Made available in DSpace on 2014-06-11T19:26:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-28Bitstream added on 2014-06-13T19:53:58Z : No. of bitstreams: 1 torres_ls_me_sjrp.pdf: 665668 bytes, checksum: 4aaf2ab7e9956b74cfe43d4216ad0030 (MD5) / A anemia falciforme (AF) afeta milhões de pessoas em todo o mundo e está associada a altas taxas de morbidade e mortalidade. Apresenta uma série de manifestações fenotípicas, que são influenciadas por fatores genéticos e ambientais, resultando em fenótipos diversificados, e um tratamento bastante eficaz tem sido o uso de hidroxiureia (HU), que ameniza os sintomas e a necessidade de transfusão sanguínea e hospitalização. Estudos de associação de genomas já demonstraram que polimorfismos genéticos podem desempenhar influência no perfil clínico dos pacientes, assim como na resposta destes à medicação. Os polimofismos -308G/A no gene TNFA e -509C/T no gene TGFB aumentam a produção das suas respectivas citocinas que atuam principalmente em vias inflamatórias e são fortes candidatos a estarem envolvidos na ocorrência de episódios vaso-oclusivos característicos da doença. Dessa forma, o objetivo do trabalho foi verificar a frequência desses polimorfismos em portadores da AF, com e sem o uso de HU, e possível relação com a gravidade das manifestações clínicas da doença. Foram obtidas 588 amostras de sangue periférico de pacientes com doença falciforme em acompanhamento no HEMORIO. A partir destas, foram separados, aleatoriamente, 240 pacientes com AF, cujo genótipo foi confirmado por procedimentos laboratoriais clássicos e moleculares. Estes foram genotipados para os polimorfismos -308G/A (TNFA) e -509C/T (TGFB) por PCR-RFLP. Os dados hematológicos e clínicos parciais de 118, dos 240 pacientes, foram obtidos por questionário e consulta aos prontuários médicos e banco de dados. A frequência do polimorfismo -308G/A foi de 0,83 em homozigose e 17,92% em heterozigose. Para o polimorfismo -509C/T, foi de 6,25% e 48,33%, respectivamente. Não foi observada associação entre o polimorfismo -308G/A e as manifestações clínicas... (Resumo completo, clicar acesso eletrônico aba / Sickle cell anemia (SCA) affects millions of people worldwide and is associated with high morbidity and mortality. This affection shows various phenotypic manifestations, which are influenced by genetic and environmental factors, resulting in many phenotypes, and the most effective treatment has been the use of hydroxyurea (HU), which improves the symptoms and the requirement for blood transfusion and hospitalization. Genome association studies have shown that genetic polymorphisms may play role on the clinical profile of patients, as well as in response to these medications. The -308G/A and -509C/T polymorphisms, in TNFA and TGFB genes respectively, increase production of their cytokines, which act on inflammatory pathways and are strong candidates to be involved in the occurrence of vaso-occlusive episodes. The aim of this study was to determine the frequency of these polymorphisms in patients with AF, with and without HU utilization, and possible relationship with the severity of clinical manifestations of disease. We obtained 588 peripheral blood samples of patients with sickle cell disease at HEMORIO. From these, were separated at random 240 patients with AF, whose genotype was confirmed by classical and molecular laboratory procedures. They were genotyped for polymorphisms-308G/A (TNFA) and-509C/T (TGFB) by PCR-RFLP. The hematological and clinical data of 118 of the 240 patients, were obtained by questionnaire and medical records and database. The frequency of polymorphism -308G/A was 0.83% in homozygous and 17.92% in heterozygous. For the polymorphism -509C/T, was 6,25% and 48.33% respectively. No association between polymorphism -308G/A and clinical manifestations in patients was found. Concerning the polymorphism-509C/T, the mutant allele (T) proved to be a risk... (Complete abstract click electronic access below)

