Introdução: A Síndrome dos Ovários Policísticos (SOP) é uma doença que implica em várias alterações como metabólicas, endócrinas e de composição corporal. Atualmente têm se discutido sobre medidas não farmacológicas para seu tratamento, e o exercício tem sido indicado como primeira conduta para melhora de diversos parâmetros. Objetivos: Avaliar os efeitos de dois protocolos de treinamento físico aeróbio sobre parâmetros hormonais, metabólicos, inflamatórios, de composição corporal, índices antropométricos e comprimento do telômero em mulheres com SOP. Material e Métodos: Trata-se de um ensaio clínico controlado com alocação aleatória e randomização estratificada pelo índice de massa corporal em 3 grupos: treinamento aeróbio contínuo (AC) com 28 voluntárias, treinamento aeróbio intermitente (AI) com 29 voluntárias e controle sem treinamento (GC) com 30 voluntárias. As avaliações dos parâmetros hormonais, metabólicos, inflamatórios e comprimento do telômero, foram realizadas por meio da dosagem sanguínea; os índices da composição corporal, avaliados pela circunferência de cintura e quadril e a composição corporal por meio da avaliação da absortometria de raio x de dupla energia. As avalições ocorreram antes e após o período de 16 semanas de intervenção do treinamento físico aeróbio ou de observação no grupo controle. Resultados: No grupo AC houve redução da circunferência de cintura (CC) (p = 0,045), circunferência de quadril (p = 0,032), níveis de colesterol total (p <= 0,01), LDL (p = 0,03) e testosterona (p <= 0,01). No grupo AI houve redução da CC (p = 0,014), relação cintura-quadril (p = 0,012), testosterona (p = 0,019) e índice de androgênio livre (p = 0,037). No grupo GC houve aumento da CC (p = 0,049), gordura corporal total (p = 0,015) e percentual da gordura corporal total (%) (p = 0,034), massa total dos braços (p < 0,01), percentual de gordura do tronco (p = 0,033), % de gordura das pernas (p = 0,021) e massa total ginóide (p = 0,011). Não houve alteração nas demais variáveis. Conclusão: Ambos os protocolos de treinamento reduziram índices antropométricos e hiperandrogenismo. O treinamento intermitente foi mais eficiente no controle do hiperandrogenismo, enquanto ocontínuo além de melhorar o hiperandrogenismo, promoveu redução nos parâmetros lipídicos, sem correlação entre a melhora de ambos parâmetros. Adicionalmente, ambos foram eficazes na prevenção do ganho de gordura corporal e do aumento da CC. Não ocorreram alterações após a intervenção no comprimento do telômero e demais variáveis analisadas. / Introduction: A Polycystic Ovary Syndrome (PCOS) is a disease that implicates in various changes like metabolic, endocrine and body composition. At present, non-pharmacological measures have been discussed for its treatment, and exercise has been indicated as the first conduit for improvement of several parameters.. Objectives: To evaluate the effects of two aerobic physical training protocols on hormonal, metabolic, inflammatory parameters, body composition, anthropometric indices and telomere length in women with PCOS. Material and methods: This was a randomized controlled trial and stratified randomized to body mass index into 3 groups: continuous aerobic training (CA) with 28 volunteers, intermittent aerobic training (IA) with 29 volunteers, and control without training with 30 volunteers. The evaluations of hormonal, metabolic, inflammatory parameters and telomere length were performed by means of a blood sample; body composition indices evaluated by waist and hip circumference and body composition by means of dual energy x-ray absorptiometry. The evaluations occurred before and after the 16-week intervention period of aerobic physical training or observation in the control group. Results: In the AC group, waist circumference (WC) (p = 0.045), hip circumference (HC) (p = 0.032), total cholesterol levels (p <= 0.01), LDL (p = 0.03) and testosterone (p <= 0.01). In the AI group there was a reduction in WC (p = 0.014), waist-hip ratio (p = 0.012), testosterone (p = 0.019) and free androgen index (p = 0.037). In the CG group there was an increase in WC (p = 0.049), total body fat (p = 0.015) and percentage (%) (p = 0.034), total arms mass (p <0.01), % trunk fat (p = 0.033), % of leg fat (p = 0.021) and total gynoid mass (p = 0.011). There was no change in the other variables. Conclusion: Both training protocols reduced anthropometric indices and hyperandrogenism. Intermittent training was more efficient in the control of hyperandrogenism, while the continuous, besides improving hyperandrogenism, promoted a reduction in lipid parameters, without correlation between the improvement of both parameters. Additionally, both wereeffective in preventing body fat gain and increased CC. There were no changes after intervention in telomere length and other variables analyzed.

