Toutes les actions biologiques de l'hormone de croissance (GH) sont initiées par l'interaction de l'hormone avec un homodimère de son récepteur spécifique (GHR2) présent au niveau de la surface de ses cellules-cibles. Cette association conduit à l'activation de différentes voies de transduction du signal intracellulaire ainsi qu'à l'internalisation du complexe GH-GHR2, notamment au niveau de la mitochondrie. L'objectif de cette étude est de montrer le mécanisme et l'implication de l'internalisation par les cavéoles dans la régulation de l'action de la GH au niveau de la fonction mitochondriale. Nous avons montré l'importance de la boîte 1 du GHR dans la stimulation de l'activité respiratoire globale ; le transport de la GH par la voie des cavéoles dans la mitochondrie ; l'importance de la localisation intramitochondriale de la GH dans la régulation des complexes II et IV de la chaîne respiratoire. Ces résultats suggèrent une nouvelle voie d'action directe de la GH sur la mitochondrie

The use of a new, more sensitive immunoassay for growth hormone (GH) revealed that the serum levels in men were lower than expected in sera drawn ambulatory in the morning after an overnight fast and that the gender difference was more than 10 times greater than reported. These observations led to a more thorough study on the impact of gender and sex steroids on the levels of GH and other hormones in ambulatory morning samples and over a 24-hour period. Furthermore, the impact of gender was studied in GH deficient (GHD) patients and healthy young adults treated with GH, and in patients with acromegaly treated with octreotide. An 80-fold gender difference in the morning GH levels was observed in young individuals as a reaction to ambulation, with decreased levels in men and increased in women. Oral contraceptives (OCs) given to women further increased the morning GH levels. During the day, higher outputs of epinephrine and lower levels of GH were seen in the men, while no gender differences were seen at night. The gender difference in morning GH levels decreased with age due to opposite changes in men and women. Administration of 17β-estradiol (E2) via subcutaneous implants in postmenopausal women, which increased the E2-concentrations to luteal phase levels, had no effect on the morning GH levels, indicating that the different reactions to ambulation do not appear to result from a direct sex steroid effect alone. Short-term administration of GH to young, healthy adults resulted in larger effects on insulin-like growth factor I (IGF-I) and other key metabolic parameters in men than in women. The smallest response was noted in women taking OCs. The clinical studies involving long-term GH treatment of patients with GHD demonstrate a gender difference in GH responsiveness, with women being less sensitive than men, a fact which should have a therapeutic impact in patients with GH disorders. A further gender difference of therapeutic importance was observed in men and women with acromegaly. Long-term treatment with a slow-release formulation of octreotide resulted in higher IGF-I levels in the men, despite equal doses of the drug and similar levels of GH.

La leptine est une hormone adipocytaire impliquée notamment dans le contrôle de la balance énergétique et de la sécrétion d'hormone de croissance (GH). Ses récepteurs ObRa et ObRb sont exprimés dans les cellules somatotropes de rat, et elle régule l'expression hypophysaire du récepteur de la ghréline. Dans notre modèle de rats obèses DIO, l'altération des taux plasmatiques de GH caractéristique de cette pathologie n'est pas liée à la résistance hypophysaire à la leptine. Chez les rats Lou/C, la GH participe à la résistance à l'obésité, les hormones ghréline et leptine jouant un rôle prépondérant dans le contrôle hypophysaire de sa sécrétion. In vitro, l'internalisation de ObRb est constitutive mais la leptine inhibe l'adressage de ce récepteur de l'appareil de Golgi vers la membrane plasmique. Cette internalisation est indispensable pour l'activation de STAT3 et ce processus pourrait donc participer à l'établissement de la résistance à la leptine.

