Teses / dissertações sobre o tema "Adaptations métaboliques"
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Delamarche, Paul. "L'enfant et l'exercice prolongé : adaptations métaboliques et hormonales". Lyon 1, 1992. http://www.theses.fr/1992LYO1H185.
Texto completo da fonteTouron, Julianne. "Adaptations métaboliques en réponse à l'exercice excentrique dynamique : application au réentrainement". Thesis, Université Clermont Auvergne (2017-2020), 2020. https://tel.archives-ouvertes.fr/tel-03177393.
Texto completo da fonteChronic pathologies are the world leading cause of death. In addition to reducing functional capacities and degrading patients' life quality, they constitute a major public health expenditure. Part of the management involves appropriate physical activity and exercise training. This aims to improve subjects' capacities, in particular endurance and muscle strength, in order to increase their autonomy and reduce the risk of morbidity and mortality. Classically, endurance cycling or treadmill running exercises are performed at a sub-maximal metabolic intensity (~60%) and in a classic concentric muscle contraction mode. These training conditions, and the associated adaptations, are however limited by the patients' ability to achieve or maintain such stresses over time. It is therefore necessary to develop alternative strategies that take into account cardiac, respiratory and/or muscular limitations linked to the pathology while allowing optimal adaptive responses. One approach is that of dynamic eccentric training through resistance pedaling or downhill running exercises. Compared to concentric mode, eccentric has the ability to generate significant mechanical loads for less cardio-respiratory stress. For several years, the feasibility of this type of training has been observed, including in patients with chronic diseases. Its effectiveness in increasing muscle mass and strength has also been widely demonstrated. Recent work also shows its interest in overweight and obesity management through its effects on body composition and fat reduction. However, aerobic adaptations following eccentric training remain incomplete with regard to initial expectations of improved oxygen uptake and mitochondrial function, for which exercise metabolic intensity appears to be the determining factor. Thus, mixed approaches can be considered in order to develop the best combination that will optimize the overall physical training outcomes by enhancing both muscle strength and endurance
Weitten, Mathieu. "Adaptations métaboliques et influence du régime alimentaire chez un hibernant food-storing". Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ080/document.
Texto completo da fonteThis thesis presents the specific adaptations of food-storing hibernators that feed during hibernation, and the impact of diet quality on their annual cycle. In contrast to the fat-Storing species which fast during hibernation, the food-storing presents metabolic responses to an alternation of short fasting phases and hyperphagia. These responses involve one hand use of fat reserves during hibernation contributing to ketogenesis, which would be induced by adiponectin. On the other hand, maintaining a functional digestive system leading to the secretion of incretins, permits optimal nutrient absorption in the short inter-torpor euthermia. Increased glucose uptake in particular would restore body reserves to spare. Moreover, a lean protein diet enriched in fat and induces increased in body mass in pre-hibernation period causing reduced use of torpor thus an increased loss of mass during hibernation, and decreased reproductive success
Wargnies, Marion. "Adaptations métaboliques de Trypanosoma brucei en réponse à des variations des conditions intra- et extracellulaires". Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0200/document.
Texto completo da fonteTrypanosoma brucei is a protozoan parasite responsible for human African trypanosomiasis. His complex life cycle alternates between mammalian hosts and the insect vector, the tsetsefly. During this cycle, the parasite encounters dissimilar environments and adapts to the sechanging conditions by regulating his metabolism. We have studied intermediate and energetic metabolism of the procyclic form living in the midgut of the insect vector. In this glucose-depleted environment, gluconeogenesis is crucial for growth and viability of the parasites. Indeed, it allows the synthesis of hexoses phosphates and in particular glucose 6-phosphate which feeds several essential biosynthetic pathways. Our work has confirmed the existence of a gluconeogenic flux fed by proline and glycerol. We have shown that glycerol is an efficiently metabolized carbon source and is preferentially used by the procyclic form rather than proline or even glucose. This situation never described before highlights glycerol repression on glucose metabolism. We have also showed that the enzyme fructose 1,6-biphosphatase (FBPase), specific of the gluconeogenesis, is not essential for the viability ofthe parasite in glucose-depleted conditions, suggesting that there is an alternative to this enzyme. However, FBPase plays an important role for virulence of T. brucei in the insect. Moreover, we have showed another adaptation strategy developed by T. brucei which is basedo n genomic rearrangements leading to the synthesis of chimeric genes
Dansou, Houndjoui Pierre. "Adaptations cardiorespiratoires, métaboliques et hormonales au cours d'un match de tennis : du laboratoire au terrain". Université Joseph Fourier (Grenoble ; 1971-2015), 1998. http://www.theses.fr/1998GRE10091.
Texto completo da fonteMartin, Bernabe Alfonso. "Une approche protéomique pour comprendre les adaptations métaboliques du cancer du poumon non à petites cellules". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAS027.
Texto completo da fonteLung cancers are broadly classified into two main groups: small cell lung cancer and non-small cell lung cancer (NSCLC), which accounts for approximately 83% of all lung cancer cases with an overall 5-year survival rate of 21%. Conventional therapies in NSCLC including radiotherapy and platinum-based chemotherapy lack specificity and often cause severe side effects as they affect healthy cells. To address this problem, targeted therapies have been successfully used due to their specificity for cancer cells. Targeted therapies against epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements have been shown to be effective in NSCLC. However, therapeutic response may be limited due to drug resistance. This is the case of patients whose tumors harbor activating KRAS mutation that leads to constitutive activity of RAS signaling independent of upstream signals. For this reason, a better comprehension of tumor progression and resistance is needed to improve cancer treatments. To date, approaches targeting oncogenic KRAS have been unsuccessful. Given the importance of metabolic reprogramming in multiple cancers including lung cancer and the regulatory role of KRAS signaling. We explored the metabolic reprogramming of KRAS-driven NSCLC cells to find vulnerabilities in the altered metabolism that can be exploited as therapeutic targets.For this, we characterized the proteome of NSCLC cell lines (A549 and NCI-H460) harboring activating mutations of the oncogene KRAS with particular focus on metabolic enzymes. We found not only up-regulation expression of glycolytic enzymes, which is frequently found in cancer as part of the “Warburg effect”, but also a remarkable up-regulation of the pentose phosphate pathway (PPP) in both oxidative and non-oxidative branches. Based on this study, we evaluated the feasibility of use PPP enzyme (glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) and transketolase (TKT)) as targets for improve or develop of new therapies.Recently, protein lysine acetylation (KDAC) has emerged as a metabolism-coordinating mechanism and mounting evidence has shown that acetylation regulation of metabolic enzymes plays a major role in cancer. Consequently, lysine deacetylases inhibitors (KDACIs) have drawn attention not only as promising strategies for therapeutic intervention but also as tool for studying the role of lysine acetylation in NSCLC metabolic reprogramming. Furthermore, metabolic reprogramming also depends strongly on the tumor microenvironment such as oxygen level. Therefore, we also analyzed the inhibition of KDAC under normoxic and hypoxic conditions in order to better understand the adaptive strategies under such perturbations. Our results showed that KDACIs induce low cell proliferation, differentiation, cell cycle arrest and apoptosis accompanied by a change in the tumor metabolic phenotype enhanced under hypoxia. Together, these results allow us to better understand how KDACIs control metabolic pathways under hypoxia in NSCLC
Refeyton, Alice. "La survie et les adaptations métaboliques des cellules primitives mésenchymateuses et hématopoïétiques en anoxie et anoxie/aglycémie". Electronic Thesis or Diss., Bordeaux, 2024. http://www.theses.fr/2024BORD0028.
