Epithelial-mesenchymal transition (EMT) regulates the cellular processes of migration, growth, and proliferation - as well as the collective cellular process of tissue remodeling - in response to mechanical and chemical stimuli in the cellular microenvironment. Cells of the epithelium form cell-cell junctions with adjacent cells to function as a barrier between the body and its environment. By distributing localized stress throughout the tissue, this mechanical coupling between cells maintains tensional homeostasis in epithelial tissue structures and provides positional information for regulating cellular processes. Whereas in vitro and in vivo models fail to capture the complex interconnectedness of EMT-associated signaling networks, previous computational models have succinctly reproduced components of the EMT program. In this work, we have developed a computational framework to evaluate the mechanochemical signaling dynamics of EMT at the molecular, cellular, and tissue scale. First, we established a model of cell-matrix and cell-cell feedback for predicting mechanical force distributions within an epithelial monolayer. These findings suggest that tensional homeostasis is the result of cytoskeletal stress distribution across cell-cell junctions, which organizes otherwise migratory cells into a stable epithelial monolayer. However, differences in phenotype-specific cell characteristics led to discrepancies in the experimental and computational observations. To better understand the role of mechanical cell-cell feedback in regulating EMT-dependent cellular processes, we introduce an EMT gene regulatory network of key epithelial and mesenchymal markers, E-cadherin and N-cadherin, coupled to a mechanically-sensitive intracellular signaling cascade. Together these signaling networks integrate mechanical cell-cell feedback with EMT-associated gene regulation. Using this approach, we demonstrate that the phenotype-specific properties collectively account for discrepancies in the computational and experimental observations. Additionally, mechanical cell-cell feedback suppresses the EMT program, which is reflected in the gene expression of the heterogeneous cell population. Together, these findings advance our understanding of the complex interplay in cell-cell and cell-matrix feedback during EMT of both normal physiological processes as well as disease progression.

Understanding the mechanisms of cardiovascular disease progression is essential in developing novel therapies to combat this disease that contributes to 1 in 3 deaths in the United States every year. Endothelial dysfunction and its effects on vessel growth and remodeling are key factors in the progression and localization of atherosclerosis. Much of our understanding in this area has come from in-vivo and in-vitro experiments however perfused organ culture systems provide an alternative approach. Organ culture systems can provide a more controlled mechanical and biochemical environment compared to in-vivo models. This study focused on furthering development of this organ culture model by introducing a novel device to produce flow waveforms at the high frequencies and low mean flows seen in the mouse model. The device is capable of monitoring pressure, flow, diameter, and nitric oxide release. Each individual mechanism in the system was integrated via a computer using a custom Labview interface. The performance of the device was characterized by developing physiologic, physiologic-oscillatory, low, low-oscillatory waveforms and sinusoidal waveforms at frequencies ranging from 1-10 Hz. Overall this system provides a robust model to test the effects of flow on various biological markers both in real-time and after culture.

In cellular MRI, micrometer-sized iron oxide particles (MPIO) are a more sensitive contrast agent for tracking inflammatory-cell migration compared to ultra-small superparamagnetic iron oxide particles (USPIO). Inflammation, which promotes adverse tissue remodeling, is known to occur in the viable myocardium adjacent to the necrosed area after a myocardial infarction (MI). This study investigated the temporal relationship between inflammatory cell infiltration and cardiac function during tissue remodeling post-MI using MPIO-enhanced MRI. The MPIO were injected into 7 C57Bl/6 mice (MI+MPIO group) via intravenous administration. The MI was induced 7 days post-MPIO injection. As control groups, 7 mice (Sham+MPIO group) underwent sham-operated surgery without myocardial injury post-MPIO injection and another 6 mice (MI-MPIO group) underwent MI surgery without MPIO injection. MRIs performed post-MI showed a significant signal attenuation at the MI zone in the MI+MPIO group compared to the control groups. The findings suggested that the inflammatory cells containing MPIO infiltrated into the myocardial injury site. Cardiac function was also measured and correlated with the labeled-cell infiltration at the MI site. This study demonstrated a noninvasive technique for monitoring inflammatory cell migration using the MPIO contrast agent. This MPIO-enhanced MRI technique could provide additional insight concerning cardiac disease progression that would improve therapeutic treatment for MI patients.

