Submitted by MARCELA DO VALLE MACHADO (marcelavmachado@gmail.com) on 2018-04-22T02:22:02Z No. of bitstreams: 1 machado_mv_me_prud.pdf: 3915564 bytes, checksum: a8e42c5376b44043a216b005b6c1615a (MD5) / Approved for entry into archive by Claudia Adriana Spindola null (claudia@fct.unesp.br) on 2018-04-23T11:50:28Z (GMT) No. of bitstreams: 1 machado_mv_me_prud.pdf: 3915564 bytes, checksum: a8e42c5376b44043a216b005b6c1615a (MD5) / Made available in DSpace on 2018-04-23T11:50:28Z (GMT). No. of bitstreams: 1 machado_mv_me_prud.pdf: 3915564 bytes, checksum: a8e42c5376b44043a216b005b6c1615a (MD5) Previous issue date: 2018-02-23 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Devido ao elevado custo de Sistemas de Varredura a LASER Aerotransportados (SVLA) e a miniaturização de sensores, sistemas de varredura a LASER (SVL) de menor peso e custo têm sido uma alternativa para estudos florestais. Aliado a estes sistemas, a crescente utilização de Veículos Aéreos Não Tripulados (VANT) possibilita a aquisição de dados com maior flexibilidade e rapidez, o que permite a utilização de SVL mais leves neste tipo de plataforma. Todavia, a integração e sincronização dos dispositivos do sistema demanda árduo trabalho de conexão eletrônica e computacional. Em casos que não seja possível realizar a sincronização eletrônica entre os dispositivos do sistema, uma alternativa é a sincronização por pósprocessamento, estabelecida por meio da relação entre os dados temporais obtidos com o LIDAR (Light Detection and Ranging) e com o GNSS (Global Navigation Sattelite Systems), durante a trajetória de voo do SVL embarcado em VANT. Para relacionar estes dados, são realizadas manobras de voo na forma senoidal durante a decolagem e pouso com o sistema, a fim de gerar pontos de máximos e mínimos. Com isso, os dados LASER e as posições da plataforma, coletados pelos dispositivos LASER e GNSS/IMU em sistemas de tempo diferentes, são relacionados por meio da diferença de distância e altura em função do tempo. Posteriormente, o tempo dos dados LASER é corrigido para tempo GPS, caracterizando a sincronização por pós-processamento, e refinado pelo Método dos Mínimos Quadrado. Desse modo, a nuvem de pontos pode então ser gerada. O controle de qualidade altimétrico utilizando pontos de apoio coletados em campo, apresentou uma acurácia de 11,6 cm. Para o controle planimétrico foi verificada uma acurácia de 45 cm para a componente E e 62 cm para a componente N. A partir das acurácias encontradas para a nuvem de pontos, conclui-se que a técnica de sincronização empregada é uma alternativa viável para relacionar dispositivos desacoplados de um SVL e que a acurácia centimétrica do sistema permite que este seja empregado em diversas aplicações, dentre as quais estão estimativa de altura de árvores. / Due to the high cost of Airborne LASER Scanning (ALS) and the miniaturization of sensors, low-cost and low-weight LASER systems have been an alternative for forestry studies. Together with these systems, the increasing use of Unmanned Aerial Vehicles (UAV) platforms, also low cost, enables the acquisition of data with greater flexibility and speed, which allows the use of low-weight SVL in this type of platform. However, the integration and synchronization of the devices of the system demands specialised work for electronic and computational connections. In cases where it is not possible to perform electronic synchronization between the devices of the system, an alternative is the post-processing synchronization, established through the relationship between the signals obtained with LIDAR (Light Detection and Ranging) and GNSS (Global Navigation Sattelite Systems), during the flight path of the SVL boarded in UAV. To relate these signals, flight maneuvers are performed in the a sinusoidal form shape during takeoff and landing with the system in order to obtain peaks of maximum and minimum. Thus, the LASER data and platform positions collected by the LASER and GNSS / IMU devices in different time systems are related by distance and height as a function of time. Subsequently, the LASER data time is corrected to match GPS time, characterizing the post-processing synchronization, and latter refined by the Least Square Method. In this way, the point cloud can then be generated. The quality control for altimetry, using control points collected in the field, achieved an obtained accuracy of 11.6 cm. The planimetric quality control achieve an accuracy of 45 cm the E component and 62 cm for the N component. From the accuracy achieved for the point cloud, it was concluded that the synchronization technique used is a viable alternative to relate decoupled devices of an ALS and that the centimetric accuracy of the system allows it to be used in several applications, such as tree height estimation. / FAPESP Proc. nº 2013/50426-4