Texto completo da fonteMesenchymal stromal cells (MStroC) comprise multipotent stem cells (SC) capable of regenerating tissues damaged by ischemic insults. However, high mortality of MStroC after transplantation is highlighted during their engraftment. Therefore, exploring strategies to improve the viability of cell grafts constitutes the challenge of cell therapy. To this end, we performed functional and metabolic analyzes on two different types of populations containing somatic SC: MStroC and a population of hematopoietic niche partner cells, CD34+.MStroC or CD34+ cells were cultured under conditions of anoxia (absence of O2) and ischemic type (anoxia/aglycemia, absence of O2 and glucose, AA) or at 3% O2 corresponding to the physiological optimal concentration, then analyzed.Functional assays reveal that MStroC and CD34+ cells exhibit complete proliferation and differentiation properties in anoxia. Functional analyzes of single cells and gene expression revealed that MStroC and CD34+ are not only maintained in an AA state, but are those in which SC, having the highest proliferation and differentiation capacity, are the most enriched. Multiparametric metabolic analysis shows that survival in anoxia is mainly supported by glycolysis and lipid metabolism. On the other hand, the energy homeostasis of MStroC in the AA condition is partially ensured by anaerobic mitochondrial activity particularly involving mitochondrial complexes I, III and ubiquinone. Furthermore, a significant accumulation of succinate in this condition for both types of SC was demonstrated. This is due in part to an inversion of succinate dehydrogenase, which in turn is driven by fumarate spillover from purine nucleotide degradation and malate-aspartate shuttle activity. However, major pathways contributing to succinate accumulation include glycogen-induced glucose/pyruvate stimulation, as well as ketone body, amino acid, and propanoate metabolism which provide succinyl-CoA converted to succinate. Furthermore, MStroC ischemia survival is linked to sulfide metabolism and H2S consumption, as well as improved survival in the presence of H2S donors. SQR-mediated H2S oxidation results in reverse electron transport at mitochondrial complex I, using glutathione as an electron acceptor. The analysis of the use of energy substrates showed that CD34+ cells in anoxia seem to mainly use simple sugars in order to fuel the glycolytic pathway and a consequent reduction in mitochondrial metabolism compared to the 3% O2 condition. In contrast, in AA, Krebs cycle intermediates are used intensively to provide the coenzyme NAD/NADH.Our results reveal a great metabolic flexibility of MStroC and CD34+ populations based on the enrichment of somatic SC detected in anoxia or in the condition mimicking ischemia. Thus, unlike differentiated cells, somatic SC (mesenchymal and hematopoietic) have the capacity to survive in conditions of anoxia and aglycemia using the evolutionary conservative energy pathways existing in early eukaryotes living in anoxic zones enriched in sulfide . Exploiting this ex vivo conditioning under conditions mimicking ischemia could constitute a strategy to improve the survival of MStroC implanted in hypoxic/ischemic tissues
Couturier, Karine. "Adaptations métaboliques et hormonales chez le rat anti-obèse Lou/C : influences du régime alimentaire et de l'activité physique". Lyon 1, 2003. http://www.theses.fr/2003LYO10104.
Texto completo da fonteEnnequin, Gaël. "Rôle de la neuréguline 1 dans les adaptations du métabolisme énergétique en condition de pathologies métaboliques : effets de l'activité physique". Thesis, Clermont-Ferrand 2, 2015. http://www.theses.fr/2015CLF20028.
Texto completo da fonteNeuregulin 1 (NRG1) is a cytokine that belongs to the epidermal growth factors family. NRG1can be released during exercise and can be define as a myokine. Initially studied for its rolein growth and maturation, NRG1 can also regulate glucose homeostasis in vitro. Thus, theaim of this work was to investigate the effect of training and metabolic disorders on NRG1pathway and its role in energy metabolism. Results showed that NRG1 pathway was notaltered in skeletal muscle of obese rats. Conversely, endurance training combined with awell-balanced diet improved NRG1 pathway activation in skeletal muscle of obese. Indeed, 8weeks of training and diet increased the cleavage of NRG1 and the activation of its receptorErbB4 through the activation of the metalloprotease ADAM17. Moreover, acute and chronictreatment improved glucose tolerance in diabetic mice (db/db). Acute treatment loweredglycemia by activating ErbB3, Akt and FOXO1 in the livre. Thus, NRG1 might play a key role inthe regulation of glucose homeostasis in people who suffers from metabolic disorders.Training might a good tool to activate this pathway in skeletal muscle
Teulier, Loïc. "Adaptations métaboliques du caneton de Barbarie (Cairina moschata) et du Manchot Royal (Aptenodytes patagonicus) en réponse à un stress chronique froid". Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00799347.
Texto completo da fonteTagliarolo, Morgana. "Adaptations métaboliques des organismes dans la zone de balancement des marées : implications sur la biodiversité locale dans un contexte de changement climatique". Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00816887.
Texto completo da fonteLe, Lay Julien. "Compréhension des mécanismes impliqués dans l’activité réductrice et dans les adaptations métaboliques à pH acide de Bacillus cereus : implication des thiols exofaciaux". Thesis, Avignon, 2014. http://www.theses.fr/2015AVIG0331/document.
Texto completo da fonteBacillus cereus is a Gram positive bacterium able to adapt and survive to numerous stress, including acid stress or oxydo-reduction potential (Eh) variations. Some adaptations are documeted for each of these two stress. However, the interaction between Eh and pH on B. cereus physiology was never studied. Here, we focus on the impact of Eh variation on the acid resistance of B. cereus, on the metabolic adaptation of these bacteria under low pH and on the interaction of bacterial cells with their redox environement. Results obtained demonstrate that the acid survival of B. cereus was slighlty higher under reductive Eh than under oxdative Eh. Concerning acid adaptations, we observed a major metabolic adjustement for cells cultivated at low pH with an important shift from mixed acid fermentation to butanediolic fermentation. Finally, we demonstrate the importance of exofacials thiols groups in the reductive abilities of B. cereus. All these conclusions will help to better understand the response of B. cereus exposed to acid stress and Eh
Mey, Louis-François. "Adaptations à la déshalogénation et à l’utilisation du chlorométhane par la voie cmu chez Methylobacterium extorquens". Electronic Thesis or Diss., Strasbourg, 2023. http://www.theses.fr/2023STRAJ126.
