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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.
841

Mécanismes impliqués dans les effets du récepteur à la (pro)rénine sur le développement de l'obésité et de ses complications cardiométaboliques associées

Tan, Paul 10 1900 (has links)
L'obésité est une maladie associée à de nombreuses complications comme le diabète de type 2, l'hypertension et le cancer. De nos jours, les modifications au mode de vie, tels l’alimentation et le niveau d’activité physique, ne sont pas suffisants pour combattre les effets délétères de l'obésité. La pharmacothérapie est un traitement alternatif bien que les effets bénéfiques soient temporaires et ne peuvent être maintenus à long terme. Le besoin pour un traitement bénéfique à long terme sans effet secondaire n'est pas comblé. Mieux connu pour son rôle dans la régulation de la pression artérielle, le système rénine-angiotensine favorise l'entreposage du gras. Le récepteur à la prorénine et à la rénine est une composante du système rénine-angiotensine. Ainsi, le récepteur qui amplifie l'activation de celui-ci pourrait avoir un rôle clé dans le gain de masse grasse. Le but de ce projet de thèse est d'évaluer le rôle du récepteur à la prorénine et à la rénine dans le développement de l'obésité et de ses complications chez la souris et ce, en utilisant une combinaison de diète riche en gras et en hydrates de carbone et du handle region peptide, un bloqueur du récepteur à la prorénine à la rénine. Après une période de 10 semaines, nous avons constaté que l'expression et la protéine du récepteur à la prorénine et à la rénine augmentent spécifiquement dans le tissu adipeux sous-cutané et viscéral des souris obèses. Lorsqu'administré en concomitance avec une diète riche en gras et en hydrates de carbone, le handle region peptide favorise chez la souris des diminutions des gains des masses corporelles et adipeuses viscérales. Une diminution de l'expression de l'enzyme catalysant la dernière étape de la lipogenèse pourrait être responsable de la réduction de gras viscéral. Chez les mêmes animaux, l'expression de plusieurs adipokines est également diminuée dans le tissu adipeux suggérant une réduction de la résistance à l'insuline, de l'inflammation et de l'infiltration des macrophages localement dans le gras sous-cutané et viscéral. L'augmentation de l'expression d’un marqueur de l'adipogenèse dans le tissu adipeux sous-cutané pourrait suggérer un plus grand nombre d'adipocytes. Cela pourrait tamponner l'excès d'acides gras libres circulants puisque nous avons constaté une diminution de ce paramètre chez les souris ayant une diète riche en gras et en hydrates de carbone et traitées avec le peptide. Nous avons émis l'hypothèse qu'un cycle futile pourrait être activé dans le gras sous-cutané car nous avons observé une augmentation de l'expression de plusieurs enzymes impliquées dans la lipogenèse et dans la lipolyse. Le ''brunissement'' du tissu adipeux est la présence de cellules similaires aux adipocytes bruns dans le tissu adipeux qui sont caractérisés par une grande densité mitochondriale et la thermogenèse. L'augmentation de l'expression des marqueurs de ''brunissement'' et de biogenèse de mitochondrie dans le gras sous-cutané suggère que le ''brunissement'' pourrait également être activé dans ce dépôt de gras. La sensibilité à l'insuline chez ces animaux pourrait être améliorée telle que suggérée en circulation par la diminution de l'insuline, par le glucose qui change peu, par l'augmentation du ratio glucose sur insuline ainsi que par un changement potentiel dans la corrélation entre le poids corporel de la souris et les niveaux d’adiponectine circulante. Nos travaux suggèrent que le handle region peptide pourrait augmenter la capacité du tissu adipeux sous-cutané à métaboliser les lipides circulants avec l'activation potentielle d'un cycle futile et le ''brunissement''. Cela préviendrait le dépôt ectopique de lipides vers les compartiments viscéraux comme le suggère la réduction de masse adipeuse viscérale chez les souris ayant une diète riche en gras et en hydrates de carbone et traitées avec le peptide. Utilisant un modèle de souris, cette étude démontre le potentiel pharmacologique du handle region peptide comme un nouveau traitement pour prévenir l'obésité. / Obesity is a disease associated with multiple complications such as type 2 diabetes, hypertension and cancer. Nowadays, lifestyle modifications, such as eating habits and physical activity, are simply not enough to counter the deleterious effects of obesity. Pharmacotherapy is used as an alternative treatment although beneficial effects are temporary and cannot be maintained in the long run. The current medical need for a treatment with long term beneficial outcomes devoid of side effects is unmet. Best known for its role in blood pressure regulation, the renin-angiotensin system has recently been attributed a role in favouring fat storage. The prorenin and renin receptor is a component of renin-angiotensin system that amplifies its activation. Thus, the prorenin and renin receptor might play a key role in gaining fat mass. The aim of this thesis is to investigate the role of the prorenin and renin receptor in the development of obesity and its complications in mice using a combination of high-fat and high carbohydrate diet and the handle region peptide, a blocker of the prorenin and renin receptor. After a period of 10 weeks, we have found that the prorenin and renin receptor is increased specifically in subcutaneous and visceral adipose tissue of obese mice. When administered simultaneously with a high-fat and high-carbohydrate diet, the handle region peptide reduced body weight gain in mice with similar decrease in visceral fat mass. Decreased expression of the enzyme catalyzing the last step of lipogenesis could be responsible for the reduction in visceral fat mass. In the same animals, the expressions of several adipokines were also decreased in adipose tissue suggesting reduced insulin resistance, inflammation and macrophage infiltration locally in subcutaneous and visceral fat. Increased expression of a marker of adipogenesis in subcutaneous adipose tissue could suggest higher adipocyte number. This would buffer excess circulating free fatty acid since we have noticed a reduction in the latter in mice on a high-fat and high-carbohydrate diet and treated with the peptide. We hypothesized that a futile cycle could be activated in subcutaneous fat because we have observed increased expression of several enzymes implicated in lipogenesis and lipolysis. « Beiging » is defined as the presence of brown-like adipocytes in adipose tissue which is characterized by high mitochondrial density and thermogenesis. Increased expression of markers for « beiging » and mitochondrial biogenesis in subcutaneous fat suggests that « beiging » could also be activated in this fat pad. Insulin sensitivity in these animals could be improved as suggested in the circulation by decreased insulin, similar glucose, increased glucose on insulin ratio as well as a possible change in the correlation between mouse body weight and circulating adiponectin levels. Our work suggests that the handle region peptide could increase the capacity of subcutaneous adipose tissue to metabolize circulating lipids with a potential activation of a futile cycle and « beiging ». This would prevent ectopic deposition of fat in visceral compartments as suggested by the reduction in visceral fat mass in mice on high-fat and high-carbohydrate diet and treated with the peptide. Using a mice model, this study demonstrates the pharmacological potential of the handle region peptide as a novel treatment to prevent obesity.
842

