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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Rôle des androgènes et progestagènes dans la remyélinisation du système nerveux central / Role of androgens and progestagens in remyelination of central nervous system

Hussain, Rashad 04 November 2011 (has links)
La sclérose en plaques (SEP) est une maladie démyélinisante dont les causes ne sont pas encore bien élucidées. Cependant, l’implication des réponses auto-immunes dans la mort des oligodendrocytes engendrant la destruction des gaines de myéline et le disfonctionnement axonal est bien documentée. Les thérapies actuelles utilisant des agents anti-inflammatoires et immunomodulateurs ciblent la réduction de l’inflammation et la progression de la maladie, mais leur efficacité reste limitée et décroit après un long traitement. Toutefois, une nouvelle stratégie de traitement, basée sur la capacité endogène du cerveau à réparer la myéline, commence à voir le jour.L’utilisation des hormones stéroïdes offre une grande opportunité, compte tenu de leurs actions pléiotropiques à la fois au cours du développement et chez les sujets adultes. Notre étude montre que les androgènes et les progéstagènes jouent un rôle très important dans la prolifération des oligodendrocytes et dans la réparation de la myéline. Ces stéroïdes permettent une remyélinisation au niveau des cultures organotypiques du cervelet de souris ou de rats après une démyélinisation par la lysolécithine. En outre, l’utilisation des souris knock-out pour le récepteur de la progestérone (PR-KO) montre l’importance de ce récepteur dans l’effet promyélinisant de la progestérone. De même, l’effet pro-remyélinisant des androgènes passe par l’intermédiaire de leur récepteur nucléaire (AR) puisque la Flutamide, agent antagonisant ces récepteurs, aboli complétement cette action. De même, l’utilisation des souris knock-out pour le récepteur de la progestérone montre l’importance de ce récepteur dans l’effet promyélinisant de la progestérone.L’influence de la testostérone et des ces métabolites sur la réparation de la myéline au niveau du corps calleux est aussi montrée in vivo, en traitant les souris C57Bl/6 par la cuprizone pendant 12 à 14 semaines. Le traitement de ces souris par la testostérone ou ces métabolites 5α- dihydrotestosterone (5α-DHT), 17β-estradiol ou par un agoniste synthétique fort, le 7α-methyl-19-nortestosterone (MENT) pendant 6 semaines, induit un remarquable recrutement des progéniteurs d’oligodendrocytes, suivie par une importante remyélinisation des zones démyélinisées. Le mécanisme d’action de ces androgènes implique le récepteur AR puisque aucun effet promyélinisant n’a été observé chez les souris dont l’AR est muté (tfm : testicular feminization mutation) et les souris ARNes/cre (mutation conditionnelle de l’AR dans les neurones et les cellules macrogliales). Les souris ArKO (Aromatse Knoctout) ne pouvant pas convertir la testostérone en estradiol sont aussi insensibles au traitement par la testérone.Ces travaux montrent que les stéroïdes jouent un rôle très important dans la remyélinisation in vitro et in vivo, fournissant une preuve expérimentale pour une utilisation des stéroïdes dans des essais cliniques futurs visant à réparer la myéline. / Multiple sclerosis (MS) is a very prominent demyelinating disease. The cause of demyelination in MS is not clear, however, it involves autoimmune responses and the death of oligodendrocytes accompanied by myelin destruction and axonal dysfunction. Currently available therapies including anti-inflammatory agents and immunomodulators are targeted to reduce inflammation and disease progression but their limited efficacy further decrease after prolonged treatment.However, another therapeutic strategy has gained recently much interest, is to boost the endogenous capacity of the brain to repair myelin.Steroid hormones offer an opportunity for therapeutic interventions in a wide range of tissue abnormalities because of their multiple actions during development and in adulthood. Our studies show that androgens and progestagens play pivotal role in oligodendrocyte proliferation and subsequent myelination. Androgens or progestagens promote remyelination after lysolecithin mediated myelin insult of organotypic cerebellar slices in culture. Moreover, remyelinating effects of testosterone can be blocked by flutamide, an androgen receptor (AR) inhibitor. Also, the remyelination induced by progestagens is abolished when cerebellar slices are used from progesterone receptors (PR) knockout mice.The influence of testosterone and its metabolites on myelin repair was also evident in toxininduced demyelination in vivo. Long-term cuprizone intoxication (12-14 weeks) of adult C57Bl/6 mice caused chronic and severe demyelination in the corpus callosum. Treatment of these mice with testosterone or its metabolites, particularly 5α-dihydrotestosterone (5α-DHT), estradiol-17β and potent testosterone analog 7α-methyl-19-nortestosterone (MENT) for 6 weeks results in a marked replenishment of the corpus callosum with oligodendrocytes and remyelination. Testosterone fails to stimulate remyelination in mice carrying testicular feminization mutation (Tfm) of AR in the cuprizone model. Furthermore, we demonstrate that testosterone directly targets neuronal and macroglial AR, because the specific ablation of neural AR in (ARNes/Cre) mice prevents the myelin repair in response to testosterone. Interestingly, blocking the conversion of testosterone into estrogens by knocking out the aromatase gene (ArKO mice), also impair the remyelinating effect of testosterone.In conclusion, we provide a strong evidence for a new role of progestagens and androgens in remyelination and thus present a sound experimental support for future clinical trials based on steroid hormone therapy for demyelinating disorders.
302

