Дисертації з теми "Métabolisme hépatique des lipides"
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Lauressergues, Emilie. "Antipsychotiques et métabolisme hépatique des lipides et du cholestérol." Lille 2, 2010. http://www.theses.fr/2010LIL2S020.
Schizophrenia is a psychiatric disorder that heavily impacts the mental functions and social relations of the patients concerned. More than 1 % of the world population suffers from this disease that is characterized by different kinds of symptoms which are commonly subclassified as either positive (hallucinations, illusions) or negative (loss of affect and motivation, social withdrawal). These symptoms can be controlled by treatment with antipsychotic drugs (APDs) which act primarily through the modulation of dopamine and serotonin receptors. Unfortunately, some of these drugs induce important metabolic side effects such as weight gain (as much as 10 kg the first year with clozapine for example), dyslipemia, alterations of glucose homeostasis and development of diabetes. The consequences of these disturbances are treatment disruption and an increase of cardiovascular risks which contributes to a death rate twice as high for schizophrenic patients versus the general population, associated with a reduction in the average life expectancy by 10 years. The mechanisms underlying the side effects by APDs are not completely understood. At the level of the central nervous system (CNS), actions on serotoninergic, dopaminergic or histaminergic receptors are believed to be implicated in metabolic side effects (particularly by modifying appetite or energy homeostasis). In the periphery, certain APDs perturb essential physiological functions such as insulin secretion by pancreatic b cells, glucose transport into skeletal muscle and lipogenesis at the adipose tissue level, as well as physiological parameters like the sensitivity of various tissues to insulin. Althoug the liver is an essential organ for maintaining the nutrients homeostasis, few studies show an interest for the direct impact of these molecules on this tissue. The main goal of this thesis is to characterise the impact of APDs on hepatic lipid and cholesterol metabolism using various markers from appropriate hepatocyte cellular models, such as de novo synthesis of lipids and cholesterol, the quantification of the mature transcription factors SREBP-1 and -2 (sterol regulatory element binding protein) as well as the evaluation of the expression of several genes of interest. In the first part, we selected hepatocyte cellular models (cells isolated from rat liver and the human IHH cell line) and showed their relevance for the study of the “potential adverse effects” of different compounds on lipid and cholesterol metabolism. For this, the physiological and sensitive character of these cultures was shown through their response to nutritional (or hormonal) changes and to pharmacological treatments. In the second part, we highlighted three profiles of APD molecules :-molecules strongly inducting de novo lipogenesis and cholesterogenesis (clozapine, olanzapine, risperidone and NDMC), -molecules with more moderate effects (haloperidol and paliperidone), -molecules with little or no effect(s) (aripiprazole, quetiapine, bifeprunox and chlorpromazine). Induction of de novo lipogenesis and cholesterogenesis by certain APDs is associated to the stimulation of the SREBP pathway (transcription factors and SREBP target genes) and correlate relatively well with the metabolic disturbances of schizophrenia patients under APD treatment. We therefore suggest that certain unfavourable effects of these APD molecules are due to a direct action on the liver. Furthermore we stated that those APDs that present the most unfavourable profiles in our in vitro models, activate the PERK pathway (protein kinase RNA-like ER kinase) of the UPR (unfolding protein response), illustrating the presence of endoplasmic reticulum (ER) stress. However, the ER stress is known to activate the SREBP pathways and to cause, in chronic, diseases such as steatosis, dyslipidemia and diabetes. This discovery opens new perspectives regarding the research for the action mechanisms of these molecules. More precisely, in our human hepatocyte model we show that the treatment with thapsigargine (inductive of ER stress by calcium depletion) stimulates the SREBP pathways. Whereas no detectable modification of the cytosolic calcium concentrations was observed following APD treatment, the use of calcium chelating agents reverses the effects of clozapine on the SREBP-1 and -2 pathways. We therefore presume that clozapine, by disturbing calcium homeostasis, generates ER stress which would activate the SREBPs pathways and lipogenesis and cholesterogenesis in consequence. To corroborate these findings, two experimental studies in rat and mouse were conducted that support our in vitro results. In the rat, a study employing acute drug administration confirms that clozapine, olanzapine and risperidone, at an early stage (1h, 3h), cause transcriptional deregulations of hepatic lipogenic, cholesterogenic and UPR genes. In the mouse, a study with chronic administration of risperidone indicates significant inductions of weight gain in relation to the activation of the SREBP-1c pathway and of FAS (fatty acid synthase). Altogether these data suggest that independent of their specific effects at the CNS level, APDs can modulate hepatic lipid metabolism. In conclusion, rat primary hepatocyte cultures and IHH cells are models of interest for the detection of potential unfavourable effects of molecules on hepatic lipid and cholesterol metabolism. Moreover, the SREBP pathways (proteins and target genes associated) are appropriate indicators of cellular metabolic disturbances and thus can be considered as pertinent markers of the respective processes. These models could therefore be integrated in the research process and in the selection of new chemical compounds destined to become APDs. With respect to the clinic, our results support the strategy to associate hypolipemic or hypocholesterolemic (statines) treatments to patients treated with clozapine, olanzapine and risperidone
Saez, Gladys. "Relation entre l’engraissement intramusculaire chez le canard, la lipogénèse hépatique, la sécrétion hépatique des lipides et la capacité de captage des lipides par les muscles." Pau, 2009. http://www.theses.fr/2009PAUU3007.
In order to explain the observed difference in intramuscular fatness between Muscovy and Pekin ducks, we compared the lipid metabolism in liver and muscle of these two species. In ad ibitum- fed ducks, we demonstrated that Muscovy duck had a higher ability to synthesise and store lipids in liver than Pekin duck which could partly explain its highest ability to produce fatty liver. Depending on feeding level (ad libitum fed or overfed ducks), the hepatic secretion of lipids under VLDL form was higher in Muscovy duck than in Pekin duck or equivalent for the two species. However, Pekin duck exporting VLDL with higher triglyceride content than those of Muscovy duck could limit the development of hepatic steatosis. This mechanism associated to a highest muscle uptake of circulating lipids, a highest ability for the storage of intramuscular lipids and a more active muscle lipogenesis could explain the highest intramuscular fatness of Pekin duck
Caselli, Claude. "Contribution à l'étude de l'absorption intestinale et du métabolisme cardiaque et hépatique de l'acide erucique chez le rat." Dijon, 1987. http://www.theses.fr/1987DIJOS027.
Cachefo, Pereira de Souza Ana Célia. "Lipogénèse hépatique et synthèse du cholestérol au cours des malabsorptions sévères et de l'hyperthyroïdie humaine." Lyon 1, 2001. http://www.theses.fr/2001LYO1T224.
Coum, Amandine. "Développement de méthodes de SRM à 4,7 T pour l'étude in vivo du métabolisme lipidique chez la souris." Thesis, Rennes 1, 2015. http://www.theses.fr/2015REN1B025/document.
