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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
541

Understanding disease and disease relationships using transcriptomic data

Oerton, Erin January 2019 (has links)
As the volume of transcriptomic data continues to increase, so too does its potential to deepen our understanding of disease; for example, by revealing gene expression patterns shared between diseases. However, key questions remain around the strength of the transcriptomic signal of disease and the identification of meaningful commonalities between datasets, which are addressed in this thesis as follows. The first chapter, Concordance of Microarray Studies of Parkinson's Disease, examines the agreement between differential expression signatures across 33 studies of Parkinson's disease. Comparison of these studies, which cover a range of microarray platforms, tissues, and disease models, reveals a characteristic pattern of differential expression in the most highly-affected tissues in human patients. Using correlation and clustering analyses to measure the representativeness of different study designs to human disease, the work described acts as a guideline for the comparison of microarray studies in the following chapters. In the next chapter, Using Dysregulated Signalling Paths to Understand Disease, gene expression changes are linked on the human signalling network, enabling identification of network regions dysregulated in disease. Applying this method across a large dataset of 141 common and rare diseases identifies dysregulated processes shared between diverse conditions, which relate to known disease- and drug-sharing-relationships. The final chapter, Understanding and Predicting Disease Relationships Through Similarity Fusion, explores the integration of gene expression with other data types - in this case, ontological, phenotypic, literature co-occurrence, genetic, and drug data - to understand relationships between diseases. A similarity fusion approach is proposed to overcome the differences in data type properties between each space, resulting in the identification of novel disease relationships spanning multiple bioinformatic levels. The similarity of disease relationships between each data type is considered, revealing that relationships in differential expression space are distinct from those in other molecular and clinical spaces. In summary, the work described in this thesis sets out a framework for the comparative analysis of transcriptomic data in disease, including the integration of biological networks and other bioinformatic data types, in order to further our knowledge of diseases and the relationships between them.
542

Development of a DNA microarray platform for the detection of viruses transmitted by small mammals and arthropods / Desenvolvimento de uma plataforma de microarranjo de DNA para detecção de vírus transmitidos por pequenos mamíferos e artrópodes

