La matriz extracelular en la curación de las heridas cutáneas. Aspectos físicos, químicos y biológicos / Extracellular matrix in healing of cutaneous wounds. Physical, chemical and biological aspects

Se revisan los nuevos conocimientos sobre la matriz extracelular (MEC), que han permitido descubrir su importante rol en la cicatrización de las heridas cutáneas. Se describen sus características morfofisiológicas y cómo interviene en la curación de las heridas cutáneas. Se presentan cuatro casos clínicos en los que se aplicó este enfoque terapéutico: los sustitutos de piel y la "cura húmeda"

We review the new knowledge about the extracellular ma-trix (ECM) that has allowed us to discover its important role in the healing of cutaneous wounds. The morpho-physiological characteristics of ECM and its role in the healing of cutaneous wounds are described. Four clinical cases are presented where this therapeutic approach was applied: the skin substitutes and the "moist wound healing".

Reparação da parede abdominal com membranas acelulares de pericárdio bovino - Parte I - Achados clínicos e radiológicos / Abdominal wall repair with acellular bovine pericardial membranes - Part I - Clinical and radiological findings

Introdução: Reduzindo os índices de recidiva de forma impactante, o emprego de biomateriais como "telas de reforço" na reparação de diferentes defeitos da parede abdominal tornou-se rotina quase obrigatória para o sucesso dessas reparações. A partir da década de 1990 houve a introdução de matrizes biológicas acelulares, iniciando-se assim uma nova era na reparação dos defeitos da parede abdominal. O objetivo é avaliar a funcionalidade do pericárdio bovino acelularizado em reparações da parede abdominal. Método: Trinta pacientes foram submetidos a reparação de defeitos da parede abdominal, com biopróteses acelulares de pericárdio bovino, perfazendo um total de 40 implantes anatomicamente individualizados. O seguimento médio foi de 31 meses, sendo os pacientes avaliados clinicamente e radiologicamente. Em três casos foram feitas biópsias das áreas implantadas permitindo análise histológica do material. Resultados: Não se observou recidiva das herniações em nenhum dos casos, tanto clinica como radiologicamente. Também não houve registro de hematomas, infecções ou qualquer fenômeno de natureza reacional local ou sistêmica. Radiologicamente, não foi possível visualizar as matrizes no local de implantação em qualquer dos períodos de pós-operatório analisados. Conclusão: As matrizes mostraram similaridade às demais membranas biológicas descritas na literatura internacional. Representando uma importante atualização e evolução conceitual, as membranas acelulares de pericárdio bovino podem ser incorporadas ao arsenal terapêutico nas reparações de parede abdominal.

Introduction: Reducing recurrence rates significantly, the use of biomaterials as "reinforcement meshes" in the repair of different abdominal wall defects has become an almost mandatory routine for the success of these repairs. From the 1990s onwards, acellular biological matrices were introduced, thus beginning a new era in the repair of abdominal wall defects. The objective is to evaluate the functionality of the acellularized bovine pericardium in abdominal wall repairs. Method: Thirty patients underwent repair of abdominal wall defects using acellular bovine pericardium bioprostheses, making a total of 40 anatomically individualized implants. The average follow-up was 31 months, with patients being evaluated clinically and radiologically. In three cases, biopsies were taken from the implanted areas, allowing histological analysis of the material. Results: No recurrence of herniations was observed in any of the cases, both clinically and radiologically. There were also no records of bruises, infections or any phenomenon of a local or systemic reaction nature. Radiologically, it was not possible to visualize the matrices at the implantation site in any of the postoperative periods analyzed. Conclusion: The matrices showed similarity to other biological membranes described in the international literature. Representing an important update and conceptual evolution, acellular bovine pericardial membranes can be incorporated into the therapeutic arsenal in abdominal wall repairs.

Reparação da parede abdominal com membranas acelulares de pericárdio bovino - Parte II - Análises histológicas e morfométricas / Repair of the abdominal wall with acellular bovine pericardial membranes - Part II - Histological and morphometric analyses

Introdução: Análise histológica é a principal ferramenta de avaliação de biopróteses acelulares, em sua maioria em caráter experimental. O objetivo é analisar histologicamente a matriz acelular de pericárdio bovino em reparações de parede abdominal implantada em humanos. Método: De uma série de 30 reparações com a membrana, 3 pacientes foram submetidas a revisão cirúrgica não relacionada aos implantes, aos 13, 22 e 23 meses de pós-operatório, obtendo-se biópsias das áreas previamente implantadas. Além da avaliação dos aspectos básicos de biocompatibilidade e neoformação tecidual, as lâminas foram digitalizadas e submetidas a análise computadorizada com o software ImageJ para quantificação da cinética de degradação das membranas, associada à análise da dimensão fractal das amostras. Os valores obtidos para porcentagens de membrana residual tiveram suas médias comparadas por análise de variância (ANOVA) e pelo teste T de Student não pareado, também utilizado para os valores da quantificação da dimensão fractal. Resultados: Foi demonstrada a biocompatibilidade do material, com neoformação tecidual, deposição de colágeno e tecido celularizado de aspecto normal, sem reações locais importantes. Fragmentos residuais da membrana foram quantificados em 40%±7% aos 13 meses, em 20%±6% aos 22 meses e em 17%±6% aos 23 meses de pós-operatório, com a análise da dimensão fractal indicando uma progressiva degradação dos implantes, com significância estatística entre 13 meses e as amostras tardias. Conclusão: Os resultados atestaram a funcionalidade do pericárdio bovino acelular sob diferentes níveis de estresse mecânico nas reparações da parede abdominal em humanos.

Introduction: Histological analysis is the main tool for evaluating acellular bioprostheses, mostly on an experimental basis. The objective is to histologically analyze the acellular matrix of bovine pericardium in abdominal wall repairs implanted in humans. Method: From a series of 30 repairs with the membrane, 3 patients underwent surgical revision unrelated to the implants at 13, 22, and 23 months postoperatively, obtaining biopsies of the previously implanted areas. In addition to evaluating the basic aspects of biocompatibility and tissue neoformation, the slides were digitalized and subjected to computerized analysis with the ImageJ software to quantify the kinetics of membrane degradation associated with the analysis of the fractal dimension of the samples. The values obtained for percentages of residual membrane had their means compared by analysis of variance (ANOVA) and the unpaired Student's T test, also used for the fractal dimension quantification values. Results: The biocompatibility of the material was demonstrated, with tissue neoformation, collagen deposition, and cellularized tissue with a normal appearance without important local reactions. Residual fragments of the membrane were quantified at 40%±7% at 13 months, at 20%±6% at 22 months, and at 17%±6% at 23 months postoperatively, with the analysis of the fractal dimension indicating a progressive degradation of implants, with statistical significance between 13 months and late samples. Conclusion: The results confirmed the functionality of the acellular bovine pericardium under different levels of mechanical stress in abdominal wall repairs in humans.

