Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (leaves 99-126).

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La maladie de Parkinson (MP) est caractérisée par la mort des neurones dopaminergiques de la substance noire et la présence de corps de Lewy. Son diagnostic reste sujet à des erreurs notamment aux stades précoces. Les cellules mononucléées sanguines périphériques (PBMC) jouent un rôle dans la cascade délétère et sont le reflet d’événements associés à la MP. Même si elles ne représentent qu’un faible pourcentage, les formes génétiquement déterminées permettent d’identifier des sujets à un stade précoce. Nous avons émis l’hypothèse que les PBMC pouvaient constituer un modèle d’étude reflétant certains mécanismes de la dégénérescence du vivant du patient. Nous avons réalisé des études du transcriptome chez différents groupes de sujets malades ou porteurs de mutations pour y déceler les gènes et voies de signalisation cellulaire dérégulés. Nous avons d’abord étudié le profil d’expression génique de sujets porteurs de la mutation G2019S de LRRK2. L’analyse des puces a permis d’identifier des perturbations de voies impliquées dans la MP comme l’oxydation mitochondriale, l’inflammation et la guidance axonale. Des altérations de la voie des MAPK, du cytosquelette d’actine et du transport vésiculaire ont été notées. La liste des gènes dérégulés permet de séparer les individus selon leur statut génétique. La mutation LRRK2 est associée à un profil d’expression génique dès les stades précoces identifiable dans les PBMC. Nous nous sommes ensuite intéressés à une autre forme de MP avec duplication de SNCA. Nous avons caractérisé la relation entre le génotype et le phénotype clinique des sujets de cette famille. La duplication s’étend sur 4,928 Mb, comporte 31 gènes et résulte d’une recombinaison homologue non allélique. L’analyse de l’expression des gènes présents dans la duplication dans les PBMC d’un sujet à un stade pauci-symptomatique a montré une surexpression de SNCA. Nous avons comparé nos analyses chez les porteurs des mutations LRRK2 et SNCA et chez des parkinsoniens sporadiques. Nos analyses montrent que les sujets LRRK2 et les sujets sporadiques présentent des dérégulations communes de voies de signalisation. En revanche, les voies dérégulées chez le sujet dupliqué reflètent la pathogénie de SNCA comme l’autophagie et les voies lysosomales. Nous nous sommes intéressés à l’expression des 4 isoformes de SNCA dans les PBMC de ces 3 groupes d’individus. Les patients sporadiques et LRRK2 montrent une diminution de l’expression des 4 isoformes de SNCA dans leur PBMC. Chez le sujet dupliqué, on observe uniquement une surexpression de l’isoforme 112. Nous avons ensuite identifié les voies moléculaires associée / Parkinson's disease (PD) is prone to misdiagnosis particularly in the early stages. A better understanding of the deleterious mechanisms is essential to identify therapeutic targets and detect the disease earlier. Peripheral blood mononuclear cells (PBMCs) play a role in the deleterious cascade and reflect molecular events associated with PD. Moreover, the study of genetically determined forms of PD enables the identification of subjects at a very early. We hypothesized that PBMCs could be an interesting model to study some mechanisms reflecting the neurodegeneration even at an early stage of the disease. Therefore, we conducted transcriptomic studies in different groups of PD subjects or patients with mutations in order to detect deregulated genes and signaling pathways.We first studied the gene expression profile of PD subjects with the mutation G2019S of the LRRK2 gene. Analysis of microarrays identified disturbances in cell signaling pathways involved in PD. Alterations in the MAPK pathway, the actin cytoskeleton and vesicular transport, associated with the pathogenesis of LRRK2, were noted. The list of deregulated genes separates individuals based on their genetic status including an asymptomatic subject. G2019S LRRK2 mutation is associated to a particular gene expression profile identifiable in PBMCs even at early stage.Then we investigated another form of genetically determined by duplication of SNCA gene. We better characterized the relationship between genotype and clinical phenotype of the subjects. The duplication extends 4.928 Mb, contains 31 genes and results from non-allelic homologous recombination. The analysis