INTRODUÇÃO: A doença de Chagas (DCh) representa um grave problema de saúde pública na maioria dos países da América Latina. Sintomatologia frequente, a dor torácica ou precordial em pacientes com DCh pode assemelhar-se àquela observada na doença arterial coronária (DAC), constituindo-se, dessa forma, em desafio diagnóstico para os clínicos. A frequência da DAC em pacientes com DCh continua indefinida na literatura, permanecendo a hipótese de que pacientes com DCh possam apresentar menor proporção de DAC. A angiografia coronária por tomografia computadorizada (ATC), em aparelho de múltiplas colunas de detectores, é um método não invasivo de alta acurácia que permite o diagnóstico precoce de placas ateromatosas, obstrutivas ou não, e que poderia detectar a frequência de DAC neste grupo de pacientes. OBJETIVO: Investigar a presença de aterosclerose coronária em pacientes com DCh, comparando com um grupo controle de indivíduos assintomáticos e sem doença coronária conhecida, utilizando a angiografia coronária por tomografia computadorizada. MÉTODOS: Foram estudados 43 pacientes portadores da DCh, sendo 16 (37,2%) homens. O grupo controle foi composto por 66 indivíduos não portadores da DCh, sendo 28 (42,4%) homens. Os grupos foram pareados pelo escore de risco de Framingham, respeitando-se a mesma faixa de risco (baixo, intermediário e alto), além do pareamento por sexo e faixa etária. Os exames foram realizados em tomografia computadorizada de 320 colunas de detectores e o diagnóstico de DAC foi definido pela presença de placa aterosclerótica, mesmo sem causar obstrução luminal. DAC obstrutiva significativa foi considerada pela presença de ao menos uma placa causando redução maior do que 50% do diâmetro da luz arterial. RESULTADOS: Foram observadas diferenças significativas nos parâmetros relacionados à DAC, sendo sua frequência significativamente menor nos pacientes portadores da DCh. A presença de DAC foi observada em 9 indivíduos (20,9%) portadores da DCh e em 32 indivíduos do grupo controle (48,5%), com p=0,004. A magnitude da estenose coronária foi significativamente menor nos pacientes com DCh que nos controles na análise por paciente, por território e por segmentos coronários (p<0,001, p=0,012 e p=0,045, respectivamente). CONCLUSÕES: Os pacientes portadores da DCh apresentam baixa frequência de DAC definida pela tomografia computadorizada de artérias coronárias. A frequência de DAC, obstrutiva ou não, em pacientes com DCh foi significativamente menor que a observada no grupo controle de pacientes sem DAC prévia conhecida / INTRODUCTION: Chagas disease (CD) is a serious public health problem in most of Latin American countries. Precordial or chest pain in patients with CD is a frequent symptom and can be similar to that observed in coronary artery disease (CAD), what represents a diagnostic challenge to the physicians. The frequency of CAD in patients with CD continues undefined in the literature, remaining the hypothesis that patients with CD could present a lower proportion of CAD. Computed tomography angiography (CTA) is a high accuracy and non-invasive method that allows an early diagnostic of atherosclerotic plaque, obstructive or not, and that could detect the frequency of CAD in this group of patients. OBJECTIVE: Investigate coronary atherosclerosis by CTA in patients with CD, comparing with an asymptomatic control group without known CAD. METHODS: 43 patients with CD were studied and 16 (37.2%) were men. The control group was composed by 66 non-carriers of CD and 28 (42.4%) were men. The groups were matched for Framingham risk score (low, medium and high) as well as sex and age. The exams were performed in 320-multidetector rows CT and the CAD diagnostic was defined as the presence of atherosclerotic plaques, even without luminal obstruction. Significant obstructive CAD was considered if at least one plaque was present causing more than 50% of reduction in the arterial lumen diameter. RESULTS: Significant differences were observed in parameters related to CAD, showing lower frequency of CAD in patients with CD. The presence of CAD was observed in 9 patients (20.9%) with CD and in 32 patients (48.5%) from the control group, with p=0.004. The magnitude of coronary stenosis was significantly lower in patients with CD than in controls, in a per patient, per territory and per segment coronary analyses (p<0.001, p=0.012 e p=0.045, respectively). CONCLUSIONS: Patients with CD have a low frequency of CAD defined by coronary CTA. The CAD frequency, obstructive or not, in patients with CD was significantly lower than the observed in the control group without known CAD

