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Study on expression of selected ABC transporters in placenta
Kučerová, Veronika ; Čečková, Martina (advisor) ; Karbanová, Sára (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Veronika Kučerová Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Consultant: PharmDr. Lenka Ťupová, Ph.D. Title of diploma thesis: Study on expression of selected ABC transporters in placenta The placenta is a temporary organ through which the fetus is supplied with nutrients and oxygen from the mother's blood and conversely waste substances are transferred into the mother's blood during pregnancy. Substance transfer through the placenta is a complex process controlled by a number of physiological mechanisms, including passive diffusion, facilitated diffusion or active transport, which is realized by activity of membrane transporters with energy consumption. Presence of active ABCs efflux transporters in the placenta has been known for a long time and their function is associated primarily with limiting the entry of harmful substances into the placenta and further into the fetus, thus contributing to its protection. Among the best described transporters belong P-glycoprotein (MDR1/ABCB1), breast cancer resistance protein (BCRP/ABCG2) and multidrug resistance protein 2 (MRP2/ABCC2), whose expression has been confirmed in the apical membrane of the placental syncitiotrophoblast facing...
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Determinants of fusogenicity of Syncytin-1, cellular glycoprotein of retroviral origin
Trávníček, Martin ; Trejbalová, Kateřina (advisor) ; Zábranská, Helena (referee)
Syncytin-1 is an endogenous retroviral envelope glycoprotein specifically expressed in human placenta, where the protein was adopted for its physiological function. After interaction with specific receptors, transmembrane proteins ASCT1 and ASCT2, Syncytin-1 initiates cell-cell fusion leading to formation of multinucleated syncytiotrophoblast, which is essential for feto-maternal nutrients exchange. In this diploma thesis a new cell-cell fusion quantification assay was implemented for characterisation of Syncytin-1 fusion determinants. The assay uses Syncytin-1 and ASCT2 expressed separately with fragments of luciferase in heterologous cell-culture system. The assay enables to specifically quantify cell-cell fusions based on activity of reconstituted luciferase reporter. This study discovered new facts about the role of intracytoplasmic tail of Syncytin-1 in the process of the cell- cell fusion. This specific part of protein contains a tandem motif sensitive to changes in amino acid sequence that led to loss of fusogenic potential of Syncytin-1. It was further confirmed, that the protein Suppressyn works as an inhibitor of cell-cell fusions initiated by Syncytin-1. Suppressyn however does not bind to receptors of Syncytin-1 and the mechanism of its inhibition remains unsolved. Finally, it was demonstrated...
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Role of selected ABC and SLC transporters in transmembrane permeability of maraviroc: effect on transport in placenta
Matiašková, Zuzana ; Čečková, Martina (advisor) ; Vopršalová, Marie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and toxikology Student: Zuzana Matiašková Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Role of selected ABC and SLC transporters in transmembrane permeability of maraviroc: effect on transport in placenta Antiretroviral drug maraviroc is an inhibitor of CCR5-trophic HIV virus and belongs to the group of entry inhibitors. Nowadays, maraviroc is administered as part of combination antiretroviral therapy (cART) primarily in adults, children over the age of two and pregnant women to reduce the risk of transmission of HIV to the fetus. The knowledge of interactions of maraviroc with drug transporters in placenta is crucial for optimizing the therapy during pregnancy, both in terms of efficacy and potential adverse effects. Maraviroc is known substrate of ABCB1 transporter, which plays a protective role to the fetus by its efflux activity in the apical membrane of trophoblast. However, the results of recent study employing dually perfused human placenta suggest involvement of other transport mechanisms in the maraviroc transplacental pharmaocokinetics, especially those operating in the opposite direction to ABCB1. The aim of this study was to evaluate in vitro studies whether, besides ABCB1,...
