Abstract Purpose To identify whether the colon mucosa is affected by ten days of gastric restriction in an animal model. Methods An experimental model of gastric restriction was devised using rats. The animals were submitted to surgical gastrostomy, and a cylindrical loofah was inserted into the stomach. We studied 30 adult male Wistar rats divided into three groups: the stomach restriction group (R10); the sham group (S10), which underwent the same procedure except for the loofah insertion; and the control group (C10). The expression of neutral and acid mucins was evaluated using histochemical techniques. Goblet cells and protein content were compared between groups using generalized estimation equations (GEEs). Bonferroni’s multiple comparison was applied to identify differences between the groups. All tests considered a 5% significance level. Results There was an increased expression of neutral mucins, acid mucins and goblet cells in the R10 group. Collagen was also enhanced in the R10 group. Conclusion The colon mucosa is affected by ten days of gastric restriction in an animal model, increasing neutral mucins, acid mucins and collagen content with trophic maintenance.

OBJECTIVES: The vulva is the primary site affected in lichen sclerosus, a chronic dermatosis in women that is histologically characterized by a zone of collagen remodeling in the superior dermis. The normal physiological properties of the vulva depend on the assembly of collagen types I (COLI), III (COLIII) and V (COLV), which form heterotypic fibers, and extracellular matrix protein interactions. COLV regulates the heterotypic fiber diameter, and the preservation of its properties is important for maintaining normal tissue architecture and function. In the current work, we analyzed the expression of COLV and its relationship with COLI, COLIII, elastic fibers and extracellular matrix protein 1 in vulvar biopsies from patients with lichen sclerosus. METHODS: Skin biopsies from 21 patients with lichen sclerosus, classified according to Hewitt histological criteria, were studied and compared to clinically normal vulvar tissue (N=21). Morphology, immunohistochemistry, immunofluorescence, 3D reconstruction and morphometric analysis of COLI, COLIII, COLV deposition, elastic fibers and extracellular matrix 1 expression in a zone of collagen remodeling in the superior dermis were performed. RESULTS: A significant decrease of elastic fibers and extracellular matrix 1 protein was present in the hyalinization zone of lichen sclerosus compared to healthy controls. The non-homogeneous distribution of collagen fibers visualized under immunofluorescence in the hyalinization zone of lichen sclerosus and control skin was confirmed by histomorphometry. Lichen sclerosus dermis shows a significant increase of COLI, COLIII and COLV expression compared to the healthy controls. Significant inverse associations were found between elastic fibers and COLV and between COLV and extracellular matrix 1 expression. A direct association was found between elastic fiber content and extracellular matrix 1 expression. Tridimensional reconstruction of the heterotypic fibers of the lichen sclerosus zone of collagen remodeling confirmed the presence of densely clustered COLV. CONCLUSIONS: Increased deposition of abnormal COLV and its correlation with extracellular matrix 1 and elastic fibers suggest that COLV may be a trigger in the pathogenesis of lichen sclerosus.

PURPOSE:To describe an effective experimental model to study the Achilles tendon healing.METHODS:Forty male Rattus norvegicus albinus,Wistar lineage adult male weighing 250 to 300g were used for this experiment and thirty were surgically submitted to bilateral partial transverse section of the Achilles tendon. The right tendon was treated with radio waves (RF) whereas the left tendon served as control. On the third postoperative day, the rats were divided into four experimental groups consisting of ten rats each which were treated with monopolar RF adjusted to 650 kHz and 2w, for two minutes twice a week and a group of normal animals without any intervention, until they were sacrificed on the 7th, 14th and 28th days, respectively. Tendons were weighed and collagen quantification was evaluated by hydroxyprolin content.RESULTS:Significant reduction in collagen content on day 7, 14 and 28 was related to control experiment to normal tendon (7 days, p<0.01; 14 e 28 days, p<0.05).CONCLUSION:The experimental model has been effective and available to be used to study Achilles tendon healing.

