Les accidents vasculaires cérébraux sont la première cause mondiale d'handicap et l'athérosclérose en est le principal facteur. Cette pathologie, liée à une mauvaise prise en charge du cholestérol pourra avoir des conséquences plus pernicieuses comme la fragilisation des unités cérébrovasculaires qui, combinée à une inflammation systémique et locale, peut entraîner d'importantes répercussions cérébrales.Pour être au plus proche de l'humain nous avons utilisé des modèles animaux murins et primate non-humain (PNH) âgés sous régime gras. Une approche translationnelle avec suivi longitudinal de biomarqueurs sanguins et d'imagerie combinée à la caractérisation tissulaire de l'inflammation a été effectuée pour tenter d'élucider les spécificités de la réponse inflammatoire dans la paroi vasculaire des grosses artères et le tissu cérébral.Nous avons montré que chez des souris ApoE-/- âgées l'exercice physique peut contrecarrer les effets délétères d'un régime gras lorsque l'apport calorique est contrôlé mais plus lorsqu'il ne l'est pas. La dégradation de la barrière hémato-encéphalique pourrait expliquer l'inflammation observée in vivo et confirmée par l'analyse tissulaire. L'étude des PNH a montré l'intérêt d'associer imagerie multimodale et dosages sanguins dans la stratification du risque cardiovasculaire ainsi que l'importance d'associer des marqueurs métaboliques, inflammatoires et anti-inflammatoires.Nous avons montré l'intérêt de contrôler les apports caloriques pour bénéficier des effets protecteurs de l'exercice sur l'athérosclérose et l'importance d'avoir une vue globale du patient pour une stratification individuelle précise du risque cardio et cérébrovasculaire / Stroke is the leading cause of disabilities worldwide and is mainly caused by atherosclerosis. But this is not the only risk for patients. Indeed, as this pathology is due to a lack of circulating cholesterol management and could lead to more pernicious outcomes such as cerebrovascular units disorganization whom, when combined with systemic and local inflammation can result in serious brain aftermath.Aged murine and non-human primate (NHP) animal models under high cholesterol diet were used to be closest to the human pathology. A translational approach with longitudinal follow-up of circulating and imaging biomarkers combined with a tissular characterization of inflammation was performed in order to elucidate the specificities of the inflammatory response in vascular wall of large vessels and brain tissue.We showed that in old ApoE-/- mice exercise can counterbalance deleterious effects of high fat diet when caloric intake is controlled but no longer when food is given ad libitum. The leakage of blood-brain barrier might explain the neuroinflammation observed in vivo and confirmed by tissular analysis. The study on NHP showed the interest of combine multimodal imaging with blood dosage for cardiovascular risk stratification and the importance of associating metabolic, inflammatory but also anti-inflammatory markers.We highlighted the importance of controlling calories intake in order to benefit of protective effects of exercise on atherosclerosis and the relevance of having an overview of the patient’s status for an accurate individual stratification of cardio and cerebrovascular risk

Les macrophages jouent un rôle clé dans l'athérosclérose. Après la captation massive des LDL oxydées (oxLDL), les macrophages sous-endothéliaux sont chargés en cholestérol et se transforment ainsi en cellules spumeuses qui contribuent à la formation de la plaque d'athérome. Les oxystérols, produits d'oxydation du cholestérol, sont retrouvés en quantité importante dans les oxLDL. Au niveau cellulaire, ils sont impliqués dans la régulation de l'homéostasie du cholestérol, l'induction du stress oxydatif cellulaire et de la cytotoxicité. Notre travail montre que le cholestérol, associé aux LDL et d'origine cellulaire, est fortement oxydé par les macrophages lors d'une exposition aux oxLDL. Les principaux produits d'oxydation sont le 7-cétocholesterol et 7α/β-hydroxycholestérol. De plus, nous démontrons que ces oxystérols sont exportés hors des macrophages via les HDL, mais pas l'apoA1. Nous avons aussi caractérisé les oxystérols formés dans les HDL suite à des modifications oxydatives et les HDL issues de patients diabétiques. Nous avons en outre montré que ces modifications sont associées à une diminution de la capacité des HDL à exporter les oxystérols. / Macrophages play a key role in atherosclerosis. After massive uptake of oxidized LDL (oxLDL), subendothelial macrophages are overloaded with cholesterol thereby leading to the formation of foam cells, which is one characteristic of atherogenesis. Oxysterols, the oxidation products of cholesterol, are one of major components of oxLDL; they are involved in the regulation of cholesterol homeostasis, induction of cellular oxidative stress and cytotoxicity. Our works show that both LDL derived-cholesterol and cellular cholesterol can be strongly oxidized in human THP1 and murine RAW macrophages, especially during exposure of oxLDL. The major oxidative products are 7-ketocholesterol and 7α/β-hydroxycholesterol. Moreover, we demonstrate that both oxysterols derived from LDL cholesterol and cellular cholesterol can be exported to HDL, whereas not to apoA1. Then, we studied the functionality of modified HDL and diabetic HDL on oxysterols efflux. A decrease of oxysterols efflux was observed with oxidized and glycoxidized HDL. Compared to the HDL of healthy controls, the HDL of diabetic subjects are less efficient to efflux oxysterols. Taken together, the increased production of oxysterols in presence of oxLDL and their lower efflux by modified HDL support the detrimental role of these oxidative compounds in pathophysiological conditions like diabetes.

