HORMONES

Author: RABANO AZURMENDI MARIA ANGELES.
Year: 2004.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGIA.
Place of preparation: FACULTAD DE CIENCIA Y TECNOLOGIA.

Summary: The biosynthesis of glucocorticoids is mainly regulated by the hormone ACTH, adrenaline and angiotensin-II (AT-II). Although it is well established that activation of the adenilato cyclase is a common mechanism of action of ACTH and adrenaline, the mechanism by which the AT-II stimulates the secretion of cortisol is less well known. The present work has been shown that AT-II regulates the secretion of cortisol via stimulation of different cell signaling pathways such as phospholipase D (PLD) / fosfatidato fosfohidrolasa (PAP), stimulated by mitogens kinase (MAPK) of the family ERK and fosfatidilinositol 3-quinasa (PI3K) / protein kinase B (PKB). Moreover, one of the most important findings in this dissertation has been the discovery of a new regulator of cortisol secretion: esfingosina-1-fosfato (Sph-1-P). We know that this fosfoesfingolípido is capable of regulating important cellular functions such as apoptosis, proliferation, cell differentiation, or angiogenesis. In this paper, we proved that Sph-1-P is as potent as adrenaline inducing secretion of cortisol in cells fasciculada. However, unlike the adrenaline and ACTH, Sph-1-P not exercised this effect via stimulation of cAMP production. The mechanism by which the Sph-1-P stimulates cortisol secretion is more akin to that of the AT-II because it involves stimulation of the activities PLD / PAP, MAPK (ERK1-2) and PI3-K/PKB.

Author: ZUAZUA VILLAR PEDRO.
Year: 2005.
University: OVIEDO [www.uniovi.es].
Place of defense: DEPARTAMENTO DE BIOQUIMICA Y BIOLOGÍA MOLECULAR.
Place of preparation: FACULTAD DE MEDICINA.

Summary: The binding of estrogen receptor alpha (ER) to calmodulina is a characteristic regard to estrogen receptor beta. This interaction makes the IR has a basal transcriptional activity and its degradation is slower, and also allows the regulation of transcriptional activity of the same by antagonists of the calmodulina and melatonin. This union are involved waste in the region hinge estrogen receptor alpha: isoleucine 298-lisina and lisinas 302-303. The results obtained in this work with different receivers mutated show that calmodulina is not required for receptor transcriptional activity induced by estradiol. Lysine 303 IR alpha is also involved in processes acetylation and has been identified with its arginine mutation in a large number of premalignant lesions of the breast. The cells in which sobreexpresa this mutated receptor (ER K303R) proliferate in response to lower concentrations of estradiol that normal cells. Our results show that this effect corresponds with increased transcriptional activity of both the homodímeros (IR K303R/RE K303R) as heterodímeros with wild alpha receptor (ER K303R/RE alpha) promoters containing estrogen response elements. The receiver IR K303R has the particularity that binds calmodulina but is not sensitive to the action of the antagonists of the same. Furthermore, the transcriptional activity of promoters containing binding sites AP-1 is inhibited by action of estradiol. This response is not conditioned by the change of lysine to arginine but associated with the disappearance of lysine 303 as is apparent from the fact that the mutant in this alanine for lysine (IR K303A) has a behavior similar to IR K303R. In this paper we also studied the mechanisms triggered by the estradiol that lead to gene expression in the line Cell MCF7, noting that affect receptor redistribution within the cell nucleus and its degradation. Our results suggest that the transcriptional activity of ER alpha involves the location of the receiver in a fraction nuclear different (identified by its solubilization with detergents) and subsequent degradation. The antiestrogen ICI 182, 780 has the same effect, even in the absence of transcription.

Author: HIDALGO BARRERA ANTONIO.
Year: 2005.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: FACULTAD DE VETERINARIA.
Place of preparation: UNIVERSIDAD AUTÓNOMA DE BARCELONA.

