of E. histolytica. Using cell surface biotinylation and mass spectrometry, 693 putative surface-associated proteins were identified. In silico analysis predicted that ∼26% of these proteins are membrane-associated, as they contain transmembrane domains and/or signal sequences, as well as sites of palmitoylation, myristoylation, or prenylation. An additional 25% of the identified proteins likely represent nonclassical secreted proteins. Surprisingly, no membrane-association sites could be predicted for the remaining 49% of the identified proteins. To verify surface localization, 23 proteins were randomly selected and analyzed by immunofluorescence microscopy. Of these 23 proteins, 20 (87%) showed definite surface localization. These findings indicate that a far greater number of E. histolytica proteins than previously supposed are surface-associated, a phenomenon that may be based on the high membrane turnover of E. histolytica.

  20. Femtosecond fabricated surfaces for cell biology

    Science.gov (United States)

    Day, Daniel; Gu, Min

    2010-08-01

    Microfabrication using femtosecond pulse lasers is enabling access to a range of structures, surfaces and materials that was not previously available for scientific and engineering applications. The ability to produce micrometre sized features directly in polymer and metal substrates is demonstrated with applications in cell biology. The size, shape and aspect ratio of the etched features can be precisely controlled through the manipulation of the fluence of the laser etching process with respect to the properties of the target material. Femtosecond laser etching of poly(methyl methacrylate) and aluminium substrates has enabled the production of micrometre resolution moulds that can be accurately replicated using soft lithography. The moulded surfaces are used in the imaging of T cells and demonstrate the improved ability to observe biological events over time periods greater than 10 h. These results indicate the great potential femtosecond pulse lasers may have in the future manufacturing of microstructured surfaces and devices.

  1. Carbohydrates in Supramolecular Chemistry.

    Science.gov (United States)

    Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

    2016-02-24

    Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed.

  2. Ficolin-1 is present in a highly mobilizable subset of human neutrophil granules and associates with the cell surface after stimulation with fMLP

    DEFF Research Database (Denmark)

    Rørvig, Sara; Honoré, Christian Le Fèvre; Larsson, Lars-Inge;

    2009-01-01

    Ficolins are soluble molecules that bind carbohydrate present on the surface of microorganisms and function as recognition molecules in the lectin complement pathway. Three ficolins have been identified in humans: ficolin-1, ficolin-2, and ficolin-3. Ficolin-1 is synthesized in monocytes and type...... associated with the surface membrane of the cells and can be detected by flow cytometry. Our studies show that neutrophils are a major source of ficolin-1, which can be readily exocytosed by stimulation....

  3. Carbohydrates as food allergens

    OpenAIRE

    SOH, Jian Yi; Huang, Chiung Hui; Lee, Bee Wah

    2015-01-01

    The literature supports the notion that carbohydrate epitopes, on their own, do not contribute significantly to the induction of allergic reactions. They bind weakly to IgE antibodies and have been termed as cross reactive carbohydrate determinants. These epitopes cause confusion in in vitro IgE testing through nonspecific cross-reactivity. Coincident with the rising trends in food allergy prevalence, there has recently been reports of anaphylaxis induced by carbohydrate epitopes. There are t...

  4. Antibody-protein A conjugated quantum dots for multiplexed imaging of surface receptors in living cells.

    Science.gov (United States)

    Jin, Takashi; Tiwari, Dhermendra K; Tanaka, Shin-Ichi; Inouye, Yasushi; Yoshizawa, Keiko; Watanabe, Tomonobu M

    2010-11-01

    To use quantum dots (QDs) as fluorescent probes for receptor imaging, QD surface should be modified with biomolecules such as antibodies, peptides, carbohydrates, and small-molecule ligands for receptors. Among these QDs, antibody conjugated QDs are the most promising fluorescent probes. There are many kinds of coupling reactions that can be used for preparing antibody conjugated QDs. Most of the antibody coupling reactions, however, are non-selective and time-consuming. In this paper, we report a facile method for preparing antibody conjugated QDs for surface receptor imaging. We used ProteinA as an adaptor protein for binding of antibody to QDs. By using ProteinA conjugated QDs, various types of antibodies are easily attached to the surface of the QDs via non-covalent binding between the F(c) (fragment crystallization) region of antibody and ProteinA. To show the utility of ProteinA conjugated QDs, HER2 (anti-human epidermal growth factor receptor 2) in KPL-4 human breast cancer cells were stained by using anti-HER2 antibody conjugated ProteinA-QDs. In addition, multiplexed imaging of HER2 and CXCR4 (chemokine receptor) in the KPL-4 cells was performed. The result showed that CXCR4 receptors coexist with HER2 receptors in the membrane surface of KPL-4 cells. ProteinA mediated antibody conjugation to QDs is very useful to prepare fluorescent probes for multiplexed imaging of surface receptors in living cells.

  5. Engineering novel cell surface chemistry for selective tumor cell targeting

    Energy Technology Data Exchange (ETDEWEB)

    Bertozzi, C.R. [Univ. of California, Berkeley, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1997-12-31

    A common feature of many different cancers is the high expression level of the two monosaccharides sialic acid and fucose within the context of cell-surface associated glycoconjugates. A correlation has been made between hypersialylation and/or hyperfucosylation and the highly metastatic phenotype. Thus, a targeting strategy based on sialic acid or fucose expression would be a powerful tool for the development of new cancer cell-selective therapies and diagnostic agents. We have discovered that ketone groups can be incorporated metabolically into cell-surface associated sialic acids. The ketone is can be covalently ligated with hydrazide functionalized proteins or small molecules under physiological conditions. Thus, we have discovered a mechanism to selectively target hydrazide conjugates to highly sialylated cells such as cancer cells. Applications of this technology to the generation of novel cancer cell-selective toxins and MRI contrast reagents will be discussed, in addition to progress towards the use of cell surface fucose residues as vehicles for ketone expression.

  6. Bacterial cell surface structures in Yersinia enterocolitica.

    Science.gov (United States)

    Białas, Nataniel; Kasperkiewicz, Katarzyna; Radziejewska-Lebrecht, Joanna; Skurnik, Mikael

    2012-06-01

    Yersinia enterocolitica is a widespread member of the family of Enterobacteriaceae that contains both non-virulent and virulent isolates. Pathogenic Y. enterocolitica strains, especially belonging to serotypes O:3, O:5,27, O:8 and O:9 are etiologic agents of yersiniosis in animals and humans. Y. enterocolitica cell surface structures that play a significant role in virulence have been subject to many investigations. These include outer membrane (OM) glycolipids such as lipopolysaccharide (LPS) and enterobacterial common antigen (ECA) and several cell surface adhesion proteins present only in virulent Y. enterocolitica, i.e., Inv, YadA and Ail. While the yadA gene is located on the Yersinia virulence plasmid the Ail, Inv, LPS and ECA are chromosomally encoded. These structures ensure the correct architecture of the OM, provide adhesive properties as well as resistance to antimicrobial peptides and to host innate immune response mechanisms.

  7. Carbohydrate functionalized carbon nanotubes and their applications.

    Science.gov (United States)

    Gorityala, Bala Kishan; Ma, Jimei; Wang, Xin; Chen, Peng; Liu, Xue-Wei

    2010-08-01

    Carbon nanotubes (CNTs) have attracted tremendous attention in biomedical applications due to their molecular size and unique properties. This tutorial review summarizes the strategies to functionalize CNTs with bioactive carbohydrates, which improve their solubility, biocompatibility and biofunctionalities while preserving their desired properties. In addition, studies on the usage of carbohydrate functionalized CNTs to detect bacteria, to bind to specific lectins, to deliver glycomimetic drug molecules into cells and to probe cellular activities as biosensors are reviewed. Improvement in biocompatibility and introduction of bio-functionalities by integration of carbohydrate with CNTs are paving the way to glyconanotechnology and may provide new tools for glycobiological studies.

  8. Radioiodinated branched carbohydrates

    Science.gov (United States)

    Goodman, Mark M.; Knapp, Jr., Furn F.

    1989-01-01

    A radioiodinated branched carbohydrate for tissue imaging. Iodine-123 is stabilized in the compound by attaching it to a vinyl functional group that is on the carbohydrate. The compound exhibits good uptake and retention and is promising in the development of radiopharmaceuticals for brain, heart and tumor imaging.

  9. Carbohydrates as allergens.

    Science.gov (United States)

    Commins, Scott P

    2015-01-01

    Complex carbohydrates are effective inducers of Th2 responses, and carbohydrate antigens can stimulate the production of glycan-specific antibodies. In instances where the antigen exposure occurs through the skin, the resulting antibody production can contain IgE class antibody. The glycan-stimulated IgE may be non-specific but may also be antigen specific. This review focuses on the production of cross-reactive carbohydrate determinants, the recently identified IgE antibody response to a mammalian oligosaccharide epitope, galactose-alpha-1,3-galactose (alpha-gal), as well as discusses practical implications of carbohydrates in allergy. In addition, the biological effects of carbohydrate antigens are reviewed in setting of receptors and host recognition.

  10. Computerized molecular modeling of carbohydrates

    Science.gov (United States)

    Computerized molecular modleing continues to increase in capability and applicability to carbohydrates. This chapter covers nomenclature and conformational aspects of carbohydrates, perhaps of greater use to carbohydrate-inexperienced computational chemists. Its comments on various methods and studi...

  11. Carbohydrates and Diabetes (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Carbohydrates and Diabetes KidsHealth > For Parents > Carbohydrates and Diabetes ... many kids with diabetes take to stay healthy. Carbohydrates and Blood Sugar The two main forms of ...

  12. Novel O-linked glycans containing 6'-sulfo-Gal/GalNAc of MUC1 secreted from human breast cancer YMB-S cells: possible carbohydrate epitopes of KL-6(MUC1) monoclonal antibody.

    Science.gov (United States)

    Seko, Akira; Ohkura, Takashi; Ideo, Hiroko; Yamashita, Katsuko

    2012-02-01

    Human serum Krebs von den Lugen-6 (KL-6) antigen is a MUC1 glycoprotein (KL-6/MUC1) recognized by anti-KL-6 monoclonal antibody (KL-6/mAb) and has been utilized as a diagnostic marker for interstitial pneumonia. KL-6/mAb is thought to recognize the specific glycopeptides sequence of MUC1, but the precise glycan structure of the epitope is unclear. In this study, we determined the carbohydrate structures of KL-6/MUC1 to search the carbohydrate epitopes for KL-6/mAb. KL-6/MUC1 was purified from the culture medium of human breast cancer YMB-S cells by KL-6/mAb-affinity chromatography; the O-linked glycan structures were determined in combination with paper electrophoresis, several lectin column chromatographies, sialidase digestion and methanolysis. KL-6/MUC1 contained core 1 and extended core 1 glycans modified with one or two sialic acid/sulfate residues. Based on these structures, several synthetic glycans binding to anti-KL-6/mAb were compared with one another by surface plasmon resonance. Sequentially, related radiolabeled oligosaccharides were enzymatically synthesized and analyzed for binding to a KL-6/mAb-conjugated affinity column. 3'-sialylated, 6'-sulfated LNnT [Neu5Acα2-3(SO(3)(-)-6)Galβ1-4GlcNAcβ1-3Galβ1-4Glc], 3'-sialylated, 6-sulfated core 1 [Neu5Acα2-3Galβ1-3(SO(3)(-)-6)GalNAc] and disulfated core 1 SO(3)(-)-3Galβ1-3(SO(3)(-)-6)GalNAc exhibited substantial affinity for KL-6/mAb, and 3'-sulfated core 1 derivatives [SO(3)(-)-3Galβ1-3(±Neu5Acα2-6)GalNAc] and 3'-sialylated core 1 weakly interacted with KL-6/mAb. These results indicated that the possible carbohydrate epitopes of KL-6/mAb involve not only 3'-sialylated core 1 but also novel core 1 and extended core 1 with sulfate and sialic acid residues. Epitope expressing changes with suppression or over-expression of the Gal6ST (Gal 6-O-sulfotransferase) gene, suggesting that Gal6ST is involved in the biosynthesis of the unique epitopes of KL-6/mAb.

  13. Antiviral and immunostimulating effects of lignin-carbohydrate-protein complexes from Pimpinella anisum.

    Science.gov (United States)

    Lee, Jung-Bum; Yamagishi, Chihiro; Hayashi, Kyoko; Hayashi, Toshimitsu

    2011-01-01

    Three antiviral and immunostimulating substances (LC1, LC2 and LC3) were isolated from a hot water extract of seeds of Pimpinella anisum by combination of anion-exchange, gel filtration and hydrophobic interaction column chromatographies. Chemical and spectroscopic analyses revealed them to be lignin-carbohydrate-protein complexes. These lignin-carbohydrate complexes (LCs) showed antiviral activities against herpes simplex virus types 1 and 2 (HSV-1 and -2), human cytomegalovirus (HCMV) and measles virus. LCs were also found to interfere with virus adsorption to the host cell surface and directly inactivate viruses. Furthermore, they enhanced nitric oxide (NO) production by inducing iNOS mRNA and protein expression in RAW 264.7 murine macrophage cells. The induced mRNA expression of cytokines including IL-1β and IL-10 was also apparent. These results suggest that the lignin-carbohydrate-protein complexes from P. anisum possessed potency as functional food ingredients against infectious diseases.

  14. Inhibition of Cell Proliferation and Growth of Pancreatic Cancer by Silencing of Carbohydrate Sulfotransferase 15 In Vitro and in a Xenograft Model.

    Directory of Open Access Journals (Sweden)

    Kazuki Takakura

    Full Text Available Chondroitin sulfate E (CS-E, a highly sulfated glycosaminoglycan, is known to promote tumor invasion and metastasis. Because the presence of CS-E is detected in both tumor and stromal cells in pancreatic ductal adenocarcinoma (PDAC, multistage involvement of CS-E in the development of PDAC has been considered. However, its involvement in the early stage of PDAC progression is still not fully understood. In this study, to clarify the direct role of CS-E in tumor, but not stromal, cells of PDAC, we focused on carbohydrate sulfotransferase 15 (CHST15, a specific enzyme that biosynthesizes CS-E, and investigated the effects of the CHST15 siRNA on tumor cell proliferation in vitro and growth in vivo. CHST15 mRNA is highly expressed in the human pancreatic cancer cell lines PANC-1, MIA PaCa-2, Capan-1 and Capan-2. CHST15 siRNA significantly inhibited the expression of CHST15 mRNA in these four cells in vitro. Silencing of the CHST15 gene in the cells was associated with significant reduction of proliferation and up-regulation of the cell cycle inhibitor-related gene p21CIP1/WAF1. In a subcutaneous xenograft tumor model of PANC-1 in nude mice, a single intratumoral injection of CHST15 siRNA almost completely suppressed tumor growth. Reduced CHST15 protein signals associated with tumor necrosis were observed with the treatment with CHST15 siRNA. These results provide evidence of the direct action of CHST15 on the proliferation of pancreatic tumor cells partly through the p21CIP1/WAF1 pathway. Thus, CHST15-CS-E axis-mediated tumor cell proliferation could be a novel therapeutic target in the early stage of PDAC progression.

  15. CZTSSe thin film solar cells: Surface treatments

    Science.gov (United States)

    Joglekar, Chinmay Sunil

    Chalcopyrite semiconducting materials, specifically CZTS, are a promising alternative to traditional silicon solar cell technology. Because of the high absorption coefficient; films of the order of 1 micrometer thickness are sufficient for the fabrication of solar cells. Liquid based synthesis methods are advantageous because they are easily scalable using the roll to roll manufacturing techniques. Various treatments are explored in this study to enhance the performance of the selenized CZTS film based solar cells. Thiourea can be used as a sulfur source and can be used to tune band gap of CZTSSe. Bromine etching can be used to manipulate the thickness of sintered CZTSSe film. The etching treatment creates recombination centers which lead to poor device performance. Various after treatments were used to improve the performance of the devices. It was observed that the performance of the solar cell devices could not be improved by any of the after treatment steps. Other surface treatment processes are explored including KCN etching and gaseous H2S treatments. Hybrid solar cells which included use of CIGS nanoparticles at the interface between CZTSSe and CdS are also explored.

  16. Frequency Selective Surfaces with Nanoparticles Unit Cell

    Directory of Open Access Journals (Sweden)

    Nga Hung Poon

    2015-09-01

    Full Text Available The frequency selective surface (FSS is a periodic structure with filtering performance for optical and microwave signals. The general periodic arrays made with patterned metallic elements can act as an aperture or patch on a substrate. In this work, two kinds of materials were used to produce unit cells with various patterns. Gold nanoparticles of 25 nm diameter were used to form periodic monolayer arrays by a confined photocatalytic oxidation-based surface modification method. As the other material, silver gel was used to create multiple layers of silver. Due to the ultra-thin nature of the self-assembled gold nanoparticle monolayer, it is very easy to penetrate the FSS with terahertz radiation. However, the isolated silver islands made from silver gel form thicker multiple layers and contribute to much higher reflectance. This work demonstrated that multiple silver layers are more suitable than gold nanoparticles for use in the fabrication of FSS structures.

  17. Glycosylated Conductive Polymer: A Multimodal Biointerface for Studying Carbohydrate-Protein Interactions.

    Science.gov (United States)

    Zeng, Xiangqun; Qu, Ke; Rehman, Abdul

    2016-09-20

    Carbohydrate-protein interactions occur through glycoproteins, glycolipids, or polysaccharides displayed on the cell surface with lectins. However, studying these interactions is challenging because of the complexity and heterogeneity of the cell surface, the inherent structural complexity of carbohydrates, and the typically weak affinities of the binding reactions between the lectins and monovalent carbohydrates. The lack of chromophores and fluorophores in carbohydrate structures often drives such investigations toward fluorescence labeling techniques, which usually require tedious and complex synthetic work to conjugate fluorescent tags with additional risk of altering the reaction dynamics. Probing these interactions directly on the cell surface is even more difficult since cells could be too fragile for labeling or labile dynamics could be affected by the labeled molecules that may interfere with the cellular activities, resulting in unwanted cell responses. In contrast, label-free biosensors allow real-time monitoring of carbohydrate-protein interactions in their natural states. A prerequisite, though, for this strategy to work is to mimic the coding information on potential interactions of cell surfaces onto different biosensing platforms, while the complementary binding process can be transduced into a useful signal noninvasively. Through carbohydrate self-assembled monolayers and glycopolymer scaffolds, the multivalency of the naturally existing simple and complex carbohydrates can be mimicked and exploited with label-free readouts (e.g., optical, acoustic, mechanical, electrochemical, and electrical sensors), yet such inquiries reflect only limited aspects of complicated biointeraction processes due to the unimodal transduction. In this Account, we illustrate that functionalized glycosylated conductive polymer scaffolds are the ideal multimodal biointerfaces that not only simplify the immobilization process for surface fabrication via electrochemical

  18. Wettability influences cell behavior on superhydrophobic surfaces with different topographies

    NARCIS (Netherlands)

    Lourenco, B.N.; Marchioli, G.; Song, W; Reis, R.L.; Blitterswijk, van C.A.; Karperien, H.B.J.; Apeldoorn, van A.A.; Mano, J.F.

    2012-01-01

    Surface wettability and topography are recognized as critical factors influencing cell behavior on biomaterials. So far only few works have reported cell responses on surfaces exhibiting extreme wettability in combination with surface topography. The goal of this work is to study whether cell behavi

  19. Broad antiviral activity of carbohydrate-binding agents against the four serotypes of dengue virus in monocyte-derived dendritic cells.

    Directory of Open Access Journals (Sweden)

    Marijke M F Alen

    Full Text Available BACKGROUND: Dendritic cells (DC, present in the skin, are the first target cells of dengue virus (DENV. Dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN is present on DC and recognizes N-glycosylation sites on the E-glycoprotein of DENV. Thus, the DC-SIGN/E-glycoprotein interaction can be considered as an important target for inhibitors of viral replication. We evaluated various carbohydrate-binding agents (CBAs against all four described serotypes of DENV replication in Raji/DC-SIGN(+ cells and in monocyte-derived DC (MDDC. METHODOLOGY/PRINCIPAL FINDINGS: A dose-dependent anti-DENV activity of the CBAs Hippeastrum hybrid (HHA, Galanthus nivalis (GNA and Urtica dioica (UDA, but not actinohivin (AH was observed against all four DENV serotypes as analyzed by flow cytometry making use of anti-DENV antibodies. Remarkably, the potency of the CBAs against DENV in MDDC cultures was significantly higher (up to 100-fold than in Raji/DC-SIGN(+ cells. Pradimicin-S (PRM-S, a small-size non-peptidic CBA, exerted antiviral activity in MDDC but not in Raji/DC-SIGN(+ cells. The CBAs act at an early step of DENV infection as they bind to the viral envelope of DENV and subsequently prevent virus attachment. Only weak antiviral activity of the CBAs was detected when administered after the virus attachment step. The CBAs were also able to completely prevent the cellular activation and differentiation process of MDDC induced upon DENV infection. CONCLUSIONS/SIGNIFICANCE: The CBAs exerted broad spectrum antiviral activity against the four DENV serotypes, laboratory-adapted viruses and low passage clinical isolates, evaluated in Raji/DC-SIGN(+ cells and in primary MDDC.

  20. CARBOHYDRATE-CONTAINING COMPOUNDS WHICH BIND TO CARBOHYDRATE BINDING RECEPTORS

    DEFF Research Database (Denmark)

    1995-01-01

    Carbohydrate-containing compounds which contain saccharides or derivatives thereof and which bind to carbohydrate binding receptors are useful in pharmaceutical products for treatment of inflammatory diseases and other diseases.......Carbohydrate-containing compounds which contain saccharides or derivatives thereof and which bind to carbohydrate binding receptors are useful in pharmaceutical products for treatment of inflammatory diseases and other diseases....

  1. Knowledge discovery of cell-cell and cell-surface interactions

    Science.gov (United States)

    Su, Jing

    High-throughput cell culture is an emerging technology that shows promise as a tool for research in tissue engineering, drug discovery, and medical diagnostics. An important, but overlooked, challenge is the integration of experimental methods with information processing suitable for handling large databases of cell-cell and cell-substrate interactions. In this work the traditional global descriptions of cell behaviors and surface characteristics was shown insufficient for investigating short-distance cell-to-cell and cell-to-surface interactions. Traditional summary metrics cannot distinguish information of cell near neighborhood from the average, global features, thus often is not suitable for studying distance-sensitive cell behaviors. The problem of traditional summary metrics was addressed by introducing individual-cell based local metrics that emphasize cell local environment. An individual-cell based local data analysis method was established. Contact inhibition of cell proliferation was used as a benchmark for the effectiveness of the local metrics and the method. Where global, summary metrics were unsuccessful, the local metrics successfully and quantitatively distinguished the contact inhibition effects of MC3T3-E1 cells on PLGA, PCL, and TCPS surfaces. In order to test the new metrics and analysis method in detail, a model of cell contact inhibition was proposed. Monte Carlo simulation was performed for validating the individual-cell based local data analysis method as well as the cell model itself. The simulation results well matched with the experimental observations. The parameters used in the cell model provided new descriptions of both cell behaviors and surface characteristics. Based on the viewpoint of individual cells, the local metrics and local data analysis method were extended to the investigation of cell-surface interactions, and a new high-throughput screening and knowledge discovery method on combinatorial libraries, local cell

  2. Quantification of intracellular phosphorylated carbohydrates in HT29 human colon adenocarcinoma cell line using liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Vizán, Pedro; Alcarraz-Vizán, Gema; Díaz-Moralli, Santiago; Rodríguez-Prados, Juan Carlos; Zanuy, Míriam; Centelles, Josep J; Jáuregui, Olga; Cascante, Marta

    2007-07-01

    The quantitative understanding of the role of sugar phosphates in regulating tumor energetic metabolism at the proteomic and genomic level is a prerequisite for an efficient rational design in combined drug chemotherapy. Therefore, it is necessary to determine accurately the concentration of the main sugar phosphate pools at the lower concentrations present in the often-limited volume of tumor cell samples. Taking as an example the human adenocarcinoma cell line HT29, we here report a fast and reliable quantitative method based on the use of liquid nitrogen, a weak acid extraction, and liquid chromatography-electrospray ionization tandem mass spectrometry to quantify simultaneously the intracellular concentration of sugar phosphate pools. The method was set up using standard addition curves. Thus, it is possible to identify and quantify hexose phosphate, pentose phosphate, and triose phosphate pools up to 0.02-0.10 ng x microL(-1), depending on the analyte. The method developed was here used for the quantitative study of changes in phosphorylated carbohydrates of central carbon metabolism when high or low glucose concentration conditions are induced in vitro in the HT29 human colon adenocarcinoma cell line.

  3. Carbohydrates and Depression.

    Science.gov (United States)

    Wurtman, Richard J.; Wurtman, Judith J.

    1989-01-01

    Describes the symptoms, such as appetite change and mood fluctuation, basic mechanisms, and some treatments of Seasonal Affective Disorder (SAD), Carbohydrate-Craving Obesity (CCO) and Premenstrual Syndrome (PMS). Provides several tables and diagrams, and three reading references. (YP)

  4. Chemistry and material science at the cell surface

    Directory of Open Access Journals (Sweden)

    Weian Zhao

    2010-04-01

    Full Text Available Cell surfaces are fertile ground for chemists and material scientists to manipulate or augment cell functions and phenotypes. This not only helps to answer basic biology questions but also has diagnostic and therapeutic applications. In this review, we summarize the most recent advances in the engineering of the cell surface. In particular, we focus on the potential applications of surface engineered cells for 1 targeting cells to desirable sites in cell therapy, 2 programming assembly of cells for tissue engineering, 3 bioimaging and sensing, and ultimately 4 manipulating cell biology.

  5. SulfoSYS (Sulfolobus Systems Biology) : towards a silicon cell model for the central carbohydrate metabolism of the archaeon Sulfolobus solfataricus under temperature variation

    NARCIS (Netherlands)

    Albers, Sonja-Verena; Birkeland, Nils-Kare; Driessen, Arnold J. M.; Gertig, Susanne; Haferkamp, Patrick; Klenk, Hans-Peter; Kouril, Theresa; Manica, Andrea; Pham, Trong K.; Ruoff, Peter; Schleper, Christa; Schomburg, Dietmar; Sharkey, Kieran J.; Siebers, Bettina; Sierocinski, Pawel; Steuer, Ralf; van der Oost, John; Westerhoff, Hans V.; Wieloch, Patricia; Wright, Phillip C.; Zaparty, Melanie; Birkeland, Nils-Kåre

    2009-01-01

    SulfoSYS (Sulfolobus Systems Biology) focuses on the study of the CCM (central carbohydrate metabolism) of Sulfolobus solfataricus and its regulation under temperature variation at the systems level. in Archaea, carbohydrates are metabolized by modifications of the classical pathways known from Bact

  6. SulfoSYS (Sulfolobus Systems Biology): towards a silicon cell model for the central carbohydrate metabolism of the archaeon Sulfolobus solfataricus under temperature variation.

    NARCIS (Netherlands)

    Albers, S.V.; Birkeland, N.K.; Driessen, A.J.; Gertig, S.; Haferkamp, P.; Klenk, H.P.; Kouril, T.; Manica, A.; Pham, T.K.; Ruoff, P.; Schleper, C.; Schomburg, D.; Sharkey, K.J.; Siebers, A.G.; Sierocinski, P.; Steuer, R.; Oost, J. van der; Westerhoff, H.V.; Wieloch, P.; Wright, P.C.; Zaparty, M.

    2009-01-01

    SulfoSYS (Sulfolobus Systems Biology) focuses on the study of the CCM (central carbohydrate metabolism) of Sulfolobus solfataricus and its regulation under temperature variation at the systems level. In Archaea, carbohydrates are metabolized by modifications of the classical pathways known from Bact

  7. SulfoSYS (Sulfolobus Systems Biology): towards a silicon cell model for the central carbohydrate metabolism of the archaeon Sulfolobus solfataricus under temperature variation

    NARCIS (Netherlands)

    Albers, S.V.; Birkeland, N.K.; Driessen, A.J.M.; Gertig, S.; Haferkamp, P.; Klenk, H.P.; Kouril, T.; Manica, A.; Pham, T.K.; Ruoff, P.; Schleper, C.; Schomburg, D.; Sharkey, K.; Siebers, B.; Sierocinski, P.; Steur, R.; Oost, van der J.; Westerhoff, H.V.; Wieloch, P.; Wright, P.C.; Zaparty, M.

    2009-01-01

    SulfoSYS (Sulfolobus Systems Biology) focuses on the study of the CCM (central carbohydrate metabolism) of Sulfolobus solfataricus and its regulation under temperature variation at the systems level. In Archaea, carbohydrates are metabolized by modifications of the classical pathways known from Bact

  8. Carbohydrate Determinants in Ferret Conjunctiva are Affected by Infection with Influenza H1N1 Virus

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Martel, Cyril J M; Aasted, Bent;

    2013-01-01

    virus to ferrets has an effect on the conjunctival cells and change their expression of glycans. Synthesized glycans are an integral part of the tear film and the present study contributes to reveal the changes that occur in the surface epithelium in the eyelid and thereby to elucidate......Abstract Background: Carbohydrates often accomplish as cell-surface receptors for microorganisms and influenza virus preferentially binds to sialic acid through the viral haemagglutinin. The virus may attach not only to the epithelium in the airways, but also to the surface ocular epithelium....... Purpose: To decide if ferrets can be used to study virus induced conjunctivitis and to evaluate changes in the conjunctival glycosylation pattern during an influenza attack. Methods: Ferrets were infected with H1N1 influenza virus via nasal inoculation. The in situ carbohydrate expressions in eyelid...

  9. Controlling cell-cell interactions using surface acoustic waves.

    Science.gov (United States)

    Guo, Feng; Li, Peng; French, Jarrod B; Mao, Zhangming; Zhao, Hong; Li, Sixing; Nama, Nitesh; Fick, James R; Benkovic, Stephen J; Huang, Tony Jun

    2015-01-06

    The interactions between pairs of cells and within multicellular assemblies are critical to many biological processes such as intercellular communication, tissue and organ formation, immunological reactions, and cancer metastasis. The ability to precisely control the position of cells relative to one another and within larger cellular assemblies will enable the investigation and characterization of phenomena not currently accessible by conventional in vitro methods. We present a versatile surface acoustic wave technique that is capable of controlling the intercellular distance and spatial arrangement of cells with micrometer level resolution. This technique is, to our knowledge, among the first of its kind to marry high precision and high throughput into a single extremely versatile and wholly biocompatible technology. We demonstrated the capabilities of the system to precisely control intercellular distance, assemble cells with defined geometries, maintain cellular assemblies in suspension, and translate these suspended assemblies to adherent states, all in a contactless, biocompatible manner. As an example of the power of this system, this technology was used to quantitatively investigate the gap junctional intercellular communication in several homotypic and heterotypic populations by visualizing the transfer of fluorescent dye between cells.

  10. Topical retinoic acid changes the epidermal cell surface glycosylation pattern towards that of a mucosal epithelium

    DEFF Research Database (Denmark)

    Griffiths, C E; Dabelsteen, Erik; Voorhees, J J

    1996-01-01

    for carbohydrate synthesis, are influenced by retinoids. Thus, we investigated whether epidermal cell surface glycosylation is altered in skin treated with topical RA, and contrasted it with changes induced by topical SLS. Skin biopsies were obtained from seven normal volunteers who had been treated, on three......-treated epidermis was not significantly different from that observed after vehicle treatment. Thus, RA treatment converts normal stratified epithelium towards the phenotype of mucosal epithelium with a decrease in T antigen and a concomitant increase in Ley. These changes are not observed following treatment......Topical all-trans retinoic acid (RA) produces a number of epidermal changes which are indistinguishable from those observed following treatment with a local irritant, namely sodium lauryl sulphate (SLS). This observation has led to criticism that the efficacy of RA in disorders such as photoageing...

  11. Dissecting the functional significance of non-catalytic carbohydrate binding modules in the deconstruction of plant cell walls

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Michael G. [Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center

    2017-03-16

    The project seeks to investigate the mechanism by which CBMs potentiate the activity of glycoside hydrolases against complete plant cell walls. The project is based on the hypothesis that the wide range of CBMs present in bacterial enzymes maximize the potential target substrates by directing the cognate enzymes not only to different regions of a specific plant cell wall, but also increases the range of plant cell walls that can be degraded. In addition to maximizing substrate access, it was also proposed that CBMs can target specific subsets of hydrolases with complementary activities to the same region of the plant cell wall, thereby maximizing the synergistic interactions between these enzymes. This synergy is based on the premise that the hydrolysis of a specific polysaccharide will increase the access of closely associated polymers to enzyme attack. In addition, it is unclear whether the catalytic module and appended CBM of modular enzymes have evolved unique complementary activities.

  12. Carbohydrate-protein interactions and their biosensing applications.

    Science.gov (United States)

    Zeng, Xiangqun; Andrade, Cesar A S; Oliveira, Maria D L; Sun, Xue-Long

    2012-04-01

    Carbohydrate recognition is clearly present throughout nature, playing a major role in the initial attachment of one biological entity to another. The important question is whether these prevalent interactions could provide a real suitable alternative to the use of antibodies or nucleic acid for detection and identification. Currently, examples of carbohydrates being employed in biological detection systems are limited. The challenges of using carbohydrate recognition for detection mainly come from the weak affinity of carbohydrate-protein interactions, the lack of versatile carbohydrate scaffolds with well-defined structures, and the less developed high-information-content, real-time, and label-free assay technology. In this review, we focus on discussing the characteristics of carbohydrate-protein interactions in nature and the methods for carbohydrate immobilization based on surface coupling chemistry in terms of their general applicability for developing carbohydrate- and lectin-based label-free sensors. Furthermore, examples of innovative design of multivalent carbohydrate-protein interactions for sensor applications are given. We limit our review to show the feasibility of carbohydrate and lectin as recognition elements for label-free sensor development in several representative cases to formulate a flexible platform for their use as recognition elements for real-world biosensor applications.

  13. Correlation of cell surface proteins of distinct Beauveria bassiana cell types and adaption to varied environment and interaction with the host insect.

    Science.gov (United States)

    Yang, Zhi; Jiang, Hongyan; Zhao, Xin; Lu, Zhuoyue; Luo, Zhibing; Li, Xuebing; Zhao, Jing; Zhang, Yongjun

    2017-02-01

    The insect fungal pathogen Beauveria bassiana produces a number of distinct cell types that include aerial conidia, blastospores and haemolymph-derived cells, termed hyphal bodies, to adapt varied environment niches and within the host insect. These cells display distinct biochemical properties and surface structures, and a highly ordered outermost brush-like structure uniquely present on hyphal bodies, but not on any in vitro cells. Here, we found that the outermost structure on the hyphal bodies mainly consisted of proteins associated to structural wall components in that most of it could be removed by dithiothreitol (DTT) or proteinase K. DTT-treatment also caused delayed germination, decreased tolerance to ultraviolet irradiation and virulence of conidia or blastospores, with decreased adherence and alternated carbohydrate epitopes, suggesting involvement in fungal development, stress responses and virulence. To characterize these cell surface molecules, proteins were released from the living cells using DTT, and identified and quantitated using label-free quantitative mass spectrometry. Thereafter, a series of bioinformatics programs were used to predict cell surface-associated proteins (CSAPs), and 96, 166 and 54 CSAPs were predicted from the identified protein pools of conidia, blastospores and hyphal bodies, respectively, which were involved in utilization of carbohydrate, nitrogen, and lipid, detoxification, pathogen-host interaction, and likely other cellular processes. Thirteen, sixty-nine and six CSAPs were exclusive in conidia, blastospores and hyphal bodies, respectively, which were verified by eGFP-tagged proteins at their N-terminus. Our data provide a crucial cue to understand mechanism of B. bassiana to adapt to varied environment and interaction with insect host.

  14. Carbohydrate nanotechnology: hierarchical assembly using nature's other information carrying biopolymers.

    Science.gov (United States)

    Han, Xu; Zheng, Yeting; Munro, Catherine J; Ji, Yiwen; Braunschweig, Adam B

    2015-08-01

    Despite their central role in directing some of the most complex biological processes, carbohydrates--nature's other information carrying biopolymer--have been largely ignored as building blocks for synthetic hierarchical assemblies. The non-stoichiometric binding and astronomical diversity characteristic of carbohydrates could lead to tantalizingly complex assembly algorithms, but these attributes simultaneously increase the difficulty of preparing carbohydrate assemblies and anticipating their behavior. Convergences in biotechnology, nanotechnology, polymer chemistry, surface science, and supramolecular chemistry have led to many recent important breakthroughs in glycan microarrays and synthetic carbohydrate receptors, where the idiosyncrasies of carbohydrate structure and binding are increasingly considered. We hope to inspire more researchers to consider carbohydrate structure, diversity, and binding as attractive tools for constructing synthetic hierarchical assemblies.

  15. Nanofabrication of Nonfouling Surfaces for Micropatterning of Cell and Microtissue

    Directory of Open Access Journals (Sweden)

    Hidenori Otsuka

    2010-08-01

    Full Text Available Surface engineering techniques for cellular micropatterning are emerging as important tools to clarify the effects of the microenvironment on cellular behavior, as cells usually integrate and respond the microscale environment, such as chemical and mechanical properties of the surrounding fluid and extracellular matrix, soluble protein factors, small signal molecules, and contacts with neighboring cells. Furthermore, recent progress in cellular micropatterning has contributed to the development of cell-based biosensors for the functional characterization and detection of drugs, pathogens, toxicants, and odorants. In this regards, the ability to control shape and spreading of attached cells and cell-cell contacts through the form and dimension of the cell-adhesive patches with high precision is important. Commitment of stem cells to different specific lineages depends strongly on cell shape, implying that controlled microenvironments through engineered surfaces may not only be a valuable approach towards fundamental cell-biological studies, but also of great importance for the design of cell culture substrates for tissue engineering. To develop this kind of cellular microarray composed of a cell-resistant surface and cell attachment region, micropatterning a protein-repellent surface is important because cellular adhesion and proliferation are regulated by protein adsorption. The focus of this review is on the surface engineering aspects of biologically motivated micropatterning of two-dimensional surfaces with the aim to provide an introductory overview described in the literature. In particular, the importance of non-fouling surface chemistries is discussed.

  16. Carbohydrates in therapeutics.

    Science.gov (United States)

    Kilcoyne, Michelle; Joshi, Lokesh

    2007-07-01

    Awareness of the importance of carbohydrates in living systems and medicine is growing due to the increasing understanding of their biological and pharmacological relevance. Carbohydrates are ubiquitous and perform a wide array of biological roles. Carbohydrate-based or -modified therapeutics are used extensively in cardiovascular and hematological treatments ranging from inflammatory diseases and anti-thrombotic treatments to wound healing. Heparin is a well-known and widely used example of a carbohydrate-based drug but will not be discussed as it has been extensively reviewed. We will detail carbohydrate-based and -modified therapeutics, both those that are currently marketed or in various stages of clinical trials and those that are potential therapeutics based on promising preclinical investigations. Carbohydrate-based therapeutics include polysaccharide and oligosaccharide anti-inflammatory, anti-coagulant and anti-thrombotic agents from natural and synthetic sources, some as an alternative to heparin and others which were designed based on known structure-functional relationships. Some of these compounds have multiple biological effects, showing anti-adhesive, anti-HIV and anti-arthrithic activities. Small molecules, derivatives or mimetics of complement inhibitors, are detailed for use in limiting ischemia/ reperfusion injuries. Monosaccharides, both natural and synthetic, have been investigated for their in vivo anti-inflammatory and cardioprotective properties. Modification by glycosylation of natural products, or glycosylation-mimicking modification, has a significant effect on the parent molecule including increased plasma half-life and refining or increasing desired functions. It is hoped that this review will highlight the vast therapeutic potential of these natural bioactive molecules.

  17. Carbohydrates, pollinators, and cycads

    Science.gov (United States)

    Marler, Thomas E; Lindström, Anders J

    2015-01-01

    Cycad biology, ecology, and horticulture decisions are not supported by adequate research, and experiments in cycad physiology in particular have been deficient. Our recent report on free sugar content in a range of cycad taxa and tissues sets the stage for developing continued carbohydrate research. Growth and development of cycad pollen, mediation of the herbivory traits of specialist pollinators, and support of expensive strobilus behavioral traits are areas of cycad pollination biology that would benefit from a greater understanding of the role of carbohydrate relations. PMID:26479502

  18. Growth of fibroblasts and endothelial cells on wettability gradient surfaces

    NARCIS (Netherlands)

    Ruardy, TG; Moorlag, HE; Schakenraad, JM; VanderMei, HC; Busscher, HJ

    1997-01-01

    The growth, spreading, and shape of human skin fibroblasts (PK 84) and human umbilical cord endothelial cells on dichlorodimethylsilane (DDS) and dimethyloctadecylchlorosilane (DOGS) gradient surfaces were investigated in the presence of serum proteins. Gradient surfaces were prepared on glass using

  19. Adhesion molecule expression stimulated by Bacteroides thetaiotaomicron cell-surface antigens.

    Science.gov (United States)

    Rokosz, A; Meisel-Mikołajczyk, F; Malchar, C; Nowaczyk, M; Górski, A

    1999-01-01

    Bacteroides thetaiotaomicron, a Gram-negative anaerobic rod belonging to the Bacteroides fragilis group (BFG), is involved in many systemic and local, most frequently suppurative infections in man. The cell envelope of these rods is composed of two carbohydrate-containing antigens: lipopolysaccharide (LPS) and capsular polysaccharide (CPS). Adhesion molecules ICAM-1, VCAM-1 and E-selectin (ELAM-1) are induced on the endothelial cells by mediators of inflammation. The aim of this study was to assay the ability of B. thetaiotaomicron surface antigens to induce adhesion molecule expression on the endothelial cells. The influence of LPS and CPS on the expression of adhesion molecules on HMEC-1 cell line was examined in an ELISA test. ELISA was performed with monoclonal mouse anti-human: ICAM-1, VCAM-1 and E-selectin antibodies of the IgG class. B. thetaiotaomicron lipopolysaccharides revealed the ability to induce ICAM-1, VCAM-1 and E-selectin expression on the endothelial cells. Their activities were similar, but lower than the activity of Eschericha coli LPS. ICAM-1 was the most stimulated adhesion molecule. The strongest activation by LPS was achieved at the concentrations of 10.0 and 1.0 micrograms/ml. The ability of capsular polysaccharide to induce the expression of adhesion molecules was considerably weaker.

  20. Calreticulin: Roles in Cell-Surface Protein Expression

    Directory of Open Access Journals (Sweden)

    Yue Jiang

    2014-09-01

    Full Text Available In order to perform their designated functions, proteins require precise subcellular localizations. For cell-surface proteins, such as receptors and channels, they are able to transduce signals only when properly targeted to the cell membrane. Calreticulin is a multi-functional chaperone protein involved in protein folding, maturation, and trafficking. However, evidence has been accumulating that calreticulin can also negatively regulate the surface expression of certain receptors and channels. In these instances, depletion of calreticulin enhances cell-surface expression and function. In this review, we discuss the role of calreticulin with a focus on its negative effects on the expression of cell-surface proteins.

  1. A mass spectrometric-derived cell surface protein atlas.

    Directory of Open Access Journals (Sweden)

    Damaris Bausch-Fluck

    Full Text Available Cell surface proteins are major targets of biomedical research due to their utility as cellular markers and their extracellular accessibility for pharmacological intervention. However, information about the cell surface protein repertoire (the surfaceome of individual cells is only sparsely available. Here, we applied the Cell Surface Capture (CSC technology to 41 human and 31 mouse cell types to generate a mass-spectrometry derived Cell Surface Protein Atlas (CSPA providing cellular surfaceome snapshots at high resolution. The CSPA is presented in form of an easy-to-navigate interactive database, a downloadable data matrix and with tools for targeted surfaceome rediscovery (http://wlab.ethz.ch/cspa. The cellular surfaceome snapshots of different cell types, including cancer cells, resulted in a combined dataset of 1492 human and 1296 mouse cell surface glycoproteins, providing experimental evidence for their cell surface expression on different cell types, including 136 G-protein coupled receptors and 75 membrane receptor tyrosine-protein kinases. Integrated analysis of the CSPA reveals that the concerted biological function of individual cell types is mainly guided by quantitative rather than qualitative surfaceome differences. The CSPA will be useful for the evaluation of drug targets, for the improved classification of cell types and for a better understanding of the surfaceome and its concerted biological functions in complex signaling microenvironments.

  2. Theory of back-surface-field solar cells

    Science.gov (United States)

    Vonroos, O.

    1979-01-01

    Report describes simple concise theory of back-surface-field (BSF) solar cells (npp + junctions) based on Shockley's depletion-layer approximation and cites superiority of two-junction devices over conventional unijunction cells.

  3. Carbohydrates, Sugar, and Your Child

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old Carbohydrates, Sugar, and Your Child KidsHealth > For Parents > Carbohydrates, Sugar, ... a 1-ounce equivalent. previous continue Sizing Up Sugar Foods that are high in added sugar (soda, ...

  4. Cell surface engineering of yeast for applications in white biotechnology.

    Science.gov (United States)

    Kuroda, Kouichi; Ueda, Mitsuyoshi

    2011-01-01

    Cell surface engineering is a promising strategy for the molecular breeding of whole-cell biocatalysts. By using this strategy, yeasts can be constructed by the cell surface display of functional proteins; these yeasts are referred to as arming yeasts. Because reactions using arming yeasts as whole-cell biocatalysts occur on the cell surface, materials that cannot enter the cell can be used as reaction substrates. Numerous arming yeasts have therefore been constructed for a wide range of uses such as biofuel production, synthesis of valuable chemicals, adsorption or degradation of environmental pollutants, recovery of rare metal ions, and biosensors. Here, we review the science of yeast cell surface modification as well as current applications and future opportunities.

  5. Molecularly engineered surfaces for cell biology: from static to dynamic surfaces.

    Science.gov (United States)

    Gooding, J Justin; Parker, Stephen G; Lu, Yong; Gaus, Katharina

    2014-04-01

    Surfaces with a well-defined presentation of ligands for receptors on the cell membrane can serve as models of the extracellular matrix for studying cell adhesion or as model cell surfaces for exploring cell-cell contacts. Because such surfaces can provide exquisite control over, for example, the density of these ligands or when the ligands are presented to the cell, they provide a very precise strategy for understanding the mechanisms by which cells respond to external adhesive cues. In the present feature article, we present an overview of the basic biology of cell adhesion before discussing surfaces that have a static presentation of immobile ligands. We outline the biological information that such surfaces have given us, before progressing to recently developed switchable surfaces and surfaces that mimic the lipid bilayer, having adhesive ligands that can move around the membrane and be remodeled by the cell. Finally, the feature article closes with some of the biological information that these new types of surfaces could provide.

  6. Specific Carbohydrate Diet: Does It Work?

    Science.gov (United States)

    ... Specific Carbohydrate Diet (SCD) Go Back The Specific Carbohydrate Diet (SCD) Email Print + Share There is no ... diet that has received attention is the Specific Carbohydrate Diet. This diet limits poorly digestible carbohydrates to ...

  7. Cell Surface-based Sensing with Metallic Nanoparticles

    OpenAIRE

    Jiang, Ziwen; Le, Ngoc D. B.; Gupta, Akash; Rotello, Vincent M.

    2015-01-01

    Metallic nanoparticles provide versatile scaffolds for biosensing applications. In this review, we focus on the use of metallic nanoparticles for cell surface sensings. Examples of the use of both specific recognition and array-based “chemical nose” approaches to cell surface sensing will be discussed.