Arteries respond to changes in global mechanical parameters (pressure, flow rate, and longitudinal stretching) by remodeling to restore local parameters (circumferential stress, shear stress, and axial strain) to baseline levels. Because a change in a single global parameter results in changes of multiple local parameters, the effects of individual local parameters on remodeling remain unknown. This study uses a novel approach to study remodeling in organ culture based on independent control of local mechanical parameters. The approach is illustrated by studying the effects of circumferential and shear stress on remodeling-related biological markers. Porcine carotid arteries were cultured for three days at a circumferential stress of 50 kPa or 150 kPa or, in separate experiments, a shear stress of 0.75 Pa or 2.25 Pa. At high circumferential stress, matrix synthesis, smooth muscle cell proliferation, and cell death are significantly greater, but matrix metalloproteinase-2 (MMP-2) and pro-MMP-2 activity are significantly less. In contrast, biological markers measured were unaffected by shear stress. Applications of the proposed approach for improved understanding of remodeling, optimizing mechanical conditioning of tissue engineered arteries, and selection of experimentally motivated growth laws are discussed.

A doença venosa crônica (DVC) é uma desordem complexa que compreende sinais e sintomas que variam das telangiectasias às úlceras ativas. A DVC é classificada de acordo com aspectos clínicos, etiológicos, anatômicos e fisiopatológicos (CEAP) em sete classes variando de C0 à C6. A principal causa da DVC é a hipertensão venosa que altera o fluxo venoso e, consequentemente, a força de cisalhamento que induz alterações fenotípicas nas células endoteliais que passam a expressar mediadores pró-inflamatórios e pró-trombóticos, que levam à adesão de leucócitos, ao aumento do estresse oxidativo, da permeabilidade vascular e do dano endotelial e ao remodelamento tecidual e vascular.Em virtude dos inúmeros mecanismos e da diversidade de moléculas envolvidas na patogênese e progressão da DVC, é essencial conhecer a interação entre elas e também saber quais são as moléculas (biomarcadores) que se correlacionam positivamente ou negativamente com a gravidade da doença. Foram avaliados os níveis de Interleucina-6 (IL-6), sL-selectina, sE-selectina, sP-selectina, molécula de adesão intercelular-1solúvel (sICAM-1), molécula de adesão das células vasculares-1 solúvel (sVCAM-1), ativador tecidual do plasminogênio (tPA), atividade do inibidor do ativador do plasminogênio-1 (PAI-1), trombomodulina solúvel (sTM), fator de von Willebrand (vWF), metaloproteinase de matriz (MMP)-2, MMP-3, MMP-9, inibidor tecidual das MMPs -1 (TIMP-1), angiopoietina-1 e -2, sTie-2 e s-Endoglina e fator de crescimento do endotélio vascular (VEGF) no sangue coletado da veia braquial de 173 mulheres com DVC primária divididas em grupos C2, C3, C4 e C4 menopausadas (C4m) e de 18 voluntárias saudáveis (grupo C0a). Foram também analisados os níveis urinários de ent-prostaglandina F2α nesses grupos. Não foram encontradas diferenças estatisticamente significativas com relação às concentrações