Telômeros são complexos DNA-proteína presentes nas extremidades dos cromossomos. Os telômeros se encurtam a cada divisão celular, sendo o comprimento telomérico, portanto, considerado um biomarcador do envelhecimento celular. Esse encurtamento é vinculado a diversas doenças relacionadas à idade avançada. Na doença de Alzheimer (DA), têm sido associados com diversas vias fisiopatológicas, como a neuroinflamação e o estresse oxidativo, porém seus mecanismos ainda são pouco conhecidos. A maioria dos estudos sobre comprimento telomérico na DA é realizada em DNA leucocitário, pouco se sabendo sobre seu estado no sistema nervoso central. O lítio é um importante estabilizador de humor, com efeitos neuroprotetores amplamente evidenciados, mas pouco se sabe sobre seu efeito na manutenção do comprimento telomérico. O objetivo do presente estudo foi avaliar o efeito do tratamento crônico com lítio no comprimento telomérico em diferentes regiões cerebrais (córtex parietal, hipocampo e epitélio olfatório) de camundongos triplo transgênicos para DA (3xTg-AD) e selvagens. Dezoito animais transgênicos e 22 selvagens foram tratados por oito meses com ração contendo 1,0 g (Li1) ou 2,0 g (Li2) de carbonato de lítio/kg, ou ração padrão (Li0). O comprimento telomérico do DNA extraído destes tecidos foi quantificado por PCR em tempo real. O tratamento crônico com lítio foi associado a telômeros mais longos no córtex parietal (Li1, p=0,04) e hipocampo (Li2, p=0,02) dos camundongos 3xTg-AD comparados com os respectivos selvagens. Nossos achados sugerem que o tratamento crônico com lítio afeta a manutenção do comprimento telomérico, mas que a magnitude desse efeito depende da concentração de lítio ministrada e das características do tecido envolvido. Esse efeito foi apenas observado quando comparando os animais triplo transgênicos com os selvagens, indicando que a presença da patologia, no caso a DA, se faz necessária para a modulação do comprimento telomérico promovida pelo lítio / Telomeres are DNA-protein complexes present in the extremities of chromosomes. Telomeres shorten at each cell division, being the telomere length, therefore, considered a cell aging biomarker. This telomere shortening is associated to several age-related diseases. In Alzheimer\'s disease (AD), telomere length has been linked to several pathophysiological pathways, such as neuroinflammation and oxidative stress, though its mechanism are still poorly understood. Majority of studies regarding telomere length in AD are based in leucocyte DNA, with little information about its status in the central nervous system. Lithium is an important mood stabilizer, with neuroprotective effects widely evidenced, but little is known about its effects in telomere length maintenance. The objective of this present study was to evaluate the effect of chronical lithium treatment on telomere length in different brain regions (parietal cortex, hippocampus and olfactory epithelium) of wild type and triple transgenic mice model for AD (3xTg-AD). Eighteen transgenic and 22 wild type male mice were treated for eight months with chow containing 1.0g (Li1) or 2.0g (Li2) of lithium carbonate/kg, or standard chow (Li0). Telomere length of extracted DNA from theses tissues was quantified by real-time PCR. Chronic lithium treatment was associated with longer telomeres in the parietal cortex (Li1, p=0.04) and in the hippocampus (Li2, p=0.02)of 3xTg-AD compared with the respective wild type.Our findings suggest that chronic lithium treatment does affect telomere maintenance, but the magnitude of this effect depends on the working concentrations of lithium and characteristics of the involved tissue. This effect was only observed when comparing triple transgenic with wild type mice, suggesting that the presence of AD pathology was required for the lithium modulation of telomere length

Os estágios avançados da DPOC são longos e dolorosos processos onde há o aumento dos sintomas, fazendo com que o paciente entre em um ciclo vicioso de deterioração da capacidade física, dispneia, ansiedade e isolamento social. Deste modo, o exercício vem se mostrando um componente importante na DPOC, auxiliando no tratamento medicamentoso para a redução dos sintomas e melhora da qualidade de vida. Neste contexto, não há muitos relatos na literatura sobre o papel da atividade física no padrão de secreção de citocinas e na resposta proliferativa de pacientes com DPOC. Além disso, não há muita concordância sobre o comprimento do telômero e fenótipo celular quando a comparados tabagistas que não desenvolvem a doença e pacientes com DPOC. O objetivo deste trabalho foi comparar alguns parâmetros imunológicos entre pacientes com DPOC e indivíduos tabagistas sem DPOC, e em pacientes com DPOC antes e após o programa de reabilitação oferecido no Hospital das Clínicas da FMUSP. As coletas de sangue foram realizadas em dois momentos para o grupo DPOC (pré e pós-programa de reabilitação pulmonar), e em um único momento para o grupo tabagista. Estas amostras foram processadas para obtenção de células mononucleares do sangue periférico, onde foram analisados os seguintes parâmetros: proliferação celular e apoptose, fenotipagem de linfócitos, comprimento relativo do telômero e dosagem de citocinas. Verificamos que indivíduos tabagistas possuem menores quantidades de proteína C reativa que pacientes com DPOC, e uma tendência a maior número de linfócitos. Além disso, o comprimento relativo do telômero em tabagistas é maior do que em pacientes com DPOC, especialmente em linfócitos TCD8+, e em menor grau em linfócitos TCD4+. Linfócitos TCD8+ de portadores de DPOC apresentaram maiores porcentagens de células terminalmente diferenciadas, sugerindo exaustão celular destes linfócitos, e menores porcentagens de células de memória central e memória