La résistance à l’insuline en insuffisance rénale chronique et le risque de développer un diabète de type 2 : un cercle vicieux

Dion, François 05 1900 (has links)
L’insuffisance rénale chronique (IRC) est caractérisée par de multiples déséquilibres homéostatiques tels que la résistance à l’insuline. Peu d’études se sont intéressées aux mécanismes sous-jacents à cette résistance à l’insuline en IRC. De plus, il est méconnu si cette résistance à l’insuline peut mener au développement d’un diabète de type II chez des patients prédisposés. Dans un modèle d’IRC, le rat Sprague-Dawley (CD) néphrectomisé 5/6e, on observe une corrélation entre la gravité de l’atteinte rénale, évaluée par la créatinine sérique, et l’hyperglycémie, évaluée par la fructosamine sérique (R2 = 0.6982, p < 0.0001). Cependant, cet état hyperglycémique n’est pas observable lors d’une glycémie à jeun. Lors d’un test de tolérance au glucose, on observe une plus grande élévation de la glycémie (AUC 1.25 fois, p < 0.0001) chez le rat atteint d’IRC. Par contre, la sécrétion d’insuline au cours de ce même test n’augmente pas significativement (AUC ≈ 1.30 fois, N.S.) en comparaison aux rats témoins. Malgré une élévation des taux d’insuline en IRC suivant un bolus de glucose, les tissus périphériques ne montrent pas d’augmentation de la captation du glucose sanguin suggérant un défaut d’expression et/ou de fonction des transporteurs de glucose chez ces rats. En effet, on observe une diminution de ces transporteurs dans divers tissus impliqués dans le métabolisme du glucose tel que le foie (≈ 0.60 fois, p < 0.01) et le muscle (GLUT1 0.73 fois, p < 0.05; GLUT4 0.69 fois, p < 0.01). En conséquence, une diminution significative du transport insulinodépendant du glucose est observable dans le muscle des rats atteint d’IRC (≈ 0.63 fois, p < 0.0001). Puisque les muscles sont responsables de la majorité de la captation insulinodépendante du glucose, la diminution de l’expression du GLUT4 pourrait être associée à la résistance à l’insuline observée en IRC. La modulation de l’expression des transporteurs de glucose pourrait être à l’origine de la résistance à l’insuline en IRC. Cela dit, d’autres mécanismes peuvent aussi être impliqués. En dépit de cette importante perturbation du transport du glucose, nous n’avons pas observé de cas de diabète de type II chez le rat CD atteint d’IRC. Dans un modèle de rat atteint d’un syndrome métabolique, le rat Zucker Leprfa/fa, l’IRC provoque une forte hyperglycémie à jeun (1.5 fois, p < 0.0001). De plus, l’IRC chez le rat Zucker provoque une réponse glycémique (AUC 1.80 fois, p < 0.0001) exagérée lors d’un test de tolérance au glucose. Une forte résistance à l’insuline est mesurée au niveau des muscles puisque la dose usuelle d’insuline (2mU/mL) n’est pas suffisante pour stimuler la captation du glucose chez le rat Zucker atteint d’IRC. De plus, une modulation similaire des transporteurs de glucose peut être observée chez ces deux espèces. Par contre, environ 30% (p < 0.001) des rats Zucker atteints d’IRC avaient une glycosurie. L’IRC en soi ne mènerait donc pas au développement d’un diabète de type II. Par contre, lorsqu’une résistance à l’insuline est présente antérieurement au développement d’une IRC, cela pourrait précipiter l’apparition d’un diabète de type II chez ces patients prédisposés. / Chronic renal failure (CRF) is characterized by multiple homeostasis imbalances such as insulin resistance. However, few studies addressed the underlying mechanisms of the insulin resistance in CRF. Moreover, it is not known if the insulin resistance in CRF could lead to type II diabetes in predisposed patients. In 5/6th nephrectomised Sprague-Dawley (CD) rat model of CRF, we observed a correlation between the severity of the renal injury, evaluated by the serum creatinine level, and the hyperglycaemia, evaluated by the serum fructosamine level (R2 = 0.6982, p < 0.0001). However, this hyperglycemia is not observed on fasting. During a glucose tolerance test, we noticed an increase of the glycaemia in CRF rats (AUC 1.25 fold, p < 0.0001) comparing to controls. Insulin secretion of CRF rats was not significantly higher (AUC ≈1.30 fold, N.S.) during glucose challenge. Interestingly, despite more increase in insulin levels in CRF rats following a glucose bolus, the peripheral tissues did not show any increase in blood glucose uptake suggesting a defect in expression and/or function of glucose transporters in these rats. Indeed, we observed decreased expression of glucose transporters in the liver (≈0.60 fold, p < 0.01) and muscles (GLUT1 0.73 fold, p < 0.05 and GLUT4 0.69 fold, p < 0.01). Accordingly, there was a significant reduction in the insulin-dependent glucose uptake in the muscles of CRF rats compared to controls (≈0.63 fold, p < 0.0001). Since muscles are responsible for the majority of insulin-sensitive glucose transport, downregulation of GLUT4 could be associated with the insulin resistance observed in CRF. The modulation of the expression of several glucose transporters may contribute to insulin resistance in CRF, but other mechanisms could also be implicated. Despite this important perturbation of glucose transport, we did not observed any case of type II diabetes in our CD rat model. In a rat model of metabolic syndrome, the Zucker Leprfa/fa, CRF causes a strong hyperglycemia on fasting (1.5 fold, p < 0.0001). Furthermore, CRF Zucker showed an exacerbated glycemic response (AUC 1.80 fold, p < 0.0001) during glucose challenge. A strong insulin resistance in muscle was measured as the usual insulin dose (2mU/mL) was not enough to stimulate glucose uptake in Zucker rats with CRF. The same modulation of glucose transporters in the peripheral tissues was observed in both rat models. As opposed to CD rats, ≈30% (p < 0.05) of CRF Zucker rats’ showed presence of glucose in their urine. CRF by itself won’t lead to type II diabetes. However, when insulin resistance is already present when developing CRF, it could precipitate the onset of type II diabetes among these patients.
843

