124 research outputs found

    Copper-containing amine oxidases contribute to terminal polyamine oxidation in peroxisomes and apoplast of Arabidopsis thaliana

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    Polyamines (PAs) are oxidatively deaminated at their primary or secondary amino-groups by copper-containing amine oxidases (CuAOs) or FAD-dependent amine oxidases (PAOs), respectively. Both enzymes have long been considered to be apoplastic proteins. However, three out of five PAO isoforms in Arabidopsis thaliana are localized in peroxisomes, while the other two PAOs are predicted to be cytosolic. Interestingly, most of these PAOs do not contribute to terminal PA oxidation, but instead are involved in the back-conversion pathway, producing spermidine from spermine and putrescine from spermidine, which in turn is inhibited by putrescine. This opens the question as to whether PAs are catabolized in the apoplast of Arabidopsis and if the terminal oxidation occurs in the peroxisomes. The main objective of this study was to know if these catabolic processes are mediated by CuAOs. Results A. thaliana contains ten genes annotated as CuAOs, but only one (ATAO1) has been characterized at the protein level. Reported herein is the characterization of three genes encoding putative Arabidopsis CuAOs (AtCuAO1, AtCuAO2 and AtCuAO3). These genes encode functional CuAOs that use putrescine and spermidine as substrates. AtCuAO1, like ATAO1, is an extracellular protein, while AtCuAO2 and AtCuAO3 are localized in peroxisomes. The three genes present a different expression profile in response to exogenous treatments, such as application of abcisic acid, methyl jasmonate, salycilic acid, flagellin 22 and wounding. Conclusions PA catabolism in the Arabidopsis apoplast is mediated predominantly by CuAOs, while in peroxisomes the co-localization of CuAO-dependent terminal catabolism with PAO-back-conversion machineries might contribute to modulating putrescine-mediated inhibition of the back-conversion, suggesting the occurrence of a tight coordination between both catabolic pathways. The expression profile of AtCuAO1-3 in response to different exogenous treatments, together with the different localization of the corresponding proteins, provides evidence for the functional diversification of Arabidopsis CuAO proteins

    Analysis of UV ink photoinitiators in packaged food by fast liquid chromatography at subambient temperature coupled to tandem mass spectrometry

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    A fast method of liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was developed for the analysis of eleven UV ink photoinitiators in packaged food. Chromatographic separation was achieved in a pentafluorophenylpropyl (PFPP) column at 5ºC and acetonitrile:25 mM formic acid-ammonium formate (pH 2.7) in gradient elution. To reduce sample treatment, a QuEChERS (quick, easy, cheap, effective, rugged and safe) method for the extraction and clean-up of UV photoinitiators in packaged foods was evaluated. Triple quadrupole working in H-SRM on Q1 mode was used for both quantitation and confirmation purposes and the most intense and selective transitions were chosen. Quality parameters of the developed QuEChERS LC-MS/MS method were established and applied for the analysis of photoinitiators in food packaged at ng kg-1 levels

    Alpha-defensins 1-3 release by dendritic cells is reduced by estrogen

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    <p>Abstract</p> <p>Background</p> <p>During pregnancy the immune system of the mother must protect any activation that may negatively affect the fetus. Changes in susceptibility to infection as well as resolution of some autoimmune disorders represent empirical evidence for pregnancy related alterations in immunity. Sex hormones reach extremely high levels during pregnancy and have been shown to have direct effects on many immune functions including the antiviral response of dendritic cells. Among the immunologically active proteins secreted by monocyte derived DCs (MDDC) are the alpha-defensins 1-3. This family of cationic antimicrobial peptides has a broad spectrum of microbicidal activity and has also been shown to link innate to adaptive immunity by attracting T cells and immature DCs, which are essential for initiating and polarizing the immune response.</p> <p>Methods</p> <p>We compare culture-generated monocyte derived DCs (MDDCs) with directly isolated myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) and measure their alpha-defensins 1-3 secretion by ELISA both, in basal situations and after hormone (E2 or PG) treatments. Moreover, using a cohort of pregnant women we isolated mDCs from blood and also measure the levels of these anti-microbial peptides along pregnancy.</p> <p>Results</p> <p>We show that mDCs and pDCs constitutively produce alpha-defensins 1-3 and at much higher levels than MDDCs. Alpha-defensins 1-3 production from mDCs and MDDCs but not pDCs is inhibited by E2. PG does not affect alpha-defensins 1-3 in any of the populations. Moreover, alpha-defensins 1-3 production by mDCs was reduced in the later stages of pregnancy in 40% of the patients.</p> <p>Conclusions</p> <p>Here, we demonstrate that mDCs and pDCs secrete alpha-defensins 1-3 and present a novel effect of E2 on the secretion of alpha-defensins 1-3 by dendritic cells.</p

