Le symporteur Sodium Iodure (NIS) est une glycoprotéine transmembranaire catalysant le transport actif de l’iodure circulant et participant ainsi à la voie de biosynthèse des hormones thyroïdiennes. L’activité de captation de l’iode médiée par NIS est à la base du diagnostic par imagerie nucléaire et du traitement par radiothérapie à l'iode 131 des cancers thyroïdiens, ce qui fait de NIS un réel marqueur d’intérêt clinique pour une utilisation potentielle dans les cancers non-thyroïdiens qui l’expriment. La connaissance des mécanismes de régulation et d’adressage membranaire de NIS est limitée. Nous identifions une nouvelle fonction de NIS dans la migration et l’invasion cellulaires indépendamment de sa fonction de transport. Cette fonction est facilitée par l’activation de RhoA suite à l’interaction protéine-protéine de NIS avec LARG (Leukemia-Associated RhoA Guanine Exchange Factor). Notre travail a révélé que cette accumulation de NIS dans les compartiments intracellulaires de cellules cancéreuses était également observée dans les cancers primitifs et métastatiques du foie. Nous montrons l’importance de la voie de signalisation du TGF-β, fréquemment activée dans les cancers humains, dans le défaut d’adressage de NIS. Nos travaux suggèrent qu’une thérapie basée sur des inhibiteurs pharmacologiques de la voie du TGF-β serait capable de corriger ce défaut d’adressage, rendant ainsi possible un traitement par radiothérapie métabolique / The sodium iodide symporter (NIS) is a glycosylated protein that mediates the active transport of iodide for thyroid hormone biosynthesis. The ability of the thyroid to accumulate iodide via NIS has provided the basis for diagnostic imaging and served as effective treatment by radioiodine to target and destroy thyroid cancers. This propriety makes NIS a real marker of clinical interest for potential use in non-thyroid cancers which express it, however, the mechanisms of regulation and membrane targeting of NIS remain unknown. We identify a new function of NIS in cell migration and invasion independently of its transport activity. This function is facilitated by the activation of RhoA after the protein-protein interaction of NIS and LARG (Leukemia-Associated RhoA Guanine Exchange Factor). Our work has shown that this accumulation of NIS in intracellular compartments of cancer cells was also observed in primary and metastatic liver cancers. Our results pointed out the importance of TGF-β signaling pathway, frequently activated in human cancers, in NIS default targeting. Our work suggests that a therapy based on pharmacological inhibitors of TGF-β could be able to correct this targeting defect, making metabolic radiotherapy possible

Neuromesodermal progenitors (NMPs) are bipotent progenitors, located at the caudal end of the embryo and are essential for axis formation. These stem cell-like progenitors possess the ability to self-renew and differentiate to both mesodermal and neural lineages, such as skeletal muscle and spinal cord derivatives. These progenitors arise at E8.5 and are localised in the caudal lateral epiblast (CLE), a posterior region of the embryo near the primitive streak. Later in development, they reside in the tail bud until cessation of axial elongation at E13.5. Throughout these stages NMPs are characteristically marked by co-expression of T(Bra) (Brachyury) and Sox2. This characteristic is also present in in vitro NMPs, which can be derived from Epiblast Stem Cells (EpiSCs) through treatment with Wnt/β-catenin signalling agonists and Fgf2, which simulates their in vivo environment. Protein and mRNA profiling of NMPs and mutant phenotypes in vivo supports the hypothesis that a non-canonical Wnt pathway, the Wnt/Planar Cell Polarity pathway (PCP) could be involved in NMP fate decision and/or maintenance. This thesis focuses on understanding more about the role of PCP by aiming to identify the spatio-temporal profile of Wnt/PCP pathway components in NMP regions during axial elongation, as well as determining its role in NMP behaviour through manipulation of this pathway via in vivo and in vitro assays Employing in situ hybridisation and immunohistochemistry techniques, key Wnt/PCP components, including Pk1, Vangl2 and Ptk7, were confirmed to be present in in vivo and in vitro NMPs, thus, providing strong evidence that Wnt/PCP may be involved regulating NMP behaviour. Disruption of Wnt/PCP signalling through overexpression of Wnt/PCP components was tested in refined in vivo and in vitro assays. Overexpression of Vangl2 and Ptk7, but not Pk1 in NMPs regions in vivo resulted in loss of contribution to neural lineages, as well as lower contribution to NMP regions themselves. Similarly, Wnt/PCP components were disrupted in vitro through generation of dox-inducible overexpression cells lines for Wnt/PCP components. These lines were used to generate NMPs from an optimised novel alternative source Epiblast-Like Cells (EpiLCs), however no clear affect to lineage was observed. Overall this work has successfully advanced our knowledge of Wnt/PCP mediated control of NMP differentiation and maintenance, and provided a finer grained description of the relationships between them.

