HARP (Heparin Affin regulatory peptide) est un facteur de croissance qui constitue avec la midkine une sous-famille des Heparin Binding Growth Factors (HBGFs). HARP est impliqué dans de nombreux processus physiologiques comme la neurogenèse et la vasculogenèse mais aussi dans des processus physiopathologiques comme l’angiogenèse et la progression tumorale. HARP interagit avec différents récepteurs (N-syndécan, RPTPβ/ζ, et ALK). Plus récemment, il a été montré au laboratoire que la nucléoline, protéine navette entre le noyau, le cytoplasme, et la surface cellulaire est un nouveau récepteur à HARP. Malgré les avancées dans ce domaine, l’interaction de HARP avec ses récepteurs n’est pas totalement élucidée. L'objectif de ce projet de thèse était la recherche de nouveaux partenaires moléculaires qui interagissent avec HARP, de comprendre le mécanisme de leurs interaction et d’analyser les effets biologiques. A ce titre, j’ai participé à l’étude de l’interaction de HARP avec le facteur de croissance des fibroblastes, le FGF-2. Ce facteur liant l’héparine est également mitogène et angiogène. En utilisant des techniques de biocapteurs optiques et d’interaction protéine-protéine, nous avons montré une interaction directe entre HARP et le FGF-2 et qui implique les domaines C-TSR-I et C-terminale de HARP. De plus, cette interaction inhibe la migration et la prolifération des cellules endothéliales, induites par le FGF-2 ou par HARP seuls. En parallèle, j’ai mis en évidence l’interaction entre HARP et la NRP-1. NRP-1 est une protéine transmembranaire, ayant comme ligands principaux, les sémaphorines de classe 3 (SEMA 3A), le facteur de croissance endothélial vasculaire (VEGF) et le FGF-2. En plus de son rôle crucial dans le développement des systèmes nerveux et cardiovasculaires, la NRP-1 est impliquée dans les processus physiopathologiques tels que l’angiogenèse et l’invasion tumorale. Ainsi, la NRP-1 présente un profil biologique similaire à HARP. En utilisant des tests d’ELISA, d’immunoprécipitation et de « pull-down », nous avons montré que HARP interagit avec la NRP-1. Cette interaction semble être directe et s’effectue via les domaines de liaison à l’héparine TSR-I. HARP induit l’internalisation de la NRP-1 au bout de 15 minutes et son recyclage partiel à la surface cellulaire au bout d’une heure. L’internalisation de la NRP-1 s’accompagne par la phosphorylation des voies MAPK (ERK1/2), Akt et FAK. L’interaction HARP/NRP-1 est cruciale pour la migration des cellules endothéliales et l’invasion des cellules tumorales. En conclusion, ces résultats apportent de nouvelles avancées concernant les partenaires moléculaires de HARP en particulier et montrent également la complexité des interactions des facteurs de croissance entre eux et avec leurs récepteurs. Plus généralement, cette étude permet d'envisager des stratégies thérapeutiques ciblant l’interaction de la NRP-1 avec HARP et aussi les autres facteurs de croissance. / HARP (Heparin Affin regulatory peptide) is a growth factor that constitutes with midkine a subfamily of Heparin Binding Growth Factors (HBGFs). HARP is involved in many physiological processes such as neurogenesis and vasculogenesis but also in pathophysiological processes such as angiogenesis and tumor progression. HARP interacts with different receptors (N-syndecan, RPTPβ / ζ and ALK). More recently, it has been shown in the laboratory that nucleolin, a protein shuttle between the nucleus, cytoplasm, and cell surface, is a new HARP receptor. Despite the advances in this field, the interaction of HARP with its receptors is not fully understood. The aim of this thesis was the search for new molecular partners that interact with HARP, to understand the mechanism of their interaction and analyze the biological effects. My work was firstly to participate to the study of the interaction of HARP with the fibroblast growth factor-2, FGF-2. This factor is also an heparin-binding factor, with mitogenic and angiogenic activities. Using techniques of optical biosensors and protein-protein interaction, we have shown a direct interaction between HARP and FGF-2 that involves C-TSR-I and C-terminus domains of HARP. In addition, HARP inhibits the migration and proliferation of endothelial cells induced by FGF-2. In parallel, I highlighted the interaction between HARP and NRP-1. NRP-1 is a transmembrane protein having as main ligands, semaphorins class 3 (SEMA 3A), the vascular endothelial growth factor (VEGF) and FGF-2. In addition to its crucial role in the development of the nervous and cardiovascular systems, the NRP-1 is involved in physiopathological processes such as angiogenesis and tumor invasion. Thus, NRP-1 has a biological profile similar to HARP. Using ELISA, immunoprecipitation and "pull-down" tests, we have shown that HARP interacts with NRP-1. This interaction appears to be direct and occurs via heparin binding domains of HARP: TSR-I. HARP induces internalization of NRP-1 after 15 minutes and partial recycling to the cell surface after one hour. The internalization of the NRP-1 is accompanied by the phosphorylation of MAPK pathways (ERK1 / 2), Akt and FAK. HARP/NRP-1 interaction is crucial for endothelial cell migration and invasion of tumor cells. In conclusion, these results provide new advances on molecular partners of HARP in particular and also show the complexity of the interactions between these growth factors and their receptors. More generally, this study allows considering therapeutic strategies targeting the interaction of NRP-1 with HARP as well as other growth factors.