Upregulation of miR-200a improves ureteral obstruction-induced renal fibrosis via GAB1/Wnt/ß-catenin signaling.

BACKGROUND: Renal fibrosis is a basic pathological change of almost all chronic kidney disorders. Epithelial-mesenchymal transition (EMT) and excessive extracellular matrix (ECM) accumulation play a crucial role in the process of fibrosis. METHODS: Western blot and qRT-PCR were accomplished to analyze the expression levels of target proteins and genes, respectively. The fibrotic levels in the renal tissues of rats were confirmed utilizing Masson staining. Expression of ECM-related α-SMA in the renal tissues was determined by immunohistochemistry assay. The combination of GRB2 associated binding protein 1 (GAB1) and miR-200a was ensured by starBase database and luciferase reporter assay. RESULTS: Our data uncovered that miR-200a was downregulated, but GAB1 was upregulated in the renal tissues of the rat experienced unilateral ureteral obstruction (UUO). Overexpression of miR-200a improved tissues fibrosis, suppressed GAB1 expression and ECM deposition, and inactivated Wnt/ß-catenin in UUO rats. Moreover, miR-200a expression was inhibited, while GAB1 expression was facilitated in the TGF-ß1-induced HK-2 cells. In TGF-ß1-induced HK-2 cells, miR-200a overexpression inhibited GAB1 expression, also declined ECM-related proteins and mesenchymal markers expression. Oppositely, miR-200a overexpression facilitated epithelial marker expression in the TGF-ß1-induced HK-2 cells. Next, the data revealed that miR-200a inhibited GAB1 expression through binding to the mRNA 3'-UTR of GAB1. Increasing of GAB1 reversed the regulation of miR-200a to GAB1 expression, Wnt/ß-catenin signaling activation, EMT and ECM accumulation. CONCLUSION: Overall, miR-200a increasing improved renal fibrosis through attenuating EMT and ECM accumulation by limiting Wnt/ß-catenin signaling via sponging GAB1, indicating miR-200a may be a promising objective for renal disease therapy.

Scaffolds Vasculares Descelularizados Provenientes de Vasos Sanguíneos de Placenta Bovina / Decellularized Vascular Scaffolds Derived from Bovine Placenta Blood Vessels

Resumo Fundamento As doenças associadas ao aparelho circulatório são as principais causas de morbidade e mortalidade em todo o mundo, implicando a necessidade de implantes vasculares. Assim, a produção de biomateriais vasculares tem se mostrado uma alternativa promissora às terapias utilizadas em estudos e pesquisas relacionados à fisiologia vascular. Objetivos O presente projeto visa ao desenvolvimento artificial de vasos sanguíneos pela recelularização de scaffolds vasculares derivados de vasos placentários bovinos. Métodos A superfície corioalantoide da placenta bovina foi utilizada para produzir biomateriais descelularizados. Para a recelularização, 2,5 x 104 células endoteliais foram semeadas acima de cada fragmento de vaso descelularizado durante três ou sete dias, quando a cultura foi interrompida e os fragmentos foram fixados para análise de adesão celular. Biomateriais descelularizados e recelularizados foram avaliados por histologia básica, microscopia eletrônica de varredura e imuno-histoquímica. Resultados o processo de descelularização produziu vasos que mantiveram a estrutura natural e o conteúdo de elastina, e não foram observadas células e gDNA remanescentes. Além disso, células precursoras endoteliais se ligaram ao lúmen e à superfície externa do vaso descelularizado. Conclusão nossos resultados mostram a possibilidade de usos futuros desse biomaterial na medicina cardiovascular, como, por exemplo, no desenvolvimento de vasos artificiais.

Background Diseases associated with the circulatory system are the main causes of worldwide morbidity and mortality, implying the need for vascular implants. Thus, the production of vascular biomaterials has proven to be a promising alternative to therapies used in studies and research related to vascular physiology. Objectives The present project aims to achieve the artificial development of blood vessels through the recellularization of vascular scaffolds derived from bovine placental vessels. Methods The chorioallantoic surface of the bovine placenta was used to produce decellularized biomaterials. For recellularization, 2.5 x 104 endothelial cells were seeded above each decellularized vessel fragment during three or seven days, when culture were interrupted, and the fragments were fixed for cell attachment analysis. Decellularized and recellularized biomaterials were evaluated by basic histology, scanning electron microscopy, and immunohistochemistry. Results The decellularization process produced vessels that maintained natural structure and elastin content, and no cells or gDNA remains were observed. Endothelial precursor cells were also attached to lumen and external surface of the decellularized vessel.Conclusion: Our results show a possibility of future uses of this biomaterial in cardiovascular medicine, as in the development of engineered vessels.

Automated Assessment of Cell Infiltration and Removal in Decellularized Scaffolds - Experimental Study in Rabbits / Avaliação automatizada da infiltração e remoção celular em scaffolds descelularizados - Estudo experimental em coelhos

Abstract Objective Semiquantitative and automated measurement of nuclear material removal and cell infiltration in decellularized tendon scaffolds (DTSs). Method 16 pure New Zealand rabbits were used, and the gastrocnemius muscle tendon was collected bilaterally from half of these animals (16 tendons collected); 4 were kept as control and 12 were submitted to the decellularization protocol (DTS). Eight of the DTSs were used as an in vivo implant in the experimental rotator cuff tear (RCT) model, and the rest, as well as the controls, were used in the semiquantitative and automated evaluation of nuclear material removal. The eight additional rabbits were used to make the experimental model of RCT and subsequent evaluation of cellular infiltration after 2 or 8 weeks, within the DTS. Results The semiquantitative and automated analysis used demonstrated a removal of 79% of nuclear material (p< 0.001 and power > 99%) and a decrease of 88% (p < 0.001 and power >99%) in the area occupied by nuclear material after the decellularization protocol. On cell infiltration in DTS, an increase of 256% (p < 0.001 and power >99%) in the number of cells within the DTS was observed in the comparison between 2 and 8 weeks postoperatively. Conclusion The proposed semiquantitative and automated measurement method was able to objectively measure the removal of nuclear material and cell infiltration in DTS.

