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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

PPARɣ Activation Rapidly Ameliorates Amyloid Pathology and Restores Cognition in a Mouse Model of Alzheimer’s Disease

Mandrekar-Colucci, Shweta Dilip January 2011 (has links)
No description available.
2

The role of retinaldehyde and PPARgamma signaling in systemic lupus erythematosus

Su, Shi 22 January 2016 (has links)
Systemic Lupus Erythematosus (SLE) is an autoimmune disease with chronic inflammation affecting multiple organ systems, as well as accelerated atherosclerosis as a major complication. Prior studies by our lab have shown beneficial effects of PPARgamma agonists towards preventing SLE in two different mouse models: the well-established lupus mouse model, MRL.lpr, and the gld.apoE^-/- model of accelerated lupus and atherosclerosis. Retinaldehyde is a retinoic acid precursor that has recently been shown to inhibit PPARgamma signaling in adipose tissue. We proposed that abnormal accumulation of retinaldehyde in lupus promotes autoimmunity by inhibition of PPARgamma signaling. We measured the serum retinaldehyde levels in both lupus mouse models using reversed-phase high-performance liquid chromatography. We also examined the mRNA expressions of genes involved in retinaldehyde metabolism and PPARgamma signaling in white adipose tissues using real-time quantitative PCR. We observed a higher level of circulating retinaldehyde in the MRL.lpr mouse model on a chow diet. The circulating retinaldehyde levels in both .gld.apoE^-/- and C57 increased when maintained on a high-cholesterol Western diet. Within visceral and subcuntaneous adipose tissue, we saw several changes to expression of the genes responsible for retinaldehyde synthesis and catabolism, however further study is required to definitively assess the role of these genes. Importantly, the expression levels of genes involved in PPARgamma signaling decreased in the subcutaneous fat of gld.apoE^-/- mice on a Western diet. Our data suggest that retinaldehyde may play a role in SLE pathogenesis and could be a potential therapeutic target for SLE.
3

Vliv eikosapentaénové a dokosahexaénové kyseliny na expresi vybraných genů podílejících se na modulaci zánětlivé reakce u modelového organismu

Charousová, Markéta January 2017 (has links)
In my study thesis Effect of eikosapentaenoic and dokosahexaenoic acids on expression of selected genes, which participate in modulation of inflammatory reaction at model organism I evaluated expression of genes GPR120, PPARgamma, LBP, ICAM, Il-4, Il-10, Il-1beta and TGF-beta. As model organism was selected pig. The pigs were divided in two groups, the control group was fed with 2,5% addition of palmic oil (P), the second group was fed with 2,5% addition of fish oil. After 70 days long fattening was each group divided into halfs. One half of each group was stimulated LPS (P+ and R+). Liver and adipose tissue were collected, mRNA was isolated (Rneasa Mini Kit), after reverse transcription the expression was measured by quantitative RT-PCR. By almost every genes there was increase in expression after LPS stimulation in groups P+ and R+. between P- and R- the expression was same or a little bit higher in R-. R+ was allways bigger than R-. The hypothesis were that EPA and DHA should reduce expression in inflammation. This hypothesis was not proofed. I recomend further studies with the same model organism to refill the results.
4

PPAR gamma AND eNOS CONTRIBUTE TO THE RESOLUTION OF CHRONIC INFLAMMATION.

Evans, Kyle William January 2011 (has links)
Chronic inflammation follows defined phases of induction, inflammation, and resolution. The resolution phase requires cycloxygenase-2 (COX-2) activity. This study aims to address what other molecules are required for a functional resolution phase. We demonstrated that in murine collagen-induced arthritis the transcription factor, PPARgamma plays a role in the resolution phase. Inhibition of COX-2 activity results in fewer PPARgamma positive cells in the arthritic synovium. Treatment with a PPARgamma antagonist, SR202, alone, also disrupts the process of resolution. PPARgamma antagonist treatment results in a decrease in eNOS phosphorylation within the arthritic synovium. These observations indicate that PPARgamma may function to regulate eNOS activity. The source of pro-resolving nitric oxide is eNOS but not, iNOS. The effect of COX-2 inhibition on the resolution phase is ameliorated by injection of a PGE2 analog. Restoration of PGE2 levels results in an increase in PPARgamma positive cells in the arthritic synovium which correlates with this restoration of resolution. Thus, this study provides in vivo evidence for the pro-resolving role of PPARgamma and its relationship with PGE2 and eNOS. / Microbiology and Immunology
5