  8. FABRICATION AND BIOCOMPATIBILITY OF CELL OUTER MEMBRANE MIMETIC SURFACES

    Institute of Scientific and Technical Information of China (English)

    Ming-ming Zong; Yong-kuan Gong

    2011-01-01

    The surface design used for improving biocompatibility is one of the most important issues for the fabrication of medical devices. For mimicking the ideal surface structure of cell outer membrane, a large number of polymers bearing phosphorylcholine (PC) groups have been employed to modify the surfaces of biomaterials and medical devices. It has been demonstrated that the biocompatibility of the modified materials whose surface is required to interact with a living organism has been obviously improved by introducing PC groups. In this review, the fabrication strategies of cell outer membrane mimetic surfaces and their resulted biocompatibilities were summarized.

  9. Mapping cell surface adhesion by rotation tracking and adhesion footprinting

    Science.gov (United States)

    Li, Isaac T. S.; Ha, Taekjip; Chemla, Yann R.

    2017-03-01

    Rolling adhesion, in which cells passively roll along surfaces under shear flow, is a critical process involved in inflammatory responses and cancer metastasis. Surface adhesion properties regulated by adhesion receptors and membrane tethers are critical in understanding cell rolling behavior. Locally, adhesion molecules are distributed at the tips of membrane tethers. However, how functional adhesion properties are globally distributed on the individual cell’s surface is unknown. Here, we developed a label-free technique to determine the spatial distribution of adhesive properties on rolling cell surfaces. Using dark-field imaging and particle tracking, we extract the rotational motion of individual rolling cells. The rotational information allows us to construct an adhesion map along the contact circumference of a single cell. To complement this approach, we also developed a fluorescent adhesion footprint assay to record the molecular adhesion events from cell rolling. Applying the combination of the two methods on human promyelocytic leukemia cells, our results surprisingly reveal that adhesion is non-uniformly distributed in patches on the cell surfaces. Our label-free adhesion mapping methods are applicable to the variety of cell types that undergo rolling adhesion and provide a quantitative picture of cell surface adhesion at the functional and molecular level.

  10. Attachment of human primary osteoblast cells to modified polyethylene surfaces.

    Science.gov (United States)

    Poulsson, Alexandra H C; Mitchell, Stephen A; Davidson, Marcus R; Johnstone, Alan J; Emmison, Neil; Bradley, Robert H

    2009-04-09

    Ultra-high-molecular-weight polyethylene (UHMWPE) has a long history of use in medical devices, primarily for articulating surfaces due to its inherent low surface energy which limits tissue integration. To widen the applications of UHMWPE, the surface energy can be increased. The increase in surface energy would improve the adsorption of proteins and attachment of cells to allow tissue integration, thereby allowing UHMWPE to potentially be used for a wider range of implants. The attachment and function of human primary osteoblast-like (HOB) cells to surfaces of UHMWPE with various levels of incorporated surface oxygen have been investigated. The surface modification of the UHMWPE was produced by exposure to a UV/ozone treatment. The resulting surface chemistry was studied using X-ray photoelectron spectroscopy (XPS), and the topography and surface structure were probed by atomic force microscopy (AFM) and scanning electron microscopy (SEM), which showed an increase in surface oxygen from 11 to 26 atom % with no significant change to the surface topography. The absolute root mean square roughness of both untreated and UV/ozone-treated surfaces was within 350-450 nm, and the water contact angles decreased with increasing oxygen incorporation, i.e., showing an increase in surface hydrophilicity. Cell attachment and functionality were assessed over a 21 day period for each cell-surface combination studied; these were performed using SEM and the alamarBlue assay to study cell attachment and proliferation and energy-dispersive X-ray (EDX) analysis to confirm extracellular mineral deposits, and total protein assay to examine the intra- and extracellular protein expressed by the cells. HOB cells cultured for 21 days on the modified UHMWPE surfaces with 19 and 26 atom % oxygen incorporated showed significantly higher cell densities compared to cells cultured on tissue culture polystyrene (TCPS) from day 3 onward. This indicated that the cells attached and proliferated more

  11. Biomaterial surface proteomic signature determines interaction with epithelial cells.

    Science.gov (United States)

    Abdallah, Mohamed-Nur; Tran, Simon D; Abughanam, Ghada; Laurenti, Marco; Zuanazzi, David; Mezour, Mohamed A; Xiao, Yizhi; Cerruti, Marta; Siqueira, Walter L; Tamimi, Faleh

    2017-03-01

    Cells interact with biomaterials indirectly through extracellular matrix (ECM) proteins adsorbed onto their surface. Accordingly, it could be hypothesized that the surface proteomic signature of a biomaterial might determine its interaction with cells. Here, we present a surface proteomic approach to test this hypothesis in the specific case of biomaterial-epithelial cell interactions. In particular, we determined the surface proteomic signature of different biomaterials exposed to the ECM of epithelial cells (basal lamina). We revealed that the biomaterial surface chemistry determines the surface proteomic profile, and subsequently the interaction with epithelial cells. In addition, we found that biomaterials with surface chemistries closer to that of percutaneous tissues, such as aminated PMMA and aminated PDLLA, promoted higher selective adsorption of key basal lamina proteins (laminins, nidogen-1) and subsequently improved their interactions with epithelial cells. These findings suggest that mimicking the surface chemistry of natural percutaneous tissues can improve biomaterial-epithelial integration, and thus provide a rationale for the design of improved biomaterial surfaces for skin regeneration and percutaneous medical devices.

  12. Carbohydrates, pollinators, and cycads

    OpenAIRE

    2015-01-01

    Cycad biology, ecology, and horticulture decisions are not supported by adequate research, and experiments in cycad physiology in particular have been deficient. Our recent report on free sugar content in a range of cycad taxa and tissues sets the stage for developing continued carbohydrate research. Growth and development of cycad pollen, mediation of the herbivory traits of specialist pollinators, and support of expensive strobilus behavioral traits are areas of cycad pollination biology th...

  13. Characterization and optimization of carbohydrate production from an indigenous microalga Chlorella vulgaris FSP-E.

    Science.gov (United States)

    Ho, Shih-Hsin; Huang, Shu-Wen; Chen, Chun-Yen; Hasunuma, Tomohisa; Kondo, Akihiko; Chang, Jo-Shu

    2013-05-01

    In this study, three indigenous microalgae isolates were examined for their ability to produce carbohydrates. Among them, Chlorella vulgaris FSP-E displayed relatively high cell growth rate and carbohydrate content. The carbohydrate productivity of C. vulgaris FSP-E was further improved by using engineering strategies. The results show that using an appropriate light intensity and inoculum size could effectively promote cell growth and carbohydrate productivity. Nitrogen starvation triggered the accumulation of carbohydrates in the microalga, achieving a carbohydrate content of 51.3% after 4-day starvation. Under the optimal conditions, the highest biomass and carbohydrate productivity were 1.437 and 0.631 g L(-1) d(-1), respectively. This performance is better than that reported in most related studies. Since glucose accounted for nearly 93% of the carbohydrates accumulated in C. vulgaris FSP-E, the microalga is an excellent feedstock for bioethanol fermentation.

  14. A comparative study of N-glycolylneuraminic acid (Neu5Gc and cytotoxic T cell (CT carbohydrate expression in normal and dystrophin-deficient dog and human skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Paul T Martin

    Full Text Available The expression of N-glycolylneuraminic acid (Neu5Gc and the cytotoxic T cell (CT carbohydrate can impact the severity of muscular dystrophy arising from the loss of dystrophin in mdx mice. Here, we describe the expression of these two glycans in skeletal muscles of dogs and humans with or without dystrophin-deficiency. Neu5Gc expression was highly reduced (>95% in muscle from normal golden retriever crosses (GR, n = 3 and from golden retriever with muscular dystrophy (GRMD, n = 5 dogs at multiple ages (3, 6 and 13 months when compared to mouse muscle, however, overall sialic acid expression in GR and GRMD muscles remained high at all ages. Neu5Gc was expressed on only a minority of GRMD satellite cells, CD8⁺ T lymphocytes and macrophages. Human muscle from normal (no evident disease, n = 3, Becker (BMD, n = 3 and Duchenne (DMD, n = 3 muscular dystrophy individuals had absent to very low Neu5Gc staining, but some punctate intracellular muscle staining was present in BMD and DMD muscles. The CT carbohydrate was localized to the neuromuscular junction in GR muscle, while GRMD muscles had increased expression on a subset of myofibers and macrophages. In humans, the CT carbohydrate was ectopically expressed on the sarcolemmal membrane of some BMD muscles, but not normal human or DMD muscles. These data are consistent with the notion that altered Neu5Gc and CT carbohydrate expression may modify disease severity resulting from dystrophin deficiency in dogs and humans.

  15. A comparative study of N-glycolylneuraminic acid (Neu5Gc) and cytotoxic T cell (CT) carbohydrate expression in normal and dystrophin-deficient dog and human skeletal muscle.

    Science.gov (United States)

    Martin, Paul T; Golden, Bethannie; Okerblom, Jonathan; Camboni, Marybeth; Chandrasekharan, Kumaran; Xu, Rui; Varki, Ajit; Flanigan, Kevin M; Kornegay, Joe N

    2014-01-01

    The expression of N-glycolylneuraminic acid (Neu5Gc) and the cytotoxic T cell (CT) carbohydrate can impact the severity of muscular dystrophy arising from the loss of dystrophin in mdx mice. Here, we describe the expression of these two glycans in skeletal muscles of dogs and humans with or without dystrophin-deficiency. Neu5Gc expression was highly reduced (>95%) in muscle from normal golden retriever crosses (GR, n = 3) and from golden retriever with muscular dystrophy (GRMD, n = 5) dogs at multiple ages (3, 6 and 13 months) when compared to mouse muscle, however, overall sialic acid expression in GR and GRMD muscles remained high at all ages. Neu5Gc was expressed on only a minority of GRMD satellite cells, CD8⁺ T lymphocytes and macrophages. Human muscle from normal (no evident disease, n = 3), Becker (BMD, n = 3) and Duchenne (DMD, n = 3) muscular dystrophy individuals had absent to very low Neu5Gc staining, but some punctate intracellular muscle staining was present in BMD and DMD muscles. The CT carbohydrate was localized to the neuromuscular junction in GR muscle, while GRMD muscles had increased expression on a subset of myofibers and macrophages. In humans, the CT carbohydrate was ectopically expressed on the sarcolemmal membrane of some BMD muscles, but not normal human or DMD muscles. These data are consistent with the notion that altered Neu5Gc and CT carbohydrate expression may modify disease severity resulting from dystrophin deficiency in dogs and humans.

  16. Cell multiplication following partial enzymatic removal of surface coat.

    Science.gov (United States)

    Wyroba, E

    1978-08-01

    Treatment of Paramecium aurelia with trypsin or pronase (1 mg per 10(5) cells, at 0 to 4 degrees C) partially removes the surface coat and modifies significantly multiplication of cells. The division rate after 24 hours of cultivation is diminished approximately twice in the case of pronase-treated cells and 1.5 for tyrpsin-digested ciliates as compared with the control. On the second day the division rate increases rapidly and number of cell divisions exceeds the values observed in the control. After 72 hours of cultivation the division rate in both untreated and enzyme-treated cells is almost the same. It is concluded that the observed inhibition of cell fission results from the enzymatic removal of the surface coat--the integrity of this surface coat seems to be necessary in the process of cell division. The influence of environmental factors on the rate of growth is presented.

  17. Surface-modified gold nanorods for specific cell targeting

    Science.gov (United States)

    Wang, Chan-Ung; Arai, Yoshie; Kim, Insun; Jang, Wonhee; Lee, Seonghyun; Hafner, Jason H.; Jeoung, Eunhee; Jung, Deokho; Kwon, Youngeun

    2012-05-01

    Gold nanoparticles (GNPs) have unique properties that make them highly attractive materials for developing functional reagents for various biomedical applications including photothermal therapy, targeted drug delivery, and molecular imaging. For in vivo applications, GNPs need to be prepared with very little or negligible cytotoxicitiy. Most GNPs are, however, prepared using growth-directing surfactants such as cetyl trimethylammonium bromide (CTAB), which are known to have considerable cytotoxicity. In this paper, we describe an approach to remove CTAB to a non-toxic concentration. We optimized the conditions for surface modification with methoxypolyethylene glycol thiol (mPEG), which replaced CTAB and formed a protective layer on the surface of gold nanorods (GNRs). The cytotoxicities of pristine and surface-modified GNRs were measured in primary human umbilical vein endothelial cells and human cell lines derived from hepatic carcinoma cells, embryonic kidney cells, and thyroid papillary carcinoma cells. Cytotoxicity assays revealed that treating cells with GNRs did not significantly affect cell viability except for thyroid papillary carcinoma cells. Thyroid cancer cells were more susceptible to residual CTAB, so CTAB had to be further removed by dialysis in order to use GNRs for thyroid cell targeting. PEGylated GNRs are further modified to present monoclonal antibodies that recognize a specific surface marker, Na-I symporter, for thyroid cells. Antibody-conjugated GNRs specifically targeted human thyroid cells in vitro.

  18. Interaction of Epithelial Cells with Surfaces and Surfaces Decorated by Molecules

    CERN Document Server

    Martini, Daniele; Beil, Michael; Paust, T; Huang, C; Moosmann, M; Jin, J; Heiler, T; Gröger, R; Schimmel, Thomas; Walheim, Stefan

    2013-01-01

    A detailed understanding of the interface between living cells and substrate materials is of rising importance in many fields of medicine, biology and biotechnology. Cells at interfaces often form epithelia. The physical barrier that they form is one of their main functions. It is governed by the properties of the networks forming the cytoskeleton systems and by cell-to-cell contacts. Different substrates with varying surface properties modify the migration velocity of the cells. On the one hand one can change the materials composition. Organic and inorganic materials induce differing migration velocities in the same cell system. Within the same class of materials, a change of the surface stiffness or of the surface energy modifies the migration velocity, too. For our cell adhesion studies a variety of different, homogeneous substrates were used (polymers, bio-polymers, metals, oxides). In addition, an effective lithographic method, Polymer Blend Lithography (PBL), is reported, to produce patterned Self-Assem...

  19. High resolution imaging of surface patterns of single bacterial cells

    Energy Technology Data Exchange (ETDEWEB)

    Greif, Dominik; Wesner, Daniel [Experimental Biophysics and Applied Nanoscience, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld (Germany); Regtmeier, Jan, E-mail: jan.regtmeier@physik.uni-bielefeld.de [Experimental Biophysics and Applied Nanoscience, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld (Germany); Anselmetti, Dario [Experimental Biophysics and Applied Nanoscience, Bielefeld University, Universitaetsstrasse 25, 33615 Bielefeld (Germany)

    2010-09-15

    We systematically studied the origin of surface patterns observed on single Sinorhizobium meliloti bacterial cells by comparing the complementary techniques atomic force microscopy (AFM) and scanning electron microscopy (SEM). Conditions ranged from living bacteria in liquid to fixed bacteria in high vacuum. Stepwise, we applied different sample modifications (fixation, drying, metal coating, etc.) and characterized the observed surface patterns. A detailed analysis revealed that the surface structure with wrinkled protrusions in SEM images were not generated de novo but most likely evolved from similar and naturally present structures on the surface of living bacteria. The influence of osmotic stress to the surface structure of living cells was evaluated and also the contribution of exopolysaccharide and lipopolysaccharide (LPS) by imaging two mutant strains of the bacterium under native conditions. AFM images of living bacteria in culture medium exhibited surface structures of the size of single proteins emphasizing the usefulness of AFM for high resolution cell imaging.

  20. Yeast surface display of dehydrogenases in microbial fuel-cells.

    Science.gov (United States)

    Gal, Idan; Schlesinger, Orr; Amir, Liron; Alfonta, Lital

    2016-12-01

    Two dehydrogenases, cellobiose dehydrogenase from Corynascus thermophilus and pyranose dehydrogenase from Agaricus meleagris, were displayed for the first time on the surface of Saccharomyces cerevisiae using the yeast surface display system. Surface displayed dehydrogenases were used in a microbial fuel cell and generated high power outputs. Surface displayed cellobiose dehydrogenase has demonstrated a midpoint potential of -28mV (vs. Ag/AgCl) at pH=6.5 and was used in a mediator-less anode compartment of a microbial fuel cell producing a power output of 3.3μWcm(-2) using lactose as fuel. Surface-displayed pyranose dehydrogenase was used in a microbial fuel cell and generated high power outputs using different substrates, the highest power output that was achieved was 3.9μWcm(-2) using d-xylose. These results demonstrate that surface displayed cellobiose dehydrogenase and pyranose dehydrogenase may successfully be used in microbial bioelectrochemical systems.

  1. Mammalian Cell Surface Display as a Novel Method for Developing Engineered Lectins with Novel Characteristics

    Directory of Open Access Journals (Sweden)

    Keisuke Soga

    2015-07-01

    Full Text Available Leguminous lectins have a conserved carbohydrate recognition site comprising four loops (A–D. Here, we randomly mutated the sequence and length of loops C and D of peanut agglutinin (PNA and expressed the proteins on the surface of mouse green fluorescent protein (GFP-reporter cells. Flow cytometry, limiting dilution, and cDNA cloning were used to screen for several mutated PNAs with distinct properties. The mutated PNA clones obtained using NeuAcα2-6(Galβ1-3GalNAc as a ligand showed preference for NeuAcα2-6(Galβ1-3GalNAc rather than non-sialylated Galβ1-3GlcNAc, whereas wild-type PNA binds to Galβ1-3GlcNAc but not sialylated Galβ1-3GalNAc. Sequence analyses revealed that for all of the glycan-reactive mutated PNA clones, (i loop C was eight amino acids in length, (ii loop D was identical to that of wild-type PNA, (iii residue 127 was asparagine, (iv residue 125 was tryptophan, and (v residue 130 was hydrophobic tyrosine, phenylalanine, or histidine. The sugar-binding ability of wild-type PNA was increased nine-fold when Tyr125 was mutated to tryptophan, and that of mutated clone C was increased more than 30-fold after His130 was changed to tyrosine. These results provide an insight into the relationship between the amino acid sequences of the carbohydrate recognition site and sugar-binding abilities of leguminous lectins.

  2. Fluid dynamics and noise in bacterial cell-cell and cell-surface scattering

    CERN Document Server

    Drescher, Knut; Cisneros, Luis H; Ganguly, Sujoy; Goldstein, Raymond E; 10.1073/pnas.1019079108

    2011-01-01

    Bacterial processes ranging from gene expression to motility and biofilm formation are constantly challenged by internal and external noise. While the importance of stochastic fluctuations has been appreciated for chemotaxis, it is currently believed that deterministic long-range fluid dynamical effects govern cell-cell and cell-surface scattering - the elementary events that lead to swarming and collective swimming in active suspensions and to the formation of biofilms. Here, we report the first direct measurements of the bacterial flow field generated by individual swimming Escherichia coli both far from and near to a solid surface. These experiments allowed us to examine the relative importance of fluid dynamics and rotational diffusion for bacteria. For cell-cell interactions it is shown that thermal and intrinsic stochasticity drown the effects of long-range fluid dynamics, implying that physical interactions between bacteria are determined by steric collisions and near-field lubrication forces. This dom...

  3. Biomechanics of cell rolling: shear flow, cell-surface adhesion, and cell deformability.

    Science.gov (United States)

    Dong, C; Lei, X X

    2000-01-01

    The mechanics of leukocyte (white blood cell; WBC) deformation and adhesion to endothelial cells (EC) has been investigated using a novel in vitro side-view flow assay. HL-60 cell rolling adhesion to surface-immobilized P-selectin was used to model the WBC-EC adhesion process. Changes in flow shear stress, cell deformability, or substrate ligand strength resulted in significant changes in the characteristic adhesion binding time, cell-surface contact and cell rolling velocity. A 2-D model indicated that cell-substrate contact area under a high wall shear stress (20 dyn/cm2) could be nearly twice of that under a low stress (0.5 dyn/cm2) due to shear flow-induced cell deformation. An increase in contact area resulted in more energy dissipation to both adhesion bonds and viscous cytoplasm, whereas the fluid energy that inputs to a cell decreased due to a flattened cell shape. The model also predicted a plateau of WBC rolling velocity as flow shear stresses further increased. Both experimental and computational studies have described how WBC deformation influences the WBC-EC adhesion process in shear flow.

  4. Aberrantly glycosylated MUC1 is expressed on the surface of breast cancer cells and a target for antibody-dependent cell-mediated cytotoxicity

    DEFF Research Database (Denmark)

    Lavrsen, Kirstine; Madsen, Caroline B; Rasch, Morten G

    2013-01-01

    not covered by immunological tolerance in MUC1 humanized mice and man. The objective of this study was to determine if mouse antibodies to this Tn-MUC1 epitope induce antibody-dependent cellular cytotoxicity (ADCC) pivotal for their potential use in cancer immunotherapy. Binding affinity of mAb 5E5 directed...... is expressed on the surface of breast cancer cells and a target for antibody-dependent cell-mediated cytotoxicity suggesting that antibodies targeting glycopeptide epitopes on mucins are strong candidates for cancer-specific immunotherapies.......Protein glycosylation often changes during cancer development, resulting in the expression of cancer-associated carbohydrate antigens. In particular mucins such as MUC1 are subject to these changes. We previously identified an immunodominant Tn-MUC1 (GalNAc-α-MUC1) cancer-specific epitope...

  5. [Immunoglobulin genes encoding antibodies directed to oncodevelopmental carbohydrate antigens].

    Science.gov (United States)

    Zenita, K; Yago, K; Fujimoto, E; Kannagi, R

    1990-07-01

    We investigated the immunoglobulin genes which encode the variable region of the monoclonal antibodies directed to the onco-developmental carbohydrate antigens such SSEA-1, fucosyl SSEA-1, SSEA-3 and SSEA-4. The VH region of these antibodies was preferentially encoded by the gene members of the X24, VH7183 and Q52 families, the families which are known to be located at the 3'-end region of the murine germ line VH gene. This result is interesting particularly when considering that the members of the 3'-end VH families are known to be preferentially expressed in embryonic B lymphocytes by an intrinsic genetic program. The comparative study of the nucleic acid sequences of mRNAs encoding these antibodies and the sequences of the corresponding germ line VH genes disclosed that the sequences encoding the antibodies contain no mutation from the germ line VH genes, or contain only a few somatic mutations, which are thought to be insignificant for the reactivity of the antibodies to the nominal antigens. These results imply that some of the embryonic B lymphocytes that express the unmutated germ line VH genes of the 3'-end families can be reactive with embryonic carbohydrate antigens, albeit rearranged with appropriate D-JH gene segments, and coupled with proper light chains. The VH region of the syngenic monoclonal anti-idiotypic antibodies directed to these anti-carbohydrate antibodies were also encoded preferentially by the members of the 3'-end VH families. We propose here that a part of the virgin embryonic B lymphocytes, which express the antibody encoded by the gene members of the 3'-end VH families at the cell surface, will be stimulated by the embryonic carbohydrate antigens which are abundantly present in the internal milieu of the embryo. The clonally expanded B lymphocytes, in turn, will facilitate the proliferation of other populations of embryonic B lymphocytes expressing the corresponding anti-idiotypic antibodies, which are also encoded by the gene members

  6. Identification of cell surface molecules involved in dystroglycan-independent Lassa virus cell entry.

    Science.gov (United States)

    Shimojima, Masayuki; Ströher, Ute; Ebihara, Hideki; Feldmann, Heinz; Kawaoka, Yoshihiro

    2012-02-01

    Although O-mannosylated dystroglycan is a receptor for Lassa virus, a causative agent of Lassa fever, recent findings suggest the existence of an alternative receptor(s). Here we identified four molecules as receptors for Lassa virus: Axl and Tyro3, from the TAM family, and dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and liver and lymph node sinusoidal endothelial calcium-dependent lectin (LSECtin), from the C-type lectin family. These molecules enhanced the binding of Lassa virus to cells and mediated infection independently of dystroglycan. Axl- or Tyro3-mediated infection required intracellular signaling via the tyrosine kinase activity of Axl or Tyro3, whereas DC-SIGN- or LSECtin-mediated infection and binding were dependent on a specific carbohydrate and on ions. The identification of these four molecules as Lassa virus receptors advances our understanding of Lassa virus cell entry.

  7. Surface Plasmon Resonance for Cell-Based Clinical Diagnosis

    Directory of Open Access Journals (Sweden)

    Yuhki Yanase

    2014-03-01

    Full Text Available Non-invasive real-time observations and the evaluation of living cell conditions and functions are increasingly demanded in life sciences. Surface plasmon resonance (SPR sensors detect the refractive index (RI changes on the surface of sensor chips in label-free and on a real-time basis. Using SPR sensors, we and other groups have developed techniques to evaluate living cells’ reactions in response to stimuli without any labeling in a real-time manner. The SPR imaging (SPRI system for living cells may visualize single cell reactions and has the potential to expand application of SPR cell sensing for clinical diagnosis, such as multi-array cell diagnostic systems and detection of malignant cells among normal cells in combination with rapid cell isolation techniques.

  8. Dynamic fluctuations of protein-carbohydrate interactions promote protein aggregation.

    Directory of Open Access Journals (Sweden)

    Vladimir Voynov

    Full Text Available Protein-carbohydrate interactions are important for glycoprotein structure and function. Antibodies of the IgG class, with increasing significance as therapeutics, are glycosylated at a conserved site in the constant Fc region. We hypothesized that disruption of protein-carbohydrate interactions in the glycosylated domain of antibodies leads to the exposure of aggregation-prone motifs. Aggregation is one of the main problems in protein-based therapeutics because of immunogenicity concerns and decreased efficacy. To explore the significance of intramolecular interactions between aromatic amino acids and carbohydrates in the IgG glycosylated domain, we utilized computer simulations, fluorescence analysis, and site-directed mutagenesis. We find that the surface exposure of one aromatic amino acid increases due to dynamic fluctuations. Moreover, protein-carbohydrate interactions decrease upon stress, while protein-protein and carbohydrate-carbohydrate interactions increase. Substitution of the carbohydrate-interacting aromatic amino acids with non-aromatic residues leads to a significantly lower stability than wild type, and to compromised binding to Fc receptors. Our results support a mechanism for antibody aggregation via decreased protein-carbohydrate interactions, leading to the exposure of aggregation-prone regions, and to aggregation.

  9. Effects of Carbohydrate Consumption Case Study: carbohydrates in Bread

    Directory of Open Access Journals (Sweden)

    Neacsu N.A.

    2014-12-01

    Full Text Available Carbohydrates perform numerous roles in living organisms; they are an important source of energy. The body uses carbohydrates to make glucose which is the fuel that gives it energy and helps keep everything going. However, excess carbohydrate consumption has negative health effects. Bread is a basic product in our nutrition and it also is a product with a high content of carbohydrates. So, it is important to find out more information on bread and on the recommended bread type best for consumption.

  10. Nanoscale crystallinity modulates cell proliferation on plasma sprayed surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Alan M. [School of Applied Sciences, University of Huddersfield, Huddersfield HD1 3DH (United Kingdom); Paxton, Jennifer Z.; Hung, Yi-Pei; Hadley, Martin J.; Bowen, James; Williams, Richard L. [School of Chemical Engineering, University of Birmingham, Edgbaston, B15 2TT (United Kingdom); Grover, Liam M., E-mail: l.m.grover@bham.ac.uk [School of Chemical Engineering, University of Birmingham, Edgbaston, B15 2TT (United Kingdom)

    2015-03-01

    Calcium phosphate coatings have been applied to the surface of metallic prostheses to mediate hard and soft tissue attachment for more than 40 years. Most coatings are formed of high purity hydroxyapatite, and coating methods are often designed to produce highly crystalline surfaces. It is likely however, that coatings of lower crystallinity can facilitate more rapid tissue attachment since the surface will exhibit a higher specific surface area and will be considerably more reactive than a comparable highly crystalline surface. Here we test this hypothesis by growing a population of MC3T3 osteoblast-like cells on the surface of two types of hip prosthesis with similar composition, but with differing crystallinity. The surfaces with lower crystallinity facilitated more rapid cell attachment and increased proliferation rate, despite having a less heterogeneous surface topography. This work highlights that the influence of the crystallinity of HA at the nano-scale is dominant over macro-scale topography for cell adhesion and growth. Furthermore, crystallinity could be easily adjusted by without compromising coating purity. These findings could facilitate designing novel coated calcium phosphate surfaces that more rapidly bond tissue following implantation. - Highlights: • Crystallinity of HA at the nano-scale was dominant over macro-scale topography. • Lower crystallinity caused rapid cell attachment and proliferation rate. • Crystallinity could be easily adjusted by without compromising coating purity.

  11. Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 cell surface hydrophobicity and survival of the cells under adverse environmental conditions.

    Science.gov (United States)

    Shakirova, Laisana; Grube, Mara; Gavare, Marita; Auzina, Lilija; Zikmanis, Peteris

    2013-01-01

    Changes in the cell surface hydrophobicity (CSH) of probiotic bacteria Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and the survival of these cells were examined in response to varied cultivation conditions and adverse environmental conditions. An inverse linear relationship (P acidophilus La5 and B. lactis Bb12 and survival of cells subjected to subsequent freezing/thawing, long-term storage or exposure to mineral and bile acids. The observed relationships were supported by significant correlations between the CSH and changes in composition of the cell envelopes (proteins, lipids and carbohydrates) of L. acidophilus La5 and B. lactis Bb12 examined using FT-IR spectroscopy and conventional biochemical analysis methods. The results also suggest that the estimates of hydrophobicity, being a generalized characteristic of cell surfaces, are important parameters to predict the ability of intact probiotic bacteria to endure extreme environments and therefore should be monitored during cultivation. A defined balance of cell components, which can be characterized by the reduced CSH values, apparently helps to ensure the resistance, improved viability and hence the overall probiotic properties of bacteria.

  12. Cell surface engineering of industrial microorganisms for biorefining applications.

    Science.gov (United States)

    Tanaka, Tsutomu; Kondo, Akihiko

    2015-11-15

    In order to decrease carbon emissions and negative environmental impacts of various pollutants, biofuel/biochemical production should be promoted for replacing fossil-based industrial processes. Utilization of abundant lignocellulosic biomass as a feedstock has recently become an attractive option. In this review, we focus on recent efforts of cell surface display using industrial microorganisms such as Escherichia coli and yeast. Cell surface display is used primarily for endowing cellulolytic activity on the host cells, and enables direct fermentation to generate useful fuels and chemicals from lignocellulosic biomass. Cell surface display systems are systematically summarized, and the drawbacks/perspectives as well as successful application of surface display for industrial biotechnology are discussed.

  13. Nitrogen and phosphorus removal coupled with carbohydrate production by five microalgae cultures cultivated in biogas slurry.

    Science.gov (United States)

    Tan, Fen; Wang, Zhi; Zhouyang, Siyu; Li, Heng; Xie, Youping; Wang, Yuanpeng; Zheng, Yanmei; Li, Qingbiao

    2016-12-01

    In this study, five microalgae strains were cultured for their ability to survive in biogas slurry, remove nitrogen resources and accumulate carbohydrates. It was proved that five microalgae strains adapted in biogas slurry well without ammonia inhibition. Among them, Chlorella vulgaris ESP-6 showed the best performance on carbohydrate accumulation, giving the highest carbohydrate content of 61.5% in biogas slurry and the highest ammonia removal efficiency and rate of 96.3% and 91.7mg/L/d respectively in biogas slurry with phosphorus and magnesium added. Additionally, the absence of phosphorus and magnesium that can be adverse for biomass accumulation resulted in earlier timing of carbohydrate accumulation and magnesium was firstly recognized and proved as the influence factor for carbohydrate accumulation. Microalgae that cultured in biogas slurry accumulated more carbohydrate in cell, making biogas slurry more suitable medium for the improvement of carbohydrate content, thus can be regarded as a new strategy to accumulate carbohydrate.

  14. Functionalized carbon nanomaterials derived from carbohydrates.

    Science.gov (United States)

    Jagadeesan, Dinesh; Eswaramoorthy, Muthusamy

    2010-02-01

    A tremendous growth in the field of carbon nanomaterials has led to the emergence of carbon nanotubes, fullerenes, mesoporous carbon and more recently graphene. Some of these materials have found applications in electronics, sensors, catalysis, drug delivery, composites, and so forth. The high temperatures and hydrocarbon precursors involved in their synthesis usually yield highly inert graphitic surfaces. As some of the applications require functionalization of their inert graphitic surface with groups like -COOH, -OH, and -NH(2), treatment of these materials in oxidizing agents and concentrated acids become inevitable. More recent works have involved using precursors like carbohydrates to produce carbon nanostructures rich in functional groups in a single-step under hydrothermal conditions. These carbon nanostructures have already found many applications in composites, drug delivery, materials synthesis, and Li ion batteries. The review aims to highlight some of the recent developments in the application of carbohydrate derived carbon nanostructures and also provide an outlook of their future prospects.

  15. Membrane Tether Formation on a Cell Surface with Reservoir

    Institute of Scientific and Technical Information of China (English)

    JIANG Yu-Qiang; GUO Hong-Lian; LIU Chun-Xiang; LI Zhao-Lin; CHENG Bing-Ying; ZHANG Dao-Zhong; JIA Suo-Tang

    2004-01-01

    @@ We propose a mathematical model to analyse the membrane tether formation process on a cell surface with reservoir. Based on the experimental results, the membrane reservoir density of breast cancer cell was obtained,p = 8.02. The membrane surface viscosity between membrane and environment η is 0.021(pN.s/μm3), and the static force F0 = 5.71 pN.

  16. Multi-scale cell/surface interaction on modified titanium aluminum vanadium surfaces

    Science.gov (United States)

    Chen, Jianbo

    This dissertation presents a series of experimental studies of the effects of multi-scale cell/surface interactions on modified Ti-6Al-4V surfaces. These include laser-grooved surfaces; porous structures and RGD-coated laser-grooved surfaces. A nano-second DPSS UV lasers with a Gaussian pulse energy profile was used to introduce the desired micro-groove geometries onto Ti-6Al-4V surfaces. This was done without inducing micro-cracks or significant changes in surface chemistry within the heat affected zones. The desired 8-12 mum groove depths and widths were achieved by the control of pulse frequency, scan speed, and the lens focal length that controls spot size. The interactions between human osteosarcoma (HOS) cells and laser-grooved Ti-6Al-4V surfaces were investigated after 48 hours of cell culture. The cell behavior, including cell spreading, alignment and adhesion, was elucidated using scanning electronic microscopy (SEM), immuno-fluorescence staining and enzymatic detachment. Contact guidance was shown to increase as grooved spacing decreased. For the range of micro-groove geometries studied, micro-grooves with groove spacings of 20 mum provided the best combination of cell orientation and adhesion. Short-term adhesion experiments (15 mins to 1 day) also revealed that there is a positive correlation between cell orientation and cell adhesion. Contact guidance on the micro-grooved surfaces is shown to be enhanced by nano- and micro-scale asperities that provide sites for the attachment of lamellopodia during cell locomotion and spreading. Contact guidance is also promoted by the geometrical confinement provided by laser grooves. An experimental study of initial cell spreading and ingrowth into Ti-6Al-4V porous structures was also carried out on porous structures with different pore sizes and geometries. A combination of SEM, the tetrazolium salt (MTT) colorimetric assay and enzymatic detachment were used to study cell spreading and adhesion. The extent of cell

  17. Comparison of the binding properties of the mushroom Marasmius oreades lectin and Griffonia simplicifolia I-B isolectin to alphagalactosyl carbohydrate antigens in the surface phase

    DEFF Research Database (Denmark)

    Kirkeby, Svend; Winter, Harry C; Goldstein, Irwin J

    2004-01-01

    The binding of two alpha-galactophilic lectins, Marasmius oreades agglutinin (MOA), and Griffonia simplicifolia I isolectin B(4) (GS I-B(4)) to neoglycoproteins and natural glycoproteins were compared in a surface phase assay. Neoglycoproteins carrying various alpha-galactosylated glycans and lam...

  18. Cell orientation on a stripe-micropatterned surface

    Institute of Scientific and Technical Information of China (English)

    SUN JianGuo; TANG Jian; DING JianDong

    2009-01-01

    Stripe-micropatterned surfaces have recently been a unique tool to study cell orientation. In this paper,we prepared,by the photolithography transfer technique,stable gold (Au) micropatterns on PEG hydrogel surfaces with defined cell-resistant (PEG hydrogel) and cell-adhesive (gold microstripes) proparties. 3T3 fibroblasts were cultured on Au-microstripe surfaces to observe cell adhesion and orientation. Five statistical parameters were defined and used to describe cell orientation on micropatterns.With the increase of inter-stripe distance,the orientational order parameter,the ratio of long and short axes of a cell,and the occupation fraction of cells on stripes increased gradually,whereas the spreading area of a single cell decreased. The abrupt changes of these four parameters did not happen at the same inter-distance. The adhesion ratio of a cell on Au stripes over cell spreading area did not change monotonically as a function of inter-stripe distance. The combination of the 5 statistical parameters represented well the cell orientation behaviors semi-quantitatively.

  19. Microfabricated surface designs for cell culture and diagnosis.

    Science.gov (United States)

    Matsuda, T; Chung, D J

    1994-01-01

    Grooved and holed surfaces with a well fabricated design may serve as microsubstrates for cell culture and microreactors for diagnosis. In this study, the authors prepared chemically treated, micrometer scale grooved and holed glass surfaces by combined surface modification and ultraviolet (UV) excimer laser ablation techniques, as follows. 1) Microcell-culture substrate: Amino group attached glass surfaces, prepared by the treatment with an aminopropylsilane, were condensed with a carboxylated radical initiator. Subsequently, polyacrylamide was grafted by surface initiated radical polymerization to create a very hydrophilic surface layer. Ultraviolet excimer laser beams (KrF: 248 nm) were irradiated through a microscope onto surfaces to create grooves or holes that were 10 and 50 microns in width or diameter, respectively. The depth, depending on the irradiation light strength, ranged from a few to several tenths of a micrometer. On endothelial cell (EC) seeding, ECs adhered and grew on the bottoms of the grooved or holed surface where glass was exposed on ablation. Little cell adhesion was observed on non ablated, grafted surfaces. Endothelial cells aligned along the groove, resulting in very narrow tube like tissue formation, whereas ECs tended to form a multilayered spherical aggregate in a hole. A single cell resided in a 10 microns square hole. 2) Microreactor for diagnosis: The glass surface, treated with a fluorinated silane, was ablated to create round holes. On addition of a few microliters of water, water could be quantitatively transferred into a hole because of the water repellent characteristics of non ablated, fluorinated glass. As a model of a microreactor, enzyme reactions to affect different levels of glucose were carried out in tiny holed surfaces.

  20. An adenovirus vector incorporating carbohydrate binding domains utilizes glycans for gene transfer.

    Directory of Open Access Journals (Sweden)

    Julius W Kim

    Full Text Available BACKGROUND: Vectors based on human adenovirus serotype 5 (HAdV-5 continue to show promise as delivery vehicles for cancer gene therapy. Nevertheless, it has become clear that therapeutic benefit is directly linked to tumor-specific vector localization, highlighting the need for tumor-targeted gene delivery. Aberrant glycosylation of cell surface glycoproteins and glycolipids is a central feature of malignant transformation, and tumor-associated glycoforms are recognized as cancer biomarkers. On this basis, we hypothesized that cancer-specific cell-surface glycans could be the basis of a novel paradigm in HAdV-5-based vector targeting. METHODOLOGY/PRINCIPAL FINDINGS: As a first step toward this goal, we constructed a novel HAdV-5 vector encoding a unique chimeric fiber protein that contains the tandem carbohydrate binding domains of the fiber protein of the NADC-1 strain of porcine adenovirus type 4 (PAdV-4. This glycan-targeted vector displays augmented CAR-independent gene transfer in cells with low CAR expression. Further, we show that gene transfer is markedly decreased in cells with genetic glycosylation defects and by inhibitors of glycosylation in normal cells. CONCLUSIONS/SIGNIFICANCE: These data provide the initial proof-of-concept for HAdV-5 vector-mediated gene delivery based on the presence of cell-surface carbohydrates. Further development of this new targeting paradigm could provide targeted gene delivery based on vector recognition of disease-specific glycan biomarkers.

  1. Carbohydrate Microarrays in Plant Science

    DEFF Research Database (Denmark)

    Fangel, Jonatan Ulrik; Pedersen, H.L.; Vidal-Melgosa, S.

    2012-01-01

    industrially and nutritionally. Understanding the biological roles of plant glycans and the effective exploitation of their useful properties requires a detailed understanding of their structures, occurrence, and molecular interactions. Microarray technology has revolutionized the massively high......-throughput analysis of nucleotides, proteins, and increasingly carbohydrates. Using microarrays, the abundance of and interactions between hundreds and thousands of molecules can be assessed simultaneously using very small amounts of analytes. Here we show that carbohydrate microarrays are multifunctional tools...... for plant research and can be used to map glycan populations across large numbers of samples to screen antibodies, carbohydrate binding proteins, and carbohydrate binding modules and to investigate enzyme activities....

  2. Sperm cell surface dynamics during activation and fertilization

    NARCIS (Netherlands)

    Boerke, A.

    2013-01-01

    Before the sperm cell can reach the oocyte it needs to be activated and to undergo a series of preparative steps. The sperm surface dynamics was studied in relation to this activation process and the modifications and removal of sperm surface components havebeen investigated. Bicarbonate-induced rad

  3. Fabrication of cell container arrays with overlaid surface topographies.

    NARCIS (Netherlands)

    Truckenmuller, R.; Giselbrecht, S.; Escalante-Marun, M.; Groenendijk, M.; Papenburg, B.; Rivron, N.; Unadkat, H.; Saile, V.; Subramaniam, V.; Berg, A. van den; Blitterswijk, C. Van; Wessling, M.; Boer, J. den; Stamatialis, D.

    2012-01-01

    This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

  4. Fabrication of cell container arrays with overlaid surface topographies

    NARCIS (Netherlands)

    Truckenmüller, R.K.; Giselbrecht, S.; Escalante, M.; Groenendijk, M.N.W.; Papenburg, B.J.; Rivron, N.C.; Unadkat, H.V.; Saile, V.; Subramaniam, V.; Blitterswijk, van C.A.; Wessling, M.; Boer, de J.; Stamatialis, D.

    2012-01-01

    This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a

  5. Immunogold labels: cell-surface markers in atomic force microscopy

    NARCIS (Netherlands)

    Putman, Constant A.J.; Grooth, de Bart G.; Hansma, Paul K.; Hulst, van Niek F.; Greve, Jan

    1993-01-01

    The feasibility of using immunogold labels as cell-surface markers in atomic force microscopy is shown in this paper. The atomic force microscope (AFM) was used to image the surface of immunogold-labeled human lymphocytes. The lymphocytes were isolated from whole blood and labeled by an indirect imm

  6. Study of surface cell Madelung constant and surface free energy of nanosized crystal grain

    Institute of Scientific and Technical Information of China (English)

    Zhang Wei-Jia; Wang Tian-Min; Rong Ai-Lun; Cui Min

    2006-01-01

    Surface cell Madelung constant is firstly defined for calculating the surface free energy of nanosized crystal grains,which explains the physical performance of small crystals and may be greatly beneficial to the analysis of surface states and the study of the dynamics of crystal nucleation and growth.A new approximative expression of the surface energy and relevant thermodynamic data are used in this calculation.New formula and computing method for calculating the Madelung constant α of any complex crystals are proposed,and the surface free energies and surface electrostatic energies of nanosized crystal grains and the Madelung constant of some complex crystals are theoretically calculated in this paper.The surface free energy of nanosized-crystal-grain TiO2 and the surface electrostatic energy (absolute value) of nanosized-crystal-grain α-A12O3 are found to be the biggest among all the crystal grains including those of other species.

  7. Study of Surface Cell Madelung Constant and Surface Free Energy of Nanosized Crystal Grain

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei-Jia; WANG Tian-Min; CUI Min

    2005-01-01

    Surface cell Madelung constant is firstly defined in calculating surface free energy of nanosized crystal grains, which explains the physical performance of small crystals and may be great benefit to make surface analysis and study dynamics of crystal nucleus growth. A new ap- proximative expression of surface energy and relevant thermodynamic data was used in this cal- culation. A new formula and computing method for calculating the Madelung constant α of any complex crystals is proposed, and surface free energies and surface electrostatic energies of nano- sized crystal grains as well as Madelung constant of some complex crystals are theoretically cal- culated in this paper. The surface free energy of nanosized crystal grain TiO2 and surface elec- trostatic energy(absolute value) of nanosized crystal grain α-Al2O3 are found to be the biggest among other crystal grains.

  8. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle

    -derived antigenic peptides, a function which is currently explored in immunotherapeutic approaches against cancer. Additionally, membrane-bound Hsp70 can stimulate antigen presenting cells to release proinflammatory cytokines and can provide a target structure for NK cell-mediated lysis. Human cancer cells...... frequently express Hsp70 on their cell surface, whereas the corresponding normal tissues do not. In addition, several clinically applied reagents, such as alkyl-lysophospholipides, chemotherapeutic agents, and anti-inflammatory reagents, have been found to enhance Hsp70 cell surface expression on cancer...... cells. We have found that inhibition of histone deacetylase (HDAC) activity leads to surface expression of Hsp70 on various hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC-inhibitor mediated Hsp70 cell surface expression was confined...

  9. Responses of fibroblasts and glial cells to nanostructured platinum surfaces

    Science.gov (United States)

    Pennisi, C. P.; Sevcencu, C.; Dolatshahi-Pirouz, A.; Foss, M.; Lundsgaard Hansen, J.; Nylandsted Larsen, A.; Zachar, V.; Besenbacher, F.; Yoshida, K.

    2009-09-01

    The chronic performance of implantable neural prostheses is affected by the growth of encapsulation tissue onto the stimulation electrodes. Encapsulation is associated with activation of connective tissue cells at the electrode's metallic contacts, usually made of platinum. Since surface nanotopography can modulate the cellular responses to materials, the aim of the present work was to evaluate the 'in vitro' responses of connective tissue cells to platinum strictly by modulating its surface nanoroughness. Using molecular beam epitaxy combined with sputtering, we produced platinum nanostructured substrates consisting of irregularly distributed nanopyramids and investigated their effect on the proliferation, cytoskeletal organization and cellular morphology of primary fibroblasts and transformed glial cells. Cells were cultured on these substrates and their responses to surface roughness were studied. After one day in culture, the fibroblasts were more elongated and their cytoskeleton less mature when cultured on rough substrates. This effect increased as the roughness of the surface increased and was associated with reduced cell proliferation throughout the observation period (4 days). Morphological changes also occurred in glial cells, but they were triggered by a different roughness scale and did not affect cellular proliferation. In conclusion, surface nanotopography modulates the responses of fibroblasts and glial cells to platinum, which may be an important factor in optimizing the tissue response to implanted neural electrodes.

