Navegando por Palavras-chave "Proteoglycan"
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- ItemAcesso aberto (Open Access)Changes in glycosaminoglycans and proteoglycans of normal breast and fibroadenoma during the menstrual cycle(Elsevier B.V., 2012-07-01) Lima, Cilene Reboucas de [UNIFESP]; Santos Júnior, José de Arimatea [UNIFESP]; Pinto Nazário, Afonso Celso [UNIFESP]; Michelacci, Yara Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background: Fibroadenoma is the most common breast tumor in young women, and its growth and metabolism may be under hormonal control. in the present paper we described the proteoglycan (PG) composition and synthesis rate of normal breast and fibroadenoma during the menstrual cycle.Methods: Samples of fibroadenoma and adjacent normal breast tissue were obtained at surgery. PGs were characterized by agarose gel electrophoresis and enzymatic degradation with glycosaminoglycan (GAG) lyases, and immunolocalized by confocal microscopy. To assess the synthesis rate, PGs were metabolic labeled by S-35-sulfate.Results: the concentration of PGs in normal breast was higher during the secretory phase. Fibroadenoma contained and synthesized more PGs than their paired controls, but the PG concentrations varied less with the menstrual cycle and, in contrast to normal tissue, peaked in the proliferative phase. the main mammary GAGs are heparan sulfate (HS, 71%-74%) and dermatan sulfate (DS, 26%-29%). the concentrations of both increased in fibroadenoma, but DS increased more, becoming 35%-37% of total. the DS chains contained more beta-D-glucuronic acid (IdoUA/GlcUA ratios were >10 in normal breast and 2-7 in fibroadenoma). the S-35-sulfate incorporation rate revealed that the in vitro synthesis rate of DS was higher than HS. Decorin was present in both tissues, while versican was found only in fibroadenoma.Conclusions: in normal breast, the PG concentration varied with the menstrual cycle. It was increased in fibroadenoma, especially DS.General significancePGs are increased in fibroadenoma, but their concentrations may be less sensitive to hormonal control. (C) 2012 Elsevier B.V. All rights reserved.
- ItemAcesso aberto (Open Access)Collagens and proteoglycans of the corneal extracellular matrix(Associação Brasileira de Divulgação Científica, 2003-08-01) Michelacci, Yara Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The cornea is a curved and transparent structure that provides the initial focusing of a light image into the eye. It consists of a central stroma that constitutes 90% of the corneal depth, covered anteriorly with epithelium and posteriorly with endothelium. Its transparency is the result of the regular spacing of collagen fibers with remarkably uniform diameter and interfibrillar space. Corneal collagen is composed of heterotypic fibrils consisting of type I and type V collagen molecules. The cornea also contains unusually high amounts of type VI collagen, which form microfibrillar structures, FACIT collagens (XII and XIV), and other nonfibrillar collagens (XIII and XVIII). FACIT collagens and other molecules, such as leucine-rich repeat proteoglycans, play important roles in modifying the structure and function of collagen fibrils.Proteoglycans are macromolecules composed of a protein core with covalently linked glycosaminoglycan side chains. Four leucine-rich repeat proteoglycans are present in the extracellular matrix of corneal stroma: decorin, lumican, mimecan and keratocan. The first is a dermatan sulfate proteoglycan, and the other three are keratan sulfate proteoglycans. Experimental evidence indicates that the keratan sulfate proteoglycans are involved in the regulation of collagen fibril diameter, and dermatan sulfate proteoglycan participates in the control of interfibrillar spacing and in the lamellar adhesion properties of corneal collagens. Heparan sulfate proteoglycans are minor components of the cornea, and are synthesized mainly by epithelial cells. The effect of injuries on proteoglycan synthesis is discussed.