Potentiel thérapeutique de l'activation du récepteur nucléaire PPARgamma dans la myélofibrose / Therapeutic Potential of Activation of the Nuclear Receptor PPARgamma Pathway in Myelofibrosis

Lambert, Juliette 16 December 2019 (has links)
La myélofibrose primitive (MFP) est un néoplasme myéloprolifératif (NMP) classique BCR-ABL négatif associé à une forte altération de la qualité de vie et à une augmentation de la mortalité. Les traitements conventionnels réduisent les symptômes mais ont peu d’effet sur l’histoire naturelle de la maladie. La MFP résulte d’interactions complexes entre le développement du clone hématopoïétique malin, l’installation d’un contexte inflammatoire et le remodelage du microenvironnement médullaire. Chacun de ces axes est une cible thérapeutique potentielle. Dans ce travail, nous avons évalué le potentiel thérapeutique de l’activation de PPARγ dans trois modèles murins de myélofibrose et nous montrons que les ligands de PPARγ permettent d’améliorer les paramètres hématologiques et histologiques en rapport avec l’installation du phénotype de myélofibrose. Chacun des axes de la physiopathologie a ensuite été exploré. Les ligands de PPARγ ont une action anti-proliférative sur le clone malin, tant dans les modèles murins de NMPs que dans les cellules JAK2V617F de lignée et dans les progéniteurs hématopoïétiques issus de patients atteints de NMPs. Le traitement atténue également l’hyperleucocytose associée au phénotype inflammatoire des NMPs et modifie la transcription de gènes de l’inflammation. Enfin, les ligands de PPARγ ont un effet protecteur sur le stroma médullaire, dépendant de la capacité de PPARγ à contrecarrer la voie de signalisation du TGF-β1, cytokine majeure du développement de la fibrose médullaire, par déplacement du cofacteur de transcription p300 de la voie du TGF-β1 vers la voie PPARγ. Par son action sur les trois composantes de la physiopathologie, l’activation de PPARγ constitue une cible thérapeutique pertinente dans la prise en charge de la MFP. / Primary myelofibrosis (PMF) is a non BCR-ABL myeloproliferative neoplasm (MPN) associated with poor quality of life and reduced survival. Current treatments are mainly symptomatic and have little effect on the natural history of the disease. PMF results from complex interactions between the emergence of a hematopoietic malignant clone, an inflammatory context and the remodeling of the bone marrow (BM) microenvironment. Each of these axes is a potential therapeutic target. Here, we evaluated the therapeutic potential of PPARγ ligands in three murine models of myelofibrosis and we showed that PPARγ ligands improve hematological and histological changes related to myelofibrosis phenotype. Then, we explored each axis of the pathophysiology. We showed that PPARγ ligands have an anti-proliferative effect and limit the proliferation of the malignant clone in murine models of MPNs, in JAK2V617F cell lines and in hematopoietic progenitors from MPNs patients. PPARγ ligands also decrease leukocytosis related to the inflammatory phenotype of MPNs and modify the transcription of inflammatory genes. Finally, we demonstrated that PPARγ ligands have a protective effect on BM stroma. They counteract the signaling pathway of TGF-β1, a major cytokine in BM fibrosis development, by moving the p300 cofactor of transcription from the TGF-β1 pathway to the PPARγ pathway. By its action on the three components of the pathophysiology, activation of PPARγ pathway is a relevant therapeutic target in PMF.
6

Caracterização de genes e proteínas plasmáticas relacionadas ao diabetes melito do tipo 2 em indivíduos tratados com pioglitazona / Characterization of genes and serum proteins related to type 2 diabetes mellitus in patients treated with pioglitazone

