Des hormones gonadotropiques sont utilisées pour la maîtrise de la reproduction dans le domaine vétérinaire. Ces hormones sont actuellement extraites de tissus ou de fluides animaux. L’entreprise CEVA Santé Animale a récemment fait le choix stratégique de produire ces hormones par voie recombinante. L’objectif de cette étude était d’obtenir une gonadotropine chorionique équine recombinante, reCG, pure et biologiquement active, à partir d’une lignée de cellules mammifères CHO. Les étapes de production, de purification et de caractérisation de l’hormone recombinante ont été développées. Les cellules CHO ont été cultivées en fiole d’Erlenmeyer dans différents milieux de culture. Le suivi de la croissance cellulaire et de la quantité d’hormone produite a permis de sélectionner deux milieux. Le procédé de production, avec ces deux milieux, a été optimisé en bioréacteur en contrôlant les paramètres de culture (température, pH). Les protéines produites dans le surnageant, de ces deux cultures, ont été nommées reCG 1 et reCG 2. Un procédé de purification en 3 étapes a été mis au point pour la reCG 1. Plusieurs résines et conditions chromatographiques ont été criblées en microplaques. Les résines multimodales utilisées ont permis d’éliminer des contaminants majeurs grâce à leur sélectivité. Les agrégats de la reCG ont été éliminés grâce à une résine anionique. Le procédé de purification global a été validé pour la reCG 1 et la reCG 2. Il a permis d’obtenir une pureté de 98 % avec un rendement de 80 %. L’activité biologique de la reCG 1 et la reCG 2, in vitro et in vivo, est comparable à celle de la protéine naturelle. L’activité biologique in vivo des reCG est cohérente avec l’étude réalisée sur les glycosylations des hormones et notamment avec leur degré de sialylation. / The gonadotrophic hormones are used for reproduction control in farming animals. Up to now, these hormones were extracted from animal fluids or tissues. The company CEVA Santé Animal has recently decided to produce recombinant versions of these hormones. The objective of this study was to obtain a pure and biologically active recombinant equine chorionic gonadotropin (reCG) after expression in CHO mammalian cells. The production, purification and characterization steps have been developed. CHO cells were grown in Erlenmeyer flasks with different culture media. Two media were selected based on their cell growth potency and of the amount of reCG produced. By using a bioreactor to control key parameters (temperature, pH), the production process was then optimized. The recombinant proteins that accumulated in the supernatant of the two conditions were called reCG 1 and reCG 2. A 3-steps purification process was then developed using reCG 1. Several resins and chromatographic conditions were screened in microplates. Multimodal resins were used to eliminate the main contaminants thanks to their selectivity. reCG aggregates were efficiently eliminated by a chromatographic step with an anionic resin. The overall purification process was finally validated for reCG 1 and reCG 2. Purity and yield were respectively, 98 % and 80 % for the two reCG. We verified that the in vitro and in vivo activities of reCG 1 and reCG 2 were comparable to those of the CG extracted from natural sources. The in vivo assays also confirmed previous studies showing that the degree of glycosylation of an hormone, and most notably their level of sialytation, is important for their biological activity.

O presente trabalho de pesquisa foi conduzido no período de outubro de 2007 a março de 2008 na Estação de Avaliação de Suínos em Tanquinho, Piracicaba SP, no Frigorífico BRESSIANI®, localizado na cidade de Capivari SP, e as avaliações bioquímicas, químicas, quantidade e qualidade de carne foram realizadas no mês de março a abril de 2008, no Centro de Pesquisa e Desenvolvimento de Carnes do Instituto de Tecnologia de Alimentos, localizado na cidade de Campinas SP. Neste experimento foram testados métodos de castração de suínos objetivando avaliar a incidência do odor de macho inteiro, causado pela androstenona e escatol, presentes no tecido adiposo dos suínos machos, composição corporal e da carcaça. Entre os métodos de castração de suínos machos existentes, foram avaliados o cirúrgico e imunológico. O primeiro consistiu na remoção cirúrgica das gônadas do leitão entre 3 a 5 dias de vida e o segundo na aplicação de duas doses da forma modificada do Fator de Liberação das Gonadotropinas (GnRF) em um sistema coadjuvante de baixa reatividade, sendo a primeira dose aplicada nos animais com 15 semanas e a segunda dose com 19 semanas de idade. Após duas semanas da segunda