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Expression of selected membrane transporters in placentas of pregnant women diagnosed for preterm rupture of membranes
Michalská, Martina ; Čečková, Martina (advisor) ; Jirkovský, Eduard (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Martina Michalská Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Expression of selected membrane transporters in placentas of pregnant women diagnosed for preterm rupture of membranes Placenta is a key organ for pregnancy maintenance. One of its main functions is transport of compounds between mother and her fetus. The transplacental penetration is ensured due to membrane transporters that are present in the apical or basal side of trophoblast. Their expression level is affected by many physiological and pathological factors, among others it can be influenced by infection and inflamatory reaction. Inflammation is also one of the risk factors of preterm deliveries and it can be therefore assumed that these pathological states are accompanied by changes in expression of placental transporters. This study was performed using 51 placentas obtained from Faculty hospital in Hradec Králové from women who underwent preterm delivery and on 15 placentas delivered in term. The study employed quantitative RT-PCR approach. The mRNA expression of membrane transporters ABCB1, ABCG2, OATP1A2, OATP1B3, OATP2A1, OATP2B1, OATP3A1, OATP4A1 was assessed and the results were compared to...
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Study on expression of selected ABC transporters in placenta
Kučerová, Veronika ; Čečková, Martina (advisor) ; Karbanová, Sára (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Veronika Kučerová Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Consultant: PharmDr. Lenka Ťupová, Ph.D. Title of diploma thesis: Study on expression of selected ABC transporters in placenta The placenta is a temporary organ through which the fetus is supplied with nutrients and oxygen from the mother's blood and conversely waste substances are transferred into the mother's blood during pregnancy. Substance transfer through the placenta is a complex process controlled by a number of physiological mechanisms, including passive diffusion, facilitated diffusion or active transport, which is realized by activity of membrane transporters with energy consumption. Presence of active ABCs efflux transporters in the placenta has been known for a long time and their function is associated primarily with limiting the entry of harmful substances into the placenta and further into the fetus, thus contributing to its protection. Among the best described transporters belong P-glycoprotein (MDR1/ABCB1), breast cancer resistance protein (BCRP/ABCG2) and multidrug resistance protein 2 (MRP2/ABCC2), whose expression has been confirmed in the apical membrane of the placental syncitiotrophoblast facing...
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Role of selected ABC and SLC transporters in transmembrane permeability of maraviroc: effect on transport in placenta
Matiašková, Zuzana ; Čečková, Martina (advisor) ; Vopršalová, Marie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and toxikology Student: Zuzana Matiašková Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Role of selected ABC and SLC transporters in transmembrane permeability of maraviroc: effect on transport in placenta Antiretroviral drug maraviroc is an inhibitor of CCR5-trophic HIV virus and belongs to the group of entry inhibitors. Nowadays, maraviroc is administered as part of combination antiretroviral therapy (cART) primarily in adults, children over the age of two and pregnant women to reduce the risk of transmission of HIV to the fetus. The knowledge of interactions of maraviroc with drug transporters in placenta is crucial for optimizing the therapy during pregnancy, both in terms of efficacy and potential adverse effects. Maraviroc is known substrate of ABCB1 transporter, which plays a protective role to the fetus by its efflux activity in the apical membrane of trophoblast. However, the results of recent study employing dually perfused human placenta suggest involvement of other transport mechanisms in the maraviroc transplacental pharmaocokinetics, especially those operating in the opposite direction to ABCB1. The aim of this study was to evaluate in vitro studies whether, besides ABCB1,...
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Role of drug transporters in placental transfer of entecavir
Lukášová, Veronika ; Červený, Lukáš (advisor) ; Hofman, Jakub (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Veronika Křečková Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Role of drug transporters in placental transfer of entecavir Entecavir (ETV), an analogue of guanosine, is a highly efficient anti-hepatitis B antiviral drug. It is the first-line therapy for both adults and children. Its use in pregnancy is limited due to a number of factors, including lack of data on placental pharmacokinetics. The placental transition of drugs is frequently controlled by drug transporters. ATP-binding (ABC) transporters, P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) or multidrug resistance-associated protein 2 (MRP2) localized in the apical membrane of syncytiotrophoblast and pumping their substrates in the feto-maternal direction belong to most significant determinants of placental pharmacokinetics. Moreover placental transport of nucleoside-derived drugs can be affected by the activity of nucleoside transporters (NTs); equilibrative nucleoside transporters (ENTs) mediate facilitated diffussion, while the concentrative nucleoside transporters (CNTs) control active influx of their substrates. The aim of the diploma thesis was to describe the role of P-gp, BCRP, MRP2 and NTs (ENTs and...