Marques, Milano Felipe dos Santos Ferreira 12 September 2008 (has links)
O diabete melito é um grupo de doenças metabólicas caracterizadas por hiperglicemia, resultado de deficiências na secreção de insulina, em sua acção ou ambos. A pioglitazona é um hipoglicemiante oral, da classe da tiazolidinedionas, que atuam pela ligação aos receptores nucleares PPARY melhorando o estado de resistência a insulina. Acredita-se que a pioglitazona também restauram a capacidade da célula beta pancreática de secretar insulina, cuja atividade é regulada pelos canais de potássio dependente de ATP (KATP) e suas subunidades SUR1 e KIR6.2. Este estudo teve como objetivo iniciar um estudo farmacogenômico da pioglitazona em indivíduos diabéticos tipo 2 e na expressão dos genes PPARY PPARY2, SUR1 e KIR6.2 no sangue periférico e no tecido adiposo e associá-los com os polimorfismo Pro12Ala e C161T do gene PPARY. Foram selecionados 36 pacientes diabéticos do tipo 2 e 16 pacientes normoglicêmicos, no Instituto Dante Pazzanese de Cardiologia. Os indivíduos diabéticos foram tratados com pioglitazona (15, 30 e 45 mg/ dia/ via oral) por 16 semanas. Foram colhidas amostras de tecido adiposo por biopsia e de sangue, antes e após o tratamento para determinação de exames laboratoriais, extração de DNA genômico e de RNA total. Os polimorfismos foram detectados pela técnica de PCR-RFLP e a expressão de mRNA foi quantificada e avaliada por RT-PCR em tempo real. Após tratamento com pioglitazona, observou-se no sangue periférico aumento de expressão de mRNA do PPARY, PPARY2 e KIR6.2, e diminuição da expressão de SUR1. Dados de analises no sangue periférico, demostraram que variação da expressão de mRNA do PPARY foi inversamente correlacionada com as variações de insulina, Homa-IR, Homa-Beta e positivamente com Colesterol Total. Em relação ao gene PPARY2, foi inversamente correlacionada com colesterol total. Variação da expressão de SUR1 foi inversamente correlacionada com Hb1Ac, Homa-IR, Homa-Beta e positivamente com insulina. Não foram detectadas diferenças entre a expressão de mRNA de KIR6.2 e parâmetros bioquímicos em resposta às variações pioglItazona. Não houve diferença da resposta terapêutica e presença dos polimorfismos Pro12Ala e C161T. Após o tratamento, no tecido adiposo, a expressão de mRNA de PPARY aumentou. Não foram observadas diferenças na expressão dos genes PPARY2, SUR1 e KIR6.2. Em leucócitos totais de sangue periférico, pioglitazona demonstrou regular a expressão dos genes PPARY e PPARY2, e também atuando sobre as subunidades SUR1 e KIR6.2, possivelmente restaurando a função secretora das células beta. No tecido adiposo, o tratamento confirma a atuação da pioglitazona sobre