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Multiple forms of dipeptidyl peptidase IV and fibroblast activation protein in brain tumors
Matrasová, Ivana ; Šedo, Aleksi (advisor) ; Kupcová Skalníková, Helena (referee) ; Modrianský, Martin (referee)
Proteolytic enzymes are known to contribute to the initiation, development and progression of a number of diseases. Dipeptidyl peptidase IV (DPP-IV) and fibroblast activation protein (FAP) are serine proteases with the unique ability to cleave dipeptides containing - highly evolutionarily conserved - proline at the penultimate position of the N- terminus of substrates/biologically active peptides. FAP also exhibits gelatinolytic activity, which it exerts during extracellular matrix remodeling processes. Glial brain tumors (gliomas) arise from resident transformed glial cells, whereas brain metastases originate from circulating transformed extracranial tumor cells. Our previous work has described an increased expression of DPP-IV and FAP in high-grade glioma tissues. The presence of DPP- IV and FAP in brain metastatic tissues has not been described to date. The aim of this thesis was to describe the multiple forms of DPP-IV and FAP, and to describe their cellular origin and possible regulation in brain tumors. DPP-IV and its molecular MW and pI forms were expressed predominantly by transformed glial cells, whereas FAP and its MW and pI forms were expressed by transformed and stromal cells present in GBM and brain metastatic tissues. The spectrum of multiple forms of DPP-IV and FAP in GBM tissues and...
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Quantitative aspects of mitochondrial genome in cancer and diabetes
Alán, Lukáš ; Ježek, Petr (advisor) ; Teisinger, Jan (referee) ; Modrianský, Martin (referee)
Mitochondria are cellular powerhouses and physiological regulators with many features resembling their prokaryotic ancestors. They maintain their own mitochondrial DNA (mtDNA) encoding 13 inner mitochondrial membrane proteins of oxidative phosphorylation machinery, 22 transfer RNAs and two ribosomal RNAs. Healthy mitochondria in normal cells form a dynamic network consisting of highly interconnected tubules. The mitochondrial disorders are very heterogeneous and difficult to diagnose and cure. It is due to combining products of two genomes, the complexity of mitochondrial structure and due to insufficiency of current state of knowledge. To understand the mitochondrial nucleic acid species distribution, we have developed and established new techniques to visualize mitochondrial network, nucleoids and different RNA species together with qPCR techniques for monitoring the mitochondrial intactness. We determined nucleoid distribution and mtDNA amount following rotenone mediated respiratory inhibition or following degeneration of the electrical component of the protonmotive force by valinomycin treatment. Native mitochondria were mostly tubular with average nucleoid spacing 1.1 +/- 0.2µm which we termed as a nucleoid code. Subsequently induced fission resulted in mitochondrial network fragmentation and each...
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Quantitative aspects of mitochondrial genome in cancer and diabetes
Alán, Lukáš ; Ježek, Petr (advisor) ; Teisinger, Jan (referee) ; Modrianský, Martin (referee)
Mitochondria are cellular powerhouses and physiological regulators with many features resembling their prokaryotic ancestors. They maintain their own mitochondrial DNA (mtDNA) encoding 13 inner mitochondrial membrane proteins of oxidative phosphorylation machinery, 22 transfer RNAs and two ribosomal RNAs. Healthy mitochondria in normal cells form a dynamic network consisting of highly interconnected tubules. The mitochondrial disorders are very heterogeneous and difficult to diagnose and cure. It is due to combining products of two genomes, the complexity of mitochondrial structure and due to insufficiency of current state of knowledge. To understand the mitochondrial nucleic acid species distribution, we have developed and established new techniques to visualize mitochondrial network, nucleoids and different RNA species together with qPCR techniques for monitoring the mitochondrial intactness. We determined nucleoid distribution and mtDNA amount following rotenone mediated respiratory inhibition or following degeneration of the electrical component of the protonmotive force by valinomycin treatment. Native mitochondria were mostly tubular with average nucleoid spacing 1.1 +/- 0.2µm which we termed as a nucleoid code. Subsequently induced fission resulted in mitochondrial network fragmentation and each...
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Gene Expression Regulation of Biotransformation Enzymes and Transporters in Placental Barrier
Stejskalová, Lucie ; Pávek, Petr (advisor) ; Modrianský, Martin (referee) ; Vondráček, Jan (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and toxicology Candidate Mgr. Lucie Stejskalová Supervisor Doc. PharmDr. Petr Pávek, Ph.D. Title of Doctoral Thesis Gene expression regulation of biotransformation enzymes and transporters in placental barrier Placenta is a unique organ facilitating the communication between mother and fetus. It serves as a respiratory, excretory, endocrine and metabolic organ during intrauterine development of the fetus and is necessary for maintenance of pregnancy and for the fetal protection. Syncytiotrophoblast is a single layer that represents the critical morphological and metabolic component of the placental metabolic and exchange barrier. The placental trophoblast contains multiple drug transporters and metabolizing enzymes that form placental metabolic barrier. The levels of the enzymes are not stable and fluctuate throughout pregnancy. Most of the enzymes are expressed at very low mRNA levels, however, in some cases there is absence of any relevant detectable protein or catalytic activity. Cytochrome CYP1A1 is the only placental xenobiotic-metabolizing enzyme of the cytochrome P450 superfamily for which significant expression and catalytic activity have been conclusively demonstrated in placental trophoblasts...
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The Role of Uncoupling in Down-regulation of Reactive Oxygen Species
Ježek, Jan ; Žáčková, Markéta (advisor) ; Modrianský, Martin (referee) ; Drahota, Zdeněk (referee)
Uncoupling attenuates Complex I-derived superoxide production by accelerating electron flux and proton pumping within Complex I. However, under circumstances leading to hampered proton pumping pathway within Complex I, e.g. due to aberrant mutations of mtDNA encoding either ND2, ND4 or ND5 Complex I H+-pumping subunit, therapeutic strategy based simply on uncoupling would fail. Experimentally, hydrophobic amiloride EIPA mimicks the model of disabled H+-pumping. We show for the first time that EIPA is a real inhibitor of H+-pumping of mitochondrial Complex I. We searched for an agent that, unlike uncoupling, would be able to counteract oxidative stress associated with obstructed proton pumping of Complex I. Mitochondria-targeted ubiquinone MitoQ10 proved to be an effective antioxidant for this purpose when the rate of superoxide formation was high due to the electron flow retardation within Complex I. Because of its pro-oxidant properties, targeted delivery of MitoQ10 as a cure to the pathological tissue is necessary. Activation of mitochondrial phospholipase iPLA2 by mild oxidative stress can provide free fatty acid hydroperoxides as the cycling substrates for UCP2 that initiates mild uncoupling leading to the attenuation of reactive oxygen species (ROS) production, as a part of feedback regulatory loop of...
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