Em nosso laboratório foi demonstrado que ratos submetidos à restrição crônica de sal na dieta apresentaram maior peso corpóreo (PC), menor sensibilidade à insulina e alterações pressóricas em comparação com ratos submetidos à sobrecarga crônica de sal na dieta. No presente estudo, o objetivo foi avaliar alguns mecanismos de obesidade e alterações hormonais associados à dieta hipossódica. Foram utilizados ratos Wistar machos submetidos à dieta hipo (HO: 0,15% NaCl), normo (NO: 1,27% NaCl) ou hipersódica (HR: 7,94% NaCl) desde o desmame até 12 semanas de idade. Nestes animais foram realizadas medidas de pressão arterial (PA), freqüência cardíaca (FC), consumo de ração, PC, perfil dos hormônios [leptina (LEP), GH, insulina (INSh - anticorpo anti-insulina humana), T3, T4 e TSH] e decaimento da 125I-insulina (DEC-INS). O consumo de ração foi avaliado durante sete dias consecutivos com um (1G) ou quatro (4G) ratos por gaiola de plástico e com um rato por gaiola metabólica (1GM). O PC também foi medido neste período. Glicemia (GLI) e insulinemia (INSr - anticorpo anti-insulina de rato) basais foram quantificadas antes da realização do estudo do DEC-INS. Para avaliar o DEC-INS, foi injetado 1mCi de 125I-insulina humana pelo cateter implantado na veia jugular, após 6 a 8 horas de jejum fisiológico. As amostras de sangue foram coletadas pelo cateter implantado na carótida a cada 30 segundos durante 2 minutos e depois a cada 1 minuto até 10 minutos de experimento. Os resultados obtidos demonstraram que ratos submetidos à dieta HR apresentaram maior PA em comparação a ratos em dieta NO e HO. Os ratos submetidos à dieta HO apresentaram menor FC cardíaca em relação ao grupo NO. A avaliação de ingestão alimentar revelou que ratos em dieta HR consumiram maiores quantidades de ração (1G e 4G) em comparação com ratos em dieta NO e HO. O grupo HO apresentou maior PC em comparação com os grupos de ratos NO e HR. Os ratos em dieta HR ou HO apresentaram níveis diminuídos de LEP em comparação com ratos submetidos à dieta NO. Os ratos que receberam dieta HO apresentaram níveis elevados de INSr em comparação com ratos em dieta HR e NO. Os ratos em dieta HR apresentaram níveis elevados de T4 total e níveis reduzidos de TSH em comparação com animais em dieta NO e HO. INSr e GLI basais foram maiores nos ratos em dieta HO do que nos ratos que receberam dieta HR e NO. O DEC-INS (decaimento exponencial) foi mais rápido no grupo HR demonstrado por meio de menor meia-vida da 125I-insulina. Os resultados sugerem que maior PC nos ratos sob restrição salina crônica é devido a maior eficiência metabólica (maior PC e menor consumo de dieta) que pode estar relacionada com alterações hormonais e com a dieta HO. Palavras-chave: Pressão arterial, sal, sódio, ingestão alimentar e perfil hormonal. / Previous studies from our laboratory have shown that chronic salt restriction decreases blood pressure, increases insulin resistance, and body weight (BW) in Wistar rats. The aim of this study was to evaluate some mechanisms of obesity and hormonal alterations associated with chronic salt restriction. Male Wistar rats were fed a low (LSD: 0,15% NaCl), normal (NSD: 1,27% NaCl), or high salt diet (HSD: 7,94% NaCl) from weaning. At the 12th week of age, tail-cuff blood pressure (TCBP), intra arterial blood pressure (BP), heart rate ((HR), food intake, BW, hormonal levels [leptin (LEP), growth hormone (GH), insulin (INSh - antibody anti-human insulin), T3, T4 and TSH] and 125I insulin decay study (DECAY-INS) were measured. To evaluate the food intake and body weight, each dietary group was divided in 3 subgroups, according to housing conditions: one (1C) or four (4C) rats per cage and one rat per metabolic cage (1MC) for daily food consumption and BW determinations during 7 days. Fasting plasma glucose (GLU) and insulin (INSr - antibody anti-rat insulin) were measured before the DECAY-INS. To evaluate the DECAY-INS, 1mCi human 125I-insulin was injected through the jugular catheter after 6-8 hours of food restriction. Blood samples were withdrawn through the carotid catheter every 30 sec during 2min, and in sequence, every 1 min for additional 10 minutes. 