A fibrose hepática é uma patologia que acompanha outras doenças crônicas do fígado como a cirrose e o hepatocarcinoma. As células estreladas hepáticas (HSC, do inglês hepatic stellate cells) compõem uma população celular heterogênea que se caracteriza por transitar entre dois fenótipos. As células com fenótipo quiescente possuem a capacidade de armazenar vitamina A em gotas lipídicas. Os insultos ao fígado desencadeiam uma resposta inflamatória que gera estímulos parácrinos e autócrinos mediados por citocinas e espécies reativas. Neste contexto, as HSC assumem um fenótipo ativado fibrogênico e tornam-se responsáveis pela cicatrização hepática. Danos crônicos ao fígado levam a uma deposição de matriz extracelular exagerada que configura o estado patológico da fibrose. O resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-estilbeno) é uma fitoalexina produzida por algumas espécies de plantas. Inúmeros efeitos benéficos à saúde são atribuídos ao RSV por causa do seu potencial antioxidante, antiinflamatório e pró-apoptótico. Estudos anteriores mostraram que tratamento da GRX, uma linhagem murina de HSC ativadas, com concentrações de RSV próximas as biodisponíveis (0,1 a 1 μM) resultou em parada do ciclo na fase S com consequente inibição de proliferação celular, um efeito associado à citotoxicidade e que pode favorecer a resolução da fibrose hepática. Neste estudo, por técnicas espectrofotométricas, foi demonstrado que tratamento da GRX por 24 horas com concentrações entre 0,1 a 50 μM de RSV promoveu um efeito pró-oxidante que causa uma citotoxicidade dependente da dose, bastante aumentada no grupo tratado com a concentração mais alta. Os efeitos citotóxicos atenuados encontrados nas células tratadas por 120 horas sugerem que a GRX pode se tornar resistente a estes efeitos. O potencial pró-oxidante do RSV foi o ponto de partida para investigar a possibilidade de que esta fitoalexina provocasse uma alteração no metabolismo mitocondrial da GRX. Para isso, os efeitos do RSV (1 a 50 μM) na função mitocondrial, na indução de morte mediada por estas organelas e na autofagia/mitofagia foram investigados por técnicas de espectrofotometria, de imunocitoquímica, de citometria de fluxo, de microscopia confocal e de microscopia eletrônica de transmissão em GRX tratadas por 24 e 120 horas. Foi demonstrado que todas as concentrações de RSV promovem apoptose por meio da ativação de caspases, alteram a dinâmica/função mitocondrial e induzem o aumento de autofagia/mitofagia na GRX. No entanto, o RSV provocou biogênese de mitocôndrias nos grupos tratados com 1 e 10 μM, enquanto que o tratamento com 50 μM causou dano celular evidente na GRX, sem induzir biogênese de mitocôndrias. Desta forma, é possível que a citotoxicidade “dose-dependente” do RSV, que causa a morte celular e dano oxidativo em 24 horas de tratamento, esteja relacionada com o desequilíbrio entre a indução concomitante de apoptose mediada por dano mitocondrial, autofagia/mitofagia e biogênese de mitocôndrias. Por fim, foi investigada a liberação de TNF-α, Interleucina-6 e Interleucina-10 pela GRX tratada por 24 e 120 horas com RSV (0,1 a 50 μM), considerando o papel antiinflamatório do RSV e o papel das HSC ativadas na sinalização autócrina que contribui para a modulação fenotípica destas células. Foi demonstrado que o tratamento da GRX com RSV por 24 e 120 horas induziu a redução da liberação de Interleucina-6; enquanto que a liberação de TNF-α e Interleucina-10 foi aumentada. Estes resultados confirmam um efeito antiinflamatório do RSV que deve contribuir na prevenção da ativação ou da perpetuação do estado ativado das HSC por meio de sinalização autócrina. Ainda que a concentração do RSV seja importante para efetivamente induzir a morte das HSC ativadas, o tratamento com esta fitoalexina pode ser promissor para a resolução da fibrose hepática por diminuir a população de células ativadas e, possivelmente, prevenir a perpetuação do estado fenotípico ativado. Estudos avaliando indicadores de quiescência em células tratadas são ainda necessários para desvendar completamente os efeitos do RSV quanto às possibilidades de inibição da perpetuação ou reversão fenotípica das HSC ativadas. / Liver fibrosis is a disease that accompanies other hepatic chronic diseases such as cirrhosis and hepatocellular carcinoma. Hepatic stellate cells (HSC) are a heterogeneous cell population characterized by transiting between two phenotypes. Cells with a quiescent phenotype are able to store vitamin A into lipid droplets. Damage to the liver trigger an inflammatory response that generates paracrine and autocrine stimulation mediated by cytokines and reactive species. In this context, HSC assume an activated and fibrogenic phenotype responsive for hepatic wound-healing. Chronic insults to the liver lead to an excessive deposition of extracellular matrix that configures the pathological state of fibrosis. Resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-stilbeno) is a phytoalexin produced by some species of plants. Several beneficial effects are attributed to this molecule due to its antioxidant, antiproliferative and pro-apoptotic potential. Previous studies showed that treatment with bioavailable concentrations of RSV (0.1 to 1 μM) promoted an arrest cycle at the S phase in GRX, a murine activated HSC model, leading to cell proliferation inhibition, a cytotoxic effect that contributes to the liver fibrosis resolution. In this study, it was shown by spectrophotometric techniques that GRX treatment for 24 hours at concentrations between 0.1 to 50 μM of RSV promoted a fairly clear pro-oxidant effect that causes a dose-dependent cytotoxicity that was higher in the group treated with 50 μM. The attenuated cytotoxicity found after 120 hours of GRX treatment suggest that these cells became resistant to this effect. The pro-oxidant potential of RSV was the starting point for investigating the possibility that this phytoalexin would cause a change in the GRX mitochondrial metabolism. Thus, the effects of RSV (1 to 50 μM) on altering the mitochondrial function, on inducing mitochondrial-mediated cell death, and autophagy/mitofagia were investigated in GRX treated for 24 and 120 hours by spectrophotometric techniques, immunocytochemistry, flow cytometry, confocal microscopy, and transmission electron microscopy. All the RSV concentrations promote cell apoptosis through caspases activation, alter the mitochondrial dynamics and function, and induce an increase of autophagy/mitofagia. Curiously, only 1 and 10 μM of RSV induced mitochondrial biogenesis in GRX, while the highest concentration caused an evident cell damage without inducing mitochondrial biogenesis. Thus, it is possible that the "dose-dependent" cytotoxicity of RSV, which causes cell death and oxidative damage in 24 hours of treatment, is related to an imbalance between the concomitant induction of mitochondrial-mediated apoptosis, autophagy/mitofagia, and mitochondrial biogenesis. Finally, it was investigated the release of TNF-α, Interleukin-6 and Interleukin-10 by GRX treated for 24 and 120 hours with RSV (0.1 to 50 μM), considering the anti-inflammatory role of RSV and the autocrine signalling role of HSC that contributes to the perpetuation of its activated phenotype. It was demonstrated that GRX treatment with RSV for 24 and 120 hours reduced the release of Interleukin-6 in the culture medium; whereas the release of TNF-α and Interleukin-10 was increased. These results confirm the anti-inflammatory properties of RSV and may contribute to the prevention of HSC activation through autocrine signalling. Although RSV concentration is important to effectively induce activated HSC death, cells treatment with this phytoalexin may be promising for liver fibrosis resolution through decreasing the population of activated cells or through preventing the perpetuation of activated state of HSC. Future studies evaluating the quiescence indicators of GRX under RSV treatment are still needed to fully unravel the effects of this phytoalexin on inhibiting the perpetuation of activated HSC or reversing its activated phenotype.

