Navegando por Palavras-chave "extracellular matrix"

Agora exibindo 1 - 20 de 27
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Actin-rich structures formed during the invasion of cultured cells by infective forms of Trypanosoma cruzi
    (Urban & Fischer Verlag, 1999-12-01) Procopio, Daniela de Oliveira [UNIFESP]; Barros, Helena Cristina [UNIFESP]; Mortara, Renato Arruda [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Previous work has shown that Trypanosoma cruzi extracellular amastigotes as well as metacyclic trypomastigotes infect cultured cells in a highly specific parasite form-cell type interaction. In this work we have investigated the mode of interaction of both forms with HeLa and Vero cells using scanning electron and confocal fluorescence microscopy. We examined the distribution of several host cell components as well as extracellular matrix elements during cell invasion by both T. cruzi infective forms. Scanning electron microscopy showed that membrane expansions formed during the invasion of cells by extracellular amastigotes. These expansions correspond to small cup-like structures in HeLa cells and are comparatively larger crater-like in Vero cells. We detected by confocal microscopy actin-rich structures associated with the internalisation of both infective forms of the parasite that correspond to the membrane expansions. Confocal fluorescence microscopy combining DIC images of cells labelled with monoclonal antibodies to phosphotyrosine, cytoskeletal elements, integrins, and extracellular matrix components revealed that some of the components like gelsolin and a-actinin accumulate in actin-rich structures formed in the invasion of amastigotes of both cell types. Others, like vinculin and alpha 2 integrin may be present in these structures without evident accumulation. And finally some actin-rich processes may be devoid of components like fibronectin or alpha V integrin. These studies provide evidence that the repertoire of host cell/extracellular matrix components that engage in the invasion process of T, cruzi forms is cell type- and parasite form-dependent.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Assembly of high molecular weight kininogen and activation of prekallikrein on cell matrix
    (F K Schattauer Verlag Gmbh, 2001-09-01) Motta, G.; Shariat-Madar, Z.; Mahdi, F.; Sampaio, Claudio AM [UNIFESP]; Schmaier, A. H.; Universidade Federal de São Paulo (UNIFESP); Univ Michigan
    Investigations determined if extracellular matrix of endothelial cells (EC) is a platform for HK assembly and PK activation. In buffers containing bovine serum albumin, biotin-RK binding to ECV304 cells or their matrix requires greater than or equal to 50 muM added Zn2+. Ortho-phenanthroline or a HK domain 5 peptide blocks HK binding, Binding to umbilical vein EC or matrix, but not ECV304 cells or matrix, is mediated by cytokeratin 1. Biotin-HK binds to ECV304 cells or matrix with a K-d of 15.8 or 9.0 nM and a B-max of 2.6 X 10(7) or 21.4 X 10(7) sites/cell, respectively. PK activation un ECV304 cells or matrix is blocked by antipain or SBTI and corn trypsin inhibitor partially inhibits kallikrein formation. PK activation occurs on ECV304 cells or matrix prepared without serum or in human factor XII deficient serum. indicating that the PK activator is not factor XIIa. EC matrix promotes plasminogen activation after the assembly of HK, PK and pro-urokinase. These studies indicate that matrix of various EC has the ability to assemble HK allowing for PK activation and subsequent activities.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Autoantibodies directed to extracellular matrix components in patients with different clinical forms of periodontitis
    (Amer Acad Periodontology, 2006-12-01) De-Gennaro, Luiz A.; Lopes, Jose D.; Mariano, Mario; Universidade Federal de São Paulo (UNIFESP)
