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The role of exosomes in communication between adipose and cardiac tissue
Novotná, Denisa Regine ; Zouhar, Petr (advisor) ; Kašík, Petr (referee)
Extracellular vesicles, including exosomes, represent an important, newly identified, factor in the information transmission between individual cells and organs of a multicellular organism. Usually, exosomes contain nucleic acids, proteins and even whole organelles such as mitochondria. The exosomes production takes place, among others, in adipocytes of adipose tissue. Because adipose tissue is the main repository of stored lipids, its metabolism and the functionality of its mitochondria react sensitively e.g. to nutritional conditions. Recent studies have demonstrated that exosome secretion from adipose tissue may play a pivotal role in the progression of metabolic syndrome. In hypertrophied tissue, mitochondria fail, and adipocytes dispose of them by secreting them as exosomes. The majority of these exosomes with damaged mitochondria are directly taken up by macrophages within the adipose tissue. However, a subset of them can escape into the circulation and reach the heart. The uptake of these exosomes by the myocardium and the incorporation of damaged mitochondria into its own mitochondrial network may have surprisingly positive effects for increasing resistance to damage in infarction. Furthermore, exosomes may also play an important role in ridding brown adipose tissue and other cells of...
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Effect of endosymbionts on composition and properties of Trichomonas vaginalis exosomes
Zdrha, Alois ; Tachezy, Jan (advisor) ; Černý, Jan (referee)
Trichomonas vaginalis is a parasite of the human reproductive tract and the causative agent of trichomoniasis, the most spread non-viral sexually transmitted disease. Although trichomoniasis usually has mild symptoms, it can lead to serious adverse effects. The course of the disease is influenced by the host immune system, microbiome and virulence of the parasite. Importantly, the virulence of T. vaginalis is extremely variable, and it depends on secreted and surface molecules. Among these are proteases and adhesins, which can be secreted as part of the secretome or through extracellular vesicles (EVs). Further potential virulence factors are the endosymbionts of T. vaginalis: Trichomonas vaginalis virus (TVV) and Mycoplasma hominis. Although extensively studied, no consensus on whether TVV exacerbates trichomoniasis has been reached. The aim of this thesis is to analyse the effect of TVV on the protein and RNA exosomal cargo and to assess the cytokines induced by exosomes of TVV-positive T. vaginalis. Key words endosymbionts, dsRNA virus, TVV, exosome, parasite, Trichomonas vaginalis, bioinfor- matics
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The role of extracellular vesicles in transmission of dsRNA viruses in parasitic protist Trichomomas vaginalis.
Horáčková, Jana ; Rada, Petr (advisor) ; Voleman, Luboš (referee)
Trichomonas vaginalis is a parasitic protist found in the human urogenital tract, where it adheres to the epithelial cells. During infection, T. vaginalis cells release extracellular vesicles that allow them to communicate with each other and modulate the host immune response. Most studied T. vaginalis strains contain dsRNA Trichomonasviruses (TVVs). These viruses belong to the Totiviridae family, which includes other dsRNA viruses from various parasitic protists. TVV is transmitted vertically to the daughter cells during cell division. Horizontal transfer of TVV between T. vaginalis cells has not yet been proven. TVV particles were found inside small extracellular vesicles that release infected T. vaginalis into the extracellular space. In this thesis, it was shown that TVV could be transmitted between trichomonads during co-cultivation of infected and uninfected trichomonads. However, stable TVV infection of trichomonads was not observed. It was also proven that extracellular vesicles from infected trichomonads could transmit TVV among other trichomonads. Nevertheless, this way of transmission did not lead to the stable TVV infection of trichomonads either.
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Role of exosomes and ectosomes in Trichomonas vaginalis virulence
Göblová, Rebeka ; Tachezy, Jan (advisor) ; Ditrich, Oleg (referee)
Trichomonas vaginalis is a causative agent of the most common non-viral sexually transmitted disease with approximately 275 mil new cases annually. Virulence of this parasitic depends on at least four factors: cell shape transformation, cytoadherence, secretion of cysteine proteases, and presence of endosymbionts. Over the past decades, extracellular vesicles appeared being another important player in the host-parasite interaction. It was discovered that T. vaginalis is one of the protists that can shed the extracellular vesicles such as exosomes and ectosomes. These vesicles are possibly involved in host-parasite communications, however limited information is available about their function. To investigate a possible role of exosomes in T. vaginalis virulence, we first selected suitable strain, which is free of endosymbionts (TV 17-2MI). Next we prepared six clones of TV 17-2MI strain to test whether the strain is homogenous concerning the virulence, or there are differences in virulence among individual cells. Mouse intraperitoneal virulence tests revealed that the clones displayed significant differences in virulence level, particularly in abscess formation and mortality of infected animals. Thus, for the first time we demonstrated heterogeneity of cells derived from a single T. vaginalis strain...
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Exosomes, their biogenesis, composition and role
Hyka, Lukáš ; Forstová, Jitka (advisor) ; Motlová, Lucia (referee)
Exosomes are a subtype of extracellular vesicles. Exosomes are distinguishable from other extracellular vesicles by their endosomal origin and their typical cup-shaped morphology. The biogenesis of exosomes begins in the early endosomes by inward budding. The endosomal sorting complex required for transport sorts ubiquitinylated proteins into the vesicles. The small volume of cytosol is also encapsulated during budding. These vesicles are called intraluminal vesicles and the whole body is called multivesicular body. Multivesicular body fuses with the plasma membrane and vesicles are released as exosomes into the extracellular space. Exosomes are present in all bodily fluids and are secreted by a high number of cells. Exosomes present antigens on their surface to trigger immunity or serve in the cellular communication by the transfer of small RNAs.
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Exosome and its role in RNA metabolism of budding yeast S. cerevisiae
Holická, Eliška ; Půta, František (advisor) ; Groušl, Tomáš (referee)
Exosome is a protein complex present in the yeast nucleus and cytoplasm, which participates in RNA degradation, processing and turnover. The core of exosome consists of nine catalytically inactive subunits, which physically associate with RNA nuclease Rrp44. The function of exosome is dependent on many cofactors or facultatively associated enzymes, and these associations provide high versatility of the complex. In different compartments the complex works by other means and plays a role in distinct processes. In nucleus, exosome acts mainly in pre-RNA processing, whereas in cytoplasm its major role is to degrade native mRNA. Nevertheless, in all of these processes, its general role is the 3' exonucleolytic cleavage of single-stranded RNA. Exosome has homologs in many various kinds of organisms - e. g. different types of bacterial nucleases, archeal exosome, human PM-Scl complex (or exosome), which implicates high conservation of this degradation machinery. Thus, it is very likely that some exosome components lost their original function over the evolution, more than that the yeast exosome is an evolutionary innovation.
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