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Sample records for potyviral resistance derived

  1. Potyviral resistance derived from cultivars of Phaseolus vulgaris carrying bc-3 is associated with the homozygotic presence of a mutated eIF4E allele

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eukaryotic translation initiation factors (eIFs) play a central role in potyviral infection. Accordingly, mutations in the gene encoding eIF4E have been identified as a source of recessive resistance in several plant species. In common bean, Phaseolus vulgaris, four recessive genes, bc-1, bc-2, bc-3...

  2. Cotranslational Coat Protein-Mediated Inhibition of Potyviral RNA Translation

    PubMed Central

    Besong-Ndika, Jane; Ivanov, Konstantin I.; Hafrèn, Anders; Michon, Thierry

    2015-01-01

    ABSTRACT Potato virus A (PVA) is a single-stranded positive-sense RNA virus and a member of the family Potyviridae. The PVA coat protein (CP) has an intrinsic capacity to self-assemble into filamentous virus-like particles, but the mechanism responsible for the initiation of viral RNA encapsidation in vivo remains unclear. Apart from virion assembly, PVA CP is also involved in the inhibition of viral RNA translation. In this study, we show that CP inhibits PVA RNA translation in a dose-dependent manner, through a mechanism involving the CP-encoding region. Analysis of this region, however, failed to identify any RNA secondary structure(s) preferentially recognized by CP, suggesting that the inhibition depends on CP-CP rather than CP-RNA interactions. In agreement with this possibility, insertion of an in-frame stop codon upstream of the CP sequence led to a marked decrease in the inhibition of viral RNA translation. Based on these results, we propose a model in which the cotranslational interactions between excess CP accumulating in trans and CP translated from viral RNA in cis are required to initiate the translational repression. This model suggests a mechanism for how viral RNA can be sequestered from translation and specifically selected for encapsidation at the late stages of viral infection. IMPORTANCE The main functions of the CP during potyvirus infection are to protect viral RNA from degradation and to transport it locally, systemically, and from host to host. Although virion assembly is a key step in the potyviral infectious cycle, little is known about how it is initiated and how viral RNA is selected for encapsidation. The results presented here suggest that CP-CP rather than CP-RNA interactions are predominantly involved in the sequestration of viral RNA away from translation. We propose that the cotranslational nature of these interactions may represent a mechanism for the selection of viral RNA for encapsidation. A better understanding of the

  3. A new approach for deriving pseudovelocity logs from resistivity logs

    SciTech Connect

    Dos Santos, W.L.B.; Ulrych, T.J.; De Lima, O.A.L.

    1988-01-01

    This paper describes a method of generating pseudovelocity logs using measurements of electrical resistivity. A theoretical relation between electrical resistivity and transit time, which is applicable to a wide range of lithologies, has been developed. The application of this relation using a method which defines lithoresistivity zones as lithological intervals related to the same formation and showing small resistivity variations, has been tested in the Reconcavo sedimentary basin in Bahia, Brazil. A comparison of derived pseudovelocity logs with actual sonic logs for five wells shows the validity of the present approach.

  4. Evaluation of novel lactone derivatives for chemically amplified EUV resists

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroyasu; Mizusaka, Tetsuhiko; Tanagi, Hiroyuki; Furukawa, Kikuo; Yamamoto, Hiroki; Kozawa, Takahiro

    2015-03-01

    EUV lithography is the most favorable process for high volume manufacturing of semiconductor devices beyond 1X nm half-pitch at present. Many efforts have revealed effective proton sources in acid generation in EUV resists, and the effective proton generation and the control of the generated acid diffusion are required to improve the breakthrough of the resolution ? line width roughness ? sensitivity(RLS) trade-off. To clarify the lithographic performance of these derivatives, we synthesized the acrylic ter/tetrapolymers containing novel lactone derivatives - LCHO and LAATB - as model photopolymers and exposed the resist samples based on these polymers to EUV and EB radiation. On the basis of the lithographic performances of these photoresists, we evaluated the characteristics of lactone derivatives upon exposure to EUV radiation. We discuss the relationship between the chemical structures of these derivatives and lithographic performance.

  5. Evaluating connectivity for tropical amphibians using empirically derived resistance surfaces.

    PubMed

    Nowakowski, A Justin; Veiman-Echeverria, Marylin; Kurz, David J; Donnelly, Maureen A

    2015-06-01

    Agricultural expansion continues to drive forest loss in species-rich tropical systems and often disrupts movement and distributions of organisms. The ability of species to occupy and move through altered habitats likely depends on the level of contrast between natural forest and surrounding land uses. Connectivity models, such as circuit theory models, are widely used in conservation biology, and their primary input consists of resistance surfaces representing movement costs associated with landscape features. Cost values are most frequently determined by expert opinion, which may not capture relevant levels of contrast among features. We developed resistance surfaces using experiments that represent different local mechanisms hypothesized to affect connectivity for two Neotropical amphibian species. Response ratios were calculated to translate experimental results to cost values used in connectivity modeling. We used relative abundance data in three land-cover types to generate resistance surfaces for evaluating independent support of models derived from experiments. Finally, we analyzed agreement among movement pathways predicted for each species and among three commonly used connectivity measures: Euclidean, least cost, and resistance distances. Experiments showed that extreme microclimates associated with altered habitats significantly increased desiccation and mortality risk for both species. Resistances estimated from microclimate experiments were concordant with those from survey data for both species. For one focal species, resistance estimates derived from predator encounter rates were also highly correlated with abundance-derived resistances. There was generally low agreement among the three alternative distance measures, which underscores the importance of choosing connectivity models that are most appropriate for the study objectives. Overall, similarity among linkages modeled for each species was high, but decreased with declining forest cover. Our

  6. Modulation of Drug Resistance in Staphylococcus aureus with Coumarin Derivatives

    PubMed Central

    de Araújo, Rodrigo Santos Aquino; Barbosa-Filho, José Maria; Scotti, Marcus Tullius; Scotti, Luciana; da Cruz, Ryldene Marques Duarte; Falcão-Silva, Vivyanne dos Santos; de Siqueira-Júnior, José Pinto; Mendonça-Junior, Francisco Jaime Bezerra

    2016-01-01

    Semisynthetic and commercial coumarins were investigated for their antibacterial and adjuvant properties with antibiotic agents against norfloxacin, erythromycin, and tetracycline resistant Staphylococcus aureus as based on efflux mechanisms. The coumarins and certain commercial antibiotics had their Minimum Inhibitory Concentrations determined by broth microdilution assay against resistant S. aureus strains which overexpress efflux pump proteins. For evaluation of the modulatory activity, the antibiotics MICs were determined in the presence of the coumarin derivatives at subinhibitory concentration. Although the coumarins did not display relevant antibacterial activity (MIC ≥ 128 µg/mL), they did modulate the antibiotics activities. Various coumarins, especially the alkylated derivatives in combination with antibiotics at subinhibitory concentrations, modulated antibiotic activity, reducing the MIC for tetracycline and norfloxacin by 2 to 8 times. Polar Surface Area (PSA) studies were performed and the fact that the presence of apolar groups is an important factor for the modulatory activity of coumarins was corroborated. Docking on the Penicillin-Binding Protein from MRSA identified that 18 is a potential ligand presenting low Ebinding. The results indicate that coumarin derivatives modulated antibiotic resistance and may be used as potential antibiotic adjuvants, acting by bacterial efflux pump inhibition in S. aureus. PMID:27200211

  7. Lactoferrin-derived resistance against plant pathogens in transgenic plants.

    PubMed

    Lakshman, Dilip K; Natarajan, Savithiry; Mandal, Sudhamoy; Mitra, Amitava

    2013-12-01

    Lactoferrin (LF) is a ubiquitous cationic iron-binding milk glycoprotein that contributes to nutrition and exerts a broad-spectrum primary defense against bacteria, fungi, protozoa, and viruses in mammals. These qualities make lactoferrin protein and its antimicrobial motifs highly desirable candidates to be incorporated in plants to impart broad-based resistance against plant pathogens or to economically produce them in bulk quantities for pharmaceutical and nutritional purposes. This study introduced bovine LF (BLF) gene into tobacco ( Nicotiana tabacum var. Xanthi), Arabidopsis ( A. thaliana ) and wheat ( Triticum aestivum ) via Agrobacterium -mediated plant transformation. Transgenic plants or detached leaves exhibited high levels of resistance against the damping-off causing fungal pathogen Rhizoctonia solani and the head blight causing fungal pathogen Fusarium graminearum . LF also imparted resistance to tomato plants against a bacterial pathogen, Ralstonia solanacearum . Similarly, other researchers demonstrated expression of LF and LF-mediated high-quality resistance to several other aggressive fungal and bacterial plant pathogens in transgenic plants and against viral pathogens by foliar applications of LF or its derivatives. Taken together, these studies demonstrated the effectiveness of LF for improving crop quality and its biopharming potentials for pharmaceautical and nutritional applications. PMID:23889215

  8. Genetic resistance to rhabdovirus infection in teleost fish is paralleled to the derived cell resistance status.

    PubMed

    Verrier, Eloi R; Langevin, Christelle; Tohry, Corinne; Houel, Armel; Ducrocq, Vincent; Benmansour, Abdenour; Quillet, Edwige; Boudinot, Pierre

    2012-01-01

    Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction--that was not observed in the susceptible cells--and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses. PMID:22514610

  9. Genetic Resistance to Rhabdovirus Infection in Teleost Fish Is Paralleled to the Derived Cell Resistance Status

    PubMed Central

    Verrier, Eloi R.; Langevin, Christelle; Tohry, Corinne; Houel, Armel; Ducrocq, Vincent; Benmansour, Abdenour; Quillet, Edwige; Boudinot, Pierre

    2012-01-01

    Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction - that was not observed in the susceptible cells - and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses. PMID:22514610

  10. High Proteolytic Resistance of Spider-Derived Inhibitor Cystine Knots

    PubMed Central

    Kikuchi, Kyoko; Sugiura, Mika; Kimura, Tadashi

    2015-01-01

    Proteolytic stability in gastrointestinal tract and blood plasma is the major obstacle for oral peptide drug development. Inhibitor cystine knots (ICKs) are linear cystine knot peptides which have multifunctional properties and could become promising drug scaffolds. ProTx-I, ProTx-II, GTx1-15, and GsMTx-4 were spider-derived ICKs and incubated with pepsin, trypsin, chymotrypsin, and elastase in physiological conditions to find that all tested peptides were resistant to pepsin, and ProTx-II, GsMTx-4, and GTx1-15 showed resistance to all tested proteases. Also, no ProTx-II degradation was observed in rat blood plasma for 24 hours in vitro and ProTx-II concentration in circulation decreased to half in 40 min, indicating absolute stability in plasma and fast clearance from the system. So far, linear peptides are generally thought to be unsuitable in vivo, but all tested ICKs were not degraded by pepsin and stomach could be selected for the alternative site of drug absorption for fast onset of the drug action. Since spider ICKs are selective inhibitors of various ion channels which are related to the pathology of many diseases, engineered ICKs will make a novel class of peptide medicines which can treat variety of bothering symptoms. PMID:26843868

  11. No recombination detected in artificial potyvirus mixed infections and between potyvirus derived transgenes and heterologous challenging potyviruses.

    PubMed

    Dietrich, Christof; Miller, Jane; McKenzie, Gaynor; Palkovics, László; Balázs, Ervin; Palukaitis, Peter; Maiss, Edgar

    2007-01-01

    Risk-assessment studies of virus-resistant transgenic plants (VRTPs) focussing on recombination of a plant virus with a transgenic sequence of a different virus should include a comparison of recombination frequencies between viruses in double-infected non-transgenic plants with those observed in singly infected transgenic plants to estimate recombination incidence in VRTPs. In this study, the occurrence of recombination events was investigated in non-transgenic plants double-infected with two different potyviruses, as well as in potyviral genomes in singly infected transgenic plants expressing potyvirus sequences. Different potyviruses, namely Potato virus A (PVA), Tobacco vein mottling virus (TVMV), two strains of Potato virus Y (PVY-O, PVY-H) and two strains of Plum pox virus (PPV-NAT, PPV-SK68), were used in three combinations for double infection of a common host. Furthermore, transgenic plants expressing either potyviral coat protein (CP), helicase (CI) or polymerase (NIb) coding sequences (PPV-NAT-CP, PVY-CI, PVY-NIb) were singly-infected with a heterologous potyvirus, which was not targeted by the respective transgenic resistance. To identify recombinant potyviral sequences, a sensitive RT-PCR was developed to detect up to one recombinant molecule out of 10(6) parental molecules. In 304 mixed infected non-transgenic plants, 92 mixed and 164 single infected transgenic plants screened for recombinant sequences no recombinant potyviral sequence was found. These results indicate that recombination events between different potyviruses in mixed infections and between a potyvirus infecting a potyvirus-resistant transgenic plant are likely to be very infrequent. PMID:18001687

  12. Plant derived compounds inactivate antibiotic resistant Campylobacter jejuni strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sixty-three Campylobacter isolates were screened for their resistance to the antibiotics ampicillin, cefaclor, ciprofloxacin, erythromycin, gentamycin, tetracycline, and trimethroprim/sulfamethoxazole. Based on this screen, the resistant strains D28a and H2a and the nonresistant strain A24a were se...

  13. Detection of plum pox potyviral protein-protein interactions in planta using an optimized mRFP-based bimolecular fluorescence complementation system.

    PubMed

    Zilian, Eva; Maiss, Edgar

    2011-12-01

    In previous studies, protein interaction maps of different potyviruses have been generated using yeast two-hybrid (YTH) systems, and these maps have demonstrated a high diversity of interactions of potyviral proteins. Using an optimized bimolecular fluorescence complementation (BiFC) system, a complete interaction matrix for proteins of a potyvirus was developed for the first time under in planta conditions with ten proteins from plum pox virus (PPV). In total, 52 of 100 possible interactions were detected, including the self-interactions of CI, 6K2, VPg, NIa-Pro, NIb and CP, which is more interactions than have ever been detected for any other potyvirus in a YTH approach. Moreover, the BiFC system was shown to be able to localize the protein interactions, which was typified for the protein self-interactions indicated above. Additionally, experiments were carried out with the P3N-PIPO protein, revealing an interaction with CI but not with CP and supporting the involvement of P3N-PIPO in the cell-to-cell movement of potyviruses. No self-interaction of the PPV helper component-proteinase (HC-Pro) was detected using BiFC in planta. Therefore, additional experiments with turnip mosaic virus (TuMV) HC-Pro, PPV_HC-Pro and their mutants were conducted. The self-interaction of TuMV_HCpro, as recently demonstrated, and the self-interaction of the TuMV_ and PPV_HC-Pro mutants were shown by BiFC in planta, indicating that HC-Pro self-interactions may be species-specific. BiFC is a very useful and reliable method for the detection and localization of protein interactions in planta, thus enabling investigations under more natural conditions than studies in yeast cells. PMID:21880839

  14. Synthesis and radiation resistance of fullerenes and fullerene derivatives

    NASA Astrophysics Data System (ADS)

    Shilin, V. A.; Lebedev, V. T.; Sedov, V. P.; Szhogina, A. A.

    2016-07-01

    The parameters of an electric-arc facility for the synthesis of fullerenes and endohedral metallofullerenes are optimized. The resistance of C60 and C70 fullerenes and C60(OH)30 and C70(OH)30 fullerenols against neutron irradiation is studied. It is established that the radiation resistance of the fullerenes is higher than that of the fullerenols, but the radiation resistance of the Gd@C2 n endometallofullerenes is lower than that of the corresponding Gd@C2 n (OH)38 fullerenols. The radiation resistance of mixtures of Me@C2 n (OH)38 ( Me = Gd, Tb, Sc, Fe, and Pr) endometallofullerenes with C60(OH)30 is determined. The factors affecting the radiation resistance of the fullerenes and fullerenols are discussed.

  15. Drug Resistance Reversal Potential of Ursolic Acid Derivatives against Nalidixic Acid- and Multidrug-resistant Escherichia coli.

    PubMed

    Dwivedi, Gaurav Raj; Maurya, Anupam; Yadav, Dharmendra Kumar; Khan, Feroz; Darokar, Mahendra P; Srivastava, Santosh Kumar

    2015-09-01

    As a part of our drug discovery program, ursolic acid was chemically transformed into six semi-synthetic derivatives, which were evaluated for their antibacterial and drug resistance reversal potential in combination with conventional antibiotic nalidixic acid against the nalidixic acid-sensitive and nalidixic acid-resistant strains of Escherichia coli. Although ursolic acid and its all semi-synthetic derivatives did not show antibacterial activity of their own, but in combination, they significantly reduced the minimum inhibitory concentration of nalidixic acid up to eightfold. The 3-O-acetyl-urs-12-en-28-isopropyl ester (UA-4) and 3-O-acetyl-urs-12-en-28-n-butyl ester (UA-5) derivatives of ursolic acid reduced the minimum inhibitory concentration of nalidixic acid by eightfold against nalidixic acid-resistant and four and eightfold against nalidixic acid-sensitive, respectively. The UA-4 and UA-5 were further evaluated for their synergy potential with another antibiotic tetracycline against the multidrug-resistant clinical isolate of Escherichia coli-KG4. The results showed that both these derivatives in combination with tetracycline reduced the cell viability in concentration-dependent manner by significantly inhibiting efflux pump. This was further supported by the in silico binding affinity of UA-4 and UA-5 with efflux pump proteins. These ursolic acid derivatives may find their potential use as synergistic agents in the treatment of multidrug-resistant Gram-negative infections. PMID:25476148

  16. Examination of Early Blight Resistance Derived From S. Raphanifolium

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early blight of potato (Solanum tuberosum L.), caused by Alternaria solani is a major cause of economic losses in many potato growing regions. Growers and breeders are interested in the development of potato cultivars with resistance to early blight as a means to decrease usage of fungicide applica...

  17. ANTIMICROBIAL RESISTANCE RATES IN CAMPYLOBACTER ISOLATES DERIVED FROM SWINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter, a microaerophilic gram-negative rod, is a major foodborne pathogen and commonly present in swine intestinal tract without causing any clinical disease. In this project, we investigated the antimicrobial resistance profiles of fecal Campylobacter isolates (n= 194) obtained from a swin...

  18. New source of TTKSK resistance derived from Thinopyrum and Aegilops species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several stem rust resistance genes of Thinopyrum and Aegilops origins appeared to be highly effective against race TTKSK (or Ug99) of Puccinia graminis f. sp. tritici. We evaluated and characterized the seedling resistance to TTKSK of 62 wheat lines derived from crosses of common or durum wheat with...

  19. A Note on Derivatives of Isoniazid, Rifampicin, and Pyrazinamide Showing Activity Against Resistant Mycobacterium tuberculosis.

    PubMed

    Nusrath Unissa, Ameeruddin; Hanna, Luke Elizabeth; Swaminathan, Soumya

    2016-04-01

    Drug-resistant tuberculosis (DR-TB) is a serious problem that impedes the success of the TB control program. Of note, multidrug-resistant (MDR)-TB and extensively drug-resistant (XDR)-TB have certainly complicated the scenario. One of the possible strategies to overcome drug resistance in an economic and simple manner would involve modification of existing anti-TB drugs to obtain derivatives that can work on resistant TB bacilli. These may have improved half-life and increased bioavailability, be more efficacious, and serve as cost-effective alternatives, as compared to new drugs identified through conventional methods of drug discovery and development. Although extensive literature is available on the activity of various derivatives of first-line drugs (isoniazid, rifampicin and pyrazinamide) on drug-susceptible Mycobacterium tuberculosis (MTB), reports on the activity of derivatives on resistant MTB are very limited, to our knowledge. In light of this, the present review aims to provide a concise report on the derivatives of first-line drugs that have the potential to overcome the resistance to the parental drug and could thus serve as effective alternatives. PMID:26613382

  20. Chemosensitization of multidrug resistant Candida albicans by the oxathiolone fused chalcone derivatives

    PubMed Central

    Ła̧cka, Izabela; Konieczny, Marek T.; Bułakowska, Anita; Kodedová, Marie; Gašková, Dana; Maurya, Indresh K.; Prasad, Rajendra; Milewski, Sławomir

    2015-01-01

    Three structurally related oxathiolone fused chalcone derivatives appeared effective chemosensitizers, able to restore in part sensitivity to fluconazole of multidrug-resistant C. albicans strains. Compound 21 effectively chemosensitized cells resistant due to the overexpression of the MDR1 gene, compound 6 reduced resistance of cells overexpressing the ABC-type drug transporters CDR1/CDR2 and derivative 18 partially reversed fluconazole resistance mediated by both types of yeast drug efflux pumps. The observed effect of sensitization of resistant strains of Candida albicans to fluconazole activity in the presence of active compounds most likely resulted from inhibition of the pump-mediated efflux, as was revealed by the results of studies involving the fluorescent probes, Nile Red, Rhodamine 6G and diS-C3(3). PMID:26300857

  1. Mining, genetic mapping and expression analysis of EST-derived resistance gene homologs (RGHs) in cotton

    PubMed Central

    2014-01-01

    Background Cotton is the dominant textile crop and also serves as an important oil crop. An estimated 15% economic loss associated with cotton production in China has been caused by diseases, and no resistance genes have been cloned in this crop. Molecular markers developed from resistance gene homologues (RGHs) might be tightly linked with target genes and could be used for marker-assisted selection (MAS) or gene cloning. Results To genetically map expressed RGHs, 100 potential pathogenesis-related proteins (PRPs) and 215 resistance gene analogs (RGAs) were identified in the cotton expressed sequence tag database, and 347 specific primers were developed. Meanwhile, 61 cotton genome-derived RGA markers and 24 resistance gene analog polymorphism (RGAP) markers from published papers were included to view their genomic distribution. As a result, 38 EST-derived and 17 genome-derived RGH markers were added to our interspecific genetic map. These 55 markers were distributed on 18 of the 26 cotton chromosomes, with 34 markers on 6 chromosomes (Chr03, Chr04, Chr11, Chr17, Chr19 and Chr26). Homologous RGHs tended to be clustered; RGH clusters appeared on 9 chromosomes, with larger clusters on Chr03, Chr04 and Chr19, which suggests that RGH clusters are widely distributed in the cotton genome. Expression analysis showed that 19 RGHs were significantly altered after inoculation with the V991 stain of Verticillium dahliae. Comparative mapping showed that four RGH markers were linked with mapped loci for Verticillium wilt resistance. Conclusions The genetic mapping of RGHs confirmed their clustering in cotton genome. Expression analysis and comparative mapping suggest that EST-derived RGHs participate in cotton resistance. RGH markers are seemed to be useful tools to detected resistance loci and identify candidate resistance genes in cotton. PMID:25064562

  2. A mutagenesis-derived broad-spectrum disease resistance locus in wheat.

    PubMed

    Campbell, Jackie; Zhang, Hongtao; Giroux, Michael J; Feiz, Leila; Jin, Yue; Wang, Meinan; Chen, Xianming; Huang, Li

    2012-07-01

    Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. Breeding durable disease resistance cultivars rely largely on continually introgressing new resistance genes, especially the genes with different defense mechanisms, into adapted varieties. Here, we describe a new resistance gene obtained by mutagenesis. The mutant, MNR220 (mutagenesis-derived new resistance), enhances resistance to three rusts and powdery mildew, with the characteristics of delayed disease development at the seedling stage and completed resistance at the adult plant stage. Genetic analysis demonstrated that the resistance in MNR220 is conferred by a single semidominant gene mapped on the short arm of chromosome 2B. Gene expression profiling of several pathogenesis-related genes indicated that MNR220 has an elevated and rapid pathogen-induced response. In addition to its potential use in breeding for resistance to multiple diseases, high-resolution mapping and cloning of the disease resistance locus in MNR220 may lead to a better understanding of the regulation of defense responses in wheat. PMID:22446929

  3. New Amphiphilic Neamine Derivatives Active against Resistant Pseudomonas aeruginosa and Their Interactions with Lipopolysaccharides

    PubMed Central

    Sautrey, Guillaume; Zimmermann, Louis; Deleu, Magali; Delbar, Alicia; Souza Machado, Luiza; Jeannot, Katy; Van Bambeke, Françoise; Buyck, Julien M.; Decout, Jean-Luc

    2014-01-01

    The development of novel antimicrobial agents is urgently required to curb the widespread emergence of multidrug-resistant bacteria like colistin-resistant Pseudomonas aeruginosa. We previously synthesized a series of amphiphilic neamine derivatives active against bacterial membranes, among which 3′,6-di-O-[(2″-naphthyl)propyl]neamine (3′,6-di2NP), 3′,6-di-O-[(2″-naphthyl)butyl]neamine (3′,6-di2NB), and 3′,6-di-O-nonylneamine (3′,6-diNn) showed high levels of activity and low levels of cytotoxicity (L. Zimmermann et al., J. Med. Chem. 56:7691–7705, 2013). We have now further characterized the activity of these derivatives against colistin-resistant P. aeruginosa and studied their mode of action; specifically, we characterized their ability to interact with lipopolysaccharide (LPS) and to alter the bacterial outer membrane (OM). The three amphiphilic neamine derivatives were active against clinical colistin-resistant strains (MICs, about 2 to 8 μg/ml), The most active one (3′,6-diNn) was bactericidal at its MIC and inhibited biofilm formation at 2-fold its MIC. They cooperatively bound to LPSs, increasing the outer membrane permeability. Grafting long and linear alkyl chains (nonyl) optimized binding to LPS and outer membrane permeabilization. The effects of amphiphilic neamine derivatives on LPS micelles suggest changes in the cross-bridging of lipopolysaccharides and disordering in the hydrophobic core of the micelles. The molecular shape of the 3′,6-dialkyl neamine derivatives induced by the nature of the grafted hydrophobic moieties (naphthylalkyl instead of alkyl) and the flexibility of the hydrophobic moiety are critical for their fluidifying effect and their ability to displace cations bridging LPS. Results from this work could be exploited for the development of new amphiphilic neamine derivatives active against colistin-resistant P. aeruginosa. PMID:24867965

  4. Introgression of FHB Resistance from Alien Species-Derived Lines into Spring Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have produced and collected over 300 wheat lines derived from the crosses of wheat with wild species related to wheat. Evaluation of these lines for reaction to Fusarium head blight (FHB) identified 74 lines with resistance comparable to “Sumai 3” in two greenhouse seasons. Most of the resistan...

  5. Draft Genome Sequence of a Metronidazole-Resistant Derivative of Gardnerella vaginalis Strain ATCC 14019

    PubMed Central

    Schuyler, Jessica A.; Mordechai, Eli; Adelson, Martin E.; Gygax, Scott E.

    2015-01-01

    We report the genome sequence of a metronidazole-resistant derivative of Gardnerella vaginalis ATCC 14019. This strain was obtained after serial selection to increase the MIC from 4 to ≥500 µg/ml. Two coding changes, in genes encoding a response regulator and an NAD+ synthetase, arose during selection. PMID:26564054

  6. Genetic Mapping of a Triticum monococcum-derived Powdery Mildew Resistance Gene in Common Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew of wheat (Triticum aestivum L.) is a major fungal disease caused by Blumeria graminis DC f sp. tritici. A microsatellite linkage map was developed for the T. monococcum-derived powdery mildew resistant gene present in the North Carolina germplasm line NCBGT96A6 (NCA6). Genetic analys...

  7. Scoring Methods for Building Genotypic Scores: An Application to Didanosine Resistance in a Large Derivation Set

    PubMed Central

    Houssaini, Allal; Assoumou, Lambert; Miller, Veronica; Calvez, Vincent; Marcelin, Anne-Geneviève; Flandre, Philippe

    2013-01-01

    Background Several attempts have been made to determine HIV-1 resistance from genotype resistance testing. We compare scoring methods for building weighted genotyping scores and commonly used systems to determine whether the virus of a HIV-infected patient is resistant. Methods and Principal Findings Three statistical methods (linear discriminant analysis, support vector machine and logistic regression) are used to determine the weight of mutations involved in HIV resistance. We compared these weighted scores with known interpretation systems (ANRS, REGA and Stanford HIV-db) to classify patients as resistant or not. Our methodology is illustrated on the Forum for Collaborative HIV Research didanosine database (N = 1453). The database was divided into four samples according to the country of enrolment (France, USA/Canada, Italy and Spain/UK/Switzerland). The total sample and the four country-based samples allow external validation (one sample is used to estimate a score and the other samples are used to validate it). We used the observed precision to compare the performance of newly derived scores with other interpretation systems. Our results show that newly derived scores performed better than or similar to existing interpretation systems, even with external validation sets. No difference was found between the three methods investigated. Our analysis identified four new mutations associated with didanosine resistance: D123S, Q207K, H208Y and K223Q. Conclusions We explored the potential of three statistical methods to construct weighted scores for didanosine resistance. Our proposed scores performed at least as well as already existing interpretation systems and previously unrecognized didanosine-resistance associated mutations were identified. This approach could be used for building scores of genotypic resistance to other antiretroviral drugs. PMID:23555613

  8. Protein resistance of surfaces modified with oligo(ethylene glycol) aryl diazonium derivatives.

    PubMed

    Fairman, Callie; Ginges, Joshua Z; Lowe, Stuart B; Gooding, J Justin

    2013-07-22

    Anti-fouling surfaces are of great importance for reducing background interference in biosensor signals. Oligo(ethylene glycol) (OEG) moieties are commonly used to confer protein resistance on gold, silicon and carbon surfaces. Herein, we report the modification of surfaces using electrochemical deposition of OEG aryl diazonium salts. Using electrochemical and contact angle measurements, the ligand packing density is found to be loose, which supports the findings of the fluorescent protein labelling that aryl diazonium OEGs confer resistance to nonspecific adsorption of proteins albeit lower than alkane thiol-terminated OEGs. In addition to protein resistance, aryl diazonium attachment chemistry results in stable modification. In common with OEG species on gold electrodes, OEGs with distal hydroxyl moieties do confer superior protein resistance to those with a distal methoxy group. This is especially the case for longer derivatives where superior coiling of the OEG chains is possible. PMID:23650106

  9. Evaluation of alcoholic hydroxyl derivatives for chemically amplified extreme ultraviolet resist

    NASA Astrophysics Data System (ADS)

    Furukawa, Kikuo; Kozawa, Takahiro; Tagawa, Seiichi

    2009-03-01

    Extreme ultraviolet (EUV) lithography is the most favorable process as next-generation lithography. For the development of EUV resists, phenolic materials such as poly (4-hydroxystyrene) have been investigated. Phenolic hydroxyl groups of polymers play an important role in acid diffusion, dissolution kinetics, and adhesion to substrates. Besides these important roles, phenolic hydroxyl groups are also an effective proton source in acid generation in EUV resists. However, the roles of alcohol hydroxyl groups have not been well-studied. To clarify the difference between phenolic and alcoholic hydroxyl groups upon exposure to EUV radiation, we synthesized acrylic terpolymers containing alcoholic hydroxyl groups as model photopolymers and exposed the resist samples based on these polymers to EUV radiation. On the basis of the lithographic performances of these resist samples, we evaluated the characteristics of alcoholic hydroxyl groups upon exposure to EUV radiation. We discuss the relationship between the chemical structures of these derivatives and lithographic performance.

  10. Gas productivity related to cleat volumes derived from focused resistivity tools in coalbed methane (CBM) fields

    SciTech Connect

    Yang, Y.H.; Peeters, M.; Cloud, T.A.; Van Kirk, C.W.

    2006-06-15

    Cleats are critical for coal-bed methane (CBM) production, but operators usually lack a viable method to determine productivity except for costly well tests. Wireline logs, run over the CBM deposits of the Drunkards Wash Unit located in the Uinta Basin of Utah, were used to develop a new method to relate productivity to the cleat volume. The latter is derived from a focused resistivity log and the wellbore-fluid resistivity. Induction tools are unsuitable for this method, because they are dominated by borehole effects in high resistivity coals and low resistivity mud. Moreover, they read too deep to be significantly affected by the substitution of formation fluid by borehole fluid in the cleats on which the method is based. The method was demonstrated by relating cleat volume to CBM gas productivity in 24 wells, an exercise that clearly separated good from poor producers.

  11. Intra- and inter-tumor heterogeneity in a vemurafenib-resistant melanoma patient and derived xenografts

    PubMed Central

    Kemper, Kristel; Krijgsman, Oscar; Cornelissen-Steijger, Paulien; Shahrabi, Aida; Weeber, Fleur; Song, Ji-Ying; Kuilman, Thomas; Vis, Daniel J; Wessels, Lodewyk F; Voest, Emile E; Schumacher, Ton NM; Blank, Christian U; Adams, David J; Haanen, John B; Peeper, Daniel S

    2015-01-01

    The development of targeted inhibitors, like vemurafenib, has greatly improved the clinical outcome of BRAFV600E metastatic melanoma. However, resistance to such compounds represents a formidable problem. Using whole-exome sequencing and functional analyses, we have investigated the nature and pleiotropy of vemurafenib resistance in a melanoma patient carrying multiple drug-resistant metastases. Resistance was caused by a plethora of mechanisms, all of which reactivated the MAPK pathway. In addition to three independent amplifications and an aberrant form of BRAFV600E, we identified a new activating insertion in MEK1. This MEK1T55delinsRT mutation could be traced back to a fraction of the pre-treatment lesion and not only provided protection against vemurafenib but also promoted local invasion of transplanted melanomas. Analysis of patient-derived xenografts (PDX) from therapy-refractory metastases revealed that multiple resistance mechanisms were present within one metastasis. This heterogeneity, both inter- and intra-tumorally, caused an incomplete capture in the PDX of the resistance mechanisms observed in the patient. In conclusion, vemurafenib resistance in a single patient can be established through distinct events, which may be preexisting. Furthermore, our results indicate that PDX may not harbor the full genetic heterogeneity seen in the patient’s melanoma. PMID:26105199

  12. Myotubes derived from human-induced pluripotent stem cells mirror in vivo insulin resistance

    PubMed Central

    Iovino, Salvatore; Burkart, Alison M.; Warren, Laura; Patti, Mary Elizabeth; Kahn, C. Ronald

    2016-01-01

    Induced pluripotent stem cells (iPS cells) represent a unique tool for the study of the pathophysiology of human disease, because these cells can be differentiated into multiple cell types in vitro and used to generate patient- and tissue-specific disease models. Given the critical role for skeletal muscle insulin resistance in whole-body glucose metabolism and type 2 diabetes, we have created a novel cellular model of human muscle insulin resistance by differentiating iPS cells from individuals with mutations in the insulin receptor (IR-Mut) into functional myotubes and characterizing their response to insulin in comparison with controls. Morphologically, IR-Mut cells differentiated normally, but had delayed expression of some muscle differentiation-related genes. Most importantly, whereas control iPS-derived myotubes exhibited in vitro responses similar to primary differentiated human myoblasts, IR-Mut myotubes demonstrated severe impairment in insulin signaling and insulin-stimulated 2-deoxyglucose uptake and glycogen synthesis. Transcriptional regulation was also perturbed in IR-Mut myotubes with reduced insulin-stimulated expression of metabolic and early growth response genes. Thus, iPS-derived myotubes from individuals with genetically determined insulin resistance demonstrate many of the defects observed in vivo in insulin-resistant skeletal muscle and provide a new model to analyze the molecular impact of muscle insulin resistance. PMID:26831110

  13. Vitamin E derivative-based multifunctional nanoemulsions for overcoming multidrug resistance in cancer.

    PubMed

    Zheng, Nannan; Gao, Yanan; Ji, Hongyu; Wu, Linhua; Qi, Xuejing; Liu, Xiaona; Tang, Jingling

    2016-08-01

    The multidrug resistance (MDR), including intrinsic and acquired multidrug resistance, is a major problem in tumor chemotherapy. Here, we proposed a strategy for modulating intrinsic and/or acquired multidrug resistance by altering the levels of Bax and Bcl-2 expression and inhibiting the transport function of P-gp, increasing the intracellular concentration of its substrate anticancer drugs. Vitamin E derivative-based nanoemulsions containing paclitaxel (MNEs-PTX) were fabricated in this study, and in vitro anticancer efficacy of the nanoemulsion system was evaluated in the paclitaxel-resistant human ovarian carcinoma cell line A2780/Taxol. The MNEs-PTX exhibited a remarkably enhanced antiproliferation effect on A2780/Taxol cells than free paclitaxel (PTX) (p < 0.01). Compared with that in the Taxol group, MNEs-PTX further decreased mitochondrial potential. Vitamin E derivative-based multifunctional nanoemulsion (MNEs) obviously increased intracellular accumulation of rhodamine 123 (P-gp substrate). Overexpression of Bcl-2 is generally associated with tumor drug resistance, we found that MNEs could reduce Bcl-2 protein level and increase Bax protein level. Taken together, our findings suggest that anticancer drugs associated with MNEs could play a role in the development of MDR in cancers. PMID:26710274

  14. 3-Iodo-4-aminoquinoline derivative sensitises resistant strains of Plasmodium falciparum to chloroquine.

    PubMed

    Edaye, Sonia; Tazoo, Dagobert; Bohle, D Scott; Georges, Elias

    2016-06-01

    Chloroquine (CQ), the first cost-effective synthetic antimalarial, is rendered ineffective in malaria-endemic regions owing to the rise and spread of CQ-resistant Plasmodium falciparum. In this report, we show that a halogen derivative of CQ, namely 3-iodo-CQ, inhibits the proliferation of CQ-sensitive and -resistant P. falciparum in a verapamil-insensitive manner. Similar to CQ, the antimalarial activity of 3-iodo-CQ is likely due to its inhibition of β-haematin formation. Interestingly, the presence of non-inhibitory concentrations of 3-iodo-CQ potentiated the antiproliferative activity of CQ against CQ-resistant strains or P. falciparum transfectants expressing wild-type or mutant P. falciparum CQ resistance transporter (PfCRT) (C2(GC03) or C4(Dd2), respectively). These findings demonstrate that halogenation of the third position of 4-aminoquinoline, with a simple one-step reaction from CQ, generates a novel derivative that is active against CQ-sensitive and -resistant P. falciparum, possibly by inhibiting the activity of mutant PfCRT. PMID:27211211

  15. Gut microbe-derived extracellular vesicles induce insulin resistance, thereby impairing glucose metabolism in skeletal muscle

    PubMed Central

    Choi, Youngwoo; Kwon, Yonghoon; Kim, Dae-Kyum; Jeon, Jinseong; Jang, Su Chul; Wang, Taejun; Ban, Minjee; Kim, Min-Hye; Jeon, Seong Gyu; Kim, Min-Sun; Choi, Cheol Soo; Jee, Young-Koo; Gho, Yong Song; Ryu, Sung Ho; Kim, Yoon-Keun

    2015-01-01

    Gut microbes might influence host metabolic homeostasis and contribute to the pathogenesis of type 2 diabetes (T2D), which is characterized by insulin resistance. Bacteria-derived extracellular vesicles (EVs) have been suggested to be important in the pathogenesis of diseases once believed to be non-infectious. Here, we hypothesize that gut microbe-derived EVs are important in the pathogenesis of T2D. In vivo administration of stool EVs from high fat diet (HFD)-fed mice induced insulin resistance and glucose intolerance compared to regular diet (RD)-fed mice. Metagenomic profiling of stool EVs by 16S ribosomal DNA sequencing revealed an increased amount of EVs derived from Pseudomonas panacis (phylum Proteobacteria) in HFD mice compared to RD mice. Interestingly, P. panacis EVs blocked the insulin signaling pathway in both skeletal muscle and adipose tissue. Moreover, isolated P. panacis EVs induced typical diabetic phenotypes, such as glucose intolerance after glucose administration or systemic insulin injection. Thus, gut microbe-derived EVs might be key players in the development of insulin resistance and impairment of glucose metabolism promoted by HFD. PMID:26510393

  16. Molecular Resists Based on Cholate Derivatives for Electron-Beam Lithography

    NASA Astrophysics Data System (ADS)

    Shiono, Daiju; Hirayama, Taku; Kasai, Kohei; Hada, Hideo; Onodera, Junichi; Arai, Tadashi; Yamaguchi, Atsuko; Shiraishi, Hiroshi; Fukuda, Hiroshi

    2006-06-01

    We have designed and synthesized cholate derivatives [1,4-bis(methyloxymethylcholate)cyclohexane: C2ChDM and 1,2-bis(oxymethylcholate)ethane: C2E] to investigate their properties as chemically amplified (CA) positive-tone electron-beam (EB) resist materials (Fig. \\reff1). C2ChDM and C2E which were easily obtained by one-step esterification from cholic acid and chloride compound, showed glass transition temperatures (Tgs) of 85 and 84 °C, respectively. These compounds were dissolved in propylene glycol monomethylether acetate (PGMEA) and formed amorphous thin films onto silicon wafers by a spin-coat method. The etch rates of C2ChDM and C2E, which were measured under CF4/CHF3/Ar mixed gas, were almost the same as poly( p-hydroxystyrene) (PHS). Model resist samples were formulated with C2ChDM and C2E as a base matrix and photo-acid generator (PAG) originating from a sulfonium salt (resist-A and -B, respectively). These resists showed good sensitivities to EB exposure. Furthermore, the FT-IR spectra of resist-A and -B films unexposed and exposed by the EB lithography tool were measured. From the spectral changes in resist-A and -B films, we confirmed that a cleavage of the ester bond occurred with EB irradiation and bake treatment, and that these resists worked as common CA positive-tone resists. The results with the resist-A and -B using EB exposure indicated a resolution of a 120 nm lines and spaces pattern.

  17. Molecular resists based on cholate derivatives for electron-beam lithography

    NASA Astrophysics Data System (ADS)

    Shiono, Daiju; Hirayama, Taku; Hada, Hideo; Onodera, Junichi; Arai, Tadashi; Yamaguchi, Atsuko; Kojima, Kyoko; Shiraishi, Hiroshi; Fukuda, Hiroshi

    2006-03-01

    We have designed and synthesized cholate derivatives (1,4-Bis(methyloxymethylcholate)cyclohexane: C2ChDM and 1,2-Bis(oxymethylcholate)ethane: C2E) to investigate the properties as a chemically amplified (CA) positive-tone Electron-beam (EB) resist material. C2ChDM and C2E which were easily obtained by one-step esterification from cholic acid and dichloride showed glass transition temperatures (Tgs), 85 and 84 °C, respectively. These compounds were dissolved in propylene glycol monomethyl ether acetate (PGMEA) and formed amorphous thin films onto silicon wafers by using a spin-coat method. The etch rates of C2ChDM and C2E, which were measured under CF 4/CHF 3/Ar mixed gas process, were almost the same as poly (p-hydroxystyrene) (PHS). The model resist samples were formulated with C2ChDM and C2E as base matrix and photo-acid generator (PAG) originated from sulfonium-salt (resist-A and B, respectively). These resists showed good sensitivities with EB exposure. Furthermore, the FT-IR spectra of resist-A and B films unexposed and exposed by the EB lithography tool were measured. From the spectral changes of resist-A and B films, we confirmed that a cleavage reaction of ester bond occurred by EB irradiation and bake treatment, and these resists worked as common CA positive-tone resist. The evaluation results with the resist-A and B by using EB exposure tool indicated the resolution of 120 nm lines and spaces pattern.