efetora. Pacientes com DPOC apresentam maiores quantidades de citocinas comparados aos tabagistas sem DPOC. Já na comparação pré e pós-reabilitação verificamos menores quantidades de leucócitos, menores pontuações nos questionários de sintomas, e maiores distâncias percorridas no teste de caminhada de 6 minutos. Na avaliação da linfoproliferação, para as células estimuladas com mitógeno (fitohemaglutinina) e antígenos (citomegalovirus e Haemophilus influenza) foi possível verificar melhora na resposta linfoproliferativa dos pacientes no período pós-reabilitação, assim como maiores níveis da citocina imunoreguladora IL-10. Deste modo concluímos que pacientes com DPOC possuem um perfil mais pró-inflamatório e de diferenciação terminal que tabagistas sem a doença e que exercício físico é capaz de modular o ambiente inflamatório melhorando alguns parâmetros da resposta imune celular / The advanced stages of COPD are long and painful with increase of symptoms making the patients enter a vicious cycle of deterioration of physical capacity, dyspnea, anxiety and social isolation. Therefore, the exercise shows an important component of COPD pathogenesis, assisting in pharmacological treatment, reducing symptoms and enhancing life quality. In this context, there are no concise reports in literature about the role of physical activity in the pattern of cytokine secretion and proliferative response in COPD patients. Besides this, there is no consensus in the data comparing smokers with COPD and smokers without COPD. Because of this, we compared some immune parameters of smokers with COPD and smokers without COPD, and evaluated the cellular immune response before and after a rehabilitation program offered at the Hospital das Clínicas FMUSP. Blood collection was performed in two moments in the COPD group (before and after the rehabilitation program), and once in smokers without COPD. After that the samples were processed to peripheral blood mononuclear cells isolation, in which were analyzed the cellular proliferation and apoptosis, the lymphocyte phenotypic characteristics, the telomere length and the cytokines levels in serum and culture supernatants. Smokers without COPD have lower levels of C reactive protein, and a trend to greater percentages of lymphocytes than in smoker with COPD. The telomere length of COPD patients was shorter than that of smokers without COPD, especially in TCD8+ lymphocytes, with a non-significant trend in the TCD4+ lymphocytes. The TCD8+ subpopulation of COPD patients comprised greater percentages of terminally differentiated cells, and lower percentages of central memory and effector memory cells, suggesting a bias to more terminally differentiated (and eventually exhausted) cells. Moreover, the levels of pro inflammatory cytokines were greater in COPD patients. Evaluation of the exercise effect, we found greater quantities of leucocytes, lower scores in the symptoms questionnaires and longer distances in the six minute walk test after the rehabilitation program. Besides this, the proliferative response to the mitogen phytohemaglutinin, and the antigens from cytomegalovirus and nontypeable Haemophilus influenza were all improved after the exercise program with greater levels of secretion of the anti-inflammatory cytokine IL-10. In conclusion, COPD patients have a pro inflammatory profile and a bias for more terminally differentiated (and eventually exhausted) cells when compared with smokers without COPD, and that the exercise program is capable of modulating the inflammatory microenvironment enhancing some parameters of the cellular immune response

O aumento da expectativa de vida é um evento mundial e tem alterado a pirâmide populacional, com aumento da população idosa e redução da população jovem, tanto em países desenvolvidos como em desenvolvimento. De acordo com projeções das Nações Unidas realizadas em 2012, a população brasileira com idade superior a 65 anos atingirá a média de 50 milhões no ano de 2050. O avanço da idade acarreta mudanças na composição, função fisiológica e competência do sistema imunológico humano, as quais são definidas pelo termo imunossenescência. Essas mudanças são importantes, pois contribuem para um aumento da incidência e gravidade das doenças infecciosas, diminuição da eficácia das vacinações, e possivelmente o surgimento de autoimunidade e câncer. Diminuição da população de linfócitos T \"naive\" com o aumento da população de linfócitos de memória, perda da molécula coestimulatória CD28, encurtamento do telômero e a presença de um background inflamatório são as principais alterações associadas à imunossenescência. No Brasil, o aumento da população idosa e consequente aumento da procura de serviço de saúde sobrecarregará o Sistema Único de Saúde. Assim, o estudo de intervenções que visem atenuar a imunossenescência é altamente relevante. Uma possível intervenção estudada é a atividade física, porém, a maior parte dos estudos avalia o impacto imediato da atividade física, e quando avaliam o impacto de atividade física regular e prolongada, o fazem com pequeno intervalo de tempo. O objetivo deste estudo foi o de avaliar o impacto da prática da atividade física moderada regular no retardo da imunossenescência em homens idosos. Trinta e um idosos do sexo masculino (65-85 anos) foram divididos em dois grupos, um com histórico de treinamento moderado por 15 ( ± 3) anos e outro sem histórico de treinamento, avaliados quanto à porcentagem de linfócitos TCD4+ e TCD8+ \"naive\" e de memória, perda da molécula coestimuladora CD28, comprimento do telômero, capacidade linfoproliferativa, expressão de marcadores pró e anti-apoptóticos, background inflamatório e produção de anticorpos anti-influenza. Os grupos foram equiparáveis quanto à idade, capacidade cognitiva, funcional e índice de massa