Resumo Objetivo Mensuração semiquantitativa e automatizada da remoção de material nuclear e da infiltração celular em scaffolds tendinosos descelularizados (STDs). Método Foram utilizados 16 coelhos Nova Zelândia puros, sendo o tendão do músculo gastrocnêmio coletado bilateralmente de metade destes animais (16 tendões coletados); 4 foram mantidos como controle e 12 foram submetidos ao protocolo de descelularização (STD). Dos STDs, 8 foram utilizados como implante in vivo no modelo experimental de lesão do manguito rotador (LMR) e os restantes, assim como os controles, foram utilizados na avaliação semiquantitativa e automatizada da remoção de material nuclear. Os oito coelhos adicionais foram utilizados na confecção do modelo experimental de LMR e posterior avaliação da infiltração celular após 2 ou 8 semanas, dentro do STD. Resultados A análise semiquantitativa e automatizada utilizada demonstrou uma remoção de 79% do material nuclear (p< 0,001 e poder > 99%) e uma diminuição de 88% (p< 0,001 e poder > 99%) na área ocupada por material nuclear após o protocolo de descelularização. Sobre a infiltração celular no STD, foi observado um aumento de 256% (p< 0,001 e poder > 99%) no número de células dentro do STD na comparação entre 2 e 8 semanas de pós-operatório. Conclusão O método de mensuração semiquantitativo e automatizado proposto foi capaz de mensurar objetivamente a remoção de material nuclear e a infiltração celular no STD.

Histological analysis of an alkaline based tissue clearing technique for fetal musculoskeletal tissue / Análisis histológico de una técnica de limpieza de tejido de base alcalina para tejido musculoesquelético fetal

SUMMARY: Tissue clearing techniques are frequently used in the observation and description of anatomical structures and pathways without altering the three-dimensional layout of the anatomical specimen. Tissue optical clearing promotes preservation of three-dimensional structures, which allows the study of the internal anatomy in its original position and original spatial interaction. Among these techniques, Potassium Hydroxide (KOH) maceration clearing is one of the most widely used. However, the histological changes of tissue after KOH maceration have yet to be fully understood. Our aim is to describe the microscopical differences between macerated and normal tissue. To better understand said changes, two human fetuses with a gestation period of 16 to 28 weeks were cleared and processed for histological analysis. Microtome slides of the fetuses' lower limbs were obtained and stained with Hematoxylin & Eosin, Periodic Acid Schiff (PAS), and Masson's trichrome with the purpose of observing the histological and macromolecule composition changes in cleared tissue. Remarkable differences at a histological level regarding the composition of the cellular structures, since diaphanized tissues showed a predominance of extracellular matrix composed of collagen fibers with the absence of most of the nucleated cellular tissue. Phospholipid's saponification, nucleic acids degradation and a change on proteins structural properties are the main factors inducing clearing. At the same time, molecular stability of collagen in alkaline conditions allows the specimen to maintain its shape after the process.

RESUMEN: Las técnicas de limpieza de tejido se utilizan con frecuencia en la observación y descripción de estructuras y vías anatómicas sin alterar el diseño tridimensional de la muestra anatómica. El aclaramiento óptico de tejidos promueve la preservación de estructuras tridimensionales, lo que permite el estudio de la anatomía interna en su posición original y la interacción espacial original. Entre estas técnicas, el aclarado por maceración con Hidróxido de Potasio (KOH) es una de las más utilizadas. Sin embargo, los cambios histológicos del tejido después de la maceración con KOH aún no se han entendido por completo. Nuestro objetivo es describir las diferencias microscópicas entre el tejido macerado y el normal. Para entender mejor dichos cambios, dos fetos humanos con un período de gestación de 16 a 28 semanas fueron aclarados y procesados para análisis histológicos. Se obtuvieron microtomos de las extremidades inferiores de los fetos y se tiñeron con hematoxilina y eosina, ácido peryódico de Schiff (PAS) y tricrómico de Masson con el fin de observar los cambios histológicos y de composición de macromoléculas en el tejido aclarado. Diferencias notables a nivel histológico en cuanto a la composición de las estructuras celulares, ya que los tejidos diafanizados mostraban un predominio de matriz extracelular compuesta por fibras de colágeno con ausencia de la mayor parte del tejido celular nucleado. La saponificación de los fosfolípidos, la degradación de los ácidos nucleicos y un cambio en las propiedades estructurales de las proteínas son los principales factores que inducen la depuración. Al mismo tiempo, la estabilidad molecular del colágeno en condiciones alcalinas permite que la muestra mantenga su forma después del proceso.

Increased Expression of Type-I Collagen in Malignant Colorectal Lesion and Positive Correlations with Clinical Factors / Expressão aumentada do colágeno tipo I na lesão colorretal maligna e correlações positivas com fatores clínicos

Abstract Objective Type-I collagen (Col-I) is one of the main macromolecules of the extracellular matrix, and it is involved in the desmoplastic stromal reaction, an indicator of worse prognosis in cases of colorectal cancer (CRC). The purpose of the present study was to investigate Col-I expression in cases of CRC and adenoma and to correlate with the clinical data and the data regarding the lifestyle of the patients. Methods A retrospective study including 22 patients with adenoma and 15 with CRC treated at a coloproctology service. The clinical and lifestyle data were obtained through medical records, and Col-I expression was investigated by immunohistochemistry. Results Women represented most cases of adenoma (63.64%), whereas CRC was found mainly in men (73.33%) (p=0.0448). Immunoexpression of Col-I showed a basement membrane thickening in areas of lining of epithelium and around the glands in both lesions. The cases of CRC had a quite evident fibrosis process in the stroma. The quantitative analysis demonstrated a higher protein expression in CRCs compared to adenomas (p=0.0109), as well as in female patients (p=0.0214), patients aged ≥ 50 years (p=0.0400), and in those with a positive family history of colorectal disease (p=0.0292). These results suggested a remodeling of the microenvironment of the Worked developed at the Department of Morphology, Centro de Ciências da Saúde, Universidade Federal do Espírito Santo, ES, Brazil. Conclusion The immunohistochemical analysis encourages the performance of more comprehensive studies to ascertain if our results could be a tool for the diagnosis and monitoring of the patients.

Resumo Objetivo O colágeno tipo I (Col-I) é uma das principais macromoléculas da matriz extracelular, e está envolvido na reação desmoplástica estromal, um indicador de pior prognóstico em casos de câncer colorretal (CCR). O objetivo foi investigar a expressão do Col-I emcasos de CCR e adenoma, e correlacioná-la comdados clínicos e de estilo de vida dos pacientes. Metodologia Foi realizado umestudoretrospectivo com22pacientes comadenoma e 15 comCCR tratadosemumserviço de coloproctologia.Os dados dos pacientes foramobtidos dos prontuários médicos, e a expressão do Col-I foi investigada por imunohistoquímica. Resultados As mulheres representaram a maioria dos casos de adenomas (63,64%), enquanto o CCR (73,33%) (p=0,0448) foi mais comum entre os homens. A imunoexpressão de Col-I mostrou espessamento da membrana basal em áreas de revestimento do epitélio e em volta de glândulas em ambas as lesões. O CCR apresentou fibrose no estroma. As análises quantitativas demonstraram maior expressão proteica no CCR (p=0,0109), assim como em mulheres (p=0,0214), pacientes com idade ≥ 50 anos (p=0,0400), e em pacientes com histórico positivo de doença colorretal na família (p=0,0292). Estes resultados sugerem a remodelação do microambiente tumoral na carcinogênese do CCR. As correlações clínico-patológicas positivas mostram uma ligação plausível entre o perfil do paciente e os achados imunohistoquímcos, o que indica uma possível forma de estratificação dos pacientes. Conclusão As análises imunohistoquímicas estimulam a execução de estudos mais abrangentes para confirmar se nossos resultados poderão ser uma ferramenta para o diagnóstico e o monitoramento dos pacientes.