OBJETIVO: A granulomatose de Wegener (GW) pode causar dano nas células endoteliais e fenômenos tromboembólicos. Entretanto, poucos estudos analisaram a microcirculação pulmonar - artérias pulmonares de pequeno/médio calibre (APPMC) - em pacientes com GW. O objetivo deste estudo foi quantificar trombos de fibrina em amostras de APPMC de pacientes com GW. MÉTODOS: Analisamos 24 APPMC de seis pacientes com GW e 16 APPMC de quatro pacientes controles sem WG. Utilizamos CD34 para a marcação do endotélio em todas as amostras e microscopia confocal a laser para detectar trombos de fibrina intravasculares. Calculamos a área total do vaso, a área livre do lúmen e a área trombótica. RESULTADOS: A média da área total do vaso foi similar no grupo GW e no grupo controle (32.604 µm² vs. 32.970 µm², p = 0,8793). Trombos foram identificados em 22 das 24 APPMC (91,67%) no grupo GW, e em nenhuma do grupo controle (p < 0,0001; OR = 297 (IC95%: 13,34-6.612). A média da área trombótica foi maior no grupo GW do que no grupo controle (10.068 µm² vs. 0.000 µm², p < 0,0001). Em contraste, a média da área livre do lúmen foi menor no grupo GW que no grupo controle (6.116 µm² vs. 24.707 µm², p < 0,0001). CONCLUSÕES: A microscopia confocal a laser mostrou uma associação significante entre trombose microvascular pulmonar e GW. Isso sugere um possível papel da trombose microvascular na fisiopatologia da GW pulmonar, evocando o potencial benefício da anticoagulação na GW pulmonar. Entretanto, novos estudos são necessários para confirmar nossos achados, assim como um ensaio clínico randomizado a fim de testar o papel da anticoagulação no tratamento de pacientes com GW pulmonar.

OBJECTIVE: Wegener's granulomatosis (WG) can cause endothelial cell damage and thromboembolic events. Nevertheless, there have been few studies on the pulmonary microcirculation-small and medium-sized pulmonary arteries (SMSPA)-in patients with WG. The objective of this study was to quantify fibrin thrombi in the SMSPA of patients with WG. METHODS: We analyzed 24 SMSPA samples collected from six patients with WG and 16 SMSPA samples collected from four patients without WG. In all samples, we used the endothelial cell marker CD34 and confocal laser scanning microscopy in order to detect intravascular fibrin thrombi. We calculated the total vessel area, the free lumen area, and the thrombotic area. RESULTS: The mean total vessel area was similar in the WG and control groups (32,604 µm² vs. 32,970 µm², p = 0.8793). Thrombi were present in 22 (91.67%) of the 24 WG group samples and in none of the control group samples (p < 0.0001; OR = 297; 95% CI: 13.34-6,612). The mean thrombotic area was greater in the WG group samples than in the control group samples (10,068 µm² vs. 0.000 µm²; p < 0.0001). In contrast, the mean free lumen area was smaller in the WG group samples than in the control group samples (6,116 µm² vs. 24,707 µm²; p < 0.0001). CONCLUSIONS: Confocal laser scanning microscopy revealed a significant association between pulmonary microvascular thrombosis and WG. This suggests a possible role of microvascular thrombosis in the pathophysiology of pulmonary WG, evoking the potential benefits of anticoagulation therapy in pulmonary WG. However, further studies are needed in order to confirm our findings, and randomized clinical trials should be conducted in order to test the role of anticoagulation therapy in the treatment of patients with pulmonary WG.