La compréhension de l'émergence des maladies infectieuses végétales causées par les bactéries passe par l'identification des populations sources, des routes d'invasion et des voies de dissémination, ainsi que par l'estimation des paramètres biotiques et abiotiques associés. Xanthomonas citri pv. citri (Xcc) est l'agent pathogène responsable du chancre Asiatique des agrumes. La bactérie est distribuée dans plusieurs pays agrumicoles du monde et listée comme organisme de quarantaine par ceux où elle est absente. Nous avons abordé l'épidémiologie moléculaire de Xcc à deux échelles spatio-temporelles grâce à un schéma de 14 microsatellites (MLVA-14) et un schéma de 31 marqueurs minisatellites (MLVA-31). Le typage MLVA-14 s'est montré adapté au génotypage d'une bactérie monomorphe comme Xcc. Le typage MLVA-31 a permis de diviser le pathovar Xcc en quatre groupes génétiques distincts correspondant aux différences de gammes d'hôtes mise en évidence chez cette bactérie. Le pathotype A (souches à large gamme d'hôtes parmi les rutacées) est séparé en deux groupes génétiques, tandis que les pathotypes A* et Aw (souches à gamme d'hôtes restreinte au limettier Mexicain et quelques espèces proches) constituent chacun un groupe génétique. Alors que l'expansion géographique de Xcc depuis son aire d'origine dans la première moitié du XXème siècle a quasi exclusivement concerné un seul groupe génétique, trois des quatre groupes décrits ont contribué à l'émergence de Xcc en Afrique au cours de la dernière décennie. La bactérie est pré-adaptée et a été introduite avec son hôte depuis sa population d'origine, faisant de la barrière migratoire la seule étape à franchir pour rencontrer un succès d'invasion. L'objectif de cette thèse a été de décrire les différentes populations émergentes grâce à des approches d'épidémiologie moléculaire et inférentielles, et identifier les différentes origines, routes et acteurs de la dissémination. Nous avons dans un premier temps montré la coexistence de deux groupes génétiques distincts au Mali : DAPC1 qui est dispersé dans quatre provinces du pays et DAPC2 qui est resté cantonné à l'espace péri-urbain de Bamako. L'analyse de l'émergence de Xcc au Sénégal a révélé le succès invasif de DAPC2 dans un autre environnement. La structure des populations DAPC1 du Mali et DAPC2 du Sénégal suggèrent que les plants de pépinières constituent une voie de dissémination majeure dans ces pays. À l'opposé, DAPC2 de Bamako n'est pas détecté en pépinières au Mali et n'a pas montré de caractère invasif. L'existence d'une population « tête de pont » invasive de souches DAPC1 au Mali donnant lieu à une épidémie au Burkina Faso a été mise en évidence par une approche ABC (calcul Bayésien approché). Les populations DAPC2 du Mali et du Sénégal ne présentent pas de lien épidémiologique direct mais partagent des liens de parenté avec des souches présentes dans le sous-continent Indien. Dans un deuxième temps, l'analyse d'une population de souches appartenant au pathotype A* en Ethiopie nous a permis de procéder à des estimations de paramètres démographiques, tels que les tailles efficaces. Nous avons montré que l'approche inférentielle nous permettait d'éclairer l'histoire démographique de Xcc dans un cas d'émergence, et de mettre en avant une dynamique saisonnière accentuant probablement le déséquilibre mutation-dérive lié à la situation d'émergence. L'émergence de Xcc en Afrique est principalement associée aux activités humaines. Sa dissémination locale et globale peut alors être considérablement limitée par des mesures de gestion plus stricte au niveau des pépinières et des flux de commerces. / Several plant emerging infectious diseases are caused by bacteria. To improve our understanding of their emergence, a description of the emerging populations, the reconstruction of invasion routes and pathways, as well as the identification of involved biotic and abiotic parameters are fundamental. The bacterium Xanthomonas citri pv. citri (Xcc) is responsible for Asiatic citrus canker. It is present in many citrus producing countries and listed as a quarantine organism in canker-free countries.Two MLVA schemes were used for molecular epidemiological analyses of Xcc. The first one, MLVA-14, targeted 14 microsatellite markers, and is useful to describe the genetic diversity of this monomorphic bacterium. The second, MLVA-31, targeted 31 minisatellite markers, is suited to global epidemiology analyses. Based on MLVA-31 data, Xcc is divided in four genetic groups (referred to as DAPC clusters) corresponding to Xcc pathotype classification based on host range. Three pathotypes were described: pathotype A strains are able to infect most citrus species, while pathotypes A* and AW strains are naturally restricted to fewer host species.DAPC 1 is responsible for almost all cases of geographical expansion of Xcc over the first half of the 20th century, we show that three Xcc genetic clusters have emerged in Africa over the last decade. Xcc is pre-adapted to its host species. Invasive success of Xcc is then mostly conditioned by migration events. Our objectives were to describe these invasive populations using a molecular epidemiology approach and to assess the origin, routes and actors of this dissemination in Africa. Two genetic clusters were found in Mali: DAPC1 is present in four provinces while DAPC2 is restricted to the Bamako urban environment. In contrast, DAPC2 emerging populations in Senegal showed an invasive succes in an other environment. Populations structures of DAPC1 in Mali and DAPC2 in Senegal highlighted the role of nurseries in Xcc dissemination. On the contrary, DAPC2 strains in Bamako were not detected in Malian nurseries and showed a limited invasive success. Approximate Bayesian Computation highlighted an invasive bridgehead scenario between DAPC1 in Mali and Burkina Faso. DAPC2 populations in Mali and Senegal were not found epidemiologically related but were genetically related to strains previously reported from the Indian subcontinent.Demographic parameters inference, such as effective population sizes, were inferred from Ethiopian pathotype A* populations. The inference approach was useful to decipher the demographic history of this emerging population, and suggested seasonal fluctuations in population sizes over time.Emergence of Xcc in Africa was found strongly related to human activities. Therefore, the local and global dispersion could be limited by a better management of nurseries and trade.

