CELL BIOLOGY

Author: FRANCISCO MORCILLO JAVIER DE.
Year: 1999.
University: EXTREMADURA.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The analysis bromodeoxiuridina and antibody anti-PCNA indicate that the cessation dela proliferation in the retina still gradients centro-periférico and dorso - ventral. At the stadium 22 not detected proliferation in the region dorso-central of the retina and into the stadium 24 is not detected in the periphery. The pattern of expression of Islet 1, calbindina, calretinina, GABA, and GFAP vimentina indicates that the maturation of the retina continues gradients vitreo-escleral, centro-periférico and dorso - ventral. In most stadiums can be seen in retinal cell death. The structural characteristics and marking with the TUNEL technique indicate that the cells degenerate by the process of apoptosis. In the ganglion cell layer, the greater intensity death takes place between stages 19 and 22, coinciding with the period sinaptogénesis. In the internal layers nuclear and nuclear external apoptosis show greater intensity in the stadium 20. The nuclear layers, the killing begins in the central quadrant dorso-temporal of the retina and progressing according senses centro-periférico, dorso - ventral and temporo-nasal. The cells degenerate in the retina are fagocitadas mostly by cells neuroepiteliales in stadiums and young cells MÃ ¼ ller in later stages of development. The expression of vimentina and GFAP begins in the optic nerve at the stadium 17. It was subsequently extended to chiasm and finally to optical tract. Both the nerve and chiasm in the expression continues gradients periférico-central and dorso - ventral. Optical Fibers positive for the protein proteolipídica are detected for the first time in the stadium 24. The expression appears simultaneously in different regions of the optical path.

Author: PADILLA LÓPEZ SEGIO RAMÓN.
Year: 2003.
University: PABLO DE OLAVIDE.
Place of defense: CIENCIAS EXPERIMENTALES.
Place of preparation: FACULTAD DE CIENCIAS EXPERIMENTALES, U. PABLO DE OLAVIDE, DE SEVILLA.

Summary: The beginning Q (CoQ) is a type of lipid benzoquinone functioning as conveyor electrons in the menbrana internal mitochondrial eukaryotic cells and molecule antioxidant which protects the menbranas of cells versus peroxidation lipída.Niveles low CoQ produce diseases such as ataxia muscle. On the other hand, CoQ is used as a therapeutic agent in certain neurodegenerative diseases and anti-aging cosmetics. In these cases, CoQ exogenous has been detected in the plasma senguíneo although there is a differential incorporation by cells of different organs. Thus, it is interesting to study the distribution of this lipid between cell membranes and the process of incorporation into a body eucariota simple as Saccharomyces cerevisiae. The studies carried out in this paper have shown that elCoQ exogenous by the cells is dependent on the process endocítico and its soluble protein binding of medio.Además, transporting CoQ6, revealing this intermediary is unable to carry out such funciones.En This paper demonstrates that the intermediary DMQ6 may have a role in regulating the synthesis of CoQ6 may serve as a reservoir for the rapid synthesis of the final product in terms fisilógicos or oxidative stress.

Author: ROQUE MORENO MERCEDES.
Year: 2003.
University: BARCELONA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: HOSPITAL CLINICO DE BARCELONA.

Author: LLUIS DUQUEZ JOSE M..
Year: 2003.
University: BARCELONA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MADICINA (U.B.).

