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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.
161

Polimorfismos dos Genes XRCC1 e XRCC3 e a Resposta aos Danos Induzidos no DNA pelo Etoposido em Pacientes com Câncer de Mama / XRCC1 and XRCC3 Polymorphisms and the Response Etoposide-Induced DNA Damage in Breast Cancer Patients

Teixeira, Ana Claudia 17 October 2008 (has links)
Apesar de intensivos estudos e substanciais progressos no entendimento dos fatores de risco e suscetibilidade ao câncer de mama (CM), esta neoplasia permanece como importante causa de morte entre mulheres. Idade, história familiar, menarca precoce, menopausa tardia, ocorrência da primeira gravidez após os 30 anos e da nuliparidade constituem fatores de risco. Além disso, polimorfismos nos genes envolvidos no reparo de danos no DNA, como os genes XRCC1 e XRCC3, podem contribuir para o aumento da suscetibilidade ao CM. Os objetivos do presente trabalho foram avaliar pelo Teste do MN e Ensaio Cometa os danos basais e a resposta celular aos danos induzidos, in vitro, no DNA pelo quimioterápico Etoposido em pacientes com CM, virgens de qualquer tipo tratamento e em mulheres saudáveis utilizadas como controles e além disso, estabelecer as freqüências dos polimorfismos nos genes XRCC1 e XRCC3 na amostra de pacientes com CM e em mulheres saudáveis e associação destes dois polimorfismos com a suscetibilidade ao CM. No Teste do MN, foi observada uma sensibilidade maior do grupo de pacientes aos danos induzidos pelo Etoposido. O Ensaio Cometa mostrou que pacientes e mulheres saudáveis respondem de modo semelhante ao tratamento com o Etoposido. Também foi observado que pacientes acima de 45 anos apresentaram um grau maior de sensibilidade aos danos induzidos pelo Etoposido na concentração de 25 M quando comparadas com pacientes abaixo de 45 anos avaliadas no Ensaio Cometa. Quanto ao hábito tabagista, este se mostrou um fator de contribuição ao aumento de sensibilidade a indução de danos pelo Etoposido no Ensaio Cometa no grupo de mulheres saudáveis, para os tratamentos com esta droga nas concentrações de 10 e 25 M. Na análise molecular, o alelo variante 241Met do gene XRCC3 mostrou-se mais freqüente no grupo de pacientes tanto na amostra estudada na análise citogenética quanto na amostra estudada na análise molecular, sugerindo uma diminuição da capacidade de reparo destas pacientes, o que poderia conferir um risco aumentado ao CM. Quanto ao hábito tabagista, somente as pacientes não fumantes, portadoras do alelo 241Met do gene XRCC3, possuem um risco aumentado para o CM. Não foi encontrada associação do polimorfismo Arg399Gln do gene XRCC1 com o risco ao CM mesmo quando associado à fatores de risco como hábito tabagista e a presença de familiares com câncer. / In spite of intensive studies and substantial improvements in the understanding of the risk factors and breast cancer (BC) susceptibility, this neoplasia remains as an important cause of death among women worldwide. Age, family history of cancer, early menarche, late menopause, the first pregnancy after the age of 30 years and nulliparity are BC risk factors. Furthermore genetic polymorphisms in repair genes like XRCC1 and XRCC3 could contribute to increase BC risk. The aims of the present study were to evaluate, by Micronucleus Test and Comet Assay, the basal damage and the cellular response to DNA damage induced by Etoposide, in vitro, in BC patients without chemotherapy treatment and in healthy women. Also establish the frequencies of polymorphisms of XRCC1 and XRCC3 genes in this sample and the association of these two polymorphisms with the susceptibility to BC. In the Micronucleus Test it was observed increased sensibility to DNA damage induced by Etoposide in patients group. Patients and healthy women exhibited the same repair capacity to DNA damage induced by Etoposide when evaluated by Comet Assay. Patients > 45 years old showed more sensibility to DNA damage induced by Etoposide (25 M) when were compared with patients 45 years old in Comet Assay. Tobacco habits contributed to increased sensibility to damage induced by Etoposide in Comet Assay in healthy women group when treated with Etoposide in 10 and 25 M. In the molecular analysis, the XRCC3 241Met allele was more frequent in patients group in both analysis (cytogenetic and molecular) suggesting a low repair capacity of DNA damage and consequently increase risk to BC. Non-smokers patients, carriers of XRCC3 241Met allele showed an increased risk to BC. The polymorphism Arg399Gln in XRCC1 gene was not associated with BC risk even if associated with risk factors like tobacco habit and family history of cancer.
162

AVALIAÇÃO DE DANOS GENÉTICOS E CORRELAÇÃO COM POLIMORFISMOS NOS GENES GSTM1 E GSTT1 EM TRABALHADORES OCUPACIONALMENTE EXPOSTOS A AGROTÓXICOS EM MUNICÍPIOS GOIANOS COM INTENSA ATIVIDADE AGRÍCOLA.

