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REGULATION OF PLATELET EXOCTOSIS AND ITS ROLE IN DISEASESAl Hawas, Rania A. 01 January 2012 (has links)
In addition to their role in hemostasis, platelets appear to contribute to vascular inflammatory diseases. Platelets achieve this through the secretion of various prothrombotic and pro-inflammatory molecules. Platelet secretion is mediated by integral membrane proteins called Soluble NSF Attachment protein REceptors (SNAREs). SNAREs come from both granule/vesicle membranes (v-SNAREs) and target membranes (t-SNAREs) to form a trans-bilayer complex that promotes membrane fusion and subsequent granule cargo release. The work described in this dissertation dissects various, yet related aspects of platelet secretion in both physiological relevant and pathological circumstances.
Atherosclerosis is a leading cause of death in the westernized countries and a major contributor to heart attacks and strokes. Given the potential involvement of platelets in atherosclerosis and previous work from our laboratory showing that VAMP-8 is the primary v-SNARE for platelet secretion, one part of this dissertation focuses on the role of VAMP-8- mediated secretion in atherosclerosis. The data showed that the deletion of VAMP-8 in the ApoE-/- null model of chronic atherosclerosis attenuated plaque development compared to the wild type littermates. Aged (50 week) VAMP-8-/-/ApoE-/- mice showed a reduction in lesion size compared to ApoE-/- controls, as measured by Oil Red-O staining of the plaques in the aortic sinus and by en face analysis of plaques in the aortic arch. These data show that the loss of VAMP-8 attenuates the development of atherosclerotic plaques and suggest that platelet secretion contributes to atherosclerosis.
Considering the vital role of platelet secretion in both physiological and pathological conditions, it is essential to understand how it is regulated. SNARE proteins are controlled by a range of regulatory molecules that affect where, when, and with whom they form trans-bilayer complexes for membrane fusion. One family of such regulators is the Munc18 family: platelets contain three (Munc18a-c). The second part of this dissertation focuses on the role of Munc18b/STXBP2. Mutations in the Munc18b/STXBP2 gene underlie Familial Hemophagocytic Lymphohistocytosis type 5 (FHL5), which is a life- threatening disease caused by dysregulation of the immune system. Platelets from two biallelic FHL5 patients had almost undetectable levels of Munc18b/STXBP2 levels; the levels of Munc18a increased slightly and Munc18c levels were unaffected. Syntaxin 11 levels were affected but the levels of other secretory machinery proteins were normal. Platelet secretion from dense and alpha granule in two biallelic patients and the one heterozygous patient was decreased. The release of serotonin from dense granules, and platelet factor 4 (PF4) from alpha granules was profoundly affected in the biallelic patients and partially affected in the heterozygote heterozygous patient. Lysosome release was affected only from the platelets of the biallelic patients. These data indicate that Munc18b plays a key role in platelet secretion.
Ras is the prototypical member of a family of low molecular weight, GTP-binding proteins. It affects various cellular functions by cycling between an active, guanine triphosphate (GTP) and an inactive guanine diphosphate (GDP) -bound state. Little is known about the role of Ras activation in platelets. The third part of this dissertation focuses on what could be learned about Ras’ role by analyzing platelets from patients with Noonan Syndrome. Specific mutations in the genes encoding elements of Ras signaling pathways are associated with Noonan Syndrome. Platelets from Noonan Syndrome patients with a mutation in kRas (F156V) were analyzed and shown to have a defect in aggregation in response to low levels of agonist. These data suggest that Ras may play a functionally relevant role in platelet activation.
In summary, the experiments presented in investigations of this dissertation support a role for platelet secretion in several pathological conditions and suggest that platelet secretion assays may serve as useful as diagnostic tools for some genetic diseases. In addition, these studies elucidate the importance of understanding the regulation of platelet exocytosis, to drive the development of new antithrombotic therapeutics.