L’interleukine (IL)-17 et le TNFa sont deux cytokines pro-inflammatoires jouant un rôle important dans diverses maladies inflammatoires systémiques et auto-immunes affectant différents organes et tissus comme le foie et les muscles. Cependant, les rôles de l’IL-17 et du TNFa restent encore mal compris dans les muscles et le foie, qui est impliqué dans la réponse en phase aiguë. En utilisant des cultures de myoblastes, d’hépatocytes et de cellules stellaires hépatiques humaines, nous avons trouvé que l’IL-17 et le TNFa augmentent en synergie la sécrétion de la cytokine pro-inflammatoire IL-6 et de plusieurs chimiokines. Dans les myoblastes, l’IL-17 et le TNFa induisent un stress oxydatif et une dérégulation de calcium montrant ainsi que les processus pathologiques immuns et non-immuns interagissent. Dans les hépatocytes, en augmentant en synergie les niveaux de la CRP et des transaminases, l’IL-17 et le TNFa participent à l’inflammation systémique et aux dommages cellulaires. Etant donné que des infiltrats de cellules immunitaires sont retrouvés lors d’atteintes inflammatoires, les interactions cellulaires contribuent certainement à la chronicité de l’inflammation. Des cellules mononuclées du sang périphérique activées ou non ont ainsi été placées en co-cultures avec les myoblastes, les hépatocytes et les cellules stellaires. Par comparaison aux monocultures, les productions de l’IL-6 et de la chimiokine IL-8 étaient augmentées dans les co-cultures. L’IL-17 et le TNFa contribuaient partiellement à ces effets. Les effets systémiques de l’IL-17 et du TNFa en font donc des cibles thérapeutiques attrayantes pour le traitement des nombreuses maladies inflammatoires systémiques / Interleukin-17A (IL-17) and tumor necrosis factor-a (TNFa) are two pro-inflammatory cytokines playing an important role in various systemic inflammatory and autoimmune disorders affecting different organs and tissues including the liver and the muscles. However, the roles of IL-17 and TNFa are not fully understood in the muscles and also in liver, which is crucial in the acute phase response. By using cultures of human myoblasts, primary human hepatocytes, human HepaRG cells and LX-2 hepatic stellate cells, we found that IL-17 and TNFa increase in synergy the production of the pro-inflammatory cytokine IL-6 and chemokines (IL-8, CCL20, MCP-1). In myoblasts, the IL-17 and TNFa stimulation induces endoplasmic reticulum stress and calcium dysregulation showing that immune and non-immune pathogenic mechanisms interplay. In hepatocytes, IL-17 and TNFa mediate systemic inflammation and cell damage by increasing in synergy the CRP acute-phase protein and transaminase levels through the induction of IL-6. Since active liver and muscle disorders are characterized by inflammatory infiltrates of immune cells, the cell interactions play certainly an important role in the chronicity of the inflammation. Peripheral blood mononuclear cells activated or not were therefore co-cultured with myoblasts, hepatocytes and/or hepatic stellate cells to assess the inflammatory role of the cell-cell interactions. Co-cultures enhance the production of IL-6 and IL-8 compared to monocultures. IL-17 and TNFa contribute partially to these inductions. The systemic effects of IL-17 and/or TNFa make them attractive therapeutic targets for the treatment of various systemic inflammatory disorders

Myofibroblast expansion is a critical event in the pathogenesis of liver fibrosis. The activation of hepatic stellate cells (HSC) to myofibroblast (MFB) results in the enhanced production of extracellular matrix (ECM). We have studied the effect of fibroblast growth factor 1 (FGF-1) on liver MFB. In the second part we investigated effect of transforming growth factor β1 (TGF-β1) and FGF-1 on cell line HSC-T6. Cells were cultured on plastic dishes and in 3D collagen gel mimicking fibrotic tissue. MFB were isolated by repeated passaging of nonparenchymal liver cell fraction. The transfer of MFB from plastic dishes to collagen gel resulted in the change in their shape and phenotype. The expression of cytokine TGF-β1 and of MFB markers, α-smooth muscle actin (α-SMA) and cellular fibronectin (EDA-FN) on protein level was significantly decreased in collagen gel. The experiments with SB 431542, the inhibitor of TGF-β receptor type I, showed that EDA-FN and α-SMA are differently regulated. EDA-FN expression is dependent on TGF-β1, while the expression of α-SMA is primarily determined by the environment and modified by TGF-β1. EDA-FN is more sensitive to the U0126, the inhibitor of protein kinases MEK 1 and 2. Collagen gel does not change the expression of metalloproteinase MMP-2 but activates the proenzyme....