PPARY, melhorando o estado de resistência a insulina. / The diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia, the result from insulin secretion or action deficiency, or both. Pioglitazone is an oral hypoglycemic drug, included in the class of thiazolidinediones, which work by binding to nuclear receptors PPARY nuclear what improve the state of resistance to insulin. Pioglitazone may also restore the ability of the pancreatic beta cell to secrete insulin, process which is regulated thought ATP dependent potassium channels (KATP) and its subunits SUR1 and KIR6.2. The aim of our study was to begin a pharmacogenomic study of pioglitazone in type 2 diabetes patients by the expression of PPARY, PPARY2, SUR1 and KIR6.2 genes in peripheral blood leukocytes and fatty tissue and its association with the PPARY Pro12Ala and C161T polimorphisms. 36 type 2 diabetes and 16 normoglycemic patients were selected at the Dante Pazzanese Institute of Cardiology. The diabetic ones were treated with pioglitazone (15, 30 and 45 mg/ daily /orally) for 16 weeks. Samples of adipose - obtained through biopsy - and blood were collected before and after treatment to aim to laboratory experiments, DNA extraction and total RNA extraction. The polymorphisms were detected by the PCR-RFLP technique while the mRNA expression was quantified and evaluated by Real Time RT-PCR. After pioglitazone treatment, the expression of the PPARY, PPARY2 and KIR6.2 genes increased, while SUR1 decreased, all of them quantified in peripheral blood. Peripheral blood data has demonstrated that the variation of expression of PPARYmRNA is inversely correlated with insulin concentrations, Homa-IR, Homa-Beta and positively correlated with total cholesterol concentrations. Differently, PPARY2 gene expression was inversely correlated with total cholesterol blood concentrations. Variations in SUR1 mRNA expression were inversely correlated with Hb1Ac, Homa-IR, Homa-Beta and positively correlated with insulin. No differences were found between the KIR6.2 expression and biochemical parameters due to pioglItazone treatment. There was no difference in response to the treatment response and no Pro12Ala and C161T polymorphisms were noticed. After the treatment, the expression of PPARY gene increased in fatty tissue. No data showed differences in the expression of genes PPARY2, SUR1 and KIR6.2. Pioglitazone regulates the expression of genes PPARY and PPARY2, and also acts on the SUR1 and KIR6.2 subunits in total peripheral blood leukocyte likely restoring the function of secreting beta pancreatic cells. In adipose, the treatment reassures the functions of pioglitazone on PPARY, improving the state of insulin resistance.
7