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-17T16:03:10Z No. of bitstreams: 1 Dissertação- Javier zambrano Ferreira.pdf: 1147973 bytes, checksum: 97e9e41bf4b5d99b09151b69f9c99dfe (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-17T20:27:39Z (GMT) No. of bitstreams: 1 Dissertação- Javier zambrano Ferreira.pdf: 1147973 bytes, checksum: 97e9e41bf4b5d99b09151b69f9c99dfe (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-17T20:29:11Z (GMT) No. of bitstreams: 1 Dissertação- Javier zambrano Ferreira.pdf: 1147973 bytes, checksum: 97e9e41bf4b5d99b09151b69f9c99dfe (MD5) / Made available in DSpace on 2015-06-17T20:29:11Z (GMT). No. of bitstreams: 1 Dissertação- Javier zambrano Ferreira.pdf: 1147973 bytes, checksum: 97e9e41bf4b5d99b09151b69f9c99dfe (MD5) Previous issue date: 2014-02-25 / Não Informada / Given the amount of information available on the internet, it becomes unfeasible the manual content analysis to identify information of interest. Among such analyses, one of particular interest is the polarity analysis, that is, the classi cation of a text document in positive, negative, and neutral, according to a certain topic. This task is particularly useful in the nance domain, where news about a company can a ect the performance of its stocks. Although most of the methods about this domain consider that documents have only one polarity, in fact most of the documents cite many entities and these entities are often the target of the polarity analysis. Thus, in this work, we intend to study strategies for polarity detection in nancial documents with multiple entities. In particular, we study methods based on the learning of multiple models, one for each observed entity, using SVM classi ers. We evaluate models based on the partition of documents according to the entities they cite and on the segmentation of documents into fragments according to the entities they cite. To segment documents we use several heuristics based on shallow and deep natural language proecssing. We found that entity-speci c models created by simply partitioning the document collection largely outperformed strategies based on single models. / Dado o volume de infoma ção disponivel na Internet torna-se inviavel a analise manual do conteudo disponvel para identi car diversas informações de interesse. Entre v arias analises de interesse, uma de destaque e a an alise de polaridade da opinião, ou seja, a classificação de um documento textual em positivo, negativo ou neutro, em rela cão a um certo topico. Esta tarefa e particularmente util no dom nio fi nanceiro, onde not cias sobre uma empresa podem afetar o seu desempenho em mercados de a cões. Embora a maioria dos m etodos nesse dom nio considere que os documentos possuem uma unica polaridade, observamos que a maioria deles e constitudo de multiplas entidades e o alvo da analise de polaridade e, em geral, as entidades que estes documentos referenciam. O objetivo deste trabalho e, portanto, estudar estrategias para a detecção de polaridade em documentos financeiros com multiplas entidades. Para tanto, estudamos m etodos baseados na cria c~ao de multiplos modelos de aprendizado com um conjunto pr e-de nido de entidades, usando o classi cador SVM. N os avaliamos tanto modelos baseados em conjuntos de documentos especcos por entidade quanto modelos baseados em segmentação de documentos usando diversas heursticas de processamento de linguagem natural. Os resultados mostraram que h a um ganho em fragmentar os textos para an alise de polaridade com r otulos de classi ca cão por entidades.

Cell polarisation is a key biological process crucial for the functioning of essentially all cells. Regulation of cell polarity is achieved through various processes determined by both internal and external factors. An example of the latter is that cell polarity can be disrupted or lost as a consequence of a variety of external stresses. When facing such stresses, cells adapt to unfavourable conditions by activating a range of molecular signalling pathways, collectively termed ‘stress response’. Despite the connections between external stress and cell polarity, whether stress-response signalling regulates cell polarisation and what the molecular basis for such regulation remains an open question. The fission yeast Schizosaccharomyces pombe presents an excellent biological platform to study the complexity of cell polarity regulation on a systematic level. This study is aimed at understanding the functional relationship between stress-response signalling and maintenance of cell polarity in this model organism. The findings presented in this thesis set the basis for establishing a functional link between the activation of the S.pombe stress-response pathway and the activity of the master regulator of cell polarity- the Rho GTPase Cdc42. Here, I describe experiments that identify an active involvement of the stress-response mitogen-activated kinase (MAPK) Sty1 in the dispersal of active Cdc42 from the sites of growth. This new role for Sty1 occurs independently from its involvement in transcription regulation and other previously identified signalling pathways involving Sty1. Furthermore, I also find that Sty1’s involvement in Cdc42 regulation has direct implications for fission yeast physiology as it is essential for the maintenance of cellular quiescence upon nitrogen starvation. This thesis also focuses on identifying the targets of Sty1 orchestrating the active Cdc42 disruption. Here, I describe a candidate-based approach, where I investigate the role of proteins from the Cdc42 regulatory network during Sty1 activation. Additionally, I present a global phospho-proteomics approach to identify novel targets of Sty1 and offer preliminary findings which might explain Sty1’s involvement in Cdc42 regulation.