125Iinsulin was determined by RIA for human insulin. Rats on HSD had higher intra arterial BP and TCBP compared to rats on NSD and LSD. Heart rate was lower on LSD than on NSD. In all housing conditions, BW was higher on LSD than on NSD and HSD. Food intake was higher on HSD (1C and 4C) than on NSD and LSD. Plasma GH and LEP were higher on NSD than on the 68 other two groups. Plasma INSh was higher in LSD compared to HSD and NSD rats. Plasma total T4 was higher on HSD than on the NSD and LSD, TSH was lower on HSD than on NSD and HSD, and T3 was not different among all groups. Fasting GLU and INSr were higher on LSD compared to HSD and NSD rats. The exponential insulin decay was faster on HSD demonstrated by a lower 125I-INS half-life. These results suggest that obesity in rats on chronic LSD is due to a higher metabolic efficiency (higher body weight and lower diet consumption), that may be related to the hormonal consequences of LSD. Key Words: blood pressure, salt, sodium, food intake and hormonal profile.

GH is important for the development and function of the immune system, but there is controversy on whether GH deficiency (GHD) is associated to immune disorders. A model of isolated GHD (IGHD), without others deficits or hormones replacement, may exclude if the lack of GH is associated with increased susceptibility to infections or with an altered responsiveness of the immune response. Our objective was to study the frequency of infectious diseases and the cellular and humoral immune response in adults with congenital, untreated IGHD. The study was performed in two steps: in the first, a cross-sectional study, 35 adults IGHD due to a homozygous mutation in the GHRH receptor gene and 31 controls were submitted to a clinical questionnaire to evaluate past and current history of infectious diseases, physical examination, and serology for tripanosomiasis, leishmaniasis, HIV, tetanus, hepatitis B and C. The only exclusion criterion for this first step was age less than 20 years old. In the second step, a study of cases with a control group for comparison of immune cellular and humoral response between the groups. The exclusion criteria were age less than 20 and more than 65 years old; diagnosis of HIV, infection or acute diseases; history of malignancies; autoimmune diseases; glucocorticoid and anti-allergic medications use; or current pregnancy. The immune response was evaluated in a subset of these subjects by serum total IgG, IgM, IgE and IgA measurement, skin tests (Protein Purified Derived (PPD), streptokinase and candidin), and response to vaccination for hepatitis B and tetanus (in individuals with negative serology), and to bacillus Calmette-Guérin (BCG) in subjects nonreactive to PPD. There was no difference between the groups in history of infectious diseases and baseline serologic data. IGHD subjects had lower total IgG, but within normal range, and a smaller induration diameter in streptokinase skin test, but no difference in the frequency of positivity to streptokinase (IGHD 2 in 21; controls 5 in 20). There was no difference in the positivity to PPD (IGHD 4 in 24; controls 10 in 28) and to candidin (IGHD 3 in 21; controls 1 in 19), or in the response to any of the vaccinations between the groups. The controls had a higher frequency of one positive skin test. In conclusion, adult untreated IGHD did not present an increased frequency of infections or significant alterations in the immunological tests, but we found lower total IgG levels and lower positivity to at least one skin test, without detectable clinical impact. / O hormônio do crescimento (GH) é importante para o desenvolvimento e função do sistema imunológico, mas há controvérsias se a deficiência do GH (DGH) é associada a distúrbios imunes. Um modelo de deficiência isolada do GH (DIGH), sem outros déficits ou reposições hormonais, excluiria efeitos confundidores na análise das ações do GH na imunidade, podendo esclarecer se a ausência do GH é associada a uma maior susceptibilidade a infecções ou a uma alteração na resposta imunológica. Nosso objetivo