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Control Procedure Analysis in EPS-IMS Networks
Šubrt, Jan ; Červenák, Rastislav (referee) ; Novotný, Vít (advisor)
The master thesis is focused on control procedures in EPS-IMS networks. Firstly the thesis describes systems IMS and EPS. The second part of thesis includes the theory of control procedures in EPS such as cell acquisition, random access procedure, identification of subscriber, authentication of subscriber, security procedures, tracking area procedure, default bearer creation, implementation of CSFB procedure and detach procedure. Processes related to subsystem IMS such as registration to IMS, bearer creation for IMS signalling and voice service VoLTE are the next part of thesis. The next main topic is the VoLTE implementation problematic and VoLTE cooperation with diverse terminals. There is also explained the principle of Circuit Switched Fallback for realization voice services in EPS without VoLTE service. All procedures mentioned above except of procedures which are related to IMS were captured and analyzed using software Wireshark and QualiPoc. The final part of the thesis is lab task creation based of the analyzed messages.
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Studies on immunoreceptor signaling molecules
Ormsby, Tereza ; Hořejší, Václav (advisor) ; Černý, Jan (referee) ; Špíšek, Radek (referee)
A delicate balance in the number, specific type and function of leukocytes is required for proper functionality of the mammalian immune system. Innate immunity, which quickly recognizes pathogens, represents the first line of defense. Later, a more specific response is generated via adaptive immunity. Deregulation of the immune system is manifested by the inability to control infection, development of allergic, autoimmune disorders or even cancer, and ultimately can lead to death. To fulfill their functions, cells develop an intricate network of intra- as well as extra-cellular molecules organized into signaling cascades, which allows them to communicate between each other. Better understanding of the molecular mechanisms of signaling pathways in leukocytes is critical for design of efficient therapies. In this thesis, leukocyte signaling was studied in several aspects. First, the role of adhesion molecules in pathogenesis of cervical cancer and the regulation of their expression was investigated. The second publication describes a new transmembrane adaptor protein (TRAP), called prolin rich 7 (PRR7), as a potentially interesting regulator of signaling and apoptosis in activated T cells. The final publication characterized the role of the Btk kinase downstream of the triggering receptor expressed...
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Characterization of CART peptide analogs in vitro and in vivo
Nagelová, Veronika ; Maletínská, Lenka (advisor) ; Vybíral, Stanislav (referee)
Peptide CART (cocaine- and amphetamine- regulated transcript) is a neuropeptide acting in the hypothalamus to reduce food intake (anorexigenic peptide). Despite all efforts the receptor and the mechanism of action is still unknown. This peptide has two biologically active forms, CART(55-102) and CART(61-102). Peptide CART is able to bind to pheochromocytoma cells PC12. PC12 cells differentiated in neuronal phenotype with NGF (nerve growth factor) showed a higher number of binding sites (11250 ± 2520 binding sites/cell) compared to undifferentiated cells (3600 ± 570 binding sites/cell). PC12 cells differentiated by dexamethasone to chromaffin cells showed high non-specific binding. Peptide CART contains three disulfide bridges. To clarify the importance of each disulfide bridge to maintain biological activity, analogues with one (analogue 3, 4 and 5) or two (2, 6, 7 and 8) disulfide bridges and a peptide analogue of CART (61-102), which has methionin at position 67 replaced with norleucine were synthesized. We showed that biological activity was unchanged at analogue 1 and analogue 7 containing disulfide bridges in positions 74-94 and 88-101. When investigating cell signaling in PC12 cells, we tested if peptide CART activate of c-Fos, c-Jun, phosphorylated ERK1/2, CREB, JNK and p38. CART peptide...
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Role of endocytosis and endosomal acidification in TRAIL-induced apoptosis
Hradilová, Naďa ; Anděra, Ladislav (advisor) ; Kovář, Jan (referee)
TRAIL (TNF-related apoptosis inducing ligand) became known for its ability to selectively eliminate cancer cells. This ligand is a member of the TNF (tumor necrosis factor) ligands family and triggers extrinsic apoptotic pathway by binding of its death receptor 4 or 5 (DR4/5), and subsequent formation of death-inducing signalling complex (DISC). This signalling complex is required for successful transmission of apoptotic signal and activation of proximal caspases. However, regulation of the initial steps leading to activation of caspases is still not fully understood. Endocytosis of a TRAIL- DR4/5-DISC complex can be one of modulators of the initiation of extrinsic apoptotic pathway. Recent studies show controversial data documenting that endocytosis of TRAIL receptosomes can in cell type specific manner either positively or negatively influence TRAIL-induced apoptotic signalling. In this study, we focus on the analysis of a role of endocytosis and acidification of endosomal compartments during TRAIL-induced apoptosis in human colorectal cancer cell lines. Our results support the view that both clathrin-dependent endocytosis of TRAIL receptosome and endosomal acidification positively affect activation of caspases during the early stages of TRAIL-induced apoptosis. Inhibition of endocytosis or endosomal...
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Small signaling molecules in yeast
Putalová, Tereza ; Váchová, Libuše (advisor) ; Horníková, Lenka (referee)
Yeasts excrete metabolitesinto the environment some of which may have a signal function. The small signalling molecules include ammonia, alcohols, esters, acids and CO2 beside other molecules. These substances may be formed as waste products of metabolism, such as some alcohols in the catabolism of amino acids. After exclusion they influence other / surrounding cells by binding to receptors or they affect their target in the cell or may form a concentration gradient or a pH gradient. New findings show that using ammonia yeasts can communicate and may diversify within colonies. Farnesol, tyrosol and other molecules use the yeasts to quorum sensing. Yeasts also secrete aromatic esters and fatty acids. High concentrations of CO2 trigger switch from yeasts to hypha. This paper summarizes existing information on the occurrence and impact of selected molecules (ammonia, alcohols, esters, acids and CO2) signaling in the yeast Saccharomyces cerevisiae and Candida albicans.