In recent years, there has been an unprecedented increase in the morbidity and mortality associated with diseases such as the steatosis, linked to obesity. In this context, pre-clinical and clinical studies are of interest in the search for new biomarkers allowing the diagnosis of steatosis. Currently, steatosis is diagnosed and graded by histological analyzes from a liver biopsy. On the other hand, it is advantageous to use non-invasive diagnostic modalities, especially in longitudinal studies. In this context, magnetic resonance spectroscopy (MRS), as a non-invasive and non-ionizing approach, is an attractive alternative method for the diagnosis of steatosis by measuring the hepatic fat fraction. Moreover, from the MRS spectrum acquired in the liver, it is possible to quantify the fatty acids (FA) composition of the hepatic lipids, which could be a potential biomarker for the follow-up of steatosis. The work of this thesis has been performed in vitro and in vivo, in the context of pre-clinical (4.7 T) and clinical (3.0 T) studies. An investigation of the optimal MRS acquisition protocol for the quantification of FA was carried out, with particular attention to the role of the water signal suppression module. Different quantification algorithms of the lipid composition were studied and validation of these algorithms was carried out in vitro and in vivo. Finally, still with the objective of determining new biomarkers of steatosis, a method (LOREEDE: LOngitudinal RElaxation time Evaluation from Dynamic Equilibrium) for the measurement in vivo of the T1 of the water resonance and the major lipid resonance, by MRS, was developped and validated in a preliminary study
Delprat, Leslie. "Effets des régimes alimentaires riches en lipides et en fructose sur la performance et le métabolisme de canards Mulard." Master's thesis, Université Laval, 2021. http://hdl.handle.net/20.500.11794/68773.
Different types of dietary carbohydrate and lipids are known to alter feed intake and adiposity in rodents. Long-term feeding of high-fat, high-fructose diets has been shown to alter feed intake and cause fatty liver in mammals. Such diets in combination with the addition of high fructose corn syrup (HFCS) in the drinking water may result in a similar phenotype in ducks destined for the production of foie gras. The aims of these studies were therefore firstly to assess the short-term effects of a diet rich in fat and fructose in mulard ducks and secondly to assess the long-term impact of this type of diet combined with sugar water. Despite its higher energy content, feed intake was not reduced by the FF diet, suggesting a potential alteration of satiety signals, which may impact body liver and weight under longer-term interventions in ducks destined to produce foie gras. However, HFCS in the drinking water reduced voluntary feed intake, whereas overall, FF and C had similar feed intake. In contrast to rodent and human studies, FF diets failed to induce hyperphagia and liver steatosis. In the absence of overfeeding, the long-term feeding of high-fructose, highfat diets, does not promote fatty liver.
Deleye, Yann. "Rôle du gène suppresseur de tumeur p16INK4a dans le métabolisme hépatique des lipides au cours du jeûne." Thesis, Lille 2, 2018. http://www.theses.fr/2018LIL2S002.
P16INK4a is a tumor suppressor protein that is a well described cell cycle regulator. Recently, genome-wide association studies (GWAS) associated the CDKN2A locus, from which p16INK4A is encoded, with increased risk for development of type 2 diabetes. A pathophysiological link between p16INK4a and hepatic glucose homeostasis has been unraveled recently, through the control of gluconeogenesis. Patients with T2D also present with disturbances in fat metabolism, associated with an increased prevalence to Non Alcoholic Fatty liver diseases (NAFLD). In this context, we investigated the role of p16INK4a in hepatic lipid metabolism in vitro using primary hepatocytes, the murin AML12 and human IHH hepatocyte cell line transfected respectively with siRNA-CDKN2A and siRNA-p16 and in vivo using p16+/+ and p16-/- mice.Transcriptomic analyses of p16+/+ and p16-/- primary hepatocytes using microarrays revealed that metabolic and PPARα signaling pathways were among the most modulated in p16 absence. Moreover, in primary hepatocytes and in hepatocyte cell lines, p16 deficiency modulates a subset of PPARα target genes associated to fatty acids oxidation (FAO). These effects were associated with an increased response to GW647, a PPAR945; agonist, and reversed by siRNA targeting PPAR45;. Investigating known PPAR945; activators and transcriptional co-activators in vitro, we found that upregulation of FAO genes expression was linked to SIRT1. AMPK is a known activator of FAO and has been shown to induce SIRT1 activation through increase of NAD/NADH ratio. Interestingly, downregulation of p16 expression in vitro led to increased AMPK phosphorylation and activation.In vitro, p16-/- primary hepatocytes demonstrated enhanced fatty acid oxidation of oleate compared to p16+/+. During fasting, enhanced FAO leads to a shift of acetyl-coA utilization from the TCA cycle to ketogenesis. Interestingly, p16-/- mice showed a tendency to produce more ketone bodies than their control littermate after sodium octanoate injection. These findings describe a new function for p16INK4a in hepatic lipid metabolism through activation of AMPK-SIRT1-PPARα pathway
Allard, Julien. "Mise en évidence de l'implication de différents mécanismes dans la survenue de la stéatose hépatique d'origine médicamenteuse en absence de dysfonction mitochondriale sévère." Thesis, Rennes 1, 2020. http://www.theses.fr/2020REN1B010.
Steatosis is a liver lesion reported with numerous pharmaceuticals. Prior studies showed that severe impairment of mitochondrial fatty acid oxidation (mtFAO) constantly leads to lipid accretion in liver. However, much less is known about the mechanism(s) of drug-induced steatosis in the absence of severe mitochondrial dysfunction, although previous studies suggested the involvement of mild-to-moderate inhibition of mtFAO, increased de novo lipogenesis (DNL) and impairment of very low-density lipoprotein (VLDL) secretion. The objective of our study, mainly carried out in human hepatoma HepaRG cells, was to investigate these 3 mechanisms with 12 drugs able to induce steatosis in human: amiodarone (AMIO, used as positive control), allopurinol (ALLO), D-penicillamine (DPEN), 5-fluorouracil (5FU), indinavir (INDI), indomethacin (INDO), methimazole (METHI), methotrexate (METHO), nifedipine (NIF), rifampicin (RIF), sulindac (SUL) and troglitazone (TRO). Hepatic cells were exposed to drugs for 4 days with concentrations inducing loss of cellular ATP always below 30% of the controls and not exceeding 100xCmax. Among the 12 drugs, AMIO, ALLO, 5FU, INDI, INDO, METHO, RIF, SUL and TRO induced steatosis in HepaRG cells. AMIO, INDO and RIF decreased mtFAO. AMIO, INDO and SUL enhanced DNL. ALLO, 5FU, INDI, INDO, SUL, RIF and TRO impaired VLDL secretion. These 7 drugs reduced the mRNA levels of genes playing a major role in VLDL assembly and also induced endoplasmic reticulum (ER) stress. Thus, in the absence of severe mitochondrial dysfunction, drug-induced steatosis can be triggered by different mechanisms, although impairment of VLDL secretion seems more frequently involved, possibly as a consequence of ER stress
Gjorgjieva, Monika. "Identification des mécanismes moléculaires impliqués dans le développement des pathologies hépatiques et rénales dans des modèles murins de glycogénose de type 1a." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSE1007/document.
Glycogen storage disease type I (GSDI) is a rare genetic disease, due to a deficiency in glucose-6 phosphatase (G6Pase), a key enzyme in the endogenous glucose production. Besides severe hypoglycemia, the loss of G6Pase leads to the accumulation of glycogen and lipids in the liver and kidneys. On the long term, most patients develop hepatic tumors and chronic kidney disease (CKD).The goal of this thesis was to characterize the molecular mechanisms involved in hepatic carcinogenesis and CKD, thanks to viable and unique mouse models with specific deletion of G6Pase in the liver or kidneys, which exhibit all hallmarks of hepatic and renal pathologies, respectively.On a hepatic level, our study allowed us to highlight a « Warburg-like » metabolic reprogramming, very similar to what is observed in cancer cells, associated with a loss of cellular defenses and tumor suppressors. Furthermore, we showed that formation of hepatocellular adenoma, which transform later in carcinoma, occurs in the absence of liver fibrosis, due to the fact that pro-fibrotic pathways are not activated. In the kidneys, the study of CKD highlighted the development of renal cysts in mice with GSDI, as well as in the patients presenting an advanced stage of CKD. Finally, the last study on the activation of the oxidation of lipids, by treating the mice with fenofibrate, allowed us to suggest a deleterious role of lipid accumulation in the development of the hepatic and renal pathologies
Leplaix-Charlat, Laurence. "Effets des acides gras et du cholestérol alimentaires sur le métabolisme des lipides et des lipoprotéines aux niveaux plasmatique et hépatique chez le veau préruminant : conséquences sur la composition lipidique des tissus." Aix-Marseille 3, 1995. http://www.theses.fr/1995AIX30085.