L'athérosclérose est une maladie inflammatoire qui commence quand les lipoprotéines de faible densité (LDL) entrent dans l'intima du vaisseau sanguin où elles sont oxydées (ox-LDL). Le ox-LDL est considéré comme un agent dangereux par le système immunitaire provoquant ainsi une réponse immunitaire. Cette réponse immunitaire déclenche le recrutement des monocytes dans l'intima où elles se transforment en macrophages et ensuite en cellules spumeuses. Ce dernier amplifie la production des cytokines inflammatoires et davantage de recrutement des monocytes. Ce processus auto-amplifié est compensé par la sécrétion de cytokines anti-inflammatoires (anti-inflammation biochimique) et la migration des cellules musculaires lisses pour former une chape fibreuse qui couvre le noyau lipidique. Cette chape fibreuse avec le noyau lipidique s'appellent la plaque d'athérosclérose. Celle-ci change la géométrie du vaisseau sanguin en le rétrécissant et interagit avec du flux sanguin. Cette interaction peut avoir des conséquences dangereuses liées à la rupture de plaque ou à la formation du caillot de sang. La thèse est consacrée à la modélisation mathématique de ces phénomènes. Elle est composée de deux parties : Nous développons des modèles mathématiques basés sur des équations de réaction diffusion afin de décrire le processus inflammatoire. Le premier modèle est unidimensionnel. Il nous permet d'expliquer comment le développement de l'athérosclérose dépend de la concentration en cholestérol (ox-LDL). Si cette concentration dans l'intima est basse, alors la maladie ne se développera pas. Les concentrations intermédiaires de ox-LDL peuvent mener au développement de la maladie dans certaines conditions. Nous montrons que l'inflammation se propage en front d'ondes de réaction-diffusion. Les concentrations élevées de ox-LDL engendre le développement de la maladie. Même une petite perturbation du cas non inflammatoire mène à une propagation d'ondes qui correspond à l'inflammation. Ensuite nous étudions un modèle bidimensionnel qui représente un système d'équations type réaction-diffusion sur une bande. La deuxième dimension correspond à la section transversale de l'intima et une condition aux limites non-linéaire décrit le recrutement des monocytes. Cette condition aux limites est une fonction des concentrations des cytokines. Nous démontrons l'existence des fronts de propagation d'onde et confirmons les résultats précédents qui montrent que l'athérosclérose se développe en tant qu'onde de réaction-diffusion. Les résultats théoriques des deux modèles sont confirmés par des simulations numériques qui montrent que le cas bidimensionnel converge vers le cas unidimensionnel quand l'épaisseur de l'intima tend vers zéro. Une fois la plaque se forme, elle interagit avec le flux sanguin engendrant de différentes conséquences mécaniques et biochimiques. Nous développons un modèle d'interaction fluide-structure. La plaque d'athérome composée d'un dépôt lipidique couvert par une chape fibreuse, les deux étant modélisés en tant que matériaux hyper-élastiques. Le sang est considéré comme un fluide non-Newtonien avec une viscosité variable modélisée selon la loi de Carreau. Les paramètres utilisés dans nos simulations sont tirés de données expérimentales mentionnées dans la littérature. Nous étudions les effets non-Newtoniens sur les recirculations du sang en aval de la plaque d'athérome et aussi sur les contraintes sur celle-ci. Les simulations montrent que le modèle Newtonien surestime les recirculations de manière significative par rapport au modèle non-Newtonien. Elles montrent aussi que le modèle Newtonien sous-estime légèrement les contraintes sur la plaque pour des taux de cisaillement usuels, mais cette sous-estimation devient importante pour des taux de cisaillement bas. / Atherosclerosis is an inflammatory disease which starts when low density lipoproteins (LDL) enter the intima of blood vessel where they are oxidized (ox-LDL). The ox-LDL is considered as a dangerous agent by the immune system provoking an anti-inflammatory response. This immune response triggers the recruitment of monocytes into the intima where they differentiate into macrophages and foam cells. The latter amplifies the production of inflammatory cytokines and further recruitment of monocytes. This auto-amplified process is compensated by the secretion of anti-inflammatory cytokines (biochemical anti-inflammation) and triggers the migration of smooth muscle cells to form a fibrous cap that covers the lipid core. These fibrous caps with the lipid core are called atherosclerosis plaque. It changes the geometry of the blood vessel by narrowing it and interacts with the blood flow. This interaction may have dangerous consequences related to the plaque rupture or to the formation of blood clot. The PhD thesis is devoted to mathematical modelling of these phenomena. It consists of two major parts : We develop mathematical models based on reaction-diffusion equations in order to describe the inflammatory process. The first model is one-dimensional. It allows us to explain how the development of atherosclerosis depends on the cholesterol (ox-LDL) concentration. If its concentration in the intima is low, then the disease will not develop. Intermediate ox-LDL concentrations can lead to the disease development under certain conditions. We show that the inflammation propagates as a reaction-diffusion wave. High ox-LDL concentrations will necessary result in the disease development. Even a small perturbation of the non inflammatory case leads to a travelling wave propagation which corresponds to a chronic inflammatory response. We then study a two-dimensional model which represents a reaction-diffusion system in a strip. The second dimension corresponds to the cross-section of the intima, nonlinear boundary conditions describe the recruitment of monocytes as a function of the cytokines concentration. We prove the existence of travelling waves and confirm our previous results which show that atherosclerosis develops as a reaction-diffusion wave. The theoretical results of the two models are confirmed by numerical simulations that show that the two-dimensional model converge to the one-dimensional one if the thickness of the intima tends to zero. When the plaque is formed, it interacts with blood flow resulting in various mechanical and bio-chemical effects. We develop a fluid-structure interaction model. The atheroma plaque is composed of a lipid pool and a fibrous cap and both are modeled as hyper elastic materials. The blood is supposed to be a non-Newtonian fluid with a variable viscosity modeled by the Carreau law. The parameters used in our simulations are taken from experimental data found in literature. We investigate the non-Newtonian effects on the re circulations downstream of the atheroma plaque and on the stress over the plaque. The simulations show that the Newtonian model significantly overestimates the re circulations in comparison with the non-Newtonian model. They also show that the Newtonian model slightly underestimates the stress over the plaque for usual shear rates, but this underestimation can become significant for low shear rates.