O presente trabalho buscou investigar a formação da placa de aterosclerose através de caracterização da autofluorescência do tecido e do plasma na presença de marcadores fluorescentes. Para realizar o estudo, coelhos foram divididos em dois grupos: um grupo controle onde os animais foram submetidos a uma dieta normal e um grupo experimental onde os animais foram submetidos a uma dieta hipercolesterolêmica. Foram realizadas duas experimentações animais: na primeira os animais foram sendo eutanasiados ao longo do experimento e suas artérias foram coletadas. Na segunda os animais foram acompanhados por no máximo 80 dias. Durante o experimento apenas o sangue foi coletado e os animais foram eutanasiados no final do experimento. Dois marcadores fluorescentes foram utilizados no trabalho: o complexo európio-clorotetraciclina (EuCTc) e o corante tioflavina T (ThT). Analisouse inicialmente a fluorescência dos marcadores na presença do plasma dos coelhos tanto para o grupo controle, quanto para o grupo experimental em função dos tempos de dieta. Para o complexo EuCTc observou-se duas bandas de emissão, com excitação em 400 nm, uma característica da clorotetraciclina, em 515 nm e uma em 617 nm característica do íon európio. A análise da banda do íon európio indicou um incremento da banda de emissão do complexo na presença do plasma do grupo experimental em relação ao grupo controle. Para o corante ThT também foi observado um aumento na banda de emissão em 480 nm, com excitação em 413 nm, para o grupo experimental em comparação com o grupo controle. A potencialidade de utilização do complexo EuCTc e EuCTcMg (EuCTc na presença do íon magnésio) para marcação da placa de aterosclerose nas artérias, foi estudada através da análise de microscopia de fluorescência. Observou-se que a emissão do complexo melhora muito a visualização da placa quando comparada com a autofluorescência. Observou-se, através de microscopia de tempo de vida de fluorescência, que há uma transferência de energia entre os fluoróforos presentes na placa e os complexos EuCTc e EuCTcMg. Essa transferência de energia ocasionou em uma diminuição drástica no tempo de vida de fluorescência dos fluoróforos nessa região. Por fim, estudou-se a geração de segundo harmônico do colágeno na placa de aterosclerose, sendo obtidas diferenças na quantidade e organização do colágeno para os diferentes grupos experimentais. / This study aimed to investigate the formation of atherosclerotic plaque by the characterization of the autofluorescence of the tissue and plasma in the presence of fluorescent markers. For this study, rabbits were divided into two groups: a control group and an experimental group submitted to a hypercholesterolemic diet. The animal experimentation was performed twice, the first animals were being euthanized during the experiment and their arteries were collected. In the second experiment, the animals were followed for a maximum of 80 days and only during the experiment the blood was collected. The animals were euthanized at the end of experimentation. Two fluorescent markers were used in this study: europiumchlortetracycline complex (EuCTc) and the dye Thioflavin T (ThT). Firstly, it was analyzed the markers fluorescence in the presence of rabbits plasma for both, the control and the experimental groups with different diet times. For EuCTc complex, it was observed two bands of emission with excitation at 400 nm, first, a characteristic of chlortetracycline at 515 nm and at 617 nm characteristic of the europium ion. Analyzing only the band of europium ion, it was observed a greater increase of the complex in the presence of plasma in the experimental group. For ThT dye the emission band at 480 nm with excitation at 413 nm for the experimental group, in comparison with the control group. I was analysed the possibility to use EuCTc and EuCTcMg complex (EuCTc the Mg ion present) for marking the atherosclerotic plaque in arteries by fluorescence microscopy analysis. The results showed that the emission of the complex increase dramatically compared to the autofluorescence. Also, there was evidence of energy transfer between the fluorophores present of the plaque and EuCTc and EuCTcMg complex by fluorescence lifetime microscopy. This energy transfer generated a drastic decrease in the fluorescence lifetime of fluorophores. Finally, the generation of second harmonic of collagen in the atherosclerotic plaque was studied and it was obtained differences in the amount of collagen and organization in the different experimental groups.