Carvalho, Wanessa Fernandes 10 February 2014 (has links)
Made available in DSpace on 2016-08-10T10:38:50Z (GMT). No. of bitstreams: 1 Wanessa Fernandes Carvalho.pdf: 6063093 bytes, checksum: 0ea1cba23ab3d2a3ae295a8c03e44030 (MD5) Previous issue date: 2014-02-10 / Os agrotóxicos tem sido alvo de preocupação por parte dos diversos segmentos da sociedade, uma vez que o uso indiscriminado (regido por fatores, como: uso inadequado, alta toxicidade, falta do uso de equipamentos de proteção e precariedade dos mecanismos de vigilância) podem gerar impactos ambientais, sociais e sanitários. A exposição ocupacional de trabalhadores agrícolas ocorre por falta de informação ou recursos técnicos qualificados. Um dos problemas da utilização de agrotóxicos é a genotoxicidade de tais produtos o que pode acarretar danos genéticos. Pouco se sabe sobre a relação entre a genotoxidade e a variação dos polimosfismos genéticos de metabolização de xenobióticos que podem modificar a suscetibilidade individual aos possíveis efeitos genotóxicos dos agrotóxicos. O objetivo deste estudo foi avaliar o efeito genotóxico e mutagênico da exposição ocupacional aos agrotóxicos, verificando a variabilidade polimórfica dos genesGSTM1 e GSTT1 em indivíduos expostos a pesticidas, associados à intoxicação, em municípios do estado de Goiás, com intensa atividade agrícola. Foram avaliados 71 trabalhadores rurais com histórico de exposição ocupacional a pesticidas e 68 controles, que apresentaram as mesmas condições socioambientais (idade, fumo, álcool). Os danos no DNA foram avaliados utilizando o teste do micronúcleo e o ensaio cometa. Para estes ensaios foram selecionados os seguintes parâmetros: comprimento da cauda do cometa, porcentagem de DNA na cauda e momento da cauda de Olive. As amostras de DNA foram obtidas a partir de linfócitos de sangue periférico utilizando o kit Ilustra MS ® (GE, EUA), de acordo com o protocolo do fabricante. Para a reação da PCR foi utilizado SYBR ® Green PCR Master Mix (AppliedBiosystems ®, EUA). A estimativa de danos genômicos para os trabalhadores que não utilizavam EPI foi de 0,82 + 0,990, para o comprimento do cometa, 0,78 + 0,94 para % de DNA na cauda e 0,20 + 1,06 para momento da cauda de Olive, demostrando assim diferença estatisticamente significativa entre os parâmetros. O estudo demonstrou uma taxa relativamente alta de micronúcleos 5,42 + 7,32 e células binucleadas 10,37 + 8,66, em indivíduos expostos que não usavam equipamentos de proteção individual (EPI), indicando que o uso destes equipamentos pode ter efeito protetor contra os agrotóxicos (p<0,001). A distribuição da frequência de GSTM1 e GSTT1 nulos no grupo exposto foi observada em 43,66% e 21,12% respectivamente, e o grupo controle apresentou deleção de GSTM1 em 39,70% dos indivíduos, e para GSTT1, 29,41% dos indivíduos apresentaram a deleção. No entanto, não houve um aumento no risco de intoxicação para os genótipos nulos.
163

Estudo de polimorfismos de MTOR e PPP3CA em receptores de transplante renal e sua relação com a resposta a imunossupressores / Study of MTOR and PPP3CA polymorphisms in renal transplant recipients and its relationship with the response to immunosuppressive agents.