Transforming growth factor β (TGF-β) and bone morphogenetic protein (BMP) signaling pathways are involved in many physiological processes during embryonic and adult life. TGF-β promotes epithelial to mesenchymal transition (EMT). We identified a gene target of TGF-β signaling, encoding the salt-inducible kinase 1 (SIK1). A potential substrate of this kinase, the polarity protein Par3, is an established regulator of tight junction assembly. SIK1 associates with Par3, can potentially phosphorylate Par3 and leads to its degradation, contributing to tight junction disassembly. Glioblastoma multiforme (GBM) is a common malignancy in the central nervous system, characterized by high heterogeneity, invasiveness, and resistance to therapy. One of the causes of heterogeneity and therapy-resistance is the existence of glioblastoma stem cells (GSCs). TGF-β signaling promotes self-renewal while BMP signaling induces differentiation of GSCs. Snail is a potent inducer of the EMT in carcinomas. However, in the context of GBM, Snail induces BMP signaling and represses TGF-β signaling through interaction with SMADs, the signaling mediators of TGF-β and BMP. In conclusion, Snail differentially regulates the activity of the opposing BMP and TGF-β pathways, thus promoting an astrocytic fate switch and repressing stemness in GSCs. Although profound changes in cell polarity is a hallmark of invasive malignancies, little is known about the role of the polarity machinery in tumor suppression. Patient transcriptomic data suggested low Par3 expression, correlating with poor survival of the GBM patients. Par3 silencing decreased the GSC self-renewal capacity and enhanced their invasiveness. Transcriptomic analysis indicates that loss of Par3 leads to downregulation of genes encoding mitochondrial enzymes that generate ATP. These results support a novel role of Par3 in GBM, beyond its contribution to junctional contacts between cells. Another regulator of TGF-β and BMP signaling is the liver kinase B1 (LKB1). According to GBM patient mRNA analysis, high levels of LKB1 correlate with poor prognosis. Silencing of LKB1 in GSCs impairs invasion and self-renewal capacity due to downregulation of genes involved in these processes. Moreover, loss of LKB1 induces mitochondrial dysfunction, leading to decreased ATP levels. Collectively, this thesis has delivered a group of novel regulatory pathways that control critical aspects of cancer cell polarity, invasion and stemness.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-19T12:54:17Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO DE MESTRADO - SILAS VALENTE.pdf: 3356138 bytes, checksum: 5efc9b5c2ec967aba4a0eded24e8fd9a (MD5) / Made available in DSpace on 2016-04-19T12:54:17Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO DE MESTRADO - SILAS VALENTE.pdf: 3356138 bytes, checksum: 5efc9b5c2ec967aba4a0eded24e8fd9a (MD5) Previous issue date: 2015-07-31 / As linhas de transmissão de energia elétrica (LT) são construções que se destinam ao transporte de energia elétrica das fontes geradoras aos centros de consumo. Uma LT possui como elementos básicos: cabos, isoladores e torres. O espaço no solo ocupado por esses elementos e entorno deve ser respeitado frente às diversas formas de ocupação. Esta área protegida é denominada Faixa de Servidão. A faixa de servidão, como território ocupado com potencial de geração de riscos à população, têm inúmeras restrições quanto à sua utilização, dada sua destinação: proteger o sistema elétrico e a sociedade. Sua largura varia em função da tensão dos cabos. Para tensões de 230 e 500 kV (kilovolts) a largura da faixa de servidão é respectivamente de 50 e 65 metros. A ocupação e conservação da faixa de servidão de forma adequada possibilitam maior segurança para as pessoas e bens localizados na vizinhança, bem como maior rapidez na localização de anomalias e na manutenção na LT. Ocupações das faixas de servidão, que não estejam contempladas no projeto de instalação da LT, são consideradas ocupação irregular ou invasão e devem ser identificadas e removidas. Atualmente existem dados de sensoriamento remoto de média e alta resolução espacial que podem auxiliar no estudo do uso e cobertura do solo. Neste contexto, esta pesquisa tem como objetivo desenvolver uma metodologia, a partir de dados de sensoriamento remoto (CBERS-2B/HRC e SRTM), para identificar áreas invadidas e suscetíveis à ocupação irregular em faixa de servidão de LT. Para isso foram aplicadas técnicas de segmentação, classificação de imagem e desenvolvido modelos