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Pathogenesis of nephrotic syndrome in children and predictors of corticosteroid treatment response
Bezdíčka, Martin ; Souček, Ondřej (advisor) ; Doležel, Zdeněk (referee) ; Reiterová, Jana (referee)
Nephrotic syndrome is a kidney disease caused by injury of the podocytes. It can be secondary due to infection, systemic disease or certain drugs, but it may also present as sudden primary nephrotic syndrome without obvious inducer. Current standard treatment has many severe adverse effects. In some patients that are resistant to the initial several-week-long glucocorticoid treatment it is possible to reveal the causative genetic aetiology of the disease, whereas in the rest of them aetiology remains unknown. Those who respond well to initial glucocorticoid treatment and achieve remission may later on develop repeated relapses requiring long-term glucocorticoid therapy. This work describes our original research studies focusing on the improvement of genetic diagnostics of nephrotic syndrome, on the exploration of molecular mechanisms of the second most common genetic cause of the steroid-resistant nephrotic syndrome (transcription factor WT1 mutants) and on the search of clinical and laboratory factors that could predict the resistence to glucocorticoid treatment. By combining Sanger and next-generation sequencing (NGS) we were the first to identify monogenic cause in 38 % of Czech and Slovak children with steroid-resistant nephrotic syndrome whose samples had been collected for 18 years. The most...
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Modulation of DNA Binding Affinity of Transcription Factors FOXO and p53 Through Protein-protein Interactions
Hofmanová, Adéla ; Obšil, Tomáš (advisor) ; Pavlíček, Jiří (referee)
5 Abstract The forkhead box "O" (FOXO) proteins are a subclass of the Forkhead family of transcription factors that play a critical role in a variety of cellular processes such as response to cellular stress, gluconeogenesis, cell cycle control, apoptosis, senescence, and repair of DNA damage. They are generally considered to be tumor suppressors. However, it has been shown that they can promote tumorigenesis and induce resistance to the chemotherapeutic agents. Despite many years of research into the biological role of FOXO proteins, a number of questions remain to be answered. For example, whether the slight structural differences observed in the otherwise highly homologous DNA-binding domains of individual FOXO transcription factors affect their DNA binding affinity. Furthermore, it is unclear how protein-protein interactions affect DNA binding affinity of FOXO proteins. Recent study has described the interaction of FOXO transcription factors with the p53 protein. Protein p53 is called the guardian of the genome due to its ability to mediate the response to acute DNA damage. The interaction of FOXO and p53 proteins appears to have a major effect on the DNA binding affinity of both these proteins. Based on this, DNA-binding domains of the human transcription factors FOXO1, FOXO3 and FOXO4 (FOXO1(144-270),...
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Study of the role of the B-chain N-terminus conformation of insulin in binding to the insulin receptor
Kosinová, Lucie ; Žáková, Lenka (advisor) ; Obšil, Tomáš (referee)
According to the International Diabetes Federation (IDF), there were 371 million people in the age from 20 to 79 years worldwide affected by diabetes in 2012. This means diabetes has become a global epidemic disease and, therefore, the importace of insulin research still grows. Insulin is a protein hormone that plays a key role in regulating blood glucose level which has a widespread impact on whole metabolism. Insulin acts through binding of its monomeric form to the insulin receptor. It is clear that insulin monomer has to undergo structural changes upon binding to the insulin receptor as the residues which are crucial for the interaction are burried within the native form. According to studies of highly active hormone analogs and the new information about the insulin-insulin receptor complex, there is a strong evidence that the C-terminal part of the B-chain is a dynamic element in insulin activation and receptor binding. Probably, there is also a great importance of the B-chain N- terminus and the transition between T and R conformations of insulin. However, the exact significance of the T and R states of insulin still remains unclear. In this work, several new insulin analogs AibB3-insulin, AibB5-insulin, AibB8- insulin, N-MeAlaB8-insulin and D-ProB8-insulin were prepared for the purpose of...
