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Influence of extracellular matrix environment on gene expression in liver myofibriloblasts
Jiroutová, Alena ; Kanta, Jiří (advisor) ; Ehrmann, Jiří (referee) ; Sedláček, Radislav (referee)
Influence of extracellular matrix environment on gene expression in liver myofibroblast (summary) Hepatic stellate cells (HSC) and liver myofibroblasts (MF) are two cell populations most likely responsible for the synthesis of majority of connective tissue components in fibrotic liver. They differ in their origin and location in the liver, and in the spectrum of genes they express. HSC are located in Disse spaces of normal rat liver around the sinusoids, in fibrotic liver they become activated, proliferate and they undergo transdifferentiation into myofibroblast-like cells. Myofibroblasts are heterogenous cell population that consists at least of portal pMF, septal sMF and interface iMF. pMF, which are adjacent to bile duct epithelia, may be a mediator of billiary type fibrosis. sMF are located within and along the collagenous septum in cirrhotic liver. Little is known about the expression of genes involved in connective tissue metabolism in MF cultured in fibrin or collagen gels that more closely resemble natural cell environment. Fibrin is deposited in liver at sites of injury and collagen type I forms a substantial part of fibrotic septa. In our study oligo cDNA array analysis was used to determine gene expression in quiescent HSC, activated HSC and MF isolated from both normal and CCl4-cirrhotic liver....
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Postranslation modifications affecting function of nuclear localization signal
Šebrle, Erik ; Sedláček, Radislav (advisor) ; Venit, Tomáš (referee)
Transport of proteins to the nucleus through a nuclear envelope is controlled mostly via nuclear localization signal (NLS). Nuclear localization signal is rich in positively charged amino acids arginine and lysine. It was observed that activity of this NLS could be regulated through a phosphorylation of serine in its close proximity. Either a phosphorylation of serine or phosphomimetic changes of these "presequences" could represent an important mechanism regulating a localization of protein in cells in relation to a cellular activation. In our laboratory was identified protein - Fragile X mental retardation syndrome 1 neighbor (Fmr1nb), whose cellular localization could be driven by this posttranslational modification.
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Generation and analysis of mutant mouse models to study pathophysiological roles of KLK5 and KLK7 in epidermis
Kašpárek, Petr ; Sedláček, Radislav (advisor) ; Stopka, Pavel (referee) ; Machoň, Ondřej (referee)
Kallikrein-related peptidases (KLKs) constitute a family of closely related serine proteases encoded by genes clustered in one chromosomal locus. KLKs are widely expressed in a variety of tissues and numerous in vitro experiments suggest their important roles in many physiological and pathological processes. However, the biological roles of KLKs in vivo are often obscured mainly due to unavailability of suitable animal models. Although gene deficient mouse models were generated for several KLK genes, they had limited use for understanding the roles of individual proteases in the complex environment in vivo. One of the main obstacles which hampers in vivo analysis is partial functional overlap between some KLKs. This makes traditional single-gene deficient animal models an inadequate tool to address the biological impact of the gene deficiency as compensatory mechanisms often result in a lack of phenotype. In this work, we used the transcription activator-like effector nuclease (TALEN) technology to generate several novel mutant mouse models to study the complex KLK proteolytic pathways and their roles in healthy organism and in disease. We prepared a novel mouse model for Netherton syndrome (NS), an autosomal recessive skin disorder caused by mutation in the gene SPINK5, which encodes the KLK-inhibitor...
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Generation of conditional animal mutants to study gene function in vivo
Herrmannová, Pavlína ; Sedláček, Radislav (advisor) ; Novák, Josef (referee)
Conditional gene targeting allows spatial and temporal control of genetic modifications and is used to study gene functions in specific tissues or cell types. Gene targeting may lead to inactivation of the gene by insertions or deletions. Conditional gene targeting uses various methods for generation of transgenic mutant animals, such as technology of targeted disruption of gene using embryonic stem cells, methodology based on bacterial artificial chromosomes, or a new revolutionary technology of targeted disruption of genes using programmable nucleases, which is rapidly evolving and seems to be more efficient and cheaper method for conditional gene targeting. The aim of this work is to overview methods and technologies for generation conditional animal models, and overview conditional recombination systems with emphasis on inducible systems, and also provides a summary of the main international resources for rodent mutagenesis. Key words: transgenic animal model, gene, targeting, conditional allele
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Function of Zinc finger protein 644 (Zfp644) in mouse organism.