Khan, Mohd Jaseem 01 December 2015 (has links)
Human activities have being responsible for the global environmental changes, resulting in an increase number of incident of vector- and rodent-borne diseases worldwide. Rodents and arthropods-borne viruses are important globally emerging and re-emerging viruses and most of them are RNA viruses. Efficient and early diagnosis of these infections are very important to prevent their spread, to improve clinical management of the patients, as wells to protect livestock and domestic animals. Currently, available diagnostic methods such as immunoassays, polymerase chain reaction and virus isolation can detect only one or few viruses in a single assay. The DNA microarray platform has emerged as diagnostic tool suitable for high throughput screening of pathogenic agents. The aim of this study was to develop a DNA microarray platform (RoboArboVirusChip) for detecting rodent- and arthropod-borne viruses, which belong to seven families: Bunyaviridae (genera Orthobunyavirus, Nairovirus and Phlebovirus), Flaviviridae (genus Flavivirus), Togaviridae (genus Alphavirus), Reoviridae (genera Orbivirus, Seadornavirus and Coltvivirus), Rhabdoviridae (genera Vesiculovirus and Ephemerovirus), and Asfarviridae (genus Asfarvirus). Specific oligonucleotide probes of 60-mer (n=4209) targeting 412 virus species and generic probes of 25-35-mer (n=87) targeting viruses at the genus level were designed. A total of 17 reference viruses belonging to the Bunyaviridae, Flaviviridae, Rhabdoviridae and Togaviridae families were used to standardize RoboArboVirusChip. All reference viruses were specifically detected without any cross hybridization; however, the generic probes were not able to identify the viruses at the genus level. The RoboArboVirusChip was able to specifically identify four viruses contained in three different mixtures: i) virus of different families, ii) virus of the Flavivirus genus, and iii) the Dengue virus (DENV) serotypes. The four DENV serotypes were use to evaluate the sensitivity of the RoboArboVirusChip, which was able to detect a minimum of 25 RNA copies/mL of the viruses, confirming its high sensitivity. The applicability of the RoboArboVirusChip to detect viruses in clinical samples was tested with serum samples obtained from dengue suspected cases (four positive cases and 40 negative cases). DENV was detected in the four positive serum samples, while in the 40 negative serum samples, it was not detected any virus. The results obtained in this study suggest that the RoboArboVirusChip platform could be a useful tool for early diagnosis of robovirus and arbovirus infections during epidemic outbreaks, helping in the rapid implementation of disease containment strategies / As atividades humanas têm sido responsável por mudanças ambientais globais, resultando num aumento do número de casos de doenças transmitidas por vetores e roedores em todo o mundo. Os vírus transmitidos por roedores e artrópodes são vírus emergentes e re-emergentes de importância global, sendo que a maioria deles são vírus de RNA. O diagnóstico eficiente e precoce dessas infecções são muito importantes para evitar a sua propagação, para melhorar o manejo clínico dos pacientes e também, para proteger o gado e os animais domésticos. Atualmente, os métodos de diagnóstico disponíveis, tais como os imunoensaios, a reação em cadeia da polimerase e o isolamento viral podem detectar apenas um ou poucos vírus em um único ensaio. A plataforma de microarranjo de DNA tem surgido como uma ferramenta de diagnóstico apropriada para o monitoramento em larga escala de agentes patogênicos. O objetivo deste estudo foi desenvolver uma plataforma de microarranjo de DNA (RoboArboVirusChip) para a detecção de vírus transmitidos por roedores e artrópodes, os quais pertencem a sete famílias: Bunyaviridae (gêneros Orthobunyavirus, Nairovirus e Phlebovírus), Flaviviridae (gênero Flavivirus), Togaviridae (gênero Alphavirus), Reoviridae (gênero Orbivirus, Seadornavirus e Coltvivirus), Rhabdoviridae (géneros Vesiculovirus e Ephemerovirus), e Asfarviridae (gênero Asfarvirus). Sondas oligonucleotídicas de 60-mer (n=4209) específicas contra 412 espécies virais, e sondas genéricas de 25-35-mer (n=87) para detecção de vírus a nível do gênero foram desenhados. Um total de 17 vírus de referência, pertencentes às famílias Bunyaviridae, Flaviviridae, Rhabdoviridae e Togaviridae foram utilizados para padronizar o RoboArboVirusChip. Todos os vírus de referência foram detectados especificamente sem apresentação de hibridação cruzada, porem as sondas genéricas não foram capazes de detectar os vírus a nível do gênero. O RoboArboVirusChip foi capaz de identificar especificamente quatro vírus contidos em diferentes misturas: i) vírus de diferentes famílias, ii) vírus pertencentes ao gênero a Flavivirus, e iii) os sorotipos do vírus da dengue (DENV). Os quatro sorotipos do DENV foram utilizados para determinar a sensibilidade do RoboArboVirusChip, o qual foi capaz de detectar um mínimo de 25 copias de RNA/mL. A aplicabilidade do RoboArboVirusChip para detectar vírus em amostras clínicas foi avaliada testando amostras de soro de pacientes com suspeita de dengue (quatro casos positivos e 40 casos negativos). Os resultados obtidos neste estudo sugerem que o RoboArboVirusChip poderá ser uma ferramenta útil para o diagnóstico precoce da infecção causada por robovírus e arbovírus, auxiliando na rápida implementação de estratégias de contenção das doenças causadas por esses vírus
543

Expressão de marcadores imunoistoquímicos em neoplasias melanocíticas de equinos por microarranjo de tecidos / Expression of immunohistochemical biomarkers in equine melanocytic neoplasms using tissue microarray

