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Mebrane adaptor proteins in hematopoiesis and immune response
Pavliuchenko, Nataliia ; Brdička, Tomáš (advisor) ; Brábek, Jan (referee) ; Smrž, Daniel (referee)
Membrane adaptor proteins are proteins associated with cellular membranes that do not themselves serve as receptors. Instead, they propagate or modify the signals of these receptors by recruiting other signaling and regulatory proteins and arranging them into supramolecular complexes. In this thesis, I sought to describe selected membrane adaptor proteins and their roles in inflammation and regulation of hematopoiesis in mouse models using a reverse genetics approach. The main part of the work focused on the role of the membrane adaptor protein PSTPIP2 in suppressing inflammation. In mice, missense mutations in the Pstpip2 gene causing loss of PSTPIP2 protein lead to the development of autoinflammatory disease chronic multifocal osteomyelitis (CMO) characterized by sterile inflammatory lesions in the bones and adjacent soft tissue. These mice represent a model of the human autoinflammatory disease, chronic recurrent multifocal osteomyelitis. At the molecular level, neutrophils in the absence of PSTPIP2 exhibit pathological hyperactivity of pathways regulating IL-1β and reactive oxygen species (ROS) production, which are both implicated in the etiology of the disease. PSTPIP2 interacts with several signaling regulators, including PEST family protein tyrosine phosphatases (PEST-PTPs) and inositol...
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Molecular mechanisms of sterile inflammation in damaged hematopoietic tissue
Čiháková, Zuzana ; Faltusová, Kateřina (advisor) ; Bačová, Barbora (referee)
Hematopoietic tissue is home to hematopoietic stem cells (HSCs), which continuously generate all blood and immune cells. Tissue damage or cellular stress can lead to sterile inflammation. In response to the sterile inflammation, HSCs are activated to proliferate and switch to emergency hematopoiesis. Long-term exposure of hematopoietic tissue to inflammatory signals leads to increased differentiation at the expense of self-renewal of HSCs, DNA damage, and genetic instability, which can lead to cell death, permanent bone marrow damage and hematopoietic damage.
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Research of epigenetic aspects of hematopoietic and spermatogenesis stem cells.
Hybešová, Michaela ; Pimková, Kristýna (advisor) ; Děd, Lukáš (referee)
Stem cell differentiation is controlled by coordinated regulation of gene transcription. One of the regulatory factors is the loosening of chromatin and the accessibility of DNA to transcription factors. Chromatin remodeling is mediated by remodeling complexes. The ISWI chromatin remodeling ATPase Smarca5 (S5) is an important factor of remodeling complexes. It is a highly conserved chromatin-remodeling factor forming a catalytic subunit that can be found in several oligosubunit complexes. In these complexes, it actively regulates nucleosome structure and remodeling during DNA replication, repair and transcription. S5 has been identified as a key protein in embryonic development. Its deficiency leads to defects in hematopoiesis and male genital development. In the presented study, we focused on the role of S5 in hematopoiesis and spermatogenesis. Using a mouse model with transgenic expression of S5, co-immunoprecipitation and mass spectrometry, we identified S5 complexes in hematopoietic and testicular cells. We also studied the phenotypic consequences of S5 deficiency in mouse testes and found that it leads to impaired sperm development and male sterility. Using transcriptomic and proteomic analysis, we identified several molecular programs that could lead to reproductive disorders. Our work...