  18. Effects of durum wheat background on the expression of hexaploid wheat-derived Fusarium head blight resistance genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple Fusarium head blight (FHB) resistance sources have been identified in common wheat, but an effective source of resistance to FHB has not found in durum wheat. Here we report preliminary results on the effects of durum background on the expression of hexaploid wheat-derived FHB resistance g...

  19. Modulation of Fibronectin Adhesins and Other Virulence Factors in a Teicoplanin-Resistant Derivative of Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Renzoni, Adriana; Francois, Patrice; Li, Dongmei; Kelley, William L.; Lew, Daniel P.; Vaudaux, Pierre; Schrenzel, Jacques

    2004-01-01

    The impact of glycopeptide resistance on the molecular regulation of Staphylococcus aureus virulence and attachment to host tissues is poorly documented. We compared stable teicoplanin-resistant methicillin-resistant S. aureus (MRSA) strain 14-4 with its teicoplanin-susceptible MRSA parent, strain MRGR3, which exhibits a high degree of virulence in a rat model of chronic foreign body MRSA infection. The levels of fibronectin-mediated adhesion and surface display of fibronectin-binding proteins were higher in teicoplanin-resistant strain 14-4 than in its teicoplanin-susceptible parent or a teicoplanin-susceptible revertant (strain 14-4rev) that spontaneously emerged during tissue cage infection. Quantitative reverse transcription-PCR (qRT-PCR) showed four- and twofold higher steady-state levels of fnbA and fnbB transcripts, respectively, in strain 14-4 than in its teicoplanin-susceptible counterparts. Analysis of global regulatory activities by qRT-PCR revealed a strong reduction in the steady-state levels of RNAIII and RNAII in the teicoplanin-resistant strain compared to in its teicoplanin-susceptible counterparts. In contrast, sarA mRNA levels were more than fivefold higher in strain 14-4 than in MRGR3 and 14-4rev. Furthermore, the alternative transcription factor sigma B had a higher level of functional activity in the teicoplanin-resistant strain than in its teicoplanin-susceptible counterparts, as evidenced by significant increases in both the sigma B-dependent asp23 mRNA levels and the sarA P3 promoter-derived transcript levels, as assayed by qRT-PCR and Northern blotting, respectively. These data provide further evidence that the emergence of glycopeptide resistance is linked by still poorly understood molecular pathways with significant pleiotropic changes in the expression and regulation of some major virulence genes. These molecular and phenotypic changes may have a profound impact on the bacterial adhesion and colonization properties of such

  20. Multiple loci govern the bone marrow-derived immunoregulatory mechanism controlling dominant resistance to autoimmune orchitis.

    PubMed Central

    Meeker, N D; Hickey, W F; Korngold, R; Hansen, W K; Sudweeks, J D; Wardell, B B; Griffith, J S; Teuscher, C

    1995-01-01

    The existence of immunoregulatory genes conferring dominant resistance to autoimmunity is well documented. In an effort to better understand the nature and mechanisms of action of these genes, we utilized the murine model of autoimmune orchitis as a prototype. When the orchitis-resistant strain DBA/2J is crossed with the orchitis-susceptible strain BALB/cByJ, the F1 hybrid is completely resistant to the disease. By using reciprocal radiation bone marrow chimeras, the functional component mediating this resistance was mapped to the bone marrow-derived compartment. Resistance is not a function of either low-dose irradiation- or cyclophosphamide (20 mg/kg)-sensitive immunoregulatory cells, but can be adoptively transferred by primed splenocytes. Genome exclusion mapping identified three loci controlling the resistant phenotype. Orch3 maps to chromosome 11, whereas Orch4 and Orch5 map to the telomeric and centromeric regions of chromosome 1, respectively. All three genes are linked to a number of immunologically relevant candidate loci. Most significant, however, is the linkage of Orch3 to Idd4 and Orch5 to Idd5, two susceptibility genes which play a role in autoimmune insulin-dependent type 1 diabetes mellitus in the nonobese diabetic mouse. PMID:7777570

  1. Reversing drug resistance of soft tumor-repopulating cells by tumor cell-derived chemotherapeutic microparticles.

    PubMed

    Ma, Jingwei; Zhang, Yi; Tang, Ke; Zhang, Huafeng; Yin, Xiaonan; Li, Yong; Xu, Pingwei; Sun, Yanling; Ma, Ruihua; Ji, Tiantian; Chen, Junwei; Zhang, Shuang; Zhang, Tianzhen; Luo, Shunqun; Jin, Yang; Luo, Xiuli; Li, Chengyin; Gong, Hongwei; Long, Zhixiong; Lu, Jinzhi; Hu, Zhuowei; Cao, Xuetao; Wang, Ning; Yang, Xiangliang; Huang, Bo

    2016-06-01

    Developing novel approaches to reverse the drug resistance of tumor-repopulating cells (TRCs) or stem cell-like cancer cells is an urgent clinical need to improve outcomes of cancer patients. Here we show an innovative approach that reverses drug resistance of TRCs using tumor cell-derived microparticles (T-MPs) containing anti-tumor drugs. TRCs, by virtue of being more deformable than differentiated cancer cells, preferentially take up T-MPs that release anti-tumor drugs after entering cells, which in turn lead to death of TRCs. The underlying mechanisms include interfering with drug efflux and promoting nuclear entry of the drugs. Our findings demonstrate the importance of tumor cell softness in uptake of T-MPs and effectiveness of a novel approach in reversing drug resistance of TRCs with promising clinical applications. PMID:27167569

  2. Triclosan Derivatives: Towards Potent Inhibitors of Drug-Sensitive and Drug-Resistant Mycobacterium tuberculosis

    SciTech Connect

    Freundlich, Joel S.; Wang, Feng; Vilchèze, Catherine; Gulten, Gulcin; Langley, Robert; Schiehser, Guy A.; Jacobus, David P.; Jacobs, Jr., William R.; Sacchettini, James C.

    2009-06-30

    Isoniazid (INH) is a frontline antitubercular drug that inhibits the enoyl acyl carrier protein reductase InhA. Novel inhibitors of InhA that are not cross-resistant to INH represent a significant goal in antitubercular chemotherapy. The design, synthesis, and biological activity of a series of triclosan-based inhibitors is reported, including their promising efficacy against INH-resistant strains of M. tuberculosis. Triclosan has been previously shown to inhibit InhA, an essential enoyl acyl carrier protein reductase involved in mycolic acid biosynthesis, the inhibition of which leads to the lysis of Mycobacterium tuberculosis. Using a structure-based drug design approach, a series of 5-substituted triclosan derivatives was developed. Two groups of derivatives with alkyl and aryl substituents, respectively, were identified with dramatically enhanced potency against purified InhA. The most efficacious inhibitor displayed an IC{sub 50} value of 21 nM, which was 50-fold more potent than triclosan. X-ray crystal structures of InhA in complex with four triclosan derivatives revealed the structural basis for the inhibitory activity. Six selected triclosan derivatives were tested against isoniazid-sensitive and resistant strains of M. tuberculosis. Among those, the best inhibitor had an MIC value of 4.7 {mu}g mL{sup -1} (13 {mu}M), which represents a tenfold improvement over the bacteriocidal activity of triclosan. A subset of these triclosan analogues was more potent than isoniazid against two isoniazid-resistant M. tuberculosis strains, demonstrating the significant potential for structure-based design in the development of next generation antitubercular drugs.

  3. Resistance of the Burkholderia cepacia complex to fosmidomycin and fosmidomycin derivatives.

    PubMed

    Messiaen, Anne-Sophie; Verbrugghen, Thomas; Declerck, Charlotte; Ortmann, Regina; Schlitzer, Martin; Nelis, Hans; Van Calenbergh, Serge; Coenye, Tom

    2011-09-01

    The Burkholderia cepacia complex (BCC) is a group of 17 closely related opportunistic pathogens that are able to infect the respiratory tract of cystic fibrosis patients. BCC bacteria are intrinsically resistant to many antibiotics and are therefore difficult to eradicate. Fosmidomycin could be a new therapeutic agent to treat BCC infections as it inhibits 1-deoxy-d-xylulose-5-phosphate reductoisomerase (Dxr), a key enzyme in the non-mevalonate pathway essential in BCC bacteria for isoprenoid synthesis. In this study, the antimicrobial activity of fosmidomycin and eight fosmidomycin derivatives towards 40 BCC strains was investigated. All BCC strains were resistant to fosmidomycin, although addition of glucose-6-phosphate reduced the minimum inhibitory concentration values of FR900098, the fosmidomycin acetyl derivative, from 512 mg/L to 64 mg/L for Burkholderia multivorans and B. cepacia. This enhanced activity was linked to increased expression of the genes involved in glycerol-3-phosphate transport, which appears to be the only route for fosmidomycin import in BCC bacteria. Furthermore, upregulation of a fosmidomycin resistance gene (fsr) encoding an efflux pump was observed during fosmidomycin and FR900098 treatment. These results strongly suggest that the observed resistance in BCC bacteria is due to insufficient uptake accompanied by fosmidomycin and FR900098 efflux. PMID:21724375

  4. Macrophage-derived Lipocalin-2 contributes to ischemic resistance mechanisms by protecting from renal injury

    PubMed Central

    Jung, Michaela; Brüne, Bernhard; Hotter, Georgina; Sola, Anna

    2016-01-01

    Renal ischemia-reperfusion injury triggers an inflammatory response associated to infiltrating macrophages which determines the further outcome of disease. Brown Norway rats are known to show endogenous resistance to ischemia-induced renal damage. By contrast, Sprague Dawley rats exhibit a higher susceptibility to ischemic injury. In order to ascertain cytoprotective mechanisms, we focused on the implication of lipocalin-2 protein in main resistance mechanisms in renal ischemia/reperfusion injury by using adoptive macrophage administration, genetically modified ex vivo either to overexpress or to knockdown lipocalin-2. In vitro experiments with bone marrow-derived macrophages both from Brown Norway rats and from Sprague Dawley rats under hypoxic conditions showed endogenous differences regarding cytokine and lipocalin-2 expression profile in the two strains. Most interestingly, we observed that macrophages of the resistant strain express significantly more lipocalin-2. In vivo studies showed that tubular epithelial cell apoptosis and renal injury significantly increased and reparative markers decreased in Brown Norway rats after injection of lipocalin-2-knockdown macrophages, while the administration of lipocalin-2-overexpressing cells significantly decreased Sprague Dawley susceptibility. These data point to a crucial role of macrophage-derived lipocalin-2 in endogenous cytoprotective mechanisms. We conclude that expression of lipocalin-2 in tissue-infiltrating macrophages is pivotal for kidney-intrinsic cytoprotective pathways during ischemia reperfusion injury. PMID:26911537

  5. Endothelium-derived Relaxing Factors of Small Resistance Arteries in Hypertension

    PubMed Central

    2014-01-01

    Endothelium-derived relaxing factors (EDRFs), including nitric oxide (NO), prostacyclin (PGI2), and endothelium-derived hyperpolarizing factor (EDHF), play pivotal roles in regulating vascular tone. Reduced EDRFs cause impaired endothelium-dependent vasorelaxation, or endothelial dysfunction. Impaired endothelium-dependent vasorelaxation in response to acetylcholine (ACh) is consistently observed in conduit vessels in human patients and experimental animal models of hypertension. Because small resistance arteries are known to produce more than one type of EDRF, the mechanism(s) mediating endothelium-dependent vasorelaxation in small resistance arteries may be different from that observed in conduit vessels under hypertensive conditions, where vasorelaxation is mainly dependent on NO. EDHF has been described as one of the principal mediators of endothelium-dependent vasorelaxation in small resistance arteries in normotensive animals. Furthermore, EDHF appears to become the predominant endothelium-dependent vasorelaxation pathway when the endothelial NO synthase (NOS3)/NO pathway is absent, as in NOS3-knockout mice, whereas some studies have shown that the EDHF pathway is dysfunctional in experimental models of hypertension. This article reviews our current knowledge regarding EDRFs in small arteries under normotensive and hypertensive conditions. PMID:25343007

  6. LL-37-Derived Peptides Eradicate Multidrug-Resistant Staphylococcus aureus from Thermally Wounded Human Skin Equivalents

    PubMed Central

    de Breij, Anna; Chan, Heelam; van Dissel, Jaap T.; Drijfhout, Jan W.; Hiemstra, Pieter S.; El Ghalbzouri, Abdoelwaheb; Nibbering, Peter H.

    2014-01-01

    Burn wound infections are often difficult to treat due to the presence of multidrug-resistant bacterial strains and biofilms. Currently, mupirocin is used to eradicate methicillin-resistant Staphylococcus aureus (MRSA) from colonized persons; however, mupirocin resistance is also emerging. Since we consider antimicrobial peptides to be promising candidates for the development of novel anti-infective agents, we studied the antibacterial activities of a set of synthetic peptides against different strains of S. aureus, including mupirocin-resistant MRSA strains. The peptides were derived from P60.4Ac, a peptide based on the human cathelicidin LL-37. The results showed that peptide 10 (P10) was the only peptide more efficient than P60.4Ac, which is better than LL-37, in killing MRSA strain LUH14616. All three peptides displayed good antibiofilm activities. However, both P10 and P60.4Ac were more efficient than LL-37 in eliminating biofilm-associated bacteria. No toxic effects of these three peptides on human epidermal models were detected, as observed morphologically and by staining for mitochondrial activity. In addition, P60.4Ac and P10, but not LL-37, eradicated MRSA LUH14616 and the mupirocin-resistant MRSA strain LUH15051 from thermally wounded human skin equivalents (HSE). Interestingly, P60.4Ac and P10, but not mupirocin, eradicated LUH15051 from the HSEs. None of the peptides affected the excretion of interleukin 8 (IL-8) by thermally wounded HSEs upon MRSA exposure. In conclusion, the synthetic peptides P60.4Ac and P10 appear to be attractive candidates for the development of novel local therapies to treat patients with burn wounds infected with multidrug-resistant bacteria. PMID:24841266

  7. LL-37-derived peptides eradicate multidrug-resistant Staphylococcus aureus from thermally wounded human skin equivalents.

    PubMed

    Haisma, Elisabeth M; de Breij, Anna; Chan, Heelam; van Dissel, Jaap T; Drijfhout, Jan W; Hiemstra, Pieter S; El Ghalbzouri, Abdoelwaheb; Nibbering, Peter H

    2014-08-01

    Burn wound infections are often difficult to treat due to the presence of multidrug-resistant bacterial strains and biofilms. Currently, mupirocin is used to eradicate methicillin-resistant Staphylococcus aureus (MRSA) from colonized persons; however, mupirocin resistance is also emerging. Since we consider antimicrobial peptides to be promising candidates for the development of novel anti-infective agents, we studied the antibacterial activities of a set of synthetic peptides against different strains of S. aureus, including mupirocin-resistant MRSA strains. The peptides were derived from P60.4Ac, a peptide based on the human cathelicidin LL-37. The results showed that peptide 10 (P10) was the only peptide more efficient than P60.4Ac, which is better than LL-37, in killing MRSA strain LUH14616. All three peptides displayed good antibiofilm activities. However, both P10 and P60.4Ac were more efficient than LL-37 in eliminating biofilm-associated bacteria. No toxic effects of these three peptides on human epidermal models were detected, as observed morphologically and by staining for mitochondrial activity. In addition, P60.4Ac and P10, but not LL-37, eradicated MRSA LUH14616 and the mupirocin-resistant MRSA strain LUH15051 from thermally wounded human skin equivalents (HSE). Interestingly, P60.4Ac and P10, but not mupirocin, eradicated LUH15051 from the HSEs. None of the peptides affected the excretion of interleukin 8 (IL-8) by thermally wounded HSEs upon MRSA exposure. In conclusion, the synthetic peptides P60.4Ac and P10 appear to be attractive candidates for the development of novel local therapies to treat patients with burn wounds infected with multidrug-resistant bacteria. PMID:24841266

  8. Determinants of Human Immunodeficiency Virus Type 1 Resistance to gp41-Derived Inhibitory Peptides

    PubMed Central

    Rimsky, Laurence T.; Shugars, Diane C.; Matthews, Thomas J.

    1998-01-01

    A synthetic peptide, DP178, containing amino acids 127 to 162 of the human immunodeficiency virus type 1 (HIV-1) gp41 Env glycoprotein, is a potent inhibitor of virus infection and virus mediated cell-to-cell fusion (C. Wild, T. Greenwell, and T. Matthews, AIDS Res. Hum. Retroviruses 9:1051–1053, 1993). In an effort to understand the mechanism of action of this peptide, we derived resistant variants of HIV-1IIIB and NL4-3 by serial virus passage in the presence of increasing doses of the peptide. Sequence analysis of the resistant isolates suggested that a contiguous 3-amino-acid sequence within the amino-terminal heptad repeat motif of gp41 was associated with resistance. Site-directed mutagenesis studies confirmed this observation and indicated that changes in two of these three residues were necessary for development of the resistant phenotype. Direct binding of DP178 to recombinant protein and synthetic peptide analogs containing the wild-type and mutant heptad repeat sequences revealed a strong correlation between DP178 binding and the biological sensitivity of the corresponding virus isolates to DP178. The results are discussed from the standpoints of the mechanism of action of DP178 and recent crystallographic information for a core structure of the gp41 ectodomain. PMID:9444991

  9. Promotive effects of alginate-derived oligosaccharides on the inducing drought resistance of tomato

    NASA Astrophysics Data System (ADS)

    Liu, Ruizhi; Jiang, Xiaolu; Guan, Huashi; Li, Xiaoxia; Du, Yishuai; Wang, Peng; Mou, Haijin

    2009-09-01

    In order to determine the role of alginate-derived oligosaccharides (ADO) in drought stress resistance of tomato ( Lycopersicon esculentum Miller) seedlings, the leaves were exposed to different concentrations of ADO (0.05%, 0.10%, 0.20%, 0.30% and 0.50%) after drought stress was simulated by exposing the roots to 0.6 molL-1 PEG-6000 solution for 6 h. Changes in biomass, electrolyte leakage and malondialdehyde (MDA), free proline, total soluble sugars (TSS) and abscisic acid (ABA), the enzyme activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD) and phenylalanine ammonia-lyase (PAL) were measured to investigate the effects of ADO treatment. The results showed that the treatment with an ADO concentration of 0.20% exhibited the highest performance of drought stress resistance in the tomato seedlings by decreasing the electrolyte leakage and the concentration of MDA, increasing the contents of free proline, TSS and ABA, and increasing the activities of CAT, SOD, POD and PAL after treatment with ADO. It is suggested that changes in electrolyte leakage, MDA, osmotic solutes, ABA, anti-oxidative enzyme and PAL activities were responsible for the increased drought stress resistance in tomato seedlings. To our best knowledge, this is the first report of the effect of ADO treatment on enhancing the drought stress resistance of tomato seedlings.

  10. Doxorubicin resistant cancer cells activate myeloid-derived suppressor cells by releasing PGE2.

    PubMed

    Rong, Yuan; Yuan, Chun-Hui; Qu, Zhen; Zhou, Hu; Guan, Qing; Yang, Na; Leng, Xiao-Hua; Bu, Lang; Wu, Ke; Wang, Fu-Bing

    2016-01-01

    Chemotherapies often induce drug-resistance in cancer cells and simultaneously stimulate proliferation and activation of Myeloid-Derived Suppressor Cells (MDSCs) to inhibit anti-tumor T cells, thus result in poor prognosis of patients with breast cancers. To date, the mechanism underlying the expansion of MDSCs in response to chemotherapies is poorly understood. In the present study, we used in vitro cell culture and in vivo animal studies to demonstrate that doxorubicin-resistant breast cancer cells secret significantly more prostaglandin E2 (PGE2) than their parental doxorubicin-sensitive cells. The secreted PGE2 can stimulate expansion and polymerization of MDSCs by directly target to its receptors, EP2/EP4, on the surface of MDSCs, which consequently triggers production of miR-10a through activating PKA signaling. More importantly, activated MDSCs can inhibit CD4(+)CD25(-) T cells as evidenced by reduced proliferation and IFN-γ release. In order to determine the molecular pathway that involves miR-10a mediated activation of MDSCs, biochemical and pharmacological studies were carried out. We found that miR-10a can activate AMPK signaling to promote expansion and activation of MDSCs. Thus, these results reveal, for the first time, a novel role of PGE2/miR-10a/AMPK signaling axis in chemotherapy-induced immune resistance, which might be targeted for treatment of chemotherapy resistant tumors. PMID:27032536

  11. Doxorubicin resistant cancer cells activate myeloid-derived suppressor cells by releasing PGE2

    PubMed Central

    Rong, Yuan; Yuan, Chun-Hui; Qu, Zhen; Zhou, Hu; Guan, Qing; Yang, Na; Leng, Xiao-Hua; Bu, Lang; Wu, Ke; Wang, Fu-Bing

    2016-01-01

    Chemotherapies often induce drug-resistance in cancer cells and simultaneously stimulate proliferation and activation of Myeloid-Derived Suppressor Cells (MDSCs) to inhibit anti-tumor T cells, thus result in poor prognosis of patients with breast cancers. To date, the mechanism underlying the expansion of MDSCs in response to chemotherapies is poorly understood. In the present study, we used in vitro cell culture and in vivo animal studies to demonstrate that doxorubicin-resistant breast cancer cells secret significantly more prostaglandin E2 (PGE2) than their parental doxorubicin-sensitive cells. The secreted PGE2 can stimulate expansion and polymerization of MDSCs by directly target to its receptors, EP2/EP4, on the surface of MDSCs, which consequently triggers production of miR-10a through activating PKA signaling. More importantly, activated MDSCs can inhibit CD4+CD25− T cells as evidenced by reduced proliferation and IFN-γ release. In order to determine the molecular pathway that involves miR-10a mediated activation of MDSCs, biochemical and pharmacological studies were carried out. We found that miR-10a can activate AMPK signaling to promote expansion and activation of MDSCs. Thus, these results reveal, for the first time, a novel role of PGE2/miR-10a/AMPK signaling axis in chemotherapy-induced immune resistance, which might be targeted for treatment of chemotherapy resistant tumors. PMID:27032536

  12. Thermal resistances in the Everest Area (Nepal Himalaya) derived from satellite imagery using a nonlinear energy balance model

    NASA Astrophysics Data System (ADS)

    Rounce, D. R.; McKinney, D. C.

    2014-01-01

    Debris thickness is an important characteristic of many debris-covered glaciers in the Everest region of the Himalayas. The debris thickness controls the melt rates of the glaciers, which has large implications for hydrologic models, the glaciers response to climate change, and the development of glacial lakes. Despite its importance, there is little knowledge of how the debris thickness varies over these glaciers. This paper uses an energy balance model in conjunction with Landsat7 ETM+ satellite imagery to derive thermal resistances, which is the debris thickness divided by the thermal conductivity. The developed model accounts for the nonlinear temperature gradient in the debris cover to derive accurate thermal resistances. Fieldwork performed on Lhotse Shar/Imja glacier in September 2013 was used to validate the satellite-derived thermal resistances. Results indicate that accounting for the nonlinear temperature gradient is crucial. Furthermore, correcting the incoming shortwave radiation term for the effects of topography and including the turbulent heat fluxes is imperative to derive accurate thermal resistances. Since the topographic correction is important, the model will improve with the quality of the DEM. The main limitation of this work is the poor resolution (60 m) of the satellite's thermal band. The derived thermal resistances are accurate at this resolution, but are unable to derive trends related to slope and aspect on a finer scale. Nonetheless, the study finds this model derives accurate thermal resistances on this scale and is transferable to other debris-covered glaciers in the Everest region.

  13. Liver-derived systemic factors drive β-cell hyperplasia in insulin resistant states

    SciTech Connect

    El Ouaamari, Abdelfattah; Kawamori, Dan; Dirice, Ercument; Liew, Chong Wee; Shadrach, Jennifer L.; Hu, Jiang; Katsuta, Hitoshi; Hollister-Lock, Jennifer; Qian, Weijun; Wagers, Amy J.; Kulkarni, Rohit N.

    2013-02-21

    Integrative organ cross-talk regulates key aspects of energy homeostasis and its dysregulation may underlie metabolic disorders such as obesity and diabetes. To test the hypothesis that cross-talk between the liver and pancreatic islets modulates β-cell growth in response to insulin resistance, we used the Liver-specific Insulin Receptor Knockout (LIRKO) mouse, a unique model that exhibits dramatic islet hyperplasia. Using complementary in vivo parabiosis and transplantation assays, and in vitro islet culture approaches, we demonstrate that humoral, non-neural, non-cell autonomous factor(s) induce β-cell proliferation in LIRKO mice. Furthermore, we report that a hepatocyte-derived factor(s) stimulates mouse and human β-cell proliferation in ex vivo assays, independent of ambient glucose and insulin levels. These data implicate the liver as a critical source of β-cell growth factors in insulin resistant states.

  14. Marinopyrrole Derivatives as Potential Antibiotic Agents against Methicillin-Resistant Staphylococcus aureus (III)

    PubMed Central

    Liu, Yan; Haste, Nina M.; Thienphrapa, Wdee; Li, Jerry; Nizet, Victor; Hensler, Mary; Li, Rongshi

    2014-01-01

    The marine natural product, marinopyrrole A (1), was previously shown to have significant antibiotic activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Although compound (1) exhibits a significant reduction in MRSA activity in the presence of human serum, we have identified key modifications that partially restore activity. We previously reported our discovery of a chloro-derivative of marinopyrrole A (1a) featuring a 2–4 fold improved minimum inhibitory concentration (MIC) against MRSA, significantly less susceptibility to serum inhibition and rapid and concentration-dependent killing of MRSA. Here, we report a novel fluoro-derivative of marinopyrrole A (1e) showing an improved profile of potency, less susceptibility to serum inhibition, as well as rapid and concentration-dependent killing of MRSA. PMID:24796304

  15. Novel Imidazopyridine Derivatives Possess Anti-Tumor Effect on Human Castration-Resistant Prostate Cancer Cells

    PubMed Central

    Muniyan, Sakthivel; D’Cunha, Napoleon; Robinson, Tashika; Hoelting, Kyle; Dwyer, Jennifer G.; Bu, Xiu R.; Batra, Surinder K.; Lin, Ming-Fong

    2015-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related death afflicting United States males. Most treatments to-date for metastatic PCa include androgen-deprivation therapy and second-generation anti-androgens such as abiraterone acetate and enzalutamide. However, a majority of patients eventually develop resistance to these therapies and relapse into the lethal, castration-resistant form of PCa to which no adequate treatment option remains. Hence, there is an immediate need to develop effective therapeutic agents toward this patient population. Imidazopyridines have recently been shown to possess Akt kinase inhibitory activity; thus in this study, we investigated the inhibitory effect of novel imidazopyridine derivatives HIMP, M-MeI, OMP, and EtOP on different human castration-resistant PCa cells. Among these compounds, HIMP and M-MeI were found to possess selective dose- and time-dependent growth inhibition: they reduced castration-resistant PCa cell proliferation and spared benign prostate epithelial cells. Using LNCaP C-81 cells as the model system, these compounds also reduced colony formation as well as cell adhesion and migration, and M-MeI was the most potent in all studies. Further investigation revealed that while HIMP primarily inhibits PCa cell growth via suppression of PI3K/Akt signaling pathway, M-MeI can inhibit both PI3K/Akt and androgen receptor pathways and arrest cell growth in the G2 phase. Thus, our results indicate the novel compound M-MeI to be a promising candidate for castration-resistant PCa therapy, and future studies investigating the mechanism of imidazopyridine inhibition may aid to the development of effective anti-PCa agents. PMID:26121643

  16. The ubiquitination of serotonin transporter in lymphoblasts derived from fluvoxamine-resistant depression patients.

    PubMed

    Mouri, Akihiro; Ikeda, Masashi; Koseki, Takenao; Iwata, Nakao; Nabeshima, Toshitaka

    2016-03-23

    There is insufficient serotonergic neuronal function in the pathophysiology of major depressive disorder (MDD). Serotonin transporter (SERT) plays a critical role in terminating the function of serotoninergic neurons. SERT is linked to vulnerability to MDD and is an important target for antidepressants. The expression of SERT in lymphocytes and platelets is associated with their expression in central nervous system. Most of the clinical studies that have analyzed the role of SERT in depression have focused on absolute expression of SERT in the brain or peripheral tissue. Our study has shown that the SERT protein is ubiquitinated, which has been implicated through the SERT stability and depressive behaviors in mice. In our study, we have used lymphoblasts derived from the peripheral blood lymphocytes to quantitatively examine SERT protein expression and ubiquitination in fluvoxamine-responsive and fluvoxamine-resistant MDD patients. We found that the protein levels of SERT were higher in the fluvoxamine-resistant MDD patients. Ubiquitinated protein levels of SERT were lower in the fluvoxamine-resistant MDD patients. The proteasome inhibitor failed to increase the protein levels of SERT in both fluvoxamine-responsive and fluvoxamine-resistant MDD patients. In sum, these findings suggest that the downregulation of the ubiquitination of SERT protein induces insufficient degradation of SERT by proteasome, which resulted in the upregulation of SERT protein in fluvoxamine-resistant MDD patients. Although further studies with various populations will be required to generalize results, SERT protein expression, ubiquitination, and the responsiveness of SERT expression to proteasome inhibitor are potential biomarkers for the diagnosis of MDD and antidepressant efficacy. PMID:26845564

  17. Identification of QTL conditioning partial resistance to white mold in kidney bean line VA19 derived from an interspecific population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scarlet-runner bean (Phaseolus coccineus L.), a representative species of the secondary gene pool of common bean, is a potential source of white mold resistance for improving dry bean and snap bean. VA19 is a light-red kidney bean line that possesses resistance to white mold putatively derived from...

  18. Transcriptomic and functional analysis of an autolysis-deficient, teicoplanin-resistant derivative of methicillin-resistant Staphylococcus aureus.

    PubMed

    Renzoni, Adriana; Barras, Christine; François, Patrice; Charbonnier, Yvan; Huggler, Elzbieta; Garzoni, Christian; Kelley, William L; Majcherczyk, Paul; Schrenzel, Jacques; Lew, Daniel P; Vaudaux, Pierre

    2006-09-01

    The molecular basis of glycopeptide-intermediate S. aureus (GISA) isolates is not well defined though frequently involves phenotypes such as thickened cell walls and decreased autolysis. We have exploited an isogenic pair of teicoplanin-susceptible (strain MRGR3) and teicoplanin-resistant (strain 14-4) methicillin-resistant S. aureus strains for detailed transcriptomic profiling and analysis of altered autolytic properties. Strain 14-4 displayed markedly deficient Triton X-100-triggered autolysis compared to its teicoplanin-susceptible parent, although microarray analysis paradoxically did not reveal significant reductions in expression levels of major autolytic genes atl, lytM, and lytN, except for sle1, which showed a slight decrease. The most important paradox was a more-than-twofold increase in expression of the cidABC operon in 14-4 compared to MRGR3, which was correlated with decreased expression of autolysis negative regulators lytSR and lrgAB. In contrast, the autolysis-deficient phenotype of 14-4 was correlated with both increased expression of negative autolysis regulators (arlRS, mgrA, and sarA) and decreased expression of positive regulators (agr RNAII and RNAIII). Quantitative bacteriolytic assays and zymographic analysis of concentrated culture supernatants showed a striking reduction in Atl-derived, extracellular bacteriolytic hydrolase activities in 14-4 compared to MRGR3. This observed difference was independent of the source of cell wall substrate (MRGR3 or 14-4) used for analysis. Collectively, our results suggest that altered autolytic properties in 14-4 are apparently not driven by significant changes in the transcription of key autolytic effectors. Instead, our analysis points to alternate regulatory mechanisms that impact autolysis effectors which may include changes in posttranscriptional processing or export. PMID:16940101

  19. Smac-Derived Aza-Peptide As an Aminopeptidase-Resistant XIAP BIR3 Antagonist.

    PubMed

    Elsawy, Mohamed A; Tikhonova, Irina G; Martin, Lorraine; Walker, Brian

    2015-01-01

    The peptidic nature of anti-IAPs N-terminus Smac-derived peptides precludes their utilization as potential therapeutic anticancer agents. Recent advances in the development of novel Smacderived peptidomimetics and non-peptidic molecules with improved anti-IAPs activity and resistance to proteolytic cleavage have been reported and led to a number of candidates that are currently in clinical trials including LCL-161, SM-406/AT-406, GDC-0512/GDC-0917, and birinapant. As an attempt to improve the proteolytic stability of Smac peptides, we developed the Aza-peptide AzaAla- Val-Pro-Phe-Tyr-NH2 (2). Unlike unmodified peptide Ala-Val-Pro-Phe-Tyr-NH2 (1), analogue (2) exhibited resistance towards proteolytic cleavage by two aminopeptidases; LAP and DPP-IV, while retaining its IAP inhibitory activity. This was due to the altered planar geometry of the P1 residue side chain. Our findings showed that using aza-isosteres of bioactive peptide sequences imbue the residue with imperviousness to proteolysis; underscoring a potential approach for developing a new generation of Smac-derived Aza-peptidomimetics. PMID:26282728

  20. Spectrum of activity and mechanisms of resistance of various nucleoside derivatives against gammaherpesviruses.

    PubMed

    Coen, Natacha; Duraffour, Sophie; Topalis, Dimitri; Snoeck, Robert; Andrei, Graciela

    2014-12-01

    The susceptibilities of gammaherpesviruses, including Epstein-Barr virus (EBV), Kaposi's sarcoma-associated herpesvirus (KSHV), and animal rhadinoviruses, to various nucleoside analogs was investigated in this work. Besides examining the antiviral activities and modes of action of antivirals currently marketed for the treatment of alpha- and/or betaherpesvirus infections (including acyclovir, ganciclovir, penciclovir, foscarnet, and brivudin), we also investigated the structure-activity relationship of various 5-substituted uridine and cytidine molecules. The antiviral efficacy of nucleoside derivatives bearing substitutions at the 5 position was decreased if the bromovinyl was replaced by chlorovinyl. 1-β-D-Arabinofuranosyl-(E)-5-(2-bromovinyl)uracil (BVaraU), a nucleoside with an arabinose configuration of the sugar ring, exhibited no inhibitory effect against rhadinoviruses but was active against EBV. On the other hand, the fluoroarabinose cytidine analog 2'-fluoro-5-iodo-aracytosine (FIAC) showed high selectivity indices against gammaherpesviruses that were comparable to those of brivudin. Additionally, we selected brivudin- and acyclovir-resistant rhadinoviruses in vitro and characterized them by phenotypic and genotypic (i.e., sequencing of the viral thymidine kinase, protein kinase, and DNA polymerase) analysis. Here, we reveal key amino acids in these enzymes that play an important role in substrate recognition. Our data on drug susceptibility profiles of the different animal gammaherpesvirus mutants highlighted cross-resistance patterns and indicated that pyrimidine nucleoside derivatives are phosphorylated by the viral thymidine kinase and purine nucleosides are preferentially activated by the gammaherpesvirus protein kinase. PMID:25267682

  1. Synergy Potential of Indole Alkaloids and Its Derivative against Drug-resistant Escherichia coli.

    PubMed

    Dwivedi, Gaurav Raj; Gupta, Shikha; Maurya, Anupam; Tripathi, Shubhandra; Sharma, Ashok; Darokar, Mahendra P; Srivastava, Santosh K

    2015-12-01

    Antibacterial and synergy potential of naturally occurring indole alkaloids (IA): 10-methoxy tetrahydroalstonine (1), isoreserpiline (2), 10 and 11 demethoxyreserpiline (3), reserpiline (4), serpentine (5), ajmaline (6), ajmalicine (7), yohimbine (8), and α-yohimbine (9) was evaluated using microbroth dilution assay. Further, α-yohimbine (9) was chemically transformed into six semisynthetic derivatives (9A-9F), and their antibacterial and synergy potential in combination with nalidixic acid (NAL) against E. coli strains CA8000 and DH5α were also evaluated. The IA 1, 2, 4, 5, 9 and the derivative 9F showed eightfold reduction in the MIC of NAL against the DH5α and four- to eightfold reduction against CA8000. These alkaloids also reduced MIC of another antibiotic, tetracycline up to 8folds, against the MDREC-KG4, a multidrug-resistant clinical isolate of E. coli. Mode of action study of these alkaloids showed efflux pumps inhibitory potential, which was supported by their in silico binding affinity and downregulation of efflux pump genes. These results may be of great help in the development of cost-effective antibacterial combinations for treating patients infected with multidrug-resistant Gram-negative infections. PMID:26132412

  2. The immune-microenvironment confers resistance to MAP kinase pathway inhibitors through macrophage-derived TNFα

    PubMed Central

    O’Brien, Kate; Brunton, Holly; Ferguson, Jennifer; Young, Helen; Dhomen, Nathalie; Flaherty, Keith T.; Frederick, Dennie T.; Cooper, Zachary A.; Wargo, Jennifer A.; Marais, Richard; Wellbrock, Claudia

    2014-01-01

    Recently the rationale for combining targeted therapy with immunotherapy has come to light, but our understanding of the immune response during MAPK pathway inhibitor treatment is limited. We discovered that the immune-microenvironment can act as source of resistance to MAPK pathway-targeted therapy, and moreover during treatment this source becomes reinforced. In particular, we identified macrophage-derived TNFα as a crucial melanoma-growth factor that provides resistance to MAPK pathway inhibitors through the lineage-transcription factor MITF. Most strikingly, in BRAF mutant melanomas of patients and BRafV600E-melanoma allografts MAPK pathway inhibitors increased the number of tumor-associated macrophages, and TNFα and MITF expression. Inhibiting TNFα-signaling with IκB-kinase inhibitors profoundly enhanced the efficacy of MAPK pathway inhibitors by targeting not only the melanoma cells, but also the microenvironment. In summary, we identify the immune-microenvironment as a novel source of resistance and reveal a new strategy to improve the efficacy of targeted therapy in melanoma. PMID:25256614

  3. Esters of the Marine-Derived Triterpene Sipholenol A Reverse P-GP-Mediated Drug Resistance

    PubMed Central

    Zhang, Yongchao; Zhang, Yun-Kai; Wang, Yi-Jun; Vispute, Saurabh G.; Jain, Sandeep; Chen, Yangmin; Li, Jessalyn; Youssef, Diaa T. A.; El Sayed, Khalid A.; Chen, Zhe-Sheng

    2015-01-01

    Our previous studies showed that several sipholane triterpenes, sipholenol A, sipholenone E, sipholenol L and siphonellinol D, have potent reversal effect for multidrug resistance (MDR) in cancer cells that overexpressed P-glycoprotein (P-gp/ABCB1). Through comparison of cytotoxicity towards sensitive and multi-drug resistant cell lines, we identified that the semisynthetic esters sipholenol A-4-O-acetate and sipholenol A-4-O-isonicotinate potently reversed P-gp-mediated MDR but had no effect on MRP1/ABCC1 and BCRP/ABCG2-mediated MDR. The results from [3H]-paclitaxel accumulation and efflux studies suggested that these two triterpenoids were able to increase the intracellular accumulation of paclitaxel by inhibiting its active efflux. In addition, western blot analysis revealed that these two compounds did not alter the expression levels of P-gp when treated up to 72 h. These sipholenol derivatives also stimulated the ATPase activity of P-gp membranes, which suggested that they might be substrates of P-gp. Moreover, in silico molecular docking studies revealed the virtual binding modes of these two compounds into human homology model of P-gp. In conclusion, sipholenol A-4-O-acetate and sipholenol A-4-O-isonicotinate efficiently inhibit the P-gp and may represent potential reversal agents for the treatment of multidrug resistant cancers. PMID:25874923

  4. Mechanistic insights into landscape genetic structure of two tropical amphibians using field-derived resistance surfaces.

    PubMed

    Nowakowski, A Justin; DeWoody, J Andrew; Fagan, Matthew E; Willoughby, Janna R; Donnelly, Maureen A

    2015-02-01

    Conversion of forests to agriculture often fragments distributions of forest species and can disrupt gene flow. We examined effects of prevalent land uses on genetic connectivity of two amphibian species in northeastern Costa Rica. We incorporated data from field surveys and experiments to develop resistance surfaces that represent local mechanisms hypothesized to modify dispersal success of amphibians, such as habitat-specific predation and desiccation risk. Because time lags can exist between forest conversion and genetic responses, we evaluated landscape effects using land-cover data from different time periods. Populations of both species were structured at similar spatial scales but exhibited differing responses to landscape features. Litter frog population differentiation was significantly related to landscape resistances estimated from abundance and experiment data. Model support was highest for experiment-derived surfaces that represented responses to microclimate variation. Litter frog genetic variation was best explained by contemporary landscape configuration, indicating rapid population response to land-use change. Poison frog genetic structure was strongly associated with geographic isolation, which explained up to 45% of genetic variation, and long-standing barriers, such as rivers and mountains. However, there was also partial support for abundance- and microclimate response-derived resistances. Differences in species responses to landscape features may be explained by overriding effects of population size on patterns of differentiation for poison frogs, but not litter frogs. In addition, pastures are likely semi-permeable to poison frog gene flow because the species is known to use pastures when remnant vegetation is present, but litter frogs do not. Ongoing reforestation efforts will probably increase connectivity in the region by increasing tree cover and reducing area of pastures. PMID:25533403

  5. MlNCD1: A novel Aegilops tauschii derived powdery mildew resistance gene identified in common wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew is a major fungal disease in wheat, especially in cool maritime climates. A novel Aegilops tauschii derived wheat powdery mildew resistance gene present in the germplasm line NC96BGTD1 was genetically characterized as a monogenic trait in field trials using F2 and F4-derived lines fr...

  6. Approach of pullulan derivatives to resist polymers for green lithography in eco-friendly optical NEMS and MEMS

    NASA Astrophysics Data System (ADS)

    Takei, Satoshi; Oshima, Akihiro; Ito, Kenta; Sugahara, Kigenn; Kashiwakura, Miki; Oyama, Tomoko G.; Kozawa, Takahiro; Tagawa, Seiichi; Hanabata, Makoto

    2014-05-01

    This presentation reported an approach of glucose derivatives to resist polymers for eco-friendly optical NEMS and MEMS. The material design concept to use the water-soluble resist material with highly efficient crosslinking, water development, and lower film thickness shrinkage was proposed for green lithography. The lithographic properties due to the glucose derivatives, and the low film thickness shrinkage due to distinctive bulky chemical structure were proposed in the resist material, and then demonstrated to be effective for creating high resolution, excellent patterning dimensional accuracy, and low line edge roughness in EB lithography. Mixing or blending of glucose and cellulose derivatives was a valuable approach to the design of resist formulations for eco-friendly optical NEMS and MEMS.