Embryonic cells of many species polarise and the cell polarity is often important for the normal developmental progression. In the mouse embryo, the prototype of epithelial cell polarity, namely apico-basal polarisation, become established at the 2.5 days' post-fertilisation, when the embryos are at the 8-cell stage. The formation of apical domain is necessary and sufficient for the first segregation of extra-embryonic and embryonic cell lineages, as well as the following up morphogenetic transitions, such as the blastocyst formation. This study aims to explore the molecular pathways triggering the first cell polarity establishment in the mouse embryo, and to reveal the mechanism that programmes the timing of this event in the mouse embryo. The results showed that cell polarity establishment during the 8-cell stage development can be divided into two major phases: in the first phase actomyosin complex became polarised to the cell-contact free surface; and in the second phase apical proteins recruited to the actomyosin enriched cell-contact free cortex, they further became centralised in the cell-contact free surface, excluding the local actomyosin meshwork, resulting in the formation of actomyosin ring. The activation and assembly of actomyosin meshwork during the first phase, but not its contractility, was essential for apical protein recruitment. Factors responsible for actin cytoskeleton reorganisation included Phospholipase C (PLC) - Protein Kinase C (PKC) pathway components, they directly activated actomyosin in the first phase through the Rho proteins such as RhoA. Further results showed that the apical protein centralisation step required a proximate transcriptional input that was induced by two transcription factors, Tfap2c and Tead4. RNAi and Genetic depletion of these two factors prevented apical protein centralisation and the final apical domain assembly. The protein expression profile indicated that Tfap2c and Tead4 expression, and therefore their activity, were induced by zygotic genome activation. Significantly, overexpression of Tfap2c, Tead4, together with constitutively activated Rho proteins were sufficient to advance the timing of apical domain formation, indicating that the timer of cell polarity establishment at the 8-cell stage is set by the Rho proteins activation, and the zygotic transcriptional accumulation of Tfap2c and Tead4. Together, these results characterised the molecular events during the cell polarity establishment at the 8-cell stage mouse embryo, and identified the timing regulation of this event.

