Dissertations / Theses on the topic 'Maladies mitochondriales'
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Aure, Karine. "Physiopathologie moléculaire et cellulaire des maladies mitochondriales à présentation neurologique." Paris 6, 2007. http://www.theses.fr/2007PA066281.
Gilleron, Mylène. "Complexité des maladies mitochondriales : à partir de deux exemples." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066136/document.
Mitochondrial diseases represent a very diverse set of pathologies. With this work, I approached their complexity in two different situations: phenotypic analysis of fibroblasts derived from patients with defects of the respiratory complex III and phenotypic analysis of a cohort of patients, the POLG gene of whom had been sequenced. The complex III plays a central role in the mitochondrial respiratory chain. Contrary to its complete biochemical characterization, its physiological role has been relatively poorly established. We selected 15 patients with complex III defect in liver and/or muscle and with fibroblasts expressing a respiratory defect. The genetic origin was initially known for four of these defects (UQCRB, BCS1L x2, MT- CYB) and during this project, we were able to identify three additional cases (CYC1, MT- CYB, LYRM7). We sought to assess the existence of a link between the disease phenotype and the defect characteristics: gene involved, tissue expression and cellular responses. Our population of fibroblasts, genetically heterogeneous, turned also to be diverse with respect to the biochemical and cellular consequences of the defect. A "typical" profile of complex III defect therefore does not seem to exist. Pathologies related to POLG mutations are often considered the most common mitochondrial diseases in adults. Their clinical presentation is very diverse. We have investigated the specificity and sensitivity of different clinical and biological signs considered as suggestive for POLG mutations and therefore leading to POLG sequencing. To that purpose, we retrospectively analyzed the clinical phenotype and mitochondrial investigations in 154 patients for which POLG had been sequenced revealing mutations affecting two alleles of the gene in 34 patients, one allele for 10 patients and a normal sequence for 110 patients. This study has shown that POLG mutations were responsible of recurrent clinical and paraclinical signs, whose sensitivity and specificity when considered in association allowed to propose a diagnostic flowchart for POLG sequencing. This study has also permitted to establish the natural story of diseases associated with deleterious POLG mutations in adults. In conclusion, classification of mitochondrial diseases by a common biochemical abnormality, a complex III defect in the present case, leads to group very different diseases that differ from their clinical, biochemical and cellular patterns. On the contrary, even in diseases considered highly diverse as those due to POLG mutations, classification by the affected gene allows to identify recurrent presentations in a population of adult patients with neurological presentation
Simon-Lombes, Anne. "Investigations moleculaires des maladies mitochondriales humaines." Paris 5, 1997. http://www.theses.fr/1997PA05N003.
Legros, Frédéric. "Étude de la dynamique du compartiment mitochondrial et des mutations hétéroplasmiques de l'ADN mitochondrial." Paris 7, 2002. http://www.theses.fr/2002PA077109.
Savagner-Albertini, Frédérique. "Fonctions mitochondriales dans l'oncocytome thyroi͏̈dien." Angers, 2002. http://www.theses.fr/2002ANGE0503.
We have studied thyroid oncocytomas, characterized by the presence of oxyphil cells containing abnormally large numbers of mitochondria, to explore the possible involvement of mitochondria in carcinogenesis. We showed that these tumors present a metabolic switch through an anaerobic synthesis of adenosine triphosphate (ATP). We also demonstrated the presence of a coupling defect between the respiratory chain and ATP production, in tumors as well as in an oncocytic oncocytic cell line named XTC. UC1. We showed that several factors regulating the mitochondrial biogenesis were involved in the accumulation of mitochondria in these tumors (UCP2, Tfam, PGC-1). We propose a model of mitochondrial accumulation in thyroid oncocytoma which could be a consequence of uncoupling
Barthélémy, Cyrille. "Variations spontanées et induites du nombre de copies de l'ADN mitochondrial." Paris 7, 2001. http://www.theses.fr/2001PA077125.
PARFAIT, COPALU BEATRICE. "Implication des genes nucleaires de structure dans les maladies mitochondriales." Paris 7, 1999. http://www.theses.fr/1999PA077190.
Beinat, Marine. "Caractérisation génétique des atteintes hépatiques mitochondriales." Thesis, Paris 5, 2013. http://www.theses.fr/2013PA05T007/document.
Genetic characterization of mitochondrial liver damage
Baillet, Francette. "Anomalies mitochondriales dans la maladie de Menkes, à propos de trois observations." Bordeaux 2, 1998. http://www.theses.fr/1998BOR2M003.
Cherif, Chabane. "Substitution de l'ADN mitochondrial entre la lignée de souris CBA/H et NZB : effets sur des traits comportementaux sensori-moteurs et mnésiques à l'âge de 6 et 12 mois." Paris 5, 1997. http://www.theses.fr/1997PA05A001.
Cambier, Linda. "Caractérisation fonctionnelle de deux nouvelles protéines mitochondriales." Montpellier 2, 2009. http://www.theses.fr/2009MON20265.
