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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.
11

Polimorfismos GSTM1, GSTT1 e GSTP1 da enzima Glutationa S-transferase como fatores moduladores do fenótipo na anemia falciforme

Barberino, Willian Marcel [UNESP] 28 February 2014 (has links) (PDF)
Made available in DSpace on 2015-04-09T12:28:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-28Bitstream added on 2015-04-09T12:47:33Z : No. of bitstreams: 1 000811540.pdf: 772912 bytes, checksum: 9fe40489ccb3153a59c8440d6126a541 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A anemia falciforme (AF) é uma anemia hemolítica hereditária que acarreta ao portador manifestações clínicas complexas e diversificadas. Na AF o estresse oxidativo é um dos fatores que interferem no fenótipo do portador, uma vez que influencia nos processos de vaso-oclusão aumentando as propriedades adesivas dos eritrócitos, leucócitos e plaquetas ao endotélio. Durante a transformação do eritrócito discóide com hemoglobina (Hb) S em eritrócito afoiçado, dentre os eventos bioquímicos e polimerizantes da célula, ocorre a degradação oxidativa dessa Hb, com a liberação agentes pró-oxidantes. Estes promovem a oxidação de lipídeos e também de proteínas e DNA, modificando mecanismos celulares que levam a célula a apoptose e, consequentemente, causam danos aos tecidos. Neste contexto, os principais meios de defesa no organismo são divididos em dois grupos, enzimáticos e não enzimáticos. Entre as enzimas detoxificantes de fase II mais estudadas estão as GSTs, que pertencem a uma família multifuncional de enzimas que catalisam a conjugação da molécula de GSH e possuem papel fundamental em mecanismos de defesa contra compostos endo e xenobióticos. Considerando a grande incidência da AF em nosso país e as manifestações clínicas diferenciadas nos portadores, o presente trabalho pretendeu investigar os polimorfismos das GSTs (GSTM1, GSTT1 e GSTP1) e verificar sua influência sob parâmetros oxidativos – peroxidação lipídica por TBARS, e lesão de DNA pela avaliação de Corpos de Howell-Jolly e Ensaio Cometa em portadores da AF. Foram avaliadas amostras de 91 indivíduos com AF com e sem o uso de HU e 99 amostas de um grupo controle. Para o desenvolvimento do trabalho, as amostras foram separadas em três grupos: indivíduos portadores de anemia falciforme em uso de hidroxiureia (AF + HU: 46 indivíduos), indivíduos portadores de anemia falciforme sem uso de hidroxiureia (AF – HU: 45 indivíduos) e o grupo ... / Sickle cell anemia (SCA) is an inherited hemolytic disease that leads complex and diverse clinical manifestations. In SCA, oxidative stress is one of the factors that affect the phenotype of the carrier, in response of its influences on vaso-occlusion processes that increases the adhesive properties of erythrocytes, leukocytes and platelets to the endothelium. During the transformation of discoid erythrocytes with hemoglobin (Hb) S into sickle cells, among the biochemical and polymerizing events, the oxidative degradation of this Hb occurs, releasing pro-oxidants agents. They promote oxidation of lipids and proteins and modify cellular mechanisms that lead to cell apoptosis and cause tissue damage. In this context, the main means of body defense are divided in two groups: enzymatic and non-enzymatic. Among the phase II detoxifying enzymes, the most studied are Glutathione S-transferases (GSTs), which belong to a family of multifunctional enzymes that catalyze the combination of the glutathione (GSH) molecule and have a central role in mechanisms of defense against xenobiotic compounds. Considering the high incidence of SCA in our country and the different clinical manifestations in patients, this study aimed to investigate polymorphisms of GSTs (GSTM1 , GSTT1 and GSTP1 ) and determine its influence on oxidative parameters - lipid peroxidation by TBARS and DNA damage by evaluation of Howell -Jolly bodies (HJB) and comet assay in patients with SCA. Samples of 91 patients with SCA with and without hydroxyurea (HU) use and 99 samples of a control group were evaluated. For the work development, the samples were separated into three groups: individuals with sickle cell anemia using hydroxyurea (SCA + HU: 46 individuals), individuals with sickle cell disease without use of hydroxyurea (SCA - HU: 45 individuals) and control group (CG: 99 individuals) to verify the influence of medication on the evaluated parameters. Only the genotypic profile ...
12