A fibrose hepática é uma patologia que acompanha outras doenças crônicas do fígado como a cirrose e o hepatocarcinoma. As células estreladas hepáticas (HSC, do inglês hepatic stellate cells) compõem uma população celular heterogênea que se caracteriza por transitar entre dois fenótipos. As células com fenótipo quiescente possuem a capacidade de armazenar vitamina A em gotas lipídicas. Os insultos ao fígado desencadeiam uma resposta inflamatória que gera estímulos parácrinos e autócrinos mediados por citocinas e espécies reativas. Neste contexto, as HSC assumem um fenótipo ativado fibrogênico e tornam-se responsáveis pela cicatrização hepática. Danos crônicos ao fígado levam a uma deposição de matriz extracelular exagerada que configura o estado patológico da fibrose. O resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-estilbeno) é uma fitoalexina produzida por algumas espécies de plantas. Inúmeros efeitos benéficos à saúde são atribuídos ao RSV por causa do seu potencial antioxidante, antiinflamatório e pró-apoptótico. Estudos anteriores mostraram que tratamento da GRX, uma linhagem murina de HSC ativadas, com concentrações de RSV próximas as biodisponíveis (0,1 a 1 μM) resultou em parada do ciclo na fase S com consequente inibição de proliferação celular, um efeito associado à citotoxicidade e que pode favorecer a resolução da fibrose hepática. Neste estudo, por técnicas espectrofotométricas, foi demonstrado que tratamento da GRX por 24 horas com concentrações entre 0,1 a 50 μM de RSV promoveu um efeito pró-oxidante que causa uma citotoxicidade dependente da dose, bastante aumentada no grupo tratado com a concentração mais alta. Os efeitos citotóxicos atenuados encontrados nas células tratadas por 120 horas sugerem que a GRX pode se tornar resistente a estes efeitos. O potencial pró-oxidante do RSV foi o ponto de partida para investigar a possibilidade de que esta fitoalexina provocasse uma alteração no metabolismo mitocondrial da GRX. Para isso, os efeitos do RSV (1 a 50 μM) na função mitocondrial, na indução de morte mediada por estas organelas e na autofagia/mitofagia foram investigados por técnicas de espectrofotometria, de imunocitoquímica, de citometria de fluxo, de microscopia confocal e de microscopia eletrônica de transmissão em GRX tratadas por 24 e 120 horas. Foi demonstrado que todas as concentrações de RSV promovem apoptose por meio da ativação de caspases, alteram a dinâmica/função mitocondrial e induzem o aumento de autofagia/mitofagia na GRX. No entanto, o RSV provocou biogênese de mitocôndrias nos grupos tratados com 1 e 10 μM, enquanto que o tratamento com 50 μM causou dano celular evidente na GRX, sem induzir biogênese de mitocôndrias. Desta forma, é possível que a citotoxicidade “dose-dependente” do RSV, que causa a morte celular e dano oxidativo em 24 horas de tratamento, esteja relacionada com o desequilíbrio entre a indução concomitante de apoptose mediada por dano mitocondrial, autofagia/mitofagia e biogênese de mitocôndrias. Por fim, foi investigada a liberação de TNF-α, Interleucina-6 e Interleucina-10 pela GRX tratada por 24 e 120 horas com RSV (0,1 a 50 μM), considerando o papel antiinflamatório do RSV e o papel das HSC ativadas na sinalização autócrina que contribui para a modulação fenotípica destas células. Foi demonstrado que o tratamento da GRX com RSV por 24 e 120 horas induziu a redução da liberação de Interleucina-6; enquanto que a liberação de TNF-α e Interleucina-10 foi aumentada. Estes resultados confirmam um efeito antiinflamatório do RSV que deve contribuir na prevenção da ativação ou da perpetuação do estado ativado das HSC por meio de sinalização autócrina. Ainda que a concentração do RSV seja importante para efetivamente induzir a morte das HSC ativadas, o tratamento com esta fitoalexina pode ser promissor para a resolução da fibrose hepática por diminuir a população de células ativadas e, possivelmente, prevenir a perpetuação do estado fenotípico ativado. Estudos avaliando indicadores de quiescência em células tratadas são ainda necessários para desvendar completamente os efeitos do RSV quanto às possibilidades de inibição da perpetuação ou reversão fenotípica das HSC ativadas. / Liver fibrosis is a disease that accompanies other hepatic chronic diseases such as cirrhosis and hepatocellular carcinoma. Hepatic stellate cells (HSC) are a heterogeneous cell population characterized by transiting between two phenotypes. Cells with a quiescent phenotype are able to store vitamin A into lipid droplets. Damage to the liver trigger an inflammatory response that generates paracrine and autocrine stimulation mediated by cytokines and reactive species. In this context, HSC assume an activated and fibrogenic phenotype responsive for hepatic wound-healing. Chronic insults to the liver lead to an excessive deposition of extracellular matrix that configures the pathological state of fibrosis. Resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-stilbeno) is a phytoalexin produced by some species of plants. Several beneficial effects are attributed to this molecule due to its antioxidant, antiproliferative and pro-apoptotic potential. Previous studies showed that treatment with bioavailable concentrations of RSV (0.1 to 1 μM) promoted an arrest cycle at the S phase in GRX, a murine activated HSC model, leading to cell proliferation inhibition, a cytotoxic effect that contributes to the liver fibrosis resolution. In this study, it was shown by spectrophotometric techniques that GRX treatment for 24 hours at concentrations between 0.1 to 50 μM of RSV promoted a fairly clear pro-oxidant effect that causes a dose-dependent cytotoxicity that was higher in the group treated with 50 μM. The attenuated cytotoxicity found after 120 hours of GRX treatment suggest that these cells became resistant to this effect. The pro-oxidant potential of RSV was the starting point for investigating the possibility that this phytoalexin would cause a change in the GRX mitochondrial metabolism. Thus, the effects of RSV (1 to 50 μM) on altering the mitochondrial function, on inducing mitochondrial-mediated cell death, and autophagy/mitofagia were investigated in GRX treated for 24 and 120 hours by spectrophotometric techniques, immunocytochemistry, flow cytometry, confocal microscopy, and transmission electron microscopy. All the RSV concentrations promote cell apoptosis through caspases activation, alter the mitochondrial dynamics and function, and induce an increase of autophagy/mitofagia. Curiously, only 1 and 10 μM of RSV induced mitochondrial biogenesis in GRX, while the highest concentration caused an evident cell damage without inducing mitochondrial biogenesis. Thus, it is possible that the "dose-dependent" cytotoxicity of RSV, which causes cell death and oxidative damage in 24 hours of treatment, is related to an imbalance between the concomitant induction of mitochondrial-mediated apoptosis, autophagy/mitofagia, and mitochondrial biogenesis. Finally, it was investigated the release of TNF-α, Interleukin-6 and Interleukin-10 by GRX treated for 24 and 120 hours with RSV (0.1 to 50 μM), considering the anti-inflammatory role of RSV and the autocrine signalling role of HSC that contributes to the perpetuation of its activated phenotype. It was demonstrated that GRX treatment with RSV for 24 and 120 hours reduced the release of Interleukin-6 in the culture medium; whereas the release of TNF-α and Interleukin-10 was increased. These results confirm the anti-inflammatory properties of RSV and may contribute to the prevention of HSC activation through autocrine signalling. Although RSV concentration is important to effectively induce activated HSC death, cells treatment with this phytoalexin may be promising for liver fibrosis resolution through decreasing the population of activated cells or through preventing the perpetuation of activated state of HSC. Future studies evaluating the quiescence indicators of GRX under RSV treatment are still needed to fully unravel the effects of this phytoalexin on inhibiting the perpetuation of activated HSC or reversing its activated phenotype.