foi estudar a frequência de doenças infecciosas e a resposta imune celular e humoral em adultos com DIGH congênita e não tratada. O estudo foi realizado em duas partes: na primeira, estudo transversal com 35 adultos DIGH devido à mutação homozigótica (C.57 + 1G > A) no gene do receptor do hormônio liberador do GH (GHRH) e 31 controles, que foram submetidos a um questionário clínico para avaliar a história prévia e atual de doenças infecciosas, exame físico e foram dosadas as sorologias para doença de Chagas, leishmaniose, HIV, tétano, hepatites B e C. O único critério de exclusão para esta primeira etapa foi ter menos de 20 anos de idade. Na segunda parte, foi feito um estudo de casos com grupo controle para comparação da resposta imunológica celular e humoral entre os grupos. Os critérios de exclusão foram ter menos do que 20 e mais do que 65 anos de idade, diagnóstico de HIV, infecções agudas, malignidades, doenças autoimunes como artrite reumatóide, lúpus eritematoso sistêmico, uso de medicações antialérgicas e glicocorticóides ou condições como gravidez. A resposta imune foi avaliada em um subgrupo destes indivíduos através das dosagens das imunoglobulinas séricas: IgG total, IgA, IgE e IgM, de testes cutâneos (Derivado Proteico Purificado (PPD), estreptoquinase e candidina), e da resposta à vacinação para hepatite B e tétano (nos indivíduos com sorologia negativa) e ao bacilo Calmette-Guérin (BCG), nos indivíduos que tivessem PPD negativo. Não houve diferença entre os grupos na história de doenças infecciosas e dados sorológicos basais. Indivíduos com DIGH apresentaram menores níveis de IgG total, mas dentro da variação normal e menor diâmetro da induração no teste cutâneo com estreptoquinase, embora sem diferença na positividade a este teste (DIGH 2 em 21; controles 5 em 20). Também não houve diferença na positividade ao PPD (DIGH 4 em 24; controles 10 em 28) e à candidina (DIGH 3 em 21; controles 1 em 19) nem na resposta às vacinações entre os grupos. Os controles tiveram uma maior frequência de um teste cutâneo positivo. Em conclusão, adultos com DIGH não tratada não apresentaram uma maior frequência de infecções ou alterações significantes nos testes imunológicos, mas apresentaram menores níveis de IgG total e menor positividade a pelo menos um teste cutâneo, embora sem impacto clínico.

Indiana University-Purdue University Indianapolis (IUPUI) / Acute and chronic activation of both ionotropic and metabotropic glutamate (glut) receptors is implicated in many neurodegenerative disorders including AD, dementia, epilepsy, stroke and neurotrauma. TRH and glut receptors (ionotropic & metabotropic) receptors are differentially coexpressed in granule and pyramidal neurons of the hippocampus. The author shows TRH to be protective when added to cultured pituitary adenoma (GH-3) cells and neuron-like pheochromocytoma (PC12) cells either prior to, during, or after glut-induced toxicity (Endo. Soc. Abs. 01), and also shows that the possible neuroprotective mechanism may involve heterologous downregulation of the metabotropic glut receptors, using superfused hippocampal slices and noting a reduction of Gαq/11 (SFN Abs. 02). He has also demonstrated that TRH protected against glut toxicity in fetal cortical cultures (Endo. Soc. Abs. 04). To extend these studies he used 14-day cultured rat fetal hippocampal neurons (Day E17) to determine if TRH is protective against toxicity induced by specific ionotropic and metabotropic glut agonists. Neuronal viability and integrity were assessed by trypan blue exclusion and LDH release after 18 hrs following 30 min exposure to glut agonists. Ten µM dihydroxyphenylglycine (DHPG, a Group 1 receptor agonist) + 30 µM N-methyl-D-aspartate (NMDA)-induced toxicity (42% vs contr. P<0.05); whereas, concurrent and continued treatment with 10 uM but not 1uM 3Me-HTRH resulted in less neuronal death and damage (86% vs contr P<0.05; 53% vs contr. P>0.05) respectively. DHPG treatment alone (10 µM) for 30 min. was non-toxic by both criteria (90% vs contr. P<0.05). The data suggest that TRH may be a selective modulator of glut-induced toxicity.

