No description available.

No description available.

The enzyme soluble epoxide hydrolase (sEH) plays a major role in the pathogenesis and pathophysiology of neurodegenerative diseases like depression by catalyzing the hydrolysis of epoxyeicosatrienoic acids (EETs) into dihydroxyicosatrienoicacids (DHETs), its less biologically active form, influencing the anti-inflammatory system and promoting inflammation. Therefore, inhibiting sEH leads to increased levels of EETs, reducing inflammation, especially in the brain and can help mitigate neurodegenerative diseases. This study investigated sEH inhibition by a phenolic carotenoid compound, astaxanthin and its inhibitory mechanism of action. Enzyme inhibitory activity and kinetics demonstrated that astaxanthin had a half-maximal inhibitory concentration (IC50) of 26 ± 0.92 μM and is a mixed-non-competitive inhibitor of sEH. In silico ADME/tox analysis showed that astaxanthin is bioavailable, biostable, and non-toxic when taken orally. Molecular docking study demonstrated that astaxanthin binds to an allosteric site of sEH and formed a contact and clashing-only interaction with the ASP333 residue of the hydrolase pocket of sEH. In this study, we highlight the potential therapeutic application of astaxanthin as a natural sEH inhibitor in the treatment of inflammation-related diseases, particularly neurodegenerative diseases.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:01:57Z No. of bitstreams: 1 DIS_KEILA_ABREU_DA_SILVEIRA_PARCIAL.pdf: 1040292 bytes, checksum: 89e950465b4a1448b10bb99039287e7a (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-30T18:02:03Z (GMT) No. of bitstreams: 1 DIS_KEILA_ABREU_DA_SILVEIRA_PARCIAL.pdf: 1040292 bytes, checksum: 89e950465b4a1448b10bb99039287e7a (MD5) / Made available in DSpace on 2017-06-30T18:02:11Z (GMT). No. of bitstreams: 1 DIS_KEILA_ABREU_DA_SILVEIRA_PARCIAL.pdf: 1040292 bytes, checksum: 89e950465b4a1448b10bb99039287e7a (MD5) Previous issue date: 2017-03-03 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Background: asthma is a heterogeneous disease characterized by chronic inflammation of the lower airways. The inflammatory process is associated with bronchial hyperresponsiveness, resulting in recurrent episodes of wheezing, coughing, dyspnea and chest tightness. Asthma affects around 300 million people worldwide, with high prevalence, mainly in children. Chronic inflammation in the airways of patients with asthma is complex and involves a range of cells from the immune system, including T lymphocytes, granulocytes, epithelial cells, among others. Granulocytes are considered key cells to maintain inflammation. Neutrophils and eosinophils have different characteristics and functions for the immune response in asthma. Both type of cells release a variety of mediators that contribute to chronic inflammation and changes in the structure of the airways, secondary to external agents. In this context, it was demonstrated that after activation neutrophils and eosinophils are able to release extracellular DNA "traps" with specific proteins that kill extracellular pathogens. On the other hand, it is possible that these DNA "traps" contribute to immunopathology in chronic inflammatory diseases, such as asthma. Therefore, it has recently been shown that neutrophils and eosinophils generate extracellular DNA traps in the airways of asthmatics, possibly contributing to tissue damage. Objective: to verify whether there is extracellular DNA traps and the presence of inflammatory cells in sputum samples of children and adolescents with asthma. Methods: this cross-sectional study selected children and adolescents with asthma, between 6 and 18 years of age, in a regular follow-up at a reference center from southern Brazil. We have performed lung function (spirometry), allergen skin test, and induced sputum to identify the inflammatory cells profile, formation of extracellular DNA traps, and quantification of extracellular DNA. To visualize the extracellular DNA traps, the cells were stained with Hoechst 33342. The images were captured on a fluorescence confocal microscope. Results: 18 children and adolescents were included, 13 with severe asthma and 5 with non-severe asthma. Of these, 17 (94.4%) had a positive skin test for some type