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Hematopoietic stem and progenitor cell defects in transgenic model of Diamond-Blackfan anemia
Holečková, Markéta ; Kokavec, Juraj (advisor) ; Valášek, Leoš (referee)
Diamond-Blackfan anemia (DBA) is a rare congenital bone marrow failure syndrome characterized by deficient development of erythroid progenitors and accompanied by a variable set of developmental defects. About 25 % of patients have mutations of the small ribosomal subunit protein RPS19, and the precise mechanism of single aminoacidic mutations of RPS19 protein in the pathology of Diamond-Blackfan anemia remains largely unknown. To understand the interaction between of genotype and phenotypic variability we have created a mouse model with homozygous mutation in a highly conserved arginine 67 (Rps19R67Δ/R67Δ ). Mouse model with this mutation display many of the same phenotypical trades as patients with DBA. We decided to focus on hematopoiesis and erythropoiesis in this mouse model and tried to characterize those processes. We discovered that Rps19R67Δ/R67Δ mice similarly to DBA patients suffer from anemia and that the erythropoiesis process is disrupted at the stage of proerythroblasts. We also observed changes in hematopoiesis in stages as early as multipotent progenitors. The role of p53 protein as a modifier of DBA phenotype is well known. We created mouse model with p53 depletion to assess the role of p53 protein in relation with mutation in Rps19. Rps19R67Δ/R67Δ Trp53-/- mice show no signs of...
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The role of HOXA9 gene in leukemogenesis
Rejlová, Kateřina ; Starková, Júlia (advisor) ; Fraiberk, Martin (referee)
The evolutionarily conserved family of homeobox genes plays an important role in the development of the anterior-posterior body axis of vertebrates. These genes significantly affect hematopoiesis, the development of blood cells. Extensive studies on homeobox genes in normal hematopoiesis confirmed their role also in leukemogenesis. Since the neoplastic transformation of blood cells, i.e. leukemia, is the most frequent malignancy in children, it has become a major subject of research for many scientists. Precisely in what stage of the malignant transformation the homeobox genes take part has not been shown yet. Neither is it known whether HOX genes are crucial in pathogenesis or whether their deregulation is only a side effect of leukemogenesis. The most studied homeobox gene in leukemogenesis is the HOXA9 gene, which showed correlation with the prognosis of patients with certain leukemias. Many studies describe the effect of HOXA9 in leukemic cell transformation, suggesting this gene could be a promising future target in leukemia therapy. This work is focused on the HOXA9 gene and its association with leukemic transformation of blood cells.
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The role of microRNAs in lymphomas with a focus on miR-155
Hušková, Hana ; Stopka, Tomáš (advisor) ; Svoboda, Petr (referee)
MicroRNAs (miRNAs) are 19-25 nucleotide noncoding RNAs which regulate the expression of target mRNAs at both posttranscriptional and translational level. The physiological functions of miRNAs include development, differentiation, cell cycle regulation and apoptosis. miRNA deregulation has been found in various human diseases, including lymphoproliferative disorders. This Bachelor thesis provides introduction to delineate roles of miRNAs in normal hematopoiesis and cites recent publications on miRNAs in lymphomas with a focus on the role of miR-155. Key words microRNA, hematopoiesis, lymphoma, miR-155
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B- and T- lymphocyte subpopulations in lymphocyte-associated immunodeficiencies
Šinkorová, Vendula ; Kalina, Tomáš (advisor) ; Javorková, Eliška (referee)
The antigen-specific immunity consists of cells called T and B lymphocytes. These cells together with cells of non-specific (innate) immunity begin their development in fetal liver and later in bone marrow from the common progenitor, the hematopoietic stem cell. Both B and T lymphocyte lineages then undergo differentiation which is regulated by many cytokines and transcriptional factors and leads to very heterogeneous cohort of subsets. Because the immune system is not only protecting the organism from infections and malignant growth but also from itself, lymphocyte differentiation must pass many checkpoints where B and T clones are strictly selected. Cells of both lineages closely communicate with each other and also with cells of innate immunity. If, due to mutation of protein encoding genes, disturbance of differentiation or malfunction of effector activities providing some of these functions occurs, an immune system malfunction called immunodeficiency arises. Multiparametric immunophenotyping followed by flow cytometry examination has been proven one of the most suitable techniques for studying lymphocyte subsets and lymphocyte- associated immunodeficiencies. Here we describe examples of primary lymphocyte- associated immunodeficiencies, how they affect individual lymphocyte subsets, what it...