    Background: Periodontal disease occurs in different clinical forms, from mild and easily controllable to more aggressive inflammatory manifestations, with difficult clinical or surgical control. There is evidence that a local autoimmune reaction may participate in the onset and persistence of the aggressive forms of periodontal disease. As the underlying mechanism in this process is not fully understood, we decided to investigate whether patients bearing this form of disease presented higher levels of antibodies directed to extracellular matrix (ECM) components such as type I collagen, fibronectin, and laminin.Methods: Three groups of patients were selected by clinical criteria: 22 subjects with aggressive periodontitis (AgP) = group A; 18 subjects with chronic periodontitis (CP) = group B; and 10 healthy (H) volunteers without periodontal disease = group C. Autoantibody levels were evaluated in the sera of these patients using the enzyme-linked immunosorbent assay (ELISA) method.Results: the levels of autoantibodies directed to ECM components (type I collagen, fibronectin and laminin) in the sera of patients with AgP and CP were shown to be statistically different (P < 0.05).Conclusions: Although the present findings suggest an involvement of autoantibodies directed to ECM components per se in the pathogeny of certain types of periodontal disease, the available data do not support the classification of the lesions as autoimmune. Nevertheless, the findings open a possibility for the development of an additional method for a differential diagnosis of the aggressive forms of periodontal disease.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Cellular prion protein binds laminin and mediates neuritogenesis
    (Elsevier B.V., 2000-03-10) Graner, E.; Mercadante, A. F.; Zanata, S. M.; Forlenza, O. V.; Cabral, ALB; Veiga, S. S.; Juliano, M. A.; Roesler, R.; Walz, R.; Minetti, A.; Izquierdo, I; Martins, V. R.; Brentani, R. R.; Ludwig Inst Canc Res; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); UFRGS; Ctr Tratamento; Pesquisa Hosp Canc
    Laminin (LN) plays a major role in neuronal differentiation, migration and survival. Here, we show that the cellular prion protein (PrPc) is a saturable, specific, high-affinity receptor for LN. the PrPc-LN interaction is involved in the neuritogenesis induced by NGF plus LN in the PC-12 cell line and the binding site resides in a carboxy-terminal decapeptide from the gamma-1 LN chain. Neuritogenesis induced by LN or its gamma-1-derived peptide in primary cultures from rat or either wild type or PrP null mice hippocampal neurons, indicated that PrPc is the main cellular receptor for that particular LN domain. These results point out to the importance of the PrPc-LN interaction for the neuronal plasticity mechanism. (C) 2000 Elsevier Science B.V. All rights reserved.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Cellular prion protein interaction with vitronectin supports axonal growth and is compensated by integrins
    (Company of Biologists Ltd, 2007-06-01) Hajj, Glaucia N. M.; Lopes, Marilene H.; Mercadante, Adriana F.; Veiga, Silvio Sanches [UNIFESP]; Silveira, Rafael Bertoni da [UNIFESP]; Santos, Tiago G.; Ribeiro, Karina C. B.; Juliano, Maria Aparecida [UNIFESP]; Jacchieri, Saul G.; Zanata, Silvio M.; Martins, Vilma R.; Hosp Alemao Oswaldo Cruz; Universidade de São Paulo (USP); Hosp Canc; Univ Fed Parana; Universidade Federal de São Paulo (UNIFESP)
    The physiological functions of the cellular prion protein, PrPC, as a cell surface pleiotropic receptor are under debate. We report that PrPC interacts with vitronectin but not with fibronectin or collagen. the binding sites mediating this PrPC-vitronectin interaction were mapped to residues 105-119 of PrPC and the residues 307-320 of vitronectin. the two proteins were co-localized in embryonic dorsal root ganglia from wild-type mice. Vitronectin addition to cultured dorsal root ganglia induced axonal growth, which could be mimicked by vitronectin peptide 307-320 and abrogated by anti-PrPC antibodies. Full-length vitronectin, but not the vitronectin peptide 307-320, induced axonal growth of dorsal root neurons from two strains of PrPC-null mice. Functional assays demonstrated that relative to wild-type cells, PrPC-null dorsal root neurons were more responsive to the Arg-Gly-Asp peptide (an integrin-binding site), and exhibited greater alpha v beta 3 activity. Our findings indicate that PrPC plays an important role in axonal growth, and this function may be rescued in PrPC-knockout animals by integrin compensatory mechanisms.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Concentração do ácido hialurônico em pregas vocais com edema de reinke