  10. Expanding the diversity of unnatural cell surface sialic acids

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Recharging Red Blood Cell Surface by Hemodialysis

    Directory of Open Access Journals (Sweden)

    Katrin Kliche

    2015-02-01

    Full Text Available Background: Similar as in vascular endothelium the negatively charged glycocalyx of erythrocytes selectively buffers sodium. Loss of glycocalyx (i.e. loss of negative charges leads to increased erythrocyte sodium sensitivity (ESS quantified by a recently developed salt-blood-test (SBT. The hypothesis was tested whether a regular 4-hour hemodialysis (4h-HD alters ESS. Methods: In 38 patients with end stage renal disease (ESRD ESS was measured before and after 4h-HD, together with standard laboratory and clinical parameters (electrolytes, acid-base status, urea, creatinine, hemoglobin, c-reactive protein and blood pressure. Results: Before 4h-HD, 20 patients (out of 38 were classified as “salt sensitive” by SBT. After 4h-HD, this number decreased to 11. Erythrocyte sodium buffering power remained virtually constant in patients with already low ESS before dialysis, whereas in patients with high ESS, 4h-HD improved the initially poor sodium buffering power by about 20%. No significant correlations could be detected between standard blood parameters and the respective ESS values except for plasma sodium concentration which was found increased by 3.1 mM in patients with high salt sensitivity. Conclusions: 4h-HD apparently recharges “run-down” erythrocytes and thus restores erythrocyte sodium buffering capacity. Besides the advantage of efficient sodium buffering in blood, erythrocytes with sufficient amounts of free negative charges at the erythrocyte surface will cause less (mechanical injury to the negatively charged endothelial surface due to efficient repulsive forces between blood and vessel wall. Hemodialysis improves erythrocyte surface properties and thus may prevent early vascular damage in patients suffering from ESRD.

  12. General Properties, Occurrence, and Preparation of Carbohydrates

    Science.gov (United States)

    Robyt, John F.

    D-Glucose and its derivatives and analogues, N-acetyl-D-glucosamine, N-acetyl-D-muramic acid, D-glucopyranosyl uronic acid, and D-glucitol represent 99.9% of the carbohydrates on the earth. D-Glucose is found in the free state in human blood and in the combined state in disaccharides, sucrose, lactose, and α,α-trehalose, in cyclic dextrins, and in polysaccharides, starch, glycogen, cellulose, dextrans; N-acetyl-D-glucosamine and an analogue N-acetyl-D-muramic acid are found in bacterial cell wall polysaccharide, murein, along with teichoic acids made up of poly-glycerol or -ribitol phosphodiesters. Other carbohydrates, D-mannose, D-mannuronic acid, D-galactose, N-acetyl-D-galactosamine, D-galacturonic acid, D-iduronic acid, L-guluronic acid, L-rhamnose, L-fucose, D-xylose, and N-acetyl-D-neuraminic acid are found in glycoproteins, hemicelluloses, glycosaminoglycans, and polysaccharides of plant exudates, bacterial capsules, alginates, and heparin. D-Ribofuranose-5-phosphate is found in many coenzymes and is the backbone of RNAs (ribonucleic acid), and 2-deoxy-D-ribofuranose-5-phosphate is the backbone of DNA (deoxyribonucleic acid). D-Fructofuranose is found in sucrose, inulin, and levan. The general properties and occurrence of these carbohydrates and general methods of isolation and preparation of carbohydrates are presented.

  13. Impact of Dietary Carbohydrate and Protein Levels on Carbohydrate Metabolism

    Science.gov (United States)

    Lasker, Denise Ann

    2009-01-01

    The goal of this dissertation was to investigate the impact of changing dietary carbohydrate (CARB) intakes within recommended dietary guidelines on metabolic outcomes specifically associated with glycemic regulations and carbohydrate metabolism. This research utilized both human and animal studies to examine changes in metabolism across a wide…

  14. Transforming ocular surface stem cell research into successful clinical practice

    Directory of Open Access Journals (Sweden)

    Virender S Sangwan

    2014-01-01

    Full Text Available It has only been a quarter of a century since the discovery of adult stem cells at the human corneo-scleral limbus. These limbal stem cells are responsible for generating a constant and unending supply of corneal epithelial cells throughout life, thus maintaining a stable and uniformly refractive corneal surface. Establishing this hitherto unknown association between ocular surface disease and limbal dysfunction helped usher in therapeutic approaches that successfully addressed blinding conditions such as ocular burns, which were previously considered incurable. Subsequent advances in ocular surface biology through basic science research have translated into innovations that have made the surgical technique of limbal stem cell transplantation simpler and more predictable. This review recapitulates the basic biology of the limbus and the rationale and principles of limbal stem cell transplantation in ocular surface disease. An evidence-based algorithm is presented, which is tailored to clinical considerations such as laterality of affliction, severity of limbal damage and concurrent need for other procedures. Additionally, novel findings in the form of factors influencing the survival and function of limbal stem cells after transplantation and the possibility of substituting limbal cells with epithelial stem cells of other lineages is also discussed. Finally this review focuses on the future directions in which both basic science and clinical research in this field is headed.

  15. Amplified effect of surface charge on cell adhesion by nanostructures

    Science.gov (United States)

    Xu, Li-Ping; Meng, Jingxin; Zhang, Shuaitao; Ma, Xinlei; Wang, Shutao

    2016-06-01

    Nano-biointerfaces with varied surface charge can be readily fabricated by integrating a template-based process with maleimide-thiol coupling chemistry. Significantly, nanostructures are employed for amplifying the effect of surface charge on cell adhesion, as revealed by the cell-adhesion performance, cell morphology and corresponding cytoskeletal organization. This study may provide a promising strategy for developing new biomedical materials with tailored cell adhesion for tissue implantation and regeneration.Nano-biointerfaces with varied surface charge can be readily fabricated by integrating a template-based process with maleimide-thiol coupling chemistry. Significantly, nanostructures are employed for amplifying the effect of surface charge on cell adhesion, as revealed by the cell-adhesion performance, cell morphology and corresponding cytoskeletal organization. This study may provide a promising strategy for developing new biomedical materials with tailored cell adhesion for tissue implantation and regeneration. Electronic supplementary information (ESI) available: Experimental details, SEM, KFM AFM, chemical modification and characterization. See DOI: 10.1039/c6nr00649c

  16. Zinc uptake by brain cells: `surface' versus `bulk'

    Science.gov (United States)

    DeStasio, Gelsomina; Pochon, S.; Lorusso, G. F.; Tonner, B. P.; Mercanti, Delio; Ciotti, M. Teresa; Oddo, Nino; Galli, Paolo; Perfetti, P.; Margaritondo, G.

    1996-08-01

    The uptake of zinc by cerebellar rat cultures upon exposure to 0022-3727/29/8/023/img12 solutions was comparatively investigated using two well known condensed matter physics techniques: synchrotron photoelectron spectromicroscopy and inductively coupled plasma atomic emission spectroscopy. The objective was to apply a strategy - well known in surface physics - to distinguish between `surface' and `bulk' phenomena. The results clearly demonstrate that exposure significantly enhances the bulk (cell cytoplasm) Zn concentration with respect to the physiological level, whereas the effect on the surface (cell membrane) is negligible.

  17. CD44 is the principal cell surface receptor for hyaluronate.

    Science.gov (United States)

    Aruffo, A; Stamenkovic, I; Melnick, M; Underhill, C B; Seed, B

    1990-06-29

    CD44 is a broadly distributed cell surface protein thought to mediate cell attachment to extracelular matrix components or specific cell surface ligands. We have created soluble CD44-immunoglobulin fusion proteins and characterized their reactivity with tissue sections and lymph node high endothelial cells in primary culture. The CD44 target on high endothelial cells is sensitive to enzymes that degrade hyaluronate, and binding of soluble CD44 is blocked by low concentrations of hyaluronate or high concentrations of chondroitin 4- and 6-sulfates. A mouse anti-hamster hyaluonate receptor antibody reacts with COS cells expressing hamster CD44 cDNA. In sections of all tissues examined, including lymph nodes and Peyer's patches, predigestion with hyaluronidase eliminated CD44 binding.

  18. Soluble and cell surface receptors for tumor necrosis factor

    DEFF Research Database (Denmark)

    Wallach, D; Engelmann, H; Nophar, Y

    1991-01-01

    Tumor necrosis factor (TNF) initiates its multiple effects on cell function by binding at a high affinity to specific cell surface receptors. Two different molecular species of these receptors, which are expressed differentially in different cells, have been identified. The cDNAs of both receptor...... have recently been cloned. Antibodies to one of these receptor species (the p55, type I receptor) can trigger a variety of TNF like effects by cross-linking of the receptor molecules. Thus, it is not TNF itself but its receptors that provide the signal for the response to this cytokine...... in certain pathological situations. Release of the soluble receptors from the cells seems to occur by proteolytic cleavage of the cell surface forms and appears to be a way of down-regulating the cell response to TNF. Because of their ability to bind TNF, the soluble receptors exert an inhibitory effect...

  19. Surface modified stainless steels for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Wang, Heli [Littleton, CO; Turner, John A [Littleton, CO

    2007-07-24

    A nitridation treated stainless steel article (such as a bipolar plate for a proton exchange membrane fuel cell) having lower interfacial contact electrical resistance and better corrosion resistance than an untreated stainless steel article is disclosed. The treated stainless steel article has a surface layer including nitrogen-modified chromium-base oxide and precipitates of chromium nitride formed during nitridation wherein oxygen is present in the surface layer at a greater concentration than nitrogen. The surface layer may further include precipitates of titanium nitride and/or aluminum oxide. The surface layer in the treated article is chemically heterogeneous surface rather than a uniform or semi-uniform surface layer exclusively rich in chromium, titanium or aluminum. The precipitates of titanium nitride and/or aluminum oxide are formed by the nitriding treatment wherein titanium and/or aluminum in the stainless steel are segregated to the surface layer in forms that exhibit a low contact resistance and good corrosion resistance.

  20. Antifouling property of highly oleophobic substrates for solar cell surfaces

    Science.gov (United States)

    Fukada, Kenta; Nishizawa, Shingo; Shiratori, Seimei

    2014-03-01

    Reduction of solar cell conversion efficiency by bird spoor or oil smoke is a common issue. Maintaining the surface of solar cells clean to retain the incident light is of utmost importance. In this respect, there has been growing interest in the area of superhydrophobicity for developing water repelling and self-cleaning surfaces. This effect is inspired by lotus leaves that have micro papillae covered with hydrophobic wax nanostructures. Superhydrophobic surfaces on transparent substrates have been developed for removing contaminants from solar cell surfaces. However, oil cannot be removed by superhydrophobic effect. In contrast, to prevent bird spoor, a highly oleophobic surface is required. In a previous study, we reported transparent-type fabrics comprising nanoparticles with a nano/micro hierarchical structure that ensured both oleophobicity and transparency. In the current study, we developed new highly oleophobic stripes that were constructed into semi-transparent oleophobic surfaces for solar cells. Solar cell performance was successfully maintained; the total transmittance was a key factor for determining conversion efficiency.

  1. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard

    , membrane-bound Hsp70 can stimulate antigen presenting cells (APCs) to release proinflammatory cytokines and can provide a target structure for NK cell-mediated lysis. Human cancer cells frequently express Hsp70 on their cell surface, whereas the corresponding normal tissues do not. In addition, several...... clinically applied reagents, such as alkyl-lysophospholipides, chemotherapeutic agents, and anti-inflammatory reagents, have been found to enhance Hsp70 surface expression on cancer cells. We have found that inhibition of histone deacetylase (HDAC) activity leads to surface expression of Hsp70 on various...... hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC-inhibitor mediated Hsp70 surface expression was confined to the apoptotic Annexin V positive cells and blocked by inhibition of apoptosis. Other chemotherapeutic inducers of apoptosis...

  2. Adhesion defective BHK cell mutant has cell surface heparan sulfate proteoglycan of altered properties

    DEFF Research Database (Denmark)

    Couchman, J R; Austria, R; Woods, A;

    1988-01-01

    In the light of accumulating data that implicate cell surface heparan sulfate proteoglycans (HSPGs) with a role in cell interactions with extracellular matrix molecules such as fibronectin, we have compared the properties of these molecules in wild-type BHK cells and an adhesion-defective ricin......-resistant mutant (RicR14). Our results showed that the mutant, unlike BHK cells, cannot form focal adhesions when adherent to planar substrates in the presence of serum. Furthermore, while both cell lines possess similar amounts of cell surface HSPG with hydrophobic properties, that of RicR14 cells had decreased...

  3. Tannic acid binding of cell surfaces in normal, premalignant, and malignant squamous epithelium of the human uterine cervix.

    Science.gov (United States)

    Davina, J H; Lamers, G E; van Haelst, U J; Kenemans, P; Stadhouders, A M

    1984-01-01

    Alterations in tannic acid (TA) binding capacity of cell surface carbohydrates in normal, premalignant, and malignant squamous epithelium of the human uterine cervix have been studied using electron microscopic visualization in combination with microdensitometric evaluation. While in normal epithelium there is distinct binding in four to five cell layers of the deep intermediate zone, cells of carcinoma in situ and invasive cancer lesions lack TA binding. In moderate dysplasia an intermediate reacting pattern is found. Deep intermediate cells in areas bordering the carcinoma in situ lesions do not show any binding, although their ultrastructure cannot be distinguished from similar cells in normal tissue. The TA deposition within the deep intermediate zone is probably related to the presence here of glycoprotein-containing membrane-coating granules. The finding that TA binding discriminates between cells in normal squamous epithelium and morphologically normal cells in juxtaposition with lesional areas in premalignant and malignant epithelium opens the possibility for a more reliable cytologic diagnosis of cervical epithelial neoplasia.

  4. Effect of hydroxyapatite surface morphology on cell adhesion.

    Science.gov (United States)

    Iwamoto, Takashi; Hieda, Yohki; Kogai, Yasumichi

    2016-12-01

    We obtained hydroxyapatite (HAp) materials as a block by mixing HAp nanoparticles and polymer, and then calcining the mixtures. The surface morphology of the HAp materials was tuned by varying heat treatment conditions. After calcining the mixtures at 1200 or 800°C for 4h, the surface morphology of the HAp materials was flat or convexo-concave, respectively. The flat surface morphology, which showed micrometer-ordered grain boundaries, was formed by the aggregation of HAp nanoparticles. On the other hand, the convexo-concave surface morphology resulted from the agglomeration of HAp nanoparticles after heat treatment at 800°C for 4h with nanometer-ordered particle size. We tested cell adhesion to HAp materials with flat or convexo-concave surface morphology and found that cells adhered well to the flat HAp materials but not to the convexo-concave HAp materials. This technique for selectively preparing HAp materials with flat or convexo-concave surface morphology was very easy because we merely mixed commercial HAp nanoparticles with polymer and then calcined the mixtures. As a result, the heat treatment temperature affected the surface morphology of our HAp materials, and their surface morphologies contributed to cell adhesion independently of other material properties.

  5. Surface modification of closed plastic bags for adherent cell cultivation

    Science.gov (United States)

    Lachmann, K.; Dohse, A.; Thomas, M.; Pohl, S.; Meyring, W.; Dittmar, K. E. J.; Lindenmeier, W.; Klages, C.-P.

    2011-07-01

    In modern medicine human mesenchymal stem cells are becoming increasingly important. However, a successful cultivation of this type of cells is only possible under very specific conditions. Of great importance, for instance, are the absence of contaminants such as foreign microbiological organisms, i.e., sterility, and the chemical functionalization of the ground on which the cells are grown. As cultivation of these cells makes high demands, a new procedure for cell cultivation has been developed in which closed plastic bags are used. For adherent cell growth chemical functional groups have to be introduced on the inner surface of the plastic bag. This can be achieved by a new, atmospheric-pressure plasma-based method presented in this paper. The method which was developed jointly by the Fraunhofer IST and the Helmholtz HZI can be implemented in automated equipment as is also shown in this contribution. Plasma process gases used include helium or helium-based gas mixtures (He + N2 + H2) and vapors of suitable film-forming agents or precursors such as APTMS, DACH, and TMOS in helium. The effect of plasma treatment is investigated by FTIR-ATR spectroscopy as well as surface tension determination based on contact angle measurements and XPS. Plasma treatment in nominally pure helium increases the surface tension of the polymer foil due to the presence of oxygen traces in the gas and oxygen diffusing through the gas-permeable foil, respectively, reacting with surface radical centers formed during contact with the discharge. Primary amino groups are obtained on the inner surface by treatment in mixtures with nitrogen and hydrogen albeit their amount is comparably small due to diffusion of oxygen through the gas-permeable bag, interfering with the plasma-amination process. Surface modifications introducing amino groups on the inner surface turned out to be most efficient in the promotion of cell growth.

  6. Engineered microtopographies and surface chemistries direct cell attachment and function

    Science.gov (United States)

    Magin, Chelsea Marie

    Harrison, in 1914, first recognized that cells respond to physicochemical cues such as substratum topography when he observed that fibroblasts elongated while cultured on spider silk. Recently, techniques developed in the micro-electronics industry have been used to create molds for producing microscaled topographies with various shapes and spatial arrangements. Although these patterning techniques are well-established, very little is known about the mechanisms underlying cell sensing and response to microtopographies. In this work cellular micro-environments with varying surface topographies and chemistries were evaluated with marine organisms and mammalian cells to investigate cellular sensing and response. Biofouling---the accumulation of micro-organisms, plants, and animals on submerged surfaces---is an environmental and economic concern. Engineered topographies, replicated in polydimethylsiloxane elastomer (PDMSe) and functionalized poly(ethylene glycol)-dimethacrylate (PEGDMA) hydrogels, were evaluated for inhibition of marine fouling organism attachment. Microtopographies replicated in PDMSe inhibited attachment of the marine bacterium, Cobetia marina up to 99% versus smooth. The average normalized attachment densities of cells of C. marina and zoospores of the green algae Ulva on PDMSe topographies scaled inversely with the Engineered Roughness Index (ERIII), a representation of surface energy. Attachment densities of Ulva from four assays and C. marina from two growth phases to PDMSe surfaces scaled inversely with one equation: ERI II multiplied by the Reynolds number of the organism (Re) (R 2 = 0.77). The same microtopographies created in PDMSe reduced the initial attachment density and attachment strength of cells of the diatoms Navicula incerta and Seminavis robusta compared to smooth PDMSe. The average normalized attachment density of Navicula after exposure to shear stress (48 Pa) was correlated with the contact area between the diatom and a

  7. Development of exosome surface display technology in living human cells.

    Science.gov (United States)

    Stickney, Zachary; Losacco, Joseph; McDevitt, Sophie; Zhang, Zhiwen; Lu, Biao

    2016-03-25

    Surface display technology is an emerging key player in presenting functional proteins for targeted drug delivery and therapy. Although a number of technologies exist, a desirable mammalian surface display system is lacking. Exosomes are extracellular vesicles that facilitate cell-cell communication and can be engineered as nano-shuttles for cell-specific delivery. In this study, we report the development of a novel exosome surface display technology by exploiting mammalian cell secreted nano-vesicles and their trans-membrane protein tetraspanins. By constructing a set of fluorescent reporters for both the inner and outer surface display on exosomes at two selected sites of tetraspanins, we demonstrated the successful exosomal display via gene transfection and monitoring fluorescence in vivo. We subsequently validated our system by demonstrating the expected intracellular partitioning of reporter protein into sub-cellular compartments and secretion of exosomes from human HEK293 cells. Lastly, we established the stable engineered cells to harness the ability of this robust system for continuous production, secretion, and uptake of displayed exosomes with minimal impact on human cell biology. In sum, our work paved the way for potential applications of exosome, including exosome tracking and imaging, targeted drug delivery, as well as exosome-mediated vaccine and therapy.

  8. A cell cycle and nutritional checkpoint controlling bacterial surface adhesion.

    Directory of Open Access Journals (Sweden)

    Aretha Fiebig

    2014-01-01

    Full Text Available In natural environments, bacteria often adhere to surfaces where they form complex multicellular communities. Surface adherence is determined by the biochemical composition of the cell envelope. We describe a novel regulatory mechanism by which the bacterium, Caulobacter crescentus, integrates cell cycle and nutritional signals to control development of an adhesive envelope structure known as the holdfast. Specifically, we have discovered a 68-residue protein inhibitor of holdfast development (HfiA that directly targets a conserved glycolipid glycosyltransferase required for holdfast production (HfsJ. Multiple cell cycle regulators associate with the hfiA and hfsJ promoters and control their expression, temporally constraining holdfast development to the late stages of G1. HfiA further functions as part of a 'nutritional override' system that decouples holdfast development from the cell cycle in response to nutritional cues. This control mechanism can limit surface adhesion in nutritionally sub-optimal environments without affecting cell cycle progression. We conclude that post-translational regulation of cell envelope enzymes by small proteins like HfiA may provide a general means to modulate the surface properties of bacterial cells.

  9. Carbohydrate biomarkers for future disease detection and treatment

    Institute of Scientific and Technical Information of China (English)

    REID; Suazette

    2010-01-01

    Carbohydrates are considered as one of the most important classes of biomarkers for cell types,disease states,protein functions,and developmental states.Carbohydrate"binders"that can specifically recognize a carbohydrate biomarker can be used for developing novel types of site specific delivery methods and imaging agents.In this review,we present selected examples of important carbohydrate biomarkers and how they can be targeted for the development of therapeutic and diagnostic agents.Examples are arranged based on disease categories including(1) infectious diseases,(2) cancer,(3) inflammation and immune responses,(4) signal transduction,(5) stem cell transformation,(6) embryo development,and(7) cardiovascular diseases,though some issues cross therapeutic boundaries.

  10. Synthesis of carbohydrate-based surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

    2016-11-22

    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

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

    Science.gov (United States)

    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.

  12. Inhibiting oral intoxication of botulinum neurotoxin A complex by carbohydrate receptor mimics.

    Science.gov (United States)

    Lee, Kwangkook; Lam, Kwok-Ho; Kruel, Anna-Magdalena; Mahrhold, Stefan; Perry, Kay; Cheng, Luisa W; Rummel, Andreas; Jin, Rongsheng

    2015-12-01

    Botulinum neurotoxins (BoNTs) cause the disease botulism manifested by flaccid paralysis that could be fatal to humans and animals. Oral ingestion of the toxin with contaminated food is one of the most common routes for botulism. BoNT assembles with several auxiliary proteins to survive in the gastrointestinal tract and is subsequently transported through the intestinal epithelium into the general circulation. Several hemagglutinin proteins form a multi-protein complex (HA complex) that recognizes host glycans on the intestinal epithelial cell surface to facilitate BoNT absorption. Blocking carbohydrate binding to the HA complex could significantly inhibit the oral toxicity of BoNT. Here, we identify lactulose, a galactose-containing non-digestible sugar commonly used to treat constipation, as a prototype inhibitor against oral BoNT/A intoxication. As revealed by a crystal structure, lactulose binds to the HA complex at the same site where the host galactose-containing carbohydrate receptors bind. In vitro assays using intestinal Caco-2 cells demonstrated that lactulose inhibits HA from compromising the integrity of the epithelial cell monolayers and blocks the internalization of HA. Furthermore, co-administration of lactulose significantly protected mice against BoNT/A oral intoxication in vivo. Taken together, these data encourage the development of carbohydrate receptor mimics as a therapeutic intervention to prevent BoNT oral intoxication.

  13. Hepatic Bel-7402 Cell Proliferation on Different Phospholipid Surfaces

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Phospholipids are believed to be important biomaterials.However, limited information is available on their cytocompatibilities.The objective of this study is to evaluate the effects of different phospholipids on the proliferation of hepatic Bel-7402 cells by comparing the adhesion, viability and proliferation of Bel-7402 cells cultured on different phospholipid surfaces.The cell adhesion, determined by counting the number of adhered cells to the surface, indicated that the cell adhesion was enhanced on charged phospolipid membranes.The cell viability evaluated by MTT[3 (4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium-bromide] showed that cells cultured on charged phospholipids have greater viability than those cultured on the control, while cells cultured on neutral phospholipids showed lower viability.The cell cycle analysis using flow cytometry demonstrated that S phase entry increased on charged phospholipids, while S phase entry decreased on neutral phospholipids.The results suggested that charged phospholipids, especially positively charged phospholipids, show better cytocompatibilities than neutral phospholipids to hepatic Bel-7402 cell.

  14. Candidate gene analysis of the human natural killer-1 carbohydrate pathway and perineuronal nets in schizophrenia: B3GAT2 is associated with disease risk and cortical surface area

    DEFF Research Database (Denmark)

    Kähler, Anna K; Djurovic, Srdjan; Rimol, Lars M

    2011-01-01

    The Human Natural Killer-1 carbohydrate (HNK-1) is involved in neurodevelopment and synaptic plasticity. Extracellular matrix structures called perineuronal nets, condensed around subsets of neurons and proximal dendrites during brain maturation, regulate synaptic transmission and plasticity....

  15. Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells

    Directory of Open Access Journals (Sweden)

    Jimin Xiong

    2016-01-01

    Full Text Available The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein “spots” were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population.

  16. Neutralization epitopes on HIV pseudotyped with HTLV-I: Conservation of carbohydrate Epitopes

    DEFF Research Database (Denmark)

    Sørensen, A M; Nielsen, C; Arendrup, M

    1994-01-01

    for pseudotypes to escape neutralization by the immune system in vivo. Previous reports have suggested that carbohydrate structures may be conserved neutralization epitopes on retroviruses. In this study, the neutralizing capacity of lectins and anti-carbohydrate monoclonal antibodies was found to block infection...... by cell-free pseudotypes in CD4-negative cells. We suggest that although viral cofactors might expand the tropism of HIV in vivo, HIV and HTLV-I seem to induce common carbohydrate neutralization epitopes....

  17. In vitro behaviour of endothelial cells on a titanium surface

    Directory of Open Access Journals (Sweden)

    Oliveira-Filho Ricardo

    2008-07-01

    Full Text Available Abstract Background Endothelial cells play an important role in the delivery of cells to the inflammation site, chemotaxis, cell adhesion and extravasation. Implantation of a foreign material into the human body determines inflammatory and repair reactions, involving different cell types with a plethora of released chemical mediators. The evaluation of the interaction of endothelial cells and implanted materials must take into account other parameters in addition to the analysis of maintenance of cell viability. Methods In the present investigation, we examined the behavior of human umbilical vein endothelial cells (HUVECs harvested on titanium (Ti, using histological and immunohistochemical methods. The cells, after two passages, were seeded in a standard density on commercially plate-shaped titanium pieces, and maintained for 1, 7 or 14 days. Results After 14 days, we could observe a confluent monolayer of endothelial cells (ECs on the titanium surface. Upon one-day Ti/cell contact the expression of fibronectin was predominantly cytoplasmatic and stronger than on the control surface. It was observed strong and uniform cell expression along the time of α5β1 integrin on the cells in contact with titanium. Conclusion The attachment of ECs on titanium was found to be related to cellular-derived fibronectin and the binding to its specific receptor, the α5β1 integrin. It was observed that titanium effectively serves as a suitable substrate for endothelial cell attachment, growth and proliferation. However, upon a 7-day contact with Ti, the Weibel-Palade bodies appeared to be not fully processed and exhibited an anomalous morphology, with corresponding alterations of PECAM-1 localization.

  18. Cell surface topology creates high Ca2+ signalling microdomains

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Olsen, Lars Folke; Hallett, Maurice B

    2010-01-01

    of a smooth cell surface predicts only moderate localized effects, the more realistic "wrinkled" surface topology predicts that Ca2+ concentrations up to 80 microM can persist within the folds of membranes for significant times. This intra-wrinkle location may account for 5% of the total cell volume. Using...... different geometries of wrinkles, our simulations show that high Ca2+ microdomains will be generated most effectively by long narrow membrane wrinkles of similar dimensions to those found experimentally. This is a new concept which has not previously been considered, but which has ramifications as the intra-wrinkle...

  19. Carbohydrate plasma expanders for passive tumor targeting

    DEFF Research Database (Denmark)

    Hoffmann, Stefan; Caysa, Henrike; Kuntsche, Judith

    2013-01-01

    The objective of this study was to investigate the suitability of carbohydrate plasma volume expanders as a novel polymer platform for tumor targeting. Many synthetic polymers have already been synthesized for targeted tumor therapy, but potential advantages of these carbohydrates include...... inexpensive synthesis, constant availability, a good safety profile, biodegradability and the long clinical use as plasma expanders. Three polymers have been tested for cytotoxicity and cytokine activation in cell cultures and conjugated with a near-infrared fluorescent dye: hydroxyethyl starches (HES 200 k......Da and HES 450 kDa) and dextran (DEX 500 kDa). Particle size and molecular weight distribution were determined by asymmetric flow field-flow fractionation (AF4). The biodistribution was investigated non-invasively in nude mice using multispectral optical imaging. The most promising polymer conjugate...

  20. Fabrication of cell container arrays with overlaid surface topographies.

    Science.gov (United States)

    Truckenmüller, Roman; Giselbrecht, Stefan; Escalante-Marun, Maryana; Groenendijk, Max; Papenburg, Bernke; Rivron, Nicolas; Unadkat, Hemant; Saile, Volker; Subramaniam, Vinod; van den Berg, Albert; van Blitterswijk, Clemens; Wessling, Matthias; de Boer, Jan; Stamatialis, Dimitrios

    2012-02-01

    This paper presents cell culture substrates in the form of microcontainer arrays with overlaid surface topographies, and a technology for their fabrication. The new fabrication technology is based on microscale thermoforming of thin polymer films whose surfaces are topographically prepatterned on a micro- or nanoscale. For microthermoforming, we apply a new process on the basis of temporary back moulding of polymer films and use the novel concept of a perforated-sheet-like mould. Thermal micro- or nanoimprinting is applied for prepatterning. The novel cell container arrays are fabricated from polylactic acid (PLA) films. The thin-walled microcontainer structures have the shape of a spherical calotte merging into a hexagonal shape at their upper circumferential edges. In the arrays, the cell containers are arranged densely packed in honeycomb fashion. The inner surfaces of the highly curved container walls are provided with various topographical micro- and nanopatterns. For a first validation of the microcontainer arrays as in vitro cell culture substrates, C2C12 mouse premyoblasts are cultured in containers with microgrooved surfaces and shown to align along the grooves in the three-dimensional film substrates. In future stem-cell-biological and tissue engineering applications, microcontainers fabricated using the proposed technology may act as geometrically defined artificial microenvironments or niches.

  1. 3D surface topology guides stem cell adhesion and differentiation.

    Science.gov (United States)

    Viswanathan, Priyalakshmi; Ondeck, Matthew G; Chirasatitsin, Somyot; Ngamkham, Kamolchanok; Reilly, Gwendolen C; Engler, Adam J; Battaglia, Giuseppe

    2015-06-01

    Polymerized high internal phase emulsion (polyHIPE) foams are extremely versatile materials for investigating cell-substrate interactions in vitro. Foam morphologies can be controlled by polymerization conditions to result in either open or closed pore structures with different levels of connectivity, consequently enabling the comparison between 2D and 3D matrices using the same substrate with identical surface chemistry conditions. Additionally, here we achieve the control of pore surface topology (i.e. how different ligands are clustered together) using amphiphilic block copolymers as emulsion stabilizers. We demonstrate that adhesion of human mesenchymal progenitor (hES-MP) cells cultured on polyHIPE foams is dependent on foam surface topology and chemistry but is independent of porosity and interconnectivity. We also demonstrate that the interconnectivity, architecture and surface topology of the foams has an effect on the osteogenic differentiation potential of hES-MP cells. Together these data demonstrate that the adhesive heterogeneity of a 3D scaffold could regulate not only mesenchymal stem cell attachment but also cell behavior in the absence of soluble growth factors.

  2. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle; Andresen, Lars; Hansen, Karen Aagaard

    2009-01-01

    We show that inhibition of HDAC activity leads to surface expression of Hsp70 on various hematopoietic cancer cells, an occurance that was not observed on naïve or activated peripheral blood cells. HDAC inhibitor-mediated Hsp70 surface expression was confined to the apoptotic Annexin V...... activity selectively induces surface expression of Hsp70 on hematopoietic cancer cells and that this may increase immunorecognition of these cells.......-positive cells and blocked by inhibition of apoptosis. Other chemotherapeutic inducers of apoptosis such as etoposide and camptothecin also led to a robust induction of Hsp70 surface expression. Hsp70 expression was, however, not caused by induction of apoptosis per se, as activated CD4 T cells remained Hsp70...

  3. Renewable Hydrogen Carrier — Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

    Directory of Open Access Journals (Sweden)

    Y.-H. Percival Zhang

    2011-01-01

    Full Text Available The hydrogen economy presents an appealing energy future but its implementation must solve numerous problems ranging from low-cost sustainable production, high-density storage, costly infrastructure, to eliminating safety concern. The use of renewable carbohydrate as a high-density hydrogen carrier and energy source for hydrogen production is possible due to emerging cell-free synthetic biology technology—cell-free synthetic pathway biotransformation (SyPaB. Assembly of numerous enzymes and co-enzymes in vitro can create complicated set of biological reactions or pathways that microorganisms or catalysts cannot complete, for example, C6H10O5 (aq + 7 H2O (l à 12 H2 (g + 6 CO2 (g (PLoS One 2007, 2:e456. Thanks to 100% selectivity of enzymes, modest reaction conditions, and high-purity of generated hydrogen, carbohydrate is a promising hydrogen carrier for end users. Gravimetric density of carbohydrate is 14.8 H2 mass% if water can be recycled from proton exchange membrane fuel cells or 8.33% H2 mass% without water recycling. Renewable carbohydrate can be isolated from plant biomass or would be produced from a combination of solar electricity/hydrogen and carbon dioxide fixation mediated by high-efficiency artificial photosynthesis mediated by SyPaB. The construction of this carbon-neutral carbohydrate economy would address numerous sustainability challenges, such as electricity and hydrogen storage, CO2 fixation and long-term storage, water conservation, transportation fuel production, plus feed and food production.

  4. Decarbonylation and dehydrogenation of carbohydrates

    Science.gov (United States)

    Andrews, Mark A.; Klaeren, Stephen A.

    1991-01-01

    Carbohydrates, especially aldose or ketose sugars, including those whose carbonyl group is masked by hemi-acetal or hemi-ketal formation, are decarbonylated by heating the feed carbohydrate together with a transition metal complex in a suitable solvent. Also, primary alcohols, including sugar alditols are simultaneously dehydrogenated and decarbonylated by heating a mixture of rhodium and ruthenium complexes and the alcohol and optionally a hydrogen acceptor in an acceptable solvent. Such defarbonylation and/or dehydrogenation of sugars provides a convenient procedure for the synthesis of certain carbohydrates and may provide a means for the conversion of biomass into useful products.

  5. Monoclonal antibody to human endothelial cell surface internalization and liposome delivery in cell culture.

    Science.gov (United States)

    Trubetskaya, O V; Trubetskoy, V S; Domogatsky, S P; Rudin, A V; Popov, N V; Danilov, S M; Nikolayeva, M N; Klibanov, A L; Torchilin, V P

    1988-02-01

    A monoclonal antibody (mAb), E25, is described that binds to the surface of cultured human endothelial cells. Upon binding E25 is rapidly internalized and digested intracellularly. Selective liposome targeting to the surface of the cells is performed using a biotinylated E25 antibody and an avidin-biotin system. Up to 30% of the cell-adherent liposomal lipid is internalized.

  6. Optimization of algae carbohydrate compound additives for cyroprotectant on response surface methodology%响应面法优化无磷复合抗冻剂研究

    Institute of Scientific and Technical Information of China (English)

    马路凯; 张宾; 王晓玲; 邓尚贵; 谢超; 朱冬丽

    2015-01-01

    Objective To evaluate the effects of antifreeze and water-holding capacity of trehalose, alginate oligosaccharides, sodium lactate and sodium citrateon the water retention and frost resistance of shrimp. Methods Shrimp (Litopenaeus vannamei)were beheaded and peeled, but not deveined. The peeled shrimp were immediately submerged in the different prepared solutions, then the solutions were wiped onto the surface, and weighted then immersion weight gain rate. Subsequently, these shrimp were frozen in a freezer at-18 ℃ for 4 d, before analysis, and frozen samples were thawed for 3 h in a refrigerator (4 ℃). The thawing loss of frozen shrimp was tested immediately after thawing. Experimental factors and their levels were determined by one-factor tests. Whereafter, the Box-Behnken experimental designed with 4 factors and 3 levels was performed, and the factors influencing the immersion weight gain rate and defrosting loss rate were estimated by means of regression analysis. Results The optimum scheme of compound additives was obtained, which the trehalose mass concentration was 0.8%, the alginate oligosaccharide mass concentration was 0.8%, the sodium lactate mass concentration was 0.7%, the sodium citrate mass concentration was 1.2%, the immersion weight gain rate was 14.62%, and the defrosting loss rate was 2.41%, which were almost accorded with the predicted data. Conclusion The results indicate that the optimum scheme of compound additives has a better anti-freeze activity, compared with the shrimp treated by distilled water (the immersion weight gain rate is 5.27%, the thawing loss rate is 9.05%). The study can lay the foundation for developing a kind of safe, natural and harmless non-phosphate additives for frozen shrimp.%目的:研究无磷复合抗冻剂海藻糖、海藻胶寡糖、乳酸钠及柠檬酸钠等对南美白对虾虾仁保水和抗冻性能的影响。方法将南美白对虾虾仁浸泡在不同溶液中,取出擦干

  7. Is the carbohydrate sialosyl-Tn a marker for altered, non-malignant activity in squamous epithelium in the head and neck region?

    DEFF Research Database (Denmark)

    Bryne, M; Gravdahl, C; Koppang, H S

    1995-01-01

    Cell surface carbohydrates are involved in many cell functions such as cellular differentiation, adhesion, and invasion. A carbohydrate, sialosyl-Tn (STn), is expressed in many human carcinomas but generally not in normal epithelia. In the oral mucosa, however, STn has recently been observed...... on basal cells in some lesions with epithelial hyperplasia and dysplasia. The aim of this study was to carry out a systematic investigation of STn expression on epithelial basal cells in hyperplastic, 'borderline' malignant, and malignant head and neck lesions, to see if the expression of STn is associated...... specifically with hyperplastic conditions. Using the primary monoclonal antibody TKH2, normal controls did not reveal STn. STn was detected on probably post-mitotic basal cells in hyperplastic head and neck lesions and on basal cells adjacent to cancers, but not within the carcinomas. A Ki67 antibody reacted...

  8. Cell surface activation of progelatinase A (proMMP—2) and cell migration

    Institute of Scientific and Technical Information of China (English)

    NAGASEHIDEAKI

    1998-01-01

    Gelatinase A (MMP-2) is considered to play a critical role in cell migration and invasion.The proteinase is cerceted from the cell as an inactive zymogen.In vivo it is postulated that activation of progelationase A (proMMP-2) takes place on the cell surface mediated by membrane-type matrix metalloproteinases (MT-MMPs).Recent studies have demonstrated that proMMP-2 is recruited to the cell surface by interacting with tissue inhibitor of metalloproteinases-2 (TIMP-2) bound to MT1-MMP by forming a ternary complex.Free MT1-MMP closely located to the ternary complex then activates proMMP-2 on the cell surface.MT1-MMP is found in cultured invasive cancer cells at the invadopodia.The MT-MMP/TIMP-2/MMP-2 system thus provides localized expression of proteolysis of the extracellular matrix required for cell migration.

  9. Functional dissection of the Clostridium botulinum type B hemagglutinin complex: identification of the carbohydrate and E-cadherin binding sites.

    Directory of Open Access Journals (Sweden)

    Yo Sugawara

    Full Text Available Botulinum neurotoxin (BoNT inhibits neurotransmitter release in motor nerve endings, causing botulism, a condition often resulting from ingestion of the toxin or toxin-producing bacteria. BoNTs are always produced as large protein complexes by associating with a non-toxic protein, non-toxic non-hemagglutinin (NTNH, and some toxin complexes contain another non-toxic protein, hemagglutinin (HA, in addition to NTNH. These accessory proteins are known to increase the oral toxicity of the toxin dramatically. NTNH has a protective role against the harsh conditions in the digestive tract, while HA is considered to facilitate intestinal absorption of the toxin by intestinal binding and disruption of the epithelial barrier. Two specific activities of HA, carbohydrate and E-cadherin binding, appear to be involved in these processes; however, the exact roles of these activities in the pathogenesis of botulism remain unclear. The toxin is conventionally divided into seven serotypes, designated A through G. In this study, we identified the amino acid residues critical for carbohydrate and E-cadherin binding in serotype B HA. We constructed mutants defective in each of these two activities and examined the relationship of these activities using an in vitro intestinal cell culture model. Our results show that the carbohydrate and E-cadherin binding activities are functionally and structurally independent. Carbohydrate binding potentiates the epithelial barrier-disrupting activity by enhancing cell surface binding, while E-cadherin binding is essential for the barrier disruption.

  10. A tyrosine-rich cell surface protein in the diatom Amphora coffeaeformis identified through transcriptome analysis and genetic transformation.

    Directory of Open Access Journals (Sweden)

    Matthias T Buhmann

    Full Text Available Diatoms are single-celled eukaryotic microalgae that are ubiquitously found in almost all aquatic ecosystems, and are characterized by their intricately structured SiO2 (silica-based cell walls. Diatoms with a benthic life style are capable of attaching to any natural or man-made submerged surface, thus contributing substantially to both microbial biofilm communities and economic losses through biofouling. Surface attachment of diatoms is mediated by a carbohydrate- and protein- based glue, yet no protein involved in diatom underwater adhesion has been identified so far. In the present work, we have generated a normalized transcriptome database from the model adhesion diatom Amphora coffeaeformis. Using an unconventional bioinformatics analysis we have identified five proteins that exhibit unique amino acid sequences resembling the amino acid composition of the tyrosine-rich adhesion proteins from mussel footpads. Establishing the first method for the molecular genetic transformation of A. coffeaeformis has enabled investigations into the function of one of these proteins, AC3362, through expression as YFP fusion protein. Biochemical analysis and imaging by fluorescence microscopy revealed that AC3362 is not involved in adhesion, but rather plays a role in biosynthesis and/or structural stability of the cell wall. The methods established in the present study have paved the way for further molecular studies on the mechanisms of underwater adhesion and biological silica formation in the diatom A. coffeaeformis.

  11. Transition metals in carbohydrate chemistry

    DEFF Research Database (Denmark)

    Madsen, Robert

    1997-01-01

    This review describes the application of transition metal mediated reactions in carbohydrate synthesis. The different metal mediated transformations are divided into reaction types and illustrated by various examples on monosaccharide derivatives. Carbon-carbon bond forming reactions are further ...

  12. Using Carbohydrate Interaction Assays to Reveal Novel Binding Sites in Carbohydrate Active Enzymes

    DEFF Research Database (Denmark)

    Cockburn, Darrell; Wilkens, Casper; Dilokpimol, Adiphol

    2016-01-01

    Carbohydrate active enzymes often contain auxiliary binding sites located either on independent domains termed carbohydrate binding modules (CBMs) or as so-called surface binding sites (SBSs) on the catalytic module at a certain distance from the active site. The SBSs are usually critical...... for the activity of their cognate enzyme, though they are not readily detected in the sequence of a protein, but normally require a crystal structure of a complex for their identification. A variety of methods, including affinity electrophoresis (AE), insoluble polysaccharide pulldown (IPP) and surface plasmon...... sites, but also for identifying new ones, even without structural data available. We further verify the chosen assays discriminate between known SBS/CBM containing enzymes and negative controls. Altogether 35 enzymes are screened for the presence of SBSs or CBMs and several novel binding sites...

  13. Multijunction Solar Cells Optimized for the Mars Surface Solar Spectrum

    Science.gov (United States)

    Edmondson, Kenneth M.; Fetzer, Chris; Karam, Nasser H.; Stella, Paul; Mardesich, Nick; Mueller, Robert

    2007-01-01

    This paper gives an update on the performance of the Mars Exploration Rovers (MER) which have been continually performing for more than 3 years beyond their original 90-day missions. The paper also gives the latest results on the optimization of a multijunction solar cell that is optimized to give more power on the surface of Mars.

  14. Cell surface hydrophobicity is conveyed by S-layer proteins - A study in recombinant lactobacilli

    NARCIS (Netherlands)

    Mei, H.C. van der; Belt-Gritter, B. van de; Pouwels, P.H.; Martinez, B.; Busscher, H.J.

    2003-01-01

    Cell surface hydrophobicity is one of the most important factors controlling adhesion of microorganisms to surfaces. In this paper, cell surface properties of lactobacilli and recombinant lactobacilli with and without a surface layer protein (SLP) associated with cell surface hydrophobicity were det

  15. Unleashing Cancer Cells on Surfaces Exposing Motogenic IGDQ Peptides.

    Science.gov (United States)

    Corvaglia, Valentina; Marega, Riccardo; De Leo, Federica; Michiels, Carine; Bonifazi, Davide

    2016-01-20

    Thiolated peptides bearing the Ile-Gly-Asp (IGD) motif, a highly conserved sequence of fibronectin, are used for the preparation of anisotropic self-assembled monolayers (SAM gradients) to study the whole-population migratory behavior of metastatic breast cancer cells (MDA-MB-231 cells). Ile-Gly-Asp-Gln-(IGDQ)-exposing SAMs sustain the adhesion of MDA-MB-231 cells by triggering focal adhesion kinase phosphorylation, similarly to the analogous Gly-Arg-Gly-Asp-(GRGD)-terminating surfaces. However, the biological responses of different cell lines interfaced with the SAM gradients show that only those exposing the IGDQ sequence induce significant migration of MDA-MB-231 cells. In particular, the observed migratory behavior suggests the presence of cell subpopulations associated with a "stationary" or a "migratory" phenotype, the latter determining a considerable cell migration at the sub-cm length scale. These findings are of great importance as they suggest for the first time an active role of biological surfaces exposing the IGD motif in the multicomponent orchestration of cellular signaling involved in the metastatic progression.

  16. Low-carbohydrate diets and prostate cancer: how low is "low enough"?

    Science.gov (United States)

    Masko, Elizabeth M; Thomas, Jean A; Antonelli, Jodi A; Lloyd, Jessica C; Phillips, Tameika E; Poulton, Susan H; Dewhirst, Mark W; Pizzo, Salvatore V; Freedland, Stephen J

    2010-09-01

    Previous studies indicate that carbohydrate intake influences prostate cancer biology, as mice fed a no-carbohydrate ketogenic diet (NCKD) had significantly smaller xenograft tumors and longer survival than mice fed a Western diet. As it is nearly impossible for humans to consume and maintain NCKD, we determined whether diets containing 10% or 20% carbohydrate kcal showed similar tumor growth as NCKD. A total of 150 male severe combined immunodeficient mice were fed a Western diet ad libitum, injected with the human prostate cancer cell line LAPC-4, and then randomized 2 weeks later to one of three arms: NCKD, 10% carbohydrate, or 20% carbohydrate diets. Ten mice not injected were fed an ad libitum low-fat diet (12% fat kcal) serving as the reference in a modified-paired feeding protocol. Mice were sacrificed when tumors reached 1,000 mm(3). Despite consuming extra calories, all mice receiving low-carbohydrate diets were significantly lighter than those receiving a low-fat diet (P Diet did not affect survival (P = 0.34). There were no differences in serum insulin-like growth factor-I or insulin-like growth factor binding protein-3 at sacrifice among the low-carbohydrate arms (P = 0.07 and P = 0.55, respectively). Insulin was significantly lower in the 20% carbohydrate arm (P = 0.03). LAPC-4 xenograft mice fed a low-carbohydrate diet (10-20% carbohydrate kcal) had similar survival as mice consuming NCKD (0% carbohydrate kcal).

