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Etudes fonctionnelles de Tyk2 dans la voie de signalisation de l'IFNα: analyse d'un nouvel interacteur et d'une mutation activatriceGakovic, Milica 10 December 2007 (has links) (PDF)
Les récepteurs des cytokines à structure α-hélicoïdale sont pour la plupart composés de deux sous-unités transmembranaires associées aux protéine tyrosine kinases de la famille Janus (Tyk2, Jak1, Jak2 et Jak3). La fixation de la cytokine à son récepteur induit une dimérisation des sous-unités ce qui entraîne l'activation des Jak par transphosphorylation. Les Jaks ainsi activées phosphorylent les facteurs de transcription STAT (Signal Transducer and Activator of Transcription) qui transloquent dans le noyau. Les tyrosine kinases Jak présentent en position N-terminale un domaine FERM (4.1-ezrin-radixin-moesin), suivi par un domaine dit 'SH2-like' et deux domaines kinases: un domaine dit 'kinase-like' (KL) à fonction régulatrice et un domaine catalytique de type tyrosine kinase en position C-terminale. L'association au récepteur se fait par la région N-terminale. Le laboratoire s'intéresse particulièrement au récepteur de l'interféron de type I (IFNα/β) composé de deux chaînes, IFNAR1 et IFNAR2, et aux kinases Tyk2 et Jak1 auxquels elles s'associent respectivement. La première partie de ma thèse a porté sur l'étude d'un nouveau partenaire de Tyk2, la protéine Pot1 (Partner of Tyk2) et de son rôle potentiel dans la voie de signalisation de l'IFNα. Plusieurs ADNc partiels de Pot1 avaient été isolés dans le laboratoire par criblage double-hybride utilisant comme appât le domaine FERM de Tyk2. Un ADNc complet de Pot1 avait été reconstruit donnant lieu à une protéine de 1003 acides aminés (aa). L'interaction entre cette protéine et les domaines FERM de Tyk2 et de Jak1 avait été confirmée par des expériences in vitro. L'analyse par northern blot de Pot1 montre une expression faible dans plusieurs tissus. L'étude de la localisation de la protéine Pot1 surexprimée avait montré une localisation cytoplasmique au niveau de vésicules non identifiées. Un des aspects de mon travail sur Pot1 a été de déterminer si l'ADNc reconstruit dans le laboratoire, appelé 'lab cDNA', correspond à un vrai transcrit. En effet, les banques de données recensent plusieurs autres transcrits issus du gène Pot1, avec une portion 3' commune et identique au 'lab cDNA', mais une région 5' divergente. Ces transcrits donnent lieu à deux isoformes ne possédant pas les 200 aa ou 250 aa en position N-terminale par rapport à la protéine de référence codée par le 'lab cDNA'. De plus, l'unique protéine murine (mPot1) recensée dans les banques de données ne possède pas les 100 aa en N-terminal par rapport à la protéine humaine de référence. Pour analyser l'expression de différents transcrits, j'ai amplifié l'ADNc de cellules humaines HEK293T avec des primers me permettant de 12 distinguer les différents transcrits. Ces expériences ont permis de confirmer l'expression du transcrit correspondant au 'lab cDNA' et codant pour une isoforme de 1003 aa (112 kDa). Par la suite j'ai étudié la localisation de la protéine Pot1 murine dans les cellules surexprimant mPot1. J'ai observé que mPot1 se trouve dans des vésicules cytoplasmiques, tout comme la protéine humaine, et semble être associée à la membrane de ces vésicules. Toutefois, nous ne pouvons pas écarter la possibilité de localisation inadéquate dû à la forte surexpression de mPot1. Il sera nécessaire de confirmer cette observation par l'analyse de la localisation de la protéine endogène. A ce jour les anticorps disponibles ne permettent pas sa détection. Afin d'évaluer le rôle de Pot1 dans la voie de signalisation de l'IFNα, j'ai mesuré la réponse à l'IFNα de cellules déplétées en Pot1 par interférence à l'ARN. J'ai mesuré la phosphorylation des protéines STAT et l'induction d'un gène rapporteur. Ces expériences ont montré que, dans ce système, la diminution de l'expression de Pot1 n'a pas d'effet sur la signalisation par l'IFNα. Afin d'éclairer