    (Universidade Federal de São Paulo (UNIFESP), 2016-11-29) Melo, Cristiana Vanderlei de [UNIFESP]; Biase, Noemi Grigoletto de Biase [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objective: The authors investigated the concentration of hyaluronic acid in Reinke's edema in the vocal fold cover. Method: For this study a hyaluronic acid binding protein isolated from bovine nasal cartilage was used. Plates containing the binding protein were successively incubated with 32 samples Reinke?s edema and 11 female vocal folds; biotin-conjugated hyaluronic acid binding protein and europium-labeled. After release of europium from streptavidin with enhancement solution the final flourescence was measured in a fluorometer. Results: Were evaluated 19 patients with Reinke's edema, with a predominance of the female sex (94%) with mean age of 57.62 years. The concentration of hyaluronic acid in vocal folds with Reinke's edema was greater and statistically significant relative to the control. There was no statistical difference between the concentration of hyaluronic acid in the samples with Reinke's edema in relation to age, grade or smoking history.Conclusion: The study of hyaluronic acid concentration in vocal folds with Reinke's edema, we conclude that vocal folds affected by Reinke's edema have higher concentrations of hyaluronic acid in relation to normal; and the concentration of hyaluronic acid is independent of age, the degree of Reinke's edema or smoking history.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Differential Gene Transcription of Extracellular Matrix Components in Response to In Vivo Corneal Crosslinking (CXL) in Rabbit Corneas
    (Assoc Research Vision Ophthalmology Inc, 2017) Kling, Sabine; Hammer, Arthur; Torres Netto, Emilio A. [UNIFESP]; Hafezi, Farhad
    Purpose: We studied changes in gene transcription after corneal crosslinking (CXL) in the rabbit cornea in vivo and identified potential molecular signaling pathways. Methods: A total of 15 corneas of eight male New-Zealand-White rabbits were deepithelialized and equally divided into five groups. Group 1 served as an untreated control. Groups 2 to 5 were soaked with 0.1% riboflavin for 20 minutes, which in Groups 3 to 5 was followed by UV-A irradiation at a fluence of 5.4 J/cm(2). Ultraviolet A (UVA) irradiation was delivered at 3 mW/cm(2) for 30 minutes (Group 3, standard CXL protocol), 9 mW/cm(2) for 10 minutes (Group 4, accelerated), and 18 mW/cm(2) for 5 minutes (Group 5, accelerated). At 1 week after treatment, corneal buttons were obtained; mRNA was extracted and subjected to cDNA sequencing (RNA-seq). Results: A total of 297 differentially transcribed genes were identified after CXL treatment. CXL downregulated extracellular matrix components (collagen types 1A1, 1A2, 6A2, 11A1, keratocan, fibromodulin) and upregulated glycan biosynthesis and proteoglycan glycosylation (GALNT 3, 7, and 8, B3GALT2). Also, CXL activated pathways related to protein crosslinking (transglutaminase 2 and 6). In 9.1% of the significantly different genes, CXL at 3 mW/cm(2) (Group 1) induced a more distinct change in gene transcription than the accelerated CXL protocols, which induced a lower biomechanical stiffening effect. Conclusions: Several target genes have been identified that might be related to the biomechanical stability and shape of the cornea. Stiffening-dependent differential gene transcription suggests the activation of mechano-sensitive pathways.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    The effect of brown spider venom on endothelial cell morphology and adhesive structures
    (Elsevier B.V., 2006-06-15) Paludo, Katia Sabrina; Gremski, Luiza Helena; Veiga, Silvio Sanches; Chaim, Olga Meiri; Gremski, Waldemiro; Freitas Buchi, Dorly de; Nader, Helena Bonciani; Dietrich, Carl Peter; Franco, Celia Regina Cavichiolo [UNIFESP]; Univ Fed Parana; Universidade Federal de São Paulo (UNIFESP); Catholic Univ Parana
    Spiders of the Loxosceles genus have been responsible for severe clinical cases of envenomation worldwide. Accidents involving brown spiders can cause dermonecrotic injury, hemorrhage, hemolysis, platelet aggregation and renal failure. Histological findings of animals treated by venom have shown subendothelial blebs, vacuoles and endothelial cell membrane degeneration of blood vessel walls, as well as fibrin and thrombus formation. the mechanisms by which the venom causes these disorders are poorly understood. in this work, with an endothelial cell line derived from rabbit aorta, we were able to demonstrate that venom binds to the cell surface and the extracellular matrix. Moreover, we observed that the venom also induced morphological alterations, such as cell retraction, homophilic