Szczerkowska, Katarzyna Izabela ; Sedláček, Radislav (advisor) ; Komrsková, Kateřina (referee) ; Blahoš, Jaroslav (referee)
ZNF644 (Zinc Finger Protein 644) is a C2H2 zinc finger gene encoding a putative transcription regulator, of which a point mutation (S672G) is associated with inherited high myopia in humans. It is also described to be a partner of the G9a/GLP (G9a- euchromatic histone- lysine N-methyltransferase 2, EHMT2; GLP - euchromatic histone-lysine N-methyltransferase 1, EHMT1) complex, known for its essential role in histone methylation, specifically H3K9me1and H3K9me2. It was reported that another transcription factor, WIZ (Widely-Interspaced Zinc Finger-Containing Protein), can bind to this complex and cooperate in gene silencing simultaneously. In order to study Zfp644 impact on myopia, we generated a mouse model, Zfp644S673G that mimics human mutation. In addition, a mouse with a persuasive truncated form of the protein, Zfp644Δ8 was created. Both mouse models went through an examination of retinal function and morphology. Moreover, with use of ultrasonography, different ocular parameters were examined. We conclude, that Zfp644 gene is causative for myopia in mice. Further examinations of Zfp644Δ8 animals show severe symptoms in metabolism and female fertility. To describe the impact of Zfp644 in mouse fertility we performed various experiments including analysis of expression of Zfp644 in reproductive...
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2nd CCP Phenogenomics Conference 2020
Sedláček, Radislav
The conference was divided into two blocks. The block focused on the theme “From chemistry via preclinical pipeline to therapeutics“, which emphasized the translation of the basic research into the application. The second block was specifically devoted to presentation of CCP users and cooperation partners projects working in the field of immunology, hematology, genetic base of diseases, and neurobiology.
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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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Chemical signals and reproductive processes of the house mouse (Mus musculus)
Černá, Martina ; Stopka, Pavel (advisor) ; Petr, Jaroslav (referee) ; Sedláček, Radislav (referee)
The aim of my thesis was to identify proteins involved in chemical communication and especially those that are involved in sexual signalling. Volatile chemical signals are transported with lipocalins in their beta-barrel structure to present their ligands to receptors or out of the body. Thus, I focused on the identification of these proteins in saliva and vaginal secretion of the house mouse using proteomic and transcriptomic approaches. Due to a cyclic manner of reproduction and its hormonal control, I have also focused on the role of estradiol on sperm phenotype in the laboratory mouse. We have identified an elevated sexual dimorphism in several lipocalins (i.e. 10 out of 20) in the saliva proteome where they may play a role in sexual signalling (i.e. similar to their described roles in the mouse urine). Interestingly, vaginal secretion also contains lipocalins and they rise from proestrus to estrus and remain steady during metestrus. Such variation provides evidence that they serve sexual signalling, however, due to their elevated levels during metestrus it is most likely that their ligands function as signals and not the proteins themselves. On the level of sperm phenotype, we have provided evidence, that experimental concentrations of estradiol have differential effects on sperm. This is due...
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Expression of ubiquitin ligases in gastrointestinal tract
Pícková, Markéta ; Sedláček, Radislav (advisor) ; Čermák, Lukáš (referee)
Ubiquitin (Ub) ligases are important regulatory and signalling molecules, which are involved in majority of cellular processes such as differentiation, DNA repair, and regulation of energetic metabolism or immune response. E3 Ubiquitin ligases are also responsible for pathophysiological changes in the organism and their activity is associated with many human diseases including cancers. This makes E3 Ubiquitin ligases to be new diagnostic markers and interesting pharmaceutical targets. Based on previous studies, these enzymes evince very specific expression in the level of tissues or cell populations. Determination of this specific expression is important for a better understanding of their biological function. In this diploma thesis we systematically screened presence of 370 genes of E3-Ub ligases in gastrointestinal tract under physiological conditions and during acute inflammatory damage of distal colon. Obtained data allowed us to select genes, which can play important role in homeostasis as well as pathophysiology and regeneration of gastrointestinal tract. The screening was based on the expression profiling using qPCR, followed by in situ hybridization to determine the exact localization of the gene expression within tissues. From qPCR analysis was predicted hundred thirty seven candidates for...
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