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Coherence-controlled holographic microscope in cell's life cycle research
Bartoníček, Jan ; Chmelík, Radim (referee) ; Uhlířová, Hana (advisor)
The subject of the bachelor thesis is live-cell imaging in a transmitted-light holographic microscope which was designed at the Institute of Physical Engineering BUT and comparing this imaging method with the phase-contrast microscopy. The first part is dedicated to a basic description of used imaging techniques and a cell biology. A description of an experiment preparation follows. In the part dedicated to a data analysis the method of dynamic phase differences is described and the method of growth monitoring is proposed. Both methods were used for the analysis of experiments which are described in the last part of this work. Experiments were focused on acquiring time-lapse data of a cell’s cycle and particularly the mitosis.
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Metabolism of the mitotic inhibitor BTB-1 by first phase biotransformation enzymes
Vančurová, Kateřina ; Indra, Radek (advisor) ; Martináková, Lenka (referee)
Cancer is still one of the most common deaths in the world and therefore new drugs are needed to be developed to stop or slow down this disease. Recently, there has been a huge expansion in drug development. Cytostatics that are still widely used include a group of mitotic inhibitors aimed at inhibiting mitosis. A representative of a mitotic inhibitor is the small newly discovered molecule BTB-1. This molecule mediates reversible inhibition of the molecular motor Kif18A, which plays an important role in cell division. In the first part of this presented bachelor thesis, a suitable method for the determination of BTB-1 using high performance liquid chromatography was developed and subsequently its sensitivity was verified. Furthermore, a suitable extracting reagent was found. In the second part of the bachelor thesis, the metabolism of BTB-1 was studied by the microsomal system of non-premedicated rats and rats premedicated with various cytochrome P450 inducers. Subsequently, the time dependence of BTB-1 conversion was studied by the microsomal system of premedicated rats. The effect of different concentrations of BTB-1 on its metabolism was also studied using the microsomal system of premedicated rats. Furthermore, the metabolism of this new molecule was studied using cytosolar systems isolated...
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Role of RecQ helicases in maintenance of genomic stability during mitosis
Černoch, Marek ; Janščák, Pavel (advisor) ; Půta, František (referee)
Helicases are proteins capable of unwinding nucleic acids, their malfunction can be dangerous for genome stability of the cell. Five RecQ-family helicases identified in human cells participate in many cellular events during the whole cell cycle, including mitosis, and therefore are very important for correct functioning. The mutations in RecQ helicases can cause them to malfunction and seriously damage various cell processes, for example DNA replication, DNA damage control or sister chromatids separation. The mutations can also lead to dangerous syndromes, with the hallmark symptom of increased risk of cancer.
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Investigating the role of zinc transporter ZIP 6 and STAT3 in mitosis
Burgetová, Lenka ; Čečková, Martina (advisor) ; Štaud, František (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lenka Burgetová Supervisor: PharmDr. Martina Čečková PhD. Specialized supervisor: Dr. Kathryn Taylor PhD. Title of diploma thesis: Investigating the role of zinc transporter ZIP 6 and STAT3 in mitosis It has been shown that STAT3 (signal transducer and activator of transcription 3) plays a role in the development of cancer. ZIP6 is the downstream target of this transcription factor. Previous research has focused mainly on the activation of STAT3 by tyrosine phosphorylation, while the effect of phosphorylation at a second site, serine 727, remained relatively uninvestigated. In this study, it is proposed that serine-phosphorylated STAT3 is activated throughout mitosis in tamoxifen-resistant (TamR) breast cancer cells and that zinc transporter ZIP6 and serine-phosphorylated STAT3 are involved in a zinc-mediated mitotic mechanism. After using nocodazole to induce mitotic arrest, the expression of tyrosine- phosphorylated STAT3 protein was observed to be reduced while the expression of serine- phosphorylated STAT3 was increased. Zinc supplementation after nocodazole treatment appeared to push cells through mitotic-arrest and cause proteolytic cleavage of STAT3 suggesting a novel...
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Regulation of mTOR pathway in the oocyte meiosis
Schmidtová, Barbara ; Šušor, Andrej (advisor) ; Krylov, Vladimír (referee)
Mammalian Target of Rapamycin (mTOR) is serin-threonin kinase, which has become a major topic in many studies in the last decade, leading to new insights into how cell works. This kinase is involved in proteosynthesis, metabolism, cell cycle regulation, proliferation and responses to nutrients and growth factors. There are certain diseases caused by mutations in mTOR gene, which lead to abnormal function of this kinase. These diseases include cancer or fertility disorders. mTOR research is also beneficial due to the search for drugs that could rescue its function and thus provide treatment for these diseases. The best-known drug is inhibitor Rapamycin and its derivates. The aim of this bachelor thesis is to summarize the knowledge about how mTOR can be regulated, the role of its substrates in cell function and to define the role of mTOR in oocyte development, translation and human health. Keywords: Oocyte, mTOR, translation, 4E-BP1, MPF, meiosis, AKT
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Storage cells and their role in tardigrade physiology.
