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In vivo application of holographic endoscopy
Tučková, Tereza ; Brzobohatý,, Oto (referee) ; Bouchal, Petr (referee) ; Uhlířová, Hana (advisor)
Pokrok v porozumění komplexním mozkovým funkcím závisí na schopnosti opticky dosáhnout jakékoli vybrané struktury a oblasti živého mozku se subbuněčným rozlišením při minimálním poškození tkáně. Zpřístupňování hlubších oblastí tkání rozptylujících světlo je v současnosti umožněno zejména vývojem optických endoskopických sond, například mikroendoskopy s gradientními čočkami (GRIN) a svazky optických vláken. Pokrok v metodách holografické modulace světla dosažený v poslední době přinesl jako další nadějný směr pro zobrazování s vysokým rozlišením hluboko ve tkáních použití vícevidových optických vláken (MMF) jako zobrazovacích prvků. Ve srovnání s endoskopy založenými na GRIN čočkách a svazcích optických vláken poskytují MMF nejvyšší poměr rozlišení obrazu ku tloušťce sondy a způsobují minimální poškození tkáně. Úvodní část práce poskytuje přehled o nejmodernějších technologiích hloubkového zobrazování mozku in vivo, vícevidové vláknové endoskopii a jejích principech s cílem představit související technologii. Hlavním technologickým zaměřením práce je použití digitálního mikrozrcátkového zařízení (DMD) k modulaci světla, šířící se MMF sondou. To umožňuje rychlé rastrování fluorescenčního vzorku v zobrazovací rovině za distální hranou vlákna. Byla sestrojena optická sestava využívající tohoto principu, bylo dosaženo vysoké stability a byly pečlivě vyhodnoceny zobrazovací vlastnosti. Ty byly demonstrovány na 2D a 3D fluorescenčních fantomových vzorcích. Dále jsme vyvinuli metodu zpracování obrazu, zlepšující jeho kvalitu a umožňující dosáhnout plného potenciálu difrakčně omezeného rozlišení. Použití algoritmů využívajících regularizované iterativní inverze, případně regularizované přímé pseudoinverze, zvyšuje kontrast a rozlišení obrazu. Další cestou k ex vivo a in vivo zobrazování bylo použití geneticky modifikované myši. Identifikovali jsme vhodné myší modely a ex vivo zobrazování mozku ukázalo, že snímky trpí silným fluorescenčním signálem pozadí z oblastí mimo ohniskovou rovinu. Proto se další práce zaměřila na vývoj technologie útlumu světla založené na konfokálním principu. Byla sestrojena optická sestava pro konfokální filtraci "dírkovou clonkou" s použitím speciální sondy složené z MMF s odstupňovaným indexem lomu spojeného s MMF se skokovým indexem, a druhého DMD. Během zobrazování byl fluorescenční signál shromážděný GRIN-SI-MMF sondou filtrován ve vzdáleném poli sondy, kde se pro každý skenovací ohniskový bod vytváří prstenec. Prstencovitý signál se pak oddělí pomocí masky na DMD2, čímž se také oddělí signál pocházející z ohniska od signálu vznikajícího mimo ohnisko. Na experimentech s použitím fantomového vzorku fluorescenčních mikrokuliček i fixované mozkové tkáně bylo prokázáno, že toto konfokální filtrování vede k zeslabení signálu pozadí, tedy signálu z mimoohniskových rovin, čímž se zvyšuje kontrast a rozlišení snímků. Tento princip konfokální filtrace v holografickém endoskopu byl rovněž demonstrován pomocí nové MMF sondy s bočním zobrazováním. Práce ukazuje jen kousek skládačky dlouhodobého komplexní vývoje optimálního nástroje pro hloubkové tkáňové zobrazování s vysokým rozlišením. Holografický endoskop využívající MMF byl zdokonalen tak, že může sloužit k rutinnímu několikahodinovému zobrazování biologických tkání s možností útlumu světla pocházejícího mimo ohniskovou rovinu. Endoskop byl testován při zobrazování fantomových vzorků i fixovaných plátků myšího mozku a in vivo cév až do hloubky 5 mm.
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Emotional transition and nonstructural changes in mouse models of autism
Nováková, Rozálie ; Kubik-Zahorodna, Agnieszka (advisor) ; Bendová, Zdeňka (referee)
Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by repetitive behaviour and impairments in social behaviour and social communication. The whole aetiological heterogeneity is still not fully elucidated. It is then very important to focus on experimental research, especially on animal models, to help with drug development and recovery. To broaden the variability of focus of behavioural tests on mouse sociability, a new modification of a test to assess transfer of emotional information was proposed. A similar test was published recently for the first time, but it is still not common to use it in mice. Results show that it is possible to measure transfer of fear between conspecifics only during their immediate direct encounter through behavioural evaluation, but not in further standardised anxiety-evaluating tests. Self-grooming behaviour was the only parameter significantly affected by transferred anxiety in the experimental setup used, and therefore should be considered as the most sensitive behavioural parameter describing animal emotional state. However, the variability in individual animal behaviour is still considerably large, which confounds the results to a great degree. Such a behavioural test for transfer of emotional information may be especially useful in...