  7. Multidrug-Resistant Bacterial Donor-Derived Infections in Solid Organ Transplantation.

    PubMed

    Lewis, Jessica D; Sifri, Costi D

    2016-06-01

    Although rare, donor-derived infections (DDIs) caused by multidrug-resistant (MDR) bacteria can have devastating consequences for organ transplant recipients. Recognition of MDR bacterial DDIs can be challenging, as MDR bacteria are prevalent in most hospitals and distinguishing their transmission through transplantation from other, more typical routes of acquisition are difficult. New technologies such as whole genome sequencing have recently proven to be a powerful advance in the investigation of MDR bacterial DDIs. Once recognized, the optimal treatment of MDR bacterial DDIs is not clear. Herein, we review the clinical manifestations, outcomes, and management of MDR bacterial DDIs, and identify areas of uncertainty toward which the transplant community should direct further research efforts. PMID:27115701

  8. Field evaluation of the bacterial volatile derivative 3-pentanol in priming for induced resistance in pepper.

    PubMed

    Choi, Hye Kyung; Song, Geun Cheol; Yi, Hwe-Su; Ryu, Choong-Min

    2014-08-01

    Plants are defended from attack by emission of volatile organic compounds (VOCs) that can act directly against pathogens and herbivores or indirectly by recruiting natural enemies of herbivores. However, microbial VOC have been less investigated as potential triggers of plant systemic defense responses against pathogens in the field. Bacillus amyloliquefaciens strain IN937a, a plant growth-promoting rhizobacterium that colonizes plant tissues, stimulates induced systemic resistance (ISR) via its emission of VOCs. We investigated the ISR capacity of VOCs and derivatives collected from strain IN937a against bacterial spot disease caused by Xanthomonas axonopodis pv. vesicatoria in pepper. Of 15 bacterial VOCs and their derivatives, 3-pentanol, which is a C8 amyl alcohol reported to be a component of sex pheromones in insects, was selected for further investigation. Pathogens were infiltrated into pepper leaves 10, 20, 30, and 40 days after treatment and transplantation to the field. Disease severity was assessed 7 days after transplantation. Treatment with 3-pentanol significantly reduced disease severity caused by X. axonopodis and naturally occurring Cucumber mosaic virus in field trials over 2 years. We used quantitative real-time polymerase chain analysis to examine Pathogenesis-Related genes associated with salicylic acid (SA), jasmonic acid (JA), and ethylene defense signaling. The expression of Capsicum annuum Pathogenesis-Related protein 1 (CaPR1), CaPR2, and Ca protease inhibitor2 (CaPIN2) increased in field-grown pepper plants treated with 3-pentanol. Taken together, our results show that 3-pentanol triggers induced resistance by priming SA and JA signaling in pepper under field conditions. PMID:25149655

  9. Endoplasmic Reticulum Ca(2+) Handling and Apoptotic Resistance in Tumor-Derived Endothelial Colony Forming Cells.

    PubMed

    Poletto, Valentina; Dragoni, Silvia; Lim, Dmitry; Biggiogera, Marco; Aronica, Adele; Cinelli, Mariapia; De Luca, Antonio; Rosti, Vittorio; Porta, Camillo; Guerra, Germano; Moccia, Francesco

    2016-10-01

    Truly endothelial progenitor cells (EPCs) can be mobilized from bone marrow to support the vascular network of growing tumors, thereby sustaining the metastatic switch. Endothelial colony forming cells (ECFCs) are the only EPC subtype belonging to the endothelial phenotype and capable of incorporating within neovessels. The intracellular Ca(2+) machinery plays a key role in ECFC activation and is remodeled in renal cellular carcinoma-derived ECFCs (RCC-ECFCs). Particularly, RCC-ECFCs seems to undergo a drop in endoplasmic reticulum (ER) Ca(2+) concentration ([Ca(2+) ]ER ). This feature is remarkable when considering that inositol-1,4,5-trisphosphate (InsP3 )-dependent ER-to-mitochondria Ca(2+) transfer regulates the intrinsic apoptosis pathway. Herein, we sought to assess whether: (1) the [Ca(2+) ]ER and the InsP3 -induced ER-mitochondria Ca(2+) shuttle are reduced in RCC-ECFCs; and (2) the dysregulation of ER Ca(2+) handling leads to apoptosis resistance in tumor-derived cells. RCC-ECFCs displayed a reduction both in [Ca(2+) ]ER and in the InsP3 -dependent mitochondrial Ca(2+) uptake, while they expressed normal levels of Bcl-2 and Bak. The decrease in [Ca(2+) ]ER was associated to a remarkable ER expansion in RCC-ECFCs, which is a hallmark of ER stress, and did not depend on the remodeling of the Ca(2+) -transporting and the ER Ca(2+) -storing systems. As expected, RCC-ECFCs were less sensitive to rapamycin- and thapsigargin-induced apoptosis; however, buffering intracellular Ca(2+) levels with BAPTA dampened apoptosis in both cell types. Finally, store-operated Ca(2+) entry was seemingly uncoupled from the apoptotic machinery in RCC-ECFCs. Thus, the chronic underfilling of the ER Ca(2+) pool could confer a survival advantage to RCC-ECFCs and underpin RCC resistance to pharmacological treatment. J. Cell. Biochem. 117: 2260-2271, 2016. © 2016 Wiley Periodicals, Inc. PMID:26917354

  10. Artificial microRNA-derived resistance to Cassava brown streak disease

    PubMed Central

    Wagaba, Henry; Patil, Basavaprabhu L.; Mukasa, Settumba; Alicai, Titus; Fauquet, Claude M.; Taylor, Nigel J.

    2016-01-01

    Artificial miRNAs (amiRNA) were generated targeting conserved sequences within the genomes of the two causal agents of Cassava brown streak disease (CBSD): Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Transient expression studies on ten amiRNAs targeting 21 nt conserved sequences of P1(CBSV and UCBSV), P3(CBSV and UCBSV), CI(UCBSV), NIb(CBSV and UCBSV), CP(UCBSV) and the un-translated region (3′-UTR) were tested in Nicotiana benthamiana. Four out of the ten amiRNAs expressed the corresponding amiRNA at high levels. Transgenic N. benthamiana plants were developed for the four amiRNAs targeting the P1 and NIb genes of CBSV and the P1 and CP genes of UCBSV and shown to accumulate miRNA products. Transgenic plants challenged with CBSV and UCBSV isolates showed resistance levels that ranged between ∼20–60% against CBSV and UCBSV and correlated with expression levels of the transgenically derived miRNAs. MicroRNAs targeting P1 and NIb of CBSV showed protection against CBSV and UCBSV, while amiRNAs targeting the P1 and CP of UCBSV showed protection against UCBSV but were less efficient against CBSV. These results indicate a potential application of amiRNAs for engineering resistance to CBSD-causing viruses in cassava. PMID:26912232

  11. The breast cancer resistance protein protects against a major chlorophyll-derived dietary phototoxin and protoporphyria

    PubMed Central

    Jonker, Johan W.; Buitelaar, Marije; Wagenaar, Els; van der Valk, Martin A.; Scheffer, George L.; Scheper, Rik J.; Plösch, Torsten; Kuipers, Folkert; Elferink, Ronald P. J. Oude; Rosing, Hilde; Beijnen, Jos H.; Schinkel, Alfred H.

    2002-01-01

    The breast cancer resistance protein (BCRP/ABCG2) is a member of the ATP-binding cassette family of drug transporters and confers resistance to various anticancer drugs. We show here that mice lacking Bcrp1/Abcg2 become extremely sensitive to the dietary chlorophyll-breakdown product pheophorbide a, resulting in severe, sometimes lethal phototoxic lesions on light-exposed skin. Pheophorbide a occurs in various plant-derived foods and food supplements. Bcrp1 transports pheophorbide a and is highly efficient in limiting its uptake from ingested food. Bcrp1−/− mice also displayed a previously unknown type of protoporphyria. Erythrocyte levels of the heme precursor and phototoxin protoporphyrin IX, which is structurally related to pheophorbide a, were increased 10-fold. Transplantation with wild-type bone marrow cured the protoporphyria and reduced the phototoxin sensitivity of Bcrp1−/− mice. These results indicate that humans or animals with low or absent BCRP activity may be at increased risk for developing protoporphyria and diet-dependent phototoxicity and provide a striking illustration of the importance of drug transporters in protection from toxicity of normal food constituents. PMID:12429862

  12. Development of novel potent orally bioavailable oseltamivir derivatives active against resistant influenza A.

    PubMed

    Schade, Dennis; Kotthaus, Joscha; Riebling, Lukas; Kotthaus, Jürke; Müller-Fielitz, Helge; Raasch, Walter; Koch, Oliver; Seidel, Nora; Schmidtke, Michaela; Clement, Bernd

    2014-02-13

    With the emergence of oseltamivir-resistant influenza viruses and in view of a highly pathogenic flu pandemic, it is important to develop new anti-influenza agents. Here, the development of neuraminidase (NA) inhibitors that were designed to overcome resistance mechanisms along with unfavorable pharmacokinetic (PK) properties is described. Several 5-guanidino- and 5-amidino-based oseltamivir derivatives were synthesized and profiled for their anti-influenza activity and in vitro and in vivo PK properties. Amidine 6 and guanidine 7 were comparably effective against a panel of different A/H1N1 and A/H3N2 strains and also inhibited mutant A/H1N1 neuraminidase. Among different prodrug strategies pursued, a simple amidoxime ethyl ester (9) exhibited a superior PK profile with an oral bioavailability of 31% (rats), which is comparable to oseltamivir (36%). Thus, bioisosteric replacement of the 5-guanidine with an acetamidine-in the form of its N-hydroxy prodrug-successfully tackled the two key limitations of currently used NA inhibitors, as exemplified with oseltamivir. PMID:24422530

  13. Prenylated flavonoids and resveratrol derivatives isolated from Artocarpus communis with the ability to overcome TRAIL resistance.

    PubMed

    Toume, Kazufumi; Habu, Tadashi; Arai, Midori A; Koyano, Takashi; Kowithayakorn, Thaworn; Ishibashi, Masami

    2015-01-23

    In a screening program on natural products that can abrogate tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) resistance, four new prenylated flavonoid and resveratrol derivatives (1-4) were isolated from Artocarpus communis, together with eight known prenylflavonoids (5-12). The structures of 1-4 were elucidated spectroscopically. Pannokin D [corrected] (1) (2 μM) and artonin E (5) (3 μM) potently exhibited the ability to overcome TRAIL resistance. Artonin E (5) induced caspase-dependent apoptosis in combination with TRAIL, increased caspase 3/7 activity, and enhanced the protein levels of p53 and DR5. Moreover, this substance decreased cell viability in combination with TRAIL and enhanced the protein levels of DR5, and these effects were mediated by increases in the production of ROS (reactive oxygen species). Thus, artonin E (5) was found to induce extrinsic apoptotic cell death by the ROS- and p53-mediated up-regulation of DR5 expression in AGS cells. PMID:25537111

  14. Artificial microRNA-derived resistance to Cassava brown streak disease.

    PubMed

    Wagaba, Henry; Patil, Basavaprabhu L; Mukasa, Settumba; Alicai, Titus; Fauquet, Claude M; Taylor, Nigel J

    2016-05-01

    Artificial miRNAs (amiRNA) were generated targeting conserved sequences within the genomes of the two causal agents of Cassava brown streak disease (CBSD): Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV). Transient expression studies on ten amiRNAs targeting 21nt conserved sequences of P1(CBSV and UCBSV), P3(CBSV and UCBSV), CI(UCBSV), NIb(CBSV and UCBSV), CP(UCBSV) and the un-translated region (3'-UTR) were tested in Nicotiana benthamiana. Four out of the ten amiRNAs expressed the corresponding amiRNA at high levels. Transgenic N. benthamiana plants were developed for the four amiRNAs targeting the P1 and NIb genes of CBSV and the P1 and CP genes of UCBSV and shown to accumulate miRNA products. Transgenic plants challenged with CBSV and UCBSV isolates showed resistance levels that ranged between ∼20-60% against CBSV and UCBSV and correlated with expression levels of the transgenically derived miRNAs. MicroRNAs targeting P1 and NIb of CBSV showed protection against CBSV and UCBSV, while amiRNAs targeting the P1 and CP of UCBSV showed protection against UCBSV but were less efficient against CBSV. These results indicate a potential application of amiRNAs for engineering resistance to CBSD-causing viruses in cassava. PMID:26912232

  15. Bone marrow derived myeloid cells orchestrate antiangiogenic resistance in glioblastoma through coordinated molecular networks.

    PubMed

    Achyut, B R; Shankar, Adarsh; Iskander, A S M; Ara, Roxan; Angara, Kartik; Zeng, Peng; Knight, Robert A; Scicli, Alfonso G; Arbab, Ali S

    2015-12-28

    Glioblastoma (GBM) is a hypervascular and malignant form of brain tumors. Anti-angiogenic therapies (AAT) were used as an adjuvant against VEGF-VEGFR pathway to normalize blood vessels in clinical and preclinical studies, which resulted into marked hypoxia and recruited bone marrow derived cells (BMDCs) to the tumor microenvironment (TME). In vivo animal models to track BMDCs and investigate molecular mechanisms in AAT resistance are rare. We exploited recently established chimeric mouse to develop orthotopic U251 tumor, which uses as low as 5 × 10(6) GFP+ BM cells in athymic nude mice and engrafted >70% GFP+ cells within 14 days. Our unpublished data and published studies have indicated the involvement of immunosuppressive myeloid cells in therapeutic resistance in glioma. Similarly, in the present study, vatalanib significantly increased CD68+ myeloid cells, and CD133+, CD34+ and Tie2+ endothelial cell signatures. Therefore, we tested inhibition of CSF1R+ myeloid cells using GW2580 that reduced tumor growth by decreasing myeloid (Gr1+ CD11b+ and F4/80+) and angiogenic (CD202b+ and VEGFR2+) cell signatures in TME. CSF1R blockade significantly decreased inflammatory, proangiogenic and immunosuppressive molecular signatures compared to vehicle, vatalanib or combination. TCK1 or CXCL7, a potent chemoattractant and activator of neutrophils, was observed as most significantly decreased cytokine in CSF1R blockade. ERK MAPK pathway was involved in cytokine network regulation. In conclusion, present study confirmed the contribution of myeloid cells in GBM development and therapeutic resistance using chimeric mouse model. We identified novel molecular networks including CXCL7 chemokine as a promising target for future studies. Nonetheless, survival studies are required to assess the beneficial effect of CSF1R blockade. PMID:26404753

  16. Novel Aminoglycoside Resistance Transposons and Transposon-Derived Circular Forms Detected in Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates

    PubMed Central

    Dwibedi, Chinmay Kumar; Sjöström, Karin; Edquist, Petra; Wai, Sun Nyunt; Uhlin, Bernt Eric

    2016-01-01

    Acinetobacter baumannii has emerged as an important opportunistic pathogen equipped with a growing number of antibiotic resistance genes. Our study investigated the molecular epidemiology and antibiotic resistance features of 28 consecutive carbapenem-resistant clinical isolates of A. baumannii collected throughout Sweden in 2012 and 2013. The isolates mainly belonged to clonal complexes (CCs) with an extensive international distribution, such as CC2 (n = 16) and CC25 (n = 7). Resistance to carbapenems was related to blaOXA-23 (20 isolates), blaOXA-24/40-like (6 isolates), blaOXA-467 (1 isolate), and ISAba1-blaOXA-69 (1 isolate). Ceftazidime resistance was associated with blaPER-7 in the CC25 isolates. Two classical point mutations were responsible for resistance to quinolones in all the isolates. Isolates with high levels of resistance to aminoglycosides carried the 16S rRNA methylase armA gene. The isolates also carried a variety of genes encoding aminoglycoside-modifying enzymes. Several novel structures involved in aminoglycoside resistance were identified, including Tn6279, ΔTn6279, Ab-ST3-aadB, and different assemblies of Tn6020 and TnaphA6. Importantly, a number of circular forms related to the IS26 or ISAba125 composite transposons were detected. The frequent occurrence of these circular forms in the populations of several isolates indicates a potential role of these circular forms in the dissemination of antibiotic resistance genes. PMID:26824943

  17. Novel Aminoglycoside Resistance Transposons and Transposon-Derived Circular Forms Detected in Carbapenem-Resistant Acinetobacter baumannii Clinical Isolates.

    PubMed

    Karah, Nabil; Dwibedi, Chinmay Kumar; Sjöström, Karin; Edquist, Petra; Johansson, Anders; Wai, Sun Nyunt; Uhlin, Bernt Eric

    2016-01-01

    Acinetobacter baumannii has emerged as an important opportunistic pathogen equipped with a growing number of antibiotic resistance genes. Our study investigated the molecular epidemiology and antibiotic resistance features of 28 consecutive carbapenem-resistant clinical isolates of A. baumannii collected throughout Sweden in 2012 and 2013. The isolates mainly belonged to clonal complexes (CCs) with an extensive international distribution, such as CC2 (n = 16) and CC25 (n = 7). Resistance to carbapenems was related to blaOXA-23 (20 isolates), blaOXA-24/40-like (6 isolates), blaOXA-467 (1 isolate), and ISAba1-blaOXA-69 (1 isolate). Ceftazidime resistance was associated with blaPER-7 in the CC25 isolates. Two classical point mutations were responsible for resistance to quinolones in all the isolates. Isolates with high levels of resistance to aminoglycosides carried the 16S rRNA methylase armA gene. The isolates also carried a variety of genes encoding aminoglycoside-modifying enzymes. Several novel structures involved in aminoglycoside resistance were identified, including Tn6279, ΔTn6279, Ab-ST3-aadB, and different assemblies of Tn6020 and TnaphA6. Importantly, a number of circular forms related to the IS26 or ISAba125 composite transposons were detected. The frequent occurrence of these circular forms in the populations of several isolates indicates a potential role of these circular forms in the dissemination of antibiotic resistance genes. PMID:26824943

  18. Analysis of bacteria-derived outer membrane vesicles using tunable resistive pulse sensing

    NASA Astrophysics Data System (ADS)

    Bogomolny, Evgeny; Hong, Jiwon; Blenkiron, Cherie; Simonov, Denis; Dauros, Priscila; Swift, Simon; Phillips, Anthony; Willmott, Geoff R.

    2015-03-01

    Accurate characterization of submicron particles within biological fluids presents a major challenge for a wide range of biomedical research. Detection, characterization and classification are difficult due to the presence of particles and debris ranging from single molecules up to particles slightly smaller than cells. Especial interest arises from extracellular vesicles (EVs) which are known to play a pivotal role in cell-signaling in multicellular organisms. Tunable resistive pulse sensing (TRPS) is increasingly proving to be a useful tool for high throughput particle-by-particle analysis of EVs and other submicron particles. This study examines the capability of TRPS for characterization of EVs derived from bacteria, also called outer membrane vesicles (OMVs). Measurement of a size distribution (124 +/- 3 nm modal diameter) and concentration (lower bound 7.4 x 109 mL-1) are demonstrated using OMVs derived from uropathogenic Escherichia coli. Important aspects of measurement are discussed, including sample preparation and size selection. Application of TRPS to study EVs could assist the development of these particles in clinical diagnostics and therapeutics.

  19. Thermal Resistances in the Everest Area derived from Satellite Imagery using a Nonlinear Energy Balance Model

    NASA Astrophysics Data System (ADS)

    Rounce, D.; McKinney, D. C.

    2013-12-01

    Debris cover has a large impact on sub-debris ablation rates and glacier evolution. A thin debris layer may enhance ablation by reducing albedo increasing radiation absorption, while thicker debris insulates the glacier causing ablation to decrease. Debris thickness, thermal conductivity, and meteorological conditions may be measured in the field, but they require extensive fieldwork (Brock et al., 2010; Nicholson and Benn, 2012). This has forced many simplifications and assumptions in models. Satellite imagery combined with an energy balance model has been used with to extract information about debris cover remotely (Nakawo and Rana, 1999; Zhang et al., 2011). The spatial distribution of thermal resistances derived from these studies have agreed well with field values; however, the values were considerably lower than the field values. The difference has been attributed to the mixed pixel effect. Foster et al. (2012) developed an energy balance model that agrees well with debris thickness measured in the field. The model requires knowledge of the thermal conductivity and utilizes a relationship between air and surface temperature to lower sensible heat fluxes. We derive thermal resistances of debris-covered glaciers from satellite imagery in the Everest area. Previous satellite studies have assumed a linear debris temperature gradient, which is valid for time periods of 24 hours or greater (Nicholson and Benn, 2006); however, gradients during the day are nonlinear (Nicholson and Benn, 2006; Reid and Brock, 2010). Landsat 7 imagery is used to account for the non-linear gradient, using the ratio of temperature gradient in the upper 10cm versus the entire debris thickness. These values are derived from temperature profiles on Ngozumpa Glacier (Nicholson, 2004). Meteorological data are obtained from the Pyramid Station. The derived thermal resistances agree well with those found on debris-covered glaciers in the Everest region. Brock, B., Mihalcea, C., Kirkbride, M

  20. Gallic acid-based indanone derivative interacts synergistically with tetracycline by inhibiting efflux pump in multidrug resistant E. coli.

    PubMed

    Dwivedi, Gaurav Raj; Tiwari, Nimisha; Singh, Aastha; Kumar, Akhil; Roy, Sudeep; Negi, Arvind Singh; Pal, Anirban; Chanda, Debabrata; Sharma, Ashok; Darokar, Mahendra P

    2016-03-01

    The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition. PMID:26658982

  1. MRI-derived bound and pore water concentrations as predictors of fracture resistance.

    PubMed

    Manhard, Mary Kate; Uppuganti, Sasidhar; Granke, Mathilde; Gochberg, Daniel F; Nyman, Jeffry S; Does, Mark D

    2016-06-01

    Accurately predicting fracture risk in the clinic is challenging because the determinants are multi-factorial. A common approach to fracture risk assessment is to combine X-ray-based imaging methods such as dual-energy X-ray absorptiometry (DXA) with an online Fracture Risk Assessment Tool (FRAX) that includes additional risk factors such as age, family history, and prior fracture incidents. This approach still does not adequately diagnose many individuals at risk, especially those with certain diseases like type 2 diabetes. As such, this study investigated bound water and pore water concentrations (Cbw and Cpw) from ultra-short echo time (UTE) magnetic resonance imaging (MRI) as new predictors of fracture risk. Ex vivo cadaveric arms were imaged with UTE MRI as well as with DXA and high-resolution micro-computed tomography (μCT), and imaging measures were compared to both whole-bone structural and material properties as determined by three-point bending tests of the distal-third radius. While DXA-derived areal bone mineral density (aBMD) and μCT-derived volumetric BMD correlated well with structural strength, they moderately correlated with the estimate material strength with gender being a significant covariate for aBMD. MRI-derived measures of Cbw and Cpw had a similar predictive ability of material strength as aBMD but did so independently of gender. In addition, Cbw was the only imaging parameter to significantly correlate with toughness, the energy dissipated during fracture. Notably, the strength of the correlations with the material properties of bone tended to be higher when a larger endosteal region was used to determine Cbw and Cpw. These results indicate that MRI measures of Cbw and Cpw have the ability to probe bone material properties independent of bone structure or subject gender. In particular, toughness is a property of fracture resistance that is not explained by X-ray based methods. Thus, these MRI-derived measures of Cbw and Cpw in cortical

  2. Valine-Resistance, a Potential Marker in Plant Cell Genetics. II. Optimization of Uv Mutagenesis and Selection of Valine-Resistant Colonies Derived from Tobacco Mesophyll Protoplasts.

    PubMed

    Grandbastien, M A; Bourgin, J P; Caboche, M

    1985-02-01

    The induction and selection of valine-resistant mutants from haploid tobacco (Nicotiana tabacum L.) mesophyll protoplast-derived cells have been studied. Using cells from an original mutant plant obtained previously, we performed reconstruction experiments in order to determine the best conditions for the recovery of resistant cells among a population of sensitive cells. Optimal selective conditions were shown to depend on various factors including cell density, time of addition of valine and seasonal variations affecting the mother plants.-Using cell densities of approximately 10( 4) cells/ml, we defined efficient selective conditions: more than 25% of the putative mutant clones selected from UV-mutagenized protoplasts were reproducibly confirmed to be valine resistant. Further characterization of some regenerated mutant plants indicated that valine-resistance was associated with an uptake deficiency, as in the case of the original mutant plant of the Val(r)-2 line used for reconstruction experiments. Spontaneous mutation rates for valine-resistance were below accurately detectable levels, i.e., less than 10(-6) per cell per generation. Induced mutation frequency varied nonlinearily with UV dose from 10(-5) to 5 x 10(-4) resistant clones per surviving colony. Two independent loci (vr2 and vr3) were previously shown to be involved in valine-resistance due to amino acid uptake deficiency. Haploid tobacco plants were produced through anther culture from an F(1) double-heterozygous plant obtained from a cross between the original mutant plant and a wild-type plant. Study of the level of resistance to valine of protoplast-derived cells allowed the classification of these haploid plants in four types: sensitive, resistant and two intermediary resistant types believed to result from the presence of a mutant allele at only one of the two loci involved. The frequencies of UV-induced mutations in cells derived from haploid plants of one of the intermediary types were

  3. Reversal of P-glycoprotein-mediated multidrug resistance by the novel tetrandrine derivative W6.

    PubMed

    Sun, Hua; Liu, Xiao-Dong; Liu, Qian; Wang, Feng-Peng; Bao, Xiu-Qi; Zhang, Dan

    2015-01-01

    Overexpression of ATP-dependent efflux pump P-glycoprotein (P-gp) is the main cause of multidrug resistance (MDR) and chemotherapy failure in cancer treatment. Inhibition of P-gp-mediated drug efflux is an effective way to overcome cancer drug resistance. The present study investigated the reversal effect of the novel tetrandrine derivative W6 on P-gp-mediated MDR. KBv200, MCF-7/adr and their parental sensitive cell lines KB, MCF-7 were used for reversal study. The intracellular accumulation with P-gp substrates of doxorubicin was determined by flow cytometry. The expression of P-gp and ERK1/2 was investigated by western blot and real-time-PCR (RT-PCR) analysis. ATPase activity of P-gp was performed by P-gp-Glo(TM) assay systems. In comparison with P-gp-negative parental cells, W6 produced a favorable reversal effect in the MDR cells, as determined using the MTT assay. W6 significantly and dose-dependently increased intracellular accumulation of P-gp substrate doxorubicin (DOX) in P-gp overexpressing KBv200 cells, and also inhibited the ATPase activity of P-gp. W6 inhibited P-gp expression in KBv200 cells in a time-dependent manner, but it had no effect on MDR1 expression. In addition, W6 significantly decreased the ERK1/2 activation in KBv200 cells. Our results showed that W6 effectively reversed P-gp-mediated MDR by inhibiting the transport function and expression of P-gp, demonstrating the potential clinical utility of W6. PMID:26235354

  4. Molecular marker-assisted alien gene introgression of Sr39 for wheat stem rust resistance derived from Aegilops speltoides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wheat (Triticum aestivum L.), stem rust resistance gene Sr39, derived from Aegilops speltoides, is highly effective against multiple stem rust races including Ug99. However, the gene has not been used in wheat breeding because it is located on a large 2S chromosomal segment in the current transl...

  5. Nonerythropoietic Erythropoietin-Derived Peptide Suppresses Adipogenesis, Inflammation, Obesity and Insulin Resistance

    PubMed Central

    Liu, Yuqi; Luo, Bangwei; Shi, Rongchen; Wang, Jinsong; Liu, Zongwei; Liu, Wei; Wang, Shufeng; Zhang, Zhiren

    2015-01-01

    Erythropoietin (EPO) has been identified as being crucial for obesity modulation; however, its erythropoietic activity may limit its clinical application. EPO-derived Helix B-surface peptide (pHBSP) is nonerythrogenic but has been reported to retain other functions of EPO. The current study aimed to evaluate the effects and potential mechanisms of pHBSP in obesity modulation. We found that pHBSP suppressed adipogenesis, adipokine expression and peroxisome proliferator-activated receptor γ (PPARγ) levels during 3T3-L1 preadipocyte maturation through the EPO receptor (EPOR). In addition, also through EPOR, pHBSP attenuated macrophage inflammatory activation and promoted PPARγ expression. Furthermore, PPARγ deficiency partly ablated the anti-inflammatory activity of pHBSP in macrophages. Correspondingly, pHBSP administration to high-fat diet (HFD)-fed mice significantly improved obesity, insulin resistance (IR) and adipose tissue inflammation without stimulating hematopoiesis. Therefore, pHBSP can significantly protect against obesity and IR partly by inhibiting adipogenesis and inflammation. These findings have therapeutic implications for metabolic disorders, such as obesity and diabetes. PMID:26459940

  6. THE TREATMENT-RESISTANT MESENCHYMAL SIGNATURE IN GLIOBLASTOMA DERIVES FROM TUMOR CELLS INDEPENDENT OF STROMA

    PubMed Central

    Sulman, Erik P.; Wang, Qianghu; Ezhilarasan, Ravesanker; Goodman, Lindsey D.; Gumen, Joy; Sun, Peng; Aldape, Ken; Alfred Yung, WK; Heffernan, Timothy; Draetta, Giulio F.; Lang, Frederick F.

    2014-01-01

    BACKGROUND: Glioma sphere-forming cells (GSCs) derived from surgical specimens are a fundamental resource to study glioblastoma (GBM) biology. Mesenchymal-expressing GSCs have been proposed as a source of treatment resistance and mesenchymal tumors correlate with poorer survival. Recently, we found that the anti-angiogensis drug bevacizumab appeared to provide no benefit to patients with mesenchymal tumors, in contradiction to expectations that a mesenchymal microenvironment may benefit from anti-angiogenesis therapy. We have developed a collection of GSCs that have undergone comprehensive genomic characterization, similar to that performed by the Cancer Genome Atlas (TCGA) for whole tumor specimens. We hypothesized that the genomic landscape of GSCs would recapitulate what was observed by TCGA. METHODS: 47 GSCs were obtained from primary culture of fresh tumor specimens obtained at surgery and cultured as 3-dimensional spheres in the absence of serum. All lines were subjected to RNAseq (75bp paired-end, 100X coverage), copy number analysis (Affymetrix Oncoscan 2.0), whole methylome (Illumina Infinium 450k bead array), and targeted resequencing of known cancer-associated genes. Whole exome sequencing was performed for 22 GSCs. Gene expression was determined by reads per kilobase per million (RPKM) using an RNA sequencing data analysis pipeline (PRADA) and somatic mutations identified by a commonly used detection method (MuTech). Consensus clustering based on none-negative matrix factorization (CNMF) was performed on expression data and correlation to TCGA clusters determined by single-sample gene set enrichment analysis (ssGSEA). RESULTS: While global copy number alterations such as gain of chromosome 7 at the EGFR locus or loss of chromosome 10 at the PTEN locus were shared between tumor and matched GSC, the rate of somatic events was significantly higher in GSCs compared to tumors (range 47-570, median 124 vs range 2-255, median 65). Optimization of CNMF

  7. Multiple determinants in the coding region of Pea seed-borne mosaic virus P3 are involved in virulence against sbm-2 resistance.

    PubMed

    Hjulsager, Charlotte Kristiane; Olsen, Birgit Schlichter; Jensen, Ditte Marie Kjaer; Cordea, Mirela Irina; Krath, Britta N; Johansen, I Elisabeth; Lund, Ole Søgaard

    2006-11-10

    Viral determinants for overcoming Pisum sativum recessive resistance, sbm-2, against the potyvirus Pea seed-borne mosaic virus (PSbMV) were identified in the region encoding the N-terminal part of the P3 protein. Codons conserved between sbm-2 virulent isolates in this region: Q21, K30 and H122 were found to specifically impair sbm-2 virulence when mutated in selected genetic backgrounds. The corresponding amino acids, Gln21 and Lys30, are neighbored by P3 residues strongly conserved among potyviruses and His122 is conserved particularly in potyviral species infecting legumes. The strongest selective inhibition of sbm-2 virulence, however, was observed by elimination of isolate specific length polymorphisms also located in the N-terminal part of the P3 protein. Length variation in N-terminal P3 is common between potyviral species. However, intra-species length polymorphism in this region was found only among PSbMV isolates. Our findings comply with a model for PSbMV pathotypes having evolved by a diversification of the P3 protein likely to extend to the level of function. PMID:16908044

  8. Putative Thinopyrum intermedium-derived stripe rust resistance gene Yr50 maps on wheat chromosome arm 4BL.

    PubMed

    Liu, Jie; Chang, Zhijian; Zhang, Xiaojun; Yang, Zujun; Li, Xin; Jia, Juqing; Zhan, Haixian; Guo, Huijuan; Wang, Jianming

    2013-01-01

    Stripe rust-resistant wheat introgression line CH223 was developed by crossing the resistant partial amphiploid TAI7047 derived from Thinopyrum intermedium with susceptible cultivars. The resistance is effective against all the existing Chinese stripe rust races, including the most widely virulent and predominant pathotypes CYR32 and CYR33. Cytological analyses using GISH detected no chromosomal segments from Th. intermedium. It was presumed that the segment was too small to be detected. Normal bivalent pairing at meiosis in CH223 and its hybrids confirmed its stability. Genetic analysis of the F(1), F(2), F(3) and BC(1) populations from crosses of CH223 with susceptible lines indicated that resistance was controlled by a single dominant gene. The resistance gene was mapped using an F(2:3) population from Taichung 29/CH223. The gene was linked to five co-dominant genomic SSR markers, Xgwm540, Xbarc1096, Xwmc47, Xwmc310 and Xgpw7272, and flanked by Xbarc1096 and Xwmc47 at 8.0 and 7.2 cM, respectively. Using the Chinese Spring nulli-tetrasomic and ditelosomic lines, the polymorphic markers and the resistance gene were assigned to chromosome arm 4BL. As no permanently named stripe rust resistance genes had been assigned to chromosome 4BL, this new resistance gene is designated Yr50. The gene, together with the identified closely linked markers, could be used in marker-assisted selection to combine two or more resistance genes in a single genotype. PMID:23052018

  9. Microsatellite mapping of a Triticum urartu Tum. derived powdery mildew resistance gene transferred to common wheat (Triticum aestivum L.).

    PubMed

    Qiu, Y C; Zhou, R H; Kong, X Y; Zhang, S S; Jia, J Z

    2005-11-01

    A powdery mildew resistance gene from Triticum urartu Tum. accession UR206 was successfully transferred into hexaploid wheat (Triticum aestivum L.) through crossing and backcrossing. The F1 plants, which had 28 chromosomes and an average of 5.32 bivalents and 17.36 univalents in meiotic pollen mother cells (PMC), were obtained through embryos rescued owing to shriveling of endosperm in hybrid seed of cross Chinese Spring (CS) x UR206. Hybrid seeds were produced through backcrossing F1 with common wheat parents. The derivative lines had normal chromosome numbers and powdery mildew resistance similar to the donor UR206, indicating that the powdery mildew resistance gene originating from T. urartu accession UR206 was successfully transferred and expressed in a hexaploid wheat background. Genetic analysis indicated that a single dominant gene controlled the powdery mildew resistance at the seedling stage. To map and tag the powdery mildew resistance gene, 143 F2 individuals derived from a cross UR206 x UR203 were used to construct a linkage map. The resistant gene was mapped on the chromosome 7AL based on the mapped microsatellite makers. The map spanned 52.1 cM and the order of these microsatellite loci agreed well with the established microsatellite map of chromosome arm 7AL. The resistance gene was flanked by the microsatellite loci Xwmc273 and Xpsp3003, with the genetic distances of 2.2 cM and 3.8 cM, respectively. On the basis of the origin and chromosomal location of the gene, it was temporarily designated PmU. PMID:16177900

  10. The resistivity structure of the North Alex Mud Volcano as derived from the interpretation of CSEM data

    NASA Astrophysics Data System (ADS)

    Hölz, Sebastian; Jegen, Marion

    2010-05-01

    Active mud volcanoes, where changing salinities of pore fluids, large temperature gradients and occurrences of free gas are frequently observed, should potentially exhibit significant variability in their internal resistivity structure. This is due to the fact that the bulk resistivity is mainly determined by the porosity of sediments and the electrical resistivity of the pore filling contained therein. The resistivity variations may be derived from controlled source electromagnetic (CSEM) measurements. CSEM systems consist of an electric dipole transmitter producing a time varying source field and electric dipole receivers, which measure the earth's response to this signal. For a RWE Dea funded investigation of fluid and gas leakages at the North Alex Mud Volcano (NAMV) - a comparatively small target with an area of about 1km2 - we have developed a new high resolution CSEM system. The system consists of several autonomous electric dipole receivers and a lightweight electric dipole transmitter, which can be mounted on a small remotely operated underwater vehicle (ROV). The use of a ROV allows for a precise placement of the transmitter, which is a necessary prerequisite for the investigation of such a small target. Furthermore, electromagnetic signals may be transmitted from different directions with respect to the stationary receivers, allowing for a 3D-style tomographic experiment. In this experiment, ten receivers were deployed over the surface of NAMV at a total of 16 receiver locations. During three successful dives with a Cherokee ROV (Ghent University, Belgium), the transmitter was deployed at a total of 80 locations. Here we present first quantitative results consisting of apparent resistivity estimations from the CSEM time domain data for each transmitter-receiver pair. The apparent resistivity map shows that the NAMV indeed has a heterogeneous resistivity structure with apparent resistivities varying by at least a factor of two: low apparent resistivities

  11. Synthetic pregnenolone derivatives as antiviral agents against acyclovir-resistant isolates of Herpes Simplex Virus Type 1.

    PubMed

    Dávola, María Eugenia; Mazaira, Gisela I; Galigniana, Mario D; Alché, Laura E; Ramírez, Javier A; Barquero, Andrea A

    2015-10-01

    The conventional therapy for the management of Herpes Simplex Virus Type 1 (HSV-1) infections mainly comprises acyclovir (ACV) and other nucleoside analogues. A common outcome of this treatment is the emergence of resistant viral strains, principally when immunosuppressed patients are involved. Thus, the development of new antiherpetic compounds remains as a central challenge. In this work we describe the synthesis and the in vitro antiherpetic activity of a new family of steroidal compounds derived from the endogenous hormone pregnenolone. Some of these derivatives showed a remarkable inhibitory effect on HSV-1 spread both on wild type and ACV-resistant strains. The results also show that these compounds seem to interfere with the late steps of the viral cycle. PMID:26259812

  12. Electrical resistivity image of the South Atlantic continental margin derived from onshore and offshore magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Kapinos, G.; Weckmann, U.; Jegen-Kulcsar, M.; Meqbel, N.; Neska, A.; Katjiuongua, T. T.; Hoelz, S.; Ritter, O.

    2016-01-01

    We present a deep electrical resistivity image from the passive continental margin in Namibia. The approximately 700 km long magnetotelluric profile follows the Walvis Ridge offshore, continues onshore across the Kaoko Mobile Belt and reaches onto the Congo Craton. Two-dimensional inversion reveals moderately resistive material offshore, atypically low for oceanic lithosphere, reaching depths of 15-20 km. Such moderate resistivities are consistent with seismic P wave velocity models, which suggest up to 35 km thick crust. The Neoproterozoic rocks of the Kaoko Mobile Belt are resistive, but NNW-striking major shear-zones are imaged as subvertical, conductive structures in the upper and middle crust. Since the geophysical imprint of the shear zones is intact, opening of the South Atlantic in the Cretaceous did not alter the middle crust. The transition into the cratonic region coincides with a deepening of the high-resistive material to depths of more than 60 km.

  13. The Nuclear Factor (Erythroid-derived 2)-like 2 and Proteasome Maturation Protein Axis Mediate Bortezomib Resistance in Multiple Myeloma.

    PubMed

    Li, Bingzong; Fu, Jinxiang; Chen, Ping; Ge, Xueping; Li, Yali; Kuiatse, Isere; Wang, Hua; Wang, Huihan; Zhang, Xingding; Orlowski, Robert Z

    2015-12-11

    Resistance to the proteasome inhibitor bortezomib is an emerging clinical problem whose mechanisms have not been fully elucidated. We considered the possibility that this could be associated with enhanced proteasome activity in part through the action of the proteasome maturation protein (POMP). Bortezomib-resistant myeloma models were used to examine the correlation between POMP expression and bortezomib sensitivity. POMP expression was then modulated using genetic and pharmacologic approaches to determine the effects on proteasome inhibitor sensitivity in cell lines and in vivo models. Resistant cell lines were found to overexpress POMP, and while its suppression in cell lines enhanced bortezomib sensitivity, POMP overexpression in drug-naive cells conferred resistance. Overexpression of POMP was associated with increased levels of nuclear factor (erythroid-derived 2)-like (NRF2), and NRF2 was found to bind to and activate the POMP promoter. Knockdown of NRF2 in bortezomib-resistant cells reduced POMP levels and proteasome activity, whereas its overexpression in drug-naive cells increased POMP and proteasome activity. The NRF2 inhibitor all-trans-retinoic acid reduced cellular NRF2 levels and increased the anti-proliferative and pro-apoptotic activities of bortezomib in resistant cells, while decreasing proteasome capacity. Finally, the combination of all-trans-retinoic acid with bortezomib showed enhanced activity against primary patient samples and in a murine model of bortezomib-resistant myeloma. Taken together, these studies validate a role for the NRF2/POMP axis in bortezomib resistance and identify NRF2 and POMP as potentially attractive targets for chemosensitization to this proteasome inhibitor. PMID:26483548

  14. Metabolomics Analysis Identifies Intestinal Microbiota-Derived Biomarkers of Colonization Resistance in Clindamycin-Treated Mice

    PubMed Central

    Jump, Robin L. P.; Polinkovsky, Alex; Hurless, Kelly; Sitzlar, Brett; Eckart, Kevin; Tomas, Myreen; Deshpande, Abhishek; Nerandzic, Michelle M.; Donskey, Curtis J.