Die Bedeutung von "Peroxisome Proliferator-Activated Receptors" in der Pathogenese von Gefäßwandläsionen und ihr Einfluß auf die Migration und Proliferation vaskulärer Zellen

Götze, Stephan 05 May 2003 (has links)
Die Migration und Proliferation vaskulärer Zellen spielt eine entscheidende Rolle in der Pathogenese atherosklerotischer Gefäßwandveränderungen und trägt zudem in hohem Maße zu restenosebedingten Komplikationen interventioneller Therapien der Atherosklerose bei. Dies bedingt ein großes Interesse an pharmakologischen Interventionsmöglichkeiten zur Prävention / Therapie atherosklerotischer und restenotischer vaskulärer Läsionen. Dabei kommen neben lokal applizierbaren Substanzgruppen insbesondere Pharmaka in Betracht, die bereits Anwendung zur Behandlung metabolischer Risikofaktoren kardiovaskulärer Erkrankungen finden. Hierzu gehören insbesondere die oralen Antidiabetika vom Typ der Thiazolidindeone, die als Liganden für den "Peroxisome Proliferator-Activated Receptor gamma" (PPARg) agieren. PPARs sind eine Gruppe neuer Regulatoren der Genexpression, für die in den vergangenen Jahren eine Reihe vaskulärer Wirkungen nachgewiesen wurden. Wir konnten zeigen, daß die Proliferation und Migration von Gefäßmuskelzellen durch PPARg-Liganden gehemmt wird. Untersuchungen zu den beteiligten Signalübertragungsschritten ergaben, daß die pharmakologische Aktivierung von PPARg in Gefäßmuskelzellen insbesondere die durch die Mitogen-aktivierten Protein Kinasen ERK1/2 vermittelte Signaltransduktion beeinflußt. Diesbezüglich haben wir nachgewiesen, daß PPARg in Gefäßmuskelzellen die mitogene Signaltransduktion via ERK1/2 MAPK -> Elk-1 -> c-fos und die chemotaktische Signalübertragung via ERK1/2 MAPK -> Ets-1 -> Matrixmetalloproteinase-9 hemmt. Wir konnten ferner zeigen, daß PPARg-Liganden die Endothelzellmigration hemmen, die durch die Neovaskularisation atherosklerotischer Plaques und der damit verbundenen erhöhten Vulnerabilität einer Plaqueruptur eine Rolle in der Pathobiologie der Atherosklerose spielt. Diese migrationshemmende Wirkung der PPARg-Liganden basiert vermutlich auf einer Inhibition der für die Endothelzellmigration erforderlichen Signaltransduktion über den PI3 Kinase -> Akt -> eNOS Pathway. Die Inhibition dieses Signalwegs könnte die Folge der von uns beobachteten PPARg-Ligand-induzierten Expression der Phosphatase PTEN sein, die den PI3K -> Akt Signalweg negativ reguliert und die Aktivierung und Phosphorylierung von Akt inhibiert. Somit haben PPARg-aktivierende Liganden eine wichtige Funktion in der Behandlung der metabolischen Hauptrisikofaktoren kardiovaskulärer Erkrankungen, spielen aber gleichzeitig eine vermutlich ebenso wichtige Rolle in der Protektion atherosklerotischer und restenosebedingter Gefäßwandveränderungen durch direkte vaskuläre Effekte. / Migration and proliferation of vascular cells not only play an important role in the pathogenesis of atherosclerotic lesion formation, but also contribute to restenosis after therapeutic angioplasty. Therefore, pharmacological strategies for the prevention and/or treatment of atherosclerotic and restenotic vascular lesions are of great clinical interest. This involves substances that can be locally administered via stents, as well as agents that are already in clinical use for the treatment of metabolic risk factors. Among the latter, antidiabetic thiazolidinediones which function as ligands for the "peroxisome proliferator-activated receptor gamma" (PPARg), have been identified as promising drugs to target vascular lesion formation. PPARs constitute a group of novel regulators of gene expression, that exert several vascular effects. We report that vascular smooth muscle cell proliferation and migration is inhibited by PPARg-ligands. Investigating the signalling steps that are involved, we find that pharmacological activation of PPARg interferes with signal transduction through the mitogen-activated protein kinases ERK1/2 in vascular smooth muscle cells. We demonstrate that PPARg inhibits mitogenic signal transduction via ERK1/2 MAPK -> Elk-1 -> c-fos and also blocks chemotactic signalling through the ERK1/2 MAPK -> Ets-1 -> matrix metalloproteinase-9 pathway in vascular smooth muscle cells. We also showed that PPARg-ligands inhibit endothelial cell migration, which participates in the neovascularization of atherosclerotic plaques, thereby contributing to plaque destabilization and increased risk of plaque hemorrhage. This antimigratory action of PPARg-ligands results from an inhibition of signal transduction via PI3 Kinase -> Akt -> eNOS, a pathway that is crucial for endothelial cell migration. Since we observed a PPARg-ligand-induced upregulation of PTEN, a phosphatase that negatively regulates the PI3K -> Akt signalling pathway, this might constitute the mechanism by which PPARg-ligands inhibit endothelial cell migration. In conclusion, PPARg-activating ligands may provide a dual benefit in cardiovascular disease by ameliorating metabolic risk factors, as well as protecting the vasculature from atherosclerotic and restenotic alterations through direct vascular effects.
8