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Immune stimulation by lipid nanoparticles
Aulichová, Veronika ; Grantz Šašková, Klára (advisor) ; Pačesová, Andrea (referee)
Lipid nanoparticles are the most advanced non-viral delivery system of nucleic acids. They enable safe and efficient transport of nucleic acids to the targeted cells and represent a key enabling technology of RNA therapeutics. RNA therapeutics represent a rapidly emerging field of genetic medicine; however, due to the nature of RNA molecules and their susceptibility to nuclease degradation, the delivery system is crucial for its translation to the clinic. This thesis explores the ability of lipid nanoparticles based on the XMAN6 ionizable lipidoid to elicit an immune response against mRNA-encoded antigen. XMAN6 is a lead lipidoid from a new class of adamantane-based ionizable lipidoids developed in our team. The mRNA-LNP formulations were first tested in vitro to evaluate their functionality and cytokine production and then in vivo using a mouse model. LNPs were applied via two different routes and in different experimental set ups, and their safety was evaluated by analyzing mouse activity. The data showed that XMAN6 is a promising lipidoid for in vivo delivery of mRNA. The mRNA-LNPs successfully induced the antibody response against the encoded antigen by intraperitoneal and intramuscular application. XMAN6 LNPs showed to be suitable for in vivo use, as they were well tolerated and caused only...
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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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Role of NEUROD1 transcriptional network on the development and function of inner ear neurons
Merc, Veronika ; Pavlínková, Gabriela (advisor) ; Mašek, Jan (referee)
Identification of transcription factors involved in a complex network regulating the development of neurosensory cells in the inner ear is a key point for understanding the pathophysiology of hearing loss, development of new therapeutic tools, and for hearing loss prevention. The aim of this thesis was to elucidate the function of the transcription factor NEUROD1 in the development of the inner ear and sensory neurons. Using the Cre-loxP recombination system, a unique mouse model was created with tissue-specific deletion of Neurod1 in NEUROD1-Cre positive cells (Neurod1ST). In the inner ear, Neurod1 was deleted only in neurons permitting to identify the secondary effects of Neurod1 elimination in neurons on sensory cell development. We showed that neither the early development of the inner ear nor the formation of the statoacoustic ganglia was significantly affected by Neurod1 deletion. The primary consequence of the deletion was manifested by increased neuronal death due to apoptosis, which resulted in a reduced number of differentiated neurons in the inner ear. Spiral and vestibular ganglia were smaller in the mutants, and there was a number of neurons misplaced, indicating impaired migration. The cochlear sensory epithelium was shortened probably due to the reduced number of neurons within the...
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Genotype influence on development of infections caused by Trypanosomatidae in mouse
Šíma, Matyáš ; Lipoldová, Marie (advisor) ; Krulová, Magdaléna (referee) ; Kolářová, Iva (referee)
Parasitic protists of genera Trypanosoma and Leishmania are members of Trypanosomatidae family. In our studies, we investigated genetic influence on infections caused by these parasites in a mouse model. These diseases are on genetic level controlled by quantitative trait loci (QTLs), when the resulting phenotype is controlled by set of genes with small individual effect. As a mouse model for mapping of QTLs controlling these infections, we used recombinant congenic strains (RCS). Each RCS carry unique set of 12.5% of the genome from donor parental strain on genetic background of other parental strain. For mapping of QTLs controlling infections caused by Trypanosoma brucei brucei (T. b. brucei) and Leishmania tropica (L. tropica) and eosinophil infiltration into inguinal lymph nodes after Leishmania major (L. major) infection, we used RCS from CcS/Dem series, where STS is donor strain and BALB/cHeA is strain of genetic background. First, it was necessary to find suitable model strains for mapping. In all three studies, we selected RCS, which exceeded range of monitored phenotype parameters in comparison with any other tested RCS or parental strains. Mice of RCS CcS-11 showed shorter survival after T. b. brucei infection and strain CcS-9 exhibited higher eosinophil infiltration after L. major infection. For...
