Navegando por Palavras-chave "glicosaminoglicanos"

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    Altered hyaluronic acid content in tear fluid of patients with adenoviral conjunctivitis
    (Academia Brasileira de Ciências, 2015-03-01) Dreyfuss, Juliana Luporini [UNIFESP]; Regatieri, Caio Vinicius Saito [UNIFESP]; Coelho, Bruno; Barbosa, José B.; Freitas, Denise de [UNIFESP]; Nader, Helena Bonciani [UNIFESP]; Martins, João R.; Universidade Federal de São Paulo (UNIFESP); New England Eye Center Department of Ophthalmology
    The adenoviral conjunctivitis is one of the biggest causes of conjunctival infection in the world. Conjunctivitis causes relatively nonspecific symptoms, as hyperaemia and chemosis. Even after biomicroscopy, complex laboratory tests, such as viral culture, are necessary to identify the pathogen or its etiology. To contribute to the better understanding of the pathobiology of the adenoviral conjunctivitis, the tear fluids of patients with unilateral acute adenovirus conjunctivitis (UAAC), normal donors (control) and patients with allergic conjunctivitis were analyzed. Tear samples were collected with Schirmer strips from control, allergic conjunctivitis and UAAC patients, diagnosed by clinical signs. UAAC tears were tested positive in viral cultures. After the elution, HA was quantified using an ELISA-like fluorometric assay and the protein profile was determined by SDS-PAGE. A profound increase in the HA tear content in UAAC patients was found when compared to control and ALC. This HA increase in UAAC tears remarkably was not observed in tears from contralateral eyes without clinical signs, nor in allergic conjunctivitis. In addition a distinct profile of UAAC tear proteins was observed in patients with UAAC. The quantification of HA in the tear fluid is a rapid, sensitive and specific test. This molecule might be a biomarker candidate for acute conjunctivitis.
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    Efeito do shear stress e estiramento mecânico na expressão de moléculas da matriz extracelular em células endoteliais
    (Universidade Federal de São Paulo (UNIFESP), 2015-04-29) Russo, Thatiane Amaral [UNIFESP]; Dreyfuss, Juliana Luporini Dreyfuss [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The mechanical stress alters the functional properties of the cells, which is called mechanotransduction. The mechanotransduction modifies molecular responses involving structural cellular elements and cell signaling. The endothelium is subject to these forces and the extracellular matrix and cell surface components, such as glycocalyx, are activated by mechanical deformation. The response of endothelial cells to mechanotransduction stimuli is important in the homeostasis of the circulatory system, and abnormal responses to these forces imply cardiovascular diseases. This study was performed an investigation of the expression of sulfated glycosaminoglycans and other extracellular matrix and cell surface molecules of cultured endothelial cells subjected to different stimulus of mechanical forces such as shear stress and cell stretching evaluating these effects on physiological and pathological conditions . The equipment Strearner'" was used which mimics a laminar blood flow to the evaluation of shear stress, where endothelial cells from rabbit aorta were subjected to forces of 4 dyn/crn" (pathological condition) and 12 dyn/cm" (physiological condition) for 4h or 24h. We also used the Flexcell FX-5000 ? equipment that is capable of promoting controlled deformation resulting in a biaxial mechanical stretching of endothelial cells, evaluating its effects at 5% stretch (physiological condition) and 15% stretch (pathological condition) for 4h or 24h. After these stimuli in mechanical forces the cells were subjected to various assays such as immunofluorescence, quantitative PCR, analysis of sulfated glycosaminoglycans and cell behavior assays. Exposure of endothelial cells to mechanical forces influences the remodeling of the extracellular matrix and interaction of cell-matrix and cell-cell. Endothelial cells change their morphology, acquiring a direction towards the applied force, in addition to changing the behavior of cells in events such as adhesion, migration and formation of capillary type structures, where in most cases modulated positively mechanotransduction under physiological conditions and negatively in pathological situations. Expression of sulfated glycosaminoglycans is also influenced by mechanical forces. Exposure of endothelial cells to a shear stress induces a higher expression of heparan sulfate and chondroitin sulfate in patholcigical conditions and lower expression in physiological conditions, both the cell fraction and the secreted into the culture medium. Mechanical stretch induces an increase in the synthesis of chondroitin sulfate in pathological conditions in cell fraction, and reduces the expression of heparan sulfate and chondroitin sulfate in pathological conditions when secreted into the culture medium. The mechanical forces modulate negatively physiological situations and positively in pathological situations expression of the proteoglycan such as Syndecan-4, Perlecam, Versican and Decorin, and expression of adhesive proteins and growth factors such as Connexin-43, VEGF-A, and Fibronectin. These studies help to better understand how the vascular biology and the extracellular matrix and cell surface molecules are affected by mechanical forces, and how these molecules behave in cardiovascular disease. 102
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    Obtenção estrutural de um antiagiogênico das vísceras da tilápia (oreochromis niloticus)
    (Universidade Federal de São Paulo (UNIFESP), 2014-01-29) Souza Junior, Airton Araujo de [UNIFESP]; Nader, Helena Bonciani Nader [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Heparan sulfate (HS) and heparin are GAGs that share similar structure, yet, HS contains reduced levels of O- and N-sulfation together with lower levels of epimerized glucuronic acid; iduronic acid. It is a ubiquitously distributed in cell surface of mammals as well as in other vertebrates and invertebrates, hence, it shows a high biotechnological relevance due to its and structural diversity which leads an extensive ?interactome? and modulatory effects on several biological/pharmacological processes. Thus, the comprehension of HS structures in different cells/tissues is crucial for the total elucidation structure-function relationships. The search for heparan-like compounds in waste material from fish farming is both economical and environmental attractive since it adds value to waste products and solves issues related to waste handling, consolidating tilapia culture as a valuable new source of ecofriendly biotechnological agents. Accordingly, this work aimed on the isolation and structural characterization of a heparan sulfate from Tilapia (Orechromis niloticus) waste material, besides its potential effects on coagulation and angiogenesis. The purified compound showed the same electrophoretic behavior, in different buffer systems, of heparan sulfate from bovine sources and the structural analysis, both chromatographic and spectroscopic, proved that the Tilapia compound has strong structural similarity with HS from bovine pancreas. Also, it was demonstrated that the isolated compound has low anticoagulant activity and inhibited capillary tube formation of endothelial cells on 2D angiogenesis assay in Matrigel. Together, our data suggests the HST is a promising bioproduct that could be used to target angiogenesis in pathophysiological processes.