Summary: The alcoholic liver disease is a multifactorial and between the mechanisms involved in their development include the production of acetaldehyde, the selective decrease in the levels of glutathione (GSH) and mitochondrial hypoxia in the area centrilobular liver consequence of oxidative metabolism of ethanol. One of the predominant features of liver damage induced by alcohol in the liver, is the alterations morfologícas and functional observed in mitochondria. Therefore, one objective of this thesis was to evaluate. 1. Acetaldehyde's role in the regulation of glutathione and transportation to the mitochondria, as well as the lipid composition and physical properties of the mitochondrial membrane. The first provides information on the mechanism of selective decrease in the mitochondrial glutathione due to chronic consumption of etanol.El acetaldehyde, the first metabolite of oxidative metabolism of ethanol reduced the affinity (increased the Km) delos two components involved in the transport GSH of the mitochondria and this was accompanied by a decrease in nieveles of glutación mitochondrial (Mgsh). This dysfunction eltrasporte of mGSH was related to an increase in the viscosity of the emnbrana mitochondrial result of an increase in cholesterol levels the mitocondria.Por Furthermore, the induced expression of acetaldehyde factors GADD153, a marker of stress in the endoplasmic reticulum, and SREBP-1, involved in the activation of enzymes responsible for synthesis of colesterol.Por Finally, the decline in the levels mGSH, sensitized cells HepG2 the cytotoxic effects of TNF. There is evidence that shows a deposit of cholesterol inthe mitochondrial membrane, which means a decrease in the fluidity of the bilayer lipídaca.Dada involvement of the mitochondrial pore opening to cytokines (TNF - Fas) in alcoholic liver disease and in order to clarify the implications of the increase in cholesterol on the process of the mitochondrial permeability transition (MPT), we ask: 2.Evaluar the effect of the flow of mitochondrial membrane cholesterol by including on the opening of the mitochondrial pore. The enrichment of cholesterol in rat liver mitochondria was accompanied by a resistance to the opening of the mitochondrial pore induced by the agent atractilósido.Como result, there was a reduction in the release of the factors proapoptóticos: cytochrome C, Smac / DIABLO and factor in inducing apoptosis (IDA). The increase in the rigidity of the mitochondrial membrane due to the accumulation of colesteros was related to this lack of response to atractilósido since the fluidificación of menbrana mitochondrial restored response to this agente.Por therefore, the process of the mitochondrial permeability transition shows a dependence on the physicochemical properties of the mitochondrial membrane. The state hipermetabólico included in hepatocytes by the metabolism of ethanol, resulting in an imbalance between demand and provision of oxygen over acino liver, which triggers a relative hypoxia in hepatocytes perivenosos respect to periportales.En various studies he is involved in the sensor cell mitochondria as compared to hypoxia, by generating free radicals (ROS) actuán as second mensajeros.Puesto that mGSH is the only antioxidant defense against the mitochondrial ROS, we decided to explore. 3.'s Role glutación mitochondrial in cell survival during hypoxia. Exposure of the cells HepG2 a 5% oxygen led to an increase in free radicals from the mitochondria acting second messengers on how transcription factors NF-KB and HIF-la.Ambos factors showed their activity transactivadora to include the words their target genes: TNF-ay Cjap2 and VEGF.Bajo these circumstances cells suffered no changes in cell viability, but the decline in the levels of GSH and, more specifically, mitochondrial pool during hypoxia, a provo 8 có au 263 ment in the production of ROS by unleashing death celular.Nuestros results show that mitochondrial glutathione is a critical factor in controlling cell viability in response to hypoxia.

Author: GALLEGO LOPEZ ANTONIO.
Year: 2003.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: HOSPITAL UNIVERSITARIO PUERTA DE HIERRO - MADRID.

Summary: The chronic lymphoid leukemia B cell neoplasia is characterized by an accumulation of monoclonal B lymphocytes in the blood, bone marrow, lymph nodes, as well as other organs. It has been suggested that the accumulation of clonal population, is due to a decreased apoptosis rather than a high proliferation. The progesión of the disease has been associated with secondary immunodeficiencies and with a high risk of infection, which could result from changes in the production of cytokines, both by the clone leucémico as the residual population of T lymphocytes The cytokines involved in circuits autocrine or paracrine in the expansion of B lymphocytes LLC through inducció or inhibition of cell proliferation and apoptosis. This paper has studied the expression of intracellular cytokines using flow cytometry in leucémicos B lymphocytes and T lymphocytes CD4 + and CD8 + ex vivo and after activation with esters forbol and ionomicina. Simultaneously, it has studied the expression of cytokines in lymphocytes ByT of healthy individuals. The results show that B lymphocytes leucémicos, unlike the healthy individuals are preactivados producing cytokines type 2 (IL-4, IL-10) spontaneously that might induce survival. After stimulation in vitro, have the capacity to produce high levels of cytokines type 1 (TNF-alpha) contributing to the expación clonal. The CD4 + T cells of patients LLC-B after activation showing diminished response type 1 with respect to healthy individuals, which may explain their immune status. Just as the population leucémica, CD8 + T cells are preactivados producing cytokines type 2 spontaneously. After activation in vitro showed a sharp response type 1 (TNF-alpha and IFN-gamma) that could contribute to the growth and survival of B lymphocytes leucémicos. This study provides information of interest regarding the biology of lymphocytes ByT of LLC-B, which may be useful in the search for new approaches pathogenic.

Author: LÓPEZ AGUADO LAURA.
Year: 2003.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD CC BIOLÓGICAS UCM.
Place of preparation: HOSPITAL RAMÓN Y CAJAL DE MADRID.

Summary: This report reflects a series of works in which we have pursued a holistic view of the electrogénesis cell neuron hipocámpicas, combining the techniques of field intracellular (experimental results from in vivo and in vitro) and computer, using as a subject study, (but not exclusively) the generation and propagation somatodendrítica an action potential and its counterpart in the population spike poblacional.Se have studied various factors involved in the generation and modulation of the same, from the macroscopic level (as steering currents in the extracellular and the variation in resistivity tissue) until subcelular.Dada the relevance of dendrites, in large part this estufio has focused on the changes electrogénicos that occur in the same and therefore its impact in other regions of the cell itself in the population.