Maria Luísa de Lima Landman 19 April 2011 (has links)
O objetivo deste estudo foi verificar o comportamento morfológico e a expressão das proteínas S-100, Melan-A, HMB-45, Ki-67, PCNA e p53, em 25 neoplasias melanocíticas de equinos. Informações clínicas (gênero, raça, pelagem, idade e localização da lesão) e morfológicas (características celulares, pigmentares, nucleares, de nucléolo, de melanófagos, presença de invasão e necrose) dos animais foram coletadas. Para a expressão das proteínas por imunoistoquímica foi confeccionado um bloco de microarranjo de tecidos das amostras teciduais, juntamente com os controles positivos das reações. A avaliação da expressão das proteínas S100, HMB-45 e Melan-A foi baseada em um escore, e a das proteínas Ki-67, PCNA e p53 foi feita por contagem de células. Animais SRD (16/25, 64%), de raça Lusitana (6/25, 24%), Árabe (2/25, 8%) e Sueca (1/25, 4%) fizeram parte deste estudo, todos tordilhos e a maioria machos (18/25, 72%). A idade dos animais variou de 4 a 24 anos (média de 13 anos). A região perianal (13/25, 52%) foi a que mais apresentou neoplasias. Na análise morfológica houve predomínio de neoplasias com celularidade moderada (52%) e intensa (40%), distribuição difusa e em feixes (52%), ausência de figuras de mitose (96,0%) e predomínio de células epitelióides e fusiformes no mesmo tumor (80%). A atipia nuclear era discreta (48%) e moderada (44%), com núcleos de formato arredondado e alongado em um mesmo tumor (76%) e cromatina dispersa (60%). Os nucléolos eram múltiplos e, em sua maioria, proeminentes (88%). Observou-se predomínio de células tumorais de pigmentação intensa (68%), distribuição difusa e localização em derme (100%). A maioria dos casos apresentou alta celularidade de macrógafos (64%) e distribuição difusa (96%). Quanto à expressão de proteínas para melanócitos por imunoistoquímica, 44% dos casos apresentaram expressão moderada a forte de S100, 56% apresentaram expressão fraca de HMB-45 e 64% apresentaram expressão negativa de Melan-A. Houve positividade de 72% dos casos para pelo menos dois dos anticorpos citados acima. Os anticorpos de proliferação celular Ki-67 e PCNA tiveram média de acima. Os anticorpos de proliferação celular Ki-67 e PCNA tiveram média de positividade de 0,0005% e 15,7%, respectivamente. A análise da expressão de p53 teve média de 6,1% de positividade. Houve associação estatisticamente positiva entre a celularidade dos macrófagos com S100 e com p53. Em conclusão: 1. os dados clínicos obtidos reproduzem o comportamento biológico das neoplasias melanocíticas em equinos, exceto pela idade dos animais; 2. as neoplasias equinas se assemelham a nevos azuis celulares em humanos e melanocitomas em cães; 3. o microarranjo de tecidos mostrou-se uma maneira econômica, rápida e com menos variáveis técnicas; 4. a utilização de um painel de anticorpos de melanócitos é pertinente na diferenciação entre tumores melanocíticos e não melanocíticos, reproduzindo o painel diagnóstico utilizado em literatura humana e canina; 5. o índice de proliferação celular encontrado sugere que os dois anticorpos (Ki-67 e PCNA) podem ser usados na contagem de células em atividade mitótica e 6. a proteína p53 tem maior relação com a parada do ciclo celular que a observada em outros estudos em equinos, podendo indicar um comportamento biológico diferente do apresentado em cães e humanos. / The aim of this study was to evaluate the morphological behavior, and expression of the following proteins: S-100, Melan-A, HMB-45, Ki-67, PCNA and p53, in 25 equine melanocytic neoplasms. Clinical (gender, breed, coat color, age and lesions location) and morphological (cellular, pigment, nuclear, nucleoli, melanophages, invasion and necrosis) data were collected. A tissue microarray block, embedded in paraffin, with equine tissue samples and positive controls, was elaborated for protein expression through immunohistochemistry. The evaluation of S100, HMB-45 and Melan-A was based on a score, and for Ki-67, PCNA and p53 it was based on cellular count. Breeds were: Mixed breed (16/25, 64%), Lusitano (6/25, 24%), Arab (2/25, 8%) and Swedich (1/25, 4%). All animals were gray and the majority males (18/25, 72%). Age varied from 4 to 24 years old (mean=13 years). The perianal region (13/25, 52%) was the most common location. Morphological analysis have shown neoplasms with predominantly moderate (52%) and intense (40%) cellularity, diffuse and fascicles distribution (52%), no mitoses figures (96%) and predominance of epithelioid and spindle cells in the same tumor (80%). There was discrete (48%) and moderate (44%) nuclear atypia, round and elongated nucleus in the same tumor (76%), and disperse chromatin (60%). Nucleoli were multiple and prominent in the majority of cases (88%). Tumor cells with diffuse and intense pigmentation, with dermal location (100%) were predominant. High cellularity of macrophages (64%) with diffuse distribution (96%) was mostly seen. The protein expression for melanocytes have shown 44% of moderate to strong expression for S100 protein, 56% of weak expression for HMB-45 protein and 64% of negative expression for Melan-A protein. It was found positivity for more than two antibodies in 72% of equine melanocytic neoplasms. The proliferation antibodies Ki-67 and PCNA had mean positivity of 0,0005% and 15,7%, respectively. The p53 expression had mean positivity of 6,1%. Macrophages cellularity was statistically associated with S100 and p53. In conclusion: 1. clinical data obtain reproduce the biological behavior of equine Macrophages celllularity was statistically associated with S100 and p53. In conclusion: 1. clinical data obtain reproduce the biological behavior of equine melanocytic neoplasms, excepting the animals age; 2. equine melanocytic neoplasms assemble to human cellular blue nevi and dogs melanocytoma; 3. the tissue microarray was shown to be an economic, rapid and less variable technique; 4. using a panel for antibodies for melanocytes is relevant to differentiate melanocytic and not melanocytic tumors, reproducing the diagnosis panel used in human and canine literature; 5. the proliferation index found suggests that both antibodies (Ki-67 and PCNA) could be used in mitotic activity cell count; and 6. p53 protein has more relation with cellular cycle stop than in other equine studies, probably indicating a different biological behavior than the presented in humans and dogs.
544