OBJECTIVE: The importance of type V collagen and its relationships with other types of collagen and with vascular and epithelial apoptosis were studied in a model of chemical carcinogenesis in the mouse lung. METHODS: Two groups of male Balb/c mice were studied: a) animals that received two intraperitoneal doses of 3 g/kg urethane carcinogen (urethane group = 24); and b) animals submitted to a sham procedure, comparable to the test group (control group = 7). Both groups were sacrificed after 120 days. In situ detection of apoptosis, immunohistochemistry, immunofluorescence and histomorphometry were used to evaluate the fraction occupied by the tumor, vascular and epithelial apoptosis, and type V, III and I collagen fibers in the lung parenchyma from both groups. RESULTS: The lung parenchyma from the urethane group showed low fractions of vascular and epithelial apoptosis as well as reduced type V collagen fibers when compared to the control group. A significant direct association was found between type V and III collagen fibers and epithelial apoptosis, type V collagen fibers and vascular apoptosis, and type V and type I collagen fibers. CONCLUSION: The results show that a direct link between low amounts of type V collagen and decreased cell apoptosis may favor cancer cell growth in the mouse lung after chemical carcinogenesis, suggesting that strategies aimed at preventing decreased type V collagen synthesis or local responses to reduced apoptosis may have a greater impact in lung cancer control.

INTRODUCTION/OBJECTIVES: Systemic sclerosis, or scleroderma, is a rheumatic disease characterized by autoimmunity, vasculopathy, and fibrosis of the skin and several internal organs. In the present study, our aim was to assess the skin alterations in animals with scleroderma during the first stages of disease induction. METHODS: To induce scleroderma, female New Zealand rabbits (n = 12) were subcutaneously immunized with 1 mg/ml of collagen V (Col V) in complete Freund's adjuvant, twice with a thirty-day interval. Fifteen days later, the animals received an intramuscular booster with type V collagen in incomplete Freund's adjuvant, twice with a fifteen-day interval. The control group was inoculated with 1 ml of 10 mM acetic acid solution diluted with an equal amount of Freund's adjuvant. Serial dorsal skin biopsies were performed at 7, 15, and 30 days and stained with H&E, Masson's trichrome and Picrosírius for morphological and morphometric analyses. RESULTS: Immunized rabbits presented a significant increase in collagen in skin collected seven days after the first immunization (p=0.05). CONCLUSION: The results from this experimental model may be very important to a better understanding of the pathogenic mechanisms involved in the beginning of human SSc. Therapeutic protocols to avoid early remodeling of the skin may lead to promising treatments for SSc in the future.

INTRODUCTION: Posterior tibial tendon dysfunction is a common cause of adult flat foot deformity, and its etiology is unknown. PURPOSE: In this study, we characterized the morphologic pattern and distribution of types I, III and V collagen in posterior tibial tendon dysfunction. METHOD: Tendon samples from patients with and without posterior tibial tendon dysfunction were stained by immunofluorescence using antibodies against types I, III and V collagen. RESULTS: Control samples showed that type V deposited near the vessels only, while surgically obtained specimens displayed type V collagen surrounding other types of collagen fibers in thicker adventitial layers. Type III collagen levels were also increased in pathological specimens. On the other hand, amounts of collagen type I, which represents 95% of the total collagen amount in normal tendon, were decreased in pathological specimens. CONCLUSION: Fibrillogenesis in posterior tibial tendon dysfunction is altered due to higher expression of types III and V collagen and a decreased amount of collagen type I, which renders the originating fibrils structurally less resistant to mechanical forces.

OBJETIVO: Estabelecer as alterações morfológicas e o remodelamento do tecido cartilaginoso na progressão da osteoartrite (OA) experimental para estudar o efeito do difosfato de cloroquina na cartilagem osteoartrítica. MÉTODOS: A osteoartrite experimental foi induzida em coelhos por meio de meniscectomia parcial. Para analisar a evolução da doença experimental foram estudados três grupos de dez animais, sacrificados a 3, 14 e 22 semanas de indução da doença. Para avaliar o efeito do difosfato de cloroquina um grupo de animais (n = 6) foi tratado preventivamente com 3 mg/kg ao dia, iniciados um mês antes da indução da osteoartrite, e mantidos até o sacrifício (22 semanas). Realizou-se análise histológica das articulações (H&E, tricrômico de Masson) e imunofluorescência para colágeno dos tipos I, II e XI. A intensidade da agressão articular foi quantificada pelo escore de Mankin. RESULTADOS: O modelo experimental reproduziu todas as alterações morfológicas observadas na osteoartrite humana. Animais que receberam difosfato de cloroquina não desenvolveram lesões histológicas observadas na OA. Neste grupo houve significante preservação da estrutura da cartilagem articular (p < 0,0001), conservação da celularidade (p < 0,0001), proteoglicanas, demonstrados pela coloração de azul de anilina (p < 0,005) e integridade da linha de crescimento (p < 0,001), além da inibição da formação de osteófitos, do bloqueio da neoformação óssea e do não-aparecimento de colágeno tipo I (tecido osteocartilaginoso). CONCLUSÃO: O modelo experimental de meniscectomia parcial reproduz de forma gradativa as alterações morfológicas encontradas na osteoartrite, e estudos preliminares com o difosfato de cloroquina sugerem tratar-se de medicamento barato e com grande potencial de emprego como droga condroprotetora.