matemáticos usando parâmetros definidos nesta pesquisa. A área de estudo é a faixa da LT 230 kV Ibicoara/Brumado, localizada no estado da Bahia. A pesquisa caracterizou de forma abrangente e eficaz, a temática de LT e faixa de servidão, envolvendo aspectos técnicos, ambientais e de segurança, e contextualizou o sensoriamento remoto relacionando-o com o tema, envolvendo sistemas sensores e aplicações. Os resultados do estudo mostraram-se eficientes na observação/fiscalização do quadro de ocupação da faixa de servidão em locais específicos, sendo possível antecipar ocorrência de invasões, auxiliando na gestão de rede transmissão de energia elétrica. / The transmission lines (TL) are constructions intended for the transport of electricity from the generating sources to consumption centers. A TL has as basic elements: cables, insulators and towers. The land space occupied by these elements and surroundings must be respected across the various forms of occupation. This protected area is called right of way. The right of way as a potential risk area for population has numerous restrictions for its use, given their destination: protect the electrical system. Its width varies depending on the tension of the cables. For voltages of 230 and 500 kV (kilovolts) the width of the right of way is respectively 50 and 65 meters. The occupation and conservation of the right of way enables greater security for people and property located in the surroundings, as well as greater speed in detecting anomalies and for the maintenance of the TL. Occupations in the right of way, which are not included in the TL installation project, are considered illegal occupation or invasion and must be identified and removed. Currently there are remote sensing data of medium and high spatial resolution that can support the study of land use and land cover. In this context, this research aims to develop a methodology, based on remote sensing data (CBERS-2B / HRC and SRTM) to identify areas invaded and susceptible to irregular occupation in the right of way. Therefore, segmentation techniques, image classification and developed mathematical models using parameters defined for this search were applied. The study area is the right of way of the TL 230 kV Ibicoara / Brumado, located in the state of Bahia. This study used a comprehensive and effective way to characterize the issues related to TL and its right of way, considering technical, environmental and safety aspects, and contextualized remote sensing relating it to the subject, considering sensor systems and applications. The results of the study showed to be efficient in the observation / surveillance for the status of occupation of the right of way, in specific locations, making possible the anticipation of occurrence of invasions, giving more support for the management of power grid.

A causa de morte da maioria das pacientes com câncer de mama se deve à doença metastática desenvolvida a partir do tumor primário. A degradação dos componentes da matriz extracelular (MEC), um dos principais eventos do processo metastático, é regulada pelo balanço entre as atividades das metaloproteinases de matriz (MMPs) e dos seus inibidores, tanto os inibidores teciduais (TIMPs) como o inibidor associado à membrana (RECK). Contudo, ainda existe pouca informação sobre os mecanismos moleculares responsáveis pela manutenção deste balanço. No presente trabalho, foi investigado o envolvimento de TGF-β1 (Transforming Growth Factor-β1), uma citocina multifuncional é capaz tanto de inibir o crescimento celular, quanto de promover invasão e metástase, dependendo do estadiamento e do tipo de tumor, na regulação da expressão de MMPs, TIMPs e RECK, em modelo de câncer de mama. Primeiramente, examinou-se os níveis de expressão de mRNA das isoformas e receptores de TGF-β, em um painel de cinco linhagens de carcinoma mamário humano, com diferentes potenciais invasivos e metastáticos, por qRT-PCR. Os resultados obtidos demonstraram uma correlação positiva entre a expressão dessas moléculas, e a progressão do caráter invasivo e metastático celular. Em seguida, a linhagem altamente invasiva, MDA-MB-231, foi tratada com diferentes concentrações de TGF-β1 recombinante. Esta citocina foi capaz de modular a expressão gênica de MMPs (MMP-2 e MMP-9) e de seus inibidores (TIMP- 2 e RECK). Tanto ERK½, quanto p38MAPK mostraram-se envolvidas neste mecanismo. Foi demonstrado que a inibição da atividade de ERK½ alterou a expressão das proteínas MMP-9, TIMP-2 e RECK, enquanto o bloqueio de p38 MAPK afetou os níveis