Submitted by Cleide Dantas (cleidedantas@ufpa.br) on 2014-02-05T14:34:49Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_FatorCrescimentoNeuronal.pdf: 38042844 bytes, checksum: b2a216ed89436f7be2266c82bad857e1 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2014-02-05T16:32:48Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_FatorCrescimentoNeuronal.pdf: 38042844 bytes, checksum: b2a216ed89436f7be2266c82bad857e1 (MD5) / Made available in DSpace on 2014-02-05T16:32:48Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Tese_FatorCrescimentoNeuronal.pdf: 38042844 bytes, checksum: b2a216ed89436f7be2266c82bad857e1 (MD5) Previous issue date: 2013 / FAPESPA - Fundação Amazônia de Amparo a Estudos e Pesquisas / A esquistossomose é uma doença tropical causada, principalmente, pelo trematódeo Schistosoma mansoni, sendo que sua ocorrência afeta, mundialmente, 110 milhões de pessoas. A deposição dos ovos do parasita pode ocorrer, de forma ectópica, no sistema nervoso central (SNC) o qual leva à formação de granulomas com consequente produção do Fator de Crescimento Neuronal (NGF). Uma vez que muitos estudos demonstram a importância do NGF no desenvolvimento das vias corticais visuais, nosso estudo visou avaliar a possível alteração dos níveis de NGF no sistema visual assim como o impacto deste sobre a morfologia de células piramidais em dois modelos animais. A alteração na concentração do fator de crescimento assim como a morfometria neuronal foram avaliadas em animais permissíveis (camundongos) e não permissíveis (ratos) à infecção. Foram utilizados 174 ratos (Hooded Lister) e 135 camundongos albinos criados e mantidos em gaiolas e alimentados ad libitum. Esses animais foram inoculados, logo após o nascimento, com 50 cercárias. Setenta e sete ratos e 73 camundongos foram inoculados com solução salina e constituíram o grupo controle do estudo. Os períodos de infecção abrangeram uma a 48 semanas. Amostras do fígado e córtex visual foram retiradas, extraídas e quantificadas com kit de imunoensaio (ChemiKineTM Nerve Growth Factor (NGF) Sandwich ELISA Kit – Chemicon International). Para a análise morfométrica utilizamos células piramidais da camada IV do córtex visual marcadas através de injeção extracelular com Dextrana-Biotinilada (10.000 kDa). Os resultados foram expressos como média ± desvio padrão. Utilizamos teste t de Student para determinar diferenças estatísticas entre os grupos estudados. O valor médio de NGF encontrado no córtex visual de ratos infectados foi 39,2% maior do que no grupo controle (infectados: 400,9 ± 143,1 pg/mL; controle: 288 ± 31,9 pg/mL; p < 0,0001). Nas amostras de fígado, o aumento foi 28,9% maior no grupo infectado (infectados: 340,9 ± 103,9 pg/mL; p < 0,01; controle: 264,4 ± 38,6 pg/mL). Nenhum aumento significativo foi detectado antes de uma semana de infecção. Entre os camundongos, o aumento de NGF na área visual foi de 94,1% (infectados: 478,4 ± 284 pg/mL; p < 0,01; controle: 246,5 ± 76,8 pg/mL). No fígado destes animais o aumento foi de 138,7% (infectados: 561,8 ± 260,7 pg/mL; p < 0,01; controle: 301,3 ± 134,6 pg/mL). Em camundongos encontramos diferenças significativas quanto aos parâmetros dendríticos avaliados. A quantidade de dendritos foi 11,41% maior no grupo infectado do que no controle (controle: 25,28 ± 5,19; infectados: 28,16 ± 7,45; p < 0,05). O comprimento total dos dendritos também foi afetado (controle: 4.916,52 ± 1.492,65 μm; infectados: 5.460,40 ± 1.214,07 μm; p < 0,05) correspondendo a um aumento de 11,06%. A área total do campo receptor dendrítico sofreu um aumento de 12,99% (controle: 29.346,69 ± 11.298,62 μm2; infectados: 33.158,20 ± 7.758,31; p < 0,05) enquanto que a área somática teve uma redução de 13,61% (controle: 119,38 ± 19,68 μm2; infectados: 103,13 ± 24,69 μm2; p < 0,001). Quando foram avaliados os efeitos do aumento de NGF em ratos infectados não observamos diferenças significativas quanto aos parâmetros dendríticos analisados, em comparação ao grupo controle, com exceção de um aumento na área do corpo neuronal da ordem de 21,18% (controle: 132,20 ± 28,46 μm2; infectados: 160,20 ± 31,63 μm2; p < 0,00001). Este trabalho mostrou que a reação de produção de NGF no SNC durante a infecção por Schistosoma mansoni ocorre em maior magnitude no modelo permissível do que no modelo não permissível. Também demonstramos que, em camundongos, os efeitos sobre a morfologia neuronal é drasticamente afetada quando o organismo é submetido a um aumento na concentração de NGF em decorrência da infecção por Schistosoma mansoni. Diante destes dados, estudos avaliando as possíveis repercussões visuais e também dos efeitos na fisiologia celular causados pela infecção mansônica torna-se necessário para avaliar o real dano causado por este aumento patológico do fator de crescimento neuronal nas vias visuais de mamíferos. / Schistosomiasis is a tropical disease caused by Schistosoma mansoni. His occurrence affects 110 million people worldwide. The deposition of eggs of the parasite may occur - in ectopic form – in the central nervous system (CNS) which leads to the formation of granulomas with consequent production of nerve growth factor (NGF). Since several studies have demonstrated the importance of NGF in the development of visual cortical pathways, our study aimed at evaluating the possible changes in the NGF concentratons in the visual system as well as the impact of this on the pyramidal cell morphology in two animal models. The change in concentration of the nerve growth factor as well as neuronal morphology were evaluated in suscetible and non-suscetible animals (mice and rats) to infection. We used 174 rats (Hooded Lister) and 135 albino mice bred and kept in cages and fed ad libitum. These animals were infected shortly after birth, with 50 cercariae. Seventy seven rats and 73 mice were inoculated with saline and constituted the control group of the study. The infection covered a period of 48 weeks . Samples of liver and visual cortex were removed, extracted and quantified with immunoassay kit (ChemiKineTM Nerve Growth Factor (NGF) Sandwich ELISA Kit - Chemicon International). For the morphometric analysis we used the pyramidal cells of the visual cortex layer IV marked by extracelular injection of biotinylated dextran (10,000 kDa). The results were expressed as mean ± standard deviation. We used Student t test to determine statistical differences between groups. The average value of NGF found in the visual cortex of rats infected was 39.2% higher than in the control group (infected: 400.9 ± 143.1 pg/ml, control: 288 ± 31.9 pg/mL, p < 0.0001). In liver samples, the increase was 28.9% higher in the infected group (infected: 340.9 ± 103.9 pg/mL, p < 0.01, control: 264.4 ± 38.6 pg/mL). No significant increase was detected within a week of infection. Among the mice group, the increase of NGF in the visual area was 94.1% (infected: 478.4 ± 284 pg/ml, p < 0.01; control: 246.5 ± 76.8 pg/ml). In the liver of these animals the increase was 138.7% (infected: 561.8 ± 260.7 pg/mL, p < 0.01, control: 301.3 ± 134.6 pg/mL). In mice group we found significant differences in dendritic parameters evaluated. The number of dendrites was 11.41% higher in the infected group than in the control (control: 25.28 ± 5.19; infected: 28.16 ± 7.45, p < 0.05). The total length of dendrites was also affected (control: 4916.52 ± 1492.65 μm; Infected: 5460.40 ± 1214.07 μm; p < 0.05), representing an increase of 11.06%. The total area of the dendritic receptive field was increased by 12.99% (control: 29.346,69 ± 11.298,62 μm2; Infected: 33.158,20 ± 7.758,31 μm2, p < 0.05) while the area had a somatic reduction of 13.61% (control: 119.38 ± 19.68 μm2; infected: 103.13 ± 24.69 μm2, p < 0.001). When we evaluated the effects of increased NGF in rats infected we did not observe significant differences in dendritic parameters analyzed, compared to the control group, except for an increase in the area of the neuronal body of approximately 21.18% (control: 132,20 ± 28.46 μm2; infected: 160.20 ± 31.63 μm2, p < 0.00001). This work showed that the reaction production of NGF in the CNS during infection with Schistosoma mansoni occurs in greater magnitude than permissible in the model in the model impermissible. We also demonstrated that in mice the effects on neuronal morphology is dramatically affected when the body is subjected to an increase in the concentration of NGF as a result of infection by Schistosoma mansoni. Given these data, studies evaluating the potential impact of visual effects and also in cell physiology caused by schistosomiasis infection becomes necessary to assess the actual damage caused by this pathological increase of nerve growth factor in the visual pathways of mammals.

Temperature and rainfall vary spatially within South Africa and they in turn affect the parasites and intermediate host snails involved in schistosomiasis transmission. The primary goal of this study was to investigate the relationship between these two abiotic variables and schistosomiasis in South Africa using a Geographic Information System (GlS) as a spatial analytical tool. The secondary goal was to estimate the population exposure to schistosomiasis. Prevalence data for Schistosoma haematobium and S. mansoni obtained from a national hardcopy atlas and two long-term, retrospective, high resolution climate datasets were used to produce two models (temperature-suitability and regression analysis) based on different GIS methodologies. The temperature-suitability model defined areas that are suitable and unsuitable for disease transmission by relating documented temperature regimes to the schistosomes' larval biology. The map outputs show that temperature minima corresponded better with the disease data than temperature maxima. Based on different climate and population data permutations, between approximately 3 903 734 and 4 379 079 school-aged children live in these temperature-suitable zones. The regression model tested the hypothesis that temperatures, especially during spring and summer favoured schistosomiasis transmission more than those of autumn and winter. Positive associations were expected with the rainfall variables. A logistic equation was used to predict, as accurately as possible within the model's limitations, the probability of schistosomiasis occurring in a given area. Increasing annual rainfall, as well as spring and autumn temperature maxima and minima predicted an increase in S. haematobium prevalence rates. Schistosoma haematobium prevalence rates of 11-25% and 26-50% were predicted in the north-eastern and eastern coastal regions. A prevalence rate of 71 to 100% was predicted from Limpopo to KwaZulu-Natal. Increasing the average monthly rainfall, spring temperature maxima and autumn temperature minima, increased the likelihood of S. mansoni transmission. Schistosoma mansoni prevalence rates of 26-50% and 71 to 100% were predicted in Limpopo, Mpumalanga, KwaZulu- Natal and Eastern Cape. This is the first time GIS has been used to correlate climate variables and schistosomiasis occurrence in South Africa. The regression model requires further refinement and it is not as applicable as the temperature-suitability model for practical purposes. / Thesis (M.Sc.)-University of Natal, Durban, 2003.