    2014-01-01

    Background The intestinal microbiota protect the host against enteric pathogens through a defense mechanism termed colonization resistance. Antibiotics excreted into the intestinal tract may disrupt colonization resistance and alter normal metabolic functions of the microbiota. We used a mouse model to test the hypothesis that alterations in levels of bacterial metabolites in fecal specimens could provide useful biomarkers indicating disrupted or intact colonization resistance after antibiotic treatment. Methods To assess in vivo colonization resistance, mice were challenged with oral vancomycin-resistant Enterococcus or Clostridium difficile spores at varying time points after treatment with the lincosamide antibiotic clindamycin. For concurrent groups of antibiotic-treated mice, stool samples were analyzed using quantitative real-time polymerase chain reaction to assess changes in the microbiota and using non-targeted metabolic profiling. To assess whether the findings were applicable to another antibiotic class that suppresses intestinal anaerobes, similar experiments were conducted with piperacillin/tazobactam. Results Colonization resistance began to recover within 5 days and was intact by 12 days after clindamycin treatment, coinciding with the recovery bacteria from the families Lachnospiraceae and Ruminococcaceae, both part of the phylum Firmicutes. Clindamycin treatment caused marked changes in metabolites present in fecal specimens. Of 484 compounds analyzed, 146 (30%) exhibited a significant increase or decrease in concentration during clindamycin treatment followed by recovery to baseline that coincided with restoration of in vivo colonization resistance. Identified as potential biomarkers of colonization resistance, these compounds included intermediates in carbohydrate or protein metabolism that increased (pentitols, gamma-glutamyl amino acids and inositol metabolites) or decreased (pentoses, dipeptides) with clindamycin treatment. Piperacillin

  15. 4-Aminoquinoline derivatives: Synthesis, in vitro and in vivo antiplasmodial activity against chloroquine-resistant parasites.

    PubMed

    Singh, Shailja; Agarwal, Drishti; Sharma, Kumkum; Sharma, Manish; Nielsen, Morten A; Alifrangis, Michael; Singh, Ashok K; Gupta, Rinkoo D; Awasthi, Satish K

    2016-10-21

    Synthetic quinoline derivatives continue to be considered as candidates for new drug discovery if they act against CQ-resistant strains of malaria even after the widespread emergence of resistance to CQ. In this study, we explored the activities of two series of new 4-aminoquinoline derivatives and found them to be effective against Plasmodium falciparum under in vitro conditions. Further, we selected four most active derivatives 1m, 1o, 2c and 2j and evaluated their antimalarial potential against Plasmodium berghei in vivo. These 4-aminoquinolines cured BALB/c mice infected with P. berghei. The ED50 values were calculated to be 2.062, 2.231, 1.431, 1.623 and 1.18 mg/kg of body weight for each of the compounds 1m, 1o, 2c, 2j and amodiaquine, respectively. Total doses of 500 mg/kg of body weight were well received. The study suggests that these new 4-aminoquinolines should be used for structure activity relationship to find lead molecules for treating multidrug-resistant Plasmodium falciparum and Plasmodium vivax. PMID:27394399

  16. In vitro anti-mycobacterial activity of (E)-N'-(monosubstituted-benzylidene) isonicotinohydrazide derivatives against isoniazid-resistant strains

    PubMed Central

    Coelho, Tatiane S.; Cantos, Jessica B.; Bispo, Marcelle L.F.; Gonçalves, Raoni S.B.; Lima, Camilo H.S.; da Silva, Pedro E.A.; Souza, Marcus V. N.

    2012-01-01

    A series of twenty-three N-acylhydrazones derived from isoniazid (INH 1-23) have been evaluated for their in vitro antibacterial activity against INH- susceptible strain of M. tuberculosis (RG500) and three INH-resistant clinical isolates (RG102, RG103 and RG113). In general, derivatives 4, 14, 15 and 16 (MIC=1.92, 1.96, 1.96 and 1.86 µM, respectively) showed relevant activities against RG500 strain, while the derivative 13 (MIC=0.98 µM) was more active than INH (MIC=1.14 µM). However, these derivatives were inactive against RGH102, which displays a mutation in the coding region of inhA. These results suggest that the activities of these compounds depend on the inhibition of this enzyme. However, the possibility of other mechanisms of action cannot be excluded, since compounds 2, 4, 6, 7, 12–17, 19, 21 and 23 showed good activities against katG-resistant strain RGH103, being more than 10-fold more active than INH. PMID:24470920

  17. Recessive Resistance Derived from Tomato cv. Tyking-Limits Drastically the Spread of Tomato Yellow Leaf Curl Virus.

    PubMed

    Pereira-Carvalho, Rita C; Díaz-Pendón, Juan A; Fonseca, Maria Esther N; Boiteux, Leonardo S; Fernández-Muñoz, Rafael; Moriones, Enrique; Resende, Renato O

    2015-05-01

    The tomato yellow leaf curl disease (TYLCD) causes severe damage to tomato (Solanum lycopersicum L.) crops throughout tropical and subtropical regions of the world. TYLCD is associated with a complex of single-stranded circular DNA plant viruses of the genus Begomovirus (family Geminiviridae) transmitted by the whitefy Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The tomato inbred line TX 468-RG is a source of monogenic recessive resistance to begomoviruses derived from the hybrid cv. Tyking F1. A detailed analysis of this germplasm source against tomato yellow leaf curl virus-Israel (TYLCV-IL), a widespread TYLCD-associated virus, showed a significant restriction to systemic virus accumulation even under continuous virus supply. The resistance was effective in limiting the onset of TYLCV-IL in tomato, as significantly lower primary spread of the virus occurred in resistant plants. Also, even if a limited number of resistant plants could result infected, they were less efficient virus sources for secondary spread owing to the impaired TYLCV-IL accumulation. Therefore, the incorporation of this resistance into breeding programs might help TYLCD management by drastically limiting TYLCV-IL spread. PMID:26008699

  18. Elicitation of induced resistance against Pectobacterium carotovorum and Pseudomonas syringae by specific individual compounds derived from native Korean plant species.

    PubMed

    Song, Geun Cheol; Ryu, Shi Yong; Kim, Young Sup; Lee, Ji Young; Choi, Jung Sup; Ryu, Choong-Min

    2013-01-01

    Plants have developed general and specific defense mechanisms for protection against various enemies. Among the general defenses, induced resistance has distinct characteristics, such as broad-spectrum resistance and long-lasting effectiveness. This study evaluated over 500 specific chemical compounds derived from native Korean plant species to determine whether they triggered induced resistance against Pectobacterium carotovorum supsp. carotovorum (Pcc) in tobacco (Nicotiana tabacum) and Pseudomonas syringae pv. tomato (Pst) in Arabidopsis thaliana. To select target compound(s) with direct and indirect (volatile) effects, a new Petri-dish-based in vitro disease assay system with four compartments was developed. The screening assay showed that capsaicin, fisetin hydrate, jaceosidin, and farnesiferol A reduced the disease severity significantly in tobacco. Of these four compounds, capsaicin and jaceosidin induced resistance against Pcc and Pst, which depended on both salicylic acid (SA) and jasmonic acid (JA) signaling, using Arabidopsis transgenic and mutant lines, including npr1 and NahG for SA signaling and jar1 for JA signaling. The upregulation of the PR2 and PDF1.2 genes after Pst challenge with capsaicin pre-treatment indicated that SA and JA signaling were primed. These results demonstrate that capsaicin and jaceosidin can be effective triggers of strong induced resistance against both necrotrophic and biotrophic plant pathogens. PMID:24135942

  19. Recessive Resistance Derived from Tomato cv. Tyking-Limits Drastically the Spread of Tomato Yellow Leaf Curl Virus

    PubMed Central

    Pereira-Carvalho, Rita C.; Díaz-Pendón, Juan A.; Fonseca, Maria Esther N.; Boiteux, Leonardo S.; Fernández-Muñoz, Rafael; Moriones, Enrique; Resende, Renato O.

    2015-01-01

    The tomato yellow leaf curl disease (TYLCD) causes severe damage to tomato (Solanum lycopersicum L.) crops throughout tropical and subtropical regions of the world. TYLCD is associated with a complex of single-stranded circular DNA plant viruses of the genus Begomovirus (family Geminiviridae) transmitted by the whitefy Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae). The tomato inbred line TX 468-RG is a source of monogenic recessive resistance to begomoviruses derived from the hybrid cv. Tyking F1. A detailed analysis of this germplasm source against tomato yellow leaf curl virus-Israel (TYLCV-IL), a widespread TYLCD-associated virus, showed a significant restriction to systemic virus accumulation even under continuous virus supply. The resistance was effective in limiting the onset of TYLCV-IL in tomato, as significantly lower primary spread of the virus occurred in resistant plants. Also, even if a limited number of resistant plants could result infected, they were less efficient virus sources for secondary spread owing to the impaired TYLCV-IL accumulation. Therefore, the incorporation of this resistance into breeding programs might help TYLCD management by drastically limiting TYLCV-IL spread. PMID:26008699

  20. Food plant derived disease tolerance and resistance in a natural butterfly-plant-parasite interactions.

    PubMed

    Sternberg, Eleanore D; Lefèvre, Thierry; Li, James; de Castillejo, Carlos Lopez Fernandez; Li, Hui; Hunter, Mark D; de Roode, Jacobus C

    2012-11-01

    Organisms can protect themselves against parasite-induced fitness costs through resistance or tolerance. Resistance includes mechanisms that prevent infection or limit parasite growth while tolerance alleviates the fitness costs from parasitism without limiting infection. Although tolerance and resistance affect host-parasite coevolution in fundamentally different ways, tolerance has often been ignored in animal-parasite systems. Where it has been studied, tolerance has been assumed to be a genetic mechanism, unaffected by the host environment. Here we studied the effects of host ecology on tolerance and resistance to infection by rearing monarch butterflies on 12 different species of milkweed food plants and infecting them with a naturally occurring protozoan parasite. Our results show that monarch butterflies experience different levels of tolerance to parasitism depending on the species of milkweed that they feed on, with some species providing over twofold greater tolerance than other milkweed species. Resistance was also affected by milkweed species, but there was no relationship between milkweed-conferred resistance and tolerance. Chemical analysis suggests that infected monarchs obtain highest fitness when reared on milkweeds with an intermediate concentration, diversity, and polarity of toxic secondary plant chemicals known as cardenolides. Our results demonstrate that environmental factors-such as interacting species in ecological food webs-are important drivers of disease tolerance. PMID:23106703

  1. Pattern of Antibiotic Resistance Among Community Derived Isolates of Enterobacteriaceae Using Urine Sample: A Study From Northern India

    PubMed Central

    Lohiya, Ayush; Kapil, Arti; Gupta, Sanjeev Kumar; Misra, Puneet; Rai, Sanjay K.

    2015-01-01

    Background Despite world-wide evidence of increased antibiotic resistance, there is scarce data on antibiotic resistance in community settings. One of the reason being difficulty in collection of biological specimen (traditionally stool) in community from apparently healthy individuals. Hence, finding an alternative specimen that is easier to obtain in a community setting or in large scale surveys for the purpose, is crucial. We conducted this study to explore the feasibility of using urine samples for deriving community based estimates of antibiotic resistance and to estimate the magnitude of resistance among urinary isolates of Escherichia coli and Klebsiella pneumonia against multiple antibiotics in apparently healthy individuals residing in a rural community of Haryana, North India. Materials and Methods Eligible individuals were apparently healthy, aged 18 years or older. Using the health management information system (HMIS) of Ballabgarh Health Demographic Surveillance System (HDSS), sampling frame was prepared. Potential individuals were identified using simple random sampling. Random urine sample was collected in a sterile container and transported to laboratory under ambient condition. Species identification and antibiotic susceptibility testing for Enterobacteriaceae was done using Clinical Laboratory and Standards Institute (CLSI) 2012 guidelines. Multi-drug resistant (MDR) Enterobacteriaceae, Extended Spectrum Beta Lactamase (ESBL) producing Enterobacteriaceae, and Carbapenem producing Enterobacteriaceae (CRE) were identified from the urine samples. Results A total of 433 individuals participated in the study (non-response rate – 13.4%), out of which 58 (13.4%) were positive for Enterobacteriaceae, 8.1% for E. coli and 5.3% for K. pneumoniae. Resistance against penicillin (amoxicillin/ampicillin) for E. coli and K. pneumoniae was 62.8% and 100.0% respectively. Isolates resistant to co-trimoxazole were 5.7% and 0.0% respectively. None of the isolates

  2. IGFBP-3 hypermethylation-derived deficiency mediates cisplatin resistance in non-small-cell lung cancer.

    PubMed

    Ibanez de Caceres, I; Cortes-Sempere, M; Moratilla, C; Machado-Pinilla, R; Rodriguez-Fanjul, V; Manguán-García, C; Cejas, P; López-Ríos, F; Paz-Ares, L; de CastroCarpeño, J; Nistal, M; Belda-Iniesta, C; Perona, R

    2010-03-18

    Cisplatin-based chemotherapy is the paradigm of non-small-cell lung cancer (NSCLC) treatment; however, it also induces de novo DNA-hypermethylation, a process that may be involved in the development of drug-resistant phenotypes by inactivating genes required for drug-cytotoxicity. By using an expression microarray analysis, we aimed to identify those genes reactivated in a set of two cisplatin (CDDP) resistant and sensitive NSCLC cell lines after epigenetic treatment. Gene expression, promoter methylation and CDDP-chemoresponse were further analyzed in three matched sets of sensitive/resistant cell lines, 23 human cancer cell lines and 36 NSCLC specimens. Results revealed specific silencing by promoter hypermethylation of IGFBP-3 in CDDP resistant cells, whereas IGFBP-3 siRNA interference, induced resistance to CDDP in sensitive cells (P<0.001). In addition, we found a strong correlation between methylation status and CDDP response in tumor specimens (P<0.001). Thus, stage I patients, whose tumors harbor an unmethylated promoter, had a trend towards increased disease-free survival (DFS). We report that a loss of IGFBP-3 expression, mediated by promoter-hypermethylation, results in a reduction of tumor cell sensitivity to cisplatin in NSCLC. Basal methylation status of IGFBP-3 before treatment may be a clinical biomarker and a predictor of the chemotherapy outcome, helping to identify patients who are most likely to benefit from CDDP therapy alone or in combination with epigenetic treatment. PMID:20023704

  3. [Transgenic wheat expressing virus-derived hairpin RNA is resistant to Barley yellow dwarf virus].

    PubMed

    Yan, Fei; Zhang, Wen-Wei; Xiao, Hong; Li, Shi-Fang; Cheng, Zhuo-Min

    2007-01-01

    An expression vector expected to induce RNA interference against Barley yellow dwarf virus (BYDV), which expressed a composite hpRNA with the dsRNA stem homologous of BYDV GPV replicase gene and the antisense RNA loop homologous of coat protein gene, was designed without marker gene. The vector was transferred into callus cells from wheat (Triticum aestivum L.) immature embryos by particle bombardment. To select the positive transformants as early as possible, a rapid PCR, which does not need extract wheat DNA instead of few leaves, was used at regeneration stage of plantlets. Totally 21 plants proved to contain alien sequence. Antivirus test with high dose infected virus revealed that, 9 plants showed low level of resistance to BVDV, 6 plants showed moderate resistance and 6 plants showed high level of resistance. Interestingly, both low and moderate levels of resistance plants were no symptoms when infected by viruses at low dose. It suggests the dose- dependent effect of the resistance mediated by hpRNA to BYDV-GPV. PMID:17284432

  4. Humanized anti-hepatocyte growth factor (HGF) antibody suppresses innate irinotecan (CPT-11) resistance induced by fibroblast-derived HGF

    PubMed Central

    Kim, BoRa; Park, Byung Hee; Shin, Kum-Joo; Song, Seong-Won; Kim, Jung Ju; Kim, Hwan-Mook; Lee, Sang-Jin; Oh, Seung Hyun

    2015-01-01

    The growth factors derived from the microenvironment create an environment conducive to tumor growth and survival. HGF deprivation using neutralizing antibody enhanced chemosensitivity in colorectal cancer cells (CRC). We determined secreted HGF in fibroblast conditioned medium (CM). Combination treatment of anti-HGF antibody and irinotecan (CPT-11) directly enhanced CPT-11 sensitivity in CRC. We generated xenograft in NOD/SCID mice inoculating HCT-116 human colorectal cancer cells subcutaneously with or without fibroblast. We found that the combination of CPT-11 and anti-HGF antibody induced marked suppression of tumor development. These results suggest that HGF produced by fibroblast induce CPT-11 resistance, and that anti-HGF antibody abrogate such resistance in vivo. fibroblast-derived HGF is important determinant of chemoresistance. Anti-HGF monoclonal antibody treatment confirmed the importance of this growth factor for chemoresistance in CRC. These results present new options toward the early diagnosis of chemoresistance and suggest novel combinations of chemotherapy and anti-HGF agents to prevent or significantly delay the onset of therapy resistance. PMID:26090722

  5. Proteomic response of methicillin-resistant S. aureus to a synergistic antibacterial drug combination: a novel erythromycin derivative and oxacillin.

    PubMed

    Liu, Xiaofen; Pai, Pei-Jin; Zhang, Weipeng; Hu, Yingwei; Dong, Xiaojing; Qian, Pei-yuan; Chen, Daijie; Lam, Henry

    2016-01-01

    The use of antibacterial drug combinations with synergistic effects is increasingly seen as a critical strategy to combat multi-drug resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). In this work, the proteome responses in MRSA under the stress of a sub-inhibitory dose of a synergistic drug combination of a novel erythromycin derivative, SIPI-8294, and oxacillin, were studied by label-free quantitative proteomics. Several control treatment groups were designed to isolate proteome responses potentially related to the synergy: (1) the non-synergistic drug combination of erythromycin and oxacillin, (2) SIPI-8294 only, (3) oxacillin only and (4) erythromycin only. Results showed that 200 proteins were differentially expressed in SIPI-8294/oxacillin-treated cells. Among these proteins, the level of penicillin binding protein 2a, the protein mainly responsible for oxacillin resistance in MRSA, was four times lower in the SIPI-8294/oxacillin group than in the erythromycin/oxacillin group, suggesting that SIPI-8294 may interfere with this known oxacillin resistance mechanism. Moreover, hierarchical clustering analysis of differentially expressed proteins under different treatments revealed that SIPI-8294/oxacillin elicits very different responses than the individual drugs or the non-synergistic erythromycin/oxacillin combination. Bioinformatic analysis indicated that the synergistic effect can be further traced to a disruption in oxidation-reduction homeostasis and cell wall biosynthesis. PMID:26806358

  6. Proteomic response of methicillin-resistant S. aureus to a synergistic antibacterial drug combination: a novel erythromycin derivative and oxacillin

    PubMed Central

    Liu, Xiaofen; Pai, Pei-Jin; Zhang, Weipeng; Hu, Yingwei; Dong, Xiaojing; Qian, Pei-yuan; Chen, Daijie; Lam, Henry

    2016-01-01

    The use of antibacterial drug combinations with synergistic effects is increasingly seen as a critical strategy to combat multi-drug resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). In this work, the proteome responses in MRSA under the stress of a sub-inhibitory dose of a synergistic drug combination of a novel erythromycin derivative, SIPI-8294, and oxacillin, were studied by label-free quantitative proteomics. Several control treatment groups were designed to isolate proteome responses potentially related to the synergy: (1) the non-synergistic drug combination of erythromycin and oxacillin, (2) SIPI-8294 only, (3) oxacillin only and (4) erythromycin only. Results showed that 200 proteins were differentially expressed in SIPI-8294/oxacillin-treated cells. Among these proteins, the level of penicillin binding protein 2a, the protein mainly responsible for oxacillin resistance in MRSA, was four times lower in the SIPI-8294/oxacillin group than in the erythromycin/oxacillin group, suggesting that SIPI-8294 may interfere with this known oxacillin resistance mechanism. Moreover, hierarchical clustering analysis of differentially expressed proteins under different treatments revealed that SIPI-8294/oxacillin elicits very different responses than the individual drugs or the non-synergistic erythromycin/oxacillin combination. Bioinformatic analysis indicated that the synergistic effect can be further traced to a disruption in oxidation-reduction homeostasis and cell wall biosynthesis. PMID:26806358

  7. Establishment and gene analysis of a cisplatin-resistant cell line, Sa-3R, derived from oral squamous cell carcinoma.

    PubMed

    Nakatani, Ken; Nakamura, Megumi; Uzawa, Katsuhiro; Wada, Takeshi; Seki, Naohiko; Tanzawa, Hideki; Fujita, Shigeyuki

    2005-04-01

    Cisplatin (CDDP) is widely used for chemotherapy of many malignancies, especially of oral squamous cell carcinoma (SCC). However, because the mechanism of resistance to CDDP is unclear, we established a CDDP-resistant cell line, Sa-3R, from a CDDP-sensitive cell line, Sa-3, which was derived from moderately differentiated SCC of the lower gingiva. The 3-(3,4-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide assay indicated that Sa-3R has 7.5-fold greater resistance to CDDP than Sa-3. Comparing gene expression levels in the cell lines using an in-house cDNA microarray, which represented 2,201 oral disease origin genes, many differentially expressed genes were identified. The ATP-binding cassette transporter genes (MDR-1, MRP-1, and MRP-2), and FANCONI, GRP58, FLJ12089, and SPINT-2 were up-regulated, whereas FOSL1, MRPS27, and PGK-1 were down-regulated. These results were confirmed by semiquantitative reverse transcriptase-polymerase chain reaction. The Sa-3/Sa-3R cell lines could be useful to identify the candidates responsible for the mechanism of CDDP-resistance and the up- or down-regulated genes identified by the gene expression profiles in the Sa-3R cell line may be, in part, associated with the mechanism. PMID:15756446

  8. Resistance to Tan Spot and Stagonospora nodorum Blotch in Wheat-Alien Species Derivatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tan spot [caused by Pyrenophora tritici-repentis (Died.) Drechs.] and Stagonospora nodorum blotch (SNB) [caused by Stagonospora nodorum (Berk.) Castellani and Germano] are destructive fungal diseases of wheat (Triticum aestivum L.) throughout the world. Host plant resistance is thought to be an effi...

  9. Affinity-Tagged Miniprion Derivatives Spontaneously Adopt Protease-Resistant Conformations

    PubMed Central

    Supattapone, Surachai; Nguyen, Hoang-Oanh B.; Muramoto, Tamaki; Cohen, Fred E.; DeArmond, Stephen J.; Prusiner, Stanley B.; Scott, Michael

    2000-01-01

    An abridged PrP molecule of 106 amino acids designated PrP106 can form infectious miniprions in transgenic (Tg) mice (29). Addition of six-histidine (His6) affinity tags to selective sites within PrP106 resulted unexpectedly in new PrP proteins that spontaneously adopted protease-resistant conformations when expressed in neuroblastoma cells and Tg mice. Acquisition of protease resistance depended on the length, charge, and placement of the affinity tag. Introduction of the disease-linked mutation E200K into the sequence of PrP106(140/6His) increased the recovery of protease-resistant PrP fivefold, whereas introduction of the mutations C213A and Δ214–220 did not affect the recovery of protease-resistant PrP. Treatment of cultured cells expressing affinity-tagged PrP106 mutants with polypropyleneimine dendrimer rendered these proteins sensitive to protease digestion in a manner similar to wild-type PrPSc. We conclude that certain affinity-tagged PrP106 proteins spontaneously fold into conformations partially resembling, yet distinct from, wild-type PrPSc. These proteins might be useful tools in the identification of new disease-causing mutations as well as for screening compounds for therapeutic efficacy. PMID:11090193

  10. Selection for Verticillium Wilt Resistance in Potato Breeding Populations Derived from Four Cross Types

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt is one of the important yield-limiting diseases for potato production. To develop resistant clones, the potential for early generation selection was studied using three basic selection methods, individual, family, and within family selection, for two clonal generations. A total o...

  11. Novel plasmid conferring kanamycin and tetracycline resistance in turkey-derived Campylobacter jejuni strain 11601MD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Campylobacter spp., resistance to the antibiotics kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095 bp.) harboring tet(O) was identified in...

  12. Chromosome engineering to enhance utility of alien-derived stem rust resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the past 50 years, a number of stem rust (Sr) resistance genes identified from wild relatives of wheat have been incorporated into wheat genomes through chromosome engineering. Some of these genes, including Sr25, Sr26, Sr32, Sr37, Sr39, Sr40, Sr43, Sr44, SrR, and three unnamed novel Sr genes fr...

  13. Characterization of early blight resistance derived from the wild potato species Solanum berthaultii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early blight (EB), caused by the fungal pathogen A. solani, is a ubiquitous potato disease of world-wide significance. Fungicides are the main method of control, as cultivated varieties offer only a few sources of moderate resistance, most of which are associated with late maturity. Strong levels of...

  14. Prediction of antibiotic resistance proteins from sequence-derived properties irrespective of sequence similarity.

    PubMed

    Zhang, H L; Lin, H H; Tao, L; Ma, X H; Dai, J L; Jia, J; Cao, Z W

    2008-09-01

    Increasing antibiotic resistance has become a worldwide challenge to the clinical treatment of infectious diseases. The identification of antibiotic resistance proteins (ARPs) would be helpful in the discovery of new therapeutic targets and the design of novel drugs to control the potential spread of antibiotic resistance. In this work, a support vector machine (SVM)-based ARP prediction system was developed using 1308 ARPs and 15587 non-ARPs. Its performance was evaluated using 313 ARPs and 7156 non-ARPs. The computed prediction accuracy was 88.5% for ARPs and 99.2% for non-ARPs. A potential application of this method is the identification of ARPs non-homologous to proteins of known function. Further genome screening found that ca. 3.5% and 3.2% of proteins in Escherichia coli and Staphylococcus aureus, respectively, are potential ARPs. These results suggest the usefulness of SVMs for facilitating the identification of ARPs. The software can be accessed at SARPI (Server for Antibiotic Resistance Protein Identification). PMID:18583101

  15. Polyamino-Isoprenic Derivatives Block Intrinsic Resistance of P. aeruginosa to Doxycycline and Chloramphenicol In Vitro

    PubMed Central

    Borselli, Diane; Lieutaud, Aurélie; Thefenne, Hélène; Garnotel, Eric; Pagès, Jean-Marie; Brunel, Jean Michel; Bolla, Jean-Michel

    2016-01-01

    Multidrug resistant bacteria have been a worldwide concern for decades. Though new molecules that effectively target Gram-positive bacteria are currently appearing on the market, a gap remains in the treatment of infections caused by Gram-negative bacteria. Therefore, new strategies must be developed against these pathogens. The aim of this study was to select an antibiotic for which a bacterium is naturally resistant and to use an escort molecule to restore susceptibility, similarly to the model of β-lactam/ β-lactamase inhibitors. High-content screening was performed on the reference strain PA01, allowing the selection of four polyamino-isoprenic compounds that acted synergistically with doxycycline. They were assayed against clinical isolates and Multi-Drug-Resistant strains. One of these compounds was able to decrease the MIC of doxycycline on the reference strain, efflux pump overproducers and clinical isolates of P. aeruginosa, to the susceptibility level. Similar results were obtained using chloramphenicol as the antibiotic. Membrane permeation assays and real-time efflux experiments were used to characterize the mechanism of doxycycline potentiation. The results showed that the selected compound strongly decreases the efficiency of glucose-triggered efflux associated with a slight destabilization of the outer membrane. According to these data, targeting natural resistance may become an interesting way to combat MDR pathogens and could represent an alternative to already devised strategies. PMID:27152508

  16. Field-derived relationships for flow velocity and resistance in high-gradient streams

    USGS Publications Warehouse

    Comiti, F.; Mao, L.; Wilcox, A.; Wohl, E.E.; Lenzi, M.A.

    2007-01-01

    We measured velocity and channel geometry in 10 reaches (bed gradient = 0.08-0.21) of a predominantly step-pool channel, the Rio Cordon, Italy, over a range of discharges (3-80% of the bankfull discharge). The resulting data were used to compute flow resistance. At-a-station hydraulic geometry relations indicate that in most reaches, the exponent describing the rate of velocity increases with discharge was between 0.48 and 0.6, which is within the range of published values for pool-riffle channels. The Rio Cordon data are also combined with published hydraulics data from step-pool streams to explore non-dimensional relationships between velocity and flow resistance and factors including unit discharge, channel gradient, and step geometry. Multiple regression analysis of this combined field dataset indicated that dimensionless unit discharge (q*) is the most important independent variable overall in explaining variations in velocity and flow resistance, followed by channel slope and the ratio of step height to step length. Empirical equations are provided both for dimensionless velocity and flow resistance, but prediction of the former variable appears more reliable. ?? 2007 Elsevier B.V. All rights reserved.

  17. Development of Durum Wwheat Germplasm with Enhanced Resistance to Fusarium Head Blight Derived from Emmer Wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Durum wheat (Triticum turgidum L. subsp. durum) is a unique class of commercial wheat specifically for making pasta products. Durum production has been seriously challenged by the Fusarium head blight (FHB) disease in the United States in the past decade. Although utilization of resistant cultivar...

  18. Enhanced pest resistance of maize leaves expressing monocot crop plant derived ribosome inactivating protein and agglutinin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although many insect resistance genes have been identified, the number of studies examining their effects in combination using transgenic systems is limited. We introduced a construct into maize containing the coding sequence for maize ribosome inactivating protein (MRIP), wheat germ agglutinin (WGA...

  19. Efflux-mediated resistance to a benzothiadiazol derivative effective against Burkholderia cenocepacia

    PubMed Central

    Scoffone, Viola C.; Ryabova, Olga; Makarov, Vadim; Iadarola, Paolo; Fumagalli, Marco; Fondi, Marco; Fani, Renato; De Rossi, Edda; Riccardi, Giovanna; Buroni, Silvia

    2015-01-01

    Burkholderia cenocepacia is a major concern for people suffering from cystic fibrosis as it contributes to serious respiratory tract infections. The lack of drugs effective against this opportunistic pathogen, along with the high level of resistance to multiple antibiotics, render the treatment of these infections particularly difficult. Here a new compound, belonging to the 2,1,3-benzothiadiazol-5-yl family (10126109), with a bactericidal effect and a minimal inhibitory concentration (MIC) of 8 μg/ml against B. cenocepacia, is described. The compound is not cytotoxic and effective against B. cenocepacia clinical isolates and members of all the known B. cepacia complex species. Spontaneous mutants resistant to 10126109 were isolated and mutations in the MerR transcriptional regulator BCAM1948 were identified. In this way, a mechanism of resistance to this new molecule was described, which relies on the overexpression of the RND-9 efflux pump. Indeed, rnd-9 overexpression was confirmed by quantitative reverse transcription PCR, and RND-9 was identified in the membrane fractions of the mutant strains. Moreover, the increase in the MIC values of different drugs in the mutant strains, together with complementation experiments, suggested the involvement of RND-9 in the efflux of 10126109, thus indicating again the central role of efflux transporters in B. cenocepacia drug resistance. PMID:26300878

  20. Contribution of Clinically Derived Mutations in ERG11 to Azole Resistance in Candida albicans

    PubMed Central

    Flowers, Stephanie A.; Colón, Brendan; Whaley, Sarah G.; Schuler, Mary A.

    2014-01-01

    In Candida albicans, the ERG11 gene encodes lanosterol demethylase, the target of the azole antifungals. Mutations in ERG11 that result in an amino acid substitution alter the abilities of the azoles to bind to and inhibit Erg11, resulting in resistance. Although ERG11 mutations have been observed in clinical isolates, the specific contributions of individual ERG11 mutations to azole resistance in C. albicans have not been widely explored. We sequenced ERG11 in 63 fluconazole (FLC)-resistant clinical isolates. Fifty-five isolates carried at least one mutation in ERG11, and we observed 26 distinct positions in which amino acid substitutions occurred. We mapped the 26 distinct variant positions in these alleles to four regions in the predicted structure for Erg11, including its predicted catalytic site, extended fungus-specific external loop, proximal surface, and proximal surface-to-heme region. In total, 31 distinct ERG11 alleles were recovered, with 10 ERG11 alleles containing a single amino acid substitution. We then characterized 19 distinct ERG11 alleles by introducing them into the wild-type azole-susceptible C. albicans SC5314 strain and testing them for susceptibilities to FLC, itraconazole (ITC), and voriconazole (VRC). The strains that were homozygous for the single amino acid substitutions Y132F, K143R, F145L, S405F, D446E, G448E, F449V, G450E, and G464S had a ≥4-fold increase in FLC MIC. The strains that were homozygous for several double amino acid substitutions had decreased azole susceptibilities beyond those conferred by any single amino acid substitution. These findings indicate that mutations in ERG11 are prevalent among azole-resistant clinical isolates and that most mutations result in appreciable changes in FLC and VRC susceptibilities. PMID:25385095

  1. Contribution of clinically derived mutations in ERG11 to azole resistance in Candida albicans.

    PubMed

    Flowers, Stephanie A; Colón, Brendan; Whaley, Sarah G; Schuler, Mary A; Rogers, P David

    2015-01-01

    In Candida albicans, the ERG11 gene encodes lanosterol demethylase, the target of the azole antifungals. Mutations in ERG11 that result in an amino acid substitution alter the abilities of the azoles to bind to and inhibit Erg11, resulting in resistance. Although ERG11 mutations have been observed in clinical isolates, the specific contributions of individual ERG11 mutations to azole resistance in C. albicans have not been widely explored. We sequenced ERG11 in 63 fluconazole (FLC)-resistant clinical isolates. Fifty-five isolates carried at least one mutation in ERG11, and we observed 26 distinct positions in which amino acid substitutions occurred. We mapped the 26 distinct variant positions in these alleles to four regions in the predicted structure for Erg11, including its predicted catalytic site, extended fungus-specific external loop, proximal surface, and proximal surface-to-heme region. In total, 31 distinct ERG11 alleles were recovered, with 10 ERG11 alleles containing a single amino acid substitution. We then characterized 19 distinct ERG11 alleles by introducing them into the wild-type azole-susceptible C. albicans SC5314 strain and testing them for susceptibilities to FLC, itraconazole (ITC), and voriconazole (VRC). The strains that were homozygous for the single amino acid substitutions Y132F, K143R, F145L, S405F, D446E, G448E, F449V, G450E, and G464S had a ≥ 4-fold increase in FLC MIC. The strains that were homozygous for several double amino acid substitutions had decreased azole susceptibilities beyond those conferred by any single amino acid substitution. These findings indicate that mutations in ERG11 are prevalent among azole-resistant clinical isolates and that most mutations result in appreciable changes in FLC and VRC susceptibilities. PMID:25385095

  2. Synthesis and bioevaluation of novel benzodipyranone derivatives as P-glycoprotein inhibitors for multidrug resistance reversal agents.

    PubMed

    Chen, Chien-Yu; Liu, Nai-Yu; Lin, Hui-Chang; Lee, Chih-Yu; Hung, Chin-Chuan; Chang, Chih-Shiang

    2016-08-01

    Multidrug resistance (MDR) is a phenomenon in which cells become resistant to structurally and mechanistically unrelated drugs, and it is one of the emerging problems in cancer therapy today. The relation between overexpression of the ABC transporter subfamily B member 1 (ABCB1/P-glycoprotein) and resistant cancers has been well characterized. In the present study, we successfully synthesized 52 novel benzodipyranone analogs and evaluated for their P-gp inhibitory activity in a P-gp transfected cell line, ABCB1/Flp-In™-293. Among these derivatives, 5a bearing on the 3-methylphenyl substituent, displayed the most potent P-gp inhibitory activity, which can enable the increase of the intracellular accumulation of P-gp substrate Calcein-AM. 5a exhibited more potency on promoted anticancer drugs cytotoxicity by reversing P-gp-mediated drug resistance in both ABCB1/Flp-In™-293 and KBvin cell lines. In particular, the compound 5a sensitized ABCB1/Flp-In™-293 cells toward paclitaxel, vincristine, and doxorubicin by 16.1, 21.0, and 1.6-fold at 10 μM, respectively. Further, 5a dramatically sensitized the resistant cell line KBvin toward paclitaxel and vincristine by 23.1 and 29.7-fold at 10 μM, respectively. It's possible that its mechanism of MDR inhibition can restore the intracellular accumulation of drugs and eventually chemosensitize cancer cells to anticancer drugs and reduce ABCB1 mRNA expression level. PMID:27131064

  3. Tumour resistance in induced pluripotent stem cells derived from naked mole-rats

    PubMed Central

    Miyawaki, Shingo; Kawamura, Yoshimi; Oiwa, Yuki; Shimizu, Atsushi; Hachiya, Tsuyoshi; Bono, Hidemasa; Koya, Ikuko; Okada, Yohei; Kimura, Tokuhiro; Tsuchiya, Yoshihiro; Suzuki, Sadafumi; Onishi, Nobuyuki; Kuzumaki, Naoko; Matsuzaki, Yumi; Narita, Minoru; Ikeda, Eiji; Okanoya, Kazuo; Seino, Ken-ichiro; Saya, Hideyuki; Okano, Hideyuki; Miura, Kyoko

    2016-01-01

    The naked mole-rat (NMR, Heterocephalus glaber), which is the longest-lived rodent species, exhibits extraordinary resistance to cancer. Here we report that NMR somatic cells exhibit a unique tumour-suppressor response to reprogramming induction. In this study, we generate NMR-induced pluripotent stem cells (NMR-iPSCs) and find that NMR-iPSCs do not exhibit teratoma-forming tumorigenicity due to the species-specific activation of tumour-suppressor alternative reading frame (ARF) and a disruption mutation of the oncogene ES cell-expressed Ras (ERAS). The forced expression of Arf in mouse iPSCs markedly reduces tumorigenicity. Furthermore, we identify an NMR-specific tumour-suppression phenotype—ARF suppression-induced senescence (ASIS)—that may protect iPSCs and somatic cells from ARF suppression and, as a consequence, tumorigenicity. Thus, NMR-specific ARF regulation and the disruption of ERAS regulate tumour resistance in NMR-iPSCs. Our findings obtained from studies of NMR-iPSCs provide new insight into the mechanisms of tumorigenicity in iPSCs and cancer resistance in the NMR. PMID:27161380

  4. Adipose- and muscle-derived Wnts trigger pancreatic β-cell adaptation to systemic insulin resistance

    PubMed Central

    Kozinski, Kamil; Jazurek, Magdalena; Dobrzyn, Pawel; Janikiewicz, Justyna; Kolczynska, Katarzyna; Gajda, Anna; Dobrzyn, Agnieszka

    2016-01-01

    Wnt signaling molecules are associated with obesity, hyperlipidemia, and type 2 diabetes (T2D). Here, we show that two Wnt proteins, WNT3a and WNT4, are specifically secreted by skeletal muscle and adipose tissue during the development of insulin resistance and play an important role in cross-talk between insulin-resistant tissues and pancreatic beta cells. The activation of Frizzled receptor and Wnt signaling in pancreatic islets via circulating WNT3a in blood resulted in higher insulin secretion and an increase in beta cell proliferation, thus leading to islet adaptation in a pre-diabetic state. Interestingly, in fully developed T2D, the expression profiles of Wnt3a and Wnt4 in adipose tissue and muscle cells and blood plasma levels of these proteins were opposite to the pre-diabetic state, thus favoring the downregulation of Wnt signaling in beta cells and resulting in dysfunctional pancreatic islets. These results demonstrate that alterations in the secretion profile of a canonical Wnt activator (WNT3a) and inhibitor (WNT4) from insulin-resistant tissues during the development of T2D are responsible for triggering progression from a pre-diabetic to a diabetic state. We also show here that WNT3a and WNT4 are potent myokines, and their expression and secretion are regulated in response to nutritional and metabolic changes. PMID:27527335

  5. Linalool, a plant-derived monoterpene alcohol, reverses doxorubicin resistance in human breast adenocarcinoma cells.

    PubMed

    Ravizza, Raffaella; Gariboldi, Marzia B; Molteni, Roberta; Monti, Elena

    2008-09-01

    Essential oils from various aromatic plants have been reported to exert chemopreventive and/or antitumor effects. In addition, a number of studies have shown the ability of chemopreventive phytochemicals to increase the sensitivity of cancer cells to conventional anticancer drugs. The success of chemotherapeutic agents is often hindered by the development of drug resistance, with multidrug resistant (MDR) phenotypes reported in a number of tumors, generally involving reduced intracellular drug accumulation due to increased drug efflux by membrane transporters. In the present study, the effects of linalool (LIN), a monoterpene alcohol found in the essential oils from many aromatic plants, on the growth of two human breast adenocarcinoma cell lines, MCF7 WT and multidrug resistant MCF7 AdrR, were investigated, both as a single agent and in combination with doxorubicin (DOX). The results reported here show that LIN only moderately inhibits cell proliferation; interestingly, however, subtoxic concentrations of LIN potentiate DOX-induced cytotoxicity and pro-apoptotic effects in both cell lines. A significant synergism can be observed in MCF7 AdrR cells, which may be due, at least in part, to the ability of LIN to increase DOX accumulation and to induce a decrease in Bcl-xL levels. In summary, the results of the present study suggest that LIN may improve the therapeutic index of anthracyclines in the management of breast cancer, especially in MDR tumors. PMID:18695915

  6. Tumour resistance in induced pluripotent stem cells derived from naked mole-rats.

    PubMed

    Miyawaki, Shingo; Kawamura, Yoshimi; Oiwa, Yuki; Shimizu, Atsushi; Hachiya, Tsuyoshi; Bono, Hidemasa; Koya, Ikuko; Okada, Yohei; Kimura, Tokuhiro; Tsuchiya, Yoshihiro; Suzuki, Sadafumi; Onishi, Nobuyuki; Kuzumaki, Naoko; Matsuzaki, Yumi; Narita, Minoru; Ikeda, Eiji; Okanoya, Kazuo; Seino, Ken-Ichiro; Saya, Hideyuki; Okano, Hideyuki; Miura, Kyoko

    2016-01-01

    The naked mole-rat (NMR, Heterocephalus glaber), which is the longest-lived rodent species, exhibits extraordinary resistance to cancer. Here we report that NMR somatic cells exhibit a unique tumour-suppressor response to reprogramming induction. In this study, we generate NMR-induced pluripotent stem cells (NMR-iPSCs) and find that NMR-iPSCs do not exhibit teratoma-forming tumorigenicity due to the species-specific activation of tumour-suppressor alternative reading frame (ARF) and a disruption mutation of the oncogene ES cell-expressed Ras (ERAS). The forced expression of Arf in mouse iPSCs markedly reduces tumorigenicity. Furthermore, we identify an NMR-specific tumour-suppression phenotype-ARF suppression-induced senescence (ASIS)-that may protect iPSCs and somatic cells from ARF suppression and, as a consequence, tumorigenicity. Thus, NMR-specific ARF regulation and the disruption of ERAS regulate tumour resistance in NMR-iPSCs. Our findings obtained from studies of NMR-iPSCs provide new insight into the mechanisms of tumorigenicity in iPSCs and cancer resistance in the NMR. PMID:27161380

  7. Adipose- and muscle-derived Wnts trigger pancreatic β-cell adaptation to systemic insulin resistance.

    PubMed

    Kozinski, Kamil; Jazurek, Magdalena; Dobrzyn, Pawel; Janikiewicz, Justyna; Kolczynska, Katarzyna; Gajda, Anna; Dobrzyn, Agnieszka

    2016-01-01

    Wnt signaling molecules are associated with obesity, hyperlipidemia, and type 2 diabetes (T2D). Here, we show that two Wnt proteins, WNT3a and WNT4, are specifically secreted by skeletal muscle and adipose tissue during the development of insulin resistance and play an important role in cross-talk between insulin-resistant tissues and pancreatic beta cells. The activation of Frizzled receptor and Wnt signaling in pancreatic islets via circulating WNT3a in blood resulted in higher insulin secretion and an increase in beta cell proliferation, thus leading to islet adaptation in a pre-diabetic state. Interestingly, in fully developed T2D, the expression profiles of Wnt3a and Wnt4 in adipose tissue and muscle cells and blood plasma levels of these proteins were opposite to the pre-diabetic state, thus favoring the downregulation of Wnt signaling in beta cells and resulting in dysfunctional pancreatic islets. These results demonstrate that alterations in the secretion profile of a canonical Wnt activator (WNT3a) and inhibitor (WNT4) from insulin-resistant tissues during the development of T2D are responsible for triggering progression from a pre-diabetic to a diabetic state. We also show here that WNT3a and WNT4 are potent myokines, and their expression and secretion are regulated in response to nutritional and metabolic changes. PMID:27527335

  8. Pyrrolopyrimidine Derivatives as Novel Inhibitors of Multidrug Resistance-Associated Protein 1 (MRP1, ABCC1).

    PubMed

    Schmitt, Sven Marcel; Stefan, Katja; Wiese, Michael

    2016-04-14

    Five series of pyrrolo[3,2-d]pyrimidines were synthesized and evaluated with respect to potency and selectivity toward multidrug resistance-associated protein 1 (MRP1, ABCC1). This transport protein is a major target to overcome multidrug resistance in cancer patients. We investigated differently substituted pyrrolopyrimidines using the doxorubicin selected and MRP1 overexpressing small cell lung cancer cell line H69 AR in a calcein AM and daunorubicin cell accumulation assay. New compounds with high potency and selectivity were identified. Piperazine residues at position 4 bearing large phenylalkyl side chains proved to be beneficial for MRP1 inhibition. Its replacement by an amino group led to decreased activity. Aliphatic and aliphatic-aromatic variations at position 5 and 6 revealed compounds with IC50 values in high nanomolar range. All investigated compounds had low affinity toward P-glycoprotein (P-gp, ABCB1). Pyrrolopyrimidines with small substituents showed moderate inhibition against breast cancer resistance protein (BCRP, ABCG2). PMID:26943020

  9. Caco-2 cells cytotoxicity of nifuroxazide derivatives with potential activity against Methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    Fernandes, Mariane B; Gonçalves, José E; Scotti, Marcus T; de Oliveira, Alex A; Tavares, Leoberto C; Storpirtis, Sílvia

    2012-04-01

    It is important to determine the toxicity of compounds and co-solvents that are used in cell monolayer permeability studies to increase confidence in the results obtained from these in vitro experiments. This study was designed to evaluate the cytotoxicity of new nifuroxazide derivatives with potential activity against Methicillin-resistant Staphylococcus aureus (MRSA) in Caco-2 cells to select analogues for further in vitro permeability analyses. In this study, nitrofurantoin and nifuroxazide, in addition to 6 furanic and 6 thiophenic nifuroxazide derivatives were tested at 2, 4, 6, 8 and 10 μg/mL. In vitro cytotoxicity assays were performed according to the MTT (methyl tetrazolium) assay protocol described in ISO 10993-5. The viability of treated Caco-2 cells was greater than 83% for all tested nitrofurantoin concentrations, while those treated with nifuroxazide at 2, 4 and 6 μg/mL had viabilities greater than 70%. Treatment with the nifuroxazide analogues resulted in viability values greater than 70% at 2 and 4 μg/mL with the exception of the thiophenic methyl-substituted derivative, which resulted in cell viabilities below 70% at all tested concentrations. Caco-2 cells demonstrated reasonable viability for all nifuroxazide derivatives, except the thiophenic methyl-substituted compound. The former were selected for further permeability studies using Caco-2 cells. PMID:22285235

  10. Mutagenicity study on pyrazole, seven pyrazole derivatives, and two nitroimidazoles with the L-arabinose resistance test of Salmonella typhimurium

    SciTech Connect

    Alejandre-Duran, E.; Ruiz-Rubio, M.; Claramunt, R.M.; Lopez, C.; Pueyo, C.