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A anemia falciforme (AF) Ã uma das alteraÃÃes genÃticas mais comuns em nosso paÃs. Os haplÃtipos da &#61538;s-globina estÃo associados com a heterogeneidade clÃnica apresentada pela doenÃa. Os portadores de AF sÃo submetidos a elevados nÃveis de estresse oxidativo. A hidroxiurÃia (HU) tem sido utilizada no tratamento por sua aÃÃo de elevar os nÃveis de hemoglobina fetal e aÃÃo antioxidante. O estudo teve como objetivo investigar o impacto do uso da HU e dos haplÃtipos no perfil oxidativo nos pacientes com AF. Foram analisadas amostras de 64 pacientes acompanhados no Hospital UniversitÃrio Walter CantÃdio - HUWC e do grupo controle de 20 indivÃduos sem hemoglobinopatias. Os pacientes foram estratificados em grupos: uso de HU > 1 ano, uso de HU &#8804; 1 ano e sem uso de HU (SHU). A confirmaÃÃo do diagnÃstico e a anÃlise dos haplÃtipos foram realizadas atravÃs de estudo molecular. As dosagens do nitrito (NO2-), malonaldeÃdo (MDA), glutationa peroxidase (GSH-Px), catalase (CAT), glutationas total (GSSG+GSH), oxidada (GSSG) e reduzida (GSH) e da relaÃÃo GSSG/GSH (glutationas oxidada/reduzida) foram realizadas por espectrofotometria. Os nÃveis mÃdios de NO2-, e MDA mostraram-se mais elevados no grupo SHU, sendo significante apenas para o MDA (p < 0,05). O grupo SHU apresentou atividade mÃdia das enzimas CAT (p = 0,031) e GSH-Px (p = 0,036) inferiores aos demais grupos e maior relaÃÃo GSSG/GSH (p < 0,05). A avaliaÃÃo do estresse oxidativo em relaÃÃo aos haplÃtipos demonstrou que na populaÃÃo sem uso de HU os nÃveis de NO2- e de MDA foram semelhantes entre os grupos, com um aumento nÃo significante da GSH-Px no grupo Bantu/n em relaÃÃo ao Benin/n e do Ãndice GSSG/GSH no grupo Benin/n em relaÃÃo ao Bantu/n. Na populaÃÃo em uso de HU verificou-se um aumento nÃo significante dos nÃveis de NO2- no grupo Bantu/n em relaÃÃo ao Benin/n com resultados semelhantes de MDA entre os grupos e um aumento significante da GSH-Px (p<0,03) no grupo Benin/n em relaÃÃo ao Bantu/n. Os resultados da CAT foram semelhantes entre os grupos. A relaÃÃo GSSG/GSH foi maior, porÃm nÃo significante no grupo Bantu/n em relaÃÃo ao Benin/n. Os resultados do presente estudo reforÃam a hipÃtese de que os pacientes com AF apresentam um estado hiperoxidativo com nÃveis elevados dos produtos do estresse oxidativo e diminuÃdos do perfil antioxidante e que a hidroxiurÃia teve um impacto sobre o perfil oxidativo. No entanto, em relaÃÃo ao impacto dos haplÃtipos no estresse oxidativo, estudos posteriores com uma maior amostragem devem ser recomendados para confirmar nossos resultados, considerando que o grupo de pacientes nÃo tratados com HU foi menor que o grupo de pacientes em uso de HU, o que pode ter interferido na anÃlise estatÃstica dos resultados. / The sickle cell anemia is one of the most common genetic disorders in our country. The &#61538;-globin haplotypes are associated with the clinical heterogeneity of the disease. Individuals with sickle cell disease are subjected to high levels of oxidative stress. Hydroxyurea (HU) has been used as treatment and it increases the levels of fetal hemoglobin having an action antioxidant. The study aimed to investigate the impact of the use of HU and haplotypes in the oxidative status in patients with sickle cell anemia. Samples from 64 patients treated at the University Hospital Walter CantÃdio - HUWC and the control group of 20 individuals without hemoglobinopathies. Patients were stratified into groups: the first one using HU > 1 year, the second using HU &#8804; 1 year and the third using of HU (SHU). Confirmation of the diagnosis and analysis of haplotypes were performed by molecular study. The measurements of nitrite (NO2-), malonaldehyde (MDA), glutathione peroxidase (GSH-Px), catalase (CAT), glutathione total (GSSG+GSH), oxidized (GSSG) and reduced (GSH) and the ratio GSSG/GSH (glutathione oxidized/reduced) were performed by spectrophotometry. Mean levels of NO2- and MDA were shown to be higher in SHU group, being significant only for MDA (p < 0,05). The assessment of oxidative stress in relation to haplotypes showed that the population without the use of HU levels of NO2- and MDA were similar between groups, with an insignificant increase of GSH-Px in the Bantu/n compared with Benin/n and index GSSG/GSH in the Benin/n compared with Bantu/n. In the population using the HU there was a nonsignificant increase in the levels of NO2- in the Bantu/n compared with Benin/n with similar results between groups of MDA and a significant increase in GSH-Px (p <0.03) in the Benin/n compared with Bantu/n. The results of CAT were similar between groups. The ratio of GSSG/GSH was higher but not significant in the Bantu/n compared to Benin/n. The results of this study support the hypothesis that patients with the sickle cell anemia have a state hiperoxidativo products with high levels of oxidative stress and decreased antioxidant status and that of hydroxyurea had an impact on oxidative stress. However, regarding the impact of the haplotypes in oxidative stress, further studies with a larger sample should be recommended to confirm our results, considering that the group of patients not treated with HU was lower than the group of patients using HU, the which may have interfered in the statistical analysis of results.

