ABSTRACT
La omentina es una nueva adipocina a la que se le ha atribuido la capacidad de regular actividades metabólicas (sensibilidad a la insulina) y antiinflamatorias, ofreciendo protección cardiovascular en la obesidad y diabetes mellitus tipo 2. Por lo anterior, es importante conocer los mecanismos a través de los cuales confiere protección cardiovascular, con el objetivo de considerar la omentina como blanco o agente terapéutico en este escenario.
The omentin is an adipokine, which role is due to the capacity of regulate metabolic (insulin sensitivity) and anti-inflammatory activities, thus conferring vascular protection during obesity and diabetes mellitus type 2. By this, it is important to know the mechanisms by which omentin confers cardiovascular protection, with the purpose of establish omentin a possible therapeutic target or molecule on this scenario.
Subject(s)
Humans , Cardiovascular Diseases/etiology , Cytokines/physiology , Inflammation/etiology , Lectins/physiology , Insulin Resistance/physiology , Endothelium, Vascular/physiopathology , Energy Metabolism , GPI-Linked Proteins/physiology , Obesity/etiologyABSTRACT
Introdução e objetivos: O glioblastoma multiforme é um glioma de alto grau que apresenta um prognóstico ruim. O diagnóstico definitivo é estabelecido pela avaliação histológica, porém este pode apresentar conflitos na classificação, com isso surge à necessidade de ferramentas que auxiliem o patologista em sua análise. Atualmente, maior ênfase tem sido dada a alterações na glicosilação, pois estão associadas a neoplasias, e a descoberta da capacidade de lectinas em reconhecer tais alterações fez destas, ferramentas aplicáveis para o diagnóstico biomédico. Dessa forma, o objetivo deste trabalho é analisar a marcação das lectinas CpL, WGA e Con A em células da linhagem C6...
Introduction and objectives: Glioblastoma multiforme is a high-grade glioma that has a poor prognosis. The definitive diagnosis is established by histological assessment. However, this can present conflicts in grading gliomas, which justifies new tools to assist the pathologist in his analysis. Currently, it is known that there are changes in glycosylation pattern of molecules associated with cancer, and the discovery of the ability of lectins to recognize these changes made these tools applicable for biomedical diagnosis. Thus, the aim of this study is to analyze the labelling of C6...
Subject(s)
Humans , Glioma/complications , Glioma/diagnosis , Glioma/immunology , Glioma/pathology , Glioma/blood , Lectins , Lectins/analysis , Lectins/physiology , Lectins/immunologyABSTRACT
Alectina ligante de manose (MBL) e uma proteina com importantepapel na primeira linha de defesa do sistema imune inato, cujos valores sericos sao determinados geneticamente. A MBL ativa a via da lectina do complemento, alem de mediar a opsonisaçao e fagocitose de microorganismos. A hanseniase e uma doença infecciosa cronica causada pelo Mycobacterium leprae, bacteria intracelular obrigatoria, que infecta fagocitos mononucleares do ospedeiro...
Subject(s)
Humans , Leprosy/physiopathology , Leprosy/immunology , Leprosy/microbiology , Lectins/physiology , Lectins/immunology , Mycobacterium leprae/cytology , Mycobacterium leprae/physiology , Mycobacterium leprae/immunology , Dolichol Monophosphate Mannose , Dolichol Monophosphate Mannose/immunologyABSTRACT
Las galectinas se definen por dos propiedades: secuencias de aminoácidos características compartidas y afinidad por azúcares ß-galactosídicos. Numerosas galactinas de mamíferos fueron secuenciadas y bien caracterizadas en diferentes especies, siendo clasificadas como galectina-1 a galectina-10, según sus homologías de secuencia. La identidad entre dominios que ligan carbohidratos de distintas galectinas de una especie de mamífero oscila entre 20-40 por ciento, mientras que la identidad de galectina-1, por ejemplo, entre distintas especies es de 80-90 por ciento. En la presente revisión, se describen las principales propiedades distintivas de las galectinas de mamífero en cuanto a estructura proteica, estructura cristalina, especificidad glicídica y ligandos específicos
Subject(s)
Humans , Mice , Rats , Animals , Cattle , In Vitro Techniques , Lectins/chemistry , Biomarkers/blood , Selectins/chemistry , Amino Acid Sequence , Carbohydrate Sequence , Cattle , Chickens , Crystallography , Laminin/chemistry , Laminin/ultrastructure , Lectins/classification , Lectins/physiology , Mammals , Molecular Sequence Data , X-Ray DiffractionABSTRACT
La aplicación de Lectinas para la identificación de oligosacáridos constituyentes de las Mucinas presentes en la superficie celular, es una herramienta técnica muy útil, debido a que, probablemente estas sustancias estén involucrados en procesos tales como invasión y metástasis. En este trabajo, nosotros estudiamos tejido endometrial normal com entidades benignas y malignas, para investigar la presencia de Galactosa beta 1-3 N Acetilgalactosamina (Galbeta 1-3GalNacalpha) y de Galactosa beta 1-3 N Acetilgalactosamina(Galbeta 1-3GalNa alpha y beta) empleando dos Lectinas: Agaricus bisporus (ABL) y Arachis hipogea (PNA) respectivamente. Lo controles fueron realizados com baños de galactosa para PNA y com mucina porcina de estómago de cerdo para ABL. El uso de estas dos Lectinas, permitió encontrar diferencias en los patrones de unión, ya que si bien ambas se unen a los mismos oligosacáridos, ABL realiza la unión en presencia de Acido Siálico mientras que PNA no. Se observaron significativas diferencias en los patrones de unión de ambas lectinas en tejidos, com entidades benignas, malignas y tejido normal. En este último, la marcación fue simpre continua com ambas Lectinas, mientras que fue irregular en el carcinoma.