    1986-01-01

    The mutagenicity of pyrazole and seven pyrazole derivatives (4-nitropyrazole, 4-bromopyrazole, 1-methyl-4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 1-methyl-4-bromopyrazole, 4,4'-dinitro-1, 1'-methylene-dipyrazole and 4,4'-dibromo-1,1'-methylene-dipyrazole) has been investigated with the L-arabinose forward mutation assay of Salmonella typhimurium. Two nitroimidazoles (1-methyl-5-nitroimidazole and metronidazole) were included as reference drugs. The mutagenicity of each chemical was determined by both preincubation and liquid tests, in the presence or absence of S9 microsomal fraction. The mutagenic responses was expressed as the absolute number of L-arabinose resistant mutants growing in selective plates, supplemented with traces of D-glucose. Strain BA13 with a wild-type lipopolysaccharide barrier was used as a comparison to the deep rough derivative BA9. No mutagenic effect was detected with pyrazole and two of its derivatives, 1-methyl-4-bromopyrazole and 4,4'-dibromo-1,1'-methylene-dipyrazole. The other five pyrazole derivatives were mutagenic to different degrees, although their mutagenic potencies were always considerably lower than those of the two nitroimidazoles. The results suggest that 4-nitropyrazoles, as well as 4,4'-dinitro-1, 1'-methylene-dipyrazoles, should be investigated further as alternatives to, or even substitutes for, the currently used nitroimidazoles.

  11. The camptothecin-resistant topoisomerase I mutant F361S is cross-resistant to antitumor rebeccamycin derivatives. A model for topoisomerase I inhibition by indolocarbazoles.

    PubMed

    Bailly, C; Carrasco, C; Hamy, F; Vezin, H; Prudhomme, M; Saleem, A; Rubin, E

    1999-07-01

    DNA topoisomerase I is a major cellular target for antitumor indolocarbazole derivatives (IND) such as the antibiotic rebeccamycin and the synthetic analogue NB-506 which is undergoing phase I clinical trials. We have investigated the mechanism of topoisomerase I inhibition by a rebeccamycin analogue, R-3, using the wild-type human topoisomerase I and a well-characterized recombinant enzyme, F361S. The catalytic activity of this mutant remains fully intact, but the enzyme is resistant to inhibition by camptothecin (CPT). Here we show that the mutated enzyme is cross-resistant to the rebeccamycin analogue. Despite their profound structural differences, CPT and R-3 interfere similarly with the activity of the wild-type and mutant topoisomerase I enzymes, and the drug-induced cleavable complexes are equally sensitive to the NaCl concentration. CPT and IND likely recognize identical structural elements of the topoisomerase I-DNA covalent complex; however, differences do exist in terms of sequence-specificity of topoisomerase I-mediated DNA cleavage. For the first time, a molecular model showing that CPT and IND share common steric and electronic features is proposed. The model helps to identify a specific pharmacophore for topoisomerase I inhibitors. PMID:10393535

  12. Epoxylathyrol Derivatives: Modulation of ABCB1-Mediated Multidrug Resistance in Human Colon Adenocarcinoma and Mouse T-Lymphoma Cells.

    PubMed

    Matos, Ana M; Reis, Mariana; Duarte, Noélia; Spengler, Gabriella; Molnár, Joseph; Ferreira, Maria-José U

    2015-09-25

    Epoxyboetirane A (1), a macrocyclic diterpene that was found to be inactive as an ABCB1 modulator, was submitted to several chemical transformations, aimed at generating a series of compounds with improved multidrug resistance (MDR)-modifying activity. Overall, 23 new derivatives were prepared, in addition to the already reported epoxylathyrol (2) and methoxyboetirol (3). Their anti-MDR potential was assessed through both functional and chemosensitivity assays on resistant human colon adenocarcinoma and human ABCB1-gene transfected L5178Y mouse lymphoma cells. Structure-activity relationship analysis showed that different substitution patterns led to distinct ABCB1 inhibitory activities, although intrinsic cellular characteristics seemed to influence the modulatory behavior. A considerable enhancement in MDR-modifying activity was observed for aromatic compounds in both cell lines, particularly in 3,17-disubstituted esters derived from 3, a Payne-rearranged Michael adduct of 2. All compounds tested were revealed to interact synergistically with doxorubicin, and ATPase inhibition by three representative MDR-modifying compounds was also investigated. On account of its outstanding ABCB1 inhibitory activity at 0.2 μM and overall remarkable bioactive profile, methoxyboetirane B (22) was found to be a new promising lead for MDR-reversing anticancer drug development. PMID:26331763

  13. Nitric oxide releasing acridone carboxamide derivatives as reverters of doxorubicin resistance in MCF7/Dx cancer cells.

    PubMed

    Rajendra Prasad, V V S; Deepak Reddy, G; Kathmann, Ietje; Amareswararao, M; Peters, G J

    2016-02-01

    A series of nitric oxide donating acridone derivatives are synthesized and evaluated for in vitro cytotoxic activity against different sensitive and resistant cancer cell lines MCF7/Wt, MCF7/Mr (BCRP overexpression) and MCF7/Dx (P-gp expression). The results showed that NO-donating acridones are potent against both the sensitive and resistant cells. Structure activity relationship indicate that the nitric oxide donating moiety connected through a butyl chain at N(10) position as well as morpholino moiety linkage through an amide bridge on the acridone ring system at C-2 position, are required to exert a good cytotoxic effect. Further, good correlations were observed when cytotoxic properties were compared with in vitro nitric oxide release rate, nitric oxide donating group potentiated the cytotoxic effect of the acridone derivatives. Exogenous release of nitric oxide by NO donating acridones enhanced the accumulation of doxorubicin in MCF7/Dx cell lines when it was coadministered with doxorubicin, which inhibited the efflux process of doxorubicin. In summary, a nitric oxide donating group can potentiate the anti-MDR property of acridones. PMID:26657603

  14. Cancer-initiating cells derived from human rectal adenocarcinoma tissues carry mesenchymal phenotypes and resist drug therapies.

    PubMed

    Fan, C-W; Chen, T; Shang, Y-N; Gu, Y-Z; Zhang, S-L; Lu, R; OuYang, S-R; Zhou, X; Li, Y; Meng, W-T; Hu, J-K; Lu, Y; Sun, X-F; Bu, H; Zhou, Z-G; Mo, X-M

    2013-01-01

    Accumulating evidence indicates that cancer-initiating cells (CICs) are responsible for cancer initiation, relapse, and metastasis. Colorectal carcinoma (CRC) is typically classified into proximal colon, distal colon, and rectal cancer. The gradual changes in CRC molecular features within the bowel may have considerable implications in colon and rectal CICs. Unfortunately, limited information is available on CICs derived from rectal cancer, although colon CICs have been described. Here we identified rectal CICs (R-CICs) that possess differentiation potential in tumors derived from patients with rectal adenocarcinoma. The R-CICs carried both CD44 and CD54 surface markers, while R-CICs and their immediate progenies carried potential epithelial-mesenchymal transition characteristics. These R-CICs generated tumors similar to their tumor of origin when injected into immunodeficient mice, differentiated into rectal epithelial cells in vitro, and were capable of self-renewal both in vitro and in vivo. More importantly, subpopulations of R-CICs resisted both 5-fluorouracil/calcium folinate/oxaliplatin (FolFox) and cetuximab treatment, which are the most common therapeutic regimens used for patients with advanced or metastatic rectal cancer. Thus, the identification, expansion, and properties of R-CICs provide an ideal cellular model to further investigate tumor progression and determine therapeutic resistance in these patients. PMID:24091671

  15. Enhancement of oxidation resistance of graphite foams by polymer derived-silicon carbide coating for concentrated solar power applications

    DOE PAGESBeta

    Kim, T.; Singh, D.; Singh, M.

    2015-05-01

    Graphite foam with extremely high thermal conductivity has been investigated to enhance heat transfer of latent heat thermal energy storage (LHTES) systems. However, the use of graphite foam for elevated temperature applications (>600 °C) is limited due to poor oxidation resistance of graphite. In the present study, oxidation resistance of graphite foam coated with silicon carbide (SiC) was investigated. A pre-ceramic polymer derived coating (PDC) method was used to form a SiC coating on the graphite foams. Post coating deposition, the samples were analyzed by scanning electron microscopy and energy dispersive spectroscopy. The oxidation resistance of PDC-SiC coating was quantifiedmore » by measuring the weight of the samples at several measuring points. The experiments were conducted under static argon atmosphere in a furnace. After the experiments, oxidation rates (%/hour) were calculated to predict the lifetime of the graphite foams. The experimental results showed that the PDC-SiC coating could prevent the oxidation of graphite foam under static argon atmosphere up to 900 °C.« less

  16. Enhancement of oxidation resistance of graphite foams by polymer derived-silicon carbide coating for concentrated solar power applications

    SciTech Connect

    Kim, T.; Singh, D.; Singh, M.

    2015-05-01

    Graphite foam with extremely high thermal conductivity has been investigated to enhance heat transfer of latent heat thermal energy storage (LHTES) systems. However, the use of graphite foam for elevated temperature applications (>600 °C) is limited due to poor oxidation resistance of graphite. In the present study, oxidation resistance of graphite foam coated with silicon carbide (SiC) was investigated. A pre-ceramic polymer derived coating (PDC) method was used to form a SiC coating on the graphite foams. Post coating deposition, the samples were analyzed by scanning electron microscopy and energy dispersive spectroscopy. The oxidation resistance of PDC-SiC coating was quantified by measuring the weight of the samples at several measuring points. The experiments were conducted under static argon atmosphere in a furnace. After the experiments, oxidation rates (%/hour) were calculated to predict the lifetime of the graphite foams. The experimental results showed that the PDC-SiC coating could prevent the oxidation of graphite foam under static argon atmosphere up to 900 °C.

  17. Partial synthesis and biological evaluation of bisbenzylisoquinoline alkaloids derivatives: potential modulators of multidrug resistance in cancer.

    PubMed

    He, Ping; Sun, Hua; Jian, Xi-Xian; Chen, Qiao-Hong; Chen, Dong-Lin; Liu, Geng-Tao; Wang, Feng-Peng

    2012-01-01

    A series of new bisbenzylisoquinoline alkaloids was partially synthesized from tetrandrine and fangchinoline and evaluated for their ability to reverse P-glycoprotein-mediated multidrug resistance (MDR) in cancer cells. All the test compounds increased the intracellular accumulation rate of rhodamine 123 in MDR cells (Bel7402 and HCT8), and most exhibited more potent MDR-reversing activity relative to the reference compound verapamil. Compounds 8, 10, 13, and 14 enhanced intracellular accumulation of doxorubicin in Bel7402 and HCT8 cells. PMID:22587798

  18. Streptococcal R plasmid pIP501: endonuclease site map, resistance determinant location, and construction of novel derivatives.

    PubMed Central

    Evans, R P; Macrina, F L

    1983-01-01

    The streptococcal resistance plasmid pIP501 (30 kilobase pairs [kb]) encodes resistance to chloramphenicol (Cmr) and erythromycin (Emr) and is capable of conjugative transfer among numerous streptococcal species. By using a streptococcal host-vector recombinant DNA system, the Cmr and Emr determinants of pIP501 were localized to 6.3-kb HindIII and 2.1-kb HindIII-AvaI fragments, respectively. pIP501 was lost at a frequency of 22% in Streptococcus sanguis cells grown at 42 degrees C but was stable in cells grown at 37 degrees C (less than 1% frequency of loss). Sequences from a cryptic multicopy plasmid, pVA380-1, were substituted for the pIP501 Emr determinant in vitro, and the resulting recombinant plasmid, designated pVA797, was recovered in transformed S. sanguis cells. The replication of pVA797 was governed by the pVA380-1 sequences based on temperature-stable replication and incompatibility with pVA380-1-derived replicons. The self-ligation of partially cleaved HindIII pIP501 DNA fragments allowed the localization of a pIP501 region involved in autonomous plasmid replication. A small pIP501 derivative (pVA798) obtained from this experiment had a greatly increased copy number but was unstably inherited. Our data indicate that the sequences encoding the resistance determinants and some of the plasmid replication machinery are relatively clustered on the pIP501 molecule. The properties of pVA797 and pVA798 indicate that these molecules will enhance current streptococcal genetic systems from the standpoint of conjugative mobilization (pVA797) and gene amplification (pVA798). PMID:6304011

  19. Discovery of Novel N-alkyl 4-anilinofuro[2,3-b]quinoline Derivatives (CIL-102 Derivatives) Against Castration-resistant Human Prostate Cancers.

    PubMed

    Lo, We-Fen; Chou, Yu-Wei; Tseng, Chih-Hua; Shiu, Yia-Huei; Chen, Yu-Wen; Yang, Shyh-Chyun; Chen, Yeh-Long; Lin, Ming-Fong; Tzeng, Cherng-Chyi

    2015-01-01

    A number of N-alkylated 4-anilinofuro[2,3-b]quinoline derivatives were synthesized and evaluated in vitro against PC-3, A549, and MCF-7 cancer cells and M-10 normal human mammary epithelial cells. The known antimitotic CIL-102 was moderately active against the growth of PC-3 prostate cancer cells with an IC50 value of 2.69 μM while it was more potent against the growth of A549, MCF-7 and M-10 cells with IC50 values of 0.61, 0.31 and 0.95 μM, respectively. However, the cytotoxic profiles of its N-alkylated derivatives, 6a - 6c, were reversed and strongly inhibited PC-3 cell growth with IC50 values of less than 1.0 μM but only weakly against the growth of A549, MCF-7 and M-10 cells. These results indicated that N-alkylation of CIL-102 increased not only selectivity but also the antiproliferative potency against PC-3 cell growth. Among these derivatives synthesized, N-(4-acetylphenyl)-N-(furo[2,3-b]quinolin- 4-yl)methylamine (6a) and its N-ethyl counterpart 6b are the two most active CIL-102 derivatives against PC-3 cell growth with IC50 value of 0.22 and 0.20 μM, respectively. Compound 6a is less cytotoxic to normal human M-10 cells than 6b and therefore was selected for further mechanism studies. The flow cytometry studies clearly indicated that compound 6a induced cell accumulation in G2/M phase in a dose-dependent manner after 24 h-treatment. While the proliferation of LNCaP C-81 prostate cancer cells was also strongly suppressed by compound 6a; compound 11a exhibited better selective activity toward LNCaP C-81 prostate cancer cells over RWPE-1 non-cancerous prostate epithelia. Thus, this group of compounds has a potential of serving as therapeutic agents toward advanced castration-resistant prostate cancers. PMID:25612680

  20. AB007. Neurotensin derived from cancer stroma contributes to castration resistance via promoting neuroendocrine transdifferentiation

    PubMed Central

    Zhu, Shimiao; Shang, Zhiqun; Tian, Hao; Flores-Morales, Amilcar; Niu, Yuanjie

    2016-01-01

    The mechanism of neuroendocrine transdifferentiation (NED) during the development of castration-resistant prostate cancer (CRPC) remains undefined. Although androgen-deprivation therapy (ADT) can impair tumor cell growth, ADT can also triggers a parallel reaction, leading to increased neurotensin (NTS) production in cancer associated stromal cells which drives NED. Here, we systematically explore the NTS network in tumor microenvironment that drives NED following ADT. The CK8+/CK14+ intermediate cells, as opposed to other epithelial cells, can be transdifferentiated to neuroendocrine (NE) status by excessive NTS through simultaneous activation of neurotensin receptor 1 (NTSR1)-PRKACB and 3 (NTSR3)-AHNAK axes. The importance of PRKACB and AHNAK in NED development was then confirmed in human prostate tumor tissues. More importantly, we demonstrated SR48692 (an inhibitor of NTSR1) could inhibit NED and prevent castration resistance in prostate tumor from xenografts and TRAMP models. We propose that targeting this pathway could provide benefit for patients with tumors expressing high levels of NTS following ADT.

  1. Water-resistive humidity sensor prepared by printing process using polyelectrolyte ink derived from new monomer.

    PubMed

    Kim, Min-Ji; Gong, Myoung-Seon

    2012-03-21

    A simple strategy was developed based on a new monomer containing both photocurable function and ammonium salt, N-(2-cinnamoyloxy)ethyl-N-(2-(methacryloyloxy)ethyl)-N,N-dimethyl ammonium bromide (CMDAB) to obtain photocurable polyelectrolyte ink and stable humidity-sensitive membranes by printing process. Humidity-sensitive membranes are photocrosslinked polyelectrolytes obtained from copolymers of [2-(methacryloyloxy)ethyl] dimethyl propyl ammonium bromide (MEPAB), CMDAB and MMA. A flexible gold electrode/polyimide was pretreated with 2-(mercaptoethyl) cinnamamide (MEC) containing a thiol-coupling agent for the purpose of anchoring the humidity-sensitive polyelectrolyte to the gold electrode. The sensors using screen printing methods reduced the deflection of sensor characteristics showing humidity precision ±1%RH. The photocured copolymer MEPAB/CMDAB/MMA = 63/7/30 show good sensitivity (0.0586 logΩ/%RH) changing resistance approximately four orders of magnitude with relative humidity varying from 20% to 95% and fast response and recovery time. The resultant sensors showed acceptable linearity (Y = -0.04X + 7.0, R(2) = -0.9900) and small hysteresis. The reliability including water resistance and a long-term stability were estimated for the application of the flexible humidity sensor prepared by screen printing process. PMID:22314679

  2. Osteoblast-derived sphingosine 1-phosphate to induce proliferation and confer resistance to therapeutics to bone metastasis-derived prostate cancer cells.

    PubMed

    Brizuela, Leyre; Martin, Claire; Jeannot, Pauline; Ader, Isabelle; Gstalder, Cécile; Andrieu, Guillaume; Bocquet, Magalie; Laffosse, Jean-Michel; Gomez-Brouchet, Anne; Malavaud, Bernard; Sabbadini, Roger A; Cuvillier, Olivier

    2014-10-01

    Sphingosine 1-phosphate (S1P) plays important roles in cell proliferation, differentiation or survival mainly through its surface G-protein-coupled receptors S1P1-5. Bone represents the major site of metastasis for prostate cancer (CaP) cells, which rely on bone-derived factors to support their proliferation and resistance to therapeutics. In the present work we have found that conditioned medium (CM) from the MC3T3 osteoblastic cell line or primary murine and human osteoblast-like cells, as well as co-culture with MC3T3 stimulate proliferation of CaP lines in S1P-dependent manner. In addition, osteoblastic-derived S1P induces resistance of CaP cells to therapeutics including chemotherapy and radiotherapy. When S1P release from osteoblastic cells is decreased (inhibition of SphK1, knock-down of SphK1 or the S1P transporter, Spns2 by siRNA) or secreted S1P neutralized with anti-S1P antibody, the proliferative and survival effects of osteoblasts on CaP cells are abolished. Because of the paracrine nature of the signaling, we studied the role of the S1P receptors expressed on CaP cells in the communication with S1P secreted by osteoblasts. Strategies aimed at down-regulating S1P1, S1P2 or S1P3 (siRNA, antagonists), established the exclusive role of the S1P/S1P1 signaling between osteoblasts and CaP cells. Bone metastases from CaP are associated with osteoblastic differentiation resulting in abnormal bone formation. We show that the autocrine S1P/S1P3 signaling is central during differentiation to mature osteoblasts by regulating Runx2 level, a key transcription factor involved in osteoblastic maturation. Importantly, differentiated osteoblasts exhibited enhanced secretion of S1P and further stimulated CaP cell proliferation in a S1P-dependent manner. By establishing the dual role of osteoblast-borne S1P on both osteoblastic differentiation and CaP cell proliferation and survival, we uncover the importance of S1P in the bone metastatic microenvironment, which may open

  3. Promising Effects of Afatinib on Leptomeningeal Carcinomatosis Derived from Erlotinib-resistant Lung Adenocarcinoma.

    PubMed

    Sekine, Akimasa; Kato, Terufumi; Iwasawa, Tae; Baba, Tomohisa; Suido, Akihiro; Sakuranaka, Haruyasu; Futaki, Masaaki; Ogura, Takashi

    2016-01-01

    We herein report a case of a 67-year-old woman previously treated with erlotinib for adenocarcinoma with an epidermal growth factor receptor (EGFR) mutation in exon 19, which rapidly developed to progressive symptomatic leptomeningeal carcinomatosis. The primary tumor and lung metastases also worsened and the performance status (PS) score declined to 3. With a re-biopsy from the pulmonary metastases, the T790M mutation was detected by the cobas EGFR mutation test, but not the cycleave test, although an exon 19 deletion was detected by both of the tests. A week after afatinib initiation, the neurological symptoms disappeared and the PS improved to 1 with a radiological response in all disease sites. Chest physicians should consider the use of afatinib for patients with leptomeningeal carcinomatosis from 1st-generation EGFR-TKI resistant adenocarcinoma, regardless of the PS score and the presence of the T790M mutation in the extracranial lesion. PMID:27580550

  4. Novel Phenol-soluble Modulin Derivatives in Community-associated Methicillin-resistant Staphylococcus aureus Identified through Imaging Mass Spectrometry*

    PubMed Central

    Gonzalez, David J.; Okumura, Cheryl Y.; Hollands, Andrew; Kersten, Roland; Akong-Moore, Kathryn; Pence, Morgan A.; Malone, Cheryl L.; Derieux, Jaclyn; Moore, Bradley S.; Horswill, Alexander R.; Dixon, Jack E.; Dorrestein, Pieter C.; Nizet, Victor

    2012-01-01

    Staphylococcus aureus causes a wide range of human disease ranging from localized skin and soft tissue infections to potentially lethal systemic infections. S. aureus has the biosynthetic ability to generate numerous virulence factors that assist in circumventing the innate immune system during disease pathogenesis. Recent studies have uncovered a set of extracellular peptides produced by community-associated methicillin-resistant S. aureus (CA-MRSA) with homology to the phenol-soluble modulins (PSMs) from Staphylococcus epidermidis. CA-MRSA PSMs contribute to skin infection and recruit and lyse neutrophils, and truncated versions of these peptides possess antimicrobial activity. In this study, novel CA-MRSA PSM derivatives were discovered by the use of microbial imaging mass spectrometry. The novel PSM derivatives are compared with their parent full-length peptides for changes in hemolytic, cytolytic, and neutrophil-stimulating activity. A potential contribution of the major S. aureus secreted protease aureolysin in processing PSMs is demonstrated. Finally, we show that PSM processing occurs in multiple CA-MRSA strains by structural confirmation of additional novel derivatives. This work demonstrates that IMS can serve as a useful tool to go beyond genome predictions and expand our understanding of the important family of small peptide virulence factors. PMID:22371493

  5. Temporal Changes in Skeletal Muscle Capillary Responses and Endothelial-Derived Vasodilators in Obesity-Related Insulin Resistance.

    PubMed

    Chadderdon, Scott M; Belcik, J Todd; Bader, Lindsay; Peters, Dawn M; Kievit, Paul; Alkayed, Nabil J; Kaul, Sanjiv; Grove, Kevin L; Lindner, Jonathan R

    2016-08-01

    The inability of insulin to increase skeletal muscle capillary blood volume (CBV) reduces glucose uptake in insulin resistance (IR). We hypothesized that abnormalities in endothelial-derived vasodilator pathways are temporally associated with the development of IR and an impaired ability to increase skeletal muscle CBV. A comprehensive metabolic and vascular screening assessment was performed on 10 adult rhesus macaques at baseline and every 4-6 months for 2 years after starting a high-fat diet supplemented with fructose. Diet changes resulted in an 80% increase in truncal fat by 4 months. Hyperinsulinemia and decreased glucose utilization were observed from 4 to 18 months. At 24 months, pancreatic secretory function and the glucose utilization rate declined. CBV at rest and during an intravenous glucose tolerance test demonstrated a sustained increase from 4 to 18 months and then abruptly fell at 24 months. Nitric oxide bioavailability progressively decreased over 2 years. Conversely, endothelial-derived vasodilators progressively increased over 18 months and then abruptly decreased at 24 months in concert with the CBV. The increase in basal and glucose-mediated CBV early in IR may represent a compensatory response through endothelial-derived vasodilator pathways. The inability to sustain a vascular compensatory response limits glucose-mediated increases in CBV, which correlates with the severity of IR. PMID:27207517

  6. Propionic acid and its esterified derivative suppress the growth of methicillin-resistant Staphylococcus aureus USA300.

    PubMed

    Wang, Y; Dai, A; Huang, S; Kuo, S; Shu, M; Tapia, C P; Yu, J; Two, A; Zhang, H; Gallo, R L; Huang, C-M

    2014-06-01

    Previously, we demonstrated that Propionibacterium acnes, a human skin commensal bacterium, ferments glycerol into short-chain fatty acids, including propionic acid. Propionic acid suppressed the growth of Staphylococcus aureus USA300, a community-acquired methicillin-resistant bacterium, in vitro and in vivo. In this study, it is demonstrated that the anti-USA300 activity of propionic acid persisted after buffering the acid with 4-(2-hydroxyethyl)-1- piperazineethanesulfonic acid. This suggests that the growth suppression of USA300 mainly resulted from the antimicrobial activity of propionic acid per se and not from the acidity of the medium. In addition, proprionic acid significantly reduced the intracellular pH of USA300 and exhibited broad-spectrum antimicrobial activity against Escherichia coli and Candida albicans. P. acnes showed a higher tolerance to propionic acid. Next, an esterified derivative of propionic acid was synthesised. Propionic acid and the esterified derivative were equivalent in their efficacy to suppress the growth of USA300 in vitro. The esterified derivative thus provides an alternative to propionic acid as an antimicrobial agent against S. aureus. PMID:24686580

  7. Caco-2 cells permeability evaluation of nifuroxazide derivatives with potential activity against methicillin-resistant Staphylococcus aureus (MRSA).

    PubMed

    B Fernandes, Mariane; Gonçalves, José E; C Tavares, Leoberto; Storpirtis, Sílvia

    2015-01-01

    Throughout the period of evaluation and selection in drug development, the assessment of the permeability potential of a compound to achieve an efficient refinement of the molecular structure has been widely appraised by the transport of substances across cell monolayers. This study aims to develop in vitro assays through Caco-2 cells in order to analyze the permeability of 5-nitro-heterocyclic compounds analogues to nifuroxazide with antimicrobial activity, especially showing promising activity against multidrug-resistant Staphylococcus aureus (MRSA). Caco-2 cell monolayers cultivated for 21 days in Transwell® plates were used for the in vitro permeability assays. The quantification of the nifuroxazide derivatives in the basolateral chambers was performed by a validated high performance liquid chromatography with UV (HPLC-UV) method. Apparent permeability values (Papp) show that these compounds can be considered as new drug candidates with the potential to present high absorption in vivo, according to the classifications of Yee and Biganzoli. The thiophenic derivatives showed permeability values higher than the furanic ones, being AminoTIO the compound with the greatest potential for the development of a new drug against MRSA, since it showed the best cytotoxicity, permeability and solubility ratio among all the derivatives. PMID:24918173

  8. In vivo selection of human embryonic stem cell-derived cells expressing methotrexate-resistant dihydrofolate reductase

    PubMed Central

    Gori, Jennifer L.; Tian, Xinghui; Swanson, Debra; Gunther, Roland; Shultz, Leonard D.; McIvor, R. Scott; Kaufman, Dan S.

    2009-01-01

    SUMMARY Human embryonic stem cells (hESCs) provide a novel source of hematopoietic and other cell populations suitable for gene therapy applications. Preclinical studies to evaluate engraftment of hESC-derived hematopoietic cells transplanted into immunodeficient mice demonstrate only limited repopulation. Expression of a drug resistance gene, such as Tyr22-dihydrofolate reductase (Tyr22-DHFR), coupled to methotrexate (MTX) chemotherapy has the potential to selectively increase engraftment of gene-modified hESC-derived cells in mouse xenografts. Here, we describe the generation of Tyr22-DHFR – GFP expressing hESCs that maintain pluripotency, produce teratomas and can differentiate into MTXr-hemato-endothelial cells. We demonstrate that MTX administered to nonobese diabetic/severe combined immunodeficient/IL-2Rγcnull (NSG) mice after injection of Tyr22-DHFR-derived cells significantly increases human CD34+ and CD45+ cell engraftment in the bone marrow (BM) and peripheral blood of transplanted MTX-treated mice. These results demonstrate that MTX treatment supports selective, long-term engraftment of Tyr22-DHFR-cells in vivo, and provides a novel approach for combined human cell and gene therapy. PMID:19829316

  9. Development of a Laboratory Experiment to Derivate the Thermal Conductivity based on Electrical Resistivity Measurments

    NASA Astrophysics Data System (ADS)

    Vienken, T.; Firmbach, L.; Dietrich, P.

    2014-12-01

    In the course of the energy transition, the number of shallow geothermal systems is constantly growing. These systems allow the exploitation of renewable energy from the subsurface, reduced CO2 emission and additionally, energy storage. An efficient performance of geothermal systems strongly depends upon the availability of exploration data (e.g. thermal conductivity distribution). However, due to high exploration costs, the dimensioning of smaller plants (< 30 kW) is generally based on literature values. While standard in-situ-tests are persistent for larger scale projects, they yield only integral values, e.g. entire length of a borehole heat exchanger. Hence, exploring the distribution of the thermal conductivity as important soil parameter requires the development of new cost-efficient technologies. The general relationship between the electrical (RE) and the thermal resistivity (RT) can be described as log(RE) = CR log(RT) with CRas a multiplier depending on additional soil parameter (e.g. water content, density, porosity, grain size and distribution). Knowing the influencing factor of these additional determining parameters, geoelectrical measurements could provide a cost-efficient exploration strategy of the thermal conductivity for shallow geothermal sites. The aim of this study now is to define the multiplier CRexperimentally to conclude the exact correlation of the thermal and electrical behavior. The set-up consists of an acrylic glass tube with two current electrodes installed at the upper and lower end of the tube. Four electrode chains (each with eight electrodes) measure the potential differences in respect to an induced heat flux initiated by a heat plate. Additional, eight temperature sensors measure the changes of the temperature differences. First, we use this set-up to analyze the influence of soil properties based on differing homogenous sediments with known chemical and petro-physical properties. Further, we analyze the influence of the water

  10. Melittin, a honeybee venom‑derived antimicrobial peptide, may target methicillin‑resistant Staphylococcus aureus.

    PubMed

    Choi, Ji Hae; Jang, A Yeung; Lin, Shunmei; Lim, Sangyong; Kim, Dongho; Park, Kyungho; Han, Sang-Mi; Yeo, Joo-Hong; Seo, Ho Seong

    2015-11-01

    Methicillin‑resistant Staphylococcus aureus (MRSA) is difficult to treat using available antibiotic agents. Honeybee venom has been widely used as an oriental treatment for several inflammatory diseases and bacterial infections. The venom contains predominantly biologically active compounds, however, the therapeutic effects of such materials when used to treat MRSA infections have not been investigated extensively. The present study evaluated bee venom and its principal active component, melittin, in terms of their antibacterial activities and in vivo protection against MRSA infections. In vitro, bee venom and melittin exhibited comparable levels of antibacterial activity, which was more marked against MRSA strains, compared with other Gram‑positive bacteria. When MRSA‑infected mice were treated with bee venom or melittin, only the latter animals were successfully rescued from MRSA‑ induced bacteraemia or exhibited recovery from MRSA‑infected skin wounds. Together, the data of the present study demonstrated for the first time, to the best of our knowledge, that melittin may be used as a promising antimicrobial agent to enhance the healing of MRSA‑induced wounds. PMID:26330195

  11. Melittin, a honeybee venom-derived antimicrobial peptide, may target methicillin-resistant Staphylococcus aureus

    PubMed Central

    CHOI, JI HAE; JANG, A YEUNG; LIN, SHUNMEI; LIM, SANGYONG; KIM, DONGHO; PARK, KYUNGHO; HAN, SANG-MI; YEO, JOO-HONG; SEO, HO SEONG

    2015-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is difficult to treat using available antibiotic agents. Honeybee venom has been widely used as an oriental treatment for several inflammatory diseases and bacterial infections. The venom contains predominantly biologically active compounds, however, the therapeutic effects of such materials when used to treat MRSA infections have not been investigated extensively. The present study evaluated bee venom and its principal active component, melittin, in terms of their antibacterial activities and in vivo protection against MRSA infections. In vitro, bee venom and melittin exhibited comparable levels of antibacterial activity, which was more marked against MRSA strains, compared with other Gram-positive bacteria. When MRSA-infected mice were treated with bee venom or melittin, only the latter animals were successfully rescued from MRSA- induced bacteraemia or exhibited recovery from MRSA-infected skin wounds. Together, the data of the present study demonstrated for the first time, to the best of our knowledge, that melittin may be used as a promising antimicrobial agent to enhance the healing of MRSA-induced wounds. PMID:26330195

  12. Eradication of metastatic mouse cancers resistant to immune checkpoint blockade by suppression of myeloid-derived cells

    PubMed Central

    Kim, KiBem; Skora, Andrew D.; Li, Zhaobo; Liu, Qiang; Tam, Ada J.; Blosser, Richard L.; Diaz, Luis A.; Papadopoulos, Nickolas; Kinzler, Kenneth W.; Vogelstein, Bert; Zhou, Shibin

    2014-01-01

    Impressive responses have been observed in patients treated with checkpoint inhibitory anti–programmed cell death-1 (PD-1) or anti–cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) antibodies. However, immunotherapy against poorly immunogenic cancers remains a challenge. Here we report that treatment with both anti–PD-1 and anti–CTLA-4 antibodies was unable to eradicate large, modestly immunogenic CT26 tumors or metastatic 4T1 tumors. Cotreatment with epigenetic-modulating drugs and checkpoint inhibitors markedly improved treatment outcomes, curing more than 80% of the tumor-bearing mice. Functional studies revealed that the primary targets of the epigenetic modulators were myeloid-derived suppressor cells (MDSCs). A PI3K inhibitor that reduced circulating MDSCs also eradicated 4T1 tumors in 80% of the mice when combined with immune checkpoint inhibitors. Thus, cancers resistant to immune checkpoint blockade can be cured by eliminating MDSCs. PMID:25071169

  13. Novel benzofuroxan derivatives against multidrug-resistant Staphylococcus aureus strains: design using Topliss' decision tree, synthesis and biological assay.

    PubMed

    Jorge, Salomão Dória; Palace-Berl, Fanny; Masunari, Andrea; Cechinel, Cléber André; Ishii, Marina; Pasqualoto, Kerly Fernanda Mesquita; Tavares, Leoberto Costa

    2011-08-15

    The aim of this study was the design of a set of benzofuroxan derivatives as antimicrobial agents exploring the physicochemical properties of the related substituents. Topliss' decision tree approach was applied to select the substituent groups. Hierarchical cluster analysis was also performed to emphasize natural clusters and patterns. The compounds were obtained using two synthetic approaches for reducing the synthetic steps as well as improving the yield. The minimal inhibitory concentration method was employed to evaluate the activity against multidrug-resistant Staphylococcus aureus strains. The most active compound was 4-nitro-3-(trifluoromethyl)[N'-(benzofuroxan-5-yl)methylene]benzhydrazide (MIC range 12.7-11.4 μg/mL), pointing out that the antimicrobial activity was indeed influenced by the hydrophobic and electron-withdrawing property of the substituent groups 3-CF(3) and 4-NO(2), respectively. PMID:21757359

  14. Nuclease-resistant c-di-AMP derivatives that differentially recognize RNA and protein receptors

    PubMed Central

    Meehan, Robert E.; Torgerson, Chad D.; Gaffney, Barbara L.; Jones, Roger A.; Strobel, Scott A.

    2016-01-01

    The ability of bacteria to sense environmental cues and adapt is essential for their survival. The use of second-messenger signaling molecules to translate these cues into a physiological response is a common mechanism employed by bacteria. The second messenger 3’-5’-cyclic diadenosine monophosphate (c-di-AMP) has been linked to a diverse set of biological processes involved in maintaining cell viability and homeostasis, as well as pathogenicity. A complex network of both protein and RNA receptors inside the cell activate specific pathways and mediate phenotypic outputs in response to c-di-AMP. Structural analysis of these RNA and protein receptors has revealed the different recognition elements employed by these effectors to bind the same small molecule. Herein, using a series of c-di-AMP analogs, we probed the interactions made with a riboswitch and a phosphodiesterase protein to identify the features important for c-di-AMP binding and recognition. We found that the ydaO riboswitch binds c-di-AMP in two discrete sites with near identical affinity and a Hill coefficient of 1.6. The ydaO riboswitch distinguishes between c-di-AMP and structurally related second messengers by discriminating against an amine at the C2 position, more than a carbonyl at the C6 position. We also identified phosphate-modified analogs that bind both the ydaO RNA and GdpP protein with high affinity, while symmetrically-modified ribose analogs exhibited a substantial decrease in ydaO affinity, but retained high affinity for GdpP. These ligand modifications resulted in increased resistance to enzyme-catalyzed hydrolysis by the GdpP enzyme. Together, these data suggest that these c-di-AMP analogs could be useful as chemical tools to specifically target subsections of the second-messenger signaling pathways. PMID:26789423

  15. Nuclease-Resistant c-di-AMP Derivatives That Differentially Recognize RNA and Protein Receptors.

    PubMed

    Meehan, Robert E; Torgerson, Chad D; Gaffney, Barbara L; Jones, Roger A; Strobel, Scott A

    2016-02-16

    The ability of bacteria to sense environmental cues and adapt is essential for their survival. The use of second-messenger signaling molecules to translate these cues into a physiological response is a common mechanism employed by bacteria. The second messenger 3'-5'-cyclic diadenosine monophosphate (c-di-AMP) has been linked to a diverse set of biological processes involved in maintaining cell viability and homeostasis, as well as pathogenicity. A complex network of both protein and RNA receptors inside the cell activates specific pathways and mediates phenotypic outputs in response to c-di-AMP. Structural analysis of these RNA and protein receptors has revealed the different recognition elements employed by these effectors to bind the same small molecule. Herein, using a series of c-di-AMP analogues, we probed the interactions made with a riboswitch and a phosphodiesterase protein to identify the features important for c-di-AMP binding and recognition. We found that the ydaO riboswitch binds c-di-AMP in two discrete sites with near identical affinity and a Hill coefficient of 1.6. The ydaO riboswitch distinguishes between c-di-AMP and structurally related second messengers by discriminating against an amine at the C2 position more than a carbonyl at the C6 position. We also identified phosphate-modified analogues that bind both the ydaO RNA and GdpP protein with high affinity, whereas symmetrically modified ribose analogues exhibited a substantial decrease in ydaO affinity but retained high affinity for GdpP. These ligand modifications resulted in increased resistance to enzyme-catalyzed hydrolysis by the GdpP enzyme. Together, these data suggest that these c-di-AMP analogues could be useful as chemical tools to specifically target subsections of second-messenger signaling pathways. PMID:26789423

  16. Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii.