Author: GALLEGO DÍAZ DE LÓPEZ DÍAZ M. VICTORIA.
Year: 2003.
University: EXTREMADURA.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: UNIVERSIDAD DE EXTREMADURA.

Summary: In this Doctoral Thesis has done an exhaustive study of the pattern of neural gene expression in epithelial and chicken embryo during induction natural processes, the region of the embryo to be developed by the nervous system. In addition, it has analyzed the effects produced by the application of growth factors in the formation of the nervous system. Specifically, we studied the effect of bone morphogenetic proteins (BMPs), the antagonists of BMPs (BMPs-A) and fibroblast growth factors (FGFs) in the processes of neural induction. The thesis represents a breakthrough in the understanding of the mode of action of these proteins, it shows that the BMPs in the chicken embryo are capable of inducing the formation and epithelial tissue, inhibiting the formation of the nervous system. For their part, GFGs and BMPs-A, molecules produced by the primary organizer in birds, are able to induce the formation of nervous tissue. These results confirm that the formation of the nervous system in vertebrates is a complex cascade of molecular signals in which proteins such as BMPs and FGFs involved establishing the neural fate or epithelial cells.

Author: GALLEGO DÍAZ DE LOPE DÍAZ M. VICTORIA.
Year: 2003.
University: EXTREMADURA.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: UNIVERSIDAD DE EXTREMADURA.

Summary: In this Doctoral Thesis has done an exhaustive study of the pattern of neural gene expression in epithelial and chicken embryo during the processes of neural induction, the region of the embryo to be developed by the nervous system. In addition, it has analyzed the effects produced by the application of growth factors in the formation of the nervous system. Specifically, we studied the effect of bone morphogenetic proteins (BMPs), the antagonists of BMPs (BMPs-A) and fibroblast growth factors (FGFs) in the processes of neural induction. The thesis represents a breakthrough in the understanding of the mode of action of these proteins, it shows that the BMPs in the chicken embryo are capable of inducing the formation of epithelial tissue, inhibiting the formation of the nervous system. For their part, FGFs and BMPs-A, molecules produced by the primary organizer in birds, are able to induce the formation of nervous tissue. These results confirm that the formation of the nervous system in vertebrates is a complex cascade of molecular signals in which proteins such as BMPs and FGFs involved establishing the neural fate or epithelial cells.

Author: SOLÉ PASCUAL MARTA.
Year: 2003.
University: BARCELONA.
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: In the first instance, this thesis evaluated processes that triggers a axotomía the road Perforating crops organotípicos entorrino-hipocámpicos in vitro. After analyzing the cellular and molecular response, we may conclude that most triggered processes are similar both in absolute terms and in the temporal pattern, the observed in vivo. This validates our model as a model for the study of injuries and as a result, for the study of the regenerative capacity of the connection entorrino-hipocámpica. Through the model in vitro cultivation organotípico entorrino-hipocámpico, analyzes the factors responsible for the failure of regeneration that occurs in the central nervous system adult. The results tell us that a dual approach on the one hand able to reverse the properties hostile generated a scar and on the other hand to attract the axones severed again on what was his target, would be the key to achieving a complete axonal regeneration. The cells Cajal-Retzius are a poblaicón neuronal transient responsible for the formation of the road Perforating developing. The transplantation of these cells, or their immediate environment, seems to be enough for neurons entorrinales axotomizadas affect a program of leongación neurítica that not only allow these axones cross the scar, but the addresses which was his original target, allowing the generation of new hippocampal synapses on a perinatal transplanted.

