CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Novos biomarcadores da funÃÃo renal estÃo sendo estudados com o propÃsito de detectar precocemente alteraÃÃes renais em portadores de AF, dentre eles encontra-se a proteÃna quimiotÃtica de monÃcitos 1 (MCP-1), uma quimiocina de monÃcitos e macrÃfagos, produzida por cÃlulas do sistema renal em resposta ao processo de isquemia-reperfusÃo. OBJETIVO: Avaliar o uso de MCP-1 como biomarcador de lesÃo renal precoce em pacientes adultos com anemia falciforme em uso ou nÃo de hidroxiureia (HU). METODOLOGIA: Participaram do estudo 50 pacientes: 30 em uso de (HU)-grupo SSHU e 20 sem HU-grupo SS. Um grupo controle foi composto por 20 indivÃduos com HbAA, sem complicaÃÃes renais. ProteinÃria, albuminÃria, creatinina e urÃia urinÃrias, marcadores do estresse oxidativo como MDA e NOx foram determinados por mÃtodos espectrofotomÃtricos. MCP-1 urinÃrio foi detectado por enzima imunoensaio (ELISA). Os dados clÃnicos e de hemograma, creatinina e ureia sÃricas foram retirados do prontuÃrio mÃdico. Foi coletada a primeira urina do dia. O programa Graph Pad Prism 5.0 foi utilizado para anÃlise estatÃstica. A comparaÃÃo das mÃdias entre os grupos foi realizada atravÃs do teste t de Student e anÃlise de variÃncia (ANOVA). RESULTADOS E DISCUSSÃO: Albumina urinÃria esteve maior nos pacientes em relaÃÃo ao grupo controle (Controle-3.12 Â 4.35; SSHU- 11.85 Â 9.16; SS- 14.13 Â 12.22; p <0.0001). A taxa de filtraÃÃo glomerular estimada apresentou-se significantemente menor no grupo controle (Controle- 95.9 Â 19.92; SSHU- 137.9 Â 40.7 e SS- 140.1 Â 53.9; p= 0.0024). Observaram-se nÃveis elevados de MCP-1 (Controle- 42.12 Â 27.6; grupo SSHU- 166.2 Â 88.37 e grupo SS- 219.7 Â 115.0; p<0.001; p=0.039); MDA (Controle- 2.29 Â 1.13; grupo SSHU-5.25 Â 2.33 e grupo SS- 6.93 Â 2.12; p<0.0001;p=0.006) e NOx (Controle-2.25Â1.9; grupo SSHU-56.54 Â 9.15 e grupo SS 39.12 Â9.02; p<0.0001; p=0.001) nos pacientes em comparaÃÃo aos controles saudÃveis, e mais elevados no grupo SS em relaÃÃo ao grupo SSHU. Os pacientes com haplÃtipo Bantu/Bantu apresentaram maior concentraÃÃo de MCP-1, independente do uso de HU, seguido de Bantu/ Benin e Benin/Benin (p=0.01). Observou-se correlaÃÃo positiva entre os uma correlaÃÃo entre os nÃveis de MCP-1 e contagem de monÃcitos (p=0.004; r= 0.42); proteinÃria (p=0.002; r=0.43); albuminÃria (p=0.0004; r=0.47); TFG (p=0.02; r=0.32); MDA (p=0.02; r=0.32) e NOx (p=0.007; r= 0.38). CONCLUSÃO: Os resultados indicam que MCP-1 foi preditivo na detecÃÃo de alteraÃÃo renal, e que pode estar correlacionado ao dano causado pelo estresso oxidativo nos rins, evidenciado pelos altos nÃveis de MDA. Ainda, a HU parece ter reduzido o dano renal, visto que os pacientes em uso do fÃrmaco apresentaram nÃveis reduzidos desses parÃmetros.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2018-05-24T17:30:38Z No. of bitstreams: 1 keniadeassisboy.pdf: 53006692 bytes, checksum: 65f398b7012273fa08a2843e4d1f6878 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-06-14T11:54:22Z (GMT) No. of bitstreams: 1 keniadeassisboy.pdf: 53006692 bytes, checksum: 65f398b7012273fa08a2843e4d1f6878 (MD5) / Made available in DSpace on 2018-06-14T11:54:22Z (GMT). No. of bitstreams: 1 keniadeassisboy.pdf: 53006692 bytes, checksum: 65f398b7012273fa08a2843e4d1f6878 (MD5) Previous issue date: 2018-03-20 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A doença falciforme (DF) é um grave problema de saúde pública mundial, com grande impacto na morbimortalidade da população acometida. Até o momento, a hidroxiureia (HU) é considerada a terapia farmacológica de maior sucesso para a DF, pois promove redução do número e gravidade dos eventos falcêmicos, melhora os parâmetros hematológicos, reduz o número de internações e aumenta a expectativa e qualidade de vida dos pacientes. Ainda que sejam evidentes os benefícios do tratamento com HU, existe grande variabilidade interindividual de resposta farmacológica e os fatores genéticos parecem estar associados, em parte, a essa variação. Assim, o objetivo do presente estudo foi investigar se polimorfismos de um único nucleotídeo (SNPs) em quatro genes candidatos relacionados à farmacocinética e farmacodinâmica da HU afetam a resposta hematológica a tal fármaco. Para tanto, foram avaliados 185 pacientes com DF tratados (n=93) ou não tratados (n=92) com HU. Os níveis médios de hemoglobina (Hb), hematócrito (Hct), reticulóticos (Rtc) e leucometria global (LG) foram medidos em cinco diferentes tempos ao longo de 18 meses, enquanto a concentração de hemoglobina fetal (HbF) foi analisada antes e após o tratamento farmacológico. Os pacientes foram agrupados como "respondedores" à HU se os níveis de HbF estivessem maiores que 20%, enquanto aqueles pacientes com níveis inferiores a esse foram considerados como "não respondedores". O DNA genômico foi extraído a partir do sangue total e amostras foram então genotipadas por PCR em tempo real (qPCR) para os polimorfismos G>T (rs1799983) e T>C (rs2070744) no gene da eNOS, C>T (rs17599586) da ARG1, A>C (rs766432) e G>A (rs4671393) do