protéicos de MMP-2 e TIMP-2. O aumento do potencial migratório e invasivo da linhagem MDA-MB-231, induzido por TGF-β1, mostrou-se também dependente da atividade de MMPs, ERK½ e p38MAPK. Dada a ausência de informações sobre o papel de RECK em modelo mamário, a função deste inibidor de MMPs também foi investigada. Primeiramente, analisou-se a expressão de RECK ao longo do desenvolvimento da mama e, posteriormente, em 1040 amostras tumorais de mama humana, através da metodologia de Tissue Microarray, tendo sido possível demonstrar que a alta expressão de RECK associa-se a menor tempo de sobrevida global e livre de doença em 10 anos. Os resultados obtidos indicaram que a expressão da proteína RECK, em oposição ao verificado em outros tipos de tumores, está relacionada ao fenótipo mais agressivo de tumores de mama. Entretanto, a análise funcional de RECK, realizada por meio da utilização de vetores shRNA específicos para a inibição desta proteína, demonstrou que RECK também atua como um inibidor de invasão celular e da expressão de MMP-9, na linhagem MDA-MB-231. Em conjunto, os resultados obtidos neste trabalho contribuíram para a elucidação dos mecanismos moleculares de regulação de RECK, por clássicas moléculas associadas ao processo de tumorigênese (TGF-β1 e MAPKs), bem como para o esclarecimento de suas funções em modelo mamário, sugerindo-o como mais um promissor candidato a marcador prognóstico e alvo molecular para a terapia do câncer de mama. / The metastatic disease is the main mortality cause of breast cancer patients. The metastatic process involves a complex cascade of events, including the organized breakdown of the extracellular matrix (ECM) compounds. The degradation of ECM is tightly regulated by the balance between the activities of matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors (TIMPs) and the membrane-associated inhibitor (RECK). Among the several molecules released and activated by ECM remodeling, TGF-β1 (Transforming Growth Factor-β1) is a multifunctional cytokine able to regulate both cell growth inhibition and invasion and metastasis promotion, depending on the tumor stage and type. Since the molecular mechanisms involved in the ECM remodeling control are still not completed understood, in this study, we investigated the involvement of TGF-β1 in regulating of MMPs, TIMPs and RECK expression, in the breast cancer model. By qRT-PCR, we first examined the gene expression levels of TGF-β isoforms and receptors, in a panel of five human breast cancer cell lines displaying different degrees of invasiveness and metastatic potential. Our results suggest a positive correlation between the mRNA expression of these molecules and the breast cancer progression. Moreover, the highly invasive breast cancer cell line MDA-MB-231 was treated with different concentrations of recombinant TGF-β1. We described that this cytokine was able to modulate the gene expression of MMPs (MMP-2 and MMP-9) and MMPs inhibitors (TIMP-2 and RECK) at both the mRNA and protein levels, with ERK½ and p38 MAPK being involved in this molecular mechanism. However, while ERK½ activity inhibition altered MMP-9, TIMP-2 and RECK expression, the p38 MAPK blockage affected the protein levels of MMP-2 and TIMP-2. Finally, we reposted that the TGF-β1-enhanced migration and invasion capacities of MDA-MB- 231 cells were blocked by MMPs, ERK½ and p38 MAPK inhibitors. Analysis of the RECK function in the breast model was also an objective of this study. We analyzed RECK expression during mammary gland development. We evaluated the RECK protein profile in 1040 breast tumor tissue samples using Tissue Microarray assays. We demonstrated that high expression levels of RECK were associated with shorter overall and disease-free survival in 10 years. Moreover, we verified that RECK is a biomarker of poor prognosis mainly for patients diagnosed with less aggressive breast tumor. Therefore, in contrast to other tumor types, our results indicate that high protein expression levels of RECK are related to a more aggressive phenotype. In fact, the RECK functional analysis, performed by using of shRNA vectors, showed that RECK function remains as an inhibitor of cellular invasion and MMP-9 expression, in MDA-MB-231 cells. Taken together, our results contribute to better understanding of the molecular mechanisms associated to RECK regulation by TGF-β1 and MAPK as well as to clarify its role in breast model. Thus, we suggests RECK as a new and promising prognostic marker and molecular target candidate for breast cancer therapy.