disadhesion and an increasing in filopodia projections. We also demonstrated that toxins present in the venom disorganized focal adhesion points and actin microfilaments of endothelial cells. Nevertheless, endothelial cell viability showed no alterations compared to controls. Additionally, venom treatment changed the fibronectin matrix profile synthesized by these cells as well as cell adhesion to fibronectin. These results suggest that the deleterious effects of venom on blood vessel walls could be a consequence of the direct effect on the endothelial cell surface and adhesive structures involved in blood vessel stability. These effects indirectly lead to leukocyte and platelet activation, disseminated intravascular coagulation and an increase in vessel permeability. (c) 2006 Elsevier B.V. All rights reserved.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    The expression of glycosaminoglycans and proteoglycans in the uterine cervix of albino rats after local hyaluronidase infusion
    (Informa Healthcare, 2014-06-01) Souza, Guilherme Negrao [UNIFESP]; Camano, Luiz [UNIFESP]; Araujo Junior, Edward [UNIFESP]; Nader, Helena Bonciani [UNIFESP]; Medeiros, Valquiria [UNIFESP]; Maciel Martins, Joao Roberto [UNIFESP]; Souza, Eduardo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objective: To assess the local effect of hyaluronidase injection on the expression of glycosaminoglycans (GAGs) and proteoglycans (PGs) in the extracellular matrix of the uterine cervix from pregnant albino rats.Methods: Ten pregnant rats were divided into two groups on day 18 of pregnancy. the experimental group (Gexp) of rats received an intracervical infusion of 0.02 mL of hyaluronidase diluted to 1mL with distilled water, whereas the control group (Gc) received 1mL of distilled water. On day 20 of pregnancy, the pregnant rats were sacrificed and the uterine cervixes from all rats were then dissected. the qualitative expression of hyaluronic acid (HA) was assessed by immunohistochemistry and quantified by sandwich ELISA. To compare the quantitative GAG values between groups, a Student's t-test for independent samples was performed. PGs were also assessed by immunohistochemical analysis.Results: the electrophoretic profile of newly synthesized radioactively labeled GAGs degraded by specific enzymes showed that there were two predominant GAGs in both Gc and Gexp, i.e. heparan sulfate (HS) and a mixture of hondroitin sulfate (CS) and dermatan sulfate (DS). the concentrations of GAGs showed a significant reduction of CS/DS (p<0.004) and HS (p<0.005) relative to Gc. HA staining was less intense in the lamina propria and area surrounding the blood vessels in Gexp compared to Gc. the HA contents were also significantly reduced (p<0.012).Conclusions: Intracervical hyaluronidase infusion promoted a significant reduction in the concentration of sulfated GAGs as assessed by both qualitative (histochemical) and quantitative (fluorometric) measurements of HA.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Extracellular matrix alterations in experimental murine Leishmania (L.) amazonensis infection
    (Cambridge Univ Press, 2004-04-01) Abreu-Silva, A. L.; Calabrese, K. S.; Mortara, R. A.; Tedesco, R. C.; Cardoso, F. O.; Carvalho, LOP; Da Costa, SCG; Univ Estadual Maranhao; Fiocruz MS; Universidade Federal de São Paulo (UNIFESP)
    Here we describe extracellular matrix alterations in footpad lesions and draining lymph nodes caused by Leishmania (L.) amazonensis in mouse strains with distinct susceptibilities to this parasite: BALB/c (susceptible), C57BL/6 (intermediate), and DBA/2 (resistant). Changes in ECM were observed mainly in BALB/c mice that, in general, presented tissue damage associated with high parasite burden. Under polarized light, Sirius Red revealed type I collagen that was predominant in the primary lesion in all strains studied at the early phase of infection, but gradually decreased and was replaced by abundant type III collagen fibre in chronic phase lesions. the presence of type III collagen seemed to provide support to inflammatory cells, mainly vacuolated and parasitized macrophages. Laminin expression was not altered during infection by L. (L.) amazonensis in any of the mouse strains studied. Furthermore, the decreased fibronectin expression, in all strains, in areas where amastigotes have been found, indicated that this decline was also not related to the genetic background.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Functional interface between cathepsins and growth factors in the kidney development