BCL11A e G>A (rs9960464) do gene do UTA. As análises de associação entre as variáveis categóricas foram feitas pelo teste do qui-quadrado ou teste exato de Fisher. Para as variáveis contínuas com distribuição normal, as análises foram realizadas utilizando ANOVA seguido pelo teste t não pareado e as variáveis que não seguiram distribuição normal foram analisadas pelos testes de Wilcoxon, Kruskal-Wallis seguidos por Mann-Whitney. As análises por regressão multivariada e logística foram realizadas através do método stepwise pelo software R. A população estudada apresentou idade de 15,8 ± 11,3 anos e foi constituída de 54% de voluntários do sexo masculino. As frequências genotípica e alélica para os seis SNPs estudados apresentaram-se em equilíbrio de Hardy-Weinberg e foram semelhantes àquelas encontradas em outras populações. Pacientes com o genótipo GT para o polimorfismo no rs1799983 do gene da eNOS apresentaram maiores valores de Hb quando comparados aos homozigotos para o alelo G (r=0,364; p=0,033). Adicionalmente, a frequência dos genótipos AC e CC no gene BCL11A (polimorfismo A>C rs766432) foi maior entre os pacientes respondedores quando comparado ao grupo dos não respondedores (p=0,03). Além disso, pacientes com o genótipo GA para o polimorfismo no gene UTA também responderam melhor à terapia com HU quando comparados àqueles com o genótipo GG (p=0,005). Não foram encontradas outras influências significativas nos demais polimorfismos avaliados após análise por regressão logística. Em conclusão, este trabalho é pioneiro ao avaliar a influência de polimorfismos nos genes da eNOS, ARG1, BCL11A e UTA na resposta à HU em pacientes com doença falciforme em Minas Gerais. Os achados nos sugerem que pacientes com genótipo GT no rs1799983 do gene da eNOS apresentam maiores valores de Hb quando comparados com genótipo GG. Os polimorfismos A>C (rs766432) no gene do BCL11A (p=0,001) e G>A (rs9960464) do gene UTA (p=0,005) parecem afetar a resposta hematológica à HU, sendo que pacientes que possuem pelo menos uma cópia do alelo de menor frequência possivelmente apresentam maior chance de resposta ao tratamento farmacológico. / Sickle cell disease (SCD) is a serious global public health problem, with great impact on the morbidity and mortality of the affected population. To date, hydroxyurea (HU) is considered the most successful pharmacological therapy for SCD since it promotes a reduction in the number and severity of sickle cell events, improves hematological parameters, reduces the number of hospitalizations and increases the expectation and quality of life of the patients. Although the benefits of the treatment with HU are evident, there is a large inter-individual variability of pharmacological response and genetic factors seem to be partially associated with this variation. Thus, the aim of the present study is to investigate whether single nucleotide polymorphisms (SNPs) in four candidates genes related to the pharmacokinetics and pharmacodynamics of HU affect the hematological response to such a drug. For this, 185 patients were evaluated with SCD, treated with HU (93) or untreated (92). The mean hemoglobin (Hb), hematocrit (Hct), reticulocytes (Rct) and global leukometry (LG) levels were measured at five different times over 18 months, while fetal hemoglobin (HbF) levels were analyzed before and after pharmacological treatment. Patients were grouped as "responders" to HU if HbF levels were higher than 20%, while those patients with levels below this value were considered "non-responders". Genomic DNA was extracted from the whole blood and samples were then genotyped by real-time PCR (qPCR) for the polymorphisms G>T (rs1799983) and T>C (rs2070744) on the eNOS gene, C>T (rs17599586) of ARG1 gene, A>C (rs766432) and G>A (rs4671393) of the gene BCL11A and G>A (rs9960464) of the UTA gene. The analysis of the association between the categorical variables was done by chi-square test or Fisher's exact test. For continuous variables with normal distribution, analyses were performed using ANOVA followed by the unpaired t-test and the variables that did not follow normal distribution were analyzed by the Wilcoxon, Kruskal-Wallis tests followed by Mann-Whitney. The multivariate and logistic regression analyses were performed through the stepwise method by software R. The population studied presented a mean age of 15.8 ± 11.3 years and was made up of 54% of male volunteers. The genotypic and allelic frequencies for the six SNPs studied were in Hardy-Weinberg equilibrium and were similar to those found in other populations. Patients with the GT genotype for rs1799983 polymorphism of the eNOS gene showed higher Hb values when compared to patients homozygous for the G allele (r=0,364; p=0,033). In addition, the frequency of AC and CC genotypes in the BCL11A gene (A>C polymorphism rs766432) was higher among the responders when compared to the non-responders group (p=0,03). In addition, patients with the GA genotype for the UTA gene polymorphism also responded better to HU therapy when compared to those with