Markers of Stroma in Lung Cancer: Influence of COPD.

BACKGROUND: Stroma, mainly composed by fibroblasts, extracellular matrix (ECM) and vessels, may play a role in tumorigenesis and cancer progression. Chronic Obstructive Pulmonary Disease (COPD) is an independent risk factor for LC. We hypothesized that markers of fibroblasts, ECM and endothelial cells may differ in tumors of LC patients with/without COPD. METHODS: Markers of cultured cancer-associated fibroblasts and normal fibroblasts [CAFs and NFs, respectively, vimentin and alpha-smooth muscle actin (SMA) markers, immunofluorescence in cultured lung fibroblasts], ECM, and endothelial cells (type I collagen and CD31 markers, respectively, immunohistochemistry) were identified in lung tumor and non-tumor specimens (thoracotomy for lung tumor resection) from 15 LC-COPD patients and 15 LC-only patients. RESULTS: Numbers of CAFs significantly increased, while those of NFs significantly decreased in tumor samples compared to non-tumor specimens of both LC and LC-COPD patients. Endothelial cells (CD31) significantly decreased in tumor samples compared to non-tumor specimens only in LC patients. No significant differences were seen in levels of type I collagen in any samples or study groups. CONCLUSIONS: Vascular endothelial marker CD31 expression was reduced in tumors of non-COPD patients, while type I collagen levels did not differ between groups. A rise in CAFs levels was detected in lung tumors of patients irrespective of airway obstruction. Low levels of CD31 may have implications in the overall survival of LC patients, especially in those without underlying airway obstruction. Identification of CD31 role as a prognostic and therapeutic biomarker in lung tumors of patients with underlying respiratory diseases warrants attention.

Matriz extracelular de la submucosa de intestino delgado (mec- sid; sid) como biomaterial versátil en medicina regenerativa basada en ingeniería de tejidos / Extracellular matrix of small intestine submucose (mec-sid; sid) as a versatile biomaterial in regenerative medicine based on tissue engineering

Resumen Durante las últimas décadas, la submucosa del intestino delgado (SID), una matriz extracelular descelularizada (MEC) de origen natural, ha atraído atención en la reparación de tejidos porque puede proporcionar abundantes factores bioactivos y un microambiente biomimético de tres dimensiones para inducir las funciones celulares deseadas. En este artículo se revisan las últimas investigaciones sobre SID, que se centran en los siguientes aspectos: superioridad principal como una notable bioactividad, baja inmunogenicidad, reabsorbibilidad y capacidad de recelularización. Se reporta como la adhesión, proliferación, migración y diferenciación de las células se ve influenciada cuando son depositadas sobre este soporte, debido a sus características. Se presenta el gran potencial de este biomaterial para resolver los problemas de cuello de botella que se encuentran en la reparación de varios tejidos, convirtiéndola en un excelente biomaterial para uso en medicina regenerativa basada en ingeniería de tejidos. Palabras clave: Reparación de tejidos, matriz extracelular, Biomateriales, Ingeniería de tejidos, Propiedades fisicoquímicas.

Over the past decades, the small intestine submucosa (SID), a naturally occurring decellularized extracellular matrix (ECM), has attracted attention in tissue repair because it can provide abundant bioactive factors and a three-dimensional biomimetic microenvironment to induce the functions desired cell phones. This article reviews the latest research on SID, which focuses on the following aspects: main superiority as remarkable bioactivity, low immunogenicity, resorbability and recellularization capacity. It is reported how the adhesion, proliferation, migration and differentiation of cells is influenced when they are deposited on this support, due to its characteristics. The great potential of this biomaterial is presented to solve the bottleneck problems found in the repair of various tissues, making it an excellent biomaterial for use in regenerative medicine based on tissue engineering.

Metaloproteinases da matriz: papel no desenvolvimento das lesões periapicais e modulação após tratamento endodôntico / Matrix metalloproteinases: role in the development of apical periodontitis and modulation after endodontic treatment

Introduction: Apical periodontitis represents a local immune response directed against the progression of microorganisms from the dental pulp to the apical foramen and periapical tissues, which results in bone and dental resorption. The aim of this review is to describe the expression of this group of proteases in apical periodontitis and its modulation during the periapical healing phase following root canal treatment. Literature review: The pathogenesis of apical periodontitis involves degradation of several extracellular matrix components. Matrix metalloproteinases (MMPs) are expressed in response to specific stimuli by resident cells of connective tissue during tissue remodeling and by inflammatory cells that arrive into the surrounding tissues during inflammatory events. MMPs have been reported in apical periodontitis, either experimentally induced or obtained from humans and there is evidence that these enzymes show diff erent expression patterns in granulomas and periapical cysts. Root canal therapy is important for the reduction of periapical inflammation as well as the synthesis of MMPs, especially when using a calcium hydroxide-based dressing. Conclusion: Apical periodontitis show high expression of matrix metalloproteinases and root canal treatment results in less expression of MMPs when compared to untreated apical periodontitis.

Introdução: A lesão periapical representa a resposta imunoinflamatória devido ao aumento do número e progressão de micro-organismos advindos dos canais radiculares contaminados em direção aos tecidos apicais e periapicais, resultando em reabsorção óssea. O objetivo desta revisão será abordar a importância das metaloproteinases da matriz no desenvolvimento das lesões periapicais e sua modulação durante a fase de reparação tecidual depois de instituído o tratamento endodôntico. Revisão da literatura: A patogênese da lesão periapical envolve a degradação progressiva de diversos componentes da matriz extracelular. Dentre as proteases responsáveis pela degradação destes componentes estão as metaloproteinases da matriz (MMPs). Estas proteinases são expressas em resposta a estímulos específicos pelas células residentes do tecido conjuntivo durante o processo de remodelação tecidual e por células inflamatórias que invadem os tecidos durante eventos inflamatórios. As MMPs foram descritas em lesões periapicais experimentais e em humanos e existem evidências de que estas enzimas apresentam padrões de expressões diferentes em granulomas e cistos periapicais. A terapia endodôntica é importante para a redução da inflamação periapical assim como da síntese das MMPs, principalmente quando utilizado um curativo de demora à base de hidróxido de cálcio. Conclusão: As lesões periapicais apresentam alta expressão de metaloproteinases da matriz e o tratamento endodôntico em dentes com lesão periapical resulta em menor expressão de MMPs quando comparado às lesões periapicais não tratadas.