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Study of the interaction between the C-terminus of DNA-binding domain of FOXO4 and DNA
Zusková, Iva ; Obšil, Tomáš (advisor) ; Teisinger, Jan (referee)
Forkhead transcription factors are structurally similar molecules containing approximately 110-amino-acid-long DNA-binding domain known as a forkhead domain. Protein FOXO4 is a member of subgroup "O" of forkhead transcription factors. Members of this subgroup play a key role in many biologically important processes. For example, FOXO factors participate in metabolism control, cell-cycle control, apoptosis and oxidative stress resistance. The forkhead domain (DNA-binding domain) consists of three α-helices (H1, H2 and H3), three β-strands (S1, S2 and S3) and two flexible loops (called wings W1 and W2). The role of the wing W2 in FOXO binding to the target DNA is still elusive. Wing W2 probably interacts with the DNA in the region upstream of the core motif. It has been speculated that the FOXO DNA-binding affinity depends on A-T content (number of A-T pairs) in the region upstream of the core motif. In order to investigate this hypothesis, DNA- binding domain of the FOXO4 protein was expressed and purified and it was determined its binding affinity for three molecules of double stranded DNA containing different number of A-T pairs in the region upstream of the core motif using steady-state fluorescence anisotropy- based method. Our results show no significant differences between obtained FOXO4...
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Synthesis and characterization of AibB8LysB28ProB29-insulin to study T a R conformations of insulin
Kosinová, Lucie ; Stiborová, Marie (advisor) ; Flegel, Martin (referee)
According to the International Diabetes Federation, there were 285 million people in the age from 20 to 79 years suffering from diabetes on the planet in 2010. This means diabetes has become a global epidemic so the importace of insulin research is still growing. Insulin is a protein hormone that plays a key role in regulating blood glucose level which has a widespread impact on the whole metabolism. Insulin acts through binding of its monomeric form to the insulin receptor. At present, however, the active monomeric structure of insulin is still unknown. It is clear that insulin monomer must undergo structural changes upon binding to the insulin receptor as the residues crucial for the interaction are burried within the native form. According to studies of highly active hormon analogs there is an ample evidence that the C-terminal part of the B-chain is a dynamic element in insulin activation and receptor binding. Probably, there is also great importance of the B-chain N- terminus and the transition between T and R conformation. However, the exact significance of the T and R states of insulin remains unclear. In this work, a new insulin analog AibB8LysB28ProB29-insulin was prepared for the purpose of studying significance of the T and R conformations of insulin and their relationship to the active...
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Preparation of insulin analogs for the study of interactions with insulin receptors.
Hanková, Kateřina ; Jiráček, Jiří (advisor) ; Dračínská, Helena (referee)
Insulin jako jeden z důležitých hormonů lidského organismu se podílí na řadě metabolických procesů. Jednou z funkcí insulinu je pak regulace hladiny glukosy v krvi a jejího vstupu do tkání, ale i stimulace růstu buněk. Insulin má velmi podobnou primární i terciální strukturu s růstovými faktory IGF-1 a IGF-2, jejichž primární funkcí je regulace růstových procesů organismu. Zprostředkování účinku těchto tří hormonů na buněčné úrovni je zajištěno díky jejich specifickým receptorům (mitogenní isoformě receptoru insulinu IR-A, metabolické isoformě IR-B a receptoru pro IGF-1), což může, díky podobnosti těchto receptorů i hormonů, vést ke křížovým interakcím mezi nimi. Poruchy tohoto systému mohou vést k závažným onemocněním. Nejrozšířenějším z těchto nemocí je diabetes mellitus, ale závažné jsou i poruchy růstu a rakovinné bujení. Vytvoření takového analogu insulinu, který bude selektivní pouze pro isoformu IR-B receptoru insulinu, by mohlo vést zejména k bezpečnější léčbě diabetu. Tato práce se zaměřuje na lepší pochopení významu jednotlivých aminokyselin na daných pozicích v A-řetězci insulinu, u kterých je předpokládáno, že jsou součástí vazebného místa hormonu pro receptory. Tyto znalosti by mohly vést k následnému lepšímu porozumění významu těchto aminokyselin ve vazbě na receptory IR-A, IR-B a...
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Preparation of insulin analogs for the study of interactions with insulin receptors.
Hanková, Kateřina ; Jiráček, Jiří (advisor) ; Dračínská, Helena (referee)
Insulin jako jeden z důležitých hormonů lidského organismu se podílí na řadě metabolických procesů. Jednou z funkcí insulinu je pak regulace hladiny glukosy v krvi a jejího vstupu do tkání, ale i stimulace růstu buněk. Insulin má velmi podobnou primární i terciální strukturu s růstovými faktory IGF-1 a IGF-2, jejichž primární funkcí je regulace růstových procesů organismu. Zprostředkování účinku těchto tří hormonů na buněčné úrovni je zajištěno díky jejich specifickým receptorům (mitogenní isoformě receptoru insulinu IR-A, metabolické isoformě IR-B a receptoru pro IGF-1), což může, díky podobnosti těchto receptorů i hormonů, vést ke křížovým interakcím mezi nimi. Poruchy tohoto systému mohou vést k závažným onemocněním. Nejrozšířenějším z těchto nemocí je diabetes mellitus, ale závažné jsou i poruchy růstu a rakovinné bujení. Vytvoření takového analogu insulinu, který bude selektivní pouze pro isoformu IR-B receptoru insulinu, by mohlo vést zejména k bezpečnější léčbě diabetu. Tato práce se zaměřuje na lepší pochopení významu jednotlivých aminokyselin na daných pozicích v A-řetězci insulinu, u kterých je předpokládáno, že jsou součástí vazebného místa hormonu pro receptory. Tyto znalosti by mohly vést k následnému lepšímu porozumění významu těchto aminokyselin ve vazbě na receptory IR-A, IR-B a...
