58 research outputs found

    Proteomic analysis of the Mycocentrospora acerina-carrot interaction during storage

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    During post harvest storage, a large proportion of carrots (more than 50%) may have to be discarded due to the development of liquorice rot caused by Mycocentrospora acerina. This fungus is soil borne and brought into the store in to soil adhering to the root. Liquorice rot development is mainly related to physiological or structural resistance of carrot, therefore the control of this storage disease is based on cultural practices and storage conditions. It is believed that carrots at the beginning of storage can resist disease developments due to chemical defence mechanisms involving some proteins, peptides and secondary metabolites. The hypothesis is that proteome changes during storage of carrots are related to the susceptibility to M. acerina. During root-pathogen interactions, several genes have been reported to provide resistance against pathogens but only few proteins have been identified using proteomic approaches. Little is known about proteins involved during M. acerina - carrot interaction. The carrots used in this study are grown under two different agricultural practices (one conventional, one organic) in order to investigate the effect of the cropping system on the susceptibility to liquorice rot. We developed a bioassay for infection studies of M. acerina on conventional and organic carrots in order to determine the important time points of the infection process. Then the proteome is investigated at these different time points. The protocol for extraction of proteins has been improved so that it can be used to obtain an optimal recovery of proteins from both plant and pathogen on their own as well as from infected carrot roots. Proteomes of carrot and of M. acerina are characterized by two dimensional gel electrophoreses and the proteins whose synthesis varies significantly in the course of pathogen infection are identified by mass spectrometry (MALDI TOF-TOF)

    MMP Mediated Degradation of Type VI Collagen Is Highly Associated with Liver Fibrosis - Identification and Validation of a Novel Biochemical Marker Assay

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    Background and Aims: During fibrogenesis, in which excessive remodeling of the extracellular matrix occurs, both the quantity of type VI collagen and levels of matrix metalloproteinases, including MMP-2 and MMP-9, increase significantly. Proteolytic degradation of type VI collagen into small fragments, so-called neo-epitopes, may be specific biochemical marker of liver fibrosis. The aim of this study was to develop an ELISA detecting a fragment of type VI collagen generated by MMP-2 and MMP-9, and evaluate this assay in two preclinical models of liver fibrosis. Methods: Mass spectrometric analysis of cleaved type VI collagen revealed a large number of protease-generated neo-epitopes. A fragment unique to type VI collagen generated by MMP-2 and MMP-9 was selected for ELISA development. The CO6-MMP assay was evaluated in two rat models of liver fibrosis: bile duct ligation (BDL) and carbon tetrachloride (CCl4)-treated rats. Results: Intra-and inter-assay variation was 4.1% and 10.1% respectively. CO6-MMP levels were significantly elevated in CCl4-treated rats compared to vehicle-treated rats at weeks 12 (mean 30.9 ng/mL vs. 12.8 ng/mL, p = 0.002); week 16 (mean 34.0 ng/mL vs. 13.7 ng/mL, p = 0.0018); and week 20 (mean 35.3 ng/mL vs. 13.3 ng/mL, p = 0.0033) with a tight correlation between hepatic collagen content and serum levels of CO6-MMP (R-2 = 0.58,

    HldE Is Important for Virulence Phenotypes in Enterotoxigenic <i>Escherichia coli</i>

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    Enterotoxigenic Escherichia coli (ETEC) is one of the most common causes of diarrheal illness in third world countries and it especially affects children and travelers visiting these regions. ETEC causes disease by adhering tightly to the epithelial cells in a concerted effort by adhesins, flagella, and other virulence-factors. When attached ETEC secretes toxins targeting the small intestine host-cells, which ultimately leads to osmotic diarrhea. HldE is a bifunctional protein that catalyzes the nucleotide-activated heptose precursors used in the biosynthesis of lipopolysaccharide (LPS) and in post-translational protein glycosylation. Both mechanisms have been linked to ETEC virulence: Lipopolysaccharide (LPS) is a major component of the bacterial outer membrane and is needed for transport of heat-labile toxins to the host cells, and ETEC glycoproteins have been shown to play an important role for bacterial adhesion to host epithelia. Here, we report that HldE plays an important role for ETEC virulence. Deletion of hldE resulted in markedly reduced binding to the human intestinal cells due to reduced expression of colonization factor CFA/I on the bacterial surface. Deletion of hldE also affected ETEC motility in a flagella-dependent fashion. Expression of both colonization factors and flagella was inhibited at the level of transcription. In addition, the hldE mutant displayed altered growth, increased biofilm formation and clumping in minimal growth medium. Investigation of an orthogonal LPS-deficient mutant combined with mass spectrometric analysis of protein glycosylation indicated that HldE exerts its role on ETEC virulence both through protein glycosylation and correct LPS configuration. These results place HldE as an attractive target for the development of future antimicrobial therapeutics