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Comparing results of cell blood count and leukocyte differential count between different series of analyzers Sysmex
Opletalová, Monika ; Blažková, Hana (advisor) ; Bártů, Iva (referee)
In this bachelor thesis I focused on comparing results of cell blood count and leukocyte differential count between three types of Sysmex analyzers. XS - 1000 i, XT - 4000i and XE - 5000 are automatic analyzers, measuring on principles of flow cytometry and impedance methods using hydrodynamic focusation. These methods provide very accurate blood cell an alysis. The theoretical part of bachelor thesis is focused on description of hematopoesis, options for measuring cell blood counts and leukocyte differential counts and general description of measuring methods used by Sysmex analysers. In the experimental part I described the composition of mentioned analysers, their measuring channels and reagents which are used for peripheral blood cells analysis. Every sample from 50 patients was measured on each analyser and results were statistically compared by using ANOVA test. Graphs showing average values of each parameter for negative and positive patient ́s samples were made. The aim of this study was to summarize the main advantages and disadvantages of all three analyzers and determine whether differences in the results of samples between analyzers are statistically significant or not. Powered by TCPDF (www.tcpdf.org)
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Role of Smarca5 (Snf2h) chromation remodeling ATPase in hematopoitic development and erythropoiesis
Kokavec, Juraj ; Stopka, Tomáš (advisor) ; Divoký, Vladimír (referee) ; Kořínek, Vladimír (referee)
The Imitation Switch (ISWI) nuclear ATPase Smarca5 (Snf2h) is one of the most conserved chromatin remodeling factors. It exists in a variety of oligosubunit complexes that move DNA with respect to the histone octamer to generate regularly spaced nucleosomal arrays. Smarca5 interacts with different accessory proteins and represents a molecular motor for DNA replication, repair and transcription. We deleted Smarca5 at the onset of definitive hematopoiesis (Vav1-iCre) and observed that animals die during late fetal development due to anemia. Hematopoietic stem and progenitor cells (HSPCs) accumulated but their maturation towards erythroid and myeloid lineages was inhibited. Proerythroblasts were dysplastic while basophilic erythroblasts were blocked in G2/M and depleted. Smarca5 deficiency led to increased p53 levels, its activation at two residues, one associated with DNA damage (S-18) second with CBP/p300 (K376Ac), and finally activation of the p53 targets. We also deleted Smarca5 in committed erythroid cells (Epor-iCre) and observed that animals were anemic postnatally. Furthermore, 4- OHT-mediated deletion of Smarca5 in the ex vivo cultures confirmed its requirement for erythroid cell proliferation. Thus, Smarca5 plays indispensable roles during early hematopoiesis and erythropoiesis.
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Differentiation plasticity of hematopoietic cells
Polgárová, Kamila ; Stopka, Tomáš (advisor) ; Otáhal, Pavel (referee) ; Šálek, Cyril (referee)
Hematopoiesis has been for many years seen as a straightforward process based on sequential restriction of cell fate potential leading to production of mature blood cells. In the last decade, however, several works documented an unexpected plasticity of hematopoietic cells with expanded potential of myeloid development from lymphoid progenitors and vice versa. Under physiologic conditions hematopoiesis is tightly controlled and the definite cell fate is denominated by multiple factors that all lead to changes in regulatory networks that include transcription factors, epigenetic changes and post-transcriptional modulations. Any disruption of this strict regulation, caused by mutations or other events, affects the proliferation and lineage fidelity of hematopoietic precursors. This may lead to clonal growth of variable significance or leukemogenesis and may possibly affect the treatment sensitivity of the hematological malignancies. For better understanding of hematopoietic regulation we described gene expression changes during physiological development of lymphoid and myeloid lineages and in leukemic specimens using our own simplified real-time PCR based platform. We investigated expression of 95 genes connected with lymphoid and myeloid differentiation or with leukemogenesis in sorted hematopoietic...
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