Czerneková, Michaela ; Svoboda, Petr (advisor) ; Delagoutte, Emmanuelle (referee) ; Weyda, František (referee)
STORAGE CELLS AND THEIR ROLE IN TARDIGRADE PHYSIOLOGY Abstract Tardigrades possess remarkable tolerance to numerous stress conditions (e.g. almost complete desiccation, exposure to very low sub-zero temperature, heat stress and even exposure to space in low Earth orbit). Indeed, they are among the most radiation-resistant multi-cellular organisms. The body cavity of tardigrades is filled with the storage cells (SC). Their role in anhydrobiosis has been discussed. The main objectives of this work were to analyse (i) the occurrence of mitosis in SC, (ii) the factors constraining anhydrobiotic survival, and (iii) the general ultrastructure of SC and their ultrastructure concerning the stress conditions. Our model species, R. cf. coronifer is one of the most extensively studied tardigrades concerning anhydrobiosis. Comprehensive histochemical techniques were used in combination with SEM, TEM, and confocal microscopy. First, mitotic divisions of tardigrade SC occur with a higher frequency in juveniles than in adults and correlate with animal growth. Mitosis is more frequent in moulting tardigrades, but the overall mitotic index is low. Furthermore, tardigrades of R. cf. coronifer can survive the maximum of 6 repeated desiccation cycles with significantly declining survival rate with repeated desiccations and...
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Gene regulation in four dimensions
Vaňková Hausnerová, Viola ; Lanctôt, Christian (advisor) ; Převorovský, Martin (referee) ; Krásný, Libor (referee)
Transcription has turned out to be a discontinuous process when imaged at a single cell level. This observation is referred to as transcriptional bursting or pulsing and has been detected in a variety of organisms ranging from bacteria to mammalian cells. The dynamics of transcriptional pulsing are influenced by the properties intrinsic to the transcriptional process, as well as by upstream factors: chromatin environment, signalling molecules, cell cycle stage etc. In the first part of this thesis, we focused on the regulation of transcriptional pulsing in the nucleolus. Using imaging of living cells, we detected pulsatile transcription of a transgene with nucleolar localization whose expression was mediated by RNA polymerase II. In the second part of the thesis, we investigated the relationship between chromatin decondensation and transcriptional dynamics. We used hyperosmotic medium to induce global condensation of chromatin and revealed that upon chromatin decondensation, a transient spike in transcriptional intensity occurs in induvial living cells. Next, we analysed expression of TFRC and POLR2A genes in several cell cycle stages using single molecule RNA FISH. We detected increase in both frequency and size of transcriptional pulses during a limited time window which coincided with chromatin...
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Investigating the role of zinc transporter ZIP 6 and STAT3 in mitosis
Burgetová, Lenka ; Čečková, Martina (advisor) ; Štaud, František (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lenka Burgetová Supervisor: PharmDr. Martina Čečková PhD. Specialized supervisor: Dr. Kathryn Taylor PhD. Title of diploma thesis: Investigating the role of zinc transporter ZIP 6 and STAT3 in mitosis It has been shown that STAT3 (signal transducer and activator of transcription 3) plays a role in the development of cancer. ZIP6 is the downstream target of this transcription factor. Previous research has focused mainly on the activation of STAT3 by tyrosine phosphorylation, while the effect of phosphorylation at a second site, serine 727, remained relatively uninvestigated. In this study, it is proposed that serine-phosphorylated STAT3 is activated throughout mitosis in tamoxifen-resistant (TamR) breast cancer cells and that zinc transporter ZIP6 and serine-phosphorylated STAT3 are involved in a zinc-mediated mitotic mechanism. After using nocodazole to induce mitotic arrest, the expression of tyrosine- phosphorylated STAT3 protein was observed to be reduced while the expression of serine- phosphorylated STAT3 was increased. Zinc supplementation after nocodazole treatment appeared to push cells through mitotic-arrest and cause proteolytic cleavage of STAT3 suggesting a novel...
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Role of RecQ helicases in maintenance of genomic stability during mitosis
Černoch, Marek ; Janščák, Pavel (advisor) ; Půta, František (referee)
Helicases are proteins capable of unwinding nucleic acids, their malfunction can be dangerous for genome stability of the cell. Five RecQ-family helicases identified in human cells participate in many cellular events during the whole cell cycle, including mitosis, and therefore are very important for correct functioning. The mutations in RecQ helicases can cause them to malfunction and seriously damage various cell processes, for example DNA replication, DNA damage control or sister chromatids separation. The mutations can also lead to dangerous syndromes, with the hallmark symptom of increased risk of cancer.
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Coherence-controlled holographic microscope in cell's life cycle research
Bartoníček, Jan ; Chmelík, Radim (referee) ; Uhlířová, Hana (advisor)
The subject of the bachelor thesis is live-cell imaging in a transmitted-light holographic microscope which was designed at the Institute of Physical Engineering BUT and comparing this imaging method with the phase-contrast microscopy. The first part is dedicated to a basic description of used imaging techniques and a cell biology. A description of an experiment preparation follows. In the part dedicated to a data analysis the method of dynamic phase differences is described and the method of growth monitoring is proposed. Both methods were used for the analysis of experiments which are described in the last part of this work. Experiments were focused on acquiring time-lapse data of a cell’s cycle and particularly the mitosis.
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