A aterosclerose é uma doença crônico-inflamatória multifatorial com o envolvimento do sistema imunológico, sendo o resultado da interação de diferentes elementos celulares. A lipoproteína de baixa densidade eletronegativa [LDL(-)], capaz de induzir o acúmulo de ésteres de colesterol em macrófagos e a subsequente formação de células espumosas, desempenha um papel-chave na doença. Anticorpos recombinantes têm sido gerados nas últimas décadas, como o scFv (single chain fragment variable), com o intuito de serem utilizados como uma novas alternativas de prevenção para o surgimento da lesão. Diante do papel da LDL(-) na aterosclerose, este projeto avaliou o efeito da imunização passiva de camundongos LDLr-/-- com scFv anti-LDL(-) em solução e scFv anti-LDL(-) conjugado a nanocápsulas, em relação ao desenvolvimento e progressão da aterosclerose. Após obtenção do scFv e sua conjugação à nanocápsulas (NC-scFv), ensaios in vitro determinaram a diminuição da captação de LDL(-) em macrófagos tratados com o scFv 2C7 anti-LDL(-) em solução. No entanto, o tratamento com NC-scFv promoveu o aumento da internalização de LDL(-) em relação ao controle, possivelmente por um mecanismo de endocitose mediada por receptor específico. Estudos in vivo determinaram que camundongos LDLr-/- com idade entre 2 e 3 meses tratados com o scFv em solução apresentaram menor área de lesão aterosclerótica (p<0,05) quando comparados ao controle e que animais com 3 a 4 meses de idade tratados com NC-scFv demonstraram uma tendência à diminuição do mesmo parâmetro. Na análise da expressão de proteínas por imunohistoquímica, ambos os grupos tratados com scFv 2C7 anti-LDL(-) em solução e NC-scFv demostraram redução significativa da expressão dos receptores CD14 e TLR-4 no local da lesão. Esse achado tem grande importância, uma vez que dados da literatura apresentam ambos os receptores como possíveis candidatos ao reconhecimento da LDL(-). Diante dos dados obtidos, o estudo evidenciou a eficácia do scFv 2C7 anti-LDL(-) em solução e da formulação NC-scFv no contexto da aterosclerose, possibilitando a sua utilização como estratégias terapêuticas na intervenção precoce para prevenir o desenvolvimento e a progressão da doença. / Atherosclerosis is a chronic inflammatory multifactorial disease related to the immune system and being the result of interaction of different cellular elements. The electronegative LDL, since the changes undergone by this particle are able to induce the accumulation of cholesterol esters in macrophages and the subsequent formation of foam cells, plays a key role in atherosclerosis. Recombinant antibodies have been generated in recent decades, such as scFv, (single chain fragment variable), and they may be used as a new alternative treatment for atherosclerosis treatment or prevention. Considering the role of LDL(-) in atherosclerosis, this project evaluated the effects of the treatment with anti-LDL(-) scFv 2C7 solution and anti-LDL(-) scFv conjugated to nanocapsules as a passive immunization strategy on atherosclerosis induced in LDL receptor knockout mice. After obtaining the anti-LDL(-) scFv 2C7 solution and its conjugation to nanocapsules (NC-scFv), in vitro tests led to the decrease in LDL(-) uptake in macrophages treated with anti-LDL(-) scFv 2C7. However, the treatment of macrophages with NC-scFv promoted increased internalization of LDL(-) as compared to control, possibly due to a mechanism of specific receptor-mediated endocytosis. In vivo studies have determined that LDLR-/- mice aged 2 and 3 months treated with anti-LDL(-) scFv 2C7 solution showed less atherosclerotic lesion area (p <0.05) compared to control and animals aged 3 to 4 months treated with NC-scFv showed a decreasing tendency of the same parameter. In the analysis of protein expression by immunohistochemistry, both groups treated with anti-LDL(-) scFv 2C7 solution and NC-scFv showed significant reduction of CD14 receptor expression and TLR-4 at the lesion site. This finding is of great importance, since the literature has both receptors as candidates for recognition of the LDL(-). From the data obtained, the study demonstrated the efficacy of treatments anti-LDL(-) scFv 2C7 in solution and NC-scFv in the context of atherosclerosis, enabling their use as therapeutic strategies in the early intervention to prevent the development and progression of the disease.

