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Effect of abacavir on the expression of nucleoside transporters, adenosine receptors, and enzymes involved in adenosine synthesis and biodegradation in trophoblasts
Gala, Viktor ; Červený, Lukáš (advisor) ; Čečková, Martina (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Viktor Gala Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Effect of abacavir on the expression of nucleoside transporters, adenosine receptors, and enzymes involved in adenosine synthesis and biodegradation in trophoblasts The nucleoside reverse transcriptase inhibitor (NRTI) abacavir (ABC) is now the mainstay of combination antiretroviral therapy (cART) for HIV in pregnant women. The introduction of cART, along with several other measures, has reduced mother-to-fetus transmission of HIV to less than 1% in recent years. The placenta is a key organ for the health of both the fetus and the mother. Imbalances in placental development can result in adaptive changes and fetal programming errors. cART recommended in pregnancy is known for its good safety profile, but some epidemiological studies suggest a higher risk of reduced fetal weight, preterm birth, etc. The placenta is a rapidly growing organ dependent on the supply of building materials that resembles tumor growth in certain aspects. Nucleosides are promoters of tumor proliferation and are involved in the development of immunotolerance. The placenta is complexly equipped for nucleoside synthesis, uptake,...
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Effect of abacavir on the expression of nucleoside transporters, adenosine receptors, and enzymes involved in adenosine synthesis and biodegradation in trophoblasts
Gala, Viktor ; Červený, Lukáš (advisor) ; Čečková, Martina (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Viktor Gala Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Effect of abacavir on the expression of nucleoside transporters, adenosine receptors, and enzymes involved in adenosine synthesis and biodegradation in trophoblasts The nucleoside reverse transcriptase inhibitor (NRTI) abacavir (ABC) is now the mainstay of combination antiretroviral therapy (cART) for HIV in pregnant women. The introduction of cART, along with several other measures, has reduced mother-to-fetus transmission of HIV to less than 1% in recent years. The placenta is a key organ for the health of both the fetus and the mother. Imbalances in placental development can result in adaptive changes and fetal programming errors. cART recommended in pregnancy is known for its good safety profile, but some epidemiological studies suggest a higher risk of reduced fetal weight, preterm birth, etc. The placenta is a rapidly growing organ dependent on the supply of building materials that resembles tumor growth in certain aspects. Nucleosides are promoters of tumor proliferation and are involved in the development of immunotolerance. The placenta is complexly equipped for nucleoside synthesis, uptake,...
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Study of adenosine effects on proliferation of BeWo cell line
Papírník, Josef ; Červený, Lukáš (advisor) ; Vokřál, Ivan (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Josef Papírník Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Studium of adenosine on proiferation activity in BeWo cell line The placenta is a rapidly developing organ that provides nutrition, protection and environment for the growing fetus. Fetal development is dependent on the supply of nutrients from the mother's blood either by passive diffusion or mediated by transporters. One of the essential nutrients are nucleosides, which are known to promote DNA synthesis and thus the growth of certain tissues. In order to pass across the plasma membrane they need nukleoside transporters (NTs) because of its hydrophilic feature. Additionally Ado takes part in cell signaling. Its wide- ranging effects, including influencing proliferation, are mediated by its binding to adenosine receptors (ARs). The placenta expresses NTs and ARs, which means that it is equipped to uptake nucleosides from maternal blood and has ability to receive signals from the external environment via the adenosine molecule. However, the importance of nucleosides for placental growth has not been investigated yet. The aim of this thesis is to test the effect of nucleosides on the proliferation of...
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Study of adenosine effects on proliferation of JEG-3 cell line
Nguyen, Ngoc Duong ; Červený, Lukáš (advisor) ; Jirkovský, Eduard (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Nguyen Ngoc Duong Supervisor: doc. PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Effect of adenosine on the proliferation of JEG-3 cell line Adenosine is a purinergic signaling molecule that is used in nucleic acid synthesis. Transport of hydrophilic nucleosides through the plasma and/or organelle membranes is provided by equilibrative nucleoside transporters (ENTs), members of the SLC29A transporter family, and concentrative nucleoside transporters (CNTs), members of the SLC28A transporter family. The placenta is a complex and rapidly growing organ. It shows some patterns similar to tumors except for the fact that the placenta's growth is fully controlled. It was found that extracellular nucleosides support the proliferation of cancerous and some non-cancerous cells. The placenta expresses high levels of NTs which indicates the placenta's ability to take up the nucleosides from circulation, however, the contribution of this process to placental growth is known. The diploma thesis aims to test the effect of adenosine and other nucleosides on trophoblast proliferation. We evaluated whether adenosine and other nucleosides increase the proliferation of the choriocarcinoma-derived JEG-3 cell...
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Adenosine metabolism and its role in cell physiology
Neumannová, Kateřina ; Novotný, Jiří (advisor) ; Hansíková, Jana (referee)
Adenosine is not just a major component of important molecules such as ATP, RNA or cAMP, but also has its own signaling function. Therefore, its extracellular level is strictly maintained by balance in its formation, degradation and transport. Both inside and outside the cell adenosine is formed mainly through degradation of ATP and is eliminated by two enzymes, adenosine kinase and adenosine deaminase. Transport of adenosine through the cell membrane is provided by nucleoside transporters, which are either equilibrative or concentrative according to the mechanism of transfer. All three processes described above contribute to maintaining adenosine level under normal conditions and its increase in pathological situations. Extracellular adenosine as a signal molecule binds to adenosine receptors (subtypes A1, A2A, A2B, A3) that affect many cellular signaling pathways via G-proteins. By these pathways adenosine regulates energy homeostasis, controls the function of various organs and also modulates the nervous and immune system and thus it may participate in a number of pathological processes. Pharmacological affecting of specific adenosine receptors or enzymes involved in its metabolism can serve as an effective therapy. Some drugs based on this system are already in use, others are being tested, and many...
