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Functional characterisation of new components of mitochondrial proteome.
Kovalčíková, Jana ; Vrbacký, Marek (advisor) ; Červinková, Zuzana (referee) ; Ješina, Pavel (referee)
1 Abstract It has been estimated that the mammalian mitochondrial proteome consists of ~1500 distinct proteins and approximately one quarter of them is still not fully characterized. One of these proteins is TMEM70, protein involved in the biogenesis of the eukaryotic F1Fo-ATP synthase. TMEM70 mutations cause isolated deficiency of ATP synthase often resulting in a fatal neonatal mitochondrial encephalocardiomyopathies in patients. To understand the molecular mechanism of TMEM70 action, we generated constitutive Tmem70 knockout mice, which led to embryonic lethal phenotype with disturbed ATP synthase biogenesis. Subsequently generated inducible Tmem70 mouse knockout was lethal by the week 8 post induction. It exhibited primarily impaired liver function, which contrasts with the predominantly cardiologic phenotype at disease onset in humans. Liver mitochondria revealed formation of labile ATP synthase subcomplexes lacking subunit c. Thus, in case of TMEM70 deficiency c-oligomer was not incorporated into ATP synthase, which led to critical impairment of mitochondrial energy provision, analogous to TMEM70 dysfunction in humans. In TMEM70 deficient models, the ATP synthase deficiency reached the 'threshold' for its pathologic presentation, which we quantified at 30 %. We observed compensatory increases in the...
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Study of expression and maturation of mitochondrial oxidative phosphorylation system during mammal's prenatal period
Mrhálková, Andrea ; Hůlková, Martina (advisor) ; Ješina, Pavel (referee)
Postnatal adaptation of neonate to extrauterine life is among others dependent on maturation of mitochondrial oxidative phosphorylation system (OXPHOS). It depends on effective mitochondrial biogenesis during fetal developement. The inadequate capacity of mitochondrial OXPHOS system plays an important role in the neonatal mortality and morbidity. Therefore the study of mitochondrial biogenesis on molecular and biochemical level is important to improve the care of very premature neonates, especially critically ill premature neonates. This thesis has been worked out in The laboratory for study of mitochondrial disorders (Department of Pediatrics, 1st Faculty of Medicine, Charles University in Prague). The thesis is based on molecular genetic analyses, which are focused on characterisation of ATP synthase gene expression and on changes in mitochondrial DNA content during human and rat fetal development. The results provide the better insight into mitochondrial respectively ATP synthase biogenesis during human and rat fetal development.
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Calcium intake in patients with disorders beta oxidation fatty acids with long chain.
Ondrová, Ellen ; Floriánková, Marcela (advisor) ; Ješina, Pavel (referee)
The bachelor thesis deals with rare hereditary metabolic disorders, LCHAD (long chain 3- hydroxyacyl-coenzyme A dehydrogenase) deficiency and MTP (mitochondrial trifunctional protein) or TFP (trifunctional protein) deficiency. Deficiencies of these enzymes cause a disturbance in the cycle of β-oxidation of long-chain fatty acids. The basis of treatment for these disorders are dietary and regimen measures. The main goal of the bachelor's thesis was to determine the level of compliance in dietary and regimen measures and calcium intake in patients with LCHAD/MTP deficiency. The theoretical part first describes hereditary metabolic disorders as a large heterogene- ous group of serious hereditary disorders, some of which occur rarely. These rare diseases include LCHAD/MTP deficiency. First, general findings of hereditary metabolic disorders, their history, occurrence, heredity, pathogenesis, diagnosis, clinical manifestations and treatment, are briefly summarized. Furthermore, the theoretical part of the thesis deals with fatty acids as a nutrient, which plays a crucial role in the diet of a patient with LCHAD/MTP deficiency, as well as the β-oxidation process, which is disrupted in these de- ficiencies. The main part of this thesis is devoted to the disease itself, the LCHAD/MTP de- ficiency. It...
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Three-parent babies - new therapies of mitochondrial disorders
Helebrandtová, Veronika ; Pecinová, Alena (advisor) ; Ješina, Pavel (referee)
Mitochondria are essential parts of living cells, as they play a key role in cellular metabolism, especially in energy production. Due to their unique structure, the energy released during the oxidation of the substrates can be used to form the ATP. Mitochondria also contain their own DNA (mtDNA), which is maternally inherited and encodes catalytic subunits of oxidative phosphorylation complexes. Mitochondrial disorders of nuclear or mitochondrial origin, are common causes of inherited diseases and affect mainly the tissues with high energy requirements, such as heart or brain. Treatment of mitochondrial diseases is usually symptomatic and does not lead to complete recovery of the patient. As a result, new causal therapies, such as a gene therapy, are currently investigated. However, using this approach it is necessary to consider the origin of the mutation. Gene therapy of mitochondrial diseases of mtDNA origin is very complicated, therefore the new treatment strategy, mitochondrial replacement therapy, has been proposed. The principle of this technique is to prevent the transmission of mutated mtDNA from mother to offspring by transferring the nuclear genome of mother with mitochondrial disorder into donor's denucleated oocyte with healthy mitochondria. In this way, the child has genetic...