Diabetes mellitus 2. typu a Alzheimerova demence: studium společných patogenetických faktorů / Study of Common Pathogenetic Factors of Alzheimer Disease and Type 2 Diabetes Mellitus

Vacínová, Gabriela January 2014 (has links)
Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) are aging-associated diseases that have rising prevalence in all industrialized countries. AD is a neurodegenerative disease characterized by progressive loss of cognitive functions. It is a complex disease which formation involves both genetic factors and environmental factors. The most important marker associated with this disease is the risk allele ε4 in APOE gene. From the latest genome-wide association study emerged another ten candidate genes. As the most significant from those genes appears the minority G allele of rs744373 polymorphism in the gene BIN1. AD is connected with many metabolic and immune disorders. To the markers of interest belongs also the new parameter visfatin which can act as a pro-inflammatory cytokine. T2DM is a chronic disease characterized by raised levels of blood glucose, which is also characterized by neurological disorders. In the case of both of these diseases can be found a large number of metabolic disorders. One of the most important disorders is insulin resistance. This thesis consists of two parts - the biochemical and genetic one. The biochemical part of the thesis studies the visfatin level in patients with AD and healthly control and studies whether visfatin is related to AD. In this part of the...
844

Odnos između pojedinih markera aterosklerotske bolesti i debljine intima-medija kompleksa karotidne arterije kod bolesnika sa metaboličkim sindromom / Relationship between individual markers of atherosclerotic disease and carotid intima-media thickness of carotid artery in the patients with metabolic syndrome