sanguíneas e urinárias de sE-selectina, sP-selectina, sICAM-1, atividade de PAI-1, MMP-3, razão TIMP-1/MMP-3, angiopoietin-2, razão angiopoietina-1/angiopoietina-2, s-Endoglina e ent-prostaglandina F2α entre os grupos estudados, possivelmente devido à alta variabilidade na concentração desses biomarcadores entre as participantes do mesmo grupo. Entretanto, as concentrações sanguíneas de IL-6 sL-selectina, sVCAM-1, tPA, vWF, sTM, MMP2, MMP-9, TIMP-1, razão TIMP-1/MMP-2, razão TIMP-1/MMP-9, angiopoietina-1 e VEGF foram estatisticamente diferentes entre os grupos. Não foi identificado nenhum biomarcador que se correlacionasse diretamente ou inversamente com a progressão da DVC, provavelmente devido à diversidade de fatores envolvidos e à complexa interação entre eles durante o curso da doença. / Chronic Venous Disease (CVD) is a complex disorder, which encompasses signs and symptoms that vary from telangiectasias to active ulcers. The CVD is classified according Clinical, Etiologic, Anatomical and Pathophysiological (CEAP) aspects into seven classes varying from C0 to C6. The main cause of CVD is venous hypertension, which alters venous flow and consequently, shear stress. Abnormal shear stress induces phenotypic changes in endothelial cells that start to express pro-inflammatory and pro-thrombotic mediators that lead to leukocyte adhesion, oxidative stress, increased vascular permeability and endothelial cell damage and tissue and vascular remodeling. Due to several mechanisms and the diversity of molecules involved in the pathogenesis and progression of CVD, is essential to know the interplay between them and which are the molecules (biomarkers) that correlate positively and negatively with the severity of the disease. We investigated the levels of interleukin-6 (IL-6), sL-selectin, sE-selectin, sP-selectin, soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) activity, soluble thrombomodulin (sTM), von Willebrand factor (vWf), matrix metalloproteinase (MMP)-2, MMP-3, MMP-9, tissue inhibitor of metaloproteinases-1 (TIMP-1), angiopoietin-1 and -2, sTie-2, s-Endoglin, vascular endothelial growth factor (VEGF) in the blood taken from the brachial vein of 173 patients with primary CVD divided into C2, C3, C4 and menopaused C4 (C4m) groups and 18 healthy volunteers (C0a group).We also investigated the urinary levels of ent-prostaglandin F2α in these groups. There was no statistically significant difference between groups with respect to blood or urinary levels of sE-selectin, sP-selectin, sICAM-1, PAI-1 activity, MMP-3, TIMP-1/MMP-3 ratio, angiopoietin-2, angiopoietin-1/angiopoietin-2 ratio, s-Endoglin and ent-prostaglandin F2α, likely due to the high variability of these biomarkers concentration among participants within the same group. However, blood levels of IL-6, sL-selectin, sVCAM-1, tPA, vWF, sTM, MMP-2, MMP-9, TIMP-1, TIMP-1/MMP-2 ratio, TIMP-1/MMP-9 ratio, angiopoietin-1 and VEGF were statistically different between groups. It was not identified any biomarker that correlated directly or inversely with the progression of CVD, probably due to the diversity of factors involved and the complex interplay between them in the course of the disease.