of allergens and all patients presented pulmonary function within the limits of normality. Patients with inflammatory cell profiles in sputum (7,12 [4,41,45,23]) showed a significant increase (p = 0.01) in extracellular DNA concentrations compared to patients with pauci-granulocytic profile (2.31 [1.47-3.56]). The extracellular DNA levels correlated positively (r = 0.73, p = 0.004) with the total granulocytic cells in the sputum of these patients. Likewise, there was a significant positive correlation between extracellular DNA and absolute sputum neutrophil counts (r = 0.71, p = 0.008) and absolute sputum eosinophils counts (r = 0.69; p = 0.0013) in the sputum samples. Conclusion: Our results show the presence of extracellular DNA traps in sputum with inflammatory pattern of children and adolescents with asthma suggesting that these traps are released by granulocytic cells, specifically neutrophils and eosinophils. / Base te?rica: a asma ? uma doen?a heterog?nea, caracterizada pela inflama??o cr?nica das vias a?reas inferiores. O processo inflamat?rio est? associado ? hiper-responsividade br?nquica, tendo como consequ?ncia, epis?dios recorrentes de sibil?ncia, tosse, dispneia e opress?o tor?cica. A doen?a atinge em torno de 300 milh?es de pessoas no mundo, sendo considerada uma doen?a com elevada preval?ncia, principalmente na popula??o infantil. A inflama??o cr?nica presente nas vias a?reas de indiv?duos com asma ? complexa e envolve um conjunto de c?lulas provenientes do sistema imunol?gico, incluindo linf?citos T, granul?citos, c?lulas epiteliais, entre outras. Os granul?citos s?o considerados c?lulas fundamentais para sustentar a inflama??o. Os neutr?filos e os eosin?filos apresentam caracter?sticas e fun??es diferentes para a resposta imune na asma. Ambos liberam uma variedade de mediadores que contribuem para inflama??o cr?nica e altera??es na estrutura das vias a?reas, com est?mulos externos. Neste contexto, foi demonstrado que os neutr?filos e eosin?filos, ap?s ativa??o, s?o capazes de liberar ?armadilhas? de DNA extracelular com prote?nas espec?ficas, que combatem agentes patog?nicos extracelularmente. Por outro lado, ? poss?vel que essas ?armadilhas? de DNA contribuam para a imunopatologia em doen?as inflamat?rias cr?nicas, como na asma. Portanto, recentemente, foi identificado que neutr?filos e eosin?filos geram redes extracelulares de DNA nas vias a?reas de asm?ticos adultos. Objetivo: verificar se existe forma??o de redes extracelulares de DNA com a presen?a de c?lulas inflamat?rias em amostra de escarro de crian?as e adolescentes com asma. M?todos: nosso estudo transversal selecionou crian?as e adolescentes com asma, entre 6 e 18 anos de idade, em acompanhamento regular em um centro de refer?ncia do sul do Brasil. Foram coletados dados relativos a fun??o pulmonar (espirometria), teste cut?neo para al?rgenos, e escarro induzido para identifica??o do perfil de c?lulas inflamat?rias, forma??o das redes extracelulares de DNA, e quantifica??o do DNA extracelular. Para a visualiza??o das redes extracelulares de DNA, as c?lulas foram coradas com Hoechst 33342. As imagens foram capturadas em microsc?pio confocal de fluoresc?ncia. Resultados: foram inclu?dos 18 crian?as e adolescentes, sendo 13 com asma grave e 5 n?o grave. Destes, 17 (94,4%) obtiveram o teste cut?neo positivo para algum tipo de al?rgenos e todos apresentaram fun??o pulmonar dentro dos limites da normalidade. Os pacientes com perfil de c?lulas inflamat?rias (7,12 [4,41-45,23]) obtiveram um aumento significativo (p=0,01) nas concentra??es extracelulares de DNA quando comparados com pacientes com perfil pauci-granuloc?tico (2,31[1,47-3,56]). Os n?veis de DNA extracelular correlacionaram-se positivamente (r=0,73; p=0, 0004) com as c?lulas granuloc?ticas totais no escarro destes pacientes. Do mesmo modo, houve uma correla??o positiva entre o DNA extracelular com a contagem absoluta de neutr?filos (r=0,71; p=0,008) e contagem absoluta de eosin?filos (r=0,69; p=0,0013) nas amostras de escarro. Conclus?o: nossos resultados mostram a presen?a de redes extracelulares de DNA no escarro com padr?o inflamat?rio em crian?as e adolescentes com asma sugerindo que estas redes s?o liberadas por c?lulas granuloc?ticas, especificamente neutr?filos e eosin?filos.