Efeitos imunotóxicos da Pteridium aquilinum em células natural killer de camundongos e a reversão destes efeitos com selênio / Immunotoxic effects of Pteridium aquilinum in natural killer cells from mice and the reversion of these effects by selenium

Andréia Oliveira Latorre 04 October 2010 (has links)
Os resultados obtidos no mestrado mostraram que a samambaia do campo (Pteridium aquilinum) reduz a citotoxicidade das células natural killer (NK) esplênicas e a resposta imune celular do tipo tardia (DTH) de camundongos. Entretanto, até aquele momento não era sabido qual a célula afetada pela planta causava a diminuição da DTH. Assim, o objetivo inicial deste estudo foi verificar qual a célula envolvida na diminuição da DTH. Além disto, buscou-se descobrir o mecanismo de ação imunotóxico da P. aquilinum, o principio tóxico envolvido e se este efeito poderia ser revertido pelo selênio (Se). Para tal, camundongos C57BL/6 foram administrados com extrato de P. aquilinum, por gavage, durante 30 dias e suplementados com Se por mais 30 dias e a análise histológica revelou redução significativa na área de polpa branca esplênica que foi completamente revertida pelo tratamento com Se. Ainda, foi possível verificar que a diminuição da DTH foi causada pela redução da produção de IFNγ pelas células NK durante a indução da resposta imune celular. Além disto, camundongos administrados com ptaquilosídeo, por gavage, durante 14 dias mostraram a mesma redução na atividade das células NK causada pelo extrato de P. aquilinum, assim como a prevenção deste efeito pela co-administração de Se. Por fim, na análise da expressão gênica das células NK esplênicas dos camundongos tratados com ptaquilosídeo e/ou selênio pôde-se observar o aumento da expressão dos genes Mt1 e Mt2, possíveis responsáveis pelo mecanismo imunotóxico da planta, sendo posteriormente confirmado pelo aumento de metalotioneína e consequente redução de Zn2+ livre no espaço intracelular das células NK. Os resultados deste estudo claramente mostram que os efeitos imunossupressores da P. aquilinum são induzidos pelo ptaquilosídeo e são decorrentes do aumento da expressão dos genes da Mt1 e Mt2 e que a suplementação com Se pode prevenir e reverter estes efeitos tóxicos. / The results obtained in the master showed that the bracken fern (Pteridium aquilinum) reduces both the cytotoxicity of splenic natural killer cells (NK) and the delayed-type hypersensitivity (DTH) from mice. However, it was not known until that time, which cell affected by the plant that caused a decrease in DTH. Thus, the initial goal of this study was to determine which cell was involved in the reduction of DTH. Moreover, we sought to discover the mechanism of action of the P. aquilinum, the toxic principle involved and whether this effect could be reversed by selenium (Se). For that, C57BL/6 mice were treated with extract of P. aquilinum, by gavage, for 30 days and supplemented with Se for following 30 days. The histological analysis revealed a significant reduction in the splenic white pulp area that was completely reversed by treatment with Se. Still, it was verified that the decrease in DTH was caused by reduced production of IFNγ by NK cells during the induction of cellular immune response. In addition, the mice administered with ptaquiloside, by gavage, for 14 days showed the same reduction in the NK cell activity caused by the extract of P. aquilinum, as well as the prevention of this effect by co-administration of Se. Finally, we could observe an increase in the expression of Mt1 and Mt2 genes in the gene expression analysis of splenic NK cells from mice treated with ptaquiloside and/or selenium. These genes were probably responsible for immunotoxic mechanism of the plant, which was confirmed later by the augment of metallothionein and consequent reduction of free Zn2+ into the intracellular space of NK cells. The results of this study clearly show that the immunosuppressive effects of P. aquilinum are induced by ptaquiloside and they are a consequence of the augment in the gene expression of Mt1 and Mt2 and that the supplementation with Se can prevent and reverse these toxic effects.
545

Análise global da expressão de RNAs não codificadores no sistema imunológico humano na senescência e sepse / Non coding RNA global expression analysis in the human immune system in sepsis and aging