Salgado, Patricia de Cássia 26 October 2012 (has links)
Os imunossupressores tacrolimo (Tac) e sirolimo (Srl) são amplamente utilizados no transplante renal. Estes medicamentos apresentam estreita faixa terapêutica e estão associados a uma vasta gama de efeitos colaterais. Polimorfismos de nucleotídeo único (SNP) parecem ter um impacto significativo sobre a farmacocinética dos imunossupressores. Com o objetivo de avaliar a associação de SNP nos genes PPP3CA e MTOR com a resposta farmacológica dos imunossupressores tacrolimo e sirolimo foram selecionados 156 indivíduos indicados para transplante renal entre os pacientes atendidos no Hospital do Rim e Hipertensão da UNIFESP. Esses indivíduos foram tratados com esquema imunossupressor baseado em tacrolimo ou convertido para sirolimo. Amostras de sangue foram coletadas antes do transplante para extração de DNA. As determinações das concentrações sanguíneas de Tac foram determinadas por chemiluminescent microparticle immunoassay (CMIA) e as concentrações sanguíneas de Srl foram obtidas pela técnica de HPLC (High- Performance Liquid Chromatography). Os polimorfismos do MTOR (c.1437T>C, T c.2997C>T e c.4731G>A) e PPP3CA (c.249G>A) foram identificados por PCR em tempo real. O polimorfismo PPP3CA c.246G>A não foi associado à dose diária de tacrolimo ou sirolimo. Já a concentração sanguínea de tacrolimo foi menor nos portadores do alelo A no terceiro dia e terceiro mês de estudo. Os polimorfismos do MTOR foram relacionados à concentração sanguínea corrigida pela dose de tacrolimo. Os portadores dos alelos raros G, T e C dos polimorfismos c.4731G>A, c.14337T>C e c.2997C>T, respectivamente, apresentaram valores de Co/Do de tacrolimo menores em relação aos não portadores destes alelos. As diferenças significativas ocorreram principalmente nos primeiros três meses de estudo. A concentração sanguínea de tacrolimo foi no geral menor nos portadores dos alelos raros, sendo significativamente menor no décimo quarto dia. Doses maiores de tacrolimo foram associadas aos alelos T do c.14337T>C e C do c.2997C>T. No sexto mês de estudo, os portadores dos alelos raros receberam doses de sirolimo significativamente maiores do que os não portadores. O alelo T do polimorfismo c.1437T>C foi associado a menores valores de Co/Do de sirolimo. Os SNPs c.2997C>T e c.1437T>C do MTOR encontram-se em desequilíbrio de ligação (D\'=0,981; r2=0,690). Nos três primeiros meses de estudo, os portadores do haplótipo TC receberam doses menores de tacrolimo e apresentaram a melhor relação Co/Do. Foi possível observar que após a randomização, o haplótipo TC continuou associado a menores doses de tacrolimo e de sirolimo e manteve a tendência de melhores índices de Co/Do de ambos os fármacos. Os polimorfismos c.1437T>C e c.4731G>A foram associados a parâmetros de função renal no grupo TAC. O alelo G do SNP c.4731G>A relacionou-se a valores menores de ureia no pré-Tx, menor redução de ureia e creatinina entre o pré-Tx e o sexto mês de estudo. O alelo T do SNP c.1437T>C também foi relacionado a menores valores de ureia no pré-Tx e menor redução de creatinina. No grupo TAC, o alelo raro do SNP PPP3CA c.249G>A foi relacionado a menores valores de triglicérides no pré-Tx e no grupo SRL uma menor variação de LDL-colesterol. Os portadores do alelo C do SNP c.2997C>T apresentaram menor aumento de colesterol total e LDL colesterol entre o pré-Tx e o sexto mês de estudo, maiores valores de HDL colesterol no pré-Tx e menores valores de triglicérides no sexto mês de estudo. Os portadores do alelo T do SNP c.1437T>C apresentaram menor aumento de colesterol total, LDL colesterol, VLDL colesterol e triglicérides. No sexto mês de estudo apresentaram menores valores de triglicérides em relação aos não portadores deste alelo. Os portadores do alelo G do SNP c.4731G>A tiveram variação menor de colesterol total, VLDL colesterol e triglicérides. Não foi encontrada relação dos polimorfimos estudados e a rejeição aguda comprovada por biópsia ou com a nefropatia crônica do enxerto. Esses resultados são sugestivos de que os polimorfismos do MTOR e PPP3CA estão associados com a dose e concentração sanguínea dos imunossupressores tacrolimo e sirolimo, assim como um perfil lipídico menos aterogênico. / The immunosuppressant tacrolimus (Tac) and Sirolimus (Srl) are widely used in renal transplantation. These drugs have a narrow therapeutic range and are associated with a wide range of side effects. Single nucleotide polymorphisms (SNPs) have a significant impact on the pharmacokinetics of immunosuppressants. In order to evaluate the association of SNPs in genes MTOR and PPP3CA with the pharmacological response of immunosuppressive drugs tacrolimus and sirolimus were selected 156 individuals referred for kidney transplantation among patients treated in the Hospital do Rim e Hipertensão, UNIFESP. These individuals were treated with tacrolimus-based immunosuppressive regimen or converted to sirolimus. Blood samples were collected before transplantation for DNA extraction. Determinations of blood concentrations of Tac were determined by Chemiluminescent microparticle immunoassay (CMIA) and blood concentrations Srl were obtained by the technique of HPLC (High-Performance Liquid Chromatography). Polymorphisms of MTOR (c.1437T>C, T c.2997C>T and c.4731G>A) and PPP3CA (c.249G>A) were identified by real-time PCR. The Polymorphism PPP3CA c.246G>A was not associated with the daily dose of tacrolimus or sirolimus. The blood concentration of tacrolimus was lower in carriers of the allele on the third day and third month of study. The Polymorphisms of MTOR were related to blood concentration corrected by the dose of tacrolimus. The carriers of rare alleles G, T and C polymorphisms c.4731G> A, c.14337T> C and c.2997C> T, respectively, had values of Co/Do tacrolimus lower than the non-carriers of these alleles. Significant differences occurred mainly during the first three months of study. The blood concentration of tacrolimus was generally lower in carriers of the rare alleles being significantly lower on the fourteenth day. Higher doses of tacrolimus were associated with alleles c.14337T T>C and C c.2997C>T. In the sixth month of study, the carriers of rare alleles received doses of sirolimus significantly higher than non-carriers. SNPs c.2997C>T and c.1437T>C MTOR are in linkage disequilibrium (D \'= 0.981; r2 = 0.690). In the first three months of study, carriers of the TC haplotype received lower doses of tacrolimus and presented the best value for Co/Do. It was observed that after randomization, the TC haplotype remained associated with lower doses of tacrolimus and sirolimus and continued the trend of higher rates of Co/Do of both drugs. Polymorphisms c.1437T>C and c.4731G>A were associated with renal function parameters in the TAC group. The G allele of SNP c.4731G> A was related to lower levels of urea in the pre-Tx, a smaller reduction of urea and creatinine between the pre-Tx and sixth months of study. The T allele of SNP c.1437T>C was also related to lower levels of urea in the pre-Tx and a smaller reduction of creatinine. In the TAC group, the rare allele of SNP PPP3CA c.249G>A was related to lower levels of triglycerides in the pre-Tx and the SRL group a smaller variation of LDL-cholesterol. The C allele of the SNP c.2997C>T showed a lower increase in total cholesterol and LDL cholesterol between pre-Tx and sixth months of study, higher HDL cholesterol in pre-Tx and lower levels of triglycerides in the sixth month of study. The T allele of SNP c.1437T>C showed a lower increase in total cholesterol, LDL cholesterol, VLDL cholesterol and triglycerides. In the sixth month of the study, they had lower triglyceride levels compared to non-carriers of this allele. The G allele of SNP c.4731G>A change had lower total cholesterol, VLDL cholesterol and triglycerides. There was no relationship between the studied polymorphisms and biopsy-proven acute rejection or chronic allograft nephropathy. These results suggest that MTOR and PPP3CA polymorphisms are associated with dose and blood concentration of immunosuppressants tacrolimus and sirolimus, as well as a less atherogenic lipid profile.
164