dose foram coletadas amostras de sangue para avaliação de testosterona através de radioimunoensaio. No momento do abate foi realizada a coleta de parte do tecido adiposo para análise de androstenona e escatol. Nas meias carcaças esquerdas foram avaliadas a qualidade de carne (pH, temperatura, capacidade de retenção de água, perda por exsudação e cor) e a quantidade (medidas lineares das carcaças e rendimentos dos cortes anatômicos). A vacinação dos animais contra o GnRF demonstrou sua eficiência em controlar os compostos responsáveis pelo odor sexual (androstenona e escatol) e em manter os níveis de testosterona comparáveis aos animais castrados cirurgicamente. A imunocastração melhorou o desempenho zootécnico e contribuiu para aumentar a quantidade de carne por animal (4,84 kg), diminuir a de gordura (1, 54 kg) e acrescentar mais carne nos cortes de maior valor comercial, como pernil (1060 g, p < 0,05), carre(400 g, p > 0,05), a barriga (840 g, p < 0,05) e paleta (1460 g, p < 0,05), que representa uma vantagem econômica para a indústria da carne, pois atende os mercados de carne fresca e de produtos industrializados (cozidos e embutidos). Em relação à avaliação sensorial foram constatadas diferenças significativas (p < 0,05) para todos os atributos sensoriais avaliados em favor dos suínos imunocastrados quando comparados com os castrados cirurgicamente. Quanto à preferência, os bifes cozidos de lombo dos suínos imunocastrados obtiveram melhor preferência (66%) em comparação com os castrados cirurgicamente (34%). A intenção de compra também foi em favor dos suínos imunocastrados e refletiu os resultados dos testes de preferência e de aceitação. A maioria dos consumidores (74,8%) provavelmente (20,2%) ou certamente (54,6%) compraria a carne dos suínos imunocastrados e somente 58,4% dos consumidores provavelmente (25,2%) ou certamente (33,2%) compraria a carne dos suínos castrados cirurgicamente. A gordura total encontrada no lombo nesse experimento foi 14.67 e 12.67 g/100g para o grupo dos suínos castrados cirurgicamente e imunocastrados, respectivamente. O rendimento de cocção e os valores da força máxima de cisalhamento (Warner - Bratzler) dos suínos castrados cirurgicamente e imunocastrados não foram estatisticamente diferentes (p > 0,05) enquanto que a cor instrumental (L*, a* e b*) apresentou diferença estatística (p < 0,05) na sua composição para os tratamentos estudados. Os resultados desse trabalho permitem dizer que a imunocastração demonstrou ser eficiente em prevenir o odor sexual bem como em melhorar o desempenho zootécnico e qualidade de carcaça quando comparada com a castração cirúrgica. Quanto à qualidade de carne dos suínos imunocastrados ficou evidenciado que essa tecnologia pode melhorar os atributos sensoriais e outras características de qualidade realizadas nessa pesquisa. / The present study was carried out from October 2007 to March 2008 at the Pig Evaluation Station in Tanquinho, located in Piracicaba city, São Paulo state, in the BRESSIANI® abattoir, located in Capivai, city, São Paulo state, and the biochemical, chemical, meat quantity and meat quality assessments were carried in March 2008, at the Meat Center for Research and Development in the Institute of Food Technology, located in Campinas city, São Paulo state. In this experiment were tested castration methods applied in pigs to evaluate the incidence of the boar taint, caused by androstenone and skatole located in the fat of boars, carcass composition and meat quality. The castration methods tested were physical and immunological. In the first one pig gonads were removed physically at the age 3 to 5 days and the last one the pigs were immunocastrated (two doses, 15 and 19 weeks of age) against the modified factor gonadotropin-releasing (GnRF). After two weeks of the second dose blood samples were taken to evaluate testosterone using radioimmunoassay. At the slaughter level a portion of backfat was collected to assess androstenone and skatole. Meat quality (pH, temperature, water holding capacity, loss of weeping and color) and quantity (linear measurements of carcasses and anatomical cuts yield) were performed at left carcass side. Vaccination of animals against GnRF demonstrated its effectiveness in controlling the boar taint compounds (androstenone and skatole) and to maintain the levels of testosterone comparable to physically castrated animals. The immunocastration improved growth performance and contributed to increase the total meat quantity per animal (4.84 kg), reducing the fat (1, 54 kg) as well as added more meat in cuts of higher commercial value, such as ham (1060 g, p < 0.05), loin (400 