OBJECTIVE: The aim of this study was to develop an experimental model of osteoarthritis (OA) that could reproduce morphologic alterations viewed in this disease and to study the effect of chloroquine diphosphate on cartilage remodeling. METHODS: osteoarthritis was induced in rabbits by performing partial meniscectomy. To establish the experimental disease evolution, three groups of ten animals were sacrificed at 3, 14, 22 weeks after disease induction. To evaluate the effect of chloroquine diphosfate in OA progression, a group of six animals was treated preventively with 3 mg/kg/day, started one month prior to osteoarthritis induction and kept until the day of sacrifice (22 weeks). Histopathological (Masson trychrome, H&E), biochemical and immunofluorescence analyses to types I, II and XI collagens were made in all animals. Mankin's score was employed to quantify the severity of articular damage. RESULTS: The experimental model reproduced all of the alterations observed in osteoarthritis. Animals treated with chloroquine diphosfate did not develop morphological changes found in OA. There was significant preservation of articular cartilage tissue (p < 0,0001), maintenance of cellular morphology (p < 0,0001), proteoglicans, as demonstrated by aniline blue coloration (p < 0,005) and tidemark protection (p < 0,001), besides inhibition of osteophytes formation and absence of type I collagen expression. CONCLUSION: The experimental model of partial meniscectomy reproduces gradually, all the cartilage morphologic changes found in human osteoarthritis. Preliminary study done with choroquine diphosfate indicates that it is a cheap and effective drug to act as condroprotective agent in OA.

INTRODUÇÃO: A participação precisa do processo de remodelamento e possíveis implicações no tratamento da bronquiolite obliterante ainda não está estabelecida. OBJETIVOS: Estabelecer a importância da tolerância nasal induzida pelo colágeno do tipo V e verificar se o processo de remodelamento do eixo broncovascular pode ser revertido com esta estratégia terapêutica comparada ao efeito do tratamento com esteróides. MATERIAL E MÉTODO: Camundongos foram divididos em quatro grupos: controle, bronquiolite obliterante, tolerância nasal com colágeno do tipo V e prednisona. Morfometria foi realizada para avaliar as dimensões do eixo broncovascular, densidade de colágeno e resposta imunocelular. Camundongos submetidos à tolerância nasal com colágeno do tipo V e tratados com prednisona exibiram significativas reduções da espessura da parede de bronquíolos terminais, da densidade de células inflamatórias ao redor do eixo peribroncovascular e da resposta imunocelular às custas de linfócitos CD3, CD4, CD8 e CD20. Houve também significativa redução da densidade de macrófagos CD68 nos camundongos tratados com prednisona. Adicionalmente, houve uma forte associação entre tolerância nasal induzida pelo colágeno do tipo V, resposta imunocelular e redução do conteúdo de colágeno peribroncovascular. RESULTADOS: O remodelamento do eixo broncovascular na bronquiolite obliterante pode ser revertido pela indução de tolerância nasal com o colágeno do tipo V, possivelmente como resultado de supressão de linfócitos T. CONCLUSÃO: Os efeitos da tolerância nasal no presente modelo estiveram fortemente relacionados à melhora no remodelamento do eixo broncovascular, despontando como um alvo promissor para estudos prospectivos.