of the expression of genes in the PBMCs of a subject carrying the mutation at preclinical stage showed overexpression of SNCA.We compared PBMCs gene expression of G2019S LRRK2 mutation carriers, SNCA duplication carrier and also sporadic PD patients. Our analysis showed that carriers of the LRRK2 mutation and sporadic PD patients have common deregulated signaling pathways that reflect the PD pathogenesis. By contrast, pathways deregulated in the subject with SNCA duplication reflect the pathogenesis of SNCA. In addition, we looked at the expression of SNCA isoforms in PBMCs of these three groups of individuals. Sporadic and LRRK2 patients showed a decreased expression of four isoforms of SNCA in their PBMCs. However, in the duplicated subject, only isoform 112 was overexpressed.Then we used this technology to identify molecular pathways associated with spino-cerebellar ataxia type 2 (SCA2), which provides rarely a parkinsonian phenotype and compared with subjects with a cerebellar phenotype. Again, we identified deregulation of gene expression associated with SCA2 pathogenesis, such as amyotrophic lateral sclerosis and actin cytoskeleton in PBMCs of subjects with parkinsonian and metabolism of RNA and inositol phosphate in cerebellar subjects.Finally, we looked at gene expression in PBMCs according to the evolutionary and clinical stage of PD including individuals at a very early. We compared their gene expression profiles with more advanced PD patients. From the early stages, we observed a deregulation of ERK/MAPK and PI3K/Akt pathways that control cell survival; these findings underscore the importance of these biological pathways in the development of PD.In conclusion, we demonstrated that PBMCs are an interesting model. The transcriptomic studies can get insight into the mechanisms associated with early stages of degeneration and into biological markers, such as SNCA. This technique could be applied in a larger number of subjects including other neurodegenerative diseases to detect specific diagnostic markers of PD.

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No description available.

Prion diseases are fatal infectious neurodegenerative disorders hypothesised to be caused by misfolding of the prion protein. Following prion infection, the infectious agent is sequestered to and replicates upon follicular dendritic cells (FDC) within lymphoid follicles prior to neuroinvasion. The mechanism of transport of the prion infectious agent from the site of infection to FDC is unknown. One of the postulated routes of transport is the specific migration of antigen presenting cells (APC) to FDC. APC specifically capture antigenic material and transport and present that material to effector cells and FDC in order to generate an appropriate acquired immune response. FDC reside within the B-cell follicle of secondary lymphoid organs. FDC organise and maintain the B-cell follicular structure by secretion of the chemokine CXCL13 which stimulates chemotactic movement of cells which express the CXCR5 receptor, e.g. B cells. Dendritic cells are specialised APC that are commonly characterised by their expression of CD11c. Transport of the prion infectious agent from the site of infection to FDC was observed to be blocked or severely delayed following depletion of CD11c+ cells. To determine whether CD11c+ cells acquire prions and subsequently deliver them to the FDC, the chemokine receptor CXCR5 was depleted from CD11c+ cells using a conditional transgenic mouse model. These mice were characterised for normal lymphoid organogenesis and monitored for their responses to oral infection with either prions or intestinal helminths. Data in this thesis show that the CD11c-mediated depletion of CXCR5 resulted in a delay in peripheral prion pathogenesis after oral exposure and significantly reduced disease susceptibility. These data suggest that efficient prion transport to FDC requires delivery by APC and is potentially mediated by CXCR5 chemotaxis. Following oral exposure to the intestinal helminth (Trichuris muris) CD11c-mediated depletion of CXCR5 prevented the establishment of a protective TH2 response. As a consequence the mice mounted a TH1-dominated response and were unable to clear the infection. These data also confirm that the effective generation of TH2 responses to oral helminth infection also requires APC localisation to B-cell follicles via CXCR5.