the GG genotype (p=0,005). No other significant influences were found in the other polymorphisms evaluated after logistic regression analysis. In conclusion, this work is a pioneer in evaluating the influence of polymorphisms in eNOS, ARG1, BCL11A and UTA genes in the response to HU in patients with sickle cell disease in Minas Gerais. The findings suggest that patients with the GT genotype for rs1799983 of the eNOS gene showed higher Hb values when compared to GG genotype. The A> C polymorphisms (rs766432) in the BCL11A (p=0,001) and G> A gene (rs9960464) of the UTA gene (p=0,005) appear to affect the hematological response to HU, and patients who have at least one copy of less frequent allele may present higher chance of respond to pharmacological treatment.

Orientador: Fernando Ferreira Costa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T03:49:55Z (GMT). No. of bitstreams: 1 Gambero_Sheley_D.pdf: 3649073 bytes, checksum: a76d9a7da22f0e08a3f4556b9b24330f (MD5) Previous issue date: 2011 / Resumo: A anemia falciforme (AF) é um distúrbio genético da hemoglobina causado por uma mutação de ponto no gene da beta-globina com consequente produção de hemoglobina S (HbS). A polimerização de HbS causa a deformação, enrijecimento e diminuição da flexibilidade das hemácias, resultando em uma série de eventos que levam a redução da sua vida média. Os principais fatores que influenciam a polimerização são: concentração de oxigênio e concentração de hemoglobina fetal (HbF). Pacientes com AF apresentam aumento dos níveis circulantes de citocinas, incluindo fator de necrose tumoral-'alfa' (TNF-'alfa') que possui efeitos pró-inflamatórios resultando no aumento das propriedades quimiotáxicas e a aderência de neutrófilos ao endotélio vascular. Muitos estudos têm sido realizados com o intuito de buscar novas estratégias terapêuticas que contribuam para o aumento dos níveis de HbF e diminuam os níveis de citocinas inflamatórias. Com este objetivo, novos compostos que agregam funções anti-inflamatórias e são moléculas doadoras de óxido nítrico, foram desenvolvidas. Deste modo, o objetivo deste trabalho foi avaliar os efeitos dos compostos derivados da hidroxiureia e da talidomida na produção de HbF, na atividade quimiotática e na produção de espécies reativas de oxigênio em células de pacientes com anemia falciforme e indivíduos controles, tratadas com o composto denominado Lapdesf 1, assim como a concentração de citocinas inflamatórias, em culturas de células mononucleares de camundongos falciforme. Os resultados obtidos demonstram que o composto Lapdesf 1 foi capaz de aumentar os níveis de HbF em cultura de células CD34+ e em linhagem celular K562. Os neutrófilos de indivíduos controles e pacientes com AF, tratados com este composto apresentaram a capacidade quimiotática induzida por Il-8 significativamente reduzida em relação ao controle, e o tratamento com Lapdesf 1 não alterou a geração de espécies reativas de oxigênio em plaquetas, neutrófilos, eritrócitos e células mononucleares. O tratamento de camundongos transgênicos para a AF demonstrou a capacidade desse composto em aumentar os níveis de HbF, além de diminuir a quantidade de citocinas inflamatórias no sobrenadante de culturas de células mononucleares de camundongos. Em resumo nossos resultados sugerem que o composto Lapdesf 1, apresenta-se como uma nova alternativa terapêutica, pela capacidade de aumentar a síntese de HbF e diminuir os níveis de citocinas inflamatórias e seus efeitos, que merece ser testada como possível tratamento da anemia falciforme / Abstract: Sickle cell anemia is a genetic hemoglobin disorder caused by a point mutation that produces hemoglobin S (HbS). Polymerization of HbS causes deformation, stiffness and decreased flexibility of red blood cells, resulting in different events. The main factors influencing polymerization are: oxygen concentration and intracellular concentration of fetal hemoglobin (HbF). It has been reported that patients with sickle cell disease have increased circulating levels of cytokines, including tumor necrosis factor-'alfa' (TNF-'alfa') which has pro-inflammatory effects, resulting in increased chemotactic properties and adhesion of neutrophils to vascular endothelium. Many studies have been conducted in order to pursue new therapeutic strategies that increase fetal hemoglobin levels and lower levels of inflammatory cytokines. New compounds have been developed for the treatment of some sickle cell anemia symptoms. These compounds have several functions: they act as antiinflammatory agents, and donate nitric oxide. Thus the objectives of this study were to evaluate effects of compounds derived from hydroxyurea and thalidomide in the production of HbF, chemotactic activity and production of reactive oxygen species in cells from patients with sickle cell anemia and controls treated with the compound called Lapdesf1, and also the concentration of inflammatory cytokines in cultures of mononuclear cells from sickle cell mice. Our results demonstrate that the compound, Lapdesf 1, was able to increase levels of