A partir des données de 2 études de population menées chez des sujets âgés, non institutionnalisés, respectivement l’étude des 3 Cités et l’étude EVA (Epidémiologie du Vieillissement Artériel), nos objectifs étaient 1) de revisiter le rôle de l’athérosclérose carotidienne dans son association avec les évènements coronaires et avec les démences, en dissociant précisément l’athérome (i.e. les plaques carotidiennes ; PC) de l’hypertrophie artérielle (i.e. l’épaississement diffus de l’intima-média mesuré au niveau de l’artère carotide commune ; EIM-ACC) et 2) dans un objectif plus mécanistique, d’analyser le lien différentiel entre l’athérome, l’hypertrophie artérielle et l’un des polymorphismes nucléotidiques (rs1333049) les plus associés à la maladie coronaire et situé sur le chromosome 9 (locus 9p21).Dans un 1er travail, nous avons montré que les PC étaient associées à une augmentation du risque d’évènement coronaire à 6 ans, à l’inverse de l’EIM-ACC qui n’était pas associée au risque coronaire. De plus l’ajout des PC à un modèle comprenant les FDRCV améliorait significativement la prédiction du risque coronaire avec près de 12% des sujets correctement reclassés en terme de risque prédit (NRI = 11,7% ; IC95% = 3,1%-20,0%). Dans la seconde analyse (3C et EVA), nous avons mis en évidence une association spécifique entre les PC et le polymorphisme nucléotidique rs1333049 (OR allèle C = 1,24 ; IC 95% = 1,13-1,36). Chez les sujets de la cohorte EVA, l’allèle C était également associé à la progression des plaques carotidiennes à 4 ans, mais pas à la progression de l’EIM. Dans le dernier volet de cette thèse et de manière similaire aux évènements coronaires, il existait une association spécifiques entre les PC et la survenue de démences vasculaires/mixtes à 7 ans (HR ≥ 2 sites avec plaques vs. 0 = 1,93 ; IC 95% = 1,13-3,28). Aucune association n’était retrouvée avec l’EIM. L’ajout des plaques carotidiennes à un modèle comprenant les FDR CV et de démence permettait de reclasser correctement 43% des sujets en terme de risque de DVasc (NRI=43,0% ; IC95% = 20,2-66,2). Enfin, dans le cadre de cette thèse, nous participons à un travail collaboratif portant sur la progression individuelle de l’EIM au cours du temps en association avec la survenue d’évènements cardiovasculaires. Les données de EVA ont été intégrées à ce projet. Un premier résultat de cette méta-analyse était que la progression annuelle de l’EIM-ACC n’était associée à aucun des évènements cardiovasculaires étudiés. Au total, les résultats de cette thèse indiquent la présence d’une association différentielle des plaques carotidiennes et de l’EIM-ACC avec les évènements coronaires et les démences. Les implications sur le plan de la prévention et en termes de cibles thérapeutiques potentielles sont discutées dans cette thèse. / Using data from 2 large French cohorts of non-institutionalized older adults, namely the Three-City Study (3C) and the Vascular Aging Study (EVA), we aimed 1) to explore the respective contribution of ultrasound detected carotid plaques (e.g. atherosclerosis) and diffuse common carotid intima-media thickness (CCA-IMT) (e.g. arteriosclerosis) to incident coronary events and dementia and 2) to assess the differential relationship between carotid plaques, CCA-IMT and the coronary heart disease (CHD)-associated single polymorphism nucleotide (rs1333049) on chromosome 9p21. First, we showed that carotid plaques but not CCA-IMT were associated with an increased risk of 6-year CHD. Furthermore, carotid plaques significantly improved CHD risk prediction beyond traditional CV risk factors, as nearly 12% of the participants were correctly reclassified in terms of predicted risk(Net Reclassification Improvement (NRI) = 11.7%; 95% CI = 3.1%-20.0%). In our second analysis, including subjects from both 3C and EVA, we found a specific association between carotid plaques and the rs1333049 genotype (OR C allele at risk= 1.24; 95% CI = 1.13-1.36). Moreover, among the EVA participants, the rs1333049 genotype was also associated with carotid plaques progression over 4 years, but not with CCA-IMT progression. Thirdly, we showed a specific relationship between carotid plaques and the occurrence of 7-year vascular/mixed dementia (VaD) (HR ≥ 2 sites with plaques vs. 0 = 1.93; 95% CI = 1.13-3.28). No relationship was found for CCA-IMT. Furthermore, adding carotid plaques to a model including vascular and dementia risk factors resulted in a significant continuous NRI of 43.0% (95% CI = 20.2%-66.2%) for VaD. At last, in line with the present work, we currently participate through the EVA Study to a collaborative project on the relationship between individual IMT progression over time and cardiovascular risk. A first result recently published, showed the absence of relationship between yearly IMT progression and cardiovascular events. In summary, the present work indicates that carotid plaques and CCA-IMT are differentially associated with coronary events and vascular/mixed dementia. Potential implications of our results regarding primary prevention and therapeutic targets are discussed in this thesis.