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The effect of caloric intake and aromatic substances on the human body odour quality
Fialová, Jitka ; Havlíček, Jan (advisor) ; Martinec Nováková, Lenka (referee)
Previous work has shown that mate choice is in part affected by cues associated with quality and condition of potential mate. These cues could be based on visual characteristics or as shown recently on chemical cues. There is growing evidence which suggest that body odour plays relatively significant role in mate choice. Moreover, body odour is to some extent affected by ingested diet. Therefore, we focused on the effect of caloric restriction and garlic consumption on axilary odour. Our results suggest that restoration of food intake improve body odour in terms of pleasantness and attractiveness (probably as a consequence of recommended specific diet), but during caloric restriction it is rated lower. The garlic consumption improves hedonic assessment of body odour. This effect could be ascribed to his well-known health effects. Our findings thus confirm assumption that ingested diet affects body odour and these changes in odour attractiveness could serve as a cue to individual condition and quality.
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Opioid receptors and their signaling system in the myocardium
Ladislav, Marek ; Novotný, Jiří (advisor) ; Neckář, Jan (referee)
The main objective of this bachelor thesis is to systematically collect and sort information about opioid receptors and their signaling system in the myocardium. Heart activity is controlled mainly by adrenergic signaling, and this work therefore contains also some data concerning the characteristic and significance of other relevant receptors. For better understanding, general basic information about opioid system, especially about the receptors and their signaling, is also provided. Relatively little is known about opioid receptors in the myocardium even though these receptors may have an important role especially in various pathophysiological conditions. There can be several reasons for this. The possibility of further characterization of opioid receptors in the myocardium is rather difficult due to the relatively small number of these receptors in heart tissue. The situation is somewhat complicated also by some differences in the modulation of cardiac function among different species. The complete molecular mechanism by which opioid receptors act on the myocardium has not yet been fully uncovered. Especially in the case of humans this knowledge can be crucial, because these receptors and their ligands could be used for medical purposes.
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Molecular physiology of opioid receptors
Valný, Martin ; Novotný, Jiří (advisor) ; Hejnová, Lucie (referee)
The opioid receptors (OR) belong to the family of G protein-coupled receptors (GPCRs). ORs mediate the effects of the opioids, leading primarily to inhibition of neuroexcitability, predominantly through the class of the inhibitory G proteins Gi/Go. Cloning of ORs confirmed the existence of four subtypes of ORs, which mediate effects of different classes of opioid ligands. The major aim of this work is to summarize the current knowledge about characteristics and function of ORs at the molecular level. Acute exposition of ORs to their agonists results in activation of the signaling cascades that trigger mechanisms leading to analgesia. Chronic exposition of ORs to their agonists leads to desensitization and internalization of the receptors and induces adaptive changes in signal transduction system that suppresses the opioid action, and may result in the development of opioid tolerance and dependence. Although a big progress has been made in the field of understanding the molecular mechanisms of the OR-mediated signaling, there are still a lot of unresolved questions that are necessary to answer.
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The role of NG2 glycoprotein in regulation of Rho/ROCK signaling
Kratochvílová, Magdalena ; Rösel, Daniel (advisor) ; Kuželová, Kateřina (referee)
NG2 is a transmembrane glycoprotein, which takes part in cellular processes such as adhesion, migration or invasivity, i.e., in processes important in tissue development but also in tumor and metastasis formation. Among other things, NG2 leads to an inhibition of neurite growth, and probably plays an important role in amoeboid type of cell invasion. These processes are in many respects similar. Both in inhibition of neurite growth and in mesenchymal-amoeboid transition occur morphological changes which lead to a loss of cell protrusions and a transition to a rounded shape. In both of these processes Rho/ROCK signaling also plays a crucial role. Connection between NG2 and the Rho/ROCK signaling pathway has been indicated in the process of inhibition of neurite growth. The mechanism of Rho/ROCK signaling regulation by NG2 glycoprotein is, however, still unknown. In this thesis is proposed a molecular mechanism of Rho/ROCK pathway activation by glycoprotein NG2 which relies on the NG2/MUPP1/Syx signaling complex where the scaffold protein MUPP1, bound to activated NG2, enables binding and activation of the Syx protein. Syx then as RhoGEF activates Rho/ROCK signaling, and the activated Rho/ROCK pathway leads to inhibition of neurite growth, increased cell contractility and traction forces. These processes are...
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The role of endocytosis in Wnt signaling pathway
Matějů, Daniel ; Libusová, Lenka (advisor) ; Doubravská, Lenka (referee)
Endocytosis and cell signaling are tightly connected processes. This connection is most obvious at the level of endocytosis of signaling receptors and ligands. For many years, endocytosis of signaling receptors was considered as a negative feedback loop mechanism, which desensitizes the cell after prolonged stimulation by ligand. Now it is evident that the situation is more complex and endocytosis can affect cell signaling both negatively and positively. In this thesis, I will summarize how Wnt signaling can be affected by endocytosis of receptors and ligands of this signaling pathway. Wnt signaling is one of the most important and intensively studied signaling pathways in the metazoan development. Several possible roles of endocytosis in Wnt signaling were uncovered in recent years, some of them unique among other signaling pathways. Understanding the relationship between endocytosis and Wnt signaling will thus help not only to deepen the knowledge of Wnt signaling but also to shed light on the possible roles of endocytosis in regulation of cell signaling in general.
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