Atualmente, as doenças cardiovasculares são apontadas como as principais causas de mortes no Brasil e no mundo. Essas doenças são causadas pelo comprometimento das artérias, principalmente as artérias coronárias. Essas artérias possuem a importante função de transportar nutrientes ao próprio coração, possibilitando que o mesmo exerça sua tarefa de suprir todo o resto do corpo com elementos essenciais à sobrevivência do indivíduo. Este trabalho é sobre um estudo do comportamento dessas artérias quando ocorre a difusão de um fluido através de suas paredes. Primeiramente, estudou-se a composição das artérias coronárias, suas funções e patologias, para extrair elementos para compor um modelo fisicamente realístico e analiticamente tratável. Devido à sua composição histológica em três túnicas, a artéria coronária foi modelada como um cilindro elástico composto de cilindros ocos e concêntricos. Investigou-se então a solução do problema da difusão de um fluido em duas e três camadas, sendo esta última configuração geométrica mais próxima da realidade. Por fim, estudou-se a difusão de um fármaco contido em um stent farmacológico, cuja função é desobstruir uma artéria aterosclerosada e evitar sua reestenose. / Currently, cardiovascular diseases are known to be the primary cause of death in Brasil and worldwide. These diseases are caused by the malfunction of the arteries, especially the coronary arteries. These arteries have the important role of transporting nutrients to the heart itself, allowing it to exert its main task of providing the rest of the body with essential elements to the survival of an individual. This work is about a study of the diffusion of a fluid through the walls of a coronary artery. First, the composition of the coronary arteries, their functions, and pathologies were studied to extract elements that could be used to construct a model that is both physically realistic and analytically amenable to analysis. Due to its histologic composition in three layers, a coronary artery was modeled as an elastic cylinder composed of hollow and concentric cylinders. The solution of the diffusion problem of a fluid in two and three layers was studied, being this last geometrical configuration the closest to reality. Finally, the diffusion of a drug contained in a pharmacological stent was investigated. The main task of this type of stent is to clear an atherosclerotic artery and to avoid its restenosis.

Background: Matrix metalloproteinases (MMPs) have been shown to be involved in cancers and atherosclerosis, the leading causes of present day mortality. The objectives of the cancer element of this project were to investigate single nucleotide polymorphisms (SNPs) in MMP1 and MMP8 regarding breast cancer and malignant melanoma, and a functional characterisation of the genetic variants, including the MMP1 polymorphism rs19799750, previously associated with multiple cancers. The objective of the second part of this project was to investigate whether MMP8 played a role in the development of atherosclerotic lesions and if so, the underlying mechanisms. Methods/Results: Genetic investigations found the MMP8 SNP rs11225395 to be associated with the occurrence of both breast cancer and malignant melanoma; furthermore it was also associated with reduced lymph node metastasis, reduced cancer relapse and greater survival. Functional luciferase assays showed that the minor allele of the polymorphism has higher promoter activity in breast cancer and melanoma cell lines. They also showed haplotypic effects on MMP1 promoter activity in several cancer cell lines by the 2G allele of polymorphism rs1799750 and one or more MMP1 promoter SNPS. The second part of the study found an association between a MMP8 SNP and the extent of coronary atherosclerosis; additionally a relationship among MMP8 gene variation, plasma VCAM-1 level, and atherosclerosis progression was observed in a prospective study. Murine studies showed reduced atherosclerosis in MMP8/ApoE knockout mice compared with ApoE knockout littermate controls. Biochemical studies confirmed that MMP8 can convert angiotensin I to angiotensin II. Conclusions: The data of the first part of this project support the notion that genetic polymorphisms in the MMP1 and MMP8 influence the expression of these genes and the development and progression of cancer. The results of the second part of this project indicate an important role of MMP8 in the pathogenesis of atherosclerosis.