Orientador: Nicola Amanda Conran Zorzetto, Fernando Ferreira Costa / Texto em português e inglês / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T19:18:22Z (GMT). No. of bitstreams: 1 Garrido_VanessaTonin_D.pdf: 6610754 bytes, checksum: 9b799d90821835bae6ac5d806b1d2f1c (MD5) Previous issue date: 2014 / Resumo: A anemia falciforme (AF) é uma hemoglobinopatia hereditária resultante de uma mutação no gene que codifica a subunidade ?-globina, levando à produção da hemoglobina S (HbS) nos eritrócitos. Com a polimerização da HbS, durante a desoxigenação, ocorre a deformação e fragilização das células vermelhas, resultando em anemia hemolítica e eventos vaso-oclusivos. As crises vaso-oclusivas são a principal causa de morbidade nos pacientes com anemia falciforme e as plaquetas parecem ter um papel importante nesse processo, pois uma vez ativadas elas secretam e expressam mediadores que induzem uma resposta inflamatória tanto em leucócitos como em células endoteliais. A proposta deste trabalho foi investigar a produção e expressão dos mediadores inflamatórios derivados de plaquetas, LIGHT e CD40L, em controles (indivíduos saudáveis; CON), pacientes com anemia falciforme (AF) e pacientes com anemia falciforme em terapia com hidroxiureia (AFHU). Também avaliamos o envolvimento das plaquetas e seus mediadores na ativação de leucócitos e células endoteliais. Os níveis plasmáticos de ambas citocinas foram significativamente maiores em indivíduos AF e AFHU do que nos indivíduos controle e, curiosamente, apesar da hidroxiureia ser capaz de diminuir a concentração plasmática de algumas citocinas inflamatórias, a terapia com essa droga não foi associada com qualquer alteração nos níveis de LIGHT ou CD40L. Foi observada uma correlação expressiva da concentração de LIGHT com níveis plasmáticos de CD40L, IL-8, ICAM-1, Trombospondina-1 e TNF-?, enquanto que a concentração plasmática de CD40L correlacionou-se com os níveis de TNF-? e principalmente com Trombospondina-1, indicando que tanto LIGHT como CD40L podem estar participando ou então refletindo a inflamação crônica presente na anemia falciforme. A expressão proteica de LIGHT foi significativamente maior na superfície de plaquetas de indivíduos AF e AFHU em comparação com plaquetas CON e apresentou uma correlação com marcadores de ativação plaquetária. A secreção de LIGHT pelas plaquetas foi determinada por ELISA e concentrações significativas dessa citocina puderam ser detectadas no sobrenadante de plaquetas CON e AF, sugerindo que essas células podem ser uma fonte importante de LIGHT na circulação. Apesar da expressão de CD40L não ter sido detectada na superfície das plaquetas de pacientes e controles, as plaquetas de pacientes AF secretaram uma quantidade maior de CD40L em comparação aos controles e foi observada uma correlação significativa entre a liberação de LIGHT e CD40L em plaquetas de pacientes AF, indicando que pode existir uma associação na secreção dessas duas citocinas. A expressão dos receptores de LIGHT (HVEM e LT?R) e de CD40L (CD40) foi avaliada por citometria de fluxo em plaquetas, neutrófilos, linfócitos e monócitos. Foi observado que o receptor HVEM estava mais expresso em plaquetas e linfócitos de pacientes com anemia falciforme, enquanto que a expressão do receptor CD40 estava elevada nas plaquetas, nos neutrófilos, nos linfócitos e nos monócitos de pacientes, comparando com o grupo controle. Esses dados mostram que a via de sinalização de LIGHT e CD40L pode estar alterada na anemia falciforme, contribuindo com a ativação dos leucócitos. Quando avaliamos a participação das plaquetas na ativação dos leucócitos, observamos que as plaquetas de indivíduos com anemia falciforme foram eficientes em aumentar a expressão do marcador de ativação, CD69, nos linfócitos e também em induzir o fenótipo pró-inflamatório nos monócitos. Enquanto que a co-cultura de HUVECs com plaquetas demonstrou que as plaquetas de pacientes com anemia falciforme