O gânglio estrelado (GE) é o principal componente da inervação cardíaca extrínseca e está envolvido na gênese de diversas cardiomiopatias. Durante o envelhecimento, o controle neural do coração dos mamíferos é alterado de forma complexa e não clara, geralmente ocasionando decremento da função cardíaca e maior propensão a doenças degenerativas. A ocorrência de resultados dissonantes quanto aos parâmetros morfoquantitativos durante o envelhecimento, como o aumento ou diminuição do número total de neurônios simpáticos, é assunto para discussões interessantes. Esta pesquisa foi conduzida em preás machos (Galea spixii), um pequeno roedor da fauna brasileira. Desta forma, estudou-se o efeito do desenvolvimento pós-natal (maturação e envelhecimento) na macro e microestrutura do gânglio estrelado esquerdo (GEe) de preás, por meio de microscopia quantitativa tridimensional (Estereologia) associada a técnicas de imuno-histoquímica. De acordo com a fase específica do desenvolvimento pós-natal, os animais foram alocados nos seguintes grupos etários: Neonatos, Jovens, Adultos e Senis. Inicialmente, os animais foram submetidos à eutanásia e seus gânglios estrelados esquerdos coletados e fixados em solução de formaldeído (4%) em PBS. Foi realizada amostragem sistemática e uniformemente aleatória (SURS), estimando-se: volume do GEe, volume neuronal e número total de neurônios do GEe. Os principais achados deste estudo foram: i) aumento do comprimento do gânglio - 42% entre Neonato e Senil; 34% entre Jovem e Senil e 35% entre Adulto e Senil; ii) hipertrofia do GEe - 171% entre os grupos Neonato e Adulto; iii) aumento do tecido não neuronal - 268% entre os grupos Neonato e Adulto; iv) estabilidade no número total de neurônios uninucleados, binucleados e total (uni+bi); v) estabilidade no tamanho (volume) dos neurônios uninucleados e binucleados; e vi) estabilidade no número total de neurônios imunorreativos ao Ki-67 (uni+bi). Espera-se que os resultados gerados por esta pesquisa possam esclarecer alguns aspectos estruturais da plasticidade neural durante o desenvolvimento pós-natal de preás, avançando assim o conhecimento acerca da inervação cardíaca extrínseca / The stellate ganglion (SG) is a main component of extrinsic cardiac innervation and is involved in the genesis of various cardiomyopathies. During ageing, the neural control of heart in mammals is altered in the complex shape and unclear, generally cause decrement in the cardiac function and a greater propensity to degenerative diseases. The occurrence of discordant results regarding the morphoquantitative parameters during ageing, such as increase or decrease in the total number of sympathetic neurons, is a subject for interesting discussions. This research was conducted in males preas (Galea spixii), a small rodent of the Brazilian fauna. Therefore, this work aimed to study the effect of postnatal development (maturation and ageing) in the macro and microstructure of the left stellate ganglion (LSG) in preas by dimensional quantitative microscopy (Stereology) associated to immunohistochemistry techniques. According to a specific stage of postnatal development, the animals were allocated into the following age groups: Newborn, Young, Adult and Elderly. The animals were euthanised and the left stellate ganglia were collected and fixed in 4% formaldehyde solution in PBS. A systematic uniformly random sampling (SURS) was performed to estimate: the volume of LSG, neuron volume and the total number of LSG neurons. The main findings of this study were: i) increase in length ganglia - 42% between Newborn and Elderly; 34% between Young and Elderly and 35% between Adult and Elderly; ii) hypertrophy of LSG - 171% between the groups Newborn and Adult; iii) increase of non-neuronal tissue - 268% between the groups Newborn and Adult; iv) stability for the total number of uninucleate neurons, binucleate neurons and total (uni+bi); v) stability in the size (volume) of uninucleate and binucleate neurons; and, vi) stability for the total number of neurons immunorreactive to Ki-67 (uni+bi). It is expected that the results generated for this research may clarify structural aspects of neural plasticity during the postnatal development of preas, thus advancing the knowledge about the extrinsic cardiac innervation

A doença de Huntington (DH) é um distúrbio neurodegenerativo hereditário e autossômico dominante e tem como características alterações motoras e mentais progressivas. Recentemente, além das alterações verificadas no sistema nervoso central, também têm sido descritas alterações em órgãos periféricos, tais como osteoporose, atrofia muscular, problemas intestinais, alterações cardíacas e, sobretudo, alterações no sistema nervoso autônomo. São evidentes as alterações autonômicas do coração nos portadores da DH, as quais, são, sobretudo, um risco potencial, tornando os pacientes suscetíveis a problemas cardiovasculares. No entanto, os mecanismos pelos quais a doença afeta os componentes autonômicos do coração não são totalmente conhecidos, por isso a importância de se estudar os componentes da inervação cardíaca, sobretudo o gânglio estrelado (GE). A DH pode ser induzida através do ácido 3-nitropropiônico (3-NP), pois essa substância produz efeitos neurotóxicos inibindo a succinato desidrogenase. Esta pesquisa objetiva analisar, por meio da indução através do 3-NP, os efeitos da DH no GE, identificando possíveis alterações morfoquantitativas dos neurônios ganglionares, com uso de técnicas baseadas em delineamento estereológico 3D e de bioimagem associadas à teste comportamental e perfil hemodinâmico, a fim de contribuir para o entendimento de como a doença age na inervação do coração. Para isso foram utilizados 14 camundongos C57BL-6 machos que foram alocados em dois grupos: Grupo