Activité PPARgamma-indépendante des ligands de PPARgamma : une piste pour le traitement des cancers du sein ? / PPARgamma-independente activity of PPARgamma ligands : a new perspective for the treatment of breast cancers ?

Colin-Cassin, Christelle 07 November 2013 (has links)
L'un des enjeux majeurs de la recherche anti-cancéreuse est de développer de nouvelles thérapies en direction des tumeurs réfractaires aux traitements conventionnels. Dans ce contexte, l'identification récente de l'activité anti-tumorale PPARgamma-indépendante des thiazolidinediones ouvre de nouvelles perspectives thérapeutiques. Au sein du laboratoire, il a été montré qu'un analogue inactif de la TGZ, la delta2-TGZ, induit une dégradation protéasome-dépendante du récepteur alpha aux oestrogènes de manière PPARgamma-indépendante. A partir de ces données, les objectifs de ma thèse ont été 1) de participer à la caractérisation de nouveaux composés à activité anti-cancéreuse 2) de mieux comprendre les mécanismes PPARgamma-indépendants mis en jeu dans l'effet anti-cancéreux des TZD. Lors de ce travail de thèse, nous avons caractérisé de nouveaux composés plus efficaces que la delta2-TGZ pour l'inhibition de la prolifération des cellules cancéreuses mammaires MCF-7 et MDA-MB-231 et faiblement toxiques sur des cultures primaires d'hépatocytes humains. De plus, nous avons montré que la delta2-TGZ est capable d'induire un stress du réticulum endoplasmique à des temps précoces dès 3 heures et une apoptose à des temps plus tardifs 48 heures. Cependant, nous n'avons pas pu conclure à l'existence d'un lien entre les deux mécanismes. Enfin, nous avons montré que la biotinylation d'un ligand naturel de PPARgamma, la 15d-PGJ2, accroît son effet anti-prolifératif sur les cellules cancéreuses mammaires MCF-7 et MDA-MB-231 et conduit à un stress du réticulum endoplasmique et à une mort par apoptose. Ces effets sont partiellement dépendants de PPARgamma pour le stress du réticulum endoplasmique mais strictement PPARgamma-indépendants pour l'apoptose. Ce travail pourrait permettre de constituer de nouveaux outils thérapeutiques dans le traitement du cancer du sein / One of the main goals of the anti-cancer research is to develop new therapeutic option for resistant tumor. In this context, the recent discovery of thiazolidinedione devoid of PPARgamma activity with a strong anti-cancer effect opens new perspectives. In a previous study, the laboratory showed that an inactive derivative of PPARgamma, the delta2-TGZ, induce a proteasome-dependent degradation of estrogen receptor alpha in PPARgamma-independent way. Thus, during my thesis we aimed 1) to participate in the study of new compounds less toxic and more effective to inhibit the proliferation of mammary cancer cells, 2) to better understand PPARgamma-independent mechanisms involved in the anti-cancer effect of the TZD. In the present work, we characterise new compounds more effective than delta2-TGZ to inhibit the proliferation of the breast cancer cells MCF-7 and MDA-MB-231 and are less toxic on primary culture of human hepatocytes. We pursued the study on mechanisms involved in PPARgamma-independent anti-proliferative activity of delta2-TGZ. We showed that delta2-TGZ is able to induce endoplasmic reticulum stress as soon as 3 hours and apoptosis in later times 48 hours of treatment. Nevertheless we could not conclude of the existence of a link between these two pathways. Finally, we studied the effect of the biotinylation of a natural ligand of PPAR?: the 15d-PGJ2. This modification drive to an increased effect of the 15d-PGJ2 on the anti-proliferative effect of breast cancer cells, reticulum endoplasmic stress and death by apoptosis. These effects are partially PPARgamma-dependent for reticulum endoplasmic stress and only PPARgamma-independent for apoptosis. This work highlighted new promising tools of breast cancers treatment
9

Rôle du facteur pro-angiogène EG-VEGF dans le développement placentaire au cours de premier trimestre de grossesse / Role of EG-VEGF in placental developpment in first trimester of pregnancy