Bioinformatical and high density cDNA hybridization studies on human genes have allowed to identify potential genes preferentially expressed in human striated muscle and of unknown function. This thesis work consists in the functional characterization of two of these genes : GENX-3587 and GENX-70612. GENX-3587 corresponds to the human FEM1A gene, which is a candidate gene for the polycystic ovary syndrome (PCOS), while the human protein FEM1A is involved in an anti-inflammatory signaling pathway mediated by prostaglandin E2. Generation of a FEM1A specific antibody allowed us to show for the first time that mouse Fem1a is a mitochondrial protein, which is preferentially expressed in organs enriched in mitochondria such as brain, heart and liver. Interestingly, we have also observed that Fem1a expression is up-regulated in hearts from mice subjected to ischemia injury, suggesting that Fem1a may be part of the prostaglandin E2 cardioprotective pathway occurring after myocardial infarction. GENX-70612 corresponds to a gene called C6orf125 encoding a protein of unknown function, we have called mitochondrin. We have demonstrated that mitochondrin is a mitochondrial protein preferentially expressed in the brain and in the heart of mice. Furthermore, we have shown that mitochondrin is involved in the energetic metabolism of mitochondria by playing a positive role on mitochondrial ATP production. We have also shown that mitochondrin is an essential positive regulator of late muscle differentiation. Finally, preliminary experiments seem to indicate that mitochondrin plays a role on insulin secretion from β-pancreatic cells
Pierron, Denis. "Anthropologie moléculaire et épidémiologie : interaction entre haplogroupes et pathologies mitochondriales." Bordeaux 1, 2008. http://www.theses.fr/2008BOR13593.
Buchet-Poyau, Karine. "Cellules humaines dépourvues d'ADN mitochondrial : métabolisme adaptatif et utilisation dans l'étude génétique des pathologies mitochondriales." Lyon 1, 1999. http://www.theses.fr/1999LYO10192.
Hassoun, Sidi Mohamed. "Dysfonction myocardique septique : conséquences des altérations de l'homéostasie calcique et mitochondriales." Lille 2, 2008. http://www.theses.fr/2008LIL2S030.
Sternberg, Damien. "Contribution à trois aspects de la génétique mitochondriale humaine : étude de transmission de l'ADN mitochondrial lors de fécondations in vitro - caractérisation de mutations de l'ADN mitochondrial dans les maladies mitochondriales et le vieillissement musculaire." Paris 12, 2002. http://www.theses.fr/2002PA120010.
Mitochondrial genetics is important to consider when dealing with infertility, mitochondrial diseases or ageing. Our work contributes to the clarification of the role and behaviour of mitochondrial DNA (mtDNA) in those three circumstances. First, we studied mtDNA inheritance in children born after a particular in vitro fertilisation technique, i. E. Intracytoplasmic injection of spermatozoon (ICSI). Although the risk of transmission of a paternal infertility-linked nuclear defect by this technique is well known, the possible transmission of the patemal mtDNA had never been addressed by means of highly sensitive detection assays. By using different sensitive techniques, we showed that there was no detectable paternally inherited mtDNA in the peripheral blood of the 27 children who were studied. Second, we aimed at determining the contribution of mtDNA tranfer RNA (tRNA) gene defects to the pathogenesis ofmitochondrial disorders. We set up an exhaustive scanning method to screen ah tRNA genes for mutations, and applied it to a large number of selected patients with mitochondrial disorders. We found numerous sequence variations of those genes, some of them already known to be pathogenic or polymorphie, others being questionable from a functional point of view. We performed an evaluation of each questionable sequence variation by all possible means, and were able to assign a precise significance to most of them. In retrospect, we tried to delineate the best indications for the screening ofmtDNA tRNA genes. Third, we wanted to determine the contribution of mtDNA mutations to the ageing process of human muscle, at a single fibre level. We looked for large-scale rearrangements and tRNA gene point mutations in a large number of fibres defective in cytochrome c oxidase (COX- fibres) activity and an equal number of normal fibres (COX+ fibres) from normal biopsy samples taken from ageing subjects. We detected large scale rearrangements in several fibres. Most interestingly, we detected, characterised and quantified tRNA gene point mutations in several COX- fibres, such mutations being absent from COX+ fibres. We showed that clonally expanded point mutations contribute toageing process in muscle, by a segmental alteration of the respiratory chain activity
Collombet, Jean-Marc. "Expression des gènes des phosphorylations oxydatives dans les cellules musculaires de patients atteints de diverses pathologies mitochondriales." Lyon 1, 1995. http://www.theses.fr/1995LYO10057.
Tudesq, Nicolas. "Encéphalomyopathies mitochondriales : à propos d'un cas de MERRF avec déficit en NADH Coenzyme Q Reductase : revue de la littérature." Bordeaux 2, 1988. http://www.theses.fr/1988BOR23006.
Haut, Sandrine. "Place de la biologie moléculaire dans le diagnostic des cytopathies mitochondriales." Paris 5, 1998. http://www.theses.fr/1998PA05P151.
Lahaye, Laurent. "Anomalies mitochondriales au niveau musculaire chez trois sportifs de haut niveau d'entrainement." Bordeaux 2, 1995. http://www.theses.fr/1995BOR2M075.
Addo, Mathew Glover. "Identification of new nuclear genes involved in the mitochondrial genome maintenance." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA112065.