possuem uma capacidade maior de induzir a expressão de ICAM-1 em células endoteliais do que as plaquetas de indivíduos controle. Na presença de anticorpos anti-CD40L observamos uma redução drástica no aumento da expressão de ICAM-1 pelas plaquetas e apesar dessa expressão também ter sido reduzida na presença de anticorpos anti-LIGHT, esses resultados não foram estatísticamente significativos. Interessantemente, altas concentrações plasmáticas de LIGHT estavam associadas com a elevada velocidade de regurgitação tricúspide, um indicativo de hipertensão pulmonar na anemia falciforme e uma associação significativa também foi encontrada entre níveis elevados de CD40L e pacientes com histórico de Síndrome Torácica Aguda. Essas evidências sugerem que LIGHT e CD40L parecem estar contribuindo com a ativação dos leucócitos e do endotélio, exercendo um papel importante na fisiopatogenia da anemia falciforme e aparentemente nas manifestações clínicas desta doença. Os resultados encontrados neste estudo evidenciam a importância que as plaquetas e seus mediadores inflamatórios, LIGHT e CD40L, podem ter na propagação da inflamação vascular presente na anemia falciforme, se tornando possíveis alvos para novas abordagens terapêuticas / Abstract: Sickle cell disease results from a single amino acid substitution in the gene encoding the ?-globin subunit, leading to hemoglobin S production in red blood cells. Polymerization of deoxygenated sickle hemoglobin leads to decreased deformability of red blood cells, resulting in hemolytic anemia and vaso-occlusive events. Platelets appear to play an important role in the vaso-occlusive process, as following their activation they express and secrete mediators that induce an inflammatory response in endothelial cells and leukocytes. The purpose of this study was to investigate the production and expression of LIGHT and CD40L on platelets, the presence of this protein in the plasma of controls (healthy subjects; CON), sickle cell anemia patients (AF) and sickle cell anemia patients on hydroxyurea therapy (AFHU). In addition, this study evaluated the involvement of platelets and their mediators, LIGHT and CD40L, in the activation of leukocytes and endothelial cells. Plasma levels of both cytokines were significantly higher in AF and AFHU individuals than in control individuals and interestingly, HU therapy was not associated with a reduction in these levels. A significant correlation was observed between levels of LIGHT with plasma levels of CD40L, IL-8, ICAM-1, Thrombospondin-1 and TNF-?, whereas the plasma concentration of CD40L correlated with levels of TNF-? and especially with plasma Thrombospondin-1. LIGHT expression was significantly higher on the surface of platelets from AF and AFHU subjects, compared with CON individuals and this expression demonstrated a correlation with markers of platelet activation. LIGHT secretion was determined by ELISA and significant concentrations of this cytokine could be detected in the supernatant of platelets from CON and AF individuals, indicating that platelets may be an important source of LIGHT. Although CD40L expression was not detected on the platelet surface in patients or controls, sickle platelets secreted an increased amount of CD40L, compared to controls. A significant correlation was observed between CD40L and LIGHT release in sickle cell patients, indicating that the production of these two proteins may be tightly coupled. The expression of LIGHT (HVEM and LT?R) and CD40L (CD40) receptors was evaluated by flow cytometry on the surface of platelets, neutrophils, lymphocytes and monocytes. An increased HVEM receptor expression was observed on the platelets and lymphocytes of sickle cell patients, whereas the expression of the CD40 receptor was elevated on platelets, neutrophils, lymphocytes and monocytes from sickle cell patients, compared to control subjects. Evaluating the contribution of platelets to leukocyte activation, we observed that platelets from sickle cell anemia individuals increased the expression of the activation marker, CD69, on lymphocytes and also induced a pro-inflammatory phenotype on monocytes. Co-culture of HUVEC with platelets demonstrated that sickle cell platelets have an increased ability to induce ICAM-1 expression on endothelial cells than platelets from control subjects. Furthermore, in the presence of anti-CD40L antibodies, a drastic reduction was observed