Expression of enamel proteins in human dental pulp stem cells by the effect of extracellular matrix / Expresión de proteínas de esmalte en células madre de pulpa dental humana por el efecto de matriz extracelular

SUMMARY: Mesenchymal stem cells are present in adult tissues such as the human dental pulp. They are pluripotent and can differentiate into various specialized cell types in vitro through appropriate stimuli. Ameloblasts produce human tooth enamel only during embryonic development before tooth eruption, so endogenous regeneration is not possible. Various efforts have been aimed at generating natural or artificial substitutes for dental enamel with properties similar to the specific components of said tissue. The purpose of this study was to induce human dental pulp stem cells to produce enamel proteins using extracellular matrix derived from the rat tail tendon and pigskin. Primary cultures of human dental pulp stem cells were established and characterized by RT-PCR and immunofluorescence, using mesenchymal cell markers such as CD14, CD40, CD44, CD105, and STRO-1. The cells were then incubated with the extracellular matrix for fourteen days and labeled with specific antibodies to detect the expression of dental enamel proteins such as amelogenin, ameloblastin, enamelisin, tuftelin, and parvalbumin, characteristics of the phenotype of ameloblasts. This work demonstrated a positive effect of the extracellular matrix to induce the expression of enamel proteins in the stem cells of the human dental pulp.

RESUMEN: Las células madre mesenquimales están presentes en los tejidos adultos como la pulpa dental humana. Son pluripotentes y pueden diferenciarse en varios tipos de células especializadas in vitro a través de estímulos adecuados. Los ameloblastos producen esmalte dental humano sólo durante el desarrollo embrionario antes de la erupción dental, por lo que no es posible su regeneración endógena. Varios esfuerzos se han orientado a generar sustitutos naturales o artificiales de esmalte dental con propiedades similares a los componentes específicos de este tejido. El propósito de este estudio fue inducir células madre de pulpa dental humana para producir proteínas del esmalte dental a través del estímulo de matriz extracelular derivada del tendón de la cola de rata y piel de cerdo. Se establecieron cultivos primarios de células madre de pulpa dental humana y se caracterizaron por RT-PCR e inmunofluorescencia utilizando marcadores de células mesenquimales como CD14, CD40, CD44, CD105 y STRO-1. Posteriormente, las células se incubaron con matriz extracelular durante un período de catorce días y se marcaron con anticuerpos específicos para detectar la expresión de proteínas de esmalte dental como amelogenina, ameloblastina, enamelisina, tuftelina y parvalbúmina, las cuales son características del fenotipo de ameloblastos. Este trabajo demostró el efecto positivo que tiene el empleo de la matriz extracelular para inducir la expresión de proteínas de esmalte en las células pluripotenciales de la pulpa dental humana.

MicroRNAs and ventricular remodeling in aortic stenosis.

INTRODUCTION AND OBJECTIVES: Several mechanisms contribute to myocardial hypertrophy and fibrosis in aortic stenosis (AS). MicroRNAs are post-transcriptional modulators of such processes. We hypothesized that their expression in myocardial biopsies from patients with AS could be linked with the degree of left ventricular (LV) hypertrophy and remodeling and to plasma levels of important biomarkers of extracellular matrix turnover. METHODS: We performed myocardial biopsies in eleven patients with isolated severe AS undergoing aortic valve replacement. Echocardiographic exams and biomarker quantification were also performed. Five explanted hearts were used as controls for microRNA expression. RESULTS: Overexpression of microRNA-101-3p was found in AS, which correlated with higher levels of preoperative valvuloarterial impedance, angiotensin II receptor and angiotensin-converting enzyme, and LV mass regression after surgery. Although not differently expressed in AS compared to controls, both upregulation of miR-4268 and downregulation of microRNA-125-5p were associated with higher LV mass. MicroRNA-125b-5p correlated negatively with LV mass and with relative wall thickness at six-month follow-up. MicroRNA-4268 correlated positively with LV mass regression and was associated with higher plasma angiotensin II receptor levels. CONCLUSIONS: MicroRNA-101-3p and microRNA-4268 have potential new roles in the modulation of the hypertrophic response to AS via the renin-angiotensin-aldosterone system and as predictors of reverse remodeling after aortic valve replacement. Our results open new avenues in the understanding of myocardial response to pressure overload and of reverse remodeling after unloading. They also support the possibility of medical therapy to modulate the renin-angiotensin-aldosterone system in hypertrophic hearts.

The prognostic value of elevated matrix metalloproteinase-9 in patients undergoing primary percutaneous coronary intervention for ST-elevation myocardial infarction: A two-year prospective study.

INTRODUCTION: Increased matrix metalloproteinase-9 (MMP-9) levels in ST-elevation myocardial infarction (STEMI) are well established; however, existing data on MMP-9 values as a prognostic marker after STEMI are limited and have been conflicting. OBJECTIVE: This study aimed to assess the clinical significance of MMP-9 in predicting two-year adverse cardiovascular events in patients who underwent primary percutaneous coronary intervention (PCI) after STEMI. METHODS: In this prospective study, 204 patients with STEMI undergoing PCI were included. Participants were classified as high MMP-9 (n=102) or low MMP-9 (n=102) based on a cutoff of 12.92 ng/ml. Both groups were assessed at one and two years after STEMI. RESULTS: Higher cardiovascular mortality at one year was observed in the high MMP-9 group (13.7% vs. 4.9% in the low MMP-9 group, p=0.03). When the follow-up period was extended to two years, the difference in cardiovascular mortality between the groups was more significant (17.6% vs. 4.9%, p=0.004). There was no significant difference at one-year follow-up in rates of advanced heart failure, however at the end of the second year, advanced heart failure was more prevalent in the high MMP-9 group (16.7% vs. 5.9%, p=0.015). After adjustment for potential confounders, a high MMP-9 value had 3.5-fold higher odds for cardiovascular mortality at two-year follow-up than low MMP-9. CONCLUSION: These results suggest that high MMP-9 levels are a strong predictor of cardiovascular mortality and advanced heart failure at two-year follow-up in STEMI patients.

Análisis de expresión de calreticulina en vena safena parva / Calreticulin expression analysis in small saphenous vein

La proteína chaperona Calreticulina (CRT), ha sido identificada en retículo endoplásmico (RE) y últimamente en la matriz extracelular (MEC) de predentina y arterias, atribuyéndole diferentes funciones extracelulares entre las que destacan la adhesión celular, regulación de la MEC y prevención en la formación de trombos. El objetivo del estudio fue identificar la presencia de CRT en MEC de vena safena parva. Se extrajo una muestra de vena safena parva de un espécimen masculino y luego fue procesada por medios histológicos e inmunohistoquímicos para identificar su presencia. Mediante técnicas de inmunohistoquímica se pudo evidenciar la presencia de CRT en la MEC de la adventicia de vena safena parva. La presencia de CRT en MEC de safena parva orienta a que CRT tienen funciones de tipo extracelular en esta localización, pero es necesario realizar estudios más precisos para dilucidar sus principales funciones en la zona.