Proprotein convertase subtilisin / kexin type 9 (PCSK9) is a negative regulator of the low-density lipoprotein receptor, and PCSK9 inhibition has become an important cholesterol-lowering therapeutic strategy. PCSK9 also associates with LDL particles, and evidence suggests that the activity of PCSK9 may be regulated by LDL binding. We have investigated the biochemistry of the interaction between PCSK9 and lipoproteins. Through mutagenesis and in-vitro binding assays, we found conserved motifs in the PCSK9 N-terminus that play a role in LDL binding. Through secondary structure studies using circular dichroism and computational modelling, we determined that the N-terminal region of the PCSK9 prodomain undergoes an environment-dependent structural shift that affects the ability of PCSK9 to bind LDL. We also found that the commonly found loss-of-function polymorphism R46L is capable of modulating this structural shift. Importantly, we found a surface-exposed region of the PCSK9 prodomain that maps a cluster of gain-of-function mutations (L108R, S127R, and D129G) that severely disrupt LDL binding. Through gel shift assays and density gradient centrifugation, we observed that PCSK9 shows remodeling-dependent ability to bind different classes of lipoprotein particles in vitro, binding strongly to LDL and IDL but showing barely detectable association to VLDL. Further, in human plasma, we found that lipoprotein-bound populations of PCSK9 shifted in response to differences in lipoprotein profiles between normolipidemic and hypercholesterolemic or hypertriglyceridemic subjects. Overall, elucidation of how lipoproteins regulate PCSK9 activity will reveal new targets for designing cholesterol-lowering therapeutics.

Introdução: As doenças cerebrovasculares são consideradas atualmente a segunda principal causa de óbito no mundo e a terceira causa de anos de vida perdidos por mortalidade1,2. A aterosclerose de grandes artérias é uma das principais condições subjacentes associadas ao AVC isquêmico (AVCi) e correlaciona-se com maiores taxas de recorrência. A detecção e a estratificação da estenose extracraniana podem ser feitas através do Doppler, da angiotomografia computadorizada (ATC), da angiorressonância magnética (ARM) e da angiografia intra-arterial digital (AIA), sendo esta última considerada o método padrão-ouro. Objetivo: Avaliar a acurácia diagnóstica e a concordância entre os métodos de ATC, ARM com contraste (AM CC) e AIA na análise da estenose extracraniana. Determinar a frequência e caracterizar a estenose extracraniana em população brasileira sintomática. Metodologia: Foram avaliados retrospectivamente os exames AIA, ATC e ARM, de pacientes adultos sintomáticos admitidos na Unidade de Emergência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto (UE HCFMRP) no período 03/2014-03/2015, para detecção e estratificação da estenose extracraniana. Foram coletados ainda dados demográficos, clínicos e laboratoriais desses pacientes. Resultados: Observou-se alta acurácia da ATC e da ARM na avaliação de segmentos carotídeos, com sensibilidade de 100% e especificidade variando entre 78% e 100% para estenoses >=50%. Para segmentos vertebrais, observou-se menor acurácia dos métodos, sobretudo da ARM, com valores de sensibilidade e especificidade variando entre 60%-85% e 33-62%, respectivamente, para estenoses >=50%. A prevalência de estenose extracraniana >=50% em nossa população foi de 38,6% e de 23,4% para estenoses >=70%. O segmento vascular mais acometido foi a origem das artérias vertebrais. Os fatores de risco associados a estenose extracraniana foram: sexo masculino, idade avançada, tabagismo e elevada pressão arterial sistólica na admissão. Conclusão: A ATC e ARM representam métodos adequados para investigação de estenoses extracranianas, sobretudo carotídeas. Ambos os métodos, sobretudo a ARM, têm acurácia limitada na avaliação dos óstios vertebrais. / Introduction: Cerebrovascular diseases are considered the second cause of death worldwide and the third cause of years of life lost (YLL)1,2. Large arteries atherosclerosis is one of the main conditions associated with stroke and correlates with higher recurrence rates. Imaging methods such as Doppler, computed tomography angiography (CTA), magnetic resonance angiography (MRA) and intra-arterial angiography (IAA) are available for extra cranial vascular study. Intra-arterial angiography remains the gold standard. Objectives: Evaluate diagnostic accuracy and concordance between CTA, MRA (contrast enhanced) and IAA for extracranial stenosis analysis. Determine frequency and distribution of extra cranial stenosis in a brazilian symptomatic population. Methods: IAA, CTA and MRA exams from adult symptomatic patients admitted between 03/2014 and 03/3015 at the Emergency Unit of Clinics Hospital of Ribeirão Preto\'s School of Medicine were retrospectively reviewed for detection and grading of extra cranial stenosis. Clinical and laboratorial information from patients was obtained. Results: Both CTA and MRA showed high sensitivity (100%) and specificity (78%-100%) in the evaluation of carotid vessels for stenosis >=50%. However, lower sensitivity (60-85%) and specificity (33-62%) were obtained for vertebral segments, Extra cranial stenosis prevalence was 38,6% for stenosis >=50% and 23,4% for stenosis >=70% among our patients. Vertebral artery origins were the most affected segments. Risk factors identified for extra cranial stenosis were: male gender, age, smoking and high systolic blood pressure on admission. Conclusions: CTA and MRA are considered adequate methods for extra cranial stenosis, specially for carotid segments. Both methods have lower accuracy in the investigation of vertebral artery origins.