Texto completo da fonteChloromethane (CH3Cl), a mainly naturally occurring organohalogen gas, is involved in ozone degradation in the atmosphere. CH3Cl is degraded by methylotrophic bacteria capable of using compounds without carbon-carbon bonds, such as methanol, as their sole source of carbon and energy. Two such methylotrophic Alphaproteobacteria, Methylobacterium extorquens CM4 and Hyphomicrobium sp. MC1, utilize CH3Cl via the cmu pathway initiated by carbon transfer from CH3Cl to tetrahydrofolate (H4F) catalyzed by CmuA and CmuB. Methyl-H4F formed is then used for biomass production or oxidized to CO2 via formate. The cmu pathway, often acquired by horizontal transfer, is not sufficient to confer growth to a recipient strain. However, little is known about the adaptations needed to overcome stresses inherent to growth with CH3Cl.To identify such adaptations in M. extorquens, the plasmid pJM105 containing the cmu genes from Hyphomicrobium sp. MC1 was transferred to two M. extorquens strains (AM1 and DM4) unable to grow with CH3Cl. An experimental evolution approach, spanning some 200 generations, was performed to improve strain growth with CH3Cl. Genome sequencing of 13 of the 162 evolved strains obtained revealed 64 mutations (SNPs, nucleotide deletions or insertions, large deletions) in 45 genes, as well as other genetic events (plasmid rearrangements, large deletions). Mutations inactivating the formyl-tetrahydrofolate ligase (FtfL) gene, essential for assimilation of carbon from methanol, were identified in 8 of the 13 sequenced strains. Construction and analysis of mutants of this gene showed that inactivation of FtfL was sufficient to confer growth with CH3Cl via the cmu pathway to M. extorquens DM4. I hypothesize that this enzyme interferes with CH3Cl oxidation for energy production while consuming the H4F cofactor essential for this metabolism, and that its activity opposes that of the homologous PurU enzyme required for growth with CH3Cl via the cmu pathway.Among the other mutations identified, a mutation in the nuo gene promoter could facilitate expression of the NADH dehydrogenase involved in NAD+ cofactor regeneration. Other FtfL-independent adaptations have also been detected, which differ according to the genetic context of the strain receiving the cmu pathway genes. For example, the evolved AM1 strains all show mutations in pJM105 (in the cmuA gene, with cointegration of an endogenous plasmid). However, these mutations have no impact on CmuA-dependent CH3Cl dehalogenation activity. Obtaining mutant strains by experimental evolution in the laboratory is a promising new tool for studying growth with CH3Cl via the cmu pathway, particularly given the difficulties encountered to date in directed mutagenesis approaches to CH3Cl-degrading bacteria
Argentin, Sébastien. "Influence du type d'exercice et d'entraînement sur les paramètres métaboliques, musculaires et de fréquence gestuelle au cours d'un exercice de pédalage des membres inférieurs". Paris 5, 2006. http://www.theses.fr/2006PA05L001.
Texto completo da fonteBeltrand, Jacques. "Programmation foetal du syndrôme métabolique et de l'insulinorésistance : rôle de la croissance ante et post natale et modifications anthropométriques et métaboliques associées". Paris 7, 2008. http://www.theses.fr/2008PA077165.
Texto completo da fonteFetal growth restriction (FGR) followed by rapid weight gain during early postnatal life has been suggested to be a sequence leading to an increased risk of metabolic disease. Anyway early growth and associated changes in body composition or metabolic statue has never been studied in a prospective way. Furthermore, birth weight (BW) is usually taken as a surrogate of fetal growth. However, B W per se is not relevant enough in assessing fetal growth restriction, which by itself may alter body composition, metabolic and hormonal profiles at birth (irrespective of BW) reflecting the necessary adaptive changes in metabolism under poor fetal environment. In a cohort of newborns in whom fetal growth velocity had been recorded in a prospective and standardized manner, we report that, independently from birth weight, fetal growth restriction by itself is able to induce changes in body composition characterized by a lower fat mass and changes in metabolism with a higher insulin sensitivity reflecting adaptive changes to an adverse fetal nutritional environment. The pattern of postnatal growth over the first year of life with respect of fetal growth velocity and the simultaneous changes in body composition and metabolism were then studied. We report that catch-up growth is related to fetal growth pattern regardless birth weight. This catch-up seems to be an intrinsic phenomenon occurring in the first months of life in order to restore the lower fat mass but without deleterious consequences neither on its repartition nor in its quantity
Villeneuve, Julien. "CD154 et adaptation cellulaire au stress métabolique : exemple de la stéatose hépatique expérimentale". Bordeaux 2, 2008. http://www.theses.fr/2008BOR21591.
Texto completo da fonteNon Alcoholic Fatty Liver Disease (NAFLD) is a major public health concern. Its prevalence is high and its severity is related to the risk of transition towards cirrhosis and hepatocellular carcinoma. A distinctive histological feature of NAFLD is liver steatosis, resulting from the triglyceride accumulation in hepatocytes. The mechanisms underlying liver steatosis are not yet understood, however, the involvement of the endoplasmic reticulum (ER) stress is being increasingly emphasized. Excess lipid input to the hepatocyte disrupts the ER homeostasis, its loading overwhelming its processing abilities, leading to what is termed the ER stress. ER stress activates the unfolded protein response (UPR) that corresponds to the activation of specific signalization pathways, whose effectors aim at adjusting the functional capacities of the ER. ER stress and the inflammatory reaction are linked, but the underlying mechanisms remain obscure. CD154 is a key mediator of inflammation and, therefore, we studied its involvement in the mechanisms leading to liver steatosis. CD154 knock-out mice developed a steatosis when fed with an olive oil-rich diet. When studying the corresponding mechanisms, we found that CD154 amplified the UPR and, more specifically, increased the unconventional splicing of an effector of the UPR, the X-box binding protein 1. Hence, CD154 increases cell adaptation by controlling the ER homeostasis. Our work highlights a new biological function for CD154, which appears to be an important mediator in the natural history of NAFLD
Andres, Jérémy. "Mécanismes adaptatifs et interactions métaboliques au sein de communautés microbiennes soumises au stress arsénié". Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAJ026/document.
Texto completo da fonteArsenic naturally occurs in earth crust and is particularly abundant in some environments. While this element is toxic for most forms of life, micro-organisms have evolved different mechanisms to cope with it. This work deals with these different processes involving individual responses as well as interactions between organisms belonging to different domains of life. Descriptive and functional genomics approaches highlight several adaptative mechanisms and cellular functions involved in the arsenic response of a bacterium and a photosynthetic protist, Rhizobium sp. NT-26 and Euglena mutabilis, respectively, both being particularly resistant to arsenic. Also, while Rhizobium sp. NT-26 seems to have lost its ability to interact with plants, E. mutabilis is on the contrary an integral part of a microbial community including different bacteria and benefits from their activity
Morin, Manon. "Rôle du régulateur post-transcriptionnel CSR dans l'adaptation métabolique de la bactérie modèle Escherichia coli". Thesis, Toulouse, INSA, 2015. http://www.theses.fr/2015ISAT0026/document.