Made available in DSpace on 2016-06-02T19:22:53Z (GMT). No. of bitstreams: 1 3146.pdf: 7150693 bytes, checksum: cd6c8d53b2bd8f45e723e67ca13309e2 (MD5) Previous issue date: 2010-03-12 / Financiadora de Estudos e Projetos / Tendons remodeling relies upon extracellular matrix restructuring by the matrix metalloproteinases (MMPs). The aim of this study was to investigate MMP-2 activity in different regions of the calcanear tendon after resistance training in ovariectomized rats. Wistar adult female rats were grouped into: sedentary (Sed-Intact); ovariectomized sedentary (Sed-Ovx); acute exercise (AcuteEx-Intact); ovariectomized acute exercise (AcuteEx-Ovx); resistance trained (ChronicEx-Intact) and ovariectomized resistance trained (ChronicEx-Ovx) (n= 10 each group). The resistance training protocol required the animals to climb a 1.1-m vertical ladder with weights attached to their tail was used. The sessions were performed once every 3 days with 4-9 climbs and 8-12 dynamic movements per scaling. The acute groups performed one session, and the chronic groups underwent a 12-week of resistance training. There was an increase in total MMP-2 activity in Sed- Ovx, AcuteEx-intact and ChronicExintact compared with Sed-Intact in the proximal region of calcanear tendon. AcuteEx-Ovx exhibited higher total MMP-2 than Sed-Ovx and AcuteEx-Intact in the distal region of calcanear tendon. Chronic-Ovx presented lower total MMP-2 activity than Sed-Ovx and Chronic-Intact in the distal region of tendon. The active MMP-2 was higher for the AcuteEx- Ovx than Sed-Ovx and AcuteEx-Intact in proximal region of tendon. There was higher active MMP-2 in the distal region of tendon in the Acute-Ovx than Sed-Ovx and AcuteEx-Intact. Ovariectomy and resistance exercise modulate MMP-2 activity according to specific tendon region, indicating a differentiated tissue remodeling. / O remodelamento dos tendões depende da re-estruturação da matriz extracelular realizada pelas metaloproteinases de matriz (MMPs). O objetivo deste estudo foi investigar a atividade da MMP-2 em diferentes regiões do tendão calcâneo de ratas após ovariectomia e treinamento resistido. Ratas adultas Wistar foram agrupadas em: sedentário (Sed-Intacto); sedentário ovariectomizado (Sed-Ovx); exercício agudo (AgudoEx-Intacto); exercício agudo e ovariectomizado (AgudoEx-Ovx); treinado resistido (CrônicoEx-Intacto) e ovariectomizado treinado resistido (CrônicoEx-Ovx) (n= 10 por grupo). O protocolo de treinamento resistido exigiu a escalada dos animais em uma escada vertical de 1.1 metros com pesos atados a suas caudas. A sessão foi realizada uma vez a cada três dias de 4 a 9 escaladas com 8 a 12 movimentos dinâmicos em cada escalada. Cada sessão de treinamento consistia de no mínimo quatro escalas, com 50%, 75%, 90% e 100% da capacidade máxima de carregamento do animal, determinada anteriormente. Durante as escaladas subseqüentes (máximo de cinco escaladas) eram adicionados 30g até que uma nova capacidade máxima de carregamento fosse atingida. Os grupos agudos realizaram apenas uma sessão e os animais dos grupos crônicos foram submetidos a 12 semanas de treinamento resistido. Foi observado na região proximal do tendão calcâneo aumento da atividade total da MMP-2 no Sed-Ovx, AgudoEx-Intacto, CrônicoEx-Intacto comparados com o Sed-Intacto (p≤0,05). Na região distal do tendão calcâneo, o AgudoEx-Ovx exibiu maior atividade da MMP-2 total do que Sed-Ovx e AgudoEx-Intacto (p≤0,05). O CrônicoEx-Ovx apresentou na região distal do tendão calcâneo menor atividade total da MMP-2 em relação ao Sed-Ovx e CrônicoEx-Intacto (p≤0,05). O AgudoEx-Ovx apresentou na região proximal e distal do tendão calcâneo maiores valores na forma ativa da MMP-2 comparado ao Sed-Ovx e AgudoEx-Intacto (p≤0,05). Ovariectomia e treinamento resistido modulam a atividade da MMP-2 de acordo com a região específica do tendão calcâneo.