Participação do fator liberador de corticotrofina nos efeitos do estradiol no controle da homeostase energética / The role of corticotropin-releasing factor on estradiol effects on regulation of energy homeostasis

Marangon, Paula Beatriz 16 May 2011 (has links)
A homeostase energética é controlada por fatores neurais, endócrinos, adipocitários e intestinais. O sistema nervoso central (SNC) recebe sinalização de fatores periféricos e exerce uma função fundamental no controle da homeostase energética, estando bem estabelecido que existem populações neuronais que expressam neuropeptídeos que medeiam efeitos específicos na ingestão e/ou gasto energético. O fator liberador de corticotrofina (CRF), além de seus efeitos no controle da atividade do eixo hipotálamo-hipófise-adrenal, tem sido descrito como potente neuropeptídeo anorexígeno, modulando a ingestão alimentar e o gasto energético. Foi observado que a síntese de CRF é influenciada pela leptina, que atuaria aumentando a ativação de neurônios produtores de CRF no núcleo paraventricular (PVN). Os hormônios gonadais também participam na regulação da ingestão alimentar, do peso e da composição corporal. O efeito anorexígeno do estradiol é mediado pela ativação de receptores presentes nas áreas envolvidas no controle da homeostase energética. Em trabalho prévio de nosso laboratório foi observado que o menor ganho de peso e ingestão alimentar com o tratamento com estradiol em ratas ovariectomizadas está associado à maior expressão de RNAm de CRF no PVN. Dessa forma, este trabalho visa esclarecer a participação do CRF nos efeitos do estradiol no controle da homeostase energética. Para tanto, foram utilizadas ratas Wistar adultas, pesando entre 200-230g, provenientes do Biotério Central do Campus de Ribeirão Preto USP. Todos os animais foram submetidos à cirurgia de ovariectomia bilateral. Em todos os experimentos, houve três grupos de animais: ratas ovariectomizadas (OVX), ratas ovariectomizadas com reposição de estradiol (OVX+E) e ratas ovariectomizadas com dieta pareada ao grupo OVX+E (OVX+DP). Durante os oitos dias de cada experimento, estes animais receberam injeção subcutânea de cipionato de estradiol (10 g/Kg peso corporal, Grupo OVX+E) ou veículo (óleo de milho: 0,2 mL/rata, Grupos OVX e OVX+DP) entre 8h e 10h. Para avaliarmos a participação do CRF nos efeitos da leptina nos animais castrados com e sem reposição de estradiol, foi realizado o tratamento com injeção central de leptina (10g/5L) com e sem injeção central prévia de antagonista de CRF (antisauvagina-30). Observamos que o tratamento com cipionato de estradiol causa a redução na ingestão alimentar e no ganho de peso corporal. Ainda, quando realizamos a administração central de leptina há anorexia, perda de peso corporal, aumento na expressão de UCP-1 no BAT e na ativação neuronal no ARQ. Esses efeitos são revertidos quando realizamos administração central prévia do antagonista de CRF-R2. Os dados obtidos sugerem que o estradiol aumenta a sensibilidade à leptina, sendo este efeito mediado, pelo menos em parte, pelo receptor tipo 2 do CRF. / Energy homeostasis is controlled by neural, endocrine, adipocyte and gut factors. Central nervous system plays a key role in the control of energy homeostasis; it receives signals from peripheral factors and it is well established that the hypothalamus contains neuronal populations that express important neuropeptides to the control of food intake and energy expenditure. Besides its action in the control of hypothalamus-pituitary-adrenal axis, corticotropin releasing factor (CRF), has been described as an anorexigenic neuropeptide, modulating food intake and energy expenditure. It was shown that CRF synthesis is influenced by leptin, which would act increasing CRF neuron activation in the paraventricular nucleus (PVN). Gonadal hormones also participate in the regulation of food intake, body weight and body composition. Estradiol anorexigenic effect is mediated by specific receptors located in areas involved in the control of energy homeostasis. It was previously demonstrated that the reduction of food intake and body weight gain in ovariectomized treated rats is associated with an increase in CRF mRNA expression in the PVN. The present study aimed to investigate the role of CRF on estradiol regulation of energy homeostasis. Wistar female rats, weighing 200 230g, were bilaterally ovariectomized and divided into three groups: ovariectomized rats (OVX), ovariectomized rats treated with estradiol (OVX+E) and ovariectomized rats pair-fed with OVX+E rats (OVX+PF). The animals received daily subcutaneous injections of either estradiol cypionate (10 g/Kg bw, OVX+E) or vehicle (corn oil, OVX, OVX+PF) between 8 10 am, during 8 days. To evaluate the role of CRF on leptins effects we performed intracerebroventricular (icv) injection of recombinant leptin (10g/5L) with or without previous icv treatment with CRF-R2 antagonist (ansauvagin-30). We observed that estradiol replacement in OVX rats induced lower food intake and body weight gain. Leptin icv treatment reduced food intake, body weight gain and increased UCP-1 expression in brown adipose tissue and neuronal activation in the arcuate nucleus. These effects were abolished with previous icv administration of CRF-R2 antagonist. In conclusion, our data suggest that estradiol increases central sensitivity to leptin and this effect is mediated, at least in part, by CRF type 2 receptor.
303