    (Taylor & Francis Inc, 2005-01-01) Vattimo, Maria de Fatima Fernandes; Santos, Oscar Fernando Pavao [UNIFESP]; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    During kidney development many proteases are involved with the remodeling process of the extracellular matrix (ECM) during nephrogenesis. This study used embryonic kidneys culture, tridimensional cell culture, and reverse transcriptase-polymerase chain reaction (RT-PCR) techniques in order to investigate the expression of cathepsins S (CS) and cathepsin H (CH) during metanephrogenesis and their functional interface with hepatic growth factor (HGF) and nerve growth factor (NGF). Results have shown that cathepsin S has been expressed early than the cathepsin H in the nephrogenesis. NGF antibody in the embryonic kidney cultures, in a dose-dependent mechanism inhibited the CS but not CH genic expression by RT-PCR. the tridimensional cells culture with MDCK and IMCD cells confirmed the interface between HGF and CS and CH once their inhibitors added to the culture, reduced the fancy branching formation induced by this growth factor. in summary, this study suggests that CS and CH are differently expressed during nephrogenesis and also that they are involved with the tubulogenesis probably mediating specific growth factors such as NGF and HGF.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Gene Expression Analysis in Patients With Traumatic Anterior Shoulder Instability Suggests Deregulation of Collagen Genes
    (Wiley-Blackwell, 2014-10-01) Belangero, Paulo Santoro [UNIFESP]; Leal, Mariana Ferreira [UNIFESP]; Figueiredo, Eduardo Antonio [UNIFESP]; Cohen, Carina [UNIFESP]; Pochini, Alberto de Castro [UNIFESP]; Smith, Marilia Cardoso [UNIFESP]; Andreoli, Carlos Vicente [UNIFESP]; Belangero, Sintia Iole [UNIFESP]; Ejnisman, Benno [UNIFESP]; Cohen, Moises [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Shoulder dislocation occurs in 1-2% of the population. Capsular deformation is a key factor in shoulder dislocation; however, little is known about capsule biology. We evaluated, for the first time in literature, the expression of COL1A1, COL1A2, COL3A1 and COL5A1 in the antero-inferior, antero-superior and posterior regions of the glenohumeral capsule of 31 patients with anterior shoulder instability and eight controls. the expression of collagen genes was evaluated by quantitative reverse transcription-PCR. the expression of COL1A1, COL3A1 and the ratio of COL1A1/COL1A2 were increased in all three portions of the capsule in patients compared to controls (p<0.05). COL1A2 expression was upregulated in the antero-superior and posterior sites of the capsule of patients (p<0.05). the ratio of COL1A2/COL3A1 expression was reduced in capsule antero-inferior and posterior sites of patients compared to controls (p<0.05). in the capsule antero-inferior site of patients, the ratios of COL1A1/COL5A1, CO1A2/COL5A1 and COL3A1/COL5A1 expression were increased (p<0.05). in patients, COL1A1/COL5A1 was also increased in the posterior site (p<0.05). We found deregulated expression of collagen genes across the capsule of shoulder instability patients. These molecular alterations may lead to modifications of collagen fibril structure and impairment of the healing process, possibly with a role in capsular deformation. (C) 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Heparan sulfate proteoglycans: structure, protein interactions and cell signaling
    (Academia Brasileira de Ciências, 2009-09-01) Dreyfuss, Juliana Luporini [UNIFESP]; Regatieri, Caio Vinicius Saito [UNIFESP]; Jarrouge, Thais R. [UNIFESP]; Cavalheiro, Renan Pelluzzi [UNIFESP]; Sampaio, Lucia O. [UNIFESP]; Nader, Helena Bonciani [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Heparan sulfate proteoglycans are ubiquitously found at the cell surface and extracellular matrix in all the animal species. This review will focus on the structural characteristics of the heparan sulfate proteoglycans related to protein interactions leading to cell signaling. The heparan sulfate chains due to their vast structural diversity are able to bind and interact with a wide variety of proteins, such as growth factors, chemokines, morphogens, extracellular matrix components, enzymes, among others. There is a specificity directing the interactions of heparan sulfates and target proteins, regarding both the fine structure of the polysaccharide chain as well precise protein motifs. Heparan sulfates play a role in cellular signaling either as receptor or co-receptor for different ligands, and the activation of downstream pathways is related to phosphorylation of different cytosolic proteins either directly or involving cytoskeleton interactions leading to gene regulation. The role of the heparan sulfate proteoglycans in cellular signaling and endocytic uptake pathways is also discussed.