Texto completo da fonteIn its natural environment, Escherichia coli (E. coli) faces strong fluctuations of the nutrient availability. A complex gene regulatory network makes the bacterium able to switch between a state of growth in the presence of an appropriate carbon source and a non-growth state in its absence. Within this network, the global post-transcriptional regulator CSR (Carbon Storage Regulator) modifies mRNA stability and/or translation initiation by the CsrA protein. This system has been shown to be essential for cells to grow on glucose and is hypothesized to be involved in the regulation of metabolic transitions. However both observations remained unexplored so far. An integrative approach has been used to investigate for the first time the essentiality of CSR on glucose as well as its involvement in the regulation of the glucose-acetate transition. Molecular and phenotypic data for different mutants of the CSR system have been produced and integrated into mathematical models. Transcriptomic and Stabilomic approaches have been used eventually to characterize the importance of the control of mRNA stability during the metabolic adaptation. mRNA stability regulations appear to be of particular importance in gene expression regulation during metabolic adaptation. To conclude, this work shed a new light upon CSR’s involvement in the regulation of E. coli’s metabolism. CSR is definitely essential to regulate glycolysis and thus constitutes another regulator to be integrated into the already complex regulations network of E.coli’s metabolism
Vila, Nova Meryl. "Détection et identification des mutations et des voies métaboliques associées à l'adaptation à l'hôte dans le pangénome de Salmonella". Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC0057.
Texto completo da fonteThe evolution of the genus Salmonella has led to the appearance of species and sub-lineages adapted to different hosts that have a major role in understanding the biological mechanisms of bacterial adaptation. Due to the heavy health and socio-economic burden of salmonellosis, the genus Salmonella is therefore controlled by hospital and food safety laboratories. We have therefore developed two analytical approaches to detect and identify mutations associated with Salmonella host adaptation without a priori on the explanatory genomic elements, identifying the fixed coregenome variants at each node of the phylogenomic inference or identifying pangenomic mutations associated with host adaptation independently of considered bacterial sublineages (GWAS). These two approaches have been linked to the enrichment of corresponding metabolic pathways (GOEA). Because of selection pressures from natural environment of animals, their feeding diets or supplements administered by humans, our results show that the host adaptation of Salmonella may have occurred inside sublineages or between them. These results reinforce the necessity to integrate clonal and panmictic sublineages in order to identify causal mutations associated with host adaptation. In a context of FBO control throughout the food chain, the identification of its recent mutations would improve the attribution models of Salmonella animals’sources and confirm the results of FBO investigations at genomic scale
Gaboyer, Frédéric. "Potentiels physiologiques et métaboliques de communautés microbiennes de sédiments de subsurface : approches culturale, génomique et métagénomique". Thesis, Brest, 2014. http://www.theses.fr/2014BRES0082/document.
Texto completo da fonteMicrobial communities inhabiting marine subsurface sediments were described up to 1922 mbsf (meters below the sea floor) andcould represent 0.6% of the total biomass. This microbial diversity, remaining elusive to cultivation, comprises groups specific to subsurface environments and groups of generalists found in contrasted habitats, all belonging to the 3 domains of life (Bacteria,Eukarya and Archaea). Although playing a major role in global geochemical cycles, the microbial ecology of the subseafloor remains largely unknown. The hostile conditions of subsurface sediments contrast with the descriptions of microbial activity andviability in the subseafloor. In this context, many questions related to the microbial physiology and the lifestyles of buried communities remain to be answered. The objective of this thesis was to better understand which adaptive strategies could be deployed by subseafloor microbial communities and to characterize their physiological potential. In that aim, 3 approaches were used.(1) A cultural approach enabled describing 2 novel sedimentary bacterial species (Halomonas lionensis, a versatile generalist and Phaeobacter leonis a typical marine bacterium). The survival of these 2 species to subseafloor conditions and of the subsurface bacteria Sunxiuqinia faeciviva, isolated at 247 mbsf, was then studied. (2) Using a structural and comparative genomic approach, the physiological plasticity of H. lionensis was investigated. (3) Finally, the functional potential of the microbial communities buried at 31 and 136 mbsf in the Canterbury Basin was analyzed, by studying the 2 corresponding metagenomes. Cultural and genomics results showed that H. lionensis and S. faeciviva are more resistant to subsurface constrains than P. leonis and, in the case of H. lionensis, this may involve various physiological properties, maybe explaining thee cological success of the genus Halomonas. Metagenomic data showed that the functional and the phylogenetic diversity of the subseafloor are distinct from the ones from surface environments and highlighted the importance of metabolic pathways like fermentation, methanogenesis and β-oxidation. Genes of ecological and evolutionary interests enabled speculating about lifestyles of buried microorganisms and analyses of genomic fragments highlighted recombination events of still uncultivated microbial groups
Troubat, Nicolas. "Régulation autonome du myocarde et activité métabolique lors de tâches à faible coût énergétique". Poitiers, 2009. http://www.theses.fr/2009POIT2295.
Texto completo da fonteThe main purpose of this work was to assess the impact of the low cost energy activities (physical and cognitive tasks) on energy metabolism through indirect calorimetry and of automatic regulation of the myocardium through measures of heart rate variability measures. The objective of the first study was to assess the effects of a psychological stress on the physiological responses. The result suggested a stimulation of the sympathetic nervous system with an unchanged of the parasympathetic system activity. Changes recorded in terms of energy substrate and sympathetic nervous system activity appeared to be due to the strong cognitive requirements of the proposed situation. Our second study was intended to test the effects of cold and a cognitive work on the physiological responses during a repetitive work. The results suggested that the combination of cold and cognitive task is responsible for strong cardio-respiratory, energy and muscle adaptations. Low energy cost activities (physical and cognitive tasks) resulted in significant variations of physiological functions which are closed from chronic stress. This project has opened new perspectives of research on the understanding of physiological phenomena governing cognitive activities and human adaptation to the multiplication of stress factors
Hurbain, Julien. "Modélisation de la réponse métabolique à un stress oxydant : rôle des régulations". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR045.
Texto completo da fonteLiving cells such as mammalian cells in particular, are continuously exposed to multiple and varied types of stress. These stresses can perturb the cellular homeostasis and induce damages on the cellular components which could induce several types of diseases. It is particularly the case for a change of cellular redox state called oxidative stress induced by an excessive production or insufficient consumption of reactive oxygen species such as hydrogen peroxide (H2O2).Cells have developed efficient defence mechanisms against oxidative stress that involve anti-oxidant systems such as glutathiones which reduce the oxidizing molecules, but also metabolic pathways such as Pentose Phosphate Pathway (PPP) and glycolysis. These metabolic pathways are known to reroute the carbon flux resources from the glycolysis toward the PPP which induces high NADPH recycling that is required for efficient detoxification rate of the anti-oxidant systems. It remains however unclear how regulatory mechanisms (i) contribute to such reallocation of metabolic flux resources during oxidative stress and (ii) give rise to observed adaptation profiles of intracellular H2O2 concentrations. In the thesis, the role of regulations in the metabolic response to oxidative stress is addressed using a comprehensive kinetic modeling framework. First, a model is built from a set of metabolomics and 13C labeling data, using conventional parameter estimation methods but also a novel metabolic flux analysis techniques based on a stochastic simulation algorithm. Systematic analysis of the model reveals that many metabolic inhibitions, especially on G6PD, PGI and GAPD, can favour flux rerouting for NADPH production. In particular, we show that all these regulations work in a dose-dependent and complementary manner, which explains some paradoxes and controversies, and is consistent with observed adaptation phenotypes. A more phenomenological model has also been developed to show how such adaptation phenotype could contribute to cell-fate heterogeneity, such as fractional killing, as a long-term outcome of oxidative stress
Flaven-Pouchon, Justin. "Perception des acides gras chez Drosophila melanogaster : plasticité et conséquences métaboliques". Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOS069/document.