The productive, controlled activation of O2 via small-molecule catalysts remains a significant challenge to bioinorganic chemistry. With enzymes, global folding energies dictate the positioning of ligands to optimize chemical pathways. Synthetic iron catalytic complexes, with open or labile coordination sites, frequently give rise to Fenton-like radical-based reactions. To minimize such peroxide/hydroxyl radicals, we developed a synthetic model for the 2-oxoglutarate-dependent dioxygenases, [FeII(N2O1)]- (N2O1 = 2-((2-dimethylamino)ethyl)-(methyl)amino)acetic acid) . We present herein an iron-based synthetic analogue system capable of utilizing dioxygen to perform velut vivum C ‒ H activation at ambient temperatures and pressures. The relationships between a range of α-ketocarboxylate adducts producing metal-to-ligand charge transfer band energies and their corresponding π → π* energy gaps (DFT simulated) are described. Electronic (MCD) and computational (DFT) methods are combined to elucidate the electronic structures of a subset of these adducts. Catalytic efficiency of 15 α-ketocarboxylates is investigated and includes the use of oxalate. The latter represents an original example of a small-molecule synthetic catalyst capable of activating O2 while using oxalate as a cofactor for C ‒ H oxidation. A series of varying N,N,Ox (x = 1 ̶ 3) carboxylate-ligated ferrous, ferric, and chromic complexes was assessed for chemical and electronic influences of increasing carboxylate metal ligation. Electrochemical and spectroscopic characterization, and initial reactivities were examined. The use of the same ligand set but with differing ‘d-electron count’ explores mechanistically dramatic changes to chemical reactivity in the presence of a terminal oxidant. A methodology for the functionalization of the N2Ox (x = 1 ̶ 3) ligand series, using an alkynyl moiety, was also developed. Such could allow ‘click’ chemistry for converting homogeneous catalysts to heterogeneous versions. Using a globally uniform and diffuse low loading resin will provide enhanced catalyst lifetime by diminishing inactivation pathways and support its use in flow chemistry reactors using O2 from air as the oxidant.

Made available in DSpace on 2014-06-11T19:30:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-11Bitstream added on 2014-06-13T20:21:25Z : No. of bitstreams: 1 pitol_dl_dr_rcla.pdf: 2375764 bytes, checksum: 1ce362e81dd4a2ee6f04869e84243e98 (MD5) / O presente estudo teve como objetivo analisar os leucócitos circulantes em microscopia de luz e eletrônica e sua distribuição sazonal, além de procurar estabelecer o período de renovação celular desses leucócitos, e principalmente de caracterizar os fagócitos mononucleares do sangue de tartaruga, e sua capacidade de fagocitose frente a material inerte. Neste trabalho utilizou-se seis tartarugas Phrynops hilarii, originárias de ilhas do estuário do rio Guaíba Porto Alegre (RS), que estavam ambientadas em nosso biotério. A coleta de sangue foi realizada em todos os períodos sazonais, por punção de vasos laterais do pescoço e coletados em tubos de ensaio heparinizados. Foram realizados esfregaços sanguíneos, corados com Leishmann e Giemsa, contando-se quinhentas células de cada animal e após a obtenção dos dados, foi aplicado o teste estatístico de Bonferroni. Para a análise autorradiográfica foi injetado 1000μCi / kg de thymidine-H A. Para microscopia eletrônica processamos a nata leucocitária obtida por meio de centrifugação do sangue, para a analise citoquímica incubamos com citidina-5'-monofosfato, betaglicerofosfato de sódio, Trimetafosfatase, para averiguar a resposta fagocitária utilizamos 0,01% de carvão coloidal.Os resultados mostram que os leucócitos de Phrynops hilarii tem descrição de leucócitos semelhantes às outras espécies, somente os basófilos e linfócitos não sofreram alterações em sua distribuição sazonal. Todos os leucócitos com exceção dos basófilos apresentaram renovação celular após sete dias. Caracterizamos monoblasto, promonócito, monócitos e macrófago no sangue circulante bem como a capacidade dos fagócitos mononucleares de fagocitar células mortas e materiais inerte. / The aim of this study was to analyze the leukocytes in the blood using electronic and light microscopy and their seasonal distribution, also to characterize the leukocyte cells replacement and mainly to characterize the mononuclear phagocytes in the blood and their phagocytic capacity. In this study, it was used six turtles (Phrynops hilarii), caught at