552 research outputs found

    The Adenovirus Type 3 Dodecahedron's RGD Loop Comprises an HSPG Binding Site That Influences Integrin Binding

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    Human type 3 adenovirus dodecahedron (a virus like particle made of twelve penton bases) features the ability to enter cells through Heparan Sulphate Proteoglycans (HSPGs) and integrins interaction and is used as a versatile vector to deliver DNA or proteins. Cryo-EM reconstruction of the pseudoviral particle with Heparan Sulphate (HS) oligosaccharide shows an extradensity on the RGD loop. A set of mutants was designed to study the respective roles of the RGD sequence (RGE mutant) and of a basic sequence located just downstream. Results showed that the RGE mutant binding to the HS deficient CHO-2241 cells was abolished and unexpectedly, mutation of the basic sequence (KQKR to AQAS) dramatically decreased integrin recognition by the viral pseudoparticle. This basic sequence is thus involved in integrin docking, showing a close interplay between HSPGs and integrin receptors

    Digital photographic technique for the production of an artificial eye

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    The use of hand painting an iris button using oil paint remains the conventional method of artificial eye manufacturing. The authors found that replacing this technique with a digital photograph taken of a patient’s unaffected eye offers several advantages over the conventional method but the process from capture to print must be standardised and colour accurate. The authors of this paper suggest a tried and tested formulated photographic process of capture and printing prior to polymerisation. It discusses issues that can arise and how these can be overcome in order to achieve a high-quality print that can be used to produce a ‘life like’ ocular prosthesis

    Survival advantages conferred to colon cancer cells by E-selectin-induced activation of the PI3K-NFκB survival axis downstream of Death receptor-3

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    International audienceABSTRACT: BACKGROUND: Extravasation of circulating cancer cells is a key event of metastatic dissemination that is initiated by the adhesion of cancer cells to endothelial cells. It requires interactions between adhesion receptors on endothelial cells and their counter-receptors on cancer cells. Notably, E-selectin, a major endothelial adhesion receptor, interacts with Death receptor-3 present on metastatic colon carcinoma cells. This interaction confers metastatic properties to colon cancer cells by promoting the adhesion of cancer cells to endothelial cells and triggering the activation of the pro-migratory p38 and pro-survival ERK pathways in the cancer cells. In the present study, we investigated further the mechanisms by which the E-selectin-activated pathways downstream of DR3 confer a survival advantage to colon cancer cells. METHODS: Cell survival has been ascertained by using the WST-1 assay and by evaluating the activation of the PI3 kinase/NFκB survival axis. Apoptosis has been assayed by determining DNA fragmentation by Hoechst staining and by measuring cleavage of caspases-8 and -3. DR3 isoforms have been identified by PCR. For more precise quantification, targeted PCR reactions were carried out, and the amplified products were analyzed by automated chip-based microcapillary electrophoresis on an Agilent 2100 Bioanalyzer instrument. RESULTS: Interaction between DR3-expressing HT29 colon carcinoma cells and E-selectin induces the activation of the PI3K/Akt pathway. Moreover, p65/RelA, the anti-apoptotic subunit of NFκB, is rapidly translocated to the nucleus in response to E-selectin. This translocation is impaired by the PI3K inhibitor LY294002. Furthermore, inhibition of the PI3K/Akt pathway increases the cleavage of caspase 8 in colon cancer cells treated with E-selectin and this effect is still further increased when both ERK and PI3K pathways are concomitantly inhibited. Intriguingly, metastatic colon cancer cell lines such as HT29 and SW620 express higher levels of a splice variant of DR3 that has no trans-membrane domain and no death domain. CONCLUSION: Colon cancer cells acquire an increased capacity to survive via the activation of the PI3K/NFκB pathway following the stimulation of DR3 by E-selectin. Generation of a DR3 splice variant devoid of death domain can further contribute to protect against apoptosis

    Absence of system xc⁻ on immune cells invading the central nervous system alleviates experimental autoimmune encephalitis

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    Background: Multiple sclerosis (MS) is an autoimmune demyelinating disease that affects the central nervous system (CNS), leading to neurodegeneration and chronic disability. Accumulating evidence points to a key role for neuroinflammation, oxidative stress, and excitotoxicity in this degenerative process. System x(c)- or the cystine/glutamate antiporter could tie these pathological mechanisms together: its activity is enhanced by reactive oxygen species and inflammatory stimuli, and its enhancement might lead to the release of toxic amounts of glutamate, thereby triggering excitotoxicity and neurodegeneration. Methods: Semi-quantitative Western blotting served to study protein expression of xCT, the specific subunit of system x(c)-, as well as of regulators of xCT transcription, in the normal appearing white matter (NAWM) of MS patients and in the CNS and spleen of mice exposed to experimental autoimmune encephalomyelitis (EAE), an accepted mouse model of MS. We next compared the clinical course of the EAE disease, the extent of demyelination, the infiltration of immune cells and microglial activation in xCT-knockout (xCT(-/-)) mice and irradiated mice reconstituted in xCT(-/-) bone marrow (BM), to their proper wild type (xCT(+/+)) controls. Results: xCT protein expression levels were upregulated in the NAWM of MS patients and in the brain, spinal cord, and spleen of EAE mice. The pathways involved in this upregulation in NAWM of MS patients remain unresolved. Compared to xCT(+/+) mice, xCT(-/-) mice were equally susceptible to EAE, whereas mice transplanted with xCT(-/-) BM, and as such only exhibiting loss of xCT in their immune cells, were less susceptible to EAE. In none of the above-described conditions, demyelination, microglial activation, or infiltration of immune cells were affected. Conclusions: Our findings demonstrate enhancement of xCT protein expression in MS pathology and suggest that system x(c)- on immune cells invading the CNS participates to EAE. Since a total loss of system x(c)- had no net beneficial effects, these results have important implications for targeting system x(c)- for treatment of MS

    Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

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    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

    Novel artificial eye service evaluation using patient reported outcome measures

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    Background This service evaluation explores patient reported outcomes from patients provided with high definition ocular prostheses (artificial eyes). Methods Validated patient questionnaires (FACE-Q, DAS24 and HADS) were utilised to evaluate patient experiences of their new ocular prosthesis. 10 patients were included in the service evaluation, which was conducted between December 2018 and September 2019. Descriptive analysis of the mean and 95% CI was undertaken for all questionnaires. Statistical analysis was performed using SPSS 21 Principal Component Analysis (PCA) for FACE-Q questionnaires. Correlations were significant when factor loading is at α > 0.4. Results A questionnaire response rate of 80% was achieved (n = 8). PCA analysis showed the number of variables tested could be reduced. Two principal components (PC1 and PC2) had very good to excellent internal consistency between variables with factor loading (α = 0.7–0.9). PC1 contained questionnaires 1–7, all of which were highly correlated. PC2 contained question number 8 with a factor loading of α = 0.8. This indicates good reliability, validity and responsiveness. Conclusions We hope to demonstrate the importance of service evaluations with respect to rapidly evolving technological advances in medical devices, pharmaceuticals and imaging modalities. Further feasibility and full clinical studies are required to confirm the positive results of the novel artificial eye service we have evaluated with respect to the traditional approach

    The xc− cystine/glutamate antiporter: a mediator of pancreatic cancer growth with a role in drug resistance

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    The xc− cystine transporter enhances biosynthesis of glutathione, a tripeptide thiol important in drug resistance and cellular defense against oxidative stress, by enabling cellular uptake of cystine, a rate-limiting precursor. Because it is known to regulate glutathione levels and growth of various cancer cell types, and is expressed in the pancreas, we postulate that it is involved in growth and drug resistance of pancreatic cancer. To examine this, we characterised expression of the xc− transporter in pancreatic cancer cell lines, MIA PaCa-2, PANC-1 and BxPC-3, as subjected to cystine-depletion and oxidative stress. The results indicate that these cell lines depend on xc−-mediated cystine uptake for growth, as well as survival in oxidative stress conditions, and can modulate xc− expression to accommodate growth needs. Immunohistochemical analysis showed that the transporter was differentially expressed in normal pancreatic tissues and overexpressed in pancreatic cancer tissues from two patients. Furthermore, gemcitabine resistance of cells was associated with elevated xc− expression and specific xc− inhibition by monosodium glutamate led to growth arrest. The results suggest that the xc− transporter by enhancing glutathione biosynthesis plays a major role in pancreatic cancer growth, therapy resistance and represents a potential therapeutic target for the disease

    The SECURE project – Stem canker of oilseed rape: : molecular methods and mathematical modelling to deploy durable resistance

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    N Evans et al, "The SECURE Project - Stem Canker of oilseed rape: Molecular methods and mathematical modeling to deploy durable resistance", in Vol 4 of the Proceedings of the 12th International Rapeseed Congress : Sustainable Development in Cruciferous Oilseed Crops Production, Wuhan, China, March 26 - 30, 2007. The proceedings are available online at: http://gcirc.org/intranet/irc-proceedings/12th-irc-wuhan-china-2007-vol-4.htmlModelling done during the SECURE project has demonstrated the dynamic nature of the interaction between phoma stem canker (Leptosphaeria maculans), the oilseed rape host (Brassica napus) and the environment. Experiments done with near-isogenic lines of L. maculans to investigate pathogen fitness support field data that suggest a positive effect of the avirulence allele AvrLm4 on pathogen fitness, and that the loss of this allele renders isolates less competitive under field conditions on cultivars without the resistance gene Rlm4. The highlight of molecular work was the cloning of AvrLm1 and AvrLm6. L. maculans is now one of the few fungal species for which two avirulence loci have been cloned. Subsequent research focused on understanding the function of AvrLm1 and AvrLm6 and on the analysis of sequences of virulent isolates to understand molecular evolution towards virulence. Isolates of L. maculans transformed with GFP and/or DsRed were used to follow growth of the fungus in B. napus near-isogenic-lines (NIL) with or without MX (Rlm6) resistance under different temperature and wetness conditions. The results greatly enhanced our knowledge of the infection process and the rate and extent of in planta growth on different cultivars. Conclusions from work to model durability of resistance have been tested under field conditions through a series of experiments to compare durability of resistance conferred by the major resistance gene Rlm6 alone in a susceptible background (EurolMX) or in a resistant background (DarmorMX) under recurrent selection over 4 growing seasons. A major priority of the project was knowledge transfer of results and recommendations to target audiences such as plant breeding companies and extension services. CETIOM developed a “diversification scheme” that encourages French growers to make an informed choice about the cultivars that are grown within the rotation based on the resistance genes carried by the individual cultivars. Use of such schemes, in association with survey data on the population structure of L. maculans at both national and European scales will provide opportunities for breeders and the industry to manage available B. napus resistance more effectively.Non peer reviewe

    Protein CoAlation: a redox-regulated protein modification by coenzyme A in mammalian cells.

