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Bacterial populations in mucosal tissues of the house mouse
Ptáčníková, Aneta ; Stopka, Pavel (advisor) ; Hampl, Vladimír (referee)
Microbiota becomes one of the most important subjects in biological research and numerous studies revealed that microbiota plays a broad spectrum of essential roles in different organisms. This master thesis focuses on the bacterial part of microbiota contained in mucosal tissues of wild house mice (Mus musculus musculus). Male and female samples were collected by nasal and oral cavity lavages, vaginal mucosa lavages and from urine and stool. We aimed to detect quantitative, qualitative and sex-specific differences in bacterial populations between mucosal tissues with particular focus on bacterial cycling in vaginal mucosa during the estrous cycles. Bacterial abundances were estimated by qPCR whilst bacterial diversity was detected by targeted metagenomic sequencing of the hypervariable region of the 16S rRNA gene. Significant differences were detected in bacterial abundances and alpha diversity between particular mucosal tissues. Stool samples contained the highest number of bacteria, while samples from the nasal mucosa and urine contained low amount of bacteria. The highest alpha diversity was discovered in stool samples, the least alpha diversity was found in the urine. Mucosal tissues also varied based on the bacterial composition on the level of particular genera. Detailed analysis of estrous cycles...
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Composition of skin microbiome in psoriatic patients
Stehlíková, Zuzana ; Jůzlová, P. ; Rob, F. ; Herzogová, J. ; Koren, O. ; Uzan, A. ; Tlaskalová-Hogenová, Helena ; Jirásková Zákostelská, Zuzana
Psoriasis is a chronic noninfectious and inflammatory skin disease, whose pathogenesis involves environmental triggers, including microbiota. In our study we compared bacterial composition between healthy controls and psoriatic patients using V1V2 hypervariable region of 16S rRNA. We found higher species diversity in psoriatic lesions than in contralateral psoriatic healthy site or in healthy control skin. Genus Propionibacterium was more abundant in contralateral healthy sites (57.77%) than in affected psoriatic sites of psoriatic patients (47.12%). On the other hand, we found higher abundance of genus Staphylococcus in psoriatic lesions (18.78%), while lower abundance in contralateral healthy sites (9.52%). Since Propionibacterium are commensal bacteria, the shift in their abundance from healthy to psoriatic skin could be due to disturbation of natural skin habitat. Interpretation of higher presence of Staphylococcus in psoriatic lesions comparing to contralateral healthy sites requires further species characterization. To complete the picture about psoriatic microbiome we will further investigate skin fungal composition in identical samples.
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Role of microbiota in mouse experimental model of psoriasis
Jirásková Zákostelská, Zuzana ; Stehlíková, Zuzana ; Klimešová, Klára ; Rossmann, Pavel ; Dvořák, Jiří ; Novosádová, Iva ; Kostovčík, Martin ; Coufal, Štěpán ; Šrůtková, Dagmar ; Hudcovic, Tomáš ; Štěpánková, Renata ; Rob, F. ; Jůzlová, P. ; Herzogová, J. ; Tlaskalová-Hogenová, Helena ; Kverka, Miloslav
Anotace v anglickém jazyce\n\nMouse model of human psoriasis and gnotobiotic are important tools in understanding the role of gut and skin microbiota in pathogenesis of psoriasis. In our experiments we showed that gnotobiotic mice, as well as conventional mice treated with antibiotics, have milder skin inflammation in comparison with control conventional mice. Treatment with broad spectrum antibiotics led to dramatic shift in gut microbial composition, in particular, we observed extensive increase of order Lactobacillales. To analyze the potential effect of Lactobacillales on skin inflammation, we further monocolonized mice with L. plantarum WCFS1. Also monocolonized mice showed lower skin inflammation in comparison with conventional mice. To understand whether microbial dysbiosis is cause or effect of psoriasis needs to be further investigated.\n\n
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Novel mechanisms of T cell-mediated intestinal autoimmunity to Paneth cells
Brabec, Tomáš ; Filipp, Dominik (advisor) ; Janečková, Lucie (referee)
(En) Paneth cells are one of the major player in the maintenance of the homeostatic relationship between intestinal microbiota and the immune system. This function is largely achieved by their production of bactericidal enteric α-defensins (ED) and other antimicrobials. Disruption of Paneth cell functions is associated with severe human disorders such as Crohn's disease (CD) and Autoimmune Polyendocrinopathy- Candidiasis-Ectodermal Dystrophy (APECED). However, there is only a very limited information regarding the interactions and regulatory circuits operating between Paneth cells and intestinal immune system in either health or under pathological conditions. The previous study conducted in our laboratory described a new mechanism for the initiation and maintenance of Paneth cells targeted autoimmunity. The suggested model was that ED-specific T cells escape the selection in the thymus, infiltrate the intestine and diminish Paneth cell numbers through autoimmune destruction. This process also lead to the accumulation of inflammation- inducing bacteria, which were implied to exacerbate the inflammatory autoimmunity. Since this model of intestinal autoimmunity is of correlative nature, its intrinsic mechanism and functional relationships between immune system, Paneth cells and microbiota are largely...