Summary: The adiponectina is a dipoquina whose mechanisms of action are not known yet exactly. Levels of plasma low adiponectina have been correlated with obesity and insulin resistance and hyperinsulinemia not even in obese individuals. The adiponectina promotes sensitivity to insulin and protects them from obesity and therefore it has been suggested that it could be used to improve sensitivity to insulin in obese and diabetic patients. The increase in the oxidation of lipids in skeletal muscle mediated by adiponectina has been seen as a major factor leading to improvement in the signaling and insulin sensitivity at the systemic level. These data suggest that the expression of constitutive adiponectina in skeletal muscle and their impact on this tissue might protect the insulin resistance and obesity induced by a diet high in fat. In the first part of this study, we analyzed the effects of adiponectina expression in skeletal muscle insulin sensitivity and obesity. To this end, we generated transgenic mice expressing adiponectina locally in skeletal muscle. These animals were fed a diet high in fat. In the same way, adiponectina was expressed in skeletal muscle in mice through the use of viral vectors. Subsequently, these animals also were fed with diets high in fat to assess the effect of the expression of adiponectina in sensitivity to insulin and obesity. It was noted that the adiponectina acted at the local level in skeletal muscle by increasing sensitivity to insulin in terms of standard food at the same time induce greater propensity to oxidize fatty acids in the tissue. However, this effect of adiponectina exclusively in skeletal muscle was not enough to counter insulin resistance induced by a diet high in fat. The second part of this study focused on analyzing the effects of expression of adiponectina muscle in a model of primary resistance to insulin. In this case, insulin resistance was not due to lipotoxidad induced intake diet high in fat but a defect in insulin signaling. To that end, we used animals genosuprimidos IRS-1- / -. First, the animals IRS-1- /-show severe insulin resistance and abnormal glucose tolerance but no obesity. Secondly, this model does not have insulin resistance in liver, and that IRS-2 compensates functionally in that tissue lack of IRS-1 (Yamauchi et al., 1996; Previs et al., 2000). In addition, the use of this model allowed to consider whether the effects of adiponectina as sensibiizador of insulin taking place regardless of the presence of IRS-1, the main substrate for insulin receptor in skeletal muscle. After electrotrasnferencia gene adiponectina in the skeletal muscle of mice IRS-1- / - was observed that the expression of adiponectina improved sensitivity to insulin. This was due to a normalization in glucose metabolism and not to an increase in fatty acid oxidation in these animals.

Author: PEÑA RUIZ ANA.
Year: 2005.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGÍA.
Place of preparation: FACULTAD DE CIENCIA Y TECNOLOGÍA.

Summary: The vasopressin is a neuroendocrine hormone involved in various physiological functions, such as controlling the balance hidromineral, regulation of blood pressure and control adenohipofisario the secretion of ACTH. These actions are mediated by the interaction of the hormone three subtypes of receptors membranares distinct, V1a, V1b, V2, which belong to the great family of G protein coupled receptors Of all the receivers subtype V1b, which controls the secretion of pituitary ACTH and certain functions of behavior as stress and anxiety, has always been the least studied by the lack of selective ligands isoform of this for a long time. The aim of this study has been to synthesize and characterize new selective ligands and define the molecular determinants receptor V1b, underpinning its pharmacological specificity. Throughout this work the changes in the structure of the natural hormone level positions 1, 4 and 8 have created the first selective agonist-receptor V1b, human and rat. Thanks to the study of molecular and modernization directed mutagenesis has demonstrated the central role of: * tronina 203 and methionine 324 in the specificity of interaction receptor V1b with antagonist selective SSR149415. * The valine at position 169 and proline at position 196 in the interaction receptor V1b with selective agonist d [Cha4] AVP. * The glutamate in position 37 and aspartate at position 95 as responsible for the interaction with the natural hormone. This research has expanded molecular data concerning the receiver V1b and characterization of new pharmacological tools. The relationship of the AVP with the phenomena of anxiety and depression encourages the continuation of this study on the prospect of developing new compounds with therapeutic potential. Moreover, the results obtained over this thesis will allow a better understanding of the physiological and / or pathophysiological associated with this receptor subtype.

Author: GARCÍA MARCOS MIKEL.
Year: 2005.
University: PAÍS VASCO [www.ehu.es].
Place of defense: FACULTAD DE CIENCIA Y TECNOLOGÍA.
Place of preparation: FACULTAD DE CIENCIA Y TECNOLOGÍA UPV/EHU.