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Heparanase expression and glycosaminoglycans profile in renal cell carcinoma
    (Wiley-Blackwell, 2012-11-01) Batista, Lucas Teixeira e Aguiar [UNIFESP]; Matos, Leandro Luongo [UNIFESP]; Machado, Leopoldo Ruiz; Suarez, Eloah Rabello [UNIFESP]; Theodoro, Therese Rachell; Maciel Martins, Joao Roberto [UNIFESP]; Nader, Helena Bonciani [UNIFESP]; Lima Pompeo, Antonio Carlos; Silva Pinhal, Maria Aparecida da [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); ABC Fdn
    A better understanding of the molecular mechanisms of renal cell carcinogenesis could contribute to a decrease in the mortality rate of this disease. the aim of this study was to evaluate the glycosaminoglycans profile and heparanase expression in renal cell carcinoma. the study included 24 patients submitted to nephrectomy with confirmed pathological diagnosis of renal cell carcinoma. the majority of the samples (87.5%) were classified in the initial stage of renal cell carcinoma (clinical stages I and II). Heparanase messenger ribonucleic acid expression was evaluated by quantitative real-time reverse transcription polymerase chain reaction, and sulfated glycosaminoglycans were identified and quantified by agarose gel electrophoresis of renal cell carcinoma samples or non-neoplastic tissues obtained from the same patients (control group). the sulfated glycosaminoglycans and hyaluronic acid were analyzed in urine samples of the patients before and after surgery. the data showed a significant statistical increase in chondroitin sulfate, and a decrease in heparan sulfate and dermatan sulfate present in neoplastic tissues compared with non-neoplastic tissues. Higher heparanase messenger ribonucleic acid expression in the neoplastic tissues was also shown, compared with the non-neoplastic tissues. the urine glycosaminoglycans profile showed no significant difference between renal cell carcinoma and control samples. Extracellular matrix changes observed in the present study clarify that heparanase is possibly involved with heparan sulfate turnover, and that heparanase and the glycosaminoglycans can modulate initial events of renal cell carcinoma development.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Lectin KM+-induced neutrophil haptotaxis involves binding to laminin
    (Elsevier B.V., 2005-01-18) Ganiko, L.; Martins, A. R.; Freymuller, E.; Mortara, R. A.; Roque-Barreira, M. C.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    The lectin KM+ from Artocarpus integrifolia, also known as artocarpin, induces neutrophil migration by haptotaxis. the interactions of KM+ with both the extracellular matrix (ECM) and neutrophils depend on the lectin ability to recognize mannose-containing glycans. Here, we report the binding of KM+ to laminin and demonstrate that this interaction potentiates the KM+-induced neutrophil migration. Labeling of lung tissue by KM+ located its ligands on the endothelial cells, in the basement membrane, in the alveolus, and in the interstitial connective tissue. Such labeling was inhibited by 400 mM D-mannose, 10 mM Manalpha1-3[Manalpha1-6]Man or 10 muM peroxidase (a glycoprotein-containing mannosyl heptasaccharide). Laminin is a tissue ligand for KM+, since both KM+ and anti-laminin antibodies not only reacted with the same high molecular mass components of a lung extract, but also determined colocalized labeling in basement membranes of the lung tissue. the relevance of the KM+-laminin interaction to the KM+ property of inducing neutrophil migration was evaluated. the inability of low concentrations of soluble KM+ to induce human neutrophil migration was reversed by coating the microchamber filter with laminin. So, the interaction of KM+ with laminin promotes the formation of a substrate-bound KM+ gradient that is able to induce neutrophil haptotaxis. (C) 2004 Elsevier B.V. All rights reserved.