Eremić Kojić Nevena 09 July 2019 (has links)
<p>S obzirom na visoku prevalencu metaboličkog sindroma (10-40% u svetskoj populaciji) i na činjenicu da prisustvo metaboličkog sindroma duplira rizik od nastanka aterosklerotske bolesti kardiovaskularnog sistema jasna je potreba za identifikacijom indivudualnih parametara koji doprinose njenom razvoju. Metabolički sindrom je klaster faktora rizika metaboličkog porekla koji je udružen sa povećanim rizikom za nastanak aterosklerotske bolesti kardiovaskularnog sistema i dijabetes melitusa tipa 2. Insulinska rezistencija, abdominalna gojaznost, aterogena dislipidemija, hipertenzija, proinflamatorno i protrombotično stanje su faktori koji su u osnovi metaboličkog sindroma a često su i praćeni nagomilavanjem masti u jetri. Cilj rada je bio da se utvrdi odnos između markera disfunkcije hepatocita (AST, ALT, GGT), serumskog nivoa inflamatornih biomarkera (broj leukocita, elektroforeza serumskih proteina, CRP, fibrinogen, TNF-&alpha;), biomarkera endotelne disfunkcije (ADMA i homocistein), kao i nivoa serumskih adipokina (leptin i adiponektin) i debljine intima-medija kompleksa (IMT) karotidne arterije kao pokazatelja prisustva aterosklerotskog procesa. Ispitivanje je dizajnirano kao studija preseka. U ispitivanje je uključeno 58 ispitanika oba pola sa karakteristikama metaboličkom sindroma (NCEP:ATP III kriterijumi). Odabir ispitanika je vr&scaron;en u Odeljenju za pravilnu ishranu i zdravstvenu bezbednost hrane, Instituta za javno zdravlje Vojvodine. Kontrolnu grupu su sačinjavale 30 klinički i biohemijski zdravih ispitanika nepu&scaron;ača koji su prema polnoj i dobnoj strukturi odgovarali ispitivanim grupama bolesnika. Iz ispitivanja su isključene osobe koje konzumiraju vi&scaron;e od 20g/dan alkohola, pu&scaron;ači, koji imaju dijagnostikovan virusni hepatitis B ili C ili pozitivan Hbs antigen, anti-Hbs antitela i anti-HCV antitela, osobe koje imaju verifikovana oboljenja kardiovaskularnog sistema, bubrega, CNS-a, infektivna, maligna i autoimuna oboljenja kao i druga oboljenja jetre i žučnih puteva, osobe koje su pod medikamentoznom terapijom koja može uticati na nivo serumskih biomarkera endotelne disfunckije, lipidni i lipoproteinski status, glikoregulaciju kao i menstruacioni ciklus. Sve laboratorijske analize su urađene u Centru za laboratorijsku medicinu, Kliničkog centra Vojvodine. Doppler ultrasonografski pregled karotidnih arterija i ultrazvuk abdomena i jetre je urađen u Centru za radiologiju Kliničkog centra Vojvodine. Signifikantna pozitivna korelacija niskog stepena je utvrđena između IMT zajedničke karotidne arterije i serumskih koncentracija GGT, hsCRP i leptina kao i odnosa neutrofili/limfociti. Prema prvom konstruisanom regresionom modelu u kojem je zavisna varijabla bila IMT preko 0,09 cm statistički značajan uticaj na predviđanje debljine IMT zajedničke karotidne arterije imaju hsCRP (Exp (B) 1,112 i glikemija (Exp (B) 1,973). Prema modelu neuronske mreže sa istom zavisnom varijablom najveću mogućnost predviđanja IMT imaju glikemija, AST i fibrinogen. Prema drugom konstruisanom regresionom modelu gde su zavisne varijable bile IMT zajedničke karotidne arterije preko 0,09 cm i prisutnost hepatične steatoze najveću mogućnost predviđanja imaju leptin Exp (B) 1,1022 i ALT Exp (B) 1,053. Prema modelu neuronske mreže sa istom zavisnom varijablom najveću mogućnost predviđanja IMT imaju ALT, ADMA i leptin.</p> / <p>Given the high prevalence of metabolic syndrome (10-40% in the world population) and the fact that the presence of metabolic syndrome doubles the risk of atherosclerotic disease of the cardiovascular system, there is a clear need to identify individual parameters that contribute to its development. Metabolic syndrome is a cluster of the risk factors of metabolic origin that is associated with an increased risk for the onset of atherosclerotic disease of the cardiovascular system and type 2 diabetes mellitus. Insulin resistance, abdominal obesity, atherogenic dyslipidemia, hypertension, proinflammatory and prothrombotic conditions are the factors at the base of the metabolic syndrome and are often accompanied by fat accumulation in the liver. The aim of this work was to determine the relation between markers of hepatic dysfunction (AST, ALT and GGT), serum levels of inflammatory biomarkers (white blood cell count, electrophoresis of serum proteins, CRP, fibrinogen, TNF-&alpha;), biomarkers of endothelial dysfunction (ADMA and homocysteine) as well as levels of serum adipokines (leptin and adiponectin) and intima-media thickness of carotid artery as indicators of atherosclerotic process in the patients with metabolic syndrome. Study was cross-sectional. It included 58 participants with metabolic syndrome (NCEP:ATP III criteria) as well as 30 clinically and biochemically healthy nonsmokers, age and gender matched controls. Participants were selected in the Department for Nutrition and Food Safety, Center of Hygiene and Human Ecology Institute of Public Health of Vojvodina. Patients that consumed alcohol more than 20g/day were excluded. Participants with positive HBsAg, anti-HBs-antibodies or anti- HCV antibodies were excluded also. Smokers were also excluded. Patients with cardiovascular diseases, renal diseases, infective, hepatic, malignant and autoimmune diseases were excluded from this study. Subjects which used drugs that could affect biomarker levels of endothelial dysfunction, lipid metabolism, glucose metabolism and menstrual cycle were also excluded. All laboratory analyzes were done in Centre for Laboratory Medicine, Clinical Centre of Vojvodina. Doppler ultrasonography of carotid arteries and ultrasound of abdomen and liver were done in Centre for Radiology, Clinical Centre of Vojvodina. Significant positive correlation of low degree was determined between IMT of common carotid artery and serum concentrations between GGT, hsCRP and leptin and relationship neutrophils/lymphocytes. According to the first constructed regression model where dependent variable was IMT of common carotid artery above 0.09 cm statistically significant influence on foreseeing IMT of common carotid artery have hsCRP (Exp (B) 1.112 and glycaemia (Exp (B) 1.973). According to the neuronal network with the same dependent variable greatest probability for foreseeing IMT have glycaemia, AST and fibrinogen. According to the second constructed regression model where dependent variable was IMT above 0.09 cm and present hepatic steatosis greatest probability for foreseeing IMT have leptin Exp (B) 1.1022 and ALT Exp (B) 1.053. According to the neuronal network with the same dependent variable greatest probability for foreseeing IMT have ALT, ADMA and leptin.</p>
845

O SP1 (transcription factor Sp1) participa da regulação transcricional do Slc2a4 mediada pelo receptor  de estrógeno ER-alfa em adipócitos 3T3-L1 / SP1 (transcription factor Sp1) participates in the transcriptional regulation of Slc2a4 mediated by estrogen receptor ER-alpha in 3T3-L1 adipocytes