corpórea. Todos os idosos apresentaram bom estado nutricional e não possuíam depressão. Os idosos moderadamente treinados apresentaram um maior gasto calórico semanal (aumento dos METs, p < 0,0001) e um maior consumo máximo de oxigênio (VO2max, p < 0,001), mostrando o seu maior condicionamento físico.Os idosos moderadamente treinados apresentaram uma maior porcentagem de linfócitos TMC e menor frequência de linfócitos Temra,maior capacidade de resposta linfoproliferativa dos linfócitos T CD8+ estimulados com mitógeno,menor expressão de marcador de apoptose na subpopulação de linfócitos T CD8+ CD28neg e produção de maiores títulos de anticorpos anti-influenza séricos antes e pós-vacinação. Os dados mostraram que a prática da atividade física moderada regular como estilo de vida contribuiu para a atenuação de alguns aspectos característicos da imunossenescência / Increase of life expectancy is a global event and has changed the population pyramid, with increasing elderly population and reducing young population, both in developed and developing countries. According to the United Nations in the 2012 Revision of the World Population Prospects, the Brazilian elderly population will reach 50 million people in 2050. Aging leads to marked detrimental changes in the composition, function, and competence of the human immune system, a phenomenon termed immunosenescence. These changes are associated with increased incidence and severity of infections, poor vaccine efficacy, and possibly the developing autoimmunity and cancer. Immunosenescence is associated with decreased number of naïve T cells and increased of memory T cells, loss of CD28 costimulatory molecule, telomere shortening and Inflamm- aging. In Brazil, the increase in the elderly population and the consequent increased demand for health care will encumber the Sistema Único de Saúde. Thus, the study of interventions to attenuate the immunosenescence is highly relevant. A possible intervention that has been studied is physical activity. However, the majority of studies evaluated the acute impact of physical activity or assessed the impact of short periods of chronic physical activity. The aim of this study was to evaluate the impact of regular moderate aerobic exercises in delaying immunosenescence in elderly people. Thirty one elderly men (65-85 years) were divided in two groups, one with history of moderate regular physical activity for 15 ( ± 3) years and the other without history of physical activity, were evaluated for percentage of CD4+ and CD8+ naïve and memory T cells, loss of CD28 costimulatory molecule, telomere length, lymphocyte proliferation, apoptosis markers, cytokine synthesis (TH1/TH2), serum levels of inflammatory cytokines and anti-influenza antibodies production. The groups were comparable regarding age, cognitive and functional abilities and body mass index. All elderly had good nutritional status and did not have depression. The moderately trained elderly had a higher weekly caloric expenditure (increase in METs, p < 0.0001) and a higher maximal oxygen uptake (VO2max, p < 0.001), showing its higher fitness. The moderately trained elderly had a higher percentage of TMC lymphocytes and lower frequency of Temra lymphocytes, higher lymphoproliferative responsiveness of CD8 + T lymphocytes stimulated with mitogen, lower expression of apoptosis markers in the subpopulation of T CD8 + CD28neg cells and production of higher titles serum anti-influenza antibodies before and after immunization. The data showed that the practice of regular moderate physical activity as a lifestyle contributed to reduce of the some typical features of immunosenescence

A anemia aplástica severa (AAS) pode ser tratada com sucesso na maioria dos casos com terapia imunossupressora (IS) ou transplante alogenêico de medula óssea (TMO). Os principais fatores que determinam a escolha da modalidade terapêutica são a idade e a disponibilidade de um doador HLA-histocompatível. Em pacientes mais jovens, o TMO de um doador aparentado é preferível, enquanto que em pacientes acima de 40-50 anos, a terapia IS é a modalidade terapêutica de escolha. Resposta hematológica é obtida em 60-75% dos casos com terapia IS na AAS, o que correlaciona com melhor sobrevida. Recidivas ocorrem em aproximadamente um terço dos respondentes e evolução clonal para mielodisplasia em 10-15% ao longo termo. A doença do enxerto-versus-hospedeiro (GVHD) agudo ocorre em 30-40% dos casos sendo a forma crônica presente em 40-50%. Infecções são frequentes e podem complicar o transplante. Portanto, a refratariedade à terapia IS, recidivas e evolução clonal limitam o sucesso da terapia IS na AAS, enquanto rejeição do enxerto, GVHD, e infecções limitam o sucesso do TMO na clínica. Fatores preditivos dessas complicações seriam de grande valor na clínica, uma vez que poder-se-iam realizar decisões terapêuticas com base mais racional, onde pacientes fossem alocados a diferentes tratamentos com base no seu perfil de risco. Ou seja, pacientes com alta probabilidade de resposta e baixo risco de recidiva e evolução clonal se beneficiariam de terapia IS, enquanto àqueles com baixa probabilidade de resposta e alto risco de recidiva e/ou evolução clonal teriam mais benefícios do TMO, por exemplo. Com base nessa premissa, desenvolvemos estudos para investigar fatores que pudessem estar associados ao sucesso da terapia IS na AAS. Os principais achados de 3 análises distintas sobre o tema evidenciou: 1) crianças (< 18 anos) apresentam alta taxa de resposta à terapia IS (em torno de 75%) com uma excelente sobrevida geral em pacientes respondentes; 2) o número absoluto de reticulócitos e de linfócitos pré-tratamento correlaciona com resposta hematológica aos seis meses após terapia IS; e 3) o comprimento telomérico não está associado à resposta