  • Imagem de Miniatura
    Item
    Acesso aberto (Open Access)
    Matriz extracelular e enzimas degradatórias na hematopoese e doenças onco-hematológicas
    (Associação Brasileira de Hematologia e Hemoterapia e Terapia Celular, 2008-10-01) Dreyfuss, Juliana Luporini [UNIFESP]; Oliveira, José Salvador Rodrigues de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The extracellular matrix (ECM) is a complex structure composed of collagens, proteoglycans, glycosaminoglycans and adhesive glycoproteins. Interactions between the cells and the ECM are crucial to determine cell behavior, such as growth, death, differentiation and motility. Hematopoiesis is the system responsible for the production of blood cells. The control of proliferation and differentiation of these cells is attained through the interaction of the cells with the bone marrow microenvironment. The adhesion of hematopoietic progenitors to ECM molecules and the integrin activation are modulated by a variety of cytokines and growth factors, and this modulation seems to be the mechanism of regulation that influences proliferation of hematopoietic cells, transendothelial/transstromal migration and homing. Both in the migration and homing process, and in tumoral invasion the cells undergo the following steps: 1 - Degradation of the ECM by enzymes, including metalloproteinase, collagenase, plasmin, cathepsin, glycosidase and heparanase, secreted by the cells; 2 - Cell migration through the region previously degraded by enzymes; and 3 - Cell adhesion to specific receptors located on the cellular surface, that generally interact with ECM components. In onco-hematologic diseases, the interaction of neoplastic cells with the extracellular matrix also influences aggressiveness and prognosis of the disease.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Modulation of hyaluronan in the migratory pathway of mouse primordial germ cells
    (Springer, 2002-03-01) Soto-Suazo, M.; Abrahamsohn, P. A.; Pereda, J.; San Martin, S.; Nader, H. B.; Sampaio, L. O.; Zorn, TMT; Universidade de São Paulo (USP); Univ Santiago Chile; Universidade Federal de São Paulo (UNIFESP)
    In the present report we followed the distribution of hyaluronan during the phases of separation, migration, and colonization of the primordial germ cell migratory process. Hyaluronan was detected by the use of two cytochemical methods: (1) ruthenium hexammine trichloride (RHT) associated with enzymatic treatment with hyaluronate lyase and (2) a binding specific probe for hyaluronan. After RHT treatment the proteoglycans and/or glycosaminoglycans were observed as a mesh-work formed by electron-dense granules connected by thin filaments. After enzymatic digestion, no filaments could be detected in the migratory pathway. Quantitative analysis showed a close correlation between cell migration and the concentration of RHT-positive filaments. It was also shown that high amounts of hyaluronan were expressed in the separation phase and migration phases whereas during the colonization phase the amount of hyaluronan was clearly diminished. This study showed that the presence of primordial germ cells in each compartment of the migratory pathway was always accompanied by a high expression of hyaluronan. These results indicate that hyaluronan is an important molecule in the migratory process, providing the primordial germ cells with a hydrated environment that facilitates their movement toward the genital ridges.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Morphological analysis of the acute effects of overdistension on the extracellular matrix of the rat urinary bladder wall
    (Urban & Fischer Verlag, 2004-02-01) Souza, GMP de; Costa, W. S.; Bruschini, H.; Sampaio, FJB; Universidade do Estado do Rio de Janeiro (UERJ); Universidade Federal de São Paulo (UNIFESP)