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ROLE OF ARYL HYDROCARBON RECEPTOR IN CHRONIC INFLAMMATORY DISEASESArsenescu, Violeta 01 January 2009 (has links)
Aryl Hydrocarbon Receptor (AhR) is a ligand-actviated receptor known as the dioxin receptor. Environmental pollutants called dioxin-like toxicants are found in food, cigarette smoke, automobile exhaust and air. Therefore, they could chronically amplify the pathology of numerous chronic inflammatory diseases. AhR is a well known target of these environmental chemicals that disrupt endocrine signaling. By the year 2020, the number of people older than 60 years is expected to top 1 billion. The burden of treating chronic disease is significant both in dollars spent and in lost productivity. The need to identify risk factors for chronic diseases must be evaluated along with diet and lifestyle factors that will promote healthy aging.
The studies presented in this dissertation tested the hypothesis that habitual exposure to dioxin-like contaminants contributes to chronic inflammatory disease states through activation of AhR pathway. Due to their lipophilicity, dioxin like toxicants (like PCB 77) accumulated in mice' visceral adipose tissue and induced adipocytes maturation and ectopic fat deposition. Exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCB 77) can cause endothelial cells activation and inflammation by inducing pro-inflammatory signaling pathways. In our studies, PCB 77 had cumulative effects in Angiotensin II - induced Abdominal Aortic Aneurysm (AAA) by exacerbating inflammation in and around the aortic wall. More, PCB 77 increased mortality in mice that developed AAA.
In order to appreciate the AhR involvement in inflammation we used a mouse model of Inflammatory Bowel Disease(IBD). Mice that had a reduced Ahr Receptor expression developed a less severe colitis and had a decreased general inflammatory status.
These data provide evidence that exposure to environmental toxicants could augment inflammation and contribute to the social burden of obesity and obesity related chronic inflammatory diseases.
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A Functional Role for Doscoidin Domain Receptor 1 (Ddr1) in the Regulation of Inflmmation and Fibrosis During Atherosclerotic Plaque DevelopmentFranco, Christopher 24 September 2009 (has links)
Collagens are abundant components of the extracellular matrix in the atherosclerotic plaque. In addition to contributing to lesion volume and mechanical stability, collagens can influence the behavior of macrophages and smooth muscle cells (SMCs) and have profound effects on both inflammation and fibrosis during lesion development. The aim of this thesis was to define a functional role for the discoidin domain receptor 1 (DDR1), a collagen receptor tyrosine kinase, in murine models of atherogenesis.
In our first study, using Ddr1+/+;Ldlr-/- and Ddr1-/-;Ldlr-/- mice fed a high fat diet, we identified DDR1 as a novel positive regulator of atherogenesis. Targeted deletion of DDR1 attenuated atherosclerotic plaque development by limiting inflammation and accelerating matrix accumulation and resulted in the formation of macrophage poor, matrix rich lesions.
In the second study, we used bone marrow transplantation to generate chimeric mice with a deficiency of DDR1 in bone marrow derived cells and reveal a central role for macrophage DDR1 in atherogenesis. Deficiency of DDR1 in bone marrow derived cells reduced lesion size by limiting macrophage accumulation in the developing plaque. Moreover using BrdU pulse labeling, we demonstrated reduced monocyte recruitment into the early fatty streak lesions of Ddr1-/-;Ldlr-/- mice.
In our third study, we again utilized bone marrow transplantation to generate mice with deficiency of DDR1 in the host derived tissues such as the vessel wall and uncovered a distinct role for DDR1 expressed on resident vessel wall smooth muscle cells in the regulation of matrix accumulation and fibrous cap formation during atherogenesis. Deficiency of DDR1 in vessel wall cells resulted in robust accumulation of collagen and elastin and resulted in the formation of larger atherosclerotic plaques, with thick fibrous caps.
Taken together, these studies support a critical role for DDR1 in the development of the atherosclerotic plaque. We demonstrate that DDR1 exerts distinct and opposing effects on lesion size by regulating both monocyte recruitment and matrix accumulation. These studies underscore the importance of collagen signaling during atherogenesis, and identify DDR1 as a key transducer; providing signals that regulate both inflammation and fibrosis during atherogenesis.