Avaliação da atividade estrogênica das águas do Rio Paraíba do Sul / Evaluation of estrogenic activity in water samples from Paraiba do Sul River

Rocha, Guilherme Casoni da 14 December 2012 (has links)
A poluição da água doce no estado de São Paulo ocorre por diversas causas. Entre elas está a ineficiência do serviço de tratamento de esgoto sanitário. Alguns componentes do esgoto sanitário são desreguladores endócrinos, entre eles estão os hormônios naturais e sintéticos excretados pelos seres humanos. Estas substâncias causam modificações no sistema reprodutivo como, por exemplo, câncer, feminização, alterações na transcrição genética, alteração nas gônadas, indução à síntese de vitelogenina, entre outros. O objetivo desse trabalho foi testar a atividade endócrina das águas do rio Paraíba do Sul, em Pindamonhangaba, SP. Para tanto, amostras de água do rio foram utilizadas para a quantificação dos hormônios, 17-etinilestradiol, 17-estradiol e levonorgestrel por meio da técnica de cromatografia líquida de alta eficiência (HPLC). Além disso, foram realizados testes crônicos com peixes (Danio rerio) no interior do rio e em laboratório, e uma posterior quantificação de vitelogenina. Os resultados não indicaram concentrações detectáveis dos hormônios pelo método empregado. Entretanto, foi detectada a indução de vitelogenina nos machos de Danio rerio. Esse fato indica a atividade estrogênica da água utilizada. São necessários outros estudos para a avaliação de quais substâncias presentes na água, estão causando as alterações endócrinas nos peixes, entre eles a utilização de índices para priorizar o local inicial dessas pesquisas. Esses estudos são importantes para a conservação da biodiversidade aquática do rio Paraíba do Sul / Freshwater pollution in São Paulo state, Brazil, occurs due a several reasons. Among them there is the inefficiency of the sewage treatment service. Some sewage components are endocrine disrupters, including natural and synthetic hormones excreted by humans. These substances cause modification on reproductive system such as cancer, feminization, gene transcription and gonad alterations, vitellogenin synthesis induction, among others. The aim of this work was to evaluate the endocrine activity of the river Paraíba do Sul, at Pindamonhangaba city, Brazil. For this, river water samples were collected for the quantification of the hormones, 17- etinylestradiol, 17-estradiol and levonorgestrel by high performance liquid chromatography (HPLC). Furthermore, chronic assays were performed with fish (Danio rerio) into the river and in the laboratory, following quantification of biomarker vitellogenin. The studied hormones were not detected by employed methods. However, induction of vitellogenin in male of Danio rerio was detected indicating estrogenic activity of water. Further studies are necessary for the assessment of which substances into the water are causing the endocrine disruption in fish. These studies are important for the preservation of aquatic biodiversity of the Paraiba do Sul River
304

Geração de inibina A após estímulo gonadotrófico: novo método de detecção de tecido ovariano em pacientes com anomalia da diferenciação sexual / Inhibin A generation after gonadotropin stimulus: a new method to detect ovarian tissue in true hermaphrodites