Uma reação relativamente simples vem auxiliando cada vez mais uma variedade de aplicações analíticas na determinação de diversos compostos. A reação peroxioxalato, que produz o fenômeno de quimiluminescência, pode identificar compostos como peróxido de hidrogênio e compostos orgânicos fluorescentes presentes em diferentes meios. O estudo dessa reação em líquidos iônicos utilizados como solvente se torna cada vez mais interessante, por se tratar de solventes verdes, beneficiando assim o meio ambiente. Neste projeto, foi estudado a reação de oxalato de bis(2,4,6-triclorofenila) (TCPO) com peróxido de hidrogênio, em 1,2-dimetoxietano (DME), carbonato de propileno (CP) e misturas binárias de líquido iônico e DME, catalisada por imidazol. Dois líquidos iônicos (LIs) foram utilizados, sendo eles o tetrafluoroborato de 1-butil-3-metilimidazólio (BuMeImBF4) e o tetrafluoroborato de 1-decil-3-metilimidazólio (DecMeImBF4). As misturas binárias foram preparadas com até 50% de sua composição constituída de LI, definindo assim diferentes condições experimentais no estudo da reação, podendo ser aproveitado em futuras aplicações analíticas. Estudos cinéticos mostraram que o imidazol age não somente como catalisador básico mas também nucleofílico, tanto nos solventes orgânicos puros quanto nos meios contendo LI. Nos solventes puros e nas misturas binárias destes com líquidos iónicos determinaram-se os valores das constantes de velocidade observadas (kobs) e os rendimentos quânticos singlete (ΦS). Os valores de kobs se tornam maiores nas misturas contendo LI em sua composição, entretanto, os valores de ΦS não sofrem alteração significativa, mostrando uma leve tendência de diminuição. A determinação dos parâmetros de polaridade e viscosidade das misturas binárias DME/LI mostra que ambos aumentam com o aumento da concentração do LI. A baixa sensibilidade dos rendimentos quânticos à composição dos meios DME/LI pode ser entendida por um efeito de composição da viscosidade e polaridade do meio. Enquanto o aumento da viscosidade deve aumentar a eficiência de quimiexcitação, o aumento da polaridade pode levar à diminuição do rendimento devido a separação dos íons radicais envolvidos no passo de quimiexcitação ocorrendo pelo mecanismo CIEEL (Chemically Initiated Electron Exchange Luminescence). De acordo com os estudos realizados, foi demonstrado que a reação peroxioxalato pode ser conduzida em meios contendo líquidos iônicos, favorecendo assim uma maior utilização destes solventes verdes. / A relatively simple chemical reaction has increasingly shown utility in a variety of analytical applications for the determination of various compounds. The peroxyoxalate reaction, which produces the chemiluminescence phenomenon, can be used to identify and quantify several compounds, such as hydrogen peroxide and fluorescent organic compounds in different reaction media. The study of this reaction in media containing ionic liquids is of increasing interest, because of its possible utilization as \"green\", environmental compatible, solvents in analytical assays. In this project, the kinetics of the imidazole catalyzed reaction of bis(2,4,6- trichlorophenyl) oxalate (TCPO) with hydrogen peroxide in 1,2-dimethoxyethane (DME), propylene carbonate (CP) and binary mixtures of ionic liquids and DME, is studied, using the two ionic liquids (LIs) 1-butyl-3-methylimidazolium tetrafluoroborate (BuMeImBF4) and 1- decyl-3-methylimidazolium tetrafluoroborate (DecMeImBF4). The binary mixtures were prepared with up to 50% of their composition consisting of LI, thus, defining different experimental conditions in the study of the reaction, which could be used in future analytical applications. Kinetic studies show that imidazole acts not only as base, but also studied as nucleophilic catalyst, in molecular solvents as well as in LI-containing media. In the binary mixtures studied, the values of the observed rate constants (kobs) and singlet quantum yields (ΦS) were determined. The kobs values are higher in mixtures containing LIs in their composition, however, ΦS values do not change significantly, showing only a slight tendency to decrease. The determination of the polarity and viscosity parameters of the binary DME / LI mixtures shows that both increase with increasing LI concentration. The low sensitivity of quantum yields to the composition of the DME / LI media can be understood by a combined medium effect of the viscosity and polarity. While increased viscosity should increase the efficiency of chemiexcitation, increased polarity may lead to decreased quantum yields due to separation of the radical ions involved in the chemiexcitation step occurring by the Chemically Initiated Electron Exchange Luminescence (CIEEL) mechanism. According to the studies, it has been demonstrated that the peroxyoxalate reaction can be conducted in media containing ionic liquids, indicating that analyical assays with the peroxyoxalate reaction migt be performed in these \"green\" solvents.

Erbin belongs to the LAP (leucine-rich repeat and PDZ domain) family of scaffolding proteins that play important roles in orchestrating cell signaling. Here, we show that Erbin functions as a tumor suppressor in colon cancer. Analysis of Erbin expression in patient specimens reveals that Erbin is downregulated at both mRNA and protein levels in tumor tissues. Functionally, knockdown of Erbin disrupts epithelial cell polarity and increases cell proliferation in 3D culture. In addition, silencing Erbin results in an increase in the amplitude and duration of signaling through Akt and RAS/RAF pathways. Moreover, Erbin-loss induces epithelial-mesenchymal transition (EMT), which coincides with a significant increase in cell migration and invasion. Erbin interacts with KSR1 and displaces it from the RAF/MEK/ERK complex to prevent signaling propagation. Furthermore, genetic deletion of Erbin in Apc knockout mice promotes tumorigenesis and significantly reduces survival. Tumor organoids derived from Erbin/Apc double knockout mice have increased tumor initiation potential along with increased Wnt target gene expression as seen by qPCR. Collectively, the studies within this dissertation identify Erbin as a negative regulator of EMT and tumor progression by directly suppressing Akt and RAS/RAF signaling in vivo.

