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Structure and function relationships of model hemoproteins
Lengálová, Alžběta ; Martínková, Markéta (advisor) ; Hudeček, Jiří (referee) ; Muchová, Lucie (referee)
Heme is one of the most important and most studied cofactors that are essential for proper function of many proteins. Heme-containing proteins comprise of a large group of biologically important molecules that are involved in many physiological processes. The presented dissertation is focused on two groups of heme sensor proteins, namely prokaryotic heme-based gas sensors and eukaryotic heme-responsive sensors. Heme-based gas sensors play an important role in regulation of many bacterial processes and consist usually of two domains, a sensor domain and a functional domain. The dissertation thesis aims at the study of two model bacterial heme-based gas sensors, histidine kinase AfGcHK and diguanylate cyclase YddV, in order to elucidate their mechanism of interdomain signal transduction. Using X-ray crystallography and hydrogen-deuterium exchange coupled to mass spectrometry approaches, significant differences in the structure of the AfGcHK protein between the active and inactive forms were described. The signal detection by the AfGcHK sensor domain affects the structural properties of the protein, and these conformational changes then have indirect impact on the enzyme activity of the functional domain. Further, the dissertation pays more attention to the effect of a sensor domain dimerization...
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Dynamics of Changes in Bile Acid Metabolomics in Estrogen-Induced Cholestasis
Alaei Faradonbeh, Fatemeh ; Mičuda, Stanislav (advisor) ; Večeřa, Rostislav (referee) ; Muchová, Lucie (referee)
Dynamics of changes in bile acid metabolomics in estrogen-induced cholestasis Bile acids are essential endobiotics with numerous exocrine and endocrine functions. In this dissertation, we evaluate three factors that were suspected of modifying bile acid metabolomics: i) the effect of metformin in estrogen-induced cholestasis, ii) the role of MRP2 (multidrug resistance-associated protein 2) protein in the described risk of more frequent intrahepatic cholestasis in pregnancy, and iii) the excessive iron accumulation in the liver. Metformin has been tested for its potential use in women with gestational diabetes mellitus (GDM) who have a higher incidence of intrahepatic cholestasis (ICP). As an ICP model, we used experimental cholestasis induced in mice by administration of ethinylestradiol. Administration of metformin in this situation significantly increased bile acid concentrations in the systemic circulation, which reached values considered significantly toxic in pregnant women. These data suggest that the possibility of developing ICP is accentuated when metformin is used in pregnant women. In another study, we demonstrated that the MRP2 transporter plays a significant role in biliary bile acid elimination and that the genetic defect itself caused an increase in the plasma concentrations in rats....
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Using the Elements of Music Therapy in the Educational Process
Muchová, Lucie ; Mašát, Vladimír (advisor) ; Šafránková, Pavla (referee)
This work is focused on the possibility of incorporating practical elements of music therapy into education and is divided into both theoretical and practical sections. In the theoretical section, I will introduce the topics of music and music therapy in general. First, I will summarize for readers the history of music therapy progression, starting with its inception and leading up to its possible application to education in the present. Furthermore, I will discuss the ways in which music therapy can help address several issues in education; namely, the specific elements of music therapy that can be used within the classroom and for which purposes. At the end of the theoretical section, I will compare the personalities of the music therapist and the educationalist. In the practical section, I will introduce several particular activities related to music therapy, which are divided into three categories: 1. Society, conflict, prevention 2. Developing empathy, self-knowledge, getting to know others 3. Concentration x relaxation The last section is dedicated to my visit at Libčická elementary school, where I had the chance to try these activities in practice. Powered by TCPDF (www.tcpdf.org)
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Metabolism of estrogene in UGT1A1-deficient rats
Módos, Anna ; Muchová, Lucie (advisor) ; Brůha, Radan (referee)
Introduction Estrogen-induced cholestasis is a disease characterized by a failure of bile flow and bile production. It can develop in women after oral contraceptives use, hormone replacement therapy or during pregnancy. The estrogen metabolism is a complex process leading to formation of metabolites with different biological activities. It takes place primarily in the liver (Phase I and Phase II including hydroxylation, methylation, sulfation and glucuronidation). The enzymes from UDP-glucuronosyltransferases family , abbreviated UGT, are responsible for the glucuronidation of estrogens. Aims The objective of my work is to define estrogen metabolism and gene expression of UGT1A1, CYP1A2 and SULT1A1 and characterize cholestatic liver damage in the UGT1A1 deficient rat strain (Gunn rats) compared to rats with normal enzyme activity and try to define possible mechanisms responsible for the liver damage. Methods Adult female Gunn and corresponding heterozygous rats were treated with ethinylestradiol (EE, 5 mg/kg body weight SC) for 5 days, while control rats received propanediol (vehicle). Day six, the animals were sacrificed and plasma and liver tissue were collected for analysis. Markers of cholestasis and liver damage ALP, AST, ALT and bilirubin were determined using an automatic analyzer, total...