fetal hemoglobin in CD34+ cultured cells and K562 lineage cells. Neutrophils from control subjects and patients with sickle cell anemia had their chemotactic capacity significantly reduced following treatment with this compound; furthermore, the compound did not alter the generation of reactive oxygen species in platelets, neutrophils, red cells and mononuclear cells. Treatment of transgenic sickle cell anemia mice demonstrated the ability of the compound to increase fetal hemoglobin in vivo and reduce the amount of inflammatory cytokines such as TNF-'alfa', IL-8, IL-6 and IL- 1ß in the supernatant of cultures of mononuclear cells from sickle mice. In summary, our results suggest that the compound Lapdesf 1 has the ability to increase HbF synthesis and decrease the levels of inflammatory cytokines and their effects. So this compound may present promise as a new drug for the treatment of sickle cell disease, minimizing the clinical complications associated with this disease / Doutorado / Biologia Estrutural, Celular, Molecular e do Desenvolvimento / Doutor em Fisiopatologia Medica

Orientadores: Fernando Ferreira Costa, Nicola Conran / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T10:27:56Z (GMT). No. of bitstreams: 1 Gambero_Sheley_M.pdf: 2005109 bytes, checksum: faec483bdfe41c20b920e16808d8eb59 (MD5) Previous issue date: 2006 / Resumo: A anemia falciforme é um distúrbio genético da hemoglobina causado por uma mutação de ponto produzindo hemoglobina S (HbS) que quando desoxigenada causa, entre outros sintomas, eventos vaso-oclusivos. Um dos mecanismos indicados como causador da vaso-oclusão é a adesão de hemácias falciformes ao endotélio dos vasos. Eritrócitos falciformes e normais aderem ao endotélio vascular utilizando moléculas de adesão como, CD 36 e integrina VLA-4, entre outras moléculas de adesão. Hidroxiuréia (HU) é um agente quimioterápico que diminui a freqüência de crises vaso-oclusivas, síndrome torácica aguda e necessidade de transfusão. Longos tratamentos com HU levam a uma redução global das proteínas de superficie dos neutrófilos, monócitos e linfócitos, além de aumentar os níveis de Hemoglobina fetal (Hb F), que inibe a polimerização da célula falciforme desoxigenada. O NO é um importante vaso-dilatador responsável por inúmeros efeitos benéficos durante as crises vaso-oclusivas. Estudos demonstram que o NO pode diminuir a expressão endotelial de moléculas de adesão, mas estudos diretos sobre os níveis de expressão dessas moléculas em anemia falciforme na presença de NO não tem sido encontrados na literatura. Deste modo objetivamos neste trabalho, analisar a expressão, gênica e protéica, e a função das moléculas de adesão VLA-4 (CD49d ou cadeia a. e CD29 ou cadeia 13) e CD 36 em células vermelhas de pacientes com anemia falciforme com e sem terapia com HU e os efeitos do tratamento in vitro com HU e agentes doadores de NO na adesão dessas células. Analisando a adesão das células vermelhas normais e de pacientes com e sem terapia com HU confirmamos que as células vermelhas de pacientes falciformes são mais aderentes que as células vermelhas normais e que a terapia com HU provoca uma diminuição dessa aderência. A citometria de fluxo comprovou a maior presença de células CD36+ e CD49d+ além de maior índice de expressão dessas moléculas nos pacientes falciformes em relação ao controle e a diminuição da expressão e positividade dessas moléculas em células de pacientes em terapia com HU quando comparadas com pacientes sem terapia. Adicionalmente, a análise por Real Time PCR demonstrou que a expressão gênica de CD36, CD49d e CD29 em reticulócitos falciformes é significativamente menor em pacientes em terapia com HU quando comparado com pacientes que não recebem essa terapia. Em resumo, nossos resultados sugerem que: as propriedades adesivas à fibronectina (FN) são aumentadas em células SS e que estas propriedades diminuem nos pacientes que tomam a terapia de HU; a terapia com HU diminui a expressão protéica e a positividade, das células vermelhas falciformes, hemácias e células jovens, para os receptores CD36 e CD49d; e a expressão gêniea das moléculas de adesão CD36 e CD49d em reticulócitos de pacientes com anemia falciforme que recebem terapia com HU é diminuída em relação ao grupo de pacientes falciformes que não recebem essa terapia / Abstract: Sickle cell vaso-occlusion constitutes a complex process involving interactions between SS red blood cells (RBC), endothelial cells, leukocytes, platelets, coagula tive factors and plasma proteins. Propagation ofthe vaso-occlusive process in sickle cell anemia (SCA) is a complex process involving the adhesion of SS red cells and reticulocytes to the vascular endothelium. The effect of hydroxyurea therapy (HUT) on the adhesive properties of sickle red cells and the expression of adhesion molecule genes by erythroid cells of SCA individuals is not yet fully understood. The expressions of the CD36 gene and the VLA-4 integrin subunit genes, CD49d (a-subunit) and CD29 (J3-subunit), were compared in the reticulocytes of steady-state SCA patients