g, p > 0.05), belly (840 g, p < 0.05) and shoulder (1460 g, p < 0.05), which represents an economic advantage for the meat industry since reaches booths markets fresh and processed meats products (sausage and cooked). Regarding the sensory evaluation were found significant differences (p < 0.05) for all sensory attributes evaluated in favor ofimmunocastrated pigs when compared with physically castrated. The preference test applied to cooked sirloin steak from immunocastrated pigs indicated better preference (66%) compared with physically castrated (34%). The panelists intent to purchase was also in favor of the immunocastrated treatment and confirmed the results from the preference and acceptance tests. The majority (74.8%) of the consumers probably (20.2%) or certainly (54.6%) would buy meat from the immunocastrated pigs compared to 58.4% of the consumers who would probably (25.2%) or certainly (33.2%) would buy meat from physically castrated pigs. Loin total fat content found in the experiment was 14.67 and 12.67 g/100g for the physical and immunocastrated groups respectively. The immunocastrated group contained 11.2% less fat than the surgical castrates. Cooking yields and peak Warner-Bratzler shear force values from physically castrated and immunocastrated pigs were not statistically different (P > 0.05) while statistically significant differences (p < 0.05) in the brightness (L*), redness (a*) and yellowness (b*) parameters were observed between the two treatments. From the above considerations it can be said that immunocastration shows very good potential for pre-venting boar taint. Pain and stress associated with physical castration can thus be avoided. It was also demonstrated that immunocastrated pigs improved some meat quality aspects evaluated. Sensory, total fat content and color were the main factors affected by immunocastration while cooking loss and instrumental tenderness had no remarkable changes. The consumers classified meat from immunocastrated pigs significantly better than physically castrated pigs as far as acceptability, preference and purchase intention are concerned. Thus, immunocastration results in production of animals with high meat quality in the carcass and still capitalizes on the growth, feed efficiency and carcass leanness of boars up to the point of immunocastration.

Die Implantation einer Blastozyste im Uterus stellt für den maternalen Organismus eine große Herausforderung dar. Neben morphologischen Veränderungen des Endometriums sind Anpassungen auch im Immun- und Gefäßsystem notwendig. Kenntnisse über die verantwortlichen Faktoren für diese Prozesse sind bei Menschen und anderen Primaten noch immer unvollständig. Dabei sind Implantationsstörungen oftmals Ursache von Fruchtbarkeitsproblemen (SHARKEY und SMITH 2003). Besonders im Bereich der assistierten Reproduktion stellen implantationsbedingte Probleme eine Hauptursache für geringe Erfolgsraten dar (APLIN und KIMBER 2004). Das Ziel der Erforschung von Mechanismen im Zusammenhang mit der Implantation ist es, ein besseres Verständnis für die physiologischen und auch pathologischen Vorgänge zu erlangen. In dessen Folge die Erkenntnisse für die Behandlung von Implantationsstörungen genutzt werden könnten. Anhand des in der reproduktionsbiologischen Forschung etablierten Primatenmodells des Weißbüschelaffen (Callithrix jacchus) wurde in der vorliegenden Arbeit die Expression ausgewählter Faktoren in verschiedenen Zyklusphasen mit dem Schwerpunkt der Implantationsphase untersucht. Dafür wurden zeitlich genau terminierte Uterusproben von konzeptiven und nicht-konzeptiven Tieren entnommen und molekularbiologisch, histologisch und immunhistochemisch analysiert. Erstmals konnte im Uterus von Weißbüschelaffen die zeitliche und räumliche Regulierung von Choriongonadotropin (CG), Östradiolrezeptor-α (ERα), Östradiolrezeptor-ß (ERß), Progesteronrezeptor (PR), Aromatase (ARO), 17β-Hydroxysterois-Dehydrogenase Typ 7 (17β-HSD7) sowie Relaxin (RLN) und Relaxinrezeptor (RXFP1) auf Gen- und Proteinebene in verschiedenen Zyklusphasen in der vorliegenden Vollständigkeit dargestellt werden. Alle in dieser Arbeit untersuchten Faktoren zeigten eine rezeptorspezifische Veränderung der Expressionsmuster, auf räumlicher und zeitlicher Ebene im Verlauf des Implantationsprozesses. Es konnte dargestellt werden, dass die feto-maternale Kommunikation bereits vor dem direkten Kontakt der Blastozyste mit dem Endometrium beginnt. So wurde bei konzeptiven Tieren eine verstärkte Expression von CG, ERα, PR, 17β-HSD7 und RXFP1 in der Implantationsphase nachgewiesen. Diese Faktoren sind geeignete Kandidaten für weiterführende Untersuchungen