la fonction de Pot1, de nouveaux interacteurs de Pot1 ont été recherchés par criblage double-hybride. Parmi les 14 protéines identifiées à haut niveau de confiance, nous nous sommes particulièrement intéressés à GIT1 (G protein-coupled receptor kinase interactor), une protéine adaptatrice impliquée dans de nombreux processus cellulaires, tels que l'internalisation de récepteurs, la signalisation induite par l'EGF (epidermal growth factor) et l'angiotensine II ainsi que la migration cellulaire. Afin d'analyser le rôle éventuel de GIT1 dans la signalisation par l'IFNα, j'ai mesuré plusieurs paramètres (internalisation des sous-unités du récepteur, phosphorylation des STAT, induction d'un gène rapporteur) dans des cellules surexprimant ou déplétées en GIT1. Les résultats obtenus ont écarté l'hypothèse d'une implication de GIT1 dans la réponse transcriptionnelle à l'IFNα. La deuxième partie de mon travail a porté sur l'étude de la mutation V678F introduite dans la protéine Tyk2.Cette substitution est située dans le domaine KL et correspond à la mutation V617F de Jak2, décrite comme étant à l'origine de la Polycythemia vera. La P. vera, ou maladie de Vaquez, est une maladie myéloproliférative caractérisée par une hyperproduction d'érythrocytes et leur hypersensibilité à l'érythropoiétine (Epo). Il a été montré que la mutation V617F induit une augmentation de l'activité kinase de base de Jak2. De même, Jak2V617F induit une prolifération indépendante de facteurs de croissance des cellules murines BaF3, confirmant son potentiel transformant. Toutefois, il a été montré que 13 Jak2V617F nécessite la coexpression d'un récepteur homodimérique, tel que récepteur à l'Epo, pour exercer une activité transformante maximale. Les questions que nous nous sommes posées sont les suivantes: 1) quel est l'effet de la substitution V678F sur l'activité catalytique de Tyk2? 2) quel est l'effet du mutant Tyk2V678F sur la signalisation par l'IFNα? 3) le mutant Tyk2V678F aurait-il un effet plus marquant ou délétère s'il est placé dans un contexte de récepteur homodimérique? A cet effet, nous avons établi, à partir de cellules Tyk2-déficientes, des clones stables exprimant la protéine sauvage ou mutante. Nos résultats montrent que la mutation V678F augmente in vivo et in vitro la capacité de Tyk2 à s'auto-phosphoryler. Par la suite, j'ai mesuré la phosphorylation sur tyrosine des protéines STAT en réponse à l'IFNα. Aucune différence de niveau de phosphorylation de STAT1/2/5 n'a pu être décélée entre les cellules exprimant la protéine sauvage et les cellules exprimant le mutant Tyk2V678F. Par contre, j'ai mis en évidence une phosphorylation basale de STAT3 augmentée en présence de Tyk2V678F. Pour déterminer si cette phosphorylation basale de STAT3 corrèle avec une augmentation de son activité transcriptionnelle, j'ai analysé l'activité transcriptionelle de STAT3 à l'aide d'un gène rapporteur. Les résultats montrent que, dans les cellules exprimant le mutant Tyk2V678F, STAT3 possède une activité transcriptionelle augmentée. Afin d'étudier l'effet du mutant Tyk2V678F placé dans un contexte de récepteur homodimérique, j'ai utilisé des cellules exprimant un récepteur chimérique comprenant l'ectodomaine du récepteur à l'Epo fusionné aux régions transmembranaire et cytoplasmique de la chaîne IFNAR1 (EpoR/R1). A l'aide de ces cellules, j'ai pu confirmer que l'expression du mutant Tyk2V678F engendre une phosphorylation basale de STAT3. De plus, dans ce contexte de récepteur homodimérique, suite à stimulation par le ligand Epo, le mutant Tyk2V678F induit une augmentation ultérieure de la phosphorylation de STAT1, STAT3 et STAT5. Nous avons aussi voulu comparer directement le niveau de phosphorylation de Tyk2V678F et de STAT3 dans différents contextes de récepteurs. Les résultats obtenus montrent que la protéine Tyk2V678F est plus phosphorylée basalement dans les cellules exprimant le récepteur homodimérique EpoR/R1. Ceci est probablement la conséquence d'une transphosphorylation plus efficace de deux kinases mutantes juxtaposées. Par contre, la phosphorylation de STAT3 ne corrèle pas directement avec le niveau d'expression du mutant Tyk2V678F, ce qui suggère une absence de corrélation linéaire entre l'activation de Tyk2 et et de STAT3. 