Made available in DSpace on 2017-07-10T18:56:06Z (GMT). No. of bitstreams: 1 CRISTIANE _Schmidt.pdf: 4791690 bytes, checksum: ba4daa08cd55807aa9a334515bd87dc2 (MD5) Previous issue date: 2016-02-16 / Diese Arbeit beschäftigt sich mit dem Lernprozess der deutschen Sprache unter Verwendung didaktischer Lehrwerke im brasilianischen universitären Kontext. Trotz der zentralen Bedeutung solcher Materialien, vor allem des Lehrbuchs als institutionalisiertem und etabliertem Element im Fremdsprachenunterricht, sind die Untersuchungen zu diesen Lehrmitteln nicht ausreichend. Darüber hinaus sind die deutschsprachigen Lehrwerke mehrheitlich in Deutschland hergestellt, und berücksichtigen in der Regel dadurch nicht die sprachliche und soziokulturelle Realität anderer Kontexte. In Anbetracht dieser Problematik geht die vorliegende Arbeit von drei Annahmen aus: (i) das deutschsprachige Lehrwerk orientiert die Lehrtätigkeit in der Lehrerausbildung an den Hochschulen in Brasilien; (ii) die Texte und die in den Lehrwerken vorhandenen didaktisch-pädagogischen Strategien schließen die kulturelle, soziokommunikative und sprachliche Dimension mit ein; und (iii) die Sichtweisen der Nutzer / Lehrer und der Verlage / Autoren haben Auswirkungen auf den Inhalt und die Bedeutung der Lehrwerke. In diesem Sinne verfolgt die vorliegende Arbeit das Ziel, die vorhandenen (oder auch nicht vorhandenen) soziokommunikativen und interkulturellen Aspekte in den Lehrwerken für Deutschlerner (Anfänger) zu untersuchen, und dabei herauszuarbeiten, in welchem Umfang diese für das Erlernen der Sprache im besagten Kontext beitragen. Als theoretische Grundlage stützt sich die Untersuchung auf die Annahmen der Angewandten Linguistik und der Soziolinguistik; sie etabliert dabei Verbindungen zu den wichtigsten angewandten Methoden im formalen Kontext des Sprachenlernens sowie zum Gegenstand dieser Untersuchung. Die Untersuchungsmethodik stützt sich im Folgenden auf einen qualitativen Ansatz, basierend auf einer interpretativen Methodik und einer dokumentarischen Analyse. Zu den wichtigsten methodologischen Verfahren zur Datensammlung zählen: (i) die Quantifizierung des Kursangebots in der Deutschsprachlehrerausbildung im aktuellen akademischen Kontext und der Kontakt mit den Lehrern selbst; (ii) die Bestandsaufnahme der zugrunde gelegten Lehrwerke in diesen Institutionen; (iii) die Auswahl der Lehrwerke - DaF kompakt, studio d und Menschen entsprechend pragmatischer und chronologischer Überlegungen; (iv) die Versendung von Fragebögen an Lehrer und Autoren der Lehrwerke und (v) die Recherche auf Dokumentenbasis. Die Ergebnisse weisen darauf hin, dass das Lehrbuch in der Tat die pädagogische Praxis in der Ausbildung der Deutschlehrer orientiert, und dass des weiteren die sprachlichen und soziokommunikativen Dimensionen anstelle der Entwicklung einer interkulturellen Kompetenz im Zentrum stehen. Darüber hinaus bestätigten die Aussagen der TeilnehmerInnen der Untersuchung ähnliche und divergierende Aspekte; seitens der Ausbildungslehrer wurde die Notwendigkeit betont, die Lehrwerke anzupassen, um sie für den soziolinguistischen und kulturellen Kontext Brasiliens geeigneter zu machen. Im Gegensatz dazu waren die Autoren der Lehrwerke in diesem Aspekt nicht dieser letzteren Meinung. Für einen der Autoren war diese Problematik völlig unbekannt, während andere behaupteten, dass das didaktische Lehrwerk an unterschiedliche kulturelle Kontexte angepasst werden könnte, wie zum Beispiel jenem Brasiliens. / Esta tese versa sobre o processo de ensino de língua alemã no contexto universitário brasileiro, mediado por materiais didáticos. Apesar da centralidade desses recursos, sobretudo do livro didático enquanto elemento institucionalizado e naturalizado nas aulas de línguas estrangeiras, os estudos com foco nesses materiais constituem-se incipientes. Além disso, os livros didáticos de língua alemã, em sua maioria, são produzidos na Alemanha e tendem a não contemplar a realidade linguística e sociocultural de outros contextos. Considerando essa problematização, o estudo considera três pressupostos, a saber: (i) o livro didático de língua alemã orienta a atuação docente na formação de professores no ensino superior no Brasil; (ii) os textos e as estratégias didático-pedagógicas, presentes nos livros didáticos contemplam as dimensões cultural, sociocomunicativa e linguística; e (iii) as vozes dos usuários/professores e dos produtores/autores têm repercussão na constituição e no papel dos livros didáticos. Nesse sentido, a tese tem como propósito investigar os aspectos sociocomunicativos e interculturais presentes (ou não) em livros didáticos para