Las enfermedades priónicas, también conocidas como EETs (Encefalopatías Espongiformes Transmisibles), son un grupo de enfermedades neurodegenerativas fatales que, debido a su transmisibilidad potencial han tenido un gran impacto social, político y económico en las últimas décadas. Las EETs afectan a los humanos y a algunos grupos de animales, presentan largos períodos de incubación y producen la muerte pocos meses después de la aparición de la sintomatología clínica. Su origen se atribuye a la presencia, multiplicación y deposición de una proteína anormal llamada prión. El prión (o PrPSc) es una forma mal conformada de la proteína priónica celular (PrPc), presente en condiciones fisiológicas en las membranas de las células. El prión es parcialmente resistente a las proteasas, resistente a desinfectantes físico-químicos convencionales, y capaz de convertir de forma auto-catalítica a la PrPc dando lugar a la propagación en cadena de la forma patogénica. El prión es transmisible, no sólo entre individuos de una misma especie sino también entre individuos de especies diferentes. Las EETs animales más importantes son el scrapie, que afecta a las ovejas y las cabras, y la encefalopatía espongiforme bovina (EEB), que afecta a las vacas (vulgarmente conocida como "mal de las vacas locas").En el caso de las EETs humanas, las más relevantes son la enfermedad de Creutzfeldt-Jakob (ECJ), el síndrome de Gerstmann-Sträussler-Scheinker (GSS), el insomnio familiar fatal (FFI) y el Kuru. La ECJ tiene una incidencia de 1 o 2 casos por millón de habitantes y año en todo el mundo, afecta por igual a hombres y mujeres, y cursa con demencia, mioclonías y ataxia cerebelar. Neuropatológicamente, provoca pérdida neuronal, astrocitosis, microgliosis y cambio espongiforme. La presencia de la proteína 14-3-3 en el LCR y de un EEG típico, son factores diagnóstico, aunque el diagnóstico definitivo se hace a nivel post-mortem con la detección de la PrPSc por inmunohistoquímica y/o western blot.El impacto social y sobre la salud pública y animal que han tenido las enfermedades priónicas en las últimas décadas fue originado, en gran medida, por la epidemia de EEB que afectó en los años 90 al Reino Unido, principalmente. Esta epidemia se atribuyó a la alimentación de las vacas con piensos enriquecidos con proteínas procedentes de ovejas infectadas con scrapie. Debido a la transmisibilidad ínter-específica de los priones, éstos infectaron a las vacas y éstas, al pasar a la cadena alimenticia, a los humanos, dando lugar a la nueva variante de la ECJ. La ECJ tiene un origen esporádico en un 85% de los casos, es decir, el inicio de la enfermedad se produce de manera espontánea, a pesar de que éste se asocia a la presencia de priones residuales en el SNC, a la generación de mutaciones puntuales en el gen de la PrP (PRNP) o bien a la conversión espontánea de la PrP debido a alteraciones físico-químicas de la proteína. En el 10% de los casos, la ECJ es genética y hereditaria, es decir, se atribuye a mutaciones en el PRNP que pasan a las células germinales y a la nueva generación. En este escenario, se habla de ECJ familiar. El 5% de los casos de ECJ restantes se asocian a una transmisión iatrogénica, es decir, por contaminación durante transplantes, tratamientos hormonales, manipulación quirúrgica, etc., aunque este tipo de transmisión está prácticamente erradicada. El propósito general de esta tesis es el estudio de las EETs dirigido a incrementar el conocimiento acerca de los mecanismos celulares y moleculares implicados en la neuropatología de estas enfermedades. Si bien la multiplicación y deposición del prión se consideran los detonantes de la neuropatología y sintomatología clínica asociadas a las EETs, es asumible que los mecanismos involucrados en estas alteraciones sean complejos y tengan un origen multifactorial. En este escenario, las alteraciones en la neurotransmisión y la disfunción de algunos grupos de proteínas relacionados con la supervivencia celular se consideran cruciales en el desarrollo de las enfermedades priónicas y de sus fenómenos neuropatológicos asociados. Atendiendo a las observaciones anteriores, esta tesis se ha enfocado a estudiar el papel que juegan ciertos grupos de proteínas en la neurotransmisión, la espongiosis y la muerte neuronal. Para abordar experimentalmente cada una de estas líneas de interés, nuestros estudios van ecaminados a: conocer el estado de la vía de señalización vinculada a la transmisión glutamatérgica y de adenosina; conocer el papel de los canales de agua o aquaporinas cerebrales