Author: FERNÁNDEZ-VIZARRA BONET PAULA.
Year: 2004.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: Alzheimer's disease (AD) is characterized by the presence of senile plaques (SPs) and neurofibrillary tangles (NFTs) in vulnerable regions of the brain. The main line of current thinking puts the primary cause of AD in the formation of SPs and éstq in the secretion of peptide beta-amiloide (Abeta) in the middle extracellular. However, this view is being challenged by several recent studies with transgenic animals and cell cultures have shown that the existence of intracellular deposits of Abeta in neurons. More recently, it has been proven the existence of intracellular deposits of Abeta in neurons in the human cerebral cortex. However, in these studies has not excluded the possibility that the antibodies generated against Abeta recognize also the precursor protein peptide beta-amiloide (PDB), or are not described how it has been ruled out this possibility. We have done an immunohistochemical study of the formation of peptide Abeta and the paired helical filaments (PHF) in the crust temporary, as an area selectively vulnerable in the DP, in individuals without dementia and aged and young patients affected by the DP sporadic clinically evaluated and ranked according to the scale clinical dementia (CDR) in the Memory and Aging Project of the Center for Research on Alzheimer's Disease at the University of Washington, USA This scale has previously been standardized neuropatológicamente. Moreover, it has been shown that the DRC is a sensitive and reliable method for distinguishing the evnejecimiento without dementia-type dementia early AD, as well as to determine the degree of involvement by the DP. Similarly, the assessment protocol used assured that no individual inlcuido in this study suffered any disease causing dementia different from the AD. We have shown through the use of an antibody that specifically recognizes Abeta, and who does not cross-react with the JPA that occurs in the DP intracellular accumulation of Abeta in subpobalciones of pyramidal neurons that have the same distribution cortical and the same characteristics that subpopulations of neurons pirmidales selectively vulnerable to neuronal death and the formation of NFTs in AD. These neuronal subpopulations are in the cortical layers where the formation of SPs in this disease. The intracellular accumulation of Abeta in pyramidal neurons is a change early in the AD and precedes the more nascent alteration of the protein tau and plaque formation. Our results show that the pyramidal neurons that accumulate Abeta intracellular morphological signs of degeneration. We have described for the first time the existence of structures with morphologies transition between pyramidal neurons and SPs. These structures of reaction products of peptide Abeta presena elm ism aspect that observed in the typical SPs. However, the morphology of the plate is clearly pyramid and it can be observed structures with morphology proximal portions of apical dendrites and baales. Our findings suggest that, at least in part, the formation of amyloid plaques is produced by cell lysis of the neurons affected by the intracellular accumulation of Abeta, and probably as a result of it. Moreover, the morphology of the reaction products of some of the pyramidal neurons immunoreactive for Abeta suggests that the formation of fibrils in beta peptide Abeta in foil characteristic of SPs takes place intracellularly. Finally, the intracellular accumulation of Abeta is a pathological phenomenon associated with envjecimiento that selectively affects the most vulnerable selectively neuronal subpopulations in the DP. This training accumulations itnracelulares of Abeta is quantitatively reduced in the aging in the DP. It is likely that the intraneuronal accumulation of Abeta asocaida at the age pyramid in subpopulations involved in the projections long as 8 ociación 957 corticortical is involved in the cognitive deficits that occur with aging. Based on the observations of the changes in the different isoforms of nitric oxide synthase (NOS) in the brain of patients with AD suggested the involvement of NO in the DP. However, so far the involvement of NO / NOS in lapatogenia the DP still not well understood. Numerous evidence, and steadily growing, suggesting the involvement of oxidative stress in the DP, and specifically in neuronal death induced by Abeta. We have found large amounts of oxidative damage in the DP, including glicación, nitración, lipid peroxidation and carbonyl formation. Therefore, the establishment of the / s source / s oxidation is key in the understanding of the pathogenesis of AD. By Immunohistochemical techniques we have demonstrated, in the temporal cortex of patients with AD classified according to the CDR, which produces an aberrant expression of neuronal NOS (nNOS) and inducible (iNOS) and formation of nitrotirosina (3-NT) in subpopulations the pyramidal neurons that have the same characteristics and distribution of cortical selectively vulnerable than those in the AD and neuronal subpopulations affected by the intracellular accumulation of Abeta. Our results show that aberrant expression of nNOS and iNOS and the formation of 3-NT precedes the formation of SPs. The sustained production of NO may be involved in neuronal death that occurs in the DP and, in this way, could be involved in the formation of the SPs. The expression of nNOS and iNOS and the formation of 3-NT in pyramidal neurons is also a pathological phenomenon associated with aging. By Western blotting techniques and stereology we noticed that the expression of these isoforms, as the formation of 3-NT is significantly lower in the aging in the DP, according to our results.

Author: DALFO CAPELLA ESTHER.
Year: 2004.
University: BARCELONA.
Place of preparation: FACULTAD DE MEDICINA , CAMPUS BELLITEE , UB.

Author: ESPINOSA PARRILLA JUAN FRANCISCO.
Year: 2004.
University: BARCELONA.
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGIA.

Summary: The spontaneous neuronal activity, characterized as spontaneous oscillations in intracellular calcium is a phenomenon necessary for the conrrecto development of neuronal connections. Although it is stipulated that activity is a general phenomenon of the central nervous system, has been characterized only in certain áreas.Nuestra intention has been studying this spontaneous activity in the cortex cerebeloso well as in cells astrogliales, trying to analyze those mechanisms that generate regulate this activity and spontaneous oscitatoria coordinated.

Author: ROMERO MUÑOZ EVA M..
Year: 2004.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE BIOLOGIA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: In order to explore the possible implications of the immune system in the pathogenesis of schizophrenia, the group led by Dr.Borrel has developed a new experimental design based on the effect of prenatal immunologic activation on information processing and sensoriomotora immune function in adulthood (Borrell and cabbage., 2002). This model consists in the administration of lipolisacárido bacterial (LPS) to pregnant rats and evaluation of the changes that occur in the processing of information, and the immune system histology of some structures related to the processing of information sensoriomotora in the offspring adulta.El purpose of this thesis was to continue and deepen the characterization of this model.