Les récepteurs Venus Kinase ou VKR forment un nouvelle famille de récepteurs tyrosine kinase découverts au laboratoire. Ces récepteurs sont caractérisés par une organisation atypique associant un domaine extracellulaire de type Venus Flytrap (VFT) similaire à ceux des récepteurs couples aux protéines G de classe C à un domaine Tyrosine Kinase (TK) intracellulaire similaire à celui du récepteur à l'insuline (IR). Cette famille est présente uniquement chez les invertébrés dont notre modèle d'étude, le parasite plathelminthe Schistosoma mansoni. Les travaux réalisées à ce jour suggèrent que ces protéines jouent un rôle dans le développement des stades larvaires et la reproduction sexuée. Mon travail de thèse s'est intéressé à l'étude de cette famille de récepteurs et comporte trois axes principaux. Le premier concerne la mise à jour phylogénétique de la famille des VKR. Une analyse approfondie des données génomiques récentes nous a permis d'étendre la présence des VKR à près de 50 espèces dans cinq phyla invertébrés. La présence d'un VKR chez le cnidaire Nematostella vectensis suggère une émergence du récepteur avant l'apparition des bilatéraliens. Des analyses phylogénétiques ont mis en évidence la monophylie de l'ensemble des récepteurs ainsi que des importants niveaux de conservation des motifs fonctionnels VFT et TK. Des analyses de modélisation du domaine de fixation au ligand suggèrent que la majorité de ces récepteurs puissent être activables par des acides aminés de type L-Arginine. La découverte de VKR chez Nematostella vectensis, Lottia gigantea ou Capitella teleta s'avère prometteuse dans la mesure où ces modèles se prêtent parfaitement à l'embryologie moléculaire, et pourraient être utilisés pour étudier la fonction des VKR dans l'embryogenèse.La deuxième partie de mon travail s'est intéressée à la caractérisation fonctionnelle de SmVKR1 et SmVKR2, les deux VKR de Schistosoma mansoni. En utilisant le modèle d'expression ovocyte de Xénope, nous avons pu dans un premier temps déterminer que SmVKR1 et SmVKR2 sont activables par plusieurs et différents L-acides aminés. L'identification de partenaires intracellulaires par un criblage en double hybride de levure nous a permis de déterminer de nouveaux et inattendus partenaires d'interaction, suggérant des fonctions dans l'activation de voies TK conservées, mais également dans le remodelage du cytosquelette ou la synthèse protéique. Si les deux récepteurs activent les voies Akt, S6K et Erk1/2, seul SmVKR1 est capable d'activer la voie JNK. Les profils d'expression ont été déterminés par hybridation in situ et, si les deux gènes s'expriment dans l'ovaire, la localisation des transcrits est clairement distincte avec une expression de SmVKR2 au sein des ovocytes immatures et de SmVKR1 dans les ovocytes matures. Enfin des expériences d'ARN interférence sont venues confirmer un rôle de ces récepteurs au sein de l'ovogenèse, la diminution d'expression entraînant des phénotypes délétères sur la croissance et ovocytes et la ponte des oeufs. L'étude des voies de signalisation SmVKR1 a été également été entreprise au laboratoire, mettant en évidence l'importance de la protéine adaptatrice SmShb dans l'induction de la voie JNK par SmVKR1. L'ensemble de des résultats suggère que SmVKR1 aurait une fonction dans la migration des ovocytes et/ou dans la reprise de méiose par l'activation de la voie JNK, tandis que SmVKR2 aurait un rôle plus précoce, dans la croissance et/ou la prolifération des ovogonies. Enfin la dernière partie de mon travail de these visait à determiner si les VKR peuvent être considérés comme des cibles thérapeutiques intéressantes en vue du développement de nouvelles drogues anti parasitaires. [...]