Boudaba, Nadia. "Régulation du métabolisme des lipides par l’AMPK dans le foie : implications dans le développement et le traitement de la stéatose hépatique." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T043.
Fatty liver disease affects between 20-40% of the population. This pathology is usually associated with metabolic disease. Its pathogenesis is poorly understood. Altered lipids metabolism in the liver resulting on hepatic fat accumulation is probably due to fatty liver. There is no specific treatment for fatty liver disease. AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism. In particular, AMPK regulates lipid metabolism by inhibiting fatty acids and cholesterol synthesis, and stimulating fatty acids oxidation. Several studies have shown an association between intracellular lipid accumulation and loss of AMPK activity in the liver. These observations suggest that AMPK may be a factor involved in the pathogenesis of hepatic steatosis. To investigate this hypothesis, we generated a new model of knockout mice lacking the catalytic subunits of AMPK α1 and α2 specifically in the liver. We analyzed the consequences of this deletion on lipid metabolism in different nutritional conditions. Deletion of AMPK in the liver does not affect hepatic triglyceride and cholesterol content in fasted or in refed conditions with a high carbohydrate diet. Also, lipogenic genes expression is not altered in the liver of these animals. Moreover, the oxidation of fatty acids is not impaired after 24 hour of fasting. Surprisingly, lacking AMPK specifically in the liver does not aggraving fatty liver, hyperglycemia, or impaired glucose tolerance when the mice are on high fat diet condition. However, the activation of AMPK in vivo with a direct activator, A-769662, normalizes hepatic steatosis in lipodystrophyc aP2-SREBP-1c mice and in obese mice placed on high-fat diet. This effect is AMPK dependent because it is completely abolished in mice lacking AMPK specifically in liver. In primary mice hepatocytes, AMPK activation by a direct activator (A-769662) or by indirect activators (metformin and AICAR) reduces lipogenesis rates and increases fatty acids oxidation rates. These effects were completely abolished in hepatocytes lacking AMPK, showing the specific action of AMPK on lipid metabolism in response to these compounds. These results obtained in mice can be extrapolated to humans. Indeed, we have shown that AMPK activation in primary humain hepatocytes inhibits effectively fatty acid and cholesterol synthesis rates. In conclusion, our results showed that inactivation of AMPK in the liver is not a triggering or an aggraving factor in the pathogenesis of hepatic steatosis. Nevertheless, AMPK re-activation has a therapeutic benefit for the treatment of fatty liver disease. Thus, AMPK is a potential target to treat fatty liver disease in human
Djaouti, Louiza. "Effets de la modulation de la masse grasse sur la production d'adiponectine chez la souris : conséquences sur le métabolisme hépatique des lipides." Phd thesis, Université de Bourgogne, 2010. http://tel.archives-ouvertes.fr/tel-00674047.
Xu, Elaine Meng. "Role of ceacam1 and shp1 in the regulation of insulin sensitivity and hepatic glucose and lipid metabolism." Doctoral thesis, Université Laval, 2012. http://hdl.handle.net/20.500.11794/23713.
L’obésité et le diabète de type 2 (T2D) sont étroitement associés à la résistance à l’insuline, une maladie métabolique qui se développe suite à un défaut causé par une réduction de la signalisation de l’insuline et de sa clairance. Afin de comprendre la pathogenèse de la résistance à l’insuline plusieurs molécules qui régulent les voies de signalisation ainsi que la clairance sous contrôle du récepteur à l’insuline ont été étudiées, incluant la protéine tyrosine phosphatase (PTP) SHP1 et la molécule carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1 or CC1) qui est régulée en aval sous le contrôle de SHP1. Les nombreuses isoformes de CC1 contribuent à différentes fonctions cellulaires. Dans le foie, l’isoforme CC1-L, qui est phosphorylée sur tyrosine (Tyr), joue un rôle métabolique essentiel dans la régulation de la clairance de l’insuline et dans la suppression de l’activité de la synthase des acides gras (FAS). Nous avons démontré que des souris invalidées pour CC1 (Cc1-/-) sous un régime standard faible en gras (SD) développent néanmoins une importante stéatose hépatique qui est démontré par une augmentation de triglycérides, de cholestérol total ainsi que de cholestérol estérifié dans le foie. Sous un régime contenant 55% de gras (HFD) ces mêmes souris démontrent une prédisposition au développement de la stéatose et dysfonction hépatique induite par le régime, indiqués par une accumulation de lipides hépatiques et une augmentation d’enzymes marqueurs de dommage hépatique dans la circulation. La stéatose hépatique dans la souris Cc1-/- est liée à une augmentation significative d’importantes enzymes lipogéniques et de la synthèse du cholestérol qui sont régulés suite à une augmentation de l’activité nucléaire des facteurs de transcription Srebp1c et Srebp2. Comparées aux souris contrôle sauvages (WT) les souris CC1-/- ont démontré une réduction de la clairance de l’insuline, une intolérance au glucose, une résistance à l’insuline hépatique et une augmentation d’expression des activateurs transcriptionels hépatiques PGC-1 et FoxO1. L’absence de CC1 a aussi exacerbé l’intolérance au glucose et la résistance à l’insuline hépatique induite par le régime à haute teneur de gras mais la clairance de l’insuline n’était pas diminuée dans les souris Cc1 -/-. Nos donnés indiquent que CC1 est un important régulateur de la lipogénèse hépatique et que les souris CC1-/- sont prédisposées à développer une stéatose hépatique qui mène à une résistance à l’insuline hépatique et des dommages dans le foie qui sont surtout évidentes sous un régime riche en lipides. Une importante Tyr phosphatase de CC1 est SHP1. Précédemment nous avons démontré que SHP1 est un important régulateur de l’homéostasie du glucose et de la clairance de l’insuline par le foie, cependant son rôle dans l’obésité liée au diabète reste méconnu. Nous rapportons ici que l’expression de SHP1 est significativement augmentée dans les tissus métaboliques de souris obèses sous régime HFD. Nous avons généré des souris invalidées pour SHP1 spécifiquement dans les hépatocytes (Ptpn6H-KO) pour investiguer le rôle de SHP1 dans le développement de la résistance à l’insuline et de la stéatose hépatique. Sous régime HFD les souris Ptpn6H-KO deviennent aussi obèses que les souris non invalidées pour SHP1 (Ptpn6f/f). Malgré ceci les souris Ptpn6H-KO démontrent une amélioration de la glycémie à jeun et une protection contre la résistance à l’insuline induite par l’obésité qui est confirmée par la suppression de la synthèse de glucose hépatique ainsi qu’une amélioration de l’activation du récepteur pour l’insuline avec une augmentation concomitante des voies de signalisation Akt. Il est aussi possible que la clairance de l’insuline accrue qu’on observe dans les souris Ptpn6H-KO soit due à une augmentation de la phosphorylation sur tyrosine de CC1. Les souris obèses Ptpn6H-KO montrent une augmentation de stéatose hépatique qui est le résultat de 1) une augmentation de lipogénèse hépatique associée à une augmentation importante de l’activité et de l’expression de SREBP-1 et des enzymes lipogéniques en aval FAS et ACC, 2) une augmentation de la