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Molecular mechanisms of interactions- interactions of constitutive androstane receptor with selected stilbene compounds
Linhartová, Lenka ; Pávek, Petr (advisor) ; Hyršová, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lenka Linhartová Supervisor: Prof. PharmDr. Petr Pávek, Ph.D. Title of diploma thesis: Molecular mechanisms of intractions - interactions of constitutive androstane receptor with selected stilbene compounds Constitutive androstane receptor (CAR), member of nuclear receptors family, is a major regulator of gene expression of phase I and II enzymes metabolizing endobiotics and xenobiotics. Changes in its activity can lead to pharmacokinetic drug interactions, ineffective treatment or higher toxicity of drugs simultaneously administered with CAR ligands. Recently another effects of this receptor, especially in homeostasis of bile acids, lipids and glucose have been discovered and CAR is now considered as a potential drug target for the treatment of metabolic diseases. Stilbenes represent a small group of plant polyphenols with typical 1,2-diphenylethylene nucleus. The most famous member is resveratrol, which has attracted great attention thanks to its antioxidant, anti-inflammatory, antiproliferative and cardioprotective effects. Others stilbene compounds such as pterostilben, piceatannol or pinosylvin have shown similar health beneficial effects as well. The aim of this diploma thesis was...
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Inhibitory effect of SPA70 on hPXR activation
Dohnalová, Klára ; Pávek, Petr (advisor) ; Červený, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Klára Dohnalová Supervisor: prof. PharmDr. Petr Pávek, Ph.D. Title of diploma thesis: Inhibitory effect of SPA70 on hPXR activation This work focuses on pregnane X receptor (PXR) and its antagonists. PXR is a ligand-activated nuclear receptor that plays a major role in detoxification of xenobiotics and protecting the organism from their toxic effects. Recent evidence also shows endogenous action of PXR in the metabolism of lipids, glucose and bile acids. However, PXR activation could be harmful, since induction of biotransformation enzymes by PXR agonists may result in reduced treatment efficacy, increased toxicity of drug metabolites and resistance to chemotherapeutic agents. Recent research has been intensively focused on PXR antagonists capable of abolishing these unfavourable effects. Recently discovered human PXR antagonist SPA70 has a promising potential for future usage. In this study, we investigated the inhibitory effect of SPA70 on activated PXR. To activate PXR we used agonists binding directly to PXR (rifampicin, hyperforin, SR12813) and also agonists activating PXR indirectly via cell signalling pathways (U0126, PD184352, PD0325901). Experiments were performed using luciferase...
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Chromatin immunoprecipitation of selected transcription factors
Smetanová, Jitka ; Vališ, Karel (advisor) ; Převorovský, Martin (referee)
The TEAD family of transcription factors regulates expression of genes affecting cell proliferation, differentiation and apoptosis. The activity of a particular transcription factor called TEAD1 is regulated by the Hippo signalling pathway. The Hippo pathway has been implicated to play a role in cancer suppression, however its precise mechanism remains unclear. MYC and GLUT1, genes which are coding two key regulators of glycolysis, were recently described as potential targets of the Hippo signalling pathway in human leukemia cells. In this diploma thesis, I tried to confirm the proposed interaction of the transcription factor TEAD1 with regulatory sequences of MYC and GLUT1 genes using chromatin immunoprecipitation (ChIP) analysis in human leukemic cells. However, I failed to successfully isolate TEAD1 complexes using ChIP. So, I discuss in my diploma thesis also possible reasons for this outcome, including biological and methodological issues. (In Czech) Key words: Transcriptional regulation, TEAD transcription factors, chromatin immunoprecipitation, leukemia
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Chromatin immunoprecipitation of selected transcription factors
Smetanová, Jitka ; Vališ, Karel (advisor) ; Převorovský, Martin (referee)
The family of transcription factors TEAD regulates the expression of genes that affect cell proliferation, differentiation and apoptosis. Activity of TEAD1 is regulated via the Hippo signaling pathway. General mechanism of tumor cell suppression by the Hippo signaling pathway remains unclear. C-MYC and GLUT1, the two key regulators of glycolysis, were recently described as targets of the Hippo signaling pathway in human leukemia cells. In this diploma thesis, the interaction of TEAD1 with M-CAT binding motifs was experimentally confirmed in the first exon of C-MYC gene. In addition, a new interaction of TEAD1 with M-CAT binding motifs has been found in the enhancer of C-MYC promoter and enhancer of GLUT1 promoter by ChIP analysis. Regulation of glucose metabolism by the Hippo signaling pathway may represent a new mechanism of tumor cell suppression. Key words: Gene regulation, transcription factors, chromatin immunoprecipitation, bioinformatics
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