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Generation and analysis of mutant mouse model to study roles of KLKs in cutaneous inflammation
Eliáš, Jan ; Kašpárek, Petr (advisor) ; Drbal, Karel (referee)
Kallikrein-related peptidases (KLKs) are a subgroup of serine proteases of undisputable importance for a variety of functions, whose dysregulation has been linked to several pathological phenotypes. Among those pathologies, the Netherton syndrome stands out, since it is one of the very few that has its mechanism directly linked to KLK proteases as the main culprit of the disease, namely KLK5, KLK7 and to a lesser degree, KLK14. In this case, a mutation in the SPINK5 gene leads to uncontrolled hyperactivity of those proteases, which results in epidermal barrier breach due to excessive epidermal desquamation and severe inflammation of the skin. Inflammation mechanisms of NS are still relatively poorly understood, with important roles being attributed to the activities of KLKs in the processing of immune system molecules and also to the dysregulation of the cutaneous microbiome. TNFα signalling plays a key role in the homeostasis and immune response in the skin. Chronic skin infections may lead to deleterious effects with strong participation of TNFα signalling. To address the degree of its effects on the pathogenesis of NS, we have created a mouse model where the TNFR1 is disrupted by knockout of the Tnfr1 gene on the background of a previously established mouse model of the Netherton syndrome. We...
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Genotype influence on development of infections caused by Trypanosomatidae in mouse
Šíma, Matyáš
Parasitic protists of genera Trypanosoma and Leishmania are members of Trypanosomatidae family. In our studies, we investigated genetic influence on infections caused by these parasites in a mouse model. These diseases are on genetic level controlled by quantitative trait loci (QTLs), when the resulting phenotype is controlled by set of genes with small individual effect. As a mouse model for mapping of QTLs controlling these infections, we used recombinant congenic strains (RCS). Each RCS carry unique set of 12.5% of the genome from donor parental strain on genetic background of other parental strain. For mapping of QTLs controlling infections caused by Trypanosoma brucei brucei (T. b. brucei) and Leishmania tropica (L. tropica) and eosinophil infiltration into inguinal lymph nodes after Leishmania major (L. major) infection, we used RCS from CcS/Dem series, where STS is donor strain and BALB/cHeA is strain of genetic background. First, it was necessary to find suitable model strains for mapping. In all three studies, we selected RCS, which exceeded range of monitored phenotype parameters in comparison with any other tested RCS or parental strains. Mice of RCS CcS-11 showed shorter survival after T. b. brucei infection and strain CcS-9 exhibited higher eosinophil infiltration after L. major infection. For...
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Role of ISL1 in development of neurosensory cells of inner ear
Vochyánová, Simona ; Pavlínková, Gabriela (advisor) ; Machoň, Ondřej (referee)
To understand the pathophysiology of hearing loss, it is necessary to identify genes responsible for embryonic development of neurosensory cells in the inner ear. The aim of this work is to clarify the role of LIM-homeodomain transcription factor ISL1 in the development of these cells. Using Cre-loxP recombination strategy, we generated a mouse line with time and site- specific deletion of Isl1 gene in NEUROD1-Cre expressing cells (Isl1 CKO). Although the early development of stato-acoustic ganglion was not affected by Isl1 deletion, at E14,5, we observed abnormalities in neuronal migration, formation of spiral ganglion and axon guidance in the Isl1 CKO cochlea. The length of the cochlear sensory epithelium was shortened by 20% as a consequence of lower proliferation activity of sensory precursor cells. Our results suggest that ISL1 is necessary for spiral ganglion formation and innervation of the Organ of Corti. Key words: transcription factor ISL1, neurons, Cre-loxP system, mouse model
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Development and function of endocrine cells of the pancreas
Hamplová, Adéla ; Pavlínková, Gabriela (advisor) ; Berková, Zuzana (referee)
Diabetes mellitus affects nearly 300 million people in the world. The development of diabetes is caused by dysfunction or by reduction of insulin-producing β-cells that are part of the endocrine pancreas. Therefore, the most critical step for understanding the pathophysiology of diabetes and for restoring lost β cells is the identification of molecular cues that specify the cellular phenotype in the pancreas. This work is based on the hypothesis that the transcription factor NEUROD1 is a key factor for the development of the pancreas and for the maintenance of endocrine tissue function. Neurod1 conditional KO mutants (Neurod1CKO) were generated using the Cre-loxP system by crossing floxed Neurod1 mice with Isl1-Cre line. Immunohistochemical analyses of the pancreas at embryonic day 17.5 and postnatal day 0 showed that the deletion of Neurod1 negatively affected the development, organization of endocrine tissue, and total mass of pancreatic endocrine cells. To better understand molecular changes, quantitative PCR was used to analyse mRNA expression in the developing pancreas at the age of embryonic day 14.5 and postnatal day 1. Genes important for the development and function of the pancreas have been selected for the study of expression changes. These analyses showed changes in expression of genes...
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