aprendizes iniciantes de língua alemã, destacando em que medida contribuem para o ensino desse idioma no referido contexto. Como fundamentação teórica, o estudo dialoga com os pressupostos da Linguística Aplicada e da Sociolinguística, estabelecendo relações com os principais métodos utilizados no contexto formal de ensino de línguas e com o objeto desta investigação. Para tanto, a metodologia da pesquisa adotada vale-se da abordagem qualitativa, baseada no método interpretativista e na análise documental. Dentre os principais procedimentos metodológicos empregados para a geração de dados constam: (i) a quantificação dos cursos de formação de professores de língua alemã no contexto acadêmico atual e contato com respectivos professores; (ii) o levantamento dos livros didáticos adotados nessas instituições; (iii) a seleção do corpus da pesquisa os livros didáticos DaF kompakt, studio d e Menschen , conforme os parâmetros pragmático e cronológico; (iv) o envio de questionário a docentes e autores dessas obras didáticas; (v) a pesquisa documental. Os resultados apontam para o predomínio do livro didático orientando a prática pedagógica no âmbito da formação de professores de língua alemã e também para o destaque das dimensões linguística e sociocomunicativa em detrimento ao desenvolvimento da competência intercultural. Além disso, as vozes dos participantes do estudo, evidenciaram aspectos similares e distintos; sendo que da parte dos professores formadores, ressaltou-se a necessidade de adaptações nos livros didáticos, para adequação ao contexto sociolinguístico e cultural brasileiros. Em contrapartida, as vozes dos autores não convergiram neste aspecto, pois um manifesta desconhecer isso e outros reiteram que a obra didática pode ser adequada a contextos culturais diversos, como o brasileiro.

La technologie de reprogrammation de cellules somatiques en cellules souches pluripotentes induites (iPS) offre aujourd’hui l’opportunité de modéliser des maladies neurodégénératives et d’étudier des neurones de patients. Nous avons utilisé cette technologie pour générer deux modèles de maladies neurodégénératives : la mucopolysaccharidose de type IIIB (MPSIIIB) et la forme ALS2 de la sclérose latérale amyotrophique (SLA). Dans le modèle MPSIIIB, nous avons montré que les iPS et les neurones de patients présentaient des défauts caractéristiques de la pathologie telle que l’accumulation de vésicules de surcharge. Des altérations de l’appareil de Golgi dans ces cellules ont également été mises en évidence. Une analyse du transcriptome de précurseurs neuraux MPSIIIB a montré des modifications transcriptionnelles touchant notamment des gènes impliqués dans les interactions de la cellule avec la matrice extracellulaire. Ainsi, dans une seconde étude, des altérations de la migration et de l’orientation de cellules de souris mutantes MPSIIIB ou de patients ont été démontrées. Ces altérations pourraient être responsables des perturbations de la neurogénèse et de la neuritogénèse chez les enfants malades. Dans le modèle SLA/ALS2, nous avons montré que les neurones de patients présentaient des défauts incluant une diminution de la surface des endosomes et des anomalies de la croissance neuritique. Alors qu’il n’existait jusqu’alors aucun modèle cellulaire pertinent reproduisant cette maladie, ce modèle permettra à présent d’étudier les processus physiopathologiques impliqués dans la maladie. En conclusion, la génération de cellules iPS permet de modéliser des maladies neurodégénératives et d’étudier les processus physiopathologiques qui sont associés sur des neurones humains en culture. Ces modèles cellulaires pourraient permettre dans un avenir proche de réaliser des criblages de molécules à visée thérapeutique / Reprogramming technology of somatic cells in induced pluripotent stem cells (iPS) now offers the opportunity to model neurodegenerative diseases and to study patient’s neurons. We used this technology for generating two models of neurodegenerative diseases: the muccopolysaccharidosis type IIIB (MPSIIIB) and the ALS2 form of amyotrophic lateral sclerosis (ALS). In the MPSIIIB model, we have shown that iPS and neurons of patients had characteristic defects of the disease such as the accumulation of storage vesicles. Alterations of the Golgi apparatus in these cells were also highlighted. Transcriptome analysis of MPSIIIB neural precursors showed transcriptional changes involving particularly genes implicated in cell-extracellular matrix interactions. Thus, in a subsequent study, alterations of migration and orientation of MPSIIIB mutant mouse cells and MPSIIIB patients’ cells have been demonstrated. These alterations may be responsible for the disruption of neurogenesis and neuritogenesis in sick children. In the ALS2 model, we have shown that patients’ neurons had defects including decreased endosomes’ surface and abnormal neurite outgrowth. As there was previously no relevant cellular model reproducing the disease, this model will now allow the study of physiopathological processes involved in the disease. In conclusion, the generation of iPS cells allows to model neurodegenerative diseases and to study associated physiopathological processes on cultured human neurons. These cell models could allow in the near future the screening of molecules of potential therapeutical interest