in this increase. Although the expression of endothelial ICAM -1 was also reduced in the presence of anti-LIGHT antibodies, these results were not statistically significant. Interestingly, high plasma concentrations of LIGHT were associated with elevated tricuspid regurgitant velocity, indicative of pulmonary hypertension in sickle cell anemia. A significant association was also found between high levels of CD40L and patients with a lifetime history of acute chest syndrome. LIGHT and CD40L appear to contribute to leukocyte and endothelial activation, playing an important role in the pathophysiology of sickle cell anemia and apparently in the clinical manifestations of this disease. These results highlight the important role that platelets and their inflammatory mediators may play in the vascular inflammation that is known to occur in sickle cell anemia / Doutorado / Fisiopatologia Médica / Doutora em Ciências

Ischemic stroke is defined as a blockage or reduced flow of blood to select areas of brain tissue due to either plaque formation or buildup of blood clots in the small blood vessels. A characteristic of sickle cell anemic patients is the potential for them to experience a similar type of blockage due to the sticky nature of the sickled red blood cells as well as defective oxygen delivery to the brain. Because of this similarity, sickle cell anemia may represent a good animal research model for therapeutic intervention based on stroke models. In recent studies, Granulocyte-Colony Stimulating Factor (GCSF), has been shown to exhibit a robust range of neuroprotective properties against neurological disorders including ischemic stroke through preservation of the endoplasmic reticulum (ER) by modulating various ER stress pathways. Through cognitive deficit analysis in the form of behavioral and locomotor experiments in addition to in situ biomarker analysis by way of western blotting and immunohistochemistry, we found that G-CSF gene therapy exhibited neurogenic and neuroprotective effects in ischemic mouse models and could possibly serve as a good therapy for other diseases that share similar pathology to stroke. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

The genetic disorder sickle cell anemia causes hemolytic anemia and sickle pain crisis, episodes of microvascular occlusion resulting in painful ischemic tissue damage. Pain crisis is thought to occur when sickle erythrocytes adhere in the post-capillary venule, partially occluding the vessel. The resulting slowed blood flow causes more extensive cell adherence and entrapment of rigid, deoxygenated erythrocytes until the vessel is entirely occluded. It was hypothesized that the inflammatory mediators histamine and tumor necrosis factor-, factors known to cause endothelial expression of adhesive ligands, might significantly increase sickle erythrocyte adhesion, and thus be capable of initiating sickle pain crisis. It was also hypothesized that the perfusion shear stress environment of the endothelium, known to be oscillatory and reduced in sickle cell patients, was a significant mediating factor of sickle cell adhesion. An in-vitro flow chamber using cultured endothelial cells and erythrocytes from blood samples of sickle cell anemic patients was used to quantify sickle erythrocyte adherence to stimulated and unstimulated endothelial cells under shear stresses from 1.0 to 0.1 dyne/cm2. Results showed that both endothelial stimulation and reduction of the perfusion shear stress increased sickle erythrocyte adherence. In combination, the use of inflammatory stimulation with reduced shear stress resulted in further increased adhesion, but only when above the range of 0.1 V 0.2 or 0.4 dyne/cm2, depending on the inflammatory mediator. Adhesion below this level of shear is not significantly increased by endothelial stimulation. The mechanism by which histamine mediates adhesion was investigated, and found to involve the endothelial H2 and H4 receptors and expression of the P-selectin ligand. These data suggest that irregular flow, typical of sickle microvasculature, may act in conjunction with the pro-inflammatory state of sickle vasculature and the histaminergic nature of some pain treatments to initiate or propagate sickle vaso-occlusion. Findings concerning histamine, tumor necrosis factor-alpha, and shear stress effects on adherence are discussed in relation to their possible applicability to patient health, future studies are outlined to confirm the relation of in vitro data to in vivo patient condition, and proposals are made for applying these methodologies to other potential mediators of sickle erythrocyte adhesion.