14 En conclusion, nous avons montré que la mutation V678F augmente l'activité catalytique de Tyk2. De plus, le mutant acquiert la capacité de phosphoryler STAT3 et ceci en absence du ligand. Cependant, le mutant Tyk2V678F n'affecte pas la réponse à l'IFNα en terme de phosphorylation de Jak1, STAT1 et STAT2. Ces résultats démontrent une interaction fonctionnelle étroite entre Tyk2 et STAT3. Etant donné que STAT3 constitutivement actif exerce des propriétés oncogéniques et que STAT3 est phosphorylé dans de nombreux cancers, il est possible de prédire aussi un rôle oncogénique pour Tyk2 constitutivement active. Récemment, il a été suggéré qu'un polymorphisme de Tyk2, P1104A, pourrait être associé à la présence de tumeurs. Cette substitution est située dans le domaine tyrosine kinase au sein d'une hélice α présente uniquement dans les membres de la famille Jak. Nous avons introduit cette mutation dans Tyk2 et analysé son effet sur l'activité kinase. Les résultats montrent que le mutant Tyk2P1104A est incapable de s'autophosphoryler in vitro. Toutefois, en réponse à l'IFNα, aucune différence du niveau de phosphorylation de STAT1/2 /3 n'est décélée dans les cellules exprimant Tyk2P1104A par rapport aux cellules exprimant la protéine sauvage. Ces résultats suggèrent que la mutation P1104A abolit la capacité autophosphorylante de l'enzyme, mais n'affecte pas l'activité enzymatique induite par l' l'IFNα envers d'autres substrats in vivo. Ces résultats préliminaires devront être renforcés par des études plus approfondies de l'effet de la mutation P1104A sur la fonction que Tyk2 exerce au sein du récepteur de l'IFNα/β ainsi qu'au sein d'autres récepteurs de cytokines de la réponse immune.
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Resequencing and Association Analysis of the KALRN and EPHB1 Genes And Their Contribution to Schizophrenia SusceptibilityOzaki, Norio, Iwata, Nakao, Kaibuchi, Kozo, Takeda, Masatoshi, Hashimoto, Ryota, Inada, Toshiya, Suzuki, Michio, Ujike, Hiroshi, Fukuo, Yasuhisa, Okochi, Tomo, Shiino, Tomoko, Ito, Yoshihito, Ikeda, Masashi, Aleksic, Branko, Nakamura, Yukako, Kushima, Itaru 03 1900 (has links)
First published online: November 1, 2010 / 名古屋大学博士学位論文 学位の種類 : 博士(医学)(課程) 学位授与年月日:平成23年3月25日 久島周氏の博士論文として提出された
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Iteratyviosios tabu paieškos algoritmo komivojažieriaus uždaviniui tyrimas / Analysis of iterated tabu search for the traveling salesman problemSimaitis, Rokas 02 June 2006 (has links)
In this work, the iterated tabu search (ITS) algorithm for the traveling salesman problem (TSP) is discussed. The TSP is a well-known combinatorial optimization problem. Thus, solving the TSP means searching for the shortest closed tour in which every city is visited exactly once. Various heuristic algorithms can be used for solving the TSP, among them, tour construction heuristics, simulated annealing, genetic algorithms, etc. One of the promising heuristic techniques is the iterated tabu search approach. ITS consists of two main parts: standard tabu search (TS) and mutation of solutions. The goal of TS is finding a locally optimal solution in the neighbourhood of the current solution, while the mutation operators are responsible for escaping from the current local optimum and moving towards new regions in the solution space. Several mutation procedures have been analyzed in this work, in particular, exchange mutation, insert mutation, inversion mutation, and others. In order to investigated the performance of the mutation operators, computational experiments with the test instances from the TSP instances library TSPLIB were carried out. The results obtained from these experiments show that the mutation operators play the important role and influence the solution quality significantly.
