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Study of the autophagosome biogenesis in Arabidopsis
Ničová, Veronika
The process of autophagy is a cellular mechanism that allows cells to dispose of both damaged and unwanted components. These components are covered by a double membrane, from which an autophagosome arises. Afterwards, the content is transported to the vacuole, where it is degraded or recycled. Due to the immobility of plants, they have evolved a number of mechanisms for defending themselves from adverse conditions. It is well known that autophagy occurs throughout the life of a plant, but it can be intensified if needed, for example in the event of a stressful condition. In view of the fact that autophagy is a relatively complex regulated mechanism, there is an ongoing effort to conduct research on this topic. Therefore, autophagy is important in stress condition responses, whether they are caused by biotic or abiotic factors. There are various types of stress that can influence autophagy in different ways, including poorly packaged proteins or the availability of nutrients. Additionally, autophagy is not only essential for the tolerance to certain applied stresses, but it is also essential for the regulation of stress memory. Functional characterization of phosphatidylinositol-3-phosphates role in autophagy and phagophore biogenesis is also very important. As part of this thesis, the mtv11 mutant plant was monitored. The mutant plants carry a mutation in the MTV11 gene that encodes an important subunit of the phosphoinositide 3-kinase complex. Plants were monitored under abiotic stress conditions to study their effects on autophagosome formation. A study of this mutant plant might be contributing to the accurate understanding of the autophagosome biogenesis.
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Mitophagy biomarkers in the continuum of Alzheimer's disease
Katonová, Alžbeta ; Veverová, Kateřina (advisor) ; Bohačiaková, Dáša (referee)
The findings of recent years have shown that impaired mitophagy is involved in the pathophysiology of Alzheimer's disease (AD) and other neurodegenerative diseases. Studies on brain biopsies of AD patients, cellular and animal models of AD show that age-dependent decline in mitophagy is a significant contributor to AD pathology, and that the levels of mitophagy proteins are altered. However, whether these changes are reflected in the biofluids of individuals with AD, and whether mitophagy proteins could be potential biomarkers of AD, is unknown.The aim of the diploma thesis was to compare the level of mitophagy markers in blood serum and cerebrospinal fluid (CSF) of patients in various stages of AD with cognitively healthy controls (CU) and determine its relationship to the degree of cognitive impairment and standard Alzheimer's biomarkers (amyloid beta (Ab42), total tau (T-tau) and tau phosphorylated at threonine 181 (P-tau181)). We have shown that mitophagy is impaired in individuals with AD, manifested by increased levels of PINK1 and BNIP3L (activators of mitophagy) and decreased levels of TFEB (master regulator of lysosomal biogenesis) compared to CU. Moreover, these changes were associated with more advanced AD pathology, manifested by increased AD biomarker positivity and cognitive...
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Monitoring of mutant huntingtin influence on autophagy in human neural stem cells
Zezulová, Kristýna ; Vodička, Petr (advisor) ; Kohoutek, Jiří (referee)
Huntington's disease is an inherited neurodegenerative disease caused by a mutation in the huntingtin gene. Its expressed product, mutated huntingtin protein, aggregates in the cell and affects wide range of cellular processes, including proteostasis mechanisms. Autophagy, classified among the mechanisms of cellular degradation and recycling of proteins and other cellular components, is one of the processes disrupted by the presence of mutated huntingtin. The goal of the project was to prepare a tandem genetic construct (fusion protein LC3-EGFP-mCherry) using chemically competent bacteria by molecular cloning methods, transfect it into prepared human lines carrying both normal and mutated huntingtin, and thus modify the lines to transiently, and if possible also constantly express this sensor of autophagy activity. Such modified lines allow monitoring the effect of the presence of normal and mutated HTT on the course of autophagy and also provide experimentally suitable conditions for influencing autophagy in these cells using inhibitors and activators from the group of small molecules. Two types of LC3-GFP-mCherry/RFP fusion proteins were successfully prepared by molecular cloning and transiently introduced by lipofection into the control ARPE19 lines. Expression of the constructs in human H9 NSC...
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Effect of illusory movements physiotherapy on vital and metabolic functions of patients with large burns
Jelínková, Pavla ; Bakalář, Bohumil (advisor) ; Jevič, Filip (referee) ; Smetana, Jiří (referee)
Name and surname of the author: Bc. Pavla Jelínková Institution: Third Faculty of Medicine, Charles University Title: Effect of illusory movements physiotherapy on vital and metabolic functions of patients with large burns Supervisor: MUDr. Bohumil Bakalář Year of defense: 2022 Keywords: large burns; illusory movements; proprioceptive neuromuscular facilitation; vital functions; catabolism; intensive care unit-acquired weakness The aim of this thesis was to determine how the usage of functional proprioceptive stimulation (so-called illusory movements) influenced vital and metabolic functions of patients with extensive burns. In the first part of the thesis we focus on defining the issues we encounter in patients with extensive trauma. Extensive damage not only affects metabolic and vital functions, but the extent of the skin injury changes prognosis of the injured person and the length of hospitalization. The longer patients are hospitalized in intensive care units, the more we encounter acquired muscle weakness. One of the ways to prevent this phenomenon is effective rehabilitation, which is quite challenging in burn patients. As an alternative, the usage of proprioceptive stimulation is offered. It creates illusions instead of real movements in the cerebral cortex. However, there has been no...
