85 research outputs found

    Vascular endothelium plays a key role in directing pulmonary epithelial cell differentiation.

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    The vascular endothelium is critical for induction of appropriate lineage differentiation in organogenesis. In this study, we report that dysfunctional pulmonary endothelium, resulting from the loss of matrix Gla protein (MGP), causes ectopic hepatic differentiation in the pulmonary epithelium. We demonstrate uncontrolled induction of the hepatic growth factor (HGF) caused by dysregulated cross talk between pulmonary endothelium and epithelium in Mgp-null lungs. Elevated HGF induced hepatocyte nuclear factor 4 α (Hnf4a), which competed with NK2 homeobox 1 (Nkx2.1) for binding to forkhead box A2 (Foxa2) to drive hepatic differentiation in Mgp-null airway progenitor cells. Limiting endothelial HGF reduced Hnf4a, abolished interference of Hnf4a with Foxa2, and reduced hepatic differentiation in Mgp-null lungs. Together, our results suggest that endothelial-epithelial interactions, maintained by MGP, are essential in pulmonary cell differentiation

    Quantification of Enterohemorrhagic Escherichia coli O157:H7 proteome using TMT-Based Analysis

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    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a human pathogen responsible for diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). EHEC infection is distributed worldwide and numerous outbreaks of diseases caused by enterohemorrhagic have been reported. To promote a comprehensive insight into the molecular basis of EHEC O157:H7 physiology and pathogenesis, the combined proteome of EHEC O157:H7 strains, Clade 8 and Clade 6 isolated from cattle in Argentina, and the standard EDL933 (clade 3) strain has been analyzed. TMT (Tandem Mass Tags)-based quantitative proteomic and emPAI analyses were performed to estimate the protein abundance in EHEC proteome. 2,234 non-redundant proteins of EHEC O157:H7 were identified. A comparison of this result with in silico data of EHEC O157:H7 genome showed that approximately 40% of the predicted proteome of this pathogen were covered. According to the emPAI analysis, 85 proteins were among the most abundant (e.g. GAPDH, FliC H-antigen, Enolase, and GroEL). Tellurite resistance proteins were also highly abundant. COG analysis showed that although most of the identified proteins are related to cellular metabolism, the majority of the most abundant proteins are associated with translation processes. A KEGG enrichment analysis revealed that Glycolysis / Gluconeogenesis was the most significant pathway. On the other hand, the less abundant detected proteins are those related to DNA processes, cell respiration and prophage. Among the proteins that composed the Type III Secretion System, the most abundant protein was EspA. Altogether, the results show a subset of important proteins that contribute to physiology and pathogenicity of EHEC O157:H7.IMPORTANCE The study of the abundance of proteins present within a complex mixture of proteins in a cell, under different conditions, can provide important information about the activities of individual protein components and protein networks that are cornerstones for the comprehension of physiological adaptations in response to biological demands promoted by environmental changes. We generated a comprehensive and accurate quantitative list of EHEC O157:H7 proteome, which provides a description of the most abundant proteins produced by this pathogen that were related to physiology and pathogenesis of EHEC. This study provides information and extends the understanding on functional genomics and the biology of this pathogen.Fil: Marques Da Silva, Wanderson. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bei, Jinlong. No especifíca;Fil: Amigo, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Valacco, Maria Pia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Amadio, Ariel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Zhang, Qi. No especifíca;Fil: Wu, Xiuju. No especifíca;Fil: Yu, Ting. No especifíca;Fil: Larzabal, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Chen, Zhuang. No especifíca;Fil: Cataldi, Angel Adrian. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Quantification of enterohemorrhagic Escherichia coli O157:H7 protein abundance by high-throughput proteome