Diogo Vieira da Silva Pellegrina 28 July 2016 (has links)
A sepse é uma das maiores causas de mortalidade em pacientes hospitalizados, e uma complicação comum, tanto em pacientes clínicos quanto de cirurgias, admitidos em hospitais por causas não infecciosas. A sepse é especialmente comum em pacientes mais velhos, sendo portanto esperado que sua incidência aumente com o envelhecimento da população, e apesar da sua maior taxa de mortalidade, a resposta imune em idosos durante o choque séptico é muito similar à dos pacientes mais jovens. O objetivo desse estudo foi de conduzir uma análise de expressão gênica dos neutrófilos da circulação, tanto de pacientes adultos como de pacientes idosos, observando tanto os mRNAs e as vias em que estão envolvidos, como o papel dos ncRNAs, para um melhor entendimento da resposta imune do indivíduo idoso a infecções severas. Os RNAs de 24 indivíduos, divididos igualmente entre idosos e adultos, e entre pacientes em choque séptico e controles, foram hibridizadas em microarranjos de DNA. Deste experimento foram encontrados genes cuja expressão pode ser utilizada para diferenciar a resposta imune entre adultos e idosos. Estes genes foram observados concentrados em algumas vias, entre elas fosforilação oxidativa, disfunção mitocondrial, sinalização do TGF-, entre outras. Além da análise usando os mRNAs, esse trabalho mostra fortes indicações de interações de mRNAs com RNAs não codificadores longos, dos quais a maioria não têm função conhecida. Para propor uma função aos RNAs não codificadores foi construída uma rede de coexpressão em que alguns RNAs de função desconhecida se mostraram fortemente ligados à genes das vias moleculares do ribossomo e da mitocôndria. Também foi observado que para os idosos a rede de coexpressão é menos centralizada, suportando a hipótese de que alterar a expressão de alguns genes chave pode ser o fator determinante para alterar a expressão gênica e um conjunto maior / Sepsis is one of the major causes of mortality in hospitalized patients, and a common complication, both in clinical patients and in surgeries, admitted to hospital for non-infectious causes. Sepsis is especially common in older patients, and is therefore expected that its incidence increases as the population ages, and despite its higher mortality rate, the immune response in the elderly during septic shock is very similar to that of younger patients. The objective of this study was to conduct a gene expression analysis of circulating neutrophils, both adults and elderly patients, noting both the mRNAs, the pathways in which those are involved, and the role of ncRNAs, for a better understanding of the immune response of the elderly to severe infections. The RNAs of 24 individuals, equally divided among the adults and the elderly, and among patients in septic shock and controls, were hybridized to DNA microarrays. From this experiment many genes whose expression can be used to differentiate the immune response in adults and the elderly were found. These genes were concentrated in some metabolic pathways, including oxidative phosphorylation, mitochondrial dysfunction, TGF- signaling, and others. Besides the analysis using mRNAs, this work shows strong indications of mRNAs interactions with non coding RNAs, most of which have no known function. To propose a role for noncoding RNAs a coexpression network was built in which some RNAs of unknown function showed strongly connected to genes of the molecular pathways of the ribosome and mitochondria. It was also noted that for the elderly, the coexpression network is less centralized, supporting the hypothesis that altering the expression of a few key genes can be a determining factor for altering the gene expression of a larger set
546

Novel Plasmonic Imaging Techniques for Measuring Protein Kinetics

January 2018 (has links)
abstract: Proteins play a central role to human body and biological activities. As powerful tools for protein detections, many surface plasmon resonance based techniques have been developed to enhance the sensitivity. However, sensitivity is not the only final goal. As a biosensor, four things really matter: sensitivity, specificity, resolution (temporal/spatial) and throughput. This dissertation presents several works on developing novel plasmonic based techniques for protein detections on the last two aspects to extend the application field. A fast electrochemically controlled plasmonic detection technique is first developed with the capability of monitoring electrochemical signal with nanosecond response time. The study reveals that the conformational gating of electron transfer in a redox protein (cytochrome c) takes place over a broad range of time scales (sub-µs to ms). The second platform integrates ultra-low volume piezoelectric liquid dispensing and plasmonic imaging detection to monitor different protein binding processes simultaneously with low sample cost. Experiment demonstrates the system can observe binding kinetics in 10×10 microarray of 6 nL droplet, with variations of kinetic rate constants among spots less than ±5%. A focused plasmonic imaging system with bi-cell algorithm is also proposed for spatial resolution enhancement. The two operation modes, scanning mode and focus mode, can be applied for different purposes. Measurement of bacterial aggregation demonstrates the higher spatial resolution. Detections of polystyrene beads binding and 50 nm gold nanoparticles oscillation show a high signal to noise ratio of the system. The real properties of protein rely on its dynamic personalities. The above works shed light upon fast and high throughput detection of protein kinetics, and enable more applications for plasmonic imaging techniques. It is anticipated that such methods will help to invoke a new surge to unveil the mysteries of biological activities and chemical process. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2018
547

O papel dos microRNAs de células T na susceptibilidade/resistência a artrite reumatóide experimental / The role of T lymphocytes microRNAs in the resistance/susceptibility to the experimental arthritis.