Texto completo da fonteFatty acids (FAs) are involved in many biological functions, from the cell membrane composition to energy storage, through hormone biosynthesis. The consequences of FAs overconsumption are of great concern in terms of public health since the WHO estimates that 2.8 million annual deaths due to obesity and its side effects. If lipid metabolism is relatively well known, the mechanisms underlying the detection and preference for FAs remain little studied. While some studies have shown that the preference of mammals for FAs is modified by early exposure to these compounds, little is known about FAs long-term effects on both their perception and food preference.The majority of studies have been conducted in mammals, invertebrates being neglected despite the benefits (life cycle, size, ease of breeding, genetic tools) of some models, such as Drosophila, and despite the good conservation of lipid metabolism actors during evolution. It has recently been shown that both Drosophila melanogaster larvae and adults are able to detect and discriminate FAs according to their unsaturation. Moreover, larval and adult preferences are different: the larvae are attracted by unsaturated FAs (UFAs) and repelled by saturated FAs (SFAs) while adults are repelled by the UFAs and indifferent to SFAs. It has been suggested that these preferences change may reflect different metabolic requirements between larvae and adults.During my PhD, I studied the effects of intra -and inter- generational exposure to a medium enriched either with a SFA (stearic acid = C18: 0) either with a UFA (oleic acid = C18: 1) on larval and adult preferences (oviposition site selection) toward these FAs, as well as on different life traits. On the other hand, I tested the evolution of both larval and adult preferences for these two FAs after two selection procedures, using these preferences as a selection criterion.My results show that if the selection processes do not permanently modify the individual preferences for both FAs considered, the behavior of individuals exposed either occasionally during development, either permanently from one to ten generations, is affected by this exposure. In particular, the egg-laying site choice by females is specifically modified by exposure to C18:0 and C18:1 during larval development. If the influence of early sensory experience on food preferences of adults had already been demonstrated in mammals and some holometabolous insects (whose nervous system is almost completely remodeled during metamorphosis), this is the first time that such a phenomenon is clearly demonstrated in Drosophila. On the other hand, continuous exposure to each of these FAs permanently alters both oviposition preferences and major life traits (development time, sex ratio, fecundity and adult survival). These results suggest that Drosophila is able to adapt to different foods, and this plasticity, probably genetically determined, may explain the success of this generalist species. In addition to their ecological interest, these results also demonstrate the usefulness of this model for the study of intra -and inter- generational preferences plasticity towards FAs
Maillet, Alain. "Comparaison des effets endocriniens, métaboliques et cardio-vasculaires observés lors d'expériences d'alitement anti-orthostatique et de confinement". Lyon 1, 1997. http://www.theses.fr/1997LYO1T243.
Texto completo da fonteVercruyssen, Fabrice. "Influence de la cadence de pédalage sur les paramètres métaboliques et neuromusculaires lors d'un enchaînement cyclisme-course à pied de durée prolongée chez des triathlètes". Toulon, 2002. http://www.theses.fr/2002TOUL0006.
Texto completo da fonteRouquet, Géraldine. "Etude du rôle de l'opéron métabolique frz dans la virulence d'escherichia coli et dans son adaptation aux conditions environnementales". Thesis, Tours, 2010. http://www.theses.fr/2010TOUR4008.
Texto completo da fonteThe metabolic frz operon codes for three subunits of a PTS transporter of the fructose sub-family, for a transcriptional activator of PTS systems of the MgA family (FrzR), for two type II ketose-1,6-bisphosphate aldolases, for a sugar specific kinase (ROK family) and for a protein of the cupin superfamily. It is highly associated with Extra-intestinal Pathogenic Escherichia coli strains. We proved that frz promotes bacterial fitness under stressful conditions, (such as oxygen restriction, late stationary phase of growth or growth in serum or in the intestinal tract). Furthermore, we showed that frz is involved in adherence to and internalization of E. coli in several eukaryotic cells by regulating the expression of type 1 fimbriae. The FrzR activator is involved in these phenotypes. Microarrays, experiments allowed the identification of several genes under the dependence of the frz system. Our data suggest that frz codes for a sensor of the environment allowing E. coli to adapt to a fluctuating environment by regulating some virulence and host adaptation genes. A regulation model is presented
Alliot, Nolwenn. "Étude phénotypique de souches de Stenotrophomonas maltophilia isolées de contextes cliniques et environnementaux. : Évaluation du lien entre les signatures métaboliques, de virulence et d'antibiorésistance". Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1152.
Texto completo da fonteIn the clinical settings, Stenotrophomonas maltophilia is described as an opportunistic bacterial pathogen responsible for nosocomial infections mainly in immunocompromised patients or with severe or chronic diseases. The heavy shield of antibiotic resistances observed in clinical strains lead to particularly complex treatments for patients. S. maltophilia strains represent a real threat to human health. Moreover, the high potential for adaptation of S. maltophilia allow their dispersion in a wide range of clinical habitats but also environmental. Indeed, S. maltophilia strains also colonize widely environmental niches such as the rhizospheric soils. The knowledge about these environmental strains is particularly limited compared to the available medical data. The properties as opportunistic pathogenic of environmental strains remain poorly known and controversial. To better assess the potential health hazard of these environmental S. maltophilia compared to the clinical ones, were assessed in this Ph-D project phenotypic characteristics of a group of S. maltophilia strains from contexts differentially affected by human and environment imprints. S. maltophilia heavily impacted by human contacts have been isolated from patients with varying disease (cystic fibrosis, nosocomial infections, severe pathologies). This group of strains considered as the most at risk to humans, was compared to a group of S. maltophilia from environmental contexts that could promote acquisition/maintaining of resistances to antimicrobial molecules such as rhizospheric soils, heavy metal-contaminated soils or agricultural soils. Firstly, metabolic signatures (growth, substrate degradations) and antibiotic resistance capacities were evaluated among the collection of S. maltophilia strains. In a second part, were studied pathogenic potentialities of these strains such as mobility, enzyme secretions, biofilm formation and virulence to amoebae. Finally, a statistical analysis made connections on the different signatures obtained from the metabolic data, antibiotic resistance and virulence with the origins of the strains and human impacts. According to the datasets of the project, four distinct signatures emerged between S. maltophilia strains structured by the effects of human proximity and origin of the strains. Environmental strains potentially the most impacted by contact with humans showed similar characteristics with the clinical strains; they could potentially be as dangerous as clinical strains
Nicolas, Céline. "Étude des modifications à long terme induites par la prise chronique de cocaïne : approches anatomique, métabolique et comportementale". Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2334/document.