Controle com 7 animais induzidos com solução salina (0,9%); Grupo 3NP com 7 animais induzidos com doses subagudas de 60 mg.kg-1dia-1 de 3-NP. Foram realizados o teste comportamental, a avaliação cardíaca e a análise estereológica. Os principais achados dessa pesquisa foram: (I) diminuição da atividade exploratória dos animais; (II) prejuízo da função sistólica; (III) aumento de 76% no volume ganglionar; (IV) aumento de 70% no volume médio dos neurônios, concluindo-se que o 3-NP produz efeitos na função cardíaca, ocasionando hipertrofia do gânglio / Huntington\'s disease (HD) is a hereditary and autosomal dominant neurodegenerative disorder and is characterized by progressive motor and mental changes. Recently, in addition to changes in the central nervous system, alterations in peripheral organs such as osteoporosis, muscular atrophy, intestinal problems, cardiac alterations and, above all, changes in the autonomic nervous system have also been described. Autonomic heart alterations in DH patients are evident, which are a potential risk, making patients susceptible to cardiovascular problems. However, the mechanisms by which the disease affects the autonomic components of the heart are not fully understood, therefore, the importance of studying the components of cardiac innervation, especially the stellate ganglion (SG). HD can be induced through 3-nitropropionic acid (3-NP), as this substance produces neurotoxic effects inhibiting succinate dehydrogenase. The aim of this research was to analyze the effects of HD on the SG by means of 3-NP induction, identifying possible morpho-quantitative changes in ganglion neurons, using techniques based on 3D stereological and bioimaging techniques associated with behavioral and hemodynamic profile, In order to contribute to the understanding of how the disease acts in the heart innervation. For this, 14 male C57BL-6 mice were used, which were allocated in two groups: Control Group with 7 animals induced with saline solution (0.9%); Group 3NP with 7 animals induced with subacute doses of 60 mg.kg-1day-1 of 3-NP. Behavioral test, cardiac evaluation and stereological analysis were performed. The main findings of this research were: (I) decrease in the exploratory activity of the animals; (II) impairment of systolic function; (III) 76% increase in ganglion volume; (IV) increase of 70% in the mean volume of the neurons, concluding that 3-NP produces effects on cardiac function, causing hypertrophy of the ganglion

Les cellules folliculo-stéllaires (FS) de l'hypophyse antérieure possèdent une forme étoilée et étendent de longues projections cytoplasmiques qui forment des pseudo-follicules entourant les cellules endocrines. Les cellules FS sont connectées entre elles par des jonctions lacunaires (des fois aussi connu sous le nom de jonction communicante) formant ainsi un réseau tridimensionnel continu. Un des rôles principaux des cellules FS est le maintien du microenvironnement de l'hypophyse antérieure, une activité qui est en partie réalisée par la sécrétion de divers facteurs de croissance et de cytokines. Ces messagers chimiques, y compris le bFGF, le VEGF, l’IL-6 et l’IL-1 contrôlent de nombreux processus cellulaires tels que l’expression des gènes d’hormones. Notre intérêt est de déterminer si la communication entre les cellules FS contribue à leur activité régulatrice. Dans notre étude, nous avons utilisé la lignée cellulaire TtT/GF qui partage de nombreuses caractéristiques morphologiques, physiologiques et biochimiques avec les cellules FS. Les jonctions lacunaires/communicantes sont formées par l’association de deux connexons de cellules adjacentes qui unissent le cytoplasme des cellules connectées et permet la diffusion de petites molécules. Chaque connexon est formé par l’oligomérisation de six protéines connexine (Cx) de la famille α, β ou γ. Les connexons, intégrés dans la membrane d’une vésicule du cytoplasme, se migrent vers la membrane cellulaire où ils s’incorporent dans la couche bilipidique. L’expression de la Cx43 (α) par les cellules FS est régulée en réponse à des facteurs de croissance et des cytokines. Des changements dans le microenvironnement de l'hypophyse antérieure causés par des molécules de signalisation sont susceptibles de modifier la Cx43, en particulier l’état de phosphorylation de la protéine. Ces modifications de la Cx43 peuvent ensuite déclencher des changements du comportement de jonctions lacunaires/communicantes formées par la Cx43, comme leur perméabilité et le renouvellement de la protéine Cx43. Les tissus expriment généralement plus d’un type de connexine. Jusqu’aujourd’hui, la Cx43 est la seule connexine à avoir été identifiée dans les cellules FS. Le cristallin exprime les connexines α: Cx43, Cx46 et Cx50. Leur expression est modulée par des facteurs de croissance. Notre hypothèse de travail a été de vérifier si la Cx46 et la Cx50 étaient exprimées par les cellules FS et si celles-ci contribuaient au rôle modulateur des cellules FS hypophysaires. Dans cette étude, nous avons identifié et caractérisé la Cx46 et la Cx50 dans la lignée cellulaire TtT/GF. Nous avons identifié les produits de transcription de Cx46 et de Cx50 par la technique d’analyse northern blot (PCR). Par la suite, les protéines Cx46 et Cx50 ont été identifiées en utilisant des anticorps dans des analyses western blot. Par microscopie confocale, nous avons déterminé la co-localisation de la Cx46 avec certaines marqueurs d’organites : réseau trans-Golgien, endosomes précoces et lysosomes. La Cx50 co-localise avec des marqueurs du réticulum endoplasmique, du réseau cis-Golgien et des endosomes précoces. Un protocole d’isolation des membranes résistantes aux détergents non-ionique a révélé que la Cx46 et la Cx50 n’étaient pas associées à des radeaux lipidiques ni aux