- ItemAcesso aberto (Open Access)Decorin is one of the proteoglycans expressed in Walker 256 rat mammary carcinoma(Associação Brasileira de Divulgação Científica, 2003-08-01) Oba-Shinjo, Sueli Mieko [UNIFESP]; Berto, Alessandra Gutierrez Andrade [UNIFESP]; Passerotti, Carlo Camargo [UNIFESP]; Barbosa, C.d. [UNIFESP]; Sampaio, Lucia de Oliveira [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Proteoglycan and glycosaminoglycan content was analyzed in a model of rat mammary carcinoma to study the roles of these compounds in tumorigenesis. Hyaluronic acid and proteoglycans bearing chondroitin and/or dermatan sulfate chains were detected in solid tumors obtained after subcutaneous inoculation of Walker 256 rat carcinoma cells. About 10% of sulfated glycosaminoglycan chains corresponded to heparan sulfate. The small leucine-rich proteoglycan, decorin, was identified as one of the proteoglycans, in addition to others of higher molecular weight, by cross-reaction with an antiserum raised against pig laryngeal decorin and by N-terminal amino acid sequencing. Decorin was separated from other proteoglycans by hydrophobic chromatography and its complete structure was determined. It has a molecular weight of about 85 kDa and a dermatan chain of 45 kDa with 4-sulfated disaccharides. After degradation of the glycosaminoglycan chain, three core proteins of different molecular weight (36, 46 and 56 kDa) were identified. The presence of hyaluronic acid and decorin has been reported in a variety of tumors and tumor cells. In the Walker 256 mammary carcinoma model, hyaluronic acid may play an important role in tumor progression, since it provides a more hydrated extracellular matrix. On the other hand, decorin, which is expressed by stromal cells, represents a host defense response to tumor growth.
- ItemSomente MetadadadosEffect of amniotic membrane transplantation on corneal healing and proteoglycan expression in an experimental model of limbal deficiency in rabbits(Wichtig Editore, 2010-03-01) Andrade, Alexandre L.; Campos, Mauro Silveira de Queiroz [UNIFESP]; Gomes, José Álvaro Pereira [UNIFESP]; Berto, Alessandra Gutierrez Andrade [UNIFESP]; Michelacci, Yara Maria [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Estadual PaulistaPURPOSE. Amniotic membrane transplantation (AMT) has been used as a graft or as a dressing in ocular surface reconstruction, facilitating epithelization, maintaining normal epithelial phenotype, and reducing inflammation, vascularization, and scarring. The corneal transparency is due, at least in part, to the arrangement in orthogonal lamellae of collagen fibrils, surrounded by proteoglycans (PGs). These PGs regulate fibrilogenesis, the matrix assembly, and ultimately the corneal transparency. The purpose of the present study was to investigate the effects of AMT upon the corneal PGs after severe limbal injury.METHODS. Experiments were performed on the right corneas of 22 New Zealand female albino rabbits, and their left corneas were used as matched controls. These animals were divided into 3 groups: G1 (n = 10): total peritomy and keratolimbectomy, followed by application of 0.5 M NaOH; G2 (n = 10): submitted to the same trauma as G1, and treated by AMT; G3: no trauma, only AMT (n = 2). The right corneas of G2 and G3 were covered by DMSO 4 cryopreserved human amniotic membrane, fixed by interrupted 9-0 mononylon sutures, with its stromal face toward the ocular surface. After 7 or 30 days, the corneas were removed and PGs were extracted.RESULTS. Normal corneas contained approximately 9 mg of PGs per gram of dry tissue. AMT on intact cornea (G3) did not cause any changes in the concentration of PGs. In contrast, injured corneas contained much less PGs, both on the seventh and on the 30th day posttrauma. The PG concentration was even lower in injured corneas treated by AMT. This decrease was due almost exclusively to dermatan sulfate PGs, and the structure of dermatan sulfate was also modified, indicating changes in the biosynthesis patterns.CONCLUSIONS. Although beneficial effects have been observed on clinical observation and concentration of soluble proteins after AMT, the normal PG composition of cornea was not attained, even 30 days postinjury, indicating that the normal ocular surface reconstruction, if possible, is a long-term process. (Eur J Ophthalmol 2010; 20: 290-9)