the Guaíba river estuary, Porto Alegre, Rio Grande do Sul, Brazil and lodged for 1 week at the Central Animal House, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. Blood was obtained during the seasonal periods by puncturing the lateral vessels of the neck. The blood samples were stained by Leishmann and Giemsa, counting five hundred cells in each animal. After the obtained data, it was applied the Bonferroni test as statistical method. For the autoradiographic analysis, it was injected in the circulating blood 1000 μCi/kg of 3Hthymidine. For electronic microscopy, it was processed the leukocyte substrate by circulating blood centrifugation. For cytochemical analyses, blood smears were air dried, post-fixed in 4% formalin and submitted to the determination of the following enzyme activities: acid phosphatases (β-g1ycerophosphatase and citidine-5′-sodium monophosphatase), and trimetaphosphatase. The results showed that the leukocytes of Phrynops hilarii have the leukocytes description similar to the other species, only the basophiles and lymphocytes did not suffer alterations in their seasonal distribution. All the leukocytes, in exception of the basophiles showed cells replacement after seven days. It was characterized the monocytes and macrophages in the circulating blood as well as the phagocytes capacity.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2014-02-07T18:54:08Z No. of bitstreams: 1 Micely D`el-Rei Hermida... Transporte de Leishmania do sitio.pdf: 12642864 bytes, checksum: 1f1b3fd2c8676340857d3b59f352212d (MD5) / Made available in DSpace on 2014-02-07T18:54:08Z (GMT). No. of bitstreams: 1 Micely D`el-Rei Hermida... Transporte de Leishmania do sitio.pdf: 12642864 bytes, checksum: 1f1b3fd2c8676340857d3b59f352212d (MD5) Previous issue date: 2013 / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / A infecção por Leishmania modula a função de integrinas em fagócitos inflamatórios, afetando a migração celular e disseminação do parasito. O conhecimento sobre as populações de fagócitos capazes de transportar Leishmania ou fragmentos de parasitos mortos, e os mecanismos de disseminação da Leishmania do sítio de infecção para os diferentes tecidos ainda está incompleto. Nesse trabalho, nós adaptamos um modelo de migração de células in vivo para estudar o efeito da infecção parasitária na capacidade das diferentes populações de fagócitos mononucleares de migrar do sítio inflamatório para o linfonodo drenante e para estudar a cinética de disseminação da Leishmania através do sistema linfático. Inicialmente, nós usamos um modelo de peritonite crônica induzida por tioglicolato para identificar populações de fagócitos inflamatórios susceptíveis a infecção por Leishmania e suas possíveis alterações na migração após a infecção. Células peritoneais estimuladas por tioglicolato coletadas de animais Ly5.1+, não infectadas ou infectadas por Leishmania, foram injetadas na cavidade peritoneal de animais Ly5.1- e as diferentes populações de fagócitos foram rastreadas no linfonodo drenante. Células migrantes corresponderam no linfonodo 1% dos leucócitos injetados. Em animais injetados com células peritoneais cultivadas somente com meio, 28-90% das células migrantes eram células dendríticas mielóides e 30-74% eram macrófagos. No grupo de animais injetados com células do exsudato peritoneal co-cultivadas com Leishmania, 9-65% das células migrantes eram células dendríticas mielóides e 20-69% eram macrófagos. Somente a migração da célula dendríticas foi consistentemente diminuída após a co-incubação Leishmania. Em seguida, nós determinamos a cinética de disseminação do parasito do sítio inflamatório para o linfonodo drenante e sistemicamente. Promastigotas de L. amazonensis foram injetadas na cavidade peritoneal de camundongos e depois de 15min e 30min; 1h, 2h, 4h, 6h, 12h e 24h amostras de fagócitos peritoneais, linfonodo, baço e pulmão foram cultivados para isolamento de Leishmania. Culturas de fagócitos peritoneais e células do linfonodo ficaram positivas após 15min a 6h da infecção. Parasitos foram detectados em culturas de células esplênicas de 15min a 1h após a infecção. Cultura de células do pulmão foram positivas 1h após a infecção ou, menos consistentemente, 15min e 30min após a inoculação. Parasitos na forma promastigota foram identificados no linfonodo drenante. Nossos dados mostraram que: (1) Uma variedade de fagócitos são capazes de migrar do sítio inflamatório para o linfonodo drenante. (2) Populações de células dendríticas infectadas por Leishmania