Andrade, João Nilton Barreto 15 May 2018 (has links)
O diabetes mellitus tipo 2 (DM2) é caracterizado pela presença de resistência à insulina, a qual pode ser modulada pelo estrógeno, tanto em fêmeas como em machos. Nesse processo, o transportador de glicose GLUT4 (gene Slc2a4, solute carrier family 2 member 4) desempenha papel importante, pois aumento da expressão do GLUT4 melhora o controle glicêmico. Estradiol (E2) regula a expressão do Slc2a4 por meio do balanço dos efeitos contrários de seus receptores (ERs): ER-alfa estimula e ER-beta inibe a expressão. Efeitos transcricionais dos ERs envolvem a participação de co-reguladores, destacadamente o SP1 (transcription factor Sp1), potente estimulador do Slc2a4. Entretanto, o papel do SP1 na regulação do Slc2a4 mediada pelos ERs é desconhecido; e este foi o objetivo do presente estudo. Investigou-se adipócitos maduros 3T3-L1, tratados por 24 horas com E2, agonista de ER-alfa (PPT) ou agonista de ER-beta (DPN). Avaliou-se: a expressão gênica (RT-qPCR) de Slc2a4 e Sp1; o conteúdo (Western blotting) total de GLUT4 e o nuclear de ER-alfa/beta e SP1; a atividade de ligação do SP1 no Slc2a4 (ensaio de mobilidade eletroforética); e a formação de complexos SP1/ER-alfa (imunoprecipitação). Os resultados confirmaram que E2 aumenta a expressão de Slc2a4/GLUT4 pela ação preponderante do ER-alfa. O agonista PPT aumentou: o conteúdo nuclear de SP1, a interação SP1/ER-alfa e a atividade de ligação do SP1 no Slc2a4. O agonista DPN indicou que a ação repressora do ER-beta não envolve o SP1. Conclui-se que o efeito estimulador do ER-alfa na expressão do Slc2a4 envolve mecanismo de transativação gênica via SP1. Essas observações colocam a cooperação ER-alfa/SP1 como um novo alvo para o desenvolvimento de medidas terapêuticas para resistência à insulina e diabetes mellitus tipo 2 / Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance, which can be modulated by estrogen in both females and males. In this process, the glucose transporter GLUT4 (solute carrier family 2 member 4 gene - Slc2a4) plays an important role, since increasing GLUT4 expression improves glycemic control. Estradiol (E2) regulates the expression of Slc2a4, by a mechanism in which estrogen receptors (ERs) play opposite effects: ER-alpha stimulates, whereas ER-beta inhibits the expression. Transcriptional effects of ERs involve co-regulators, notably the transcription factor SP1, a powerful enhancer of Slc2a4. However, the role of SP1 in the ERs-mediated regulation of Slc2a4 is unknown; and that was the aim of the present study. Differentiated adipocytes 3T3-L1 were treated (24 hours) with E2, ER-alpha agonist (PPT) or ER-beta agonist (DPN). It was analyzed: gene expression (RT-qPCR) of Slc2a4 and Sp1; total content o GLUT4 and nuclear content of ER-alpha/beta and SP1 (Western blotting); binding activity of SP1 into Slc2a4 promoter (electrophoretic mobility shift assay); and content of nuclear SP1/ER-alpha complexes (immunoprecipitation). Results confirmed that E2 increases the expression of Slc2a4/GLUT4, by the dominant effect of ER-alpha. The ER-alpha agonist PPT increased the nuclear content of SP1, the interaction of SP1/ER-alpha, and the binding activity of SP1 into the Slc2a4. The agonist DPN evinced that ER-beta activity does not involve the SP1. In conclusion, the enhancer effect of ER-alpha upon Slc2a4 gene expression involves a transactivation mechanism via SP1. This observation point outs the cooperation of ER-alpha/SP1 as a new target for the development of approaches to treat insulin resistance and T2DM
846

"Alterações hepáticas em grandes obesos: avaliações clínico-laboratoriais e histopatológicas antes do tratamento cirúrgico da obesidade" / Hepatic alterations in severely obese patients: clinical-laboratory and histopatological evaluations before surgical treatment of obesity

Oliveira, Cacilda Pedrosa de 18 April 2006 (has links)
A doença hepática gordurosa não-alcoólica (DHGNA) e a esteatohepatite (EHNA) são freqüentes nos obesos. O objetivo foi determinar a prevalência de DHGNA/EHNA e Síndrome Metabólica (SM) nos grandes obesos; definir preditores de EHNA; estabelecer critérios histológicos para o diagnóstico da EHNA. Avaliados 325 pacientes encaminhados à cirurgia bariátrica (IMC = 35 kg/m2), dos quais 146 foram submetidos à análise histológica; as variáveis clínicas e bioquímicas analisadas e correlacionadas com a histologia. A DHGNA ocorreu em 111 (76%) pacientes e a prevalência de EHNA, conforme critério histológico usado, em 25,3% a 55,5%; SM ocorreu em 57,2%. Os preditores da EHNA foram: SM; alterações glicêmicas; hipertrigliceridemia e HAS. Foram preditores de fibrose: idade acima de 30 anos e AST elevada / Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) has been associated with obesity. Determine prevalence of NAFLD/NASH and metabolic syndrome (MS) in severe obesity; define clinical predictor of steatohepatitis; establish histological criteria necessary to diagnose NASH. Evaluation of 325 patients submitted to bariatric surgery (BMI = 35 kg/m2), among which 146 were submitted to histological analysis; variables clinical and biochemical were analyzed and correlated to histological characteristics. NAFLD occurred in 111 (76%) patients and NASH, according to histological criteria used, in 25.3% to 55.5%; MS was present in 57.2%. Predictors of NASH: MS; glycaemic alterations; hypertriglyceridaemia and high blood pressure (HBP). Predictors of fibrosis: age above 30 years and high AST
847

Avaliação das consequências da limitação do tamanho da prole de ratos Wistar ao nascimento sobre seu desenvolvimento ponderal e características morfofuncionais na idade adulta / Evaluation of the consequences of limiting the litter size of rats on their birth about weight development and morphofunctional characteristics in adulthood