cavéoles. Cependant, la microscopie confocale a montré une co-localisation cytoplasmique de la Cx50 et de la flotilline-1. Nous avons poursuivi l’étude sur la localisation de la Cx46 dans le noyau en utilisant une technique d’isolation des fractions enrichies en noyau. Nous avons établi que plusieurs isoformes de la Cx46 sont exclusivement associées au noyau. De plus, avec la microscopie confocale nous avons démontrée une co-localisation de la Cx46 avec un marqueur du nucléole/corps de Cajal. Nous avons démontré un effet du bFGF sur l'expression temporelle de la Cx46 et de la Cx50. L’expression de la Cx46 diminue au cours de longues expositions au bFGF tandis que les niveaux de Cx50 augmentent de façon transitoire au cours du traitement. Dans une autre étude nous avons démontré des changements importants dans les niveaux de la Cx46 et de la Cx50 dans l’hypophyse antérieure des visons durant le cycle de reproduction annuel. Notre étude démontre que les cellules FS expriment la Cx46 et la Cx50. Nous avons aussi établi que la Cx46 et la Cx50 sont localisées dans différentes structures sous-cellulaires, ce qui suggère des rôles différents dans les cellules FS pour ces protéines de jonction lacunaire/communicante. Il est possible que la Cx46 et la Cx50 ne jouent pas un rôle majeur dans la communication intercellulaire dans les cellules FS quiescentes. Nos résultats suggèrent que la Cx46 et la Cx50 peuvent avoir d'autres fonctions : des isoformes de la Cx46 peuvent contribuer à la biogenèse des ribosomes tandis que la Cx50 pourrait avoir un rôle dans la communication dans les cellules stimulées au bFGF. Nos études établissent une base pour des recherches futures. / The folliculo-stellate (FS) cells of the anterior pituitary are star-shaped and extend long cytoplasmic processes forming pseudo-follicles encircling hormone-secreting cells. Dispersed throughout the anterior pituitary gland, FS cells are joined to form a continuous three dimensional network through communicating gap junctions. One of the primary roles of FS cells is the maintenance of the anterior pituitary microenvironment, accomplished through the expression and secretion of various growth factors and cytokines. These chemical messengers, including bFGF, VEGF, IL-6 and IL-1 mediate a range of cellular processes such as hormone gene expression. Our aim is to study whether intercellular communication among FS cells contributes to the modulatory activity of the FS cells within the anterior pituitary gland. To pursue this, we use the TtT/GF cell line that shares many morphological, physiological and biochemical characteristics with FS cells. Gap junctions are formed by the joining of two connexons/hemichanels from adjacent cells that link their cytoplasms allowing for the passive diffusion of small molecules. Connexons/hemichannels are themselves formed by the oligomerization of six connexin (Cx) proteins from the family α, β or γ, which then migrate into the lipid bilayer of the cell membrane. FS cells express Cx43 (α-connexin), which is regulated in response to growth factors and cytokines. Changes in the anterior pituitary microenvironment due to signaling molecules results in modifications to Cx43, particularly in the phosphorylation status of the protein. Such alterations yield alterations in the physiological behaviour of Cx43 gap junctions such as permeability and turnover. Tissues generally express more than one connexin type and to date, Cx43 has been the sole connexin to be identified in FS cells. The ocular lens expresses the α-connexins: Cx43, Cx46 and Cx50, which are modulated by growth factors that are also present in the anterior pituitary. Based on these facts, we hypothesize that Cx46 and Cx50 are also expressed by the FS cells and contribute to the FS modulatory role in the anterior pituitary gland. In the present study, we have identified and characterized Cx46 and Cx50 in the TtT/GF cell line. We identified Cx46 and Cx50 transcripts through northern blots and identified the corresponding protein products using antibodies and western blot analyses. Through confocal microscopy, we determined that Cx46 co-localized with the organelle markers: trans-Golgi, early endosomes and lysosomes. Cx50 co-localized with markers for the ER, cis-Golgi and early endosomes. An isolation procedure using a non-ionic detergent we showed that neither Cx46 nor Cx50 were associated to lipid rafts or caveolae. However, confocal microscopy showed a cytoplasmic co-localization between Cx50 and flotillin-1. We pursued a finding that localized Cx46 to the nucleus and using a nuclear isolation technique, demonstrated that several isoforms of Cx46 are exclusively located in the nuclear compartment. Furthermore, with confocal microscopy we found a co-localization of Cx46 with a nucleolus/coiled body marker. We demonstrated an effect of bFGF on the temporal expression patterns of Cx46 and Cx50 and showed that Cx46 levels decreased over longer exposures to the growth factor while Cx50 levels transiently increased. Lastly, drastic changes were noted in an in situ study of Cx46 and Cx50 in the male and female mink anterior pituitary during the annual reproductive cycle. Our study indicates that addition to Cx43, FS cells also express Cx46 and Cx50. We also demonstrated that Cx46 and Cx50 localize to different sub-cellular structures, suggesting different roles in the FS cells. While they may not play a major role in intercellular communication in quiescent FS cells, our results suggest that Cx46 and Cx50 may serve other functions: Cx46 isoforms may contribute to ribosome biogenesis and Cx50 may have communication-related responsibilities in stimulated cells. Importantly, our identification and characterization studies provide a foundation on which future studies can be built.