captation postprandiale des acides gras qui est possiblement liée à une augmentation de l’expression du gène et de l’activité nucléaire de PPARγ, 3) une diminution de la sécrétion des triglycérides et de l’apolipoprotéine B sous le forme de lipoprotéines de très basse densité (VLDL). Étonnamment, malgré le niveau élevé de stéatose hépatique, le profil inflammatoire dans le foie des souris Ptpn6H-KO était similaire ou même amélioré comparé aux souris contrôles Ptpn6f/f et ceci était accompagné d’une diminution de dommage hépatocellulaire. Ces résultats démontrent que SHP1 est un nouveau médiateur de la résistance à l’insuline dans les hépatocytes et contribue à la détérioration du métabolisme du glucose induite par l’obésité. Chez la souris Ptpn6H-KO la stéatose hépatique induite par le régime suggère par ailleurs un autre rôle de SHP1 dans la régulation du métabolisme hépatique des lipides. Malgré le fait que CC1 et SHP1 se retrouvent dans le même complexe que Cdk2 et le récepteur de l’insuline, ils jouent des rôles opposés, CC1 étant un régulateur positif et SHP1 un régulateur négatif de la clairance de l’insuline. Ceci est en accord avec la régulation hépatique par le glucose des voies de signalisation de l’insuline pour ces deux molécules car les souris Cc1-/- démontrent une détérioration du métabolisme du glucose et de la signalisation de l’insuline alors que les souris Ptpn6H-KO démontrent une amélioration. Notre observation de stéatose hépatique chez ces deux modèles animaux suggère que CC1 et SHP1 limitent la synthèse et l’entreposage des lipides hépatiques de façon dépendante ou indépendante de la signalisation de l’insuline. Les résultats de ces études utilisant des modèles invalidés pour CC1 ou SHP1 révèlent des mécanismes du contrôle de la synthèse de glucose hépatique et du métabolisme des lipides qui sont très complexes et distincts. En plus ces résultats nous apportent une compréhension importante de la régulation hépatique de l’action et de la clairance de l’insuline.
Obesity and type 2 diabetes mellitus (T2D) are tightly associated with a common link, insulin resistance, a metabolic disorder developed from defective insulin action involving impaired insulin signaling and clearance. To investigate the pathogenesis of insulin resistance, many molecules modulating its signaling pathways as well as insulin receptor-mediated insulin clearance have been studied, including the protein tyrosine phosphatase (PTP) SHP1 and its regulated downstream molecule carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1 or CC1). CC1 in multiple isoforms contributes differentially to various cellular functions, the tyrosine (Tyr)-phosphorylated isoform of CC1 (CC1-L) is known to play an essential metabolic role in the hepatic regulation of insulin clearance and insulin-mediated acute inhibition of fatty acid synthase (FAS) activity. We have found that CC1-deficient (Cc1-/-) mice on standard diet (SD) already develop spontaneous hepatic steatosis with significantly elevated accretion of triglyceride (TG), total and esterified cholesterol. When challenged with a 55% kcal high-fat diet (HFD), these mice show greater susceptibility to the development of diet-induced hepatic steatosis and dysfunction, indicated by higher hepatic lipid content and serum levels of hepatic enzymes as markers of liver damage. Hepatic steatosis in the Cc1-/- mice is linked to a significant increase of key lipogenic (FAS, ACC) and cholesterol synthetic (HMGCR) enzymes, which is a result of increased nuclear activity of their positive gene transcription factors Srebp1c and Srebp2. Compared to their wild-type (WT) littermate controls, Cc1-/- mice exhibited impaired insulin clearance, glucose intolerance, liver insulin resistance, and elevated hepatic key gluconeogenic transcriptional activators Pgc1 and FoxO1. Lack of CC1 also exacerbated the HFD-induced glucose intolerance and hepatic insulin resistance, while insulin clearance was not further deteriorated. These data demonstrate that CC1 is a key regulator of hepatic lipogenesis and that Cc1-/- mice are predisposed to liver steatosis, leading to hepatic insulin resistance and liver damage, particularly when chronically exposed to dietary fat. An important Tyr phosphatase of CC1, SHP1, has been found previously by our lab to regulate glucose homeostasis and liver insulin clearance, but its potential implication in obesity-linked insulin resistance and hepatic steatosis has not yet been examined. We hereby report that SHP1 expression is significantly upregulated in metabolic tissues of HFD-fed obese mice. We have also further investigated the role of hepatocyte SHP1 in promoting insulin resistance and hepatic steatosis by generating hepatocyte-specific SHP1 knockout mice (Ptpn6H-KO). Upon HFD feeding, Ptpn6H-KO mice develop obesity as their Ptpn6f/f littermates. With consistently improved fasting glycemia, these mice are protected from obesity-induced liver insulin resistance as revealed by normalized insulin suppression of hepatic glucose production and hepatic insulin signaling with improved activation of insulin receptor and downstream signaling through Akt. More rapid insulin clearance in Ptpn6H-KO mice due to heightened CC1 tyrosine phosphorylation is also a possible contribution to the improved insulin action. Unexpectedly, obese Ptpn6H-KO mice exhibit enhanced hepatic steatosis. In detailed mechanisms, this is a result of 1) augmented hepatic lipogenesis, marked by upregulated activity and expression of SREBP-1 as well as the downstream regulated lipogenic enzymes such as FAS and ACC, 2) increased postprandial fatty acid uptake, possibly linked to the upregulation of PPAR gene expression and nuclear activity, and 3) decreased postprandial TG output in apolipoprotein B (ApoB)-associated lipoprotein particles, i.e. very low density lipoprotein (VLDL). More interestingly, the steatotic livers of these Ptpn6H-KO mice display comparable or even reduced level of inflammation accompanied by significantly less hepatocellular damage than that in their Ptpn6f/f counterparts. These results present hepatocyte SHP1 as a novel mediator of insulin resistance compromising hepatic glucose metabolism in diet-induced obesity. The enhanced diet-induced hepatic steatosis in Ptpn6H-KO mice provides a new role for SHP1 in liver lipid metabolism and further supports the bifurcation of insulin signaling in the regulation of hepatic glucose and lipid homeostasis or also confirms a possible disconnection between hepatic regulation of glucose and lipid metabolism. Although both CC1 and SHP1 are found in the same complex with Cdk2 and insulin receptor to regulate insulin clearance, they play opposing roles as CC1 is the positive regulator and SHP1 being the negative one. This is in accordance with the hepatic glucoregulation of insulin signaling for both molecules, since Cc1-/- mice show impaired glucose metabolism and insulin signaling whereas Ptpn6H-KO mice exhibit improvement. Interestingly, our observation of hepatic steatosis in both animal models, though with different characteristics, suggests that both CC1 and SHP1 limit hepatic lipid synthesis and storage, dependent or independent of insulin signaling. Findings from these studies using animal models lacking CC1 and SHP1 reveal complex and differential regulatory mechanisms of hepatic glucose and lipid metabolism, and they also provide important understanding of the hepatic regulation of insulin action and clearance.