    Preventing false negatives with high-resolution mass spectrometry: the benzophenone case

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    Benzophenone (BP) is one of the many contaminants reported as present in foodstuff due to its migration from food packaging materials. Liquid chromatography tandem mass spectrometry (LC-MS/MS) is acknowledged in the literature as the method of choice for this analysis. However, cases have been reported where the use of this methodology was not enough to unambiguously confirm the presence of a contaminant. In previous work performed by the authors, the unequivocal identification of BP in packaged foods was not possible even when monitoring two m/z transitions, since ion ratio errors higher than 20% were obtained. In order to overcome this analytical problem a fast, sensitive and selective liquid chromatography-high resolution-mass spectrometry (LC-HRMS) methodology has been developed and applied to the analysis of BP in packaged foods. A direct comparison between liquid chromatography high resolution mass spectrometry (LC-HRMS) and LC-MS/MS data indicated better selectivity when working with LC-HRMS at a resolving power of 50,000 FWHM than when monitoring two m/z transitions by LC-MS/MS. The resolving power used enabled the detection and identification of Harman as the compound impeding the confirmation of BP by LC-MS/MS. Similar quantitative results were obtained by an Orbitrap mass analyser (Exactive ¿) and a triple quadrupole mass analyser (TSQ Quantum Ultra AM ¿)

    Atmospheric pressure photoionization mass spectrometry of fullerenes

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    Atmospheric pressure photoionization (APPI) was evaluated for the analysis of fullerenes. An important response improvement was found when using toluene mediated APPI in negative mode if compared with other API sources (electrospray and atmospheric pressure chemical ionization). Fullerene APPI negative mass spectra were dominated by the isotopic cluster of the molecular ion, although isotopic patterns for M+1, M+2 and M+3 ions showed higher than expected relative abundances. These discrepancies are explained by the presence of two isobaric ions, one due to 13C and the other to the addition of hydrogen to a double bond of the fullerene structure. Triple quadrupole tandem mass spectrometry and ultra-high resolution mass spectrometry and accurate mass measurements were used to confirm these assignments. Additionally, cluster ions M+16 and M+32 were characterized following the same strategy. Ions due to the addition of oxygen and alkyl additions were attributed to the presence of methanol in the mobile phase. For the fast chromatographic separation of fullerenes (less than 3.5 min) a sub-2 µm C18 column and isocratic elution (toluene:methanol 45:55 v/v) was used. Highly selective-selected ion monitoring (H-SIM) mode (mass resolving power >12,500 FWHM) was proposed monitoring the two most intense isotope ions in the [M]-¿ cluster. Method limits of quantitation down to 10 pg L-1 for C60 and C70 fullerenes and between 0.75-5.0 ng L-1 for larger fullerenes were obtained. Finally, the UHPLC-APPI-MS method was used to analyze fullerenes in river and pond water samples

    New branches in the degradation pathway of monochlorocatechols by Aspergillus nidulans: a metabolomics analysis

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    A collective view of the degradation of monochlorocatechols in fungi is yet to be attained, though these compounds are recognised as key degradation intermediates of numerous chlorinated aromatic hydrocarbons, including monochlorophenols. In the present contribution we have analysed the degradation pathways of monochlorophenols in Aspergillus nidulans using essentially metabolomics. Degradation intermediates herein identified included those commonly reported (e.g. 3-chloro-cis,cis-muconate) but also compounds never reported before in fungi revealing for 4-chlorocatechol and for 3- chlorocatechol unknown degradation paths yielding 3-chlorodienelactone and catechol, respectively. A different 3-chlorocatechol degradation path led to accumulation of 2- chloromuconates (a potential dead-end), notwithstanding preliminary evidence of chloromuconolactones and protoanemonin simultaneous formation. In addition, some transformation intermediates, of which sulfate conjugates of monochlorophenols/ chlorocatechols were the most common, were also identified. This study provides critical information for understanding the role of fungi in the degradation of chlorinated aromatic hydrocarbons; furthering their utility in the development of innovative bioremediation strategies

    Pharmacogenetics of efficacy and safety of HCV treatment in HCV-HIV coinfected patients: significant associations with IL28B and SOCS3 gene variants.