A aterosclerose é classificada como enfermidade crônica não transmissível e é considerada uma das principais causas de morte e morbidade em vários países, incluindo o Brasil. Entre as possíveis causas de sua gênese está o hábito alimentar, especificamente o consumo de ácidos graxos, principalmente saturados e trans. Ácidos graxos saturados possuem características biológicas e fisico-químicas diferentes dos insaturados. Os mais abundantes na dieta humana são o palmítico e esteárico. Sua associação com acometimentos cardiovasculares vem sendo cada vez mais investigada, principalmente os que possuem mais de dez carbonos em sua cadeia interferindo no metabolismo de lipoproteínas podendo desencadear todo o processo aterosclerótico. A indústria de alimentos vem desenvolvendo algumas tecnologias opcionais para reduzir ou eliminar ácidos graxos trans, em especial, o elaídico, dentre elas a modificação no processo de hidrogenação que aumenta a quantidade de ácidos graxos saturados. Alguns alimentos industrializados necessitam de uma grande quantidade de ácidos graxos saturados promovendo um aumento no teor de ácido palmítico e esteárico, sendo este último considerado um ácido graxo saturado neutro, mas dependendo da concentração utilizada, pode contribuir no decréscimo da HDL-c (High Density Lipoprotein), dentre outras alterações deletérias. Desta forma, investigar as alterações de determinados parâmetros biológicos diante da mudança da proporção de ácidos graxos saturados, respeitando o teor total de lipídios de uma dieta é a base deste estudo. Foram realizados ensaios em material biológico para a determinação dos seguintes parâmetros: 1) Atividade de enzimas antioxidantes; 2) Peroxidação lipídica em tecidos; 3) Lipidograma; 4) Determinação do perfil de ácidos graxos de tecidos e rações e 5) Expressão de genes relacionados com o processo aterosclerótico (ICAM-1, VCAM-1, CD36 e MCP-1). A determinação da atividade de enzimas antioxidantes foi realizada considerando somente as enzimas Catalase (CAT) e Superóxido Dismutase (SOD), por se tratarem de enzimas com alteração expressiva no processo aterogênico, na ocorrência de disfunção endotelial. Neste trabalho, foi analisada a atividade das referidas enzimas no tecido hepático e cardíaco, onde não foram constatadas alterações. O mesmo processo biológico que estimula a produção excessiva de espécies reativas pode levar ao aumento da peroxidação lipídica, principalmente de ácidos graxos polinsaturados das membranas celulares, em tecidos como fígado, cérebro e coração. A peroxidação lipídica apresentou diferenças significativas no tecido hepático. O grupo alimentado com ração enriquecida com tripalmitato apresentou peroxidação lipídica aumentada em relação ao grupo controle. Correlacionando com o perfil de ácidos graxos do tecido hepático, notamos que houve maior incorporação de ácido palmítico nesse tecido, que por apresentar configuração linear, quando incorporado à membrana celular, pode levar à disfunção e possível suscetibilidade a danos, como a peroxidação. No tecido cardíaco e no tecido cerebral não foram observadas alterações e diferenças entre os tratamentos. O lipidograma consiste na quantificação de lipoproteínas e frações lipídicas, compondo o perfil lipídico no plasma sanguíneo. Os resultados obtidos mostraram que o colesterol total foi significativamente menor no grupo controle, assim como triacilglicerol e LDL colesterol (LDL-c). Já HDL colesterol (HDL-c) está reduzida no grupo que recebeu ração suplementada com ácido palmítico, assim como este grupo apresentou parâmetros aumentados nas dosagens de triacilglicerol e colesterol total. Os grupos alimentados com ração suplementada com triestearato e trioleato apresentaram resultados intermediários para a dosagem de HDL-c, com valores tendendo ao grupo suplementado com tripalmitato. Em relação à dosagem de LDL-c, foi constatada diferença entre os grupos suplementados e o grupo controle. Destaca-se que não houve diferença entre a dosagem entre os grupos suplementados. Portanto, o grupo alimentado com dieta enriquecida com ácido oleico (monoinsaturado) equipara-se aos grupos alimentados com dietas enriquecidas com ácido esteárico e palmítico (saturados). O perfil de ácidos graxos do tecido hepático mostrou uma porcentagem elevada de ácido palmítico no grupo alimentado com ração enriquecida com o mesmo ácido graxo, com diferença estatística em relação aos demais grupos. Já em relação ao ácido esteárico, não houve diferenças significativas entre os grupos. Em compensação, o teor de ácido oleico no grupo suplementado com este mesmo ácido graxo e com ácido palmítico foi significativamente diferente em relação aos demais, com valores superiores. Este resultado demonstra que não houve dessaturação do ácido esteárico a oleico, ao menos neste modelo. No tecido cardíaco, foi observado o mesmo comportamento. No tecido cardíaco não houve diferença estatística significativa da concentração de ácidos graxos, indicando que não houve incorporação ou dessaturação. Ressalta-se que de acordo com determinação realizada utilizando a técnica de cromatografia gasosa, as rações apresentavam em sua composição o teor de lipídios adequado ao modelo animal e as proporções de ácidos graxos alteradas como proposto no objetivo deste trabalho. Em relação às moléculas de adesão e quimiocinas (VCAM-1, ICAM-1, CD-36 e MCP-1) relacionadas com o processo aterosclerótico, houve somente alteração na molécula CD-36 no grupo alimentado com ração enriquecida com trioleato, com redução em relação aos demais. Mas, as moléculas de adesão relacionadas com o processo inicial da aterogênese, a expressão gênica realizada através da técnica de q-RT-PCR não foi relevante, não apresentando diferença entre os tratamentos. Conclui-se, portanto, que os tratamentos aplicados ao modelo animal selecionado possui o potencial de alterar lipoproteínas plasmáticas, mas não de manter a continuidade e desencadear o processo inflamatório relacionado à aterogênese. / Atherosclerosis is chronic a non-communicable disease considered one of a major cause of morbidity and mortality in several countries, including Brazil. Among all the possible causes of their genesis the dietary habit of high fatty acid intake, especially saturated and trans fatty acids is the most important. Saturated and unsaturated fatty acids possess different biological and physicochemical characteristics. The most abundant fatty acid in the human diet are palmitic and stearic and they association with cardiovascular events has been increasingly investigated, especially those one with more than ten carbons in its chain which interfers in the lipoproteins metabolism and can initiate the atherosclerotic process. The food industry has developed