und Evaluierung von Markern für die Präimplantationsphase und rezeptiven Uteri von Weißbüschelaffen. Die ebenfalls untersuchten Faktoren ERβ, ARO und RLN zeigten Expressionsmuster, welche erst nach der Implantation bei konzeptiven Tieren Unterschiede aufwiesen. Aus diesem Grund sind diese Faktoren nicht als frühe Marker der Implantationsphase geeignet, gleichwohl sie wichtige Funktionen in der Postimplantationsphase übernehmen. Die Ergebnisse dieser Arbeit verdeutlichen, dass nicht alleine ein einzelner Faktor eine herausragende Bedeutung im Implantationsprozess hat, sondern vielmehr ein äußerst komplexes Netzwerk von Signalen nötig ist, um eine erfolgreiche Gravidität zu gewährleisten. Die Aufgabe der Steroidrezeptoren ERα und PR liegt in der grundlegenden Bereitstellung eines rezeptiven Uterus während des Implantationszeitfensters. Gleichzeitig erfolgt eine sehr genau koordinierte Regulation dieser Steroidrezeptoren über die lokal produzierten Faktoren CG, ARO, 17β-HSD7, RLN und der Rezeptoren RXFP1 und ERβ. Neben den morphologischen Veränderungen des Endometriums, sind einzelne Faktoren auch bei der Angiogenese und Entwicklung der maternalen Immuntoleranz beteiligt. Es kann demnach davon ausgegangen werden, dass die präzise Regulation dieser Faktoren eine essentielle Voraussetzung für den Erfolg der Implantation und Gravidität ist.

17 beta-Hydroxy-11 beta(4-dimethylaminophenyl)-17 alpha-(1-propynyl)estra-4, 9-dien-3-one (RU486) inhibited the in vitro development of different stages of mouse preimplantation embryos under study. Two-celled embryos, morulae, and early blastocysts were obtained from B6D2F1 mice. The embryos were grown in Ham F-10 nutrient mixture (with glutamine) supplemented with sodium bicarbonate (2.1 g/L), calcium lactate (282 mg/L), and bovine serum albumin (fraction V, 3 mg/mL) at 37 degrees C in a humidified incubator supplied with 5% CO2 in air. RU486 was added to the culture medium at concentrations of 1, 5, 10, and 20 micrograms/mL. Culture medium with 0.05% ethanol served as the control. In vitro growth of embryos was assessed by the following criteria: (i) two-celled stage embryo development to blastocyst stage after 72 h, (ii) morula stage grown to blastocyst stage after 24 h, and (iii) early blastocyst stage development to hatching blastocyst after 12 h, in culture. RU486 inhibited the in vitro development of two-celled embryos, morulae, and early blastocysts at concentrations of 5, 10, and 20 micrograms/mL culture medium (p less than 0.001). The inhibitory effect of RU486 at these concentrations on the development of all the stages of embryos under study was irreversible. However, RU486 did not affect embryo development at 1 microgram/mL culture medium. The study indicates the direct adverse effect of RU486 at 5 micrograms/mL and higher concentrations in culture medium on the development of mouse preimplantation embryos in vitro, and it encourages its further investigation as a postcoital contraceptive in animal models and humans.

No description available.

Ce travail a consisté à analyser, par des approches toxicocinétiques (TK) et mécanistiques, les effets oestrogéniques du Bisphenol A (BPA) sur un biomarqueur précoce et sensible : la sécrétion de l'hormone lutéinisante (LH) chez la brebis prépubère ovariectomisée. La plus faible concentration plasmatique en BPA induisant une inhibition de LH s'est avérée proche des concentrations maximales décrites chez l'Homme. Cette inhibition de LH pourrait impliquer une inhibition des systèmes neuronaux à kisspeptine. L'approche TK comparative d'espèces a montré que la clairance du BPA est toujours élevée, proche du débit sanguin hépatique. Pour une exposition à la dose journalière admissible, cette approche permet de prédire chez l'Homme des concentrations en BPA très inférieures à celles associées à une inhibition de LH dans notre modèle. / The goal of this thesis was to analyse through toxicokinetic (TK) and mechanistic approaches the estrogeno-mimetic effects of bisphenol A (BPA) on a precocious and sensitive biomarker: LH secretion in ovariectomized female lambs. The lowest plasma BPA concentrations associated to an inhibition of LH secretion appeared to be close to the highest one reported in human. LH suppression could be mediated by an inhibition of hypothalamic kisspeptin systems. The multispecies TK approach showed that BPA clearance is always high and equivalent to the liver blood flow. For an exposure scheme corresponding to the tolerable daily intake, this approach allows to predict human BPA concentration much lower than the one associated to LH inhibition in our highly sensitive lamb model.