    PubMed

    Nakano, Hiroki; Mizuno, Nobuyuki; Tosa, Yukio; Yoshida, Kentaro; Park, Pyoyun; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions. PMID:25806790

  17. In vitro and in vivo multidrug resistance reversal activity by a Betti-base derivative of tylosin

    PubMed Central

    Gyémánt, N; Engi, H; Schelz, Z; Szatmári, I; Tóth, D; Fülöp, F; Molnár, J; de Witte, P A M

    2010-01-01

    Background: The multidrug resistance (MDR) proteins are present in a majority of human tumours. Their activity is important to understand the chemotherapeutic failure. A search for MDR-reversing compounds was conducted among various Betti-base derivatives of tylosin. Methods: Here, we evaluate the in vitro and in vivo P-glycoprotein (P-gp)-modulating activity of the most promising compound N-tylosil-1-α-amino-(3-bromophenyl)-methyl-2-naphthol (TBN) using human MDR1 gene-transfected and parental L5178 mouse lymphoma cell lines. Results: In vitro experiments showed that TBN dramatically increased the P-gp-mediated cellular uptake of the fluorescent substrate rhodamine 123. Similarly, TBN was found to act as a very potent enhancer of the cytotoxicity of doxorubicin on the resistant cell line. We also provide in vivo evidence using DBA/2 mice in support for an increased tumoural accumulation of doxorubicin, without affecting its tissue distribution, resulting in an enhanced antitumoural effect. Conclusion: Our results suggest that TBN is a potent modulator of the P-gp membrane pump and that the compound could be of clinical relevance to improve the efficacy of chemotherapy in MDR cancers. PMID:20551959

  18. Accelerated Senescence and Enhanced Disease Resistance in Hybrid Chlorosis Lines Derived from Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii

    PubMed Central

    Tosa, Yukio; Yoshida, Kentaro; Park, Pyoyun; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions. PMID:25806790

  19. Host-derived probiotics Enterococcus casseliflavus improves resistance against Streptococcus iniae infection in rainbow trout (Oncorhynchus mykiss) via immunomodulation.

    PubMed

    Safari, Reza; Adel, Milad; Lazado, Carlo C; Caipang, Christopher Marlowe A; Dadar, Maryam

    2016-05-01

    The present study evaluated the benefits of dietary administration of host-derived candidate probiotics Enterococcus casseliflavus in juvenile rainbow trout Oncorhynchus mykiss. Experimental diets were prepared by incorporating the microorganisms in the basal feed at 3 inclusion levels (i.e. 10(7) CFU g(-1) of feed [T1], 10(8) CFU g(-1) of feed [T2], 10(9) CFU g(-1) of feed [T3]). The probiotic feeds were administered for 8 weeks, with a group fed with the basal diet serving as control. The effects on growth performance, gut health, innate immunity and disease resistance were evaluated. Results showed that growth performance parameters were significantly improved in T2 and T3 groups. Activities of digestive enzymes such as trypsin and lipase were significantly higher in these two groups as well. Gut micro-ecology was influenced by probiotic feeding as shown by the significant increase in intestinal lactic acid bacteria and total viable aerobic counts in T2 and T3. Humoral immunity was impacted by dietary probiotics as total serum protein and albumin were significantly elevated in T3. The levels of serum IgM significantly increased in all probiotic fed groups at week 8; with the T3 group registering the highest increment. Respiratory burst activity of blood leukocytes were significantly improved in T2 and T3. Hematological profiling further revealed that neutrophil counts significantly increased in all probiotic fed groups. Challenge test showed that probiotic feeding significantly improved host resistance to Streptococcus iniae infection, specifically in T2 and T3 where a considerable modulation of immune responses was observed. Taken together, this study demonstrated E. casseliflavus as a potential probiotics for rainbow trout with the capability of improving growth performance and enhancing disease resistance by immunomodulation. PMID:26997202

  20. Landform-derived placement of electrical resistivity prospecting for paleotopography reconstruction in the loess landforms of China

    NASA Astrophysics Data System (ADS)

    Xiong, Li-Yang; Tang, Guo-An; Zhu, A.-Xing; Li, Ji-Long; Duan, Jia-Zhen; Qian, Ye-Qing

    2016-08-01

    The paleotopography of loess landform represents the initial surface before the evolution of the Aeolian depositional process. This paleotopography served as an indicator of the paleo-geography and erosion base that restrained the evolution of the current landform. In this case study, a landform-derived placement method involving electrical resistivity prospecting is proposed for paleotopography reconstruction. The method consists of extracting terrain feature knowledge and terrain feature-based paleotopography prospecting and reconstruction. The field experiment is validated and used in three typical loess landform areas in the Chinese Loess Plateau. These typical loess landforms include loess hill, loess ridge, and loess tableland. Terrain features considered include peaks, saddles, ridges, and gullies. The results show significant electrical resistivity difference between the paleotopography and loess strata. The electrical resistivity method could effectively detect the paleotopography and different loess layers. The reconstructed paleotopography using the feature-based method could effectively represent the morphology of the paleosurface compared to the result of the interpolation method. The reconstructed paleotopography also appears as a coincident terrain relief compared to modern topography; such a relief demonstrates significant landform inheritance between modern terrain and paleotopography. In the loess hill and ridge landform areas, the relative elevation difference of paleotopography is approximately 50 m whereas that of the modern terrain is roughly 150 m, indicating that the loess deposition process increased the topographic relief from paleotopography to modern terrain by approximately 100 m. Similar altitude of the paleotopographic peaks (roughly 10 m height difference) appears in the two nearby loess ridge and hill areas. The results indicate that paleo-geography of this area should be a landform of peneplain and almost a planation surface.

  1. Encapsulation-Induced Stress Helps Saccharomyces cerevisiae Resist Convertible Lignocellulose Derived Inhibitors

    PubMed Central

    Westman, Johan O.; Manikondu, Ramesh Babu; Franzén, Carl Johan; Taherzadeh, Mohammad J.

    2012-01-01

    The ability of macroencapsulated Saccharomyces cerevisiae CBS8066 to withstand readily and not readily in situ convertible lignocellulose-derived inhibitors was investigated in anaerobic batch cultivations. It was shown that encapsulation increased the tolerance against readily convertible furan aldehyde inhibitors and to dilute acid spruce hydrolysate, but not to organic acid inhibitors that cannot be metabolized anaerobically. Gene expression analysis showed that the protective effect arising from the encapsulation is evident also on the transcriptome level, as the expression of the stress-related genes YAP1, ATR1 and FLR1 was induced upon encapsulation. The transcript levels were increased due to encapsulation already in the medium without added inhibitors, indicating that the cells sensed low stress level arising from the encapsulation itself. We present a model, where the stress response is induced by nutrient limitation, that this helps the cells to cope with the increased stress added by a toxic medium, and that superficial cells in the capsules degrade convertible inhibitors, alleviating the inhibition for the cells deeper in the capsule. PMID:23109889

  2. Resistance of LPS-activated bone marrow derived macrophages to apoptosis mediated by dexamethasone

    PubMed Central

    Haim, Yasmin Ohana; Unger, Naamit Deshet; Souroujon, Miriam C.; Mittelman, Moshe; Neumann, Drorit

    2014-01-01

    Glucocorticoids (GC) display pleiotropic effects on the immune system. Macrophages are a major target for GC action. Here we show that dexamethasone (DEX), a synthetic GC, decreased viability of naïve bone marrow-derived macrophages (BMDM), involving an apoptotic mechanism. Administration of DEX together with lipopolysaccharide (LPS) protected BMDM against DEX-mediated cell death, suggesting that activated BMDM respond to DEX differently than naïve BMDM. An insight to the molecular basis of LPS actions was provided by a 7 fold increase in mRNA levels of glucocorticoid receptor beta (GRβ), a GR dominant-negative splice variant which inhibits GRα's transcriptional activity. LPS did not inhibit all DEX-mediated effects on BMDM; DEX significantly reduced the percentage of BMDM expressing high levels of the cell surface markers F4/80 and CD11b and led to a decrease in macrophage inflammatory protein 1 alpha (MIP1-α) mRNA and protein levels. These two DEX-mediated effects were not prevented by LPS. Our finding that LPS did not reduce the DEX-induced elevation of glucocorticoid-induced leucine zipper (GILZ), a mediator of GCs anti-inflammatory actions, may provide an underlying mechanism. These findings enable a better understanding of clinical states, such as sepsis, in which macrophages are activated by endotoxins and treatment by GCs is considered. PMID:24608810

  3. Genomic signatures for paclitaxel and gemcitabine resistance in breast cancer derived by machine learning.

    PubMed

    Dorman, Stephanie N; Baranova, Katherina; Knoll, Joan H M; Urquhart, Brad L; Mariani, Gabriella; Carcangiu, Maria Luisa; Rogan, Peter K

    2016-01-01

    Increasingly, the effectiveness of adjuvant chemotherapy agents for breast cancer has been related to changes in the genomic profile of tumors. We investigated correspondence between growth inhibitory concentrations of paclitaxel and gemcitabine (GI50) and gene copy number, mutation, and expression first in breast cancer cell lines and then in patients. Genes encoding direct targets of these drugs, metabolizing enzymes, transporters, and those previously associated with chemoresistance to paclitaxel (n = 31 genes) or gemcitabine (n = 18) were analyzed. A multi-factorial, principal component analysis (MFA) indicated expression was the strongest indicator of sensitivity for paclitaxel, and copy number and expression were informative for gemcitabine. The factors were combined using support vector machines (SVM). Expression of 15 genes (ABCC10, BCL2, BCL2L1, BIRC5, BMF, FGF2, FN1, MAP4, MAPT, NFKB2, SLCO1B3, TLR6, TMEM243, TWIST1, and CSAG2) predicted cell line sensitivity to paclitaxel with 82% accuracy. Copy number profiles of 3 genes (ABCC10, NT5C, TYMS) together with expression of 7 genes (ABCB1, ABCC10, CMPK1, DCTD, NME1, RRM1, RRM2B), predicted gemcitabine response with 85% accuracy. Expression and copy number studies of two independent sets of patients with known responses were then analyzed with these models. These included tumor blocks from 21 patients that were treated with both paclitaxel and gemcitabine, and 319 patients on paclitaxel and anthracycline therapy. A new paclitaxel SVM was derived from an 11-gene subset since data for 4 of the original genes was unavailable. The accuracy of this SVM was similar in cell lines and tumor blocks (70-71%). The gemcitabine SVM exhibited 62% prediction accuracy for the tumor blocks due to the presence of samples with poor nucleic acid integrity. Nevertheless, the paclitaxel SVM predicted sensitivity in 84% of patients with no or minimal residual disease. PMID:26372358

  4. Genomic profiling of acquired resistance to apoptosis in cells derived from human atherosclerotic lesions: potential role of STATs, cyclinD1, BAD, and Bcl-XL.

    PubMed

    Gagarin, Dmitry; Yang, Zhaoqing; Butler, Jason; Wimmer, Monika; Du, Baoheng; Cahan, Patrick; McCaffrey, Timothy A

    2005-09-01

    Current theories suggest that atherosclerosis, plaque rupture, stroke, and restenosis after angioplasty may involve defective apoptotic mechanisms in vascular cells. Prior work has demonstrated that cells from human atherosclerotic lesions, and cells from the aorta of aged rats, exhibit functional resistance to apoptosis induced by TGF-beta and glucocorticoids. The present studies demonstrate that human lesion-derived cells (LDC) are also resistant to apoptosis induced by fas ligation compared to cells derived from the adjacent media, and that in vitro expansion of LDC causes acquired resistance to apoptosis. Microarray profiling of fas-resistant versus sensitive cells identified a set of genes including STATs, caspase 1, cyclin D1, Bcl-xL, VDAC2, and BAD. The STAT proteins have been implicated in resistance to apoptosis, potentially via their ability to modulate caspase 1 (ICE), Bcl-xL, and cyclin D1 expression. Western blot analysis of sensitive and resistant LDC clonal lines confirmed increases in cyclin D1, STAT6, Bcl-xL, and BAD, with decreased expression of caspase 1. Thus, transcript profiling has identified a potential pathway of apoptotic regulation in subsets of lesion cells. The resistant phenotype may contribute to plaque stability and excessive vascular repair, while sensitive cells may be involved in plaque rupture and infarction. The data suggests both genetic interventions and novel small-molecule inhibitors that may be effective modulators of apoptosis in atherosclerosis, angina, and in-stent restenosis. PMID:16005468

  5. Effective antimicrobial activity of Cbf-14, derived from a cathelin-like domain, against penicillin-resistant bacteria.

    PubMed

    Ma, Lingman; Wang, Yanrong; Wang, Mengxiao; Tian, Yuwei; Kang, Wei; Liu, Hanhan; Wang, Hui; Dou, Jie; Zhou, Changlin

    2016-05-01

    Cbf-14, a cationic peptide derived from a cathelin-like domain, was designed by inserting the highly α-helical sequence RLLR into an antibacterial sequence and deleting the inactive amino acids in Cbf-K16. Clinical penicillin-resistant isolates as well as NDM-1-carrying Escherichia coli and a correspondingly infected mice model were employed to evaluate Cbf-14 antibacterial activity. The results showed that Cbf-14 possessed potent antimicrobial effects with an MIC of 8-64 μg/ml, and killed almost all bacteria within 240 min. Cbf-14-treated mice achieved an 80% survival rate and approximate 2.5 log unit reduction in CFU in tissues; additionally, this peptide significantly suppressed the production of pro-inflammatory cytokines by the disaggregation of lipopolysaccharide (LPS), suggesting its anti-inflammatory effects. Furthermore, Cbf-14, concentration higher than 2 × MIC value, increased membrane uptake to NPN and PI dye by 96.2% and 63.7%, respectively, neutralised the negative zeta potential of LPS and bacteria surface, and induced 100% leakage of liposome-entrapped calcein and cytoplasmic membrane disruption of E. coli, indicating obvious membrane permeation. Finally, it bound to DNA and respectively evoked 85.0% and 63.3% inhibition of gene replication and protein expression of NDM-1 at sub-MIC concentration in E. coli BL21 (DE3)-NDM-1. These data indicated that Cbf-14 possessed effective antimicrobial activity against penicillin-resistant bacteria in vitro/vivo through membrane disruption, DNA binding, down-regulating NDM-1 expression by plasmid replication inhibition, and anti-inflammatory activity by LPS disaggregation, suggesting a potential anti-infective clinical agent. PMID:26897538

  6. Isohumulones, bitter acids derived from hops, activate both peroxisome proliferator-activated receptor alpha and gamma and reduce insulin resistance.

    PubMed

    Yajima, Hiroaki; Ikeshima, Emiko; Shiraki, Maho; Kanaya, Tomoka; Fujiwara, Daisuke; Odai, Hideharu; Tsuboyama-Kasaoka, Nobuyo; Ezaki, Osamu; Oikawa, Shinichi; Kondo, Keiji

    2004-08-01

    The peroxisome proliferator-activated receptors (PPARs) are dietary lipid sensors that regulate fatty acid and carbohydrate metabolism. The hypolipidemic effects of fibrate drugs and the therapeutic benefits of the thiazolidinedione drugs are due to their activation of PPARalpha and -gamma, respectively. In this study, isohumulones, the bitter compounds derived from hops that are present in beer, were found to activate PPARalpha and -gamma in transient co-transfection studies. Among the three major isohumulone homologs, isohumulone and isocohumulone were found to activate PPARalpha and -gamma. Diabetic KK-Ay mice that were treated with isohumulones (isohumulone and isocohumulone) showed reduced plasma glucose, triglyceride, and free fatty acid levels (65.3, 62.6, and 73.1%, respectively, for isohumulone); similar reductions were found following treatment with the thiazolidinedione drug, pioglitazone. Isohumulone treatment did not result in significant body weight gain, although pioglitazone treatment did increase body weight (10.6% increase versus control group). C57BL/6N mice fed a high fat diet that were treated with isohumulones showed improved glucose tolerance and reduced insulin resistance. Furthermore, these animals showed increased liver fatty acid oxidation and a decrease in size and an increase in apoptosis of their hypertrophic adipocytes. A double-blind, placebo-controlled pilot study for studying the effect of isohumulones on diabetes suggested that isohumulones significantly decreased blood glucose and hemoglobin A1c levels after 8 weeks (by 10.1 and 6.4%, respectively, versus week 0). These results suggest that isohumulones can improve insulin sensitivity in high fat diet-fed mice with insulin resistance and in patients with type 2 diabetes. PMID:15178687

  7. Highly potent oxathiin carboxanilide derivatives with efficacy against nonnucleoside reverse transcriptase inhibitor-resistant human immunodeficiency virus isolates.

    PubMed Central

    Buckheit, R W; Snow, M J; Fliakas-Boltz, V; Kinjerski, T L; Russell, J D; Pallansch, L A; Brouwer, W G; Yang, S S

    1997-01-01

    The structure-activity relationships of a series of compounds related to the nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) oxathiin carboxanilide have been described (R. W. Buckheit, Jr., T. L. Kinjerski, V. Fliakas-Boltz, J. D. Russell, T. L. Stup, L. A. Pallansch, W. G. Brouwer, D. C. Dao, W. A. Harrison, R. J. Schultz, J. P. Bader, and S. S. Yang, Antimicrob. Agents Chemother. 39:2718-2727, 1996). From these studies, the furanyl-containing analog UC10 was identified as the most potent inhibitor of human immunodeficiency virus type 1 (HIV-1) replication and a promising candidate for further development. Three new UC analogs (UC040, UC82, and UC781) have been determined to inhibit laboratory-derived and low-passage-number, primary virus isolates at low nanomolar concentrations in both established and fresh human cells. Each of the compounds synergistically interacted with the nucleoside analogs zidovudine, dideoxyinosine, dideoxycytosine, and lamivudine to inhibit HIV-1 replication. As a group, the UC compounds were found to be less active against viruses with the L100I, K103N, and Y181C amino acid changes in the RT and, upon in vitro selection, yielded resistant virus with the Y181C mutation in the RT. The most potent of the three new compounds, UC781, contains a furanyl side chain, similar to UC10, but differs in having an extended ether side chain instead of an oxime chain. The broad therapeutic index of UC781 (>62,000) resulted in effective inhibition of NNRTI-resistant virus isolates at high nanomolar concentrations. Furthermore, UC781 and the NNRTI costatolide were able to synergistically inhibit HIV-1 replication when used in combination, suggesting that UC781 may interact with the RT differently than the other UC analogs. The favorable anti-HIV properties of the UC compounds suggest they should be considered for further clinical development. PMID:9087499

  8. Chromosomal location of Pm35, a novel Aegilops tauschii derived powdery mildew resistance gene introgressed into common wheat (Triticum aestivum L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A single gene controlling powdery mildew resistance was identified in the North Carolina germplasm line NC96BGTD3 (NCD3) using genetic analysis of F2 derived lines from a NCD3 X Saluda cross. Microsatellite markers linked to this Pm gene were identified and their most likely order was Xcfd7, 10.3cM,...

  9. Coke- and sintering-resistant monolithic catalysts derived from in situ supported hydrotalcite-like films on Al wires for dry reforming of methane.

    PubMed

    Du, Xianjun; Zhang, Dengsong; Shi, Liyi; Gao, Ruihua; Zhang, Jianping

    2013-04-01

    Monolithic catalysts derived from in situ supported hydrotalcite-like films on Al wires display high resistance to coke formation and sintering in the dry reforming of methane due to their hierarchical porous structure, well dispersed metallic nickel species, more basic sites and strong metal-support interaction effect. PMID:23463343

  10. Identification and characterization of a monocyte-derived neutrophil-activating factor in corticosteroid-resistant bronchial asthma.

    PubMed Central

    Wilkinson, J R; Crea, A E; Clark, T J; Lee, T H

    1989-01-01

    Peripheral blood mononuclear cells (PBMC) were isolated from seven normal subjects, eight asthmatic subjects clinically sensitive to corticosteroids (CS), and eight asthmatic subjects clinically resistant to corticosteroids (CR). PBMC were cultured at 37 degrees C for 24 h in the absence or presence of 10(-16) to 10(-4) M hydrocortisone. Calcium ionophore (A23187)-activated neutrophils (PMN) primed by supernatants of PBMC from asthmatic subjects cultured in the absence of hydrocortisone generated approximately threefold more leukotriene B4 than PMN primed by supernatants of PBMC from normal subjects (P less than 0.05). Incubation of PBMC derived from CS subjects with 10(-8) M hydrocortisone completely inhibited the production of the enhancing activity (P less than 0.01), whereas in CR subjects hydrocortisone at concentrations up to 10(-4) M did not suppress the release of enhancing activity. The enhancing activity was produced by monocytes. Enhancing activity eluted with an Mr of 3,000 D and a pI of 7.1. It eluted at 10% acetonitrile after reverse-phase HPLC. The activity was destroyed by heating to 60 degrees C for 60 min and was sensitive to pronase treatment. The purified factor also enhanced superoxide generation by PMN which had been stimulated submaximally by phorbol myristate acetate. Images PMID:2556450

  11. Epithelial-mesenchymal transition mediates anoikis resistance and enhances invasion in pleural effusion-derived human lung cancer cells.

    PubMed

    Chunhacha, Preedakorn; Sriuranpong, Virote; Chanvorachote, Pithi

    2013-03-01

    Epithelial-mesenchymal transition (EMT) is implicated in cancer pathological processes, particularly cancer invasion and metastasis. The present study demonstrated that EMT was critical for the metastasic potential of lung cancer cells isolated from a patient. P1 primary lung cancer cells were found to exhibit increased anoikis resistance compared with established A549, H23 and H460 lung cancer cells. Results of migration and invasion assays revealed that the invasion capability of P1 and A549 cells was higher than that of H23 and H460 cells. However, the migration of P1 cells was similar to that of H23 and H460 cells while A549 demonstrated a superior migrating ability. Western blot analysis indicated that while E-cadherin levels in all lung cancer cells were identified as comparable, P1 cells expressed the highest levels of N-cadherin. In the present study, detachment of cells was demonstrated for the first time to stimulate further transition of E-cadherin to N-cadherin. In addition, this obervation was more pronounced in P1 cells. These observations highlight the importance of EMT in cancer metastasis. In order to study the effect of ethnicity on cancer cell behavior, in the future a large number of Thai patient-derived cell lines must be analyzed. PMID:23426647

  12. Neutrophils confer T cell resistance to myeloid-derived suppressor cell-mediated suppression to promote chronic inflammation.

    PubMed

    Ryan, Sean O; Johnson, Jenny L; Cobb, Brian A

    2013-05-15

    Low-grade chronic inflammation can persist in aging humans unnoticed for years or even decades, inflicting continuous damage that can culminate later in life as organ dysfunction, physical frailty, and some of the most prominent debilitating and deadly age-associated diseases, including rheumatoid arthritis, diabetes, heart disease, and cancer. Despite the near universal acceptance of these associations, the mechanisms underlying unresolved inflammation remain poorly understood. In this study, we describe a novel inducible method to examine systemic chronic inflammation using susceptible animal models. Induced inflammation results in unresolved innate cellular responses and persistence of the same serum proinflammatory molecules used as diagnostic biomarkers and therapeutic targets for chronic inflammation in humans. Surprisingly, we found long-term persistence of an inflammation-associated neutrophil cell population constitutively producing the proinflammatory IFN-γ cytokine, which until now has only been detected transiently in acute inflammatory responses. Interestingly, these cells appear to confer T cell resistance to the otherwise potent anti-inflammatory function of myeloid-derived suppressor cells, revealing a novel mechanism for the maintenance of chronic inflammatory responses over time. This discovery represents an attractive target to resolve inflammation and prevent the inflammation-induced pathologies that are of critical concern for the well-being of the aging population. PMID:23576679

  13. An isocorydine derivative (d-ICD) inhibits drug resistance by downregulating IGF2BP3 expression in hepatocellular carcinoma

    PubMed Central

    Ge, Chao; Chen, Lijuan; Fang, Tao; Li, Hong; Tian, Hua; Liu, Junxi; Chen, Taoyang; Jiang, Guoping; Xie, Haiyang; Cui, Ying; Yao, Ming; Li, Jinjun

    2015-01-01

    In our previous studies, we reported that CD133+ cancer stem cells (CSCs) were chemoresistant in hepatocellular carcinoma (HCC) and that isocorydine treatment decreased the percentage of CD133+ CSCs. Here, we found that a derivative of isocorydine (d-ICD) inhibited HCC cell growth, particularly among the CD133+ subpopulation, and rendered HCC cells more sensitive to sorafenib treatment. d-ICD inhibited IGF2BP3 expression in a time-dependent manner, and IGF2BP3 expression negatively correlated with d-ICD-induced growth suppression. IGF2BP3 overexpression enriched the CD133+ CSC subpopulation in HCC, enhanced tumor sphere formation and suppressed the cytotoxic effects of sorafenib and doxorubicin. The expression of drug resistance-related genes, including ABCB1 and ABCG2, and the CSC marker CD133 expression was increased after IGF2BP3 overexpression. The significance of these observations was underscored by our findings that high IGF2BP3 expression predicted poor survival in a cohort of 236 patients with HCC and positively correlated with ABCG2 and CD133 expression in vivo. These results suggested that the d-ICD may inhibit HCC cells growth by IGF2BP3 decrease and that IGF2BP3 may serve as a therapeutic target for HCC. PMID:26327240

  14. Mefloquine and its oxazolidine derivative compound are active against drug-resistant Mycobacterium tuberculosis strains and in a murine model of tuberculosis infection.

    PubMed

    Rodrigues-Junior, Valnês S; Villela, Anne D; Gonçalves, Raoni S B; Abbadi, Bruno Lopes; Trindade, Rogério Valim; López-Gavín, Alexandre; Tudó, Griselda; González-Martín, Julian; Basso, Luiz Augusto; de Souza, Marcus V N; Campos, Maria Martha; Santos, Diógenes Santiago

    2016-08-01

    Repurposing of drugs to treat tuberculosis (TB) has been considered an alternative to overcome the global TB epidemic, especially to combat drug-resistant forms of the disease. Mefloquine has been reported as a potent drug to kill drug-resistant strains of Mycobacterium tuberculosis. In addition, mefloquine-derived molecules have been synthesised and their effectiveness against mycobacteria has been assessed. In this work, we demonstrate for the first time the activities of mefloquine and its oxazolidine derivative compound 1E in a murine model of TB infection following administration of both drugs by the oral route. The effects of associations between mefloquine or 1E with the clinically used antituberculosis drugs isoniazid, rifampicin, ethambutol, moxifloxacin and streptomycin were also investigated. Importantly, combination of mefloquine with isoniazid and of 1E with streptomycin showed a two-fold decrease in their minimum inhibitory concentrations (MICs). Moreover, no tested combinations demonstrated antagonist interactions. Here we describe novel evidence on the activity of mefloquine and 1E against a series of quinolone-resistant M. tuberculosis strains. These data show MICs against quinolone-resistant strains (0.5-8 µg/mL) similar to or lower than those previously reported for multidrug-resistant strains. Taking these results together, we can suggest the use of mefloquine or 1E in combination with clinically available drugs, especially in the case of resistant forms of TB. PMID:27364701

  15. Confirmation By QTL mapping Of The Malus Robusta (Cv. Robusta 5) derived powdery mildew resistance gene Pl1

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Geneva® apple rootstock breeding program has made extensive use of Malus robusta cv. Robusta 5 as a source of resistance to fire blight. Robusta 5 has also been used as the source of powdery mildew resistance by other breeding programs and a single locus Pl1 has been associated with this resist...

  16. [Effects of a new derivative of 5-alkyl-3N-furanones on the colonization resistance of the intestine in albino mice].

    PubMed

    Tomnikov, A Iu; Shub, G M

    1990-05-01

    By its antagonistic function normal microflora provides the intestine with resistance to colonization with exogenic opportunistic and pathogenic microorganisms. The drug was effective in inducing a decrease in the intestine colonization resistance which in its turn leads to filling of free ecological niches with exogenic microflora. In this connection the suggestion that specification of a new chemical agent should include along with other criteria its effect on colonization resistance is valid. It was shown with the use of indicator microorganisms that when administered per os in doses of 40 and 80 mg/kg daily for 3 and 6 days, respectively, a new original compound 1929, a derivative of 5-alkyl-3H-furanones, with high antimicrobial activity induced no significant or more pronounced changes in the colonization resistance of the gastrointestinal tract of noninbred albino mice than furagin used as the reference drug. PMID:2200373

  17. Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils.

    PubMed

    Chueca, Beatriz; Berdejo, Daniel; Gomes-Neto, Nelson J; Pagán, Rafael; García-Gonzalo, Diego

    2016-01-01

    The improvement of food preservation by using essential oils (EOs) and their individual constituents (ICs) is attracting enormous interest worldwide. Until now, researchers considered that treatments with such antimicrobial compounds did not induce bacterial resistance via a phenotypic (i.e., transient) response. Nevertheless, the emergence of genotypic (i.e., stable) resistance after treatment with these compounds had not been previously tested. Our results confirm that growth of Escherichia coli MG1655 in presence of sub-inhibitory concentrations of the ICs carvacrol, citral, and (+)-limonene oxide do not increase resistance to further treatments with either the same IC (direct resistance) or with other preservation treatments (cross-resistance) such as heat or pulsed electric fields (PEF). Bacterial mutation frequency was likewise lower when those IC's were applied; however, after 10 days of re-culturing cells in presence of sub-inhibitory concentrations of the ICs, we were able to isolate several derivative strains (i.e., mutants) displaying an increased minimum inhibitory concentration to those ICs. Furthermore, when compared to the wild type (WT) strain, they also displayed direct resistance and cross-resistance. Derivative strains selected with carvacrol and citral also displayed morphological changes involving filamentation along with cell counts at late-stationary growth phase that were lower than the WT strain. In addition, co-cultures of each derivative strain with the WT strain resulted in a predominance of the original strain in absence of ICs, indicating that mutants would not out-compete WT cells under optimal growth conditions. Nevertheless, growth in the presence of ICs facilitated the selection of these resistant mutants. Thus, as a result, subsequent food preservation treatments of these bacterial cultures might be less effective than expected for WT cultures. In conclusion, this study recommends that treatment with ICs at sub

  18. Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils

    PubMed Central

    Chueca, Beatriz; Berdejo, Daniel; Gomes-Neto, Nelson J.; Pagán, Rafael; García-Gonzalo, Diego

    2016-01-01

    The improvement of food preservation by using essential oils (EOs) and their individual constituents (ICs) is attracting enormous interest worldwide. Until now, researchers considered that treatments with such antimicrobial compounds did not induce bacterial resistance via a phenotypic (i.e., transient) response. Nevertheless, the emergence of genotypic (i.e., stable) resistance after treatment with these compounds had not been previously tested. Our results confirm that growth of Escherichia coli MG1655 in presence of sub-inhibitory concentrations of the ICs carvacrol, citral, and (+)-limonene oxide do not increase resistance to further treatments with either the same IC (direct resistance) or with other preservation treatments (cross-resistance) such as heat or pulsed electric fields (PEF). Bacterial mutation frequency was likewise lower when those IC's were applied; however, after 10 days of re-culturing cells in presence of sub-inhibitory concentrations of the ICs, we were able to isolate several derivative strains (i.e., mutants) displaying an increased minimum inhibitory concentration to those ICs. Furthermore, when compared to the wild type (WT) strain, they also displayed direct resistance and cross-resistance. Derivative strains selected with carvacrol and citral also displayed morphological changes involving filamentation along with cell counts at late-stationary growth phase that were lower than the WT strain. In addition, co-cultures of each derivative strain with the WT strain resulted in a predominance of the original strain in absence of ICs, indicating that mutants would not out-compete WT cells under optimal growth conditions. Nevertheless, growth in the presence of ICs facilitated the selection of these resistant mutants. Thus, as a result, subsequent food preservation treatments of these bacterial cultures might be less effective than expected for WT cultures. In conclusion, this study recommends that treatment with ICs at sub

  19. A complex protein derivative acts as biogenic elicitor of grapevine resistance against powdery mildew under field conditions

    PubMed Central

    Nesler, Andrea; Perazzolli, Michele; Puopolo, Gerardo; Giovannini, Oscar; Elad, Yigal; Pertot, Ilaria

    2015-01-01

    Powdery mildew caused by Erysiphe necator is one of the most important grapevine diseases in several viticulture areas, and high fungicide input is required to control it. However, numerous synthetic chemical pesticides are under scrutiny due to concerns about their impact on human health and the environment. Biopesticides, such as biogenic elicitors, are a promising alternative to chemical fungicides. Although several studies have reported on effective elicitors against grapevine diseases, their efficacy under field conditions has not been investigated extensively or has occurred at rather limited levels. Our goal was to examine the efficacy of a protein-based composition, namely nutrient broth (NB), against powdery mildew under field conditions and to characterize its mechanism of action. Weekly treatments with NB was highly effective in controlling powdery mildew on grapevine across seasons with different disease pressures. The level of disease control achieved with NB was comparable to standard fungicide treatments both on leaves and bunches across three different years. NB has no direct toxic effect on the germination of E. necator conidia, and it activates plant resistance with both systemic and translaminar effect in experiments with artificial inoculation under controlled conditions. NB induced the expression of defense-related genes in grapevine, demonstrating stimulation of plant defense mechanisms, prior to and in the early stages of pathogen infection. NB is a natural derivative from meat and yeast, substances that tend not to raise concerns about toxicological and ecotoxicological properties. NB represents a valid control tool for integrated plant protection programs against powdery mildew, to reduce the use of synthetic pesticides on grapevine. PMID:26442029

  20. Alterations in the Quinolone Resistance-Determining Regions and Fluoroquinolone Resistance in Clinical Isolates and Laboratory-Derived Mutants of Mycoplasma bovis: Not All Genotypes May Be Equal

    PubMed Central

    Khalil, Dima; Becker, Claire A. M.

    2015-01-01

    Mycoplasma bovis is considered a major contributor to respiratory diseases in young cattle. Resistant M. bovis isolates have increasingly been reported worldwide due to extensive use of antimicrobials to treat bovine pneumonia. The frequency of isolates resistant to fluoroquinolones varies considerably from one country to another. The MICs of isolates collected in France have only increased from “very low” to “low.” The present study was conducted to investigate whether alterations in the quinolone resistance-determining regions (QRDRs) could account for this slight modification in susceptibility. No correlation between QRDR alterations and increased MICs was evidenced in clinical isolates. In addition, all clinical isolates were subtyped, and the tendencies of the different sequence types to develop resistance through mutations in QRDRs under selective pressure in vitro were examined. In vitro, 3 hot spots for mutations in QRDRs (position 83 in GyrA and positions 80 and 84 in ParC) were associated with a high level of resistance when cumulated. We showed that the point mutations in the QRDRs observed in vitro were different (in location and selection rapidity) between the different subtypes. Our in vitro observations were corroborated by the recent detection of a clinical isolate highly resistant to fluoroquinolones (MIC ≥ 16 μg/ml) and belonging to the subtype which easily accumulates QRDR alterations in vitro. The current increased prevalence of this subtype in clinical isolates highlights the urgent need to control fluoroquinolone usage in veterinary medicine. PMID:26637606

  1. Coke- and sintering-resistant monolithic catalysts derived from in situ supported hydrotalcite-like films on Al wires for dry reforming of methane

    NASA Astrophysics Data System (ADS)

    Du, Xianjun; Zhang, Dengsong; Shi, Liyi; Gao, Ruihua; Zhang, Jianping

    2013-03-01

    Monolithic catalysts derived from in situ supported hydrotalcite-like films on Al wires display high resistance to coke formation and sintering in the dry reforming of methane due to their hierarchical porous structure, well dispersed metallic nickel species, more basic sites and strong metal-support interaction effect.Monolithic catalysts derived from in situ supported hydrotalcite-like films on Al wires display high resistance to coke formation and sintering in the dry reforming of methane due to their hierarchical porous structure, well dispersed metallic nickel species, more basic sites and strong metal-support interaction effect. Electronic supplementary information (ESI) available: Experimental details, XRD patterns, SEM images, and TEM images. See DOI: 10.1039/c3nr33921a

  2. MlAB10: a Triticum turgidum subsp. dicoccoides derived powdery mildew resistance gene identified in common wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew is an economically important disease in wheat growing areas with a cool maritime environment. Host genetic resistance is the most economical, consistent, and environmentally sound method of control. NC97BGTAB10 is a germplasm line containing powdery mildew resistance introgressed fr...

  3. QTL analysis of ICA Bunsi-derived resistance to white mold in a pinto x navy bean cross

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding for genetic resistance to white mold [Sclerotinia sclerotiorum (Lib.) de Bary] in dry bean (Phaseolus vulgaris L.) is difficult because of low heritability. To facilitate breeding, researchers have sought to identify QTL underpinning genetic resistance to white mold. We identified two QTL ...

  4. Resistance training inhibits the elevation of skeletal muscle derived-BDNF level concomitant with improvement of muscle strength in zucker diabetic rat

    PubMed Central

    Kim, Hee-Jae; So, Byunghun; Son, Jun Seok; Song, Han Sol; Oh, Seung Lyul; Seong, Je Kyung; Lee, Hoyoung; Song, Wook

    2015-01-01

    [Purpose] In the present study, we investigated the effects of 8 weeks of progressive resistance training on the level of skeletal muscle derived BDNF as well as glucose intolerance in Zucker diabetic rats. [Methods] Six week-old male Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were randomly divided into 3 groups: sedentary ZLC (ZLC-Con), sedentary ZDF (ZDF-Con), and exercised ZDF (ZDF-Ex). Progressive resistance training using a ladder and tail weights was performed for 8 weeks (3 days/week). [Results] After 8 weeks of resistance training, substantial reduction in body weight was observed in ZDF-Ex compared to ZDF-Con. Though the skeletal muscle volume did not change, grip strength grip strength was significantly higher in ZDF-Ex compared to ZDF-Con. In the soleus, the level of BDNF was increased in ZDF-Con, but was significantly decreased (p<0.05) in ZDF-Ex, showing a training effect. Moreover, we found that there was a negative correlation (r=-0.657; p=0.004) between grip strength and BDNF level whereas there was a positive correlation (r=0.612; p=0.008) between plasma glucose level and BDNF level in skeletal muscle. [Conclusion] Based upon our results, we demonstrated that resistance training inhibited the elevation of skeletal muscle derived-BDNF expression concomitant with the improvement of muscle strength in zucker diabetic rats. In addition, muscle-derived BDNF might be a potential mediator for the preventive effect of resistance training on the progress of type 2 diabetes. PMID:27274460

  5. Macrolides from a Marine-Derived Fungus, Penicillium meleagrinum var. viridiflavum, Showing Synergistic Effects with Fluconazole against Azole-Resistant Candida albicans.

    PubMed

    Okabe, Miki; Sugita, Takashi; Kinoshita, Kaoru; Koyama, Kiyotaka

    2016-04-22

    Two new 13-membered macrolides (1, 7), along with known 13-membered macrolides PF1163A, B, D, H, and F (2-6), were isolated from a strain of a marine-derived fungus, Penicillium meleagrinum var. viridiflavum. The structures of 1 and 7 were elucidated from spectroscopic data (NMR, MS, IR). Compounds 1-7 showed synergistic effects with fluconazole against azole-resistant Candida albicans by a checkerboard assay. PMID:27014845

  6. Complete Genome Sequence of emm28 Type Streptococcus pyogenes MEW123, a Streptomycin-Resistant Derivative of a Clinical Throat Isolate Suitable for Investigation of Pathogenesis

    PubMed Central

    Jacob, Kristin M.; Spilker, Theodore; LiPuma, John J.; Dawid, Suzanne R.

    2016-01-01

    We present here the complete genome sequence of Streptococcus pyogenes type emm28 strain MEW123, a streptomycin-resistant derivative of a pediatric throat isolate. The genome length is 1,878,699 bp, with 38.29% G+C% content. The genome sequence adds value to this virulent emm28 representative strain and will aid in the investigation of streptococcal pathogenesis. PMID:26988051

  7. Synthesis of novel 1,8-acridinediones derivatives: Investigation of MDR reversibility on breast cancer cell lines T47D and tamoxifen-resistant T47D.

    PubMed

    Moallem, S A; Dehghani, N; Mehri, S; Shahsavand, Sh; Alibolandi, M; Hadizadeh, F

    2015-01-01

    Multi drug resistance (MDR) is a serious obstacle in the management of breast cancer. Therefore, overcoming MDR using novel anticancer agents is a top priority for medicinal chemists. It was found that dihydropyridines lacking calcium antagonistic activity (e.g acridinediones) possess MDR modifier potency. In this study, the capability of four novel acridine-1,8-diones derivatives 3a-d were evaluated as MDR reversing agents. In addition, the relationship between structural properties and biological effects of synthesized compounds was discussed. In vitro cytotoxicity of acridine-1,8-diones 3a-d derivatives in combination with doxorubicin (DOX) on T47D and tomoxifen-resistant T47D (TAMR-6) breast cancer cell lines were investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. Drug resistant index (DRI), which is equal to the ratio of IC50 in drug-resistant cells over IC50 in drug-sensitive cells, was calculated for each substance. Flowcytometry experiments were also implemented to distinguish cells undergoing apoptosis from those undergoing necrosis. The results from MTT and flowcytometry experiments indicated that 1 nM 3c derivative along with DOX significantly (P<0.05) increased the DOX cytotoxicity in T47D and TAMR-6 breast cancer cell lines. Synthesized compounds 3a and 3b also at concentrations of 1 nM with DOX significantly increased the cytotoxicity of DOX on T47D and TAMR-6 breast cancer cell lines. Meanwhile, 3d derivative with DOX did not exhibit good synergistic effect on cytotoxic activity of DOX, and slightly increased DOX cytotoxicity in both cell lines. Our results proposed that 3c may be an attractive lead compound for further development as a chemotherapeutic agent for MDR breast cancer therapy in combination with routine chemotherapeutic agents such as DOX. PMID:26600848

  8. A peptide derived from alpha-fetoprotein prevents the growth of estrogen-dependent human breast cancers sensitive and resistant to tamoxifen.