and patients on HUT using Real-Time PCR Basal adhesion of red cells ftom these subjects was also compared using static adhesion assays, as was surface protein expression, using flow cytometry. Basal sickle red cell adhesion to fibronectin was significantly greater than that of normal cells (P<O.OI); in contrast, HUT significantly decreased (P<O.OI) red cell adhesion to levels similar to those of control cells and this decrease could not be justified solely by alterations in reticulocyte numbers in this population. Accordingly, flow cytometry demonstrated that HUT significantly decreased CD36 and CD49d surface expression (P<O.Ol) and, importantly, significant reductions in the expressions of the CD36, CD49d and CD29 genes were seen (P<O.O5) in the reticulocytes of SCA patients on HU. Taken together, data support the hypothesis that HUT reduces the adhesive properties of sickle cells and that this decrease appears to be mediated, at least in part, by a decrease in the gene and, consequently, surface protein expression of adhesion molecules such as VLA-4 and CD36 / Mestrado / Patologia Clinica / Mestre em Ciências Médicas

Orientador: Nicola Amanda Conran Zorzetto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T23:21:17Z (GMT). No. of bitstreams: 1 Vital_DaianaMorelli_M.pdf: 1971637 bytes, checksum: 022329e1e83ad1bd2ea02de3d37d61c9 (MD5) Previous issue date: 2015 / Resumo: A inflamação é uma resposta fisiológica normal à infecção ou lesão tecidual que permite a sobrevivência do indivíduo a diversos agentes lesivos e mantém a homeostase dos tecidos sob uma variedade de condições nocivas. Os neutrófilos têm um papel importante em processos inflamatórios e, na presença de estímulos inflamatórios, como citocinas e quimiocinas, são recrutados da circulação para o tecido inflamado por uma sequência de interações adesivas. Recentemente, novas técnicas in vitro têm levado a importantes avanços no entendimento de patologias vasculares e hematológicas e sistemas microfluídicos, que mimetizam a microcirculação humana, demonstrando a utilidade para o estudo de interações adesivas de células inflamatórias. As interações dos neutrófilos e outros leucócitos com a parede vascular tem contribuição importante para as doenças inflamatórias crônicas, como a anemia falciforme (AF) e aterosclerose, pois podem participar em processos de oclusão vascular. O objetivo deste trabalho foi avaliar se a hidroxiureia (HU), uma droga utilizada como terapia na AF, modula as propriedades adesivas de neutrófilos quando incubados in vitro com a droga e frente um estímulo inflamatório. Os neutrófilos, isolados do sangue periférico de indivíduos saudáveis, foram estimulados com a citocina TNF-? (Fator de Necrose Tumoral alfa) e tratados com HU em três concentrações (100, 500, 1000 ?M); as propriedades adesivas das células foram avaliadas por ensaios de adesão estática e por ensaios microfluídicos, utilizando como ligantes proteínas expressas no endotélio (ICAM-1 e E-selectina), proteínas da matriz extracelular (fibronectina - FN) e células endoteliais (HUVEC). Além disso, foi analisada a ativação celular (spreading celular, observado como o espalhamento das células redondas que se tornam achatadas sobre um substrato sólido 2D). Observamos que os neutrófilos, quando estimulados com TNF-?, demonstram aumentos significantes na adesão e spreading celular. O pré-tratamento das células com HU reduziu significativamente o spreading dos neutrófilos nas três proteínas estudas (FN, ICAM-1 e E-selectina). Sob condições estáticas, o pré e o pós-tratamento dos neutrófilos com a HU diminuiu significativamente a adesão à FN quando comparados ao estimulados por TNF-?. Nos ensaios de adesão em fluxo, foi possível observar que o pré-tratamento com HU nas três concentrações (100, 500 e 1000 ?M) diminuiu significativamente a adesão dos neutrófilos a FN e o pós-tratamento com HU diminuiu apenas na concentração de 100 ?M. Avaliamos a adesão em fluxo de neutrófilos aderidos a proteínas de adesão presentes no endotélio, ICAM-1 e E-selectina; o pré e o pós-tratamento de neutrófilos com HU diminuiu a suas propriedades adesivas frente ao estímulo inflamatório de TNF-? à proteína E-selectina, enquanto que o pré-tratamento nas três concentrações diminuiu a adesão dos neutrófilos ao ICAM-1 e ao ICAM-1 e E-selectina adicionados juntos ao chip. A técnica de citometria de fluxo demonstrou que as integrinas LFA-1 (CD11a) e Mac-1 (CD11b), mostraram-se aumentadas na superfície dos neutrófilos após estímulo com TNF-?. Todavia, a expressão da L-selectina, mostrou-se diminuída com este potente estímulo inflamatório, provavelmente devido o mecanismo de "shedding" celular. A incubação dos neutrófilos com HU, após o estímulo com o TNF-?, reduziu significativamente a expressão de CD11a nos neutrófilos tratados com HU nas concentrações de 100 e 1000 ?M para níveis de expressão equivalentes ao grupo de neutrófilos não estimulados com TNF-?. Observamos também que houve aumento da presença da integrina LFA-1 (CD11a) na sua conformação ativada, após estímulo com TNF-? e que a