Avaliação de polimorfismos de DNA em genes candidatos de pacientes com comprometimento cognitivo leve e doença de Alzheimer / Evaluation of DNA polymorphisms in candidate genes of mild cognitive impairment and Alzheimer\'s disease Patients

Izzo, Giselle 26 April 2010 (has links)
A doença de Alzheimer (DA) é complexa e de etiologia desconhecida. Provavelmente componentes multifatoriais influenciam no desencadeamento dessa patologia, sendo que o único fator genético de risco bem estabelecido até o momento para a doença é a variante alélica APOE*E4. Nos últimos anos, descobriu-se uma série de polimorfismos em genes diferentes sugerindo que essas alterações possam ter participação discreta na patologia. O presente estudo avaliou vinte e um polimorfismos distribuídos em treze genes, sendo estes APOE, ACE, APP, BDNF, CALHM1, CST3, GAB2, GAPDH, GSK3B, GSTP1, IL1A, IL1B e SORL1 , em pacientes, controles idosos e indivíduos com comprometimento cognitivo leve, na tentativa de verificar se existe algum tipo de associação entre os polimorfismos investigados como fatores de risco para DA. Nossos resultados mostraram associações positivas entre cinco polimorfismos conferindo risco elevado para o desenvolvimento de DA (rs429358 e rs7412 de APOE, rs2373115 de GAB2, rs6438552 de GSK3B e rs641120 de SORL1). Outro achado consistente de nosso estudo foi que 20/21 polimorfismos estudados apresentaram ao menos um genótipo associado com risco elevado para DA na presença de um alelo APOE*E4. Com nosso trabalho contribuímos para aumentar o conhecimento sobre a etiologia da DA, identificando possíveis marcadores moleculares de suscetibilidadenessa patologia. / Alzheimers disease (AD) is complex, and its ethiology is not completely understood yet. It is likely that multifactorial components do account for this pathology development, being the allelic variant APOE*E4 is the only well-established genetic risk factor so far. Recently, a series of polymorphisms located at different genes were related to AD, suggesting that those variations might have a modest participation in this pathology. The present study evaluated twenty-one polymorphisms distributed in thirteen genes, being them APOE, ACE, APP, BDNF, CALHM1, CST3, GAB2, GAPDH, GSK3B, GSTP1, IL1A, IL1B and SORL1, in elderly controls, AD and mild cognitive impairment patients, attempting to verify if there is any kind of association between the selected polymorphisms as risk factors for AD. Our results show positive associations between five polymorphisms and AD (APOE rs429358 and rs7412, GAB2 rs2373115, GSK3B rs6438552 and SORL1 rs641120). Another consistent finding was that 20/21 polymorphisms analyzed showed at least one genotype associated with increased risk for AD at the presence of at least one APOE*E4 allele. We intend that our research might contribute to increase what is known about AD ethiology, by deciphering possible molecular susceptibility markers evolved with this pathology.
165

Polymorphisms in gene promoters and their transactivation activities. / CUHK electronic theses & dissertations collection