    PubMed

    Bennett, James A; Mesfin, Fassil B; Andersen, Thomas T; Gierthy, John F; Jacobson, Herbert I

    2002-02-19

    An 8-mer peptide (EMTOVNOG) derived from alpha-fetoprotein was compared with tamoxifen for activity against growth of human breast cancer xenografts implanted in immune-deficient mice. Both peptide and tamoxifen prevented growth of estrogen-receptor-positive MCF-7 and T47D human breast cancer xenografts. A subline of MCF-7, made resistant to tamoxifen by a 6-month exposure to this drug in culture, was found to be resistant to tamoxifen in vivo. Peptide completely prevented the xenograft growth of this tamoxifen-resistant subline of MCF-7. Neither peptide nor tamoxifen was effective in slowing the xenograft growth of the estrogen-receptor-negative MDA-MB-231 human breast cancer. A worrisome side effect of tamoxifen is its hypertrophic effect on the uterus. In this study, tamoxifen was shown to stimulate the growth of the immature mouse uterus in vivo, and the peptide significantly inhibited tamoxifen's uterotrophic effect. The mechanism of action of peptide is different from that of tamoxifen in that the peptide does not interfere with the binding of [(3)H]estradiol to the estrogen receptor. In conclusion, alpha-fetoprotein-derived peptide appears to be a novel agent that interferes with the growth of tamoxifen-sensitive as well as tamoxifen-resistant estrogen-receptor-positive human breast cancers; it inhibits the uterotrophic side effect of tamoxifen and, thus, it may be useful in combination with or in place of tamoxifen for treatment of estrogen-receptor-positive human breast cancers. PMID:11830647

  9. Synthesis and mode of action of hydrophobic derivatives of the glycopeptide antibiotic eremomycin and des-(N-methyl-D-leucyl)eremomycin against glycopeptide-sensitive and -resistant bacteria.

    PubMed

    Printsevskaya, Svetlana S; Pavlov, Andrey Y; Olsufyeva, Evgenia N; Mirchink, Elena P; Isakova, Elena B; Reznikova, Marina I; Goldman, Robert C; Branstrom, Arthur A; Baizman, Eugene R; Longley, Clifford B; Sztaricskai, Ferenc; Batta, Gyula; Preobrazhenskaya, Maria N

    2002-03-14

    Des-(N-methyl-D-leucyl)eremomycin was obtained by Edman degradation of eremomycin. Derivatives with a hydrophobic substituent at the exterior of the molecule were then synthesized, and their antibacterial activities were compared with similar derivatives of eremomycin. Comparison of derivatives of eremomycin containing the n-decyl or p-(p-chlorophenyl)benzyl substituent in the eremosamine moiety (N') and n-decyl or p-(p-chlorophenyl)benzylamides with similar derivatives of eremomycin possessing the damaged peptide core (a defective binding pocket) showed that compounds of both types are almost equally active against glycopeptide-resistant strains of enterococci (GRE), whereas eremomycin derivatives are more active against staphylococci. Hydrophobic 7d-alkylaminomethylated derivatives of eremomycin (9, 10) demonstrated similar antibacterial properties. Since the basic mode of action of glycopeptide antibiotics involves binding to cell wall intermediates terminating in -D-Ala-D-Ala and this interaction is seriously decreased in the hexapeptide derivatives (lacking the critical N-methyl-D-leucine), we suggest that these hydrophobic derivatives may inhibit peptidoglycan synthesis in the absence of dipeptide binding. NMR binding experiments using Ac-D-Ala-D-Ala show that binding constants of these hexapeptide derivativies are decreased in comparison with the corresponding heptapeptides with intact binding pocket. This is in agreement with the decreased biological activity of the hexapeptide derivatives against vancomycin-sensitive strains in comparison with the activity of parent compounds. Binding to the lactate cell wall analogue Ac-D-Ala-D-Lac with decylamide of eremomycin 8 was not observed, demonstrating that the interaction with this target in GRE does not occur. While hydrophobic glycopeptide derivatives retain the ability to inhibit the synthesis of peptidoglycan in manner of natural glycopeptides, biochemical investigation supports the hypothesis that they

  10. Comparative Fitness of a Parent Leishmania donovani Clinical Isolate and Its Experimentally Derived Paromomycin-Resistant Strain

    PubMed Central

    Hendrickx, Sarah; Leemans, Annelies; Mondelaers, Annelies; Rijal, Suman; Khanal, Basudha; Dujardin, Jean-Claude; Delputte, Peter; Cos, Paul; Maes, Louis

    2015-01-01

    Paromomycin has recently been introduced for the treatment of visceral leishmaniasis and emergence of drug resistance can only be appropriately judged upon its long term routine use in the field. Understanding alterations in parasite behavior linked to paromomycin-resistance may be essential to assess the propensity for emergence and spread of resistant strains. A standardized and integrated laboratory approach was adopted to define and assess parasite fitness of both promastigotes and amastigotes using an experimentally induced paromomycin-resistant Leishmania donovani strain and its paromomycin-susceptible parent wild-type clinical isolate. Primary focus was placed on parasite growth and virulence, two major components of parasite fitness. The combination of in vitro and in vivo approaches enabled detailed comparison of wild-type and resistant strains for which no differences could be demonstrated with regard to promastigote growth, metacyclogenesis, in vitro infectivity, multiplication in primary peritoneal mouse macrophages and infectivity for Balb/c mice upon infection with 2 x 107 metacyclic promastigotes. Monitoring of in vitro intracellular amastigote multiplication revealed a consistent decrease in parasite burden over time for both wild-type and resistant parasites, an observation that was subsequently also confirmed in a larger set of L. donovani clinical isolates. Though the impact of these findings should be further explored, the study results suggest that the epidemiological implications of acquired paromomycin-resistance may remain minimal other than the loss of one of the last remaining drugs effective against visceral leishmaniasis. PMID:26469696

  11. Establishment and characterization of therapy-resistant mantle cell lymphoma cell lines derived from different tissue sites.

    PubMed

    Ahrens, Adam K; Chaturvedi, Nagendra K; Nordgren, Tara M; Dave, Bhavana J; Joshi, Shantaram S

    2012-11-01

    Mantle cell lymphoma (MCL) is a rare but aggressive form of B cell non-Hodgkin lymphoma in which therapy resistance is common. New therapeutic options have extended survival in refractory MCL but have not provided durable remission. Tools are needed to assess the molecular and genetic changes associated with therapy resistance. Therefore, therapy-resistant MCL cell lines were established from the liver, kidney and lungs of human Granta 519-bearing NOD-SCID (non-obese diabetic-severe combined immunodeficiency) mice following treatment with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy in combination with bortezomib. The cytomorphologies, immunophenotypes, growth patterns in semi-solid agar, cytogenetic profiles and gene expression differences between these cell lines were characterized to identify major changes associated with therapy resistance. Therapy-resistant cell lines exhibit more aggressive growth patterns and markedly different gene expression profiles compared to parental Granta 519 cells. Thus, these stable therapy-resistant cell lines are useful models to further study the molecular basis of drug resistance and to identify clinically relevant molecular targets in MCL. PMID:22568512

  12. MECHANISM OF TOXICITY AND RESISTANCE TO D-MANNOSE AND CERTAIN DERIVATIVES IN SPECIES OF THE GENUS CHLORELLA BEIJ.(1) (2).

    PubMed

    Gross, R E

    1968-06-01

    d-Mannose and related derivatives, e.g., d-glucosa-mine and 2-deoxy-resistant strain was isolated. Prolonged incubation in glucose media in darkness brought about a reversion to the sensitive condition. These metabolic shifts could not be explained on the basis of adaptation or nuclear gene mutation because of the permanency and high frequency of the resistant cells. The mechanism was suggested to be cytoplasmically controlled. The shift in sensitivity to the inhibitors was considered a reproducible characteristic of certain species. In contrast to the normal, rnannose-sensitive strain of C. infusionum var. acetophila, cells of a resistant strain carried a gelatinous envelope. The resistant strain utilized glucosamine as a source of nitrogen, but lost the capacity to use sugars for dark growth. This was reflected in drastic reductions in glucose and mannose uptake. The hexokinase activities in cell extracts were equivalent for both strains. The resistant strain did not accumulate hexose-6-phos-phates and showed an increased phosphatase activity at an alkaline pH. PMID:27067950

  13. Protection of stromal cell-derived factor 2 by heat shock protein 72 prevents oxaliplatin-induced cell death in oxaliplatin-resistant human gastric cancer cells.

    PubMed

    Takahashi, Katsuyuki; Tanaka, Masako; Yashiro, Masakazu; Matsumoto, Masaki; Ohtsuka, Asuka; Nakayama, Keiichi I; Izumi, Yasukatsu; Nagayama, Katsuya; Miura, Katsuyuki; Iwao, Hiroshi; Shiota, Masayuki

    2016-08-01

    Heat shock protein 72 (Hsp72) is a molecular chaperone that assists in the folding of nascent polypeptides and in the refolding of denatured proteins. In many cancers, Hsp72 is constitutively expressed at elevated levels, which can result in enhanced stress tolerance. Similarly, following treatment with anticancer drugs, Hsp72 binds to denatured proteins that may be essential for survival. We therefore hypothesized that Hsp72 client proteins may play a crucial role in drug resistance. Here, we aimed to identify proteins that are critical for oxaliplatin (OXA) resistance by analyzing human gastric cancer cell lines, as well as OXA-resistant cells via a mass spectrometry-based proteomic approach combined with affinity purification using anti-Hsp72 antibodies. Stromal cell-derived factor 2 (SDF-2) was identified as an Hsp72 client protein unique to OCUM-2M/OXA cells. SDF-2 was overexpressed in OXA-resistant cells and SDF-2 silencing promoted the apoptotic effects of OXA. Furthermore, Hsp72 prevented SDF-2 degradation in a chaperone activity-dependent manner. Together, our data demonstrate that Hsp72 protected SDF-2 to avoid OXA-induced cell death. We propose that inhibition of SDF-2 may comprise a novel therapeutic strategy to counteract OXA-resistant cancers. PMID:27157913

  14. JNK1 in hematopoietically derived cells contributes to diet-induced inflammation and insulin resistance without affecting obesity.

    PubMed

    Solinas, Giovanni; Vilcu, Cristian; Neels, Jaap G; Bandyopadhyay, Gautam K; Luo, Jun-Li; Naugler, Willscott; Grivennikov, Sergei; Wynshaw-Boris, Anthony; Scadeng, Miriam; Olefsky, Jerrold M; Karin, Michael

    2007-11-01

    Obesity-induced insulin resistance is a major factor in the etiology of type 2 diabetes, and Jun kinases (JNKs) are key negative regulators of insulin sensitivity in the obese state. Activation of JNKs (mainly JNK1) in insulin target cells results in phosphorylation of insulin receptor substrates (IRSs) at serine and threonine residues that inhibit insulin signaling. JNK1 activation is also required for accumulation of visceral fat. Here we used reciprocal adoptive transfer experiments to determine whether JNK1 in myeloid cells, such as macrophages, also contributes to insulin resistance and central adiposity. Our results show that deletion of Jnk1 in the nonhematopoietic compartment protects mice from high-fat diet (HFD)-induced insulin resistance, in part through decreased adiposity. By contrast, Jnk1 removal from hematopoietic cells has no effect on adiposity but confers protection against HFD-induced insulin resistance by decreasing obesity-induced inflammation. PMID:17983584

  15. Potent and rapid antigonococcal activity of the venom peptide BmKn2 and its derivatives against different Maldi biotype of multidrug-resistant Neisseria gonorrhoeae.

    PubMed

    Arpornsuwan, Teerakul; Buasakul, Brisana; Jaresitthikunchai, Janthima; Roytrakul, Sittiruk

    2014-03-01

    The emergence of multidrug-resistant strains of Neisseria gonorrhoeae constitutes a serious threat to public health and necessitates the discovery of new types of antimicrobial agents. Among the 18 clinical isolates of N. gonorrhoeae with susceptible to spectinomycin, ceftriaxone and cefixime, 14 isolates were resistance to penicillin, tetracycline and ciprofloxacin, while 2 isolates were susceptible to tetracycline and another was penicillin intermediate isolate. Significant differences between laboratory strain and multidrug resistant strains were revealed by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry profiling and bioinformatics examination using the MALDI BioTyper software. However, Maldi Biotyper was not successfully separated ciprofloxacin-penicillin resistance and ciprofloxacin-tetracycline resistance from ciprofloxacin-penicillin-tetracycline resistant N. gonorrhoeae isolates. BmKn2 is a basic, alpha-helical peptide with no disulfide-bridge venom peptides that was first isolated from Buthus martensii Kasch. A panel of BmKn2 scorpion venom peptide and its derivatives of varying length and characteristics were synthesized chemically and evaluated for their ability to inhibit the growth of clinical N. gonorrhoeae isolates. Synthetic BmKn2 displayed potent activity against 18 clinical isolates of N. gonorrhoeae with MIC50 values of 6.9-27.6 μM. BmKn2 exerted its antibacterial activity via a bactericidal mechanism. Cyclic BmKn1 did not show antigonococcal activity. Decreasing the cationicity and helix percentage at the C-terminus of BmKn2 reduced the potency against N. gonorrhoeae. Taken together, the BmKn1 peptide can be developed as a topical therapeutic agent for treating multidrug-resistant strains of N. gonorrhoeae infections. PMID:24184420

  16. Responsiveness of different citrus genotypes to the Xanthomonas citri ssp. citri-derived pathogen-associated molecular pattern (PAMP) flg22 correlates with resistance to citrus canker.

    PubMed

    Shi, Qingchun; Febres, Vicente J; Jones, Jeffrey B; Moore, Gloria A

    2015-06-01

    The bacterial agent of citrus canker disease (Xanthomonas citri ssp. citri, Xcc) has caused tremendous economic losses to the citrus industry around the world. Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is important to plant immunity. In this study, we compared the defence responses of citrus canker-resistant and citrus canker-susceptible genotypes to the Xcc-derived PAMP flg22 (Xflg22) by analysing the expression of 20 citrus defence-associated genes. We showed that, in the most resistant genotype, 'Nagami' kumquat, there was significant induction of several defence genes (EDS1, NDR1, PBS1, RAR1, SGT1, PAL1, NPR2 and NPR3) as early as 6 h and up to 72 h after Xflg22 treatment. At the other end of the spectrum, highly susceptible 'Duncan' grapefruit showed no induction of the same defence genes, even 120 h after treatment. Citrus genotypes with partial levels of resistance showed intermediate levels of transcriptional reprogramming that correlated with their resistance level. Xflg22 also triggered a rapid oxidative burst in all genotypes which was higher and accompanied by the induction of PTI marker genes (WRKY22 and GST1) only in the more resistant genotypes. Pretreatment with Xflg22 prior to Xcc inoculation inhibited bacterial growth in kumquat, but not in grapefruit. A flagellin-deficient Xcc strain (XccΔfliC) showed greater growth increase relative to wild-type Xcc in kumquat than in grapefruit. Taken together, our results indicate that Xflg22 initiates strong PTI in canker-resistant genotypes, but not in susceptible ones, and that a robust induction of PTI is an important component of citrus resistance to canker. PMID:25231217

  17. Novel Glycoconjugate of 8-Fluoro Norfloxacin Derivatives as Gentamicin-resistant Staphylococcus aureus Inhibitors: Synthesis and Molecular Modelling Studies.

    PubMed

    Azad, Chandra S; Bhunia, Shome S; Krishna, Atul; Shukla, Praveen K; Saxena, Anil K

    2015-10-01

    Antibiotic resistance has been the subject of interest in clinical practice due to high prevalence of antibiotic-resistant pathogenic organisms. In view of the prevalence of lesser resistance in antibiotics belonging to aminoglycoside class of compounds viz. Food and Drug Administration-approved gentamicin for the treatment of Staphylococcus infections, which also has instances of resistance in the clinical isolates of Staphylococcus aureus, a series of novel glycoconjugates of 8-fluoro norfloxacin analogues with high regio-selectivity by employing copper (I)-catalyzed 1, 3-dipolar cycloaddition of 1-O-propargyl monosaccharides has been synthesized and evaluated for the antibacterial activity against gentamicin resistance Staphylococcus aureus. Among these compounds, the compound 10g showed better antibacterial activity (MIC = 3.12 μg/ml) than gentamicin (Escherichia coli (12.5 μg/ml), Staphylococcus aureus (6.25 μg/ml) and Klebsiella pneumonia (6.25 μg/ml), including gentamicin resistant (>50 μg/ml) strain in vitro). The docking studies suggest DNA gyrase of Staphylococcus aureus as a probable target for the antibacterial action of compound 10g. PMID:25546316

  18. Studies on the mechanism of resistance to mitomycin C and porfiromycin in a human cell strain derived from a cancer-prone individual.

    PubMed

    Marshall, R S; Paterson, M C; Rauth, A M

    1991-05-01

    The mechanism of aerobic resistance to the quinone-containing anti-tumour agents mitomycin C (MMC) and porfiromycin (PM) has been investigated using non-transformed human cells. One of the cell strains used (3437T) was derived from an afflicted member of a cancer-prone family. This cell strain had been shown previously to be six times more resistant to the cytotoxic effects of these agents under aerobic but not hypoxic conditions when compared to a cell strain derived from an unrelated, normal donor (GM38). Differences could not be detected in the ability of cell sonicates prepared from either cell strain to produce alkylating species under aerobic conditions using a 4-(p-nitrobenzyl)pyridine assay. However, using 3H-labelled PM to monitor rapid drug uptake and subsequent accumulation due to drug metabolism, results were obtained indicating that the resistant cell strain (3437T) was deficient in an enzymatic pathway capable of metabolizing these compounds under aerobic but not hypoxic conditions. Dicumarol, an inhibitor of the quinone reductase DT-diaphorase (EC 1.6.99.2), decreased aerobic drug accumulation and cytotoxicity in the control cell strain, but did not alter the lack of accumulation noted in the resistant cell strain. Under hypoxic conditions, dicumarol increased cytotoxicity and drug accumulation in both cell strains. The mechanism of this enhanced cytotoxicity remains unclear. These results suggested that the resistant cells were deficient in the enzyme DT-diaphorase, a potential activator of PM. Enzymatic assays confirmed this and revealed no alterations in cytochrome P450 reductase (EC 1.6.2.4) activity or glutathione content. No protein characteristic of DT-diaphorase was detected in the resistant cell strain using a polyclonal rabbit-anti-rat antibody raised against this enzyme. Southern blot analysis using a rat DT-diaphorase cDNA probe demonstrated differences between the normal and resistant cell strains in the restriction fragment patterns

  19. Activation of the Silent Secondary Metabolite Production by Introducing Neomycin-Resistance in a Marine-Derived Penicillium purpurogenum G59

    PubMed Central

    Wu, Chang-Jing; Yi, Le; Cui, Cheng-Bin; Li, Chang-Wei; Wang, Nan; Han, Xiao

    2015-01-01

    Introduction of neomycin-resistance into a marine-derived, wild-type Penicillium purpurogenum G59 resulted in activation of silent biosynthetic pathways for the secondary metabolite production. Upon treatment of G59 spores with neomycin and dimethyl sulfoxide (DMSO), a total of 56 mutants were obtained by single colony isolation. The acquired resistance of mutants to neomycin was testified by the resistance test. In contrast to the G59 strain, the EtOAc extracts of 28 mutants inhibited the human cancer K562 cells, indicating that the 28 mutants have acquired the capability to produce bioactive metabolites. HPLC-photodiode array detector (PDAD)-UV and HPLC-electron spray ionization (ESI)-MS analyses further indicated that diverse secondary metabolites have been newly produced in the bioactive mutant extracts. Followed isolation and characterization demonstrated that five bioactive secondary metabolites, curvularin (1), citrinin (2), penicitrinone A (3), erythro-23-O-methylneocyclocitrinol (4) and 22E-7α-methoxy-5α,6α-epoxyergosta-8(14),22-dien-3β-ol (5), were newly produced by a mutant, 4-30, compared to the G59 strain. All 1–5 were also not yet found in the secondary metabolites of other wild type P. purpurogenum strains. Compounds 1–5 inhibited human cancer K562, HL-60, HeLa and BGC-823 cells to varying extents. Both present bioassays and chemical investigations demonstrated that the introduction of neomycin-resistance into the marine-derived fungal G59 strain could activate silent secondary metabolite production. The present work not only extended the previous DMSO-mediated method for introducing drug-resistance in fungi both in DMSO concentrations and antibiotics, but also additionally exemplified effectiveness of this method for activating silent fungal secondary metabolites. This method could be applied to other fungal isolates to elicit their metabolic potentials to investigate secondary metabolites from silent biosynthetic pathways. PMID:25913704

  20. Deep electrical resistivity structure of the northwestern U.S. derived from 3-D inversion of USArray magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Meqbel, Naser M.; Egbert, Gary D.; Wannamaker, Philip E.; Kelbert, Anna; Schultz, Adam

    2014-09-01

    Long period (10-20,000 s) magnetotelluric (MT) data are being acquired across the continental USA on a quasi-regular grid of ˜70 km spacing as an electromagnetic component of the National Science Foundation EarthScope/USArray Program. These data are sensitive to fluids, melts, and other orogenic indicators, and thus provide a valuable complement to other components of EarthScope. We present and interpret results of 3-D MT data inversion from 325 sites acquired from 2006-2011 to provide a regional scale view of electrical resistivity from the middle crust to nearly the mantle transition zone, covering an area from NW Washington to NW Colorado. Beneath the active extensional subprovinces in the south-central region, on average we see a resistive upper crust, and then extensive areas of low resistivity in the lower crust and uppermost mantle. Further below, much of the upper half of the upper mantle appears moderately resistive, then subsequently the lower upper mantle becomes moderately conductive. This column suggests a dynamic process of moderately hydrated and fertile deeper upper mantle upwelling during extension, intersection of that material with the damp solidus causing dehydration and melting, and upward exodus of generated mafic melts to pond and exsolve saline fluids near Moho levels. Lithosphere here is very thin. To the east and northeast, thick sections of resistive lithosphere are imaged under the Wyoming and Medicine Hat Cratons. These are punctuated with numerous electrically conductive sutures presumably containing graphitic or sulfide-bearing meta-sediments deeply underthrust and emplaced during ancient collisions. Below Cascadia, the subducting Juan de Fuca and Gorda lithosphere appears highly resistive. Suspected oceanic lithosphere relicts in the central NW part of the model domain also are resistive, including the accreted “Siletzia” terrane beneath the Coast Ranges and Columbia Embayment, and the seismically fast “slab curtain” beneath

  1. Reliable control of filament formation in resistive memories by self-assembled nanoinsulators derived from a block copolymer.

    PubMed

    You, Byoung Kuk; Park, Woon Ik; Kim, Jong Min; Park, Kwi-Il; Seo, Hyeon Kook; Lee, Jeong Yong; Jung, Yeon Sik; Lee, Keon Jae

    2014-09-23

    Resistive random access memory (ReRAM) is a promising candidate for future nonvolatile memories. Resistive switching in a metal-insulator-metal structure is generally assumed to be caused by the formation/rupture of nanoscale conductive filaments (CFs) under an applied electric field. The critical issue of ReRAM for practical memory applications, however, is insufficient repeatability of the operating voltage and resistance ratio. Here, we present an innovative approach to reliably and reproducibly control the CF growth in unipolar NiO resistive memory by exploiting uniform formation of insulating SiOx nanostructures from the self-assembly of a Si-containing block copolymer. In this way, the standard deviation (SD) of set and reset voltages was markedly reduced by 76.9% and 59.4%, respectively. The SD of high resistance state also decreased significantly, from 6.3 × 10(7) Ω to 5.4 × 10(4) Ω. Moreover, we report direct observations of localized metallic Ni CF formation and their controllable growth using electron microscopy and discuss electrothermal simulation results based on the finite element method supporting our analysis results. PMID:25192434

  2. Identification of expressed resistance gene-like sequences by data mining in 454-derived transcriptomic sequences of common bean (Phaseolus vulgaris L.)

    PubMed Central

    2012-01-01

    Background Common bean (Phaseolus vulgaris L.) is one of the most important legumes in the world. Several diseases severely reduce bean production and quality; therefore, it is very important to better understand disease resistance in common bean in order to prevent these losses. More than 70 resistance (R) genes which confer resistance against various pathogens have been cloned from diverse plant species. Most R genes share highly conserved domains which facilitates the identification of new candidate R genes from the same species or other species. The goals of this study were to isolate expressed R gene-like sequences (RGLs) from 454-derived transcriptomic sequences and expressed sequence tags (ESTs) of common bean, and to develop RGL-tagged molecular markers. Results A data-mining approach was used to identify tentative P. vulgaris R gene-like sequences from approximately 1.69 million 454-derived sequences and 116,716 ESTs deposited in GenBank. A total of 365 non-redundant sequences were identified and named as common bean (P. vulgaris = Pv) resistance gene-like sequences (PvRGLs). Among the identified PvRGLs, about 60% (218 PvRGLs) were from 454-derived sequences. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis confirmed that PvRGLs were actually expressed in the leaves of common bean. Upon comparison to P. vulgaris genomic sequences, 105 (28.77%) of the 365 tentative PvRGLs could be integrated into the existing common bean physical map. Based on the syntenic blocks between common bean and soybean, 237 (64.93%) PvRGLs were anchored on the P. vulgaris genetic map and will need to be mapped to determine order. In addition, 11 sequence-tagged-site (STS) and 19 cleaved amplified polymorphic sequence (CAPS) molecular markers were developed for 25 unique PvRGLs. Conclusions In total, 365 PvRGLs were successfully identified from 454-derived transcriptomic sequences and ESTs available in GenBank and about 65% of PvRGLs were integrated into the common

  3. Novel plasmid conferring kanamycin and tetracycline resistance in the turkey-derived Campylobacter jejuni strain 11601MD.

    PubMed

    Crespo, M D; Altermann, E; Olson, J; Miller, W G; Chandrashekhar, K; Kathariou, S

    2016-07-01

    In Campylobacter spp., resistance to the antimicrobials kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095nt) harboring tet(O) was identified in C. jejuni strain 11601MD, which was isolated from the jejunum of a turkey produced conventionally in North Carolina. Analysis of the p11601MD sequence revealed the presence of a high-GC content cassette with four genes that included tet(O) and a putative aminoglycoside transferase gene (aphA-3) highly similar to kanamycin resistance determinants. Several genes putatively involved in conjugative transfer were also identified on the plasmid. These findings will contribute to a better understanding of the distribution of potentially self-mobilizing plasmids harboring antibiotic resistance determinants in Campylobacter spp. from turkeys and other sources. PMID:27268853

  4. Prevalence of virulence determinants and antimicrobial resistance among commensal Escherichia coli derived from dairy and beef cattle.

    PubMed

    Bok, Ewa; Mazurek, Justyna; Stosik, Michał; Wojciech, Magdalena; Baldy-Chudzik, Katarzyna

    2015-01-01

    Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to

  5. Prevalence of Virulence Determinants and Antimicrobial Resistance among Commensal Escherichia coli Derived from Dairy and Beef Cattle

    PubMed Central

    Bok, Ewa; Mazurek, Justyna; Stosik, Michał; Wojciech, Magdalena; Baldy-Chudzik, Katarzyna

    2015-01-01

    Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to

  6. A new class of nifuroxazide analogues: synthesis of 5-nitrothiophene derivatives with antimicrobial activity against multidrug-resistant Staphylococcus aureus.

    PubMed

    Masunari, Andrea; Tavares, Leoberto Costa

    2007-06-15

    Hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) has been an increasing problem worldwide since the initial reports over 40 years ago. To examine new drug leads with potential antibacterial activities, 14 p-substituted benzoic acid [(5-nitro-thiophen-2-yl)-methylene]-hydrazides were designed, synthesized, and tested against standard and multidrug-resistant S. aureus strains by serial dilution tests. All compounds exhibited significant bacteriostatic activity and some of them also showed bactericidal activity. The results confirmed the potential of this class of compounds as an alternative for the development of selective antimicrobial agents. PMID:17419064

  7. Technological characterization and survival of the exopolysaccharide-producing strain Lactobacillus delbrueckii subsp. lactis 193 and its bile-resistant derivative 193+ in simulated gastric and intestinal juices.

    PubMed

    Burns, Patricia; Vinderola, Gabriel; Reinheimer, Jorge; Cuesta, Isabel; de Los Reyes-Gavilán, Clara G; Ruas-Madiedo, Patricia

    2011-08-01

    The capacity of lactic acid bacteria to produce exopolysaccharides (EPS) conferring microorganisms a ropy phenotype could be an interesting feature from a technological point of view. Progressive adaptation to bile salts might render some lactobacilli able to overcome physiological gut barriers but could also modify functional properties of the strain, including the production of EPS. In this work some technological properties and the survival ability in simulated gastrointestinal conditions of Lactobacillus delbrueckii subsp. lactis 193, and Lb. delbrueckii subsp. lactis 193+, a strain with stable bile-resistant phenotype derived thereof, were characterized in milk in order to know whether the acquisition of resistance to bile could modify some characteristics of the microorganism. Both strains were able to grow and acidify milk similarly; however the production of ethanol increased at the expense of the aroma compound acetaldehyde in milk fermented by the strain 193+, with respect to milk fermented by the strain 193. Both microorganisms produced a heteropolysaccharide composed of glucose and galactose, and were able to increase the viscosity of fermented milks. In spite of the higher production yield of EPS by the bile-resistant strain 193+, it displayed a lower ability to increase viscosity than Lb. delbrueckii subsp. lactis 193. Milk increased survival in simulated gastric juice; the presence of bile improved adhesion to the intestinal cell line HT29-MTX in both strains. However, the acquisition of a stable resistance phenotype did not improve survival in simulated gastric and intestinal conditions or the adhesion to the intestinal cell line HT29-MTX. Thus, Lb. delbrueckii subsp. lactis 193 presents suitable technological properties for the manufacture of fermented dairy products; the acquisition of a stable bile-resistant phenotype modified some properties of the microorganism. This suggests that the possible use of bile-resistant derivative strains should be

  8. A 20(S)-protopanoxadiol derivative overcomes multi-drug resistance by antagonizing ATP-binding cassette subfamily B member 1 transporter function

    PubMed Central

    Chen, Wantao; Xu, Qin; Xiao, Meng; Hu, Lihong; Mao, Li; Wang, Xu

    2016-01-01

    In cancer cells, failure of chemotherapy is often caused by the ATP-binding cassette subfamily B member 1 (ABCB1), and few drugs have been successfully developed to overcome ABCB1-mediated multi-drug resistance (MDR). To suppress ABCB1 activity, we previously designed and synthesized a new series of derivatives based on 20(S)-protopanoxadiol (PPD). In the present study, we investigated the role of PPD derivatives in the function of ABC transporters. Non-toxic concentrations of the PPD derivative PPD12 sensitized ABCB1-overexpressing cells to their anti-cancer substrates better than either the parental PPD or inactive PPD11. PPD12 increased intracellular accumulation of adriamycin and rhodamine123 in resistant cancer cells. Although PPD12 did not suppress the expression of ABCB1 mRNA or protein, it stimulated the activity of ABCB1 ATPase. Because PPD12 is a competitive inhibitor, it was predicted to bind to the large hydrophobic cavity of homology-modeled human ABCB1. PPD12 also enhanced the efficacy of adriamycin against ABCB1-overexpressing KB/VCR xenografts in nude mice. In conclusion, PPD12 enhances the efficacy of substrate drugs in ABCB1-overexpressing cancer cells. These findings suggest that a combination therapy consisting of PPD12 with conventional chemotherapeutic agents may be an effective treatment for ABCB1-mediated MDR cancer patients. PMID:26824187

  9. 3-Dimensional Patient-Derived Lung Cancer Assays Reveal Resistance to Standards-of-Care Promoted by Stromal Cells but Sensitivity to Histone Deacetylase Inhibitors.

    PubMed

    Onion, David; Argent, Richard H; Reece-Smith, Alexander M; Craze, Madeleine L; Pineda, Robert G; Clarke, Philip A; Ratan, Hari L; Parsons, Simon L; Lobo, Dileep N; Duffy, John P; Atherton, John C; McKenzie, Andrew J; Kumari, Rajendra; King, Peter; Hall, Brett M; Grabowska, Anna M

    2016-04-01

    There is a growing recognition that current preclinical models do not reflect the tumor microenvironment in cellular, biological, and biophysical content and this may have a profound effect on drug efficacy testing, especially in the era of molecular-targeted agents. Here, we describe a method to directly embed low-passage patient tumor-derived tissue into basement membrane extract, ensuring a low proportion of cell death to anoikis and growth complementation by coculture with patient-derived cancer-associated fibroblasts (CAF). A range of solid tumors proved amenable to growth and pharmacologic testing in this 3D assay. A study of 30 early-stage non-small cell lung cancer (NSCLC) specimens revealed high levels of de novo resistance to a large range of standard-of-care agents, while histone deacetylase (HDAC) inhibitors and their combination with antineoplastic drugs displayed high levels of efficacy. Increased resistance was seen in the presence of patient-derived CAFs for many agents, highlighting the utility of the assay for tumor microenvironment-educated drug testing. Standard-of-care agents showed similar responses in the 3D ex vivo and patient-matched in vivo models validating the 3D-Tumor Growth Assay (3D-TGA) as a high-throughput screen for close-to-patient tumors using significantly reduced animal numbers. Mol Cancer Ther; 15(4); 753-63. ©2016 AACR. PMID:26873730

  10. Overexpression of FGFR2 contributes to inherent resistance to MET inhibitors in MET-amplified patient-derived gastric cancer xenografts

    PubMed Central

    LIU, KAI; SONG, XILIN; ZHU, MEIRONG; MA, HENG

    2015-01-01

    Gastric cancer is one of the most malignant diseases and one of the leading causes of cancer-associated mortality worldwide. Although advances have been made in surgical techniques, perioperative management and the combined use of surgery with chemotherapy and/or radiotherapy, patients with advanced stage gastric cancer continue to face poor outcomes. Furthermore, it was reported that MET gene amplification and overexpression predicted the sensitivity to MET inhibitors in gastric cancer. However, the identification of drug-resistant tumors has encouraged the pre-emptive elucidation of the possible mechanisms of clinical resistance. The current study assessed a number of patient-derived gastric cancer models with MET amplification and overexpression, including CNGAS028. The tumor tissues were subjected to microarray analysis (using single nucleotide polymorphism 6.0 and human genome U133 arrays) followed by western blotting. The results demonstrated that CNGAS028 xenograft tumors did not respond to treatment with a selective MET inhibitor. Additional analysis indicated that FGFR2 overexpression contributed to the resistance to MET inhibitors. Furthermore, treatment with a combination of fibroblast growth factor receptor 2 and MET inhibitors inhibited the growth of CNGAS028 xenograft tumors in vivo. In conclusion, the current results aid in understanding the mechanism of inherent resistance to selective MET inhibitors as well as provide important information for patient selection and clinical treatment strategies. PMID:26622787

  11. Development and characterization of wheat lines carrying stem rust resistance gene Sr43 derived from Thinopyrum ponticum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem rust resistance gene Sr43, transferred into common wheat (Triticum aestivum) from tall wheatgrass (Thinopyrum ponticum), is an effective gene against stem rust Ug99 races. However, this gene has not been used in wheat breeding because it is located on a large Th. ponticum 7el2 chromosome segme...

  12. Phytochemical analysis and cytotoxicity towards multidrug-resistant leukemia cells of essential oils derived from Lebanese medicinal plants.

    PubMed

    Saab, Antoine M; Guerrini, Alessandra; Sacchetti, Gianni; Maietti, Silvia; Zeino, Maʼen; Arend, Joachim; Gambari, Roberto; Bernardi, Francesco; Efferth, Thomas

    2012-12-01

    Juniperus excelsa fruit essential oil as well as J. oxycedrus, Cedrus libani, and Pinus pinea wood essential oils have been obtained with yields between 2.2 ± 0.3 % to 3.4 ± 0.5 % and analyzed by gas chromatography. Sesquiterpenes mainly characterized C. libani and J. oxycedrus essential oils, while in P. pinea and J. excelsa, monoterpenes were the most abundant compounds. In J. oxycedrus, cis-calamenene (7.8 %), cuparene (3.8 %), and cis-thujopsenal (2.0 %) have been detected for the first time. The cytotoxic activity of these essential oils against drug-sensitive CCRF-CEM and multidrug-resistant P-glycoprotein-expressing CEM/ADR5000 leukemia cells has been investigated (IC₅₀ values: 29.46 to 61.54 µg/mL). Remarkably, multidrug-resistant CEM/ADR5000 cells did not reveal cross-resistance, indicating that these essential oils might be useful to treat otherwise drug-resistant and refractory tumors. PMID:23154840

  13. Evaluation and Characterization of Seedling Resistances to Stem Rust Ug99 Races in Wheat-Alien Species Derivatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stem rust, a devastating disease (caused by Puccinia graminis Pers.:Pers. f. sp. tritici Eriks. & Henn.) of wheat (Triticum aestivium L.), has been effectively controlled worldwide for the past 50 years by deployment of stem rust resistance (Sr) genes in wheat cultivars. However, a new stem rust ra...

  14. Planktonic and biofilm community characterization and Salmonella resistance of 14-day old chicken cecal microflora derived continuous-flow cultures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    These studies were initiated to compare the composition of GIT bacterial communities in birds during the transition period in age where their susceptibility to Salmonella shifts to resistance. One of the challenges to developing probiotics is to develop an efficacious culture of minimal diversity, ...

  15. Selection of VSH-derived Pol-line honey bees and evaluation of their Varroa-resistance characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Honey bees, Apis mellifera, that have high expression of the trait “Varroa sensitive hygiene” (VSH) have good resistance to Varroa destructor. We selected “Pol-line” bees by outcrossing VSH queens in three U.S. commercial beekeeping companies annually during 2008-2014 and selecting colonies with the...

  16. Endothelial cell-derived angiopoietin-2 is a therapeutic target in treatment-naive and bevacizumab-resistant glioblastoma.

    PubMed

    Scholz, Alexander; Harter, Patrick N; Cremer, Sebastian; Yalcin, Burak H; Gurnik, Stefanie; Yamaji, Maiko; Di Tacchio, Mariangela; Sommer, Kathleen; Baumgarten, Peter; Bähr, Oliver; Steinbach, Joachim P; Trojan, Jörg; Glas, Martin; Herrlinger, Ulrich; Krex, Dietmar; Meinhardt, Matthias; Weyerbrock, Astrid; Timmer, Marco; Goldbrunner, Roland; Deckert, Martina; Braun, Christian; Schittenhelm, Jens; Frueh, Jochen T; Ullrich, Evelyn; Mittelbronn, Michel; Plate, Karl H; Reiss, Yvonne

    2016-01-01

    Glioblastoma multiforme (GBM) is treated by surgical resection followed by radiochemotherapy. Bevacizumab is commonly deployed for anti-angiogenic therapy of recurrent GBM; however, innate immune cells have been identified as instigators of resistance to bevacizumab treatment. We identified angiopoietin-2 (Ang-2) as a potential target in both naive and bevacizumab-treated glioblastoma. Ang-2 expression was absent in normal human brain endothelium, while the highest Ang-2 levels were observed in bevacizumab-treated GBM. In a murine GBM model, VEGF blockade resulted in endothelial upregulation of Ang-2, whereas the combined inhibition of VEGF and Ang-2 leads to extended survival, decreased vascular permeability, depletion of tumor-associated macrophages, improved pericyte coverage, and increased numbers of intratumoral T lymphocytes. CD206(+) (M2-like) macrophages were identified as potential novel targets following anti-angiogenic therapy. Our findings imply a novel role for endothelial cells in therapy resistance and identify endothelial cell/myeloid cell crosstalk mediated by Ang-2 as a potential resistance mechanism. Therefore, combining VEGF blockade with inhibition of Ang-2 may potentially overcome resistance to bevacizumab therapy. PMID:26666269

  17. GENETIC CHARACTERIZATION AND CORRELATION TO MULTIDRUG RESISTANCE OF ISOLATES OF SALMONELLA NEWPORT DERIVED FROM BEEF AND DAIRY CATTLE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High-throughput genotyping of Salmonella isolates obtained from food production animals is an essential component of food safety to evaluate pathogenic and antimicrobial resistance profiles. A total of 99 strains of Salmonella enterica serovar Newport were studied by pulsed-field gel electrophoresi...

  18. Development and characterization of wheat lines with Sr37 for stem rust resistance derived from wild Timopheev's wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The stem rust resistance gene Sr37, an effective gene against the newly emerged Ug99 races of Puccinia graminis f. sp. tritici in wheat, was originally transferred from wild Timopheev's wheat (Triticum timopheevii Zhuk, AAGG genomes) through a translocation between wheat chromosome 4B and T. timophe...

  19. Rye-derived powdery mildew resistance gene Pm8 in wheat is suppressed by the Pm3 locus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic suppression of disease resistance is occasionally observed in hexaploid wheat or in its interspecific crosses. The phenotypic effects of genes moved to wheat from relatives with lower ploidy are often smaller than in the original sources, suggesting the presence of modifiers or partial inhib...

  20. Genetic mapping of MlUM15: an Aegilops neglecta-derived powdery mildew resistance gene in common wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Powdery mildew, caused by Blumeria graminis DC f. sp. tritici, is a major fungal disease of wheat (Triticum aestivum L.) in cool and humid climates. Race-specific host plant resistance is a reliable, economical, and environmentally benign form of disease prevention. The identification of molecular m...

  1. MIAG12: A Triticum timopheevii-derived powdery mildew resistance gene in common wheat on chromosome 7AL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat powdery mildew is an economically important disease in cool and humid 2 environments. Powdery mildew causes yield losses as high as 48 percent through a reduction in 3 tiller survival, kernels per head and kernel size. Race-specific host resistance is the most 4 consistent, environmentally fri...

  2. Resistance to the Ug99 race group of Puccinia graminis f. sp. tritici in wheat-intra/intergeneric hybrid derivatives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New races of Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, threaten global wheat production. In particular, races belonging to the Ug99 race group, threaten wheat yield. Genetic resistance remains the most effective means for controlling this disease. A collection of 546 whe...

  3. Synthesis and Evaluation of 1-Substituted-Biguanide Derivatives as Anti-Diabetic Agents for Type II Diabetes Insulin Resistant.