The demand for complex structures and the urge to perform more detailed structural analyses in an early stage of the project design phase has increased the use of parametric design in the construction sector, especially among architects and structural engineers. Also, an increasing demand for sustainable structures is creating pressure on engineers and architects to design optimized structures that consume as little resources as possible. Keeping these demands in mind, this thesis tries to uncover the benefits of parametric design and optimization by applying these processes to industrial roof truss structures.The primary objective of the thesis is to investigate the feasibility and reliability of parametric design and optimization processes in real-life designs. For this purpose, a parametric algorithm has been developed in the visual programming software Grasshopper 3D. The workflow performs structural analysis and design verification on a parametric FE-model using the FEA software for parametric engineering, Karamba 3D in combination with Python where standards for design verification were scripted. These procedures were developed to be applied on both steel and timber truss structures. The workflow then performs a constrained cross-sectional and geometrical optimization of the truss structures. For the optimization process, the plug-in Galapagos have been used which uses evolutionary and simulated annealing techniques.After analyses of different cases and on comparison of the results from the model response verification, the resulting models showed that the workflow and analysis procedure was capable of obtaining a solution that is more effective and as reliable as the traditional structural analysis procedures and thus can be used for real case. When used during preliminary design, the parametric design procedure displayed great potential in saving time, thus saving resources and cost which paves a promising path for implementations in this sector.

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Las hormonas recombinantes eritropoyetina (EPO) y hormona de crecimiento (GH), prácticamente iguales a las endógenas y de corta vida media en circulación, son de difícil detección directa en el control antidopaje. Se determinaron los valores poblacionales de los biomarcadores indirectos EPO, receptor soluble de la transferrina, insulin-like growth factor-I (IGF-I) y procolágeno tipo III péptido (P-III-P), en poblaciones seleccionadas de deportistas, y el efecto del ejercicio y los distintos tipos de entrenamiento sobre su concentración sérica. La comparación de resultados obtenidos mediante distintos ensayos demostró la necesidad de una validación exhaustiva previa a su utilización. A excepción del P-III-P, los biomarcadores séricos propuestos para la detección de rhEPO y rhGH no se encuentran directamente afectados por el nivel atlético, el ejercicio o la distinta carga de entrenamiento realizada a lo largo de la temporada deportiva. La edad es la principal influencia sobre las concentraciones séricas de IGF-I y P-III-P. / Direct detection of recombinant peptidic hormones erythropoietin (EPO) and growth hormone (GH), very similar to endogen molecules and with a short half life in blood, is difficult in antidoping control. The main objective of this work is to determine indirect biomarkers' values of EPO, soluble transferrin receptor, insulin-like growth factor-I (IGF-I) and procollagen type III peptide (P-III-P), in selected populations of athletes, and the effect of exercise and different types of training on their concentration in serum. The comparison of results obtained by the different assays showed the need of extensive validation of the analytical techniques before their use in the antidoping field. Excepting P-III-P, proposed biomarkers for the detection of rhEPO and rhGH abuse are not directly influenced by the athletic level, exercise or different training workload along the sport season. Age is the main factor affecting IGF-I and P-III-P concentrations in serum.