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The Nature of Variation in Mutational Properties: Context-dependent Changes in Mutation Rates and Mutational Fitness EffectsWang, Alethea 13 August 2013 (has links)
Evaluating the evolutionary role of mutations depends on an understanding of their major properties, including their rate of origin, U, and the distribution of their fitness effects, f(s). While substantial effort has been put into measuring these properties, most studies have only examined their distributions in a single context. In nature, spontaneous mutations are likely to experience heterogeneity in genetic and environmental context, and this could lead to variation in both U and f(s). My thesis investigates the changes in U and f(s) with different genetic and environmental factors in Drosophila melanogaster, in order to elucidate the nature of context-associated variation in mutational properties. Examination of condition-dependent variation in DNA repair showed that high and low conditioned individuals differ in the use of alternative repair pathways. This could ultimately lead to variance in their heritable mutation rates. However, the assumption that condition dependence in repair arises solely due to a presumed trade-off between accuracy and the energetic costs associated with different repair pathways is too simplistic. Instead, physiological considerations appear to mediate condition-dependent changes in DNA repair. Measurements of selection on individual mutations across different genetic and environment contexts showed that context-associated changes in mutational fitness effects are common. I found that heterogeneity in fitness effects across different environments result in changes to the overall mean and variance of f(s). This does not, however, seem attributable to the degree of ‘adaptedness’ of a population to a particular environment (a prediction generated by previous theoretical analysis). On the other hand, f(s) appears to be relatively robust to differences among genotypes, with epistasis averaging close to zero. This finding suggests that genetic and environmental perturbations may affect mutations differently. Overall, my thesis represents the most rigorous empirical investigation to date of the conceptual and theoretical predictions regarding the nature of context-dependent heterogeneity in U and f(s) for multicellular eukaryotes.
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Molecular insights into the disease-causing mechanisms of human phospholamban mutationsCeholski, Delaine K Unknown Date
No description available.
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The Nature of Variation in Mutational Properties: Context-dependent Changes in Mutation Rates and Mutational Fitness EffectsWang, Alethea 13 August 2013 (has links)
Evaluating the evolutionary role of mutations depends on an understanding of their major properties, including their rate of origin, U, and the distribution of their fitness effects, f(s). While substantial effort has been put into measuring these properties, most studies have only examined their distributions in a single context. In nature, spontaneous mutations are likely to experience heterogeneity in genetic and environmental context, and this could lead to variation in both U and f(s). My thesis investigates the changes in U and f(s) with different genetic and environmental factors in Drosophila melanogaster, in order to elucidate the nature of context-associated variation in mutational properties. Examination of condition-dependent variation in DNA repair showed that high and low conditioned individuals differ in the use of alternative repair pathways. This could ultimately lead to variance in their heritable mutation rates. However, the assumption that condition dependence in repair arises solely due to a presumed trade-off between accuracy and the energetic costs associated with different repair pathways is too simplistic. Instead, physiological considerations appear to mediate condition-dependent changes in DNA repair. Measurements of selection on individual mutations across different genetic and environment contexts showed that context-associated changes in mutational fitness effects are common. I found that heterogeneity in fitness effects across different environments result in changes to the overall mean and variance of f(s). This does not, however, seem attributable to the degree of ‘adaptedness’ of a population to a particular environment (a prediction generated by previous theoretical analysis). On the other hand, f(s) appears to be relatively robust to differences among genotypes, with epistasis averaging close to zero. This finding suggests that genetic and environmental perturbations may affect mutations differently. Overall, my thesis represents the most rigorous empirical investigation to date of the conceptual and theoretical predictions regarding the nature of context-dependent heterogeneity in U and f(s) for multicellular eukaryotes.