Bien moins médiatisées que la déforestation ou le changement climatique, les invasions biologiques n’en demeurent pas moins problématiques pour la conservation de nombreux écosystèmes ou le bon déroulement de nombreuses activités socio-économiques.Comprendre la façon dont les espèces exotiques envahissantes s’étendent dans les différents milieux qu’elles colonisent c’est permettre à la fois de mieux appréhender leurs impacts, de pouvoir de prédire leur expansion, et de trouver les endroits stratégiques où agir pour contrer ou atténuer les effets indésirables de ces espèces. Le problème est que dynamiques d’invasions d’une espèce regroupent en fait une hiérarchie de processus se produisant simultanément à différentes échelles spatiotemporelles et qui sont contrôlés par des facteurs qui changent en fonction du temps et du contexte d’invasion. Pour acquérir une compréhension profonde de ces dynamiques, il faut donc étudier leurs manifestations et leurs causes aux diverses échelles spatiales et temporelles auxquelles elles se produisent.Présentes sur les cinq continents et très envahissante sur au moins deux, les renouées asiatiques (Reynoutria spp.) sont reconnues comme faisant partie des espèces les plus invasives de la planète. Dotées d’une grande tolérance environnementale et d’importantes capacités de multiplication végétatives, ces plantes herbacées géantes peuvent former rapidement de grandes monocultures clonales qui excluent les autres espèces végétales, modifient les cycles biogéochimiques des zones envahies et perturbent diverses activités anthropiques. Cibles de campagnes de gestion depuis des décennies, elles affichent cependant une résilience insolente qui désespère de nombreux gestionnaires. Bien que très étudiées, de nombreux détails concernant leurs dynamiques nous échappent toujours. Dans ce travail de thèse, nous avons donc cherché à identifier quels sont les facteurs qui contrôlent les dynamiques spatiotemporelles des renouées à différentes échelles, et comment une meilleure compréhension de ces dynamiques clés pourrait profiter à leur gestion ?Pour ce faire, nous nous sommes donc d’abord intéressés à leur dynamiques clonales et à leurs variations en fonction de différentes conditions de stress (ombrage) ou de perturbation (fauchage répétée). Nous avons montré que si les renouées sont bien affectées par des conditions stressantes ou perturbées, cela ne les empêche ni de s’établir, ni de croître. En fait, les renouées semblent pouvoir adopter différentes stratégies de croissance pour pallier ces contraintes, soulevant différentes questions liées à la gestion. Dans une deuxième étude, nous avons cherché quels étaient les variables qui expliquaient l’expansion des taches de renouées le long d’un gradient altitudinal. Si nous avons montré que les dynamiques d’expansion des taches étaient principalement contrôlées par leur taille (et donc potentiellement leur âge) ainsi que par la proximité de routes et de rivières, nous avons également apporté des indices qui suggèrent que les renouées pourraient être potentiellement capables d’envahir les montagnes. Ensuite, pour tenter d’aider à résoudre le problème de l’acquisition des données de distribution des renouées à large échelle, nous avons développé une méthode pour détecter et cartographier les populations de renouées à partir d’images satellites et issues de drones. Notre méthode a montré des résultats encourageants et celle-ci pourrait être utile à l’étude des invasions ainsi qu’à la détection des nouveaux foyers d’invasion pour une gestion plus précoce et efficace des renouées.Enfin, nous avons tenté de dresser un portrait global de la compréhension actuelle des dynamiques d’invasion des renouées en réalisant, en guise de discussion, une grande revue de littérature sur les mouvements de ces plantes à travers les échelles spatiales et temporelles et en y intégrant les apports des autres travaux de cette thèse. / Although less mediatized than deforestation or climate change, biological invasions remain problematic for the conservation of many ecosystems and the maintenance of various socio-economical activities.Understanding the way invasive non-native species spread in their introduced range is enabling a better apprehension of their impacts, the possibility to predict their expansion, and the development of better management strategies. A problem is that a species invasion dynamics are actually composed of a hierarchy of processes occurring simultaneously at various spatiotemporal scales and which are controlled by drivers that are time- or context-dependent. To gain more profound insights into these dynamics, one has to study the patterns they create and their underlying processes at all relevant scales.Occurring on the five continents and highly invasive on at least two of them, Asian knotweeds (Reynoutria spp.) are acknowledged as being among the most invasive species in the world. Gifted with a large environmental tolerance and high abilities for vegetative multiplication, these giant herbaceous plants can quickly form large clonal monocultures that exclude the other plant species, modify biogeochemical cycles, and affect various anthropic activities. Target of management campaigns for decades, knotweeds display an insolent resilience to the great despair of many stakeholders. Despite having been extensively studied, many aspects of their dynamics are still elusive. Consequently, in this thesis, we have tried to highlight what the drivers of the spatiotemporal dynamics of knotweeds across scales are, and how their management could benefit from a better understanding of these dynamics?To answer these questions, we first focused our attention on the clonal dynamics of knotweeds and on their variations when they experience differing conditions in terms of light availability and disturbance (repeated mowing). We have shown that although shade or mowing affects the vigour and the development of clones, it does not prevent their establishment or their growth. In fact, knotweeds seem able to adopt different growth strategies to cope with environmental heterogeneity, suggesting some management avenues. In a second study, we tried to identify the drivers that controlled the expansion of knotweed stands along an elevational gradient. If we showed that the lateral expansion of stands is mostly constrained by their size (and thus, possibly their age) and the vicinity of roads and rivers, we also brought evidences that knotweeds could have the potential to invade mountain regions. Then, to help for the acquisition of large-scale datasets on knotweeds’ distribution, we developed a procedure to accurately detect and map knotweeds using satellite or drone imagery. Our results were quite encouraging and could be useful to both the basic research and to the detection of newly invaded areas, enabling earlier control operations and more efficient management.Finally, we tried to draw a full picture of the current knowledge on the invasion dynamics of knotweeds by reviewing the literature on the movement of these plants across spatial and temporal scales, to discuss and expand the reach of the insights gained in the various chapters of this thesis.