Author: BARTOLOMÉ CONDE RUBÉN ÁLVARO.
Year: 2004.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: CENTRO DE INVESTIGACIÓNES DE BIOLOGÍA (C.S.I.C.).

Summary: SUMMARY: The invasion of tissues by tumor cells involves their migration through basal membranes by coordinated activation of the degradation of the matrix and mechanisms of cellular locomotion. The quimioquinas provide guíasquimotácticas to various organs, and thus could potentially participate in the spread of tumor cells. Here we show that several lines of melanoma cells and melanoma gánglios nodes express receptors quimioquinas CXCR4 and CXCR3, and their ligands, CXCL12 (SDF-1) and CXCL9 (Mig), promote the invasion of melanoma cells to trvés of membranes baseline. The proteolytic activity of MT1-MMPera required for these invasions, and CXCL12inducía an increased expression of MT1-MMP.Además CXCL12 and CXCL9 promote the activation of GTPasas RhoA and Rac, and expression of dominant negative forms of these inhibited GTPasas invasion of transfectantes in response to both quimioquinas. We found that cells melanomaexpresan Vav1yVav2, which are proteins GEFque catalyze the activaciónde GTPasas Rho.CXCL12 induces activation of Vav1 and Vav2 and the interference of the expression of these GEF resulted in an inhibition of the activation of RhoA and Rac, increased expression of MT1-MMP, and the invasion of melanoma cells in response to CXCL12. Additionally, the expression of CXCR4 in melanoma cells was significantly enhanced by TGF. ~ 1, a component of the basal membranes, and antibodies anti-TGF-B inhibited this increased expression of CXCR4 and the invasion of melanoma cells towards CXCL12. The stimulation by CXCL12 in the path Vav / GTPasas Rho/MT1-MMPen cells of melanoma, as well as the regulation of the expression of CXCR4, are mechanisms that contribute to the invasion of melanoma cells to CXCL12. Our results provide the basis for future research or therapies aimed at inhibiting the spread of melanoma cells. The integrins, a 4 are membrane receptors expressed mainly in leukocytes, upon accession célula-matriz and célula-célula. The adhesive activity of integrins, a 4 can be quickly modulated during migration. We show that TGF.B1 increases rapidly and transiently accession mediated integrins a.4 their ligands VCAM-1y CS-1/fibronectina. Here we show that TGF-B1 active quickly GTPasa RhoA and p38 MAPquinasa, but the increase in membership does not require the activity of these molecules. In contrast, actin polymerization triggered by TGF-B1es need for increased adherence to mediated by integrins, 4, and that elevated levels of cAMP opposes both the polymerization and the increasing invasion. Additionally, TGF.B1 increases further increasing membership via integrina, a 4 induced by CXCL12. These data suggest that TGF-B1 can potentially contribute to cell migration by regulating the dynamics of cell adhesion by integrins a4.

Author: ALONSO ARANA EDURNE.
Year: 2004.
University: PAÍS VASCO.
Place of defense: FACULTAD DE MEDICINA Y ODONTOLOGÍA.
Place of preparation: FACULTAD DE MEDICINA Y ODONTOLOGÍA.

Summary: Cells Germinales Primordiales (PGCs) appear very early in embryonic development and in a region very far from somatic cells that form the fabric accessory in the future gonads. Through active migration, these cells reach and colonize the genital ridges that give rise to the gonads in the adult. Several factors are involved in these movements of migration. The extracellular matrix adjacent is the basis by which they will head towards their destination and also to be composed of molecules that allow such movements is the way in which different signaling molecules diffuse. Also sugars of glycoconjugates of the surface of these cells seem involved in the recognition of these molecules. According to these premises and the Xenopus laevis embryo as experimental model, this paper has tried to identify the presence of certain molecules that may be involved in these mechanisms migration. On the one hand, we have identified sequences oligosacarídicas of glycoconjugates of the surface of PGCs while actively migrate through the mesentery and their possible involvement in the process. On the other hand, seha cloned and analyzed gene expression x-cxcr4b, since gene counterparts in mice and zebrafish are involved in the migratory movements of the PGCs and signs for the peak genitals. The findings on histochemical analysis with lectin and pretratamientos chemical and enzymatic desglicosilativos indicate that the composition oligosacarídica the surface of the PGCs migrate while actively and once colonize the genital ridge shows no apparent change of employer. Sequences identified relate primarily to O-oligosacáridos: (Neu5Acalfa (2, 3)) Galbeta (1.4) GlcNAc, (Neu5Ac) GalNAcalfa (1.3) GalNAc, GlcNAc, Fucalfa (1.3) or alpha (1, 4), and something of Man. While the N-glicoconjugados are more limited and relate to the sequence: Manalfa (1.6) [Manalfa (1.3)] Manbeta (1.4) GlcNacbeta (1.4) GlcNAc-Asn, Fucalfa (1, 6) GlcNAc-Asn and GlcNAc. The gene cxcr4 get involved in a number of migratory processes primarily relates to the nervous system and the blood-producing cells. Recently s eha described involved in the migratory movements of the PGCs in mice and zebrafish. The expression of the gene x-cxcr4b, analyzed by RT-PCR techniques, northern blot, and in situ hybridization, it appears very early linked to important roles in embryonic development. It has been observed how has low expression of maternal origin, which could be stored in the germ plasm. His expression zigótica starts from the stadium gastrula temparan and disminye from stage 45. The results derived delas hibridaciones spot, suggest that the gene appears implicated in various processes during embryonic development, such as development of the central and peripheral nervous system, and hematopoietic embryonic and definitive. However, their involvement is not evident during the migration process from active PGCs of Xenopus embryo.