Leandra Steinmetz 29 May 2006 (has links)
Introdução: O hermafroditismo verdadeiro, caracterizado pela demonstração histológica de tecido ovariano e testicular no mesmo indivíduo, responde por cerca de 5% dos casos de anomalia da diferenciação sexual. Como a variabilidade fenotípica é muito grande, desde mulheres com genitália externa normal até homens com genitália externa normal, passando por toda uma gama de apresentações intermediárias, torna-se impossível o diagnóstico baseado apenas em dados clínicos. A avaliação da presença de tecido testicular é bem estabelecida, mas não há teste para a demontração de tecido ovariano. A inibina A é produzida exclusivamente no ovário e é estimulada pelas gonadotrofinas. Objetivos: 1. Avaliar a efetividade do método de estimulação gonadal com a associação LH/FSH na demonstração de tecido ovariano; 2. Avaliar a eventual presença de tecido ovariano em pacientes com anomalias da diferenciação sexual através da dosagem sérica de Inibina A e de estradiol após estímulo gonadotrófico e; 3. Facilitar o diagnóstico de hermafroditismo verdadeiro antes da fase de exploração cirúrgica das gônadas. Métodos: Foram incluídos no estudo, dez pacientes com hiperplasia congênita de supra-renal, dez pacientes com criptorquidia unilateral isolada, treze pacientes com anomalia da diferenciação sexual sem etiologia definida e sete pacientes com hermafroditismo verdadeiro com diagnóstico histológico. Todos os pacientes foram submetidos a um teste de estímulo gonadotrófico, representado pela administração de gonadotrofina humana da menopausa (menotropina), que tem em sua composição LH e FSH, na dose de 150 UI de cada gonadotrofina, por via intramuscular, durante três dias subseqüentes. Dosagens de LH, FSH, estradiol, testosterora e inibina A foram realizadas antes (B), 24h após a primeira dose (A1) e 24 horas após a terceira dose (A2). Resultados: O LH não apresentou elevação significativa nos quatro grupos. O FSH elevou-se nos quatro grupos de forma progressiva e semelhante. O estradiol elevou-se significativamente nos grupos de pacientes com hiperplasia congênita das supra-renais (p=0,005) e de pacientes com hermafroditismo verdadeiro (p=0,031), enquanto a testosterona elevou-se nos grupos com criptorquidia isolada (p=0,027) e de pacientes com ambigüidade genital sem etiologia definida (p=0,028). A inibina A elevou-se significativamente nos grupos de pacientes com hiperplasia congênita das supra-renais (p=0,005) e com hermafroditismo verdadeiro (p=0,043). Conclusão: O teste de estímulo com LH e FSH mostrou-se útil para o diagnóstico da presença de tecido ovariano tanto em pacientes com hiperplasia congênita das supra-renais, como naqueles com hermafroditismo verdadeiro. / Introduction: True hermaphrodism (TH) is characterized by the presence of ovarian and testicular tissue in the same patient comprises 5% of the intersex cases. A large spectrum of phenotypical variation is observed, ranging from normal female genitalia to normal male genitalia, covering a wide range of intermediary presentations, it becomes very difficult to make the diagnosis of TH on clinical basis. The detection of testicular tissue is well stablished but there is no available test to demonstrate the presence of ovarian tissue. Objectives: 1. To evaluate the effectiveness of the LH/FSH gonadal stimulation in demonstrating ovarian functiom 2. To evaluate the presence of ovarian tissue in intersex patients under gonadotropic stimulation and 3. To make the TH diagnosis before the surgical procedure. Patients and Methods: Ten patients with congenital adrenal hyperplasia (CAH), 10 with unilateral cryptorchidism, 13 intersex patients with no defined etiology, and seven TH patients have been included in the study. All the patients had a gonadotropic stimulation test with human menopausal gonadotropin (menotropin-hMG),150 IU, intramuscular, for three consecutive days. LH, FSH, estradiol, testosterone, and Inhibin A were measured before (0 time), 24h after the first gonadotropin dose, and 24h after the third gonadotropin dose. Results: LH did not show any significant increase in the four groups studied. FSH increased in the four groups in a similar way. Estradiol increased in CAH pacients (p=0.005) and in TH patients (p=0,031), while testosterone increased in patients whit unilateral cryptorchidism (p=0.027) as well as in the intersex patients without defined etiology. Inhibin A levels increased in CAH patients (p=0.005) and in the TH patients (p=0.043). Conclusion: The LH/FSH stimulation test demonstrated to be a useful method to diagnose the presence of ovarian tissue in CAH patients as well as in TH patients, becoming an important tool to diagnose TH even before the surgical procedure and histologic studies of the gonads.
305

Avalia??o do efeito do 17?-estradiol sobre a express?o g?nica da conexina40 e suas implica??es na propaga??o da atividade el?trica card?aca / Evaluation of the effect of 17 ?-estradiol on the gene expression of Connexin40 and its implications for the spread of cardiac electrical activity.