hematológica, porém, está associado a probabilidade de recidiva, evolução clonal, e sobrevida geral após terapia IS. Esses parâmetros identificados nesses estudos podem servir de base em algoritmos futuros onde faz-se estratificação de risco de cada paciente, a fim de alocar a modalidade terapêutica mais apropriada com base no perfil individual de risco. No que diz respeito ao comprimento telomérico, é provável que esse marcador biológico não só esteja associado ao processo de evolução clonal na AAS, mas que também participe na biologia da instabilidade genômica de células na medula óssea levando a aberrações cromossômicas e o desenvolvimento de mielodisplasia e leucemias. / Severe aplastic anemia (SAA) can be treated successfully in the majority of cases with immunosuppressive therapy (IST) or allogeneic bone marrow transplantation (BMT). The principal factors that determine the choice of treatment modalities are age and availability of an HLA-histocompatible donor. In younger patients, BMT from a related donor is preferred, while in patients over 40-50 years of age, IST is often employed. Hematologic response is achieved in 60-75% of cases with IST, which correlates with better survival. Relapses occur in approximately one third of responders and clonal evolution to myelodysplasia occurs in 10-15% of cases long-term. Acute graft-versus-host disease (GVHD) occurs in 30-40% of cases and chronic GVHD in 40-50%. Infections are common and complicate transplant outcomes. Therefore, refractoriness, relapses and clonal evolution limit the success of IST in SAA, while graft rejection, GVHD, and infections limited the success of BMT in the clinic. Predictors for these complications would be of great value in the clinic since one could make more rational treatment decisions where patients were allocated to different treatment modalities based on their risk profile. For example, patients with high probability of response and low risk of relapse and clonal evolution would benefit more from IST, while those with low probability of hematologic response and high risk of recurrence and/or clonal evolution most likely to benefit from BMT. Based on this premise, we developed studies to investigate factors that could be associated with the success of IST in SAA. The main findings of three separate analysis on the subject showed: 1) children ( < 18 years) have a high response rate to IST (around 75%) with an excellent long-term survival rate among responders; 2) the absolute number of reticulocytes and lymphocytes pre-treatment correlates with hematologic response at 6 months after IST, and 3) telomere length is not associated with hematologic response, but, associated with the likelihood of relapse, clonal evolution, and overall survival after IST. These parameters may serve as a basis for future algorithms allowing for risk stratification for each individual patient allowing for better treatment allocation. With respect to the telomere length, it is likely that it not only represents a biological marker but that it is involved in the process of clonal evolution contributing to genomic instability in bone marrow cells leading to the development of myelodysplasia and leukemia

No presente trabalho, foi utilizada uma coleção de 14 isolados de Sporisorium scitamineum coletados em diferentes regiões canavieiras, para estudar a diversidade genética por RFLP da região telomérica de maneira comparativa a marcadores AFLP. Os teliósporos, esporos de resistência do fungo, foram coletados a partir do sintoma mais característico da planta infectada que é formação do chicote. Os teliósporos são diplóides e quando germinam dão origem ao probasídio, onde, por meiose formam-se os esporídios haplóides. Estes quando compatíveis sexualmente voltam a se fundir formando um micélio dicariótico infectivo. A fase do ciclo de vida escolhida para as análises foram os derivados haplóides de cada linhagem dicariótica obtida a partir dos teliósporos. Na técnica de AFLP foram encontrados 40 loci polimórficos (3%) entre 1311 analisados obtidos a partir de 2 enzimas de corte raro, 1 de corte frequente e 19 combinações de primers. A técnica de RFLP da região telomérica foi comparativamente mais eficiente, no qual foram utilizadas três enzimas de restrição que geraram 102 loci, sendo 36 polimórficos (34,3%). O agrupamento com base nos coeficientes de similaridade e os resultados de atribuição pelo programa Structure revelaram dois grupos genotípicos homogêneos, tanto quando os marcadores foram analisados separadamente como na análise conjunta. Não houve agrupamento por localidade, mas ficou claro que o fluxo desses isolados é baixo. Os derivados haplóides de tipos de reação sexual opostos de cada linhagem dicariótica (teliósporo) permaneceram dentro do mesmo grupo, com exceção de uma única linhagem. Desta forma, de maneira geral na natureza, a fusão entre os esporídios deve acontecer entre aqueles que estão mais próximos. Uma análise molecular de diversidade genética em isolados obtidos em diferentes regiões do mundo por outros autores revelou uma alta homogeneidade entre eles, de forma que somente em localidades da Ásia foi possível revelar, com os marcadores utilizados, alguma diversidade genética. Nossos resultados indicam que a escolha do marcador foi fundamental para revelar diversidade entre os isolados de S. scitamineum, sendo que o RFLP-tel revelou um fingerprinting de DNA quase que específico para cada isolado, sendo assim mais apropriado do que os descritos anteriormente. A quantidade de loci AFLP necessária para revelar polimorfismo foi mais alta do que para RFLP-tel. Uma segunda contribuição deste trabalho foi a detecção de heterozigotos quando consideramos a análise conjunta de derivados haplóides por teliósporo. Um alto grau de homozigosidade foi detectado quando as análises