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Changes in the composition and localization of gangliosides in cholestasis associated with other markers of pathological processes in hepatocytes.
Petr, Tomáš ; Muchová, Lucie (advisor) ; Mičuda, Stanislav (referee) ; Befekadu, Asfaw (referee)
This thesis is focused on the study of glycosphingolipids in the rat liver in different types of cholestasis and the effect of oxidative stress on changes in the composition and localization of gangliosides. First, it was necessary to optimize the immunochemical detection of glycosphingolipids. GM1 ganglioside was selected as a representative of a large glycolipid family. We found that minimum water content in the fixing solution was a key condition for fixation of histological sections. Optimized method of GM1 detection was subsequently used in in vivo experiments. We have demonstrated that estrogen-induced cholestasis characterized by high concentrations of bile acids and increased oxidative stress caused changes in the synthesis and distribution of liver gangliosides. HMOX induction is associated with a reduction in oxidative stress level and accompanied by normalization in GSL content. In experiments with obstructive cholestasis, we found that changes in the distribution and synthesis of gangliosides were not strictly specific to a particular type of cholestasis. We assume that it represents a general mechanism of hepatoprotection. We also confirmed the important role of bilirubin, product of HMOX reaction, in protection of hepatocytes against oxidative damage caused by high concentrations of...
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Heme catabolic pathway in pathogenesis of liver diseases
Váňová, Kateřina ; Muchová, Lucie (advisor) ; Brůha, Radan (referee) ; Neužil, Jiří (referee)
This thesis focuses on the role of heme catabolic pathway in the pathogenesis of selected liver diseases. The aim was to clarify if the modulation of heme oxygenase (Hmox) and its catabolic products - especially carbon monoxide (CO) and bilirubin - affected the development and progression of liver diseases, focusing on inflammatory and cholestatic pathways. Firstly, we discovered that the induction of hmox1 prevented hepatocellular damage in endotoxin-induced inflammation. Furthermore, administration of CO in vivo in early-phase of endotoxin-induced cholestasis decreased the inflammatory cytokine production in the liver and simultaneously prevented downregulatory effect of cytokines on hepatocyte transporters resulting in hepatoprotection. For the first time, we characterized in vivo tissue distribution and elimination of inhaled CO in rats. In vitro experiments and the model of extrahepatic cholestasis revealed the significant role of intracellular bilirubin in hepatocellular protection against oxidative damage which accompanies cholestatic disorders. Last but not least, hmox1 induction by heme increased hepatocyte transporters expression and subsequently stimulated bile flow participating in conferring protection against estrogen-induced cholestasis. Presented results demonstrate that the heme...
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Structure and function relationships of model hemoproteins
Lengálová, Alžběta ; Martínková, Markéta (advisor) ; Hudeček, Jiří (referee) ; Muchová, Lucie (referee)
Heme is one of the most important and most studied cofactors that are essential for proper function of many proteins. Heme-containing proteins comprise of a large group of biologically important molecules that are involved in many physiological processes. The presented dissertation is focused on two groups of heme sensor proteins, namely prokaryotic heme-based gas sensors and eukaryotic heme-responsive sensors. Heme-based gas sensors play an important role in regulation of many bacterial processes and consist usually of two domains, a sensor domain and a functional domain. The dissertation thesis aims at the study of two model bacterial heme-based gas sensors, histidine kinase AfGcHK and diguanylate cyclase YddV, in order to elucidate their mechanism of interdomain signal transduction. Using X-ray crystallography and hydrogen-deuterium exchange coupled to mass spectrometry approaches, significant differences in the structure of the AfGcHK protein between the active and inactive forms were described. The signal detection by the AfGcHK sensor domain affects the structural properties of the protein, and these conformational changes then have indirect impact on the enzyme activity of the functional domain. Further, the dissertation pays more attention to the effect of a sensor domain dimerization...