Calreticulin (CRT) protein, has been identified in the endoplasmic reticulum (ER) and lately in the extracellular matrix (ECM) of predentine and arteries. It is responsible for different extracellular functions, such as cell adhesion, ECM regulation, and the prevention of thrombosis. The aim was to identify the presence of CRT in ECM of small saphenous vein. A sample of small saphenous vein from a male specimen was extracted and then processed by histological and immunohistochemical assays to identify its presence. The presence of CRT in the ECM of the small saphenous vein was observed by immunohistochemical techniques. The presence of CRT in the small saphenous vein ECM, indicates that CRT have extracellular functions in this area, however, more precise studies are necessary to determine its main functions.

Evaluation of the fibulin 5 gene polymorphism as a factor related to the occurrence of pelvic organ prolapse

SUMMARY OBJECTIVE Pelvic organ prolapse (POP) is a very frequent situation in our population that may lead to a significant decrease in patients' quality of life. Currently, we are looking for predictive factors for the development of POPs; thus, this study seeks to evaluate whether the Fibulin 5 polymorphism (FBLN5) is associated with the occurrence of POP. METHODS This is a cohort study with postmenopausal women who were divided into groups by POP stage: POP stages 0 and I (control group) and POP stages III and IV (case group). Subsequently, analyses of genetic polymorphisms of FBLN5 were performed using the Restriction Fragment Length Polymorphism (RFLP) technique. RESULTS A total of 292 women were included in the study. Pregnancy, parity and vaginal delivery in the patients, as well as in data described in the literature, were related to the occurrence of POP in the univariate analysis. However, after binary logistic regression, home birth and age remained independent risk factors for POP. We found no association between the FBLN5 polymorphism and the occurrence of POP (p = 0.371). CONCLUSION There was no association between the FBLN5 polymorphism and the occurrence of POP in Brazilian women.

RESUMO OBJETIVOS O prolapso de órgãos pélvicos (POP) é uma situação muito frequente em nossa população que pode levar a uma diminuição significativa da qualidade de vida dos pacientes. Atualmente, buscam-se fatores preditivos para o desenvolvimento de POPs e, assim, este estudo correlaciona um polimorfismo de Fibulina 5 (FBLN5) com a ocorrência da doença. MÉTODOS Estudo de coorte com mulheres na pós-menopausa, divididas por grupos pelos estádios 0 e I do POP (grupo controle) e POP III e IV (grupo caso). Posteriormente, análises do polimorfismo genético de FBLN5 foram realizadas utilizando a técnica de Polimorfismo de Comprimento de Fragmentos de Restrição (RFLP). RESULTADOS Um total de 292 mulheres foi incluído no estudo. Gestação, paridade e parto vaginal, como bem descritos na literatura, foram relacionados à ocorrência de POPs na análise univariada. No entanto, após a regressão logística binária, o parto domiciliar e a idade permaneceram como fatores de risco independentes para os POPs. Não encontramos associação deste polimorfismo FBLN5 com a ocorrência de POP (p=0,371). CONCLUSÃO Não houve associação deste polimorfismo FBLN5 com a ocorrência de POPs em mulheres brasileiras.

Is the expression of the components of the carotid matrix of rats influenced by estrogen, progestin and tibolone? / A expressão dos componentes da matriz carotídea de ratos é influenciada pelo estrogênio, progestagênio e tibolona?

Abstract Objective To analyze the effects of estrogen alone or in combination with progestogens and tibolone (TIB) on the expression of the extracellular matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9), of perlecan, and of heparanase (HPSE) of the vascular walls of the carotid arteries. Methods A total of 30 250-day-old ovariectomized Wistar rats were orally treated for 5 weeks with: a) 1 mg/kg of estradiol benzoate (EB); b) EB + 0.2 mg/kg of medroxyprogesterone acetate (MPA); c) EB + 0.2mg/kg of norethisterone acetate (NETA); d) EB + 2 mg/kg of dydrogesterone (DI); e) 1 mg/kg of TIB; f) placebo (CTR). Following treatment, the expression of mRNA for MMP-2, MMP-9, and HPSE was analyzed by realtime polymerase chain-reaction (PCR), and the expression of MMP-2, of MMP-9, of tissue inhibitor of metalloproteinase 2 (TIMP-2), and of perlecan was quantified by immunohistochemistry in the carotid arteries. Results The groups showed significant differences on mRNA HPSE expression (p = 0.048), which was higher in the EB, EB + MPA, and TIB groups. There was no statistically significant difference in mRNA MMP-2 or MMP-9 expression. The immunohistochemical expression of MMP-2, of TIMP-2, of MMP-9, of HPSE, and of perlecan showed no differences between groups. Conclusion Estradiol alone or associated with MPA and TIB treatment can increase mRNA HSPE expression of the walls of the carotid arteries in ovariectomized rats.

Resumo Objetivo Analisar os efeitos do estrogênio isolado ou em combinação com progestogênios e tibolona (TIB) na expressão das metaloproteinases 2 e 9 da matriz extracelular (MMP-2 e MMP-9), da perlecan e da heparanase (HPSE) das paredes vasculares das artérias carótidas. Métodos Trinta ratas Wistar ovariectomizadas com 250 dias de idade foram tratadas oralmente por 5 semanas com: a) 1 mg/kg de benzoato de estradiol (EB); b) EB + 0,2 mg/kg de acetato de medroxiprogesterona (MPA); c) EB + 0,2mg/kg de acetato de noretisterona (NETA); d) EB + 2 mg/kg de didrogesterona (DI); e) 1 mg/kg de TIB; f) placebo (CTR). Após o tratamento, a expressão de mRNA para MMP-2, MMP- 9, e HPSE foi analisada por reação em cadeia da polimerase (RCP) em tempo real, e a expressão de MMP-2, MMP-9, inibidor tecidual de metaloproteinase 2 (TIMP-2), e de perlecan foi quantificado por imunohistoquímica em artérias carótidas. Resultados Os grupos apresentaram diferenças significativas na expressão do mRNA HPSE (p = 0,048), sendo maiores nos grupos EB, EB + MPA e TIB. Não houve diferença estatisticamente significativa nas expressões de mRNA MMP-2 ou MMP-9. A expressão imunohistoquímica de MMP-2, TIMP-2, MMP-9, HPSE e perlecan não mostrou diferenças entre os grupos. Conclusão O estradiol isolado ou associado ao tratamento com MPA e TIB pode aumentar a expressão de mRNA HSPE nas paredes das artérias carótidas em ratas ovariectomizadas.