No description available.

In this research project the question is raised whether it is possible to detect and analyse differences between incidental and intentional vocabulary acquisition within a traditional, systematic teaching setting of German as an L3. The ten par-ticipating Swedish students at the upper secondary level worked with two differ-ent German newspaper articles in two different ways. One set of lessons focused mainly on textual content (incidental learning) while the other involved both dis-cussions about the contents of the text and explicit vocabulary practice (inten-tional learning). The students were later tested on four separate occasions using a self-report-test involving 16 pre-tested words. The two main research questions are: How many of the encountered words will the students recall and what depth of knowledge does this recall represent? Results point to a very limited vocabu-lary acquisition through incidental learning compared to the acquisition through intentional learning which gave a higher score. The overall tendency is for ac-quired vocabulary knowledge to change over time and more so if intentionally acquired. This raises a further question: How much and what kind of work in-volving texts is needed in the classroom for long lasting vocabulary acquisition, incidental or intentional, to take place? Furthermore the results indicate that the self-report test used in the research project shows deficiencies regarding validity as well as reliability issues, which puts further focus on the test methods used in educationally applied vocabulary acquisition research.

Cerca de 20 % dos casos familiares de esclerose lateral amiotrófica (ELAf) são causados por mutações na enzima Cu,Zn-superóxido dismutase (SOD1). Inicialmente se supôs que as enzimas mutantes teriam a atividade SOD comprometida, entretanto isto não foi comprovado. Atualmente, considera-se que as enzimas mutantes adquiram propriedades tóxicas. Quais seriam estas propriedades e como levariam à degeneração do neurônio motor são questões ainda não respondidas. Neste trabalho, comparamos neuroblastomas humanos transfectados com SOD1 G93A associada à ELAf (SH-SY5YG93A), e SOD1 selvagem (SH-SY5YWT) com células parentais (SH-SY5Y) em relação ao crescimento, viabilidade, produção basal de oxidantes, atividades SOD e peroxidásica e modificações estruturais da SOD. As células transfectadas apresentaram aumento na taxa de crescimento e na produção basal de oxidantes. As células SH-SY5YWT e SH-SY5YG93A mantiveram a expressão de SOD1 e atividade consistente com o aumento esperado de duas vezes, em estágios iniciais de cultura. A atividade peroxidásica do homogenato da célula SH-SY5YG93A foi maior. Após quatro semanas, a linhagem SH-SY5YG93A manteve a expressão de SOD1, mas as atividades dismutásica e peroxidásica diminuíram. A expressão de SOD1 aumentou a proporção de formas alteradas de SOD1, como enzima reduzida, multímeros formados por ponte dissulfeto e formas insolúveis em detergente, particularmente na linhagem SH-SY5YG93A. Entre estas formas insolúveis, identificamos um dímero covalente de SOD. Estas formas alteradas provavelmente são responsáveis pela ativação do proteassomo e estresse do retículo endoplasmático, verificados nas células transfectadas. Concluindo, a superexpressão da SOD1 foi suficiente para elevar as formas imaturas e oligomerizadas de SOD1 e a oxidação basal, e a mutação G93A ressaltou estes processos. / Some familial ALS (fALS) are caused by mutations in the Cu,Zn-superoxide dismutase enzyme (SOD1). It was thought that the mutated enzymes would have impaired SOD activity, but this has not been corroborated so far. Presently, it is more accepted that the mutated enzymes acquire a new toxic function. What this new toxic function is and how it relates to the degeneration of motor neurons remains debatable. Here, we compared human neuroblastoma cells transfected with fALS mutant G93A (SH-SY5YG93A) or wild-type SOD1 (SH-SY5YWT) with parent cells (SH-SY5Y) in regard to growth, viability, basal oxidant production, SOD and peroxidase activities, and SOD forms. Transfected cells presented