Adhesion of sickle erythrocytes to vascular endothelium may initiate or propagate occlusive events in sickle cell anemia, many of which are accompanied by infection and the associated inflammatory response. Inflammatory markers are also present in sickle patients during asymptomatic periods. Inflammatory cytokines upregulate expression of endothelial adhesion molecules that promote adhesion of sickle erythrocytes. The data in this work demonstrate that after 2 hrs of stimulation with the cytokine TNF- and alpha;, E-selectin, but not VCAM-1 is upregulated on human dermal microvascular endothelial cells. After 6 hrs of TNF- and alpha; stimulation, both VCAM-1 and E-selectin expression are upregulated on MECs, and sickle erythrocytes bind to both receptors. Because strategies to control inflammation-associated adhesion in vivo may need to account for both VCAM-1 and E-selectin mediated events, control of intracellular signaling pathways leading to receptor expression is an attractive strategy for inhibiting adhesion. Cyclic AMP and nitric oxide are two intracellular signaling molecules important to cytokine-induced receptor expression. The data in this work demonstrate that TNF- and alpha; induced VCAM-1 and E-selectin expression on endothelial cells and sickle erythrocyte adhesion are abated by increasing endothelial cyclic AMP concentrations using Forskolin, IBMX, or Bt2cAMP. Conversely, when sickle erythrocytes, rather than endothelial cells, are treated with reagents that increase intracellular cAMP, adhesion to unstimulated endothelial cells is increased in some patients. Treatment of endothelial cells with reagents such as SNP and DETA-NO that increase nitric oxide significantly inhibits VCAM-1, but not E-selectin expression, induced by TNF- and alpha; stimulation and significantly inhibits sickle erythrocyte adhesion. Treatment of sickle erythrocytes directly with these reagents may also inhibit adhesion. Together these data suggest that cAMP- and nitric oxide-dependent signaling are useful therapeutic targets to inhibit cytokine-induced sickle erythrocyte adhesion to endothelium.

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A continuous need for blood products, specifically for those who require frequent transfusions, such as individuals with sickle cell disease, warrants the need for targeted interventions to increase blood donations from underrepresented populations. One population in particular, African Americans, only account for 1% of blood donors in the United States. Literature indicates numerous reasons why this population is underrepresented amongst donors, including fear, lack of knowledge about the blood donation, and specific to this population, lack of trust in the medical community. This study involves the development, implementation, and assessment of a targeted educational approach, incorporating the Theory of Planned Behavior and various teaching methods, to motivate African Americans non-donors to attempt to donate blood. Participants attended a 1-hour educational session where they completed two surveys, one before the session and one directly after. A third survey was completed 2 months after the session. Of the 155 individuals enrolled in the study, 142 subjects were included in the data analysis. Sixteen percent of the study participants presented to donate as a result of attending the educational session. This resulted in a statistically significantly higher proportion of African Americans presenting to donate than the current proportion in Virginia. Analysis of results from the first two surveys indicated that subjective norm and attitude were significant predictors of one’s intent to donate blood, while perceived behavioral control was not a factor. The educational session increased survey scores related to intent to donate in comparison to scores obtained prior to the session. While this study resulted in a significant proportion of new donors, there is still a need for interventions that will focus specifically on changing attitudes toward blood donation and a need for methods to motivate African Americans to educate individuals in the community on the importance of becoming blood donors.