foram realizadas considerando o comportamento dicariótico como diplóide, no entanto, loci heterozigotos puderam ser encontrados. Esta é a primeira vez que um estudo desta natureza foi realizado com isolados de Sporisorium scitamineum do Brasil. / The genetic diversity of Sporisorium scitamineum, the sugarcane smut agent, was characterized in a 14 isolates collection. The isolates were obtained from various sugarcane growing areas and RFLP of the telomeric region was used as molecular marker, compared with AFLP. Teliospores were collected from the whip of infected plants. Teliospores are diploids and germinate producing a probasidium where meiosis takes place originating four haploid cells. These cells if sexually compatible can fuse and a dikaryotic mycelium is formed. The haploid phase, derived from each dikaryotic line obtained from teliósporos, was used to perform the analysis. Our results showed that 40 polymorphic loci (3%) were described among 1,311 analyzed. These were obtained with two rare-cutter restriction enzymes, one frequent-cutter restriction enzyme and 19 primers combinations. The RFLP markers were more efficient when compared to AFLP to reveal polymorphisms. Three restriction enzymes produced 102 loci, from which 36 were polymorphic (34.3%). Clustering using similarity coefficients and results obtained by Structure software revealed two genotypic groups. The analyses were performed with individual markers and combining RFLP and AFLP markers. Locations were not responsible for clustering, and low flux of isolates was evident. The opposite sexual types haploid derivatives originated from the same teliospore were clustered together, with only one exception. This implies that sporideos that are located close together are more likely to fuse. Our data suggest that choosing RFLP as markers were the key for unrevealing diversity among isolates of S. scitamineum. RFLP-tel revealed almost unique DNA fingerprintings to various isolates. A second contribution of this work was that heterozygous were detected when considering a combined analyses of haploids derivatives from the same teliospore. This is the first time a study of this nature was organized with Brazilian isolates of S. scitamineum.

<p>The telomeres are specialized structures at the end of the chromosomes composed of the repeated DNA sequence (TTAGGG)n and specific proteins bound to the DNA. The telomeres protect the chromosomes from degradation and end to end fusions. Due to the end-replication problem, the telomeric DNA shortens every cell division, forcing the cells into senescence at a critical telomere length. This process can be counteracted by activating a specialized enzyme, telomerase, which adds telomeric repeats to the chromosome ends leading to an extended or infinite cellular life span. Telomerase activity is absent in most somatic tissues but is found in germ cells, stem cells, activated lymphocytes and the vast majority of tumor cells and permanent cell lines. Hence, telomerase has been suggested as a target for cancer treatment as malignant cells almost exclusively express the enzyme and in that context telomere length measurements will be of great importance.</p><p>Telomere length is traditionally measured with a Southern blot based technique. A new method for telomere analysis of cells in suspension, called flow-FISH, was developed based on fluorescence in situ hybridization using a telomeric peptide nucleic acid (PNA) probe,</p><p>DNA staining with propidium iodide and quantification by flow cytometry. Flow-FISH had high reproducibility and the telomere length measurements showed good correlation with Southern blotting results. The flow-FISH technique also allows studies of cells in specific phases of the cell cycle and the replication timing of telomeric, centromeric and other repetitive sequences were analyzed in a number of cells. Like previous studies, centromeres were shown to replicate late in S phase while the telomere repeats were found to replicate early in S phase or concomitant with the bulk DNA, which is opposite to the patterns described in yeast.</p><p>In benign immunopurified lymphocytes from tonsils, high telomerase activity was found in germinal center (GC) B cells. This population also had high hTERT mRNA levels and displayed a telomere elongation as shown by flow-FISH and Southern blotting. Combined immunophenotyping and flow-FISH on unpurified tonsil cells confirmed the results.</p><p>Chronic lymphocytic leukemia (CLL), the most common leukemia in adults, can be divided into pre-GC CLL, characterized by unmutated immunoglobulin VH genes and worse prognosis, and post-GC CLL, with mutated VH genes and better prognosis. In 61 cases of CLL, telomere length was measured with Southern blotting and VH gene mutation status was analyzed. A new association was found between VH mutation status and telomere length, where cases with longer telomeres and mutated VH genes (post-GC CLL) had better prognosis</p><p>than CLL with short telomeres and unmutated VH genes (pre-GC CLL). A larger study of 112 CLL cases was performed using flow-FISH. The same correlation between telomere length and VH mutation status was found but gender seemed to be of importance as telomere length was a significant prognostic factor for the male CLL patients but not in the female group. Age of the patients and spread of disease seemed to affect the prognostic value of VH gene mutation status.</p>