INTRODUCTION: The precise role of the remodeling process and possible therapies for bronchiolitis obliterans remain to be established. OBJETIVE: In the present study, we sought to validate the importance of nasal collagen V tolerance to verify whether bronchovascular axis remodeling could be reverted by this therapeutic approach when compared to steroid treatment. METHODS: Mice were randomly divided into 4 groups: control, bronchiolitis obliterans, collagen V tolerance, and prednisone groups. Morphometry was employed to evaluate bronchovascular axis dimensions, collagen density, and immune cell response. Collagen V nasal tolerance and steroid-treated mice showed significantly lower values of terminal bronchiole wall thickness and reduction in peribronchovascular cells; bronchioalveolar lymphoid tissue; and CD3+, CD4+, CD8+, and CD20+ lymphocytes. A significant decrease in CD68+ macrophage density was found in prednisone-treated mice. In addition, a strong quantitative relationship was found between collagen V tolerance, and reduction in density of immune cells and collagen. RESULTS: Our results indicate that bronchovascular axis remodeling in bronchiolitis obliterans can be reverted by collagen V nasal tolerance, possibly as the result of T-cell suppression. CONCLUSION: We concluded that the tolerance effects in this model were strongly related to the improvement in bronchovascular remodeling, and these may be an appropriate targets for further prospective studies on nasal collagen V tolerance.

As proteínas da matriz extracelular (MEC) e seus componentes estão sendo amplamente estudados na literatura médica, assim como sua relação com o remodelamento tecidual presente nas doenças reumáticas. Neste artigo, mostramos a importância do estudo do colágeno do tipo V no entendimento da etiologia da esclerodermia, no que se refere ao desencadeamento da auto-imunidade nesta enfermidade. Estudos em nosso laboratório demonstram que a sensibilização com colágeno do tipo V em coelhos pode resultar em um modelo animal de esclerodermia. Diante destes fatos, sugerimos que pesquisas neste campo podem ser de grande valia no desenvolvimento de novas condutas terapêuticas.

The extracellular matrix (ECM) proteins and their components have been widely studied in medical literature, as well its relationship with the tecidual remodeling present in the rheumatic disease. In this paper we show the importance of understanding the role of type V collagen as an important trigger of rheumatic autoimmune diseases. Studies in our laboratory demonstrate that type V collagen sensibilization in rabbits, could result in an animal scleroderma model. In this way we suggested that researches in this field can be worthy in development of new therapeutic procedures.

A cartilagem articular é um tecido altamente especializado, composto por células, os condrócitos, e um conjunto de macromoléculas, como o colágeno e os proteoglicanos. O colágeno é uma proteína fibrilar que garante resistência ao tecido, enquanto os proteoglicanos têm a função de mola biológica, sendo responsáveis pela compressibilidade da cartilagem. A complexa interação entre estas duas proteínas garante a elasticidade. Estas características específicas da cartilagem são essenciais para amortecer as grandes forças de impacto a que as articulações diartrodiais estão submetidas, sem muito gasto de energia, visto tratar-se de um tecido avascular. Em processos artrósicos ocorre um desequilíbrio entre a produção de componentes da matriz extracelular e destruição pelas metaloproteases, levando à degradação e perda do tecido cartilaginoso. A fase inicial da osteoartrose é marcada por perda de fragmentos de proteoglicanos para o líquido sinovial, aumento dos colágenos tipo II e tipo VI, aparecimento dos colágenos I e III, não típicos da cartilagem, e diminuição do colágeno tipo IX, que é importante para manter a integridade da matriz extracelular, além do entumescimento da cartilagem. Como conseqüência, a cartilagem perde suas características específicas, levando a alterações na função articular. A evolução da doença promove diminuição significativa das proteínas, até mesmo do colágeno tipo XI, que tem localização mais interna na estrutura da fibrila heterotípica, e, portanto levando até a exposição do osso. Até o momento, o tratamento da osteoartrose está baseado principalmente no controle da dor e/ou inflamação, não diminuindo ou impedindo a degradação da cartilagem articular. Neste aspecto a perspectiva de tratamento futuro da osteoartrose estaria na utilização de inibidores das metaloproteases associadas a condroprotetores interferindo no "turnover" da cartilagem e impedindo, deste modo, o processo de degradação.