La schistosomiase représente actuellement la seconde endémie parasitaire mondiale après le paludisme. Annuellement, cette pathologie est responsable de 280 000 décès et 700 millions d'individus y sont exposés dans 74 pays à travers le monde. Actuellement, le traitement de la schistosomiase repose sur l'utilisation d'un seul médicament, le Praziquantel®. Ainsi, le développement de nouveaux médicaments est devenu une priorité absolue pour l'OMS. Dans cette étude, notre objectif a été d'identifier de nouvelles cibles thérapeutiques afin de développer de nouveaux précurseurs de médicaments. Au cours de ce projet, nous avons focalisé nos recherches sur les enzymes impliquées dans la modification des histones et plus particulièrement sur les sirtuines, qui sont des lysines désacétylases NAD+ dépendantes.Dans une première partie, nous avons caractérisé 5 orthologues de sirtuines de mammifères chez Schistosoma mansoni (SmSirt1, 2, 5, 6 et 7). De plus, nous avons étudié le potentiel des sirtuines comme cibles thérapeutiques pour le traitement de la schistosomiase en évaluant la toxicité d'inhibiteurs génériques de sirtuines humaines sur des parasites maintenus en culture. Ainsi, nous avons montré que les inhibiteurs de sirtuines humaines affectent in vitro la viabilité des schistosomules ainsi que la stabilité de l'accouplement et la production d'oeufs des vers adultes. De plus, ces inhibiteurs induisent des changements morphologiques de l'appareil génital du ver femelle.Dans une seconde partie, nous avons entrepris d'étudier plus spécifiquement le rôle de SmSirt2 en tant que cible thérapeutique. Ainsi, l'expression de la protéine recombinante en bactérie E. coli (collaboration: C. Romier, IGBMC, Illkirch) ainsi que l'optimisation d'un dosage fluorimétrique nous ont permis de montrer que SmSirt2 présente une activité lysine désacétylase in vitro (collaboration: M. Jung, Université Albert-Ludwigs, Freibourg). De plus, l'utilisation de ce dosage nous a permis de mettre en place le criblage à haut débit d'une chimiothèque de plus de 80 000 composés afin d'identifier de nouvelles molécules inhibitrices de l'enzyme SmSirt2 (collaboration: J. Schultz, Kancera AB, Stockholm). Les composés les plus prometteurs, ont été testés in vitro sur des parasites en culture. Les résultats obtenus démontrent que les inhibiteurs de SmSirt2 affectent également la viabilité des schistosomules ainsi que la stabilité de l'accouplement et la production d'oeufs des vers adultes.Dans une dernière partie, nous avons mis en place un criblage d'une banque d'ADNc de vers adultes par la technique du double hybride en levure dans le but d'identifier les partenaires protéiques de Sirt1 chez S. mansoni. L'analyse partielle des résultats nous a permis de mettre en évidence que SmSirt1 interagit avec plusieurs protéines impliquées dans la régulation des gènes chez le schistosome. Au cours de ce projet, nous avons également développé et optimisé un protocole permettant d'étudier l'activité enzymatique de SmSirt1 par injection d'ARNm dans des ovocytes de Xénope. Ainsi, nous avons pu montrer que le sirtinol et la salermide, deux inhibiteurs de Sirt1 humaine, présentent également une activité inhibitrice sur l'enzyme du parasite (collaboration: K. Cailliau, Université des Sciences et Technologies, Lille).L'ensemble des résultats obtenus au cours de ce projet de thèse suggère que les sirtuines sont des cibles thérapeutiques potentielles dans le traitement de la schistosomiase. Parmi les 5 orthologues identifiés chez S. mansoni, SmSirt2 semble une cible prometteuse. De plus, le criblage à haut débit que nous avons réalisé sur l'enzyme recombinante a permis d'identifier des molécules qui, après bio-optimisation, pourront être des candidats médicaments. Pour finir, ces résultats participent à une meilleure compréhension du rôle biologique des sirtuines chez S. mansoni et plus particulièrement sur leur implication dans la survie et la reproduction du parasite.

The host immune response to parasitic helminths is usually characterized by a Th2 phenotype. As the Jagged/Notch pathway has been implicated in driving Th2 development, it was hypothesized that host macrophages and dendritic cells (DCs) could detect helminth products and mount an appropriate response via this pathway. Schistosoma mansoni soluble egg antigen (SEA) rapidly up-regulated expression of the Notch ligand, Jagged 1, in both mouse and human macrophages, as well as in conventional mouse DCs. Other factors associated with Th cell development, including the Th1-promoting factor IL-12 p40, as well as another potential Th2-promoting factor, interleukin (IL)-33, were not transcriptionally responsive to SEA in these same cell types, thus indicating the selectivity of the response. Inducible gene expression was modified by the presence of the macrophage growth factor colony-stimulating factor (CSF)-1, which inhibited Jagged 1 induction by SEA and lipopolysaccharide (LPS), but enhanced LPS-induced IL-12p40 expression. Despite the observation that SEA upregulated Jagged 1 in both macrophages and DCs, only SEA-pulsed DCs promoted IL-4 production upon T-cell activation, suggesting that Jagged 1 induction alone is insufficient for instructing Th2 development. A recombinant form of the extracellular region of Jagged 1 did, however, enhance IFN-γ production in splenocytes, thus implying that the rapid induction of Jagged 1 in macrophages and DCs can regulate T cell responses. A potential role for SEA-induced Jagged 1 in autocrine responses in macrophages was also investigated through studies with recombinant extracellular Jagged 1, as well as ectopic expression of Jagged 1 in macrophages. A comparison of the responses initiated in macrophages by SEA and the bacterial endotoxin lipopolysaccharide (LPS) revealed common activation of extracellular signal regulated kinase-1/2 (ERK-1/2) and p38 phosphorylation. However, only LPS triggered IκB degradation, phosphorylation of c-Jun N-terminal kinase (JNK) and phosphorylation of Tyr701 of signal transducer and activator of transcription 1 (STAT1). SEA robustly activated signalling in HEK293 cells expressing either Toll-like receptor 2 (TLR2) or TLR4/MD2, as well as variably in cells expressing TLR3. Jagged 1 upregulation by SEA was not abrogated in TLR4 knockout macrophages, in contrast to the LPS response. Pharmacological inhibition of the ERK-1/2 pathway impaired both SEA- and LPS-inducible Jagged 1 expression in macrophages. In conclusion, the data within this thesis suggests that Jagged 1 is an ERK-dependent target of TLR signalling that has a macrophage-specific function in the response to SEA.