  17. Methods To Identify Aptamers against Cell Surface Biomarkers

    Directory of Open Access Journals (Sweden)

    Frédéric Ducongé

    2011-09-01

    Full Text Available Aptamers are nucleic acid-based ligands identified through a process of molecular evolution named SELEX (Systematic Evolution of Ligands by Exponential enrichment. During the last 10-15 years, numerous aptamers have been developed specifically against targets present on or associated with the surface of human cells or infectious pathogens such as viruses, bacteria, fungi or parasites. Several of the aptamers have been described as potent probes, rivalling antibodies, for use in flow cytometry or microscopy. Some have also been used as drugs by inhibiting or activating functions of their targets in a manner similar to neutralizing or agonistic antibodies. Additionally, it is straightforward to conjugate aptamers to other agents without losing their affinity and they have successfully been used in vitro and in vivo to deliver drugs, siRNA, nanoparticles or contrast agents to target cells. Hence, aptamers identified against cell surface biomarkers represent a promising class of ligands. This review presents the different strategies of SELEX that have been developed to identify aptamers for cell surface-associated proteins as well as some of the methods that are used to study their binding on living cells.

  18. Surface modification of hydrophobic polymers for improvement of endothelial cell-surface interactions

    NARCIS (Netherlands)

    Dekker, A.; Reitsma, K.; Beugeling, T.; Bantjes, A.; Feijen, J.; Kirkpatrick, C.J.; Aken, van W.G.

    1992-01-01

    The aim of this study is to improve the interaction of endothelial cells with polymers used in vascular prostheses. Polytetrafluoroethylene (PTFE; Teflon) films were treated by means of nitrogen and oxygen plasmas. Depending on the plasma exposure time, modified PTFE surfaces showed water-contact an

  19. Cell adhesion on Ti surface with controlled roughness

    Energy Technology Data Exchange (ETDEWEB)

    Burgos-Asperilla, L.; Garcia-Alonso, M. C.; Escudero, M. L.; Alonso, C.

    2015-07-01

    In this report, the in situ interaction between Saos-2 osteoblast cells and a smooth Ti surface was examined over time. The adhesion kinetics and mechanisms of cellular proliferation were monitored by quartz crystal microbalance (QCM) and electrochemical impedance spectroscopy (EIS). The rate of Saos-2 attachment on Ti surfaces, obtained from the measurements performed with the QCM, is a first-order reaction, with k=2.10{sup -}3 min{sup -}1. The impedance measurements indicate that in the absence of cells, the Ti resistance diminishes over time (7 days), due to the presence of amino acids and proteins from the culture medium that have been adsorbed, while in the presence of osteoblasts, this decrease is much greater because of the compounds generated by the cells that accelerate the dissolution of Ti. (Author)

  20. "Race for the Surface": Eukaryotic Cells Can Win.

    Science.gov (United States)

    Pham, Vy T H; Truong, Vi Khanh; Orlowska, Anna; Ghanaati, Shahram; Barbeck, Mike; Booms, Patrick; Fulcher, Alex J; Bhadra, Chris M; Buividas, Ričardas; Baulin, Vladimir; Kirkpatrick, C James; Doran, Pauline; Mainwaring, David E; Juodkazis, Saulius; Crawford, Russell J; Ivanova, Elena P

    2016-08-31

    With an aging population and the consequent increasing use of medical implants, managing the possible infections arising from implant surgery remains a global challenge. Here, we demonstrate for the first time that a precise nanotopology provides an effective intervention in bacterial cocolonization enabling the proliferation of eukaryotic cells on a substratum surface, preinfected by both live Gram-negative, Pseudomonas aeruginosa, and Gram-positive, Staphylococcus aureus, pathogenic bacteria. The topology of the model black silicon (bSi) substratum not only favors the proliferation of eukaryotic cells but is biocompatible, not triggering an inflammatory response in the host. The attachment behavior and development of filopodia when COS-7 fibroblast cells are placed in contact with the bSi surface are demonstrated in the dynamic study, which is based on the use of real-time sequential confocal imaging. Bactericidal nanotopology may enhance the prospect for further development of inherently responsive antibacterial nanomaterials for bionic applications such as prosthetics and implants.

  1. Surface manipulation of biomolecules for cell microarray applications.

    Science.gov (United States)

    Hook, Andrew L; Thissen, Helmut; Voelcker, Nicolas H

    2006-10-01

    Many biological events, such as cellular communication, antigen recognition, tissue repair and DNA linear transfer, are intimately associated with biomolecule interactions at the solid-liquid interface. To facilitate the study and use of these biological events for biodevice and biomaterial applications, a sound understanding of how biomolecules behave at interfaces and a concomitant ability to manipulate biomolecules spatially and temporally at surfaces is required. This is particularly true for cell microarray applications, where a range of biological processes must be duly controlled to maximize the efficiency and throughput of these devices. Of particular interest are transfected-cell microarrays (TCMs), which significantly widen the scope of microarray genomic analysis by enabling the high-throughput analysis of gene function within living cells. This article reviews this current research focus, discussing fundamental and applied research into the spatial and temporal surface manipulation of DNA, proteins and other biomolecules and the implications of this work for TCMs.

  2. Carbohydrate drugs: current status and development prospect.

    Science.gov (United States)

    Zhang, Yan; Wang, Fengshan

    2015-04-01

    In recent years, there has been a great effort devoted to the investigation of the roles of carbohydrates in various essential biological processes and the development of carbohydrates to therapeutic drugs. This review summarizes the carbohydrate drugs which have been recorded in several pharmacopoeias, marketed, and under development. A prospect of the future development of carbohydrate drugs is discussed as well.

  3. The role of β2-glycoprotein I (β2GPI) carbohydrate chains in the reactivity of anti-β2GPI antibodies from patients with primary antiphospholipid syndrome and in the activation and differentiation of U937 cells.

    Science.gov (United States)

    Hernández-Ramírez, Diego F; Olivares-Martínez, Elizabeth; Núñez-Álvarez, Carlos A; Chavelas, Eneas A; García-Hernández, Enrique; Gómez-Hernández, Gregoria; Llorente, Luis; Cabral, Antonio R

    2014-10-10

    Several studies have shown that conformational changes of β(2)-glycoprotein I (β(2)GPI) when bound to negatively charged components expose cryptic epitopes and subsequent binding of anti-β(2)GPI from patients with antiphospholipid syndrome (APS). However, the role of the carbohydrate chains of β(2)GPI in this anti-β(2)GPI reactivity is poorly understood. We therefore studied the reactivity and inhibition of anti-β(2)GPI antibodies from APS patients with native, partially glycosylated β(2)GPI (pdβ(2)GPI; without sialic acid) and completely deglycosylated β(2)GPI (cdβ(2)GPI). To determine the potential biologic importance of these glycoforms and their interaction with anti-β(2)GPI in vitro, stimulation assays were performed with the U937 cell line. Circular dichroism (CD) and fluorescence analysis of the three β(2)GPI forms were also studied. We found an increased reactivity of anti-β(2)GPI against pdβ(2)GPI and cdβ(2)GPI compared to native β(2)GPI. Both deglycosylated β(2)GPI isoforms showed higher inhibition of the anti-β(2)GPI reactivity than the native protein in soluble-phase. Likewise, the antibody/β(2)GPI/glycoform complexes increased the synthesis of IL-6, IFNγ and TNFα and the expression of HLA-DR, CD14 and CD11c in U937 cells. CD and fluorescence studies of the glycoforms yielded considerable changes in the fluorescence signals. Our work suggests that the partial or complete removal of the carbohydrate chains uncover cryptic epitopes present in β(2)GPI. The differentiation and increased synthesis of pro-inflammatory cytokines by U937 cells in vitro may have pathogenetic implications.

  4. Proteomics and glycoproteomics of pluripotent stem-cell surface proteins.

    Science.gov (United States)

    Sun, Bingyun

    2015-03-01

    Pluripotent stem cells are a unique cell type with promising potential in regenerative and personalized medicine. Yet the difficulty to understand and coax their seemingly stochastic differentiation and spontaneous self-renewal have largely limited their clinical applications. A call has been made by numerous researchers for a better characterization of surface proteins on these cells, in search of biomarkers that can dictate developmental stages and lineage specifications, and can help formulate mechanistic insight of stem-cell fate choices. In the past two decades, proteomics has gained significant recognition in profiling surface proteins at high throughput. This review will summarize the impact of these studies on stem-cell biology, and discuss the used proteomic techniques. A systematic comparison of all the techniques and their results is also attempted here to help reveal pros, cons, and the complementarity of the existing methods. This awareness should assist in selecting suitable strategies for stem-cell related research, and shed light on technical improvements that can be explored in the future.

  5. Fixation and stabilization of Escherichia coli cells displaying genetically engineered cell surface proteins.

    Science.gov (United States)

    Freeman, A; Abramov, S; Georgiou, G

    1996-12-05

    A large biotechnological potential is inherent in the display of proteins (e.g., enzymes, single-chain antibodies, on the surface of bacterial cells) (Georgiou et al., 1993). Applications such as immobilized whole-cell biocatalysts or cellular adsorbents require cell fixation to prevent disintegration, stabilization of the anchored protein from leakage, denaturation or proteolysis, and total loss of cell viability, preventing medium and potential product contamination with cells. In this article we describe the adaptation of a simple two-stage chemical crosslinking procedure based on "bi-layer encagement" (Tor et al., 1989) for stabilizing Escherichia coli cells expressing an Lpp-OmpA (46-159)-beta-lactamase fusion that displays beta-lactamase on the cell surface. Bilayer crosslinking and coating the bacteria with a polymeric matrix is accomplished by treating the cells first with either glutaraldehyde or polyglutaraldehyde, followed by secondary crosslinking with polyacrylamide hydrazide. These treatments resulted in a 5- to 25-fold reduction of the thermal inactivation rate constant at 55 degrees C of surface anchored beta-lactamase and completely prevented the deterioration of the cells for at least a week of storage at 4 degrees C. The stabilization procedure developed paves the way to scalable biotechnological applications of E. coli displaying surface anchored proteins as whole-cell biocatalysts and adsorbents.

  6. Surface modification of substrates for bacteria and cell culture.

    Science.gov (United States)

    Baede, Tom; Sladek, Raymond; Stoffels, Eva

    2006-10-01

    The plasma needle is a medical device that consists of a tungsten wire placed in a tube through which helium flows. A RF voltage frequency of 13.05 MHz is applied to the wire to produce the plasma. The device has a non-thermal effect and is therefore suited for both organic and inorganic surfaces. It was designed to manipulate tissues, but can also be used to modify the bacterial adhesion properties of material surfaces. The surface modification has a number of applications, most notably cell culture and the preventive treatment of caries. The research consists of two sets of experiments. In the first experiments the effect of the plasma treatment on the wettability was studied by means of contact angle measurements. The wettability quantifies the hydrophilic behavior of a surface. Plasma treatment with the plasma needle significantly increased the wettability of the studied materials. The persistence of the wettability change was also examined. For some materials the effect was only temporary. Bacteria are very particular about the surfaces they adhere to and the wettability of the surface plays an important role in their preference. The next set of experiments dealt with the effect of plasma treatment on bacterial adhesion. This effect was measured by comparing the growth rates of E. coli and S. mutans bacteria that were cultured on both plasma and non-treated surfaces. The effect appears to be species specific.

  7. Surface science studies of model fuel cell electrocatalysts

    Science.gov (United States)

    Marković, N. M.; Ross, P. N.

    2002-04-01

    The purpose of this review is to discuss progress in the understanding of electrocatalytic reactions through the study of model systems with surface spectroscopies. Pure metal single crystals and well-characterized bulk alloys have been used quite successfully as models for real (commercial) electrocatalysts. Given the sheer volume of all work in electrocatalysis that is on fuel cell reactions, we will focus on electrocatalysts for fuel cells. Since Pt is the model fuel cell electrocatalyst, we will focus entirely on studies of pure Pt and Pt bimetallic alloys. The electrode reactions discussed include hydrogen oxidation/evolution, oxygen reduction, and the electrooxidation of carbon monoxide, formic acid, and methanol. Surface spectroscopies emphasized are FTIR, STM/AFM and surface X-ray scattering (SXS). The discussion focuses on the relation between the energetics of adsorption of intermediates and the reaction pathway and kinetics, and how the energetics and kinetics relate to the extrinsic properties of the model system, e.g. surface structure and/or composition. Finally, we conclude by discussing the limitations that are reached by using pure metal single crystals and well-characterized bulk alloys as models for real catalysts, and suggest some directions for developing more realistic systems.

  8. Analysis of cell surface alterations in Legionella pneumophila cells treated with human apolipoprotein E.

    Science.gov (United States)

    Palusinska-Szysz, Marta; Zdybicka-Barabas, Agnieszka; Cytryńska, Małgorzata; Wdowiak-Wróbel, Sylwia; Chmiel, Elżbieta; Gruszecki, Wiesław I

    2015-03-01

    Binding of human apolipoprotein E (apoE) to Legionella pneumophila lipopolysaccharide was analysed at the molecular level by Fourier-transform infrared spectroscopy, thereby providing biophysical evidence for apoE-L. pneumophila lipopolysaccharide interaction. Atomic force microscopy imaging of apoE-exposed L. pneumophila cells revealed alterations in the bacterial cell surface topography and nanomechanical properties in comparison with control bacteria. The changes induced by apoE binding to lipopolysaccharide on the surface of L. pneumophila cells may participate in: (1) impeding the penetration of host cells by the bacteria; (2) suppression of pathogen intracellular growth and eventually; and (3) inhibition of the development of infection.

  9. Stable-isotope-labeled carbohydrates and nucleosides: Synthesis and applications in chemistry and biology

    Energy Technology Data Exchange (ETDEWEB)

    Serianni, A.S. [Univ. of Notre Dame, IN (United States)

    1994-12-01

    Carbohydrates play important roles in many key biochemical processes in living cells. For example, they are metabolized to produce energy, mediate cell-cell recognition, and play an indirect role (as constituents of DNA and RNA) in DNA replication, RNA transcription, and protein synthesis. These roles, and others of comparable biochemical significance, have been studied to varying extends with the use of stable isotopically labeled molecules, usually in conjunction with NMR spectroscopy and/or mass spectrometry. For example, carbohydrate metabolism has been monitored in vitro and in vivo with the use of isotopically labeled compounds. Molecular aspects of cell-cell recognition, mediated by cell-surface glycoproteins and glycolipids, have been probed through NMR studies of isotopically labeled oligosaccharides. More recently, the solution behavior of DNA and RNA has been examined through the use of labeled oligonucleotides. In all of these pursuits, the effort and expense to prepare labeled molecules, both of which can be substantial, are more than offset by the wealth of information derived from these studies. This information often cannot be accessed, or can be accessed only with great difficulty, using natural (unlabeled) compounds.

  10. Recent advance in carbohydrate-based cancer vaccines%肿瘤糖疫苗的研究进展

    Institute of Scientific and Technical Information of China (English)

    霍常鑫; 叶新山

    2012-01-01

    The abnormal glycans expressing on the surface of tumor cells are good targets to develop carbohydrate-based anti-cancer vaccines. However, one of the major problems is that carbohydrate antigens possess weak immunogenicity. This review summarizes the recent efforts to overcome this problem: glycoconjugates produced by coupling the carbohydrate antigens and proper carrier proteins improve their immunogenicity, many glycoconjugates have entered clinical trials; the vaccines become chemically well-defined when coupling the carbohydrate antigens with a T-cell peptide epitope and an immunostimulant to form fully synthetic multi-component glycoconjugate vaccines; the modification of carbohydrate antigens in combination with the technology of metabolic oligosaccharide engineering of tumor cells induces a strong immune response; and the fact that the antibodies elicited against the unnatural carbohydrate antigens can recognize the native carbohydrate antigens on tumor cells provides a new promising strategy for the development of anti-cancer vaccines.%肿瘤细胞表面异常表达的糖抗原为肿瘤糖疫苗的研究提供了合适的靶标,然而由于这些糖抗原的免疫原性较差,这又给糖疫苗的发展带来了很大的困难.本文概述了近年来科学工作者在提高肿瘤糖疫苗的免疫原性方面所做的努力:半合成的肿瘤糖疫苗将糖抗原与蛋白共价连接,已经有很多疫苗进入了临床试验;随后发展的全合成的肿瘤糖疫苗将糖抗原、T细胞表位和内源性佐剂共价连接,使疫苗的结构和组成更加确定;基于细胞代谢糖工程的肿瘤糖疫苗将非天然的糖疫苗与细胞表面代谢糖工程相结合,得到了强烈的免疫应答;某些基于天然糖抗原结构修饰的疫苗产生的抗体也可以与天然糖抗原发生交叉反应,这为肿瘤糖疫苗的发展提供了新的方向.

  11. Surface modified alginate microcapsules for 3D cell culture

    Science.gov (United States)

    Chen, Yi-Wen; Kuo, Chiung Wen; Chueh, Di-Yen; Chen, Peilin

    2016-06-01

    Culture as three dimensional cell aggregates or spheroids can offer an ideal platform for tissue engineering applications and for pharmaceutical screening. Such 3D culture models, however, may suffer from the problems such as immune response and ineffective and cumbersome culture. This paper describes a simple method for producing microcapsules with alginate cores and a thin shell of poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) to encapsulate mouse induced pluripotent stem (miPS) cells, generating a non-fouling surface as an effective immunoisolation barrier. We demonstrated the trapping of the alginate microcapsules in a microwell array for the continuous observation and culture of a large number of encapsulated miPS cells in parallel. miPS cells cultured in the microcapsules survived well and proliferated to form a single cell aggregate. Droplet formation of monodisperse microcapsules with controlled size combined with flow cytometry provided an efficient way to quantitatively analyze the growth of encapsulated cells in a high-throughput manner. The simple and cost-effective coating technique employed to produce the core-shell microcapsules could be used in the emerging field of cell therapy. The microwell array would provide a convenient, user friendly and high-throughput platform for long-term cell culture and monitoring.

  12. Activation of pyrophosphate:fructose-6-phosphate 1-phosphotransferase by fructose 2,6-bisphosphate stimulates conversion of hexose phosphates to triose phosphates but does not influence accumulation of carbohydrates in phosphate-deficient tobacco cells.

    Science.gov (United States)

    Fernie, Alisdair R; Roscher, Albrecht; Ratcliffe, R. George; Kruger, Nicholas J

    2002-02-01

    The aim of this work was to investigate the contribution of fructose 2,6-bisphosphate to the regulation of carbohydrate metabolism under phosphate stress. The study exploited heterotrophic tobacco callus lines expressing a modified mammalian 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase that increased the fructose 2,6-bisphosphate content of the tissue. The phosphate status of two transgenic and one untransformed cell line was perturbed by incubation with 2-deoxyglucose, a phosphate-sequestering agent, and by growth of callus on phosphate-depleted media. 31P-NMR spectroscopy confirmed that both treatments decreased cellular levels of inorganic phosphate and phosphorylated metabolites. Despite large decreases in the amounts of phosphate esters, UDPglucose and adenylates in response to phosphate deficiency, the fructose 2,6-bisphosphate content of each line was unaffected by 2-deoxyglucose and increased during growth on phosphate-limited media. Short-term treatment of callus with 2-deoxyglucose had only minor effects on the carbohydrate status of each line, whereas long-term phosphate deficiency caused an increase in starch and a decrease in soluble sugar content in both transgenic and control lines. There were no consistent differences between the three callus lines in metabolism of [U-14C]glucose in response to incubation with 2-deoxyglucose. In contrast, there was a decrease in partitioning of label into glycolytic products (particularly organic acids) in untransformed callus during growth on phosphate-depleted medium. This decrease was greatly attenuated in the transgenic lines with increased fructose 2,6-bisphosphate content. This suggests that the conversion of hexose phosphates to triose phosphates is constrained under phosphate-deficient conditions, and that this restriction can be relieved by activation of pyrophosphate:fructose-6-phosphate 1-phosphotransferase. However, since the transgenic and control lines did not differ in the extent to which the

  13. Preparation of water-soluble glycoconjugated poly(acrylamide) for NMR analyses of carbohydrate-carbohydrate interactions

    Science.gov (United States)

    Xuan, Trinh Anh; Trung, Phan Nghia; Dinh, Bui Long; Yamaguchi, Takumi; Kato, Koichi

    2014-05-01

    Oligosaccharide chains of glycoconjugates are important biopolymers not only as carriers of information in cell-cell interactions but also as markers of cellular differentiation, aging, and malignant alteration. Molecular interactions where carbohydrates are involved are usually considered as weak interactions, so the study and evaluation of these interactions is still in its infancy. The evidences and studies of carbohydrate-carbohydrate interactions (CCI) will be confirming the importance of this mechanism for specific cell adhesion and communication. Their development will go hand in hand with the development of new and more sensitive techniques to study weak interactions. Recently, synthetic glycopolymers with functions similar to those of such natural carbohydrates and with specific pendant saccharide moieties were used as a solution for enhancement CCI when forming polyvalent interactions. Carbohydrates are ubiquitous components of cell wall membranes and occur as glycolipids, glycoproteins, proteoglycans, and capsular polysaccharides. As such they can participate in forefront intramolecular and intracellular events. Apart from their recognized roles in the physicochemical properties of glycolipids and glycoproteins. In this study, we designed trisaccharide monomers for free radical polymerization. Subsequently, the trisaccharide unit for chemical conjugation was synthesized from galactosamine in good yield. For further NMR analyses of CCI, glycopolymers composed of these sugar derivatives will be provided.

  14. Stable isotope labeling of oligosaccharide cell surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Silks, L.A. III; Martinez, R.A. [and others

    1998-12-31

    The overall goal of this Laboratory Directed Research and Development (LDRD) project was to develop new methods for synthesis of {sup 13}C-labeled oligosaccharides that are required for nuclear magnetic resonance (NMR) studies of their solution conformation. Oligosaccharides are components of the cell`s outer surface and are involved in important processes such as cell-cell recognition and adhesion. Recently, Danishefsky and coworkers at Slone-Kettering Cancer Center developed a method for the solid-phase chemical synthesis of oligosaccharides. The specific goal of this LDRD project was to prepare uniform {sup 13}C-labeled aldohexose precursors required for the solid-phase synthesis of the Lewis blood-group antigenic determinants. We report the synthesis of {sup 13}C-labeled D-glucal, D-galactal and Fucosyl precursors. We have been collaborating with the Danishefsky group on the synthesis of the Lewis oligosaccharides and the NMR analysis of their solution conformation.

  15. Carbohydrate Mimetic Peptides for Pan Anti-Tumor Responses

    Directory of Open Access Journals (Sweden)

    Thomas eKieber-Emmons

    2014-06-01

    Full Text Available Molecular mimicry is fundamental to biology which transcends to many disciplines ranging from immune pathology to drug design. Structural characterization of molecular partners has provided insight into the origins and relative importance of complementarity in mimicry. Chemical complementarity is easy to understand; amino acid sequence similarity between peptides, for example, can lead to cross-reactivity triggering similar reactivity from their cognate receptors. However, conformational complementarity is difficult to decipher. Molecular mimicry of carbohydrates by peptides is often considered one of those. Extensive studies of innate and adaptive immune responses suggests the existence of carbohydrate mimicry, but the structural basis for this mimicry yields confounding details; peptides mimicking carbohydrates in some cases fail to exhibit both chemical and conformational mimicry. Deconvolution of these two types of complementarity in mimicry and its relationship to biological function can nevertheless lead to new therapeutics. Here, we discuss our experience in bringing a tumor-associated carbohydrate mimetic peptide to the clinic. Emphasis is placed on the rationale, the lessons learned from the methodologies to identify mimics, a perspective on the limitations of structural analysis, the biological consequences of mimicking tumor associated carbohydrate antigens and the notion of reverse engineering to develop carbohydrate mimetic peptides in vaccine design strategies to induce responses to pan-glycan antigens expressed on cancer cells.

  16. Brown spider venom toxins interact with cell surface and are endocytosed by rabbit endothelial cells.

    Science.gov (United States)

    Nowatzki, Jenifer; de Sene, Reginaldo Vieira; Paludo, Katia Sabrina; Veiga, Silvio Sanches; Oliver, Constance; Jamur, Maria Célia; Nader, Helena Bonciani; Trindade, Edvaldo S; Franco, Célia Regina C

    2010-09-15

    Bites from the Loxosceles genus (brown spiders) cause severe clinical symptoms, including dermonecrotic injury, hemorrhage, hemolysis, platelet aggregation and renal failure. Histological findings of dermonecrotic lesions in animals exposed to Loxosceles intermedia venom show numerous vascular alterations. Study of the hemorrhagic consequences of the venom in endothelial cells has demonstrated that the degeneration of blood vessels results not only from degradation of the extracellular matrix molecule or massive leukocyte infiltration, but also from a direct and primary activity of the venom on endothelial cells. Exposure of an endothelial cell line in vitro to L. intermedia venom induce morphological alterations, such as cell retraction and disadhesion to the extracellular matrix. The aim of the present study was to investigate the interaction between the venom toxins and the endothelial cell surface and their possible internalization, in order to illuminate the information about the deleterious effect triggered by venom. After treating endothelial cells with venom toxins, we observed that the venom interacts with cell surface. Venom treatment also can cause a reduction of cell surface glycoconjugates. When cells were permeabilized, it was possible to verify that some venom toxins were internalized by the endothelial cells. The venom internalization involves endocytic vesicles and the venom was detected in the lysosomes. However, no damage to lysosomal integrity was observed, suggesting that the cytotoxic effect evoked by L. intermedia venom on endothelial cells is not mediated by venom internalization.

  17. Basic surface properties of Aedes albopictus cells: effect of Mayaro virus infection on electrostatic charge and surface tension.

    Science.gov (United States)

    Mezêncio, J M; Costa e Silva Filho, F; Rebello, M A

    1997-01-01

    Aedes albopictus cells possess a negative cell surface charge of -12.7 mV with an isoelectrophoretic point (IEP) located between pH 3.0 and 4.0. Infection with Mayaro virus rendered the surface of A. albopictus cells less negative reaching a zeta-potential value of -9.7 mV after 100 h of infection. Concomitantly, the IEP of the infected cells were also altered from 3.0-4.0 to 4.0-5.0. Furthermore, the contact angle measurements clearly showed qualitative alterations in the cell surface of infected cells.

  18. Characterization of atrial natriuretic peptide degradation by cell-surface peptidase activity on endothelial cells

    Science.gov (United States)

    Frost, S. J.; Whitson, P. A.

    1993-01-01

    Atrial natriuretic peptide (ANP) is a fluid-regulating peptide hormone that promotes vasorelaxation, natriuresis, and diuresis. The mechanisms for the release of ANP and for its clearance from the circulation play important roles in modulating its biological effects. Recently, we have reported that the cell surface of an endothelial cell line, CPA47, could degrade 125I-ANP in the presence of EDTA. In this study, we have characterized this degradation of 125I-ANP. The kinetics of ANP degradation by the surface of CPA47 cells were first order, with a Km of 320 +/- 60 nM and Vmax of 35 +/- 14 pmol of ANP degraded/10 min/10(5) cells at pH 7.4. ANP is degraded by the surface of CPA47 cells over a broad pH range from 7.0-8.5. Potato carboxypeptidase inhibitor and bestatin inhibited 125I-ANP degradation, suggesting that this degradative activity on the surface of CPA47 cells has exopeptidase characteristics. The selectivity of CPA47 cell-surface degradation of ANP was demonstrated when 125I-ANP degradation was inhibited in the presence of neuropeptide Y and angiotensin I and II but not bradykinin, bombesin, endothelin-1, or substance P. The C-terminal amino acids phe26 and tyr28 were deduced to be important for ANP interaction with the cell-surface peptidase(s) based on comparison of the IC50 of various ANP analogues and other natriuretic peptides for the inhibition of ANP degradation. These data suggest that a newly characterized divalent cation-independent exopeptidase(s) that selectively recognizes ANP and some other vasoactive peptides exists on the surface of endothelial cells.

  19. Gender Differences in Carbohydrate Metabolism and Carbohydrate Loading

    Directory of Open Access Journals (Sweden)

    Willoughby Darryn

    2006-06-01

    Full Text Available Abstract Prior to endurance competition, many endurance athletes participate in a carbohydrate loading regimen in order to help delay the onset of fatigue. The "classic" regimen generally includes an intense glycogen depleting training period of approximately two days followed by a glycogen loading period for 3–4 days, ingesting approximately 60–70% of total energy intake as carbohydrates, while the newer method does not consist of an intense glycogen depletion protocol. However, recent evidence has indicated that glycogen loading does not occur in the same manner for males and females, thus affecting performance. The scope of this literature review will include a brief description of the role of estradiol in relation to metabolism and gender differences seen in carbohydrate metabolism and loading.

  20. Surface proteome analysis and characterization of surface cell antigen (Sca or autotransporter family of Rickettsia typhi.

    Directory of Open Access Journals (Sweden)

    Khandra T Sears

    Full Text Available Surface proteins of the obligate intracellular bacterium Rickettsia typhi, the agent of murine or endemic typhus fever, comprise an important interface for host-pathogen interactions including adherence, invasion and survival in the host cytoplasm. In this report, we present analyses of the surface exposed proteins of R. typhi based on a suite of predictive algorithms complemented by experimental surface-labeling with thiol-cleavable sulfo-NHS-SS-biotin and identification of labeled peptides by LC MS/MS. Further, we focus on proteins belonging to the surface cell antigen (Sca autotransporter (AT family which are known to be involved in rickettsial infection of mammalian cells. Each species of Rickettsia has a different complement of sca genes in various states; R. typhi, has genes sca1 thru sca5. In silico analyses indicate divergence of the Sca paralogs across the four Rickettsia groups and concur with previous evidence of positive selection. Transcripts for each sca were detected during infection of L929 cells and four of the five Sca proteins were detected in the surface proteome analysis. We observed that each R. typhi Sca protein is expressed during in vitro infections and selected Sca proteins were expressed during in vivo infections. Using biotin-affinity pull down assays, negative staining electron microscopy, and flow cytometry, we demonstrate that the Sca proteins in R. typhi are localized to the surface of the bacteria. All Scas were detected during infection of L929 cells by immunogold electron microscopy. Immunofluorescence assays demonstrate that Scas 1-3 and 5 are expressed in the spleens of infected Sprague-Dawley rats and Scas 3, 4 and 5 are expressed in cat fleas (Ctenocephalides felis. Sca proteins may be crucial in the recognition and invasion of different host cell types. In short, continuous expression of all Scas may ensure that rickettsiae are primed i to infect mammalian cells should the flea bite a host, ii to remain

  1. Bacterial Cell Surface Adsorption of Rare Earth Elements

    Science.gov (United States)

    Jiao, Y.; Park, D.; Reed, D.; Fujita, Y.; Yung, M.; Anderko, A.; Eslamimanesh, A.

    2015-12-01

    Rare earth elements (REE) play a critical role in many emerging clean energy technologies, including high-power magnets, wind turbines, solar panels, hybrid/electric vehicle batteries and lamp phosphors. In order to sustain demand for such technologies given current domestic REE shortages, there is a need to develop new approaches for ore processing/refining and recycling of REE-containing materials. To this end, we have developed a microbially-mediated bioadsorption strategy with application towards enrichment of REE from complex mixtures. Specifically, the bacterium Caulobacter crescentus was genetically engineered to display lanthanide binding tags (LBTs), short peptides that possess high affinity and specificity for rare earth elements, on its cell surface S-layer protein. Under optimal conditions, LBT-displayed cells adsorbed greater than 5-fold more REE than control cells lacking LBTs. Competition binding experiments with a selection of REEs demonstrated that our engineered cells could facilitate separation of light- from heavy- REE. Importantly, binding of REE onto our engineered strains was much more favorable compared to non-REE metals. Finally, REE bound to the cell surface could be stripped off using citrate, providing an effective and non-toxic REE recovery method. Together, this data highlights the potential of our approach for selective REE enrichment from REE containing mixtures.

  2. Nematic twist cell: Strong chirality induced at the surfaces

    Science.gov (United States)

    Lin, Tzu-Chieh; Nemitz, Ian R.; Pendery, Joel S.; Schubert, Christopher P. J.; Lemieux, Robert P.; Rosenblatt, Charles

    2013-04-01

    A nematic twist cell having a thickness gradient was filled with a mixture containing a configurationally achiral liquid crystal (LC) and chiral dopant. A chiral-based linear electrooptic effect was observed on application of an ac electric field. This "electroclinic effect" varied monotonically with d, changing sign at d =d0 where the chiral dopant exactly compensated the imposed twist. The results indicate that a significant chiral electrooptic effect always exists near the surfaces of a twist cell containing molecules that can be conformationally deracemized. Additionally, this approach can be used to measure the helical twisting power (HTP) of a chiral dopant in a liquid crystal.

  3. Active screen plasma nitriding enhances cell attachment to polymer surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kaklamani, Georgia, E-mail: g.kaklamani@bham.ac.uk [University of Birmingham, College of Engineering and Physical Sciences, School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom); Bowen, James; Mehrban, Nazia [University of Birmingham, College of Engineering and Physical Sciences, School of Chemical Engineering, Edgbaston, Birmingham B15 2TT (United Kingdom); Dong, Hanshan [University of Birmingham, College of Engineering and Physical Sciences, School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom); Grover, Liam M. [University of Birmingham, College of Engineering and Physical Sciences, School of Chemical Engineering, Edgbaston, Birmingham B15 2TT (United Kingdom); Stamboulis, Artemis [University of Birmingham, College of Engineering and Physical Sciences, School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2013-05-15

    Active screen plasma nitriding (ASPN) is a well-established technique used for the surface modification of materials, the result of which is often a product with enhanced functional performance. Here we report the modification of the chemical and mechanical properties of ultra-high molecular weight poly(ethylene) (UHMWPE) using 80:20 (v/v) N{sub 2}/H{sub 2} ASPN, followed by growth of 3T3 fibroblasts on the treated and untreated polymer surfaces. ASPN-treated UHMWPE showed extensive fibroblast attachment within 3 h of seeding, whereas fibroblasts did not successfully attach to untreated UHMWPE. Fibroblast-coated surfaces were maintained for up to 28 days, monitoring their metabolic activity and morphology throughout. The chemical properties of the ASPN-treated UHMWPE surface were studied using X-ray photoelectron spectroscopy, revealing the presence of C-N, C=N, and C≡N chemical bonds. The elastic modulus, surface topography, and adhesion properties of the ASPN-treated UHMWPE surface were studied over 28 days during sample storage under ambient conditions and during immersion in two commonly used cell culture media.

  4. Carbohydrates Through Animation: Preliminary Step

    Directory of Open Access Journals (Sweden)

    J.K. Sugai

    2004-05-01

    Full Text Available Methods of education are changing, so the educational tools must change too. The developmentof the systems of information and communication gave the opportunity to bring new technology tothe learning process. Modern education needs interactive programs that may be available to theacademic community, in order to ease the learning process and sharing of the knowledge. Then,an educational software on Carbohydrates is being developed using concept maps and FLASH-MXanimations program, and approached through six modules. The introduction of Carbohydrates wasmade by the module Carbohydrates on Nature, which shows the animations gures of a teacher andstudents, visiting a farm, identifying the carbohydrates found in vegetables, animals, and microor-ganisms, integrated by links containing short texts to help understanding the structure and functionof carbohydrates. This module was presented, as pilot experiment, to teachers and students, whichdemonstrated satisfaction, and high receptivity, by using animation and interactivitys program asstrategy to biochemistrys education. The present work is part of the project Biochemistry throughanimation, which is having continuity.

  5. Recent Insights into Cell Surface Heparan Sulphate Proteoglycans and Cancer

    DEFF Research Database (Denmark)

    Couchman, John R; Multhaupt, Hinke; Sanderson, Ralph D

    2016-01-01

    A small group of cell surface receptors are proteoglycans, possessing a core protein with one or more covalently attached glycosaminoglycan chains. They are virtually ubiquitous and their chains are major sites at which protein ligands of many types interact. These proteoglycans can signal and re...... or fragmented proteoglycans into exosomes that can be paracrine effectors or biomarkers, and lateral interactions between some proteoglycans and calcium channels that impact the actin cytoskeleton....

  6. Recent Insights into Cell Surface Heparan Sulphate Proteoglycans and Cancer

    DEFF Research Database (Denmark)

    Couchman, John R; Multhaupt, Hinke; Sanderson, Ralph D

    2016-01-01

    behaviour. Here, we review some recent advances, emphasising that many tumour-related functions of proteoglycans are revealed only after their modification in processes subsequent to synthesis and export to the cell surface. These include enzymes that modify heparan sulphate structure, recycling of whole...... or fragmented proteoglycans into exosomes that can be paracrine effectors or biomarkers, and lateral interactions between some proteoglycans and calcium channels that impact the actin cytoskeleton....

  7. Live Cell Surface Labeling with Fluorescent Ag Nanocluster Conjugates†

    OpenAIRE

    Yu, Junhua; Choi, Sungmoon; Richards, Chris I.; Antoku, Yasuko; Dickson, Robert M

    2008-01-01

    DNA-encapsulated silver clusters are readily conjugated to proteins and serve as alternatives to organic dyes and semiconductor quantum dots. Stable and bright on the bulk and single molecule levels, Ag nanocluster fluorescence is readily observed when staining live cell surfaces. Being significantly brighter and more photostable than organics and much smaller than quantum dots with a single point of attachment, these nanomaterials offer promising new approaches for bulk and single molecule b...

  8. Ultrasensitive photoelectrochemical immunoassay of antibody against tumor-associated carbohydrate antigen amplified by functionalized graphene derivates and enzymatic biocatalytic precipitation.

    Science.gov (United States)

    Zhang, Xiaoru; Liu, Mingshuai; Mao, Yaning; Xu, Yunpeng; Niu, Shuyan

    2014-09-15

    Tumor-associated carbohydrate antigens (TACAs) are often found on the surface of cancer cells. The determination of the carbohydrate components of glycoconjugates is challenging because of the chemical complexity of glycan chains. Through monitoring corresponding antibody, we can get a good solution for clinical diagnosis. Here breast tumor-associated carbohydrate antigens Tn were used as a model and a new photoelectrochemical biosensor for ultrasensitive detection of antibody against Tn was developed. To enhance the sensitivity, both graphene oxide and graphene were used during the construction of biosensor. Through the formation of immunocomplex and the insoluble biocatalytic precipitation (BCP) product, photocurrent intensity was decreased greatly and the antibody could be detected from 0.5 to 500 pg/mL with a detection limit of 1.0×10(-13) g/mL. At the same time, the developed biosensor showed acceptable selectivity and could be used in the complex matrix. Compared with the traditional glycoarray method, this PEC method is more sensitive (5 orders of magnitude), and thus provides another platform to monitor the immune response to carbohydrate epitopes at different stages during differentiation, metastasis, or treatment.

  9. The Mesenchymal Precursor Cell Marker Antibody STRO-1 Binds to Cell Surface Heat Shock Cognate 70.

    Science.gov (United States)

    Fitter, Stephen; Gronthos, Stan; Ooi, Soo Siang; Zannettino, Andrew C W

    2016-12-27

    Since its discovery more than 25 years ago, the STRO-1 antibody has played a fundamental role in defining the hierarchical nature of mesenchymal precursor cells (MPC) and their progeny. STRO-1 antibody binding remains a hallmark of immature pluripotent MPC. Despite the significance of STRO-1 in the MPC field, the identity of the antigen has remained elusive. Using a combination of two-dimensional gel electrophoresis, coupled with Western blotting and Tandem mass spectroscopy, we have identified the STRO-1 antigen as heat shock cognate 70 (HSC70;HSPA8). STRO-1 binds to immune-precipitated HSC70 and siRNA-mediated knock down of HSPA8 reduced STRO-1 binding. STRO-1 surface binding does not correlate with HSC70 expression and sequestration of cholesterol reduces STRO-1 surface binding, suggesting that the plasma membrane lipid composition may be an important determinant in the presentation of HSC70 on the cell surface. HSC70 is present on the surface of STRO-1(+) but not STRO-1(-) cell lines as assessed by cell surface biotinylation and recombinant HSC70 blocks STRO-1 binding to the cell surface. The STRO-1 epitope on HSC70 was mapped to the ATPase domain using a series of deletion mutants in combination with peptide arrays. Deletion of the first four amino acids of the consensus epitope negated STRO-1 binding. Notably, in addition to HSC70, STRO-1 cross-reacts with heat shock protein 70 (HSP70), however all the clonogenic cell activity is restricted to the STRO-1(BRIGHT) /HSP70(-) fraction. These results provide important insight into the properties that define multipotent MPC and provide the impetus to explore the role of cell surface HSC70 in MPC biology. Stem Cells 2016.

  10. Simulation and Optimization of Silicon Solar Cell Back Surface Field

    Directory of Open Access Journals (Sweden)

    Souad TOBBECHE

    2015-11-01

    Full Text Available In this paper, TCAD Silvaco (Technology Computer Aided Design software has been used to study the Back Surface Field (BSF effect of a p+ silicon layer for a n+pp+ silicon solar cell. To study this effect, the J-V characteristics and the external quantum efficiency (EQE are simulated under AM 1.5 illumination for two types of cells. The first solar cell is without BSF (n+p structure while the second one is with BSF (n+pp+ structure. The creation of the BSF on the rear face of the cell results in efficiency h of up to 16.06% with a short-circuit current density Jsc = 30.54 mA/cm2, an open-circuit voltage Voc = 0.631 V, a fill factor FF = 0.832 and a clear improvement of the spectral response obtained in the long wavelengths range. An electric field and a barrier of potential are created by the BSF and located at the junction p+/p with a maximum of 5800 V/cm and 0.15 V, respectively. The optimization of the BSF layer shows that the cell performance improves with the p+ thickness between 0.35 – 0.39 µm, the p+ doping dose is about 2 × 1014 cm-2, the maximum efficiency up to 16.19 %. The cell efficiency is more sensitive to the value of the back surface recombination velocity above a value of 103 cm/s in n+p than n+pp+ solar cell.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9565

  11. Structure of a bacterial cell surface decaheme electron conduit.

    Science.gov (United States)

    Clarke, Thomas A; Edwards, Marcus J; Gates, Andrew J; Hall, Andrea; White, Gaye F; Bradley, Justin; Reardon, Catherine L; Shi, Liang; Beliaev, Alexander S; Marshall, Matthew J; Wang, Zheming; Watmough, Nicholas J; Fredrickson, James K; Zachara, John M; Butt, Julea N; Richardson, David J

    2011-06-07

    Some bacterial species are able to utilize extracellular mineral forms of iron and manganese as respiratory electron acceptors. In Shewanella oneidensis this involves decaheme cytochromes that are located on the bacterial cell surface at the termini of trans-outer-membrane electron transfer conduits. The cell surface cytochromes can potentially play multiple roles in mediating electron transfer directly to insoluble electron sinks, catalyzing electron exchange with flavin electron shuttles or participating in extracellular intercytochrome electron exchange along "nanowire" appendages. We present a 3.2-Å crystal structure of one of these decaheme cytochromes, MtrF, that allows the spatial organization of the 10 hemes to be visualized for the first time. The hemes are organized across four domains in a unique crossed conformation, in which a staggered 65-Å octaheme chain transects the length of the protein and is bisected by a planar 45-Å tetraheme chain that connects two extended Greek key split β-barrel domains. The structure provides molecular insight into how reduction of insoluble substrate (e.g., minerals), soluble substrates (e.g., flavins), and cytochrome redox partners might be possible in tandem at different termini of a trifurcated electron transport chain on the cell surface.

  12. Extraction of cell surface-associated proteins from living yeast cells.

    NARCIS (Netherlands)

    F.M. Klis; M. de Jong; S. Brul; P.W.J. de Groot

    2007-01-01

    To extract cell surface-associated proteins from living fungal cells, reducing agents such as beta-mercaptoethanol and dithiothreitol are often used. We show here that both compounds are moderately lipophilic and may perturb the plasma membrane, thus causing the release of cytosolic proteins, especi

  13. Cell surface heparan sulfate proteoglycans control adhesion and invasion of breast carcinoma cells

    DEFF Research Database (Denmark)

    Lim, Hooi Ching; Multhaupt, Hinke A. B.; Couchman, John R.

    2015-01-01

    phenotype of mammary carcinoma cells. Finally, both syndecan-2 and caveolin-2 were upregulated in tissue arrays from breast cancer patients compared to normal mammary tissue. Moreover their expression levels were correlated in triple negative breast cancers. Conclusion: Cell surface proteoglycans, notably...

  14. A Simple Hydrophilic Treatment of SU-8 Surfaces for Cell Culturing and Cell Patterning

    DEFF Research Database (Denmark)

    Wang, Zhenyu; Stangegaard, Michael; Dufva, Hans Martin;

    2005-01-01

    SU-8, an epoxy-based photoresist, widely used in constitution different mTAS systems, is incompatible with mammalian cell adhesion and culture in its native form. Here, we demonstrate a simple, cheap and robust two-step method to render a SU-8 surface hydrophilic and compatible with cell culture...

  15. Cell surface alpha 2,6 sialylation affects adhesion of breast carcinoma cells.

    Science.gov (United States)

    Lin, Shaoqiang; Kemmner, Wolfgang; Grigull, Sabine; Schlag, Peter M

    2002-05-15

    Tumor-associated alterations of cell surface glycosylation play a crucial role in the adhesion and metastasis of carcinoma cells. The aim of this study was to examine the effect of alpha 2,6-sialylation on the adhesion properties of breast carcinoma cells. To this end mammary carcinoma cells, MDA-MB-435, were sense-transfected with sialyltransferase ST6Gal-I cDNA or antisense-transfected with a part of the ST6Gal-I sequence. Sense transfectants showed an enhanced ST6Gal-I mRNA expression and enzyme activity and an increased binding of the lectin Sambucus nigra agglutinin (SNA), specific for alpha 2,6-linked sialic acid. Transfection with ST6Gal-I in the antisense direction resulted in less enzyme activity and SNA reactivity. A sense-transfected clone carrying increased amounts of alpha 2,6-linked sialic acid adhered preferentially to collagen IV and showed reduced cell-cell adhesion and enhanced invasion capacity. In contrast, antisense transfection led to less collagen IV adhesion but enhanced homotypic cell-cell adhesion. In another approach, inhibition of ST6Gal-I enzyme activity by application of soluble antisense-oligodeoxynucleotides was studied. Antisense treatment resulted in reduced ST6 mRNA expression and cell surface 2,6-sialylation and significantly decreased collagen IV adhesion. Our results suggest that cell surface alpha 2,6-sialylation contributes to cell-cell and cell-extracellular matrix adhesion of tumor cells. Inhibition of sialytransferase ST6Gal-I by antisense-oligodeoxynucleotides might be a way to reduce the metastatic capacity of carcinoma cells.

  16. Characterization and use of crystalline bacterial cell surface layers

    Science.gov (United States)

    Sleytr, Uwe B.; Sára, Margit; Pum, Dietmar; Schuster, Bernhard

    2001-10-01

    Crystalline bacterial cell surface layers (S-layers) are one of the most common outermost cell envelope components of prokaryotic organisms (archaea and bacteria). S-layers are monomolecular arrays composed of a single protein or glycoprotein species and represent the simplest biological membranes developed during evolution. S-layers as the most abundant of prokaryotic cellular proteins are appealing model systems for studying the structure, synthesis, genetics, assembly and function of proteinaceous supramolecular structures. The wealth of information existing on the general principle of S-layers have revealed a broad application potential. The most relevant features exploited in applied S-layer research are: (i) pores passing through S-layers show identical size and morphology and are in the range of ultrafiltration membranes; (ii) functional groups on the surface and in the pores are aligned in well-defined positions and orientations and accessible for chemical modifications and binding functional molecules in very precise fashion; (iii) isolated S-layer subunits from a variety of organisms are capable of recrystallizing as closed monolayers onto solid supports (e.g., metals, polymers, silicon wafers) at the air-water interface, on lipid films or onto the surface of liposomes; (iv) functional domains can be incorporated in S-layer proteins by genetic engineering. Thus, S-layer technologies particularly provide new approaches for biotechnology, biomimetics, molecular nanotechnology, nanopatterning of surfaces and formation of ordered arrays of metal clusters or nanoparticles as required for nanoelectronics.