Summary: The submandibular gland is a good model for the study of coupling stimulus-and cell signaling mechanisms. In this tissue are expressed in various types such as adrenergic receptors, muscarinic and purinérgicos. Moreover, in recent years it has been proposed that the plasma membrane of the cell is not a homogeneous structure, but there are discrete domains (rafts) with a composition and physical characteristics than the rest of the membrane. Moreover, there is a relationship between these microdominios membrane processes and signaling and cellular traffic. In the present work has been characterized both the response purinérgica the ATP observed in the submandibular gland, as well as the role of microdominios membrane on routes to different signaling coupled receptors expressed in this cell type. Using both pharmacological tools such as genetically modified mice that do not express a receiver purinérigoc P2X7 functional, it has been possible to characterize this receptor is primarily responsible for marking purinérgica observed in response to ATP. In addition, this receptor is involved in some aspects of salivary secretion in vivo. On the other hand have been isolated and characterized microdominios membrane districts purified by two methods, with and without detergent. In both cases it is possible to isolate a membrane fraction with properties similar to the 'rafts' lipid: high in cholesterol, saturated fatty acids, vaeolina-1, ganglioside GM1, as well as greater rigidity the rest of the membrane. The disintegration of these domains effectively block the mobilization of calcium from intracellular calcium deposits by muscarinic agonists, adrenergic and peptidérgicos, but not at the entrance capacitativa calcium. Moreover, the receiver proapoptótico P2X7 is distributed in two populations, one in the fraction of the fluid membrane that attaches to the formation of a nonspecific cation channel and the other in 'rafts', coupled to the activation of a esfingomielinasa neutral and consequent production of cerámido.

Author: MONTERO PEDRAZUELA ANA.
Year: 2005.
University: AUTÓNOMA DE MADRID [www.uam.es].
Place of defense: INSTITUTO DE INVESTIGACIONES BIOMÉDICAS.
Place of preparation: INSTITUTO DE INVESTIGACIONES BIOMÉDICAS.

Summary: The hormonal alterations are implicated in many diseases associated with age as neurodegenerative diseases and psychiatric disorders. In the adult, changes in the state thyroid circulate with frequency changes and psychological state of mood disorders such as depression. It has been shown that adult mammals, including humans, continues generating neurons from stem cells in the teeth GD turn, the formation of the hippocampus. Neurons generated functionally integrated and could be involved in memory and learning processes, as well as in maintaining the mood. It has been described to a decrease in neurogenesis in the adult induce depressive disorders and that the effectiveness of antidepressants depends on the generation of new neurons in the GD. Therefore, knowledge of the process of acquisition of new neurons in the adult and modulation can make an important tool to mitigate brain damage and neurodegenerative and psychiatric diseases. Numerous studies have shown that thyroid hormones HT, is essential for neurogenesis and gliogénesis during development, but there is very little work that examined its role in the adult. The objective of this thesis was to analyze the possible in vivo differentiation of adult neurogenesis in the GD by HT, as well as explore possible functional implications related to this modulation. Our results indicate that hypothyroidism for a short period of time in the adult significantly reduces the proliferative capacity of GD, reducing both the number of neural precursors in proliferation, as the number of units proliferativas. Moreover, hypothyroidism is seriously affecting the neuroblastos immature reducing its number, altering its distribution and causing an abnormal development of dendritic tree. These changes in neurogenesis affect some functions dependent on the hippocampus. The hypothyroid animals show a higher rate of depressive behavior that eutiroideos in an experimental model of depression (forced swimming test). Chronic treatment of rats hipotiroideas HT was able to retrieve rate neurogenesis in the GD and standardize the behavior of these animals. Our results indicate that HT is essential for neurogenesis in the adult GD and suggest that the depressive behavior disorders caused for hypothyroidism in the adult human can be linked, among others, with the decrease in neurogenesis in the GD. All of this could be important for future therapeutic applications in the modulation of endogenous neurogenesis and behavior disorders.

Author: SANTANA SANTANA JOSÉ RAMÓN.
Year: 2005.
University: LAS PALMAS DE GRAN CANARIA [www.ulpgc.es].
Place of defense: CENTRO SUPERIOR DE CIENCIAS DE LA SALUD.
Place of preparation: CENTRO SUPERIOR DE CIENCIAS DE LA SALUD.