Amarante, D?bora Barbosa 26 February 2016 (has links)
Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-26T11:36:13Z No. of bitstreams: 1 2016 - D?bora Barbosa Amarante.pdf: 1603287 bytes, checksum: 8c473e3225022499b4e4dc93119df63f (MD5) / Made available in DSpace on 2017-01-26T11:36:13Z (GMT). No. of bitstreams: 1 2016 - D?bora Barbosa Amarante.pdf: 1603287 bytes, checksum: 8c473e3225022499b4e4dc93119df63f (MD5) Previous issue date: 2016-02-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The 17?-estradiol (E2) regulate many cardiac genes via its estrogen receptor (ER). The propagation of electrical activity in the myocardium depends on the current transfer at gap junctions. Connexins 40 (Cx40) and 43 are the predominant junctional proteins. In mice, Cx40 is restricted to the atrium and conduction system. Alterations of Cx40 expression or activity are associated with atrial fibrillation. Here we evaluate the effect of the E2 onCx40 mRNA expression, in vitro, and in vivo the effect on atrium expression of Cx40 mRNA in correlation to ECG studies. We treated A7r5 cells (smooth muscle cells from rat thoracic aorta) with low and high doses ofestradiol benzoate, EB, (10-8 M and 10-6M) for 24h and rat neonatal cardiomyocytes with EB 10-6 M for 2, 4 and8 hours. A7r5 cells were trasiently transfected with 0.5 microgramas of the test plasmid (-1190/+121Cx40Luc pGL3) and treated with 10-6M of EB for 24 hours. Female mice were subjected to ovariectomy (OVX) and then, treated with a low (2?g) and a high dose (20?g) of estradiol benzoate (EB; OVX+EB2 and OVX+EB20) for 15 days. ECG recordings were obtained from mice and atrium Cx40 mRNA expression were evaluated by RT-PCR real time. First, we observed that high doses of EB down regulated Cx40 mRNA in vitro (A7r5 cells and rat atrial cardiomyocytes). The transcriptional activity of Cx40 promoter was inhibited by 10-6M of EB in A7r5 cells. We observed lower heart rate for OVX animals when to compared to control animals, FO. In this regard, no difference was observed between OVX+EB2 and OVX+BE20 heart rate. The OVX group showed decrease P wave duration when to compared to FO group, but no difference in the P wave duration was observed among the others groups. No difference was observed in another ECG intervals among the experimental groups. The atrial Cx40mRNA level was reduced in OVX+BE20group when to compared to FO group. Our data indicate, for the first time, high doses of estradiol benzoate reduce Cx40 mRNA in vitro and ovariectomized mice. We proposed that when E2 levels are high, the complex ER-E2 acts directly from the DNA, inhibiting the transcriptional activity of Cx40 promoter / O 17?-estradiol (E2), regula muitos genes card?acos atrav?s de seu receptor (receptor para estr?geno, RE). A propaga??o da atividade el?trica no mioc?rdio depende da transfer?ncia de corrente atrav?s das jun??es comunicantes. As conexinas 40 (Cx40) e 43 s?o as principais conexinas que formam as jun??es expressas no cora??o. Em camundongos, a Cx40 ? restrita ao ?trio e sistema de condu??o. Altera??es na express?o ou atividade da Cx40 est?o associadas a fibrila??o atrial. Aqui n?s avaliamos o efeito do E2 in vitro e in vivo sobre a express?o do RNAm da Cx40 nos ?trios e correlacionamos aos estudos eletrocardiogr?ficos (ECG). N?s tratamos a linhagem A7r5 (derivada de m?sculo liso a?rtico de rato embrion?rio) com alta e baixa concentra??es de benzoato de estradiol, BE, (10-6 M e 10-8 M) durante 24 horas e cultura prim?ria de cardiomi?citos atriais de ratos neonatos foram incubados com BE 10-6 M durante 2, 4 e 8 horas. Ensaios de transfec??o transiente foram realizados na linhagem A7r5 com um plasm?deo contendo um segmento da regi?o promotora da Cx40 (-1190/+121Cx40LucpGL3) e tratadas com 10-6 M de BE durante 24 horas. Camundongos f?meas foram ovariectomizadas (OVX) e ent?o tratadas com baixa (2 microgramas) e alta (20 microgramas) doses de benzoato de estradiol (OVX+BE2 e OVX+BE20) durante 15 dias, sendo que o grupo controle sofreu apenas estresse cir?rgico (FO). Foram realizados registros ECG e a express?o atrial do RNAm da Cx40 foi avaliada por RT-PCR em tempo real. N?s observamos que altas doses de BE diminui a express?o do RNAm da Cx40 in vitro (na linhagem A7r5 e na cultura de cardiomi?citos). A atividade transcricional do promotor foi inibida por BE10-6 M. N?s observamos diminui??o da frequ?ncia card?aca dos animais do grupo OVX em rela??o ao controle, grupo FO. Nenhuma diferen?a foi observada na frequ?ncia card?aca entre os grupos OVX+BE2 e OVX+BE20. Os animais do grupo OVX apresentaram diminui??o na dura??o da onda P em rela??o ao grupo FO, no entanto nenhuma diferen?a foi observada na dura??o da onda P entre os outros grupos. Nenhuma diferen?a foi observada nos outros intervalos eletrocardiogr?ficos entre os grupos experimentais. A express?o atrial do RNAm da Cx40 estava reduzida nos animais do grupo OVX+BE20 em rela??o ao grupo FO. Nossos dados demonstram que altas doses de benzoato de estradiol reduzem a express?o do RNAm da Cx40 in vitro e em camundongos ovariectomizados. N?s propomos que altas doses de E2 ativa o seu receptor, e o complexo RE-E2 age diretamente no DNA, inibindo a atividade transcricional do promotor da Cx40
306

Role of 17β-estradiol in controlling the self-renewal of undifferentiated mouse embryonic stem cells via calcium signaling pathway.