Orientadores: Paulo Pinto Joazeiro, Stephen Hyslop / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-17T23:19:29Z (GMT). No. of bitstreams: 1 Rosa_RenataGiardini_D.pdf: 6665917 bytes, checksum: bfaa430fcdeef027dd2744caa78df851 (MD5) Previous issue date: 2010 / Resumo: A remodelação que a sínfise púbica (SP) sofre durante a prenhez, parto e pós-parto é um dos eventos importantes para o parto normal, e ocorre no trato reprodutor feminino como útero, cérvice uterina e sínfise púbica em alguns mamíferos. Durante a prenhez de alguns roedores ocorre um acentuado processo de remodelação da sínfise púbica (SP). No camundongo, esta articulação fibrocartilaginosa é gradativamente modificada, formando o ligamento interpúbico (LI) da etapa final da prenhez. Logo após o parto, este ligamento é rapidamente remodelado e o espaço entre os ossos púbicos se fecha, por volta do quinto dia pós-parto. Contudo, alterações no metabolismo celular durante o relaxamento da sínfise púbica do camundongo durante a prenhez, parto e pós-parto não foram extensivamente estudadas. Neste trabalho, foram utilizadas sínfises de camundongos virgens (V) e de animais prenhes como também no pós-parto. Os experimentos evidenciaram que as enzimas Metaloproteinases (MMPs) -2, -9, Tissue Inhibitors of Metalloproteinases (TIMPs) -1, -2 assim como as catepsinas B e K foram detectadas em todos os dias estudados. Por meio do Western Blotting foi observado que a MMP-8 teve sua maior expressão protéica no (12º Dia de prenhez) D12, onde as modificações da sínfise em ligamento se iniciam. Através da zimografia foi possível observar que as MMPs -2 e -9 tiveram suas atividades mais evidentes no início das modificações decorrentes da prenhez no D12, D15. Estas MMPs ainda se mantiveram em níveis mais altos de expressão/atividade até o final da prenhez quando comparados com o animal virgem. As catepsinas tiveram sua expressão mais alta no final da prenhez, porém a catepsina B não foi detectada em sua forma ativa sugerindo participação no processo de remodelação da sínfise, porém não tão significativa do que as MMPs. O teste de solubilidade evidenciou um aumento no conteúdo de água não significativo durante a prenhez com um ápice significativo durante o parto D19 quando comparado com o animal não prenhe. O conteúdo de colágeno não se alterou e nem a solubilidade do colágeno demonstrou modificações significativas durante a prenhez, excetuando-se o 24HPP (horas pós-parto) em relação a solubilidade de colágeno. O Western blotting demonstrou que tanto a concentração do colágeno I, da molécula C-propeptídeo e do Decorin não se alteraram significativamente durante a prenhez, parto e pós-parto. O FACE (Fluorophore-assisted carbohydrate electrophoresis) evidenciou aumento qualitativo de moléculas AH (Ácido Hialurônico) de maiores pesos moleculares no ligamento interpúbico no final da prenhez. Este ensaio permitiu observar que não há quebra de moléculas de AH durante a prenhez e pós-parto, como é observado na cérvice uterina. Quantitative real-time PCR (QRT-PCR) evidenciou alta expressão relativa do Hyaluronic acid synthases (Has) 1 e 2 diferente das hialuronidases que tiveram sua expressão relativamente baixa. Estes dados são condizentes com aqueles que mostraram que o AH de alto peso molecular encontrado na sínfise púbica do camundongo não sofreu digestão enzimática. Dentre os proteoglicanos, o Versican foi altamente expresso juntamente com Adamts 1 e 2 que estão envolvidas em sua ativação. De modo geral, a remodelação é facilitada por mudanças nas regulações traducionais, pós-traducionais de efetores multifuncionais que participam ativamente da remodelação da MEC (Matriz Extracelular) in vivo. A identificação de etapas finamente reguladas na maturação de componentes celulares e da matriz poderá proporcionar avanços no entendimento de processos que ocorrem na preparação para a parturição normal, como também prevenir disfunções da sínfise púbica durante a parturição / Abstract: The remodeling that the pubic symphysis (PS) goes through pregnancy, parturition and post-partum is an important event for normal birth, and occurs in the female reproductive tract such as uterus, cervix and pubic symphysis in some mammals. During pregnancy of some rodents an acentuated remodeling process occurs in the PS. In