>Magister Scientiae - MSc / Glucose oxidase (GOx) and horseradish peroxidase (HRP) are important enzymes for the development of amperometric enzyme linked immunosensors. The selectivity of each enzyme towards its analyte deepens its importance in determining the sensitivity of the resultant immunosensor. In designing immunosensors that have customized transducer surfaces, the incorporation with FAD and iron based enzymes ensures that electron kinetics remains optimal for electrochemical measurement. Various different immobilization strategies are used to produce response signals directly proportional to the concentration of analyte with minimal interferences. The combination of self-assembled monolayers and supramolecular chemistry affords stability and simplicity in immunosensor design. In this work, two electrochemical strategies for the detection of human chorionic gonadotropin(hCG) is presented. This involves the modification of a gold surface with a thiolated β-cyclodextrin epichlorohydrin polymer (βCDPSH) to form a supramolecular inclusion complex with ferrocene (Fc)-functionalised carboxymethyl cellulose polymer (CMC). Cyclic voltammetry indicated that ferrocene is in close proximity to the electrode surface due to the supramolecular complex formed with βCDPSH. Furthermore, strategy (a) for the detection of hCG used α-antihCG labelled (HRP) as reporter conjugate. Strategy (b) maintained the CMC bifunctionalised with Fc and recognition antibody for hCG hormone. However, the system was functionalised with a HRP enzyme and detection is done by using GOx reporter conjugates for in situ production of hydrogen peroxide. The reduction of H2O2 was used for the amperometric detection of hCG by applying a potential of 200 mV. The sensitivity and limit of detection of both strategies were calculated from calibration plots. For strategy (a) the LOD was found to be 3.7283 ng/mL corresponding to 33.56 mIU/mL and a sensitivity of 0.0914 nA ng-1 mL-1. The corresponding values for strategy (b) are 700 pg/mL (6.3 mIU/mL) and 0.94 nA ng-1 mL-1.

O complexo de sinalização kisspeptina-GPR54 é um regulador chave para ativação dos neurônios de GnRH e do eixo reprodutivo. Mutações inativadoras no GPR54 foram identificadas em pacientes com hipogonadismo hipogonadotrófico normósmico isolado (HHIn). A partir desse achado, hipotetizamos que mutações ativadoras no GPR54 resultariam na liberação prematura de GnRH e, conseqüentemente, no aparecimento de puberdade precoce, dependente de gonadotrofinas (PPDG). No presente estudo, investigamos a presença de mutações ativadoras e/ou polimorfismos em pacientes com PPDG, assim como a presença de mutações inativadoras e/ou polimorfismos em pacientes HHIn ou retardo constitucional do crescimento e desenvolvimento puberal (RCCP). Cento e catorze pacientes com distúrbios puberais centrais idiopáticos foram selecionados, sendo 53 com PPDG, 33 com HHIn e 28 com RCCP. Cento e cinqüenta controles brasileiros que relatavam desenvolvimento puberal normal foram estudados. A região codificadora do GPR54 de todos os pacientes foi amplificada utilizando-se oligonucleotídeos intrônicos específicos, seguida de purificação enzimática e seqüenciamento automático. No grupo de puberdade precoce, identificamos uma nova variante em heterozigose no exon 5 do GPR54, que se caracterizou pela troca do aminoácido arginina por prolina na posição 386 (R386P) do receptor. Esta substituição foi encontrada em uma menina adotada com PPDG e estava ausente nos controles normais. Estudos in vitro demonstraram que as quantidades de fosfatidil-inositol (IP) e o grau de fosforilação da quinase regulada por sinal extracelular (pERK) em condições basais não foram significativamente diferentes entre as células transfectadas com o receptor selvagem ou com o receptor contendo a mutação R386P, indicando que não havia ativação constitutiva do receptor. No entanto, estudos por tempos mais prolongados demonstraram que a quantidade de IP e o grau de pERK permaneceram significativamente mais altos nas células transfectadas com o receptor mutante quando comparadas ao selvagem, indicando ativação da sinalização intracelular, porém por um mecanismo não-constitutivo. No grupo de hipogonadismo, duas novas variantes foram identificadas em três pacientes. Uma mutação do tipo inserção/deleção (indel) em homozigoze no sítio aceptor de splicing no intron 2 (IVS2-4_-2delGCAinsACCGGCT) do GPR54 foi identificada em dois irmãos com HHIn. Uma troca em heterozigose, E252Q, foi identificada em um paciente com HHIn esporádico. As duas alterações