January 2010 (has links)
Wong, Chun Kit. / "September 2010." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 104-118). / Abstracts in English and Chinese. / Thesis Committee --- p.i / Acknowledgements --- p.ii / Contents --- p.iii / Declaration --- p.vi / Abstract --- p.vii / 摘要 --- p.x / Abbreviations --- p.xi / List of Figures --- p.xiii / Chapter CHAPTER ONE: --- INTRODUCTION / Chapter 1.1 --- Embryonic Stem Cells (ESCs) / Chapter 1.1.1 --- Characteristics of ESC --- p.1 / Chapter 1.1.2 --- Therapeuticotential of ESCs --- p.2 / Chapter 1.2 --- 17β-estradiol (E2) / Chapter 1.2.1 --- Genomic Actions of E2 --- p.3 / Chapter 1.2.2 --- Non-genomic Actions of E2 --- p.5 / Chapter 1.2.3 --- hysiological Roles of E2 on Early Mammalian Development --- p.9 / Chapter 1.2.4 --- E2 and Cell Proliferation --- p.10 / Chapter 1.3 --- Ca2+ homeostasis / Chapter 1.3.1 --- Overview --- p.11 / Chapter 1.3.2 --- Ca2+ Signaling in mESCs --- p.14 / Chapter 1.4 --- Store-operated Ca2+ Entry (SOCE) / Chapter 1.4.1 --- Overview --- p.15 / Chapter 1.4.2 --- Store Depletion --- p.15 / Chapter 1.4.3 --- Activation of SOCE --- p.16 / Chapter 1.5 --- Molecular Identities of Store-operated Ca2+ Channels (SOCCs) on plasma Membrane / Chapter 1.5.1 --- TRPC Channels --- p.17 / Chapter 1.5.2 --- ORAI Channels --- p.18 / Chapter 1.5.3 --- Regulation of SOCCs at Different Levels --- p.18 / Chapter 1.5.4 --- Regulation of SOCE --- p.19 / Chapter 1.6 --- Nuclear Factor of Activated T-cells (NFAT) / Chapter 1.6.1 --- Overview --- p.20 / Chapter 1.6.2 --- Mechanisms of Action --- p.21 / Chapter 1.6.3 --- Functions --- p.22 / Chapter 1.7 --- Aims of the Study --- p.23 / Chapter CHAPTER TWO: --- MATERIALS AND METHODS / Chapter 2.1 --- Maintenance of mESCs --- p.24 / Chapter 2.2 --- Cell proliferation Assay and Viability Test --- p.24 / Chapter 2.3 --- "RNAreparation, Reverse Transcription (RT) and Quantitative Polymerase Chain Reaction (qPCR)" --- p.25 / Chapter 2.4 --- Totalrotein Extraction --- p.27 / Chapter 2.5 --- Measurement of protein Concentration --- p.27 / Chapter 2.6 --- De-phosphorylation Assay --- p.28 / Chapter 2.7 --- Western Blot --- p.28 / Chapter 2.8 --- Ca2+ Measurement by Confocal Microscopy --- p.30 / Chapter 2.9 --- Ca2+ Measurement by Flow Cytometry --- p.31 / Chapter 2.10 --- siRNA Transfection --- p.31 / Chapter 2.11 --- DNAlasmid Transfection --- p.32 / Chapter 2.12 --- Molecular and Fluorescence Imaging --- p.33 / Chapter 2.13 --- Statistical Analysis --- p.34 / Chapter 2.14 --- Primers used in the Study (Table 1:Primers List) --- p.34 / Chapter 2.15 --- Drugs used in the Study (Table 2: Drugs List) --- p.36 / Chapter 2.16 --- Antibodies used in the Study (Table 3: Antibodies List) --- p.37 / Chapter CHAPTER THREE: --- RESULTS / Chapter 3.1 --- Expression of SOCE in mESCs --- p.38 / Chapter 3.2 --- SOCC Blockers Attenuated mESCroliferation --- p.43 / Chapter 3.3 --- E2 Increased mESCroliferation --- p.48 / Chapter 3.4 --- E2 Increased Intracellular Ca2+ ([Ca2+]i) Level in mESCs --- p.48 / Chapter 3.5 --- E2 Increased the Amplitude of SOCE --- p.51 / Chapter 3.6 --- Increase in mESC proliferation and SOCE Caused by E2 Could be Reversed by SOCC Blocker --- p.51 / Chapter 3.7 --- Relative Expression of SOCC Candidates at mRNA Level Under the Treatment of E2 --- p.56 / Chapter 3.8 --- E2 Down-regulated the Expression of ORAI3 --- p.56 / Chapter 3.9 --- Knockdown of ORAI3 in mESCs --- p.61 / Chapter 3.10 --- Identification of NFATc3 Specific Bands --- p.63 / Chapter 3.11 --- E2 Increased the phosphorylation of NFATc3 --- p.67 / Chapter 3.12 --- Effects of 2-APB on NFATc3 phosphorylation Status --- p.67 / Chapter 3.13 --- Identification of NFATc4 Specific Bands ? --- p.72 / Chapter 3.14 --- E2 Increased the Translocation of GFP-NFATc4 From the Cytoplasm to the Nucleus and This Effect Could be Reversed by 2-APB --- p.80 / Chapter 3.15 --- CsA Reversed E2-induced Increase in proliferation --- p.82 / Chapter CHAPTER FOUR: --- DISCUSSION / Chapter 4.1 --- Expression of SOCE in mESCs --- p.84 / Chapter 4.2 --- proliferation of mESCs Depends on SOCE --- p.85 / Chapter 4.3 --- E2 Acts an Extrinsic Factor for Stimulatingroliferation of mESCs Via SOCE --- p.87 / Chapter 4.4 --- roposed Mechanism to Show an Increment of SOCE Can be Due to a Down-regulation of ORAI3 --- p.89 / Chapter 4.5 --- Experiments Aiming to Knockdown ORAI3 --- p.92 / Chapter 4.6 --- roposed Mechanism to Show an Increment of SOCE by Other SOCC Candidates Rather than ORAI3 --- p.93 / Chapter 4.7 --- Activation of NFATc3 and NFATc4 by E2 in mESCs --- p.94 / Chapter 4.8 --- possible Downstream Targets of NFAT Responsible for E2-induced mESCs proliferation --- p.96 / Chapter CHAPTER FIVE: --- FUTUREERSPECTIVES --- p.98 / Chapter CHAPTER SIX: --- CONCLUSION --- p.100 / REFERENCES --- p.104
307