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    Background and Aims This was a safety and efficacy pharmacogenetic study of a previously performed randomized trial which compared the effectiveness of treatment of hepatitis C virus infection with pegylated interferon alpha (pegIFNα) 2a vs. 2b, both with ribavirin, for 48 weeks, in HCV-HIV coinfected patients. Methods The study groups were made of 99 patients (efficacy pharmacogenetic substudy) and of 114 patients (safety pharmacogenetic substudy). Polymorphisms in the following candidate genes IL28B, IL6, IL10, TNFα, IFNγ, CCL5, MxA, OAS1, SOCS3, CTLA4 and ITPA were assessed. Genotyping was carried out using Sequenom iPLEX-Gold, a single-base extension polymerase chain reaction. Efficacy end-points assessed were: rapid, early and sustained virological response (RVR, EVR and SVR, respectively). Safety end-points assessed were: anemia, neutropenia, thrombocytopenia, flu-like syndrome, gastrointestinal disturbances and depression. Chi square test, Student's T test, Mann-Whitney U test and logistic regression were used for statistic analyses. Results As efficacy is concerned, IL28B and CTLA4 gene polymorphisms were associated with RVR (p<0.05 for both comparisons). Nevertheless, only polymorphism in the IL28B gene was associated with SVR (p = 0.004). In the multivariate analysis, the only gene independently associated with SVR was IL28B (OR 2.61, 95%CI 1.2-5.6, p = 0.01). With respect to safety, there were no significant associations between flu-like syndrome or depression and the genetic variants studied. Gastrointestinal disturbances were associated with ITPA gene polymorphism (p = 0.04). Anemia was associated with OAS1 and CTLA4 gene polymorphisms (p = 0.049 and p = 0.045, respectively), neutropenia and thromobocytopenia were associated with SOCS3 gene polymorphism (p = 0.02 and p = 0.002, respectively). In the multivariate analysis, the associations of the SOCS3 gene polymorphism with neutropenia (OR 0.26, 95%CI 0.09-0.75, p = 0.01) and thrombocytopenia (OR 0.07, 95%CI 0.008-0.57, p = 0.01) remained significant. Conclusions In HCV-HIV coinfected patients treated with PegIFNα and ribavirin, SVR is associated with IL28B rs8099917 polymorphism. HCV treatment-induced neutropenia and thrombocytopenia are associated with SOCS3 rs4969170 polymorphism

    Association of breast and gut microbiota dysbiosis and the risk of breast cancer: a case-control clinical study

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    We would like to thank M Luisa Puertas-Martin and Isabel Manzano-Jimenez, nurses at the Unit of Mammary Pathology, General Surgery Service, San Cecilio University Hospital (Granada), without whose enthusiasm the enrolment of participants in Granada would still be stalled. We are indebted to all the women taking part in the study.The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Trial registration ClinicalTrials.gov NCT03885648, 03/25/2019. Retrospectively registered.Background Breast cancer ranks first in women, and is the second cause of death in this gender. In addition to genetics, the environment contributes to the development of the disease, although the factors involved are not well known. Among the latter is the influence of microorganisms and, therefore, attention is recently being paid to the mammary microbiota. We hypothesize that the risk of breast cancer could be associated with the composition and functionality of the mammary/gut microbiota, and that exposure to environmental contaminants (endocrine disruptors, EDCs) might contribute to alter these microbiota. Methods We describe a case-control clinical study that will be performed in women between 25 and 70 years of age. Cases will be women diagnosed and surgically intervened of breast cancer (stages I and II). Women with antecedents of cancer or advanced tumor stage (metastasis), or who have received antibiotic treatment within a period of 3 months prior to recruitment, or any neoadjuvant therapy, will be excluded. Controls will be women surgically intervened of breast augmentation or reduction. Women with oncological, gynecological or endocrine history, and those who have received antibiotic treatment within a period of 3 months prior to recruitment will also be excluded. Blood, urine, breast tissue and stool samples will be collected. Data regarding anthropometric, sociodemographic, reproductive history, tumor features and dietary habits will be gathered. Metabolomic studies will be carried out in stool and breast tissue samples. Metagenomic studies will also be performed in stool and breast tissue samples to ascertain the viral, fungal, bacterial and archaea populations of the microbiota. Quantitation of estrogens, estrogen metabolites and EDCs in samples of serum, urine and breast tissue will also be performed. Discussion: This is the first time that the contribution of bacteria, archaea, viruses and fungi together with their alteration by environmental contaminants to the risk of breast cancer will be evaluated in the same study. Results obtained could contribute to elucidate risk factors, improve the prognosis, as well as to propose novel intervention studies in this disease.This work is funded by grants PI-0538-2017 (Junta de Andalucía, Spain, to LF) and Biomedical Research Networking Center-CIBER de Epidemiología y Salud Pública (CIBERESP) of the Institute of Health Carlos III -supported by European Regional Development Fund/FEDER (FIS-PI16/01812) (to MFF)
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