Subject(s)
Humans , Endometrium/chemistry , Galactose/isolation & purification , Lectins/physiology , Mucins/chemistry , Biomarkers , Carcinoma/metabolism , Endometrial Hyperplasia/metabolism , Endometrial Neoplasms/metabolism , LectinsABSTRACT
Sobre la base de estudios estructurales y funcionales, las lectinas animales se han clasificado en dos tipos: el Tipo C, caracterizado por su dependencia de los iones de calcio y el Tipo S que no es calciodependiente, sino tioldependiente. Entre estas últimas, se ha estudiado ampliamente el grupo de lectinas S-Lac, que son extraídas con buffers salinos con lactosa, en presencia de tioles. Contituyen una familia de proteínas realcionadas estructuralmente, que contienen una serie de aminoácidos conservados. Se unen específicamente a glicoconjugados complementarios y su biosíntesis y localización son reguladas por el desarrolo. Su rol puede relacionarse con diversas actividades biológicas que poderían variar según el órgano.
Subject(s)
Humans , Animals , Cattle , Rats , Galactosides/metabolism , Lectins/metabolism , alpha-Fetoproteins/pharmacology , Amino Acid Sequence , Amphibians , Binding Sites , Bufo arenarum , Carbohydrates/pharmacology , Electric Fish , Fundulidae , Hemagglutinins/pharmacology , Lectins/antagonists & inhibitors , Lectins/physiology , Molecular Sequence Data , Molecular Weight , Solubility , Xenopus laevisABSTRACT
The thymus is a primary lymphoid organ in wich bone narrow-derived T cell precursors undergo a complex maturation process in the context of the thymic microenvironment, represented by non-lymphoid cells and extracellular matrix (ECM) components. The thymic epithelial cells are the major cellular component of the thymic microenvironment, and influence different aspects of thymocyte differentiation, via cell-cell interactions and secretion of soluble factors, such as thymic hormones. The thymic nurse cell (TNC) complexes are multicellular lymphoepithelial structures formed by one thymic epithelial cell harboring 2-200 thymocytes, primary bearing the CD4/CD8 double-positive phenotype. TNCs probably create a special microenvironment for thymocyte differentiation and/or proliferation, with thymocytes being exposed to major histocompatibility complex (MHC) antigens and thymic hormones. Such differentiation parallels cell migration into and out of the complex. We showed the expression of ECM components and respective receptors by TNCs, and that interactions between the epithelial component of TNC and TNC-lymphocytes can be modulated by ECM components and respective receptors. Moreover, we demonstrated that intrinsic as well as extrinsic biological circuits can be involved in the control of such ECM-mediated thymic epithelial cell (TEC)/thymocyte interactions. For example, interferon-gamma can biphasically modulate the expression of ECM ligands and receptors by TEC, with results in corresponding modulation of their ability to interact with TNC-thymocytes. Additionally, hormones such as triiodothyronine, prolactin and growth hormone can influence the degree of these lymphocyte/epithelial cell adhesive interactions. Lastly, we recently furnished evidence for a de-adhesive mechanism within TNC aparently mediated by galectin 3 (an endogenous soluble beta-galactoside-binding lectin). Taken together, our data strongly indicate that thymic nurse cells can be regarded as an in vitro model for intrathymic T cell migration, particularly with respect to those events mediated by the extracellular matrix.
Subject(s)
Animals , Mice , Cell Movement/physiology , Extracellular Matrix/physiology , In Vitro Techniques , Thymus Gland/cytology , Cell Differentiation , Interferon-gamma/physiology , Lectins/physiologyABSTRACT
Alguns aspectos da estrutura e do modo de açäo das lectinas säo brevemente revisados. Especial ênfase é dada as funçöes biológicas dessas moléculas, bem como às suas aplicaçöes como ferramentas em diversas áreas