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The role of ADAM17 and other metalloproteases in liver pathological processes
Žbodáková, Oľga ; Sedláček, Radislav (advisor) ; Muchová, Lucie (referee) ; Stříšovský, Kvido (referee)
1 Abstract Liver fibrosis is a condition described by extensive accumulation of scar tissue in the liver. With further progression, it leads to cirrhosis or even to hepatocellular carcinoma. Liver fibrosis accompanies every chronic liver disease and its prevalence in adult European population is estimated to be around 4%. During my dissertation work, I studied the function of three members of Metzincin family of metalloproteinases - ADAM17, ADAM10 and MMP-19, in liver fibrosis and liver regeneration using mouse genetic models. ADAM17 and ADAM10 are important regulators of signalling pathways which are involved in immune response as well as differentiation. Both proteases are able to cleave ectodomains of their substrates from cell membrane, affecting bioavailability of ligands and functionality of receptors. Several of their substrates are involved in liver pathologies. MMP-19 on the other hand, is a metalloprotease mainly involved in extracellular matrix cleavage, important process in fibrosis development, as well as resolution of fibrosis. Our results demonstrate that ablation of ADAM10 results in increased susceptibility to liver fibrosis in mice, both spontaneous and toxin induced. ADAM10 deficiency affected biliary epithelium, as we detected higher markers of biliary damage in serum of ADAM10 deficient...
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Antioxidant and antiinflammatory effects of bilirubin.
Valášková, Petra ; Muchová, Lucie (advisor) ; Martínková, Markéta (referee) ; Dvořák, Karel (referee)
For a long time, bilirubin (BR) has been considered a waste molecule with potential toxic effects especially on the central nervous system. Later, it was found that BR exhibited cytoprotective effects and mildly elevated BR levels showed antioxidant, anti-inflammatory and immunomodulatory properties, however, exact mechanisms of the anti-inflammatory actions of BR have not been fully understood yet. The main aim of this study was to assess the protective effects of BR using experimental in vivo and in vitro models in relation to inflammation and oxidative stress. Partial goal was to establish validated analytical method for determination of BR and lumirubin. Gunn and heterozygous rats were treated with lipopolysaccharide (LPS, 6 mg/kg, IP) or vehicle (saline). After 12 hours, blood and organs were collected for analyses of inflammatory and hepatic injury markers. Primary rat hepatocytes were treated with BR and TNF-α, HepG2 and SH-SY5Y cell lines were treated with BR and chenodeoxycholic acid. LPS-treated Gunn rats had a significantly decreased inflammatory response and hepatic injury compared to LPS- treated normobilirubinemic controls. We found different profile of leukocytes subsets and decreased systemic mRNA expressions and concentrations of IL-6, TNF-α, IL-1β and IL-10 in Gunn rats. Hepatic mRNA...
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Induction of heme oxygenase and biological role of its metabolic products.
Šuk, Jakub ; Muchová, Lucie (advisor) ; Jirsa, Milan (referee) ; Neužil, Jiří (referee)
Heme oxygenase (HMOX) catalyzes first and rate-limiting step in heme degradation. By its action, carbon monoxide (CO), ferrous iron and biliverdin which is subsequently reduced to bilirubin are produced. Before discovery of HMOX reaction mechanism, CO was considered only a toxic waste product without any significant importance for human organism. Bilirubin, marker of liver dysfunction, has been also exposed to similar perception. But results from past decades show that HMOX and its metabolic products play an important role in number of physiological as well as defense against pathophysiological processes. The aim of this thesis was to clarify the role of HMOX and its metabolic products, presumably CO and bilirubin, in vivo and in vitro. We focused on the role of CO in a rat model of lipopolysaccharide-induced cholestasis. We were first to describe tissue distribution and pharmacokinetics of inhaled CO in this animal model and found out that CO inhalation is associated with anti-inflammatory and hepatoprotective effects. In a rat model of ethinylestradiol-induced cholestasis, we demonstrated the anticholestatic effect of HMOX. The induction of HMOX by its substrate heme increased the expression of liver transporters thereby increasing bile flow and simultaneously facilitated effective clearance of...
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