La perte auditive est le trouble sensoriel le plus commun avec 40 % des personnes de plus de 65 ans affectées, entraînant, chez ces patients une dégradation de leur qualité de vie et un isolement sociale. Les principales causes sont le vieillissement ou l'exposition au bruit, mais les mutations génétiques sont aussi à l'origine de déficits auditifs. Parmi ces surdités, le Syndrome de Chudley McCullough (CMCS) est une maladie rare caractérisée par une surdité sévère et précoce associée à des anomalies cérébrales (Chudley et al., 1997). Récemment, des mutations du gène GPSM2 (G protein signaling modulator 2) ont été décrites comme étant responsables de cette pathologie sans que l'on en connaisse les mécanismes (Walsh et al., 2010). A l'aide d'un modèle d'étude murin de cette pathologie, nous avons identifié les bases moléculaires de la pathologie ainsi qu’une nouvelle fonction moléculaire pour Gpsm2 sur la modulation du cytosquelette d’actine. La perturbation de cette fonction affect à la fois la maturation des cellules auditives et la croissance des jeunes neurones, pouvant expliquer les surdités et l’hypoplasie du corps calleux décrits chez ces patients (Mauriac et al., 2017). De plus, nous avons identifié les partenaires de Gpsm2, les protéines Gαi, comme indispensables à la fonction auditive (Beer-Hammer et al., 2018). Au niveau moléculaire, nous avons découvert une nouvelle interaction de Gpsm2 avec une protéine essentielle à la maturation des cellules auditives et impliquées dans les surdités de type Usher, la Whirlin.Par conséquent, notre étude a permis de clarifier l’étiologie du CMCS et de montrer que sa complexité et son aspect multisyndromique sont dus au rôle multifonctionnel du complexe Gpsm2/G⍺i non seulement sur la dynamique de la tubuline dans des cellules en prolifération et en post-mitotiques (Ezan et al., 2013), mais aussi sur la dynamique d’actine (Mauriac et al., 2017). / Hearing loss is the most common sensory disorder, affecting 40% of people over 65 years old, leading for these patients, to the deterioration of their quality of life and to their social isolation. The main causes are aging or exposure to noise. However, many genes can also cause deafness. Among these deafnesses, the Chudley McCullough Syndrome (CMCS) is a rare disease characterized by severe and early deafness associated with brain abnormalities (Chudley et al., 1997). Recently, mutations in the GPSM2 (G protein signaling modulator 2) gene were found to be causative of this pathology, but the molecular basis were unknown (Walsh et al., 2010). Using a murine model of this pathology, we identified the molecular basis of this pathology as well as a new molecular function for Gpsm2 on the modulation of actin cytoskeleton. The disruption of this function leads to defect of the maturation of auditory hair cells and the reduction of the outgrowth of young neurons which may explain the deafness and the hypoplasia of the corpus callosum described in these patients (Mauriac et al., 2017). In addition, we identified partners of Gpsm2, Gαi proteins, as essential for auditory function (Beer-Hammer et al., 2018). At the molecular level, we have discovered a new interaction of Gpsm2 with a protein essential for the maturation of auditory cells and involved in Usher type deafness, Whirlin.Therefore, our study clarified the etiology of CMCS and show that the complexity and multisyndromic aspect of this pathology is due to the multifunctional role of the complex Gpsm2/G⍺i not only on tubulin dynamics in proliferating cells and post-mitotic cells (Ezan et al., 2013), but also on actin dynamics (Mauriac et al., 2017).

This thesis looks at the Jungian concept of the archetypes and the connection between the process of individuation and social ecology. An unnatural split between thinking and feeling is seen to be entrenched in society and to be a cause for conflict. It is argued that this split has its origins in the individual 's unresolved inner conflict of ego and shadow. The idea of the archetype is examined in the context of Jung's observations about psychic features which he made throughout his lifetime. While it is true the psychic archetypes have an immense significance for a society in general, it is also true that archetypes are absolutely central in the life of the individual. The central part played by mythology and fairy tale in Jungian psychology is explored using a North American Indian myth as a vehicle for an exposition for some major concepts. Inheritance of archetypes is perhaps the central feature of controversy surrounding the Jungian concept of psychic archetypes and a possible mechanism of inheritance based on the idea of the 'meme' and its relationship to the gene, is examined. The ancient story of Aladdin and the Lamp, is found to contain inherent psychic features or artefacts, which elucidate the concept of the ego/shadow polarity, and so can be seen to constitute an example of an 'archaeology' of archetypes. The apparent dual nature of the archetype is further explored by comparing and contrasting the archetypes of the 'wise old man' and the 'wicked magician', and this dual nature exploration is seen to be in essence an examination of the ego/shadow equilibrium, which exerts its influence on all manifestations at the moment of expression. This unexpected influence on the archetype, despite the archetype's collective nature, explains the positive and negative faces of the archetypes and seems to resolve some questions about their moral, amoral and/or polar nature. The resolution of psychic conflict in the context of Jungian individuation and how the individuation process may influence the expression of collective features, is also found to have the ego/shadow equilibrium as the central psychic structure. / Master of Science (Hons) (Social Ecology)

Thesis (M.S.)--Brigham Young University. Dept. of Physiology and Developmental Biology, 2006. / Includes bibliographical references (p. 34-36).