Evidence for glycosylation on a DNA-binding protein of Salmonella enterica

BACKGROUND: All organisms living under aerobic atmosphere have powerful mechanisms that confer their macromolecules protection against oxygen reactive species. Microorganisms have developed biomolecule-protecting systems in response to starvation and/or oxidative stress, such as DNA biocrystallization with Dps (DNA-binding protein from starved cells). Dps is a protein that is produced in large amounts when the bacterial cell faces harm, which results in DNA protection. In this work, we evaluated the glycosylation in the Dps extracted from Salmonella enterica serovar Typhimurium. This Dps was purified from the crude extract as an 18-kDa protein, by means of affinity chromatography on an immobilized jacalin column. RESULTS: The N-terminal sequencing of the jacalin-bound protein revealed 100% identity with the Dps of S. enterica serovar Typhimurium. Methyl-alpha-galactopyranoside inhibited the binding of Dps to jacalin in an enzyme-linked lectin assay, suggesting that the carbohydrate recognition domain (CRD) of jacalin is involved in the interaction with Dps. Furthermore, monosaccharide compositional analysis showed that Dps contained mannose, glucose, and an unknown sugar residue. Finally, jacalin-binding Dps was detected in larger amounts during the bacterial earlier growth periods, whereas high detection of total Dps was verified throughout the bacterial growth period. CONCLUSION: Taken together, these results indicate that Dps undergoes post-translational modifications in the pre- and early stationary phases of bacterial growth. There is also evidence that a small mannose-containing oligosaccharide is linked to this bacterial protein

Characterization of the mechanisms underlying the crosstalk between galectins and notch in gastric cancer

Gastric cancer is the fourth most common cancer and the second leading cause of cancer-related deaths worldwide. Galectins form a family of β-galactosides binding proteins that recognize a variety of glycan-containing proteins at the cell surface and are overexpressed in various tumors, including gastric cancer. Galectins overexpression as well as changes in their subcellular distribution has been associated with gastric cancer progression and poor prognosis. It is not well understood, however, how the interaction between galectins and glycosylated receptors modulates tumor development and growth. Since Notch receptors and ligands contain glycan structures known to bind galectins, we aim to demonstrate that galectins expression in the tumor microenvironment may interfere with Notch signaling activation during tumor development and progression.\ud \ud Materials and methods\ud Immunoprecipitation procedures with gastric cancer cell line AGS (ATCC CRL-1739) and MKN45 (ACC 409) were used to test for association between galectin-1/-3 and Notch-1 receptor. Furthermore, we transfected AGS cell line with siRNA against galectin-1/-3 or scramble using standard protocols (IDT DNA technologies), stimulate them with immobilized human recombinant delta-4 or Jagged-1 and assessed Notch-1 receptor activation.\ud \ud Results\ud Galectin-1 and -3 interact with Notch-1 receptor and differentially modulate Notch signaling pathway upon activation by Delta/Jagged ligands. Galectin-1 knockdown alters Notch-1 activation induced by Delta-4 whereas galectin-3 knockdown alters jagged-1-mediated Notch-1 activation. Furthermore, we found that exogenously added galectin-3 can enhance Notch-1 activation by Jagged-1.\ud \ud Conclusion\ud Our results suggest that galectin-1 and -3 interact with Notch-1 receptor and differentially modulate Notch signaling activation induced by Jagged-1 and Delta-4

Galectin-3 negatively regulates the frequency and function of CD4+CD25+Foxp3+ regulatory T cells and influences the course of Leishmania major infection

Galectin-3, an endogenous glycan-binding protein, plays essential roles during microbial infection by modulating innate and adaptive immunity. However, the role of galectin-3 within the CD4+CD25+Foxp3+ T regulatory (TREG) cell compartment has not yet been explored. Here, we found, in a model of Leishmania major infection, that galectin-3 deficiency increases the frequency of peripheral TREG cells both in draining lymph nodes (LNs) and sites of infection. These observations correlated with an increased severity of the disease, as shown by increased footpad swelling and parasite burden. Galectin-3-deficient (Lgals3−/−) TREG cells displayed higher CD103 expression, showed greater suppressive capacity, and synthesized higher amounts of IL-10 compared with their wild-type (WT) counterpart. Furthermore, both TREG cells and T effector (TEFF) cells from Lgals3−/− mice showed higher expression of Notch1 and the Notch target gene Hes-1. Interestingly, Notch signaling components were also altered in both TREG and TEFF cells from uninfected Lgals3−/− mice. Thus, endogenous galectin-3 regulates the frequency and function of CD4+CD25+Foxp3+ TREG cells and alters the course of L. major infection.Fil: Fermino, Marise L.. Universidade de Sao Paulo; BrasilFil: Dias, Fabrício C.. Universidade de Sao Paulo; BrasilFil: Lopes, Carla D.. Universidade de Sao Paulo; BrasilFil: Souza, Maria A.. Universidade de Sao Paulo; BrasilFil: Cruz, Ângela K.. Universidade de Sao Paulo; BrasilFil: Liu, Fu Tong. University of California at Davis; Estados UnidosFil: Chammas, Roger. Universidade de Sao Paulo; BrasilFil: Roque Barreira, Maria C.. Universidade de Sao Paulo; BrasilFil: Rabinovich, Gabriel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Bernardes, Emerson S.. Universidade de Sao Paulo; Brasi