  17. Carbohydrate Microarrays Identify Blood Group Precursor Cryptic Epitopes as Potential Immunological Targets of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Denong Wang

    2015-01-01

    Full Text Available Using carbohydrate microarrays, we explored potential natural ligands of antitumor monoclonal antibody HAE3. This antibody was raised against a murine mammary tumor antigen but was found to cross-react with a number of human epithelial tumors in tissues. Our carbohydrate microarray analysis reveals that HAE3 is specific for an O-glycan cryptic epitope that is normally hidden in the cores of blood group substances. Using HAE3 to screen tumor cell surface markers by flow cytometry, we found that the HAE3 glycoepitope, gpHAE3, was highly expressed by a number of human breast cancer cell lines, including some triple-negative cancers that lack the estrogen, progesterone, and Her2/neu receptors. Taken together, we demonstrate that HAE3 recognizes a conserved cryptic glycoepitope of blood group precursors, which is nevertheless selectively expressed and surface-exposed in certain breast tumor cells. The potential of this class of O-glycan cryptic antigens in breast cancer subtyping and targeted immunotherapy warrants further investigation.

  18. The center for plant and microbial complex carbohydrates at the University of Georgia Complex Carbohydrate Research Center

    Energy Technology Data Exchange (ETDEWEB)

    Albersheim, P.; Darvill, A.

    1991-08-01

    Research from the Complex Carbohydrates Research Center at the University of Georgia is presented. Topics include: Structural determination of soybean isoflavones which specifically induce Bradyrhizobium japonicum nodD1 but not the nodYABCSUIJ operon; structural analysis of the lipopolysaccharides (LPSs) from symbiotic mutants of Bradyrhizobium japonicum; structural characterization of lipooligosaccharides from Bradyrhizobium japonicum that are required for the specific nodulation of soybean; structural characterization of the LPSs from R. Leguminosarum biovar phaseoli, the symbiont of bean; characterization of bacteroid-specific LPS epitopes in R. leguminosarum biovar viciae; analysis of the surface polysaccharides of Rhizobium meliloti mutants whose lipopolysaccharides and extracellular polysaccharides can have the same function in symbiosis; characterization of a polysaccharide produced by certain Bradyrhizobium japonicum strains within soybean nodules; structural analysis of a streptococcal adhesin polysaccharide receptor; conformational studies of xyloglucan, the role of the fucosylated side chain in surface-specific cellulose-xyloglucan interactions; the structure of an acylated glucosamine oligosaccharide signal molecule (nod factor) involved in the symbiosis of Rhizobium leguminosarum biovar viciae with its host Vicia sativa; investigating membrane responses induced by oligogalacturonides in cultured cells; the polygalacturonase inhibitor protein; characterization of the self-incompatability glycoproteins from Petunia hybrida; investigation of the cell wall polysaccharide structures of Arabidopsis thaliana; and the glucan inhibition of virus infection of tabacco.

  19. Advances in the theory and application of BSF cells. [Back Surface Field solar cells

    Science.gov (United States)

    Mandelkorn, J.; Lamneck, J. H.

    1975-01-01

    A study to determine the influence of fabrication processes and bulk material properties on the behavior of back surface field (BSF) cells is reported. It is concluded that a photovoltage is generated at the p(+), p back junction of the cell. The concept of majority carrier collection is proposed as a possible mechanism for this generation. Advantages accruing to the advent of BSF cells are outlined.

  20. Characteristic Changes in Cell Surface Glycosylation Accompany Intestinal Epithelial Cell (IEC) Differentiation: High Mannose Structures Dominate the Cell Surface Glycome of Undifferentiated Enterocytes.

    Science.gov (United States)

    Park, Dayoung; Brune, Kristin A; Mitra, Anupam; Marusina, Alina I; Maverakis, Emanual; Lebrilla, Carlito B

    2015-11-01

    Changes in cell surface glycosylation occur during the development and differentiation of cells and have been widely correlated with the progression of several diseases. Because of their structural diversity and sensitivity to intra- and extracellular conditions, glycans are an indispensable tool for analyzing cellular transformations. Glycans present on the surface of intestinal epithelial cells (IEC) mediate interactions with billions of native microorganisms, which continuously populate the mammalian gut. A distinct feature of IECs is that they differentiate as they migrate upwards from the crypt base to the villus tip. In this study, nano-LC/ESI QTOF MS profiling was used to characterize the changes in glycosylation that correspond to Caco-2 cell differentiation. As Caco-2 cells differentiate to form a brush border membrane, a decrease in high mannose type glycans and a concurrent increase in fucosylated and sialylated complex/hybrid type glycans were observed. At day 21, when cells appear to be completely differentiated, remodeling of the cell surface glycome ceases. Differential expression of glycans during IEC maturation appears to play a key functional role in regulating the membrane-associated hydrolases and contributes to the mucosal surface innate defense mechanisms. Developing methodologies to rapidly identify changes in IEC surface glycans may lead to a rapid screening approach for a variety of disease states affecting the GI tract.

  1. Fixation and stabilization of Escherichia coli cells displaying genetically engineered cell surface proteins

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, A.; Abramov, S. [Tel-Aviv Univ. (Israel); Georgiou, G. [Univ. of Texas, Austin, TX (United States). Dept. of Chemical Engineering

    1996-12-05

    A large biotechnological potential is inherent in the display of proteins. Applications such as immobilized whole-cell biocatalysts or cellular adsorbents require cell fixation to prevent disintegration, stabilization of the anchored protein from leakage, denaturation or proteolysis, and total loss of cell viability, preventing medium and potential product contamination with cells. In this article the authors describe the adaptation of a simple two-stage chemical crosslinking procedure based on bi-layer encagement for stabilizing Escherichia coli cells expressing an Lpp-OmpA-{beta}-lactamase fusion that displays {beta}-lactamase on the cell surface. Bilayer crosslinking and coating the bacteria with a polymeric matrix is accomplished by treating the cells first with either glutaraldehyde or polyglutaraldehyde, followed by secondary crosslinking with polyacrylamide hydrazide. These treatments resulted in a 5- to 25-fold reduction of the thermal inactivation rate constant at 55 C of surface anchored {beta}-lactamase and completely prevented the deterioration of the cells for at least a week of storage at 4 C. The stabilization procedure developed paves the way to scalable biotechnological applications of E. coli displaying surface anchored proteins as whole-cell biocatalysts and adsorbents.

  2. Challenges with nonfiber carbohydrate methods.

    Science.gov (United States)

    Hall, M B

    2003-12-01

    Nonfiber carbohydrates (NFC) encompass a compositionally and nutritionally diverse group exclusive of those carbohydrates found in NDF. Their content in feeds has often been described as a single value estimated by difference as 100% of dry matter minus the percentages of CP, NDF (adjusted for CP in NDF), ether extract, and ash. A calculated value was used because of difficulties with assays for individual NFC, but it does not differentiate among nutritionally distinct NFC. Errors in NFC estimation can arise from not accounting for CP in NDF and when multipliers other than 6.25 are appropriate to estimate CP. Analyses that begin to distinguish among NFC are those for starch, soluble fiber (non-NDF, nonstarch polysaccharides), and low molecular weight carbohydrates (mono- and oligosaccharides). Many starch analyses quantify alpha-glucans through specific hydrolysis of alpha-(1 --> 4) and alpha-(1 --> 6) linkages in the glucan, and measurement of released glucose. Incomplete gelatinization and hydrolysis will lead to underestimation of starch content. Starch values are inflated by enzyme preparations that hydrolyze carbohydrates other than alpha-glucan, measurement of all released monosaccharides without specificity for glucose, and failure to exclude free glucose present in the unhydrolyzed sample. Soluble fiber analyses err in a fashion similar to NFC if estimation of CP requires multipliers other than 6.25, or if contaminants such as CP and starch have not been properly accounted. Depolymerization and incomplete precipitation can also decrease soluble fiber estimates. The low molecular weight carbohydrates have been defined as carbohydrates soluble in 78 to 80% ethanol, which separates them from polysaccharides. They can be measured in extracts using broad-spectrum colorimetric assays (phenol-sulfuric acid assay or reducing sugar analysis of acid hydrolyzed samples) or chromatographic methods. Limitations of the colorimetric assays include lack of differentiation

  3. RPE cell surface proteins in normal and dystrophic rats

    Energy Technology Data Exchange (ETDEWEB)

    Clark, V.M.; Hall, M.O.

    1986-02-01

    Membrane-bound proteins in plasma membrane enriched fractions from cultured rat RPE were analyzed by two-dimensional gel electrophoresis. Membrane proteins were characterized on three increasingly specific levels. Total protein was visualized by silver staining. A maximum of 102 separate proteins were counted in silver-stained gels. Glycoproteins were labeled with 3H-glucosamine or 3H-fucose and detected by autoradiography. Thirty-eight fucose-labeled and 61-71 glucosamine-labeled proteins were identified. All of the fucose-labeled proteins were labeled with glucosamine-derived radioactivity. Proteins exposed at the cell surface were labeled by lactoperoxidase-catalyzed radioiodination prior to preparation of membranes for two-dimensional analysis. Forty separate 125I-labeled surface proteins were resolved by two-dimensional electrophoresis/autoradiography. Comparison with the glycoprotein map showed that a number of these surface labeled proteins were glycoproteins. Two-dimensional maps of total protein, fucose-labeled, and glucosamine-labeled glycoproteins, and 125I-labeled surface proteins of membranes from dystrophic (RCS rdy-p+) and normal (Long Evans or RCS rdy+p+) RPE were compared. No differences in the total protein or surface-labeled proteins were observed. However, the results suggest that a 183K glycoprotein is more heavily glycosylated with glucosamine and fucose in normal RPE membranes as compared to membranes from dystrophic RPE.

  4. Ovarian carcinoma cells synthesize both chondroitin sulfate and heparan sulfate cell surface proteoglycans that mediate cell adhesion to interstitial matrix.

    Science.gov (United States)

    Kokenyesi, R

    Metastatic ovarian carcinoma metastasizes by intra-peritoneal, non-hematogenous dissemination. The adhesion of the ovarian carcinoma cells to extracellular matrix components, such as types I and III collagen and cellular fibronectin, is essential for intra-peritoneal dissemination. The purpose of this study was to determine whether cell surface proteoglycans (a class of matrix receptors) are produced by ovarian carcinoma cells, and whether these proteoglycans have a role in the adhesion of ovarian carcinoma cells to types I and III collagen and fibronectin. Proteoglycans were metabolically labeled for biochemical studies. Both phosphatidylinositol-anchored and integral membrane-type cell surface proteoglycans were found to be present on the SK-OV-3 and NIH:OVCAR-3 cell lines. Three proteoglycan populations of differing hydrodynamic size were detected in both SK-OV-3 and NIH:OVCAR-3 cells. Digestions with heparitinase and chondroitinase ABC showed that cell surface proteoglycans of SK-OV-3 cells had higher proportion of chondroitin sulfate proteoglycans (75:25 of chondroitin sulfate:heparan sulfate ratio), while NIH:OVCAR-3 cells had higher proportion of heparan sulfate proteoglycans (10:90 of chondroitin sulfate:heparan sulfate ratio). RT-PCR indicated the synthesis of a unique assortment of syndecans, glypicans, and CD44 by the two cell lines. In adhesion assays performed on matrix-coated titer plates both cell lines adhered to types I and III collagen and cellular fibronectin, and cell adhesion was inhibited by preincubation of the matrix with heparin, heparan sulfate, chondroitin sulfate, dermatan sulfate, or chondroitin glycosaminoglycans. Treatment of the cells with heparitinase, chondroitinase ABC, or methylumbelliferyl xyloside also interfered with adhesion confirming the role of both heparan sulfate and chondroitin sulfate cell surface proteoglycans as matrix receptors on ovarian carcinoma cells.

  5. Surface modification for interaction study with bacteria and preosteoblast cells

    Science.gov (United States)

    Song, Qing

    Surface modification plays a pivotal role in bioengineering. Polymer coatings can provide biocompatibility and biofunctionalities to biomaterials through surface modification. In this dissertation, initiated chemical vapor deposition (iCVD) was utilized to coat two-dimensional (2D) and three-dimensional (3D) substrates with differently charged polyelectrolytes in order to generate antimicrobial and osteocompatible biomaterials. ICVD is a modified CVD technique that enables surface modification in an all-dry condition without substrate damage and solvent contamination. The free-radical polymerization allows the vinyl polymers to conformally coat on various micro- and nano-structured substrates and maintains the delicate structure of the functional groups. The vapor deposition of polycations provided antimicrobial activity to planar and porous substrates through destroying the negatively charged bacterial membrane and brought about high contact-killing efficiency (99.99%) against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli. Additionally, the polyampholytes synthesized by iCVD exhibited excellent antifouling performance against the adhesion of Gram-positive Listeria innocua and Gram-negative E. coli in phosphate buffered saline (PBS). Their antifouling activities were attributed to the electrostatic interaction and hydration layers that served as physical and energetic barriers to prevent bacterial adhesion. The contact-killing and antifouling polymers synthesized by iCVD can be applied to surface modification of food processing equipment and medical devices with the aim of reducing foodborne diseases and medical infections. Moreover, the charged polyelectrolyte modified 2D polystyrene surfaces displayed good osteocompatibility and enhanced osteogenesis of preosteoblast cells than the un-modified polystyrene surface. In order to promote osteoinduction of hydroxyapatite (HA) scaffolds, bioinspired polymer-controlled mineralization was conducted

  6. Adenovirus-mediated expression of pig α(1, 3) galactosyltransferase reconstructs Gal α(1, 3) Gal epitope on the surface of human tumor cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Gal α(1,3)Gal(gal epitope)is a carbohydrate epitope and synthesized in large amount by α(1,3)galactosyltransferase [α(1,3)GT] enzyme on the cells of lower mammalian animals such as pigs and mice.Human has no gal epitope due to the inactivation of α(1,3)GT gene but produces a large amount of antibodies(anti-Gal)which recognize Gal α(1,3)Gal structures specifically.In this study,a replicationdeficient recombinant adenoviral vector Ad5sGT containing pig α(1,3)GT cDNA was constructed and characterized.Adenoviral vector-mediated transfer of pig α(1,3)GT gene into human tumor cells such as malignant melanoma A375,stomach cancer SGC-7901,and lung cancer SPC-A-1 was reported for the first time.Results showed that Gal epitope did not increase the sensitivity of human tumor cells to human complement-mediated lysis,although human complement activation and the binding of human IgG and IgM natural antibodies to human tumor cells were enhanced significantly after Ad5sGT transduction.Appearance of gal epitope on the human tumor cells changed the expression of cell surface carbohydrates reacting with Ulex europaeus I(UEA I)lectins,Vicia villosa agglutinin(VVA),Arachis hypogaea agglutinin(PNA),and Glycine max agglutinin(SBA)to different degrees.In addition,no effect of gal epitope on the growth in vitro of human tumor cells was observed in MTT assay.

  7. Galectin-3 induces clustering of CD147 and integrin-β1 transmembrane glycoprotein receptors on the RPE cell surface.

    Directory of Open Access Journals (Sweden)

    Claudia S Priglinger

    Full Text Available Proliferative vitreoretinopathy (PVR is a blinding disease frequently occurring after retinal detachment surgery. Adhesion, migration and matrix remodeling of dedifferentiated retinal pigment epithelial (RPE cells characterize the onset of the disease. Treatment options are still restrained and identification of factors responsible for the abnormal behavior of the RPE cells will facilitate the development of novel therapeutics. Galectin-3, a carbohydrate-binding protein, was previously found to inhibit attachment and spreading of retinal pigment epithelial cells, and thus bares the potential to counteract PVR-associated cellular events. However, the identities of the corresponding cell surface glycoprotein receptor proteins on RPE cells are not known. Here we characterize RPE-specific Gal-3 containing glycoprotein complexes using a proteomic approach. Integrin-β1, integrin-α3 and CD147/EMMPRIN, a transmembrane glycoprotein implicated in regulating matrix metalloproteinase induction, were identified as potential Gal-3 interactors on RPE cell surfaces. In reciprocal immunoprecipitation experiments we confirmed that Gal-3 associated with CD147 and integrin-β1, but not with integrin-α3. Additionally, association of Gal-3 with CD147 and integrin-β1 was observed in co-localization analyses, while integrin-α3 only partially co-localized with Gal-3. Blocking of CD147 and integrin-β1 on RPE cell surfaces inhibited binding of Gal-3, whereas blocking of integrin-α3 failed to do so, suggesting that integrin-α3 is rather an indirect interactor. Importantly, Gal-3 binding promoted pronounced clustering and co-localization of CD147 and integrin-β1, with only partial association of integrin-α3. Finally, we show that RPE derived CD147 and integrin-β1, but not integrin-α3, carry predominantly β-1,6-N-actyl-D-glucosamine-branched glycans, which are high-affinity ligands for Gal-3. We conclude from these data that extracellular Gal-3 triggers

  8. Cell-Surface Protein Profiling Identifies Distinctive Markers of Progenitor Cells in Human Skeletal Muscle

    Directory of Open Access Journals (Sweden)

    Akiyoshi Uezumi

    2016-08-01

    Full Text Available Skeletal muscle contains two distinct stem/progenitor populations. One is the satellite cell, which acts as a muscle stem cell, and the other is the mesenchymal progenitor, which contributes to muscle pathogeneses such as fat infiltration and fibrosis. Detailed and accurate characterization of these progenitors in humans remains elusive. Here, we performed comprehensive cell-surface protein profiling of the two progenitor populations residing in human skeletal muscle and identified three previously unrecognized markers: CD82 and CD318 for satellite cells and CD201 for mesenchymal progenitors. These markers distinguish myogenic and mesenchymal progenitors, and enable efficient isolation of the two types of progenitors. Functional study revealed that CD82 ensures expansion and preservation of myogenic progenitors by suppressing excessive differentiation, and CD201 signaling favors adipogenesis of mesenchymal progenitors. Thus, cell-surface proteins identified here are not only useful markers but also functionally important molecules, and provide valuable insight into human muscle biology and diseases.

  9. Role of N-glycosylation in cell surface expression and protection against proteolysis of the intestinal anion exchanger SLC26A3.

    Science.gov (United States)

    Hayashi, Hisayoshi; Yamashita, Yukari

    2012-03-01

    SLC26A3 is a Cl(-)/HCO(3)(-) exchanger that plays a major role in Cl(-) absorption from the intestine. Its mutation causes congenital chloride-losing diarrhea. It has been shown that SLC26A3 are glycosylated, with the attached carbohydrate being extracellular and perhaps modulating function. However, the role of glycosylation has yet to be clearly determined. We used the approaches of biochemical modification and site-directed mutagenesis to prevent glycosylation. Deglycosylation experiments with glycosidases indicated that the mature glycosylated form of SLC26A3 exists at the plasma membrane, and a putative large second extracellular loop contains all of the N-linked carbohydrates. Deglycosylation of SLC26A3 causes depression of transport activity compared with wild-type, although robust intracellular pH changes were still observed, suggesting that N-glycosylation is not absolutely necessary for transport activity. To localize glycosylation sites, we mutated the five consensus sites by replacing asparagine (N) with glutamine. Immnoblotting suggests that SLC26A3 is glycosylated at N153, N161, and N165. Deglycosylation of SLC26A3 causes a defect in cell surface processing with decreased cell surface expression. We also assessed whether SLC26A3 is protected from tryptic digestion. While the mature glycosylated SLC26A3 showed little breakdown after treatment with trypsin, deglycosylated SLC26A3 exhibited increased susceptibility to trypsin, suggesting that the oligosaccharides protect SLC26A3 from tryptic digestion. In conclusion, our data indicate that N-glycosylation of SLC26A3 is important for cell surface expression and for protection from proteolytic degradation that may contribute to the understanding of pathogenesis of congenital disorders of glycosylation.

  10. Fibronectin on the Surface of Myeloma Cell-derived Exosomes Mediates Exosome-Cell Interactions.

    Science.gov (United States)

    Purushothaman, Anurag; Bandari, Shyam Kumar; Liu, Jian; Mobley, James A; Brown, Elizabeth E; Sanderson, Ralph D

    2016-01-22

    Exosomes regulate cell behavior by binding to and delivering their cargo to target cells; however, the mechanisms mediating exosome-cell interactions are poorly understood. Heparan sulfates on target cell surfaces can act as receptors for exosome uptake, but the ligand for heparan sulfate on exosomes has not been identified. Using exosomes isolated from myeloma cell lines and from myeloma patients, we identify exosomal fibronectin as a key heparan sulfate-binding ligand and mediator of exosome-cell interactions. We discovered that heparan sulfate plays a dual role in exosome-cell interaction; heparan sulfate on exosomes captures fibronectin, and on target cells it acts as a receptor for fibronectin. Removal of heparan sulfate from the exosome surface releases fibronectin and dramatically inhibits exosome-target cell interaction. Antibody specific for the Hep-II heparin-binding domain of fibronectin blocks exosome interaction with tumor cells or with marrow stromal cells. Regarding exosome function, fibronectin-mediated binding of exosomes to myeloma cells activated p38 and pERK signaling and expression of downstream target genes DKK1 and MMP-9, two molecules that promote myeloma progression. Antibody against fibronectin inhibited the ability of myeloma-derived exosomes to stimulate endothelial cell invasion. Heparin or heparin mimetics including Roneparstat, a modified heparin in phase I trials in myeloma patients, significantly inhibited exosome-cell interactions. These studies provide the first evidence that fibronectin binding to heparan sulfate mediates exosome-cell interactions, revealing a fundamental mechanism important for exosome-mediated cross-talk within tumor microenvironments. Moreover, these results imply that therapeutic disruption of fibronectin-heparan sulfate interactions will negatively impact myeloma tumor growth and progression.

  11. Tetraploid cells from cytokinesis failure induce aneuploidy and spontaneous transformation of mouse ovarian surface epithelial cells.

    Science.gov (United States)

    Lv, Lei; Zhang, Tianwei; Yi, Qiyi; Huang, Yun; Wang, Zheng; Hou, Heli; Zhang, Huan; Zheng, Wei; Hao, Qiaomei; Guo, Zongyou; Cooke, Howard J; Shi, Qinghua

    2012-08-01

    Most ovarian cancers originate from the ovarian surface epithelium and are characterized by aneuploid karyotypes. Aneuploidy, a consequence of chromosome instability, is an early event during the development of ovarian cancers. However, how aneuploid cells are evolved from normal diploid cells in ovarian cancers remains unknown. In the present study, cytogenetic analyses of a mouse syngeneic ovarian cancer model revealed that diploid mouse ovarian surface epithelial cells (MOSECs) experienced an intermediate tetraploid cell stage, before evolving to aneuploid (mainly near-tetraploid) cells. Using long-term live-cell imaging followed by fluorescence in situ hybridization (FISH), we demonstrated that tetraploid cells originally arose from cytokinesis failure of bipolar mitosis in diploid cells, and gave rise to aneuploid cells through chromosome mis-segregation during both bipolar and multipolar mitoses. Injection of the late passage aneuploid MOSECs resulted in tumor formation in C57BL/6 mice. Therefore, we reveal a pathway for the evolution of diploid to aneuploid MOSECs and elucidate a mechanism for the development of near-tetraploid ovarian cancer cells.

  12. Interaction of KSHV with Host Cell Surface Receptors and Cell Entry

    Directory of Open Access Journals (Sweden)

    Mohanan Valiya Veettil

    2014-10-01

    Full Text Available Virus entry is a complex process characterized by a sequence of events. Since the discovery of KSHV in 1994, tremendous progress has been made in our understanding of KSHV entry into its in vitro target cells. KSHV entry is a complex multistep process involving viral envelope glycoproteins and several cell surface molecules that is utilized by KSHV for its attachment and entry. KSHV has a broad cell tropism and the attachment and receptor engagement on target cells have an important role in determining the cell type-specific mode of entry. KSHV utilizes heparan sulfate, integrins and EphrinA2 molecules as receptors which results in the activation of host cell pre-existing signal pathways that facilitate the subsequent cascade of events resulting in the rapid entry of virus particles, trafficking towards the nucleus followed by viral and host gene expression. KSHV enters human fibroblast cells by dynamin dependant clathrin mediated endocytosis and by dynamin independent macropinocytosis in dermal endothelial cells. Once internalized into endosomes, fusion of the viral envelope with the endosomal membranes in an acidification dependent manner results in the release of capsids which subsequently reaches the nuclear pore vicinity leading to the delivery of viral DNA into the nucleus. In this review, we discuss the principal mechanisms that enable KSHV to interact with the host cell surface receptors as well as the mechanisms that are required to modulate cell signaling machinery for a successful entry.

  13. Yeast cell surface display for lipase whole cell catalyst and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yun; Zhang, Rui; Lian, Zhongshuai; Wang, Shihui; Wright, Aaron T.

    2014-08-01

    The cell surface display technique allows for the expression of target proteins or peptides on the microbial cell surface by fusing an appropriate protein as an anchoring motif. Yeast display systems, such as Pichia pastoris, Yarowia lipolytica and Saccharomyces cerevisiae, are ideal, alternative and extensive display systems with the advantage of simple genetic manipulation and post-translational modification of expressed heterologous proteins. Engineered yeasts show high performance characteristics and variant utilizations. Herein, we comprehensively summarize the variant factors affecting lipase whole cell catalyst activity and display efficiency, including the structure and size of target proteins, screening anchor proteins, type and chain length of linkers, and the appropriate matching rules among the above-mentioned display units. Furthermore, we also address novel approaches to enhance stability and activity of recombinant lipases, such as VHb gene co-expression, multi-enzyme co-display technique, and the micro-environmental interference and self-assembly techniques. Finally, we represent the variety of applications of whole cell surface displayed lipases on yeast cells in non-aqueous phases, including synthesis of esters, PUFA enrichment, resolution of chiral drugs, organic synthesis and biofuels. We demonstrate that the lipase surface display technique is a powerful tool for functionalizing yeasts to serve as whole cell catalysts, and increasing interest is providing an impetus for broad application of this technique.

  14. Carbohydrates of human immunodeficiency virus

    DEFF Research Database (Denmark)

    Hansen, J E

    1992-01-01

    Elucidation of the mechanism by which viral infection induces the appearance of carbohydrate neoantigens is highly important. Results from such studies could be expected to be significant for a general understanding of the regulation of glycosylation, and perhaps especially important for the unde...

  15. Racemic carbohydrates - fact or fiction?

    DEFF Research Database (Denmark)

    Senning, Alexander Erich Eugen

    2007-01-01

    Chemical Abstracts Service has developed unsound practices in the naming and handling of simple carbohydrates such as aldopentoses 1, aldohexoses 2, and ketohexoses 3. Typically, the common name glucose is sometimes, inappropriately, interpreted as meaning DL-glucose DL-2d. Thus, a considerable...

  16. Evaluation of Relative Yeast Cell Surface Hydrophobicity Measured by Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Lisa Colling

    2005-01-01

    Full Text Available Objective: To develop an efficient method for evaluating cell surface hydrophobicity and to apply the method to demonstrate the effects of fungal growth conditions on cell surface properties.

  17. Carbohydrate Supplementation Influences Serum Cytokines after Exercise under Hypoxic Conditions

    Directory of Open Access Journals (Sweden)

    Aline Venticinque Caris

    2016-11-01

    Full Text Available Introduction: Exercise performed at the hypoxia equivalent of an altitude of 4200 m is associated with elevated inflammatory mediators and changes in the Th1/Th2 response. By contrast, supplementation with carbohydrates has an anti-inflammatory effect when exercise is performed under normoxic conditions. The objective of this study was to evaluate the effect of carbohydrate supplementation on cytokines and cellular damage markers after exercise under hypoxic conditions at a simulated altitude of 4200 m. Methods: Seven adult male volunteers who exercised for 60 min at an intensity of 50% VO2Peak were randomly evaluated under three distinct conditions; normoxia, hypoxia and hypoxia + carbohydrate supplementation. Blood samples were collected at rest, at the end of exercise and after 60 min of recovery. To evaluate hypoxia + carbohydrate supplementation, volunteers received a solution of 6% carbohydrate (maltodextrin or a placebo (strawberry-flavored Crystal Light®; Kraft Foods, Northfield, IL, USA every 20 min during exercise and recovery. Statistical analyses comprised analysis of variance, with a one-way ANOVA followed by the Tukey post hoc test with a significance level of p < 0.05. Results: Under normoxic and hypoxic conditions, there was a significant increase in the concentration of IL-6 after exercise and after recovery compared to at rest (p < 0.05, while in the hypoxia + carbohydrate group, there was a significant increase in the concentration of IL-6 and TNF-α after exercise compared to at rest (p < 0.05. Furthermore, under this condition, TNF-α, IL-2 and the balance of IL-2/IL-4 were increased after recovery compared to at rest (p < 0.05. Conclusion: We conclude that carbohydrate supplementation modified the IL-6 and TNF-α serum concentrations and shifted the IL-2/IL-4 balance towards Th1 in response without glycemic, glutaminemia and cell damage effects.

  18. Separation of carbohydrates using hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Fu, Qing; Liang, Tu; Li, Zhenyu; Xu, Xiaoyong; Ke, Yanxiong; Jin, Yu; Liang, Xinmiao

    2013-09-20

    A strategy was developed to rapidly evaluate chromatographic properties of hydrophilic interaction chromatography (HILIC) columns for separating carbohydrates. Seven HILIC columns (Silica, Diol, TSK Amide-80, XAmide, Click Maltose, Click β-CD, and Click TE-Cys columns) were evaluated by using three monosaccharide and seven disaccharides as probes. The influence of column temperature on the peak shape and tautomerization of carbohydrates, as well as column selectivity were investigated. The influence of surface charge property on the retention was also studied by using glucose, glucuronic acid, and glucosamine, which indicated that buffer salt concentration and pH value in mobile phase was necessary to control the ionic interactions between ionic carbohydrates and HILIC columns. According to evaluation results, the XAmide column was selected as an example to establish experimental schemes for separation of complex mixtures of oligosaccharide.

  19. Identification of Novel Human Breast Carcinoma (MDA-MB-231 Cell Growth Modulators from a Carbohydrate-Based Diversity Oriented Synthesis Library

    Directory of Open Access Journals (Sweden)

    Elena Lenci

    2016-10-01

    Full Text Available The application of a cell-based growth inhibition on a library of skeletally different glycomimetics allowed for the selection of a hexahydro-2H-furo[3,2-b][1,4]oxazine compound as candidate inhibitors of MDA-MB-231 cell growth. Subsequent synthesis of analogue compounds and preliminary biological studies validated the selection of a valuable hit compound with a novel polyhydroxylated structure for the modulation of the breast carcinoma cell cycle mechanism.

  20. Identification of Novel Human Breast Carcinoma (MDA-MB-231) Cell Growth Modulators from a Carbohydrate-Based Diversity Oriented Synthesis Library.

    Science.gov (United States)

    Lenci, Elena; Innocenti, Riccardo; Biagioni, Alessio; Menchi, Gloria; Bianchini, Francesca; Trabocchi, Andrea

    2016-10-20

    The application of a cell-based growth inhibition on a library of skeletally different glycomimetics allowed for the selection of a hexahydro-2H-furo[3,2-b][1,4]oxazine compound as candidate inhibitors of MDA-MB-231 cell growth. Subsequent synthesis of analogue compounds and preliminary biological studies validated the selection of a valuable hit compound with a novel polyhydroxylated structure for the modulation of the breast carcinoma cell cycle mechanism.

  1. Carbohydrate-based immune adjuvants

    Science.gov (United States)

    Petrovsky, Nikolai; Cooper, Peter D

    2011-01-01

    The role for adjuvants in human vaccines has been a matter of vigorous scientific debate, with the field hindered by the fact that for over 80 years, aluminum salts were the only adjuvants approved for human use. To this day, alum-based adjuvants, alone or combined with additional immune activators, remain the only adjuvants approved for use in the USA. This situation has not been helped by the fact that the mechanism of action of most adjuvants has been poorly understood. A relative lack of resources and funding for adjuvant development has only helped to maintain alum’s relative monopoly. To seriously challenge alum’s supremacy a new adjuvant has many major hurdles to overcome, not least being alum’s simplicity, tolerability, safety record and minimal cost. Carbohydrate structures play critical roles in immune system function and carbohydrates also have the virtue of a strong safety and tolerability record. A number of carbohydrate compounds from plant, bacterial, yeast and synthetic sources have emerged as promising vaccine adjuvant candidates. Carbohydrates are readily biodegradable and therefore unlikely to cause problems of long-term tissue deposits seen with alum adjuvants. Above all, the Holy Grail of human adjuvant development is to identify a compound that combines potent vaccine enhancement with maximum tolerability and safety. This has proved to be a tough challenge for many adjuvant contenders. Nevertheless, carbohydrate-based compounds have many favorable properties that could place them in a unique position to challenge alum’s monopoly over human vaccine usage. PMID:21506649

  2. Organic biomarkers in deep-sea regions affected by bottom trawling: pigments, fatty acids, amino acids and carbohydrates in surface sediments from the La Fonera (Palamós) Canyon, NW Mediterranean Sea

    OpenAIRE

    E. Sañé; Martín, J.; Puig, P.; Palanques, A.

    2013-01-01

    Deep-sea ecosystems are in general adapted to a limited variability of physical conditions, resulting in high vulnerability and slow recovery rates from anthropogenic perturbations such as bottom trawling. Commercial trawling is the most recurrent and pervasive of human impacts on the deep-sea floor, but studies on its consequences on the biogeochemistry of deep-sea sediments are still scarce. Pigments, fatty acids, amino acids and carbohydrates were analysed in sediments fr...

  3. Organic biomarkers in deep-sea regions affected by bottom trawling: pigments, fatty acids, amino acids and carbohydrates in surface sediments from the La Fonera (Palamós) Canyon, NW Mediterranean Sea

    OpenAIRE

    E. Sañé; Martín, J.; Puig, P.; Palanques, A.

    2012-01-01

    Deep-sea ecosystems are in general adapted to a limited variability of physical conditions, resulting in high vulnerability and slow recovery rates from anthropogenic perturbations such as bottom trawling. Commercial trawling is the most recurrent and pervasive of human impacts on the deep-sea floor, but studies on its consequences on the biogeochemistry of deep-sea sediments are still scarce. Pigments, fatty acids, amino acids and carbohydrates were analyzed in sediments from the flanks of t...

  4. Cell receptor and surface ligand density effects on dynamic states of adhering circulating tumor cells.

    Science.gov (United States)

    Zheng, Xiangjun; Cheung, Luthur Siu-Lun; Schroeder, Joyce A; Jiang, Linan; Zohar, Yitshak

    2011-10-21

    Dynamic states of cancer cells moving under shear flow in an antibody-functionalized microchannel are investigated experimentally and theoretically. The cell motion is analyzed with the aid of a simplified physical model featuring a receptor-coated rigid sphere moving above a solid surface with immobilized ligands. The motion of the sphere is described by the Langevin equation accounting for the hydrodynamic loadings, gravitational force, receptor-ligand bindings, and thermal fluctuations; the receptor-ligand bonds are modeled as linear springs. Depending on the applied shear flow rate, three dynamic states of cell motion have been identified: (i) free motion, (ii) rolling adhesion, and (iii) firm adhesion. Of particular interest is the fraction of captured circulating tumor cells, defined as the capture ratio, via specific receptor-ligand bonds. The cell capture ratio decreases with increasing shear flow rate with a characteristic rate. Based on both experimental and theoretical results, the characteristic flow rate increases monotonically with increasing either cell-receptor or surface-ligand density within certain ranges. Utilizing it as a scaling parameter, flow-rate dependent capture ratios for various cell-surface combinations collapse onto a single curve described by an exponential formula.

  5. Phospholipid polymer-based antibody immobilization for cell rolling surfaces in stem cell purification system.

    Science.gov (United States)

    Mahara, Atsushi; Chen, Hao; Ishihara, Kazuhiko; Yamaoka, Tetsuji

    2014-01-01

    We previously developed an antibody-conjugated cell rolling column that successfully separates stem cell subpopulations depending on the cell surface marker density, but a large amount of the injected cells were retained in the column because of non-specific interactions. In this study, an amphiphilic copolymer, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (nBMA)-co-N-vinyl formamide (NVf)], with phospholipid polar side groups was designed as a novel antibody-immobilizing modifier. The formamide groups in NVf units were converted to active maleimide groups. A plastic flow microfluidic chamber was coated with the copolymers, and a reduced anti-CD90 antibody was immobilized. The adipose tissue-derived stem cells isolated from the rat were injected into the flow chamber, and their rolling behavior was observed under a microscope with a high-speed camera. Non-specific cell adhesion was reduced strongly by means of this immobilization method because of the MPC unit, resulting in a high percentage of rolling cells. These results demonstrate that a surface coated with phospholipid polar groups can be used in an effective stem cell separation system based on the cell rolling process.

  6. Mechanotransduction Across the Cell Surface and Through the Cytoskeleton

    Science.gov (United States)

    Wang, Ning; Butler, James P.; Ingber, Donald E.

    1993-05-01

    Mechanical stresses were applied directly to cell surface receptors with a magnetic twisting device. The extracellular matrix receptor, integrin β_1, induced focal adhesion formation and supported a force-dependent stiffening response, whereas nonadhesion receptors did not. The cytoskeletal stiffness (ratio of stress to strain) increased in direct proportion to the applied stress and required intact microtubules and intermediate filaments as well as microfilaments. Tensegrity models that incorporate mechanically interdependent struts and strings that reorient globally in response to a localized stress mimicked this response. These results suggest that integrins act as mechanoreceptors and transmit mechanical signals to the cytoskeleton. Mechanotransduction, in turn, may be mediated simultaneously at multiple locations inside the cell through force-induced rearrangements within a tensionally integrated cytoskeleton.

  7. Measurement of diffusion length and surface recombination velocity in Interdigitated Back Contact (IBC) and Front Surface Field (FSF) solar cells

    Science.gov (United States)

    Verlinden, Pierre; Van de Wiele, Fernand

    1985-03-01

    A method is proposed for measuring the diffusion length and surface recombination velocity of Interdigitated Back Contact (IBC) solar cells by means of a simple linear regression on experimental quantum efficiency values versus the inverse of the absorption coefficient. This method is extended to the case of Front Surface Field (FSF) solar cells. Under certain conditions, the real or the effective surface recombination velocity may be measured.

  8. Horizontal transfer of carbohydrate metabolism genes into ectomycorrhizal Amanita

    NARCIS (Netherlands)

    Chaib De Mares, Maryam; Hess, Jaqueline; Floudas, Dimitrios; Lipzen, Anna; Choi, Cindy; Kennedy, Megan; Grigoriev, Igor V.; Pringle, Anne

    2015-01-01

    - The genus Amanita encompasses both symbiotic, ectomycorrhizal fungi and asymbiotic litter decomposers; all species are derived from asymbiotic ancestors. Symbiotic species are no longer able to degrade plant cell walls. The carbohydrate esterases family 1 (CE1s) is a diverse group of enzymes invol

  9. Targeting pancreatic progenitor cells in human embryonic stem cell differentiation for the identification of novel cell surface markers.

    Science.gov (United States)

    Fishman, Bettina; Segev, Hanna; Kopper, Oded; Nissenbaum, Jonathan; Schulman, Margarita; Benvenisty, Nissim; Itskovitz-Eldor, Joseph; Kitsberg, Danny

    2012-09-01

    New sources of beta cells are needed in order to develop cell therapies for patients with diabetes. An alternative to forced expansion of post-mitotic beta cells is the induction of differentiation of stem-cell derived progenitor cells that have a natural self-expansion capacity into insulin-producing cells. In order to learn more about these progenitor cells at different stages along the differentiation process in which they become progressively more committed to the final beta cell fate, we took the approach of identifying, isolating and characterizing stage specific progenitor cells. We generated human embryonic stem cell (HESC) clones harboring BAC GFP reporter constructs of SOX17, a definitive endoderm marker, and PDX1, a pancreatic marker, and identified subpopulations of GFP expressing cells. Using this approach, we isolated a highly enriched population of pancreatic progenitor cells from hESCs and examined their gene expression with an emphasis on the expression of stage-specific cell surface markers. We were able to identify novel molecules that are involved in the pancreatic differentiation process, as well as stage-specific cell markers that may serve to define (alone or in combination with other markers) a specific pancreatic progenitor cell. These findings may help in optimizing conditions for ultimately generating and isolating beta cells for transplantation therapy.

  10. Interactions of carbohydrates and proteins by fluorophore-assisted carbohydrate electrophoresis

    Indian Academy of Sciences (India)

    Gang-Liang Huang; Xin-Ya Mei; Peng-George Wang

    2006-06-01

    A sensitive, specific, and rapid method for the detection of carbohydrate-protein interactions is demonstrated by fluorophore-assisted carbohydrate electrophoresis (FACE). The procedure is simple and the cost is low. The advantage of this method is that carbohydrate-protein interactions can be easily displayed by FACE, and the carbohydrates do not need to be purified.

  11. Surface Properties of Cell-treated Polyethylene Terephthalate

    Directory of Open Access Journals (Sweden)

    Bing Shi

    2006-01-01

    Full Text Available The materials used in artificial joints undergo degradation through fatigue and corrosive wear in human body. The lifetime for well-designed artificial joints like hip joints is at most 12 years and a patient will usually have two total joint replacements during his/her lifetime. Tissue engineering, an alternative to total joint implantation, is the replacement of damaged tissue with the tissue that is designed and constructed to meet the needs of the individual patient. In this study, polyethylene terephthalate (PET in the form of overhead transparency films were investigated on their cell interactions and the tribological properties as an alternative tissue-engineering matrix. The base material of the transparency films is PET. Cell culture methods as well as atomic force microscope (AFM, contact angle goniometer, confocal microscope and universal tribotester were used to study the properties of the substrate materials and the interactions between the surface and the substrate materials. Results showed that cells grew on the substrate of the base materials of the PET. The tribological properties of the slides have been changed after being cell-treated.

  12. Different allocation of carbohydrates and phenolics in dehydrated leaves of triticale.

    Science.gov (United States)

    Hura, Tomasz; Dziurka, Michał; Hura, Katarzyna; Ostrowska, Agnieszka; Dziurka, Kinga

    2016-09-01

    Carbohydrates are used in plant growth processes, osmotic regulation and secondary metabolism. A study of the allocation of carbohydrates to a target set of metabolites during triticale acclimation to soil drought was performed. The study included a semi-dwarf cultivar 'Woltario' and a long-stemmed cultivar 'Moderato', differing in the activity of the photosynthetic apparatus under optimum growth conditions. Differences were found in the quantitative and qualitative composition of individual carbohydrates and phenolic compounds, depending on the developmental stage and water availability. Soluble carbohydrates in the semi-dwarf 'Woltario' cv. under soil drought were utilized for synthesis of starch, soluble phenolic compounds and an accumulation of cell wall carbohydrates. In the typical 'Moderato' cv., soluble carbohydrates were primarily used for the synthesis of phenolic compounds that were then incorporated into cell wall structures. Increased content of cell wall-bound phenolics in 'Moderato' cv. improved the cell wall tightness and reduced the rate of leaf water loss. In 'Woltario' cv., the increase in cell osmotic potential due to an enhanced concentration of carbohydrates and proline was insufficient to slow down the rate of leaf water loss. The mechanism of cell wall tightening in response to leaf desiccation may be the main key in the process of triticale acclimation to soil drought.

  13. Carbohydrate-Mimetic Peptides for Pan Anti-Tumor Responses

    Science.gov (United States)

    Kieber-Emmons, Thomas; Saha, Somdutta; Pashov, Anastas; Monzavi-Karbassi, Behjatolah; Murali, Ramachandran

    2014-01-01

    Molecular mimicry is fundamental to biology and transcends to many disciplines ranging from immune pathology to drug design. Structural characterization of molecular partners has provided insight into the origins and relative importance of complementarity in mimicry. Chemical complementarity is easy to understand; amino acid sequence similarity between peptides, for example, can lead to cross-reactivity triggering similar reactivity from their cognate receptors. However, conformational complementarity is difficult to decipher. Molecular mimicry of carbohydrates by peptides is often considered one of those. Extensive studies of innate and adaptive immune responses suggests the existence of carbohydrate mimicry, but the structural basis for this mimicry yields confounding details; peptides mimicking carbohydrates in some cases fail to exhibit both chemical and conformational mimicry. Deconvolution of these two types of complementarity in mimicry and its relationship to biological function can nevertheless lead to new therapeutics. Here, we discuss our experience examining the immunological aspects and implications of carbohydrate–peptide mimicry. Emphasis is placed on the rationale, the lessons learned from the methodologies to identify mimics, a perspective on the limitations of structural analysis, the biological consequences of mimicking tumor-associated carbohydrate antigens, and the notion of reverse engineering to develop carbohydrate-mimetic peptides in vaccine design strategies to induce responses to glycan antigens expressed on cancer cells. PMID:25071769

  14. Structure-property relationships and biocompatibility of carbohydrate crosslinked polyurethanes.

    Science.gov (United States)

    Solanki, Archana; Mehta, Jayen; Thakore, Sonal

    2014-09-22

    Biocompatible and biodegradable polyurethanes (PUs) based on castor oil and polypropylene glycols (PPGs) were prepared using various carbohydrate crosslinkers: monosaccharide (glucose), disaccharide (sucrose) and polysaccharides (starch and cellulose). The mechanical and thermal properties were investigated and interpreted on the basis of SEM study. The advantage of incorporating various carbohydrates is to have tunable mechanical properties and biodegradability due to variety in their structure. The glass transition temperature and sorption behavior were dominated by the type of polyol than by the type of crosslinker. All the PUs were observed to be biodegradable as well as non-cytotoxic as revealed by MTT assay in normal lung cell line L132. The study supports the suitability of carbohydrates as important components of biocompatible PUs for development of biomedical devices.

  15. Neisseria lactamica selectively induces mitogenic proliferation of the naive B cell pool via cell surface Ig.

    Science.gov (United States)

    Vaughan, Andrew T; Brackenbury, Louise S; Massari, Paola; Davenport, Victoria; Gorringe, Andrew; Heyderman, Robert S; Williams, Neil A

    2010-09-15

    Neisseria lactamica is a commensal bacteria that colonizes the human upper respiratory tract mucosa during early childhood. In contrast to the closely related opportunistic pathogen Neisseria meningitidis, there is an absence of adaptive cell-mediated immunity to N. lactamica during the peak age of carriage. Instead, outer membrane vesicles derived from N. lactamica mediate a B cell-dependent proliferative response in mucosal mononuclear cells that is associated with the production of polyclonal IgM. We demonstrate in this study that this is a mitogenic human B cell response that occurs independently of T cell help and any other accessory cell population. The ability to drive B cell proliferation is a highly conserved property and is present in N. lactamica strains derived from diverse clonal complexes. CFSE staining of purified human tonsillar B cells demonstrated that naive IgD(+) and CD27(-) B cells are selectively induced to proliferate by outer membrane vesicles, including the innate CD5(+) subset. Neither purified lipooligosaccharide nor PorB from N. lactamica is likely to be responsible for this activity. Prior treatment of B cells with pronase to remove cell-surface Ig or treatment with BCR-specific Abs abrogated the proliferative response to N. lactamica outer membrane vesicles, suggesting that this mitogenic response is dependent upon the BCR.