some optional technologies to reduce or eliminate the presence of trans fatty acids in foods, in particular elaidic, which after the hydrogenation process increases the saturated fatty acids content. Some industrialized foods requires a large amount of saturated fatty acids that promote an increase of palmitic and stearic content, the last fatty acid mentioned is considered a neutral saturated fatty acid that can contribute to the decrease in HDL-c (High Density lipoprotein), depending on the concentration used, among other deleterious changes. Thus, investigate changes of specifics biological parameters in response to consumption of different saturated fatty acids, respecting the total content of lipids in a normolipidic diet is the aim of this study. Assays were conducted to determine the following parameters in the tissues: 1) Activity of antioxidant enzymes, 2) Lipid peroxidation, 3) Lipidogram; 4) Fatty acid composition 5) Expression of genes related the atherosclerotic process (ICAM-1, VCAM-1, CD36 and MCP- 1). The determination of the activity of antioxidant enzymes was carried out considering only the enzymes Catalase (CAT) and Superoxide Dismutase (SOD), because they are enzymes more sensitive and readily available in changes resulted of an atherosclerotic process with endothelial dysfunction. In the study, no changes were observed in activity of these enzymes in the liver and heart. The same biological process that stimulates the overproduction of reactive species can lead to increased lipid peroxidation, especially of polyunsaturated fatty acids present in cell membranes of tissues such as liver, brain and heart. The group fed with diet enriched with tripalmitate showed increased lipid peroxidation compared to control group. Correlating this information with the fatty acid profile in liver tissue, we noted that there was a greater incorporation of palmitic acid, which exhibit linear configuration when incorporated into the cell membrane and can lead to dysfunction and higher susceptibility to damages such as oxidation. No differences were observed in the others tissues analyzed. The lipidogram is the quantification of lipoprotein and lipid fractions, composing the lipid profile in blood plasma. The results showed that total cholesterol was significantly lower in the control group, as well triglyceride and LDL cholesterol (LDL-c). HDL cholesterol (HDL-C) concentration is reduced and triacylglycerol and cholesterol increased n the group fed with diet supplemented with palmitic. The groups fed with diets supplemented with tristearate and trioleate presented intermediate results for the measurement of HDL-c, with values tending to the group supplemented with tripalmitate. Regarding LDL-c levels, significant differences were observed between the supplemented groups and the control group. Emphasis that there was no difference between the dosage between the supplemented groups. Therefore, the group fed with oleic acid (monounsaturated) supplemented diet equates to the groups fed with diets enriched with stearic and palmitic acid (saturated). The fatty acid profile of liver tissue showed a high percentage of palmitic acid in the group fed with diet enriched with the same fatty acid, with a statistical difference compared to the other groups. In relation to stearic acid, there were no significant differences between groups. As compensation, the oleic acid content in the group supplemented with the same fatty acid and palmitic acid was significantly higher when compared to the others. This result demonstrates that no desaturation of stearic acid to oleic happened in this experimental model. In cardiac tissue there was no statistically significant difference in the concentration of fatty acids, indicating no incorporation or desaturation. Regarding adhesion molecules and chemokines (VCAM-1, ICAM- 1, CD-36 and MCP-1) related to the atherosclerotic process, there was only change in the gene expression of CD-36 molecule in the group fed diet enriched with trioleate, with reduction in relation to others. No other alterations were observed. In conclusion, we verified that the consumption of the different fatty acids in this experimental model has potential to alter lipoproteins levels but not to iniciate or maintain the inflammatory process associated with atherogenesis.

INTRODUÇÃO: O envolvimento vascular tem sido reconhecido como uma importante causa de morbidade e mortalidade na Doença de Behçet (DB), mas a importância de métodos não-invasivos em identificar lesões vasculares precoces ainda não foi bem estabelecida. OBJETIVO: Avaliar as propriedades estruturais e funcionais dos vasos na DB utilizando a medida da velocidade de onda de pulso (VOP) carótido-femoral e a avaliação de carótida pelo echo-tracking system. MÉTODOS: Pacientes com DB sem fatores de risco cardiovasculares tradicionais (hipertensão, diabetes, tabagismo e obesidade) foram selecionados consecutivamente. Todos os pacientes com DB realizaram aferição de VOP e ultrasom de carótida. Pacientes com DB foram divididos de acordo com a presença ou não de envolvimento sistêmico (vascular e/ou ocular e/ou sistema nervoso central) e vascular. Controles saudáveis, pareados para sexo e idade, com os mesmos critérios de exclusão foram selecionados. RESULTADOS: Os vinte e três pacientes com DB (11 homens, média de idade de 35,0±7,6 anos), tiveram níveis significativamente maiores de VOP, comparados ao grupo controle (8,4±1,1 vs. 7,5±1,4 m/s, p=0,017). A espessura íntima-média (594,8±138,6 vs. 561,0±134,2 m, p=0,371), o diâmetro diastólico (6383,7±960,4 vs. 6447,6±1159,7 m, p=0,840), a distensão (401,9±117,7 vs. 337,9±175,3 m, p=0,225) e a distensão relativa (6,2±2,8 vs. 5,4±2,4 m, p=0,293) da artéria carótida foram semelhantes entre os grupos. O grupo com doença sistêmica teve níveis significativamente maiores de VOP (8,7±1,2 vs. 7,8±0,7 m/s, p=0,036) comparado àqueles com manifestação exclusivamente mucocutânea. Pacientes com DB e acometimento vascular tiveram os parâmetros de VOP e echotracking similares aos pacientes sem acometimento vascular, mas apresentaram níveis maiores de colesterol total e LDL (p=0,019 e p=0,012, respectivamente). Uma análise de regressão linear multivariada identificou o nível de triglicerídeos como o mais importante fator associado ao aumento dos níveis de VOP (p=0,001) na DB. CONCLUSÕES: A VOP é mais útil do que o ultra-som de carótida para detectar dano vascular em pacientes com DB e enfatizamos o papel da própria doença em promover essas alterações. Os achados reforçam a necessidade de um controle rigoroso de todos os fatores de risco cardiovasculares na DB, particularmente lipoproteínas / INTRODUCTION: Vascular involvement has been recognized as an important