January 2008 (has links)
Briefly, some findings in my research are as follows: (1) The genetic variants of the CA repeats in IGF1 promoter 1 can affect the activity of promoter 1, and the CA repeat showed a suppressive effect on the activity of the promoter 1 of IGF1 gene. EMSA results have shown that the CA repeats could bind to certain nuclear protein. (2) The SNPs T/C (rs5742612) and T/A (rs2288377) can also affect the activity of the promoter 1 in IGF1 gene, and the activity of C-A haplotype is significantly higher than that of T-T haplotype. EMSA results have shown that the SNP T/A (rs2288377) could bind to certain nuclear protein. (3) I developed the new dual reporter assay method to investigate the transactivation interaction between the SNP T/G (rs2071430) and C/A (rs17000900) in the MxA promorer. This new method can not only improve the detection limit for small difference between haplotypes, but also calculate the model of transactivation effect between these two SNPs. The results were better than those of traditional method, and it gave a clear-cut demonstration of the effect of interaction between these two SNPs on the activity of MxA promoter. / In addition, in the IGF1 study, the core promoter region of promoter 2 was identified through 5' deletion mutagenesis methods. Moreover, a cell-type specific mechanism of bidirectional activation of promoter was found. / Recently, more and more studies focus on gene function with the completion of the Human Genome Project. It is well known that polymorphism of human genome sequence is a common phenomenon in the human population. Specially, a lot of genetic polymorphisms, including single nucleotide polymorphisms (SNPs) and microsatellites, have been reported in the regulatory region of many genes. However, the effects of most of these genetic polymorphisms on gene expression are still unknown. The polymorphisms in the promoter can play an important role in the gene regulation. For example, some SNPs located in the transcription factor binding site (TFBS) can affect gene transcription. So, it is very necessary to directly study the effect of genetic variants on promoter transactivation activities. In this study, we studied the effect of genetic polymorphisms on gene expression through reporter gene assay, electrophoretic mobility shift assay (EMSA), and so on. And the candidate genes include insulin-like growth factor 1 (IGF1) and myxovirus resistence 1 (MxA). Some SNPs and microsatellites have been reported in the promoters of these genes. In our previous researches, we focused on the study of the association between these polymorphisms and some diseases, and it was found that a few SNPs significantly associated with relevant diseases. Based on the previous results, in my project, I developed new functional assays and also improved existing methods to analyse the functional effect of these genetic variants of promoters on transactivation activities. / by Huang, Wei. / "March 2008." / Adviser: Nelson Leung Sang Tang. / Source: Dissertation Abstracts International, Volume: 70-03, Section: B, page: 1483. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (p. 139-145). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
166

A functional study of blood-pressure-associated SNPs at natriuretic peptide receptor C gene locus

Ren, Meixia January 2016 (has links)
Background: Essential hypertension is regarded as a complex disease, the phenotype of which results from interactions between numerous genes and environmental factors. Genome-wide association studies of blood pressure (BP) and hypertension have been developed to explore the potential genes involved in blood pressure and identified a number of trait-associated variants. Among those variants, single nucleotide polymorphisms (SNPs) rs1173771 (G/A) and rs1421811 (G/C) are located at the natriuretic peptide receptor C (NPR3) gene locus. Their major alleles are related with blood pressure elevation. Studies have implicated NPR-C in mediating some of the cardio-protective actions of natriuretic peptides and its direct involvement in the pathogenesis of hypertension. However, the precise role of these association between genetic variants at NPR3 and blood pressure control has not been elucidated. Objective: To functionally characterise the effect of BP-associated SNPs at the NPR3 gene locus in the context of BP regulatory pathways. Methods: Primary human umbilical artery smooth muscle (HUASMCs) and vein endothelial (HUVECs) cells were genotyped for BP-associated NPR3 variants. Endogenous mRNA and protein expression levels were assessed by qRT-PCR, allelic expression imbalance assay and western blotting. Open chromatin regions were assayed using formaldehyde-assisted isolation of regulatory elements (FAIRE). Interaction between variants flanking region with nuclear protein was detected by electrophoretic mobility shift assay (EMSA). Cell proliferation and migration were 4 determined by cell counting and scratch assays. Angiotensin II (Ang II)-induced calcium flux was evaluated using the intracellular fluorescent probe. Results: The BP-elevating allele of the NPR3 variants in rs1173771 linkage disequilibrium (LD) block was associated with lower endogenous mRNA and protein levels in HUASMCs. This is consistent with the finding that BP-elevating allele is less located within open chromatin. The decreased NPR3 expression in HUASMCs carrying the BP-elevating allele is associated with increased cell proliferation and intracellular calcium flux in response to Ang II stimulation. No differences in migration rates were detected. No genotype-dependent characteristics were observed in HUVECs NPR3 expression and cell proliferation. Moreover, RT-PCR showed a linkage between of the BP-elevating allele of the NPR3 variants in rs1421811 LD block and lower endogenous mRNA in HUASMCs. Intracellular calcium flux detection also revealed a trend of higher response to Ang II stimulation in BP-elevating allele homozygous HUASMCs. However, No genetic differences were detected in proliferation and migration rates of HUASMCs, and HUVECs NPR3 expression and cell proliferation studies did not present any significant genotype-dependent association. Conclusions: This study has identified a potential mechanism for BP-associated SNPs at NPR3 locus to influence BP predominantly via an effect on vascular smooth muscle cell behaviours.
167

Interactions between NOS3 and HMOX1 on methyldopa responsiveness in preeclampsia.