    PubMed

    Abbas, S Y; Basyouni, W M; El-Bayouki, K A M; Abdel-Rahman, R F

    2016-07-01

    New 1-substituted-biguanide derivatives 1-3 were synthesized by the reaction of 2,4-dimethoxyaniline, hydrazine and methylhydrazine with dicyandiamide in diluted hydrochloric acid. The resulting biguanide salts were fully characterized by spectroscopic methods. The synthesized compounds were screened for their anti-diabetic activity with standard metformin drug. Oral treatment of hyperglycemic rats with the synthesized biguanide derivatives (200 mg/kg/day) for 2 weeks significantly decreased the elevated blood glucose level. Oral administration of biguanide derivative 2 significantly decreased the level of total cholesterol. While, the triglycerides level was little decreased following administration of biguanide 1 as compared to hyperglycemic rats. Additionally, anti-diabetic properties towards liver function enzyme activities (AST and ALT) and kidney functions (urea and critinine) as well as histopathological studies relative to metformin hydrochloride were investigated and discussed. PMID:27191826

  4. Resistive Switching Properties of Sol-Gel-Derived V-Doped SrTiO3 Thin Films

    NASA Astrophysics Data System (ADS)

    Tang, Zhen Hua; Xiong, Ying; Xu, Ding Lin; Tang, Ming Hua; Wang, Zi Ping; Xiao, Yong Guang; Zeng, Bo Wen; Gu, Xiao Chen; Li, Jian Cheng; Wang, Long Hai

    2013-08-01

    V-doped and undoped SrTiO3 (V:STO and STO) thin films on Pt/Ti/SiO2/Si substrates were synthesized using a sol-gel method to form metal-insulator-metal (MIM) structures. Coexistence of the bipolar and unipolar resistive switching (BRS and URS) modes in Pt/STO/Pt and Pt/V:STO/Pt structures was observed as a irreversible transition from BRS to URS on adjustment of the compliance current ( I comp). Both states were stable and reproducible over 60 cycles, and the maximum operating voltage of the Pt/STO/Pt was reduced from 10 V to 2 V by doping with V. Linear fitting of current-voltage curves suggests that space-charge-limited leakage was the limiting leakage mechanism for these two devices. Based on these results, a switching mechanism based on filament theory is proposed to explain both resistive switching modes.

  5. Resistance to Spodoptera frugiperda (Lepidoptera: Noctuidae) and Euxesta stigmatias (Diptera: Ulidiidae) in sweet corn derived from exogenous and endogenous genetic systems.

    PubMed

    Nuessly, G S; Scully, B T; Hentz, M G; Beiriger, R; Snook, M E; Widstrom, N W

    2007-12-01

    Field trials using Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) and Euxesta stigmatias Loew (Diptera: Ulidiidae) were conducted to evaluate resistance and potential damage interactions between these two primary corn, Zea mays L., pests against Lepidoptera-resistant corn varieties derived from both endogenous and exogenous sources. The endogenous source of resistance was maysin, a C-glycosyl flavone produced in high concentrations in varieties 'Zapalote Chico 2451' and 'Zapalote Chico sh2'. The exogenous resistance source was the Bacillus thuringiensis (Bt)11 gene that expresses Cry1A(b) insecticidal protein found in 'Attribute GSS-0966'. Damage by the two pests was compared among these resistant varieties and the susceptible 'Primetime'. Single-species tests determined that the Zapalote Chico varieties and GSS-0966 effectively reduced S. frugiperda larval damage compared with Primetime. E. stigmatias larval damage was less in the Zapalote Chico varieties than the other varieties in single-species tests. E. stigmatias damage was greater on S. frugiperda-infested versus S. frugiperda-excluded ears. Ears with S. frugiperda damage to husk, silk and kernels had greater E. stigmatias damage than ears with less S. frugiperda damage. Reversed phase high-performance liquid chromatography analysis of nonpollinated corn silk collected from field plots determined that isoorientin, maysin, and apimaysin plus 3'-methoxymaysin concentrations followed the order Zapalote Chico sh2 > Zapalote Chico 2451 > Attribute GSS-0966 = Primetime. Chlorogenic acid concentrations were greatest in Zapalote Chico 2451. The two high maysin Zapalote Chico varieties did as well against fall armyworm as the Bt-enhanced GSS-0966, and they outperformed GSS-0966 against E. stigmatias. PMID:18232407

  6. A Novel Plant Sesquiterpene Lactone Derivative, DETD-35, Suppresses BRAFV600E Mutant Melanoma Growth and Overcomes Acquired Vemurafenib Resistance in Mice.

    PubMed

    Feng, Jia-Hua; Nakagawa-Goto, Kyoko; Lee, Kuo-Hsiung; Shyur, Lie-Fen

    2016-06-01

    Acquired resistance to vemurafenib develops through reactivation of RAF/MEK/ERK signaling or bypass mechanisms. Recent combination therapies such as a MEK inhibitor combined with vemurafenib show improvement in major clinical end points, but the percentage of patients with adverse toxic events is higher than with vemurafenib monotherapy and most patients ultimately relapse. Therefore, there is an urgent need to develop new antimelanoma drugs and/or adjuvant agents for vemurafenib therapy. In this study, we created a novel semiorganically modified derivative, DETD-35, from deoxyelephantopin (DET), a plant sesquiterpene lactone demonstrated as an anti-inflammatory and anti-mammary tumor agent. Our results show that DETD-35 inhibited proliferation of a panel of melanoma cell lines, including acquired vemurafenib resistance A375 cells (A375-R) established in this study, with superior activities to DET and no cytotoxicity to normal melanocytes. DETD-35 suppressed tumor growth and reduced tumor mass as effectively as vemurafenib in A375 xenograft study. Furthermore, DETD-35 also reduced tumor growth in both acquired (A375-R) and intrinsic (A2058) vemurafenib resistance xenograft models, where vemurafenib showed no antitumor activity. Notably, the combination of DETD-35 and vemurafenib exhibited the most significant effects in both in vitro and in vivo xenograft studies due to synergism of the compound and the drug. Mechanistic studies suggested that DETD-35 overcame acquired vemurafenib resistance at least in part through deregulating MEK-ERK, Akt, and STAT3 signaling pathways and promoting apoptosis of cancer cells. Overall, our results suggest that DETD-35 may be useful as a therapeutic or adjuvant agent against BRAF(V600E) mutant and acquired vemurafenib resistance melanoma. Mol Cancer Ther; 15(6); 1163-76. ©2016 AACR. PMID:27048951

  7. New hypotheses derived from the structure of a flaviviral Xrn1-resistant RNA: Conservation, folding, and host adaptation

    PubMed Central

    Kieft, Jeffrey S; Rabe, Jennifer L; Chapman, Erich G

    2015-01-01

    Arthropod-borne flaviviruses (FVs) are a growing world-wide health threat whose incidence and range are increasing. The pathogenicity and cytopathicity of these single-stranded RNA viruses are influenced by viral subgenomic non-protein-coding RNAs (sfRNAs) that the viruses produce to high levels during infection. To generate sfRNAs the virus co-opts the action of the abundant cellular exonuclease Xrn1, which is part of the cell's normal RNA turnover machinery. This exploitation of the cellular machinery is enabled by discrete, highly structured, Xrn1-resistant RNA elements (xrRNAs) in the 3′UTR that interact with Xrn1 to halt processive 5′ to 3′ decay of the viral genomic RNA. We recently solved the crystal structure of a functional xrRNA, revealing a novel fold that provides a mechanistic model for Xrn1 resistance. Continued analysis and interpretation of the structure reveals that the tertiary contacts that knit the xrRNA fold together are shared by a wide variety of arthropod-borne FVs, conferring robust Xrn1 resistance in all tested. However, there is some variability in the structures that correlates with unexplained patterns in the viral 3′ UTRs. Finally, examination of these structures and their behavior in the context of viral infection leads to a new hypothesis linking RNA tertiary structure, overall 3′ UTR architecture, sfRNA production, and host adaptation. PMID:26399159

  8. New hypotheses derived from the structure of a flaviviral Xrn1-resistant RNA: Conservation, folding, and host adaptation.

    PubMed

    Kieft, Jeffrey S; Rabe, Jennifer L; Chapman, Erich G

    2015-01-01

    Arthropod-borne flaviviruses (FVs) are a growing world-wide health threat whose incidence and range are increasing. The pathogenicity and cytopathicity of these single-stranded RNA viruses are influenced by viral subgenomic non-protein-coding RNAs (sfRNAs) that the viruses produce to high levels during infection. To generate sfRNAs the virus co-opts the action of the abundant cellular exonuclease Xrn1, which is part of the cell's normal RNA turnover machinery. This exploitation of the cellular machinery is enabled by discrete, highly structured, Xrn1-resistant RNA elements (xrRNAs) in the 3'UTR that interact with Xrn1 to halt processive 5' to 3' decay of the viral genomic RNA. We recently solved the crystal structure of a functional xrRNA, revealing a novel fold that provides a mechanistic model for Xrn1 resistance. Continued analysis and interpretation of the structure reveals that the tertiary contacts that knit the xrRNA fold together are shared by a wide variety of arthropod-borne FVs, conferring robust Xrn1 resistance in all tested. However, there is some variability in the structures that correlates with unexplained patterns in the viral 3' UTRs. Finally, examination of these structures and their behavior in the context of viral infection leads to a new hypothesis linking RNA tertiary structure, overall 3' UTR architecture, sfRNA production, and host adaptation. PMID:26399159

  9. Rapid, low-cost fluorescent assay of β-lactamase-derived antibiotic resistance and related antibiotic susceptibility

    NASA Astrophysics Data System (ADS)

    Erdem, S. Sibel; Khan, Shazia; Palanisami, Akilan; Hasan, Tayyaba

    2014-10-01

    Antibiotic resistance (AR) is increasingly prevalent in low and middle income countries (LMICs), but the extent of the problem is poorly understood. This lack of knowledge is a critical deficiency, leaving local health authorities essentially blind to AR outbreaks and crippling their ability to provide effective treatment guidelines. The crux of the problem is the lack of microbiology laboratory capacity available in LMICs. To address this unmet need, we demonstrate a rapid and simple test of β-lactamase resistance (the most common form of AR) that uses a modified β-lactam structure decorated with two fluorophores quenched due to their close proximity. When the β-lactam core is cleaved by β-lactamase, the fluorophores dequench, allowing assay speeds of 20 min to be obtained with a simple, streamlined protocol. Furthermore, by testing in competition with antibiotics, the β-lactamase-associated antibiotic susceptibility can also be extracted. This assay can be easily implemented into standard lab work flows to provide near real-time information of β-lactamase resistance, both for epidemiological purposes as well as individualized patient care.

  10. Rapid, low-cost fluorescent assay of β-lactamase-derived antibiotic resistance and related antibiotic susceptibility

    PubMed Central

    Erdem, S. Sibel; Khan, Shazia; Palanisami, Akilan; Hasan, Tayyaba

    2014-01-01

    Abstract. Antibiotic resistance (AR) is increasingly prevalent in low and middle income countries (LMICs), but the extent of the problem is poorly understood. This lack of knowledge is a critical deficiency, leaving local health authorities essentially blind to AR outbreaks and crippling their ability to provide effective treatment guidelines. The crux of the problem is the lack of microbiology laboratory capacity available in LMICs. To address this unmet need, we demonstrate a rapid and simple test of β-lactamase resistance (the most common form of AR) that uses a modified β-lactam structure decorated with two fluorophores quenched due to their close proximity. When the β-lactam core is cleaved by β-lactamase, the fluorophores dequench, allowing assay speeds of 20 min to be obtained with a simple, streamlined protocol. Furthermore, by testing in competition with antibiotics, the β-lactamase-associated antibiotic susceptibility can also be extracted. This assay can be easily implemented into standard lab work flows to provide near real-time information of β-lactamase resistance, both for epidemiological purposes as well as individualized patient care. PMID:25321396

  11. A Vancomycin Derivative with a Pyrophosphate-Binding Group: A Strategy to Combat Vancomycin-Resistant Bacteria.

    PubMed

    Yarlagadda, Venkateswarlu; Sarkar, Paramita; Samaddar, Sandip; Haldar, Jayanta

    2016-06-27

    Vancomycin, the drug of last resort for Gram-positive bacterial infections, has also been rendered ineffective by the emergence of resistance in such bacteria. To combat the threat of vancomycin-resistant bacteria (VRB), we report the development of a dipicolyl-vancomycin conjugate (Dipi-van), which leads to enhanced inhibition of cell-wall biosynthesis in VRB and displays in vitro activity that is more than two orders of magnitude higher than that of vancomycin. Conjugation of the dipicolyl moiety, which is a zinc-binding ligand, endowed the parent drug with the ability to bind to pyrophosphate groups of cell-wall lipids while maintaining the inherent binding affinity for pentapeptide termini of cell-wall precursors. Furthermore, no detectable resistance was observed after several serial passages, and the compound reduced the bacterial burden by a factor of 5 logs at 12 mg kg(-1) in a murine model of VRB kidney infection. The findings presented in this report stress the potential of our strategy to combat VRB infections. PMID:27010764

  12. Synthesis of methylated quercetin derivatives and their reversal activities on P-gp- and BCRP-mediated multidrug resistance tumour cells.

    PubMed

    Yuan, Jian; Wong, Iris L K; Jiang, Tao; Wang, Si Wen; Liu, Tao; Wen, Bin Jin; Chow, Larry M C; Wan Sheng, Biao

    2012-08-01

    Three methylated quercetins and a series of O-3 substituted 5,7,3',4'-tetra-O-methylated quercetin derivatives have been synthesized and evaluated on the modulating activity of P-gp, BCRP and MRP1 in cancer cell lines. Compound 17 (with a 2-((4-methoxybenzoyl)oxy)ethyl at O-3) is the most potent P-gp modulator. Three derivatives, compound 9 (3,7,3',4'-tetra-O-methylated quercetin), compound 14 (with a 2-((3-oxo-3-(3,4,5trimethoxyphenyl)prop-1-en-1-yl)oxy)ethyl at O-3) and compound 17, consistently exhibited promising BCRP-modulating activity. Interestingly, compound 17 was found to be equipotent against both P-gp and BCRP. Importantly, these synthetic quercetin derivatives did not exhibit any inherent cytotoxicity to cancer cell lines or normal mouse fibroblast cell lines. These quercetin derivatives can be employed as safe and effective modulators of P-gp- or BCRP-mediated drug resistance in cancer. PMID:22743241

  13. Effect of the plant derivative Compound A on the production of corticosteroid-resistant chemokines in airway smooth muscle cells.

    PubMed

    Gavrila, Adelina; Chachi, Latifa; Tliba, Omar; Brightling, Christopher; Amrani, Yassine

    2015-11-01

    Preclinical models of human conditions including asthma showed the therapeutic potential of Compound A (CpdA), a dissociated glucocorticoid (GC) receptor (GRα) ligand. Whether CpdA inhibits GC resistance, a central feature of severe asthma, has not been addressed. We investigated whether CpdA modulates cytokine-induced GC resistance in human airway smooth muscle (ASM) cells. Healthy and asthmatic ASM cells were treated with TNF-α/IFN-γ for 24 hours in the presence or absence of CpdA. ELISA and quantitative PCR assays were used to assess the effect of CpdA on chemokine expression. Activation of GRα by CpdA was assessed by quantitative PCR, immunostaining, and receptor antagonism using RU486. An effect of CpdA on the transcription factor interferon regulatory factor 1 (IRF-1) was investigated using immunoblot, immunostaining, and small interfering RNA (siRNA) knockdown. CpdA inhibited production of fluticasone-resistant chemokines CCL5, CX3CL1, and CXCL10 at protein and mRNA levels in both asthmatic and healthy cells. CpdA failed to induce expression of GC-induced Leucine Zipper while transiently inducing mitogen-activated protein kinase phosphatase 1 (MKP-1) at both mRNA and protein levels. CpdA inhibitory action was not associated with GRα nuclear translocation, nor was it prevented by RU486 antagonism. Activation of IRF-1 by TNF-α/IFN-γ was inhibited by CpdA. IRF-1 siRNA knockdown reduced cytokine-induced CCL5 and CX3CL1 production. siRNA MKP-1 prevented the inhibitory effect of CpdA on cytokine-induced CXCL10 production. For the first time, we show that CpdA inhibits the production of GC-resistant chemokines via GRα-independent mechanisms involving the inhibition of IRF-1 and up-regulation of MKP-1. Thus, targeting CpdA-sensitive pathways in ASM cells represents an alternative therapeutic approach to treat GC resistance in asthma. PMID:25897650

  14. Release of EL54 Sugarbeet Germplasm Derived from WB879 Wild Germplasm With Resistance to Aphanomyces and Excellent Stand Establishment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    EL54 (PI 654357) is a sugarbeet germplasm derived from wild beet (Beta vulgaris ssp. maritima) accession WB879 (PI 540625). EL54 is being released in the interest of broadening the genetic base of sugar beet. The parent accession WB879, collected in 1989 from Port-de-Houet, France (3 m elevation), w...

  15. Effects of dietary plant-derived phytonutrients on the genome-wide profiles and coccidiosis resistance in the broiler chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The present study was conducted to investigate the effects of dietary plant-derived phytonutrients, carvacrol, cinnamaldehyde and Capsicum oleoresin, on the translational regulation of genes associated with immunology, physiology and metabolism using high-throughput microarray analysis and in vivo d...

  16. New results on the resistivity structure of Merapi Volcano(Indonesia), derived from 3D restricted inversion of long-offsettransient electromagnetic data

    SciTech Connect

    Commer, Michael; Helwig, Stefan, L.; Hordt, Andreas; Scholl,Carsten; Tezkan, Bulent

    2006-06-14

    Three long-offset transient electromagnetic (LOTEM) surveyswerecarried out at the active volcano Merapi in Central Java (Indonesia)during the years 1998, 2000, and 2001. The measurements focused on thegeneral resistivity structure of the volcanic edifice at depths of 0.5-2km and the further investigation of a southside anomaly. The measurementswere insufficient for a full 3D inversion scheme, which could enable theimaging of finely discretized resistivity distributions. Therefore, astable, damped least-squares joint-inversion approach is used to optimize3D models with a limited number of parameters. The mode ls feature therealistic simulation of topography, a layered background structure, andadditional coarse 3D blocks representing conductivity anomalies.Twenty-eight LOTEM transients, comprising both horizontal and verticalcomponents of the magnetic induction time derivative, were analyzed. Inview of the few unknowns, we were able to achieve reasonable data fits.The inversion results indicate an upwelling conductor below the summit,suggesting hydrothermal activity in the central volcanic complex. Ashallow conductor due to a magma-filled chamber, at depths down to 1 kmbelow the summit, suggested by earlier seismic studies, is not indicatedby the inversion results. In conjunction with an anomalous-density model,derived from arecent gravity study, our inversion results provideinformation about the southern geological structure resulting from amajor sector collapse during the Middle Merapi period. The density modelallows to assess a porosity range andthus an estimated vertical salinityprofile to explain the high conductivities on a larger scale, extendingbeyond the foothills of Merapi.

  17. Adenine-DNA adducts derived from the highly tumorigenic dibenzo[a,l]pyrene are resistant to nucleotide excision repair while guanine adducts are not

    PubMed Central

    Kropachev, Konstantin; Kolbanovskiy, Marina; Liu, Zhi; Cai, Yuqin; Zhang, Lu; Schwaid, Adam G.; Kolbanovskiy, Alexander; Ding, Shuang; Amin, Shantu; Broyde, Suse; Geacintov, Nicholas E.

    2013-01-01

    The structural origins of differences in susceptibilities of various DNA lesions to nucleotide excision repair (NER) are poorly understood. Here we compared, in the same sequence context, the relative NER dual incision efficiencies elicited by two stereochemically distinct pairs of guanine (N2-dG) and adenine (N6-dA) DNA lesions, derived from enantiomeric genotoxic diol epoxides of the highly tumorigenic fjord region polycyclic aromatic hydrocarbon dibenzo[a,l]pyrene (DB[a,l]P). Remarkably, in cell-free HeLa cell extracts, the guanine adduct with R absolute chemistry at the N2-dG linkage site is ~ 35 times more susceptible to NER dual incisions than the stereochemically identical N6-dA adduct. For the guanine and adenine adducts with S stereochemistry, a similar, but somewhat smaller effect (factor of ~15) is observed. The striking resistance of the bulky N6-dA in contrast to the modest to good susceptibilities of the N2-dG adducts to NER are interpreted in terms of the balance between lesion-induced DNA-distorting and DNA-stabilizing van der Waals interactions in their structures, that are partly reflected in the overall thermal stabilities of the modified duplexes. Our results are consistent with the hypothesis that the high genotoxic activity of DB[a,l]P is related to the formation of NER-resistant and persistent DB[a,l]P-derived adenine adducts in cellular DNA. PMID:23570232

  18. Derivation of Permeability-Pore Relationship for Fractal Porous Reservoirs Using Series-Parallel Flow Resistance Model and Lattice Boltzmann Method

    NASA Astrophysics Data System (ADS)

    Wang, Baoyu; Jin, Yi; Chen, Qing; Zheng, Junling; Zhu, Yibo; Zhang, Xiaobing

    2014-09-01

    Permeability of porous reservoirs plays a significant role in engineering and scientific applications. In this study, we investigated the relationship between pore size fractal dimension (Df) and its porosity, as well as that between Df and the pore structure parameters, and consequentially developed an algorithm to generate pore spaces with arbitrary fractal dimension characterizing the pore size distribution. Using the series-parallel flow resistance model and lattice Boltzmann method (LBM) in combination, we then systematically analyzed the effects of physical properties on the fluid flows in two-dimensional (2D) context, and quantitatively derived a permeability-pore relationship for fractal porous media. The new relationship shows that: (i) the permeability of a fractal porous medium is proportional to the square of its maximum pore size λmax; (ii) the larger the fractal dimension Df of a pore space, the smaller the flow resistance of the porous medium; (iii) porosity φ to the power of (4 - Df)/(2 - Df) is proportional to the permeability of a porous medium; (iv) similar to the Kozeny-Carman (KC) equation, the tortuosity τ has its square inversely proportional to the permeability; more importantly, it is found to be a function of porosity approximately satisfying the relationship τ = φDf-2 in a fractal porous medium. Moreover, we demonstrated that the newly derived fractal permeability-pore relationship is equivalent to KC equation and Poiseuille's law respectively, at Df = 1 and Df = 2.

  19. Cross-resistance profile determination of two second-generation HIV-1 integrase inhibitors using a panel of recombinant viruses derived from raltegravir-treated clinical isolates.

    PubMed

    Van Wesenbeeck, L; Rondelez, E; Feyaerts, M; Verheyen, A; Van der Borght, K; Smits, V; Cleybergh, C; De Wolf, H; Van Baelen, K; Stuyver, L J

    2011-01-01

    The integrase inhibitor raltegravir (RAL) is currently used for the treatment of both treatment-naïve and treatment-experienced HIV-1-infected patients. Elvitegravir (EVG) is in late phases of clinical development. Since significant cross-resistance between RAL and EVG is observed, there is a need for second-generation integrase inhibitors (INIs) with a higher genetic barrier and limited cross-resistance to RAL/EVG. A panel of HIV-1 integrase recombinants, derived from plasma samples from raltegravir-treated patients (baseline and follow-up samples), were used to study the cross-resistance profile of two second-generation integrase inhibitors, MK-2048 and compound G. Samples with Q148H/R mutations had elevated fold change values with all compounds tested. Although samples with the Y143R/C mutation had reduced susceptibility to RAL, they remained susceptible to MK-2048 and compound G. Samples with the N155H mutation had no reduced susceptibility to compound G. In conclusion, our results allowed ranking of the INIs on the basis of the antiviral activities using recombinant virus stocks from RAL-treated patient viruses. The order according to decreasing susceptibility is compound G, MK-2048, and EVG. PMID:20956600

  20. A new cyclic dipeptide penicimutide: the activated production of cyclic dipeptides by introduction of neomycin-resistance in the marine-derived fungus Penicillium purpurogenum G59.

    PubMed

    Wang, Nan; Cui, Cheng-Bin; Li, Chang-Wei

    2016-06-01

    A novel cyclic dipeptide, named penicimutide (1), and four known cyclic dipeptides, cyclo(L-Val-L-Pro) (2), cyclo(L-Ile-L-Pro) (3), cyclo(L-Leu-L-Pro) (4) and cyclo(L-Phe-L-Pro) (5), were isolated from a neomycin-resistant mutant of the marine-derived fungus Penicillium purpurogenum G59. The structure of 1, including the absolute configuration, was determined by spectroscopic and chemical methods, especially NMR and Marfey's analysis. An unusual amino acid in 1, 4,5-didehydro-L-leucine, was found for the first time occurring in nature. HPLC-ESI-MS analysis evidenced that 1-3 were produced only in the mutant strain, but 4 and 5 were produced in both the mutant and parental strains, indicating that the introduction of neomycin-resistance in the mutant activated pathways of 1-3 biosynthesis that were silent in the parental strain. Compound 1 selectively inhibited HeLa cells (among five tested human cancer cell lines) with an inhibition rate (IR %) of 39.4 % at 100 µg/mL, a similar inhibition intensity to that of the positive control 5-fluorouracil (IR % of 41.4 % at 100 µg/mL against HeLa cells). The present work exemplifies the effectiveness of our previous DMSO-mediated method for introducing drug-resistance in fungi to activate silent biosynthetic pathways to obtain new bioactive compounds. PMID:27129688

  1. FSL-1, a bacterial-derived toll-like receptor 2/6 agonist, enhances resistance to experimental HSV-2 infection

    PubMed Central

    2009-01-01

    Background Herpes simplex virus type 2 (HSV-2) is a leading cause of genital ulceration that can predispose individuals to an increased risk of acquiring other sexually transmitted infections. There are no approved HSV-2 vaccines and current suppressive therapies require daily compound administration that does not prevent all recurrences. A promising experimental strategy is the use of toll-like receptor (TLR) agonists to induce an innate immune response that provides resistance to HSV-2 infection. Previous studies showed that anti-herpetic activity varied based on origin of the agonists and activation of different TLR indicating that activity likely occurs through elaboration of a specific innate immune response. To test the hypothesis, we evaluated the ability of a bacterial-derived TLR2/6 agonist (FSL-1) to increase resistance to experimental genital HSV-2 infection. Methods Vaginal application of FSL-1 at selected doses and times was evaluated to identify potential increased resistance to genital HSV-2 infection in the mouse model. The FSL-1 induced cytokine profile was quantified using kinetically collected vaginal lavages. Additionally, cytokine elaboration and organ weights were evaluated after single or multiple FSL-1 doses to establish a preliminary safety profile. Human vaginal EC cultures were used to confirm the mouse model outcomes. Results The results showed that vaginally-applied FSL-1 created an environment resistant to a 25-fold higher HSV-2 challenge dose. Mechanistically, vaginal FSL-1 application led to transient elaboration of cytokines linked to anti-herpetic innate immune responses. No gross local or peripheral immunotoxicity was observed even after multiple dosing. FSL-1 also created an anti-herpetic environment in cultures of human vaginal epithelial cells (EC). Conclusion The results showed, for the first time, that the bacterial-derived TLR2/6 agonist FSL-1 induced significant resistance to HSV-2 infection when applied in mice or human

  2. Agrobacterium tumefaciens-mediated transformation of poinsettia, Euphorbia pulcherrima, with virus-derived hairpin RNA constructs confers resistance to Poinsettia mosaic virus

    PubMed Central

    Spetz, Carl; Haugslien, Sissel; Xing, Shaochen; Dees, Merete W.; Moe, Roar; Blystad, Dag-Ragnar

    2008-01-01

    Agrobacterium-mediated transformation for poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch) is reported here for the first time. Internode stem explants of poinsettia cv. Millenium were transformed by Agrobacterium tumefaciens, strain LBA 4404, harbouring virus-derived hairpin (hp) RNA gene constructs to induce RNA silencing-mediated resistance to Poinsettia mosaic virus (PnMV). Prior to transformation, an efficient somatic embryogenesis system was developed for poinsettia cv. Millenium in which about 75% of the explants produced somatic embryos. In 5 experiments utilizing 868 explants, 18 independent transgenic lines were generated. An average transformation frequency of 2.1% (range 1.2–3.5%) was revealed. Stable integration of transgenes into the poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Both single- and multiple-copy transgene integration into the poinsettia genome were found among transformants. Transgenic poinsettia plants showing resistance to mechanical inoculation of PnMV were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Northern blot analysis of low molecular weight RNA revealed that transgene-derived small interfering (si) RNA molecules were detected among the poinsettia transformants prior to inoculation. The Agrobacterium-mediated transformation methodology developed in the current study should facilitate improvement of this ornamental plant with enhanced disease resistance, quality improvement and desirable colour alteration. Because poinsettia is a non-food, non-feed plant and is not propagated through sexual reproduction, this is likely to be more acceptable even in areas where genetically modified crops are currently not cultivated. PMID:18327592

  3. Agrobacterium tumefaciens-mediated transformation of poinsettia, Euphorbia pulcherrima, with virus-derived hairpin RNA constructs confers resistance to Poinsettia mosaic virus.

    PubMed

    Clarke, Jihong Liu; Spetz, Carl; Haugslien, Sissel; Xing, Shaochen; Dees, Merete W; Moe, Roar; Blystad, Dag-Ragnar

    2008-06-01

    Agrobacterium-mediated transformation for poinsettia (Euphorbia pulcherrima Willd. Ex Klotzsch) is reported here for the first time. Internode stem explants of poinsettia cv. Millenium were transformed by Agrobacterium tumefaciens, strain LBA 4404, harbouring virus-derived hairpin (hp) RNA gene constructs to induce RNA silencing-mediated resistance to Poinsettia mosaic virus (PnMV). Prior to transformation, an efficient somatic embryogenesis system was developed for poinsettia cv. Millenium in which about 75% of the explants produced somatic embryos. In 5 experiments utilizing 868 explants, 18 independent transgenic lines were generated. An average transformation frequency of 2.1% (range 1.2-3.5%) was revealed. Stable integration of transgenes into the poinsettia nuclear genome was confirmed by PCR and Southern blot analysis. Both single- and multiple-copy transgene integration into the poinsettia genome were found among transformants. Transgenic poinsettia plants showing resistance to mechanical inoculation of PnMV were detected by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Northern blot analysis of low molecular weight RNA revealed that transgene-derived small interfering (si) RNA molecules were detected among the poinsettia transformants prior to inoculation. The Agrobacterium-mediated transformation methodology developed in the current study should facilitate improvement of this ornamental plant with enhanced disease resistance, quality improvement and desirable colour alteration. Because poinsettia is a non-food, non-feed plant and is not propagated through sexual reproduction, this is likely to be more acceptable even in areas where genetically modified crops are currently not cultivated. PMID:18327592

  4. An Adenine-DNA Adduct Derived from Nitroreduction of 6-Nitrochrysene is more Resistant to Nucleotide Excision Repair than Guanine-DNA Adducts

    PubMed Central

    Krzeminski, Jacek; Kropachev, Konstantin; Reeves, Dara; Kolbanovskiy, Aleksandr; Kolbanovskiy, Marina; Chen, Kun-Ming; Sharma, Arun K.; Geacintov, Nicholas; Amin, Shantu; El-Bayoumy, Karam

    2013-01-01

    Previous studies in rats, mice and in vitro systems showed that 6-NC can be metabolically activated by two major pathways: 1) the formation of N-hydroxy-6-aminochrysene by nitroreduction to yield three major adducts: N-(dG-8-yl)-6-AC, 5-(dG-N2-yl)-6-AC and N-(dA-8-yl)-6-AC, and 2) the formation of trans-1,2-dihydroxy-1,2-dihydro-6-hydroxylaminochrysene (1,2-DHD-6-NHOH-C) by a combination of nitroreduction and ring oxidation pathways to yield: N-(dG-8-yl)-1,2-DHD-6-AC, 5-(dG-N2-yl)-1,2-DHD-6-AC and N-(dA-8-yl)-1,2-DHD-6-AC. These DNA lesions are likely to cause mutations if they are not removed by cellular defense mechanisms before DNA replication occurs. Here we compared for the first time, in HeLa cell extracts in vitro, the relative nucleotide excision repair (NER) efficiencies of DNA lesions derived from simple nitroreduction and from a combination of nitroreduction and ring oxidation pathways. We show that the N-(dG-8-yl)-1,2-DHD-6-AC adduct is more resistant to NER than the N-(dG-8-yl)-6-AC adduct by a factor of ~2. Furthermore, the N-(dA-8-yl)-6-AC is much more resistant to repair since its NER efficiency is ~ 8-fold lower than that of the N-(dG-8-yl)-6-AC adduct. On the basis of our previous study and the present investigation, lesions derived from 6-NC and benzo[a]pyrene can be ranked from the most to the least resistant lesion as follows: N-(dA-8-yl)-6-AC > N-(dG-8-yl)-1,2-DHD-6-AC > 5-(dG-N2-yl)-6-AC ~ N-(dG-8-yl)-6-AC ~ (+)-7R,8S,9S,10S-benzo[a]pyrene diol epoxide-derived trans-anti-benzo[a]pyrene-N2-dG adduct. The slow repair of the various lesions derived from 6-NC and thus their potential persistence in mammalian tissue, could in part account for the powerful carcinogenicity of 6-NC as compared to B[a]P in the rat mammary gland. PMID:24112095

  5. Enhanced cancer immunotherapy using STAT3-depleted dendritic cells with high Th1-inducing ability and resistance to cancer cell-derived inhibitory factors.

    PubMed

    Iwata-Kajihara, Tomoko; Sumimoto, Hidetoshi; Kawamura, Naoshi; Ueda, Ryo; Takahashi, Tomomi; Mizuguchi, Hiroyuki; Miyagishi, Makoto; Takeda, Kiyoshi; Kawakami, Yutaka

    2011-07-01

    STAT3 signaling constitutes an important negative feedback mechanism for the maintenance of immune homeostasis, a suppressive signal for the Th1 immune response in murine macrophages, and a cancer immune evasion signal in various immune cells. The strategy for STAT3 signal inhibition should be considered, because these features could impede effective cancer immunotherapy. We have evaluated the effects of STAT3 inactivation in dendritic cells (DCs) on immune responses in mice and humans. DCs derived from LysMcre/STAT3(flox/flox) mice displayed higher cytokine production in response to TLR stimulation, activated T cells more efficiently, and were more resistant to the suppression of cytokine production by cancer-derived immunosuppressive factors compared with DCs from control littermates. Antitumor activities of STAT3-depleted and control DCs were compared by intratumoral administration of gp70 Ag peptide-pulsed DCs in the therapeutic MC38 tumor model. Intratumoral administration of STAT3-depleted DCs significantly inhibited MC38 tumor growth of both injected and nontreated remote tumors. The inhibition was accompanied by an increase in gp70-specific T cell response as well as in systemic Th1 immune response. STAT3-depleted human DCs with adenoviral STAT3 short hairpin RNA were also capable of producing more cytokines with TLR stimulation and more resistant to cancer-derived factors, and they induced tumor Ag-specific T cells more efficiently than control DCs. The identified role of DC STAT3 signaling in both in vivo therapeutic tumor models in mice and in vitro-specific T cell induction in humans indicates that STAT3-inactivated DCs may be a promising approach for cancer immunotherapy. PMID:21632716

  6. Development of diagnostic markers for use in breeding potatoes resistant to Globodera pallida pathotype Pa2/3 using germplasm derived from Solanum tuberosum ssp. andigena CPC 2802.

    PubMed

    Moloney, Claire; Griffin, Denis; Jones, Peter W; Bryan, Glenn J; McLean, Karen; Bradshaw, John E; Milbourne, Dan

    2010-02-01

    Quantitative resistance to Globodera pallida pathotype Pa2/3, originally derived from Solanum tuberosum ssp. andigena Commonwealth Potato Collection (CPC) accession 2802, is present in several potato cultivars and advanced breeding lines. One genetic component of this resistance, a large effect quantitative trait locus (QTL) on linkage group IV (which we have renamed GpaIV(adg)(s)) has previously been mapped in the tetraploid breeding line 12601ab1. In this study, we show that GpaIV(adg)(s) is also present in a breeding line called C1992/31 via genetic mapping in an F(1) population produced by crossing C1992/31 with the G. pallida susceptible cultivar Record. C1992/31 is relatively divergent from 12601ab1, confirming that GpaIV(adg)(s) is an ideal target for marker-assisted selection in currently available germplasm. To generate markers exhibiting diagnostic potential for GpaIV(adg)(s), three bacterial artificial chromosome clones were isolated from the QTL region, sequenced, and used to develop 15 primer sets generating single-copy amplicons, which were examined for polymorphisms exhibiting linkage to GpaIV(adg)(s) in C1992/31. Eight such polymorphisms were found. Subsequently, one insertion/deletion polymorphism, three single nucleotide polymorphisms and a specific allele of the microsatellite marker STM3016 were shown to exhibit diagnostic potential for the QTL in a panel of 37 potato genotypes, 12 with and 25 without accession CPC2082 in their pedigrees. STM3016 and one of the SNP polymorphisms, C237(119), were assayed in 178 potato genotypes, arising from crosses between C1992/31 and 16 G. pallida susceptible genotypes, undergoing selection in a commercial breeding programme. The results suggest that the diagnostic markers would most effectively be employed in MAS-based approaches to pyramid different resistance loci to develop cultivars exhibiting strong, durable resistance to G. pallida pathotype Pa2/3. PMID:19882336

  7. Corrosion resistant performances of alkanoic and phosphonic acids derived self-assembled monolayers on magnesium alloy AZ31 by vapor-phase method.

    PubMed

    Ishizaki, Takahiro; Okido, Masazumi; Masuda, Yoshitake; Saito, Naobumi; Sakamoto, Michiru

    2011-05-17

    Alkanoic and phosphonic acid derived self-assembled monolayers (SAMs) were formed on magnesium alloy by the vapor phase method. AFM and XPS studies showed that SAMs were formed on Mg alloy. The chemical and anticorrosive properties of the SAMs prepared on magnesium alloys were characterized using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. Water contact angle measurements revealed that, although SA and ISA have the same headgroup to anchor to the magnesium alloy surface, the packing density on the magnesium alloy surface could be considerably different. The contact angle hysteresis of SAMs with a carboxylate headgroup is much larger than that of SAMs with a phosphonic acid group. The XPS O 1s peaks indicated more likely a mix of mono-, bi-, or tridentate binding of phosphonic acid SAM to the oxide or hydroxide surface of the Mg alloy. The electrochemical measurements showed that the phosphonic acid derived SAM had better corrosion resistance compared to alkanoic acid derived SAM. The chemical stability of SAMs modified magnesium alloy was investigated using water contact angle and XPS measurements. The water contact angle and XPS measurements revealed that the molecular density of OP and PFEP on magnesium alloy would be higher than those of SA and ISA on magnesium alloy. PMID:21504153

  8. Pattern of Functional TTX-Resistant Sodium Channels Reveals a Developmental Stage of Human iPSC- and ESC-Derived Nociceptors.

    PubMed

    Eberhardt, Esther; Havlicek, Steven; Schmidt, Diana; Link, Andrea S; Neacsu, Cristian; Kohl, Zacharias; Hampl, Martin; Kist, Andreas M; Klinger, Alexandra; Nau, Carla; Schüttler, Jürgen; Alzheimer, Christian; Winkler, Jürgen; Namer, Barbara; Winner, Beate; Lampert, Angelika

    2015-09-01

    Human pluripotent stem cells (hPSCs) offer the opportunity to generate neuronal cells, including nociceptors. Using a chemical-based approach, we generated nociceptive sensory neurons from HUES6 embryonic stem cells and retrovirally reprogrammed induced hPSCs derived from fibroblasts. The nociceptive neurons expressed respective markers and showed tetrodotoxin-sensitive (TTXs) and -resistant (TTXr) voltage-gated sodium currents in patch-clamp experiments. In contrast to their counterparts from rodent dorsal root ganglia, TTXr currents of hPSC-derived nociceptors unexpectedly displayed a significantly more hyperpolarized voltage dependence of activation and fast inactivation. This apparent discrepancy is most likely due to a substantial expression of the developmentally important sodium channel NAV1.5. In view of the obstacles to recapitulate neuropathic pain in animal models, our data advance hPSC-derived nociceptors as a better model to study developmental and pathogenetic processes in human nociceptive neurons and to develop more specific small molecules to attenuate pain. PMID:26321143

  9. [Genetics determination of wheat resistance to Puccinia graminis F. sp. tritici deriving from Aegilops cylindrica, Triticum erebuni and amphidiploid 4].

    PubMed

    Babaiants, O V; Babaiants, L T; Horash, A F; Vasil'ev, A A; Trackovetskaia, V A; Paliasn'iĭĭ, V A

    2012-01-01

    The lines of winter soft wheat developed in the Plant Breeding and Genetics Institute contain new effective introgressive Sr-genes. Line 85/06 possess SrAc1 gene, lines 47/06, 54/06, 82/06, 85/06, 87/06, 238/06, and 367/06 possess SrAc1 and SrAc2 derived from Aegilops cylindrica, line 352/06 - SrTe1 and SrTe2 from Triticum erebuni, line 12/86-04 - SrAd1 and SrAd2 from Amphidiploid 4 (Triticum dicoccoides x Triticum tauschii). PMID:22420215

  10. Effects of dietary plant-derived phytonutrients on the genome-wide profiles and coccidiosis resistance in the broiler chickens

    PubMed Central

    2011-01-01

    Background The present study was conducted to investigate the effects of dietary plant-derived phytonutrients, carvacrol, cinnamaldehyde and Capsicum oleoresin, on the translational regulation of genes associated with immunology, physiology and metabolism using high-throughput microarray analysis and in vivo disease challenge model of avian coccidiosis. Methods In this study, we used nutrigenomics technology to investigate the molecular and genetic mechanisms of dietary modulation of host innate immunity and metabolism by three phytonutrients. To validate their immunomodulatory effects in a disease model, young broiler chickens fed a standard diet supplemented with three phytochemicals (carvacrol, cinnamaldehyde, and Capsicum oleoresin) from one day post-hatch were orally challenged with E. acervulina. The body weight gain and fecal oocyst production were used to evaluate coccidiosis disease parameters. Results Analysis of global gene expression profiles of intestinal tissues from phytonutrient-fed birds indicated that Capsicum oleoresin induced the most gene changes compared to the control group where many of these genes were associated with those of metabolism and immunity. The most reliable network induced by dietary cinnamaldehyde treatment was related with the functions of antigen presentation, humoral immune response, and inflammatory disease. Furthermore, dietary supplementation with these phytonutrients significantly protected broiler chickens against live coccidiosis challenge infection based on body weight and parasite fecundity. Conclusions The results of this study provide clear evidence to support the idea that plant-derived phytochemicals possess immune-enhancing properties in chickens and these new findings create a new possibility to develop effective drug-free alternative strategies for disease control for poultry infectious diseases. PMID:21645315