en relación a la vacuolización y al cambio espongiforme característico de las EETs y, por último, estudiar la vía de señalización de las MAPKs en relación a la degeneración neuronal. Estos estudios se realizan sobre corteza frontal de material humano post-mortem de casos con ECJ y sobre la corteza cerebral de un modelo murino de la EEB, esto es, de ratones transgénicos para la PrP bovina infectados con EEB en diferentes estadíos de desarrollo de la enfermedad. Los resultados obtenidos muestran, en primer lugar, un deterioro de las vías de señalización de los receptores metabotrópicos de glutamato de grupo I en la corteza frontal de ECJ así como en la corteza cerebral de un modelo murino de la EEB asociado al progreso de la enfermedad, lo cual sugiere que las fosfolipasas y los elementos constituyentes de la transducción de señales de dicha vía son particularmente sensibles a las EETs. En segundo lugar, se ha encontrado un incremento de la expresión y la actividad de los receptores A1 de adenosina en la corteza frontal de casos con ECJ así como un aumento de la expresión de estos receptores en corteza cerebral de un modelo murino de la EEB asociado al progreso de la enfermedad. El incremento en los niveles de A1Rs puede ser una respuesta al daño neuronal, teniendo en cuenta su papel neuroprotector en el SNC. En tercer lugar, se ha detectado un incremento de la expresión de AQP1 y AQP4 en la corteza frontal de casos con ECJ así como en la corteza cerebral de un modelo murino de la EEB asociado al progreso de la enfermedad. El incremento de la expresión de AQPs se puede asociar a una alteración de la homeostasis celular y a la formación de vacuolas que pueden contribuir al cambio espongiforme característico de las enfermedades priónicas. Por último, se ha encontrado un descenso de los niveles proteicos de los factores de transcripción c-fos y CREB en la corteza frontal de casos con ECJ, en contraste con el mantenimiento de los niveles de las MAPKs. El agotamiento de c-fos y CREB puede inducir neurodegeneración en estadios terminales de ECJ, considerando su papel mediador en los fenómenos de muerte y supervivencia celular.Si bien, los resultados que se desprenden de esta tesis mejoran la comprensión de los fenómenos celulares y moleculares que acompañan a la patología de las EETs, serán necesarios estudios ulteriores con modelos celulares y animales para conocer con mayor exactitud de qué modo y en qué medida contribuye el prión a estas alteraciones. / Prion diseases, also known as Transmissible Spongiform Encephalopathies (TSEs), are a group of fatal neurodegenerative diseases that have had an important social, political and economical impact in the last decades, according to their potential transmissibility. TSEs affect human and animals, and their incubation period is long. They caused death after a few months from the first clinical symptoms. TSEs origin is associated to the presence, multiplication and deposition of an abnormal protein called prion. Prion, also called PrPSc, is an abnormal form of the cellular prion protein (PrPC), which is a cell-anchored glycoprotein expressed in a wide range of animal tissues but it is enriched into the central nervous system (CNS). Prions are partially resistant to protease digestion and also resistant to conventional physical-chemical treatments. Prions are able to recruit PrPC leading to the propagation of the pathogenic conformation. Prions are transmissible, not only between individuals from the same specie, but also between individuals from different species.The most important animal TSEs are scrapie, affecting sheep and goats, and Bovine Spongiform Encephalopathy (BSE) affecting cows (also called mad cow disease). In humans, TSEs include Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), Fatal Familial Insomnia (FFI) and Kuru. CJD has an incidence of 1 or 2 cases per million of population within a year around the world, affects both men and women and causes dementia, myoclonia and cerebellar ataxia. Neuropathologically, CJD is characterized by neuron loss, astrocytosis, mycroglyosis and spongiform change. The presence of 14-3-3 protein in CSF and a typical EEG are diagnosis factors but final diagnosis is done by PrPSc detection by immunohistochemistry of Western blotting. The impact of TSEs on public and animal health in the last decades was originated, mainly, by the BSE epidemic which affected United Kingdom in the nineties. This epidemic was attributed to the enrichment of cows food with proteins derived from scrapie-infected sheep. Due to