cause of morbidity and mortality in Behçets disease (BD) but the role of noninvasive methods in identify early vascular lesions is not established. OBJECTIVE: To evaluate structural and functional properties of vessels in BD using carotid-femoral pulse wave velocity (PWV) and echo-tracking system. METHODS: BD patients without traditional cardiovascular risk factors (hypertension, diabetes, smoking, and obesity) were consecutively selected. All BD patients performed PWV and carotid ultrasound. BD patients were divided according to the presence or not of systemic (vascular and/or ocular and/or central nervous system involvement) and vascular involvement. Healthy controls age- and sex-matched with the same exclusion criteria were selected. RESULTS: The twenty-three BD patients (11 male, mean age 35.0±7.6 years), had a significantly higher PWV levels compared to control group (8.4±1.1 vs. 7.5±1.4 m/s, p=0.017). Intima-media thickness (594.8±138.6 vs. 561.0±134.2 m, p=0.371), diastolic diameter (6383.7±960.4 vs. 6447.6±1159.7 m, p=0.840), distension (401.9±117.7 vs. 337.9±175.3 m, p=0.225), and relative distension (6.2±2.8 vs. 5.4±2.4 m, p=0.293) were similar in both groups. Multivariate linear regression analysis identified triglycerides as the most important factor in increasing PWV levels (p=0.001) in BD. Systemic disease group had significant higher levels of PWV (8.7±1.2 vs. 7.8±0.7 m/s, p=0.036) compared to those with exclusive mucocutaneous manifestations. BD patients with vascular involvement had similar PWV and echo-tracking parameters compared to those without, but had higher total and LDL cholesterol levels (p=0.019 and p=0.012, respectively). CONCLUSIONS: PWV is more useful than carotid ultrasound in detecting structural and functional vascular damage in BD and emphasize the role of the disease itself in promoting these alterations. Our findings also reinforce the need of a rigorous control of all risk factors in BD, particularly lipoproteins

Os riscos provocados pela Terapia de Reposição Hormonal, levaram à busca de novas terapias, como os fitoestrógenos. São substâncias com ação estrogênica e propriedades que podem retardar a formação de placas ateroscleróticas. Isoflavonas são os fitoestrógenos mais estudados e são encontradas na soja, no red clover e em outras plantas. Avaliamos os efeitos dos fitoestrógenos extraídos da soja Glycine max: genisteína, formononetina, biocanina A e daidzeína; a mistura entre eles (Mix1); o extrato padronizado de red clover (Menoflavon 40mg) e uma segunda mistura com os fitoestrógenos extraídos da Glycine max nas concentrações encontradas no Menoflavon (Mix2), na expressão de moléculas de adesão de leucócitos, VCAM-1, ICAM-1 e E-selectina, em cultura de células endoteliais de cordão umbilical humano (HUVEC), assim como na linhagem modificada de célula endotelial, ECV304, estimuladas com LPS. Resultados: foram padronizados os tempos e concentrações de exposição ao LPS no cultivo de HUVEC de 1ug durante 12 horas de exposição para as três moléculas de adesão; e no cultivo de ECV304 para a expressão de VCAM-1, de 500ng durante 12 horas, para ICAM-1 de 1ug durante 18 horas, para E-selectina 100ng durante 18 horas na superfície celular e 200ng durante 24 horas no sobrenadante de culturas de ECV304, permitindo que este tipo celular seja utilizado como modelo de inflamação. Os fitoestrógenos reduziram VCAM-1, ICAM-1 e E-selectina na superfície celular assim como as formas solúveis dessas moléculas, tanto em ECV304 como em HUVEC, sendo efetivos como agentes preventivos e também para tratamento da aterosclerose. A mistura entre os fitoestrógenos não apresentou maior eficiência na redução das moléculas de adesão na superfície celular, mas apresentou diferenças significativas na produção das formas solúveis. Tanto em ECV304, quanto em HUVEC os fitoestrógenos extraídos do red clover e os extraídos da soja Glycine max reduziram as moléculas de adesão na superfície celular e no sobrenadante, sendo que o Menoflavon, apresentou maior efetividade na redução das moléculas de adesão que os fitoestrógenos extraídos da soja Glycine max, em HUVEC. Ocorreram interações entre os fitoestrógenos e o 17 estradiol, tanto em ECV304 quanto em HUVEC, principalmente quando este se encontrava em baixas concentrações, sugerindo proteção para mulheres na menopausa. Esses efeitos dos fitoestrógenos ocorreram via receptor de estrógeno, como demonstrado pela inibição de suas ações por ICI. Conclusão: tanto os fitoestrógenos extraídos da soja Glycine max quanto os extraídos do red clover apresentaram efeitos anti-aterogênicos, podendo atuar como cardioprotetores para mulheres pós-menopausa. / The risks of hormone replacement therapy have led to a search for new alternatives such as the use of phytoestrogens, plant compounds with estrogen-like biological activity. Isoflavones are the phytoestrogens most extensively studied and can be found in soy, red clover and other plants. Due this estrogen-like activity phytoestrogens can have some effect on atherosclerosis. We evaluated the effects of the phytoestrogens extracts from Glycine max soy: genistein, formononetin, biocanin A and daidzein; a Mix between them (Mix1); a standardized red clover extracts (Menoflavon 40mg) and a second Mix using phytoestrogens from Glycine max with same Menoflavon concentrations (Mix2) on adhesion molecules expression, VCAM-1, ICAM-1 and E-selectin by endothelial cell HUVEC, and by endothelial cell line ECV304, stimulated with LPS. Results: were standardized time and concentration to LPS exposure, being 1ug during 12 hours for the three adhesion molecules expression on HUVEC, and 500ng during 12 hours for VCAM-1 expression, 1ug during 18 hours for ICAM-1 expression and 100ng during 18 hours for E-selectin expression on cell surface as well as 200ng during 24 hours to E-selectin increase on culture supernadant, on ECV 304 cell line. The phytoestrogens decreased VCAM-1, ICAM-1 and E-selectin levels on cell surface and on culture supernadant in HUVEC and ECV304, being useful as preventive agents as well as treatment agents. Mix1 were not most effective than isolated phytoestrogens on cell surface, but presented decreased results on soluble forms. Menoflavon presented more effectiveness than Glycine max on HUVEC. Phytoestrogens interacted with 17 oestradiol mainly, in low concentrations (10pg), showing protection for post menopausal women. These phytoestrogens effects happened by oestrogen receptor activation, this was demonstrated through phytoestrogens inhibition by ICI. Conclusions: the phytoestrogens from Glycine max as well as phytoestrogens from red clover presented antiatherogenic effects, mainly when 17 estradiol is low, being usefull for postmenopausal women.