estavam ausentes no grupo controle. Polimorfismos foram encontrados nos pacientes com RCCP. Em conclusão, descrevemos a primeira mutação ativadora do GPR54 associada ao fenótipo de PPDG. Descrevemos uma nova mutação inativadora em sítio de splicing em pacientes com HHIn, entretanto mutações inativadoras do GPR54 são uma causa rara de HHIn. / The kisspeptin-GPR54 signaling complex is a gatekeeper of pubertal activation of GnRH neurons and of the reproductive axis. Inactivating mutations in the GPR54 receptor were identified in patients with normosmic isolated hypogonadotropic hypogonadism (nIHH). Based on this observation, we hypothesized that gain-of-function mutations of the human GPR54 receptor might be associated with premature activation of GnRH release, leading to gonadotropin-dependent precocious puberty (GDPP). In the present study, we investigated the presence of GPR54 activating mutations or polymorphisms in patients with GDPP and inactivating mutations or polymorphisms in patients with nIHH or constitucional delay of puberty (CDP). A hundred fourteen patients were selected; 53 with GDPP, 33 with nIHH and 28 with CDP. A hundred and fifty Brazilian controls who reported normal pubertal development were also studied. The entire coding region of GPR54 of all patients was amplified using specific intronic oligonucleotides followed by enzymatic purification and automated sequencing. We have identified a novel variant in heterozygous state in exon 5 of GPR54, R386P, in an adopted girl with GDPP. This substitution was absent in all controls. Basal inositol phosphate (IP) and phosphorilated extracellular signalregulated kinase (pERK) levels in cells transfected with WT or R386P GPR54 were not significantly different indicating that there was not a constitutive activation of the receptor. However, studies performed in more prolonged times demonstrated that the IP and the pERK levels were significantly higher in cells transfected with the mutant receptor when compared to the wild type, indicating that the signaling pathway was still activated although by a non-constitutive mechanism. In the nIHH cohort, we have identified two novel variants in three patients. The first variant was an insertion/deletion (indel) in homozygous state within the constitutive acceptor splice site of intron 2 of GPR54 (IVS2-4_-2delGCAinsACCGGCT) identified in two male siblings with nIHH. The second variant was the change E252Q in heterozygous state in a patient with sporadic nIHH. Both alterations were absent in the control population. We have found only polymorphisms in patients with CDP. In conclusion, we have described the first activating mutation in GPR54 associated with the GDPP phenotype. We have also described a novel splice site inactivating mutation in patients with nIHH however, inactivating mutations of GPR54 represent a rare cause of nIHH.

Mutações inativadoras nos genes TAC3 e TACR3, os quais codificam a neurocinina B (NKB) e o seu receptor NK3R, respectivamente, foram descritas em pacientes com hipogonadismo hipogonadotrófico isolado (HHI) normósmico. A partir desse achado, hipotetizamos que mutações ativadoras na NKB e/ou NK3R resultariam na secreção prematura de GnRH e, consequentemente, no desenvolvimento de puberdade precoce dependente de gonadotrofinas (PPDG). Nesse estudo, investigamos a presença de mutações ativadoras e/ou polimorfismos nos genes TAC3 e TACR3 em pacientes com PPDG, bem como mutações inativadoras e/ou polimorfismos nesses genes em pacientes com retardo constitucional do crescimento e desenvolvimento (RCCD), e HHI normósmico. Duzentos e trinta e sete pacientes com distúrbios puberais centrais idiopáticos foram selecionados, sendo 114 com PPDG, 50 com RCCD, e 73 com HHI normósmico. Um grupo de 150 indivíduos que apresentaram desenvolvimento puberal normal foi utilizado como controle. As regiões codificadoras dos genes TAC3 e TACR3 foram amplificadas pela reação em cadeia da polimerase, seguido de purificação enzimática e seqüenciamento automático direto. Análises in silico e in vitro foram realizadas. Um nova variante foi identificada no gene TAC3, p.A63P, em uma paciente do sexo feminino com PPDG, a qual desenvolveu puberdade aos sete anos de idade. Essa variante (p.A63P) está localizada na proneurocinina B, e análises in silico sugeriram que ela não altera sítios constitutivos de splicing e é benigna para a estrutura da proteína. A análise de segregação familiar mostrou que a mãe da paciente, a qual apresentou um desenvolvimento puberal normal, também apresentava a alteração p.A63P em