Articular cartilage is a highly specialized tissue, composed by cells, the chondrocytes, and macromolecules, such as collagen and proteoglicans. Collagen is a fibrilar protein responsible for the tissue resistance. Proteoglicans have a spring-like biologic function, being responsible for compressibility of cartilage. The complex interaction between these proteins warrants the elasticity of articular cartilage. These specific cartilage characteristics are essential to amortize the shock to which the diarthrodial joints are submitted, without excess of energy expense, because it is an avascular tissue. It is observed in osteoarthritis an imbalance between extracellular matrix components production and the destruction done by matrix metalloproteinases, promoting cartilage degradation. In the early osteoarthritis process, proteoglicans fragments are lost into synovial fluid, types II and VI collagen increases, atypical types I and III collagen appears and type IX collagen decreases. These biochemical alterations modify the specific characteristics of cartilage and, consequently, the articular function. The disease progression leads to a high decrease of proteins, including also type XI collagen, located deeply into the heterotypical cartilage fibril, contributing to bone exhibition. Until now, the osteoarthritis treatment is based on the use of drugs to relief the pain and/or inflammation, without protective effect on cartilage degradation. Regarding this aspect, the synthetic metalloproteinases inhibitors associated with chondroprotector drugs may reduce the cartilage degradation and can represent a future advance treatment in osteoarthritis.

Os componentes de matriz extracelular têm sido amplamente pesquisados nos últimos anos quanto ao seu papel na patogênese de diversas doenças difusas do tecido conjuntivo e síndromes vasculíticas. No caso da arterite de Takayasu, muito pouco se sabe sobre o assunto e são propostas teorias relacionadas com a participação da imunidade celular ou humoral para explicar a causa desta doença. Neste sentido, avaliamos a imunidade humoral nesta patologia. OBJETIVO: Pesquisar anticorpos contra componentes da matriz extracelular, incluindo a identificação de anticorpos anticolágeno e antiaorta. MÉTODOS: Soros de 13 pacientes com arterite de Takayasu e de 8 pacientes normais foram utilizados para pesquisa de auto-anticorpos anticolágeno tipos I, III, IV e V e antiaorta pelo método ELISA. RESULTADOS: Soros dos pacientes com arterite de Takayasu revelaram-se negativos para colágenos dos tipos III e IV e apenas um paciente apresentou positividade para os tipos I e V, enquanto todos os soros de pacientes com arterite de Takayasu revelaram-se negativos para anticorpos anti-aorta. CONCLUSÕES: Nossos dados demonstraram que as freqüências de anticorpos anticolágenos dos tipos I, III, IV e V não estiveram significativamente aumentadas no soro de pacientes com arterite de Takayasu, assim como os anticorpos antiextrato de aorta, sugerindo que a etiopatogenia desta vasculite esteja possivelmente relacionada com distúrbio da imunidade celular.

The pathogenic role of the components of extracellular matrix as causative factor of diffuse connective diseases and vasculitis has been studied extensively. The pathogenesis of Takayasu´s arteritis is unknown, and many theories have been proposed to explain the etiology of this disease, involving disturbances of the humoral or cellular immune responses. OBJECTIVE: To research antibodies directed to components of the extracellular matrix and aorta extract. METHODS: Serum from thirteen patients with Takayasu´s arteritis and from eight normal patients was tested to show the presence of autoantibodies directed to anti types I, III, IV and V collagen and anti-aorta employing ELISA methodology. RESULTS: Serum from patients with Takayasu´s arteritis didn't show the presence of antibodies directed to types III and IV collagen and only one patient was positive for type I and V collagen. No serum was reactive with aorta extract in patients with Takayasu´s arteritis as well. CONCLUSIONS: Our results didn't show the presence of antibodies directed to types I, III, IV and V collagen, as well as against aorta extract, suggesting that cell immune mediated disturbance should be the mechanism involved in the etiopathogenesis of this form of vasculitis.