Tavares, Neuziane Kloos Amorim 11 July 2013 (has links)
Durante a vida intrauterina, o desenvolvimento do embrião e do feto é suscetível a mudanças ambientais que podem alterar o fenótipo do indivíduo na vida pós-natal. Eventos que ocorrem durante períodos críticos de rápida divisão celular, nos quais são formados os diversos órgãos e tecidos, podem alterar a estrutura e função de sistemas orgânicos gerando consequências precoces (baixo peso ao nascimento) e tardias (doenças na vida adulta). Os protocolos experimentais da maior parte dos estudos sobre a programação fetal reduz o tamanho da ninhada logo após o nascimento. Essa abordagem dificulta a interpretação e reprodutibilidade dos resultados observados. O objetivo deste estudo foi determinar se a pressão sanguínea, o metabolismo de carboidratos e gasto energético em proles adultas é influenciado pelo tamanho da ninhada. Ratas Wistar foram alimentadas com ração padrão ad libitum e foram acasaladas com ratos machos com 12 semanas de idade. Após o nascimento, a prole foi dividida em três grupos: tamanho da ninhada sem redução (Gc), proles reduzido a oito filhotes (G8) e proles reduzidos a quatro filhotes (G4). Ao fim de 12 semanas de idade, o peso corporal, pressão arterial, consumo de ração, glicemia, insulina, colesterol e triacilgliceróis, massa de tecido adiposo marrom, índice de adiposidade, massa renal e cardíaca foram determinados. O peso corporal, índice de adiposidade, glicemia, nível de insulina e índice HOMA foram maiores em machos e fêmeas no grupo G4 do que nos grupos G8 e Gc. No entanto, o consumo de ração foi menor no grupo G4. A pressão arterial foi maior no grupo Gc em machos e fêmeas. Em resumo, a redução do tamanho da ninhada está relacionada com a obesidade, resistência à insulina e possíveis alterações no gasto energético na prole adulta / During intrauterine life, the developing fetus is susceptible to environmental changes that can alter the phenotype of the individual in postnatal life. This phenomenon is called fetal programming. Events that occur during critical periods of rapid cell division may alter the structure and function of organ systems, resulting in consequences both early (low birth weight) and late (diseases in adulthood) in life. The experimental protocols of most of the studies on fetal programming involve a reduction in litter size soon after birth. This approach hampers the interpretation and reproducibility of the observed results. The purpose of this investigation was to determine if blood pressure, carbohydrate metabolism and energy expenditure in adult offspring are influenced by litter size. Female Wistar rats were fed standard rat chow ad libitum and were mated with male rats at 12 weeks of age. After birth, the offspring were divided into three groups: unchanged litter size (GU), culled to eight neonates (G8) and culled to four neonates (G4). At 12 weeks of age, the body weight; blood pressure; food intake; glucose, insulin, cholesterol and triacylglycerol levels; brown adipose tissue mass; adiposity index; renal mass; and cardiac mass were determined. The body weight, adiposity index, glucose level, insulin level and HOMA index were higher in males and females in the G4 group than in the G8 and GU groups. However, food consumption was lower in G4 males. The blood pressure was higher in the GU group. In summary, a small litter size is related to obesity, possible alterations in energy expenditure and insulin resistance in adult offspring
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Avaliação da resistência à insulina em pacientes com hepatite C crônica não diabéticos / Evaluation of insulin resistance in patients with chronic hepatitis C non-diabetics

Vallenas, Maria Cristina Tejero 19 June 2013 (has links)
INTRODUÇÃO: O vírus da hepatite C (VHC) é a maior causa de hepatite crônica em todo o mundo. É um vírus hepatotrópico e linfotrópico que está associado a diversas manifestações extra-hepática que tem sido associada à infecção pelo VHC. A presença de RI nos pacientes com hepatite C está implicada em pior resposta ao tratamento antiviral com interferon, na progressão da fibrose hepática, na instalação da esteatose e maior risco de carcinoma hepatocelular. O método mais comumente utilizado para o diagnóstico da RI é o índice HOMA-IR (homeostasis model assessment). OBJETIVOS: Avaliar a frequência de resistência à insulina e os fatores associados em pacientes infectados com o vírus da hepatite C. MÉTODOS: Incluídos 202 pacientes infectados pelo VHC e não diabéticos em estudo transversal realizado no ambulatório de hepatites virais do DMIP- HCFMUSP de março de 2010 a fevereiro de 2012. Foram avaliados dados demográficos, antropométricos, bioquímicos (incluindo HOMA-IR) e dados de estudo anatomopatológico do fígado. Os pacientes foram divididos em dois grupos: resistentes à insulina (HOMA-IR >= 3) e não resistentes à insulina (HOMA-IR < 3). Esses grupos foram submetidos à análise uni e multivariada (regressão logística), para ajuste dos fatores de confusão. RESULTADOS: Dos pacientes incluídos no estudo, 87 (43,1%) eram do sexo masculino e 115 (56,9%) do sexo feminino. A média de idade foi de 49,65 anos. O fator de risco mais frequente para aquisição da VHC foi a transfusão sanguínea. O genótipo 1 foi o mais frequente (77,2%), seguido pelo genótipo 3 (18,3%). Trinta e três pacientes (16,3%) apresentaram grau de fibrose avançado (3 e 4). Noventa e cinco pacientes (47%) apresentaram algum grau de esteatose. Cinquenta e dois pacientes (25,74%) apresentaram HOMA-IR >= 3. Entre os pacientes infectados pelo VHC genótipo 1 (n = 156), encontramos 41 pacientes (26,3%) com resistência à insulina; entre os pacientes com genótipo 3 (n = 37), encontramos 10 pacientes (27,0%) com HOMA-IR >= 3. Encontramos associação positiva entre índice de massa corpórea maior ou igual a 25 kg/m2, presença de esteatose hepática e presença de resistência à insulina. Atividade necroinflamatória e esteatose hepática foram fatores independentes associados à fibrose hepática. CONCLUSÕES: Considerando a prevalência e as implicações clínicas da resistência à insulina, são necessários mais estudos para se conhecer a melhor abordagem para os pacientes resistentes à insulina nos pacientes com hepatite C crônica / BACKGROUND: Hepatitis C virus (HCV) is the leading cause of chronic hepatitis worldwide. It is a hepatotropic and lymphotropic virus that is associated with several extrahepatic manifestations. Insulin resistance (IR) is an extrahepatic manifestations that have been associated with HCV infection. The presence of IR in patients with hepatitis C is implicated in poor response to antiviral therapy with interferon, in the progression of liver fibrosis, the installation of steatosis and increased risk of hepatocellular carcinoma. The most commonly used method for the diagnosis of IR is the HOMA-IR (homeostasis model assessment). OBJECTIVES: To assess the frequency of insulin resistance and associated factors in patients infected with hepatitis C. METHODS: The sample comprised 202 non-diabetic patients infected with HCV and non-diabetic study performed in the outpatient clinic of the viral hepatitis DMIP-HCFMUSP between March 2010 and December 2011. We evaluated demographic, anthropometric, biochemical (including HOMA-IR) data and histological features of of the liver. The patients were divided into two groups: insulin resistant (HOMA-IR >=3) and non-insulin resistant (HOMA-IR < 3). These groups were subjected to univariate and multivariate analysis (logistic regression) to adjust for confounding factors. RESULTS: Of the patients studied, 87 (43.1%) were male and 115 (56.9%) females. The mean age was 49.65 years. The most common risk factor for acquisition of HCV was blood transfusion. Genotype 1 was the most frequent (77.2%), followed by genotype 3 (18.3%). Thirty-three patients (16.3%) had advanced fibrosis (3 and 4). Ninety-five patients (47%) had some degree of steatosis. Fifty-two patients (25.74%) had HOMA-IR >= 3. CONCLUSIONS: Among patients infected with HCV genotype 1 (n = 156), we found 41 patients (26.3%) with insulin resistance, among patients with genotype 3 (n = 37), we found 10 patients (27.0% ) with HOMA-IR >= 3. We found a positive association between body mass index greater than or equal to 25 kg/m2, presence of hepatic steatosis and presence of insulin resistance. Necroinflammatory activity and hepatic steatosis were independent factors associated with liver fibrosis. CONCLUSIONS: Given the prevalence and clinical implications of insulin resistance, further studies are needed to know the best approach for insulin resistant patients with chronic hepatitis C
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Avaliação da gordura visceral e subcutânea em pacientes portadores de doença gordurosa não alcoólica do fígado (DHGNA): correlação com a resistência insulínica, medidas antropométricas, síndrome plurimetabólica e hábitos alimentares / Visceral and subcutaneous fat in patients with NAFL: correlation with insulin resistance, presence of metabolic syndrome, anthropometric measurements and dietary intake