heterozigose, sugerindo que essa variante não desempenha um papel direto no fenótipo de PPDG. Uma nova variante em heterozigose no gene TACR3, p.A449S, foi identificada em uma paciente do sexo feminino com RCCD, que teve início puberal aos treze anos de idade. A análise do grau de conservação da alanina na posição 449 mostrou que esse aminoácido não é conservado entre as diferentes espécies, e análises in silico sugeriram que essa variante não altera os sítios constitutivos de splicing, e é benigna para a estrutura do NK3R. Três novas variantes no NK3R foram identificadas, p.G18D, p.L58L (c.172C>T) e p.W275*, em três pacientes do sexo masculino não relacionados com HHI normósmico. As variantes p.G18D e p.L58L foram identificadas em heterozigose, enquanto que a variante p.W275* foi identificada em heterozigose associada a variante silenciosa p.L58L (c.172C>T), e em homozigose em outro paciente. Análises in silico sugeriram que a variante p.G18D poderia afetar a funcionalidade do NK3R. Estudos in vitro dessa nova variante foram realizados, e mostraram que a mesma não altera a função do NK3R, visto que o aumento na produção de fosfatidil inositol não diferiu significativamente entre o receptor mutado e selvagem. Todas as novas variantes descritas nos genes TAC3 e TACR3 não foram identificadas em 300 alelos controles. Em conclusão, nosso trabalho identificou novas variantes nos genes TAC3 e TACR3 em pacientes brasileiros com distúrbios puberais centrais idiopáticos, e confirmou o envolvimento do complexo NKB/NK3R na etiologia do HHI normósmico / Inactivating mutations of the TAC3 and TACR3 genes, which encode the neurokinin B (NKB) and its receptor, NK3R, respectively, were described in patients with normosmic isolated hypogonadotropic hypogonadism (IHH). Based on these observations, we hypothesized that gain-of-function mutations in the NKB and/or NK3R might be associated with premature activation of GnRH release, leading to gonadotropin-dependent precocious puberty (GDPP). In this study, we investigated the presence of activating mutations and/or polymorphisms in the TAC3 and TACR3 genes in patients with GDPP, and inactivating mutations and/or polymorphisms in these genes in patients with constitutional delay of growth and puberty (CDGP) and normosmic IHH. It was selected 237 patients with idiopathic central pubertal disorders: 114 with GDPP, 50 with CDGP, and 73 with normosmic IHH. Indeed, a group 150 individuals who had puberty at adequate age was used as controls. The coding regions of TAC3 and TACR3 genes were amplified by polymerase chain reaction followed by enzymatic purification and direct automatic sequencing. In silico and in vitro analyses were performed. A new heterozygous variant in the TAC3 gene, p.A63P, was identified in a Brazilian girl with GDPP who had puberty onset at seven years of age. The p.A63P variant was located in the proneurokinin B and in silico analysis suggested that this variant does not alter constitutive splice sites, and it was benign to the protein. The segregation analysis revealed that her mother was heterozygous for the p.A63P variant (who had a normal pubertal development), suggesting that this variant does not play a role in the GDPP phenotype. It was identified a new heterozygous variant, p.A449S, in the TACR3 gene in a Brazilian girl with CDGP, who had puberty onset at thirteen years of age. Conservation degree analysis of alanine at position 449 showed that this amino acid is not a conserved residue among different species. In silico analyses suggested that this new variant does not alter splice sites or affects the structure of NK3R. Indeed, it was identified three new distinct variants in the TACR3 gene, p.G18D, p.L58L (c.172C>T) and p.W275*, in three unrelated males with normosmic IHH. Both p.G18D and p.L58L (c.172C>T) were identified in heterozygous state, and the p.W275* variant was identified in two of these males, since one in homozygous and in another in heterozygous state in association with the silent variant p.L58L (c.172C>T). In silico analyses suggested that p.G18D might be damaging to the NK3R. In vitro studies of this variant (p.G18D) showed that the amount of inositol phosphate (IP) was not significantly different in cells transfected with the p.G18D mutant receptor than in cells transfected with the wild type receptor, indicating that this variant did not alter the function of the neurokinin B receptor. All new variants identified in the TAC3 and TACR3 genes were absent in 300 control alleles. In conclusion, we identified new variants in the TAC3 and TACR3 genes in Brazilian patients with idiopathic central pubertal disorders. We confirm the key role of the NKB/NK3R complex in the etiology of normosmic IHH