Determinantes genéticos, bioquímicos e clínicos na resposta ao uso de hidroxiureia na doença falciforme

Belini Júnior, Édis [UNESP] 24 February 2014 (has links) (PDF)
Made available in DSpace on 2014-12-02T11:16:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-24Bitstream added on 2014-12-02T11:21:27Z : No. of bitstreams: 1 000799353_20160224.pdf: 289799 bytes, checksum: 0b2547aa37c5af1df5323abf3c3ac04e (MD5) Bitstreams deleted on 2016-02-24T11:27:50Z: 000799353_20160224.pdf,. Added 1 bitstream(s) on 2016-02-24T11:28:33Z : No. of bitstreams: 1 000799353.pdf: 4598958 bytes, checksum: c90c43cb77dd0d3eaea210da3979de05 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A doença falciforme (DF) é caracterizada por heterogeneidade clínica variando de pessoas com relativamente poucas complicações clínicas e expectativa de vida normal, até aqueles com complicações graves, como hipertensão pulmonar, priapismo, acidente vascular cerebral (AVC), úlceras de perna, episódios de dor, síndrome torácica aguda (STA) e osteonecrose. O tratamento com a hidroxiureia (HU) tem conquistado espaço na terapia adotada pelos clínicos e sua experiência na DF vem sendo acumulada ao longo dos últimos 25 anos. Porém, muitos estudos têm sido elaborados para investigar as variações genéticas que possam explicar o porquê de alguns pacientes tolerarem e respondem ao uso de HU, enquanto, outros ainda precisam ser tratados por terapias alternativas. Diante disso, nosso objetivo foi avaliar a resposta ao tratamento com a HU considerando a influência dos polimorfismos genéticos envolvidos na fisiopatologia da DF. Para isso, usamos a calculadora de gravidade da DF (CGDF); rastreamos os polimorfismos -509C/T (TGFB1), -308G/A (TNFA), 313 A/G (GSTP1), -786T/C (NOS3), nulos (GSTM1 e GSTT1); e avaliamos os marcadores de estresse oxidativo (catalase, glutationa peroxidase-GPx, glutationa S-transferase-GST, glutationa redutase-GR e as espécies reativas ao ácido tiobarbitúrico-TBARS). O estudo envolveu 520 pacientes, acima de cinco anos de idade, provenientes do Instituto de Hematologia do Rio de Janeiro/RJ-HEMORIO. A CGDF foi validada para os pacientes brasileiros e os escores de gravidade foram relacionados com os marcadores de estresse oxidativo. Em relação aos polimorfismos, a presença do alelo nulo do gene GSTM1 aumentou a chance de ocorrência de priapismo em pacientes com a DF. A mutação do gene TGFB1 mostrou efeito protetor na ocorrência de STA e úlceras de perna, e à presença do alelo mutante para o gene NOS3 diminuiu a chance de ocorrência de retinopatia e priapismo. Para os marcadores bioquímicos, ... / Sickle cell disease (SCD) is characterized by a very heterogeneous clinical ranging from patients who have normal life expectancy with relatively few complications; others can have severe complications such as pulmonary hypertension, priapism, stroke, leg ulceration, recurrent painful episodes, acute chest syndrome (ACS) and avascular necrosis of bone (AVN). Treatment with hydroxyurea (HU) has become more adopted by medical and HU experience in DF has been accumulated over the last 25 years. However, many studies have been designed to investigate the genetic variations that may explain why some patients tolerate and respond to the use of HU, while others still need to be treated with alternative therapies. In view of this, we aimed to evaluate the response to HU treatment considering the genetic polymorphisms influence involved in the pathophysiology of SCD. For this, we used the calculator severity of DF (CGDF); detected the polymorphisms -509C/T (TGFB1), -308G/A (TNFA), 313 A/G (GSTP1), -786T/C (NOS3), null (GSTM1 and GSTT1), we assessed markers of oxidative stress (catalase, glutathione peroxidase-GPx, glutathione S-transferase-GST, glutathione reductase-GR and the thiobarbituric acid reactive species-TBARS). The study involved 520 patients older than 5 years, from the Instituto de Hematologia do Rio de Janeiro/RJ-HEMORIO. The CGDF was validated for Brazilian patients and severity scores were related to oxidative stress markers. The presence of the GSTM1 null allele increased the occurrence chance of priapism in SCD patients. TGFB1 gene mutation had a protective effect on the occurrence of STA and leg ulcers, and the presence of the mutant allele for the NOS3 gene decreased the occurrence chance of retinopathy and priapism. For biochemical markers, we found that the decreased of enzymes activity (catalase, Gpx and GR), and the increased in GST activity were associated with greater SCD severity. In addition, lipid peroxidation levels ...
13