The telomeres are specialized structures at the end of the chromosomes composed of the repeated DNA sequence (TTAGGG)n and specific proteins bound to the DNA. The telomeres protect the chromosomes from degradation and end to end fusions. Due to the end-replication problem, the telomeric DNA shortens every cell division, forcing the cells into senescence at a critical telomere length. This process can be counteracted by activating a specialized enzyme, telomerase, which adds telomeric repeats to the chromosome ends leading to an extended or infinite cellular life span. Telomerase activity is absent in most somatic tissues but is found in germ cells, stem cells, activated lymphocytes and the vast majority of tumor cells and permanent cell lines. Hence, telomerase has been suggested as a target for cancer treatment as malignant cells almost exclusively express the enzyme and in that context telomere length measurements will be of great importance. Telomere length is traditionally measured with a Southern blot based technique. A new method for telomere analysis of cells in suspension, called flow-FISH, was developed based on fluorescence in situ hybridization using a telomeric peptide nucleic acid (PNA) probe, DNA staining with propidium iodide and quantification by flow cytometry. Flow-FISH had high reproducibility and the telomere length measurements showed good correlation with Southern blotting results. The flow-FISH technique also allows studies of cells in specific phases of the cell cycle and the replication timing of telomeric, centromeric and other repetitive sequences were analyzed in a number of cells. Like previous studies, centromeres were shown to replicate late in S phase while the telomere repeats were found to replicate early in S phase or concomitant with the bulk DNA, which is opposite to the patterns described in yeast. In benign immunopurified lymphocytes from tonsils, high telomerase activity was found in germinal center (GC) B cells. This population also had high hTERT mRNA levels and displayed a telomere elongation as shown by flow-FISH and Southern blotting. Combined immunophenotyping and flow-FISH on unpurified tonsil cells confirmed the results. Chronic lymphocytic leukemia (CLL), the most common leukemia in adults, can be divided into pre-GC CLL, characterized by unmutated immunoglobulin VH genes and worse prognosis, and post-GC CLL, with mutated VH genes and better prognosis. In 61 cases of CLL, telomere length was measured with Southern blotting and VH gene mutation status was analyzed. A new association was found between VH mutation status and telomere length, where cases with longer telomeres and mutated VH genes (post-GC CLL) had better prognosis than CLL with short telomeres and unmutated VH genes (pre-GC CLL). A larger study of 112 CLL cases was performed using flow-FISH. The same correlation between telomere length and VH mutation status was found but gender seemed to be of importance as telomere length was a significant prognostic factor for the male CLL patients but not in the female group. Age of the patients and spread of disease seemed to affect the prognostic value of VH gene mutation status.

While the latent genome of most Herpesviruses persists as a nuclear circular episome, previous research has suggested that Human Herpesvirus 6 (HHV-6) may integrate into host cell chromosomes, and be vertically transmitted in the germ-line. Because the HHV-6 genome encodes a perfect TTAGGG telomere repeat array at the right end direct repeat (DRR) and an imperfect TTAGGG repeat at the end of the left end direct repeat (DRL), we established a hypothesis that during latency, the HHV-6A and HHV-6B genome integrates into the telomeres of human chromosomes through homologous recombination with the n(TTAGGG) viral repeats, and the integrated virus can be induced to lytic replication. We sought, first, to definitively illustrate the in vitro and in vivo integration of HHV-6A and HHV-6B. Following infection of naïve Jjhan and HEK-293 cell lines by HHV-6A and Molt3 cell line by HHV-6B, the virus integrated into telomere of chromosomes. Next, peripheral blood mononuclear cells (PBMCs) were isolated from families in which several members, including at least one parent and child, had unusually high copy numbers of HHV-6 DNA per ml of blood. FISH confirmed that HHV-6 DNA co-localized with telomeric regions of one allele on chromosomes 17p13.3, 18q23, and 22q13.3, while the integration site was identical among members of the same family. Partial sequencing of the viral genome identified the same integrated HHV-6A strain within members of families, confirming vertical transmission of the viral genome through the germ-line [inherited HHV-6 (iHHV-6)]. Amplification and sequencing of the HHV-6A and more recently HHV-6B viral-chromosome junction identified DRR integrated into the telomere directly adjacent to the subtelomere of the chromosome. After mapping the DRR of iHHV-6, we subsequently focused on determining if the DRL was present in the integrated genome and whether the remaining telomere sequence of the chromosome was extended beyond the DRL. Southern hybridization of PCR amplified HHV-6 integrated cell lines and iHHV-6 patients PBMCs indicate the presence of DRL within the integrated viral genome. Therefore, the genomic structure of the iHHV-6 is as follows: chromosome-subtelomere-(TTAGGG)5-41-DRR-U-DRL-(TTAGGG)n. During latent integration, no circular episomes were detected even by PCR. However, trichostatin-A treatment of PBMCs and in vitro integrated HEK-293 cells induced the reactivation of iHHV-6 from its latent integrated state. We demonstrated the induction of integrated iHHV-6 with trichostatin-A lead to the excision of the integrated genome and generation of the U-DR-U junction which signifies circularization and/or concatemer formation of the viral genome through rolling-circle replication. Taken together, the data suggests that HHV-6A and HHV-6B are unique among human herpesviruses: they specifically and efficiently integrate into telomeres of chromosomes during latency rather than forming episomes, and the integrated viral genome is capable of producing virions.