A anemia falciforme (AF) é uma doença monogênica de elevada mortalidade e morbidade, que afeta milhões de pessoas em todo o mundo. Não há tratamento definitivo que seja amplo, eficaz e seguro para a AF, de forma que os tratamentos paliativos são os mais utilizados. O tratamento definitivo disponível é transplante alogênico de células-tronco hematopoiéticas, porém com várias complicações envolvidas. O estabelecimento de um modelo in vitro permite uma melhor compreensão de como a doença ocorre, além de permitir o desenvolvimento de novos testes e tratamentos mais eficazes contra a doença. Neste contexto, a tecnologia das células-tronco pluripotentes induzidas (iPSC), que surgiu em 2006, é uma ferramenta poderosa na pesquisa básica, na pesquisa da diferenciação de tecidos e no modelamento de doenças, e uma promessa para futuras aplicações clínicas, na descoberta e triagem de novas drogas mais eficazes e seguras, além da possibilidade de utilização na medicina regenerativa, na produção de células paciente-específicas para terapia celular. Este trabalho teve como objetivo obter um modelo de estudo e tratamento da AF utilizando iPSC. Para isso, vetores epissomais foram utilizados para a reprogramação de células mononucleares de sangue periférico para obter iPSC livres de integração. Estas células foram coletadas de pacientes tratados com o medicamento hidroxiureia e sem tratamento, para avaliação do impacto da droga na reprogramação. As linhagens de iPSC PBscd geradas foram caracterizadas quanto ao potencial pluripotente e de diferenciação. Todas as linhagens geradas se mostraram pluripotentes com potencial de auto renovação e potencial de formar células e tecidos dos 3 folhetos germinativos. O rastreamento dos vetores utilizados na reprogramação mostrou que as células estão livres após cerca de 10 passagens em média, e que eles não se integram espontaneamente nas células. As linhagens de iPSC foram diferenciadas em progenitores hematopoiéticos através da agregação forçada associada à indução com citocinas específicas e um cultivo em suspensão. Dessa forma, nós obtivemos um protocolo dinâmico e eficiente de produção de células CD34+CD45+ com poucos dias de indução. Foram realizados experimentos iniciais de padronização da metodologia de CRISPR, para que essa metodologia possa ser utilizada no futuro para a correção da mutação da AF no gene da ?- globin. Além disso, a reação padronizada para o rastreamento da mutação no gene da ?-globin poderá ser usado em experimentos futuros de edição gênica para avaliar a correção da mutação. Em resumo, oferecemos uma ferramenta valiosa para uma melhor compreensão de como a AF ocorre, além de tornar possível o desenvolvimento de drogas e tratamentos mais eficazes e de fornecer um melhor entendimento dos tratamentos amplamente utilizados, como a hidroxiurea / Sickle cell anemia (SCA) is a monogenic disease of high mortality and morbidity, that affects millions of people worldwide. There is no definitive treatment that is broad, effective and safe for SCA, so the palliative treatments are the most used. The definitive treatment available is the allogeneic transplantation of hematopoietic stem cells, but with several complications involved. The establishment of an in vitro model allows better understanding of how the disease occurs, besides allowing the development of more effective new tests and treatments against the disease. In this context, the induced pluripotent stem cell (iPSC) technology, that emerged in 2006, is a powerful tool for basic research, tissue differentiation research and disease modeling, and a promise for future clinical applications, to find and screen new, more effective and safe drugs, besides the possibility of use in regenerative medicine, in the production of patient-specific cells for cell therapy. This work aimed to obtain a model for study and treatment of SCA using iPSC. For this, episomal vectors were used for reprogramming peripheral blood mononuclear cells to obtain integration-free iPSC. This cells were collected from patients treated with hydroxyurea and without treatment, for evaluation of the impact of the drug in reprogramming. The generated iPSC PBscd lines were characterized