increased growth rate and basal oxidant production. SH-SY5YWT and SH-SY5YG93A cells in early culture stage showed SOD expression and activity consistent with the expected two-fold increase; SH-SY5YWT homogenates showed increased peroxidase activity. After four weeks, SH-SY5YG93A maintained SOD1 expression levels but peroxidase and dismutase activities were lower. SOD1 expression increased the levels of altered SOD1 forms such as the reduced enzyme, disulfide multimers and detergent-insoluble forms, particularly in SH-SY5YG93A cells. Among the insoluble forms a covalent SOD dimer was identified. These altered SOD forms are probably responsible for proteasome activation and endoplasmatic reticulum stress response verified in transfected cells. In conclusion, SOD1 over-expression was sufficient to increase intracellular immature and oligomerized SOD1 forms and basal oxidation and the G93A mutation enhanced these processes.

The article focuses on the non-agent construction of the ASKRIPTION of aussehen (er sieht mitgenommen aus, see basically Lasch 2016a) in the center of the considerations. On the basis of a corpuslinguistic evaluation of the KERN corpus at the DWDS it is shown that and why this construction belongs to the repertoire of linguistic patterns, which are especially established for descriptions in narrative texts.

En digital terrängmodell (DTM) är en representation av enbart själva markytan. Det finns flera metoder för att framställa DTM:er, där laserskanning har blivit en alltmer vanlig metod. Inom laserskanning är flygburen laserskanning (FLS) en flitigt använd metod, då metoden har fördelen av att kunna täcka stora områden på kort tid. Det finns dock nackdelar med FLS då datainsamlingen kan bli bristfällig i t.ex. skogsområden, där laserstrålar inte kan tränga igenom tät vegetation. Här kan handhållen laserskanning (HLS) vara ett bra alternativ då HLS går snabbt och inte behöver samma omfattande planering. Tidigare studier visar att HLS har många fördelar, men som dock inte kan hålla samma låga osäkerhet som terrester laserskanning (TLS). Det saknas däremot studier om hur HLS ställer sig mot mätningar med FLS. Syftet med studien är därför att utvärdera möjligheten att använda och tillämpa mätningar med HLS för framställning av DTM i skogsterräng gentemot FLS. Detta görs genom att jämföra respektive DTM:s lägesosäkerhet. I studien användes instrumentet ZEB-REVO för insamlingen av data för metoden HLS. Medan för FLS användes laserdata från Lantmäteriet. Från insamlad laserdata skapades därefter DTM:er. Dessa jämfördes mot ett antal kontrollprofiler som mättes in med totalstation. För respektive metod, HLS och FLS, beräknades medelvärde för höjdavvikelserna mot kontrollprofilerna där även standardavvikelse beräknades. Resultatet visar att DTM:en skapad av data från FLS beräknades ha en höjdavvikelse för hela området på 0,055 m som medelvärde gentemot inmätta kontrollprofiler. Standardavvikelsen för denna höjdavvikelse beräknades till 0,046 m för FLS. För DTM:en med data från HLS beräknades en höjdavvikelse på 0,043 m i medelvärde som bäst, där standardavvikelse beräknades till 0,034 m. Studien visar att metoderna HLS och FLS gav likvärdiga resultat gentemot de inmätta kontrollprofilerna, dock gav HLS generellt mindre standardavvikelse i jämförelse mot FLS. Vidare ansågs ZEB-REVO och dess tillhörande databearbetningsprogram GeoSLAM vara väldigt användarvänligt, där själva skanningen med instrumentet tog endast 10 minuter för studiens område på ca 2000 m2. Utifrån studiens resultat drogs slutsatsen att mätningar med HLS kan ge en likvärdig DTM, sett till osäkerheten, som FLS-mätningar. HLS kan därmed vara en kompletterande metod men att FLS är en fortsatt effektiv metod. / A digital terrain model (DTM) represent exclusively the earth surface. There are several methods which can be utilized to create DTMs, where laser scanning have become a common used method. Airborne laser scanning (ALS) is often used since the method can cover a large area in a relatively short time. However a disadvantage with ALS is that the data collection, for a wooded area, can be inadequate due to penetration difficulties for some laser beams. For that reason a handheld laser scanner (HLS) can be an alternative since measurements can be done fast and does not need the same extensive planning. Earlier studies mention HLS to have several advantages but can still not yet be compared with terrestrial laser scanning (TLS) concerning the measurements uncertainty. There are, however, no studies that investigates how measurements with HLS stands against FLS. The purpose with the study is to evaluate the ability to use measurements from HLS to create a DTM for a wooded area in comparison with ALS. This