O papel da angiogênese e da hemólise na úlcera de perna de pessoas com anemia falciforme /

Oliveira, Renan Garcia de. January 2016 (has links)
Orientador: Claudia Regina Bonini-Domingos / Banca: Flávio Augusto Naoum / Banca: Ana Paula Girol / Resumo: A anemia falciforme (AF) é uma anemia hemolítica hereditária, autossômica recessiva, causada pela mutação em um único nucleotídeo no gene da beta globina (HBB:c.20A>T). Essa alteração resulta na produção de uma hemoglobina anormal, denominada hemoglobina S (Hb S). Em condições de hipóxia, essas hemoglobinas se polimerizam dentro do eritrócito, ocasionando alteração em sua estrutura e resultando na formação de eritrócitos falciformes, que são menos flexíveis, aderem ao endotélio e são propensos à hemólise, favorencendo os dois principais eventos fisiopatológicos da AF, a hemólise e a vasoclusão, que dirigem os processos envolvidos nos diferentes tipos de manifestações clínicas que esses indivíduos podem apresentar ao longo da vida. A úlcera de perna é uma condição clínica frequente nesses indivíduos e a etiologia dessa complicação pode estar relacionada a eventos hemolíticos e angiogênicos. Dessa forma, o objetivo desse trabalho foi avaliar a presença de marcadores hemolíticos e de angiogenese em pacientes com AF, na presença ou ausência de úlcera de perna, a fim de contribuir com o entendimento a respeito dos mecanismos envolvidos na ocorrência de tal manifestação clínica. Para isso, foram avaliados os polimorfismos que regulam a expressão de proteínas que participam do processo de angiogênese, como TGF-β1, VEGFA1 e HIF-1α; os marcadores de hemólise, como níveis de hemoglobina (Hb), lactato desidrogenase (LDH), bilirrubina indireta (BI), aspartato aminotransferase (AST) e... / Abstract: The sickle cell anemia (SCA) is an inherited hemolytic anemia, autosomal recessive, caused by mutations in a single nucleotide in the beta globin gene (HBB:c.20A>T). This change results in production of an abnormal hemoglobin called hemoglobin S (Hb S). In hypoxic conditions, these hemoglobins polymerize within the erythrocyte, causing changes in their structure and resulting in the formation of sickle erythrocytes, which are less flexible, adhere to the endothelium and are prone to hemolysis, favoring the two main pathophysiological events of alpha hemolysis and vasoclusão, driving the processes involved in different types of clinical manifestations that these individuals may have lifelong. The leg ulcer is a common clinical condition of these individuals and the etiology of this complication may be related to haemolytic and angiogenic events. Thus, the objective of this study was to evaluate the presence of hemolytic markers and angiogenesis in patients with AF in the presence or absence of leg ulcer in order to contribute to the understanding of the mechanisms involved in the occurrence of such clinical manifestation. For this, we evaluated the polymorphisms that regulate the expression of proteins involved in the angiogenesis process, such as TGF-β1, VEGFA1 and HIF-1α; the markers of hemolysis, such as hemoglobin (Hb), lactate dehydrogenase (LDH), bilirubin indirect (BI), aspartate aminotransferase (AST) and reticulocyte count (RET); addition of protein synthesis of VEGFA ... / Mestre
14

Relação entre o índice de massa corpórea, diabetes mellitus tipo 2, estresse oxidativo e polimorfismos nos genes da enzima conversora de angiotensina (ECA) e metilenotetrahidrofolato redutase (MTHRF) /