Diss. (sammanfattning) Umeå : Univ., 2009. / Härtill 4 uppsatser.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-08-29T20:29:44Z No. of bitstreams: 1 Sheilla Andrade deOliveira. Estudo do potencial terapêutico de células mononucleares de medula óssea em lesões hepáticas crônicas em camundongos - UFBA-FIOCRUZ-CPqGM - Tese Doutorado.pdf: 16762445 bytes, checksum: f804f2624774de877295c8841f4ff9c1 (MD5) / Made available in DSpace on 2012-08-29T20:29:44Z (GMT). No. of bitstreams: 1 Sheilla Andrade deOliveira. Estudo do potencial terapêutico de células mononucleares de medula óssea em lesões hepáticas crônicas em camundongos - UFBA-FIOCRUZ-CPqGM - Tese Doutorado.pdf: 16762445 bytes, checksum: f804f2624774de877295c8841f4ff9c1 (MD5) Previous issue date: 2007 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / O potencial terapêutico das células-tronco em doenças hepáticas vem sendo investigado. Estudos em modelos animais têm servido de base para a realização de ensaios clínicos utilizando células de medula óssea. Embora os resultados iniciais venham sendo bastante promissores, os mecanismos envolvidos na melhora hepática ainda não estão claros e novas avaliações em modelos experimentais se fazem necessárias. O objetivo da presente investigação foi avaliar a eficácia terapêutica de células mononucleares de medula óssea em doenças hepáticas crônicas. Inicialmente estabeleceu-se cirrose hepática no camundongo C57Bl/6, pela administração de uma solução de 20% de tetracloreto de carbono (CCI4) diluído em azeite de oliva combinado com 5% de etanol (EtOR) na água. Neste estudo observamos que, após seis meses de administração dos agentes hepatotóxicos, ocorre o desenvolvimento de lesões crônicas características de cirrose hepática. O segundo modelo utilizado foi o da infecção crônica pelo Schistosoma mansoni. Uma vez estabelecidas as lesões hepáticas crônicas nos animais, os estímulos "lesivos foram retirados e células mononucleares de medula óssea (3xl07) obtidas de tíbia e fêmures de camundongos transgênicos para proteína fluorescente verde (GFP) foram infundidas. A avaliação da capacidade migratória das células infundidas, bem como das alterações ocorridas após a terapia celular foi avaliada por meio de métodos histológicos, de imunofluorescência, morfológicos e imunológicos no tecido hepático. Após a terapia celular, observamos, nos dois modelos de fibrose hepática analisados, que as células GFP+ infundidas foram capazes de migrar e permanecer nas áreas de lesão do fígado. Inicialmente estas células apresentam formas arredondadas sem adentrar o tecido fibroso. Posteriormente, estas células tendem a invadir o tecido fibroso e assumem formas fusiformes. Uma redução do tecido fibroso foi verificada no 2° mês pós-terapia, em todos os grupos que receberam a terapia celular tanto nas áreas de fibrose septal e portal, quanto nas áreas dos granulomas. Os níveis de TGF-B no tecido hepático estavam diminuídos, após a terapia celular. O número de células ovais, conhecidas como células-tronco do fígado, estava aumentado no parênquima hepático após terapia celular. Os animais esquistossomóticos tratados com células de medula óssea recuperaram parcialmente a produção de albumina, quando comparado aos animais infectados. As observações sobre a terapia celular nos dois modelos de lesão crônica dos fígados avaliados nos permitem concluir que o transplante de células mononucleares de medula óssea diminui as alterações teciduais decorrentes de agressões crônicas ao fígado e reforçam a utilização deste tratamento para pacientes portadores de lesões hepáticas crônicas. / The therapeutic potential of stem cells on chronic liver diseases has been widely investigated. Based on results obtained mainly in studies using experimental models of acute liver injury, phase I clinical trials have already been carried out in patients with chronic liver diseases using therapy with bone marrow cells. Although the initial results were promising, the mechanisms involved on improvement of hepatic function are not clear and new evaluations with experimental models akin to human chronic liver diseases are needed. The object of the present investigation was the evaluation of the therapeutic efficacy of bone marrow mononuclear cells in chronic hepatic disease models. InitialIy, a mouse model of hepatic cirrhosis was induced in C57BI/6 mice by administration of 20% carbon tetrachloride solution (CCI4) diluted in olive oil combined with 5% ethanol (EtOH) in water was established. In this study we observed the development of chronic lesions characteristic of cirrhosis afier at least 6 months of administration of the hepatotoxic agents. The second model used was hepatic fibrosis caused by chronic infection by Schistosoma mansoni. Once the chronic lesions were established, the lesion stimulus was suspended and bone marrow mononuclear cells (3x I 07) obtained from tibiae and femurs of green fluorescence protein (GFP) transgenic mice were administered. The migratory capacity of the administered celIs, as well as the alterations occurring afier