is done by comparing the different uncertainties for each DTM. In the study the acquisition of HLS laser data was collected with the instrument ZEB-REVO and the ALS laser data was received from Lantmäteriet (cadastral mapping and surveying authority in Sweden). After the data acquisition a DTM were created from each data set (method). The DTMs were then compared to control profiles, which have been measured with total station. From the comparison with the control profiles average height deviation and standard deviation were calculated for each DTM. The result shows that the DTM created from ALS data received an average height deviation of 0,055 m for the whole area with a standard deviation of 0,046 m. Corresponding result for the DTM created from HLS data were calculated, at best, to 0,043 m in average height deviation and 0,034 m in standard deviation. The study shows that the methods HLS and ALS gave equivalent result regarding the comparison with the control profiles, however HLS gave a generally lower value for standard deviation. Furthermore ZEB-REVO with its processing program GeoSLAM was considered to be very easy and user friendly. The area (approx. 2000 m2) for the study was scanned within only 10 min. The conclusion which were drawn from the obtained result was that measurements with HLS can generate an equivalent DTM, concerning the uncertainty, as measurements with FLS. Thereby HLS can be a complementing method but still FLS is seen as an effective method.

TDP-43 est une protéine de liaison aux acides nucléiques qui joue un rôle essentiel dans le métabolisme de l'ARN. À l'état physiologique, un contrôle strict des niveaux d’expression de cette protéine est critique pour la fonction et la survie cellulaire. Une boucle d'autorégulation négative est à la base de ce contrôle du taux intracellulaire de TDP-43. Laquelle a été identifiée comme le constituant principal des inclusions observées chez une majorité des patients atteints de Sclérose Latérale Amyotrophique (SLA) ou de Dégénérescence Lobaire Fronto-Temporale (DLFT). A ce jour, plus de 50 mutations faux-sensdu gène TARDBP/TDP-43 ont été décrites chez des patients DLFT/SLA, démontrant le rôle clé de TDP-43 dans ces pathologies neurodégénératives. Notons cependant que les conséquences fonctionnelles de ces mutations ne sont pas complètement déterminées. Plusieurs études suggèrent qu’une élévation des niveaux d’accumulation de TDP-43 pourraitparticiper aux mécanismes physiopathologiques. La modulation du cycle de production de TDP-43 pourrait donc constituer une nouvelle stratégie thérapeutique. Ce travail de recherche avait donc pour principal objectif d’identifier des modulateurs génétiques de la production de TDP-43 en utilisant un nouveau modèle de drosophile transgénique mimant les principales étapes d’autorégulation de TDP-43. Nous avons ainsi pu montrer que la modulation des niveaux d’expression de la protéine TCERG1 et de plusieurs facteurs d'épissage, parmi lesquels SRSF1, SRSF3 et SF3B1, influe sur les niveaux de production deTDP-43. Nous avons également montré que la présence des mutations DLFT/SLA n’altère pas la capacité de la protéine à s’autoréguler. / TDP-43 is a DNA/RNA binding protein that plays an important role in RNA metabolism. In the physiological state, strict control of its expression levels is critical for cell function and survival. TDP-43 expression is tightly regulated through an autoregulatory negative feedback loop. This protein has been identified as the principal component of the inclusions observed in a majority of patients with Amyotrophic Lateral Sclerosis (ALS) or FrontoTemporal Lobar Degeneration (FTLD). To date, more than 50 missense mutations of the TARDBP / TDP-43 gene have been described in FTLD / ALS patients, demonstrating the key role of TDP-43 in these neurodegenerative pathologies. However, the functional consequences of TDP-43 mutations are not completely determined. Several studies suggest that high accumulation levels of TDP-43 may participate in pathophysiological mechanisms. The modulation of the production cycle of TDP-43 may therefore provide a new therapeutic strategy. The main goal of this research project was to identify genetic modulators of TDP-43 production by using a novel transgenic Drosophila model mimicking main steps of TDP-43 the autoregulatory mechanism. We identified several splicing factors, including SF2, Rbp1 and Sf3b1, as genetic modulators of TDP-43 production. We have also shown that modulation of TCERG1 expression levels affect TDP-43 production levels in flies. Finally, we found that FTLD/ALSlinked TDP-43 mutations do not alter TDP-43’s ability to self-regulate its expression and consequently of the homeostasis of TDP-43 protein levels.