Textos informativos nos manuais escolares : um contributo para a formação de leitores no contexto de prática de ensino supervisionada

Na sequência da conclusão do Mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico redigiu-se o presente Relatório que, de forma integrada, apresenta o trabalho desenvolvido durante a Prática de Ensino Supervisionada (PES) e a investigação nela desenvolvida. Este estudo, com o tema “Textos informativos nos manuais escolares: um contributo para a formação de leitores”, tem como propósito analisar em que medida os textos informativos, presentes nas unidades didáticas de manuais escolares das diferentes áreas do conhecimento, de uma turma do 1.º ano de escolaridade do Ensino Básico, contribui para a formação leitores. Estruturado em duas partes, o estudo inicia-se com uma reflexão sobre as práticas em contexto de Educação Pré-Escolar e 1.º Ciclo do Ensino Básico, seguindo-se a apresentação do trabalho de investigação, desenvolvido ao longo de dois semestres, que careceu da elaboração de um enquadramento teórico que integra e desenvolve temas indispensáveis à sua concretização. Este insere-se num paradigma qualitativo e quantitativo, que privilegia a análise de conteúdo e constitui os manuais escolares como o principal objeto de análise. Os resultados obtidos revelaram uma presença visível de textos informativos no manual de Português e Estudo do Meio, que vão sendo cada vez mais extensos à medida que o ano letivo avança e que a capacidade de leitura se começa a dominar e automatizar. Destacamos, igualmente, a necessidade de promoção de textos de caráter informativo, desde tenra idade, em todas as áreas do conhecimento como estratégia para o desenvolvimento das capacidades de estruturação e organização de informação mais complexa.Abstract Following the completion of the master´s degree in Preschool Education and teaching of the first Cycle of basic education drafted the present report that, in a integrated manner, presents the work developed during the Supervised teaching Practice (PES) and her research developed. With the theme “Informational texts in textbooks: a contribution to the formation of readers”, this study aims to analyze the extent to which the informative texts, present in the didactic units of textbooks of different areas of knowledge, of a class of the 1st year of primary schooling, contributes to the formation readers. Divided into two parts, the study begins with a reflection on the practices in Preschool Education context and 1st Cycle of basic education, followed by the presentation of the research work, developed over two semesters, which lacked the elaboration of a theoretical framework that integrates and develops themes which are indispensable for its implementation. This is part of a qualitative and quantitative paradigm, which focuses on content analysis and constitutes the textbooks as the main object of analysis. The results obtained revealed a visible presence of informative texts in Portuguese manual and Study of the medium, which are being increasingly extensive as the school year progresses and that the ability to read begins to dominate and automate. We highlight, also, the need for promotion of informative texts, from an early age, in all areas of knowledge as a strategy for the development of capacities of structuring and organizing information more complex

Lack of galectin-3 increases Jagged1/Notch activation in bone marrow-derived dendritic cells and promotes dysregulation of T helper cell polarization

Galectin-3, an endogenous glycan-binding protein, is abundantly expressed at sites of inflammation and immune cell activation. Although this lectin has been implicated in the control of T helper (Th) polarization, the mechanisms underlying this effect are not well understood. Here, we investigated the role of endogenous galectin-3 during the course of experimental Leishmania major infection using galectin-3-deficient (Lgals3-/-) mice in a BALB/c background and the involvement of Notch signaling pathway in this process. Lgals3-/- mice displayed an augmented, although mixed Th1/Th2 responses compared with wild-type (WT) mice. Concomitantly, lymph node and footpad lesion cells from infected Lgals3-/- mice showed enhanced levels of Notch signaling components (Notch-1, Jagged1, Jagged2 and Notch target gene Hes-1). Bone marrow-derived dendritic cells (BMDCs) from uninfected Lgals3-/- mice also displayed increased expression of the Notch ligands Delta-like-4 and Jagged1 and pro-inflammatory cytokines. In addition, activation of Notch signaling in BMDCs upon stimulation with Jagged1 was more pronounced in Lgals3-/- BMDCs compared to WT BMDCs; this condition resulted in increased production of IL-6 by Lgals3-/- BMDCs. Finally, addition of exogenous galectin-3 to Lgals3-/- BMDCs partially reverted the increased sensitivity to Jagged1 stimulation. Our results suggest that endogenous galectin-3 regulates Notch signaling activation in BMDCs and influences polarization of T helper responses, thus increasing susceptibility to L. major infection.Fil: Fermino, Marise L.. Universidade de Sao Paulo; BrasilFil: Dergan Dylon, Leonardo Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Cecílio, Nerry T.. Universidade de Sao Paulo; BrasilFil: Santos, Sofia N.. Comissão Nacional de Energia Nuclear. Centro de Radiofarmácia; BrasilFil: Toscano, Marta Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Dias Baruffi, Marcelo. Universidade de Sao Paulo; BrasilFil: Roque Barreira, Maria C.. Universidade de Sao Paulo; BrasilFil: Rabinovich, Gabriel Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; ArgentinaFil: Bernardes, Emerson S.. Comissão Nacional de Energia Nuclear. Centro de Radiofarmácia; Brasi