National Repository of Grey Literature 205 records found  beginprevious68 - 77nextend  jump to record: Search took 0.01 seconds. 
Cell death-regulating micro RNAs and their role in the development and pathological processes.
Běhounek, Matěj ; Anděra, Ladislav (advisor) ; Seifertová, Eva (referee)
MicroRNAs are small protein non-coding, ~ 22 nucleotides long dsRNAs. Their main task is suppression of gene expression via removal/destabilization of mRNA or its targeting to degradation. These small molecules play an important role in the regulation of many cellular processes and have been found to affect expression of more than 30% of human genes. Among the processes affected or regulated by miRNAa belongs also programmed cell death. Although this work is mainly focused on the analysis and characterization a role of distinct miRNAs in the regulation of apoptotic cell death, miRNAs can also participate in the regulation of autophagic cell death or programmed necrosis. MiRNA can enhance cellular sensitivity to apoptosis by suppressing the expression of death receptor genes, but can also drive cells to apoptosis by regulating expression of anti-apoptotic protein Bcl-2. In many different organisms were already discovered and described thausends of micro RNAs anddozens of them participate in the regulation of cell death. Poor or impaired function of miRNAs and related disturbance in apoptotic signaling could lead to a number of pathological processes as tumorigenesis or disturbances in tissue development and homeostasis. . Understanding how miRNA functions in cell death and possible practical...
Molecular mechanisms of mutagenesis and resistence in CML cell lineages
Karasová, Dominika ; Čuřík, Nikola (advisor) ; Savvulidi Vargová, Karina (referee)
Chronic myeloid leukemia is a clonal haematopoietic disease, with characteristic BCR-ABL1 fusion gene. Despite the significant improvement in patient treated with tyrosine kinase inhibitors (TKI), 20-30 % of patients develop resistance. One of the main causes of treatment failure are mutations in the BCR-ABL1 kinase domain (KD). The aim of this work was to elucidate the molecular mechanisms of resistance and mutagenesis development in CML using an in vitro CML model KCL-22. The main part of this work was focused on the identification of genes involved in DNA damage response and repair, that could play a role in the process of mutagenesis of BCR-ABL1. We used the RT2 Profiler PCR Arrays method for the group of selected genes regulating DNA damage response and repair. We identified the genes XRCC6 and PARP1 whose gene expression was significantly and specifically decreased during KD BCR-ABL1 mutagenesis. Products of these genes are involved in repairing DNA double-strand breaks through non-homologous end joining (NHEJ). During study of the KD BCR-ABL1 mutagenesis we also found that clones, which developed mutations, did not show the increased BCR-ABL1 expression in the beginning of the culture compared to the clones in which mutations have not evolved. Key words: myeloid leukemia, mutation,...
Gene expression in chicken embryo: micromanipulation and visualization methods
Bendová, Michaela ; Dvořák, Michal (advisor) ; Hirsch, Ivan (referee) ; Krylov, Vladimír (referee)
The aim of this work was to obtain better insight into the principles of cell structures and organs in the chicken embryo development. To reach this goal special methods of micromanipulations and visualization in vitro, ex vivo, ex ovo and in ovo were implemented and adjusted. These methods were used to study gene expression in neural crest development and eye development. In the course of long term research in our laboratory we observed that oncoprotein v-Myb influences the development of the neural crest and has the capacity to change natural cell fate. We performed a series of experiments to investigate v-Myb protein influence on neural crest cells differentiation, especially melanocyte lineage development, and its influence on gene expression in the neural crest. Therefore we focused on Gremlin 2 (PRDC), the gene upregulated by v-Myb in the neural crest. The established procedure of electroporation in ovo was adjusted to transfect cells of the developing eye and used to study gene expression during lens induction. The results obtained from chicken embryo experiments endorsed the study performed on mouse embryos. Futhermore, the electroporation technique was slightly modified for manipulations of the neural retina in the developing eye in ovo. Thereafter, the retinas were processed ex vivo and...