Piodi, Aurélie. "Caractérisation des déterminants viraux de la stéatose hépatocytaire induite par le virus de l'hépatite." Thesis, Paris Est, 2008. http://www.theses.fr/2008PEST0013/document.
Hepatocellular steatosis is common in patients with chronic hepatitis C. Steatosis can be considered as a true cytopathic lesion induced by hepatitis C virus genotype 3, suggesting that one or more viral proteins produced during genotype 3 infection are involved in the steatogenic process, while the same proteins produced during infection by other genotypes are not. Our objective was to identify the viral determinants of HCV-induced steatosis and to understand the underlying mechanisms. Extensive analysis performed on HCV sequences selected on their genotype and their association with in vivo steatosis are revealed putative viral determinants of viral-induced steatosis in E1-E2 and NS3 proteins coding regions. However, we can not rule out the potential role of these positions in HCV-induced steatosis and experimental study should be drawn to explore this issue. In addition, the FATG164-167 motif, which has been implicated in HCV core protein induced steatosis, was constantly present on genotype 3a sequences independently of the original presence or absence of liver steatosis. We examined in vitro interactions between lipid droplets and full-length core protein isolated from patients with HCV genotype 3a infection, with and without steatosis, and from steatosis-free patients infected by hepatitis C HCV 1b. We also examined morphological changes in the lipid droplets according to the HCV genotype and the presence of steatosis in vivo. We showed that the core protein of both HCV genotypes 1b and 3a binds tightly to the surface of intracellular lipid droplets. However, cells transfected with genotype 3a contain more neutral lipids in lipid droplets, and more large lipid droplets, than cells transfected with genotype 1b sequences. This suggests that hepatitis C virus core protein-lipid droplet interaction could play a role in virus-induced steatosis. Importantly, we found no genetic or functional differences between genotype 3a core proteins from patients with and without hepatitis C virus-induced steatosis. This suggests that other viral proteins and/or host factors are involved in the development of hepatocellular steatosis in patients infected by hepatitis C virus genotype 3a
Romestaing, Caroline. "Stéatohépatite et adaptations métaboliques:Effets d'un régime enrichi en lipides saturés, ou carencé en choline et méthionine, sur la bioénergétique et le métabolisme hépatique de rat." Phd thesis, Université Claude Bernard - Lyon I, 2007. http://tel.archives-ouvertes.fr/tel-00262387.
Dans un premier temps, nous avons élaboré un régime alimentaire enrichi en acides gras saturés afin d'induire une NASH. Au terme de 14 semaines de régime, nous n'avons pas mis en évidence de surcharge lipidique au niveau du foie des animaux recevant ce régime enrichi. Les mesures effectuées avec des mitochondries isolées de foies et avec des hépatocytes isolés n'ont montré aucune différence au niveau de la bioénergétique ou du métabolisme hépatique entre les différents groupes de rats. En revanche, une modification de la répartition tissulaire a été observée, avec une augmentation des masses des tissus adipeux blanc et brun. Dans cette étude, l'absence de stéatose hépatique et de NASH semble due à une augmentation du stockage des lipides au niveau du tissu adipeux blanc, et à une augmentation de leur oxydation par un processus thermogène au niveau du tissu adipeux brun, permettant ainsi de « brûler » l'excès calorique.
La deuxième partie du travail concernait l'étude des modifications bioénergétiques et métaboliques induites par un régime carencé en choline et méthionine connu pour induire une NASH chez le rat. Nous avons montré que les mitochondries de foie et les hépatocytes isolés de rats traités, avaient une respiration augmentée. Cette stimulation de la respiration était due à un découplage de la chaîne respiratoire par un mécanisme de « proton leak » ET de « redox slipping » au niveau de la cytochrome c oxydase. Ce découplage avait pour conséquence de stimuler l'utilisation de substrats lipidiques et de diminuer la production de radicaux libres de l'oxygène. En parallèle, l'étude avec des hépatocytes isolés nous montre une augmentation de l'oxydation lipidique et de la néoglucogenèse.
Ces résultats suggèrent des adaptations des fonctions mitochondriales et métaboliques des foies de rats atteints de NASH qui permettraient de limiter la surcharge lipidique et le stress oxydant
Laraki, Loubaba. "Effets des phytostérols de maïs sur le métabolisme lipidique (sanguin, hépatique, biliaire et fecal) et sur l'agrégation des plaquettes sanguines chez le rat wistar." Nancy 1, 1989. http://www.theses.fr/1989NAN10201.
Dubuquoy, Céline. "Expression et fonction de l’adiponutrine/PNPLA3 dans le foie : Relation entre la voie Wnt/β-caténine, la sensibilité à l’insuline et la stéatose hépatique". Thesis, Paris 5, 2012. http://www.theses.fr/2012PA05T008/document.
The prevalence of metabolic syndrome (MetS) has increased in industrial countries. The hallmark of MetS in the liver is an excessive accumulation of triglyceride, which is called hepatic steatosis. Different SNP (Single Nucleotide Polymorphism) are associated with hepatic steatosis or MetS. One of them is found on adiponutrin/PNPLA3 (Patatin-like Phospholipase Domain-Containing) gene (SNP I148M) and is now considered as a new marker of hepatic steatosis and severity of NAFLD (Non-alcoholic Fatty Liver diseases). In order to understand the physiological role of adiponutrin in the liver, we studied its transcriptional regulation by SREBP1c (Sterol Responive Element Binding Protein) and ChREBP (Carbohydrate Responsive Element Binding Protein), mediators of insulin and glucose respectively. Moreover, by overexpressing adiponutrin in mice liver, we investigated its role in hepatic carbohydrate and lipid metabolism. We showed that adiponutrin is regulated as lipogenic genes and could have a role lipid metabolism. As for adiponutrin I148M, different SNP are found on substrats of Wnt/β-catenin pathway, a major pathway controlling acinus zonation. We examined the regulation of this pathway by nutritionnal status and in a pathophysiological context of insulin resistance and steatosis. We showed that Wnt/β-catenin pathway is regulated by pancreatic hormones (insulin and glucagon) in the liver in order to adapt hepatocyte phenotype to energetic needs. Moreover, this pathway is dysregulated in insulin resistant mice liver. These data may suggest a link between Wnt/β-catenin pathway deregulation and hepatic metabolic disorders
Cerec, Virginie. "Potentiel de différenciation et de transdifférenciation de cellules d'hépatome humain HepaRG : étude des mécanismes associés." Rennes 1, 2005. http://www.theses.fr/2005REN1S172.
Braud, Laura. "Effets lipotropes des molécules antioxydantes du thé (Camellia sinensis)." Thesis, Toulon, 2015. http://www.theses.fr/2015TOUL0014/document.
Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrializedcountries because being strongly associated with the development of metabolic syndrome and relateddyslipidemia. To date, the mechanisms of pathology remain poorly defined and available therapeutic meanshave moderate efficacy. Epidemiological studies have reported a beneficial effect of tea consumption in thefight against liver disorders and cardiovascular risk factors such as dyslipidemia. However, the mechanismsby which a blend of green tea, oolong tea and Pu-erh tea, Hao Ling tea, reduces fatty liver and dyslipidemiaremain unknown. Therefore, the objective of this thesis was to evaluate the effects and mechanisms of actionof Hao Ling tea on NAFLD and dyslipidemia, through two approaches, one on cellular model and the other onanimal model. Our results show that Hao Ling tea reduces the hepatic lipogenesis in vitro and in vivo and thusattenuates steatosis induced by a high fat-high sucrose diet in a rat model. We observed that this tea improvesthe blood lipid profile by increasing plasma HDL levels. We were also able to highlight that tea ownsantioxidant and hepato-protective properties to counteract an inducer of oxidative stress in vitro and todecrease lipid peroxidation in vivo. Finally, we have shown that the oxidative stress per se resulted in anaccumulation of intracellular lipid in isolated hepatocytes and that the tea, due to its antioxidant properties,prevented this phenomenon. The Hao Ling tea is a good nutritional approach in preventing NAFLD and tomaintain LDL/HDL ratio
Coilly, Audrey. "Marqueurs diagnostiques et pronostiques de la stéatohépatite métabolique Metabolism dysregulation induces a specific lipid signature of nonalcoholic steatohepatitis in patients MMP9 Identified as predictive factors of poor prognosis in patients with nonalcoholic fatty liver using data mining approaches and gene expression analysis Recent Insights into Treatment of Non-Alcoholic Steatohepatitis International Liver Transplantation Consensus Statement on End-stage Liver Disease Due to Nonalcoholic Steatohepatitis and Liver Transplantation. Quantitative assessment of triglycerides by Fourier Transform InfraRed (FTIR) spectroscopy of donor liver helps predicting outcome after liver transplantation." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS211.
Obesity is a major public health problem in France since 50% of the population has overweight. Several hepatic complications of obesity exist including NASH, pathology characterized by the combination of histological lesions of hepatic steatosis and hepatitis, liver test abnormalities and the absence of known liver disease, particularly toxic (alcohol) or virus. In one third of patients, NASH leads to fibrosis and then cirrhosis. It also promotes the development of hepatocellular carcinoma.The pathophysiology of NASH is characterized by a deregulation of lipid metabolism that leads to the accumulation of lipids in the hepatocytes. This accumulation of lipids is toxic and one of the causes of insulin resistance and the development of diabetes mellitus. All stages of lipid metabolism are affected by an accumulation of triglycerides, an increase in hepatic lipogenesis and a decrease in ß-oxidation. The composition and the role of lipids as a promoter of NASH is being increasingly studied.The first part of the thesis concerns the detection of diagnostic markers of NASH. In this study, we established for the first time a lipid signature of nonalcoholic steatohepatitis by quantification of 32 lipids. The overall lipid signature allowed distinguishing controls from NAFL and NASH. We have also demonstrated a deregulation of the metabolic pathway involved in the synthesis of fatty acids in NASH. This deregulation has been observed in both humans and animal models in our study.The second part aimed to identify new hepatic prognostic markers of NASH. Microarray analysis of gene expression showed 1549 genes discriminating patients with NAFL or NASH, healthy obese or controls. Among them, 58 genes discriminated NASH from simple steatosis. These genes were involved in extracellular matrix remodeling and inflammation. The most discriminating gene was FABP4 (fatty acid binding protein 4). Among genes strongly associated with high expression of FABP4, matrix metalloproteinase-9 (MMP9) was overexpressed in 55% of NASH patients. We identified a total of 330 differentially regulated genes, of which 229 genes were overexpressed in NASH patients with high levels of MMP9 expression. Using the gene expression levels of the liver FABP4 and MMP9 genes as indicators of disease progression in an independent cohort of NAFLD patients, we identified patients with NAFL and NASH who may have a poor prognosis.Finally, in the third part, we looked at the diagnostic and prognostic value of steatosis of liver grafts, measured by FTIR (Infrared Fourier Transform Microspectroscopy). Indeed, steatosis, when it exceeds 60% and is macrovacuolar, is known to significantly impact the function and survival of liver grafts. In our study, among 58 graft samples, the average percentage of macrovacuolar steatosis and microvesicular steatosis assessed by the pathologist was 2% to 30%, respectively. The average concentration of liver triglycerides measured by gas chromatography-spectrometry was 214 [10-1045] nmol/mg liver tissue. The FTIR triglyceride content estimate was significantly correlated (r2=0.812) with the results of the average hepatic triglyceride concentration measured by gas chromatography-spectrometry. Thirty-four (58%) patients had complications defined by a Dindo-Clavien stage ≥2, including 2 non-primary graft function and 5 deaths. The most discriminating threshold between triglyceride level and TH failure was 59.29 and 54.02 nmol/mg hepatic tissue obtained by spectrometry and FTIR, respectively. Quantification of hepatic triglyceride content by GC/MS was significantly associated with patient survival at the end of follow-up (p <0.0001) and failure of transplantation (p <0.0001). Estimating hepatic triglyceride content using FTIR was significantly associated with one-year post-transplant survival (p <0.0001)
Blanchard, Géraldine. "Etude des lipoprotéines chez le chat : application à la lipidose hépatique induite : effets d'une supplémentation en L-carnitine durant la phase d'induction de l'obésité." Paris, Institut national d'agronomie de Paris Grignon, 2002. http://www.theses.fr/2002INAP0046.
Karsenty, Julie. "Les Isoformes intestinales et hépatiques des "fatty acid binding proteins" dans le trafic intracellulaire des acides gras et leur expression dans un modèle animal de syndrome métabolique." Aix-Marseille 2, 2008. http://www.theses.fr/2008AIX20697.
Excessive consumption of fat has emerged as a major cause of increased prevalence of metabolic diseases. After their hydrolysis in the intestinal lumen, fatty acid (FA) and monoglycerides are absorbed by the enterocytes. Inside these cells FA are bound to small cytosolic proteins, the FABPs, before to be re-esterified into triglycerides then secreted as lipoproteins into the chyle. Enterocytes express I-FABP and L-FABP whose specific role in intracellular FA trafficking is still unknown. To clarify this point we have carried out an in vivo structure-function study by immunocytochemical characterization of transfected Cos-1 cells expressing large amounts of proteins. These proteins target a fluorescent FA to cellular sites of metabolism (mitochondria and endoplasmic reticulum / Golgi apparatus). When each protein is expressed within the cell, the fluorescent bound-FA is specifically distributed, suggesting a specific function. Conversely, when both proteins are present they cooperate for the distribution of the FA in similar areas than those targeted by the I-FABP expressed alone suggesting a sensor role for this protein. Another approach has been to show that the regulation of the expression of I-FABP and L-FABP differed in the rat model of metabolic syndrome induced by a fructose-enriched diet. To enlarge our knowledge of this model, the effects of polyunsaturated omega-3 FA intake on the expression of genes involved in energetic homeostasis and infammatory pathways were described. A specific role of PPAR delta in the liver and the heart was evidenced
Akbar, Samina. "Régulation de l'expression hépatique de récepteur LSR (lipolys stimulated lipoprotein receptor) : rôles de l'acide docosahexaénoïque et du récepteur PPARa ( peroxisome proliferator-activated receptor alpha)." Thesis, Université de Lorraine, 2013. http://www.theses.fr/2013LORR0288/document.