Background: Recent studies have revealed an association between genetic variants at the ADAMTS7 (a disintegrin-like and metalloprotease with thrombospondin type 1 motif, 7) locus and susceptibility to coronary artery disease (CAD). ADAMTS-7 has been reported to facilitate vascular smooth muscle cell (VSMC) migration and promote neointima formation. We sought to study the functional mechanisms underlying this relationship and to further investigate the role of ADAMTS-7 in atherosclerosis. Methods and Results: In vitro assays showed that the CAD-associated non-synonymous single nucleotide polymorphism rs3825807, which results in a serine to proline (Ser-to- Pro) substitution at residue 214 in the ADAMTS-7 pro-domain, affected ADAMTS-7 prodomain cleavage. Immunohistochemical analyses showed that ADAMTS-7 localised to vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) in human coronary and carotid atherosclerotic plaques. Cell migration assays demonstrated that VSMCs and ECs from individuals who were homozygous for the adenine (A) allele (encoding the Ser214 isoform) had increased migratory ability compared with cells from individuals who were homozygous for the G allele (encoding the Pro214 isoform). Western blot analyses revealed that media conditioned by VSMCs of the A/A genotype contained more cleaved ADAMTS-7 pro-domain and more of the cleaved form of thrombospondin-5 (TSP-5, an ADAMTS-7 substrate that had been shown to be produced by VSMCs and inhibit VSMC migration). In in vitro angiogenesis assays, ECs of the A/A genotype exhibited increased capillary-like network formation. ADAMTS-7 over-expression in ECs by transfection of an ADAMTS7-214Ser expressing plasmid significantly accelerated EC migration and in vitro angiogenesis, whereas ADAMTS-7 knockdown by shRNA had opposite effects. Preliminary proteomics analyses of conditioned media of ECs overexpressing ADAMTS-7 and ECs with ADAMTS-7 knockdown indicated that ADAMTS- 7 can cleave thrombospondin-1 (TSP-1), a well-recognised angiogenesis inhibitor. Conclusion: The results of this study indicate that rs3825807 has a functional effect on ADAMTS-7 maturation, TSP-5 cleavage, VSMC and EC migration, and angiogenesis. As VSMC migration and angiogenesis play important roles in atherosclerosis, these results provide a mechanistic explanation for the association between rs3825807 and CAD.