La métastase et la chimiorésistance sont les principales causes de mortalité chez les patients atteints d’un cancer. La compréhension des mécanismes moléculaires régissant ces deux processus devient donc un domaine de recherche important pour la conception de nouvelles stratégies thérapeutiques. Dans ma thèse, je me concentre sur la compréhension du rôle du facteur d’initiation de la traduction chez les eucaryotes 4E (eIF4E) dans l’invasion du cancer, et je décris un nouveau mécanisme de résistance que nous avons découvert en étudiant le développement de la résistance à un inhibiteur connu d’eIF4E, la ribavirine. eIF4E est un puissant oncogène qui est connu pour être élevé dans une multitude de cancers comprenant entre autres les sous-types M4 / M5 de la leucémie myéloïde aiguë (AML). Il fonctionne dans la traduction et l'exportation nucléocytoplasmique d'ARNm en se liant à la coiffe m7G des ARNm possédant des codes USER spécifiques dans leur région UTR 5' et/ou 3'. En reconnaissant ces codes USER, le complexe dans lequel se trouve eIF4E régule de manière coordonnée l'expression de gènes essentiels à la croissance, à la prolifération et à la survie, et ainsi, eIF4E a été placée en tant que nœud central d'un régulon d'ARN régissant la prolifération. En analysant les voies dans lesquelles l’export est régulé de façon coordonnée par eIF4E et les effets physiologiques qui en découlent, j'ai trouvé un enrichissement de la voie biosynthétique de l'acide hyaluronique (HA) et de son principal récepteur CD44 qui sont des médiateurs clés connus des métastases cancéreuses. J’ai également démontré que l'élévation d’eIF4E modifie la surface des cellules cancéreuses en les recouvrant de protrusions riches en HA de type microvillus et enrichies d'armes de destruction métastatique. Heureusement, en dégradant le manteau HA ou en utilisant des inhibiteurs de CD44 en combinaison avec la ribavirine, nous pouvons alors nous défendre. Compte tenu de l'avantage prolifératif que confère la surexpression d’eIF4E, il est devenu un talon d'Achille attrayant pour le traitement de cancers ayant un niveau élevé d'eIF4E. En effet, lors d'un essai clinique de phase II parmi des patients atteints de leucémie myéloïde aiguë M4 / M5 réfractaire et récidivante, la ribavirine a conduit au ciblage d'eIF4E et a donné lieu à des réponses cliniques significatives, incluant des réponses complètes ou partielles. Cependant, tel qu’attendu lors d’un traitement monothérapique, les patients ayant répondu finissent par développer une résistance au médicament. Mon analyse a révélé que cette résistance est due à un mécanisme nouveau caractérisé par l'élévation du facteur de transcription Sonic Hedgehog GLI1 qui conduit à la glucuronidation du médicament et donc à la perte de l'interaction entre la drogue et sa cible. Heureusement, ce mécanisme peut être inversé en utilisant des inhibiteurs de la voie Hedgehog. En conclusion, ces découvertes fournissent de nouvelles cibles thérapeutiques pour le traitement des cellules cancéreuses agressives et résistantes. / Metastasis and chemoresistance are the leading cause of mortality among cancer patients. The discovery of molecular mechanisms governing these two processes is becoming an important area of research for the design of novel therapeutic strategies. In my thesis, I focus on understanding the role of the eukaryotic translation initiation factor 4E (eIF4E) in cancer invasion and describe a novel mechanism of resistance that we discovered while studying the development of resistance to a known eIF4E inhibitor, ribavirin. eIF4E is a potent oncogene that is known to be elevated in a multitude of cancers including M4/M5 subtypes of acute myeloid leukemia (AML). It functions in mRNA translation and nucleocytoplasmic export by binding to the m7G cap of mRNAs possessing specific USER codes in their 5’ and/or 3’ UTRs. By recognizing these USER codes, eIF4E complex coordinately regulates the expression of genes essential for growth, proliferation and survival and as such has been placed as a central node of an RNA regulon governing proliferation. When analyzing which pathways have their export coordinately regulated by eIF4E and what physiological effects arise from it, I found an enrichment in the hyaluronic acid (HA) biosynthetic pathway as well as its major receptor CD44 which are known key mediators of cancer metastasis. I demonstrate that eIF4E elevation changes the surface of cancer cells sugar-coating them with HA-rich microvillus-like protrusions that are enriched with weapons of metastatic destruction. Luckily, through degrading the HA-coat or using inhibitors of CD44 in combination with ribavirin we can strike back. Given the proliferative advantage that eIF4E overexpression conveys, this rendered it as an attractive Achilles heel for the treatment of cancers where eIF4E levels are high. Indeed, in a phase II clinical trial in refractory and relapsed poor prognosis M4/M5 AML patients, ribavirin led to eIF4E targeting and resulted in significant clinical responses including complete and partial remissions. However, as it is expected for monotherapy treatment, all responding patients eventually developed resistance to the drug. My analysis revealed that resistance is due to a novel mechanism characterized by elevation of the Sonic Hedgehog transcription factor GLI1 which leads to drug glucuronidation and the subsequent loss of drug-to-target interaction. Fortunately, this mechanism can be reversed using Hedgehog pathway inhibitors. Taken together, these findings provide novel therapeutic venues for the treatment of aggressive and resistant cancer cells.