Estudo da interação entre vias de sinalização dos estrógenos e fatores de crescimento  no controle da transcrição dos genes HNRPK, PAWR e PHLDA1 / Study to evaluate the crosstalk between estrogens and growth factors pathways on the transcriptional regulation of HNRPK, PAWR and PHLDA1.

Garcia, Simone Aparecida de Bessa 18 December 2009 (has links)
A interação entre as vias de sinalização dos estrógenos e fatores de crescimento está relacionada a maior agressividade dos tumores de mama. Assim, o objetivo deste trabalho foi verificar a interação entre as vias do E2 e do EGF no controle da expressão dos genes HNRPK, PAWR e PHLDA1 nas células MCF-7 (ER+) e MDA-MB-231 (ER-). Nas células MCF-7, o EGF e o E2 diminuíram a expressão do PAWR e aumentaram a expressão de PHLDA1. A inibição do ER pelo ICI resultou no aumento da expressão de PAWR sendo que a adição do E2 ou do EGF diminuiu sua expressão sem retomar os níveis observados nos tratamentos com E2 ou EGF isoladamente. Para o gene PHLDA1, o efeito do E2 e do EGF não variou após o tratamento com ICI. Nas células MDA-MB-231, a ação do EGF foi mais efetiva sobre a expressão de PAWR. A via ERK1/2 é importante na ativação do ER pelo EGF. O efeito do EGF sobre o PHLDA1 ocorre através da ativação das vias ERK1/2 e p38 MAPK. Estes resultados mostram a interação entre as vias do E2 e do EGF no controle da expressão do PAWR, mas não do PHLDA1. / The crosstalk between estrogens and growth factors pathways has been associated with breast cancer aggressiveness. Based on this, the present study aimed to determine the possible crosstalk between E2 and EGF pathways on the HNRPK, PAWR and PHLDA1 expression regulation in MCF-7 (ER+) and MDA-MB-231 (ER-) cells. In MCF-7 cells, treatments with E2 and EGF decreased PAWR expression and increased PHLDA1 expression. The ER inhibition by the ICI treatment resulted in increased PAWR expression. The E2 or EGF addition down-regulated its expression without a return to the levels observed after the E2 or EGF treatments alone. To the PHLDA1 gene, the effect of E2 and EGF treatments did not change after the ICI treatment. In MDA-MB-231 cells, the EGF effect was more significant on the PAWR gene expression control. The ERK1/2 pathway is important to the ER activation by EGF. The EGF effect over the PHLDA1 is dependent on the ERK1/2 and p38 MAPK activation. These findings suggest a crosstalk between E2 and EGF pathways on the PAWR expression control but not to PHLDA1.
308

Estradiol regulates multiple tetrodotoxin-sensitive sodium currents in gonadotropin releasing hormone neurons implications for cellular regulation of reproduction /

Wang, Yong, Kuehl-Kovarik, M. Cathleen. January 2009 (has links)
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from PDF of title page (University of Missouri--Columbia, viewed on January 6, 2010). Thesis advisor: M. Cathleen Kuehl-Kovarik. Includes bibliographical references.
309