the celI therapy, was evaluated by histological, immunofluorescence, morphological and immunological methods in the liver tissue. After cell therapy in both hepatic fibrosis models it was observed that administered GFP+ cells were able to migrate and remain on hepatic lesion areas. Initially those celIs presented an oval shape outside thc fibrous tissue. At latter timepoints, those cells invadcd the fibrous tissue and acquired a fusifonll shape. A reduction of fibrosis was verified after the second month oftherapy in alI groups that received the celI therapy in the granuloma areas, as welI as in areas of septal and frontal fibrosis. The levels of TGF-~ were lower after the cell therapy, with statistical significance only in schistossomotic animaIs. The number of oval cells, known as liver stem cells, was increased in hepatic parenchyma afier cell therapy. The schistossomotic animaIs treated with bone marrow celIs recovered partialIy the production of albumin when compared to infected controls. Based on our observations about cell therapy in both models of chronic liver diseases evaluated we conc1ude that bone marrow mononuclear cell transplantation decreases tissue alterations caused by chronic aggressions to the liver and reinforce the use of this therapy in patients with chronic liver lesions.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-10-11T12:04:16Z No. of bitstreams: 1 DissACMF.pdf: 2760486 bytes, checksum: 27824647d350872bddb22f28a9206da8 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T13:38:00Z (GMT) No. of bitstreams: 1 DissACMF.pdf: 2760486 bytes, checksum: 27824647d350872bddb22f28a9206da8 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-20T13:38:07Z (GMT) No. of bitstreams: 1 DissACMF.pdf: 2760486 bytes, checksum: 27824647d350872bddb22f28a9206da8 (MD5) / Made available in DSpace on 2016-10-20T13:38:15Z (GMT). No. of bitstreams: 1 DissACMF.pdf: 2760486 bytes, checksum: 27824647d350872bddb22f28a9206da8 (MD5) Previous issue date: 2016-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The mansoni schistosomiasis is the most important of human helminthiasis. Despite advances in its control this disease continues to spread to new geographical areas. It currently affects more than 250 million people. However, limited options are available for and Praziquantel is the drug of choice. Various authors have been searching new drugs and vaccines to control schistosomiasis. This study aimed to evaluate the effects of a prior immunization with recombinant enzymes of Schistosoma mansoni: Adenosine Kinase (AK) and Hypoxanthine-guanine Phosphoribosyltransferase (HGPRT), which are important for parasite purine metabolism, as well as a MIX of these enzymes, and subsequent challenge with cercariae of the parasite in the control of murine infection. Female Balb/c mice were divided into 5 groups. The groups were enzyme-immunized in three doses and 15 days after the last immunization, animals were infected with S. mansoni. After infection in the 47º day egg count were carried in mice faeces and in the 48º day mice were sacrificed for evaluation of leukocyte numbers (blood and peritoneal cavity), worm burden, antibodies production, cytokines quantification and histopathological analysis of the liver of these animals. Our results strongly suggest that, immunization with a MIX originated in these animals reduction in the number of eggs in faeces by 46% when compared with the animals of the infected group. Animals of the groups immunized with AK, HGPRT and/or MIX seem to induce a reduction in the number of eosinophils in the peritoneal cavity when compared to the animals of the infected group. Concerning worm burden, the animals of the MIX group presented greater reduction (31.27%) when compared to the animals of the infected group. The animals of the immunized groups, AK, HGPRT and/or MIX were capable of producing IgG1 antibodies and IgE anti the enzymes and anti the parasite proteins. The animals of the immunized group MIX showed a slight increase in IL-4 production and observed reduction of IL-10, and in the HGPRT group induced a slight increase on IFN-γ production when in compared with the infected group. In addition, the animals of the AK group showed a decrease in the number of hepatic granulomas in tissue (44,55%) and the eggs present in liver (42,31%). Therefore, it suggests that immunization with these enzymes can contributes to schistosomiasis control, as well as it might helps to modulate experimental infection inducing reduction of physiopathology of this parasitosis. / A esquistossomose mansônica é a mais importante das helmintíases humanas. Apesar dos avanços no seu controle continua se espalhando para novas áreas geográficas. Atualmente afeta mais de 250 milhões de pessoas. Entretanto, opções limitadas estão disponíveis para o tratamento da doença e o único fármaco de escolha é o Praziquantel. Assim, vários estudos têm sido propostos para encontrar novos fármacos e vacinas para combater a esquistossomose. Dessa forma, o presente estudo teve como proposta avaliar os