- ItemSomente MetadadadosEstudo dos pequenos proteoglicanos ricos em leucina em glândulas harderianas de camundongos fêmeas com hiperprolactinemia induzida pela metoclopramida(Universidade Federal de São Paulo (UNIFESP), 2020-12-10) Araujo, Ariadne Stavare Leal [UNIFESP]; Simoes, Manuel De Jesus [UNIFESP]; Universidade Federal de São PauloIntrodution: The small proteoglycans rich in leucine are bioactive components of the extracellular matrix associated with collagen fibrillogenesis, cell growth, apoptosis, tissue remodeling, and are involved in inflammatory processes. Your study can provide information about changes in the functioning of the harderian glands. Objective: To evaluate the gene and protein expression of small proteoglycans rich in leucine. Material and Methods: the 40 female mice were divided into 20 / group: control group: received 0.2 mL of saline solution (vehicle) and the experimental group: received 200 µg / day of metoclopramide dissolved in the vehicle. After 50 consecutive days of treatment, 10 females (control group) and 10 females (experimental group) were euthanized (in the proestrus phase), the rest were placed for mating and continued receiving the treatments corresponding to each group until the 5th - 6th day post-coitus when they were euthanized. At the end of the experiments, 4 groups were formed: not pregnant (control and experiment) and pregnant (control and experiment). The harderian glands were removed and processed for immunohistochemistry and gene expression using the RT-qPCR technique. The results were submitted to the statistical t Student test. Results: The immunohistochemistry data: there was a significant decrease in decorum, lumicam and fibromodulin in the non-pregnant and experimental pregnant group compared to the control group. The gene expression data: 1) there was a significant increase in decorin and lumican and a significant decrease in biglycan and fibromodulin in the non-pregnant group compared to the control group, and 2) there was a significant increase in decorin and biglicam and a significant decrease in fibromodulin in the experimental pregnant group compared to the control group. Conclusion: The data revealed that the state of hyperprolactinemia alters the gene and protein expression of small proteoglycans rich in leucine.
- ItemAcesso aberto (Open Access)Evaluation of chitosan-GP hydrogel biocompatibility in osteochondral defects: an experimental approach(Biomed Central Ltd, 2014-08-27) Martins, Edivaldo A. N.; Michelacci, Yara M. [UNIFESP]; Baccarin, Raquel Yvonne Arantes [UNIFESP]; Cogliati, Bruno; Silva, Luis C. L. C.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Background: Articular cartilage, because of its avascular nature, has little capacity for spontaneous healing, and tissue engineering approaches, employing different biomaterials and cells, are under development. Among the investigated biomaterials are the chitosan-based hydrogels. Although thoroughly studied in other mammalian species, studies are scarce in equines. So, the aim of the present study was to investigate the biocompatibility of chitosan-GP in horse joints submitted to high mechanical loads.Results: An osteochondral defect was created by arthroscopy in the medial surface of lateral trochlea of talus of left or right leg, randomly selected, from six healthy geldings. the defect was filled up with chitosan-GP. the contralateral joint received an identical defect with no implant. the chondral fragment removed to produce the defect was collected, processed and used as the Initial sample (normal cartilage) for histology, immunohistochemistry, and metabolic labelling of PGs. After 180 days, the repair tissues were collected, and also analyzed. At the end of the experiment (180 days after lesion), the total number of cells per field in repair tissues was equal to control, and macrophages and polymorphonuclear cells were not detected, suggesting that no significant inflammation was present. These cells were able to synthesize type II collagen and proteoglycans (PGs). Nevertheless, the cell population in these tissues, both in presence of chitosan-GP and in untreated controls, were heterogeneous, with a lower proportion of type II collagen-positives cells and some with a fibroblastic aspect. Moreover, the PGs synthesized in repair tissues formed in presence or absence of chitosan-GP were similar to those of normal cartilage. However, the chitosan-GP treated tissue had an disorganized appearance, and blood vessels were present.Conclusions: Implanted chitosan-GP did not evoke an important inflammatory reaction, and permitted cell growth. These cells were able to synthesize type II collagen and PGs similar to those synthesized in normal cartilage and in healing tissue without implant, indicating its chondrocyte nature.