Mitochondrial respiratory chain diseases of nuclear origin represent one of the major causes of metabolic disorders. These diseases are characterized by a huge clinical and genetic heterogeneity which is a major problem in identifying the disease causing gene. Although several gene mutations have already been found in some patients or families, the disease causing gene of the majority is yet to be determined. The overall structure and gene content of the mitochondrial genome and the proteins required for mtDNA transactions are largely conserved from yeast to human offering the opportunity to use animal models to understand the molecular basis of mitochondrial dysfunctions. To expand the number of human candidate genes of mitochondrial diseases involved in mtDNA maintenance, we have developed in this study, the nematode Caenorhabditis elegans as a model organism to identify new proteins involved in mtDNA maintenance by combining RNAi and ethidium bromide exposure. We have developed a large-scale screening method of genes required for mtDNA maintenance in the worm and initially indentified four new C. elegans genes (atad-3, dnj-10, polrmt, phi-37 and immt-1) involved in mtDNA stability. The human homologs of these genes (ATAD3, DNAJA3, POLRMT and ATP5A1) can be now considered as candidate genes for patients with quantitative mtDNA deficiencies. Using our screening design we have begun to screen all the C. elegans genes encoding mitochondrial proteins. Of the 721 estimated C. elegans mitochondrial genes homologous to human genes, we have tested 185 genes and found that 41 genes are required for the maintenance of the mitochondrial genome in post mitotic cells. These genes fall into three main functional categories of metabolism, protein synthesis and oxidative phosphorylation. Finally, in this study, we investigated the reversibility of mtDNA depletion with drugs to counteract POLG dificiency. Three molecules, Chlorhexidine, Resveratrol and Bezafibrate, have been tested to restore normal mtDNA content and worm life cycle. These experiments hold promise for future work using C. elegans as a pharmacological model for mitochondrial diseases.Altogether, the data generated in this work is a starting point for promising advances in the mitochondrial field, showing the relevance of the nematode as a model organism to study fundamental processes as well as human health research
Bouzidi, Mohamed Fouad. "Expression de protéines impliquées dans diverses pathologies mitochondriales : recherche de l'origine génétique de déficiences en ubiquinol-cytochrome c réductase ou en cytochrome oxydase." Lyon 1, 1997. http://www.theses.fr/1997LYO10053.
Berg, Alonso Laetitia. "Déficits de la chaîne respiratoire mitochondriale avec instabilité de l’ADN mitochondrial : identification de nouveaux gènes et mécanismes." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4101/document.
Non communiqué
Dubot, Audrey. "Étude des déficiences en cytochrome c oxydase et en ATPase-ATPsynthétase dans des pathologies mitochondriales humaines et chez le nématode C. Elegans." Lyon 1, 2003. http://www.theses.fr/2003LYO10215.
Bris, Céline. "Influence de la génétique mitochondriale en pathologie : apport des techniques de séquençage haut débit Deep sequencing shows that oocytes are not prone to accumulate mtDNA heteroplasmic mutations during ovarian ageing Novel NDUFS4 gene mutation in an atypical late-onset mitochondrial form of multifocal dystonia." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0093.
Mitochondrial diseases are common metabolic disorders characterized by strong clinical and genetic heterogeneity, in particular due to the dependence on 2 genomes, nuclear (nDNA) and mitochondrial DNA (mtDNA), and the concept of mitochondrial heteroplasmy. The purpose of this work was to develop a strategy for the analysis of the mtDNA through next-generation sequencing (NGS), and then to apply it to the study of mitochondrial diseases and those related to aging: primary open-angle glaucoma (POAG) and ovarian aging. After validating the performances of our NGS strategy for the detection and quantification of mtDNA variations, we confirmed the power of systematic analysis of the whole mitochondrial genome with the use of uroepithelial cells for mitochondrial diseases diagnosis and the identification of novel mtDNA variants. However, these advances generate new challenges such as the interpretation of low percentages of mtDNA mutations or the prediction of the pathogenicity of new variants. For aging-related diseases, we have identified the possible protective role of the mitochondrial haplogroups T and H in women, respectively in the occurrence and severity of POAG, suggesting that mtDNA influence is drivenby gender, and thus the importance of gender stratification for association studies. By contrast, we did not observe any accumulation of mtDNA abnormalities in early ovarian aging. In perspective, we report the identification of a nDNA mutation in an atypical phenotype, highlighting the complexity of mitochondrial diseases diagnosis, due to this double genome
Delettre-Cribaillet, Cécile. "Génétique des dystrophies héréditaires de la rétine : identification du gène responsable de l'atrophie optique dominante OPA1." Montpellier 1, 2002. http://www.theses.fr/2002MON1T002.
Schwenzer, Hagen. "Aminoacyl-ARNt synthétases mitochondriales humaines : aspects fondamentaux et contribution à la compréhension de pathologies reliées." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAJ045/document.