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The Effects of Mitochondrial DNA Mutations on Cell GrowthTsao, Chihyi January 2005 (has links)
Mitochondrial DNA encodes thirteen protein subunits in the oxidative phosphorylation system (OXPHOS) that is responsible for cellular energy production. Mitochondrial disorders have been identified to be associated with mtDNA mutations. However, the molecular mechanisms of specific mtDNA mutations are still being explored in order to establish causative links. This study tries to elucidate the mutational effects of mtDNA on OXPHOS complex activities and cell growths. Using mouse 3T3 fibroblasts as a cell model, single-cell clones with different growth rates were isolated. The entire mtDNA genome was sequenced for mutations. The enzymatic activities of OXPHOS complex I to V were analysed. Three growth patterns represented by five clones were identified. Three clones (clone #2, #3, and #6) had the shortest doubling times (11.5 - 14.9 hours). Clone #1 had a medium growth rate (19.2 hous); and clone #5 had a significantly slow growth rate (22 hours). MtDNA sequencing results revealed that clone #5 had several heteroplasmic mutations (one in 16S rRNA, two in tRNAser (UCN), three in tRNAasp, one in tRNAlys, one in COI, five in COII, and one in ATPase8) while the other four clones showed sequence homology. Enzymatic analyses showed that on average clone #5 had significantly low complex III, IV, and V activities (p < 0.05). Changes in biochemical properties and protein structure were analyzed to deduct possible mechanisms for reduced respiration. In conclusion, the slow growth rate is associated with reduced OXPHOS enzyme functions. It is most likely that the combination of COI and COII mutations resulted in the reduction of complex IV function. It is still unclear whether the ATPase8 mutation (T7869A) in the non-conserved region alone can have such a pronounced phenotypic effect. A reduction in complex III also cannot be explained since there were no mutations in the only mtDNA-encoded complex III gene, but it is possible that there are mutations in the nDNA-encoded complex III genes. Mutations in tRNA and rRNA genes may also be responsible for reduced protein syntheses and consequently reduced OXPHOS activities. It is unclear why complex I activity was not affected. Although the mutational effect of individual mtDNA mutation observed cannot be clearly identified, this study establishes a correlation between mtDNA mutation and cell energy production and growth.
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Investigação de mutações nos genes da CCR5 e langerina e suas associações com a infecção pelo HIV-1 / Mutations investigation at CCR5 and Langerin genes and their associations with HIV-1 infectionCosta, Giselle Calasans de Souza January 2012 (has links)
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Previous issue date: 2012 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / O HIV-1 é o agente etiológico da AIDS. Sabe-se que fatores virais e do hospedeiro podem
influenciar na susceptibilidade à infecção pelo vírus e na progressão para a AIDS. Em relação
aos fatores intrínsecos ao hospedeiro, tem sido demonstrado que algumas alterações na CCR5
podem afetar sua ligação com a gp120 do HIV-1, influenciando na infecção pelo vírus. Além
disso, a proteína Langerina, encontrada na superfície das Células de Langerhans (LCs),
apresenta um papel importante em relação à infecção pelo HIV-1, por ter a capacidade de se
ligar à gp120 viral através de seu Domínio de Reconhecimento de Carboidrato (CRD). Esta
interação permite que as LCs internalizem o vírus em Grânulos de Birbeck, os quais
degradam a partícula viral, inibindo a apresentação do HIV-1 para os linfócitos T. Desta
forma, diferenças na função da langerina, devido a mutações no promotor do gene Langerina
e na região codificante do CRD, por exemplo, podem influenciar a susceptibilidade à
infecção pelo HIV-1. Sendo assim, o objetivo principal deste trabalho foi verificar a
existência de mutações nas regiões do gene CCR5 que codificam para os domínios N e Cterminal
da proteína, no promotor do gene da Langerina e na região codificante do CRD, bem
como verificar a existência de possíveis associações entre as mutações encontradas e a
infecção pelo HIV-1. Para tal, através de sequenciamento, foi analisado um total de 128
amostras de DNA de indivíduos infectados pelo HIV-1 de Feira de Santana, Bahia e 197
amostras de DNA de indivíduos não-infectados de Salvador, Bahia. Os possíveis sítios de
ligação para fatores de transcrição da região promotora do gene da Langerina foram
analisados pela ferramenta MatInspector implementada no software Genomatix. Análises
físico-químicas, de domínios protéicos potenciais, de predição da estrutura proteica
secundária e de modelagem tridimensional proteica foram também realizadas, utilizando
diferentes ferramentas de bioinformática. Os estudos na região N-terminal da CCR5
revelaram a existência de uma mutação de sentido trocado no aminoácido 55 (p.L55Q)
apenas em indivíduos não-infectados, com uma frequência do alelo mutante de 1,8%.