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Intestinal microbiota and mood disorders
Ambrožová, Lucie ; Herink, Josef (advisor) ; Jílek, Petr (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Candidate: Lucie Ambrožová Supervisor: Doc. MUDr. Josef Herink, DrSc. Title of diploma thesis: Intestinal microbiota and mood disorders The intestinal microbiom is composed mainly of two dominated strains - Bacteroidetes and Firmicutes. The other strains are just not numerous like the previous ones. The specimens have the invariable core of microbiom which doesn't change in time. Nevertheless they have also the transient gut bacteria, which change during their life. Intestinal microbiom is influenced by many factors. Between them we can categorize for example the way of the childbirth, the breast - feeding, the alimentation, the state of health, and the medicaments. Every specimen has own specific microbiom. It was found that human population is possible to divide into three intestinal groups or enterotypes. To each enterotype dominates different bacterial strain. It was proved that intestinal microbiom communicates with the brain and it works also vice versa. This communication system is called "brain - intestine" and takes several ways in several body systems (such as nervous, endocrine, metabolic, and immune). To normal development of the brain is needed the right colonisation of non...
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Research of vertebrate-microbiota relationship using germ-free organisms
Kubovčiak, Jan ; Kreisinger, Jakub (advisor) ; Hájková, Petra (referee)
Germ free (axenic) animals are individuals reared under specific conditions preventing their contact with surrounding microorganisms. Some of the features observed in these individuals vary from those observed in naturally colonized counterparts. These differences probably reflect the influence of presence of a complex intestinal microbial population in the intestine, which influences important physiological functions of the host body by various mechanisms. Thus, nature of these differences allows to study relationship of the host, vertebrate in this case and its microbiota, which evolved into a complicated system of interactions providing relatively stable coexistence. Germ free research of this relationship is focused on interactions between microbiota and host's immune system, metabolism, morphology of digestive tract and behavior. This thesis provides summary of research outcomes on previously mentioned topics. Powered by TCPDF (www.tcpdf.org)
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The effects of bacterial lysates on the gut barrier function and microbiota composition
Zákostelská, Zuzana ; Tlaskalová - Hogenová, Helena (advisor) ; Prokešová, Ludmila (referee) ; Rada, Vojtěch (referee)
Dynamic molecular interactions between the microbiota and the intestinal mucosa play an important role in the establishment and maintenance of mucosal homeostasis. Aberrant host- microbiota interaction could lead to many diseases such as inflammatory bowel disease. The aim of our study was to evaluate the commensal and probiotic bacteria activities and their ability to induce pathological or exert beneficial effects. The most important trigger for immune system development is an exposure to microbial components. Here, we show that there is a time window at about three weeks of age, which enables the artificial colonization of germ free mice by a single oral dose of cecal content. The delayed colonization by either inoculation or co-housing causes permanent changes in immune system reactivity, which may downgrade the results of experiments performed on first generation of colonized animals. In this thesis we report that even non-living commensal bacteria such as Parabacteroides distasonis (mPd) or well known probiotics such as L. casei DN-114 001 (Lc) possess anti-inflammatory effects in experimental model of colitis. The mechanisms that this effect is achieved by the lysate of L. casei DN-114 001 comprise: a) improvement in the gut barrier function, b) correction of the dysbiosis, and c) modulation of the...
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Bacterial components in experimental intestinal inflammation prevention and therapy
Kverka, Miloslav ; Tlaskalová - Hogenová, Helena (advisor) ; Šedivá, Anna (referee) ; Stříž, Ilja (referee)
Although strong protective immune response is essential for preventing invasion by pathogens, equivalent responses against antigens originating from commensal bacteria can lead to chronic inflammatory diseases, such as inflammatory bowel disease (IBD). Manipulating the mucosal immune responses with microbial antigens might be an excellent tool to IBD therapy or prevention. Our aim was to gain some insight into the regulation of the intestinal inflammation and to isolate bacterial immunomodulatory components that could be used in intestinal inflammation therapy and prevention. One particular mechanism of how healthy colon tissue regulates the inflammation during acute experimental colitis is through modulation of bioavailability of glucocorticoids (GCs) in gut mucosa. Here, we show that intestinal inflammation changes the local GC metabolism, which ultimately leads to decrease in inflammatory readiness of cells in the gut mucosa and in mesenteric lymph nodes. This pre-receptor regulation of GC function could represent an important homeostatic function of the gut mucosa. The actual triggers of intestinal inflammation in IBD seem to be either microbial dysbiosis or microbes with special "pathogenic" abilities, which both could be rectified by feeding with probiotics. Here, we report that oral feeding with live...
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Role of bacteria and mucosal immune system and their interaction in the pathogenesis of inflammatory bowel disease
Du, Zhengyu ; Hudcovic, Tomáš (advisor) ; Prokešová, Ludmila (referee) ; Kamanová, Jana (referee)
Although the etiology and pathogenesis of inflammatory bowel disease (IBD) is not fully understood, it is generally accepted that the inflammation results from aberrant immune responses to antigens of gut microbiota in genetically susceptible individuals (Sartor et al., 2006). Alteration in intestinal microbiota has been found in IBD patients with increased abundance of certain bacteria and decreased abundance of others. Due to the complexity of the disease, multifaceted interactions between genetic factors, host immune response, gut microbiota and environment factors need to be taken into account. In this thesis, the pathogenesis of IBD was first reviewed in respect with the four factors mentioned above. Then we concentrated on the interaction between IBD-associated bacteria and mucosal immune system. We investigated the ability of mucosal-associated bacteria (MAB) from IBD patients to induce spontaneous colitis in germ-free (GF) mice and the impact of those bacteria on the development of dextran sulfate sodium (DSS)-colitis. Together with the analysis of the composition of gut microbiota of MAB colonized mice, we demonstrated the potential deleterious microbes were able to increase the susceptibility to DSS-colitis once they found a suitable niche. We revealed the mechanism of an E.coli strain...
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