    Measurement of MMP-9 and -12 degraded elastin (ELM) provides unique information on lung tissue degradation

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    BACKGROUND: Elastin is an essential component of selected connective tissues that provides a unique physiological elasticity. Elastin may be considered a signature protein of lungs where matrix metalloprotease (MMP) -9-and -12, may be considered the signature proteases of the macrophages, which in part are responsible for tissue damage during disease progression. Thus, we hypothesized that a MMP-9/-12 generated fragment of elastin may be a relevant biochemical maker for lung diseases. METHODS: Elastin fragments were identified by mass-spectrometry and one sequence, generated by MMP-9 and -12 (ELN-441), was selected for monoclonal antibody generation and used in the development of an ELISA. Soluble and insoluble elastin from lung was cleaved in vitro and the time-dependent release of fragments was assessed in the ELN-441 assay. The release of ELN-441 in human serum from patients with chronic obstructive pulmonary disease (COPD) (n = 10) and idiopathic pulmonary fibrosis (IPF) (n = 29) were compared to healthy matched controls (n = 11). RESULTS: The sequence ELN-441 was exclusively generated by MMP-9 and -12 and was time-dependently released from soluble lung elastin. ELN-441 levels were 287% higher in patients diagnosed with COPD (p < 0.001) and 124% higher in IPF patients (p < 0.0001) compared with controls. ELN-441 had better diagnostic value in COPD patients (AUC 97%, p = 0.001) than in IPF patients (AUC 90%, p = 0.0001). The odds ratios for differentiating controls from COPD or IPF were 24 [2.06–280] for COPD and 50 [2.64–934] for IPF. CONCLUSIONS: MMP-9 and -12 time-dependently released the ELN-441 epitope from elastin. This fragment was elevated in serum from patients with the lung diseases IPF and COPD, however these data needs to be validated in larger clinical settings

    Assessment of proteolytic degradation of the basement membrane: a fragment of type IV collagen as a biochemical marker for liver fibrosis

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    <p>Abstract</p> <p>Background</p> <p>Collagen deposition and an altered matrix metalloproteinase (MMP) expression profile are hallmarks of fibrosis. Type IV collagen is the most abundant structural basement membrane component of tissue, which increases 14-fold during fibrogenesis in the liver. Proteolytic degradation of collagens by proteases produces small fragments, so-called neoepitopes, which are released systemically. Technologies investigating MMP-generated fragments of collagens may provide more useful information than traditional serological assays that crudely measure total protein. In the present study, we developed an ELISA for the quantification of a neoepitope generated by MMP degradation of type IV collagen and evaluated the association of this neoepitope with liver fibrosis in two animal models.</p> <p>Methods</p> <p>Type IV collagen was degraded <it>in vitro </it>by a variety of proteases. Mass spectrometric analysis revealed more than 200 different degradation fragments. A specific peptide sequence, 1438'GTPSVDHGFL'1447 (CO4-MMP), in the α1 chain of type IV collagen generated by MMP-9 was selected for ELISA development. ELISA was used to determine serum levels of the CO4-MMP neoepitope in two rat models of liver fibrosis: inhalation of carbon tetrachloride (CCl<sub>4</sub>) and bile duct ligation (BDL). The levels were correlated to histological findings using Sirius red staining.</p> <p>Results</p> <p>A technically robust assay was produced that is specific to the type IV degradation fragment, GTPSVDHGFL. CO4-MMP serum levels increased significantly in all BDL groups compared to baseline, with a maximum increase of 248% seen two weeks after BDL. There were no changes in CO4-MMP levels in sham-operated rats. In the CCl<sub>4 </sub>model, levels of CO4-MMP were significantly elevated at weeks 12, 16 and 20 compared to baseline levels, with a maximum increase of 88% after 20 weeks. CO4-MMP levels correlated to Sirius red staining results.</p> <p>Conclusion</p> <p>This ELISA is the first assay developed for assessment of proteolytic degraded type IV collagen, which, by enabling quantification of basement membrane degradation, could be relevant in investigating various fibrogenic pathologies. The CO4-MMP degradation fragment was highly associated with liver fibrosis in the two animal models studied.</p