  16. Cell surface and transcriptional characterization of human adipose-derived adherent stromal (hADAS) cells.

    Science.gov (United States)

    Katz, Adam J; Tholpady, Ashok; Tholpady, Sunil S; Shang, Hulan; Ogle, Roy C

    2005-03-01

    Adult human subcutaneous adipose tissue contains cells with intriguing multilineage developmental plasticity, much like marrow-derived mesenchymal stem cells. Putative stem or progenitor cells from fat have been given many different names in the literature, reflecting an early and evolving consensus regarding their phenotypic characterization. The study reported here used microarrays to evaluate over 170 genes relating to angiogenesis and extracellular matrix in undifferentiated, early-passage human adipose-derived adherent stromal (hADAS) cells isolated from three separate donors. The hADAS populations unanimously transcribed 66% of the screened genes, and 83% were transcribed by at least two of the three populations. The most highly transcribed genes relate to functional groupings such as cell adhesion, matrix proteins, growth factors and receptors, and proteases. The transcriptome of hADAS cells demonstrated by this work reveals many similarities to published profiles of bone marrow mesenchymal stem cells (MSCs). In addition, flow analysis of over 24 hADAS cell surface proteins (n = 7 donors) both confirms and expands on the existing literature and reveals strong intergroup correlation, despite an inconsistent nomenclature and the lack of standardized protocols for cell isolation and culture. Finally, based on flow analysis and reverse transcription polymerase chain reaction studies, our results suggest that hADAS cells do not express several proteins that are implicated as markers of "stemness" in other stem cell populations, including telomerase, CD133, and the membrane transporter ABCG2.

  17. Engineered antifouling microtopographies: surface pattern effects on cell distribution.

    Science.gov (United States)

    Decker, Joseph T; Sheats, Julian T; Brennan, Anthony B

    2014-12-23

    Microtopography has been observed to lead to altered attachment behavior for marine fouling organisms; however, quantification of this phenomenon is lacking in the scientific literature. Here, we present quantitative measurement of the disruption of normal attachment behavior of the fouling algae Ulva linza by antifouling microtopographies. The distribution of the diatom Navicula incerta was shown to be unaffected by the presence of topography. The radial distribution function was calculated for both individual zoospores and cells as well as aggregates of zoospores from attachment data for a variety topographic configurations and at a number of different attachment densities. Additionally, the screening distance and maximum values were mapped according to the location of zoospore aggregates within a single unit cell. We found that engineered topographies decreased the distance between spore aggregates compared to that for a smooth control surface; however, the distributions for individual spores were unchanged. We also found that the local attachment site geometry affected the screening distance for aggregates of zoospores, with certain geometries decreasing screening distance and others having no measurable effect. The distribution mapping techniques developed and explored in this article have yielded important insight into the design parameters for antifouling microtopographies that can be implemented in the next generation of antifouling surfaces.

  18. Distribution of Prestin on Outer Hair Cell Basolateral Surface

    Institute of Scientific and Technical Information of China (English)

    YU Ning; ZHAI Suo-qiang; YANG Shi-ming; HAN Dong-yi; ZHAO Hong-bo

    2008-01-01

    Prestin has been identified as a motor protein responsible for outer hair cell (OHC) electromotility and is expressed on the OHC surface. Previous studies revealed that OHC eleetromotility and its associated nonlinear capacitance were mainly located at the OHC lateral wall and absent at the apical cutieular plate and the basal nucleus region. Immunofluorescent staining for prestin also failed to demonstrate prestin expression at the OHC basal ends in whole-mount preparation of the organ of Corti. However, there lacks a definitive demonstration of the pattern of prestin distribution. The OHC lateral wall has a trilaminate organization and is composed of the plasma membrane, cortical lattice, and subsurface cisternae. In this study, the location of prestin proteins in dissociated OHCs was examined using immunofluorescent staining and confocal microscopy. We found that prestin was uniformly expressed on the basolateral surface, including the basal pole. No staining was seen on the cuticular plate and stereocilia. When co-stained with a membrane marker di-8-ANEPPS, prestin-labeling was found to be in the outer layer of the OHC lateral wall. After separating the plasma membrane from the underlying subsurface eisternae using a hypotonic extracellular solution, prestin-labeling was found to be in the plasma membrane, not the subsurface cisternae. The data show that prestin is expressed in the plasma membrane on the entire OHC basolateral surface.

  19. Heat-transfer-method-based cell culture quality assay through cell detection by surface imprinted polymers.

    Science.gov (United States)

    Eersels, Kasper; van Grinsven, Bart; Khorshid, Mehran; Somers, Veerle; Püttmann, Christiane; Stein, Christoph; Barth, Stefan; Diliën, Hanne; Bos, Gerard M J; Germeraad, Wilfred T V; Cleij, Thomas J; Thoelen, Ronald; De Ceuninck, Ward; Wagner, Patrick

    2015-02-17

    Previous work has indicated that surface imprinted polymers (SIPs) allow for highly specific cell detection through macromolecular cell imprints. The combination of SIPs with a heat-transfer-based read-out technique has led to the development of a selective, label-free, low-cost, and user-friendly cell detection assay. In this study, the breast cancer cell line ZR-75-1 is used to assess the potential of the platform for monitoring the quality of a cell culture in time. For this purpose, we show that the proposed methodology is able to discriminate between the original cell line (adherent growth, ZR-75-1a) and a descendant cell line (suspension growth, ZR-75-1s). Moreover, ZR-75-1a cells were cultured for a prolonged period of time and analyzed using the heat-transfer method (HTM) at regular time intervals. The results of these experiments demonstrate that the thermal resistance (Rth) signal decays after a certain number of cell culture passages. This can likely be attributed to a compromised quality of the cell culture due to cross-contamination with the ZR-75-1s cell line, a finding that was confirmed by classical STR DNA profiling. The cells do not express the same functional groups on their membrane, resulting in a weaker bond between cell and imprint, enabling cell removal by mechanical friction, provided by flushing the measuring chamber with buffer solution. These findings were further confirmed by HTM and illustrate that the biomimetic sensor platform can be used as an assay for monitoring the quality of cell cultures in time.

  20. Disorders of carbohydrate digestion and absorption.

    Science.gov (United States)

    Heitlinger, L A; Lebenthal, E

    1988-04-01

    The carbohydrate malabsorptive syndromes are frequently seen by pediatricians. The congenital deficiency states are quite rare, but adult type hypolactasia and lactose intolerance following rotavirus infection are recognized with increasing frequency by primary care physicians. Therapy for these disorders involves identification of the offending carbohydrate, removal of the carbohydrate from the diet, and exclusion of other entities that may result in carbohydrate malabsorption but not respond to its removal from the diet. Prognosis for both the primary and secondary carbohydrate malabsorption syndromes is excellent. Compliance with diets for those pediatric patients who will require lifelong therapy remains problematic.

  1. Substrate recognition by the cell surface palmitoyl transferase DHHC5.

    Science.gov (United States)

    Howie, Jacqueline; Reilly, Louise; Fraser, Niall J; Vlachaki Walker, Julia M; Wypijewski, Krzysztof J; Ashford, Michael L J; Calaghan, Sarah C; McClafferty, Heather; Tian, Lijun; Shipston, Michael J; Boguslavskyi, Andrii; Shattock, Michael J; Fuller, William

    2014-12-09

    The cardiac phosphoprotein phospholemman (PLM) regulates the cardiac sodium pump, activating the pump when phosphorylated and inhibiting it when palmitoylated. Protein palmitoylation, the reversible attachment of a 16 carbon fatty acid to a cysteine thiol, is catalyzed by the Asp-His-His-Cys (DHHC) motif-containing palmitoyl acyltransferases. The cell surface palmitoyl acyltransferase DHHC5 regulates a growing number of cellular processes, but relatively few DHHC5 substrates have been identified to date. We examined the expression of DHHC isoforms in ventricular muscle and report that DHHC5 is among the most abundantly expressed DHHCs in the heart and localizes to caveolin-enriched cell surface microdomains. DHHC5 coimmunoprecipitates with PLM in ventricular myocytes and transiently transfected cells. Overexpression and silencing experiments indicate that DHHC5 palmitoylates PLM at two juxtamembrane cysteines, C40 and C42, although C40 is the principal palmitoylation site. PLM interaction with and palmitoylation by DHHC5 is independent of the DHHC5 PSD-95/Discs-large/ZO-1 homology (PDZ) binding motif, but requires a ∼ 120 amino acid region of the DHHC5 intracellular C-tail immediately after the fourth transmembrane domain. PLM C42A but not PLM C40A inhibits the Na pump, indicating PLM palmitoylation at C40 but not C42 is required for PLM-mediated inhibition of pump activity. In conclusion, we demonstrate an enzyme-substrate relationship for DHHC5 and PLM and describe a means of substrate recruitment not hitherto described for this acyltransferase. We propose that PLM palmitoylation by DHHC5 promotes phospholipid interactions that inhibit the Na pump.

  2. Impact of dietary polyphenols on carbohydrate metabolism.

    Science.gov (United States)

    Hanhineva, Kati; Törrönen, Riitta; Bondia-Pons, Isabel; Pekkinen, Jenna; Kolehmainen, Marjukka; Mykkänen, Hannu; Poutanen, Kaisa

    2010-03-31

    Polyphenols, including flavonoids, phenolic acids, proanthocyanidins and resveratrol, are a large and heterogeneous group of phytochemicals in plant-based foods, such as tea, coffee, wine, cocoa, cereal grains, soy, fruits and berries. Growing evidence indicates that various dietary polyphenols may influence carbohydrate metabolism at many levels. In animal models and a limited number of human studies carried out so far, polyphenols and foods or beverages rich in polyphenols have attenuated postprandial glycemic responses and fasting hyperglycemia, and improved acute insulin secretion and insulin sensitivity. The possible mechanisms include inhibition of carbohydrate digestion and glucose absorption in the intestine, stimulation of insulin secretion from the pancreatic beta-cells, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in the insulin-sensitive tissues, and modulation of intracellular signalling pathways and gene expression. The positive effects of polyphenols on glucose homeostasis observed in a large number of in vitro and animal models are supported by epidemiological evidence on polyphenol-rich diets. To confirm the implications of polyphenol consumption for prevention of insulin resistance, metabolic syndrome and eventually type 2 diabetes, human trials with well-defined diets, controlled study designs and clinically relevant end-points together with holistic approaches e.g., systems biology profiling technologies are needed.

  3. Impact of Dietary Polyphenols on Carbohydrate Metabolism

    Directory of Open Access Journals (Sweden)

    Kati Hanhineva

    2010-03-01

    Full Text Available Polyphenols, including flavonoids, phenolic acids, proanthocyanidins and resveratrol, are a large and heterogeneous group of phytochemicals in plant-based foods, such as tea, coffee, wine, cocoa, cereal grains, soy, fruits and berries. Growing evidence indicates that various dietary polyphenols may influence carbohydrate metabolism at many levels. In animal models and a limited number of human studies carried out so far, polyphenols and foods or beverages rich in polyphenols have attenuated postprandial glycemic responses and fasting hyperglycemia, and improved acute insulin secretion and insulin sensitivity. The possible mechanisms include inhibition of carbohydrate digestion and glucose absorption in the intestine, stimulation of insulin secretion from the pancreatic b-cells, modulation of glucose release from the liver, activation of insulin receptors and glucose uptake in the insulin-sensitive tissues, and modulation of intracellular signalling pathways and gene expression. The positive effects of polyphenols on glucose homeostasis observed in a large number of in vitro and animal models are supported by epidemiological evidence on polyphenol-rich diets. To confirm the implications of polyphenol consumption for prevention of insulin resistance, metabolic syndrome and eventually type 2 diabetes, human trials with well-defined diets, controlled study designs and clinically relevant end-points together with holistic approaches e.g., systems biology profiling technologies are needed.

  4. Regulation of ADAM12 cell-surface expression by protein kinase C epsilon

    DEFF Research Database (Denmark)

    Sundberg, Christina; Thodeti, Charles Kumar; Kveiborg, Marie;

    2004-01-01

    as a constitutively active protein. However, little is known about the regulation of ADAM12 cell-surface translocation. Here, we used human RD rhabdomyosarcoma cells, which express ADAM12 at the cell surface, in a temporal pattern. We report that protein kinase C (PKC) epsilon induces ADAM12 translocation to the cell...

  5. 糖类抗原检测在非小细胞肺癌诊疗中的应用%Application of the carbohydrate antigen detection for diagnosis and treatment in non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    吴小进; 米燕燕; 胡安康; 王伟; 桑纯利; 冯苏梅; 殷咏梅; 鄂云祥

    2013-01-01

    目的 探讨糖类抗原检测用于非小细胞肺癌(NSCLC)诊疗的临床意义.方法 采用血清糖类抗原多肿瘤标志物蛋白芯片检测系统对已确诊的60例NSCLC患者的血清CA19-9、CA242、CA125和CA153水平进行检测,并与肺良性病变对照组和健康对照组进行比较.结果 肺癌组血清CA19-9、CA242、CA125和CA153的阳性检出率高于肺良性病变对照组和健康对照组,且3组血清CA19-9、CA125和CA153的差异尤为显著(P<0.05).肺腺癌患者血清CA19-9和CA125的阳性检出率高于肺鳞癌患者(P<0.05).NSCLC患者分期越晚,4种糖类抗原的阳性检出率越高,其中CA125和CA153在Ⅰ~Ⅱ期的阳性检出率分别为38.5%和30.8%,高于CA19-9和CA242的7.7%和7.7%(P<0.05).结论 糖类抗原检测在NSCLC诊疗方面具有较好的临床应用价值,可以作为诊断、分期及病程监测等方面常规检测方法的辅助手段.%Objective To explore the clinical significance of the carbohydrate antigen detection for diagnosis and treatment in non-small cell lung cancer(NSCLC). Methods The levels of serum CA19-9, CA242, CA125 and CA153 of 60 confirmed patients with NSCLC were measured by multiple tumor marker protein chip detection system and were compared with benign lung lesions control group and the healthy control group. Results The positive rate of serum CA19-9, CA242, CA125 and CA153 in the lung cancer group were higher than benign lung lesions control group and healthy control group, but there was particularly apparent difference in serum CA19-9, CA125 and CA153( P <0. 05). The positive rates of serum CA19-9 and CA125 in the patients with lung adenocarcinoma were significantly higher than those in patients with squamous cell carcinoma ( P <0. 05) . The positive rates of 4 carbohydrate antigens raised with clinical stages. The positive rates of CA125 and CA153 in stage I -II were 38. 5% and 30. 8% , which were higher than those of CA19-9 and CA242, with significant

  6. Tunable Nanocarrier Morphologies from Glycopolypeptide-based Amphiphilic Biocompatible Star Copolymers and Their Carbohydrate Specific Intracellular Delivery

    KAUST Repository

    Pati, Debasis

    2015-12-21

    Nano-carriers with carbohydrates on the surface represent a very interesting class of drug delivery vehicles since carbohydrates are involved in bio-molecular recognition events in vivo. We have synthesized biocompatible miktoarm star copolymers comprising glycopolypeptide and poly(ε-caprolactone) chains, using ring opening polymerization and ‘click chemistry’. The amphiphilic copolymers were self-assembled in water into morphologies such as nanorods, polymersomes and micelles with carbohydrates displayed on the surface. We demonstrate that, the formation of nanostructure could be tuned by chain length of the blocks and was not affected by the type of sugar residue. These nanostructures were characterized in detail using a variety of techniques such as TEM, AFM, cryogenic electron microscopy, spectrally resolved fluorescence imaging and dye encapsulation techniques. We show that it is possible to sequester both hydrophobic as well as hydrophilic dyes within the nanostructures. Finally, we show that these non-cytotoxic manno-sylated rods and polymersomes were selectively and efficiently taken up by MDA-MB-231 breast cancer cells demonstrating their potential as nanocarriers for drug delivery.

  7. Wolbachia surface protein induces innate immune responses in mosquito cells

    Directory of Open Access Journals (Sweden)

    Pinto Sofia B

    2012-01-01

    Full Text Available Abstract Background Wolbachia endosymbiotic bacteria are capable of inducing chronic upregulation of insect immune genes in some situations and this phenotype may influence the transmission of important insect-borne pathogens. However the molecules involved in these interactions have not been characterized. Results Here we show that recombinant Wolbachia Surface Protein (WSP stimulates increased transcription of immune genes in mosquito cells derived from the mosquito Anopheles gambiae, which is naturally uninfected with Wolbachia; at least two of the upregulated genes, TEP1 and APL1, are known to be important in Plasmodium killing in this species. When cells from Aedes albopictus, which is naturally Wolbachia-infected, were challenged with WSP lower levels of upregulation were observed than for the An. gambiae cells. Conclusions We have found that WSP is a strong immune elicitor in a naturally Wolbachia-uninfected mosquito species (Anopheles gambiae while a milder elicitor in a naturally-infected species (Aedes albopictus. Since the WSP of a mosquito non-native (nematode Wolbachia strain was used, these data suggest that there is a generalized tolerance to WSP in Ae. albopictus.

  8. Carbohydrate Metabolism in Submariner Personnel

    Science.gov (United States)

    1983-06-01

    metabolism the Wilkerson Point System, for glucose values, used in conjunction with patterns of insulin response described by Kraft(4) serves as the means...amount of exercise and carbohydrate metabolism characteristics occurred in both submariners and non-submariners. An inverse relationship also seems to...individuals(7). In the present study a significant negative correlation was also found between exercise vs one and two hour postprandial glucose and two hour

  9. Carbohydrates Through Animation: Preliminary Step

    OpenAIRE

    J.K. Sugai; M.S.R. Figueiredo; ANTÔNIO, R. V.; P. M. Oliveira; V.A Cardoso; Ricardo, J.; Merino, E.; L.F Figueiredo; D.N. Heidrich

    2004-01-01

    Methods of education are changing, so the educational tools must change too. The developmentof the systems of information and communication gave the opportunity to bring new technology tothe learning process. Modern education needs interactive programs that may be available to theacademic community, in order to ease the learning process and sharing of the knowledge. Then,an educational software on Carbohydrates is being developed using concept maps and FLASH-MXanimations program, and approach...

  10. Dynamic interplay between adhesion surfaces in carcinomas:Cell-cell and cell-matrix crosstalk

    Institute of Scientific and Technical Information of China (English)

    Yvonne E Smith; Sri HariKrishna Vellanki; Ann M Hopkins

    2016-01-01

    Cell-cell and cell-matrix signaling and communication between adhesion sites involve mechanisms which are required for cellular functions during normal development and homeostasis; however these cellular functions and mechanisms are often deregulated in cancer. Aberrant signaling at cell-cell and cell-matrix adhesion sites often involves downstream mediators including Rho GTPases and tyrosine kinases. This review discusses these molecules as putative mediators of cellular crosstalk between cell-cell and cell-matrix adhesion sites, in addition to their attractiveness as therapeutic targets in cancer. Interestingly, inter-junctional crosstalk mechanisms are frequently typified by the way in which bacterial and viral pathogens opportunistically infect or intoxicate mammalian cells. This review therefore also discusses the concept of learning from pathogen-host interaction studies to better understand coordinated communication between cell-cell and cell-matrix adhesion sites, in addition to highlighting the potential therapeutic usefulness of exploiting pathogens or their products to tap into inter-junctional crosstalk. Taken together, we feel that increased knowledge around mechanisms of cell-cell and cell-matrix adhesion site crosstalk and consequently a greater understanding of their therapeutic targeting offers a unique opportunity to contribute to the emerging molecular revolution in cancer biology.

  11. Identifying Carbohydrate Ligands of a Norovirus P Particle using a Catch and Release Electrospray Ionization Mass Spectrometry Assay

    Science.gov (United States)

    Han, Ling; Kitova, Elena N.; Tan, Ming; Jiang, Xi; Klassen, John S.

    2014-01-01

    Noroviruses (NoVs), the major cause of epidemic acute gastroenteritis, recognize human histo-blood group antigens (HBGAs), which are present as free oligosaccharides in bodily fluid or glycolipids and glycoproteins on the surfaces of cells. The subviral P particle formed by the protruding (P) domain of the NoV capsid protein serves as a useful model for the study NoV-HBGA interactions. Here, we demonstrate the application of a catch-and-release electrospray ionization mass spectrometry (CaR-ESI-MS) assay for screening carbohydrate libraries against the P particle to rapidly identify NoV ligands and potential inhibitors. Carbohydrate libraries of 50 and 146 compounds, which included 18 and 24 analogs of HBGA receptors, respectively, were screened against the P particle of VA387, a member of the predominant GII.4 NoVs. Deprotonated ions corresponding to the P particle bound to carbohydrates were isolated and subjected to collision-induced dissociation to release the ligands in their deprotonated forms. The released ligands were identified by ion mobility separation followed by mass analysis. All 13 and 16 HBGA ligands with intrinsic affinities >500 M-1 were identified in the 50 and the 146 compound libraries, respectively. Furthermore, screening revealed interactions with a series of oligosaccharides with structures found in the cell wall of mycobacteria and human milk. The affinities of these newly discovered ligands are comparable to those of the HBGA receptors, as estimated from the relative abundance of released ligand ions.

  12. HOS cell adhesion on Ti6Al4V surfaces texturized by laser engraving

    Science.gov (United States)

    Sandoval Amador, A.; Carreño Garcia, H.; Escobar Rivero, P.; Peña Ballesteros, D. Y.; Estupiñán Duran, H. A.

    2016-02-01

    The cell adhesion of the implant is determinate by the chemical composition, topography, wettability, surface energy and biocompatibility of the biomaterial. In this work the interaction between human osteosarcoma HOS cells and textured Ti6Al4V surfaces were evaluated. Ti6Al4V surfaces were textured using a CO2 laser in order to obtain circular spots on the surfaces. Test surfaces were uncoated (C1) used as a control surface, and surfaces with points obtained by laser engraving, with 1mm spacing (C2) and 0.5mm (C3). The HOS cells were cultured in RPMI-1640 medium with 10% fetal bovine serum and 1% antibiotics. No cells toxicity after one month incubation time occurred. The increased cell adhesion and cell spreading was observed after 1, 3 and 5 days without significant differences between the sample surfaces (C2 and C3) and control (uncoated) at the end of the experiment.

  13. Back surface cell structures for reducing recombination in CZ silicon solar cells

    Science.gov (United States)

    King, R. R.; Mitchell, K. W.; Gee, J. M.

    1994-12-01

    Mass-produced terrestrial CZ silicon solar cells are currently entering the domain in which bulk diffusion length is comparable to the cell thickness, so that recombination at the back surface can have a significant effect on device performance. Three manufacturable processes that address the problem of back recombination are examined here: boron diffusion from a deposited doped SiO2, layer; Al-alloyed layers using screen-printed paste; and use of a collecting n* layer on the back interdigitated with the positive electrode. 104 sq cm cells fabricated at Siemens Solar Industries using these back surface structures are characterized by current-voltage, spectral response, photoconductivity decay, and SIMS measurements.

  14. Cell surface glycan alterations in epithelial mesenchymal transition process of Huh7 hepatocellular carcinoma cell.

    Directory of Open Access Journals (Sweden)

    Shan Li

    Full Text Available BACKGROUND AND OBJECTIVE: Due to recurrence and metastasis, the mortality of Hepatocellular carcinoma (HCC is high. It is well known that the epithelial mesenchymal transition (EMT and glycan of cell surface glycoproteins play pivotal roles in tumor metastasis. The goal of this study was to identify HCC metastasis related differential glycan pattern and their enzymatic basis using a HGF induced EMT model. METHODOLOGY: HGF was used to induce HCC EMT model. Lectin microarray was used to detect the expression of cell surface glycan and the difference was validated by lectin blot and fluorescence cell lectin-immunochemistry. The mRNA expression levels of glycotransferases were determined by qRT-PCR. RESULTS: After HGF treatment, the Huh7 cell lost epithelial characteristics and obtained mesenchymal markers. These changes demonstrated that HGF could induce a typical cell model of EMT. Lectin microarray analysis identified a decreased affinity in seven lectins ACL, BPL, JAC, MPL, PHA-E, SNA, and SBA to the glycan of cell surface glycoproteins. This implied that glycan containing T/Tn-antigen, NA2 and bisecting GlcNAc, Siaα2-6Gal/GalNAc, terminal α or βGalNAc structures were reduced. The binding ability of thirteen lectins, AAL, LCA, LTL, ConA, NML, NPL, DBA, HAL, PTL II, WFL, ECL, GSL II and PHA-L to glycan were elevated, and a definite indication that glycan containing terminal αFuc and ± Sia-Le, core fucose, α-man, gal-β(α GalNAc, β1,6 GlcNAc branching and tetraantennary complex oligosaccharides structures were increased. These results were further validated by lectin blot and fluorescence cell lectin-immunochemistry. Furthermore, the mRNA expression level of Mgat3 decreased while that of Mgat5, FucT8 and β3GalT5 increased. Therefore, cell surface glycan alterations in the EMT process may coincide with the expression of glycosyltransferase. CONCLUSIONS: The findings of this study systematically clarify the alterations of cell surface

  15. Interaction of progenitor bone cells with different surface modifications of titanium implant

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wen-Cheng, E-mail: wencchen@fcu.edu.tw [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Chen, Ya-Shun [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Ko, Chia-Ling [Advanced Medical Devices and Composites Laboratory, Department of Fiber and Composite Materials, College of Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Dental Medical Devices and Materials Research Center, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Lin, Yi; Kuo, Tzu-Huang; Kuo, Hsien-Nan [Medical Device Development Division, Metal Industries Research and Development Centre, Kaohsiung 82151, Taiwan (China)

    2014-04-01

    Changes in the physical and chemical properties of Ti surfaces can be attributed to cell performance, which improves surface biocompatibility. The cell proliferation, mineralization ability, and gene expression of progenitor bone cells (D1 cell) were compared on five different Ti surfaces, namely, mechanical grinding (M), electrochemical modification through potentiostatic anodization (ECH), sandblasting and acid etching (SLA), sandblasting, hydrogen peroxide treatment, and heating (SAOH), and sandblasting, alkali heating, and etching (SMART). SAOH treatment produced the most hydrophilic surface, whereas SLA produced the most hydrophobic surface. Cell activity indicated that SLA and SMART produced significantly rougher surfaces and promoted D1 cell attachment within 1 day of culturing, whereas SAOH treatment produced moderate roughness (Ra = 1.26 μm) and accelerated the D1 cell proliferation up to 7 days after culturing. The ECH surface significantly promoted alkaline phosphatase (ALP) expression and osteocalcin (OCN) secretion in the D1 cells compared with the other surface groups. The ECH and SMART-treated Ti surfaces resulted in maximum ALP and OCN expressions during the D1 cell culture. SLA, SAOH, and SMART substrate surfaces were rougher and exhibited better cell metabolic responses during the early stage of cell attachment, proliferation, and morphologic expressions within 1 day of D1 cell culture. The D1 cells cultured on the ECH and SMART substrates exhibited higher differentiation, and higher ALP and OCN expressions after 10 days of culture. Thus, the ECH and SMART treatments promote better ability of cell mineralization in vitro, which demonstrate their great potential for clinical use. - Highlights: • Progenitor bone cells onto Ti with different modifications are characterized. • Surface roughness and hydrophilicity encourage early stage cell attachment. • Composition and surface treatments are more vital in bone cell mineralization.

  16. Enteroendocrine cells are specifically marked by cell surface expression of claudin-4 in mouse small intestine.

    Directory of Open Access Journals (Sweden)

    Takahiro Nagatake

    Full Text Available Enteroendocrine cells are solitary epithelial cells scattered throughout the gastrointestinal tract and produce various types of hormones, constituting one of the largest endocrine systems in the body. The study of these rare epithelial cells has been hampered by the difficulty in isolating them because of the lack of specific cell surface markers. Here, we report that enteroendocrine cells selectively express a tight junction membrane protein, claudin-4 (Cld4, and are efficiently isolated with the use of an antibody specific for the Cld4 extracellular domain and flow cytometry. Sorted Cld4+ epithelial cells in the small intestine exclusively expressed a chromogranin A gene (Chga and other enteroendocrine cell-related genes (Ffar1, Ffar4, Gpr119, and the population was divided into two subpopulations based on the activity of binding to Ulex europaeus agglutinin-1 (UEA-1. A Cld4+UEA-1- cell population almost exclusively expressed glucose-dependent insulinotropic polypeptide gene (Gip, thus representing K cells, whereas a Cld4+UEA-1+ cell population expressed other gut hormone genes, including glucagon-like peptide 1 (Gcg, pancreatic polypeptide-like peptide with N-terminal tyrosine amide (Pyy, cholecystokinin (Cck, secretin (Sct, and tryptophan hydroxylase 1 (Tph1. In addition, we found that orally administered luminal antigens were taken up by the solitary Cld4+ cells in the small intestinal villi, raising the possibility that enteroendocrine cells might also play a role in initiation of mucosal immunity. Our results provide a useful tool for the cellular and functional characterization of enteroendocrine cells.

  17. Solvent structure improves docking prediction in lectin-carbohydrate complexes.

    Science.gov (United States)

    Gauto, Diego F; Petruk, Ariel A; Modenutti, Carlos P; Blanco, Juan I; Di Lella, Santiago; Martí, Marcelo A

    2013-02-01

    Recognition and complex formation between proteins and carbohydrates is a key issue in many important biological processes. Determination of the three-dimensional structure of such complexes is thus most relevant, but particularly challenging because of their usually low binding affinity. In silico docking methods have a long-standing tradition in predicting protein-ligand complexes, and allow a potentially fast exploration of a number of possible protein-carbohydrate complex structures. However, determining which of these predicted complexes represents the correct structure is not always straightforward. In this work, we present a modification of the scoring function provided by AutoDock4, a widely used docking software, on the basis of analysis of the solvent structure adjacent to the protein surface, as derived from molecular dynamics simulations, that allows the definition and characterization of regions with higher water occupancy than the bulk solvent, called water sites. They mimic the interaction held between the carbohydrate -OH groups and the protein. We used this information for an improved docking method in relation to its capacity to correctly predict the protein-carbohydrate complexes for a number of tested proteins, whose ligands range in size from mono- to tetrasaccharide. Our results show that the presented method significantly improves the docking predictions. The resulting solvent-structure-biased docking protocol, therefore, appears as a powerful tool for the design and optimization of development of glycomimetic drugs, while providing new insights into protein-carbohydrate interactions. Moreover, the achieved improvement also underscores the relevance of the solvent structure to the protein carbohydrate recognition process.

  18. Graphene Oxide Modulates B Cell Surface Phenotype and Impairs Immunoglobulin Secretion in Plasma Cell.

    Science.gov (United States)

    Xu, Shaohai; Xu, Shengmin; Chen, Shaopeng; Fan, Huadong; Luo, Xun; Yang, Xiaoyao; Wang, Jun; Yuan, Hang; Xu, An; Wu, Lijun

    2016-04-01

    Since discovery, graphene oxide (GO) has been used in all aspects of human life and revealed promising applications in biomedicine. Nevertheless, the potential risks of GO were always being revealed. Although GO was found to induce immune cell death and innate immune response, little is known regarding its toxicity to the specific adaptive immune system that is crucial for protecting against exotic invasion. The B-cell mediated adaptive immune system, which composed of highly specialized cells (B and plasma cell) and specific immune response (antibody response) is the focus in our present study. Using diverse standard immunological techniques, we found that GO modulated B cell surface phenotype, both costimulatory molecules (CD80, CD86 and especially CD40) and antigen presenting molecules (both classical and nonclassical) under the condition without causing cell death. Meanwhile, the terminal differentiated immunoglobulin (Ig) secreting plasma cell was affected by GO, which displayed a less secretion of Ig and more severe ER stress caused by the retention of the secreted form of Ig in cell compartment. The combined data reveal that GO has a particular adverse effect to B cell and the humoral immunity, directly demonstrating the potential risk of GO to the specific adaptive immunity.

  19. Cell adhesion behavior on the silicone rubber surface modified by using ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, In Tae; Jung, Chan Hee; Nh, Young Chang; Choi, Jae Hak [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kuk, In Seol [Hanyang University, Seoul (Korea, Republic of); An, Mi Young [Chungnam National University, Daejeon (Korea, Republic of)

    2009-12-15

    In this study we studied cell adhesion and proliferation on the surface of a silicone rubber modified by ion beam irradiation. The surface property of the irradiated silicone rubber was characterized by water contact angle and FT-IR analyses. It was observed that human (HEK293) fibroblast cells exhibit strong adhesion to the irradiated silicone surface. This enhanced adhesion of mammalian cells can be attributed to the increase in the hydrophilicity of the silicone surface by ion beam irradiation.

  20. A yeast surface display system for the discovery of ligands that trigger cell activation.

    Science.gov (United States)

    Cho, B K; Kieke, M C; Boder, E T; Wittrup, K D; Kranz, D M

    1998-11-01

    Opposing cells often communicate signalling events using multivalent interactions between receptors present on their cell surface. For example, T cells are typically activated when the T cell receptor (TCR) and its associated costimulatory molecules are multivalently engaged by the appropriate ligands present on an antigen presenting cell. In this report, yeast expressing high cell-surface levels of a TCR ligand (a recombinant antibody to the TCR Vbeta domain) were shown to act as 'pseudo' antigen presenting cells and induce T cell activation as monitored by increased levels of CD25 and CD69 and by downregulation of cell surface TCR. Similar levels of T cell activation could occur even when a 30-fold excess of irrelevant yeast was present, suggesting that such a yeast display system, by virtue of its ability to present ligands multivalently, may be used in highly sensitive procedures to identify novel polypeptides that interact multivalently with cell surface receptors and thereby trigger specific cellular responses.

  1. Peroxisome proliferator-activated receptor alpha (PPARalpha) protects against oleate-induced INS-1E beta cell dysfunction by preserving carbohydrate metabolism

    DEFF Research Database (Denmark)

    Frigerio, F; Brun, T; Bartley, C;

    2009-01-01

    AIMS/HYPOTHESIS: Pancreatic beta cells chronically exposed to fatty acids may lose specific functions and even undergo apoptosis. Generally, lipotoxicity is triggered by saturated fatty acids, whereas unsaturated fatty acids induce lipodysfunction, the latter being characterised by elevated basal...... enzyme pyruvate carboxylase. PPARalpha overproduction increased both beta-oxidation and fatty acid storage in the form of neutral triacylglycerol, revealing overall induction of lipid metabolism. These observations were substantiated by expression levels of associated genes. CONCLUSIONS...

  2. Carbohydrates in size fractionated dissolved organic matter in a station of the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, L.; DeSouza, F.; Bhosle, N.B.

    of the dissolved organic matter (DOM) were collected using Amicon stirred Ultrafiltration Cell, and analysed for dissolved organic carbon (UDOC), total carbohydrates (UTCHO) and neutral sugars (UNS). UDOC concentrations were relatively higher in HMW fraction...

  3. A systematic study of chemogenomics of carbohydrates.

    Science.gov (United States)

    Gu, Jiangyong; Luo, Fang; Chen, Lirong; Yuan, Gu; Xu, Xiaojie

    2014-03-04

    Chemogenomics focuses on the interactions between biologically active molecules and protein targets for drug discovery. Carbohydrates are the most abundant compounds in natural products. Compared with other drugs, the carbohydrate drugs show weaker side effects. Searching for multi-target carbohydrate drugs can be regarded as a solution to improve therapeutic efficacy and safety. In this work, we collected 60 344 carbohydrates from the Universal Natural Products Database (UNPD) and explored the chemical space of carbohydrates by principal component analysis. We found that there is a large quantity of potential lead compounds among carbohydrates. Then we explored the potential of carbohydrates in drug discovery by using a network-based multi-target computational approach. All carbohydrates were docked to 2389 target proteins. The most potential carbohydrates for drug discovery and their indications were predicted based on a docking score-weighted prediction model. We also explored the interactions between carbohydrates and target proteins to find the pathological networks, potential drug candidates and new indications.

  4. Micropatterned polysaccharide surfaces via laser ablation for cell guidance

    Energy Technology Data Exchange (ETDEWEB)

    Barbucci, Rolando; Lamponi, Stefania; Pasqui, Daniela; Rossi, Antonella; Weber, Elisabetta

    2003-03-03

    Micropatterned materials were obtained by a controlled laser ablation of a photoimmobilised homogeneous layer of hyaluronic acid (Hyal) and its sulphated derivative (HyalS). The photoimmobilisation was performed by coating the polysaccharide, adequately functionalised with a photoreactive group, on aminosilanised glass substrate and immobilising it on the surface under UV light. Hyal or HyalS photoimmobilised samples were then subjected to laser ablation with wavelengths in the UV regions in order to drill the pattern. Four different patterns with stripes of 100, 50, 25 and 10 {mu}m were generated. A chemical characterisation by attenuated total reflection/Fourier transform infrared (ATR/FT-IR) and time of flight-secondary ions mass spectrometry (TOF-SIMS) confirmed the success of the laser ablation procedure and the presence of alternating stripes of polysaccharide and native glass. The exact dimensions of the stripes were determined by atomic force microscopy. The analysis of cell behaviour in terms of adhesion, proliferation and movement using mouse fibroblasts (3T3 line) and bovine aortic endothelial cells (BAEC) was also performed.

  5. MC3T3-E1 Cells on Titanium Surfaces with Nanometer Smoothness and Fibronectin Immobilization

    Directory of Open Access Journals (Sweden)

    Tohru Hayakawa

    2012-01-01

    Full Text Available The present study was aimed to evaluate the viability and total protein contents of osteoblast-like cells on the titanium surface with different surface mechanical treatment, namely, nanometer smoothing (Ra: approximately 2.0 nm and sandblasting (Ra: approximately 1.0 μm, and biochemical treatment, namely, with or without fibronectin immobilization. Fibronectin could be easily immobilized by tresyl chloride-activation technique. MC3T3-E1 cells were seeded on the different titanium surfaces. Cell viability was determined by MTT assay. At 1 day of cell culture, there were no significant differences in cell viability among four different titanium surfaces. At 11 days, sandblasted titanium surface with fibronectin immobilization showed the significantly highest cell viability than other titanium surface. No significant differences existed for total protein contents among four different titanium surfaces at 11 days of cell culture. Scanning electron microscopy observation revealed that smoothness of titanium surface produced more spread cell morphologies, but that fibronectin immobilization did not cause any changes of the morphologies of attached cells. Fibronectin immobilization provided greater amount of the number of attached cells and better arrangement of attached cells. In conclusion, the combination of sandblasting and fibronectin immobilization enhanced the cell viability and fibronectin immobilization providing better arrangements of attached cells.

  6. Flow cytometry detection of planktonic cells with polycyclic aromatic hydrocarbons sorbed to cell surfaces

    KAUST Repository

    Cerezo, Maria I.

    2017-02-17

    Polycyclic aromatic hydrocarbons are very important components of oil pollution. These pollutants tend to sorb to cell surfaces, exerting toxic effects on organisms. Our study developed a flow cytometric method for the detection of PAHs sorbed to phytoplankton by exploiting their spectral characteristics. We discriminated between cells with PAHs from cells free of PAHs. Clear discrimination was observed with flow cytometer provided with 375 or 405nm lasers in addition to the standard 488nm laser necessary to identify phytoplankton. Using this method, we measured the relationship between the percentages of phytoplankton organisms with PAHs, with the decrease in the growth rate. Moreover, the development of this method could be extended to facilitate the study of PAHs impact on cell cultures from a large variety of organisms.

  7. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors

    DEFF Research Database (Denmark)

    Isa, Adiba; Nehlin, Jan; Sabir, Hardee Jawad;

    2010-01-01

    HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C...... at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either...... undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC) using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced...

  8. Cell adhesion on Ti surface with controlled roughness

    Directory of Open Access Journals (Sweden)

    Burgos-Asperilla, Laura

    2015-06-01

    Full Text Available In this report, the in situ interaction between Saos-2 osteoblast cells and a smooth Ti surface was examined over time. The adhesion kinetics and mechanisms of cellular proliferation were monitored by quartz crystal microbalance (QCM and electrochemical impedance spectroscopy (EIS. The rate of Saos-2 attachment on Ti surfaces, obtained from the measurements performed with the QCM, is a first-order reaction, with k=2.10−3 min−1. The impedance measurements indicate that in the absence of cells, the Ti resistance diminishes over time (7 days, due to the presence of amino acids and proteins from the culture medium that have been a dsorbed, while in the presence of osteoblasts, this decrease is much greater because of the compounds generated by the cells that accelerate the dissolution of Ti.En este trabajo, se ha estudiado la interacción in situ entre células osteoblásticas Saos-2 y una superficie de Ti de rugosidad controlada a lo largo del tiempo. El estudio de la cinética y los mecanismos de proliferación celular de adhesión se ha realizado a través de la microbalanza de cristal de cuarzo (QCM y espectroscopía de impedancia electroquímica (EIS. La velocidad de adhesión de los osteoblastos sobre la superficie de Ti obtenida a través de medidas con la QCM, sigue una reacción de primer orden, con k=2×10−3 min−1. Los ensayos de impedancia indican que, en ausencia de las células, la resistencia del Ti disminuye con el tiempo (7 días, debido a la presencia de aminoácidos y proteínas del medio de cultivo que se han adsorbido, mientras que en presencia de células, esta disminución es mucho mayor debido a los productos metabólicos generados por las células que aceleran la disolución del Ti.

  9. X-ray photoelectron spectroscopy for the study of microbial cell surfaces

    NARCIS (Netherlands)

    van der Mei, Henderina C; de Vries, Jacob; Busscher, Hendrik J

    2000-01-01

    X-ray photoelectron spectroscopy (XPS) is well known for the characterisation of material surfaces, but at first glance, is an unexpected technique to study the composition of microbial cell surfaces. Despite the fact that intimate contact between materials and microbial cell surfaces occurs in many

  10. Targeting Cell Surface Proteins in Molecular Photoacoustic Imaging to Detect Ovarian Cancer Early

    Science.gov (United States)

    2013-07-01

    10-1-0422 TITLE: Targeting Cell Surface Proteins in Molecular Photoacoustic Imaging to Detect Ovarian Cancer Early PRINCIPAL...DATES COVERED 1 July 2010 - 30 June 2013 4. TITLE AND SUBTITLE Targeting Cell Surface Proteins in Molecular 5a. CONTRACT NUMBER Photoacoustic ...upon request). Aim 2) Prioritize ovarian cancer-associated surface proteins for their utility as molecular photoacoustic imaging targets and

  11. Carbohydrates

    Science.gov (United States)

    ... products, and do not help you feel as satisfied. FIBER High-fiber foods include: Whole grains, such ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  12. Surface topography during neural stem cell differentiation regulates cell migration and cell morphology.

    Science.gov (United States)

    Czeisler, Catherine; Short, Aaron; Nelson, Tyler; Gygli, Patrick; Ortiz, Cristina; Catacutan, Fay Patsy; Stocker, Ben; Cronin, James; Lannutti, John; Winter, Jessica; Otero, José Javier

    2016-12-01

    We sought to determine the contribution of scaffold topography to the migration and morphology of neural stem cells by mimicking anatomical features of scaffolds found in vivo. We mimicked two types of central nervous system scaffolds encountered by neural stem cells during development in vitro by constructing different diameter electrospun polycaprolactone (PCL) fiber mats, a substrate that we have shown to be topographically similar to brain scaffolds. We compared the effects of large fibers (made to mimic blood vessel topography) with those of small-diameter fibers (made to mimic radial glial process topography) on the migration and differentiation of neural stem cells. Neural stem cells showed differential migratory and morphological reactions with laminin in different topographical contexts. We demonstrate, for the first time, that neural stem cell biological responses to laminin are dependent on topographical context. Large-fiber topography without laminin prevented cell migration, which was partially reversed by treatment with rock inhibitor. Cell morphology complexity assayed by fractal dimension was inhibited in nocodazole- and cytochalasin-D-treated neural precursor cells in large-fiber topography, but was not changed in small-fiber topography with these inhibitors. These data indicate that cell morphology has different requirements on cytoskeletal proteins dependent on the topographical environment encountered by the cell. We propose that the physical structure of distinct scaffolds induces unique signaling cascades that regulate migration and morphology in embryonic neural precursor cells. J. Comp. Neurol. 524:3485-3502, 2016. © 2016 Wiley Periodicals, Inc.

  13. Carbohydrate composition of compost during composting and mycelium growth of Agaricus bisporus.

    Science.gov (United States)

    Jurak, Edita; Kabel, Mirjam A; Gruppen, Harry

    2014-01-30

    Changes of plant cell wall carbohydrate structures occurring during the process to make suitable compost for growth of Agaricus bisporus are unknown. In this paper, composition and carbohydrate structures in compost samples collected during composting and mycelium growth were analyzed. Furthermore, different extracts of compost samples were prepared with water, 1M and 4M alkali and analyzed. At the beginning of composting, 34% and after 16 days of mycelium growth 27% of dry matter was carbohydrates. Carbohydrate composition analysis showed that mainly cellulose and poorly substituted xylan chains with similar amounts and ratios of xylan building blocks were present in all phases studied. Nevertheless, xylan solubility increased 20% over the period of mycelium growth indicating partial degradation of xylan backbone. Apparently, degradation of carbohydrates occurred over the process studied by both bacteria and fungi, mainly having an effect on xylan-chain length and solubility.

  14. Effect of methyl jasmonate in combination with carbohydrates on gene expression of PR proteins, stilbene and anthocyanin accumulation in grapevine cell cultures.

    Science.gov (United States)

    Belhadj, Assia; Telef, Nadège; Saigne, Cassandrine; Cluzet, Stéphanie; Barrieu, François; Hamdi, Saïd; Mérillon, Jean-Michel

    2008-04-01

    Grapevine (Vitis vinifera L.) is subject to a number of diseases which affect yield and wine quality. After veraison, berries become strongly susceptible to pathogens due to different physiological changes including the accumulation of glucose and fructose, on the one hand, and to the decrease of anti-microbial compounds called stilbenes, on the other. To obtain berry protection, pesticides are excessively used leading to important cost to the grower and to undesirable environmental impact of the residues, especially in grape, soil and water. As a consequence, alternative strategies have to be developed. Exogenously applied biotic elicitors induce defense responses. We studied the effects of methyl jasmonate in combination with sucrose on defense-related gene expression, stilbene and anthocyanin production in grapevine cell suspensions. The methyl jasmonate/sucrose treatment was effective in stimulating phenylalanine ammonia lyase, chalcone synthase, stilbene synthase, UDP-glucose: flavonoid-O-glucosyltransferase, proteinase inhibitor and chitinase gene expression, and triggered accumulation of both piceids and anthocyanins in cells, and trans-resveratrol and piceids in the extracellular medium. Methyl jasmonate treatment might be an efficient natural strategy to protect grapevine berries in vineyard.

  15. Surface Grafted Glycopolymer Brushes to Enhance Selective Adhesion of HepG2 Cells

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Jensen, Bettina Elisabeth Brøgger; Shimizu, Kyoko;

    2013-01-01

    of the cell periphery. On the other hand the cells on bare glass substrate display spheroid morphology. Further analysis using ToF-SIMS imaging shows that the HepG2 cells on glycopolymer surfaces is enriched with protein fragment along the cell periphery which is absent in the case of cells on bare glass...