Pilan, Eliane Graciela January 2019 (has links)
Orientador: Valéria Cristina Sandrim / Resumo: A pré-eclâmpsia (PE) é a principal causa de mortalidade e morbidade entre as gestantes no Brasil e em vários países. A fisiopatologia desta doença é complexa e envolve vários processos. Um destes, amplamente validado na literatura, relaciona-se a um status oxidativo, onde há prevalência de produção de radicais livres e/ou redução da atividade antioxidante. Apesar destas evidências, a suplementação clínica com antioxidantes (vitamina C e E) não se demonstrou promissora em PE. Recentemente, vem sendo explorado como terapia em várias doenças, a ativação de um fator de transcrição, o NRF2 (do inglês - nuclear factor, erythroid 2-like 2), que atua induzindo a transcrição de diversos genes que promovem a proteção celular através da codificação de proteínas com atividade desintoxicante e antioxidante. Entre elas a heme oxigenase (HO-1) é a mais estudada, pois apresenta efeitos antiapoptóticos, antioxidantes e citoprotetor. Além disso, o aumento do estresse oxidativo na PE pode potencialmente reduzir a biodisponibilidade de óxido nítrico (NO) que pode ser modulado por alguns polimorfismos localizados no gene da óxido nítrico sintase (NOS3). Notavelmente, os haplótipos formados pela combinação de polimorfismos foram associados a diferentes subgrupos de resposta à terapia anti-hipertensiva em PE. No presente estudo, comparamos as distribuições dos polimorfismos localizados nos genes NFE2L2 rs35652124 (C/T) e no gene HMOX1 rs2071746 (A/T) em gestantes com PE que respondem à metildopa ou... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Preeclampsia (PE) is the leading cause of mortality and morbidity among pregnant women in Brazil and several countries. Its pathophysiology is complex and involves several processes, including the oxidative stress (increase of free radicals and/or decrease of antioxidant defense). Although evidences, clinical supplementation with vitamins (C and E) was not promising in preeclampsia. Currently, therapeutically the activation of transcription factor, NRF2 (nuclear factor, erythroid 2-like 2), has been explored in several diseases. This factor promote cytoprotection by activates the transcription of several antioxidant and detoxification proteins. Hemeoxigenase-1 (HO-1) is the most studied, because has antiapoptotic, anti-inflammatory and cytoprotection activities. In addition, the increased oxidative stress in PE can potentially reduce the bioavailability of nitric oxide (NO) which may impaired by some SNPs on endothelial nitric oxide synthase (NOS3) gene. Notably, haplotypes formed by the combination of polymorphisms of were associated with different subgroups of response to antihypertensive therapy in PE. Therefore, in the present study we compared the distributions of rs35652124 (C/T) NFE2L2 and rs2071746 (A/T) HMOX1 polymorphisms in PE patients who respond to methyldopa or antihypertensive therapy with those found in PE patients who do not respond to methyldopa or total antihypertensive therapy. We also examined whether NFE2L2 and HMOX1 polymorphisms affect plasma HO-1 leve... (Complete abstract click electronic access below) / Mestre
168

Detecção de polimorfismos do gene da proteína priônica no rebanho ovino do Estado de São Paulo: métodos e aplicabilidade à seleção para resistência ao scrapie / Detection of Polymorphisms in the prion protein gene in Sheeps flock in the State of São Paulo: Methods and Applicability of Selection for Scrapie Resistance

Santos, Caio Rodrigues dos 31 May 2012 (has links)
Scrapie ou paraplexia enzoótica dos ovinos é uma doença neurodegenerativa fatal que acomete ovinos e raramente caprinos. A doença é influenciada por polimorfismos nos códons 136, 154 e 171 do gene prnp que codifica a proteína priônica. Os animais podem ser susceptíveis ou resistentes, de acordo com as sequências alélicas observadas nos referidos códons. No Brasil ocorreram apenas casos de animais que foram importados, sendo o país considerado livre da doença. Neste trabalho foi realizada a genotipagem dos diferentes polimorfismos associados ao desenvolvimento do scrapie e a categorização em animais susceptíveis e resistentes. Foram sequenciadas 118 amostras provenientes de ovinos da raça Santa Inês criados em propriedades localizadas no Estado de São Paulo. Destas amostras foram identificados 6 alelos e 11 genótipos (ARQ/ARQ, ARR/ARQ, ARQ/AHQ, ARQ/VRQ, AHQ/AHQ, ARR/ARR, ARR/AHQ, VRQ/VRQ, ARQ/TRQ, TRR/TRR, TRQ/TRQ), dentre os quais o genótipo ARQ/ARQ teve ocorrência de 56,7%. Em nosso estudo foi detectada a presença da tirosina no códon 136, observação rara na medida em quenão existem relatos nacionais e relatos envolvendo a raça Santa Inês descrevendo este polimorfismo. Com os resultados obtidos, foi possível determinar a existência de grande variabilidade genética relacionada à raça Santa Inês no Estado de São Paulo, apesar da variabilidade, apenas 1,69% dos genótipos observados são extremamente resistentes ao scrapie. Estes dados demonstram que a raça nativa Santa Inês pode ser considerada potencialmente susceptível ao scrapie. / Enzootic paraplexia or scrapie is a fatal neurodegenerative disease affecting mainly sheep and rarely goats. The disease is influenced by polymorphisms at codons 136, 154 and 171 of prnp gene that encodes the prion protein. The animals may be susceptible or resistant to the development of the disease according to the allelic sequences observed in these codons. In Brazil there were only cases of scrapie in imported animals, therefore the country is considered free of the disease. This study performed the genotyping of different polymorphisms associated to the development of scrapie. Then, based on these findings the animals were categorized in resistant and susceptible. A total of 118 samples were sequenced from the Santa Ines sheep raised on properties located in the State of Sao Paulo. From these samples, 6 alleles and 11 genotypes were identified (ARQ / ARQ, ARR / ARQ, ARQ / AHQ, ARQ / VRQ, AHQ / AHQ, ARR / ARR, ARR / AHQ, VRQ / VRQ, ARQ / TRQ, TRR / TRR, TRQ / TRQ), the genotype ARQ / ARQ presented a frequency of 56.7%. It was also detected the presence of tyrosine at codon 136, which may be considered a rare observation, since there is no report regarding Santa Ines breeding presenting this polymorphism. These results showed the great genetic variability in Santa Ines in Sao Paulo and only 1,69% of the genotypes observed are extremely resistant to scrapie. These data demonstrate that the Santa Ines sheep can be considered potentially susceptible to scrapie.
169