Introdução: As doenças cardiovasculares permanecem como a principal causa de morbimortalidade entre as mulheres no Brasil e no mundo. Estratégias de prevenção primária baseadas na detecção dos fatores de risco tradicionais para aterosclerose, têm sido pouco eficazes para reduzir as altas taxas de mortalidade nessa população. O presente estudo tem como objetivo primário detectar e quantificar a presença de aterosclerose na sua fase subclínica, em mulheres climatéricas e pós-menopausadas. Métodos: Foram estudadas 823 mulheres de 45 a 65 anos de idade (idade média 54,3 ± 5,3 anos), no período peri e pós-menopausa, sem doença cardiovascular conhecida, ou em uso de terapia de reposição hormonal, residentes em Recife, Nordeste do Brasil. Todas foram submetidas a avaliação clínica e dosagens bioquímicas, que incluíram os níveis de glicose, lipídios, proteína C-reativa, hormônio folículo-estimulante, adiponectina e aldosterona. Ultrassonografia modo B foi utilizada na avaliação carotídea; medidas da espessura íntima média carotídea (EIMC) foram determinadas na parede posterior da artéria carótida comum (ACC) utilizando-se um \"software\" de leitura automatizada; aterosclerose carotídea foi definida quando da presença de placa carotídea e/ou EIMC > 1mm. Resultados: De 823 mulheres, 10,2% eram fumantes, 58% tinham hipertensão e 9,9% eram diabéticas. A prevalência de doença aterosclerótica subclínica entre a população analisada foi de 12,7%, e a média da EIMC foi de 0,645 ± 0,124 milímetros. Na análise univariada, foram detectadas associações significativas entre presença de aterosclerose carotídea e: a idade (p < 0,001), o fumo (p=0,014), a hipertensão (p=0,002), a pressão arterial sistólica (p=0,003), o colesterol total (p=0,001) e o LDL-colesterol (p=0,001). No modelo ajustado, a idade (p < 0,001), o fumo (p=0,001), a pressão arterial sistólica (p=0,030) e o colesterol total (p=0,008) se correlacionaram de forma significativa e independente com a aterosclerose carotídea. Conclusão: O presente estudo revelou uma alta prevalência de aterosclerose carotídea entre as mulheres brasileiras a partir do climatério. Assim como a idade, os fatores de risco clássicos se correlacionaram de forma independente com aterosclerose carotídea. Esses resultados são de particular relevância, visto que as estratégias para redução do risco cardiovascular são baseadas em modelos de predição de risco onde as mulheres são frequentemente classificadas no grupo de baixo risco cardiovascular. Consequentemente, as oportunidades de envolvê-las mais cedo na prevenção da doença aterosclerótica são muitas vezes perdidas / Aims: Cardiovascular diseases continue to be the main cause of morbidity and mortality among women in Brazil and worldwide. Strategies of primary prevention, based on the detection of traditional risk factors for atherosclerosis, have had a small impact in reducing the high rates of mortality in this population. Therefore, the main purpose of this study was to analyse the prevalence of subclinical carotid atherosclerosis in peri- and postmenopausal women. Methods: We studied 823 peri- and postmenopausal women, 45 to 65 years-old (mean age 54.3±5.3 years), from Recife city, without known cardiovascular disease and hormone therapy utilization. All of them were submitted to a careful medical evaluation, and biochemical analyses that included glucose and lipids levels, C-reactive protein, follicle-stimulating hormone, adiponectin and aldosterone. B-mode ultrasound was utilized for carotid evaluations; intima-media thickness (IMT) measures were determined on the far wall common carotid artery (CCA) with automated reading software; presence of carotid atherosclerosis was defined as either the presence of plaque and/or IMT >= 1.00mm. Results: Of the 823 women, 10.2% were current smokers, 58% had hypertension and 9.9% were diabetics. The prevalence of subclinical atherosclerotic disease among the analyzed population was 12.7%, and the mean CCA-IMT was 0.645±0.124 mm. By univariate analyses, a positive and statistically significant correlation was found between carotid atherosclerosis and age (p < 0.001), current smoker (p=0.014), hypertension (p=0.002), systolic blood pressure (p=0.003), total cholesterol (p=0.001) and LDL cholesterol (p=0.001). In the adjusted model, age (p < 0.001), current smoker (p=0.001), systolic blood pressure (p=0.030) and total cholesterol (p=0.008), remained correlating significantly and independently with carotid atherosclerosis. Conclusion: Our study showed a high prevalence of carotid atherosclerosis among asymptomatic pre- and post-menopausal Brazilian women. As well as age, classic risk factors correlated independently with carotid atherosclerosis. These findings are of particular relevance as strategies for reducing cardiovascular risk are based on risk prediction models in which women are often classified as having low cardiovascular risk, and opportunities for engaging them in prevention at a younger age are very often missed