Aminoacyl-tRNA synthetases (aaRSs) are housekeeping enzymes involved in translation. In human cells, 2 different sets of nuclear genes code for aaRSs. One codes for cytosolic (cyt) aaRSs, and the second one codes for aaRSs of mitochondrial (mt) location. Mt-aaRSs are translated in the cytosol, targeted and imported into mitochondria.Mutations in 9 mt-aaRSs have been described. Some of the mutations do not display significant influence on the housekeeping aminoacylation activity. It has been proposed that those mutations affect alternative functions.Alternate functions have been described for cyt-aaRSs. While the organization of cyt-aaRSs is explored and their involvement into alternate functions established, the properties of the human mt-aaRSs remain unknown. On one site, this thesis integrate mt-AspRS into new functional networks (sub-mitochondrial localization and partnership). On the other site, it expand the view of the sub-mitochondrial organization to the full set of mt-aaRSs and should ultimately shed light into the molecular mechanisms underlying some of the pathologies. These results open the door for additional investigations to gain a complete view about the sub-mitochondrial organization of aaRSs. Those contributions will be of help for the understanding of molecular mechanisms underlying some mitochondrial disorders
Su, Xin. "Yeast models of diseases linked to the mitochondrial ATP6 gene : molecular bases and therapeutic prospects." Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0216.
By definition, mitochondrial diseases result from a defect in the process of oxidative phosphorylation (OXPHOS). This is responsible for the production of ATP, the main source of cellular energy. In this process, four multiprotein complexes (I-IV) inserted into the inner mitochondrial membrane transfer to molecular oxygen the reducing equivalents released by the oxidation of carbohydrates and fatty acids. This activity generates a proton motive force used for the synthesis of ATP from ADP and inorganic phosphate by the Complex V or ATP synthase.Diseases including NARP (Neuropathy Ataxia Retinitis Pigmentosa) and MILS (Maternally Inherited Leigh Syndrome) have been associated with mutations in the subunit a of ATP synthase. Its gene (ATP6) is in the mitochondrial genome. This genome is present in up to several thousand copies per cell. Mutations in the ATP6 gene often coexist with wild-type copies of the mitochondrial genome in patients' cells and tissues (heteroplasmy), which makes their study difficult. The yeast Saccharomyces cerevisiae, whose mitochondrial genome can be modified at will, makes it possible to overcome this genetic heterogeneity owing to its incapacity to stably maintaining heteroplasmy. In addition, thanks to its good fermentation capacity, this organism is able to survive mutations that inactivate the OXPHOS system.During my thesis, I exploited these characteristics to better define the consequences on ATP synthase of five ATP6 gene mutations identified in patients: m.8969G>A, m.9191T>C, m.8993T>G, m.8909T>C, and m.9166T>C. The pathogenicity of the first three has been established. The last two are new mitochondrial DNA variants. Through the identification of intragenic suppressors, and in the light of high-resolution structures of ATP synthase described recently, I was able to define the molecular bases of the pathogenic mechanisms induced by the m.8993T>G, m.9191T>C and m.8969G>A mutations. The m.8909T>C variant was identified in combination with a well-known pathogenic mutation in tRNALeu (m.3243A>G). We have found that an equivalent of this new mutation in yeast has deleterious effects on the assembly/stability of the subunit a comparable to those induced by mutations of the ATP6 gene (m.8993T>C, m.9176T>C) with a well-established pathogenicity, and therefore has the potential to affect human health on its own. My studies in yeast are consistent with studies that recently concluded on the pathogenicity of the m.9166T>C variant and allow to better understand how it impacts ATP synthase.I have identified an active suppressor mechanism in yeast models of pathogenic subunit a mutations. It involves the oxodicarboxylate transporter (Odc1) located in the inner mitochondrial membrane. I have found that artificially overexpressing Odc1 allows for greater Krebs cycle (or TCA) activity. This cycle is involved in the oxidation of organic substrates whose reducing equivalents are then transferred to oxygen by the respiratory chain. It runs low in ATP synthase mutants with impaired proton channel activity. The Odc1-dependent suppressor activity results from a partial uncoupling of the inner membrane so that the TCA cycle is stimulated despite the presence of defect in ATP synthase. This effect allows a greater production of ATP via ADP phosphorylation coupled with one of the reactions of the Krebs cycle. These results open interesting perspectives for the treatment of diseases associated with alterations in ATP synthase, and possibly other metabolic disorders. This study also sheds new light on the control of complex IV biogenesis by ATP synthase
Rossignol, Rodrigue. "Expression métabolique de défauts dans le fonctionnement des oxydations phosphorylantes mitochondriales : effet de seuil et théorie du contrôle du métabolisme appliqués à l'étude de la spécificité tissulaire des cytopathies." Bordeaux 2, 2000. http://www.theses.fr/2000BOR28781.
Damiano, Maria. "Rôle de la dysfonction mitochondriale dans deux maladies neurodégénératives, la Maladie de Huntington et la Maladie de Parkinson." Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066584/document.