Pirozzi, Flavio Fontes. January 2016 (has links)
Orientador: Milton Artur Ruiz / Coorientador: Claudia Regina Bonini Domingos / Banca: Antônio Carlos Pires / Banca: Sônia Maria Oliani / Resumo: Introdução: o aumento da prevalência da obesidade e do diabetes mellitus tipo 2 (DM2) é um grande desafio de saúde pública mundial e, por serem doenças heterogêneas e que elevam a chance do surgimento de doenças cardiovasculares, parâmetros de avaliação de risco são necessário na avaliação destes indivíduos. Objetivos: correlacionar diferentes variáveis como o índice de massa corpórea (IMC), os polimorfismos I/D ECA e C677T MTHFR e provas de estresse oxidativo em uma população de obesos brasileiros, com e sem diabetes, e doenças associadas com a síndrome metabólica. Casuística e métodos: avaliamos 125 indivíduos com obesidade (IMC maior ou igual a 30 Kg/m2 ) que foram divididos em dois grupos: grupo DM2 (obesos com DM2, n = 47) e grupo controle (obesos sem DM2, n= 78). Os pacientes do grupo DM2 apresentavam maior média de idade (p=0,02) e maior número de indivíduos com dislipidemia (p<0,05). Por meio de uma amostra de sangue periférico foi avaliado os polimorfismos I/D ECA e C677T MTHRF e as provas de estresse oxidativo, o TBARS e o TEAC. Resultados: na comparação entre os grupos com os polimorfismos analisados, não encontramos diferença significativa de chance de ocorrência e proteção para o DM2 em diferentes modelos de herança, na avaliação dos genótipos e no sinergismo entre eles. No polimorfismo I/D ECA, o genótipo mais frequente em ambos os grupos é o DD. Também não encontramos diferença significativa destes polimorfismos e as complicações microvasculares no grupo DM2. Correlacionando o IMC com o estresse oxidativo, encontramos uma correlação diretamente com o TBARS (r =0,7941) e inversamente proporcional com o TEAC (r=-0,6022) de forma significativa (p<0,0001). Entretanto, não houve diferença nos valores médios de TBARS e do TEAC entre os grupos DM2 e controle. O genótipo DD foi o mais frequente em ambos e o mesmo... / Abstract: Introduction: the increase in the prevalence of obesity and type 2 diabetes mellitus (T2DM) is a major global public health challenge and, because they are heterogeneous diseases that increase the chance of cardiovascular diseases, risk assessment parameters are necessary in the evaluation of these individuals. Aims: to correlate different variables such as body mass index (BMI), ACE I/D and MTHFR C677T polymorphisms, and oxidative stress tests in a population of obese Brazilians, with and without diabetes, and diseases associated with metabolic syndrome. Casuistry and methods: we evaluated 125 individuals with obesity (BMI greater than or equal to 30 kg /m 2 ) who were divided into two groups: T2DM group (obese with T2DM, n = 47) and control group (obese without T2DM, n = 78). Patients in the T2DM group presented higher mean age (p=0.02) and higher number of individuals with dyslipidemia (p<0.05). The ACE I/D and MTHRF C677T polymorphisms and the oxidative stress, TBARS and TEAC tests, were evaluated using a peripheral blood sample. Results: in the comparison between the groups with the analyzed polymorphisms, we do not find a significant difference in the chance of occurrence and protection for T2D in different inheritance models, in the evaluation of genotypes and in the synergism between them. In the ACE I/D polymorphism, the most frequent genotype in both groups is DD. We also do not find a significant difference of these polymorphisms and the microvascular complications in the T2DM group. Relating BMI to oxidative stress, we found a correlation directly with TBARS (r=0.7941) and inversely proportional to the TEAC (r =-0.6022) in a significant way (p <0.0001). However, there was no difference in the mean values of TBARS and TEAC between T2DM and control groups. The DD genotype was the most frequent in both, and the same is related to increased cardiovascular risk. In the ... / Mestre
15

Etude génétique de maladies rares chez des patients issus de mariages consanguins