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Alternative Nf-kb Signaling in AtherogenesisDühring, Sarah 30 July 2014 (has links) (PDF)
Inflammatory processes mark all stages of atherogenesis. One of the key regulators of inflammation is the transcription factor nuclear factor kappa B (Nf-kb). Nf-kb is the general name for a whole family of dimeric transcription factors. One can distinguish between a classical and an alternative pathway with Rela/p50 (Nf-kb1) and Relb/p52 (Nf-kb2) representing the terminal transcription factors, respectively. Classical Nf-kb1 signaling has been associated with atherosclerotic lesion development many times, mainly because of its regulation of many pro-inflammatory proteins with an established role in atherogenesis. Recent studies provided evidence of crosstalk between classical Nf-kb1 and alternative Nf-kb2 signaling, implicating a potential role for Nf-kb2 in atherogenesis. The aim of the present study was to investigate the influence of Nf-kb2 on atherosclerotic lesion development in a knockout mouse model.
Nfkb2 knockout (Nfkb2-/-) mice were generated on two different atherosclerosis sensible backgrounds, the Apoe- and Ldlr- deficient background. Quantification of atherosclerotic lesion development showed, that Nfkb2-/- mice developed significantly more atherosclerosis at the brachiocephalic artery than wild type controls, indicating a protective effect of Nf-kb2 on atherogenesis. Further expression analyses in bone marrow-derived macrophages (BMDM) revealed highly significant upregulation of matrix metalloproteinase 9 (Mmp9) in Nfkb2-/- mice. Overexpression of Mmp9 was associated with enhanced macrophage migration across extracellular matrix in vitro and an inflammatory plaque phenotype with advanced, macrophage-rich lesions. Accordingly, increased Mmp9 expression in Nfkb2-/- macrophages might have contributed to enhanced lesion development in these mice.
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Carotid plaque vulnerability assessment by microscopic morphology analysis, ultrasound and 3D model reconstructionChoudhury, Ahsan Raza January 2012 (has links)
Research suggests that plaque morphology plays a crucial role in determining plaque vulnerability. However the relationship between plaque morphology and rupture is still not clearly understood due to the limited information of plaque morphology. The aim of this study is to improve our understanding of the relationship between plaque morphology and rupture, and to use this to predict the risk of plaque rupture from the morphology at the molecular level. This can enable the identification of culprit lesions in clinical situations for assessing plaque rupture risk. Histological assessments were carried out on 18 carotid plaque specimens. The 3-D collagen, lipid and macrophage distributions along the entire length of the plaque were analysed in both ruptured and non-ruptured symptomatic plaques. In addition, plaque morphology on the rupture sites were examined and compared with the surrounding regions. It was found that ruptured plaques had thinner fibrous caps and larger lipid cores compared to non-ruptured plaques. Also, ruptured plaques had lower collagen content compared to non-ruptured plaques, and higher collagen contents upstream compared to downstream region from the plaque throat. At the rupture site there was lower collagen content, and a larger lipid core thickness behind a thin fibrous cap compared with the mean for the longitudinally adjacent and circumferential regions. Macrophage cells were located nearer to the boundary of the luminal wall in ruptured plaques. For both groups, the area occupied by macrophages is greater at the upstream shoulder of the plaque. There is a positive correlation between macrophage area and lipid core area, a negative correlation between macrophage area and collagen content, and between lipid core size and collagen content for both plaque groups. 3D reconstruction of ex-vivo specimens of carotid plaques were carried out by a combined analysis of US imaging and histology. To reconstruct accurate 3D plaque morphology, the non-linear tissue distortion in histological images caused by specimen preparation was corrected by a finite element (FE) based deformable registration procedure. This study shows that it is possible to generate a 3D patient specific plaque model using this method. In addition, the study also quantitatively assesses the tissue distortion caused by histological procedures. It shows that at least 30% tissue shrinkage is expected for plaque tissues. The histology analysis result was also used to evaluate ultrasound (US) tissue characterization accuracy. An ex-vivo 2D ultrasound scan set-up was used to obtain serial transverse images through an atherosclerotic plaque. The different plaque component region obtained from ultrasound images was compared with the associated histology result and photograph of the sections. Plaque tissue characterisation using ex-vivo US can be performed qualitatively, whereas lipid core assessment from ultrasound scan can be semi-quantitative. This finding combined with the negative correlation between lipid core size and collagen content, suggests the ability of US to indirectly quantify plaque collagen content. This study may serve as a platform for future studies on improving ultrasound tissue characterization, and may also potentially be used in risk assessment of plaque rupture.