Mitochondrial dysfunction has been implicated in several neurodegenerative diseases and is correlated with augmented levels of intracellular oxydant stress. The mitochondrial defects observed in tissues from patients, as well as in animal and cellular models of Huntington’s and Parkinson’s diseases, suggest the implication of mitochondria in the pathogenesis of these diseases. The two projects discussed in this manuscript focus on the role of particular aspects of mitochondrial physiology in these diseases. By the first project we show the role of defective mitochondrial respiratory chain compex II in several rodent models of Huntington’s disease. By using a lentivirus-based gene transfert strategy we highlight the neuroprotective potential of the striatal overexpression of the subunits of complex II. The second project focus on Parkin and PINK1, two proteins implicated in the autosomal recessive, hereditary forms of Parkinson’s disease and in mitochondrial quality control mechanisms, such as mitophagy. In a cellular model we show that the two proteins facilitate Drp1-dependent mitochondrial fission. We show that Parkin may facilitate the signaling pathways controlling the activity of the pro-fission protein Drp1. This effect is probably indirect and mostly PINK1-independent. On the contrary, in mitochondrial depolarization conditions, by FRET (Förster Resonance Energy Transfer) a direct spatial coordination of Parkin, PINK1 and Drp1 is observed, which seems to be determinant for the efficiency of mitophagy. My projects shed new light on pathogenic mechanisms and open new perspectives in the research on these diseases
Ferré, Marc. "Analyse bio-informatique du protéome mitochondrial et du spectre des mutations de la protéine Opa1." Phd thesis, Université d'Angers, 2009. http://tel.archives-ouvertes.fr/tel-00457327.
Haut, Sandrine. "Déficit en complexe III de la chaîne respiratoire mitochondriale : étude de cinq cas." Paris 5, 2003. http://www.theses.fr/2003PA05P630.
The ubiquinol-cytochrome c réductase (complex III of mitochondrial respiratory chain) deficiencies could be attibuated to mitochondrial or nuclear genetic origin. We identified 5 patients with an isolated complex III (CIII) deficiency. A molecular abnormality was found in two cases. In the first, an homoplasmic mutation was found in the mitochondrial cytochrome b (cytb) gene, the patient have a staturo-ponderal delay. The mutation was also present in two healthy individuals of family members. Studies carried out in vitro confirmed the pathogenic role of the mutation, already considered as a cardiomyopathy generating mutation in a previously reported case. In the second patient, we describe, for the first time, a mutation located in a nuclear gene encoding a structural subunit of CIII : the HUMQPC gene encoding the human ubiquinone-binding protein. This mutation induces a full reduction in cytb content and consequently destabilizes the CIII
Baratli, Yosra. "Etude de la toxicité des nanoparticules d'oxyde de fer (Fe3O4) chez le rat : analyses mitochondriales et du stress oxydant." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ023/document.
The objective of our work is to characterize iron oxide nanoparticles (Fe3O4) and study their acute toxicity in Wistar rats. Our results showed that acute oral administration of Fe3O4, results in a dose and time-dependent alteration of oxidative stress parameters as well as liver damage. Regarding the in vitro study on isolated mitochondria, our results showed that these nanoparticles do not adversely affect the various complexes of the mitochondrial respiratory chain or mitochondrial coupling in any of the organs studied (brain, heart, lung, liverand kidneys) and regardless of the concentration used (100, 200, 300 and 500 μg/ml) while the isolated liver mitochondria from aged rats (18 months), an alteration is observed at all the complexes of the liver mitochondrial respiratory chain as well as the mitochondrial coupling regardless of the concentration used (250, 300 and 350 μg/ml), whereas for the young rats (3 months) no change is observed
Rouzier, Cécile. "Déficits de la chaîne respiratoire mitochondriale avec instabilité de l'ADN mitochondrial : identification de nouveaux gènes et mécanismes." Nice, 2012. http://www.theses.fr/2012NICE4066.
Dovydenko, Ilya. "Mise au point d'aptamères aux capacités thérapeutiques basés sur les ARN importables dans les mitochondries humaines." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ046/document.
Defects in mitochondrial genome cause neuromuscular diseases, for which no efficient therapy has been developed. Since most mitochondrial mutations are heteroplasmic, wild type and mutated mitochondrial DNA (mtDNA) coexist in the same cell, and the shift in proportion between two mtDNA types could restore mitochondrial functions. The aim of the project was development of carrier-free system for targeting the therapeutic mitochondrially importable RNA into living human cells. During my PhD study, I have synthesized a set of new anti-replicative RNAs containing various chemical modifications, aiming to increase their stability in the cell, and developed a new method for the chemical synthesis of RNA molecules containing cholesterol attached through a biodegradable bridge. Cholesterol containing antireplicative RNAs were characterised by efficient cellular uptake, partial colocalisation with mitochondria and ability to decrease the proportion of mutant mtDNA
Lefevre, Sophie. "Modèle levure de l'ataxie de Friedreich : stress oxydant, apoptose et dynamique mitochondriale." Paris 6, 2010. http://www.theses.fr/2010PA066204.
Jacoupy, Maxime. "Perte de fonction de la voie de signalisation <> dans la physiopathologie de la maladie de Parkinson - Mécanismes et conséquences." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066387/document.