Désir, Julie 06 February 2009 (has links)
La découverte du défaut moléculaire en cause dans les maladies rares est une étape importante en vue d'un traitement spécifique ainsi que d'un meilleur diagnostic, ce qui permet de réduire le délai diagnostique, de mieux connaître l'histoire naturelle de la maladie, et ainsi d'améliorer les traitements symptomatiques et la prévention secondaire. Les gènes de plus de 1500 maladies rares monogéniques restent à découvrir. Beaucoup de maladies rares qui frappent les enfants de parents en bonne santé correspondent à des maladies génétiques récessives autosomiques. Certaines paraissent extrêmement rares mais, une fois le gène identifié dans une famille princeps, beaucoup d'autres cas s'avèrent dus à des défauts du même gène. Les patients que nous étudions sont issus de familles consanguines comptant souvent de nombreux sujets atteints. Une seule famille de ce type peut permettre l'identification du gène par cartographie d'homozygotie et clonage positionnel.<p>Nous avons recruté dans ce travail des cas familiaux ou sporadiques de six maladies autosomiques récessives rares de gène inconnu. <p>La stratégie de cartographie par homozygotie nous a permis de mettre en évidence de nouveaux loci morbides dans quatre de ces maladies (épilepsie myoclonique progressive EPM3 ;syndrome marfanoïde avec microsphérophakie ;atrophie optique isolée ;et syndrome de microcéphalie et diabète précoce) ou de réduire la taille de loci déjà connus (microcéphalies primaires MCPH2 et MCPH4 ;et syndrome de Harboyan CDPD1). Nous avons pu caractériser de nouvelles mutations dans les gènes déjà connus ASPM (microcéphalie primaire MCPH5) et SLC4A11 (syndrome de Harboyan) et corréler celles-ci aux données cliniques. Enfin nous avons identifié les gènes KCTD7 et LTBP2 comme responsables respectivement des maladies EPM3 et syndrome marfanoïde avec microsphérophakie, en y découvrant des mutations chez les malades.<p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished
16

Determinantes genéticos, bioquímicos e clínicos na resposta ao uso de hidroxiureia na doença falciforme /

Belini Júnior, Édis. January 2014 (has links)
Orientador: Claudia Regina Bonini Domingos / Banca: Luiz Carlos de Mattos / Banca: Ana Elizabete Silva / Banca: Paulo Caleb Junior de Lima Santos / Banca: Isabeth da Fonseca Estevão / Resumo: A doença falciforme (DF) é caracterizada por heterogeneidade clínica variando de pessoas com relativamente poucas complicações clínicas e expectativa de vida normal, até aqueles com complicações graves, como hipertensão pulmonar, priapismo, acidente vascular cerebral (AVC), úlceras de perna, episódios de dor, síndrome torácica aguda (STA) e osteonecrose. O tratamento com a hidroxiureia (HU) tem conquistado espaço na terapia adotada pelos clínicos e sua experiência na DF vem sendo acumulada ao longo dos últimos 25 anos. Porém, muitos estudos têm sido elaborados para investigar as variações genéticas que possam explicar o porquê de alguns pacientes tolerarem e respondem ao uso de HU, enquanto, outros ainda precisam ser tratados por terapias alternativas. Diante disso, nosso objetivo foi avaliar a resposta ao tratamento com a HU considerando a influência dos polimorfismos genéticos envolvidos na fisiopatologia da DF. Para isso, usamos a calculadora de gravidade da DF (CGDF); rastreamos os polimorfismos -509C/T (TGFB1), -308G/A (TNFA), 313 A/G (GSTP1), -786T/C (NOS3), nulos (GSTM1 e GSTT1); e avaliamos os marcadores de estresse oxidativo (catalase, glutationa peroxidase-GPx, glutationa S-transferase-GST, glutationa redutase-GR e as espécies reativas ao ácido tiobarbitúrico-TBARS). O estudo envolveu 520 pacientes, acima de cinco anos de idade, provenientes do Instituto de Hematologia do Rio de Janeiro/RJ-HEMORIO. A CGDF foi validada para os pacientes brasileiros e os escores de gravidade foram relacionados com os marcadores de estresse oxidativo. Em relação aos polimorfismos, a presença do alelo nulo do gene GSTM1 aumentou a chance de ocorrência de priapismo em pacientes com a DF. A mutação do gene TGFB1 mostrou efeito protetor na ocorrência de STA e úlceras de perna, e à presença do alelo mutante para o gene NOS3 diminuiu a chance de ocorrência de retinopatia e priapismo. Para os marcadores bioquímicos,... / Abstract: Sickle cell disease (SCD) is characterized by a very heterogeneous clinical ranging from patients who have normal life expectancy with relatively few complications; others can have severe complications such as pulmonary hypertension, priapism, stroke, leg ulceration, recurrent painful episodes, acute chest syndrome (ACS) and avascular necrosis of bone (AVN). Treatment with hydroxyurea (HU) has become more adopted by medical and HU experience in DF has been accumulated over the last 25 years. However, many studies have been designed to investigate the genetic variations that may explain why some patients tolerate and respond to the use of HU, while others still need to be treated with alternative therapies. In view of this, we aimed to evaluate the response to HU treatment considering the genetic polymorphisms influence involved in the pathophysiology of SCD. For this, we used the calculator severity of DF (CGDF); detected the polymorphisms -509C/T (TGFB1), -308G/A (TNFA), 313 A/G (GSTP1), -786T/C (NOS3), null (GSTM1 and GSTT1), we assessed markers of oxidative stress (catalase, glutathione peroxidase-GPx, glutathione S-transferase-GST, glutathione reductase-GR and the thiobarbituric acid reactive species-TBARS). The study involved 520 patients older than 5 years, from the Instituto de Hematologia do Rio de Janeiro/RJ-HEMORIO. The CGDF was validated for Brazilian patients and severity scores were related to oxidative stress markers. The presence of the GSTM1 null allele increased the occurrence chance of priapism in SCD patients. TGFB1 gene mutation had a protective effect on the occurrence of STA and leg ulcers, and the presence of the mutant allele for the NOS3 gene decreased the occurrence chance of retinopathy and priapism. For biochemical markers, we found that the decreased of enzymes activity (catalase, Gpx and GR), and the increased in GST activity were associated with greater SCD severity. In addition, lipid peroxidation levels ... / Doutor
17