pós-incubação das células estimuladas com HU na concentração de 1000 ?M, reduziu a ativação da subunidade CD11a da molécula de adesão LFA-1, comparado ao grupo apenas estimulado com TNF-?. Diante destes resultados, é possível concluir que o tratamento de neutrófilos com HU foi capaz de proteger ou até reverter algumas das ações inflamatórias do TNF-?. A HU é utilizada como uma terapia de uso crônico em pacientes com AF, mas estes dados indicam que a HU também pode exercer efeitos imediatos que são independentes da elevação de hemoglobina fetal. Dados melhor clarificam o mecanismo de ação de HU na AF e sugerem que a droga pode ter potencial para uso em outras doenças inflamatórias. Ainda será necessário entender como a HU exerce estes efeitos anti-inflamatórios nos neutrófilos / Abstract: Inflammation is a normal physiological response to infection or tissue injury that defends against various damaging agents and maintains tissue homeostasis in a variety of deleterious conditions. Neutrophils play an important role in inflammatory processes and, in the presence of inflammatory stimuli, such as cytokines and chemokines, are recruited from the circulation into the inflamed tissue by a sequence of adhesive interactions. Recently, new in vitro techniques have led to significant advances in our understanding of vascular and hematological conditions and microfluidic systems that mimic the human microcirculation have been shown to be useful for the study of adhesive interactions in inflammatory cells. The interaction of neutrophils and other leukocytes with the vascular wall makes an important contribution to chronic inflammatory diseases, such as sickle cell anemia (SCA) and atherosclerosis, as these may participate in vascular occlusion processes. The aim of this study was to evaluate whether hydroxyurea (HU), a drug used as a therapy in SCA, modulates the adhesive properties of neutrophils in vitro under an inflammatory stimulus. The neutrophils isolated from the peripheral blood of healthy subjects were stimulated with the cytokine TNF-? (Tumor Necrosis Factor alpha) and treated with HU in three concentrations (100, 500, 1000 ?M); the adhesive properties of the cells were evaluated by static adhesion assays and microfluidic assays using ligands such as proteins expressed on the endothelium (ICAM-1 and E-selectin), extracellular matrix proteins (fibronectin - FN) and endothelial cells (HUVEC). Furthermore, cellular activation was evaluated as cell spreading (observed when round cells become flattened and spread on a 2D solid substrate). When stimulated with TNF-?, neutrophils presented a significant increase in cell adhesion and spreading. Pre-treatment of cells with HU significantly reduced neutrophil spreading on all three proteins studied (FN, ICAM-1 and E-selectin). Under static conditions, the pre-treatment and post-treatment of neutrophils with HU significantly decreased adhesion to FN, compared to TNF-?-stimulated cells. In the flow adhesion assays, pre-treatment of neutrophils with HU at three concentrations (100, 500 and 1000 ?M) significantly reduced the adhesion of neutrophils to FN and post-treatment with HU decreased only at the concentration of 100 ?M. We evaluated the in vitro flow adhesion of neutrophils to proteins present on endothelial cells, ICAM-1 and E-selectin; pre-treatment and post-treatment of neutrophils with HU decreased their adhesive properties after TNF-? inflammatory stimulus to the E-selectin ligand, while pre-treatment in the three concentrations decreased neutrophil adherence to ICAM-1 ligand and ICAM-1/E-selectin ligands added together to the chip. Flow cytometry demonstrated that the expressions of the integrins LFA-1 (CD11a) and Mac-1 (CD11b) were elevated on the surface of neutrophils after a TNF-? stimulus. However, L-selectin expression was reduced with this potent inflammatory stimulus, probably due to the mechanism of "shedding". Incubation of neutrophils with HU (100 and 1000 ?M), after stimulation with TNF-?, significantly reduced the CD11a expression on neutrophils to levels similar to those found on the neutrophils of the non-TNF-?-stimulated group. We also observed that there was an increased expression of the LFA-1 (CD11a) integrin in its active conformation after stimulation with TNF-? and that, post-incubation with HU (1000 ?M) was able to reduce the activation of the adhesion molecule CD11a (LFA-1 subunit), compared to the group with TNF-? stimulus only. Given these results, it is possible to conclude that treatment of neutrophils with HU was able to protect or even reverse some of the inflammatory actions of TNF-?. HU is used as a chronic therapy in patients with SCA, but our data indicate that HU may also have immediate effects that are independent of the increase in fetal hemoglobin usually observed in patients in therapy. Our results further clarify the mechanism of action of HU in SCA and suggest that this drug may have potential for use in other inflammatory diseases. Further studies will be needed to better comprehend how these HU anti-inflammatory effects act on neutrophils / Mestrado / Fisiopatologia Médica / Mestra em Ciências