In the present study, the ease of rearing, short generation time and molecular research tools available for the zebrafish model (Danio rerio, Hamilton) were exploited to investigate transcriptional regulation in relation to feeding, photoperiod and experimental selection. Chapter 2 describes transcriptional regulation in fast skeletal muscle following fasting and a single satiating meal of bloodworms. Changes in transcript abundance were investigated in relation to the food content in the gut. Using qPCR, the transcription patterns of 16 genes comprising the insulin-like growth factor (IGF) system were characterized, and differential regulation between some of the paralogues was recorded. For example, feeding was associated with upregulation of igf1a and igf2b at 3 and 6h after the single-meal was offered, respectively, whereas igf1b was not detected in skeletal muscle. On the other hand, fasting triggered the upregulation of the igf1 receptors and igfbp1a/b, the only binding proteins whose transcription was responsive to a single-satiating meal. In addition to the investigation of the IGF-axis, an agnostic approach was used to discover other genes involved in transcriptional response to nutritional status, by employing a whole-genome microarray containing 44K probes. This resulted in the discovery of 147 genes in skeletal muscle that were differentially expressed between fasting and satiation. Ubiquitin-ligases involved in proteasome-mediated protein degradation, and antiproliferative and pro-apoptotic genes were among the genes upregulated during fasting, whereas satiation resulted in an upregulation of genes involved in protein synthesis and folding, and a gene highly correlated with growth in mice and fish, the enzyme ornithine decarboxylase 1. Zebrafish exhibit circadian rhythms of breeding, locomotor activity and feeding that are controlled by molecular clock mechanisms in central and peripheral organs. In chapter 3 the transcription of 17 known clock genes was investigated in skeletal muscle in relation to the photoperiod and food content in the gut. The hypothesis that myogenic regulatory factors and components of the IGF-pathway were clock-controlled was also tested. Positive (clock1 and bmal1 paralogues) and negative oscillators (cry1a and per genes) showed a strong circadian pattern in skeletal muscle in anti-phase with each other. MyoD was not clock-controlled in zebrafish in contrast to findings in mice, whereas myf6 showed a circadian pattern of expression in phase with clock and bmal. Similarly, the expression of two IGF binding proteins (igfbp3 and 5b) was circadian and in phase with the positive oscillators clock and bmal. It was also found that some paralogues responded differently to photoperiod. For example, clock1a was 3-fold more responsive than clock1b. Cry1b did not show a circadian pattern of expression. These patterns of expression provide evidence that the molecular clock mechanisms in skeletal muscle are synchronized with the molecular clock in central pacemaker organs such as eyes and the pineal gland. Using the short generation time of zebrafish the effects of selective breeding for body size at age were investigated and are described in chapter 4. Three rounds of artificial selection for small (S-lineage) and large body size (L-lineage) resulted in zebrafish populations whose average standard length were, respectively, 2% lower and 10% higher than an unselected control lineage (U-lineage). Fish from the L-lineage showed an increased egg production and bigger egg size with more yolk, possibly contributing to the larger body size observed in the early larval stage (6dpf) of fish from this lineage. Fish from S- and L-lineage exposed to fasting and refeeding showed very similar feed intake, providing evidence that experimental selection did not cause significant changes in appetite control. Investigation of the expression of the IGF-axis and nutritionally-response in skeletal muscle after fasting and refeeding revealed that the pattern of expression was not different between the selected lineages, but that a differential responsiveness was observed in a limited number of genes, providing evidence that experimental selection might have changed the way fish allocate the energy acquired through feeding. For example, a constitutive higher expression of igf1a was recorded in skeletal muscle of fish from the L-lineage whereas igfbp1a/b transcripts were higher in muscle of fish from the S-lineage. These findings demonstrate the rapid changes in growth and transcriptional response in skeletal muscle of zebrafish after only three rounds of selection. Furthermore, it provides evidences that differences in growth during embryonic and larval stages might be related to higher levels of energy deposited during oogenesis, whereas differences in adult fish were better explained by changes in energy allocation instead of energy acquisition. In chapter 5 the main findings made during this study and their impact on the literature are discussed.