Normality test of the gene expression data
Shokirov, Bobosharif ; Klebanov, Lev (advisor) ; Hušková, Marie (referee) ; Kalina, Jan (referee)
This thesis deals with a test of normality of gene expressions data. Based on characterization theorems of the normal distribution, the test of normality is replaced by a test of spherical uniformity. Due to strong correlations between the gene expression data, the normality test is conducted with $\delta$ sequences. A new characterization theorem of the normal distribution is proven. Based on that, the normality test is conducted using Kolmogorov's test statistic. The obtained characterization results for the normal distribution are extended to the complete type of distributions and based on that, a test is conducted to verify whether the distributions of the two data sets of the gene expressions belong to the same type. Powered by TCPDF (www.tcpdf.org)
Factors interacting with bacterial RNA polymerase
Sudzinová, Petra ; Krásný, Libor (advisor) ; Fišer, Radovan (referee)
The bacterial cell must be able to rapidly change its gene expression to survive unstable external conditions. Transcription is the key level that affects gene expression. The pivotal enzyme of transcription is RNA polymerase (RNAP). Activity of RNAP is tightly regulated by transcription factors (TFs). These factors affect RNAP in different ways. This work presents an overview of various proteins and others factors, description of their effects on transcription and also mechanisms of their actions. TFs could be divided according to various criteria. In this work, TFs are divided according to how they interact with RNAP: TFs interacting only with RNAP; TFs binding simultaneously DNA and RNAP; TFs interacting with RNA and RNAP. This work presents a comprehensive overview of various TFs that are involved in the bacterial cell's reprogramming of gene expression that is required to withstand the changes in the environment.
The effect of 6S-like RNAs on physiological differentiation of Streptomyces coelicolor
Burýšková, Barbora ; Bobek, Jan (advisor) ; Branny, Pavel (referee)
The variety of bacteria and their genomes sometimes causes conservation of homologue molecules to be displayed not in sequence but in secondary and tertiary structures. In the case of the regulatory 6S RNA, sequence homologues have been found in over 100 bacterial species so far. However, none were found in the genus Streptomyces. The unique genome of these soil- dwelling bacteria, known for their capacity to produce antibiotics, has a high G/C content and diverges substantially from distantly related bacteria. Yet in the non-coding 6S RNA it is the secondary structure that is crucial for its function. The 6S RNAs trap sigma factors by mimicking target promoter sequences in order to help with switching sets of expressed genes during developmental transitions. 6S-like RNA genes in Streptomyces coelicolor have been computationally predicted by comparison of in silico modelled secondary structures of known 6S RNAs. The aim of this thesis was the verification of these 6S-like RNA predictions. The experimental approach was based on RNA co-immunoprecipitation (RNA CoIP), as well as RT- PCR from RNA samples. The outcomes of this project are the detection of six novel ncRNA transcripts with possible 6S-like RNA functions, which also served as the wet-lab verification of the in silico prediction technique...
Rare cells in diagnostics and monitoring of gynecological diseases
Kiss, Imrich ; Bobek, Vladimír (advisor) ; Špaček, Jiří (referee) ; Klézl, Petr (referee)
In the last two decades there is an enormous effort to discover a non-invasive marker to diagnose, predict and monitor therapy effect of malignant diseases. Circulating tumor cells (CTC) have the ability to fulfil all these criteria. The introduction of the monothematic thesis deals with the problematics of CTC in general and its application in clinical medicine. It is followed by the author's first publication, which reviews the current status of CTC in gynecological malignancies. The next publication is an original article about CTC in patients with endometrial carcinoma. It reports a successful isolation of vital CTC in 75% of tested patients and identifies CTC as an individual marker of the disease without correlation to the stage, grade or lymph nodes involvement. The second part of this thesis deals with endometriosis, a benign but often recurrent disease worsening the life quality of women in reproductive age. The multicentre study presents a successful isolation of circulating endometrial cells (CEC) in patients with histologically proven endometriosis with various stages and symptoms. From the total of 423 samples 78.4% were CEC positive. Eleven patients were monitored during their menstrual cycle and CEC tested in different phases, being the early post-ovulatory period in which the...