In vivo analysis of human LHX3 enhancer regulation

Park, Soyoung 03 January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The LHX3 transcription factor is essential for pituitary gland and nervous system development in mammals. In humans, mutations in the LHX3 gene underlie combined pituitary hormone deficiency (CPHD) disease featuring deficits in anterior pituitary hormones and defects in the nervous system. The mechanisms that control temporal and spatial expression of the LHX3 gene are poorly understood. The proximal promoters of the human LHX3 gene are insufficient to guide expression in vivo and downstream elements including a conserved 7.9 kilobase (kb) enhancer region appear to play a role in tissue-specific expression in the pituitary and nervous system. In this study, I characterized the activity of this downstream enhancer region in regulating gene expression at the cellular level during development. Human LHX3 enhancer-driven Cre reporter transgenic mice were generated to facilitate studies of enhancer actions. The downstream LHX3 enhancer primarily guides gene transcription in αGSU-expressing cells secreting the TSHβ, LHβ or FSHβ hormones and expressing the GATA2 and SF1 transcription factors. In the developing nervous system, the enhancer serves as a targeting module for expression specifically in V2a interneurons. These results demonstrate that the downstream LHX3 enhancer is important in specific endocrine and neural cell types but also indicate that additional regulatory elements are likely involved in LHX3 gene expression in other cell types. Further, these studies demonstrate significant gonadotrope cell heterogeneity during pituitary development, providing insights into the cellular physiology of this key reproductive regulatory cell. The human LHX3 enhancer-driven Cre reporter transgenic mice provide a valuable tool for further developmental studies of cell determination and differentiation in the pituitary and nervous system. Furthermore understanding the regulation of human LHX3 gene will help develop tools to better diagnose and treat pituitary CPHD disease.
18

Transcription regulation of the class II alcohol dehydrogenase 7 (ADH7)

Jairam, Sowmya January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The class IV alcohol dehydrogenase (ADH7, µ-ADH, σ-ADH) efficiently metabolizes ethanol and retinol. ADH7 is expressed mainly in the upper gastrointestinal tract with no expression in the liver unlike the other ADHs, and is implicated in various diseases including alcoholism, cancer and fetal alcohol syndrome. Genome wide studies have identified significant associations between ADH7 variants and alcoholism and cancer, but the causative variants have not been identified. Due to its association with two important metabolic pathways and various diseases, this dissertation is focused on studying ADH7 regulation and the effects of variants on this regulation using cell systems that replicate endogenous ADH7 expression. We identified elements regulating ADH7 transcription and observed differences in the effects of variants on gene expression. A7P-G and A7P-A, two promoter haplotypes differing in a single nucleotide at rs2851028, had different transcriptional activities and interacted with variants further upstream. A sequence located 12.5 kb upstream (7P10) can function as an enhancer. These complex interactions indicate that the effects of variants in the ADH7 regulatory elements depend on both sequence and cellular context, and should be considered in interpretation of the association of variants with alcoholism and cancer. The mechanisms governing the tissue-specific expression of ADH7 remain unexplained however. We identified an intergenic region (iA1C), located between ADH7 and ADH1C, having enhancer blocking activity in liver-derived HepG2 cells. This enhancer blocking function was cell- and position- dependent with no activity seen in CP-A esophageal cells. iA1C had a similar effect on the ectopic SV40 enhancer. The CCCTC-binding factor (CTCF) bound iA1C in HepG2 cells but not in CP-A cells. Our results suggest that in liver-derived cells, iA1C blocks the effects of downstream ADH enhancers and thereby contributes to the cell specificity of ADH7 expression. Thus, while genetic factors determine level of ADH7 transcriptional activity, iA1C helps determine the cell specificity of transcription.
19