Life history effects on neutral polymorphism and divergence rates, in autosomes and sex chromosomes

Amster, Guy January 2019 (has links)
Much of modern population genetics revolves around neutral genetic differences among individuals, populations, and species. In this dissertation, I study how sex-specific life history traits affects neutral diversity levels within populations (polymorphism) and between species (divergence) on autosomes and sex chromosomes. In chapter 1, I consider the effects of sex specific life histories, and particularly generation times, on substitution rates along the great ape phylogeny. Using a model that approximates features of the mutational process in most mammals, and fitting the model on data from pedigree-studies in humans, I predict the effects of life history traits on specific great ape lineages. As I show, my model can account for a number of seemingly disparate observations: notably, the puzzlingly low X-to-autosome ratios of substitution rates in humans and chimpanzees and differences in rates of autosomal substitutions among great ape lineages. The model further suggests how to translate pedigree-based estimates of human mutation rates into split times among extant apes, given sex-specific life histories. In so doing, it largely bridges the gap reported traditional fossil-based estimates of mutation rates, and recent pedigree-based estimates. In chapter 2, I consider the effects of sex- and age- dependent mortalities, fecundities, reproductive variances and mutation rates on polymorphism levels in humans. Using a coalescence framework, I provide closed formulas for the expected polymorphism rate, accounting for life history effects. These formulas generalize and simplify previous models. Applying the model to humans, my results suggest that the effects of life history – and of sex differences in generation times in particular – attenuate how changes in historical population sizes affect X to autosome polymorphism ratios. Applying these results to observations across human populations, I find that life history effects and demographic histories can largely explain the reduction in X to autosome polymorphism ratios outside Africa. More generally, my work elucidates the major role of sex-specific life history traits – and male and female generation times in particular – in shaping patterns of neutral genetic diversity within and between species.
170

Relação entre polimorfismos dos genes LEP, FTO, APOA5, ADRB3, TCF7L2, ENPP1, CYP11B2 e PPARG e a síndrome metabólica / Relationship between polymorphisms of the LEP, FTO, APOA5, ADRB3, TCF7L2, ENPP1, PPARG and CYP11B2 and metabolic syndrome.

