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Regulation of alternative splicing
Dušková, Eva ; Staněk, David (advisor) ; Trejbalová, Kateřina (referee)
Alternative splicing is an important cellular mechanism. It allows to produce multiple protein isoforms from a limited number of genes. Regulation of alternative splicing involves cis-acting elements on pre-mRNA and trans-acting splicing factors (SR and hnRNP proteins). Because splicing occurs co-transcriptionaly, chromatin structure appears to have a role in the regulation of alternative splicing. We have studied the effect of histone acetylation on alternative splicing. We have prepared splicing reporter for alternative EDB exon, which is part of the fibronectin gene. We have shown, that the inhibition of histone deacetylases affects splicing pattern of EDB exon from the reporter in the same way as the splicing of the endogenous EDB exon. Furthermore, we have shown, that the structure of the promoter affects splicing of alternative EDB exon from splicing reporter. Currently we have found out, that the structure of the promoter influences the degree of histone H4 acetylation. Inclusion of alternative EDB exon in mRNA was inversely proportional to histon acetylation on the reporter. This work might explain why various promoters have different splicing patterns of alternative exons.
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Alterations of the oncogenic properties of tumor cell lines by modulating oncogene expression. Example of v-src transformed chicken cell lines
Kovářová, Denisa ; Hejnar, Jiří (advisor) ; Španielová, Hana (referee)
4 Alterations of the oncogenic properties of tumor cell lines by modulating oncogene expression. Example of v-src transformed chicken cell lines Abstract v-Src protein tyrosine kinase is the product of the transforming gene transduced by avian Rous sarcoma virus. In contrast to proto-oncogene c-src, v-src lacks the negative-regulatory C-terminal domain and consequently shows a higher level of activity and transforming ability. In addition, v-Src contains point mutations throughout its coding region that probably contribute to the high level of intrinsic kinase activity. Long terminal repeats (LTR) comprise strong promoter-enhancer sequences and ensure efficient expression of the v-src gene. v-Src protein has a strong transforming potential in vitro and induces tumor development and growth in vivo. Moreover, it is implicated in metastatic formation. In several cancer types the elevated c-Src kinase activity caused pleiotropic cellular responses inducing transformation and metastasis. The aim of this diploma work was to reveal the role of v-Src in mediating tumor and metastatic progression in chicken cell lines PR9692 and PR9692-E9. Despite the low propensity of the chicken cells to immortalization, comparatively high immoratlization efficiency was observed in cells from ex vivo tumours growing progressively...
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Two essays on the modeling of monetary policy transmission mechanism
Rusnák, Marek ; Svoboda, Svatopluk (referee) ; Horváth, Roman (advisor)
In first essay, we investigate the evolution of monetary policy transmission mechanism in the Czech Republic over 1993:1 - 2009:9 period by employing time varying parameters Bayesian vector autoregression model with stochastic volatility. We document relative stability of monetary policy transmission mechanism over time. However, there is some evidence that the transmission to prices was weakened temporarily during the climax of the financial crisis, but appear to be back to its pre-crisis strength already in the second half of 2009. Further, we augment the estimated system with a financial variable to investigate the significance of financial shocks for the transmission. The results suggest that financial shocks indeed play relatively important role in explaining the fluctuations of the output and prices. Second essay presents a meta-analysis of the effects of a monetary policy shock on prices. First, we present some summary statistics that document the pervasiveness of the price puzzle, which denotes an increase in the price level following a contractionary monetary policy shock, in the results of empirical studies. Next, using meta-regression methods such as funnel asymmetry test, we find the evidence of publication selection bias that increases with the horizon studied. Finally, we use explanatory...
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Simulation of long heat pipeline operation control
Seriš, Richard ; Nykodým, Libor (referee) ; Němec, Zdeněk (advisor)
The objective of this diploma thesis is to design a model of long heat pipeline operation control using Matlab software. The model should simply correspond to real heat pipeline system Melnik – Praha. After this, simulate operation control of sets of pumps. The role is to simulate usual and critical modes of operations. After evaluation of results, optimize the conditions for operation control of this system.
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Epididymal maturation – a crucial step in the post-testicular sperm development
Postlerová, Pavla ; Pohlová, Alžběta ; Zigo, Michal ; Jonáková, Věra
Mammalian spermatozoa after their development in testis undergo the post-testicular maturation in epididymis where acquire their fertilization ability and competence of movement. The epididymis is tissue with very active fluid-absorbing and fluid-secreting activity. Epididymal fluid contains ions and small molecules, proteins, glycoproteins and enzymes. The surface of spermatozoa is exposed directly to the epididymal fluid, and the sperm plasma membrane is significantly changed. Some testicular proteins are altered, masked, or replaced by new proteins/glycoproteins of epididymal origin. Several proteins produced by epididymis have been described in various mammalian species and shown to be associated with spermatozoa suggesting a role in the sperm maturation and/or sperm-egg binding and fusion. We isolated proteins from fluid, tissue and sperm of boar epididymis, and separated them by chromatographic and electrophoretic methods. We searched for known proteins using panel of antibodies and tested proteins of epididymal fluid for binding abilities. In the epididymis, we found proteins described as proteins of seminal plasma and associated with the sperm surface, such as spermadhesins, beta-microseminoprotein and acrosin inhibitor. These proteins were detected in epididymal sperm, fluid and tissue. We showed that some epididymal proteins may bind the spermatozoa and change the binding sites on the sperm surface. We determined and identified some proteins from boar epididymal fluid with affinity to heparin, hyaluronan and zona pellucida glycoproteins. These phenomena indicate that epididymal fluid proteins bind to the sperm surface during epididymal maturation and might subsequently play role in the sperm capacitation or sperm-zona pellucida binding.
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Signalling of protein kinase B and expression of cyclooxygenase in early phases of diabetic nephropathy
Ždychová, Jana ; Komers, Radko (advisor) ; Haluzík, Martin (referee) ; Matoušovic, Karel (referee) ; Škrha, Jan (referee)
Introduction: Renal hypertrophy, extracellular matrix accumulation, aItered apoptosis as well as changes in regional hemodynamics have been implicated in the pathophysiology of nephropathy in diabetes mellitus (DM). On the molecular level the detailed mechanisms for development of diabetic nephropathy (DN) have becn intensively studied. Insulin induces a variety of biologicaI effects in a number of cell types via phosphatidylinositol-3 kinase (PI3K)/Akt kinase signaling pathway. Considering multiple function of Akt that incIude potentiaIly hannful pro-growth effects mediated by mTOR and cyclooxygenas-2 (COX-2), as well as protective effects mediated by endotheliaI nitric oxide synthase (eNOS), it is possible that aIterations in activities of Akt may play role in the pathophysiology ofDN. Renal corticaI activity and expression of Akt, its down-strearn effectors mTOR, eNOS, and "C<JIX-:Z. as well as PTEN, an endogenous Akt inhibitor, were investigated in streptozotocin (STZ): diabetic rats as a model of Type 1 DM with different levels of glycenůc control, and in Zucker ~d.iabetic fatty rats, a model ofDM2, and in nondiabetic rats as controls. Methods: Akt activity was measured by kinase assay. Protein expressions were measured by .immunoblotting and immunohistochemistry in renal cortex of 4- and 12- week old...
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