Texto completo da fonteDrugs addiction is a chronic brain disorder representing a major public health problem. Although important advances allowed a better understanding of the cerebral modifications induced by chronic exposure to drugs, the therapies still nowadays limited. Therefore the investigation of cerebral processes that underlie the persistent risks of relapse, seem to be crucial to offer new therapeutic strategies. A part of this thesis aims at investigating the cerebral modifications induced in a long term during the withdrawal, due to a chronic voluntary intake of cocaine. In our first study we found a reduction of the density of cerebral vessels during the early withdrawal selectively localized in the cingular cortex. In our second study we found that cocaine intake leads to modifications of cerebral metabolism that evolve during the withdrawal. After one month of withdrawal, at a time when the phenomenon of incubation of craving is found, we found a decrease in cortical and striatal metabolism and a hyperactivation of the amygdala which demonstrates a persistent disregulation of brain functioning. Finally, in our third study, we tried to dissect the mechanism underlying the anti-craving effect of the enriched environment (EE). We hypothesized that the EE acts as an alternative reward to decrease the cocaine seeking behavior. Thus we tested the effects of exposure to sucrose or the physical exercise on relapse to cocaine. We demonstrated that the access to an alternative reward during the withdrawal does not allow reducing cocaine seeking which suggests that the EE does not act exclusively as an alternative reward
Clement, Tiphaine. "Utilisation d'un fermenteur continu multi-étagé pour la compréhension des mécanismes d'adaptation de la levure à des ajouts d'azote en conditions oenologiques". Thesis, Montpellier, SupAgro, 2012. http://www.theses.fr/2012NSAM0017/document.
Texto completo da fonteWe set up a multi-stage continuous fermentor (MSCF) to mimic the conditions of alcoholic fermentation. In this bioreactor, the yeasts are in a steady and well controlled state representative of the growth and stationary phases of the batch. The ability of the MSCF to reproduce batch fermentation was assessed using an integrated approach (measurement of kinetic parameters, intra and exo-cellular metabolites and gene expression). We then used the MSCF to study the impact of nitrogen supplementation performed during the stationary phase, on yeasts metabolism. Several original results were obtained, concerning the TCA cycle, the transport of nitrogenous sources and the synthesis of higher alcohols and esters. This work points out the interest of using the MSCF to assess the effect of medium perturbations during alcoholic fermentation, especially during the stationary phase. More generally, the accuracy of the MSCF and the originality of the data obtained open new prospects for a better understanding of yeasts metabolism and regulation mechanisms
Morin-Sardin, Stéphanie. "Etudes physiologiques et moléculaires de l'adaptation des Mucor aux matrices fromagères". Thesis, Brest, 2016. http://www.theses.fr/2016BRES0065/document.
Texto completo da fonteIn the cheese industry context, Mucor species exhibit an ambivalent behavior, as some species are essential technological organisms contributing to the required organoleptic characteristics of some cheeses while some others can be spoiling agents. The present study aimed at better understanding this ambivalence and investigating the putative adaptation mechanisms to cheese existing in Mucor technological species. Morphology and radial growth of 7 representative Mucor species: technological, contaminant and non-cheese related (plant endophyte) species were monitored on different media (synthetic, cheese-mimicking media and cheese) in function of key parameters for cheese manufacture (temperature, aw, pH). Cardinal values were determined on synthetic medium and as a result a predictive model was proposed and validated on cheese matrices for the temperature parameter. Interestingly, cheese technological species exhibited higher optimal growth rates on cheese related matrices than on synthetic media, while the opposite was observed for non-technological species. A comparative proteomic approach allowed unraveling the main metabolic pathways playing a role in growth of 4 of the 7 studied strains on both synthetic medium and cheese-mimicking medium. This proteomic study also highlighted the occurrence of 35 proteins specifically expressed by the technological strains M. lanceolatus UBOCC-A-109153 on the cheese-mimicking medium. Putative competitive and adaptative advantages of these hypothetical adaptation markers will be tested through additional investigations
Consuegra, Bonilla Jessika. "Bases écologiques et moléculaires de la diversification adaptative chez Escherichia coli". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAV090/document.
Texto completo da fonteDiversification events are central issues in evolution since they generate phenotypic innovation such as colonization of novel ecological niches and, ultimately, speciation. To study the ecological and molecular drivers of adaptive diversification, we used the longest still-running evolution experiment. Twelve independent populations are propagated in a glucose limited minimal medium from a common ancestor of Escherichia coli by serial daily transfers since 1988 for more than 60,000 generations. In one of the twelve populations, called Ara–2, a unique diversification event occurred: two phenotypically-differentiated lineages, named S (Small) and L (Large) according to their cell size, emerged from a common ancestor at ~ 6500 generations. The two lineages co-exist ever since, owing to negative frequency-dependent selection whereby each lineage is favored and invades the other when rare, such that no lineage gets extinct. Moreover, and before the split between the two S and L lineages, the population Ara–2 evolved a hypermutator phenotype, owing to a defect in a DNA repair gene. The objective of this thesis is to characterize the ecological, physiological and molecular mechanisms that allowed the emergence and stable co-existence of the S and L lineages.First, we used a combination of in vivo and in silico experimental evolution to determine the ecological and physiological drivers of the emergence of the polymorphism. Several ecological mechanisms including tradeoff, seasonality and character displacement are involved in the emergence and long-term persistence of diversity. In particular, we showed that the L lineage secretes acetate which generates a new ecological opportunity that the S lineage exploited. In addition, the S and L lineages became fitter and fitter over time in their respective ecological niches, respectively acetate and glucose. Second, we propagated S and L clones separately to remove competition between the two lineages. In these conditions, frequency-dependent interactions between the S and L clones evolved separately were completely abolished, revealing the importance of competition in the maintenance of the polymorphism. Third, we combined genetic, physiological and biochemical approaches to determine the role of an S-specific mutation that was previously found in arcA, encoding a global regulator, in the emergence of the S and L polymorphism. We showed that the evolved arcA allele conferred to the S lineage the capacity to growth on acetate by increasing the transcription of target genes involved in acetate consumption. During this study, we found an additional mutation, in the acs gene involved in acetate metabolism, that was also involved in the emergence of the S lineage. We further showed that these two mutations were favorable to the S lineage early during its emergence, and that other mutations occurred later that interacted epistatically with the acs and arcA evolved alleles. Therefore, these data showed that the establishment and further maintenance of the S and L polymorphism was a multi-step process involving epistatic interactions between several mutations. Fourth, we identified the long-term dynamics of mutation rates in this divergent population. A first early rise of a hypermutator was followed by a full reversion of this mutator state twice independently in each of the two S and L lineages.The emergence of a long-term bacterial polymorphism reflects a complex restructuration of the metabolic and regulatory networks in the co-existing lineages, resulting in the generation and exploitation of a new ecological opportunity. Competition and evolution of divergent resource consumption were the selective forces driving the maintenance of the polymorphism
Rager, Marie-Noëlle. "Apport de la résonance magnétique nucléaire à l'étude du métabolisme bactérien". Paris 11, 2006. http://www.theses.fr/2006PA114830.