A fibrose hepática é uma patologia que acompanha outras doenças crônicas do fígado como a cirrose e o hepatocarcinoma. As células estreladas hepáticas (HSC, do inglês hepatic stellate cells) compõem uma população celular heterogênea que se caracteriza por transitar entre dois fenótipos. As células com fenótipo quiescente possuem a capacidade de armazenar vitamina A em gotas lipídicas. Os insultos ao fígado desencadeiam uma resposta inflamatória que gera estímulos parácrinos e autócrinos mediados por citocinas e espécies reativas. Neste contexto, as HSC assumem um fenótipo ativado fibrogênico e tornam-se responsáveis pela cicatrização hepática. Danos crônicos ao fígado levam a uma deposição de matriz extracelular exagerada que configura o estado patológico da fibrose. O resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-estilbeno) é uma fitoalexina produzida por algumas espécies de plantas. Inúmeros efeitos benéficos à saúde são atribuídos ao RSV por causa do seu potencial antioxidante, antiinflamatório e pró-apoptótico. Estudos anteriores mostraram que tratamento da GRX, uma linhagem murina de HSC ativadas, com concentrações de RSV próximas as biodisponíveis (0,1 a 1 μM) resultou em parada do ciclo na fase S com consequente inibição de proliferação celular, um efeito associado à citotoxicidade e que pode favorecer a resolução da fibrose hepática. Neste estudo, por técnicas espectrofotométricas, foi demonstrado que tratamento da GRX por 24 horas com concentrações entre 0,1 a 50 μM de RSV promoveu um efeito pró-oxidante que causa uma citotoxicidade dependente da dose, bastante aumentada no grupo tratado com a concentração mais alta. Os efeitos citotóxicos atenuados encontrados nas células tratadas por 120 horas sugerem que a GRX pode se tornar resistente a estes efeitos. O potencial pró-oxidante do RSV foi o ponto de partida para investigar a possibilidade de que esta fitoalexina provocasse uma alteração no metabolismo mitocondrial da GRX. Para isso, os efeitos do RSV (1 a 50 μM) na função mitocondrial, na indução de morte mediada por estas organelas e na autofagia/mitofagia foram investigados por técnicas de espectrofotometria, de imunocitoquímica, de citometria de fluxo, de microscopia confocal e de microscopia eletrônica de transmissão em GRX tratadas por 24 e 120 horas. Foi demonstrado que todas as concentrações de RSV promovem apoptose por meio da ativação de caspases, alteram a dinâmica/função mitocondrial e induzem o aumento de autofagia/mitofagia na GRX. No entanto, o RSV provocou biogênese de mitocôndrias nos grupos tratados com 1 e 10 μM, enquanto que o tratamento com 50 μM causou dano celular evidente na GRX, sem induzir biogênese de mitocôndrias. Desta forma, é possível que a citotoxicidade “dose-dependente” do RSV, que causa a morte celular e dano oxidativo em 24 horas de tratamento, esteja relacionada com o desequilíbrio entre a indução concomitante de apoptose mediada por dano mitocondrial, autofagia/mitofagia e biogênese de mitocôndrias. Por fim, foi investigada a liberação de TNF-α, Interleucina-6 e Interleucina-10 pela GRX tratada por 24 e 120 horas com RSV (0,1 a 50 μM), considerando o papel antiinflamatório do RSV e o papel das HSC ativadas na sinalização autócrina que contribui para a modulação fenotípica destas células. Foi demonstrado que o tratamento da GRX com RSV por 24 e 120 horas induziu a redução da liberação de Interleucina-6; enquanto que a liberação de TNF-α e Interleucina-10 foi aumentada. Estes resultados confirmam um efeito antiinflamatório do RSV que deve contribuir na prevenção da ativação ou da perpetuação do estado ativado das HSC por meio de sinalização autócrina. Ainda que a concentração do RSV seja importante para efetivamente induzir a morte das HSC ativadas, o tratamento com esta fitoalexina pode ser promissor para a resolução da fibrose hepática por diminuir a população de células ativadas e, possivelmente, prevenir a perpetuação do estado fenotípico ativado. Estudos avaliando indicadores de quiescência em células tratadas são ainda necessários para desvendar completamente os efeitos do RSV quanto às possibilidades de inibição da perpetuação ou reversão fenotípica das HSC ativadas. / Liver fibrosis is a disease that accompanies other hepatic chronic diseases such as cirrhosis and hepatocellular carcinoma. Hepatic stellate cells (HSC) are a heterogeneous cell population characterized by transiting between two phenotypes. Cells with a quiescent phenotype are able to store vitamin A into lipid droplets. Damage to the liver trigger an inflammatory response that generates paracrine and autocrine stimulation mediated by cytokines and reactive species. In this context, HSC assume an activated and fibrogenic phenotype responsive for hepatic wound-healing. Chronic insults to the liver lead to an excessive deposition of extracellular matrix that configures the pathological state of fibrosis. Resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-stilbeno) is a phytoalexin produced by some species of plants. Several beneficial effects are attributed to this molecule due to its antioxidant, antiproliferative and pro-apoptotic potential. Previous studies showed that treatment with bioavailable concentrations of RSV (0.1 to 1 μM) promoted an arrest cycle at the S phase in GRX, a murine activated HSC model, leading to cell proliferation inhibition, a cytotoxic effect that contributes to the liver fibrosis resolution. In this study, it was shown by spectrophotometric techniques that GRX treatment for 24 hours at concentrations between 0.1 to 50 μM of RSV promoted a fairly clear pro-oxidant effect that causes a dose-dependent cytotoxicity that was higher in the group treated with 50 μM. The attenuated cytotoxicity found after 120 hours of GRX treatment suggest that these cells became resistant to this effect. The pro-oxidant potential of RSV was the starting point for investigating the possibility that this phytoalexin would cause a change in the GRX mitochondrial metabolism. Thus, the effects of RSV (1 to 50 μM) on altering the mitochondrial function, on inducing mitochondrial-mediated cell death, and autophagy/mitofagia were investigated in GRX treated for 24 and 120 hours by spectrophotometric techniques, immunocytochemistry, flow cytometry, confocal microscopy, and transmission electron microscopy. All the RSV concentrations promote cell apoptosis through caspases activation, alter the mitochondrial dynamics and function, and induce an increase of autophagy/mitofagia. Curiously, only 1 and 10 μM of RSV induced mitochondrial biogenesis in GRX, while the highest concentration caused an evident cell damage without inducing mitochondrial biogenesis. Thus, it is possible that the "dose-dependent" cytotoxicity of RSV, which causes cell death and oxidative damage in 24 hours of treatment, is related to an imbalance between the concomitant induction of mitochondrial-mediated apoptosis, autophagy/mitofagia, and mitochondrial biogenesis. Finally, it was investigated the release of TNF-α, Interleukin-6 and Interleukin-10 by GRX treated for 24 and 120 hours with RSV (0.1 to 50 μM), considering the anti-inflammatory role of RSV and the autocrine signalling role of HSC that contributes to the perpetuation of its activated phenotype. It was demonstrated that GRX treatment with RSV for 24 and 120 hours reduced the release of Interleukin-6 in the culture medium; whereas the release of TNF-α and Interleukin-10 was increased. These results confirm the anti-inflammatory properties of RSV and may contribute to the prevention of HSC activation through autocrine signalling. Although RSV concentration is important to effectively induce activated HSC death, cells treatment with this phytoalexin may be promising for liver fibrosis resolution through decreasing the population of activated cells or through preventing the perpetuation of activated state of HSC. Future studies evaluating the quiescence indicators of GRX under RSV treatment are still needed to fully unravel the effects of this phytoalexin on inhibiting the perpetuation of activated HSC or reversing its activated phenotype.