efeitos da imunização prévia com as enzimas recombinantes de Schistosoma mansoni Adenosina Quinase (AK) e Hipoxantina-Guanina Fosforibosiltransferase (HGPRT), que participam do metabolismo de purinas do parasito, bem como com o MIX das duas enzimas, e posterior desafio com cercárias do parasito, para o controle da infecção murina. Camundongos fêmea Balb/c foram divididos em 5 grupos. Os grupos imunizados receberam três doses das enzimas e após 15 dias da última imunização, os animais foram infectados com S. mansoni. Após a infecção, no 47° dia foi realizada a contagem de ovos nas fezes e no 48° dia foi realizada a eutanásia dos animais para avaliação de resposta leucocitária (sangue e lavado da cavidade peritoneal), carga parasitária, produção de anticorpos, quantificação de citocinas e análise histopatológica do fígado desses animais. Os resultados demonstraram que, a imunização com o MIX promoveu nesses animais redução do número de ovos nas fezes de 46% quando comparado com os animais do grupo somente infectado. Os animais dos grupos imunizados com AK, HGPRT e/ou MIX apresentaram diminuição na quantidade de eosinófilos na cavidade peritoneal quando comparados com os animais do grupo somente infectado. Em relação à carga parasitária, os animais do grupo imunizado com o MIX apresentaram maior redução (31,27%) quando comparados aos animais do grupo somente infectado. Os animais dos grupos imunizados com AK, HGPRT e/ou MIX foram capazes de produzir anticorpos IgG1 e IgE anti as enzimas e anti as proteínas do parasito. Os animais do grupo imunizado com o MIX apresentaram aumento discreto de IL-4 e foi observada redução de IL-10, e no grupo imunizado com HGPRT houve aumento discreto de IFN-γ, quando comparados com os animais do grupo somente infectado. Além disso, os animais do grupo imunizado com AK apresentaram redução do número de granulomas hepáticos (44,55%) e de ovos no fígado (42,31%), quando comparados com o grupo somente infectado. Assim, sugere-se que a imunização com essas enzimas pode contribuir para o controle da esquistossomose, bem como auxiliar na modulação da infecção experimental, induzindo redução da fisiopatologia desta parasitose.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2014-11-13T17:53:26Z No. of bitstreams: 2 dissertacao - Cleber Camilo de Melo Filho - 2014.pdf: 4135177 bytes, checksum: 8cda88d9da11bbe2de5d43dbb24799a9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-11-17T15:09:35Z (GMT) No. of bitstreams: 2 dissertacao - Cleber Camilo de Melo Filho - 2014.pdf: 4135177 bytes, checksum: 8cda88d9da11bbe2de5d43dbb24799a9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-17T15:09:35Z (GMT). No. of bitstreams: 2 dissertacao - Cleber Camilo de Melo Filho - 2014.pdf: 4135177 bytes, checksum: 8cda88d9da11bbe2de5d43dbb24799a9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-03-10 / Schistosomiasis is a neglected tropical disease (NTD) that affects many individuals, mainly in tropical areas. This disease is caused by blood flukes of the genus Schistosoma, which have the snails of the genus Biomphalaria as their intermediate hosts. The most used drug in schistosomiasis treatment is praziquantel, which because of its widespread use, brings concerns about the development of resistance. The enzyme Thioredoxin Glutathione Reductase of Schistosoma mansoni (SmTGR) has an important function in reactive oxygen species (ROS) detoxification, allowing the survival of parasites for a very long time in blood stream, protecting them against the host immune system. The dependence of the parasite on a single system for ROS detoxification, makes the SmTGR a promissing target in the development of new schistosomicidal drugs. Facing the need for development of new drugs against schistosomiasis, quantitative structure activity relationships (QSAR) studies were carried out for a series of oxadiazoles-2-oxides reported in literature as SmTGR inhibitors. Hologram-QSAR (HQSAR) analysis, a two-dimensional QSAR method (2D-QSAR), was performed. Furthermore comparative molecular field analysis (CoMFA) and comparative similarity indices analysis (CoMSIA), that are three-dimensional QSAR (3D-QSAR), were also carried out. In 3D-QSAR methods, two partial charge calculation methods were used: the empirical method Gasteiger-Hückel and the semiempirical method AM1-BCC. Two alignment strategies were also tested, one based on molecular volume superposition and the other based on a morphological similarity function. The QSAR models generated showed great robustness and external predictivity and can be used to predict the biological activity of new compounds inhibitors of SmTGR. The contribution and contour maps showed important structural information about oxadiazoles-2-oxides that was used for the design of new SmTGR inhibitors. / A esquistossomose é uma doença tropical negligenciada (DTN) que afeta grande número de indivíduos, principalmente em áreas tropicais. Esta doença é causada por vermes platelmintos do gênero Schistosoma, que possuem como hospedeiros intermediários os caramujos do gênero