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Engineering a 3D ultrasound system for image-guided vascular modellingHammer, Steven James January 2009 (has links)
Atherosclerosis is often diagnosed using an ultrasound (US) examination in the carotid and femoral arteries and the abdominal aorta. A decision to operate requires two measures of disease severity: the degree of stenosis measured using B-mode US; and the blood flow patterns in the artery measured using spectral Doppler US. However other biomechanical factors such as wall shear stress (WSS) and areas of flow recirculation are also important in disease development and rupture. These are estimated using an image-guided modelling approach, where a three-dimensional computational mesh of the artery is simulated. To generate a patient-specific arterial 3D computational mesh, a 3D ultrasound (3DUS) system was developed. This system uses a standard clinical US scanner with an optical position sensor to measure the position of the transducer; a video capture card to record video images from the scanner; and a PC running Stradwin software to reconstruct 3DUS data. The system was characterised using an industry-standard set of calibration phantoms, giving a reconstruction accuracy of ± 0.17 mm with a 12MHz linear array transducer. Artery movements from pulsatile flow were reduced using a retrospective gating technique. The effect of pressure applied to the transducer moving and deforming the artery was reduced using an image-based rigid registration technique. The artery lumen found on each 3DUS image was segmented using a semi-automatic segmentation technique known as ShIRT (the Sheffield Image Registration Toolkit). Arterial scans from healthy volunteers and patients with diagnosed arterial disease were segmented using the technique. The accuracy of the semi-automatic technique was assessed by comparing it to manual segmentation of each artery using a set of segmentation metrics. The mean accuracy of the semi-automatic technique ranged from 85% to 99% and depended on the quality of the images and the complexity of the shape of the lumen. Patient-specific 3D computational artery meshes were created using ShIRT. An idealised mesh was created using key features of the segmented 3DUS scan. This was registered and deformed to the rest of the segmented dataset, producing a mesh that represents the shape of the artery. Meshes created using ShIRT were compared to meshes created using the Rhino solid modelling package. ShIRT produced smoother meshes; Rhino reproduced the shape of arterial disease more accurately. The use of 3DUS with image-guided modelling has the potential to be an effective tool in the diagnosis of atherosclerosis. Simulations using these data reflect in vivo studies of wall shear stress and recirculation in diseased arteries and are comparable with results in the literature created using MRI and other 3DUS systems.
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Innate immunity in human atherosclerosis and myocardial infarction : Role of CARD8 and NLRP3Paramel Varghese, Geena January 2017 (has links)
Atherosclerosis is complex inflammatory disease of the arterial wall with progressive accumulation of lipids and narrowing of the vessel. Increasing evidence suggest that inflammation plays an important role in plaque stability and often accelerate cardiovascular events such as myocardial infarction (MI). Among the vast number of inflammatory cytokines, IL-1β is known to be a key modulator in vessel wall inflammation and acceleration of the atherosclerotic process. The biologically active IL-1β is regulated by a multiprotein complex known as the NLRP3 inflammasome complex. In this thesis, we have focused on polymorphisms in the NLRP3 and CARD8 genes and their possible association to atherosclerosis and/or MI. We have also investigated the expression of inflammasome components NLRP3 and CARD8 in atherosclerosis and the role of genetic variants for the expression of these genes. The expression of NLRP3, CARD8, ASC, caspase-1, IL-1β, and IL-18 were found significantly upregulated in atherosclerotic lesions compared to normal arteries. Human carotid plaques not only express the NLRP3 inflammasome, but also release IL-1β upon exposure to lipopolysaccharide (LPS), adenosine triphosphate (ATP) and cholesterol crystals, which suggest NLRP3 inflammasome activation in human atherosclerotic lesions. Also, CARD8 was found to be important in the regulation of several inflammatory markers in endothelial cells, like RANTES, IP10 and ICAM-1. We further assessed the potential association of a CARD8 polymorphism and polymorphisms located downstream of the NLRP3 gene to the risk of MI in two independent Swedish cohorts. The CARD8 variant exhibited no association to risk of MI in either of the two cohorts. Some of the minor alleles of NLRP3 variants were associated with increased IL-1β levels and to NLRP3 mRNA levels in peripheral blood monocytic cells (PBMC). Taken together, the present thesis shows that NLRP3 inflammasome activation and increased expression of CARD8 in the atherosclerotic plaque might be possible contributors to the enhanced inflammatory response and leukocyte infiltration in the pathophysiology of atherosclerosis.