    Influence Of Tax Havens On The Functioning Of Developing And Developed Countries

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    This article discusses the impact of tax havens on developing and developed countries. Economic research in this area has proved that tax havens not only play a key role on the international capital market, but above all are responsible for the internationalisation of economic activity on a global scale. Representatives of theory, practitioners and regulators for decades conducted research related to the assessment of the impact of tax havens on countries with high taxes in terms of the erosion of their base. The obtained results clearly show that these countries face a significant decline in income, however, some researchers (especially Hines) show that there are positive side effects of this process indicating the creation of a new model in the global financial symbiosis

    Black lists as an instrument preventing the use of tax havens

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    Czarne listy sporządzone przez OECD są najbardziej wpływowym narzędziem w walce przeciwko rajom podatkowym. Dzięki swemu autorytetowi i przewodniej roli wśród międzynarodowych organizacji gospodarczych, używany przez OECD termin „raje podatkowe” zaczął być uznawany za negatywny. Kraje zareagowały na olbrzymi wzrost sektora rajów podatkowych poprzez wprowadzenie określonych przepisów prawnych i administracyjnych ograniczających transfery finansowe do rajów podatkowych, a także wytoczyły sądowe procesy o oszustwa. Głównym celem tych działań było zapobieganie temu, by lokalni podatnicy nie ukrywali swych dochodów w rajach podatkowych. By nadmiernie nie ograniczać zasadnego handlu międzynarodowego i transgranicznej działalności inwestycyjnej, krajowe przepisy wymierzone w raje podatkowe zwykle wyznaczają granicę pomiędzy działalnością rajów podatkowych a rzeczywistym biznesem międzynarodowym i stosują się tylko do tych pierwszych.Black lists are the most influential in the project against tax havens. By relying on its authority and pre-eminence among economically-oriented international organisations, the OECD’s use of the expression “tax havens” started being regarded as endowed with a pejorative meaning. Countries have reacted to the massive growth of tax haven sectors by enacting specific legislation and administrative rules aiming at curbing transfers to tax havens, and judicially attacked tax haven transactions as shams. The main purpose of these measures was to prevent local taxpayers from sheltering income in tax havens through the use of formal structures lacking economic substance. In order not to unduly restrict legitimate international trade and cross-border investment activities, domestic anti-tax haven regulations generally draw a line between tax haven operations and legitimate international business activities, and apply only with reference to the former

    Quantitative proteomics by 2DE and MALDI MS/MS uncover the effects of organic and conventional cropping methods on vegetable products

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    Organic farming aims to be environmentally sound, but the question as to whether organic cropping brings more nutritional benefits to farmers and consumers than the conventional cropping needs still to be answered. To gain insights into the molecular effects of organic farming we used proteome analysis to analyze cabbage (Brassica oleracea L. var ‘capitata’) and carrot (Daucus carota var. ‘sativus’) Our aim was to identify the metabolic pathways that are affected by different cropping regimes and thus, may have an effect on quality, storability and pathogen resistance of crops. By means of two dimensional gel electrophoresis and MALDI tandem mass spectrometry we compared proteomes of cabbage and carrot root, obtained in the first growth season, cropped under three different schemes. These included a conventional scheme (C) and two organic schemes, O1, in which nutrients were delivered in a form of slurry, in accordance to regulations of organic farming and O2, in which nutrient supply was based mainly on autumn green manures. Proteins were extracted from lyophilized plant tissues into a buffer containing high concentrations of urea/thiourea, two detergents and reducing agent. This approach allowed short handling times of fresh plant materials. In the case of cabbage samples, the abundance levels of 58 out of more than 1300 quantified protein spots varied significantly between conventional farming and any of the organic cropping systems. Proteome profiles were also very similar between carrot root samples, where 68 out of 1800 resolved protein spots varied significantly. Proteins of the glycolytic pathway and Krebs cycle as well as several proteins related to amino acid and protein metabolism were overexpressed in organically farmed cabbage. Proteins related to detoxification processes were overexpressed in conventionally grown cabbage. Proteins involved in metabolism of carbohydrates, polypeptides and secondary metabolites were affected by different cropping regimes in carrots. The proteomes of conventionally grown vegetables varied from organically grown vegetables to a larger extent than the two organic cropping schemes varied from each other. In conclusion, this proteomics platform is suitable and useful for systematic studies of the effects of organic and conventional farming techniques on plant metabolism

    Proteomics in the backyard: 2DE based comparison of vegetables grown at conventional farming conditions and organic farming conditions

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    We used 2D electrophoresis and mass spectrometry to compare two organic farming systems with conventional farming of cabbage and carrot. For both vegetable proteomes we observed differential responses that depended on farming conditions. We detected significant protein abundance changes in a series of metabolic processes including glycolysis and protein synthesis. This study provides a framework for detailed molecular analysis of vegetables in large scale field studies and the influence of environmental conditions on plant growth
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