    Purpose: To investigate the morphological effects of acute overdistension in the structure of the extracellular matrix of the bladder wall in rats. - Materials and Methods: the bladders of a group of 6 male Wistar rats were transurethrally overdistended for 3 hours. Another identical group (the control group) was only submitted to a sham operation. Specimens from the bladder dome were analyzed with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). - Results: LM - the control group bladders had a 4 to 5 layer urothelium, a lamina propria, and a smooth muscle layer with longitudinal and transversal fibers. the overdistended bladders presented an intense interstitial infiltrate in the lamina propria, and a less intense infiltrate among the smooth muscle fibers. TEM the cells of the overdistended bladders had a significant amount of vacuoles, unlike the control bladders, where such vacuoles were scarce or absent. SEM - A delicate three-dimensional mesh of collagen fibrils was observed in the lamina propria of the bladder walls from the control group. Whilst for the control group this mesh consisted of distinct geometric structures, with mostly circular cellular spaces surrounded by the fibrils, the overdistended group showed evidence of distortion of the mesh, with flattened and elongated cellular spaces. - Conclusions: Acute bladder overdistension induces structural modifications, altering the arrangement and interaction of collagen fibrils, as well as incipient tissue damage as edema in the lamina propria and smooth muscle layers.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Nitric oxide: a potential inducer of adhesion-related apoptosis-anoikis
    (Elsevier B.V., 2004-02-01) Monteiro, H. P. [UNIFESP]; Silva, E. F.; Stern, A.; Universidade Federal de São Paulo (UNIFESP); Univ Paulista; Universidade de São Paulo (USP); NYU
    Among the many initiating events that lead to apoptosis or programmed cell death, loss of contact between the cell and the extracellular matrix has been extensively studied. Adhesion-related apoptosis referred to as anoikis is initiated by the action of anti-adhesive substances. Nitric oxide is one of these anti-adhesive substances that have the capacity to signal and trigger pro-apoptotic events in a variety of cell types. Nitric oxide can inhibit cell adhesion, interfere with the assembly of focal adhesion complexes, and disrupt the cell-extracellular matrix interactions. These actions occur in cell that exhibit a dissociation of growth factor signals from alterations in the cytoskeleton, ultimately leading to apoptosis. Since this involves anti-adhesive events, nitric oxide can be considered as causing anoikis. This review article summarizes the available evidence of how nitric oxide participates in apoptosis induced by loss of anchorage (anoikis). (C) 2004 Elsevier Inc. All rights reserved.
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Overexpression of the ITGAV Gene Is Associated with Progression and Spread of Colorectal Cancer
    (Int Inst Anticancer Research, 2014-10-01) Waisberg, Jaques [UNIFESP]; Viana, Luciano de Souza [UNIFESP]; Affonso Junior, Renato Jose [UNIFESP]; Silva, Sandra Regina Morini da [UNIFESP]; Denadai, Marcos Vinicius Araujo [UNIFESP]; Margeotto, Fernando Beani; Souza, Carolina Salinas de [UNIFESP]; Matos, Delcio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Barretos Canc Hosp; ABC Med Sch
    Background/ Aim: The interaction of neoplastic cells with the extracellular matrix is a critical event for the initiation of cancer invasion and metastasis. We evaluated the relationship between the expression of SPARC, ITGAV, THBS1 and VCAM-1 genes of extracellular matrix in the progression and dissemination of colorectal cancer (CRC). Patients and Methods: Adult patients (N=114) underwent resection of CRC. Gene expression in CRC was determined by quantitative real-time polymerase chain reaction (PCR). Protein expression was analyzed by immunohistochemistry (IHC). Correlation with pathway-related molecules (p53, Bcl-2, Ki-67, EGFR and VEGF) was assessed. Results: Tumors with perineural invasion showed overexpression (p=0.028) of the ITGAV gene with regard to cancers without perineural invasion and validation of the result through IHC expression of the corresponding proteins, was significant for the expression of ITGAV protein (p=0.001). Conclusion: The overexpression of ITGAV gene was associated with higher progression and spread of CRC via perineural invasion.