La glycosylation est la forme la plus courante de modification post-traductionnelle (PTM) des protéines humaines, puisque plus de 70% d’entre elles sont glycosylées. Celle-ci régule de nombreuses propriétés biologiques comme leur stabilité, leur demi-vie et leur activité. Néanmoins, les protéines peuvent également présenter d'autres types de PTM, ce qui peut conduire pour une protéine donnée à un très grand nombre d'isoformes variant par leur masse, leurs propriétés biologiques et physico-chimiques et leur concentration dans les échantillons biologiques. Ainsi, caractériser une glycoprotéine comporte de nombreux défis et nécessite la mise en œuvre de méthodes séparatives très performantes et de détection très sensibles et informatives.La gonadotrophine chorionique humaine (hCG) est l’hormone spécifique de la grossesse humaine. Elle est essentielle au développement du placenta et du fœtus. Elle est composée de deux sous-unités hCGα et hCGβ qui sont fortement glycosylées (4 sites de N-glycosylation et 4 sites d’O-glycosylation). Récemment, des travaux ont montré une corrélation entre sa glycosylation et une bonne implantation du fœtus. Une caractérisation des ces glycoformes s’avère donc nécessaire.Par conséquent, de nouvelles méthodes en LC/CE-MS ont été développées pour la caractérisation de la hCG à l’échelle intacte en utilisant deux médicaments à base de hCG ayant des glycosylations différentes. Alors que la méthode en CZE-MS (TQ) a permis de différencier les profils des glycoformes de la sous-unité hCGα des deux médicaments, la complémentarité des méthodes RP- et HILIC-MS (qTOF) a conduit à leur identification.Pour limiter les erreurs potentielles d’identification dues au chevauchement des profils isotopiques, le profil de chaque isoforme a été résolu par FT-ICR MS. Dans ce but, une séparation au format nanoLC en mode RP a été développée, améliorant ainsi la sensibilité de la méthode d’un facteur 500 par rapport au format conventionnel. Cette méthode a permis de confirmer l’identification des glycoformes de la sous-unité hCGα. D’autre part, il a été possible d’obtenir des profils différents de glycosylation de la sous-unité hCGβ en favorisant leur ionisation par réduction de la hCG. Enfin, un traitement à la PNGase a conduit à l’élimination des N-glycanes pour l’obtention des profils d’O-glycosylation de la sous-unité hCGβ. / Glycosylation is the most common form of post-translational modifications (PTMs) of human proteins, since more than 70% are glycosylated. It regulates numerous biological properties including their stability, half-life, and activity. Nevertheless, proteins can also exhibit other types of PTMs that lead to a very large number of isoforms, varying in mass, properties and concentration in the biological samples. Therefore, the characterization of a glycoprotein is highly challenging and requires the use of powerful separation techniques and sensitive and informative detection modes.The human chorionic gonadotropin (hCG) is the hormone specific to human pregnancy. It is essential for the development of placenta and fetus. It is based on two heavily glycosylated subunits, hCGα and hCGβ, having 8 glycosylation sites (4 N- and 4 O-glycosylation sites). Some recent studies demonstrated that here is a correlation between the hCG glycosylation state and the fetus implantation. This is why the characterization of the hCG glycoformes is needed.Therefore, new LC/CE-MS methods were developed for the characterisation of hCG at the intact level using two hCG-based drugs having different glycosylation profiles. While the CZE-MS (TQ) method showed its potential for glycosylation fingerprinting, the complementarity of LC-(qTOF) MS methods in RP and HILIC modes allowed the identification of the glycoforms of the hCGα subunit.To limit the identification errors due to the overlapping of isotopic distribution patterns, the profile of each isoform was resolved by FT-ICR MS. For this purpose, a nanoLC separation in RP mode was developed, thus improving the sensitivity of the method by a factor 500 compared to the conventional format. This method allowed the confirmation of the identification of hCGα glycoforms. Then, it was possible to obtain different glycosylation patterns of the hCGβ by promoting its ionization after hCG reduction. Then, a PNGase treatment was carried out to remove the N-glycans in order to obtain the O-glycoprofiles of hCGβ isoforms.