Garnier, Vanessa 22 September 2014 (has links)
Le développement placentaire est un processus finement contrôlé dans le temps et dans l'espace. Il est caractérisé par une invasion précoce et profonde, de l'endomètre et du premier tiers du myomètre, par les cytotrophoblastes extravilleux, cellules responsables du remodelage des artères spiralées utérines et de l'établissement de la circulation fœto-maternelle. Tout déficit dans ces processus physiologiques conduit à des complications de la grossesse, telles que la Pré-Eclampsie (PE), ou le Retard de Croissance Intra-Utérin (RCIU). Les travaux récents de l'équipe suggèrent l'implication d'un nouveau facteur angiogène, nommé EG-VEGF (Endocrine Gland Derived Vascular Endothelial Growth Factor), dans le développement de la PE. L'objectif de ma thèse fut de mieux caractériser le rôle de l'EG-VEGF dans le développement placentaire normal au cours du premier trimestre de la grossesse. Pour cela trois axes ont été explorés : i) l'étude de la régulation de l'EG-VEGF par le récepteur nucléaire PPARγ (Peroxisome proliferator-activated receptor gamma), ii) la détermination de son rôle dans les différenciations hématopoïétique et angiogénique placentaires et iii) la contribution au développement d'un modèle murin de la PE. A l'issue de cette thèse, mes travaux ont montré que non seulement l'expression de l'EG-VEGF et de son récepteur PROKR2 étaient régulées positivement par PPARγ, mais aussi, que ce récepteur nucléaire est directement impliqué dans la mise en place de la vascularisation intra-placentaire, avec la participation des deux récepteurs PROKR1 et PROKR2, et que l'inhibition de l'invasion trophoblastique par PPARγ, seraient en partie contrôlée par l'EG-VEGF, via PROKR2. Mon travail a également mis en évidence que l'EG-VEGF serait impliqué dans le contrôle de la différenciation hématopoïétique et endothéliale placentaire. Il aurait un effet inhibiteur sur la différenciation des cellules hématopoïétiques et endothéliales, mais plus particulièrement sur les cellules endothéliales hémogéniques. Enfin, ma contribution au développement d'un modèle in vivo de la PE a permis de montrer qu'un maintien de la libération de l'EG-VEGF, au-delà de sa période normale de production, serait responsable du développement de la PE, suite à un défaut de l'invasion trophoblastique, entraînant la libération par le placenta, de sFlt-1 et de sEndogline. Ces derniers vont induire un dysfonctionnement rénal et une hypertension artérielle. L'ensemble de ces trois projets a contribué à l'avancée de nos connaissances actuelles sur les mécanismes physiologiques du développement placentaire, ainsi que sur un facteur clé de la placentation, l'EG-VEGF, et a également permis de mieux appréhender les causes de l'établissement des pathologies de la grossesse, comme la PE et le RCIU. / Placental development is a process that is finely controlled. It is characterized by early and deep invasion of the endometrium and the first third of the myometrium by extravillous cytotrophoblasts that participate to the remodeling of the spiral arteries and to the establishment of the feto-maternal circulation. Poor remodeling of spiral arteries by trophoblastic cells, leads to the development pregnancy pathologies such as, Preeclampsia (PE) and Intra-Uterine Growth Restriction (IUGR). During the last decade, our team has gathered interesting data that propose the new factor, EG-VEGF (Endocrine Gland Derived Vascular Endothelial Growth Factor) as a potential marker for PE. My thesis project aimed at further characterizing the role of EG-VEGF during pregnancy. Three main axis were addressed, i) The study of the regulation of EG-VEGF by PPARγ (Peroxisome proliferator-activated receptor gamma), ii) The study of the role in hematopoietic and angiogenic placental cells differentiations and iii) The development of an in vivo model of PE. My thesis showed that 1) EG-VEGF and PROKR2 expression are upregulated by PPARγ, 2) that the regulation of intra-placental vascularization and trophoblastic invasion by PPARγ is mediated by EG-VEGF through PROKR1 and PROKR2 and through PROKR2 receptors, respectively, 3) that EG-VEGF controls hematopoietic and endothelial cell differentiation and 4) that maintenance of EG-VEGF production beyond its normal period of secretion during pregnancy leads to the development of PE in a gravid mouse model. Altogether, these projects contributed to have a better knowledge about physiological mechanisms of placental development and about a key factor of placentation EG-VEGF. Moreover they improved our understanding of the origins of pregnancy diseases establishment such as PE and RCIU.
10

Caracterização de genes e proteínas plasmáticas relacionadas ao diabetes melito do tipo 2 em indivíduos tratados com pioglitazona / Characterization of genes and serum proteins related to type 2 diabetes mellitus in patients treated with pioglitazone