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CHANGES IN SERUM ICAM-1, SERUM VCAM-1, AND SERUM E-SELECTIN CONCENTRATION FOLLOWING PERIODONTAL SCALING AND ROOT PLANINGDiehl, Jeremy Howard 01 January 2007 (has links)
Cellular adhesion molecules (CAMs) and selectins are cell-surface proteins involved in the binding of cells to the vascular endothelium. Elevated levels of sCAMs and soluble E-selectin (sE-selectin) have been reported in patients with periodontitis. The aim of this study was to determine if periodontal scaling and root planing would influence the serum concentration of sICAM-1, sVCAM-1, and sE-selectin. Twenty-one subjects with chronic periodontitis received scaling and root planing in conjunction with blood serum sample analysis using enzyme-linked immunosorbent assay (ELISA), to determine if periodontal instrumentation results in changes in serum concentrations of sICAM-1, sVCAM-1, and sE-selectin. No change was observed in serum concentration of sICAM-1 or sVCAM-1. However, in a subset of 17 patients a statistically significant change in serum sE-selectin was observed (P < 0.05). This suggests that there is a decrease in endothelial activation following periodontal treatment.
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A multiscale study of magnetic nanovectors : application to USPIO contrast agents for MRI of atherotic inflammation in a murine model / Etude multi-échelle des nanovecteurs magnétiques : application pour des agents de contraste à vase d’oxyde de fer pour IRM de l’Inflammation athérotique dans un modèle animalMaraloiu, Valentin-Adrian 10 December 2010 (has links)
Dans le cadre du développement des nanotechnologies pour les sciences de la vie et de la santé, les nanovecteurs magnétiques connaissent un essor considérable. Ces structures composites constituées de sphères polymériques encapsulant des nanoparticules magnétiques ou d`un coeur nanoparticulaire magnétique entouré d`une couverture organique présentent une combinaison de propriétés physico-chimiques et magnétiques très performante pour le diagnostic en imageries par exemple, notamment Imagerie par Résonance Magnétique (IRM), ou la thérapie : vectorisation pharmaceutique ciblée, hyperthermie thérapeutique…L`obtention de tels vecteurs avec une taille nanométrique permet l`injection intraveineuse chez les patients et la propagation dans l`organisme, tout en augmentant l`action liée à la surface spécifique. Les présents travaux de doctorat ont porté sur deux familles importantes de nanovecteurs magnétiques : - des nanosphères de polymère biocompatible chargé en composé radioactivable et encapsulant des nanoparticules de magnétite, pour la thérapie tumorale - des agents de contraste pour l`IRM de l`inflammation vasculaire ou cérébrale chez la souris, constituée d`un coeur nanoparticulaire d`oxyde de fer (maghémite ou magnétite) entourée d`une enveloppe organique pour le ciblage de la région visée (ultrasmall superparamagnetic iron oxide – USPIO, en anglais) Pour cerner le comportement de ces nanovecteurs en interaction avec le milieu liquide de suspension, puis avec les régions ciblées dans l`organisme, une approche physique multiéchelle de leurs structure et propriétés a été développée. Les études structurales des nanovecteurs ont été menées à bien grâce à des développements innovants s`appuyant sur les microscopies électroniques à résolution nanométrique. Par l`application du mode Wet-STEM, un nouveau mode en transmission de microscopie électronique à balayage environnementale, l`image en transmission de la structure interne organique/nanoparticule(s) magnétiques(s) a été obtenue et les simulations d`images par méthode de Monte Carlo ont montré qu`une résolution nanométrique pouvait être obtenue. Pour les nanovecteurs en environnement tissulaire, on a utilisé la microscopie électronique en transmission (MET) pour laquelle on a fait varier le degré de coloration dans des préparations de tissus ex vivo inclus en résine ; on a ainsi obtenu les premières images MET en haute résolution (METHR) spatiale d`agents de contraste USPIO cristallisés dans les tissus de l`aorte ou la rate chez la souris athérotique. En combinant ces études structurales avec la mesure des propriétés magnétiques par SQUID, un suivi longitudinal d`agents USPIO injectés