Myeloid cells induce neurofibromatosis type 1 aneurysm formation through inflammation and oxidative stress

Downing, Brandon David January 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Neurofibromatosis Type 1 (NF1) is a genetic disorder resulting from mutations in the NF1 tumor suppressor gene. Neurofibromin is the protein product of NF1 and functions as a negative regulator of Ras activity in both hematopoietic and vascular wall cells, which are critical for maintaining blood vessel homeostasis. NF1 patients are predisposed to chronic inflammation and premature cardiovascular disease, including development of large arterial aneurysms, which may result in sudden death secondary to their rupture. However, the molecular pathogenesis of NF1 aneurysm formation is completely unknown. Utilizing a novel model of Nf1 murine aneurysm formation, we demonstrate that heterozygous inactivation of Nf1 (Nf1+/-) results in enhanced aneurysm formation with myeloid cell infiltration and increased reactive oxygen species in the vessel wall. Using cell lineage-restricted transgenic mice, we show that loss of a single Nf1 allele in myeloid cells is sufficient to recapitulate the Nf1+/- aneurysm phenotype in vivo. Additionally, oral administration of simvastatin, a statin with antioxidant and anti-inflammatory effects, significantly reduced aneurysm formation in Nf1+/- mice. Finally, the antioxidant apocynin was administered orally and also resulted in a significant reduction of Nf1+/- aneurysms. These data provide genetic and pharmacologic evidence that neurofibromin-deficient myeloid cells are the central cellular triggers for aneurysm formation in a novel model of NF1 vascular disease, implicated oxidative stress as the key biochemical mechanisms of NF1 aneurysm formation and provide a potential therapeutic target for NF1 vasculopathy.
20

ROLE OF GENOMIC COPY NUMBER VARIATION IN ALZHEIMER'S DISEASE AND MILD COGNITIVE IMPAIRMENT

Swaminathan, Shanker 14 February 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Alzheimer's disease (AD) is the most common form of dementia defined by loss in memory and cognitive abilities severe enough to interfere significantly with daily life activities. Amnestic mild cognitive impairment (MCI) is a clinical condition in which an individual has memory deficits not normal for the individual's age, but not severe enough to interfere significantly with daily functioning. Every year, approximately 10-15% of individuals with MCI will progress to dementia. Currently, there is no treatment to slow or halt AD progression, but research studies are being conducted to identify causes that can lead to its earlier diagnosis and treatment. Genetic variation plays a key role in the development of AD, but not all genetic factors associated with the disease have been identified. Copy number variants (CNVs), a form of genetic variation, are DNA regions that have added genetic material (duplications) or loss of genetic material (deletions). The regions may overlap one or more genes possibly affecting their function. CNVs have been shown to play a role in certain diseases. At the start of this work, only one published study had examined CNVs in late-onset AD and none had examined MCI. In order to determine the possible involvement of CNVs in AD and MCI susceptibility, genome-wide CNV analyses were performed in participants from three cohorts: the ADNI cohort, the NIA-LOAD/NCRAD Family Study cohort, and a unique cohort of clinically characterized and neuropathologically verified individuals. Only participants with DNA samples extracted from blood/brain tissue were included in the analyses. CNV calls were generated using genome-wide array data available on these samples. After detailed quality review, case (AD and/or MCI)/control association analyses including candidate gene and genome-wide approaches were performed. Although no excess CNV burden was observed in cases compared to controls in the three cohorts, gene-based association analyses identified a number of genes including the AD candidate genes CHRFAM7A, RELN and DOPEY2. Thus, the present work highlights the possible role of CNVs in AD and MCI susceptibility warranting further investigation. Future work will include replication of the findings in independent samples and confirmation by molecular validation experiments.

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