Análises físico-químicas demonstraram que esta mutação aumentou a flexibilidade e a
acessibilidade da CCR5 e a modelagem protéica demonstrou que a mutação levou a um
pequeno desvio para a direita, bem como alterou levemente a carga eletrostática dessa região
da proteína. Foi observada diferença estatisticamente significante entre as frequências
alélicas (p=0,039) e genotípicas (p=0,038) da mutação p.L55Q quando os indivíduos
infectados e não-infectados foram comparados. Os estudos na região C-terminal da CCR5
demonstraram a existência de três mutações silenciosas em indivíduos infectados pelo HIV-
1: c.3,765C>T, c.3,777A>T e c.3,831A>G. Em relação à análise da região promotora do
gene da Langerina, foram observadas três mutações (-577T>C, -517T>C e -160T>C) que,
segundo o MatInspector, criaram novos sítios de ligação para fatores de transcrição, tais
como: NFAT5, HOXB9.01 e STAT6.01. Entretanto, comparando as frequências alélicas e
genotípicas dessas mutações entre os indivíduos infectados e não-infectados, não foi
observada diferença estatisticamente significante. Já as análises realizadas na região gênica
que codifica o CRD da Langerina demonstraram a existência de três mutações: p.K313I
(c.937T>A), c.941C>T (g.4728C>T) e c.983C>T (g.4770C>T) As análises físico-químicas
revelaram que a mutação p.K313I aumentou a hidrofobicidade e as hélices transmembranares
e diminuiu a hidrofilicidade, a acessibilidade e a antigenicidade da proteína. Entretanto, a
presença do alelo mutante não alterou a predição da estrutura secundária da Langerina e não
foi observada diferença estatisticamente significante nas frequências alélicas e genotípicas
quando os dois grupos estudados foram comparados. Estes resultados sugerem que a mutação
p.L55Q, encontrada no domínio N-terminal da CCR5, pode afetar a entrada do HIV-1 na
célula. Foi possível, também, observar que as mutações encontradas no gene da Langerina
não apresentam associação com a infecção pelo HIV-1. No entanto, é importante que novos
estudos sejam realizados com o intuito de compreender melhor o verdadeiro papel da
mutação p.L55Q na infecção pelo HIV-1, assim como, novas análises voltadas para a busca
de variações no gene da Langerina também devam ser conduzidas, uma vez que este é o
primeiro estudo que investiga mutações na Langerina em indivíduos infectados pelo HIV-1. / HIV-1 is the etiologic agent of AIDS. It has been demonstrated that the mechanisms
underlying HIV-1 infection and pathogenesis require a combination of viral and host factors.
Concerned to the host intrinsic factors, some mutations at CCR5 human gene can affect the
interaction between CCR5 protein and HIV-1 gp120, influencing the virus infection. Besides,
the Langerin protein, located exclusively on Langerhans cells surface, has an important role
in HIV-1 infection due to its ability of binding to gp120 through its Carbohydrate
Recognition Domain (CRD). This interaction ables HIV-1 internalization into Birbeck
granules, which degrade the virus and prevent LC infection and viral dissemination. So,
differences in Langerin function due to mutations at promoter and CRD encoding regions of
the human Langerin gene, for example, might influence the susceptibility to HIV-1 infection.
Thus, the main purpose of this study is to investigate the existence of mutations at the regions
of CCR5 gene that encodes the N- and C-terminal protein domains and at promoter and CRD
encoding regions of the human Langerin gene, and finally to stablish possible associations
among the observed mutations and HIV-1 infection. Using DNA sequencing, it was studied a
total of 128 DNA samples of HIV-1 infected individuals from Feira de Santana, Bahia and
197 DNA samples of HIV-1 non-infected individuals from Salvador, Bahia. The transcription
factors binding sites were analyzed using the MatInspector tool implemented in the
Genomatix software. Physico-chemical, potential protein domain, prediction of protein
secondary structure and protein modeling analyses were also performed, using Bioinformatic
tools. The studies into the N-terminal protein domain revealed a new missense mutation at
aminoacid 55 (p.L55Q), only in HIV-1 non-infected individuals, with allelic frequency of
1.8%. Physico-chemical analysis revealed that this mutation magnified the flexibility and
accessibility profiles and the modeling of CCR5 structures showed that this mutation resulted
in a small deviation to the right, as well as, a hydrophobic to hydrophilic property alteration.