Lipolysis stimulated lipoprotein receptor (LSR) plays an important role in the clearance of ApoB/ApoE containing triglyceride-rich lipoproteins during postprandial phase. In this study, we demonstrated that in vitro treatment of mouse hepatoma cells, Hepa 1-6, with docosahexaenoic acid (DHA) led to an increase in LSR protein levels as well as its activity. Furthermore, the mice placed on the diet supplemented with DHA showed an increase in hepatic LSR protein. However, the mRNA levels remained unchanged in both in vitro and in vivo studies, suggesting that DHA enrichment may result in changes in LSR microenvironment that could affect its anchorage at the surface of cell membrane. Specific peroxisome proliferator response elements were identified in the upstream region of human, mouse and rat lsr gene by in silico analysis. We therefore sought to determine the role of the transcription factor, peroxisome proliferator-activated receptor (PPAR[alpha]), in LSR regulation. In vitro pharmacological studies using PPAR[alpha]-selective agonist and antagonist agents demonstrated that PPAR[alpha] is indeed involved in the transcriptional regulation of LSR expression. Furthermore, qPCR array analysis revealed the downregulation of PPAR[alpha] and various genes involved in hepatic lipid metabolism in LSR+/- mice on standard and high-fat diets. In conclusion, these studies show that the hepatic LSR activity is controlled by dietary factors that can activate various pathways involved in regulating lipid homeostasis, therefore representing LSR as a potential target for either nutritional or therapeutic strategies towards the prevention or treatment of dyslipidemia
Depla, Marion. "Modélisation in vitro et étude bioclinique de la stéatose induite par le virus de l'hépatite C." Thesis, Tours, 2011. http://www.theses.fr/2011TOUR3318/document.
The results presented in this thesis illustrate the difficulty of assessing the part related to the virus and that related to host factors in the induction of hepatic steatosis in patients chronically infected with HCV. In vitro data suggest that the virus plays a direct role in the induction of steatosis, due to the properties of its capsid protein, and that the variability of the virus can affect the intensity of the steatosis. Our bio-clinical study suggests that this variability seems to have a much more moderate impact in vivo. Thus, in patients chronically infected with HCV, host factors seem to play a major role to modulate the degree of steatosis associated with the virus. Further studies are needed to establish the nature of these factors
Fortin, Émilie. "Effet de différents ratios d’acides linoléique/α-linolénique et de l’entérolactone sur les marqueurs du métabolisme des lipides, d’inflammation et de stress oxydatif dans un modèle in vitro de culture de tissus hépatiques bovins". Mémoire, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9798.
Fabre, Jean-Michel. "Métabolisme hépatique et transplantation." Montpellier 1, 1994. http://www.theses.fr/1994MON1T013.
Gatineau, Eva. "Impact d'un régime riche en saccharose sur la sarcopénie chez le rat âgé ; Conséqences métaboliques au niveau hépatique et cérébral. Effets préventifs d'un mélange de micronutriments. Spécialité." Thesis, Clermont-Ferrand 1, 2015. http://www.theses.fr/2015CLF1MM14/document.
With aging, several alterations occur, including a loss of muscle mass and function, called sarcopenia. Many factors are responsible for the development of sarcopenia, but some factors as inflammation, oxidative stress and insulin resistance, which have many deleterious effects during aging, can reduce meal-induced stimulation of muscle protein synthesis which was shown to partly explain age-related muscle mass loss. Those factors can be induced by a diet rich in added sugar, characteristic of current dietary habits. Although this kind of diet could accelerate aging features, little is known about combined effect of aging and high sugar diet, particularly on sarcopenia. Thus, the purpose of this work was to determine whether high chronic intake of added sugars could accelerate sarcopenia. We also interested in the combined effect of added sugars and aging on other exposed tissues: liver and brain. Finally, we assessed the preventive effects of a micronutrient supplementation both in vivo and in vitro.In order to do that, for 5 months, 16 month old rats were starch fed or sucrose fed (62% sucrose), with or without micronutrients supplementation (rutin, vitamin A, vitamin E, vitamin D, selenium and zinc). Additionally, an adult control group of 8 month old rats was included. Besides, anti-inflammatory effects of micronutrients were tested in vitro.We showed that high sucrose diet accelerated age-related muscle mass loss by impairing postprandial protein synthesis, likely through decreased insulin sensitivity since inflammation and oxidative stress were only slightly affected by high sucrose diet. This diet also resulted in fat mass gain and increased plasma and liver triglycerides, by modulating the activity of enzymes involved in liver lipid metabolism. In the brain, high sucrose consumption led to decreased protein concentration independently of protein synthesis alteration. Micronutrients supplementation only partially reversed high sucrose diet effects: it did not act on lean body mass but prevented fat mass gain, by inhibiting hepatic lipogenesis. It also restored brain protein synthesis, which was reduced by aging. In vitro, it reduced experimentally induced inflammation.Thus, this work showed that a high sucrose diet accelerates sarcopenia in old rats but also induces liver and brain alterations. Prevention by micronutrients remained limited
Duez, Hélène. "Rôle des récepteurs nucléaires PPARα et Rev-erbα dans le métabolisme des lipides et lipoprotéines, et le développement de l'athérosclérose". Lille 2, 2003. http://www.theses.fr/2003LIL2P007.
Tempesta, Marie-Caroline. "Enzymologie des arylsulfatases lysosomiques et non lysosomiques. Métabolisme des sulfolipides dans les cellules en culture." Toulouse 3, 1993. http://www.theses.fr/1993TOU30163.
Ballet, François. "Effet de la norépinéphrine sur la microcirculation hépatique." Paris 6, 1988. http://www.theses.fr/1988PA066038.
Troufflard, Stéphanie. "Etude du métabolisme carboné dans l'embryon de lin oléagineux lors de l'accumulation des réserves lipidiques." Amiens, 2004. http://www.theses.fr/2004AMIE0419.
Broccardo, Cyril. "Etude de la sous-classe ABCA de la famille des transporteurs ABC : Analyse génomique et inactivation fonctionnelle du gène ABC-1." Aix-Marseille 2, 2000. http://www.theses.fr/2000AIX22011.
Yonkeu, Jeanne. "Métabolisme des lipides erythrocytaires dans l'anémie à hématies falciformes." Tours, 1986. http://www.theses.fr/1986TOUR3301.
Sentex, Emmanuelle. "Régulation du métabolisme des lipides cardiaques par la trimétazidine." Dijon, 1997. http://www.theses.fr/1997DIJOS049.
Flamment, Mélissa. "Métabolisme énergétique mitochondrial dans le développement de la stéatose hépatique." Phd thesis, Université d'Angers, 2009. http://tel.archives-ouvertes.fr/tel-00455835.
Désy, François. "Effets de l'exercice sur la zonation du métabolisme glucidique hépatique." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ65303.pdf.
Perlemuter, Gabriel. "Capside du virus de l'hépatite C et métabolisme lipidique hépatique." Paris 7, 2002. http://www.theses.fr/2002PA077147.
Le, Louët Hervé. "Caféine et métabolisme des médicaments : influence de la pathologie hépatique." Paris 12, 2003. https://athena.u-pec.fr/primo-explore/search?query=any,exact,990003949340204611&vid=upec.
Quantitative liver function assessment is a major concept in drug biotransformation studies. Caffeine metabolism, which is pluri-enzymatic and under polygenic control, was used to assess the effect of liver disease. Studies concerning primary biliary cirrhosis, alcoholic cirrhosis, hepatitis of viral and drug origin, liver transplantation were conducted. They displayed differential modification of caffeine metabolism pathways according to pathologies. N-acetyltransferase investigation using caffeine test was conducted in chronic autoimmune thrombocytopenic purpura and comparing khmer and caucasian populations. Therapeutic drug monitoring and Pharmacogenomic approach were discussed in comparison
Hilaire, Nathalie. "Métabolisme cellulaire des lipides neutres cytoplasmiques et myopathie à surcharge lipidique multisystémique." Toulouse 3, 1994. http://www.theses.fr/1994TOU30051.