Parkinson’s disease (PD) is linked to a specific loss of dopaminergic neurons of the substancia nigra. The disease is most often sporadic but familial monogenic forms exist, for example due to mutations in PARK2 or PINK1. Those genes encore the cytosolic ubiquitin-protein ligase Parkin and the mitochondrial serine/threonine kinase PINK1, both essential for mitochondrial quality control. This work studies the role of their interaction at the outer mitochondrial membrane in the regulation of mitochondrial homeostasis. We found that the association of PINK1 and Parkin to the mitochondrial import TOM complex during mitochondrial stress induces the import of most proteins targeted to mitochondria; that destabilizing this complex is sufficient to initiate mitophagy; and that Parkin activation by PINK1 facilitates the import of its substrate, HSD17β10. We developed an inducible BRET-based molecular biosensor to study the classical pre-sequence import pathway. We also found, in a neuronal model, that mitochondrial stress induced a strong increase in the expression of mitochondrial biogenesis key genes, in the presence of Parkin; and that these genes are basally up-regulated in PARK2-/- neurons, possibly reflecting an alteration of acute stress response. These results increase our understanding of the pathophysiology of autosomal recessive forms of PD, underlining the importance of the PINK1/Parkin pathway in mitochondrial import and biogenesis
Lebigot, Elise. "Exploration d'anomalies mitochondriales dans les fibroblastes de patients atteints de déficit dans les voies de biogenèse des centres fer-soufre ou de synthèse de l'acide lipoïque." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS027.
The aim of this work is to study mitochondrial dysfunctions related to a defect of protein lipoylation in fibroblasts of 14 patients. These patients carry a point mutation in a gene encoding for a protein involved either in lipoic acid biosynthesis (LIPT1 or LIPT2) or in the mitochondrial pathway devoted to iron-sulfur cluster biogenesis (FDX1L, ISCA1, ISCA2, IBA57, NFU1, BOLA3) essential for maturation of mitochondrial Fe-S proteins such as lipoic acid synthase (LIAS). This work describes the second case of FDX1L deficiency and a patient with a new mutation in ISCA1 gene.We found that mitochondrial [4Fe-4S] proteins (mitochondrial aconitase, complexes I and II of the respiratory chain and LIAS) are mainly affected in fibroblasts of patients with defect in the mitochondrial Fe-S maturation pathway. Secondary, LIAS dysfunction leads to decreased lipoylation of PDHc and KGDHc, complexes involved in energy metabolism. Neither mitochondrial network nor oxidative stress biomarkers was modified in our study. Addition of exogenous lipoic acid did not rescue the mitochondrial deficiency.Protein expression profiles obtained in fibroblasts of patients suggest that NFU1, BOLA3 and IBA57 and also ISCA1, ISCA2 and IBA57 could function and interact together to form protein complexes
Sayadi, Kéfi. "Myopathie mitochondriale : discussion d'une observation avec déficit des groupes II et IV de la chaîne respiratoire mitochondriale." Montpellier 1, 1991. http://www.theses.fr/1991MON11157.
Kelly-Aubert, Mairead. "Anomalies de la balance redox mitochondriale dans la mucoviscidose." Paris 6, 2011. http://www.theses.fr/2011PA066027.
Reynier, Pascal. "Etude des délétions de l'ADN mitochondrial dans diverses maladies musculaires." Aix-Marseille 2, 1995. http://www.theses.fr/1995AIX22061.
Comte, Caroline. "Caractérisation d’ARN artificiels importables dans les mitochondries humaines à des fins thérapeutiques." Strasbourg, 2010. https://publication-theses.unistra.fr/public/theses_doctorat/2010/COMTE_Caroline_2010.pdf.
Mitochondrial DNA mutations, important cause of incurable human neuromuscular diseases, are mostly heteroplasmic: mutated mtDNA is present in cells simultaneously with wild-type genomes, the pathogenic threshold being generally > 70% of mutant mtDNA. We studied if heteroplasmy level could be decreased by RNAs complementary to mutant mtDNA regions. To target specifically designed oligoribonucleotides into the organelle, mitochondrial import of RNA was exploited, the pathway delivering nucleic acids into mitochondria in vivo. Using mitochondrially targeted RNAs as mitochondrial vectors we demonstrated, in cultured transmitochondrial cybrid cells, that RNAs complementary to the mutant mtDNA region can specifically reduce the proportion of mtDNA bearing a large deletion associated with the Kearns Sayre Syndrome. These findings may be relevant to developing of a new tool for therapy of mtDNA associated diseases
Godard, Francois. "ATP synthase mitochondriale : fonction de la sous-unité ε et biogenèse du F0." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0092/document.
At first, I am interested in the ε subunit of mitochondrial ATP synthase in yeast, an organism that is well suited for the study of mitochondrial functions. This protein is a part of the ATP synthase called central stalk. This allows the coupling of proton translocator domain of this enzyme (FO) to its catalytic domain (F1) where ATP is synthesized. Using a tetO expression system, I showed that in the absence of the ε subunit, F1 and FO domains are no longer coupled. It results in a massive proton leakage across the inner membrane of mitochondria. I then showed that the absence of the ε subunit can be compensated by mutations slowing the activity of FO. These data allow to conclude that the ε subunit is necessary to maintain the physical integrity of the ATP synthase for oxydative phosphorylation. Later, I tried to identify new factors involved in the biogenesis of the FO. For this, I used a genetic screen where the survival of yeast cells is conditioned by mutations inactivating the FO. About a thousand clones were analyzed. The mutations were localized in mitochondrial and nuclear genomes. Eighteen clones with mutations in genes encoding not yet known ATP synthase expression factors were completely sequenced. Several new cellular systems that are potentially involved in the biogenesis of FO were identified
Rocher, Christophe. "Anomalies de l'ADN mitochondrial et métabolisme mitochondrial : Mécanismes des déplétions et des délétions." Bordeaux 2, 2001. http://www.theses.fr/2001BOR28910.