When HIV-1 infected and non-infected groups were compared, the allelic and genotypic
frequencies of the p.L55Q mutation were statistically significant (p=0.039 and 0.038,
respectively). Three novel silent mutations were found at encoding region of C-terminal
protein domain in the HIV-1 infected individuals: c.3,765C>T, c.3,777A>T and c.3,831A>G.
Concerned to the analyses at promoter Langerin region, the studies revealed three mutations:
-577T>C, -517T>C and -160T>C. The search for possible transcription factors binding sites
using MatInspector demonstrated that these promoter mutations created new binding sites to
some transcription factors, such as NFAT5, HOXB9.01 and STAT6.01. However, when HIV-
1 infected and non-infected groups were compared, the allelic and genotypic frequencies of
the analyzed promoter sites were not statistically significant. It was observed three mutations
at Langerin gene region that encodes to the protein CRD: p.K313I (c.937T>A), c.941C>T
(g.4728C>T) and c.983C>T (g.4770C>T). The physico-chemical analysis revealed that the
p.K313I polymorphism magnified the hydropathy and transmembrane profiles and reduced
the hydrophilicity, accessibility and anitigenicity profiles. However, this mutation did not
modify the protein secondary structure prediction and when HIV-1 infected and non-infected
individuals were compared, it was not observed a statistically significant difference in the
allelic and genotypic frequencies from the p.K313I polymorphism. These results suggest that
the p.L55Q mutation can affect HIV-1 infection through CCR5 entry. It was also observed
that the mutations detected at the promoter and CRD encoding regions of the human
Langerin gene are not associated with HIV-1 infection susceptibility. However, it is
important to accomplish future studies in order to better understand the role of the p.L55Q
mutation at HIV-1 infection, as well as, conduct new search for variations at Langerin gene
that could influence HIV-1 infection, since this is the first study that analyzes mutations at
promoter and encoding regions of Langerin gene in a HIV-1 infected population.
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Henri Michaux : déplacements et mutations de l'ailleurs poétique. / Henri Michaux : shifting and mutations of the poetic spaceNantois, Aurélien 23 October 2009 (has links)
L'ailleurs est une notion primordiale en poésie et Henri Michaux, à la suite de Baudelaire et de Rimbaud en est l'un des principaux représentants. La notion d'un ailleurs spécifique à la création poétique et artistique est utilisée pour analyser comment le poète transforme la poésie. Les ailleurs réels de ses voyages et les ailleurs imaginaires de sa poésie s'unissent alors dans un voyage intérieur qui permet au poète de se réconcilier avec lui-même. Henri Michaux utilise sa volonté d'impuissance pour s'extraire de la tradition classique et du romantisme artistique et pour résister au monde qui l'entoure. Mais l'exploration de son intériorité et la modification de l'espace qu'elle impliquent le confrontent à l'universelle douleur de l'existence humaine. Le poète s'attache alors, malgré les blessures de sa vie, à apaiser son espace intérieur. Il s'inspire des philosophies asiatiques et de l'ancienne magie chamanique pour enchanter le monde. Il parvient à un art de guérison qui renouvelle la poésie par le recours aux déplacements et aux mutations de l'ailleurs poétique / Being "anywhere out of the world" as a poetical space, is a central concept of poetry. Henri Michaux, following Baudelaire and Rimbaud is one of the main explorers of the poetical space. The notion of a specific space of poetic and artistic creation is used to analyze how the poet transforms poetry. The real space of travel and the space of imagination in his poetry join together for a journey in which the poet reconciles with himself. Henri Michaux uses his will of weakness to escape the classical and romantic tradition and resist to the world around him. The exploration of his interiority, and the modification of space that it requires, make him confront to the universal pain of men. The poet, despite the wounds of his life, wants his inner space to be in peace. He bases his art on Asian philosophies and the ancient shamanic magic. He reaches a healing art which renews poetry by using of shifting and mutations of the poetic space.