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A study of adenosine receptors and their signaling in the rat myocardium
Eichlerová, Lenka ; Novotný, Jiří (advisor) ; Nováková, Olga (referee)
Adenosine plays a critical role in the heart signalling while affecting heart rate, contractility or coronary flow. Nowadays, four adenosine receptor subtypes are distinguished which are present in most of tissues and cells: A1, A2A, A2B and A3. All these receptors belong to the family of G protein-coupled receptors. Upon activation, their main target is an enzyme adenylyl cyclase which produces an important second messenger cAMP. The main goal of this thesis was characterization of adenosine receptors in the rat myocardium, assessment of their distribution, binding properties and signalling. We examined a possible disparity in receptors distribution between the left and right ventricles using SDS-PAGE electrophoresis and Western blotting. The same methods have been used in studies of adenosine receptor distribution in lipid rafts. Samples of lipid rafts and soluble fraction were prepared using a nonionic detergent Triton X-100. We did not find any evidence of different distribution between the left and right ventricles and our results did not confirm compartmentation of the receptors either. For determination of binding properties of the receptors we used radioligand binding assays with the A1 selective radioligand [H3 ]DPCPX. We did not observe any significant difference between the receptor...
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A study of adenosine receptors and their signaling in the rat myocardium
Eichlerová, Lenka ; Novotný, Jiří (advisor) ; Nováková, Olga (referee)
Adenosine plays a critical role in the heart signalling while affecting heart rate, contractility or coronary flow. Nowadays, four adenosine receptor subtypes are distinguished which are present in most of tissues and cells: A1, A2A, A2B and A3. All these receptors belong to the family of G protein-coupled receptors. Upon activation, their main target is an enzyme adenylyl cyclase which produces an important second messenger cAMP. The main goal of this thesis was characterization of adenosine receptors in the rat myocardium, assessment of their distribution, binding properties and signalling. We examined a possible disparity in receptors distribution between the left and right ventricles using SDS-PAGE electrophoresis and Western blotting. The same methods have been used in studies of adenosine receptor distribution in lipid rafts. Samples of lipid rafts and soluble fraction were prepared using a nonionic detergent Triton X-100. We did not find any evidence of different distribution between the left and right ventricles and our results did not confirm compartmentation of the receptors either. For determination of binding properties of the receptors we used radioligand binding assays with the A1 selective radioligand [H3 ]DPCPX. We did not observe any significant difference between the receptor...
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Adenosine receptors and transporters in rat myocardium: the effect of adaptation to chronic hypoxia
Neumannová, Kateřina ; Novotný, Jiří (advisor) ; Hlaváčková, Markéta (referee)
2. Abstract Adaptation to chronic hypoxia is in addition to ischemic preconditioning one of the two known cardioprotective mechanisms. The precise molecular basis of these processes is still not fully explained. There are some studies that suggest the possible involvement of the adenosinergic signaling system in this adaptation. In this work, we focused on the characterization of the adenosinergic system in the myocardium of rats adapted to two regimens of chronic hypoxia - a protective continuous normobaric hypoxia (CNH) and non-protective intermittent hypoxia (INH/R, 23 h hypoxia and 1 h normoxia). Initially, we compared the total amount of adenosine receptors in samples from different groups of adapted animals. We discovered changes mainly at A2B receptor, which increased at CNH and declined in INH/R. This result suggests the possible involvement of A2B receptors in cardioprotection afforded by adaptation to chronic hypoxia. Furthermore, we investigated the distribution of various types of adenosine receptors and transporters in the plasma membrane of cardiac cells. We observed that A2A and A3 localize in membrane microdomains together with membrane enzyme CD73 that produces adenosine in the extracellular space by degrading AMP. A1 and A2B receptors similarly as nucleoside transporters ENT1, ENT2 and...
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Adenosine metabolism and its role in cell physiology
Neumannová, Kateřina ; Novotný, Jiří (advisor) ; Hansíková, Jana (referee)
Adenosine is not just a major component of important molecules such as ATP, RNA or cAMP, but also has its own signaling function. Therefore, its extracellular level is strictly maintained by balance in its formation, degradation and transport. Both inside and outside the cell adenosine is formed mainly through degradation of ATP and is eliminated by two enzymes, adenosine kinase and adenosine deaminase. Transport of adenosine through the cell membrane is provided by nucleoside transporters, which are either equilibrative or concentrative according to the mechanism of transfer. All three processes described above contribute to maintaining adenosine level under normal conditions and its increase in pathological situations. Extracellular adenosine as a signal molecule binds to adenosine receptors (subtypes A1, A2A, A2B, A3) that affect many cellular signaling pathways via G-proteins. By these pathways adenosine regulates energy homeostasis, controls the function of various organs and also modulates the nervous and immune system and thus it may participate in a number of pathological processes. Pharmacological affecting of specific adenosine receptors or enzymes involved in its metabolism can serve as an effective therapy. Some drugs based on this system are already in use, others are being tested, and many...
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