Milano Felipe dos Santos Ferreira Marques 12 September 2008 (has links)
O diabete melito é um grupo de doenças metabólicas caracterizadas por hiperglicemia, resultado de deficiências na secreção de insulina, em sua acção ou ambos. A pioglitazona é um hipoglicemiante oral, da classe da tiazolidinedionas, que atuam pela ligação aos receptores nucleares PPARY melhorando o estado de resistência a insulina. Acredita-se que a pioglitazona também restauram a capacidade da célula beta pancreática de secretar insulina, cuja atividade é regulada pelos canais de potássio dependente de ATP (KATP) e suas subunidades SUR1 e KIR6.2. Este estudo teve como objetivo iniciar um estudo farmacogenômico da pioglitazona em indivíduos diabéticos tipo 2 e na expressão dos genes PPARY PPARY2, SUR1 e KIR6.2 no sangue periférico e no tecido adiposo e associá-los com os polimorfismo Pro12Ala e C161T do gene PPARY. Foram selecionados 36 pacientes diabéticos do tipo 2 e 16 pacientes normoglicêmicos, no Instituto Dante Pazzanese de Cardiologia. Os indivíduos diabéticos foram tratados com pioglitazona (15, 30 e 45 mg/ dia/ via oral) por 16 semanas. Foram colhidas amostras de tecido adiposo por biopsia e de sangue, antes e após o tratamento para determinação de exames laboratoriais, extração de DNA genômico e de RNA total. Os polimorfismos foram detectados pela técnica de PCR-RFLP e a expressão de mRNA foi quantificada e avaliada por RT-PCR em tempo real. Após tratamento com pioglitazona, observou-se no sangue periférico aumento de expressão de mRNA do PPARY, PPARY2 e KIR6.2, e diminuição da expressão de SUR1. Dados de analises no sangue periférico, demostraram que variação da expressão de mRNA do PPARY foi inversamente correlacionada com as variações de insulina, Homa-IR, Homa-Beta e positivamente com Colesterol Total. Em relação ao gene PPARY2, foi inversamente correlacionada com colesterol total. Variação da expressão de SUR1 foi inversamente correlacionada com Hb1Ac, Homa-IR, Homa-Beta e positivamente com insulina. Não foram detectadas diferenças entre a expressão de mRNA de KIR6.2 e parâmetros bioquímicos em resposta às variações pioglItazona. Não houve diferença da resposta terapêutica e presença dos polimorfismos Pro12Ala e C161T. Após o tratamento, no tecido adiposo, a expressão de mRNA de PPARY aumentou. Não foram observadas diferenças na expressão dos genes PPARY2, SUR1 e KIR6.2. Em leucócitos totais de sangue periférico, pioglitazona demonstrou regular a expressão dos genes PPARY e PPARY2, e também atuando sobre as subunidades SUR1 e KIR6.2, possivelmente restaurando a função secretora das células beta. No tecido adiposo, o tratamento confirma a atuação da pioglitazona sobre PPARY, melhorando o estado de resistência a insulina. / The diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia, the result from insulin secretion or action deficiency, or both. Pioglitazone is an oral hypoglycemic drug, included in the class of thiazolidinediones, which work by binding to nuclear receptors PPARY nuclear what improve the state of resistance to insulin. Pioglitazone may also restore the ability of the pancreatic beta cell to secrete insulin, process which is regulated thought ATP dependent potassium channels (KATP) and its subunits SUR1 and KIR6.2. The aim of our study was to begin a pharmacogenomic study of pioglitazone in type 2 diabetes patients by the expression of PPARY, PPARY2, SUR1 and KIR6.2 genes in peripheral blood leukocytes and fatty tissue and its association with the PPARY Pro12Ala and C161T polimorphisms. 36 type 2 diabetes and 16 normoglycemic patients were selected at the Dante Pazzanese Institute of Cardiology. The diabetic ones were treated with pioglitazone (15, 30 and 45 mg/ daily /orally) for 16 weeks. Samples of adipose - obtained through biopsy - and blood were collected before and after treatment to aim to laboratory experiments, DNA extraction and total RNA extraction. The polymorphisms were detected by the PCR-RFLP technique while the mRNA expression was quantified and evaluated by Real Time RT-PCR. After pioglitazone treatment, the expression of the PPARY, PPARY2 and KIR6.2 genes increased, while SUR1 decreased, all of them quantified in peripheral blood. Peripheral blood data has demonstrated that the variation of expression of PPARYmRNA is inversely correlated with insulin concentrations, Homa-IR, Homa-Beta and positively correlated with total cholesterol concentrations. Differently, PPARY2 gene expression was inversely correlated with total cholesterol blood concentrations. Variations in SUR1 mRNA expression were inversely correlated with Hb1Ac, Homa-IR, Homa-Beta and positively correlated with insulin. No differences were found between the KIR6.2 expression and biochemical parameters due to pioglItazone treatment. There was no difference in response to the treatment response and no Pro12Ala and C161T polymorphisms were noticed. After the treatment, the expression of PPARY gene increased in fatty tissue. No data showed differences in the expression of genes PPARY2, SUR1 and KIR6.2. Pioglitazone regulates the expression of genes PPARY and PPARY2, and also acts on the SUR1 and KIR6.2 subunits in total peripheral blood leukocyte likely restoring the function of secreting beta pancreatic cells. In adipose, the treatment reassures the functions of pioglitazone on PPARY, improving the state of insulin resistance.

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