One of the fundamental problems of the study of mitochondrial metabolism integration in cellular metabolism is to understand how mitochondrial metabolism is controlled (regulated) ? The subject of this thesis concerns this topic and tries to answer the two following questions : 1- What are the repercussions of a mitochondrial DNA (mtDNA) amount variation at the level of the energy metabolism ? We used two models which are : (i) a lymphoblastoid cell line coming from a patient for whom a 99 % decrease of the muscle mtDNA amount was observed (depletion), but also (ii) a series of stable mtDNA depleted cell lines obtained by treatment of a control one with nucleotides analogues (AZT and ddC). The results clearly indicate that cellular mtDNA amount is one important parameter in the regulation of oxidative phosphorylations. Indeed, despite the high copy number of mtDNA, a small decrease in its content has severe implications on mitochondrial bioenergetics. Consequently, the quantity of mtDNA in the cell is a parameter to take into account for the study of mitochondrial pathologies as well as the nature or the heteroplasmlic level of a mtDNA mutation. 2- What are the molecular mechanisms involved in the generation of human mitochondrial DNA rearrangements, such as large-scale deletions ? Some mitochondrial pathologies areare due to such reorganizations of mtDNA and different mechanisms have been proposed to explain these rearrangements. The mechanism of slipped mispairing has been proposed but no molecular bases are described. The results we obtained show that the formation of a triple helix could be involved in the generation of mtDNA deletions as well as partial duplications or triplications
El, Fissi Najla. "Caractérisation d'allèles de mitofusine associés à la maladie de Charcot-Marie-Tooth : mise en évidence de l'implication d'un déséquilibre entre fusion et fission mitochondriale dans le dysfonctionnement des neurones." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0250/document.
Mitochondria form a dynamic network remodeled by two antagonistic processes called mitochondrial fusion and fission. While mitochondrial fusion creates interconnections between mitochondria, mitochondrial fission result in fragmentation. These processes are mediated by Dynamin-related GTPases, the outer-membrane fusion protein mitofusin, and the fission factor DPR1.The main aim of my resaearch was to characterize the impact of an imbalance between mitochondrial fusion and fission in neurons in the context of a severe hereditary neuropathy called Charcot-Marie-Tooth type 2A (CMT2A). Indeed, this disease is caused by dominant mutations in the mitofusinMFN2.In order to dissect the mechanisms by which these mutations alter mitofusin properties and neuronal function, we developed four drosophila models of CMT2A expressing the two most frequent substitutions (R94Q, R364W) and two others localizing to similar domains (T105M, L76P). The four alleles resulted in mitochondrial depletion at neuromuscular junctions, decreased oxidative metabolism, increased mtDNA mutations, and impaired locomotion that were associated with aberrant mitochondrial morphology. Interestingly, while GTPase domain-associated mutations (R94Q, T105M) aggregate unfused mitochondria, mutations within helix bundle 1 (R364W, L76P) unexpectedly enhance mitochondrial fusion, as demonstrated by rescue of mitochondrial morphology and locomotion provided by the DRP1 fission factor. In conclusion, we show that both dominant negative and dominant active forms of mitofusin can cause CMT2A, and propose for the first time that excessive mitochondrial fusion drives CMT2A pathogenesis in a large number of patients
Favory, Raphaël. "Syndrome de Détresse Microcirculatoire et Mitochondriale dans le sepsis." Phd thesis, Université du Droit et de la Santé - Lille II, 2007. http://tel.archives-ouvertes.fr/tel-00476831.
Trzepizur, Wojciech. "Impact vasculaire et métabolique de l'hypoxie intermittente et de l'obésité dans un modèle murin." Thesis, Angers, 2014. http://www.theses.fr/2014ANGE0038/document.
Decades increases the prevalence of many overweigh tassociated diseases including obstructive sleep apnea (OSA). Both OSA and obesity are considered as independent cardio-vascular and metabolic risk factors.The frequent association of OSA and obesity in clinical setting makes difficult to investigate their independent contribution to metabolic and vascular diseases. In the present thesis, we aimed to evaluate the impact of a short term intermittent hypoxia (IH), (animal model of OSA), of a high fat diet (HFD), and of both experimental conditions together (IH and HFD) on the vascular and metabolic outcomes. Short term IH alone had no impact on glucose and lipids levels and mitochondrial and vascular function. Animals fed with HFD presented dyslipidemia, hepatic steatosis, mitochondrial and endothelial dysfunction. Interestingly, when short term IH was applied to HFD fed mice, insulin level was increased, restored endothelial function and mitochondrial activity was restored and limited liver lipid accumulation was limited.Those data underline the polymorphic effects of IH that might target beneficial outcomes when applied for a short term in obesity, which contrast with the deleterious long term outcomes observed in OSA
Karicheva, Olga. "Modelling gene therapy for a mitochondrial disease MELAS by exploiting the pathway of RNA mitochondrial import." Strasbourg, 2010. http://www.theses.fr/2010STRA6115.