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    Coenzyme A (CoA) is an obligatory cofactor in all branches of life. CoA and its derivatives are involved in major metabolic pathways, allosteric interactions and the regulation of gene expression. Abnormal biosynthesis and homeostasis of CoA and its derivatives have been associated with various human pathologies, including cancer, diabetes and neurodegeneration. Using an anti-CoA monoclonal antibody and mass spectrometry, we identified a wide range of cellular proteins which are modified by covalent attachment of CoA to cysteine thiols (CoAlation). We show that protein CoAlation is a reversible post-translational modification that is induced in mammalian cells and tissues by oxidising agents and metabolic stress. Many key cellular enzymes were found to be CoAlated in vitro and in vivo in ways that modified their activities. Our study reveals that protein CoAlation is a widespread post-translational modification which may play an important role in redox regulation under physiological and pathophysiological conditions

    Genomic analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

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    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared to <1% of B. cinerea. The arsenal of genes associated with necrotrophic processes is similar between the species, including genes involved in plant cell wall degradation and oxalic acid production. Analysis of secondary metabolism gene clusters revealed an expansion in number and diversity of B. cinerea–specific secondary metabolites relative to S. sclerotiorum. The potential diversity in secondary metabolism might be involved in adaptation to specific ecological niches. Comparative genome analysis revealed the basis of differing sexual mating compatibility systems between S. sclerotiorum and B. cinerea. The organization of the mating-type loci differs, and their structures provide evidence for the evolution of heterothallism from homothallism. These data shed light on the evolutionary and mechanistic bases of the genetically complex traits of necrotrophic pathogenicity and sexual mating. This resource should facilitate the functional studies designed to better understand what makes these fungi such successful and persistent pathogens of agronomic crops.Fil: Ten Have, Arjen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigaciones Biológicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Biológicas; ArgentinaFil: Amselem, Joelle. Institut National de la Recherche Agronomique; FranciaFil: Cuomo, Christina A.. Broad Institute of MIT and Harvard; Estados UnidosFil: Jan, A. L. van Kan. Wageningen University; Países BajosFil: Viaud, Muriel. Institut National de la Recherche Agronomique; FranciaFil: Benito, Ernesto P.. Universidad de Salamanca; EspañaFil: Couloux, Arnaud. Centre National de Séquençage. Genoscope; FranciaFil: Coutinho, Pedro M.. Centre National de la Recherche Scientifique; FranciaFil: Vries, Ronald P. de. Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países Bajos. Fungal Biodiversity Centre; Países BajosFil: Dyer, Paul S.. The University Of Nottingham; Reino UnidoFil: Fillinger, Sabine. Institut National de la Recherche Agronomique; FranciaFil: Fournier, Elisabeth. Institut National de la Recherche Agronomique; Francia. Centre de coopération internationale en recherche agronomique pour le développement; FranciaFil: Gout, Lilian. Institut National de la Recherche Agronomique; FranciaFil: Hahn, Matthias. University Of Kaiserlautern; AlemaniaFil: Kohn, Linda. University Of Toronto; CanadáFil: Lapalu, Nicolas. Institut National de la Recherche Agronomique; FranciaFil: Plummer, Kim M.. la Trobe University; AustraliaFil: Pradier, Jean-Marc. Institut National de la Recherche Agronomique; FranciaFil: Quévillon, Emmanuel. Institut National de la Recherche Agronomique; Francia. Centre National de la Recherche Scientifique; FranciaFil: Sharon, Amir. Tel Aviv University. Department of Molecular Biology and Ecology of Plants; IsraelFil: Simon, Adeline. Institut National de la Recherche Agronomique; FranciaFil: Tudzynski, Bettina. Institut für Biologie und Biotechnologie der Pflanzen; AlemaniaFil: Tudzynski, Paul. Institut für Biologie und Biotechnologie der Pflanzen; AlemaniaFil: Wincker, Patrick. Centre National de Séquençage. Genoscope; FranciaFil: Andrew, Marion. University Of Toronto; CanadáFil: Anthouard, Véronique. Centre National de Séquençage. Genoscope; FranciaFil: Beever, Ross E.. Landcare Research; Nueva ZelandaFil: Beffa, Rolland. Centre National de la Recherche Scientifique; FranciaFil: Benoit, Isabelle . Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países BajosFil: Bouzid, Ourdia. Microbiology and Kluyver Centre for Genomics of Industrial Fermentations; Países Bajo
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