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Interactions of selected antiretroviral drugs and methylmercury with placental membrane transporters
Ťupová, Lenka ; Čečková, Martina (advisor) ; Fusek, Josef (referee) ; Kacerovský, Marian (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Mgr. Lenka Ťupová Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Title of doctoral thesis: Interactions of selected antiretroviral drugs and methylmercury with placental membrane transporters. Pregnant women are especially in developed countries exposed to high amount of various xenobiotic including environmental pollutants and drugs. Antiretroviral therapy (ART) is administered to HIV positive pregnant women for the purpose of prevention of HIV mother- to-child-transmission. Pharmacokinetics of many antiretrovirals is limited or enhanced by activity of ATP-binding cassette (ABC) or Solute carrier's transporters, of which many are expressed also in placental tissue. ART therapy usually consists of combination of 3 - 4 antiretroviral drugs, thereby leading to higher risk for development of drug-drug interactions on ABC and SLC transporters. In this study we described influence of non-nucleoside reverse transcriptase inhibitors etravirin and rilpivirin on BCRP- and MDR1-mediated transport of tenofovir disoproxil fumarate (TDF) and/or abacavir. Etravirin showed potent inhibition of BCRP transporter significantly changing transport of both, TDF and abacavir, across monolayers of MDCKII-BCRP...
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The effect of in vitro and ex vivo placental cells stimulation on expression of selected ABC and OATP transporters
Dudičová, Simona ; Čečková, Martina (advisor) ; Jirkovská, Anna (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Simona Dudičová Supervisor: Assoc. Prof. PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: The effect of in vitro and ex vivo placental cells stimulation on expression of selected ABC and OATP transporters The placenta is an organ that plays a key role throughout pregnancy for proper fetal development. One of the important functions provided by the placenta is the transport of substances between the mother and the fetus. This transfer of substances enabled mainly by membrane transporters, which are located on the apical and basal membranes of the syncytiotrophoblast. During various physiological or pathological changes in the human body, their expression and amount can vary significantly. Inflammatory reactions that may occur during pregnancy are also related to these changes, and therefore we have addressed this issue and believed that this condition may alter the expression of placental transporters. The aim of this work was to investigate the changes in the expression of membrane transporters using placental cells on BeWo cell lines and placental villous explants that were stimulated by pro-inflammatory mediators. The change in the expression of individual ATP-binding cassettes,...
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Interactions of selected antiretroviral drugs and methylmercury with placental membrane transporters
Ťupová, Lenka ; Čečková, Martina (advisor) ; Fusek, Josef (referee) ; Kacerovský, Marian (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Mgr. Lenka Ťupová Supervisor: doc. PharmDr. Martina Čečková, Ph.D. Title of doctoral thesis: Interactions of selected antiretroviral drugs and methylmercury with placental membrane transporters. Pregnant women are especially in developed countries exposed to high amount of various xenobiotic including environmental pollutants and drugs. Antiretroviral therapy (ART) is administered to HIV positive pregnant women for the purpose of prevention of HIV mother- to-child-transmission. Pharmacokinetics of many antiretrovirals is limited or enhanced by activity of ATP-binding cassette (ABC) or Solute carrier's transporters, of which many are expressed also in placental tissue. ART therapy usually consists of combination of 3 - 4 antiretroviral drugs, thereby leading to higher risk for development of drug-drug interactions on ABC and SLC transporters. In this study we described influence of non-nucleoside reverse transcriptase inhibitors etravirin and rilpivirin on BCRP- and MDR1-mediated transport of tenofovir disoproxil fumarate (TDF) and/or abacavir. Etravirin showed potent inhibition of BCRP transporter significantly changing transport of both, TDF and abacavir, across monolayers of MDCKII-BCRP...
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