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Study of the role of the B-chain N-terminus conformation of insulin in binding to the insulin receptor
Kosinová, Lucie ; Žáková, Lenka (advisor) ; Obšil, Tomáš (referee)
According to the International Diabetes Federation (IDF), there were 371 million people in the age from 20 to 79 years worldwide affected by diabetes in 2012. This means diabetes has become a global epidemic disease and, therefore, the importace of insulin research still grows. Insulin is a protein hormone that plays a key role in regulating blood glucose level which has a widespread impact on whole metabolism. Insulin acts through binding of its monomeric form to the insulin receptor. It is clear that insulin monomer has to undergo structural changes upon binding to the insulin receptor as the residues which are crucial for the interaction are burried within the native form. According to studies of highly active hormone analogs and the new information about the insulin-insulin receptor complex, there is a strong evidence that the C-terminal part of the B-chain is a dynamic element in insulin activation and receptor binding. Probably, there is also a great importance of the B-chain N- terminus and the transition between T and R conformations of insulin. However, the exact significance of the T and R states of insulin still remains unclear. In this work, several new insulin analogs AibB3-insulin, AibB5-insulin, AibB8- insulin, N-MeAlaB8-insulin and D-ProB8-insulin were prepared for the purpose of...
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Synthesis and characterization of AibB8LysB28ProB29-insulin to study T a R conformations of insulin
Kosinová, Lucie ; Stiborová, Marie (advisor) ; Flegel, Martin (referee)
According to the International Diabetes Federation, there were 285 million people in the age from 20 to 79 years suffering from diabetes on the planet in 2010. This means diabetes has become a global epidemic so the importace of insulin research is still growing. Insulin is a protein hormone that plays a key role in regulating blood glucose level which has a widespread impact on the whole metabolism. Insulin acts through binding of its monomeric form to the insulin receptor. At present, however, the active monomeric structure of insulin is still unknown. It is clear that insulin monomer must undergo structural changes upon binding to the insulin receptor as the residues crucial for the interaction are burried within the native form. According to studies of highly active hormon analogs there is an ample evidence that the C-terminal part of the B-chain is a dynamic element in insulin activation and receptor binding. Probably, there is also great importance of the B-chain N- terminus and the transition between T and R conformation. However, the exact significance of the T and R states of insulin remains unclear. In this work, a new insulin analog AibB8LysB28ProB29-insulin was prepared for the purpose of studying significance of the T and R conformations of insulin and their relationship to the active...
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Study of the interaction between the C-terminus of DNA-binding domain of FOXO4 and DNA
Zusková, Iva ; Teisinger, Jan (referee) ; Obšil, Tomáš (advisor)
Forkhead transcription factors are structurally similar molecules containing approximately 110-amino-acid-long DNA-binding domain known as a forkhead domain. Protein FOXO4 is a member of subgroup "O" of forkhead transcription factors. Members of this subgroup play a key role in many biologically important processes. For example, FOXO factors participate in metabolism control, cell-cycle control, apoptosis and oxidative stress resistance. The forkhead domain (DNA-binding domain) consists of three α-helices (H1, H2 and H3), three β-strands (S1, S2 and S3) and two flexible loops (called wings W1 and W2). The role of the wing W2 in FOXO binding to the target DNA is still elusive. Wing W2 probably interacts with the DNA in the region upstream of the core motif. It has been speculated that the FOXO DNA-binding affinity depends on A-T content (number of A-T pairs) in the region upstream of the core motif. In order to investigate this hypothesis, DNA- binding domain of the FOXO4 protein was expressed and purified and it was determined its binding affinity for three molecules of double stranded DNA containing different number of A-T pairs in the region upstream of the core motif using steady-state fluorescence anisotropy- based method. Our results show no significant differences between obtained FOXO4...
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