Efetividade das coberturas e agentes tópicos de matriz no tratamento de úlceras de perna: revisão sistemática e metanálise / Effectiveness of coverings and topical matrix agents in the treatment of leg ulcers: systematic review and meta-analysis

Resumo: As úlceras vasculogênicas (venosas, arteriais e mistas) são um tipo de ferida crônica, apresentam altos índices de prevalência e incidência mundial, são recorrentes, alteram a qualidade de vida, são susceptíveis a complicações, como a infecção, e geram altos custos para os prestadores de serviço. Em feridas crônicas os altos níveis de metaloproteinases, na fase inflamatória, destroem as proteínas essenciais para a formação da matriz extracelular (MEC), impedem a aderência das células, a angiogênese, a MEC degrada-se e retarda a cicatrização. As tecnologias de matriz estimulam os componentes ou substituem a matriz extracelular danificada, para otimizar a cicatrização. Esta revisão sistemática (RS) objetivou sintetizar as evidências da diversidade das tecnologias de matriz (origem, fonte e composição), aplicadas como coberturas e agentes tópicos, no tratamento de úlceras vasculogênicas, em adultos, a partir dos 18 anos, em qualquer ambiente de cuidado. Os desfechos foram: cicatrização, tempo para completar a cicatrização, infecção, redução da área, dor e qualidade de vida. Foram seguidas as recomendações do Instituto Joanna Briggs, o protocolo foi publicado (JBISRIR-2017-003400R1) e registrado no PROSPERO (CRD42018100125). Incluíram-se ensaios clínicos randomizados (ECR), publicados em inglês, português e espanhol, a partir de 1960. Os estudos foram identificados por meio da busca nas bases de dados MEDLINE/PUBMED, EMBASE, CINAHL, LILACS, WEB OF SCIENCE; banco de teses e dissertações e plataformas de registros de ECR. A qualidade da evidência foi classificada com base no sistema GRADE. Identificaram-se 992 estudos, após a aplicação dos critérios de elegibilidade por dois revisores independentes; 41 estudos foram incluídos, desses 7 inclusos à metanálise. Os produtos de matriz foram organizados em três categorias (Colágeno, Biocelulose e Outras matrizes) e dez subcategorias. No desfecho cicatrização, comparado à cobertura não-aderente, na subcategoria colágeno humano, a metanálise favoreceu o grupo colágeno humano de camada dérmica, porém, sem significância estatística (RR=1,21; IC95%:0,91-1,60; p=0,20), heterogeneidade baixa (I2= 28%). Na subcategoria colágeno suíno, o percentual de cicatrização foi, significativamente, maior para o grupo colágeno suíno (RR=1,57; IC95%:1,18-2,09; p=0,002), heterogeneidade baixa (I2=0%). Na subcategoria biocelulose bacteriana, houve diferença significativa no percentual de cicatrização entre os grupos, porém, sem significância estatística (RR=0,74; IC:95%:0,37-1,48; p=0,39), heterogeneidade baixa (I2=0%). No desfecho infecção, na subcategoria colágeno humano, o resultado da metanálise favoreceu o colágeno humano, porém, sem significância estatística (RR=0,92; IC 95%:0,64-1,31; p=0,64), heterogeneidade baixa (I2=0%). Embora as matrizes tenham demonstrado superioridade, em alguns dos demais desfechos, como: tempo para completar a cicatrização, redução da área, dor e qualidade de vida, as evidências ainda são limitadas ou muito limitadas, em decorrência de viés metodológico e imprecisão, levando à certeza baixa ou muito baixa, atribuídas aos estudos, conforme julgamento por meio do GRADE. Entretanto, não houve evidências que refutassem a aplicação dessas tecnologias de matriz nas úlceras vasculogênicas. Recomenda-se, dessa forma, a realização de novos estudos que poderão alterar a confiança na estimativa de efeito e, portanto, o grau de certeza destes achados.

Abstract: Vasculogenic ulcers (venous, arterial and mixed) are a type of chronic wound, presenting high prevalence rates and global incidence, they are recurrent, alter the quality of life, susceptible to complications, such as infection, and generate high costs for the service providers. In chronic wounds, high levels of metalloproteinases, in the inflammatory phase, destroy essential extracellular matrix (ECM) proteins, impede cell adhesion, angiogenesis, ECM degrades and delays healing. Matrix technologies stimulate the components or replace the damaged extracellular matrix to optimize healing. This systematic review aimed to synthesize evidence of the diversity of matrix technologies (origin, source and composition), applied as topical coverages and agents in the treatment of vasculogenic ulcers in adults, from 18 years of age, in any care environment. The outcomes were: healing, time to complete healing, infection, reduction of area, pain and quality of life. The recommendations of the Joanna Briggs Institute were followed, the protocol was published (JBISRIR-2017- 003400R1) and registered in PROSPERO (CRD42018100125). It were included Randomized Controlled Trials (RCTs), published in English, Portuguese and Spanish, published from 1960. The studies were identified through the search in the databases MEDLINE/PUBMED, EMBASE, CINAHL, LILACS, WEB OF SCIENCE; bank of theses, dissertations, and platforms of records of RTCs. The quality of the evidence was classified based on the GRADE system. Two independent reviewers identified 992 studies following the eligibility criteria; 41 studies were included, of these 7 included in the metaanalysis. The matrix products were organized into three categories (Collagen, Biocellulose and Other Matrices) and ten subcategories. In the outcome "healing", compared to the non-adherent coverages, in the subcategory human collagen, the meta- analysis favored the human collagen group of the dermal layer, but without statistical significance (RR = 1.21, 95% CI: 0.91-1.60; p = 0.20), low heterogeneity (I 2 = 28%). In the subcategory pig collagen, the percentage of healing was significantly higher for the pig collagen group (RR = 1.57, 95% CI: 1.18-2.09, p = 0.002), low heterogeneity (I 2 = 0%). In the subcategory bacterial biocellulose, there was a significant difference in the percentage of healing between the groups, however, without statistical significance (RR = 0.74, CI: 95%: 0.37-1.48, p = 0.39), low heterogeneity (I 2 = 0%). In the outcome "infection", in the subcategory of human collagen, the results of the meta- analysis favored human collagen, but, without statistical significance (RR = 0.92, 95% CI: 0.64-1.31, p = 0.64), heterogeneity low (I 2 = 0%). Although the matrices have shown superiority, in some of the other outcomes, such as: time to complete healing, reduction of area, pain and quality of life, the evidence is still limited or very limited, due to methodological bias and imprecision, leading to low or very low confidence, attributed to the studies, according to GRADE judgment. However, there was no evidence to refute the application of these matrix technologies in vasculogenic ulcers. Therefore, it is recommended to carry out new studies that may after the confidence in the effect estimate and, therefore, the degree of certainty of these findings.