Author: URIGÒEN ECHEVERRÍA LEYRE.
Year: 2004.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: SUMMARY: The development in the last decade, numerous studies using A9-tetrahidrocannabinol (THC), the active ingredient of cannabis, or various synthetic agonists of reqeptor cannabinoid, has contributed very significantly to the advancement of knowledge of the pharmacological actions and neurobiological processes involved in the activation of cannabinoid receptors. This dramatic progress has identified 1m new neurotransmission system consists of two types of cannabinoid receptor: the receiver CB1, located fundamentalmenteen central nervous system and the receiver CB2, featuring relacionadas.con regulation of the immune system. In addition, it is. Have identified several ligands endógen () s (anandamide and 2-araquidonil-glicerol) and an enzyme system (amidohidrolasa fatty acid) permitela completionof accionesde these ligandosen synapses. Preclinical and clinical studies related to the consumption of THC or cannabinoid receptor agonists suggest that the endogenous cannabinoid system plays an important role in the reguláción state of anxiety. This idea is based on the neurochemical and behavioral changes that occur in experimental animals and in humans after acute or chronic consumption of cannabis derivatives, such as alterations in the regulation of neuroendocrine hypothalamus pituitary adrenal axis (HHA), changes in the expression of genes asociadosal control the response to stress and increase the reactividadconductual and neuroquímicaante estímulosansiogénicos. The colocalización of cannabinoid receptor CB1 receptors GABAérgicos and serotonergic neurons in brain areas closely related to the regulation of anxiety, such as the hippocampus and amygdala, suggests that the alterations in the function of cannabinoid receptors may likewise affect the therapeutic efficacy of anxiolytic agents such as benzodiacepinasy agonists receptor serotoninérgico5-HT1A. Eliminating receiver cannabinoid CB1 therefore could generate mice in some of the symptoms of anxiety disorders. From mislÍ1o so that the administration of cannabinoids derived produces alterations in the functioning of the neuroendocrine system, one would expect some sort of disturbance in the operation of the constituent hypothalamus pituitary adrenal axis in these animals that had been eliminated receiver cannabinoid CB1. If we can see these changes in the comportamientoy in the hypothalamus pituitary adrenal axis, it is very likely that these changes are caused by malfunctions at neuroquímico and that these dysfunctions are associated with the systems operating on drugs anxiolytics. The results of this study demonstrate that the receiver cannabinoid CB1 plays an important role in 1 $ regulation of emotional response in a variety of experimental situations and that the presence of the receptor gene cannabinoid CB1 is necessary to maintain an adequate baseline activity (homeostatic) in several elements of hi Jotalamohipófisis adrenal axis and a proportionate response to stress. Ademásla ausenciadel receptorcannabinoideCB1modifICala functionality receivers Ky. s-opioidesy the expression of genes precursoresde peptides opioicleslo queconfirma close InteractionBetweenCollective systems receptorialesopioidey cannabinoid. Moreover gonadales hormones in male interacting with the cannabinoid system in controlling anxiety and the elimination of circulating hormones gonadales pharmacological response amending the benZodiacepinasen function of the presence or absence of receiver cannabinoid CB1. The low response anxiolytic of buspirone and alteration of the function of receptors 5-HT1Aen the hippocampus of animals without receiver ca 8 nnabinoi 4bc to suggest the need for a proper functioning of cannabinoid receptor to which this drug can produce adequate response ansiolitica. Similarly, the lack of response anxiolytic of bromazepam in mice lacking the receptor cannabinoid CB1 and functional changes in the receiver GABAAy GABABY him that the administration of bromazepam in mice reduces the role of natural cannabinoid CB1 suggests recipient of this participation receiver in action ansiolíticas of benzodiazepines. The above results suggest posibitidad that functional alterations in varying degrees in the cannabinoid receptor CB1 can relacionarsecon the emergence and respuestafarmacológica amended pathologies psiquiátricasque circulate with anxiety.