Vilar, Lisis Karine 12 January 2007 (has links)
Introdução: O aumento alarmante da obesidade em todo mundo é um fator independente para o aumento da prevalência de doenças crônicas, como diabetes, hipertensão arterial e doença hepática gordurosa não alcoólica (DHGNA). A DHGNA engloba um amplo espectro de doença desde esteatose simples sem sinais inflamatórios, evoluindo para esteatohepatite (ENA) e até cirrose. Por ser uma patologia multifatorial sua patogênese e terapêutica ainda apresentam pontos obscuros. A resistência à insulina é um dos fatores que já foram determinados como importantes na fisiopatogênese da DHGNA e, está diretamente relacionado ao estilo de vida e hábitos alimentares. Objetivo: Avaliar a correlação entre a presença da gordura visceral e subcutânea à resistência insulínica, síndrome metabólica, medidas antropométricas e hábitos alimentares em pacientes portadores DHGNA. Resultados: Sessenta por cento dos pacientes com DHGNA apresentavam Síndrome Plurimetabólica de acordo com os critérios do ATP III. Dentre os critérios mais prevalentes da síndrome metabólica, níveis baixos HDL e circunferência de cintura (CC) aumentada ocorreram em 56%. Ao dividirmos os pacientes em grupos, os critérios se modificaram. Nos pacientes portadores de esteatose simples, o critério mais prevalente foi CC 77%. Já naqueles com ENA o aumento do nível de triglicérides ocorreu em 68% dos pacientes, sendo o de maior prevalência. As correlações entre CT e IMC (p=0,001), CC (p=0,003) e percentual de massa gorda (p=0,031), apresentam significância estatística negativa entre os pacientes com DHGNA. Não houve significância estatística entre CT e HOMA, ingestão total de energia, proteínas, carboidratos e lipídios nestes pacientes mesmo quando foram divididos de acordo com o grau de inflamação, esteatose e ENA. Por outro lado, a CC ao ser correlacionada com IMC (p=0,000), HOMA (p=0,049), ingestão total de energia (p=0,043), lipídios e dos ácidos graxos mono (p=0,020) e poliinsaturados (0,045) apresentaram significância estatística nos pacientes com DHGNA. Quando divididos segundo o grau de esteatose houve correlação positiva entre CC e HOMA (p=0,045) nos pacientes com esteatose simples. Já nos pacientes portadores de ENA houve correlação positiva entre CC e ingestão total de calorias (p=0,031). Houve diferença estatística positiva quanto ao consumo de lipídios totais (p=0,005) entre o grupo de esteatose e ENA, onde os pacientes com ENA, tinham um maior consumo de lipídios. Conclusões: A circunferência de cintura se mostrou melhor parâmetro de diagnóstico complementar ao ser comparado com a tomografia computadorizada em pacientes com DHGNA. Ao associarmos o IMC com a CC conseguimos obter uma avaliação nutricional mais fidedigna dos riscos de doenças decorrentes da síndrome metabólica. O alto consumo de lipídios apresentou correlação positiva com maior grau de inflamação em pacientes com DHGNA. / Introduction: The dramatic increasing of obesity in the world is a predictive factor to increase the prevalence of chronic diseases, as type II diabetes, hypertension and Nonalcoholic fatty liver disease (NAFLD). It is part of large spectrum of liver damage ranging from simple steatosis and cirrhosis. The pathogenesis of NAFLD is multifactorial and some points in the mechanisms and therapeutic still unknown. The insulin resistance is the major risk factors, recognized in the pathophysiology of NAFLD and it is strongly related with life style and diet. Objective: Evaluate the correlation between visceral and subcutaneous fat with insulin resistance, presence of metabolic syndrome, anthropometric measurements and dietary intake in patients with NAFLD. Results: Sixty percent of patients with NAFLD, classified by ATPIII criteria, had the metabolic syndrome. Waist circumference and low HDL -C were the most positive criteria, observed in 56% of total cases. However the criteria modifies when the group were divided. In patients with simple steatosis WC was the most prevalent criteria 77%, where as in NASH patients the high level of TGL 68%, was the most prevalent. Correlations between CT and BMI (p=0,001), WC (p=0,033) and fat mass (p =0,031) had a negative statistic significant correlation in all cases of NAFLD. No significant associations were found between CT (umbilical circumference) and fat mass, WC, HOMA, Intake of calories, carbohydrates, proteins, lipids and fat acids in patients divided in steatosis and NASH patients. The correlation between Waist circumference (WC) with BMI (p=0,000), HOMA (p:0,049), total of energy intake (p=0,043) , monounsaturated (p:0,020) and polyunsaturated (p:0,045) fat acids intake showed a statistic significance in all cases of NAFLD. Significant different correlations were found as the group were divided in steatosis and NASH cases. The values of fat mass correlated with WC was (p: 0,045) in the steatosis group where as in NASH patients the only correlation found was WC and total consumption of daily energy (p=0,031). NASH patients showed a statistic higher intake of lipids (p=0,005), compared with steatosis patients. Conclusions: CT measurement of visceral fat did not contribute to differential diagnosis as much as WC in patients with NAFLD. The use of both measurements BMI and WC showed to be a better predictor of the risks of Metabolic Syndromes. NASH subjects had a higher intake o total fat as well as of lipid fractions.
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Mecanismos fisiopatológicos do remodelamento vascular associado à  calcificação em camundongos com obesidade e resistência à insulina / Mechanisms of vascular remodeling associated with calcification in obesity and insulin resistance