mice, this fibrocartilaginous joint is gradually modify, forming the interpubic ligament (IpL) by the end of pregnancy. Right after birth, this ligament is rapidly restored and the gap between the pubic bones closes, around the fifth day postpartum. However, changes in cellular metabolism during relaxation of the pubic symphysis of mice during pregnancy, birth and postpartum has not been extensively studied. In this work, we used symphysis of virgin mice and interpubic ligaments of pregnant animals as well as postpartum. The experiments showed that the enzymes Metalloproteinases (MMPs) -2, -9, Tissue Inhibitors of Metalloproteinases (TIMPs) -1, -2 as well as cathepsins B and K were detected at all studied days. By Western blotting it was observed that MMP-8 was most expressed on 12º Day of pregnancy (D12), where the pubic symphysis changes into changes ligament begin. The zymography observed that MMPs -2 and -9 activities were more evident in early pregnancy D12, D15. These MMPs remained at higher levels of expression/activity until the end of pregnancy when compared to virgin animal. Cathepsins had its highest expression in late pregnancy, but cathepsin B was not detected in its active form suggesting involvement in the remodeling of the symphysis, but not as significant as MMPs. The solubility test showed an increase in water content that was not significant during pregnancy with a significant peak during birth D19 compared to the non-pregnant animal. The collagen content did not change and neither the solubility of collagen showed significant changes during pregnancy excepting the 24HPP (hours postpartum) in respect to the solubility of collagen. Western blotting analysis showed that both type I collagen, the molecule Cpropeptide and decorin did not change significantly during pregnancy, birth and postpartum. FACE (fluorophore-assisted carbohydrate electrophoresis) showed a qualitative increase of HA molecule (Hyaluronic Acid) from higher molecular weights in the interpubic tissue at the end of pregnancy. This essay has observed that there is no breaking down of HA during pregnancy and postpartum, as observed in the uterine cervix. Quantitative real-time PCR (QRT-PCR) revealed high relative expression of Hyaluronic acid synthases (Has) 1 and 2 different from hyaluronidase that had relatively low expression. These data are consistent with those that showed high molecular weight of HA found in the pubic symphysis of mice suffered no brakes. Among the Proteoglycans, Versican was highly expressed along with ADAMTS 1 and 2 that are involved in its activation. In general, the remodeling is facilitated by changes in translational, post-translational regulations of multifunctional effectors that participate actively in the remodeling of ECM (extracellular matrix) in vivo. The identification of finely regulated steps in the maturation of cellular components and matrix could provide breakthroughs in the understanding of processes that occur in preparation for normal birth, but also prevent dysfunctions with the PS during parturition / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-04-26T15:54:34Z No. of bitstreams: 1 klausrubackbertges.pdf: 2812002 bytes, checksum: 85312f3aa11372affe21388fe45dce43 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-04-27T11:52:01Z (GMT) No. of bitstreams: 1 klausrubackbertges.pdf: 2812002 bytes, checksum: 85312f3aa11372affe21388fe45dce43 (MD5) / Made available in DSpace on 2018-04-27T11:52:01Z (GMT). No. of bitstreams: 1 klausrubackbertges.pdf: 2812002 bytes, checksum: 85312f3aa11372affe21388fe45dce43 (MD5) Previous issue date: 2018-03-21 / A esofagite eosinofílica vem tendo uma importância crescente na literatura médica. É uma doença inflamatória crônica, imunoantígeno mediada, caracterizada por sintomas de disfunção esofágica e uma infiltração predominantemente eosinofílica na mucosa do esôfago. O diagnóstico histopatológico é definido pela presença de 15 ou mais eosinófilos por campo de grande aumento e o tratamento de cada paciente deve ser individualizado. O processo de remodelamento do esôfago na esofagite eosinofílica ainda não está completamente esclarecido, mas parece envolver a presença de fibrose na lâmina própria, sendo a grande responsável pelos sintomas de disfagia e impactação alimentar. A IL-13 