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Mechanisms of retromer - dependent protein recycling from endosomes
Horázná, Monika ; Macůrková, Marie (advisor) ; Černý, Jan (referee)
Most processes in nature are very effective concerning saving energy and minimizing waste. A good example of saving on cellular level is receptor recycling. Whether it concerns receptors for lysosomal enzymes or for proteins destined for secretion, after releasing their cargo protein the fate of the receptor would be sealed in lysosomes. Nevertheless, some transmembrane receptors contain a signal motif through which they are recognized by specific proteins or protein complexes and they escape the degradation in lysosomes. One such complex is the retromer. Its first discovered function was the recycling of receptors for lysosomal hydrolases in yeast. Later it was proved that it has a similar role in transport of many other proteins in other eukaryotes. The task for retromer is to sort the cargo proteins on the endosomal membrane and together with others auxiliary proteins create a transport vesicle which is then transported to the Golgi. This makes the cell able to recycle proteins that would otherwise be transported from endosomes to lysosomes for degradation.
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Mechanisms of MHCII signaling in B lymphocytes
Kotlabová, Klára ; Brdička, Tomáš (advisor) ; Černý, Jan (referee)
During the initiation of an antigen-specific immune response, peptide fragments originating from the antigen are presented in complex with MHC class II glycoproteins (MHCgpII) on the surface of the antigen presenting cells (APC). Antigen recognition by T lymphocyte is accompanied by the formation of the molecular structure at the interface with APC called immunological synapse (IS). During this contact, signal transduction is initiated at both, T lymphocyte and APC, sides of the IS. For a long time it was thought that the only function of MHCgpII is presentation of antigen. However, later it was found that stimulation of MHCgpII led to triggering of signals contributing to decision about the further fate of APC. MHCgpII do not have any signaling motifs in their cytoplasmatic domains, and so associated molecules are necessary for the transduction of the signals. This work focuses on B lymphocytes in which the associated molecules are Ig alfa/beta, MPYS, CD19 and CD20. After the stimulation of MHCgpII these proteins mediate signaling events including activation of several families of protein kinases, phospholipase C, mobilization of calcium and activation of transcriptional factors NFAT and AP-1. In B lymphocytes, activities of these pathways may result in proliferation and differentiation but also in the...
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The clinical relevance of implementation of new technologies in extracorporeal circulation
Svitek, Vladimír ; Harrer, Jan (advisor) ; Tošovský, Jan (referee) ; Černý, Jan (referee)
The clinical relevance of implementation of new technologies in extracorporeal circulation Summary Background: An organism's inflammatory response related to cardiopulmonary bypass (CPB) use is caused by activation of immune system cells with the production of a whole spectrum of mediators, whose activity can result in organ dysfunction. Current research, in trying to eliminate the negative effects of CPB, is engaging in innovating technology of systems for CPB. One of the last complex innovations is the so-called miniinvasive cardiopulmonary bypass. Till now though, the clinical benefits of using this system has not been clearly proven. Methods: A group of 54 patients, who were indicated for elective coronary surgery were randomised into two groups - group cCPB (patients operated on using classic CPB in the open modification) and group mCPB (patients operated on using minicircuit). We monitored and compared concentration of interleukin-6, polymorphonuclear elastase, monocyte chemoattractant protein-1, interleukin-10 and soluble receptors for tumour necrosis factor-α in both groups during operation and postoperatively. At the same time we compared the postoperative clinical course. Results: Both groups did not differ in the basic pre and peroperative characteristics (age, EuroScore, ejection fraction,...
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Functional studies of selected members of the Arabidopsis formin family
Oulehlová, Denisa ; Cvrčková, Fatima (advisor) ; Binarová, Pavla (referee) ; Černý, Jan (referee)
Formins are multidomain proteins containing a conserved formin-homology 2 (FH2) domain, which catalyzes de novo nucleation of actin filaments. In yeast and animal cells, both mechanisms and regulation of formin function have been extensively studied, yet much less is known about action of plant formins, which considerably differ from yeast and animal ones in the domain composition. In higher plants, formins are classified into two groups, Class I and Class II, and so far, experimental data are available only for the first group members. Here I present results of experimental study of several members of the large formin family in Arabidopsis, including the characterization of a Class II formin AtFH16. Arabidopsis genome contains 21 formin-encoding genes, and though they greatly differ in their expression levels and pattern, all of them are transcriptionally active. We selected 17 homozygous T-DNA insertional mutants in 14 formin genes. Under standard cultivation conditions, no obvious phenotypic discrepancies between wild type and mutant plants were found. To impair two dominant pollen formins, an atfh3atfh5 double-mutant was prepared and even in this case, both microspore development and pollen tube growth remained unaffected. Consistently, polarized growth of tobacco pollen tubes was not altered...