PURPOSE: Sickle cell disease (SCD) is an inherited blood disorder that affects the hemoglobin protein of red blood cells and has a significant impact on morbidity, mortality, and quality of life. Hydroxyurea has been FDA approved since 1998 as a disease-modifying therapy for SCD. However, hydroxyurea has not been optimally utilized for those with SCD. The purpose of this study was to evaluate reasons for hydroxyurea use, from the perspectives of providers, adults with SCD, and parents/caregivers of children with SCD, as well as perceived barriers to its use. We examined indications and reasons for being “on hydroxyurea,” defined by patients as currently taking hydroxyurea, and reported on pain frequency, perceptions of barriers, hydroxyurea adherence, and health care access for patients with SCD who were either on and not on hydroxyurea. METHODS: We conducted a cross sectional analysis of data collected within the Pacific Sickle Cell Regional Collaborative (PSCRC), a consortium of nine western U.S. states. Individuals were eligible for this study if they 1) had a confirmed diagnosis of SCD, 2) were followed at one of the PSCRC sites, and 3) were eligible for hydroxyurea therapy. Parents/caregivers of children with SCD less than 18 years and adults with SCD 18 years and older completed a brief survey about hydroxyurea use, indications, side effects, pain frequency, number of hospital and emergency department (ED) admissions per year, and individual and family perceptions of barriers to hydroxyurea use. Participants completed a follow-up survey annually, but we reported only on baseline data. Data collection occurred between February 2016 and May 2018. RESULTS: Individuals with SCD (n = 413) included 1) children (n=178; 6.7 ± 3.4 years), 2) adolescents (n=66; 15.0 ± 1.4 years), 3) young adults (n=57; 21.4 ± 2.6 years), and 4) adults (n=112; 39.2 ± 10.6 years). The majority were predominantly female (51.6%), African American (93.2%), and had HgbSS (74.1%) genotype. The majority of children (65.2%), adolescents (62.1%), and young adults (54.4%) were on hydroxyurea; fewer adults (39.3%) were on hydroxyurea. The majority with HgbSS (65.5%) were adherent to hydroxyurea. There was no significant difference in hospitalizations for pain, ED visits, and pain severity in the previous 12 months between individuals who were and were not on hydroxyurea, and between individuals who were and were not adherent to hydroxyurea. For those with a current prescription for hydroxyurea, the majority (66.5%) were receiving hydroxyurea for recurrent pain episodes or acute chest syndrome (19.9%). Hydroxyurea was discontinued because of patient/family preference (34.5%), chronic transfusions (31.1%), and side effects (24.1%). Patients prescribed hydroxyurea for empiric use (n=21) had fewer hospitalizations for pain, ED visits, and severe pain interfering with daily activities. The major barriers to hydroxyurea use, from the perspective of individuals with SCD or their caregivers, were 1) forgetting to take the medicine (19.4%), 2) worried about side effects (16.4%), and 3) lack of knowledge about hydroxyurea (13.6%). Fewer young adults (49.1%) and adults (50.0%) had primary care providers than children (78.1%) and adolescents (65.2%). CONCLUSIONS: Barriers to hydroxyurea use persist with emerging solutions to alleviate these barriers. For this sample, while hydroxyurea prescription rates by sickle cell specialists were similar to what has been seen in some other studies, neither hydroxyurea use nor adherence were associated with decreased frequency of hospitalizations for pain, ED visits, and severe acute pain episodes in the previous 12 months. Future studies need to evaluate hydroxyurea prescription patterns, duration on hydroxyurea, and adherence to hydroxyurea. Healthcare providers are recommended to prescribe hydroxyurea for eligible individuals who may benefit from it, such as those HgbSS or HgbS-β0 thalassemia genotype, and prescribe for empiric use to minimize complications. Provider and patient education about hydroxyurea could reduce common barriers experienced by individuals with SCD. It is important to customize educational resources to specific concerns for different age groups. Individuals 18 years and older with SCD have been documented with more ED visits and hospitalizations due to pain, most likely because they did not have a primary care provider and an adult hematologist with expertise in SCD. Future studies need to evaluate whether primary care providers who receive SCD education may promote hydroxyurea use and adherence. Dedicating time and resources for shared decision making between providers and patients/families can address concerns about hydroxyurea and increase patient/family confidence when deciding about hydroxyurea. As more disease-modifying therapies become available for individuals with SCD, strategies for shared decision making facilitate standardization and optimize the use of hydroxyurea and emerging therapies.