contrarregula a expressão de filagrina nas células epiteliais, promovendo um mecanismo pelo qual antígenos alimentares ativam o sistema imunológico. Este estudo objetivou avaliar a prevalência das características histopatológicas de remodelamento tecidual e a expressão da filagrina em biópsias esofágicas de pacientes com esofagite eosinofílica. Foram avaliadas, retrospectivamente, 50 pacientes com suspeita clínica e/ou endoscópica de esofagite eosinofílica. Deste total, 27 foram selecionados e distribuídos em dois grupos: GI, com 15 a 24 eosinófilos por campo de grande aumento e GII, contendo mais de 24. Após a histomorfometria e imuno-histoquímica para filagrina, comparou-se os dois grupos. Nos parâmetros de fibrose, houve diferença estatisticamente significante, com maior prevalência no GII (p < 0,05). Também houve mais espessamento da camada basal no GII (p < 0,001). No estudo de correlação entre o número de eosinófilos e o percentual de fibrose, encontrou-se correlação positiva: 50,8% (p = 0,016), ou seja, mais fibrose nos casos do GII. Na correlação entre o número de eosinófilos e a espessura da camada basal, o resultado também foi positivo: 52,1% (p = 0,08), ou seja, membrana basal mais espessa no GII. A filagrina mostrou-se reduzida nos pacientes com esofagite eosinofílica. / Eosinophilic esophagitis is of increasing importance in the medical literature. It is a chronic inflammatory disease, mediated immunoantigen, characterized by symptoms of esophageal dysfunction and a predominantly eosinophilic infiltration in the esophagic mucosa. The histopathological diagnosis is defined by the presence of 15 or more eosinophils per large increase field and the treatment of each patient should be individualized. The process of esophageal remodeling into eosinophilic esophagitis is still not fully understood, but it seems to involve a presence of fibrosis in the lamina propria, being a major cause of the symptoms of dysphagia and food impaction. IL-13 counteracts the expression of filaggrin in epithelial cells, promoting a mechanism by which food antigens activate the immune system. This study aimed to evaluate a prevalence of the histopathological characteristics of tissue remodeling and the filaggrin expression in esophageal biopsies of patients with eosinophilic esophagitis. Fifty patients with clinical and/or endoscopic suspicion of eosinophilic esophagitis were retrospectively evaluated. Of these, 27 were selected and distributed in two groups: GI, with 15 to 24 eosinophils per large increase field and GII, containing more than 24. After a histomorphometry and immunohistochemistry for filaggrin, the two groups were compared. In the fibrosis parameters, there was a statistically significant difference, with a higher prevalence in GII (p < 0.05). There was also more thickening of the basal layer in GII (p < 0.001). The correlation study between the number of eosinophils and the percentage of fibrosis found a positive correlation: 50.8% (p = 0.016), that means, more fibrosis in cases of GII. In the correlation between the number of eosinophils and the thickness of the basal layer, the result was also positive: 52.1% (p = 0.08), that means, thicker basal layer in GII. Filaggrin was reduced in patients with eosinophilic esophagitis.

Les vésicules extracellulaires (VE), incluant exosomes et microparticules (MP), vecteurs d’information biologique, peuvent moduler la fonction de cellules cibles. Une élévation du taux de VE circulantes est observée dans les pathologies cardiovasculaires dont l’obésité est l’un des facteurs de risque majeur. Cependant, il existe peu de données concernant la production de VE adipocytaires et leur capacité à moduler le métabolisme des adipocytes. Tout d’abord, nous avons caractérisé de manière morphologique et biochimique les MP et les exosomes adipocytaires. Nous montrons une production accrue de ces VE dans un contexte d’obésité murine. L’analyse protéomique des VE adipocytaires révèle un enrichissement spécifique des MP et des exosomes en protéines clé du métabolisme énergétique et de l’inflammation, respectivement. Dans une seconde partie, nous avons étudié l’effet de MP lymphocytaires portant le morphogène Hedgehog (MPHh+) sur la différenciation adipocytaire. A l’instar d’une activation classique de la voie de signalisation