- ItemSomente MetadadadosGlycosaminoglycan chains from alpha(5)beta(1) integrin are involved in fibronectin-dependent cell migration(Canadian Science Publishing, Nrc Research Press, 2009-08-01) Franco, Celia Regina Cavichiolo [UNIFESP]; Trindade, Edvaldo da Silva [UNIFESP]; Rocha, Hugo Alexandre de Oliveira [UNIFESP]; Silveira, Rafael Bertoni da [UNIFESP]; Paludo, Katia Sabrina; Chammas, Roger; Veiga, Silvio Sanches; Nader, Helena Bonciani [UNIFESP]; Dietrich, Carl Peter [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Univ Fed Parana; Univ Fed Rio Grande do Norte; Universidade de São Paulo (USP)alpha(5)beta(1) integrin from both wild-type CHO cells (CHO-K1) and deficient in proteoglycan biosynthesis (CHO-745) is post-translationally modified by glycosaminoglycan chains. We demonstrated this using [S-35]sulfate metabolic labeling of the cells, enzymatic degradation, immunoprecipitation reaction with monoclonal antibody, fluorescence microscopy, and flow cytometry. the alpha(5)beta(1) integrin heterodimer is a hybrid proteoglycan containing both chondroitin and heparan sulfate chains. Xyloside inhibition of sulfate incorporation into alpha(5)beta(1) integrin also supports that integrin is a proteoglycan. Also. cells grown with xyloside adhered on fibronectin with no alteration in alpha(5)beta(1) integrin expression. However, haptotactic motility on fibronectin declined in cells grown with xyloside or chlorate as compared with controls. Thus, alpha(5)beta(1) integrin is a proteoglycan and the glycosaminoglycan chains of the integrin influence cell motility on fibronectin. Similar glycosylation of alpha(5)beta(1) integrin was observed in other normal and malignant cells, suggesting that this modification is conserved and important in the function of this integrin. Therefore, these glycosaminoglycan chains of alpha(5)beta(1) integrin are involved in cellular migration on fibronectin.
- ItemAcesso aberto (Open Access)Investigação do processamento das proteínas do sistema calicreína-cinina plasmático na interação com células endoteliais(Universidade Federal de São Paulo (UNIFESP), 2019-02-28) Assis, Mirian Coelho de [UNIFESP]; Motta, Guacyara da [UNIFESP]; Oliveira, Cleide de [UNIFESP]; http://lattes.cnpq.br/4060773569354807; http://lattes.cnpq.br/0050968690289066; http://lattes.cnpq.br/7024315470446395; Universidade Federal de São Paulo (UNIFESP)Endothelial cells (ECs) correspond to the coating of both vessels the lymphatic vessels and constitute the inner layer of these glasses These cells are flattened epithelial and distributed in monolayer presenting great heterogeneity, since they differ in size, length and height, shape and number of stored vesicles, and this is related to the caliber of the blood vessel or a tissue (Aird, 2007; Dela-Paz et al., 2009). The endothelium is considered an endocrine organ capable of producing and secreting a variety of chemicals that control clotting, tonus and plasma levels of endogenous mediators and lipoproteins (Carvalho et al., 2005). However, it is also involved in a number of pathological conditions, such as atherosclerosis and cancer (Dela-Paz et al., 2009), and in diffuse intravascular coagulation the endothelium is the interface between inflammation and inappropriate activation of the coagulation system (Kato, 2014). The endothelium exerts several functions as regulation of the inflammatory response and inhibition of cell proliferation and migration. The release of substances such as vasodilators and vasoconstrictors conserve laminar blood flow, preserving the fluidity of the plasma membrane, creating mechanisms anticoagulants. Vasodilators such as nitric oxide, bradykinin and adenosine, in channels of K + dependent on ATP, its activation by vasodilators, associated with hyperpolarization of the membrane, the closure of the K + , act on the cells of the smooth muscle cells present in the tunica media of arterioles resulting in reduced blood flow resistance and decreased blood pressure. On the other hand vasoconstrictors include endothelin and angiotensin II which promote smooth muscle contraction and increase the (Baxter et al., 2006), and the effect of the antihypertensive effect on the blood pressure (Baxter et al. The functions exerted by the endothelium regulate cell-cell interactions and cell-matrix, the expression and presence of membrane-bound receptors being associated with numerous molecules including proteins, carrier particles of lipids, metabolites and hormones, and glycosaminoglycan sugars (Rajendran et al., 2013, Muller, 2013).