The effect on DNA repair in ultraviolet-irradiated human skin fibroblasts by hydroxyurea has been examined in this study using three independent methods for measuring DNA repair: the 5-bromodeoxyuridine photolysis assay which measures DNA repair replication, chromatographic measurement of thymine-containing dimers, and measurement of specific ultraviolet-endonucleasesensitive sites in irradiated DNA. Little effect of hydroxyurea was observed at the concentration of 2 mM, which is often used to inhibit semiconservative DNA synthesis; however, 10 mM hydroxyurea resulted in marked inhibition (65-70%) of excision repair. This inhibition was accompanied by a possible doubling in the size of the repaired region. The accumulation of large numbers of single-strand breaks following ultraviolet irradiation and hydroxyurea incubation seen by other investigators was not observed with the normal skin fibroblasts used in this study. A comparison of hydroxyurea effects on the different DNA repair assays indicates inhibition of one step in DNA repair also results in varying degrees of inhibition of other steps as well.

Aging of the brain is the leading risk factor for neurodegenerative diseases and brain cancers and has deleterious effects on brain functions. It follows that attempts to reverse the aging process may be therapeutically valuable. Neural stem cells (NSC) have been shown to play a critical role in maintaining brain functions, and their number is severely decreased with age. The development of senescence-like characteristics and declining functions in NSCs have been proposed to be responsible for brain aging and tumorigenesis. MS-818 is a pyrrolopyrimidine that has been shown to increase the NSC population and reverse the decline of behavioral function in aged rodent models. While MS-818 has demonstrated such benefits, the mechanism by which it affects particular pathways of biological age in NSCs is not yet known. Understanding how MS-818 relates to the molecular mechanisms underlying cellular aging may help accelerate the development of anti-aging therapies for neurodegenerative diseases and cancer. This study attempts to elucidate the mechanism of action of MS-818 on NSCs using an in vitro accelerated-aging model produced by Hydroxyurea (HU) treatment. Our analysis of NSC population size post-MS-818 exposure supports the idea that MS-818 treatment can increase NSC proliferation. qPCR analysis of aging-related genes revealed HU treatment produced a trend of increased p16 and Il-6 and decreased Lamin B1 relative expression, supporting the notion that HU treatment can induce senescence in NSCs. MS-818 treatment alone also produced notable trends for targets including BRCA1. In addition, MS-818 treatment post-HU exposure appeared to influence the relative expression of targets, including PGC1a and Lamin B1. Such MS-818 treatment produced similarly noteworthy trends for the expression of genes including PGC1a, Lamin B1, BRCA1, RPTOR, and Il-6, whether in media containing 2.5% or 7.5% serum. These results indicate that MS-818 may have influenced some aging-related pathways.

No description available.

Hydroxyurea was used as a model teratogen to investigate the role of oxidative stress and stress-response pathways in mediating developmental toxicity. When administered to pregnant mice during early organogenesis, hydroxyurea induced fetal death and growth retardation, as well as external and skeletal malformations. The malformed fetuses displayed hindlimb, vertebral column, and tail defects. Hydroxyurea treatment enhanced the production of 4-hydroxynonenal, a lipid peroxidation end product, in malformation sensitive regions of the embryo. Depletion of glutathione, a major cellular antioxidant, specifically enhanced hydroxyurea-induced malformations and elevated the region-specific production of 4--hydroxynonenal protein adducts in the embryo, without affecting the incidence or extent of hydroxyurea-induced fetal death or growth retardation. The major proteins modified by 4-hydroxynonenal were involved in energy metabolism. Thus, oxidative stress is important in the induction of malformations by hydroxyurea. / Exposure to hydroxyurea stimulated the DNA binding activity of activator protein 1 (AP-1), an early response redox-sensitive transcription factor. Activated AP-1 was composed mainly of c-Fos heterodimers. Glutathione depletion did not change the effects of hydroxyurea on AP-1/c-Fos DNA binding activities despite an augmentation of the incidence of embryo malformations. Mitogen-activated protein kinases (MAPKs) activate AP-1 in response to stress by post-transcriptional phosphorylation of AP-1 proteins. Hydroxyurea treatment dramatically enhanced the activation of stress-responsive p38 MAPKs and JNKs (c-Jun N-terminal protein kinases). Selectively blocking p38 MAPKs enhanced the incidence of fetal death, whereas selective inhibition of JNKs specifically elevated the limb defects induced by hydroxyurea. Thus, activation of stress-response pathways impacts on the response of the embryo to a teratogenic insult.