Texto completo da fonteKnowledge of metabolic features of each bacterial species is of major interest in the medical, environmental and biotechnological fields. This work shows the contribution made by NMR to the investigation of metabolic diversity notably thanks to its overall and noninvasive approach. Sugar metabolism was studied on Plesiomonas shigelloides, Pasteurella multocida, Aeromonas hydrophila and Escherichia coli. 13C NMR allowed us to characterize transport systems, metabolic pathways and flux. 31P NMR allowed us to study cellular energetic state evolution, enzymatic activities and to characterize regulation factors. Thus, new metabolic pathways could be described. These approaches were applied for the study of bacteria on various states: culturable, nonculturable and encapsulated in silica gel
Caiveau, Olivier. "Propriétés dynamiques et fonctionnelles des membranes des mitochondries de mutants d'Arabidopsis thaliana affectés dans les activités désaturases du reticulum endoplasmique". Paris 6, 2001. http://www.theses.fr/2001PA066403.
Texto completo da fonteFeillet, François. "Adaptation métabolique à la malnutrition : modèle des lipides, de la cobalamine, de la riboflavine et des acides organiques dans la malnutrition protéino-énergétique de l'enfant et dans l'anorexie mentale". Nancy 1, 2000. http://docnum.univ-lorraine.fr/public/SCD_T_2000_0296_FEILLET.pdf.
Texto completo da fonteNobis, Séverine. "Étude du métabolisme protéique au niveau hypothalamique, colique et gastrique dans un modèle murin d'anorexie par une approche protéomique". Thesis, Normandie, 2017. http://www.theses.fr/2017NORMR071/document.
Texto completo da fonteAnorexia nervosa, a multifactorial eating disorder, is a major public health problem and results in a severe body weight loss. The severe malnutrition observed in anorectic patients is associated with metabolic alterations inducing disturbance of the gut-brain axis. However, involved mechanisms remained poorly understood. The aim of the present thesis was to better understand the alterations of the gut-brain axis in the activity-based anorexia (ABA) model by evaluating the protein metabolism of various tissues (hypothalamus, colon and stomach) by proteomic approach. Firstly, we have better characterized the response to ABA model according to sex. Then, different proteomic analyses were performed using female C57BL/6 mice. Our results revealed a tissue-dependent adaptation of protein and energy metabolism with an increased hypothalamic activity and a decrease in the gastrointestinal tract. Indeed, ABA mice exhibited an increased expression of proteins involved in mitochondrial metabolism at the level of the hypothalamus, and conversely a decrease of proteins involved in protein and energy metabolism in colonic mucosa with a key role of the mTOR signaling pathway. Both in hypothalamus and colon, autophagy was increased. We were also able to show that gastric emptying was delayed in ABA mice that is mainly due to malnutrition. In addition, proteomic analysis revealed an increase in gastric oxidative stress in female ABA mice. These alterations may contribute to the gastrointestinal functional disorders frequently described in anorexia nervosa. In conclusions, our study underlined tissue-dependent adaptive metabolic process during anorexia that should be further explored
Givaudan, Nicolas. "Adaptation strategies of soil biodiversity (earthworms) to pesticides : mechanisms in play and ecosystemic cost assessment". Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S083/document.
Texto completo da fonteThis work investigated if long-term residual contamination of agricultural soils leads to adaptation of earthworm populations to pesticides. It also aimed at identifying the costs of adaptation from the individual to the population level, and the consequences for the ecosystem. Residual contamination by pesticides was assessed and compared in three fields under conventional management (classified after evaluation of pesticide applications as ''high-'', ''medium-'', and ''low-''pesticide input), one field under organic agriculture requirements and one organic permanent pasture, all in this type of management for more than 20 years. Using a water extraction method, as indicative of the amount of bioavailable pesticides 6, 8 and 4 residues of pesticides were recovered in the ''high-'', ''medium-'', and ''low-input'' fields, respectively, and almost no pesticides were detected in the soil of the organic field except for low levels of residual (possibly 20 years old) atrazine. The endogeic species Aporrectodea caliginosa and Allolobophora chlorotica were found in common to the five fields, -except A. chlorotica which was absent from the organic field-, and were used as biological models. Adaptation strategies were investigated by comparing the populations of these earthworms between the different fields according to several endpoints in field and laboratory assessments. The endpoints measured ranged from the molecular (biotransformation and anti-oxidant enzymes), biochemical (main energy resources), and metabolic (respiration rate, metabolomics) levels, to individual (weight, length) and population-related parameters (cocoon and juvenile life traits), and to the possible consequences for the ecosystem in terms of bioturbation (earthworm burrowing behaviour) and pesticide disappearance as an crucial ecosystem service. Enhanced detoxification and anti-oxidant potential was demonstrated along the gradient of contamination in the fields, and in particular comparing the response to an experimental pesticide exposure between the pre-exposed, thus possibly adapted earthworms from the ''high-input'' field-, and the naïve population from the organic field. Distinct energetic demands and metabolic rearrangements were observed between the populations, more pronounced in the pre-exposed earthworms. Physiological adaptation was demonstrated in pre-exposed animals, and this was associated with an increase in burrowing behaviour and pesticide disappearance in the soil. Population-level consequences were assessed in life traits of the two populations. The conventional farming including the use of pesticides decreased the weight of adult worms in the field and resulted in reallocation of energy resources, possibly from reproductive to metabolic function. This led to lower fecundity and hatching success and could partly explain lower earthworm densities in pesticide-impacted soils
I dette arbejde blev der forsket i om langsigtet residualforurening af landbrugsjord fører til pesticidadaptation hos regnorme. Forskningen sigtede også efter at identificere adaptations-omkostningerne fra individ- til populationsniveau, og konsekvenserne for økosystemet. Pesticiders residualforurening blev vurderet og sammenlignet i; tre konventionelt styrede marker (klassificeret efter evaluering af pesticid-anvendelser som ”højt-”, ”medium-”, og ”lav-input”), en mark styret ud fra økologiske betingelser, og et økologisk permanent græsningsareal, alle havde været styret på denne måde i mere end 20 år. Ved hjælp af en vand-ekstraktionsmetode blev 6,8 og 4 pesticidresiduums udvundet i henholdsvis ”høj-”, ”medium-”, og ”lav-input” markerne, og næsten ingen pesticider blev detekteret i jorden fra den økologiske mark bortset fra lave niveauer af resterende (højst sandsynligt 20 år gammelt) atrazin. Regnorms-populationerne Aporrectodea caliginosa og Allolobophora chlorotica blev fundet i alle fem marker, bortset fra A. chlorotica som ikke var til stede i den økologiske mark. Adaptationsstrategier blev undersøgt ved at sammenligne populationerne af disse regnorme de forskellige marker imellem ifølge flere parametre i felt- og laboratoriebedømmelserne. De målte parametre rangerede fra molekylære- (biotransformation og antioxiderende enzymer), biokemiske- (primære energiressourcer), og metaboliske- (respirationsrate, metabolomics) niveauer, til individuelle- (vægt, længde) og populations-relaterede parametre (puppe og juvenile livskarakterer), og til de mulige konsekvenser for økosystemet med hensyn til bioturbation (regnormes grave-adfærd) og nedgang i koncentrationen af ekstraherbare pesticider. Forbedret afgiftnings- og antioxiderende potentiale blev demonstreret langs gradienten af pesticid forurening i felten. Forbedret afgiftning i den pre-eksponerede population var særdeles tydeliggjort ved eksponeringen til pesticider i laboratoriet sammenliget med den økologiske population. Der blev observeret distinkte energibehov og metabolisk omgruppering populationerne imellem, dette var mere udtalt hos de pre-eksponerede regnorme. Der blev detekteret fysiologiske adaptationer hos de pre-eksponerede dyr, og dette hang sammen med en kompensatorisk øgning i grave-adfærd og nedgang i koncentrationen af ekstraherbare pesticider i jorden. Konsekvenser, på populationsniveau, blev bedømt ud fra de to populationers livskarakterer. Brug af pesticider resulterede i vægtnedgang hos de voksne orme i felten og omfordeling af energiressourcer, formodentlig fra reproduktiv til metabolisk funktion. Dette førte til lavere frugtbarhed og udklæknings-succes og kunne til dels forklare de lavere regnorme-densiteter i den pesticid-påvirkede jord
Calmettes, Guillaume. "Analyse intégrative de l'adaptation de l'énergétique cardiaque à l'hypoxie chronique". Thesis, Bordeaux 2, 2010. http://www.theses.fr/2010BOR21711/document.