Made available in DSpace on 2017-07-24T19:22:25Z (GMT). No. of bitstreams: 1 Caroline Michelis Nascimento.pdf: 1850538 bytes, checksum: ef9b5b6eb0f2144523223dd6c55ee614 (MD5) Previous issue date: 2012-08-31 / The occurrence of oral diseases is related to habits, stress levels, diet and emotional factors. The oral cavity is the site of entry for many microorganisms and are manifested niche where the first symptoms of a number of diseases of systemic character. Periodontal disease (PD) is a chronic infectiousinflammatory that affects the supporting tissues of the teeth and support, and toxoplasmosis, a protozoonosis worldwide distribution, caused by an intracellular parasite Toxoplasma gondii, which infects 50% of the world population and has its transmission by feeding undercooked meats. The aim of this study was to assess the degree of impairment of periodontal diseases in humans checking the correlation with toxoplasmosis and Coronary Artery Disease (CAD). Sixty-four patients underwent coronary angiography and were divided into two groups: patients with CAD (n = 47) and patients without CAD (n = 17). The results of angiography of patients with / without CAD demonstrated that the category of coronary obstructive lesions between 25% and 50% and> 50% the number of injuries among experimental groups in the right coronary artery, anterior and circumflex were statistically different (p = 0.0001) concluding that atherosclerosis can cause lesions in various arteries varying degree at the same time. The number of patients with hyperglycemia in the group with coronary disease, caused by stress hyperglycemia during hospitalization of patients with acute myocardial infarction without history of diabetes, show a higher rate of glycemic alterations in these patients (48.9%). Patients with /without CAD, have also been analyzed qualitatively for the presence or absence of IgG, IgM and IgA anti-toxoplasma in serum, saliva and blood samples collected during angiography catheter. Although they are not statistically different among the experimental groups, the rates of absorbance in serum (p =0,476) and saliva (p = 0.7632) were higher for patients without CAD, indicating that the presence of antibodies to Toxoplasma gondii is higher in patients without CAD than in patients with CAD. Regarding the parameters of periodontal health the number of patients with bleeding sites and the number of bleeding sites was higher in patients with CAD (p = 0.0491 and p = 0.002, respectively), with the average number of sites with exudate higher in the group with no difference DAC (p = 0.6052) and number of missing teeth larger than in the group without CAD (p = 0.0001), suggesting a correlation between the parameters of oral and periodontal health with coronary atherosclerosis. The results suggest the correlation of oral problems systemic conditions with high prevalence in the population in case of toxoplasmosis and coronary atherosclerosis. / A ocorrência de doenças bucais está relacionada aos hábitos, aos níveis de estresse, à aliment ão e aos fatores emocionais. A cavidade oral é o local de entrada para diversos microrganismos e o nicho onde se manifestam os primeiros sintomas de uma série de doenças de caráter sistêmico. A doença periodontal (DP) é uma doença infecto-inflamatória que acomete os tecidos de suporte e sustentação dos dentes, e a toxoplasmose, uma protozoonose de distribuição mundial, causada pelo Toxoplasma gondii um parasita intracelular, que infecta 50% da população mundial e tem sua transmissão através da alimentação de carnes mal cozidas. O objetivo desta pesquisa foi avaliar o grau de comprometimento de doenças periodontais em humanos verificando a correlação com a toxoplasmose e a Doença Arterial Coronariana (DAC). Sessenta e quatro pacientes foram submetidos a cinecoronariografia e divididos em dois grupos: pacientes com DAC (n=47) e pacientes sem DAC (n=17). Os resultados da cinecoronariografia de pacientes com/sem DAC demonstraram que na categoria das lesões obstrutivas coronarianas entre 25% e 50% e >50% o número de lesões entre os grupos experimentais nas artérias coronária direita, interventricular anterior e circunflexa foram estatisticamente diferentes (p = 0.0001) concluindo que aterosclerose pode provocar lesões de grau variado em várias artérias ao mesmo tempo. O número de pacientes com hiperglicemia no grupo que apresenta doença coronariana, causada por hiperglicemia de estresse durante admissão hospitalar de pacientes com infarto agudo do miocárdio sem histórico de diabetes, demonstram uma elevada taxa de alterações glicêmicas nesses pacientes (48.9%). Os pacientes com/sem DAC, também foram analisados qualitativamente para presença ou ausência de anticorpos IgG, IgM e IgA anti-toxoplasma em amostras de soro, saliva e em amostras sanguíneas obtidas com cateter durante coronariografia. Apesar de estatisticamente não serem diferentes entre os grupos experimentais, os índices de absorbância no soro (p=0.476) e na saliva (p=0.7632) foram maiores para os pacientes sem DAC, indicando que a presença de anticorpos anti Toxoplasma gondii é mais elevado em pacientes sem DAC do que em pacientes com DAC. Em relação aos parâmetros da saúde periodontal o número de pacientes com sítios sangrantes e o número de sítios sangrantes foi maior nos pacientes com DAC (p=0.0491 e p=0.002, respectivamente), com número médio de sítios com exsudato maior no grupo com DAC sem diferença estatística (p=0.6052) e número de dentes perdidos maior que no grupo sem DAC (p=0.0001), sugerindo uma correlação entre os parâmetros da saúde oral e periodontal com a doença aterosclerótica coronariana. Os resultados sugerem a correlação de problemas bucais, com condições sistêmicas de alta prevalência na população no caso da toxoplasmose e a aterosclerose coronariana.