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Perfil de resistência genótica do HIV-1 em pacientes com falha na terapia antirretroviral atendidos pela Rede Nacional de Genotipagem (RENAGENO) na região de Botucatu, SP-BrasilMunhoz, Lilian da Silva Reis [UNESP] 16 February 2011 (has links) (PDF)
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munhoz_lsr_me_botfm.pdf: 9483369 bytes, checksum: 914df7a3c919410ceb93de705a530cd4 (MD5) / Ministério da Saúde / Os antirretrovirais (ARVs) interferem nas enzimas virais resultando na inibição da replicação do HIV. O uso combinado destas drogas tem demonstrado grande eficácia no controle da progressão da infecção pelo HIV e aumento da sobrevida do paciente. Entretanto estes benefícios podem ser comprometidos pelo desenvolvimento de resistência às drogas, consequência da emergência de mutações nas enzimas virais, representando um grande obstáculo para o sucesso do tratamento de pacientes infectados pelo HIV-1. Os testes de resistência, principalmente de genotipagem do HIV-1, permitem a orientação de novos esquemas, possibilitando o retorno da supressão viral. Este estudo teve como objetivo avaliar o perfil de mutações e a resistência genotípica aos Inibidores da Transcriptase Reversa análogos de Nucleosídeos (ITRN), Inibidores da Transcriptase Reversa Não-análogos de Nucleosídeos (ITRNN) e Inibidores da Protease (IP) em pacientes com falha terapêutica submetidos ao exame de genotipagem, realizado no Laboratório de Rotinas Diagnósticas em Biologia Molecular do Hemocentro da FMB - UNESP ponto executor da RENAGENO (Rede Nacional de Genotipagem do HIV-1). Foram analisadas sequências genômicas da região pol do HIV-1 provenientes de todos os pacientes com exame de genotipagem realizados durante os anos de 2008 e 2009. Dois grupos distintos foram formados: grupo “Adulto” (idade ≥ 18 anos), com 386 indivíduos, e grupo “Pediátrico” (<18 anos), com 45 pacientes, totalizando 431 pacientes. A genotipagem foi realizada pelo kit comercial Trugene HIV-1 Genotyping Kit (Siemens Healthcare Diagnostics). As sequências obtidas foram submetidas ao Algoritmo de Interpretação de Resistência Genotípica da Universidade de Stanford (HIVdb) e a subtipagem foi realizado pelo REGA HIV-1 Subtyping Tool e pelo programa RIP 3.0. O subtipo B foi o mais frequente nos dois grupos estudados... / Antiretrovirals (ARV) interfere with viral enzymes resulting in the inhibition of HIV replication. The use of antiretroviral combinations has demonstrated highly effectiveness in controlling of the progression of HIV infection and increased of the patients’ survival. However these benefits can be compromised by the development of drug resistance, as consequence of the mutations emergence in viral enzymes, representing a major obstacle to successful treatment of HIV-1 patients infected. Resistance tests, mainly HIV-1 genotyping, allow the orientation of new schemes, enabling the return of viral suppression. This study aimed to evaluate the profile of mutations and genotypic resistance to the Nucleoside Reverse Transcriptase Inhibitors (NRTI), Nonnucleoside Reverse Transcriptase Inhibitors (NNRTI) and Protease Inhibitors (PI) in the patients in therapeutic failure submitted to the genotyping test, performed in Diagnostic Routine Laboratory in Molecular Biology at the Blood Center of FMB – UNESP, part of RENAGENO (National Network of HIV-1 Genotyping). HIV-1 pol region genomic sequences from all patients with genotype test performed during the years 2008 and 2009 were analyzed. The patients were separated in two distinct groups: “Adult group” (age ≥ 18 years), with 386 individuals, and “Pediatric group” (<18 years), with 45 patients, in a total of 431 patients. Genotyping was performed by Trugene HIV-1 Genotyping Kit (Siemens Healthcare Diagnostics). The sequences obtained were submitted to the Genotypic Resistance Interpretation Algorithm of Stanford University (HIVdb) and the subtyping was performed by REGA HIV-1 Subtyping Tool and by RIP 3.0 program. Subtype B was the most frequent in both groups followed by hybrid forms B and F (BF or FB) and subtype F1. Resistance mutations were found in 97.15% of patients in the adult group... (Complete abstract click electronic access below)
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