Author: NONTOLIO DEL OLMO MARISOL.
Year: 2004.
University: BARCELONA.
Place of defense: FACULTAT DE BIOLOGÍA.
Place of preparation: FACULTAT DE BIOLOGIA.

Summary: Our data show that a peptoide, sichi, is able to specifically inhibit the quimorepulsión produced by semaforina 3A, exogenous yendogenamente, growth axoles hipocampicos in different models. This blockade of the quimiorepulsión is mainly due to a collapse of preventing axonal cone, and is dasis-dependiente. Serves level gives ligando-receptor and is capable of producing axonal regeneration of the track after a puncture injury, in addition to increasing the survival of neuronal cells hippocampus, and cerebellum ganglion nodosum. On the other hand, our results suggest involvement in intracellular calcium signaling mediated semafarina 3A. By explants of hippocampus confronted with semafarina 3A treated with calcium binders, or calcineurin inhibitors and calmoducinkinasa II observed involvement of calcineurin in -- signaling semaforina 3A. Also note as semaforfina 3A and calcineurin but not calmodulinkinasa II control the nuclear translocation of transcription factor NFATc4.

Author: RODRÍGUEZ VILARIÑO VICTORIA.
Year: 2004.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD DE BIOLOGÍA.
Place of preparation: FACULTAD DE BIOLOGÍA.

Summary: In cells politenizadas, like those of the salivary glands of larvae Chorinomus, the amplified DNA is forming chromosomes polytechnics, as a result of amplification side of the sister chromatids that are held together over successive rounds of replication. The ribosomal genes are also amplified and its activity leads to the formation of a giant nucleolus, the so-called "Cell Nucleolus Polytechnics." (PCN), which can reach a diameter of 10-15 um. We have used the advantages of this model to study biological some basic aspects of the organization of the NCP, helping to clarify outstanding issues on the functional organization of the nucleolus. At the ultrastructural level, the NCP appeared composed solely of dense fibrillary components (CDF) and granular components (CG). They have not been identified in these centers fibrillary nucleoli (CFs). However, the CFs it is still present in nucleoli of nerve cells not politéncias of the same individual. The absence of CFs in the NCP could be related to the levels and distribution of the structural proteins of the nucleolus, which could be a specific feature of cell type. Alternatively, it could be the result of the high activity of the NCP. However, the CFs also appeared in the NCP following treatment with cicloheximida (CHM), which inhibits transcription nucleolar. Treatment with this drogar resulted in a reorganization or segregation in the structural components of the NCP, so that the CFD is situated in the areas surrounding the chromosome and CG in the periphery. The confocal microscope and the scanning electron microscope we studied the distribution of DNA in the NCP. The DNA intranucleolar noted widespread in the CFD, in the form of chromatin descondensada. The organization noted widespread in the CFD, in the form of chromatin descondensada. The organization of DNA is very dynamic, and that after treatment with CHM, there is a strong condensation of the chromatin and retraction nucleolar. The use of in situ hybridization with fluorescent markers (FISH), has enabled the specific location of rDNA, whose distribution was observed targeted, ie concentrated in small accumulations distributed irregularly, the emerging fiber dispersed. In addition, through an experiment in vitro transcription have located sites where CFD is the transcript. The pattern in situ transcription appeared nucleolar also targeted in the same way. These pockets have the same functional meaning that the CFs in cells that have, so that the non-existence of CFs does not entail a change in the pattern of structural organization of rDNa and transcription in the nucleolus. Moreover, it has been carried out inmunodetección of fibrilarina and nucleolina, two proteins involved in the processing of pre-rNA. Both proteins were localized in the CFD, but in colocalización both, we note that there are areas where only located the fibrilarina, areas where only located the nucleolina and were localized areas where the two proteins simultaneously. Although ultraestructuralmente the CFD component appears as a homogeneous, their molecular composition and its functional organization show that is heterogeneous. Treatment with CHM inhibitor of the transcription, resulting in the emergence in areas of active transcription, both in the chromosome as free in nucleoplasma of nature fibrillar structures, called droplets. Experiments inmunocitoquímicos helped locate them nucleolar proteins as fibrilarina and nucleolina, but did not appear signal DNA. The origin of these structures could be a segregation and microfragmentación of CFD, formed aggregations nucleoplásmicas of nucleolar proteins, which can not be transported to the nucleolus where the transcription of rRNA genes is altered. Finally, it has addressed the issue of involvement of nucleolus in other cellular functions other than the synthesis of ribosomes. Specifically, we studied locates 8-nuc 4d0 leolar of a protein unrelated to the biogenesis of ribosomes, reverse transcriptase (rt), obtained through an antibody against a protein recombinate containing reasons for this enzyme phylogenetically conserved. The presence of this enzyme is related to the strategy of maintaining the telomeres in Dípteros. Amazing, reverse transcriptase appeared located in the NCP, possibly in connection with the regulatory mechanisms of enzyme activity. From our results we can conclude that, despite the nucleolar organizer (NOR) originates from the NCP side as the addition of multiple copies of the original NOR, the nucleolus is organized functionally as a single entity and integrated, not the mere juxtaposition of the activity of multiple NORs.