Yabuta, Paula Barbim Donate 01 March 2012 (has links)
Os microRNAs são pequenos RNAs, não-codificantes que funcionam como reguladores a nível pós-transcricional da expressão gênica. Nos últimos anos, novas evidências demonstram o papel importante dos microRNAs na regulação e desenvolvimento do sistema imune. Apesar da função de poucos microRNAs ser conhecida, a sua expressão alterada vêm sendo associada a patogênese de diversas doenças autoimunes, incluindo a artrite reumatóide (AR). Recentemente a expressão desregulada de uma série de microRNAs está sendo descrita em pacientes com AR, e o papel patogênico de apenas uma parte deles foi investigada em modelos animais. A artrite reumatóide é uma doença autoimune sistêmica caracterizada por um intenso processo inflamatório na sinóvia, podendo causar destruição óssea e articular. Os linfócitos T apresentam papel importante na indução, manutenção e progressão da doença. A artrite induzida por colágeno é um modelo animal amplamente utilizado por suas características fisiopatológicas muito similares à doença em humanos. A linhagem de camundongos DBA-1/J desenvolve a doença após imunização e booster com colágeno do tipo II, enquanto que a linhagem DBA-2/J se mostra refratária. Isso confere um sistema modelo de susceptibilidade/resistência à artrite, que pode ser estudado em diferentes abordagens. O objetivo do nosso estudo foi identificar o perfil transcricional e as redes de interação entre um grupo de microRNAs e seus respectivos alvos nos timócitos e linfócitos T CD3+ periféricos nos camundongos da linhagem DBA-1/J e DBA-2/J. Para a avaliação da expressão gênica, utilizou-se a tecnologia de microarrays. O uso de programas de análise e para a construção das redes foi imprescindível. Os resultados encontrados evidenciam uma expressão diferenciada de mRNAs e microRNAs em timócitos e linfócitos T CD3+ periféricos entre as duas linhagens utilizadas. Novos microRNAs foram encontrados nos diferentes estágios de desenvolvimento do linfócito T. Nas redes de interação microRNA-RNAm obtidas, genes importantes associados aos processos de sistema imune, adesão e diferenciação celular, apoptose, recombinação, ativação de linfócitos T e resposta inflamatória, foram encontrados como potenciais alvos. Além disso, em uma perspectiva clínica, baseados nos resultados obtidos em camundongo, nos encontramos a expressão do miR-505 nos linfócitos T de pacientes com AR. Nossos resultados contribuem para a melhor compreensão dos mecanismos molecular envolvidos na resistência/susceptibilidade a CIA. / MicroRNAs (miRNAs) are small non-coding RNA molecules that modulate the expression of multiple protein-encoding genes at the post-transcriptional level. During the last several years, evidence has emerged to show their critical role for the regulation and development of immune system. Although the function of most mammalian miRNAs has yet to be determined, their aberrant expression has been associated with several autoimmune conditions, including rheumatoid arthritis (RA). Recently, the deregulated expression of a dozen miRNAs has been reported in patients with RA, and the pathogenic role of only a few of these has been investigated in experimental mouse models. RA is a systemic autoimmune disorder mainly characterized by the inflammation of synovial tissue that can lead to destruction of bone and cartilage. The role of effectors T cells in induction, maintenance and progression of the disease is now becoming better understood. Collagen-induced arthritis is an animal model widely studied due to its similarities to human disease. The DBA-1/J mouse strain develops arthritis after immunization process and booster with Type II collagen, and the DBA-2/J strain is refractory to the disease induction. This offers an useful susceptibility/resistance model-system to study RA. The aim of this study was to identify the expression profiles and interaction networks between a set of microRNAs and their mRNA targets in thymocytes and peripheral CD3+ T lymphocytes in DBA-1/J and DBA-2/J mice strain. For this purpose we used the microarray technology to evaluate the expression of the miRNAs and mRNAs as possible targets involved in this process. The use of bioinformatics software to reconstruct the networks was essential. The results show differential expression of mRNAs and miRNAs in thymocytes and peripheral CD3+ T lymphocytes between both strains. New miRNAs were found during all the stages of T cells development. The microRNA-mRNA interaction networks obtained in this study showed that important genes related to apoptose, immune system, recombination, cell adhesion and differentiation, inflammatory process and T cell activation were found as potential targets. In addition, in a clinical prospects, based on the results obtained in mice, we found the expression of the miRNA miR-505 in T cells of RA patients. Our results contribute to a better understand of the molecular mechanisms evolved in the resistance/susceptibility to CIA.
548

Análise global da expressão de RNAs não codificadores no sistema imunológico humano na senescência e sepse / Non coding RNA global expression analysis in the human immune system in sepsis and aging