Glucagon-like peptide-1 (GLP-1) synthetic analog therapies are prescribed for type 2 diabetes due to their effects on insulin and glucagon secretion, and glycemic control. Recent studies also suggest that they may have cardiovascular benefits; however, the mechanism responsible for this is unknown. To examine this question, we evaluated the effects of GLP-1 and the GLP-1 synthetic analog, liraglutide on cell signaling and function in human aortic endothelial cells (HAECs). The results indicate that both agents inhibit TNFα and LPS induced cellular adhesion molecule expression and monocyte adhesion. They also show that incubation with 30pM GLP-1 and 100nM liraglutide stimulates an immediate increase in intracellular calcium, which activates calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ). This in turn led to a 2.5 fold increase in the phosphorylation of both AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent protein kinase 1 (CaMK1) within 5 minutes. In addition both GLP-1 and liraglutide caused a 2-fold increase in the phosphorylation of the downstream AMPK/CaMK1 targets: endothelial nitric oxide synthase (eNOS) and cAMP response element-binding protein (CREB). Inhibition of CaMKKβ with STO-609 (0.5ug/mL) blocked the phosphorylation of both AMPK and CaMK1, confirming its pivotal role. Incubation of the HAECs for three hours with lipopolysaccharide (LPS, 2ug/mL) and TNFα (10ng/mL) increased the expression of vascular cell adhesion molecule-1 (VCAM-1) and E-selectin by 5 and 2 fold, respectively. Comparable increases in THP-1 monocyte adhesion to the HAECs, a putative initiating event in atherogenesis, also occurred. Pre-incubation for one hour with either GLP-1 or liraglutide inhibited these events. Likewise, pre-incubation with the CaMKK inhibitor STO-609, or use of lentivirus shRNA to knock down AMPK, blocked the inhibitory effects of both GLP-1 and liraglutide on monocyte adhesion. These results suggest that the recently observed cardiovascular benefits of GLP-1 and liraglutide could be mediated by their effects on CaMKKβ, AMPK and CaMK1 activation, which lead to decreased adhesion molecule expression and monocyte adhesion in endothelial cells. The finding that these effects occur at concentrations of GLP-1 (30pM) and liraglutide (100nM) observed in vivo also suggests they are physiologically relevant.

Atherosclerotic cardiovascular disease secondary to deposition of apolipoprotein B-containing lipoproteins in the artery wall is a leading cause of mortality. Therapies that reduce serum levels of atherogenic lipoprotein-cholesterol have been successful in reducing cardiovascular mortality, but this approach requires long-term treatment and substantial residual risk remains. Here, we investigate mechanistic determinants of atherosclerosis protection by two potential therapeutic approaches for lowering of residual cardiovascular risk. Using mouse models, we show that the nuclear receptor liver X receptor exerts an anti-inflammatory activity on innate immunity and atherosclerosis through both promotion of cholesterol efflux and a direct cis-repressive activity affecting neutrophil inflammation. We then assess the causal role of the cholesterol efflux pathway in human cardiovascular events by using genetic variants that modify high density lipoprotein-cholesterol in instrumental variable analysis. We show that this pathway is associated with protection from cardiovascular disease in a precise and robust Mendelian randomization analysis on an FDR-controlled set of variants, which suggests a causal effect. Thus, agents that target the cholesterol efflux and liver X receptor cis-repression pathways may be protective in atherosclerosis.