parecem estar retidas no sítio inflamatório. (3) Os mecanismos de disseminação da Leishmania da cavidade peritoneal para o linfonodo ocorre em menos de 15 minutos após a injeção. (4) O trânsito para a corrente sanguínea ocorre nas primeiras horas após a infecção. Nossos dados também sugerem que mesmo antes do tempo requerido para alterações nas populações de células inflamatórias ocorra no sítio inflamatório, parasitos de Leishmania e seus antígenos podem chegar ao linfonodo drenante. / Leishmania infection modulates integrin function in inflammatory phagocytes, affecting cell migration and parasite dissemination. The knowledge on the phagocyte populations capable of transporting Leishmania or fragments of dead parasites, and the mechanisms of Leishmania dissemination from the infection site to the different tissues is still incomplete. In this work, we adapted a model of cell migration in vivo to study the effect of parasite infection upon the ability of different mononuclear phagocyte populations to migrate from the inflammatory site to the draining lymph node and to study the kinetics of Leishmania dissemination through the lymphatic system. First, we used a model of chronic peritonitis induced by thioglycollate to identify inflammatory phagocytes populations susceptible to Leishmania infection and the potential changes in their migratory patterns after infection. Uninfected and Leishmania-infected, thioglycollate-elicited peritoneal exudate cells from Ly5.1+ mice were injected into the peritoneal cavity of Ly5.1- mice, and the different phagocyte populations were tracked to the draining lymph node. Migrating cells corresponded 1% of the injected leukocytes. In the animals injected with peritoneal cells cultivated with medium alone, 28-90% of the migrating cells were myeloid dendritic cells and 30-74% were macrophages. In the group of animals injected with peritoneal exudate cells co-cultivated with Leishmania, 9-65% of the migrating cells were myeloid dendritic cells and 20-69% were macrophages. Only dendritic cell migration was consistently decreased after co-incubation with Leishmania. Afterwards, we determined the kinetic of parasite dissemination from the inflammatory site to the draining lymph node and systemically. L. amazonensis promastigotes were injected into BALB/c mice peritoneal cavity and after 15min and 30min; 1h, 2h, 4h, 6h, 12h and 24h samples of peritoneal phagocytes, lymph nodes, spleen and lungs were cultivated for Leishmania isolation. Peritoneal phagocytes and lymph nodes were positive after 15min to 6h of infection. Parasites were detected in splenic cells cultures 15min to 1h after infection. Lungs cultures were positive after 1h of infection or, less consistently, 15min and 30min after inoculation. Labeled parasites were identified in the draining lymph nodes. Our data show that: (1) A variety of phagocytes are able to migrate from the inflammatory site to the draining lymph node. (2) Populations of Leishmania-infected dendritic cells appear to be retained in the inflammatory site. (3) The mechanisms of Leishmania dissemination from peritoneal cavity to the lymph node occur in less than 15 minutes after injection. (4) The transit to bloodstream occurs in the first hour of infection. Our data also suggest that even before the time required for deep changes in inflammatory cell population takes place in the inflammatory site, Leishmania parasites and their antigens can reach the draining lymph node.

Pulmonary hypertension (PH), when it complicates sarcoidosis, carries a poor prognosis, in part because it is difficult to detect early in patients with worsening respiratory symptoms. Pathogenesis of sarcoidosis occurs via incompletely characterized mechanisms that are distinct from the mechanisms of pulmonary vascular remodeling well known to occur in conjunction with other chronic lung diseases. To address the need for a biomarker to aid in early detection as well as the gap in knowledge regarding the mechanisms of PH in sarcoidosis, we used genome-wide peripheral blood gene expression analysis and identified an 18-gene signature capable of distinguishing sarcoidosis patients with PH (n = 8), sarcoidosis patients without PH (n = 17), and healthy controls (n = 45). The discriminative accuracy of this 18-gene signature was 100% in separating sarcoidosis patients with PH from those without it. If validated in a large replicate cohort, this signature could potentially be used as a diagnostic molecular biomarker for sarcoidosis-associated PH.