Hepatocellular carcinoma (HCC) is the most common liver malignancy that usually develops in patients suffering from chronic liver diseases. One of the major problems faced in the treatment of HCC is severe chemoresistance. Endoplasmic reticulum (ER) stress and hepatic stellate cells play an important role in tumour survival and growth as well as fibrosis. This study further investigates the crosstalk between ER-stress and hepatic stellate cells in HCC resistant cells as well as their relation to chemoresistance markers expression. Mice with chemically induced HCC were divided in 3 different treatment group; one was only treated with doxorubicin, one only with pharmacological ER-stress inhibitor 4μ8C, and one was treated with a combination of doxorubicin and 4μ8C. Tumour burden, fibrosis and cell proliferation were assessed through histological analysis and ImageJ processing. Chemoresistance markers expression was evaluated through mRNAs determination using real-time qPCR. While the combined treatment consisting of doxorubicin and pharmacological ER-stress inhibitor (4μ8C) has shown to positively reduce tumour progression, ferroptosis and collagen deposition, consequently decreasing fibrosis, drug resistance markers’ expression, on the other hand, seems to be more intricate, thus indicating that further investigations are probably needed. / Hepatocellulärt karcinom (HCC) är den vanligaste maligniteten i levern som vanligtvis utvecklas hos patienter som lider av kroniska leversjukdomar. Ett av de största problemen vid behandling av HCC är svår kemoresistens. Stress i endoplasmatiska retikulum (ER) och hepatiska stellatceller spelar en viktig roll för tumörernas överlevnad och tillväxt samt för fibros. I denna studie undersöks vidare samspelet mellan ER-stress och hepatiska stellatceller i HCC-resistenta celler samt deras relation till uttryck av kemoresistensmarkörer. Möss med kemiskt inducerad HCC delades in i tre olika behandlingsgrupper; en behandlades enbart med doxorubicin, en enbart med den farmakologiska ER-stresshämmaren 4μ8C och en behandlades med en kombination av doxorubicin och 4μ8C. Tumörbörda, fibros och cellproliferation bedömdes genom histologisk analys och ImageJ-bearbetning. Kemoresistensmarkörernas uttryck utvärderades genom bestämning av mRNA med hjälp av qPCR i realtid. Medan kombinationsbehandlingen bestående av doxorubicin och farmakologisk ER-stresshämmare (4μ8C) har visat sig minska tumörprogressionen, ferroptos och kollagenavlagring och därmed minska fibros, verkar uttrycket av läkemedelsresistensmarkörer å andra sidan vara mer invecklat, vilket tyder på att det troligen behövs ytterligare undersökningar.

<p>Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer in part due to inherent resistance to chemotherapy, including the first-line drug gemcitabine. Gemcitabine is a nucleoside pyrimidine analog that has long been the backbone of chemotherapy for PDAC, both as a single agent, and more recently, in combination with nab-paclitaxel. Since gemcitabine is hydrophilic, it must be transported through the hydrophobic cell membrane by transmembrane nucleoside transporters. Human equilibrative nucleoside transporter-1 (hENT1) and human concentrative nucleoside transporter-3 (hCNT3) both have important roles in the cellular uptake of the nucleoside analog gemcitabine. While low expression of hENT1 and hCNT3 has been linked to gemcitabine resistance clinically, mechanisms regulating their expression in the PDAC tumor microenvironment are largely unknown. We identified that the matricellular protein Cysteine-Rich Angiogenic Inducer 61 (CYR61) negatively regulates expression of hENT1 and hCNT3. CRISPR/Cas9-mediated knockout of CYR61 significantly increased expression of hENT1 and hCNT3 and cellular uptake of gemcitabine. CRSIPR-mediated knockout of CYR61 sensitized PDAC cells to gemcitabine-induced apoptosis. Conversely, adenovirus-mediated overexpression of CYR61 decreased hENT1 expression and reduced gemcitabine-induced apoptosis. We demonstrate that CYR61 is expressed primarily by stromal pancreatic stellate cells (PSCs) within the PDAC tumor microenvironment, with Transforming Growth Factor- β (TGF-β) inducing the expression of CYR61 in PSCs through canonical TGF-β-ALK5-Smad signaling. Activation of TGF-β signaling or expression of CYR61 in PSCs promotes resistance to gemcitabine in an in vitro co-culture assay with PDAC cells. Our results identify CYR61 as a TGF-β induced stromal-derived factor that regulates gemcitabine sensitivity in PDAC and suggest that targeting CYR61 may improve chemotherapy response in PDAC patients.</p> / Dissertation