Hh, les MPHh+ inhibent l’adipogenèse. Bien que dépendant du récepteur Smoothened (Smo), cet effet inhibiteur est indépendant des facteurs de transcription Gli. Nous montrons que les MPHh+ activent un axe anti-adipogénique Smo/Lkb1/Ampk pouvant être stimulé par un nouvel agoniste de Smo, le GSA-10. Nos résultats démontrent, d’une part, la capacité des adipocytes à sécréter des VE, et d’autre part, le potentiel fonctionnel des MPHh+ à inhiber l’adipogenèse par une voie de signalisation Hhnon-canonique. Les VE pourraient contribuer aux dysfonctions métaboliques associées à l’obésité en véhiculant des messages métaboliques à l’échelle de l’organisme. / Extracellular vesicles (EV), including microparticles (MP) and exosomes, are able to modulate target cell function through exchange or transfer of biological material. Although EV are present in the blood of healthy individuals, an elevated quantity of circulating EV is associated with cardiovascular diseases, which obesity is a major cardiovascular risk factor. Nevertheless, few studies have reported the ability of adipocytes to release EV and their implication in adipose tissue metabolism. First of all, we could determine morphological and biochemical features of adipocyte-derived exosomes and MP through a combination of methods. We were able to demonstrate an increase in adipocyte EV production in a murine model of obesity. Proteomic analysis of adipocyte EV further revealed a specific enrichment of proteins crucial for glucose and lipid metabolism and related to inflammation in MP and exosomes respectively. We then evaluated the ability of lymphocytes-derived MP harboring the Sonic Hedgehog morphogen to control adipocyte differentiation. Activation of the Hedgehog canonical pathway inhibited adipogenesis, as did MPHh+. Surprisingly, although Smo dependent, inhibitory potential of such MP did not involve the Gli transcription factors. We show that MPHh+ inhibit adipocyte differentiation through a Smo/Lkb1/Ampk axis as does a new agonist of Smo, GSA-10. Our results demonstrate, on one hand, the ability of adipocyte to release EV and on the other hand, the capacity of MPHh+ to control adipogenesis through a non-canonical Hh signaling pathway. In conclusion, EV might contribute to obesity related metabolic dysfunctions through systemic regulation of metabolic pathways.

Indiana University-Purdue University Indianapolis (IUPUI) / Rationale: Tissue remodeling and complement activation are asthma hallmarks. Type V collagen [col(V)], a cryptic antigen, becomes exposed during lung remodeling. IL-17 is key to anti-col(V) immunity, and regulates complement activation. We have reported that col(V)-induced tolerance down regulates IL-17 and prevents immune-mediated lung diseases. Objectives: Determine a role for anti-col(V) immunity in asthma. Methods: Serum anti-col(V) antibodies were measured in asthma patients, and immunohistochemistry utilized to detect interstitial col(V) in fatal asthma. Balb/c mice were tolerized with col(V) prior to sensitization with ovalbumin (OVA), and subsequent OVA intranasal challenge. Airway hyper-responsiveness (AHR) to methacholine was measured; and RT-PCR utilized to determine local Il17 transcripts. Bronchoalveolar lavage levels of C3a¸ C5a and OVA-specific IgE were measured; and immunohistochemistry utilized to detect expression of complement regulatory proteins, expression, CD46/Crry and CD55, in lung tissue. Results: Compared to normal subjects, anti-col(V) antibodies were increased in asthmatics; and interstitial col(V) was over expressed in fatal asthma. OVA-induced AHR up regulated anti-col(V) antibodies systemically, and increased OVA-specific IgE and C3a in BAL, and parenchymal Il17 transcripts. Col(V)-induced tolerance abrogated AHR, down regulated OVA-induced T cell proliferation, as well as total and OVA-specific IgE, C3a, IL-17 expression and tracheal smooth muscle contraction. Crry/CD46 and CD55, key to preventing complement activation, were down regulated on goblet cells in murine allergic airway disease. Conclusions: Anti-col(V) immunity correlates with asthma pathogenesis, and col(V)-induced tolerance may be a novel therapeutic for asthma. Decreased expression of Crry/CD46 and CD55 on goblet cells may in part account for complement activation in asthma.