Pellegrina, Diogo Vieira da Silva 28 July 2016 (has links)
A sepse é uma das maiores causas de mortalidade em pacientes hospitalizados, e uma complicação comum, tanto em pacientes clínicos quanto de cirurgias, admitidos em hospitais por causas não infecciosas. A sepse é especialmente comum em pacientes mais velhos, sendo portanto esperado que sua incidência aumente com o envelhecimento da população, e apesar da sua maior taxa de mortalidade, a resposta imune em idosos durante o choque séptico é muito similar à dos pacientes mais jovens. O objetivo desse estudo foi de conduzir uma análise de expressão gênica dos neutrófilos da circulação, tanto de pacientes adultos como de pacientes idosos, observando tanto os mRNAs e as vias em que estão envolvidos, como o papel dos ncRNAs, para um melhor entendimento da resposta imune do indivíduo idoso a infecções severas. Os RNAs de 24 indivíduos, divididos igualmente entre idosos e adultos, e entre pacientes em choque séptico e controles, foram hibridizadas em microarranjos de DNA. Deste experimento foram encontrados genes cuja expressão pode ser utilizada para diferenciar a resposta imune entre adultos e idosos. Estes genes foram observados concentrados em algumas vias, entre elas fosforilação oxidativa, disfunção mitocondrial, sinalização do TGF-, entre outras. Além da análise usando os mRNAs, esse trabalho mostra fortes indicações de interações de mRNAs com RNAs não codificadores longos, dos quais a maioria não têm função conhecida. Para propor uma função aos RNAs não codificadores foi construída uma rede de coexpressão em que alguns RNAs de função desconhecida se mostraram fortemente ligados à genes das vias moleculares do ribossomo e da mitocôndria. Também foi observado que para os idosos a rede de coexpressão é menos centralizada, suportando a hipótese de que alterar a expressão de alguns genes chave pode ser o fator determinante para alterar a expressão gênica e um conjunto maior / Sepsis is one of the major causes of mortality in hospitalized patients, and a common complication, both in clinical patients and in surgeries, admitted to hospital for non-infectious causes. Sepsis is especially common in older patients, and is therefore expected that its incidence increases as the population ages, and despite its higher mortality rate, the immune response in the elderly during septic shock is very similar to that of younger patients. The objective of this study was to conduct a gene expression analysis of circulating neutrophils, both adults and elderly patients, noting both the mRNAs, the pathways in which those are involved, and the role of ncRNAs, for a better understanding of the immune response of the elderly to severe infections. The RNAs of 24 individuals, equally divided among the adults and the elderly, and among patients in septic shock and controls, were hybridized to DNA microarrays. From this experiment many genes whose expression can be used to differentiate the immune response in adults and the elderly were found. These genes were concentrated in some metabolic pathways, including oxidative phosphorylation, mitochondrial dysfunction, TGF- signaling, and others. Besides the analysis using mRNAs, this work shows strong indications of mRNAs interactions with non coding RNAs, most of which have no known function. To propose a role for noncoding RNAs a coexpression network was built in which some RNAs of unknown function showed strongly connected to genes of the molecular pathways of the ribosome and mitochondria. It was also noted that for the elderly, the coexpression network is less centralized, supporting the hypothesis that altering the expression of a few key genes can be a determining factor for altering the gene expression of a larger set
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Genetic Imbalances in Endometriosis Detected by Oligonucleotide-Array Based Comparative Genomic Hybridization

Burke, Natalie 01 May 2013 (has links)
Endometriosis is one of the most common gynecological diseases as it is thought to affect up to 15% of the female population. Characterized by the growth and proliferation of endometrial tissue outside of the uterine cavity, it is a complex condition with varying degrees of severity and can affect multiple regions of the body with symptoms ranging from a total lack of symptoms to debilitating pain and infertility. The most accepted theory of how endometriosis initiates is that of retrograde menstruation; however, approximately 90% of women with unobstructed fallopian tubes are thought to have some menstrual debris in the peritoneal cavity. Therefore, this theory does not explain in full why endometriosis occurs in some but not all women who experience retrograde bleeding. Genetic factors are thought to play a major role in the pathogenesis of endometriosis as women with a family history are 5 to 10 times more likely to develop the disease. The goal of this study was to determine if common chromosomal aberrations in the form of additions, deletions, or regions of loss of heterozygosity that may contribute to the establishment or progression of the disease are present in a population of endometriosis patients. DNA was isolated from the peripheral blood of endometriosis patients and endometriosis tissue biopsies, and it was analyzed using oligonucleotide based array comparative genomic hybridization. The results suggest that an addition on chromosome 17p13.3 may play a role in the biological mechanisms involved in endometriosis as it was identified in 75% of the DNA samples obtained from the peripheral blood and 100% of the DNA samples obtained from the tissue biopsies. This chromosomal imbalance is of particular interest as it is located in a region that harbors the tumor suppressor gene, hypermethylated in cancer-1 (HIC-1), whose aberrant expression has been reported in multiple cancers. Endometriosis has long been thought of as a benign disease despite its malignant characteristics, and individuals with endometriosis have been demonstrated to have an increased chance of developing ovarian cancer. This was the first study to examine the DNA from endometriosis patients using oligonucleotide based array comparative genomic hybridization to investigate genetic abnormalities in endometriosis. The findings may provide a novel target for future therapeutic options as well as indicate a link between endometriosis and cancer that has not been previously reported.
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Mise en oeuvre de microréseaux de lectines naturelles et recombinantes dédiés au suivi de production des glycoprotéines d'intérêt thérapeutique / Development of natural and recombinant lectin microarrays for monitoring the production of glycosylated protein drugs