Rigalleau, Vincent. "Interactions lipides-glucides et hyperglycémie." Lyon 1, 1998. http://www.theses.fr/1998LYO1T203.
Bedu, Elodie. "Adaptation du métabolisme hépatique chez le caneton en croissance au froid." Lyon 1, 2002. http://www.theses.fr/2002LYO10100.
Leblanc, Alix. "Effets d’un mélange de polluants organiques persistants sur le métabolisme hépatique." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05P629/document.
Epidemiological studies have shown that exposure to certain xenobiotics is associated with an increased prevalence of metabolic diseases. Humans are exposed to mixtures of xenobiotics in a chronic and inevitable way. We studied the effects of the interaction of two xenobiotics on metabolism in the liver, the major organ for detoxification in the body. We chose two endocrine disruptors and persistent organic pollutants which activate different signaling pathways: 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD), which uses the AhR (Aryl hydrocarbon receptor) pathway, and α-endosulfan, an organochlorine pesticide, which acts via the PXR (pregnane X receptor) and/or the ER (estrogen receptor) pathway. Our aim was to determine the effects of this pollutant mixture, as compared to each pollutant alone, on the regulation in vitro of some hepatic metabolism pathways in the human hepatic cell line, HepaRG. In the first publication, a transcriptomic study of differentiated HepaRG cells was performed. The cells were exposed for 30h to 25nM TCDD, to 10 µM α-endosulfan or to the mixture. We observed that the mixture strongly inhibited the expression of some genes involved in the metabolism of glucose and alcohol. In the second study, we studied the mechanism of action of the mixture of pollutants on the metabolism of glucose. The expression of two genes involved in hepatic gluconeogenesis, glucose transporter 2 (GLUT2) and glucose-6-phosphatase (G6Pc), were reduced 80% by the mixture. The expression of other glucose metabolism genes (pyruvate kinase, glycogen synthase, glycogen phosphorylase, pyruvate dehydrogenase 2) also was decreased suggesting that the mixture might impact markedly carbohydrate metabolism. Furthermore, glucose production decreased 40% with the mixture under gluconeogenic conditions. Under glycolytic conditions, the oxidation of glucose into CO2 decreased 30% after 72h of exposure of the cells to the mixture. Long-term treatment (8 days) with lower doses (0.2 to 5 nM TCDD, 3 µM α-endosulfan) similarly decreased G6Pc and GLUT2 expression. We showed that TCDD activated the AhR pathway, and that ER was partly involved in the α-endosulfan effect. In the third part of this thesis, we studied the regulation of several enzymes involved in the metabolism of alcohol (alcohol dehydrogenase, ADH, cytochrome P450 2E1, CYP2E1) after activation of AhR. AhR agonists led to a decrease in the amounts of mRNAs for ADH1, 4, 6 and CYP2E1 and the corresponding proteins. We showed that this regulation uses the AhR genomic pathway. Furthermore, this effect was also observed after 8 days of treatment with lower doses of TCDD. Chronic exposure of individuals to low doses of xenobiotics in mixtures might significantly affect hepatic carbohydrate metabolism and be a contributing factor for the development of the metabolic syndrome
Essassi, Dalila. "Liaisons sanguines, transferts cérébral et hépatique de la pipequaline." Paris 12, 1991. http://www.theses.fr/1991PA120008.
Durand, Le Lay Véronique. "L'obésité et ses répercussions au niveau du métabolisme lipidique : point sur les connaissances actuelles." Nantes, 1985. http://www.theses.fr/1985NANT375P.
Benkhaled, Sami. "Influence de l'état corporel au vélage et du niveau d'alimentation en début de lactation sur la stéatose hépatique chez la vache laitière." Paris 12, 1986. http://www.theses.fr/1987PA120004.
Taki, Hassan. "Contribution à l'étude de la régulation endocrine du métabolisme des lipides neutres et des phospholipides chez les Néréidiens (Annélides Polychètes)." Lille 1, 1987. http://www.theses.fr/1987LIL10123.
Abolghasemi, Armita. "Lipid mediators as regulators of lipid and energy metabolism during energy balance derangement in animal models." Doctoral thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/67011.
Les facteurs environnementaux jouent un rôle clé dans le développement du syndrome métabolique et de l'obésité, qui sont maintenant de véritables épidémies soulevant des problèmes de santé publique. Les excès de graisse corporelle dans l'obésité et la perte de masse grasse et maigre dans les conditions de dénutrition ou d'anorexie mentale sont le résultat d'un déséquilibre énergétique. Par conséquent, le maintien de l'équilibre énergétique est crucial à la fois pour la prévention de l'obésité et pour le traitement de l'anorexie mentale et d'autres formes de dénutrition. Les signaux lipidiques tels que ceux médiés par les médiateurs des endocannabinoidomes sont profondément impliqués dans le contrôle du métabolisme énergétique. Dans cette thèse, au sein de deux projets différents, nous avons étudié comment différents facteurs environnementaux, y compris la restriction calorique, l'activité physique, la supplémentation en vitamine D et les médicaments antipsychotiques, peuvent conduire à une modification du métabolisme énergétique par la modulation de la signalisation des endocannabinoïdomes. Les résultats des travaux expérimentaux montrent comment les différentes conditions étudiées provoquent des changements dans les niveaux tissulaires du médiateur lipidique endocannabinoïdome ainsi que dans l'expression de leurs récepteurs et enzymes métaboliques, ce qui peut contribuer aux changements observés de la masse grasse corporelle et du métabolisme énergétique au sein des modèles. Nous concluons que les conditions étudiées peuvent provoquer des changements dans le bilan énergétique par altération de l'endocannabinoidome.
Environmental factors play a key role in the development of obesity-induced metabolic syndrome and obesity, which are now true epidemics raising public health concerns. Both excess body fat in obesity, and fat and lean mass loss in undernutrition conditions or anorexia nervosa, are the result of energy imbalance. Therefore, maintaining energy balance is crucial for both the prevention of obesity and the treatment of anorexia nervosa and other forms of undernutrition. Lipid signals such as those mediated by endocannabinoidome mediators are deeply involved in the control of energy metabolism. In this thesis, within two different projects, we studied how different environmental factors including calorie restriction, physical activity, vitamin D supplementation and antipsychotic drugs, may lead to energy metabolism modification through modulation of the endocannabinoidome signaling. The results of the experimental work show how the different studied conditions cause changes in the tissue levels of endocannabinoidome lipid mediator as well as in the expression of their receptors and metabolic enzymes, which may contribute to the observed changes in body fat mass and energy metabolism within the models. We conclude that the investigated conditions may cause changes in energy balance through alteration of the endocannabinoidome.
Marques-Vidal, Pedro. "Rôle de la triglycéride lipase hépatique dans le catabolisme des lipoprotéines de haute densité." Toulouse 3, 1991. http://www.theses.fr/1991TOU30238.
Bennis, Abdel-Haq. "Contribution à l'étude des lipides et lipoprotéines sériques ou plasmatiques de la chèvre." Toulouse, INPT, 1992. http://www.theses.fr/1992INPT013A.
Verreault, Mélanie. "LXR[alpha] et UGT1A3 : deux protéines essentielles à la détoxification hépatique des acides biliaires." Master's thesis, Université Laval, 2005. http://hdl.handle.net/20.500.11794/18596.