Carmo, Luciana Simão do 12 December 2017 (has links)
O remodelamento vascular é uma resposta adaptativa a estímulos específicos, participando da fisiopatologia de diversas doenças cardiovasculares. Devido à intersecção de fatores de risco cardiovasculares relacionados tanto ao remodelamento vascular como à calcificação vascular (CV), propomos a investigação de mecanismos que inter-relacionam tais condições. Postulamos que camundongos ob/ob com obesidade e resistência à insulina têm resposta exacerbada de remodelamento vascular associado à CV quando comparado aos camundongos controles C57BL/6 (C57) após estímulo com vitamina D3 (VD) in vivo. Camundongos C57 e ob/ob (OB) machos foram injetados com 8x103 UI/kg de vitamina D3 intraperitoneal (IP) ou solução fisiológica (CT) durante 14 dias (n=6). Houve aumento da circunferência da lâmina elástica externa da aorta, determinando aumento da área circunferencial do vaso em camundongos OBVD. A hipervitaminose D aumentou o comprimento da lâmina elástica interna da aorta, aumentando o lúmen vascular em camundongos OBVD. Ocorreu também diminuição da espessura da parede do vaso em camundongos OBVD, caracterizando remodelamento vascular positivo hipotrófico. Observamos ainda maior deposição de colágeno na parede do vaso e elastólise em camundongos OBVD. O remodelamento vascular positivo em camundongos OBVD se correlacionou diretamente com o aumento da calcificação na aorta (R2=0,8; p < 0,003). Aortas de camundongos OBVD apresentaram aumento na expressão de espécies reativas de oxigênio (ERO), que foi associado a aumento da atividade de metaloproteinases de matriz (MMP). Estes resultados fornecem evidências que camundongos obesos, insulino-resistentes, e com diabetes tipo 2 desenvolveram remodelamento vascular positivo hipotrófico correlacionado diretamente com calcificação vascular em camundongos OBVD após estímulo com vitamina D3. O desenvolvimento de remodelamento vascular positivo hipotrófico neste modelo murino é possivelmente mediado pela ativação de MMP na parede da aorta e a geração de ERO pode ter contribuído para a ativação de MMP no nosso modelo / Vascular remodeling is a vessel response to mechanical and hemodynamic stimuli, which is a major determinant of changes in vessel lumen caliber. The mechanisms that influence arterial remodeling include calcification. We hypothesized that ob/ob mice develop positive vascular remodeling associated with calcification. We quantify and assess mechanisms of vascular remodeling and vascular calcification in ob/ob mice (OB) after vitamin D3 stimulation (VD) or phosphate buffered saline (CT), compared with (C57BL/6) mice. Both ob/ob (OBVD) and C57BL/6 (C57VD) mice received 8x103 IU/day of (IP) vitamin D3 for 14 days. Control ob/ob (OBCT) and C57BL/6 (C57CT) mice received IP phosphate buffered saline (PBS) for 14 days (n=6). Hypervitaminosis D increased the external and internal elastic length in aortas from OB mice, resulting in increased total vascular area and lumen vascular area respectively, which characterizes positive vascular remodeling. OBVD mice decreased the aortic wall thickness, resulting in hypotrophic vascular remodeling. We demonstrated increases in collagen deposition, elastolysis and calcification in the aortas of OBVD mice. These results showed a positive correlation between expansive vascular remodeling and vascular calcification in OBVD mice (R2=0,8; p < 0,003). Furthermore, aorta from OBVD increased oxidative stress, coincidently with augmented metalloproteinase activity. Our data provide evidence that obese type 2 diabetes mellitus and insulin-resistant mice (ob/ob) developed positive hypotrophic vascular remodeling correlated directly with increased vascular calcification in OBVD mice after chronic vitamin D3 stimulation. The development of positive hypotrophic vascular remodeling in this mouse model is possibly mediated by the activation in the aortic wall of MMP and ROS may have contributed to the activation of MMP in our model

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