Machon, Oriane 12 June 2019 (has links)
Mise en oeuvre de microréseaux de lectines naturelles et recombinantes dédiés au suivi de production des glycoprotéines d’intérêt thérapeutiqueLes anticorps thérapeutiques, biomédicaments dont le marché est en pleine expansion, sont des glycoprotéines obtenues en bioproduction dans des cellules eucaryotes. Leur N-glycosylation, cruciale pour la modulation des fonctions effectrices des anticorps, confère un effet pro-inflammatoire ou anti-inflammatoire aux anticorps. Les anticorps thérapeutiques recombinants actuellement commercialisés présentent des glycosylations dites tronquées (GlcNAc terminaux) ou non humaines (α-Gal, NeuGc) rendant les anticorps immunogènes et, par conséquent, réduisant notablement leur efficacité. Les Agences de Santé exigent de réduire cet effet secondaire. La société SiaMed’Xpress a développé un savoir-faire pour obtenir une glycosylation complète, incluant la sialylation terminale des N-glycanes par ingénierie des cellules eucaryotes. Il est nécessaire de disposer d’outils d’analyse permettant de suivre la qualité de la N-glycosylation au cours de la production.La modification du milieu de culture par ajout de suppléments nutritionnels permet une modulation supplémentaire de la glycosylation. L’utilisation de suppléments nutritionnels commerciaux augmentent le taux de production mais bloquent la glycosylation au stade G0(F) (GlcNAc terminaux) alors que l’utilisation d’un supplément propre à SiaMed’Xpress permet de poursuivre jusqu’à la galactosylation et la sialylation, mettant ainsi en évidence un carrefour métabolique clé dans la glycosylation. Pour suivre les modifications de glycosylation dans différentes conditions de production, un test utilisant des lectines a été développé. Un jeu de treize lectines naturelles et recombinantes a été sélectionné par analyse bio-informatique et intégré dans un glycotest. L’utilisation de ce glycotest pour l’analyse de la glycosylation de trois anticorps produits en présence de différents suppléments nutritionnels permet d’obtenir de façon rapide, fiable et reproductible les profils de glycosylation des anticorps. Ainsi, le glycotest développé est fonctionnel et permet de caractériser la glycosylation des anticorps thérapeutiques recombinants. / Development of natural and recombinant lectin microarrays for monitoring the production of glycosylated protein drugsTherapeutic antibodies, biologic drugs whose market is growing, are glycoproteins obtained though bioproduction in eukaryotic cells. Their N-glycosylation, which is crucial for the modulation of effector functions, confers a pro-inflammatory or anti-inflammatory effect to antibodies. Currently, marketed therapeutic recombinant antibodies have truncated (terminal GlcNAc) or non human (α-Gal, NeuGc) glycosylation, inducing immunologic reaction and, consequently, reducing their effectiveness. Health agencies demand to reduce such secondary effects. SiaMed’Xpress developped a knowledge to obtained a complete glycosylation, including terminal sialylation of N-glycans by engineering eukaryotic cells for production. It is now necessary to develop analysis tools to monitor the quality of the N-glycosylation during bioproduction.Modification of culture media with feeds allows to further modulate glycosylation. The use of marketed feeds increase the production rate but block the glycosylation process in the G0(F) state (terminal GlcNAc) whereas SiaMed’Xpress feed allows for galactosylation and sialylation, highlighting a metabolic key point during the glycosylation. To follow the glycosylation modifications under different conditions of production, an assay using lectins has been developed. A panel of 13 lectins, recombinants and naturals, has been determined by bio-informatic analysis and integrated into a glycotest. The use of this glycotest to analyse glycosylation of 3 antibodies produced with different feeds allows fast, reliable and reproductible glycosylation profils of these antibodies. So, this developped glycotest is functionnal and this using permits to monitore therapeutic recombinant antibody glycosylation during bioproduction.

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