chez la souris pour l`IRM de la plaque d`athérome a été menée à bien dans l`aorte et la rate : les résultats ont été interprétés en terme d`agglomération de particules à taille variable en fonction du temps de séjour dans l`organisme et confrontés à un modèle in vitro de dégradation en milieu acide (métabolisme lysosomal). / As applications of nanotechnologies for life and health sciences get booming, magnetic nanovectors undergo a considerable development. Such composite structures made from polymer spheres encapsulating magnetic nanoparticles or from a nanoparticular magnetic core surrounded by an organic coverage exhibit a combination of physical, chemical and magnetic properties very appropriate for diagnostic by imaging such as Magnetic Resonance Imaging (MRI), or for therapy: targeted pharmaceutical vectorization, therapeutic hyperthermia... When such vectors exhibit a nanometric size, intravenous injection and easy spread in the body of the patients are allowed, while effects related to the specific surface area are increased. The present doctoral work was concerned by two important families of magnetic nanovectors: - nanospheres of biocompatible polymer having loaded a radioactivable compound for tumoral therapy and having encapsulated magnetite nanoparticles for diagnostic by MRI: a system for thera-diagnostic is thus obtained.- contrast agents for MRI of vascular or cerebral inflammation, consisting of a nanometric iron oxide (maghemite or magnetite) core i.e. ultrasmall superparamagnetic iron oxide – USPIO - surrounded by an organic coverage for targeting the affected region. These USPIO were used to study inflammation in the atherotic plaque of the aorta in a murine model.Most of the time, such nanovectors are administered to the patients in liquid suspensions by intravenous injection. It is thus crucial to characterize both the collective behaviour and the individual structure of the vectors in liquid suspension. On the other hand their interactions with the targeted regions in the body have to be understood. For this purposes, a multiscale approach of the structure and properties of such nanovectors has been developed, with structural studies carried out through innovative developments based on electron microscopies down to subnanometric resolution and correlated with physical properties. To achieve characterization of nanovectors in liquid media we have developed the application of Wet-STEM, a new mode in transmission of environmental scanning electron microscopy (ESEM), to image the internal structure of the magnetic nanoparticles in liquid suspension and image calculations by Monte Carlo simulations have shown that a nanometric resolution could be theoretically achieved. By the same technique, stability or tendency to flocculation in suspensions can be evidenced with respect to the collective behavior of different nanovectors.In a second step we have investigated the interactions of the nanoparticles with targeted regions. The biodistribution and biotransformation of the USPIO contrast agents in the tissular and cellular environments were investigated at increasing spatial resolution using different techniques. The biodistribution of a MRI contrast agent grafted with a fluorophore, in ex vivo samples from atherotic aorta and spleen were revealed by biphoton microscopy with a resolution of a few hundred nanometers, down to macrophage scale. Then preparation of ex vivo samples for transmission electron microscopy (TEM) was adapted from standard protocols especially with respect to staining after inclusion in resin. This way, the first high resolution HR(TEM) images and electron diffraction patterns of crystallized USPIO contrast agents in the aorta or the spleen of an atheromatous mouse were obtained. Combining such structural studies with measurement (using a SQUID setup) of magnetic properties, a longitudinal follow-up of USPIO nanoparticles injected in mice for MRI of the atherotic plaque has been completed for USPIO particles embedded in the aorta and the spleen: the results were interpreted in terms of agglomeration of the particles with a decreasing size depending on time after injection and found consistent with a model of in vitro degradation in acidic environment proposed to mimick the lysosomal metabolism.