Summary: INTRODUCTION The TPO is a membrane protein regulated by the TSH essential for the production of thyroid hormones. The quantitative or qualitative changes in the OPT is related to abnormalities in its biosynthesis due to thyroid diseases. It has been suggested that thyroid cancer is associated with abnormal expression of TPO. In this way the study of the TPO immunostaining using antibodies as MAB-47, is necessary in normal and pathological thyroid tissue. Some findings suggest that the qualitative changes in the OPTs could occur in some stages of the neoplastic process. SE has been a reduction of immunohistochemistry OPTs by monoclonal antibody mAb-47 in more than 95% of malignant tumors. This anomaly has been used as a factor in predicting malignancy in thyroid nodules studied by puncture with a higher than 95% sensitivity and specificity exceeding 85% follicular tumors. This difference allows discriminating benign from malignant tumors in at approximately 50% of cases. But the specificity of this method of diagnosis is low because the percentages of immunostaining of TPO are intermediate in the remaining cases. APPROACH AND OBJECTIVES We raised in this Doctoral Thesis, the study of immunohistochemical expression of the protein TPO (Moab-47) in normal and pathological Thyroid using statistical tools, as well as its comparative study with the factor of proliferation ki67 and protein cell cycle p53. The main objective is to assess whether the immunohistochemical expression may have a prognostic value and survival in thyroid cancer. MATERIALS AND METHODS We studied a total of 139 patients operated on for thyroid cancer in HUIGC of whom were 42 carcinomas papilary 38 carcinomas and 16 medullary and follicular undifferentiated and 43 cases of benign adenomas between, thyroiditis and hyperplasia. The results were measured by dual score of staining intensity and percentage and the data were analyzed by statistical methods in package SPSS-13. RESULTS AND DISCUSSION The expression of TPO decreased significantly with the histologic tumor type and TNM stage, being negative in anaplastic carcinomas and in some core. Similar results, though inverse were obtained with the p53 and factor proliferation Ki67. Results were obtained in the shoot Follicular carcinoma, but not in Papilares, which appreciated reduction OPTs in relation to the degree of desdiferenciación of them. For overall survival OPTs the refusal is related to tumors but forecast to 15 years of follow-up, being equally bad for leisure sickness. Equally it was for the chaos with weak or moderate intensity. For patients with TPO intense at the time of diagnosis, and overall survival time free of disease were optimal for the 20 years of follow-up. The comparison between the results obtained by us and the literature reviewed, in relation to the papillary and follicular carcinomas both in its classic form as in their histologic type is the common denominator of reduced expression TPO agree with the loss of cell differentiation and TNM grade, getting our data different meaning, perhaps by the number and cases studied by using a method of counting the TPO expression and statistical study, including survival is not addressed in the literature. CONCLUSIONS 8 May 4fd oría of papillary 81% had carcinomas little TPO, as a good marker for these malignancies. The undifferentiated carcinomas and anaplastic not express. By linking the OPTs and overall survival to you 20 years, this was about 72% in patients with TPO negative, while for a TPO intense all survived. It seems reasonable to propose that the tiroperoxidasa by immunohistochemistry procedures, should be included as a factor in the prognosis of thyroid cancer with others as histological type, tumor size, age and regional invasion and distance.

Author: MARTÍ SANCHIS ESMERALDA.
Year: 2006.
University: POLITÉCNICA DE VALENCIA [www.upv.es].
Place of defense: Dep. Biotecnologia.
Place of preparation: Universidad Politécnica de Valencia.

Summary: The tomato is a horticultural species that, thanks to their genetic characteristics, is a model system for studies of development in plants. Micro-Tom is a cultivar of tomato that has been taken as a model in different biotechnological studies conducted recently in this species. His dwarf phenotype, his short life cycle and the ease of being transformed by Agrobacterium are characteristics that make it a good model system. However there were no known genetic or molecular bases that generate particular phenotype of this cultivar. In this paper have been molecularly characterized two mutations that generate two phenotypic characteristics of Micro-Tom: dwarf mutation (d), which affects a gene biosynthesis brasinosteroides (BR) and causes dwarfism and roughness in the leaves, and the mutation self-pruning (sp), which affects a gene involved in controlling the process in which alternate vegetative and reproductive stages, causing a rapid determination of the units sympodial and giving the plant an appearance very compact. In addition it has been determined that in Micro-Tom, gibberellin (GAs), hormones necessary for the normal growth of the plant, have not altered the route of biosynthesis and response, so that a third mutation proposed in the literature for this cultivar, miniature (mnt), is not related to the metabolism and signaling of these hormones. The cuajado and development of the fruit, particularly the type partenocárpico are two of the characters of interest in biotech tomato and both processes depend on GAs. The present work has been carried out a comparative study of the expression of a gene biosynthesis GAs tomato (SlGA20ox1) involved in fruiting, Micro-Tom (through analysis by RT-PCR) and Arabidopsis (using a fragment 851 bp promoter fused to the GUS gene).