Mutations in human mitochondrial DNA are often associated with incurable human neuromuscular diseases. Among these mutations, more than 170 have been identified in tRNA genes, including 29 in the tRNALeu(UUR) gene (MT-TL1). The m. 3243A>G mutation in MT-TL1 was described as the major cause of the MELAS syndrome (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes). This mutation reduces tRNALeu(UUR) aminoacylation level and leads to a hypomodification of the wobble position of its anticodon, which results in a decreased level of mitochondrial protein synthesis and reduced activities of respiratory chain complexes. The thesis was aimed to test if the allotopic expression of recombinant leucine tRNAs in the nucleus of transmitochondrial cybrid cells carrying MELAS m. 3243A>G mutation and their subsequent targeting into mitochondria can rescue mutation-induced dysfunctions. It was shown that expression of specifically designed recombinant tRNAsLeu is accompanied by a significant improvement of mitochondrial translation, an increase of steadystate level of several mtDNA-encoded protein subunits of respiratory chain, and a partial rescue of respiration. These findings prove the possibility to direct into mitochondria tRNAs with changed aminoacylation specificity possessing potential therapeutic activity, thus extending the potential of allotopic expression as the approach to cure mitochondrial disorders
BLANC, SANDRINE. "Role des mutations mitochondriales de la maladie de leber dans la sclerose en plaques." Lyon 1, 1994. http://www.theses.fr/1994LYO1M220.
Bertholet, Ambre. "Influence de la protéine de fusion mitochondriale OPA1 sur le métabolisme oxydatif neuronal et la transmission synaptique." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/2180/.
In the past few years, multiple findings have suggested that disruptions of mitochondrial functions and dynamics contribute to neurodegenerative diseases. Mitochondrial functions in neurons include regulation of calcium and redox signaling, developmental and synaptic plasticity as well as the arbitration of cell survival and death. Mitochondrial dynamics controls the organelle's morphology via a delicate balance of two opposing forces: mitochondrial fusion and fission that are regulated by large dynamin-related GTPases evolutionary conserved from yeast to human. We have previously demonstrated that the fusion protein OPA1 loss or mutations led to mitochondrial inner membrane dysfunctions and apoptosis of particular importance in optic nerve pathologies like ADOA1 (autosomal dominant optic atrophy). While links emerge between defects in mitochondrial fusion and neurodegeneration, the processes involved are still largely unknown. To understand the mechanisms by which alterations of mitochondrial dynamics could contribute to mitochondria dysfunction, eventually leading to neurodegeneration, we studied the effects of OPA1 loss of function in neurons ex vivo. In cortical neurons, RNA interference of the fusion protein OPA1 led to mitochondrial fragmentation without altering neither mitochondrial distribution nor neuronal death rate. While there was no incidence on dendrites and axon size and numbers, the quantity of several synaptic proteins was reduced, suggesting synaptic impairment. In these conditions, the redox state of OPA1 depleted-neurons was impaired and specific respiratory complex proteins quantities were decreased. Finally, electrophysiological recordings showed that OPA1 depletion induced changes in synaptic transmission, particularly in decreasing of EPSC frequency and by increasing IPSC frequency. Interestingly, forskolin treatment rescue these electrophysiological defaults. In conclusion, our data may offer new insights not only into mitochondrial dynamics-linked neurodegenerative diseases like ADOA1 but to other neurodegenerative pathologies correlated with oxidative metabolism such as Huntington's, Parkinson's and Alzheimer's diseases
Escoubas-Güney, Caroline. "Le rôle de l’AMPK dans le vieillissement et la perte de plasticité neuronale liée au vieillissement chez C. elegans." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4029/document.
The dramatic increase in life expectancy during the 20th century was accompanied by a resultant epidemic of age-related pathologies including neurodegenerative diseases. Unfortunately, current therapeutics primarily focusing on protein misfolding aspects of diseases such as Alzheimer’s Disease (AD) have been unsuccessful in the clinical trials. Recent epidemiological studies have suggested a strong association between metabolic dysfunction and neurodegeneration. Therefore, an alternative approach is to target metabolic pathways disrupted in AD models for therapeutics. AMP activated protein kinase (AMPK) is activated in a low energy state via sensing the AMP: ATP ratio. Once active, AMPK promotes longevity in model organism and protects against a wide range of age related diseases including neurodegenerative diseases. In addition, AMPK regulates mitochondrial homeostasis and mitochondrial networks in mammals. However, whether mitochondrial regulation causally links AMPK to protection against neurodegenerative disease is unknown. Here we use a learning and memory protocol in C. elegans as readout of neuronal function. We show that nematodes expressing the toxic amyloid peptide Aβ1-42 in the neurons display impaired learning ability, which can be rescued by constitutive activation of AMPK (CA-AMPK). We further show that CA-AMPK enhances learning ability in wild type nematodes by promoting mitochondrial fusion. Indeed, fusion deficient worms show impaired learning, which can be rescued by restoring mitochondrial fusion specifically in the neurons. Additional results suggest that AMPK might promote its beneficial effects on neuronal function via inhibition of CREBregulated transcriptional co-activator 1 (CRTC-1). Our results show that targeting neuronal metabolism may be a viable therapeutic option to restore neuronal function in the context of neurodegenerative diseases