  16. Comparison of the carbohydrate moieties of recombinant soluble Fc epsilon receptor (sFc epsilon RII/sCD23) expressed in Saccharomyces cerevisiae and Chinese hamster ovary cells. Different O-glycosylation sites are used by yeast and mammalian cells.

    Science.gov (United States)

    Kalsner, I; Schneider, F J; Geyer, R; Ahorn, H; Maurer-Fogy, I

    1992-08-01

    Recombinant human soluble low affinity receptor for the Fc portion of IgE (sFc epsilon RII/sCD23) was produced in Saccharomyces cerevisiae or Chinese hamster ovary cells and subjected to carbohydrate analysis. Applied methods included analytical SDS-PAGE, reversed phase HPLC, methylation analysis and sequential degradation with exoglycosidases. The results revealed that sFc epsilon RII derived from Chinese hamster ovary cells is glycosylated exclusively at Ser-147, containing mainly the trisaccharide Sia(alpha 2-3)Gal(beta 1-3)GalNAc, whereas the yeast derived glycoprotein was glycosylated at Ser-167 and contained only alpha-mannosyl residues. It is shown here for the first time that different amino acids of a given protein can be O-glycosylated when expressed in yeast or Chinese hamster ovary cells.

  17. Distribution, Arrangement and Interconnectedness of Cell Surface Receptor sites in the body of an Organism

    Directory of Open Access Journals (Sweden)

    Utoh-Nedosa

    2011-01-01

    Full Text Available Cell surface receptors have been identified as the sites of disease infectivity in living organisms in a previous study. Drugs used for the treatment or cure of infections have to eliminate infections through attacking infective organisms at the cell surface receptors to which the infective organisms are attached. Problem statement: The present study examines a wide sample of living things to get more information on the relationship of one cell surface receptor to other cell surface receptors in the body of an organism. Approach: The arrangement of cell surface receptors on the external covering of a few samples of fruits, leaves, stems, dry wood of a plant; wall gecko and some parts of the human body, were examined and photographed. Transverse and/or Longitudinal sections of soursop fruit and sycamore fruit were also examined and photographed. The five different coverings of the fleshy part of a coconut were also photographed. The photographs were studied to note the relationship of disease infection attached to cell surface receptors on the external surface of an organ to disease infection on the innermost covering of the same organ. Results: The results of the study showed that all living things had ubiquitous distribution of cell surface receptors which are usually observable with the unaided eye as dots or spots on the external covering of an organ, tissue or cell. The dots or receptor sites of cell surface receptors in the study are arranged in lines which were perpendicular, oblique, transverse or arranged in any other lineal geometrical form. The lineally arranged cell surface receptors were noted to be connected by grooves, channels or pipes which joined other receptor channels or intersected with them. Smaller cell surface receptor channels emptied into bigger channels or continued as small sized channels that ran side by side in a connective tissue bundle. These connective tissue bundles that carried many independent small-sized cell

  18. Quantitative comparison of a human cancer cell surface proteome between interphase and mitosis.

    Science.gov (United States)

    Özlü, Nurhan; Qureshi, Mohammad H; Toyoda, Yusuke; Renard, Bernhard Y; Mollaoglu, Gürkan; Özkan, Nazlı E; Bulbul, Selda; Poser, Ina; Timm, Wiebke; Hyman, Anthony A; Mitchison, Timothy J; Steen, Judith A

    2015-01-13

    The cell surface is the cellular compartment responsible for communication with the environment. The interior of mammalian cells undergoes dramatic reorganization when cells enter mitosis. These changes are triggered by activation of the CDK1 kinase and have been studied extensively. In contrast, very little is known of the cell surface changes during cell division. We undertook a quantitative proteomic comparison of cell surface-exposed proteins in human cancer cells that were tightly synchronized in mitosis or interphase. Six hundred and twenty-eight surface and surface-associated proteins in HeLa cells were identified; of these, 27 were significantly enriched at the cell surface in mitosis and 37 in interphase. Using imaging techniques, we confirmed the mitosis-selective cell surface localization of protocadherin PCDH7, a member of a family with anti-adhesive roles in embryos. We show that PCDH7 is required for development of full mitotic rounding pressure at the onset of mitosis. Our analysis provided basic information on how cell cycle progression affects the cell surface. It also provides potential pharmacodynamic biomarkers for anti-mitotic cancer chemotherapy.

  19. Applications of synthetic carbohydrates to chemical biology.

    Science.gov (United States)

    Lepenies, Bernd; Yin, Jian; Seeberger, Peter H

    2010-06-01

    Access to synthetic carbohydrates is an urgent need for the development of carbohydrate-based drugs, vaccines, adjuvants as well as novel drug delivery systems. Besides traditional synthesis in solution, synthetic carbohydrates have been generated by chemoenzymatic methods as well as automated solid-phase synthesis. Synthetic oligosaccharides have proven to be useful for identifying ligands of carbohydrate-binding proteins such as C-type lectins and siglecs using glycan arrays. Furthermore, glyconanoparticles and glycodendrimers have been used for specific targeting of lectins of the immune system such as selectins, DC-SIGN, and CD22. This review focuses on how diverse carbohydrate structures can be synthetically derived and highlights the benefit of synthetic carbohydrates for glycobiology.

  20. Surface complexation of neptunium (V) onto whole cells and cell componets of Shewanella alga

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald Timothy [Los Alamos National Laboratory; Deo, Randhir P [ASU; Rittmann, Bruce E [ASU; Songkasiri, Warinthorn [UNAFFILIATED

    2008-01-01

    We systematically quantified surface complexation of neptunium(V) onto whole cells of Shewanella alga strain BrY and onto cell wall and extracellular polymeric substances (EPS) of S. alga. We first performed acid and base titrations and used the mathematical model FITEQL with constant-capacitance surface-complexation to determine the concentrations and deprotonation constants of specific surface functional groups. Deprotonation constants most likely corresponded to a carboxyl site associated with amino acids (pK{sub a} {approx} 2.4), a carboxyl group not associated with amino acids (pK{sub a} {approx} 5), a phosphoryl site (pK{sub a} {approx} 7.2), and an amine site (pK{sub a} > 10). We then carried out batch sorption experiments with Np(V) and each of the S. alga components at different pHs. Results show that solution pH influenced the speciation of Np(V) and each of the surface functional groups. We used the speciation sub-model of the biogeochemical model CCBATCH to compute the stability constants for Np(V) complexation to each surface functional group. The stability constants were similar for each functional group on S. alga bacterial whole cells, cell walls, and EPS, and they explain the complicated sorption patterns when they are combined with the aqueous-phase speciation of Np(V). For pH < 8, NpO{sub 2}{sup +} was the dominant form of Np(V), and its log K values for the low-pK{sub a} carboxyl, other carboxyl, and phosphoryl groups were 1.75, 1.75, and 2.5 to 3.1, respectively. For pH greater than 8, the key surface ligand was amine >XNH3+, which complexed with NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-}. The log K for NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} complexed onto the amine groups was 3.1 to 3.6. All of the log K values are similar to those of Np(V) complexes with aqueous carboxyl and N-containing carboxyl ligands. These results point towards the important role of surface complexation in defining key actinide-microbiological interactions in the subsurface.

  1. The effect of cerium valence states at cerium oxide nanoparticle surfaces on cell proliferation

    KAUST Repository

    Naganuma, Tamaki

    2014-05-01

    Understanding and controlling cell proliferation on biomaterial surfaces is critical for scaffold/artificial-niche design in tissue engineering. The mechanism by which underlying integrin ligates with functionalized biomaterials to induce cell proliferation is still not completely understood. In this study, poly-l-lactide (PL) scaffold surfaces were functionalized using layers of cerium oxide nanoparticles (CNPs), which have recently attracted attention for use in therapeutic application due to their catalytic ability of Ce4+ and Ce3+ sites. To isolate the influence of Ce valance states of CNPs on cell proliferation, human mesenchymal stem cells (hMSCs) and osteoblast-like cells (MG63) were cultured on the PL/CNP surfaces with dominant Ce4+ and Ce3+ regions. Despite cell type (hMSCs and MG63 cells), different surface features of Ce4+ and Ce3+ regions clearly promoted and inhibited cell spreading, migration and adhesion behavior, resulting in rapid and slow cell proliferation, respectively. Cell proliferation results of various modified CNPs with different surface charge and hydrophobicity/hydrophilicity, indicate that Ce valence states closely correlated with the specific cell morphologies and cell-material interactions that trigger cell proliferation. This finding suggests that the cell-material interactions, which influence cell proliferation, may be controlled by introduction of metal elements with different valence states onto the biomaterial surface. © 2014 Elsevier Ltd.

  2. Cell-surface proteoglycan in sea urchin primary mesenchyme cell migration

    Energy Technology Data Exchange (ETDEWEB)

    Lane, M.C.

    1989-01-01

    Early in the development of the sea urchin embryo, the primary mesenchyme cells (PMC) migrate along the basal lamina of the blastocoel. Migration is inhibited in L. pictus embryos cultured in sulfate-free seawater and in S. purpuratus embryos exposed to exogenous {beta}-D-xylosides. An in vitro assay was developed to test the migratory capacity of normal PMC on normal and treated blastocoelic matrix. Sulfate deprivation and exposure to exogenous xyloside render PMC nonmotile on either matrix. Materials removed from the surface of normal PMC by treatment with 1 M urea restored migratory ability to defective cells, whereas a similar preparation isolated from the surface of epithelial cells at the same stage did not. Migration also resumed when cells were removed from the xyloside or returned to normal seawater. The urea extract was partially purified and characterized by radiolabeling, gel electrophoresis, fluorography, ion exchange chromatography, and western blotting. The PMC synthesize a large chondroitin sulfate/dermatan sulfate proteoglycan that is present in an active fraction isolated by chromatography. Chondroitinase ABC digestion of live cells blocked migration reversibly, further supporting the identification of the chondroitin sulfate/dermatan sulfate proteoglycan as the active component in the urea extract. Much of the incorporated sulfate was distributed along the filopodia in {sup 35}SO{sub 4}-labelled PMC by autoradiography. The morphology of normal and treated S. purpuratus PMC was examined by scanning electron microscopy, and differences in spreading, particularly of the extensive filopodia present on the cells, was observed. A model for the role of the chondroitin sulfate/dermatan sulfate proteoglycan in cell detachment during migration is proposed.

  3. Low-carbohydrate nutrition and metabolism.

    Science.gov (United States)

    Westman, Eric C; Feinman, Richard D; Mavropoulos, John C; Vernon, Mary C; Volek, Jeff S; Wortman, James A; Yancy, William S; Phinney, Stephen D

    2007-08-01

    The persistence of an epidemic of obesity and type 2 diabetes suggests that new nutritional strategies are needed if the epidemic is to be overcome. A promising nutritional approach suggested by this thematic review is carbohydrate restriction. Recent studies show that, under conditions of carbohydrate restriction, fuel sources shift from glucose and fatty acids to fatty acids and ketones, and that ad libitum-fed carbohydrate-restricted diets lead to appetite reduction, weight loss, and improvement in surrogate markers of cardiovascular disease.

  4. Digestion of carbohydrates in the pig.

    Science.gov (United States)

    Drochner, W

    1993-01-01

    A review of carbohydrate digestion in the pig is given. The cascade of digestion in the mouth, stomach, small and large intestine is described. Principles of enzymatic and fermentative digestion according to new results with fistulated animals are discussed. The efficacy and quality of fermentation in the large intestine depending on level and quality of carbohydrates in the diet are demonstrated. Some aspects of energetical efficacy of hindgut digestion are discussed. Dietetic effects of carbohydrates are described.

  5. Regioselective azidotrimethylsilylation of carbohydrates and applications thereof.

    Science.gov (United States)

    L, Mallikharjuna Rao; Yousuf, Syed Khalid; Mukherjee, Debaraj; Taneja, Subhash Chandra

    2012-12-07

    Azidotrimethylsilylation of carbohydrates (monosaccharides and disaccharides) has been achieved in high yields under Mitsunobu conditions. The azidation of carbohydrates is effected at 0 °C essentially only at the primary alcoholic position in mono, di- and triols in protected/unprotected glycosides, whereas the remaining secondary hydroxyl groups got silylated. Surprisingly, no azidation of the secondary hydroxyls was observed in all the carbohydrate substrates. Applications of the methodology for the synthesis of amino sugars, triazoles and azasugars are reported.

  6. Carbohydrate-mediated inhibition of ice recrystallization in cryopreserved human umbilical cord blood.

    Science.gov (United States)

    Wu, Luke K; Tokarew, Jacqueline M; Chaytor, Jennifer L; von Moos, Elizabeth; Li, Yuhua; Palii, Carmen; Ben, Robert N; Allan, David S

    2011-01-01

    Cryopreservation of human umbilical cord blood (UCB) typically involves the cryoprotectant dimethylsulfoxide (DMSO), however, infusional toxicity and reductions in cell viability remain a concern. Ice recrystallization (IR) is an important source of cryopreservation-induced cellular injury and limits the stem cell dose in UCB units. Carbohydrates have wide-ranging intrinsic IR inhibition (IRI) activity related to structural properties. We investigated the impact of carbohydrate IRI on cell viability, induction of apoptosis and hematopoietic progenitor function in cryopreserved UCB. Mononuclear cells (MNCs) from UCB were cryopreserved in storage media containing specific carbohydrates (200mM) and compared to 5% DMSO. Samples were analyzed under conditions of high IR ('slow' thaw) and low IR ('fast' thaw). Thawed samples were analyzed for viability and apoptosis by flow cytometry and hematopoietic function using colony-forming unit (CFU) assays. IRI of carbohydrate solutions was determined using the 'splat cooling' assay. Greater IRI capacity of carbohydrates correlated with increased yield of viable MNCs (r(2)=0.92, p=0.004) and CD34(+) cells (r(2)=0.96, p=0.019) after thawing under conditions of high IR. The correlations were less apparent under conditions of low IR. Carbohydrates with greater IRI modulate the induction of early apoptosis during thawing, especially in CD34+ cells (r(2)=0.96, p=0.0001) as compared to total mononuclear cells (p=0.006), and preserve CFU capacity in vitro (r(2)=0.92, p=<0.0001). Our results suggest that carbohydrates with potent IRI increase the yield of non-apoptotic and functional hematopoietic progenitors and provide a foundation for the development of novel synthetic carbohydrates with enhanced IRI properties to improve cryopreservation of UCB.

  7. Carbohydrate Mimetic Peptides Augment Carbohydrate-Reactive Immune Responses in the Absence of Immune Pathology

    Energy Technology Data Exchange (ETDEWEB)

    Hennings, Leah; Artaud, Cecile; Jousheghany, Fariba; Monzavi-Karbassi, Behjatolah; Pashov, Anastas; Kieber-Emmons, Thomas, E-mail: tke@uams.edu [Winthrop P. Rockefeller Cancer Institute and Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States)

    2011-11-11

    Among the most challenging of clinical targets for cancer immunotherapy are Tumor Associated Carbohydrate Antigens (TACAs). To augment immune responses to TACA we are developing carbohydrate mimetic peptides (CMPs) that are sufficiently potent to activate broad-spectrum anti-tumor reactivity. However, the activation of immune responses against terminal mono- and disaccharide constituents of TACA raises concerns regarding the balance between “tumor destruction” and “tissue damage”, as mono- and disaccharides are also expressed on normal tissue. To support the development of CMPs for clinical trial testing, we demonstrate in preclinical safety assessment studies in mice that vaccination with CMPs can enhance responses to TACAs without mediating tissue damage to normal cells expressing TACA. BALB/c mice were immunized with CMPs that mimic TACAs reactive with Griffonia simplicifolia lectin 1 (GS-I), and tissue reactivity of serum antibodies were compared with the tissue staining profile of GS-I. Tissues from CMP immunized mice were analyzed using hematoxylin and eosin stain, and Luxol-fast blue staining for myelination. Western blots of membranes from murine mammary 4T1 cells, syngeneic with BALB/c mice, were also compared using GS-I, immunized serum antibodies, and naive serum antibodies. CMP immunization enhanced glycan reactivities with no evidence of pathological autoimmunity in any immunized mice demonstrating that tissue damage is not an inevitable consequence of TACA reactive responses.

  8. Carbohydrate Mimetic Peptides Augment Carbohydrate-Reactive Immune Responses in the Absence of Immune Pathology

    Directory of Open Access Journals (Sweden)

    Thomas Kieber-Emmons

    2011-11-01

    Full Text Available Among the most challenging of clinical targets for cancer immunotherapy are Tumor Associated Carbohydrate Antigens (TACAs. To augment immune responses to TACA we are developing carbohydrate mimetic peptides (CMPs that are sufficiently potent to activate broad-spectrum anti-tumor reactivity. However, the activation of immune responses against terminal mono- and disaccharide constituents of TACA raises concerns regarding the balance between “tumor destruction” and “tissue damage”, as mono- and disaccharides are also expressed on normal tissue. To support the development of CMPs for clinical trial testing, we demonstrate in preclinical safety assessment studies in mice that vaccination with CMPs can enhance responses to TACAs without mediating tissue damage to normal cells expressing TACA. BALB/c mice were immunized with CMPs that mimic TACAs reactive with Griffonia simplicifolia lectin 1 (GS-I, and tissue reactivity of serum antibodies were compared with the tissue staining profile of GS-I. Tissues from CMP immunized mice were analyzed using hematoxylin and eosin stain, and Luxol-fast blue staining for myelination. Western blots of membranes from murine mammary 4T1 cells, syngeneic with BALB/c mice, were also compared using GS-I, immunized serum antibodies, and naive serum antibodies. CMP immunization enhanced glycan reactivities with no evidence of pathological autoimmunity in any immunized mice demonstrating that tissue damage is not an inevitable consequence of TACA reactive responses.

  9. Carbohydrate Mimetic Peptides Augment Carbohydrate-Reactive Immune Responses in the Absence of Immune Pathology

    Science.gov (United States)

    Hennings, Leah; Artaud, Cecile; Jousheghany, Fariba; Monzavi-Karbassi, Behjatolah; Pashov, Anastas; Kieber-Emmons, Thomas

    2011-01-01

    Among the most challenging of clinical targets for cancer immunotherapy are Tumor Associated Carbohydrate Antigens (TACAs). To augment immune responses to TACA we are developing carbohydrate mimetic peptides (CMPs) that are sufficiently potent to activate broad-spectrum anti-tumor reactivity. However, the activation of immune responses against terminal mono- and disaccharide constituents of TACA raises concerns regarding the balance between “tumor destruction” and “tissue damage”, as mono- and disaccharides are also expressed on normal tissue. To support the development of CMPs for clinical trial testing, we demonstrate in preclinical safety assessment studies in mice that vaccination with CMPs can enhance responses to TACAs without mediating tissue damage to normal cells expressing TACA. BALB/c mice were immunized with CMPs that mimic TACAs reactive with Griffonia simplicifolia lectin 1 (GS-I), and tissue reactivity of serum antibodies were compared with the tissue staining profile of GS-I. Tissues from CMP immunized mice were analyzed using hematoxylin and eosin stain, and Luxol-fast blue staining for myelination. Western blots of membranes from murine mammary 4T1 cells, syngeneic with BALB/c mice, were also compared using GS-I, immunized serum antibodies, and naive serum antibodies. CMP immunization enhanced glycan reactivities with no evidence of pathological autoimmunity in any immunized mice demonstrating that tissue damage is not an inevitable consequence of TACA reactive responses. PMID:24213131

  10. Cell surface estrogen receptor alpha is upregulated during subchronic metabolic stress and inhibits neuronal cell degeneration.

    Directory of Open Access Journals (Sweden)

    Cristiana Barbati

    Full Text Available In addition to the classical nuclear estrogen receptor, the expression of non-nuclear estrogen receptors localized to the cell surface membrane (mER has recently been demonstrated. Estrogen and its receptors have been implicated in the development or progression of numerous neurodegenerative disorders. Furthermore, the pathogenesis of these diseases has been associated with disturbances of two key cellular programs: apoptosis and autophagy. An excess of apoptosis or a defect in autophagy has been implicated in neurodegeneration. The aim of this study was to clarify the role of ER in determining neuronal cell fate and the possible implication of these receptors in regulating either apoptosis or autophagy. The human neuronal cell line SH-SY5Y and mouse neuronal cells in primary culture were thus exposed to chronic minimal peroxide treatment (CMP, a form of subcytotoxic minimal chronic stress previously that mimics multiple aspects of long-term cell stress and represents a limited molecular proxy for neurodegenerative processes. We actually found that either E2 or E2-bovine serum albumin construct (E2BSA, i.e. a non-permeant form of E2 was capable of modulating intracellular cell signals and regulating cell survival and death. In particular, under CMP, the up-regulation of mERα, but not mERβ, was associated with functional signals (ERK phosphorylation and p38 dephosphorylation compatible with autophagic cytoprotection triggering and leading to cell survival. The mERα trafficking appeared to be independent of the microfilament system cytoskeletal network but was seemingly associated with microtubular apparatus network, i.e., to MAP2 molecular chaperone. Importantly, antioxidant treatments, administration of siRNA to ERα, or the presence of antagonist of ERα hindered these events. These results support that the surface expression of mERα plays a pivotal role in determining cell fate, and that ligand-induced activation of mER signalling exerts a

  11. Tuning cell adhesion on polymeric and nanocomposite surfaces: Role of topography versus superhydrophobicity

    Energy Technology Data Exchange (ETDEWEB)

    Zangi, Sepideh [Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, P.O. Box 36155-163, Shahrood (Iran, Islamic Republic of); Hejazi, Iman [Department of Polymer Engineering & Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Seyfi, Javad, E-mail: Jseyfi@gmail.com [Department of Chemical Engineering, Shahrood Branch, Islamic Azad University, P.O. Box 36155-163, Shahrood (Iran, Islamic Republic of); Hejazi, Ehsan [Department of Clinical Nutrition and Dietetics, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Khonakdar, Hossein Ali [Department of Polymer Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, P.O. Box 19585-466, Tehran (Iran, Islamic Republic of); Davachi, Seyed Mohammad [School of Chemical Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of)

    2016-06-01

    Development of surface modification procedures which allow tuning the cell adhesion on the surface of biomaterials and devices is of great importance. In this study, the effects of different topographies and wettabilities on cell adhesion behavior of polymeric surfaces are investigated. To this end, an improved phase separation method was proposed to impart various wettabilities (hydrophobic and superhydrophobic) on polypropylene surfaces. Surface morphologies and compositions were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Cell culture was conducted to evaluate the adhesion of 4T1 mouse mammary tumor cells. It was found that processing conditions such as drying temperature is highly influential in cell adhesion behavior due to the formation of an utterly different surface topography. It was concluded that surface topography plays a more significant role in cell adhesion behavior rather than superhydrophobicity since the nano-scale topography highly inhibited the cell adhesion as compared to the micro-scale topography. Such cell repellent behavior could be very useful in many biomedical devices such as those in drug delivery and blood contacting applications as well as biosensors. - Highlights: • A novel method is presented for fabrication of superhydrophobic surfaces. • The presence of nanoparticles in non-solvent bath notably promoted phase separation. • Topography had a more notable impact on cell adhesion than superhydrophobicity. • Nano-scale topographical features highly impeded cell adhesion on polymer surfaces.

  12. An efficient delivery of DAMPs on the cell surface by the unconventional secretion pathway

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Haiyan; Wang, Lan; Ruan, Yuanyuan; Zhou, Lei; Zhang, Dongmei [Department of Biochemistry and Molecular Biology, Shanghai Medical Collage, Fudan University, Shanghai 200032 (China); Min, Zhihui [Biomedical Research Center, Zhongshan Hospital, Fudan University, Shanghai 200032 (China); Xie, Jianhui [Department of Biochemistry and Molecular Biology, Shanghai Medical Collage, Fudan University, Shanghai 200032 (China); Yu, Min, E-mail: minyu@shmu.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical Collage, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, Shanghai Medical Collage, Fudan University, Shanghai 200032 (China)

    2011-01-21

    Research highlights: {yields} Hsp60 transported to cell surface through the classical secretory pathway was modified with N-glycosylation. {yields} HSAPB-N18 could efficiently deliver Hsp60 to the cell surface via the unconventional secretory pathway. {yields} Cell surface Hsp60 delivered by HASPB-N18 has a proper conformation. {yields} HASPB-N18 is an efficient delivery signal for other DAMP molecules such as Hsp70 and HMGB1. -- Abstract: Damage-associated molecular patterns (DAMPs) are signals released from dying cells evoking the immune system response in several inflammatory disorders. In normal situations, many of DAMPs are nuclear or cytosolic proteins with defined intracellular function, but they could be found on the cell surface following tissue injury. The biological function of the translocated DAMPs is still not well known and an efficient delivery of these molecules on the cell surface is required to clarify their biological effects. In this study, we demonstrated that an unclassical secretory signal peptide, N-terminal 18 amino acids of HASPB (HASPB-N18), could efficiently deliver Hsp60, Hsp70, and HMGB1 on the cell surface. Furthermore, the delivery of these molecules on the cell surface by HASPB-N18 is not limited to a special cell line because several cell lines could use this delivery signal to deliver these molecules on the cell surface. Moreover, we demonstrated that Hsp60 on the cell surface delivered by HASPB-N18 could be recognized by a soluble form of LOX-1, which implies that DAMPs on the cell surface delivered by HASPB-N18 have a proper conformation during transport. Therefore, delivery of DAMPs by HASPB-N18 is a reliable model to further understand the biological significance of DAMPs on the cell surface.

  13. The effects of carbohydrate variation in isocaloric diets on glycogenolysis and gluconeogenesis in healthy men

    NARCIS (Netherlands)

    Bisschop, PH; Arias, AMP; Ackermans, MT; Endert, E; Pijl, H; Kuipers, F; Meijer, AJ; Sauerwein, HP; Romijn, JA

    2000-01-01

    To evaluate the effect of dietary carbohydrate content on postabsorptive glucose metabolism, we quantified gluconeogenesis and glycogenolysis after 11 days of high carbohydrate (85% carbohydrate), control (44% carbohydrate), and very low carbohydrate (2% carbohydrate) diets in six healthy men. Diets

  14. Field Measurements of PCB emissions from Building Surfaces Using a New Portable Emission Test Cell

    DEFF Research Database (Denmark)

    Lyng, Nadja; Haven, Rune; Gunnarsen, Lars Bo

    2016-01-01

    The purpose of the study was to measure PCB-emission rates from indoor surfaces on-site in contaminated buildings using a newly developed portable emission test cell. Emission rates were measured from six different surfaces; three untreated surfaces and three remediated surfaces in a contaminated...... Danish elementary school. The emission test cell was capable of measuring widely varying specific emission rates of PCBtotal (8-3357 ng/(m2·h)). Remediated measures were found to reduce the emission rates by more than 96% compared with similar untreated surfaces. Emission rates may be affected...... by the conditions in the test cell (such as clean air and increased air velocity) and thereby potentially be different without the test cell attached to the surface. Still the measured emission rates obtained by using the test cell are valuable for determination of mitigation strategies. Additionally the test cell...

  15. Effects on markers of inflammation and endothelial cell function of three ad libitum diets differing in type and amount of fat and carbohydrate

    DEFF Research Database (Denmark)

    Bladbjerg, Else-Marie; Larsen, Thomas Meinert; Due, Anette Pia

    2011-01-01

    Diet is important for the prevention of CVD, and diets high in MUFA might be more cardioprotective than low-fat diets. We hypothesise that inflammation and endothelial cell function will be improved most favourably by a high-MUFA diet compared with a low-fat diet. This was tested in a parallel...... randomised intervention trial on overweight individuals (aged 28·2 (sd 4·6) years) assigned to a diet moderate in the amount of fat (35-45% of energy; >20% of fat as MUFA; MUFA diet, n 39), a low-fat (20-30% of energy) diet (LF diet, n 43) or a control diet (35 % of energy as fat, n 24) for 6 months after...... weight loss. Protein constituted 10-20 % of energy in all diets. Food was provided free of charge. Fasting blood samples were collected before and after the intervention and analysed for C-reactive protein (CRP), IL-6, intercellular adhesion molecule, von Willebrand factor (vWF) and tissue factor pathway...

  16. Proteomic inventory of "anchorless" proteins on the colon adenocarcinoma cell surface.

    NARCIS (Netherlands)

    Tjalsma, H.; Pluk, W.J.G.; Heuvel, L.P.W.J. van den; Peters, W.H.M.; Roelofs, R.H.W.M.; Swinkels, D.W.

    2006-01-01

    Surface proteins play important pathophysiological roles in health and disease, and accumulating proteomics-based studies suggest that several "non-membrane" proteins are sorted to the cell surface by unconventional mechanisms. Importantly, these proteins may comprise attractive therapeutic targets

  17. Nanoindentation characterisation of human colorectal cancer cells considering cell geometry, surface roughness and hyperelastic constitutive behaviour

    Science.gov (United States)

    Boccaccio, Antonio; Uva, Antonio E.; Papi, Massimiliano; Fiorentino, Michele; De Spirito, Marco; Monno, Giuseppe

    2017-01-01

    Characterisation of the mechanical behaviour of cancer cells is an issue of crucial importance as specific cell mechanical properties have been measured and utilized as possible biomarkers of cancer progression. Atomic force microscopy certainly occupies a prominent place in the field of the mechanical characterisation devices. We developed a hybrid approach to characterise different cell lines (SW620 and SW480) of the human colon carcinoma submitted to nanoindentation measurements. An ad hoc algorithm was written that compares the force-indentation curves experimentally retrieved with those predicted by a finite element model that simulates the nanoindentation process and reproduces the cell geometry and the surface roughness. The algorithm perturbs iteratively the values of the cell mechanical properties implemented in the finite element model until the difference between the experimental and numerical force-indentation curves reaches the minimum value. The occurrence of this indicates that the implemented material properties are very close to the real ones. Different hyperelastic constitutive models, such as Arruda-Boyce, Mooney-Rivlin and Neo-Hookean were utilized to describe the structural behaviour of indented cells. The algorithm was capable of separating, for all the cell lines investigated, the mechanical properties of cell cortex and cytoskeleton. Material properties determined via the algorithm were different with respect to those obtained with the Hertzian contact theory. This demonstrates that factors such as: the cell geometry/anatomy and the hyperelastic constitutive behaviour, which are not contemplated in the Hertz’s theory hypotheses, do affect the nanoindentation measurements. The proposed approach represents a powerful tool that, only on the basis of nanoindentation measurements, is capable of characterising material at the subcellular level.

  18. Magnetic loading of graphene-nickel nanoparticle hybrid for electrochemical sensing of carbohydrates.

    Science.gov (United States)

    Qu, Weidong; Zhang, Luyan; Chen, Gang

    2013-04-15

    Graphene-nickel nanoparticle hybrid was prepared by the one-step far infrared-assisted reduction of graphene oxide and nickel (II) ions using hydrazine. It was loaded on the surface of a magnetic electrode for electrochemical sensing. The feasibility and performance of the novel electrode were demonstrated by measuring carbohydrates using cyclic voltammetry and amperometry. It demonstrated that nickel nanoparticles decorated on graphene sheets exhibited higher electrocatalytic activity toward the oxidation of carbohydrates while graphene improved the electron transduction. The synergistic effect significantly enhanced the current response of carbohydrates.

  19. Regioselective monodeprotection of peracetylated carbohydrates.

    Science.gov (United States)

    Filice, Marco; Guisan, Jose M; Terreni, Marco; Palomo, Jose M

    2012-10-01

    This protocol describes the regioselective deprotection of single hydroxyls in peracetylated monosaccharides and disaccharides by enzymatic or chemoenzymatic strategies. The introduction of a one-pot enzymatic step by using immobilized biocatalysts obviates the requirement to carry out tedious workups and time-consuming purifications. By using this straightforward protocol, different per-O-acetylated glycopyranosides (mono- or disaccharides, 1-substituted or glycals) can be transformed into a whole set of differentially monodeprotected 1-alcohols, 3-alcohols, 4-alcohols and 6-alcohols in high yields. These tailor-made glycosyl acceptors can then be used for stereoselective glycosylation for oligosaccharide and glycoderivative synthesis. They have been successfully used as building blocks to synthesize tailor-made di- and trisaccharides involved in the structure of lacto-N-neo-tetraose and precursors of the tumor-associated carbohydrate antigen T and the antitumoral drug peracetylated β-naphtyl-lactosamine. We are able to prepare a purified monoprotected carbohydrate in between 1 and 4 d. With this protocol, the small library of monodeprotected products can be synthesized in 1-2 weeks.

  20. Polymer surface functionalities that control human embryoid body cell adhesion revealed by high throughput surface characterization of combinatorial material microarrays.

    Science.gov (United States)

    Yang, Jing; Mei, Ying; Hook, Andrew L; Taylor, Michael; Urquhart, Andrew J; Bogatyrev, Said R; Langer, Robert; Anderson, Daniel G; Davies, Martyn C; Alexander, Morgan R

    2010-12-01

    High throughput materials discovery using combinatorial polymer microarrays to screen for new biomaterials with new and improved function is established as a powerful strategy. Here we combine this screening approach with high throughput surface characterization (HT-SC) to identify surface structure-function relationships. We explore how this combination can help to identify surface chemical moieties that control protein adsorption and subsequent cellular response. The adhesion of human embryoid body (hEB) cells to a large number (496) of different acrylate polymers synthesized in a microarray format is screened using a high throughput procedure. To determine the role of the polymer surface properties on hEB cell adhesion, detailed HT-SC of these acrylate polymers is carried out using time of flight secondary ion mass spectrometry (ToF SIMS), X-ray photoelectron spectroscopy (XPS), pico litre drop sessile water contact angle (WCA) measurement and atomic force microscopy (AFM). A structure-function relationship is identified between the ToF SIMS analysis of the surface chemistry after a fibronectin (Fn) pre-conditioning step and the cell adhesion to each spot using the multivariate analysis technique partial least squares (PLS) regression. Secondary ions indicative of the adsorbed Fn correlate with increased cell adhesion whereas glycol and other functionalities from the polymers are identified that reduce cell adhesion. Furthermore, a strong relationship between the ToF SIMS spectra of bare polymers and the cell adhesion to each spot is identified using PLS regression. This identifies a role for both the surface chemistry of the bare polymer and the pre-adsorbed Fn, as-represented in the ToF SIMS spectra, in controlling cellular adhesion. In contrast, no relationship is found between cell adhesion and wettability, surface roughness, elemental or functional surface composition. The correlation between ToF SIMS data of the surfaces and the cell adhesion demonstrates

  1. Isolation of cell surface proteins for mass spectrometry-based proteomics.

    Science.gov (United States)

    Elschenbroich, Sarah; Kim, Yunee; Medin, Jeffrey A; Kislinger, Thomas

    2010-02-01

    Defining the cell surface proteome has profound importance for understanding cell differentiation and cell-cell interactions, as well as numerous pathogenic abnormalities. Owing to their hydrophobic nature, plasma membrane proteins that reside on the cell surface pose analytical challenges and, despite efforts to overcome difficulties, remain under-represented in proteomic studies. Limitations in the classically employed ultracentrifugation-based approaches have led to the invention of more elaborate techniques for the purification of cell surface proteins. Three of these methods--cell surface coating with cationic colloidal silica beads, biotinylation and chemical capture of surface glycoproteins--allow for marked enrichment of this subcellular proteome, with each approach offering unique advantages and characteristics for different experiments. In this article, we introduce the principles of each purification method and discuss applications from the recent literature.

  2. Heparanase facilitates cell adhesion and spreading by clustering of cell surface heparan sulfate proteoglycans.

    Directory of Open Access Journals (Sweden)

    Flonia Levy-Adam

    Full Text Available Heparanase is a heparan sulfate (HS degrading endoglycosidase participating in extracellular matrix degradation and remodeling. Apart of its well characterized enzymatic activity, heparanase was noted to exert also enzymatic-independent functions. Non-enzymatic activities of heparanase include enhanced adhesion of tumor-derived cells and primary T-cells. Attempting to identify functional domains of heparanase that would serve as targets for drug development, we have identified heparin binding domains of heparanase. A corresponding peptide (residues Lys(158-Asp(171, termed KKDC was demonstrated to physically associate with heparin and HS, and to inhibit heparanase enzymatic activity. We hypothesized that the pro-adhesive properties of heparanase are mediated by its interaction with cell surface HS proteoglycans, and utilized the KKDC peptide to examine this possibility. We provide evidence that the KKDC peptide interacts with cell membrane HS, resulting in clustering of syndecan-1 and syndecan-4. We applied classical analysis of cell morphology, fluorescent and time-lapse microscopy and demonstrated that the KKDC peptide efficiently stimulates the adhesion and spreading of various cell types, mediated by PKC, Src, and the small GTPase Rac1. These results support, and further substantiate the notion that heparanase function is not limited to its enzymatic activity.

  3. Scanning the cell surface proteome of cancer cells and identification of metastasis-associated proteins using a subtractive immunization strategy

    DEFF Research Database (Denmark)

    Rasmussen, Nicolaj; Ditzel, Henrik J

    2009-01-01

    characterization of the identified proteins. The strategy is based on subtractive immunization of mice, and we used the two isogenic cell lines, NM-2C5 and M-4A4, derived from the MDA-MB-435 cancer cell line, as a model system. Although the two cell lines are equally tumorigenic, only M-4A4 has metastatic...... of the immune system itself to scan the cell surface proteome for differentially expressed proteins. The subtractive immunization strategy should be broadly applicable as a quantitative and comparative proteomic approach for screening the cell surface and also allow generation of mAbs to study these cell...

  4. Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology

    Directory of Open Access Journals (Sweden)

    Tam Yew

    2012-10-01

    Full Text Available Abstract Background Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg from Pichia pastoris expression cells were optimized using response surface methodology (RSM based on the central composite design (CCD. The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells. Results The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR and HBsAg concentration of 29.20 mg/L respectively. Conclusions The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing.

  5. Controlling cell adhesion via replication of laser micro/nano-textured surfaces on polymers

    Energy Technology Data Exchange (ETDEWEB)

    Koufaki, Niki; Ranella, Anthi; Barberoglou, Marios; Psycharakis, Stylianos; Fotakis, Costas; Stratakis, Emmanuel [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), 711 10, Heraklion, Crete (Greece); Aifantis, Katerina E, E-mail: stratak@iesl.forth.gr [Lab of Mechanics and Materials, Aristotle University of Thessaloniki, Thessaloniki (Greece)

    2011-12-15

    The aim of this study is to investigate cell adhesion and viability on highly rough polymeric surfaces with gradient roughness ratios and wettabilities prepared by microreplication of laser micro/nano-textured Si surfaces. Negative replicas on polydimethylsiloxane as well as positive ones on a photocurable (organically modified ceramic) and a biodegradable (poly(lactide-co-glycolide)) polymer have been successfully reproduced. The final culture substrates comprised from forests of micron-sized conical spikes exhibiting a range of roughness ratios and wettabilities, was achieved by changing the laser fluence used to fabricate the original template surfaces. Cell culture experiments were performed with the fibroblast NIH/3T3 and PC12 neuronal cell lines in order to investigate how these surfaces are capable of modulating different types of cellular responses including, viability, adhesion and morphology. The results showed a preferential adhesion of both cell types on the microstructured surfaces compared to the unstructured ones. In particular, the fibroblast NIH/3T3 cells show optimal adhesion for small roughness ratios, independent of the surface wettability and polymer type, indicating a non-monotonic dependence of cell adhesion on surface energy. In contrast, the PC12 cells were observed to adhere well to the patterned surfaces independent of the roughness ratio and wettability. These experimental findings are correlated with micromechanical measurements performed on the unstructured and replicated surfaces and discussed on the basis of previous observations describing the relation of cell response to surface energy and rigidity.

  6. ProtEx: a novel technology to display exogenous proteins on the cell surface for immunomodulation.

    Science.gov (United States)

    Singh, Narendra P; Yolcu, Esma S; Askenasy, Nadir; Shirwan, Haval

    2005-11-01

    Gene therapy as an immunomodulatory approach has the potential to treat various inherited and acquired immune-based human diseases. However, its clinical application has several challenges, varying from the efficiency of gene transfer, control of gene expression, cell and tissue targeting, and safety concerns associated with the introduction of exogenous DNA into cells/tissues. Gene therapy is also a time- and labor-intensive procedure. As an alternative, we recently developed a novel technology, ProtEx, that allows for rapid, efficient, and durable display of exogenous proteins on the surface of cells, tissues, and organs without detectable toxicity. This technology exploits the strong binding affinity (Kd = 10(-15) M) of streptavidin with biotin and involves generation of chimeric molecules composed of the extracellular portions of immunological proteins of interest and a modified form of streptavidin, biotinylation of biological surfaces, and decoration of the modified surface with chimeric proteins. Biotin persists on the cell surface for weeks both in vitro and in vivo, thereby providing a platform to display exogenous proteins with extended cell surface kinetics. Two chimeric proteins, rat FasL (SA-FasL) and human CD80 (CD80-SA), were generated and tested for cell surface display and immunomodulatory functions. SA-FasL and CD80-SA molecules persisted on the surface of various cell types for extended periods, varying from days to weeks in vitro and in vivo. The cell surface kinetics, however, were protein and cell type dependent. SA-FasL showed potent apoptotic activity against Fas+ cells as a soluble protein or displayed on the cell surface and effectively blocked alloreactive responses. The display of CD80-SA on the surface of tumor cells, however, converted them into antigen-presenting cells for effective stimulation of autologous and allogeneic T-cell responses. ProtEx technology, therefore, represents a practical and effective alternative to DNA

  7. Nucleolin on the cell surface as a new molecular target for gastric cancer treatment.

    Science.gov (United States)

    Watanabe, Tatsuro; Hirano, Kazuya; Takahashi, Atsushi; Yamaguchi, Kensei; Beppu, Masatoshi; Fujiki, Hirota; Suganuma, Masami

    2010-01-01

    Nucleolin is an abundant non-ribosomal protein found in nucleolus and a major component of silver-stained nucleolar organizer region (AgNOR), a histopathological marker of cancer which is highly elevated in cancer cells. We recently reported that nucleolin on the cell surface of mouse gastric cancer cells acts as a receptor for tumor necrosis factor-alpha-inducing protein (Tipalpha), a new carcinogenic factor of Helicobacter pylori. In this study, we first examined the localization of nucleolin on cell surface of five gastric cancer cell lines by cell fractionation and flow cytometry: We found that large amounts of nucleolin were present on surface of MKN-45, KATOIII, MKN-74, and AGS cells, with smaller amounts on surface of MKN-1 cells. The membrane fraction of normal epithelial cells of mouse glandular stomach did not contain much nucleolin, suggesting that translocation of nucleolin to the cell surface occurs during carcinogenesis, making for easier binding with Tipalpha. AS1411, a nucleolin targeted DNA aptamer, inhibited growth of gastric cancer cell lines in this order of potency: MKN-45>KATOIII>AGS>MKN-74=MKN-1, associated with induction of S-phase cell cycle arrest. Fluorescein isothiocyanate (FITC)-AS1411 was more rapidly incorporated into MKN-45 and AGS than into MKN-1 cells, based on varying amounts of cell surface nucleolin. We think that AS1411 first binds to nucleolin on the cell surface and that the binding complex is then incorporated into the cells. All results indicate that nucleolin on the cell surface is a new and promising therapeutic target for treatment of gastric cancer.

  8. The effects of poly(dimethylsiloxane) surface silanization on the mesenchymal stem cell fate.

    Science.gov (United States)

    Chuah, Yon Jin; Kuddannaya, Shreyas; Lee, Min Hui Adeline; Zhang, Yilei; Kang, Yuejun

    2015-02-01

    In recent years, poly(dimethylsiloxane) (PDMS)-based microfluidic devices have become very popular for on-chip cell investigation. Maintenance of mammalian cell adhesion on the substrate surface is crucial in determining the cell viability, proliferation and differentiation. However, the inherent hydrophobicity of PDMS is unfavourable for cell culture, causing cells to eventually dislodge from the surface. Although physically adsorbed matrix proteins can promote initial cell adhesion, this effect is usually short-lived. To address this critical issue, in this study, we employed (3-aminopropyl) triethoxy silane (APTES) and cross-linker glutaraldehyde (GA) chemistry to immobilize collagen type 1 (Col1) on PDMS. These modified surfaces are highly efficient to support the adhesion of mesenchymal stem cells (MSCs) with no deterioration of their potency. Significant changes of the native PDMS surface properties were observed with the proposed surface functionalization, and MSC adhesion was improved on PDMS surfaces modified with APTES + GA + Protein. Therefore, this covalent surface modification could generate a more biocompatible platform for stabilized cell adhesion. Furthermore, this modification method facilitated long-term cell attachment, which is favourable for successful induction of osteogenesis and cell sheet formation with an increased expression of osteogenic biomarkers and comparable extracellular matrix (ECM) constituent biomarkers, respectively. The surface silanization can be applied to PDMS-based microfluidic systems for long-term study of cellular development. Similar strategies could also be applied to several other substrate materials by appropriate combinations of self-assembled monolayers (SAMs) and ECM proteins.

  9. Cell shape and spreading of stromal (mesenchymal) stem cells cultured on fibronectin coated gold and hydroxyapatite surfaces

    DEFF Research Database (Denmark)

    Dolatshahi-Pirouz, A; Jensen, Thomas Hartvig Lindkjær; Kolind, Kristian;

    2011-01-01

    In order to identify the cellular mechanisms leading to the biocompatibility of hydroxyapatite implants, we studied the interaction of human bone marrow derived stromal (mesenchymal) stem cells (hMSCs) with fibronectin-coated gold (Au) and hydroxyapatite (HA) surfaces. The adsorption of fibronectin...... the number of polyclonal and monoclonal antibodies directed against the cell-binding domain (CB-domain) on the fibronectin (Fn) is significantly larger on the (HA) surfaces. Moreover, a higher number of antibodies bound to the fibronectin coatings formed from the highest bulk fibronection concentration....... In subsequent cell studies with hMSC's we studied the cell spreading, cytoskeletal organization and cell morphology on the respective surfaces. When the cells were adsorbed on the uncoated substrates, a diffuse cell actin cytoskeleton was revealed, and the cells had a highly elongated shape. On the fibronectin...

  10. Distinct roles for dystroglycan, beta1 integrin and perlecan in cell surface laminin organization

    DEFF Research Database (Denmark)

    Henry, M D; Satz, J S; Brakebusch, C;

    2001-01-01

    Dystroglycan (DG) is a cell surface receptor for several extracellular matrix (ECM) molecules including laminins, agrin and perlecan. Recent data indicate that DG function is required for the formation of basement membranes in early development and the organization of laminin on the cell surface....... Here we show that DG-mediated laminin clustering on mouse embryonic stem (ES) cells is a dynamic process in which clusters are consolidated over time into increasingly more complex structures. Utilizing various null-mutant ES cell lines, we define roles for other molecules in this process. In beta1...... integrin-deficient ES cells, laminin-1 binds to the cell surface, but fails to organize into more morphologically complex structures. This result indicates that beta1 integrin function is required after DG function in the cell surface-mediated laminin assembly process. In perlecan-deficient ES cells...