Innerhalb des letzten Jahrzehnts wurde immer deutlicher, dass einwärts-gleichrichtende Kaliumkanäle (Kir) neben ihrer klassischen Rolle im Aufbau und der Konstanthaltung des Ruhemembranpotentials weitere zellspezifische Aufgaben erfüllen.In der vorliegenden Arbeit konnte mittels transgener Maustechnologie gezeigt werden, dass Kir4.1 früh postnatal zunächst Zellkörper-assoziiert auf Oligodendrozyten in der weißen Substanz des Rückenmarks exprimiert wird. Im weiteren Verlauf der Entwicklung kommt es zu einer Hochregulation der Proteinexpression auf perivaskulären und perineuralen astrozytären Fortsätzen in der grauen Substanz. Hier konnte die Kolokalisation von Kir4.1 und einem Wasserkanal (AQP4) auf astroglialen Endfüßen nachgewiesen werden. Das Kir4.1-Expressionsmuster im Rückenmark legt eine Rolle des Kanals in der Kaliumpufferung und möglicherweise in der Kalium-gesteuerten Volumenregulation nahe.Basierend auf den Ergebnissen der Expressionsstudie dieser Arbeit wurde die konkrete Hypothese aufgestellt, dass Kir4.1-Kanäle mittels Kontrolle des transmembranösen Kaliumtransports einen Einfluss auf die osmotische Volumenregulation von Astrozyten haben. Anhand eines Modellsystems konnte unter Verwendung konfokaler 2-Photonen-Lasermikroskopie gezeigt werden, dass die genetische Inaktivierung von Kir4.1 im Knock-Out-Mausmodell zu einer Beeinträchtigung der Wassersekretion aus astrozytären Fortsätzen mit nachfolgender Schwellung führt. Dies zeigt, dass Kir4.1-Kanäle wesentlich zur Volumenregulation in Astrozyten beitragen und dass der Kalium-sekretorische Volumenausgleich über astrogliale Endfüße vermittelt wird. Eine Beeinträchtigung von Expression oder Funktion astroglialer Kir4.1-Kanäle könnte unter pathophysiologischen Bedingungen zu einer Anschwellung von Astrozyten und Verringerung des extrazellulären Raumes beitragen.Eine mögliche pathogenetische Bedeutung von glialen Kir4.1-Kanälen bei neurodegenerativen Erkrankungen wurde anhand eines etablierten Tiermodells für die Motoneuronerkrankung Amyotrophe Lateralsklerose (ALS) untersucht. Erstmals konnte eine Krankheits-assoziierte, fortschreitende Reduktion der Kir4.1-Expression im Ventralhorn des Rückenmarks im SOD1-vermittelten ALS-Mausmodell nachgewiesen werden. Die daraus resultierende extrazelluläre Akkumulation von Kalium könnte durch chronische Depolarisation der Membran der Motoneurone zu deren Tod beitragen. Diese Schlussfolgerung unterstützend konnte in einem in vitro Modellsystem gezeigt werden, dass eine erhöhte extrazelluläre Kaliumkonzentration neurotoxisch wirkt. Die differentielle Expression von Kir4.1 im Rückenmark und die daraus abgeleitete Bedeutung für die Neuron-Glia Interaktion unter physiologischen und pathophysiologischen Aspekten unterstützt die Sichtweise einer dynamischen Interaktion von neuronalen und glialen Zellen im gesunden und kranken Gewebe.