the inter-specific transmissibility of prions, cows became infected from consumption of cow-derived food. CJD has a sporadic origin in 85% of cases. This origin is associated to the presence of residual prions into the brain or to punctual mutations in the prion protein gene (PRNP) or to a spontaneous PrP conversion due to physical or chemical environmental changes. The rest of CJD cases have an inherited or an iatrogenic transmission.The general purpose of this thesis is the study of TSEs directed to increase knowledge about cellular and molecular mechanisms involved in the neuropathology of prion diseases. It can be assumed that the multiplication and accumulation of prions into the CNS are likely the causes of TSEs, but also that mechanisms associated to neuropathologycal alterations linked to prion pathology have probably a multifactor origin. In this scenario, the alterations in neurotransmission and the dysfunction of many groups of proteins related to cell survival are considered crucial in the development of prion diseases and their neuropathological features. Giving some consideration to these observations, this thesis has been focused in the study of the role of some groups of proteins in neurotransmission, spongiform change and neuron loss. More specifically, we have studied signalling pathways linked to glutamate and adenosine transmission, water channel brain aquaporins in relation with vacuolization and spongiform change, and MAPKs signaling in relation with neurodegeneration. All these studies have been done on human cerebral cortex from neurological post-mortem material of CJD cases and on the cerebral cortex of BSE-infected PrP-bovine transgenic mice at different stages of disease progression. The results obtained show, first of all, impaired group I metabotropic glutamate transmission and also increased adenosine A1 receptor signaling in the cerebral cortex of CJD cases and, on the other hand, in the cerebral cortex of a BSE murine model with disease progression. Increased adenosine A1 receptor levels could be a response to neuronal damage due to the neuroprotective role of these receptors into the brain. In addition, we have found an increased AQP1 and AQP4 expression in the cerebral cortex of CJD cases and in the cortex of a BSE murine model with disease progression. Increased AQPs expression in brain could be associated with abnormal cell homeostasis and with the formation of vacuoles which can lead to spongiform change. Finally, we have also found decreased c-fos and CREB levels, in both inactivated and activated forms, in frontal cortex of CJD cases and also in the cerebral cortex of a BSE murine model with disease progression. Decreased c-fos and CREB transcription factors are associated with cell death and cell death, so could lead to neurodegeneration in terminal stages of CJD. Although the results presented here can improve the understanding of cellular and molecular events involved in TSEs pathology, further studies using animals and cell models would be necessary to know more exactly whether prions can lead to these alterations.

This thesis deals with the issue of interoperability of electronic toll systems in road transport. The first chapter contains basic information from the charging of infrastructure with a focus on technology EFC systems. The second chapter focuses on chosen toll systems. The third chapter is focused on the European Electronic Toll Service and the basic concepts of interoperability. The fourth chapter is a key part dealing with interoperable EFC systems in Europe. The final part of this thesis evaluates this topic and summarizes the basic knowledge, while also evaluates the state of charging infrastructure in the Czech Republic and its possibility of development in the field of interoperability EFC.

The thesis deals with electronic fee collection systems and their interoperability within European Electronic Toll Service. It closely looks on future of Czech EFC system with scope on dealing with obligations of European Electronic Toll Service legislation. In the first part the basic terms of EFC systems are described and basic technologies to be used within EFC systems are explained. The second part then deals with European Electronic Toll Service matters, its legislation and present stage of implementation. In the third part, there are specific technological applications on national EFC systems of chosen European Union countries described. The last part closely describes Czech EFC system, its history, present and its possible future outcomes.