  11. Polymer microfilters with nanostructured surfaces for the culture of circulating cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Makarova, Olga V. [Creatv MicroTech, Inc., 2242 West Harrison St., Chicago 60612, IL (United States); Adams, Daniel L., E-mail: dan@creatvmicrotech.com [Creatv MicroTech, Inc., 1 Deer Park Drive, Monmouth Junction, NJ 08852 (United States); Divan, Ralu; Rosenmann, Daniel [Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Ave., Argonne 60439, IL (United States); Zhu, Peixuan; Li, Shuhong; Amstutz, Platte; Tang, Cha-Mei [Creatv MicroTech, Inc., 11609 Lake Potomac Drive, Potomac 20854, MD (United States)

    2016-09-01

    There is a critical need to improve the accuracy of drug screening and testing through the development of in vitro culture systems that more effectively mimic the in vivo environment. Surface topographical features on the nanoscale level, in short nanotopography, effect the cell growth patterns, and hence affect cell function in culture. We report the preliminary results on the fabrication, and subsequent cellular growth, of nanoscale surface topography on polymer microfilters using cell lines as a precursor to circulating tumor cells (CTCs). To create various nanoscale features on the microfilter surface, we used reactive ion etching (RIE) with and without an etching mask. An anodized aluminum oxide (AAO) membrane fabricated directly on the polymer surface served as an etching mask. Polymer filters with a variety of modified surfaces were used to compare the effects on the culture of cancer cell lines in blank culture wells, with untreated microfilters or with RIE-treated microfilters. We then report the differences of cell shape, phenotype and growth patterns of bladder and glioblastoma cancer cell lines after isolation on the various types of material modifications. Our data suggest that RIE modified polymer filters can isolate model cell lines while retaining ell viability, and that the RIE filter modification allows T24 monolayering cells to proliferate as a structured cluster. - Highlights: • Surface topographical effects the growth patterns and cell function of cancer cells • Nanoscale surface topography on polymer filters for circulating tumor cell culture • Membrane fabricated directly on polymer surfaces utilized for polymer etching • Nanotopography alters cell shape, phenotype and growth patterns of cancer cells • Nanoscale surface topography dictates monolayering or 3D structured cell culture.

  12. Construction of 3D micropatterned surfaces with wormlike and superhydrophilic PEG brushes to detect dysfunctional cells.

    Science.gov (United States)

    Hou, Jianwen; Shi, Qiang; Ye, Wei; Fan, Qunfu; Shi, Hengchong; Wong, Shing-Chung; Xu, Xiaodong; Yin, Jinghua

    2014-12-10

    Detection of dysfunctional and apoptotic cells plays an important role in clinical diagnosis and therapy. To develop a portable and user-friendly platform for dysfunctional and aging cell detection, we present a facile method to construct 3D patterns on the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS) with poly(ethylene glycol) brushes. Normal red blood cells (RBCs) and lysed RBCs (dysfunctional cells) are used as model cells. The strategy is based on the fact that poly(ethylene glycol) brushes tend to interact with phosphatidylserine, which is in the inner leaflet of normal cell membranes but becomes exposed in abnormal or apoptotic cell membranes. We demonstrate that varied patterned surfaces can be obtained by selectively patterning atom transfer radical polymerization (ATRP) initiators on the SEBS surface via an aqueous-based method and growing PEG brushes through surface-initiated atom transfer radical polymerization. The relatively high initiator density and polymerization temperature facilitate formation of PEG brushes in high density, which gives brushes worm-like morphology and superhydrophilic property; the tendency of dysfunctional cells adhered on the patterned surfaces is completely different from well-defined arrays of normal cells on the patterned surfaces, providing a facile method to detect dysfunctional cells effectively. The PEG-patterned surfaces are also applicable to detect apoptotic HeLa cells. The simplicity and easy handling of the described technique shows the potential application in microdiagnostic devices.

  13. Evaluation of certain crop residues for carbohydrate and protein fractions by cornell net carbohydrate and protein system

    Directory of Open Access Journals (Sweden)

    Venkateswarulu Swarna

    2015-06-01

    Full Text Available Four locally available crop residues viz., jowar stover (JS, maize stover (MS, red gram straw (RGS and black gram straw (BGS were evaluated for carbohydrate and protein fractions using Cornell Net Carbohydrate and Protein (CNCP system. Lignin (% NDF was higher in legume straws as compared to cereal stovers while Non-structural carbohydrates (NSC (% DM followed the reverse trend. The carbohydrate fractions A and B1 were higher in BGS while B2 was higher in MS as compared to other crop residues. The unavailable cell wall fraction (C was higher in legume straws when compared to cereal stovers. Among protein fractions, B1 was higher in legume straws when compared to cereal stovers while B2 was higher in cereal stovers as compared to legume straws. Fraction B3 largely, bypass protein was highest in MS as compared to other crop residues. Acid detergent insoluble crude protein (ADICP (% CP or unavailable protein fraction C was lowest in MS and highest in BGS. It is concluded that MS is superior in nutritional value for feeding ruminants as compared to other crop residues.

  14. The bacterial metabolism of carbohydrates used in tests of intestinal permeability

    OpenAIRE

    Qureishy, Gulzar A.

    1984-01-01

    Carbohydrates have been used for tests of intestinal function for many years and the impaired absorption of carbohydrates in the intestinal lumen is either due to the damaged intestinal absorptive surface, as in coeliac disease etc., in some types of acute gastroenteritis , when the absorptive area is reduced by villous atrophy , or due to the bacterial overgrowth in the small intestinal lumen as in blind loop syndrome , some types of malabsorption , which possibly produce alteration in the m...

  15. Exocellular esterase and emulsan release from the cell surface of Acinetobacter calcoaceticus.

    OpenAIRE

    Shabtai, Y; Gutnick, D L

    1985-01-01

    An esterase activity has been found, both in the cell-free growth medium and on the cell surface of the hydrocarbon-degrading Acinetobacter calcoaceticus RAG-1. The enzyme catalyzed the hydrolysis of acetyl and other acyl groups from triglycerides and aryl and alkyl esters. Emulsan, the extracellular heteropolysaccharide bioemulsifier produced by strain RAG-1, was also a substrate for the enzyme. Gel filtration showed that the cell-free enzyme was released from the cell surface either emulsan...

  16. Biochemical software: Carbohydrates on Laboratory

    Directory of Open Access Journals (Sweden)

    D.N. Heidrich

    2005-07-01

    Full Text Available Educators around  the  world  are  being  challenged  to  develop  and  design  better and  more  effective strategies for student learning  using a variety  of modern  resources.  In this  present  work, an educa- tional  hypermedia  software  was constructed as a support tool to biochemistry teaching.  Occurrence, structure, main  characteristics and  biological  function  of the  biomolecule  Carbohydrates were pre- sented  through  modules.  The  software was developed  using concept  maps,  ISIS-Draw,  and  FLASH- MX animation program.  The chapter  Carbohydrates on Laboratory illustrates experimental methods of carbohydrates characterization, through  animation of a laboratory scenery.   The  subject was de- veloped showing reactions  as Bial, Benedict, Selliwanoff, Barfoed, Phenol  Sulphuric,  and Iodines, and also enzymatic  reactions  as glucose oxidase and amylase.  There are also links with short texts  in order to help the understanding of the contents  and principles of laboratory practice  as well as background reactions. Application of the software to undergraduate students and high school teachers  showed an excellent  acceptance.   All of them  considered  the  software  a very good learning  tool.  Both  teachers and students welcomed this program  as it is more flexible, and allows the learning in a more individual rhythm. In addition, application of the software would be suitable  to a more effective learning  and it is less expensive than conventional experimental teaching.

  17. Influence of charge densities of randomly sulfonated polystyrene surfaces on cell attachment and proliferation.

    Science.gov (United States)

    Khatua, Dibyendu; Kwak, Byeongdo; Shin, Kwanwoo; Song, Ju-Myung; Kim, Joon-Seop; Choi, Jai-Hak

    2011-05-01

    Attachment and proliferation of NIH-3T3 fibroblast cells on random polymer surfaces, polystyrene sulfonated acid (PSSAx) with five different degrees of sulfonation (x = 0%, 5%, 10%, 15% and 33%) and on a tissue culture polystyrene (TCPS) surface were studied. The surface properties, wettability and roughness were measured by water-contact angle and atomic force microscopy measurement. The wettability and surface roughness increased with increasing the content of sulfonic acid groups on the surfaces. The number of cells attached on the surface after seeding increased with increasing x and reached to the maximum value on PSSA15. The cell proliferation also increased with increasing x. However, cell proliferation was slow down on PSSA33 in comparison to PSSA10 and PSSA15 surfaces after 48 h culture.

  18. Functionalized titanium oxide surfaces with phosphated carboxymethyl cellulose: characterization and bonelike cell behavior.

    Science.gov (United States)

    Pasqui, Daniela; Rossi, Antonella; Di Cintio, Federica; Barbucci, Rolando

    2007-12-01

    The performance of dental or orthopedic implants is closely dependent on surface properties in terms of topography and chemistry. A phosphated carboxymethylcellulose containing one phosphate group for each disaccharide unit was synthesized and used to functionalize titanium oxide surfaces with the aim to improve osseointegration with the host tissue. The modified surfaces were chemically characterized by means of X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The investigation of the surface topography was performed by atomic force microscopy measurements before and after the polysaccharide coating. In vitro biological tests using osteoblastlike cells demonstrated that functionalized TiO(2) surfaces modulated cell response, in terms of adhesion, proliferation,and morphology. Phosphated carboxymethylcellulose promoted better cell adhesion and significantly enhanced their proliferation. The morphology of cells was polygonal and more spread on this type of modified surface.These findings suggest that the presence of a phosphate polysaccharide coating promotes osteoblast growth on the surface potentially improving biomaterial osseointegration.

  19. Carbohydrate metabolism in the mosquito pathogen Bacillus sphaericus 2362.

    OpenAIRE

    Russell, B L; Jelley, S A; Yousten, A A

    1989-01-01

    Bacillus sphaericus 2362 is pathogenic for mosquito larvae and is being considered for large-scale production as a larvicide. The inability of the bacteria to metabolize carbohydrates requires that they be grown on proteinaceous media. This bacterium was found to be unable to transport glucose or sucrose into the cell, and it lacked glucokinase and hexokinase activity. In addition, it lacked phosphoglucose isomerase, phosphofructokinase, and glucose 6-phosphate dehydrogenase, which are early ...

  20. Hydrophobic fractal surface from glycerol tripalmitate and the effects on C6 glioma cell growth.

    Science.gov (United States)

    Zhang, Shanshan; Chen, Xuerui; Yu, Jing; Hong, Biyuan; Lei, Qunfang; Fang, Wenjun

    2016-06-01

    To provide a biomimic environment for glial cell culture, glycerol tripalmitate (PPP) has been used as a raw material to prepare fractal surfaces with different degrees of hydrophobicity. The spontaneous formation of the hydrophobic fractal surfaces was monitored by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The surface morphologies were observed by a scanning electron microscope (SEM), and then the fractal dimension (FD) values of the surfaces were determined with the box-counting method. C6 glioma cells were cultured and compared on different hydrophobic PPP surfaces and poly-L-lysine (PLL)-coated surface. The cell numbers as a function of incubation time on different surfaces during the cell proliferation process were measured, and the cell morphologies were observed under a fluorescence microscope. Influences of hydrophobic fractal surfaces on the cell number and morphology were analyzed. The experimental results show that the cell proliferation rates decrease while the cell morphology complexities increase with the growth of the fractal dimensions of the PPP surfaces.

  1. Complete structure of the cell surface polysaccharide of Streptococcus oralis ATCC 10557: A receptor for lectin-mediated interbacterial adherence

    Energy Technology Data Exchange (ETDEWEB)

    Abeygunawardana, C.; Bush, C.A. (Univ. of Maryland, Baltimore (United States)); Cisar, J.O. (National Inst. of Dental Research, Bethesda, MD (United States))

    1991-07-02

    Lectin-carbohydrate binding is known to play an important role in a number of different cell-cell interactions including those between certain species of oral streptococci and actinomyces that colonize teeth. The cell wall polysaccharides of Streptococcus oralis ATCC 10557, S. oralis 34, and Streptococcus mitis J22, although not identical antigenically, each function as a receptor molecule for the galactose and N-acetylgalactosamine reactive fimbrial lectins of Actinomyces viscosus and Actinomyces naeslundii. Carbohydrate analysis of the receptor polysaccharide isolated from S. oralis ATCC 10557 shows galactose (3 mol), glucose (1 mol), GalNAc (1 mol), and rhamnose (1 mol). {sup 1}H NMR spectra of the polysaccharide show that is partially O-acetylated. Analysis of the {sup 1}H NMR spectrum of the de-O-acetylated polysaccharide shows that it is composed of repeating subunits containing six monosaccharides and that the subunits are joined by a phosphodiester linkage. The {sup 1}H and {sup 13}C NMR spectra were completely assigned by two-dimensional homonuclear correlation methods and by {sup 1}H-detected heteronuclear multiple-quantum correlation ({sup 1}H({sup 13}C)HMQC). The complete {sup 1}H and {sup 13}C assignment of the native polysaccharide was carried out by the same techniques augmented by a {sup 13}C-coupled hybrid HMQC-COSY method, which is shown to be especially useful for carbohydrates in which strong coupling and overlapping peaks in the {sup 1}H spectrum pose difficulties.

  2. Wood adhesives containing proteins and carbohydrates

    Science.gov (United States)

    In recent years there has been resurgent interest in using biopolymers as sustainable and environmentally friendly ingredients in wood adhesive formulations. Among them, proteins and carbohydrates are the most commonly used. In this chapter, an overview is given of protein-based and carbohydrate-...

  3. Mastering ectomycorrhizal symbiosis: the impact of carbohydrates.

    Science.gov (United States)

    Nehls, Uwe

    2008-01-01

    Mycorrhiza formation is the consequence of a mutualistic interaction between certain soil fungi and plant roots that helps to overcome nutritional limitations faced by the respective partners. In symbiosis, fungi contribute to tree nutrition by means of mineral weathering and mobilization of nutrients from organic matter, and obtain plant-derived carbohydrates as a response. Support with easily degradable carbohydrates seems to be the driving force for fungi to undergo this type of interaction. As a consequence, the fungal hexose uptake capacity is strongly increased in Hartig net hyphae of the model fungi Amanita muscaria and Laccaria bicolor. Next to fast carbohydrate uptake and metabolism, storage carbohydrates are of special interest. In functional A. muscaria ectomycorrhizas, expression and activity of proteins involved in trehalose biosynthesis is mainly localized in hyphae of the Hartig net, indicating an important function of trehalose in generation of a strong carbon sink by fungal hyphae. In symbiosis, fungal partners receive up to approximately 19 times more carbohydrates from their hosts than normal leakage of the root system would cause, resulting in a strong carbohydrate demand of infected roots and, as a consequence, a more efficient plant photosynthesis. To avoid fungal parasitism, the plant seems to have developed mechanisms to control carbohydrate drain towards the fungal partner and link it to the fungus-derived mineral nutrition. In this contribution, current knowledge on fungal strategies to obtain carbohydrates from its host and plant strategies to enable, but also to control and restrict (under certain conditions), carbon transfer are summarized.

  4. Vacuum ultraviolet photoionization of carbohydrates and nucleotides

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Joong-Won, E-mail: jshin@govst.edu [Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States); Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States); Bernstein, Elliot R., E-mail: erb@lamar.colostate.edu [Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)

    2014-01-28

    Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ′}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a general mechanism and explanation of the experimental results.

  5. Derivatization Reaction of Carbohydrates with Urea as the Reagent and Fluorimetric Determination of Carbohydrates

    Institute of Scientific and Technical Information of China (English)

    YANG,Jing-He(杨景和); CAO,Xi-Hui(曹西慧); WANG,Min(王敏); WU,Xia(吴霞); SUN,Chang-Xia(孙长侠)

    2002-01-01

    It is found that in the presence of sulfuric acid carbohydrates condense with urea to afford the condensation products, which emit fluorescence. Under optimum conditions, the fluorescence intensities of system are proportional to the concentrations of carbohydrates. Based on this linear relationship,quantitative determination of kinds of carbohydrates has been made. Among an the carbohydrates tested, the sensitivity of α-rhamnose is the highest and its limits of detection reaches 3.5 × 10-8 mol/L. So α-rhamnose can be selectively determed in the presence of other carbohydrates. A interaction mechanism is also discussed.

  6. Industrial applications of marine carbohydrates.

    Science.gov (United States)

    Sudha, Prasad N; Aisverya, S; Nithya, R; Vijayalakshmi, K

    2014-01-01

    Biomaterials have been used increasingly in various fields, such as drug delivery, imaging, and tissue engineering. The main reason justifying the widespread use of biomaterials relies on its valuable and low-cost source of new drugs. Current research goals are focused on identifying more potent and specific compounds with antitumor, immunomodulatory, antihyperlipidemic, anticoagulant, and antiviral activities. The increasing knowledge of structural analysis and chemical modifications enables the use of these marine carbohydrates in a newer way for the human welfare. This chapter focuses on the recent developments related to industrial and biomedical applications using chitin, chitosan, alginate, agar, and carrageenan derivatives and reports the main advances published over the last 10-15 years.

  7. Nondigestible carbohydrates and mineral bioavailability.

    Science.gov (United States)

    Greger, J L

    1999-07-01

    Generally, fiber and compounds associated with fiber in cereal products (e.g., phytates) have been found to reduce the apparent absorption of minerals (such as calcium, magnesium, zinc and manganese) in humans, livestock and animal models. The effects of "soluble" forms of fiber (specifically pectins, gums, resistant starches, lactulose, oligofructose and inulin) on mineral absorption are more difficult to characterize. The addition of these soluble forms of fiber has been found in various studies to add viscosity to the gut contents, promote fermentation and the production of volatile fatty acids in the cecum, have a trophic effect on the ceca of animals and increase serum enteroglucagon concentrations. Thus it is not surprising that the addition of soluble forms of fiber to diets often has been found to improve absorption of minerals. This may reflect absorption of electrolytes from the large intestine. Future work should address the mechanisms by which ingestion of nondigestible carbohydrates improves mineral absorption in humans.

  8. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Huang, Xiaohua [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Biochemistry, College of Laboratory Medicine, Dalian Medical University, Dalian 116044 (China); An, Yue [Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Ren, Feng [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); He, Xiaowen; Schachner, Melitta [Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ (United States); Xiao, Zhicheng, E-mail: zhicheng.xiao@monash.edu [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); Ma, Keli, E-mail: makeli666@aliyun.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Li, Yali, E-mail: yalilipaper@gmail.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Anatomy, National University of Singapore, Singapore 119078 (Singapore)

    2013-10-25

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression.

  9. Effects of surface molecular chirality on adhesion and differentiation of stem cells.

    Science.gov (United States)

    Yao, Xiang; Hu, Yiwen; Cao, Bin; Peng, Rong; Ding, Jiandong

    2013-12-01

    Chirality is one of the most fascinating and ubiquitous cues in nature, especially in life. The effects of chiral surfaces on stem cells have, however, not yet been revealed. Herein we examined the molecular chirality effect on stem cell behaviors. Self assembly monolayers of L- or D-cysteine (Cys) were formed on a glass surface coated with gold. Mesenchymal stem cells (MSCs) derived from bone marrow of rats exhibited more adhering preference and thus less cell spreading on the L surface than on the d one at the confluent condition. More protein adsorption was observed on the L surface after immersed in cell culture medium with fetal bovine serum. After osteogenic and adipogenic co-induction at the confluent condition, a larger proportion of cells became osteoblasts on the d surface, while the adipogenic fraction on the L surface was found to be higher than on the D surface. In order to interpret how this chirality effect worked, we fabricated Cys microislands of two sizes on the non-fouling poly(ethylene glycol) hydrogel to pre-define the spreading areas of single cells. Then the differentiation extents did not exhibit a significant difference between L and D surfaces under a given area of microislands, yet very significant differences of osteogenesis and adipogenesis were found between different areas. So, the molecular chirality influenced stem cells, probably via favored adsorption of natural proteins on the L surface, which led to more cell adhesion; and the larger cell spreading area with higher cell tension in turn favored osteogenesis rather than adipogenesis. As a result, this study reveals the molecular chirality on material surfaces as an indirect regulator of stem cells.

  10. Ketone isosteres of 2-N-acetamidosugars as substrates for metabolic cell surface engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hang, Howard C.; Bertozzi, Carolyn R.

    2000-08-22

    Novel chemical reactivity can be engendered on cell surfaces by the metabolic incorporation of unnatural sugars into cell surface glycoconjuagtes. 2-N-Acetamido sugars such as GalNAc and GlcNAc are abundant components of cell surface glycoconjugates, and hence attractive targets for metabolic cell surface engineering. Here we report (1) the synthesis of isosteric analogs bearing a ketone group in place of the N-acetamido group, and (2) evaluation of their metabolic incorporation into mammalian cell surface glycans. A ketone isostere of GalNAc was metabolized by CHO cells through the salvage pathway and delivered to O-linked glycoproteins on the cell surface. Its residence at the core position of O-linked glycans is suggested by studies with a-benzyl GalNAc, an inhibitor of O-linked oligosaccharide extension. A mutant CHO cell line lacking endogenous UDP-GalNAc demonstrated enhanced metabolism of the GalNAc analog, suggesting that competition with native intermediates might limits enzymatic transformation in mammalian cells. A ketone isostere of GlcNAc could not be detected on CHO or human cell surfaces after incubation. Thus, the enzymes in the GlcNAc salvage pathway might be less permissive of unnatural substrates than those comprising the GalNAc salvage pathway. Alternatively, high levels of endogenous GlcNAc derivatives might compete with the ketone isostere and prevent its incorporation into oligosaccharides.

  11. Surface design of antibody-immobilized thermoresponsive cell culture dishes for recovering intact cells by low-temperature treatment.

    Science.gov (United States)

    Kobayashi, Jun; Hayashi, Masaki; Ohno, Takahiro; Nishi, Masanori; Arisaka, Yoshinori; Matsubara, Yoshinori; Kakidachi, Hiroshi; Akiyama, Yoshikatsu; Yamato, Masayuki; Horii, Akihiro; Okano, Teruo

    2014-11-01

    Antibody-immobilized thermoresponsive poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide) [poly(IPAAm-co-CIPAAm)]-grafted cell culture surfaces were designed to enhance both the initial adhesion of weakly adhering cells and the ability of cells to detach in response to low temperature through the regulation of affinity binding between immobilized antibodies and antigens on the cellular surface. Ty-82 cells and neonatal normal human dermal fibroblasts (NHDFs), which express CD90 on the cell surface, adhered to anti-CD90 antibody-immobilized thermoresponsive surfaces at 37°C, a condition at which the grafted thermoresponsive polymer chains shrank. Adherent Ty-82 cells were detached from the surfaces by lowering the temperature to 20°C and applying external forces, such as pipetting, whereas cultured NHDF sheets spontaneously detached themselves from the surface in response to reduced temperature alone. When the temperature was decreased to 20°C, the swelling of grafted thermoresponsive polymer chains weakened the affinity binding between immobilized antibody and antigen on the cells due to the increasing steric hindrance of the polymer chains around the antigen-recognition site of the immobilized antibodies. No contamination was detected on cells harvested from covalently immobilized antibodies on the culture surfaces by low-temperature treatment, whereas a carryover of the antibody and avidin from the avidin-biotin binding surface was observed. Furthermore, the initial adhesion of adipose tissue-derived cells, which adhere weakly to PIPAAm-grafted surfaces, was enhanced on the antibody-immobilized thermoresponsive surfaces.

  12. Cell detachment and label-free cell sorting using modulated surface acoustic waves (SAW) in droplet-based microfluidics

    CERN Document Server

    Bussonnière, Adrien; Baudoin, Michael; Bou-Matar, Olivier; Grandbois, Michel; Charette, Paul; Renaudin, Alan

    2014-01-01

    We present a droplet-based surface acoustic wave (SAW) system designed to viably detach biological cells from a surface and sort cell types based on differences in adhesion strength (adhesion contrast), without the need to label cells with molecular markers. The system uses modulated SAW to generate pulsatile flows in the droplets and efficiently detach the cells, thereby minimizing SAW excitation power and exposure time. As a proof-of-principle, the system is shown to efficiently sort HEK 293 from A7r5 cells based on adhesion contrast. Results are obtained in minutes with sorting purity and efficiency reaching 97 % and 95 %, respectively.

  13. Role of Site-Specific N-Glycans Expressed on GluA2 in the Regulation of Cell Surface Expression of AMPA-Type Glutamate Receptors.

    Science.gov (United States)

    Takeuchi, Yusuke; Morise, Jyoji; Morita, Ippei; Takematsu, Hiromu; Oka, Shogo

    2015-01-01

    The AMPA-type glutamate receptor (AMPAR), which is a tetrameric complex composed of four subunits (GluA1-4) with several combinations, mediates the majority of rapid excitatory synaptic transmissions in the nervous system. Cell surface expression levels of AMPAR modulate synaptic plasticity, which is considered one of the molecular bases for learning and memory formation. To date, a unique trisaccharide (HSO3-3GlcAβ1-3Galβ1-4GlcNAc), human natural killer-1 (HNK-1) carbohydrate, was found expressed specifically on N-linked glycans of GluA2 and regulated the cell surface expression of AMPAR and the spine maturation process. However, evidence that the HNK-1 epitope on N-glycans of GluA2 directly affects these phenomena is lacking. Moreover, it is thought that other N-glycans on GluA2 also have potential roles in the regulation of AMPAR functions. In the present study, using a series of mutants lacking potential N-glycosylation sites (N256, N370, N406, and N413) within GluA2, we demonstrated that the mutant lacking the N-glycan at N370 strongly suppressed the intracellular trafficking of GluA2 from the endoplasmic reticulum (ER) in HEK293 cells. Cell surface expression of GluA1, which is a major subunit of AMPAR in neurons, was also suppressed by co-expression of the GluA2 N370S mutant. The N370S mutant and wild-type GluA2 were co-immunoprecipitated with GluA1, suggesting that N370S was properly associated with GluA1. Moreover, we found that N413 was the main potential site of the HNK-1 epitope that promoted the interaction of GluA2 with N-cadherin, resulting in enhanced cell surface expression of GluA2. The HNK-1 epitope on N-glycan at the N413 of GluA2 was also involved in the cell surface expression of GluA1. Thus, our data suggested that site-specific N-glycans on GluA2 regulate the intracellular trafficking and cell surface expression of AMPAR.

  14. Role of Site-Specific N-Glycans Expressed on GluA2 in the Regulation of Cell Surface Expression of AMPA-Type Glutamate Receptors.

    Directory of Open Access Journals (Sweden)

    Yusuke Takeuchi

    Full Text Available The AMPA-type glutamate receptor (AMPAR, which is a tetrameric complex composed of four subunits (GluA1-4 with several combinations, mediates the majority of rapid excitatory synaptic transmissions in the nervous system. Cell surface expression levels of AMPAR modulate synaptic plasticity, which is considered one of the molecular bases for learning and memory formation. To date, a unique trisaccharide (HSO3-3GlcAβ1-3Galβ1-4GlcNAc, human natural killer-1 (HNK-1 carbohydrate, was found expressed specifically on N-linked glycans of GluA2 and regulated the cell surface expression of AMPAR and the spine maturation process. However, evidence that the HNK-1 epitope on N-glycans of GluA2 directly affects these phenomena is lacking. Moreover, it is thought that other N-glycans on GluA2 also have potential roles in the regulation of AMPAR functions. In the present study, using a series of mutants lacking potential N-glycosylation sites (N256, N370, N406, and N413 within GluA2, we demonstrated that the mutant lacking the N-glycan at N370 strongly suppressed the intracellular trafficking of GluA2 from the endoplasmic reticulum (ER in HEK293 cells. Cell surface expression of GluA1, which is a major subunit of AMPAR in neurons, was also suppressed by co-expression of the GluA2 N370S mutant. The N370S mutant and wild-type GluA2 were co-immunoprecipitated with GluA1, suggesting that N370S was properly associated with GluA1. Moreover, we found that N413 was the main potential site of the HNK-1 epitope that promoted the interaction of GluA2 with N-cadherin, resulting in enhanced cell surface expression of GluA2. The HNK-1 epitope on N-glycan at the N413 of GluA2 was also involved in the cell surface expression of GluA1. Thus, our data suggested that site-specific N-glycans on GluA2 regulate the intracellular trafficking and cell surface expression of AMPAR.

  15. Detection of cells captured with antigens on shear horizontal surface-acoustic-wave sensors.

    Science.gov (United States)

    Hao, Hsu-Chao; Chang, Hwan-You; Wang, Tsung-Pao; Yao, Da-Jeng

    2013-02-01

    Techniques to separate cells are widely applied in immunology. The technique to separate a specific antigen on a microfluidic platform involves the use of a shear horizontal surface-acoustic-wave (SH-SAW) sensor. With specific antibodies conjugated onto the surface of the SH-SAW sensors, this technique can serve to identify specific cells in bodily fluids. Jurkat cells, used as a target in this work, provide a model of cells in small abundance (1:1000) for isolation and purification with the ultimate goal of targeting even more dilute cells. T cells were separated from a mixed-cell medium on a chip (Jurkat cells/K562 cells, 1/1000). A novel microchamber was developed to capture cells during the purification, which required a large biosample. Cell detection was demonstrated through the performance of genetic identification on the chip.

  16. Effects of Polymer Surfaces on Proliferation and Differentiation of Embryonic Stem Cells and Bone Marrow Stem Cells

    Science.gov (United States)

    Qin, Sisi; Liao, Wenbin; Ma, Yupo; Simon, Marcia; Rafailovich, Miriam; Stony Brook Medical Center Collaboration; Stony Brook Dental Schoo Collaboration

    2013-03-01

    Currently, proliferation and differentiation of stem cell is usually accomplished either in vivo, or on chemical coated tissue culture petri dish with the presence of feeder cells. Here we investigated whether they can be directly cultured on polymeric substrates, in the absence of additional factors. We found that mouse embryonic stem cells did not require gelatin and could remain in the undifferentiated state without feeder cells at least for four passages on partially sulfonated polystyrene. The modulii of cells was measured and found to be higher for cells plated directly on the polymer surface than for those on the same surface covered with gelatin and feeder cells. When plated with feeder cells, the modulii was not sensitive to gelatin. Whereas the differentiation properties of human bone marrow stem cells, which are not adherent, are less dependent on either chemical or mechanical properties of the substrate. However, they behave differently on different toughness hydrogels as oppose to on polymer coated thin films.

  17. Global transcriptomic analysis of model human cell lines exposed to surface-modified gold nanoparticles: the effect of surface chemistry

    Science.gov (United States)

    Grzincic, E. M.; Yang, J. A.; Drnevich, J.; Falagan-Lotsch, P.; Murphy, C. J.

    2015-01-01

    Gold nanoparticles (Au NPs) are attractive for biomedical applications not only for their remarkable physical properties, but also for the ease of which their surface chemistry can be manipulated. Many applications involve functionalization of the Au NP surface in order to improve biocompatibility, attach targeting ligands or carry drugs. However, changes in cells exposed to Au NPs of different surface chemistries have been observed, and little is known about how Au NPs and their surface coatings may impact cellular gene expression. The gene expression of two model human cell lines, human dermal fibroblasts (HDF) and prostate cancer cells (PC3) was interrogated by microarray analysis of over 14 000 human genes. The cell lines were exposed to four differently functionalized Au NPs: citrate, poly(allylamine hydrochloride) (PAH), and lipid coatings combined with alkanethiols or PAH. Gene functional annotation categories and weighted gene correlation network analysis were used in order to connect gene expression changes to common cellular functions and to elucidate expression patterns between Au NP samples. Coated Au NPs affect genes implicated in proliferation, angiogenesis, and metabolism in HDF cells, and inflammation, angiogenesis, proliferation apoptosis regulation, survival and invasion in PC3 cells. Subtle changes in surface chemistry, such as the initial net charge, lability of the ligand, and underlying layers greatly influence the degree of expression change and the type of cellular pathway affected.Gold nanoparticles (Au NPs) are attractive for biomedical applications not only for their remarkable physical properties, but also for the ease of which their surface chemistry can be manipulated. Many applications involve functionalization of the Au NP surface in order to improve biocompatibility, attach targeting ligands or carry drugs. However, changes in cells exposed to Au NPs of different surface chemistries have been observed, and little is known about how

  18. Survey of surface proteins from the pathogenic Mycoplasma hyopneumoniae strain 7448 using a biotin cell surface labeling approach.

    Directory of Open Access Journals (Sweden)

    Luciano Antonio Reolon

    Full Text Available The characterization of the repertoire of proteins exposed on the cell surface by Mycoplasma hyopneumoniae (M. hyopneumoniae, the etiological agent of enzootic pneumonia in pigs, is critical to understand physiological processes associated with bacterial infection capacity, survival and pathogenesis. Previous in silico studies predicted that about a third of the genes in the M. hyopneumoniae genome code for surface proteins, but so far, just a few of them have experimental confirmation of their expression and surface localization. In this work, M. hyopneumoniae surface proteins were labeled in intact cells with biotin, and affinity-captured biotin-labeled proteins were identified by a gel-based liquid chromatography-tandem mass spectrometry approach. A total of 20 gel slices were separately analyzed by mass spectrometry, resulting in 165 protein identifications corresponding to 59 different protein species. The identified surface exposed proteins better defined the set of M. hyopneumoniae proteins exposed to the host and added confidence to in silico predictions. Several proteins potentially related to pathogenesis, were identified, including known adhesins and also hypothetical proteins with adhesin-like topologies, consisting of a transmembrane helix and a large tail exposed at the cell surface. The results provided a better picture of the M. hyopneumoniae cell surface that will help in the understanding of processes important for bacterial pathogenesis. Considering the experimental demonstration of surface exposure, adhesion-like topology predictions and absence of orthologs in the closely related, non-pathogenic species Mycoplasma flocculare, several proteins could be proposed as potential targets for the development of drugs, vaccines and/or immunodiagnostic tests for enzootic pneumonia.

  19. Levorotatory carbohydrates and xylitol subdue Streptococcus mutans and Candida albicans adhesion and biofilm formation.

    Science.gov (United States)

    Brambilla, Eugenio; Ionescu, Andrei C; Cazzaniga, Gloria; Ottobelli, Marco; Samaranayake, Lakshman P

    2016-05-01

    Dietary carbohydrates and polyols affect the microbial colonization of oral surfaces by modulating adhesion and biofilm formation. The aim of this study was to evaluate the influence of a select group of l-carbohydrates and polyols on either Streptococcus mutans or Candida albicans adhesion and biofilm formation in vitro. S. mutans or C. albicans suspensions were inoculated on polystyrene substrata in the presence of Tryptic soy broth containing 5% of the following compounds: d-glucose, d-mannose, l-glucose, l-mannose, d- and l-glucose (raceme), d- and l-mannose (raceme), l-glucose and l-mannose, sorbitol, mannitol, and xylitol. Microbial adhesion (2 h) and biofilm formation (24 h) were evaluated using MTT-test and Scanning Electron Microscopy (SEM). Xylitol and l-carbohydrates induced the lowest adhesion and biofilm formation in both the tested species, while sorbitol and mannitol did not promote C. albicans biofilm formation. Higher adhesion and biofilm formation was noted in both organisms in the presence of d-carbohydrates relative to their l-carbohydrate counterparts. These results elucidate, hitherto undescribed, interactions of the individually tested strains with l- and d-carbohydrates, and how they impact fungal and bacterial colonization. In translational terms, our data raise the possibility of using l-form of carbohydrates and xylitol for dietary control of oral plaque biofilms.

  20. Cells cultured on microgrooves with or without surface coating: Correlation between cell alignment, spreading and local membrane deformation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiongtu [Ecole Normale Superieure, CNRS-ENS-UPMC UMR 8640, 24 rue Lhomond, 75231 Paris (France); College of physics and information engineering, Fuzhou University, 350002 Fuzhou (China); Shi, Jian; Hu, Jie [Ecole Normale Superieure, CNRS-ENS-UPMC UMR 8640, 24 rue Lhomond, 75231 Paris (France); Chen, Yong, E-mail: yong.chen@ens.fr [Ecole Normale Superieure, CNRS-ENS-UPMC UMR 8640, 24 rue Lhomond, 75231 Paris (France); Institute for Integrated Cell-Material Science, Kyoto University, Kyoto 606-8507 (Japan)

    2013-03-01

    The behaviors of cells cultured on patterned substrates vary with the material stiffness, the geometry and the biochemical properties of the pattern. By using a reversed cell imprinting (RCI) technique, together with phase contrast microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM), we have exploited reversed side cellular morphology on patterned microgrooves of different geometries with or without surface coating of adhesion molecules. We have shown a close correlation between the effect of contact guidance and penetration of cellular membrane. Without surface coating, roughly 80% of HeLa cells were aligned along the groove direction regardless of the groove spacing. When the microgrooves were coated with fibronectin, the area of cell spreading was increased but the percentage of aligned cells was significantly decreased. In both cases, the deformation of cell membrane at the cell-pattern interfaces could be measured. We found that the local penetration of the cellular membrane into the grooves was correlated to the cellular alignment for both HeLa and NIH 3T3 cells, and that such a correlation was cell-type dependent. - Highlights: Black-Right-Pointing-Pointer Quantitatively assessment of cell deformation was obtained using RCI technique. Black-Right-Pointing-Pointer Cell alignment is correlated to the cell penetration into microgrooves. Black-Right-Pointing-Pointer Cell spreading is also correlated to the cell penetration into microgrooves. Black-Right-Pointing-Pointer The cell penetration and the cell alignment are cell-type dependent.

  1. Alterations in cell surface area and deformability of individual human red blood cells in stored blood

    CERN Document Server

    Park, HyunJoo; Lee, SangYun; Kim, Kyoohyun; Sohn, Yong-Hak; Jang, Seongsoo; Park, YongKeun

    2015-01-01

    The functionality and viability of stored human red blood cells (RBCs) is an important clinical issue in transfusion. To systematically investigate changes in stored whole blood, the hematological properties of individual RBCs were quantified in blood samples stored for various periods with and without a preservation solution called CPDA-1. With 3-D quantitative phase imaging techniques, the optical measurements of the 3-D refractive index (RI) distributions and membrane fluctuations were done at the individual cell level. From the optical measurements, the morphological (volume, surface area and sphericity), biochemical (hemoglobin content and concentration), and mechanical parameters (dynamic membrane fluctuation) were simultaneously quantified to investigate the functionalities and their progressive alterations in stored RBCs. Our results show that the stored RBCs without CPDA-1 had a dramatic morphological transformation from discocytes to spherocytes within 2 weeks which was accompanied with significant ...

  2. Spatial and temporal changes in the morphology of preosteoblastic cells seeded on microstructured tantalum surfaces

    DEFF Research Database (Denmark)

    Justesen, Jørn; Lorentzen, M.; Andersen, L. K.;

    2009-01-01

    of time with regard to the two-dimensional pattern and vertical dimension of the structure. Microstructures of parallel grooves/ridges caused elongated cell growth after 1 and 4 h in comparison to a flat, nonstructured, reference surface. For microstructures consisting of pillars, cell spreading was found......, and length of preosteoblastic cells (MC3T3-E1). Cells were examined after 0.5, 1, 4, and 24 h on different Ta microstructures with vertical dimensions (heights) of 0.25 and 1.6 mu m. Cell morphologies depended upon the underlying Surface topography, and the length and spreading of cells varied as a function...

  3. Surface position, not signaling from surrounding maternal tissues, specifies aleurone epidermal cell fate in maize.

    Science.gov (United States)

    Gruis, Darren Fred; Guo, Hena; Selinger, David; Tian, Qing; Olsen, Odd-Arne

    2006-07-01

    Maize (Zea mays) endosperm consists of an epidermal-like surface layer of aleurone cells, an underlying body of starchy endosperm cells, and a basal layer of transfer cells. To determine whether surrounding maternal tissues perform a role in specifying endosperm cell fates, a maize endosperm organ culture technique was established whereby the developing endosperm is completely removed from surrounding maternal tissues. Using cell type-specific fluorescence markers, we show that aleurone cell fate specification occurs exclusively in response to surface position and does not require specific, continued maternal signal input. The starchy endosperm and aleurone cell fates are freely interchangeable throughout the lifespan of the endosperm, with internalized aleurone cells converting to starchy endosperm cells and with starchy endosperm cells that become positioned at the surface converting to aleurone cells. In contrast to aleurone and starchy endosperm cells, transfer cells fail to develop in in vitro-grown endosperm, supporting earlier indications that maternal tissue interaction is required to fully differentiate this cell type. Several parameters confirm that the maize endosperm organ cultures described herein retain the main developmental features of in planta endosperm, including fidelity of aleurone mutant phenotypes, temporal and spatial control of cell type-specific fluorescent markers, specificity of cell type transcripts, and control of mitotic cell divisions.

  4. Microarray of neuroblastoma cells on the selectively functionalized nanocrystalline diamond thin film surface

    Science.gov (United States)

    Park, Young-Sang; Son, Hyeong-Guk; Kim, Dae-Hoon; Oh, Hong-Gi; Lee, Da-Som; Kim, Min-Hye; Lim, Ki-Moo; Song, Kwang-Soup

    2016-01-01

    Nanocrystalline diamond (NCD) film surfaces were modified with fluorine or oxygen by plasma treatment in an O2 or C3F8 gas environment in order to induce wettability. The oxygenated-NCD (O-NCD) film surface was hydrophilic and the fluorinated-NCD (F-NCD) surface was hydrophobic. The efficiency of early cell adhesion, which is dependent on the wettability of the cell culture plate and necessary for the growth and proliferation of cells, was 89.62 ± 3.92% on the O-NCD film and 7.78 ± 0.77% on the F-NCD film surface after 3 h of cell culture. The wettability of the NCD film surface was artificially modified using a metal mask and plasma treatment to fabricate a micro-pattern. Four types of micro-patterns were fabricated (line, circle, mesh, and word) on the NCD film surface. We precisely arrayed the neuroblastoma cells on the micro-patterned NCD film surfaces by controlling the surface wettability and cell seeding density. The neuroblastoma cells adhered and proliferated along the O-NCD film surface.

  5. The surface charge of a cell lipid membrane

    CERN Document Server

    Pekker, M

    2014-01-01

    In this paper the problem of surface charge of the lipid membrane is considered. It is shown that the membrane surface is negatively charged. Negative ions are in potential wells formed by the dipole heads of membrane phospholipids. The binding energy of the ion with the membrane surface is much greater than its thermal energy. A self-consistent model of the potential in solution is developed, and a stationary charge density on the membrane surface is found. The estimates given in the paper show that the potential difference across the membrane of the unexcited axon (resting potential) can be explained by the difference in surface densities of the bound charges on the inner and outer surfaces of the membrane.

  6. A reference guide to microbial cell surface hydrophobicity based on contact angles

    NARCIS (Netherlands)

    van der Mei, HC; Busscher, HJ; Bos, R.R.M.

    1998-01-01

    Acid-base interactions form the origin of the hydrophobicity of microbial cell-surfaces and can be quantitated from contact angle measurements on microbial lawns with water, formamide, methyleneiodide and/or alpha-bromonaphthalene. This review provides a reference guide to microbial cell surface hyd

  7. Facile Discovery of Cell-Surface Protein Targets of Cancer Cell Aptamers.

    Science.gov (United States)

    Bing, Tao; Shangguan, Dihua; Wang, Yinsheng

    2015-10-01

    Cancer biomarker discovery constitutes a frontier in cancer research. In recent years, cell-binding aptamers have become useful molecular probes for biomarker discovery. However, there are few successful examples, and the critical barrier resides in the identification of the cell-surface protein targets for the aptamers, where only a limited number of aptamer targets have been identified so far. Herein, we developed a universal SILAC-based quantitative proteomic method for target discovery of cell-binding aptamers. The method allowed for distinguishing specific aptamer-binding proteins from nonspecific proteins based on abundance ratios of proteins bound to aptamer-carrying bait and control bait. In addition, we employed fluorescently labeled aptamers for monitoring and optimizing the binding conditions. We were able to identify and validate selectin L and integrin α4 as the protein targets for two previously reported aptamers, Sgc-3b and Sgc-4e, respectively. This strategy should be generally applicable for the discovery of protein targets for other cell-binding aptamers, which will promote the applications of these aptamers.

  8. Cytokine-Induced Cell Surface Expression of Adhesion Molecules in Vascular Endothelial Cells In vitro

    Institute of Scientific and Technical Information of China (English)

    陈红辉; 刘昌勤; 孙圣刚; 梅元武; 童萼塘

    2001-01-01

    Regulation of the adhesion molecules expression by cytokine in vascular endothelial cells was investigated. Human umbilical vein endothelial cells (HUVEC) were stimulated with cytokines, TNF-α (1-250 U/ml) or IL-1β (0.1-50 U/ml) for 24 h. HUVEC were also cultured with cytokines, TNF-α (100 U/ml) or IL-1β (10 U/ml), for 4-72 h, cell surface expression of adhesion molecules (ICAM-1 and VCAM-1) were detected and quantitated by immunocytochemical methods and computerized imaging analysis technique. Adhesion molecules expression were up-regulated by TNF-α, IL-1β in a concentration- and time-dependent manner. Some significant differences were observed between the effects of cytokines on the ICAM-1 and on VCAM-1 expression. Cytokines might directly induce the expression of ICAM-1 and VCAM-1 in vascular endothelial cells. Our observations indicate differential functions of the two adhesion molecules during the evolution of inflammatory responses in stroke.

  9. Impurity concentrations and surface charge densities on the heavily doped face of a silicon solar cell

    Science.gov (United States)

    Weinberg, I.; Hsu, L. C.

    1977-01-01

    Increased solar cell efficiencies are attained by reduction of surface recombination and variation of impurity concentration profiles at the n(+) surface of silicon solar cells. Diagnostic techniques are employed to evaluate the effects of specific materials preparation methodologies on surface and near surface concentrations. It is demonstrated that the MOS C-V method, when combined with a bulk measurement technique, yields more complete concentration data than are obtainable by either method alone. Specifically, new solar cell MOS C-V measurements are combined with bulk concentrations obtained by a successive layer removal technique utilizing measurements of sheet resistivity and Hall coefficient.

  10. Pancreatic hormones are expressed on the surfaces of human and rat islet cells through exocytotic sites

    DEFF Research Database (Denmark)

    Larsson, L I; Hutton, J C; Madsen, O D

    1989-01-01

    . Electron microscopy reveals the labeling to occur at sites of exocytotic granule release, involving the surfaces of extruded granule cores. The surfaces of islet cells were labeled both by polyclonal and monoclonal antibodies, excluding that receptor-interacting, anti-idiotypic hormone antibodies were...... responsible for the staining. Human insulin cells were surface-labeled by monoclonal antibodies recognizing the mature secretory products, insulin and C-peptide but not with monoclonal antibodies specific for proinsulin. Thus, routing of unprocessed preproinsulin to the cell surface may not account...... for these results. It is concluded that the staining reflects interactions between the appropriate antibodies and exocytotic sites of hormone release....

  11. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    Energy Technology Data Exchange (ETDEWEB)

    Kado, T.; Hidaka, T. [Division of Periodontology and Endodontology, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Aita, H. [Division of Occlusion and Removable Prosthodontics, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Endo, K. [Division of Biomaterials and Bioengineering, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan); Furuichi, Y., E-mail: furuichi@hoku-iryo-u.ac.jp [Division of Periodontology and Endodontology, Department of Oral Rehabilitation, School of Dentistry, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu, Hokkaido 061-0293 (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Cell-adhesive molecules were covalently immobilized on a Ti surface. Black-Right-Pointing-Pointer Immobilized cell-adhesive molecules maintained native function on the Ti surface. Black-Right-Pointing-Pointer Immobilized collagen enhanced adhesion of periodontal ligament cells to the Ti. - Abstract: A simple chemical modification method was developed to immobilize cell-adhesive molecules on a tit