[An integral view of cancer (I). The study, classification and reprogramming of the tumoral microclimate]. / Una visión integral del cáncer (I). Microambiente tumoral: estudio, clasificación y reprogramación.

The group of diseases that we call cancer share a biological structure formed by a complex ecosystem, with altered intercellular communication, information fields, development and tissue function. Beyond the genetic alterations of the tumor cell, the demonstration of an altered ecosystem, with interconnections at systemic levels, opens up a new perspective on cancer biology and behavior. Different tumor facets, such as morphology, classification, clinical aggressiveness, prognosis and response to treatment now appear under a comprehensive vision that offers a new horizon of study, research and clinical management. The Somatic Mutation Theory in cancer, in force for more than one hundred years, is now completed by the study of the tumor microenvironment, the extracellular matrix, the stromal cells, the immune response, the innervation, the nutrition, the mitochondria, the metabolism, the interstitial fluid, the mechanical and electromagnetic properties of the tissue and many other areas of emerging knowledge; thus opening the door to a reprogramming exercise of the tumor phenotype through the modification of the keys offered by this new paradigm. Its recognition makes it possible to go from considering the oncological process as a cellular problem to a supracellular alteration based on the disorganization of tissues, immersed in the relationships of the complex system of the living being.

Identificação das proteínas interagentes de Yes-Associated protein (YAP), um efetor da via Hippo, em células epiteliais mamárias expostas à matriz extracelular rica em laminina / Identification of interacting proteins of Yes-Associated Protein (Yap) in mammary epithelial cells exposed to laminin-rich extracellular matrix

A sinalização da matriz extracelular (MEC) é essencial para a determinação do destino e comportamento de células epiteliais da glândula mamária. Entretanto, pouco é conhecido sobre os mecanismos moleculares envolvidos nesse processo. A via Hippo, uma cascata de sinalização que participa da regulação de diversos comportamentos celulares, incluindo o tamanho de órgãos, parece ser uma importante candidata a mediadora sinalização da MEC. Resultados preliminares do laboratório indicam que a arquitetura tecidual e a membrana basal, componente da MEC de epitélios e outros tecidos, influenciam a localização, concentração e atividade de YAP, uma proteína efetora da via Hippo, em células epiteliais mamárias. Neste contexto, o objetivo deste trabalho foi identificar as proteínas que interagem com Yap (ortólogo de YAP em camundongo) nas células epiteliais da glândula mamária em resposta à membrana basal. Foram utilizadas células EpH4, uma linhagem mamária não-tumoral murina, como modelo de diferenciação funcional e formação de ácinos em um ensaio de cultura tridimensional (3D). O tratamento de estruturas multicelulares 3D pré-formadas em placas nãoadesiva com uma matriz rica em laminina (lrECM) alterou a localização e o padrão subcelular de Yap, assim como a expressão gênica de membros da via Hippo e dos alvos de Yap, mas não alterou a expressão das proteínas da via em nível de proteína. O ensaio de co-imunoprecipitação (CoIP) seguida de análise por espectrometria de massas identificou um conjunto diferencial de proteínas que interagem com Yap na fração citoplasmática de células EpH4 cultivadas na ausência ou na presença de lrECM em um modelo de ECM-overlay. Uma análise realizada junto à database KEGG Pathways revelou que os possíveis interagentes Yap nas células cultivadas não-tratadas com lrECM participam de processos relacionados à proteólise mediada por ubiquitina, enquanto nas células expostas à lrECM os possíveis interagentes estão associados a processos metabólicos e são especialmente proteínas-chave do metabolismo de lipídios. A busca na plataforma de redes de interação STRING não identificou trabalhos que destaquem a interação de Yap com estas proteínas. A plataforma Vizit indica a participação de Yap em processos relacionados à síntese e atividade de lipídios e hormônios, o que reforça as evidências de que está pode ser uma nova função de Yap ainda não explorada em detalhes. A fim de se obter resultados complementares à CoIP, padronizamos o ensaio de identificação por biotinilação dependente de proximidade (BioID) em células embrionárias de rim humano da linhagem 293FT. As proteínas isoladas por pulldown foram identificadas por espectrometria de massas e uma análise junto à database Gene Ontology indicou que os possíveis interagentes de Yap nestas células são em sua maioria proteínas relacionadas à via Hippo, o que reforça a robustez do ensaio. Nós pretendemos transpor este sistema para as células EpH4. A expectativa é que, em conjunto, estes resultados nos orientem em projetos futuros para compreender os mecanismos de sinalização da MEC na morfogênese e diferenciação da glândula mamária

Extracellular matrix (ECM)-signaling is crucial for determination of epithelial cell fate and behavior in the mammary gland. However, little is known about the molecular mechanisms involved in these processes. The Hippo pathway, a signaling cascade involved in the regulation of several cellular processes, including organ size, seems to be an important candidate as a mediator of this signaling. Our preliminary results indicate that the tissue architecture and the basement membrane, an ECM component of epithelia and other tissues, influence the location, level and activity of YAP, an effector of the Hippo pathway. In this context, the goal of this work was to identify the proteins that interact with Yap (ortholog of YAP in mouse) in mammary epithelial cells in response to the basement membrane. We used EpH4 cells, a nontumoral murine mammary cell, in a functional differentiation and acini-forming in tridimensional (3D) culture assay. Treatment of 3D multicellular structures pre-formed on nonadhesive plates with a laminin-rich extracellular matrix (lrECM) altered the subcellular localization and pattern of Yap, as well as gene expression of Hippo pathway proteins and Yap targets, but did not altered the expression of the pathway members at the protein level. Coimmunoprecipitation (CoIP) followed by mass spectrometry analysis identified a differential set of proteins interacting with Yap in cytoplasmic fractions of EpH4 cells in the absence or presence of lrECM in an ECM-overlay culture model. An analysis performed with the KEGG Pathways database revealed that putative Yap interactors in non-treated cells participate in processes related to ubiquitin-mediated proteolysis, whereas in cells exposed to lrECM Yap interactors are associated to metabolic processes and are mainly key-proteins of metabolism of lipids and carbohydrates. A search in interaction networks platform STRING did not identify previous works that showing the interaction of Yap with these proteins. Vizit platform indicated the participation of Yap in processes related to the synthesis and activity of lipids and hormones, which reinforces the evidences that Yap can play a novel poorly explored role. To obtain complementary results to CoIP, we devised the proximity-dependent biotinylation identification (BioID) assay on embryonic renal cells of 293FT cell line. Pulldown-isolated proteins were identified by mass spectrometry and an analysis performed with Gene Ontology database revealed that putative Yap interactors are Hippo pathway-related proteins, which reinforces the robustness of the assay. We intend to transpose this system to the EpH4 cells. We expect that, together, these results will guide us in future projects to understand the signaling mechanisms of ECM in mammary gland morphogenesis and differentiation