Author: TONY VALENTE.
Year: 2004.
University: BARCELONA.
Place of defense: FACULTAT DE BIOLOGÍA.
Place of preparation: FACULTAT DE BIOLOGÍA, UNIVERSITAT DE BARCELONA.

Summary: The rate of cell proliferation is a balance between various cellular processes: mitosis, cell differentiation and apoptotic cell death. The regulation of this assessment is critical during embryonic development, regeneration and cellular aging, as well as different processes and degenerative disease. Recently, it has cloned a gene, designated Zac1, which encodes an actor transcription regulating apoptosis and cell cycle of unemployment, through independent channels. It has been found that in mice adults Zac1 expressed in the pituitary gland in the brain and peripheral tissues different, and in the neural tube of mouse embryos with 9 days. Various studies have shown that Zac1 is involved in tumor development, transient neonatal diabetes mellitus, in the activation and / or suppression of nuclear receptors in the coactivación the road apoptotic p53/Apaf-1, etc.. However, its role in the central nervous system is still unknown. This thesis aims to generally determine the role of Zac1 in the central nervous system of mice. In this regard, it was determined the pattern of expression and Zac1 during embryonic development of neuroectodermo and mesodermo and, during maturation of the central nervous system (using in situ hybridization techniques and Immunohistochemical). In addition, it is characterized the phenotype of the cell populations that express Zac1 during development. In the development of neuroectodermo, the results show that Zac1 expressed in the stem cell / progenitorias central nervous system, both in developing cm in the adult animal (Zoning germ). Its expression in differentiated cells is restricted to neuronal subpopulations of nature GABAérgica and catecolinérgica. In the development of mesodermo, the results revealed that Zac1 expressed during all phases of the life cycle of chondrocytes (condrogénesis) and the development of muscle cells (miogénesis), suggesting that Zac1 can play an important role in the development of skeleton and skeletal muscle. Moreover, we studied the role of Zac1 in the central system, analyzing neural the phenotype of ratone mutants for Zac1, and to explore the role of Zac1 in neurodegenerative processes associated with apoptotic cell death. The mutant animals to Zac1 rates of neural proliferation higher than that of wild animals, strengthening the role of Zac1 in controlling the rate of cell proliferation (cell cycle and apoptosis). Moreover, the results obtained killed the regional expression of Zax1 is essential for the selection and / or different progenitorios neural differentiation (such as in oligodendrocytes, neurons, astrocytes, etc..). In neurodegenerative models, the results show that Zac1 is essential to activate apoptotic processes that lead to the fragmentation of DAN, pointing to his involvement in the early stages of the activation of apoptotic cascades. Therefore, the new results obtained in this study thesis opens different lines of approach on the role of Zac1 in the central nervous system, particularly in the processes of cell proliferation and differentiation, in the apoptotic process and the mechanisms of neural plasticity that occur during the early development of the body and, after activating neural taking place in the processes of neurodegeneration.

Author: GARCÍA GONZALO FRANCESC.
Year: 2004.
University: BARCELONA.
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: The family HERC protein in humans consists of six members, whose sequences are characterized by domains type HECT Domain and peer RCC1. The presence of these domains implies that the proteins HERC act as E3 ubiquitina ligasas and perhaps as factors exchangers nucleotides on GTPasas monomer. HERC1 is a giant protein of 532 kDa able to interact with the heavy chain of clatrina and GTPasas of families ARF and Rab. Using biochemical techniques for detecting interactions, we have identified the Pyruvate kinase M2, the light chain of clatrina, ARF6 and several fosfoinosítidos as new molecules capable of joining HERC1. Also, the use of microscopic techniques has enabled us to establish that HERC1 is in vesicles from Golgi apparatus and its distribution in the cell is regulated by the activation of ARF6. Moreover, we have seen that the reduction in levels of HERC1 Techniques for RNA interference will not affect operation of the tracks endocíticas and secreting cells, but the expression of certain truncation of HERC1 it leads to an inhibition of the endocytosis.