for pluripotent and differentiation potential. All the generated lines were shown to be pluripotent with potential for self-renewal and to form cells and tissues of the 3 germ layers. Screening of the vectors used for reprogramming showed that they are absent after about 10 passages, and that they do not integrate spontaneously into the cells. The iPSC lines were differentiated into hematopoietic progenitors through forced aggregation associated with induction with specific cytokines and culture in cell suspension. Thus, we obtained a dynamic and efficient protocol of CD34+CD45+ cells production with a few days of induction. Initial standardization experiments of CRISPR methodology was performed, so that this methodology can be used in the future to correct the ?-globin chain mutation of SCA. Also, the standardized reaction for the screening of ?-globin chain mutation can be used in future gene-editing experiments to evaluate the mutation correction. In summary, we offer a valuable tool for a better understanding of how SCA occurs, in addition to make possible the development of more effective drugs and treatments and providing better understanding of widely used treatments, such hydroxyrea

Nos últimos anos, o desenvolvimento de novas plataformas biossensoras trouxe importantes avanços à área médica, incluindo maior rapidez na detecção de biomarcadores, menor custo de análise e portabilidade. Essa tese traz a descrição do desenvolvimento de três tipos de biossensores que visam à auxiliar o diagnóstico de diferentes doenças. No primeiro capítulo, detalha-se a construção de um dispositivo microfluídico baseado em papel para a quantificação simultânea de dois biomarcadores da doença de Alzheimer: Fetuína B e Clusterina. O dispositivo foi capaz de quantificar as proteínas estudadas de maneira precisa e de baixo custo através do uso de técnicas eletroquímicas e colorimétricas, apresentando limites de detecção na ordem de p-nmol/L. O segundo capítulo trata do desenvolvimento de um imunossensor eletroquímico para a quantificação de melatonina. O dispositivo foi capaz de detectar a biomolécula em amostras biológicas rapidamente e com boa especificidade, diferenciando a melatonina de componentes com alta semelhança estrutural. Por fim, o terceiro capítulo descreve um genossensor eletroquímico para diagnóstico e determinação do traço da doença genética mais comum no Brasil, a anemia falciforme. O sensor foi capaz de diferenciar sequências normais de mutadas de maneira simples e rápida, sendo adequado para o diagnóstico e a determinação de seu traço. Esperamos que os dispositivos aqui apresentados levem à diagnósticos mais acessíveis fornecendo assim melhores condições de saúde à população. / The development of new biosensor platforms has brought important advances to the medical field, including faster detection of biomarkers, lower cost of analysis and portability. This thesis provides a description of the development of three biosensors that aim to assist the diagnosis of three different diseases. The first chapter describes the construction of a paper-based microfluidic device for the simultaneous quantification of two Alzheimer\'s disease biomarkers: Fetuin B and Clusterin. The device was able to quantify the studied proteins in a precise and low cost manner through the use of electrochemical and colorimetric techniques, presenting limits of detection in the order of p-nmol/L. The second chapter details the the development of an electrochemical immunosensor for the quantification of melatonin. The device was able to detect the biomolecule in biological samples quickly and with good specificity, differentiating melatonin from components with high structural similarity. Finally, the third chapter describes an electrochemical genosensor for diagnosis and determination of the trait of the most common genetic disease in Brazil, sickle cell anemia. The sensor was able to differentiate normal and mutated sequences in a simple and fast manner, being suitable for the diseases diagnosis and the determination of its trait. Therefore, we expect the devices presented here to lead to more accessible diagnoses, providing better health conditions for the population.