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Functional characterisation of new components of mitochondrial proteome.
Kovalčíková, Jana ; Vrbacký, Marek (advisor) ; Červinková, Zuzana (referee) ; Ješina, Pavel (referee)
1 Abstract It has been estimated that the mammalian mitochondrial proteome consists of ~1500 distinct proteins and approximately one quarter of them is still not fully characterized. One of these proteins is TMEM70, protein involved in the biogenesis of the eukaryotic F1Fo-ATP synthase. TMEM70 mutations cause isolated deficiency of ATP synthase often resulting in a fatal neonatal mitochondrial encephalocardiomyopathies in patients. To understand the molecular mechanism of TMEM70 action, we generated constitutive Tmem70 knockout mice, which led to embryonic lethal phenotype with disturbed ATP synthase biogenesis. Subsequently generated inducible Tmem70 mouse knockout was lethal by the week 8 post induction. It exhibited primarily impaired liver function, which contrasts with the predominantly cardiologic phenotype at disease onset in humans. Liver mitochondria revealed formation of labile ATP synthase subcomplexes lacking subunit c. Thus, in case of TMEM70 deficiency c-oligomer was not incorporated into ATP synthase, which led to critical impairment of mitochondrial energy provision, analogous to TMEM70 dysfunction in humans. In TMEM70 deficient models, the ATP synthase deficiency reached the 'threshold' for its pathologic presentation, which we quantified at 30 %. We observed compensatory increases in the...
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Mitochondrial energy generating capacity in cultured skin fibroblasts
Daňhelovská, Tereza ; Tesařová, Markéta (advisor) ; Ješina, Pavel (referee)
Mitochondrial disorders, with incidence 1:5000 live births children, are one of the most common metabolic diseases. Clinically, it is heterogeneous group of disorders caused by mutations in more than 250 genes. Diagnostic of patients with suspected mitochondrial disorder relies on broad spectrum of biochemical analysis. One of them is a measurement of Mitochondrial Energy Generating Capacity (MEGC). The principle of MEGC analysis is measuring oxidations rate of 14 C - labeled substrates in 10 different incubations. These incubations contain [1-14 C]pyruvate, [U-14 C]malate or [1,4-14 C]succinate, donors and acceptors of Acetyl-CoA and inhibitors of TCA cycle. The results of MEGC analysis provide a variety of information about mitochondrial energy metabolism (MEM) of individual in particular tissue. In diagnostic of patients with suspected mitochondrial disorder is MEGC routinely determined in skeletal muscle. The aim of this study is to optimize MEGC analysis for its use in cultures skin fibroblasts. In sum, MEGC analysis was performed in 23 patients with primary deficiency of oxidative phosphorylation (OXPHOS), in 7 patients with secondary deficiency of OXPHOS and in 15 controls cell lines. The results of MEGC in cultured skin fibroblasts were then compared with results of spectrophotometric...
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Study of expression and maturation of mitochondrial oxidative phosphorylation system during mammal's prenatal period
Mrhálková, Andrea ; Hůlková, Martina (advisor) ; Ješina, Pavel (referee)
Postnatal adaptation of neonate to extrauterine life is among others dependent on maturation of mitochondrial oxidative phosphorylation system (OXPHOS). It depends on effective mitochondrial biogenesis during fetal developement. The inadequate capacity of mitochondrial OXPHOS system plays an important role in the neonatal mortality and morbidity. Therefore the study of mitochondrial biogenesis on molecular and biochemical level is important to improve the care of very premature neonates, especially critically ill premature neonates. This thesis has been worked out in The laboratory for study of mitochondrial disorders (Department of Pediatrics, 1st Faculty of Medicine, Charles University in Prague). The thesis is based on molecular genetic analyses, which are focused on characterisation of ATP synthase gene expression and on changes in mitochondrial DNA content during human and rat fetal development. The results provide the better insight into mitochondrial respectively ATP synthase biogenesis during human and rat fetal development.
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