Osteogenesis and bone healing in congenital short femur
Frydrychová, Monika ; Dungl, Pavel (advisor) ; Havlas, Vojtěch (referee) ; Charvát, Jan (referee)
Introduction: Congenital short femur, or proximal femoral focal deficiency (PFFD), is a rare complex deformity of the lower extremity with femoral dominance. The clinical findings cover wide range of variety, from femoral absence till inconspicuous shortening of the femur. Aim of the study: 1. Molecular analysis of pseudoarthrosis tissue in congenital short femur with focusing on osteogenic and angiogenic gene expression in comparison with physiological bone. The differences in gene expression were expected. 2. Retrospective analysis of femoral healing after prolongation calculating the severity of affection, age, distance of elongation and complication. The extended healing according to severity type and age was expected compared to control group. Material and methods: The RNA from piece of one was isolated and transcription profile of possible 113 genes of osteogenesis and angiogenesis was detected by biochip technology (SuperArray Bioscience Corporation). 10 samples analyses were performed (7 of PFFD, 3 controls). The data of 57 PFFD patients indicated for elongation of the femur with the types Pappas III, IV, VII, VIII and IX and 12 patients in control group were evaluated retrospectively and statistically by GLS method. Results: The expected differences in gene expression in PFFD tissue...
Factors affecting gene expression in Bacillus subtilis
Sudzinová, Petra ; Krásný, Libor (advisor) ; Vopálenský, Václav (referee) ; Vohradský, Jiří (referee)
Bacterial DNA-dependent RNA polymerase (RNAP) is a key enzyme of bacterial transcription. Its activity must be tightly regulated. This could be done on the level of promoter DNA topology recognition, by changing the intracellular levels of metabolites, or by binding proteins, known as transcription factors. Even though the RNAP regulatory network has been intensively studied for decades, new regulators are still being described. The main focus of this Thesis is to characterize some of them: i) HelD, a novel RNAP interacting factor, with so far unknown protein 3D structure; ii) RNase J1, an enzyme with a unique mechanism of functioning; iii) Spx, a major regulator of gene expression in Bacillus subtilis, with still new roles to be defined and iv) the effect of the topological state of promoters on transcription. We identified HelD as an interacting protein of RNAP in Bacillus subtilis and described its biochemical properties. It stimulates transcription in an ATP-dependent manner, by enhancing recycling of RNAP molecules (Publication I). We published the first insight into the HelD structure by SAXS (small angle X-ray scattering) and deepened the understanding of HelD domain composition (Publication III). And finally, we were able to solve the cryo-EM structure of HelD:RNAP complexes from...
Characterization of the Caenorhabditis elegans pop-1 gene
Jakšová, Soňa ; Vacík, Tomáš (advisor) ; Macůrková, Marie (referee)
The TCF/LEF transcriptional factors regulate the target genes of the Wnt signalling pathway - one of the key signalling mechanisms involved in development of multicellular organisms. The TCF/LEF genes produce a number of various protein isoforms, which consequently leads to a great functional diversity of the TCF/LEF proteins. In this diploma project we focused on the Caenorhabditis elegans gene pop-1, the ortholog of the TCF/LEF genes, whose isoforms have not been studied yet. Using the Northern blot analysis we tried to identify alternative isoforms of the pop-1 mRNA in C. elegans. Using quantitative RT-PCR we also analyzed the pop-1 mRNA levels during seven developmental stages of C. elegans. Further, we also determined the expression profile of two important partners of pop-1, the bar-1 and sys-1 genes, whose protein products function as transcriptional co-activators. Key words: canonical Wnt signaling pathway, TCF/LEF transcription factors, Caenorhabditis elegans, pop-1

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