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health benefits of the intermittent fasting
BRABCOVÁ, Simona
This bachelor thesis focuses on the issue of intermittent fasting and its impact on human health. The thesis is conceived as literary research. It presents various forms of intermittent fasting and their influence on physiological processes in the body and on specific diseases. Furthermore, this bachelor thesis focuses on negative side effects. The main aim of the thesis is to present the findings in a comprehensive form. The content of the thesis emerges mainly from foreign literature, articles and studies dealing with the issue. The work presents intermittent fasting as an alternative approach to eating with the potential to cure various diseases. It also discusses the advantages and disadvantages of other eating styles, such as a caloric restriction diet.
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Molecular consequences of electron transport chain deficiency in proliferating and quiescent cells
Magalhães Novais, Silvia Carina ; Rohlena, Jakub (advisor) ; Panicucci Zíková, Alena (referee) ; Eelen, Guy (referee)
Oxidative phosphorylation (OXPHOS) system is best known for producing ATP in mitochondria. As a major metabolic hub, OXPHOS also supports other biological functions that are unrelated to ATP synthesis. Are these additional roles of OXPHOS unique to different cell states, such as to proliferation and quiescence, two of the most contrasting states of a mammalian cell? In this thesis we used genetic models of OXPHOS deficiency to show that in proliferating cells and in tumors OXPHOS primarily supports biosynthesis of nucleotides, whereas in quiescent cells OXPHOS provides oxidative stress resistance. Mechanistically, in growing tumors OXPHOS drives dihydroorotate dehydrogenase (DHODH), an enzyme crucial for de novo synthesis of pyrimidines. Complex II of OXPHOS also acts as a sensor of mitochondrial dysfunction and regulates pyrimidine synthesis for energy conservation. In contrast, in quiescent cells OXPHOS maintains autophagy by continuous low level ROS generation and together with the antioxidant defense provides constitutive oxidative stress protection. In summary, beyond ATP production OXPHOS has additional vital roles tailored to the particular requirements of quiescence and proliferation, with relevance for pathophysiology in cancer and vascular biology.
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Study of mechanisms influencing inflammatory and neurodegenerative processes and their subsequent treatment in ALS and spinal cord injury
Vargová, Ingrid ; Jendelová, Pavla (advisor) ; Jiruška, Přemysl (referee) ; Balaštík, Martin (referee)
Study of mechanisms influencing inflammatory and neurodegenerative processes and their subsequent treatment in models of ALS and spinal cord injury The mechanisms of neurodegeneration during spinal cord injury (SCI) and amyotrophic lateral sclerosis (ALS) are complex and poorly understood, which is why it's troublesome to counteract them with effective therapies. This thesis explores the pathways of autophagy, endoplasmic reticulum (ER) stress, and the mammalian target of rapamycin (mTOR) pathway that regulates these mechanisms in models of both SCI and ALS. Upregulation of autophagy and the mTOR pathway in an in vivo contusion SCI injury model was confirmed. The mTOR inhibition led to upregulation of autophagy, reduction of inflammation, and recovery in acute SCI. Upregulated autophagy was discovered in the SOD1G93A rat model of ALS. By treating the ALS rats with human mesenchymal stem cells, prolonged survival of the animals and preservation of motor neurons (MNs) possibly occurred through modulation of autophagy. The involvement of the mTOR pathway in the degeneration of MNs was further explored in the context of astrocytes. Pleckstrin homology like domain family A member 3 (PHLDA3), a newly discovered repressor of the mTOR pathway, was found to lead to ER stress if overexpressed in astrocytes...
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Mitochondrial transfer-mediated modulatory action of stem cells on immune cells
Somova, Veronika ; Krulová, Magdaléna (advisor) ; Balounová, Jana (referee)
Stem cells use different mechanisms of intercellular communication to modulate an immune response. Mitochondrial transfer is one of the mechanisms which induce metabolic changes, support cell survival, and change the phenotype of immune cells. Nevertheless, little is known about the mechanism used for transfer of mitochondria between different cell populations and the faith of mitochondria inside the acceptor cell. This thesis aims to describe the mechanism of transfer and the provided modulation. Factors that could affect mitochondrial transfer including reactive oxygen species production, apoptosis and mitochondria function were analyzed. And the impact of mitochondrial transfer on cell survival and mitophagy was described. The next aim was to compare the ability of mesenchymal stem cells (MSC) and Sertoli cells (SC) to transfer mitochondria, with MSC being more productive in the transfer of mitochondria than SC. Significant differences in the presence of mitochondria from donor MSC or SC in individual populations of immune cells were also detected. To explain these findings, the impact of reactive oxygen species on the transfer of mitochondria was analyzed in detail, although it wasn't confirmed. However, it needs to be highlighted that mitophagy plays an important role before and after...
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Mitochondrial production of reactive oxygen species and its role in physiological regulations
Holzerová, Eliška ; Mráček, Tomáš (advisor) ; Kalous, Martin (referee)
The production of mitochondrial reactive oxygen species and the resulting oxidative stress is an important phenomenon driving long-lasting research and intense discussions. Knowledge of exact mechanisms of reactive oxygen species production and pathways leading to their formation could help us to directly affect their production, a task with potential terapeutic implications. The molecular nature of the production of reactive oxygen species by some enzymes has already been well documented, but others still remain controversial and current theories are obviously far from the truth. Much more interesting is the question of physiological importace of this production. The reactive oxygen species were considered harmful factors clearly distorting the integrity of the organism for a long time. However, recent research suggest that their existence can also be beneficial and effective. Evidently they can serve as a signaling molecules in several metabolic and regulatory pathways occurring in the organism. This bachelor thesis offers insight into the current state of knowledge. It focuses on the most detailed description of the reactive oxygen species production by mitochondrial respiratory chain enzymes. Furthermore, it deals with some signaling cascades, where involvement of mitochondrially generated...
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