Biomphalaria. O fármaco mais utilizado no tratamento atualmente é o praziquantel, que devido à grande disseminação do seu uso, traz preocupações quanto ao desenvolvimento de resistência. A enzima tioredoxina glutationa redutase de Schistosoma mansoni (SmTGR) desempenha um papel importante na detoxificação de espécies reativas de oxigênio (ROS), permitindo a sobrevivência dos parasitos por muito tempo na circulação sanguínea, protegendo-os do sistema imune do hospedeiro. A dependência do parasito de um único sistema para detoxificação de ROS, torna a SmTGR um alvo promissor no desenvolvimento de novos fármacos esquistossomicidas. Frente à necessidade de se desenvolver novos fármacos contra esquistossomose, foram realizados estudos quantitativos da relação entre estrutura e atividade (QSAR) para uma série de oxadiazóis-2-óxidos reportados na literatura como inibidores de SmTGR. Foi realizada análise de holograma-QSAR (HQSAR), que é um método de QSAR bidimensional (QSAR-2D). Além disso, foram utilizadas a análise comparativa de campos moleculares (CoMFA) e a análise comparativa dos índices de similaridade molecular (CoMSIA), que são métodos de QSAR tridimensional (QSAR-3D). Nos métodos de QSAR-3D foram utilizados dois métodos de cálculo de cargas parciais: o método empírico Gasteiger-Hückel e o semi-empírico AM1-BCC. Foram também testadas duas estratégias de alinhamento, uma baseada na sobreposição de volumes moleculares e outra baseada em uma função de similaridade morfológica. Os modelos de QSAR gerados demonstraram boa robustez e preditividade externa e foram usados para predição da atividade biológica de novos compostos inibidores de SmTGR. Os mapas de contribuição e de contorno obtidos forneceram informações estruturais importantes a respeito dos oxadizóis-2-óxidos, que foram utilizadas no planejamento de novos inibidores da SmTGR.

Schistosoma mansoni é um dos agentes causadores da esquistossomose, doença infecciosa negligenciada que afeta milhões de pessoas no mundo. É um platelminto parasitário dióico, com um complexo ciclo de vida, composto de seis estágios. Nos últimos cinco anos, projetos de seqüenciamento em larga escala de etiquetas de genes expressos (ESTs) de Schistosoma geraram uma quantidade razoável de dados que ainda pode ser mais bem explorada. O objetivo central deste trabalho é analisar computacionalmente a expressão gênica de S. mansoni, sob três focos distintos: (i) micro-arranjos de DNA, para os quais descrevemos o desenho e análise de dados de uma plataforma de cDNA (4,600 elementos) e outra de oligonucleotídeos (44,000 elementos). Estão também descritas diversas ferramentas de análise que implementamos e são amplamente usadas em nosso grupo. Os micro-arranjos têm servido de base para vários projetos, como o estudo da resposta do parasita a hormônios e drogas e expressão gênica durante o ciclo de vida. (ii) Identificação in silico de pares de transcritos senso- antisenso com possível ação em trans, potencialmente importantes na regulação gênica. (iii) Análises da coleção de ESTs existentes sob uma perspectiva evolutiva. Através dessa abordagem encontramos genes importantes como um possível inibidor de angiogênese e um regulador da via do mevalonato, conhecido como essencial para a produção de ovos; estes constituem a principal causa de morbidez da esquistossomose. Os resultados aqui apresentados contribuem para o entendimento da complexa biologia inerente ao ciclo de vida de S. mansoni e para acelerar a busca de futuras possibilidades de tratamento. / Schistosoma mansoni is one of the causative agents of schistosomiasis, a neglected infectious disease which affects millions of people worldwide. It is a dioecious parasitic platyhelminth, with a complex life cycle composed of six stages. In the past five years, large scale sequencing projects have generated a reasonable amount of expressed sequence tag (EST) data that can still be better explored. The goal of this thesis is to computationally analyze the S. mansoni gene expression, under three different focuses: (i) DNA microarrays, for which we describe the design and data analyses of a cDNA (4,600 elements) and an oligonucleotide (44,000 elements) platform. We also describe the implementation of several analysis tools which are widely used in our group. Our microarrays are being used in several projects, such as the study of parasite response to drugs and hormones, as well as its gene expression pattern during the life cycle. (ii) In silico identification of possible trans acting natural sense-antisense pairs, potentially important in gene regulation. (iii) Analyses of the available EST dataset under an evolutionary perspective. We have found interesting genes such as a possible angiogenesis inhibitor and a regulator of the mevalonate pathway, known to be essential for egg production; eggs are the main cause of morbidity of schistosomiasis. The results reported here contribute to the understanding of the complex biology underlying the S. mansoni life cycle and to accelerate the search for future possibilities of treatment.