Le contrôle de la longueur des télomères est une étape critique régissant le potentiel réplicatif des cellules eucaryotes. A cause du problème de fin de réplication, les chromosomes raccourcissent à chaque cycle de division. Ce raccourcissement se produit dans des séquences particulières appelées télomères. La longueur des télomères est en relation directe avec les capacités prolifératives des cellules et est responsable de la limite de division de Hayflick. Cependant, dans certains types cellulaires et dans plus de 90% des cancers, la longueur des télomères va être maintenue par une enzyme spécialisée appelée télomérase. Encore aujourd’hui, comprendre la biogénèse de la télomérase et savoir comment elle est régulée reste un élément clé dans la lutte contre le cancer. Depuis la découverte de cette enzyme en 1985, de nombreux facteurs impliqués dans sa maturation ont été identifiés. Cependant, comment ces facteurs sont intégrés dans le temps et dans l’espace, afin de produire une forme active de la télomérase, est une question restée sans réponse. Dans ce projet, nous avons utilisé la levure Saccharomyces cerevisiæ comme modèle d’étude des voies de biogénèse et de trafic intracellulaire de l’ARN de la télomérase, en condition endogène. La première étape de mon travail fut d’identifier les facteurs requis pour l’assemblage et la localisation de la télomérase aux télomères en utilisant des techniques d’Hybridation In Situ en Fluorescence (FISH). Nous avons pu montrer que la composante ARN de la télomérase fait la navette entre le noyau et le cytoplasme, en condition endogène, dans les cellules sauvages. Nos travaux suggèrent que ce trafic sert de contrôle qualité puisqu’un défaut d’assemblage de la télomérase conduit à son accumulation cytoplasmique et prévient donc sa localisation aux télomères. De plus, nous avons identifié les voies d’import/export nucléaire de cet ARN. Dans une deuxième approche, nous avons réussi à développer une méthode de détection des particules télomérasiques in vivo en utilisant le système MS2-GFP. Notre iv étude montre que contrairement à ce qui a été précédemment décrit, la télomérase n’est pas associée de façon stable aux télomères au cours du cycle cellulaire. En fin de phase S, au moment de la réplication des télomères, la télomérase se regroupe en 1 à 3 foci dont certains colocalisent avec les foci télomériques, suggérant que nous visualisons la télomérase active aux télomères in vivo. La délétion des gènes impliqués dans l’activation et le recrutement de la télomérase aux télomères entraine une forte baisse dans l’accumulation des foci d’ARN au sein de la population cellulaire. Nos résultats montrent donc pour la première fois la localisation endogène de l’ARN TLC1 in situ et in vivo et propose une vue intégrée de la biogenèse et du recrutement de la télomérase aux télomères. / Telomere length control is a critical step that governs the replicative potential of eukaryotic cells. Due to the end replication problem, chromosomes shorten at each round of division. This attrition occurs in specialized sequences at the extremity of chromosomes called telomeres. Telomere size is in direct relationship with proliferative potential and responsible for Hayflick’s division limit. However, in different cell type and in cancers, an end-specialized enzyme called telomerase maintains telomere length. Reactivation of telomerase in somatic cells triggers a pre-tumoral phenotype and more than 90% of cancers highly express this enzyme. Still today, understanding how telomerase is synthesized and reactivated can be a key step for the understanding of cancer arising and progression. Since the discovery of this enzyme in 1985, several factors involved in the regulation of this enzyme have been discovered. However, the spatio-temporal regulation of telomerase biogenesis and regulation has not been determined. We used the yeast S.cerevisiæ to study the biogenesis and recruitment of telomerase to telomeres. The first step in my work was to determine the factors required for the biogenesis and recruitment of telomerase to telomeres using fluorescence in situ hybridization. We have shown that the telomerase RNA component shuttles between the nucleus and the cytoplasm in wild type endogenous conditions. We have shown that this intracellular trafficking is used as a quality control mechanism that prevents the nuclear localization of miss assembled telomerase complexes. Moreover, we have identified the import/export pathways of the telomerase RNA. In a second step, we developed an in vivo localization system to follow the telomerase RNA dynamics. We used the MS2-GFP system to track this RNA in vivo. Our study shows that, contrary to what was previously described, telomerase is not stably associated to telomeres during the cell cycle but freely diffuses in the nucleus of G1 cells. In late S phase, at the moment of telomere replication, telomerase clusters in 1 to 3 big foci vi that colocalizes with telomeres clusters in vivo, suggesting the visualization of active telomerase particles replicating telomeres. Disruption of gene coding for telomerase activators triggers a great reduction of telomerase RNA clusters in a cell population. Altogether, our results shows for the first time the localization of the endogenous form of the telomerase RNA and propose an integrated view of telomerase biogenesis and recruitment to telomeres.