- ItemSomente MetadadadosLow-level laser therapy prevents degenerative morphological changes in an experimental model of anterior cruciate ligament transection in rats(Springer, 2014-09-01) Bublitz, Caroline [UNIFESP]; Medalha, Carla Christina [UNIFESP]; Oliveira, Poliani de [UNIFESP]; Assis, Livia [UNIFESP]; Milares, Luiz Paulo [UNIFESP]; Fernandes, Kelly Rossetti [UNIFESP]; Tim, Carla Roberta [UNIFESP]; Vasilceac, Fernando Augusto [UNIFESP]; Mattiello, Stela Márcia [UNIFESP]; Renno, Ana Claudia Muniz [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The aim of this study was to analyze the effects of low-level laser therapy (LLLT) on the prevention of cartilage damage after the anterior cruciate ligament transection (ACLT) in knees of rats. Thirty male rats (Wistar) were distributed into three groups (n = 10 each): injured control group (CG); injured laser-treated group at 10 J/cm(2) (L10), and injured laser-treated group at 50 J/cm(2) (L50). Laser treatment started immediately after the surgery and it was performed for 15 sessions. An 808 nm laser, at 10 and 50 J/cm(2), was used. To evaluate the effects of LLLT, the qualitative and semi-quantitative histological, morphometric, and immunohistochemistry analysis were performed. Initial signs of tissue degradation were observed in CG. Interestingly, laser-treated animals presented a better tissue organization, especially at the fluence of 10 J/cm(2). Furthermore, laser phototherapy was able of modulating some of the aspects related to the degenerative process, such as the prevention of proteoglycans loss and the increase in cartilage area. However, LLLT was not able of modulating chondrocytes proliferation and the immunoexpression of markers related to inflammatory process (IL-1 and MMP-13). This study showed that 808 nm laser, at both fluences, prevented features related to the articular degenerative process in the knees of rats after ACLT.
- ItemAcesso aberto (Open Access)Noncrystalline uric acid inhibits proteoglycan and glycosaminoglycan synthesis in distal tubular epithelial cells (MDCK)(Associação Brasileira de Divulgação Científica, 2010-10-01) Borges, Fernanda Teixeira [UNIFESP]; Dalboni, Maria Aparecida [UNIFESP]; Michelacci, Yara Maria [UNIFESP]; Schor, Nestor [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Hyperuricemia is associated with renal stones, not only consisting of uric acid (UrAc) but also of calcium oxalate (CaOx). Glycosaminoglycans (GAGs) are well-known inhibitors of growth and aggregation of CaOx crystals. We analyzed the effect of noncrystalline UrAc on GAG synthesis in tubular distal cells. MDCK (Madin-Darby canine kidney) cells were exposed to noncrystalline UrAc (80 µg/mL) for 24 h. GAGs were labeled metabolically and characterized by agarose gel electrophoresis. The expression of proteoglycans and cyclooxygenase 2 (COX-2) was assessed by real-time PCR. Necrosis, apoptosis and prostaglandin E2 (PGE2) were determined by acridine orange, HOESCHT 33346, and ELISA, respectively. CaOx crystal endocytosis was evaluated by flow cytometry. Noncrystalline UrAc significantly decreased the synthesis and secretion of heparan sulfate into the culture medium (UrAc: 2127 ± 377; control: 4447 ± 730 cpm) and decreased the expression of perlecan core protein (UrAc: 0.61 ± 0.13; control: 1.07 ± 0.16 arbitrary units), but not versican. Noncrystalline UrAc did not induce necrosis or apoptosis, but significantly increased COX-2 and PGE2 production. The effects of noncrystalline UrAc on GAG synthesis could not be attributed to inflammatory actions because lipopolysaccharide, as the positive control, did not have the same effect. CaOx was significantly endocytosed by MDCK cells, but this endocytosis was inhibited by exposure to noncrystalline UrAc (control: 674.6 ± 4.6, CaOx: 724.2 ± 4.2, and UrAc + CaOx: 688.6 ± 5.4 geometric mean), perhaps allowing interaction with CaOx crystals. Our results indicate that UrAc decreases GAG synthesis in MDCK cells and this effect could be related to the formation of UrAc and CaOx stones.
- ItemSomente MetadadadosPapel da matriz extracelular no estímulo da síntese do heparam sulfato antitrombótico promovido pela heparina em células endoteliais(Universidade Federal de São Paulo (UNIFESP), 2004) Trindade, Edvaldo da Silva [UNIFESP]; Nader, Helena Bonciani [UNIFESP]