Texto completo da fonteAn important issue in the comprehension of the link between molecular events developed in pathologies such as chronic hypoxia adaptation, is the development of new experimental strategies aimed at the study of the integrated organ physiology. Our Modular Control Analysis (MoCA), gives quantitative information on the internal control and regulation of integrated heart energetics on the basis of a supply-demand system and is therefore of particular interest to better understand the overall effect as well as the relative importance of the various modi?cations developed during pathologies. In this thesis, MoCA was applied on isolated hearts of control and chronic hypoxic mice perfused with high or low oxygen in the medium. Despite a severe mitochondrial alteration after chronic hypoxia exposure, a surprizing higher response of energy supply (elasticity) to energetic intermediates changes (PCr, ATP, Pi) was detected in chronic hypoxic hearts. Moreover, chronic hypoxic hearts energetics was unchanged by oxygen reduction while a strong concomitant decrease in heart contractile activity and in PCr concentration, was measured in control hearts. As suggested by these results, this increase in energy-supply elasticity could be considered as an adaptive mechanism developed after chronic hypoxia counteracting hypoxia-induced altered cardiac energetics
Salle, Agnès. "Métabolisme énergétique chez l'obèse et le diabetique de type 2". Angers, 2006. http://www.theses.fr/2006ANGE0054.
Texto completo da fonteWeight change in type 2 diabetic patients (T2D) is distinctive with an inclination towards weight gain with insulin, and conversely a difficulty in weight loss in weight reduction programmes. Our results show that after one year of insulin treatment, resultant weight gain is composed primarly of fat-free mass and it appears not to incrase cardivascular risk. Our results also show that in the early stage of their disease, T2D lose the same amount of weight as obese nondiabetic patients and that in both cases there is non whole body or mitochondrial energy metabolism adaptation that can explain the stabilisation of weight observed from the 5th month onwards. Furthermore, there is no specific adaptation of energy metabolism in T2D as their basal metabolism is not any different to that of obese nondiabetic patients or after weight loss. Insulin resistance is not a determinant of energy metabolism
Auriol, Clement. "Compréhension globale de l'évolution in vivo d'Escherichia coli lors de cultures sous contraintes de rapports NADPH/NADP+ artificiellement élevés". Thesis, Toulouse, INSA, 2011. http://www.theses.fr/2011ISAT0038/document.
Texto completo da fonteBacterial metabolism is characterized by robustness and plasticity that allow it to adjust too many metabolic perturbations. This present work demonstrates Escherichia coli abilities of evolution and adaptation under stress of NADPH accumulation. We constructed the E. coli MG1655 Δpgi::FRT ΔudhA::FRT Δedd::FRT Δqor::FRT strain where central metabolism has been rationally engineered to produce two mol of NADPH and two mol of NADH during the oxidation of glucose to acetyl-CoA, while a wild-type strain produces 4 mol of NADH per mole of glucose. Consequently, this strain presents a weak growth on glucose mineral medium. So as to evaluate bacterial abilities to overcome such metabolic stress, in vivo evolution of this strain has been forced in laboratory by serial transfer subcultures. After four evolution subcultures, an individual clone has been characterized by a six fold increased growth rate compared to non-evolved strain. CGS (Comparative Genome Sequencing) analysis allowed us to correlate growth improvement with one mutation apparition in respiratory complex: NuoF*(E183A) in NuoF subunit from the NADH dependant complex I. Further biochemical and physiological studies demonstrated that the evolved respiratory complex is able to oxidize both NADH and NADPH, resulting in a new NADPH reoxydation pathway in the cell. In vivo evolution experiments were then continued until eleven subcultures, where a new individual clone has been characterized by an eleven fold increased growth rate compared to non-evolved strain. Additional CGS analysis allowed us to correlate growth improvement with apparition of two mutations: NuoF*(E183A) and another mutation within the RNA polymerase alpha subunit, rpoA*. Thus, a second E. coli MG1655 ΔpfKA::FRT ΔpfKB::FRT ΔudhA::FRT Δedd::FRT Δqor::FRT strain has been rationally engineered to produce three mol of NADPH and one mole of NADH per mole of glucose oxidized to acetyl-coA. As this train was unable to growth in liquid glucose mineral medium, we performed a solid-state screening on glucose mineral medium that led to two different types of NuoF mutations in strains having recovered growth capacity. In addition to the previously seen E183A mutation other clones showed an E183G mutation, both having NADH and NADPH oxidizing ability. This result highlights need of this new NADPH reoxydation pathway for NADPH accumulating cells. This solution creates a new function for NADPH that is no longer restricted to anabolic synthesis reactions but can now be also used to directly produce catabolic energy. Finally, global understanding of evolution process allowed conception of new engineered strains, well designed for NADPH dependant production of chemicals of interest
Ba, Yéro Seydi. "Régulation de l'activité cytochrome c oxydase de blé (Triticum aestivum L.) par le froid et le CO₂". Mémoire, 2011. http://www.archipel.uqam.ca/4347/1/M12091.pdf.
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