Purification and identification of specific RNA-binding protein that binds to the 3'UTR region of cytochrome P450aromatase mRNA in bovine granulosa cells

Xue, Siqi January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
310

NÍVEIS SÉRICOS MATERNOS DE ESTRADIOL, ESTRIOL E PROGESTERONA EM PARTOS INDUZIDOS COM DINOPROSTONA EM GESTANTES A TERMO / MATERNAL SERUM LEVELS OF ESTRADIOL, ESTRIOL AND PROGESTERONE IN DINOPROSTONE-INDUCED LABOR IN TERM PREGNANT WOMEN

Konopka, Cristine Kolling 13 July 2011 (has links)
Hormonal-mediated uterine quiescence involves the maintenance of a decreased inflammatory responsiveness. However, no study has investigated whether labor induction with prostanoids is associated with changes in maternal serum hormones. The objective of this study was to determine whether changes in circulating levels of progesterone, estradiol and estriol from admission to delivery are associated with successful labor induction with dinoprostone. A cohort of 81 pregnant women at term was followed from admission to birth until delivery, during the period of 2010-2011. The study was performed at the Hospital of the Federal University of Santa Maria, a tertiary care hospital. Unselected subjects were recruited and blood samples were obtained at admission and immediately before delivery. Sixteen patients had vaginal delivery after spontaneous labor, 12 required emergency cesarean after spontaneous labor and 16 underwent elective cesarean. Thirty-seven patients had labor induction with dinoprostone. Eligible patients received a vaginal insert of dinoprostone (10 mg), and patients were followed up until delivery. Progesterone (P4), estradiol (E2) and estriol (E3) plasma level and P4/E2, P4/E3 and E3/E2 ratio changes were observed from admission to immediately before birth, and the association of these measures with the resulting clinical classification outcome (route of delivery and induction responsiveness) were assessed. Progesterone plasma level decreased from admission to delivery in patients who underwent successful labor induction with dinoprostone [vaginal and cesarean delivery after induced labor: 23% (P<0.001) and 18% (P<0.025) decrease, respectively], but not in those whose induction failed (6.4% decrease, P>0.05). Estriol and estradiol levels did not differ between groups. Successful dinoprostone-induced labor was associated with maternal progesterone level decrease along time. While a causal relationship between progesterone decrease and effective dinoprostone-induced labor can not be established, it is tempting to propose that it may contribute for progesterone withdrawal and favor labor induction in humans. / A quiescência uterina mediada por hormônios envolve a manutenção de uma responsividade inflamatória reduzida. Contudo, nenhum estudo investigou se a indução do parto com prostanóides está associada com alterações em hormônios séricos maternos. Os objetivos deste estudo foram determinar se as alterações nos níveis circulantes de progesterona, estradiol e estriol desde a admissão até o parto estão associados à indução bem sucedida do parto com dinoprostona. Uma coorte de 81 mulheres grávidas a termo foi acompanhada desde a admissão até o parto, durante o período de 2010-2011. O estudo foi realizado no Hospital da Universidade Federal de Santa Maria, um hospital de cuidados terciários. Indivíduos não selecionados foram recrutados e amostras de sangue foram obtidas na admissão e imediatamente antes do nascimento. Dezesseis pacientes tiveram parto vaginal após trabalho de parto espontâneo, 12 necessitaram a realização de cesariana de emergência após trabalho de parto espontâneo e 16 foram submetidas à cesárea eletiva. Trinta e sete pacientes tiveram indução de trabalho de parto com dinoprostona. As pacientes elegíveis receberam um pessário de inserção vaginal de dinoprostona (10 mg), e foram acompanhadas até o parto. Os níveis plasmáticos de progesterona (P4), estradiol (E2) e estriol (E3) e as relações P4/E2, P4/E3 e E3/E2 foram observadas da admissão até imediatamente antes do nascimento, e a associação destas medidas com a classificação clínica resultante foi avaliada (via de parto e resposta à indução). Os níveis plasmáticos de progesterona diminuíram desde a admissão até o nascimento em pacientes que responderam à indução com dinoprostona [parto vaginal e cesáreo após trabalho de parto induzido: redução de 23% (P<0.001) e 18% (P<0.025), respectivamente], mas não nos quais a indução falhou (redução de 6.4%, P>0.05). Os níveis de estriol e estradiol, e as relações P4/E2, P4/E3 e E3/E2 não foram diferentes entre os grupos. O sucesso da resposta à indução de parto com dinoprostona esteve associado com a redução no nível de progesterona materna ao longo do tempo. Enquanto uma relação causal entre a redução na progesterona e o trabalho de parto efetivo induzido pela dinoprostona não pode ser estabelecida, é tentador propor que possa contribuir para a retirada da progesterona e favorecer a indução do parto em humanos.

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