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    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a human pathogen responsible fordiarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). To promote a comprehensiveinsight into the molecular basis of EHEC O157:H7 physiology and pathogenesis,the combined proteome of EHEC O157:H7 strains, Clade 8 and Clade 6 isolated from cattlein Argentina, and the standard EDL933 (clade 3) strain has been analyzed. From shotgunproteomic analysis a total of 2,644 non-redundant proteins of EHEC O157:H7 were identified,which correspond approximately 47% of the predicted proteome of this pathogen. Normalizedspectrum abundance factor analysis was performed to estimate the proteinabundance. According this analysis, 50 proteins were detected as the most abundant ofEHEC O157:H7 proteome. COG analysis showed that the majority of the most abundantproteins are associated with translation processes. A KEGG enrichment analysis revealedthat Glycolysis / Gluconeogenesis was the most significant pathway. On the other hand, theless abundant detected proteins are those related to DNA processes, cell respiration andprophage. Among the proteins that composed the Type III Secretion System, the mostabundant protein was EspA. Altogether, the results show a subset of important proteins thatcontribute to physiology and pathogenicity of EHEC O157:H7.Fil: Marques Da Silva, Wanderson. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Bei, Jinlong. Guangdong Academy Of Agricultural Sciences; ChinaFil: Amigo, Natalia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; ArgentinaFil: Valacco, Maria Pia. Universidad de Buenos Aires; ArgentinaFil: Amadio, Ariel Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Zhang, Qi. Guangdong Academy Of Agricultural Sciences; ChinaFil: Wu, Xiuju. Guangdong Academy Of Agricultural Sciences; ChinaFil: Yu, Ting. Guangdong Academy Of Agricultural Sciences; ChinaFil: Larzabal, Mariano. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; ArgentinaFil: Chen, Zhuang. Guangdong Academy Of Agricultural Sciences; ChinaFil: Cataldi, Ángel Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentin

    Ultrahigh-current-density niobium disulfide catalysts for hydrogen evolution

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    Metallic transition metal dichalcogenides (TMDs)1???8 are good catalysts for the hydrogen evolution reaction (HER). The overpotential and Tafel slope values of metallic phases and edges9 of two-dimensional (2D) TMDs approach those of Pt. However, the overall current density of 2D TMD catalysts remains orders of magnitude lower (~10???100 mA cm???2) than industrial Pt and Ir electrolysers (>1,000 mA cm???2)10,11. Here, we report the synthesis of the metallic 2H phase of niobium disulfide with additional niobium (2H Nb1+xS2, where x is ~0.35)12 as a HER catalyst with current densities of >5,000 mA cm???2 at ~420 mV versus a reversible hydrogen electrode. We find the exchange current density at 0 V for 2H Nb1.35S2 to be ~0.8 mA cm???2, corresponding to a turnover frequency of ~0.2 s???1. We demonstrate an electrolyser based on a 2H Nb1+ xS2 cathode that can generate current densities of 1,000 mA cm???2. Our theoretical results reveal that 2H Nb1+ xS2 with Nb-terminated surface has free energy for hydrogen adsorption that is close to thermoneutral, facilitating HER. Therefore, 2H Nb1+ xS2 could be a viable catalyst for practical electrolysers

    Improved Control of Tuberculosis and Activation of Macrophages in Mice Lacking Protein Kinase R

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    Host factors that microbial pathogens exploit for their propagation are potential targets for therapeuic countermeasures. No host enzyme has been identified whose genetic absence benefits the intact mammalian host in vivo during infection with Mycobacterium tuberculosis (Mtb), the leading cause of death from bacterial infection. Here, we report that the dsRNA-dependent protein kinase (PKR) is such an enzyme. PKR-deficient mice contained fewer viable Mtb and showed less pulmonary pathology than wild type mice. We identified two potential mechanisms for the protective effect of PKR deficiency: increased apoptosis of macrophages in response to Mtb and enhanced activation of macrophages in response to IFN-gamma. The restraining effect of PKR on macrophage activation was explained by its mediation of a previously unrecognized ability of IFN-gamma to induce low levels of the macrophage deactivating factor interleukin 10 (IL10). These observations suggest that PKR inhibitors may prove useful as an adjunctive treatment for tuberculosis
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