This dissertation traces the emergence of the air raid shelter as the paradigmatic architecture of air defense under the Nationalist Party government in China during the War of Resistance against Japan (1937–1945). More broadly, it explores how air defense in general became an integral technology for the Nationalists’ “war of resistance and reconstruction” (kangzhan jianguo), a fascist project derived from total war, the globally circulating military-political idea that modern wars would enlist the entire populations and economies of nations in warfare while subjecting national populations and infrastructures to equally comprehensive violence. The Nationalists joined the world in confronting aerial bombing after the Empire of Japan bombed Shanghai in 1932. In response, the government and its military constructed air defense, a political and technological complex combining mass mobilization, through air raid drills and air defense organizations, with material technologies, like searchlights, anti-aircraft guns, and bomb shelters. The Nationalists found in air defense more than a military technology. To them, it also offered a set of tools and resources for fortifying their flailing attempts to unite China in a common national project, and even recasting the substance of that project. Air defense could forge a new society that invested all Chinese people in war as a necessary precondition for overcoming China’s colonial subjection. Where democratic institutions collapsed and appeals to common heritage and customs failed, the Nationalists used air defense to turn survival (shengcun) into the bedrock value of the national community. Meanwhile, a group of young architects associated with the journal Xin jianzhu in Canton identified air defense as an organizing problem for the nascent professional field of architecture. Rather than the stale historicism endorsed in Nanjing, and against China’s craft building traditions, the group championed modernist architecture, especially the International Style, whose principles of simplicity, functionalism, and rationality they saw as necessary for building modern, industrial, and hygienic Chinese cities capable of enhancing human life. Moreover, they argued that the technological instrumentality informing modernism made it the only style capable of preserving Chinese cities and people from modern threats like bombing. After the fall of Canton in 1938, members of the group took their mission to Chongqing, where they joined the Nationalist government in building air defenses in the wartime capital. In particular, this dissertation argues that the air raid shelter and air defense focused contradictions in the Nationalists’ fascist project for uniting and revolutionizing China as it traveled to Chongqing following the Nationalist escape from Japan’s invasion of the coast. Over the course of the War of Resistance, the principal technology of air defense shifted away from mass mobilization, as the Nationalists came to administer refugees and displaced people they had never governed before, and became located in infrastructure like city plans and air raid shelters. Air defense served to exclude surplus populations like women and the elderly, rendered redundant according to the state’s wartime needs for industrial production and conscripts, by dispersing them in satellite settlements outside the city, from which they constantly returned in search of work or material goods. Shoddy air raid shelters, in the meantime, revealed the fragile biology of real bodies beneath the fascist fantasy of the heroic political subject, as shelters failed to provide for basic needs like respiration. Over time, these two problems collided, as the state closed shelters in the city to dispersed people, exposing surplus populations to bombing, while civilians also languished in shelters that could still kill them. The goal of building national unity through survival collapsed into a confusion of inclusion and exclusion, life and death, with disastrous results, like the asphyxiation of around one thousand people in Chongqing’s largest public air raid shelter in June 1941. In these circumstances, professionals like the Cantonese architects and new state regulatory bodies produced proposals and standards for building better shelters, offering a technological resolution of air defense’s political contradictions and consolidating the transformation of air defense into a technical expertise.

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Bibliographic note KLIMEŠOVÁ, Tereza. The Implications of the Intervention in Iraq for the United States' Policy of Democracy Promotion. Master thesis. Charles University, Faculty of Social Sciences, Institute of International Studies, Supervisor Ph.Dr. Jan Hornát, Ph.D. Abstract Democracy promotion has been an integral part of US foreign policy for more than a century. Particularly at the end of the 20th century, democracy flourished worldwide as autocratic regimes collapsed at large and scholars talked about the "End of History." Nevertheless, the current situation is very different, and substantial democratic backsliding is observable. Many scholars are tracing the origins of this decline to the Bush's Freedom Agenda, particularly the intervention in Iraq in 2003, arguing that it was the initial turning point for US democracy promotion. However, this thesis argues that the invasion and the subsequent war were pivotal only in part. The most visible implications were within the public perception of democracy promotion. Due to the US engagement in Iraq, domestic support deteriorated substantially. Moreover, the international community's perception of the US as a benign democracy exporter crumbled as well. Another change was observable within the rhetoric of President Obama after taking office in 2009. In...