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Molecular Mechanisms of the Interaction of Interacellular Pathogen Francisella Tularensis and Antigen Presenting Cells
Härtlová, Anetta ; Kročová, Zuzana (advisor) ; Černý, Jan (referee) ; Krejsek, Jan (referee)
Title of the PhD thesis: The molecular mechanisms of the interaction of Francisella tularensis and antigen presenting cells Abstract: Over the past few decades, reductionist approaches dominated in the study of biological systems and helped to understand many basic principles that underlie host- pathogen interaction. Nevertheless, recent advances in genomics, transcriptomics and proteomics have enabled to design new type of experiments and get thus novel information of all the components of biological systems, as well as to characterize interaction among them. Profiling of proteins, as main carriers of biological activity, is especially of great interest in order to elucidate the molecular mechanisms of infection in space and time. Nowadays, there is a need to develop new antibiotic and anti-viral drugs, extensively investigate the respective infectious agents in regard to pathogen-specific signaling processes or enzymes that do not occur in human cells. However, pathogens have evolved different strategies to avoid the host defense mechanisms. The fact that pathogens exploit many factors of the host cell signaling machinery for finding safe niche for their replication provides the basis for an alternative, host-directed strategy to prevent establishing of infection in a host. This PhD thesis applies...
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Assessment of expression markers of HLA class II genes.
Zajacová, Marta ; Černá, Marie (advisor) ; Černý, Jan (referee)
BACKGROUND: HLA molecules play a central role in the immune response. HLA class II are involved in the selection of the T-cell repertoire in the thymus, and in presentation of antigenic peptides to antigen reactive CD4-positive T cells. The HLA class II act as restriction determinants in the presentation of antigens to T lymphocytes and their expression on the cell surface is necessary for triggering the immune responses. Regulated transcription of HLA class II genes is a complex system involving cis-acting sequence elements and trans-acting protein factors. It has been reported that allelic polymorphism exists in the regulatory regions of HLA class II DQA1, DQB1 and DRB1 genes. Most of the polymorphisms appear to be conserved within a haplotype. The hierarchy of sequence homology which exists among the structural genes is not paralleled among their promoter sequences. It is of interest that the most striking discrepancy was found for the DR4 linked alleles, DQB1*0301 and DQB1*0302, which were described as frequent risk factors for a variety of autoimmune diseases. The structural genes of these two alleles are the most closely related, but their regulatory sequences are the most heterogeneous among DQB1 variants. These sequence differences correspond to functional variation: The promoter strength...
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Expression and function of molecules of innate system in embryonal phagocytes
Vavrochová, Tereza ; Filipp, Dominik (advisor) ; Černý, Jan (referee)
Phagocytes of an early embryo represent a mixture of myeloid lineages that differ from adult macrophages phenotypically, biochemically and by their origin. Recent studies suggested that there are at least three waves of macrophages populating the early embryo: a maternally-derived one and two waves of extraembryonic, YS-derived origin. In addition, the occurence of early embryonic phagocytes of undetermined origin in developing anterior head mesoderm in evolutionary distinct species is well documented. This origin-related heterogeneity among early embryonic phagocyte subpopulations coupled with the lack of specific markers makes it difficult to distinguish them phenotypically and study their potentially distinct physiological roles in early development. The aim of this study is to identify and characterize a set of novel markers suitable for identification of embryonic phagocytes. Here, using qRT-PCR approach, we have established the kinetics of expression of Toll like receptors (TLRs) and their TIR-domain containing adaptors during early embryogenesis (E7.5-E12.5) and demonstrate that their major cellular source are indeed phagocytes. Using whole-mount embryo immunohistochemistry we also show that negative regulator of TLR signaling Sigirr is expressed during very early stages of mouse...
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God and Suffering - the Problem of Theodicy in Theology J. B. Metz
Hartman, Tomáš ; Noble, Ivana (advisor) ; Černý, Jan (referee)
Die Arbeit befasst sich mit dem Werk des deutschen katholischen Theologen Johann Baptist Metz mit Fokussierung auf die Theodizeefrage. Im Bezug auf das Theodizeethema werden biographische, theologische sowie philosophische Einwirkungen auf das Metzsche Denken in dieser Frage verfolgt. Die Arbeit stellt die Auffassung der Theodizeefrage bei Metz vor, einschließlich seiner kritischen Auseinandersetzung mit anderen Ansätzen (Augustin, Trinitätstheologie), und weiterhin seine Auffassung von "Theologie nach Auschwitz" und sein Konzept der theodizee-empfindlichen Theologie (Mystik des "Leidens an Gott", "Compassion"). Powered by TCPDF (www.tcpdf.org)
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