Moraes, Tamiris Invencioni 04 December 2013 (has links)
A síndrome metabólica (SM) é um conjunto de alterações metabólicas caracterizadas por três de cinco fatores sendo estes; obesidade abdominal, resistência à insulina, hiperglicemia, dislipidemia e hipertensão. As alterações fisiopatológicas da SM são importantes fatores de risco para a doença cardiovascular que tem alta prevalência na maioria das populações. Estudos genéticos têm mostrado que polimorfismos em genes envolvidos em vias do metabolismo glicídico e lipídico estão relacionados com maior predisposição à SM, porém há poucos dados na nossa população. O objetivo deste projeto é estudar a relação entre polimorfismos nos genes LEP, FTO, APOA5, ADRB3, TCF7L2, ENPP1, CYP11B2 e PPARG e a SM. Foram avaliados parâmetros antropométricos, composição corporal, perfil metabólico e de adipocinas, em 167 indivíduos com SM e 262 sem SM, 321 mulheres e 108 homens, e idade entre 30 e 70 anos. Amostras de sangue periférico foram utilizadas para extração de DNA e determinações de perfil lipídico, glicêmico e de adipocinas. Os polimorfismos FTO (rs1421085 T>C, rs1558902 T>A, rs17817449 T>G, rs8050136 C>A, rs9939609 T>A e rs9930506 A>G), LEP rs7799039 G>A, APOA5 rs662799 T>C, ADRB3 rs4994 T>C, TCF7L2 rs7903146 C>T, ENPP1 rs1044498 A>C, CYP11B2 rs1799998 A>G e PPARG rs2972162 C>T foram analisados por PCR em tempo real. As frequências gênicas e alélicas dos polimorfismos estudados foram similares entre os grupos com e sem SM (p>0,05). O haplótipo FTO TTTCAG foi mais frequente no grupo SM (4,2%) do que sem SM (<1,0%, p=0,003), sugerindo que os portadores deste haplótipo tem maior risco de desenvolver síndrome metabólica. Maiores valores de índice de massa corporal (IMC), circunferência abdominal (CA) ou razão cintura-quadril (RCQ) foram observadas nos portadores dos polimorfismos FTO rs1481085 (alelo C), FTO rs1558902 (alelo A), FTO rs17817449 (alelo G), FTO rs8050136 (alelo A), FTO rs9939609 (alelo A), LEP rs7799019 (alelo A), TCF7L2 rs7903146 (alelo C) em comparação com os portadores de genótipos ancestrais (p<0,05), principalmente no grupo SM. Além disso, o polimorfismo FTO rs9930506 (alelo G) foi relacionado com maior teor de gordura corporal (p=0,040), no grupo SM. O SNP CYP11B2 rs1799998 (alelo G) foi relacionado com maior concentração sérica de LDL colesterol e menor concentração de apoAI (p<0,05), grupo SM. Enquanto que a variante ENPP1 rs1044498 (alelo C) foi associada com menor trigliceridemia (p=0,024), no grupo sem SM. Portadores do alelo A do SNP LEP rs7799019 tiveram maior insulinemia e maiores valores de HOMA-&#946; e HOMA-IR que os portadores do genótipo GG (p<0,05), em ambos os grupos, sugerindo a relação desta variante com resistência a insulina. Menores concentrações de leptina foram observadas nos portadores dos SNPs LEP rs7799019 (alelo A) (p=0,031) e ENPP1 rs1044498 (alelo C) (p=0,021) grupo SM; e FTO rs9939609 (alelo A) (p=0,047) no grupo sem SM. A variante FTO rs9930506 (alelo G) foi relacionada com maior adiponectinemia (p<0,05), no grupo SM. Enquanto o SNP ENPP1 rs1044498 (alelo C) foi relacionado com menor concentração sérica de adiponectina nos grupos com (p=0,010) e sem (p=0,006) SM. Em síntese, polimorfismos FTO, LEP e TCF7L2 tem importante papel na adiposidade associada com a síndrome metabólica, em nossa população, e junto com as variantes CYP11B2 ENPP1 contribuem para a variabilidade do perfil metabólico e de adipocinas principalmente em indivíduos com SM. / Metabolic syndrome (MS) is a group of metabolic disorders characterized by three of five factors, which are: abdominal obesity, insulin resistance, hyperglycemia, dyslipidemia and hypertension. The pathophysiological changes of MS are important risk factors for cardiovascular disease that has a high prevalence in most populations. Genetic studies have shown that polymorphisms in genes involved in pathways of glucose and lipid metabolism are associated with increased predisposition to MS, but there are few data on our population. The objective of this project is to study the relationship between polymorphisms in LEP, FTO, APOA5, ADRB3, TCF7L2, ENPP1, PPARG and CYP11B2 and the SM. We evaluated anthropometric parameters, body composition, metabolic profile and adipokines in 167 individuals with MS and 262 without MS, 321 women and 108 men, aged between 30 and 70 years. Peripheral blood samples were used for DNA extraction and determination of lipid profile, glycemic and adipokines. The polymorphisms FTO (rs1421085 T>C rs1558902 T>A rs17817449 T>G rs8050136 C>A rs9939609 T>A and rs9930506 A>G), LEP rs7799039 G>A APOA5 rs662799 T>C ADRB3 rs4994 T>C TCF7L2 rs7903146 C>T, ENPP1 rs1044498 A>C CYP11B2 rs1799998 A>G and PPARG rs2972162C G>T were analyzed by real-time PCR. Genic and allelic frequencies of polymorphisms were similar between the groups with and without MS (p> 0.05). The FTO TTTCAG haplotype was more frequent in the SM group (4.2%) than without MS (<1.0%, p = 0.003), suggesting that carriers of this haplotype have higher risk of developing metabolic syndrome. Higher values of body mass index (BMI), waist circumference (WC) or waist-hip ratio (WHR) were observed in carriers of the FTO rs1481085 polymorphism (C allele), FTO rs1558902 (allele A), FTO rs17817449 (G allele), FTO rs8050136 (allele A), FTO rs9939609 (allele A), LEP rs7799019 (allele A), TCF7L2 rs7903146 (C allele) compared with those with ancestral genotypes (p <0.05), especially in the SM group. In addition, FTO rs9930506 polymorphism (G allele) was associated with higher fat body mass (p = 0.040) in MS group. CYP11B2 SNP rs1799998 (G allele) was associated with increased serum concentration of LDL cholesterol and apoAI lower concentration (p <0.05) SM group. While the ENPP1 variant rs1044498 (C allele) was associated with lower plasma triglycerides (p = 0.024) in the group without MS. Carriers of the A allele of SNP rs7799019 LEP had higher insulin and higher HOMA-&#946; and HOMA-IR than carriers of the GG genotype (p <0.05) in both groups, suggesting the relationship of this variant with insulin resistance. Lower concentrations of leptin were observed in carriers of the LEP SNPs rs7799019 (allele A) (p = 0.031) and ENPP1 rs1044498 (allele C) (p = 0.021) SM group, and FTO rs9939609 (allele A) (p = 0.047) in the group without MS. The variant FTO rs9930506 (G allele) was associated with higher adiponectinemia (p <0.05) in group SM. While the ENPP1 SNPs rs1044498 (C allele) was associated with lower serum concentration of adiponectin in groups with (p = 0.010) and without (p = 0.006) MS. In summary, polymorphisms FTO, TCF7L2 and LEP play an important role in adiposity associated with metabolic syndrome in our population, and along with the CYP11B2 ENPP1 variants contribute to the variability of the metabolic profile of adipokines, especially in individuals with MS.

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