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Effets et recherche de mécanismes d'action d'un extrait de sarments de vigne et de vins rouges riches en resvératrol et ses oligomères : Quel rôle dans la prévention des maladies cardio-vasculaires ? / Effects and mechanisms of action of a vine-shoot extract and red wines rich in resveratrol and its oligomers : What role in the prevention of cardiovascular disease?Romain, Cindy 04 December 2013 (has links)
Les maladies cardiovasculaires (MCV) sont en augmentation au niveau mondial et sont désormais un problème de santé publique coûteux. La suralimentation et le manque d'activité physique sont des facteurs clé dans le développement pathologique. Ces dernières années, les études sur la pathogenèse des MCV ont mis en évidence de nombreux facteurs contribuant au développement de ces pathologies complexes, notamment le surpoids, l'obésité centrale, le stress oxydant, l'inflammation vasculaire et systémique, la résistance à l'insuline ou encore la dysfonction endothéliale. La prévention de ces désordres est donc la cible des stratégies pharmaceutiques et diététiques et les polyphénols ont d'ores et déjà démontré des effets bénéfiques et préventifs. Parmi les 8000 composés phénoliques décrits à ce jour, le resvératrol a émergé en tant que candidat robuste dans la prévention des pathologies liées à la nutrition. L'objectif de ce travail a été d'étudier les potentialités d'action d'un extrait de sarment de vigne (Vineatrol®) et de vins rouges riches en resvératrol et ses oligomères, sur un modèle animal d'athérosclérose nutritionnellement induite. La première partie de cette étude a consisté à mettre au point un régime alimentaire déclenchant au mieux l'athérosclérose précoce chez le hamster Syrien doré. A partir de ce modèle, un effet préventif du Vineatrol® a été mis en évidence : le Vineatrol® induit une diminution des dépôts lipidiques aortiques mais améliore également le statut oxydatif et inflammatoire des animaux. Dans une troisième partie, des vins rouges enrichis en Vineatrol® ont démontré des effets préventifs sur certains facteurs de risque de la pathologie athéromateuse et sur les désordres liés à la consommation d'un régime gras. Des mécanismes d'action possibles, expliquant les effets bénéfiques de ces vins, ont été envisagés et recherchés. Ces mécanismes pourraient impliquer une modulation de la voie du NF-κB et/ou de SIRT1. Le degré d'importance de ces différentes voies devra être confirmé. / Cardiovascular diseases (CVD) are increasing globally and are now an expensive public health problem. Overnutrition and lack of physical activity are key factors in the disease development. In recent years, studies on the pathogenesis of CVD showed many factors contributing to the development of these complex diseases including overweight, centralobesity, oxidative stress, vascular and systemic inflammation, insulin ressitance or endothelial dysfunction. Prevention of these disorders is the focus of pharmaceutical and dietarystrategies and polyphenols have already demonstrated beneficial and preventive effects. Among the 8000 phenolic compounds described to date, resveratrol has emerged as a strong candidate for the prevention of nutrition-related diseases.The objective of this work was to study the potential action of vine shoot extract (Vineatrol®) and red wines rich in resveratrol and its oligomers, in an animal model of nutritionallyinduced atherosclerosis.The first part of this study was to develop a diet triggering the best early atherosclerosis in theSyrian golden hamster. From this model, a preventive effect of Vineatrol® was highlighted: Vineatrol® induces adecrease in aortic lipid deposition but also improves the oxidative and inflammatory status of the animals. In the third part , Vineatrol®-enriched red wines showed preventive effects on risk factors foratherosclerotic disease and disorders related to the consumption of a high-fat diet. Possible mechanisms of action, explaining the beneficial effects of these wines have been consideredand sough. These mechanisms could involve modulation of the NF-κB and/or SIRT1pathways. The degree of importance of these different pathways will have to be confirmed.
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