INTRODUÇÃO: A angiotomografia computadorizada com múltiplos detectores (ATCMD) apresenta alta acurácia para a detecção de estenose luminal significativa das artérias coronárias ( 50%) quando comparada à angiografia coronária invasiva (ACI). Recentemente, esse método vem sendo investigado na avaliação de pacientes com dor torácica aguda de baixo risco. No entanto, poucos estudos investigaram a capacidade da ATCMD na avaliação de pacientes com maior risco para síndrome coronária aguda (SCA). OBJETIVOS: Investigar a acurácia diagnóstica da ATCMD com 64 colunas de detectores para a detecção de estenose luminal coronária 50% definida pela ACI em indivíduos com suspeita de SCA sem supradesnível do segmento ST e comparar estes resultados com a acurácia encontrada em pacientes com suspeita de doença coronária crônica; avaliar a capacidade da ATCMD em predizer revascularização miocárdica nos 30 primeiros dias de seguimento. Adicionalmente objetivamos verificar a prevalência e a acurácia da presença de calcificação coronária para detecção de estenose luminal coronária significativa. MÉTODOS: Pacientes que participaram do estudo multicêntrico internacional CorE64 foram classificados nos grupos SCA e não-SCA de acordo com critérios clínicos, incluindo a presença de angina ao repouso, alterações isquêmicas ao ECG e elevação de marcadores de necrose miocárdica. Todos os pacientes foram submetidos à ATCMD e posteriormente à ACI e para a análise primária foram considerados apenas aqueles com escore de cálcio (EC) 600. RESULTADOS: Dos 291 pacientes incluídos, 80 (27%) foram classificados no grupo SCA. A prevalência de estenose coronária 50% foi de 68% neste grupo e de 52% no grupo não-SCA (p=0,015). A acurácia diagnóstica da ATCMD, em análise por paciente, para detecção de estenose coronária significativa demonstrada pela análise da área sob a Curva de Características Operacionais (AUC) foi de 0,95 (IC 95%: 0,90-0,99) e 0,92 (IC 95%: 0,89-0,96) nos grupos SCA e não-SCA, respectivamente (p=0,44). Nos 30 dias de seguimento, 98 pacientes foram submetidos à revascularização miocárdica (48 do grupo SCA e 50 do grupo não-SCA). A AUC da ATCMD e da ACI para predição de revascularização foi de 0,91 (95% IC: 0,83-0,99) e 0,89 (95% IC: 0,80-0,98), respectivamente, no grupo SCA (p=0,61) e 0,80 (95% IC: 0,74-0,86) e 0,79 (95% IC: 0,73-0,85) no grupo não-SCA, p=0,75. Comparando os dois grupos estudados, a ATCMD foi melhor preditora de revascularização no grupo SCA (p=0,035). No grupo SCA, 6 pacientes (7,5%) tinham EC zero e estenose coronária significativa, comparado a 8 indivíduos (3,8%) do grupo não-SCA (p=0,22). Considerando pacientes com EC baixo (0 a 9), 12 (15%) do grupo SCA e 11 (5,2%) do não- SCA apresentaram estenose coronária 50% (p=0,012). A acurácia do EC para detecção de estenose coronária significativa nos grupos SCA e não- SCA foi de 0,73 (IC 95%: 0,63-0,82) e 0,70 (IC 95%: 0,64-0,76), respectivamente (p=0,75), sendo que o valor preditivo negativo no grupo SCA foi estatisticamente menor que no grupo não-SCA [0,63 (IC95%: 0,39- 0,86) e 0,86 (IC 95%: 0,77-0,95), respectivamente, p=0,038]. CONCLUSÕES: A ATCMD apresentou alta acurácia diagnóstica para detecção de estenose coronária significativa nos grupos SCA e não-SCA, não havendo diferença significativa entre ambos. A ATCMD obteve acurácia semelhante à ACI na predição de revascularização, sendo maior no grupo SCA que no não-SCA. A acurácia do EC para a detecção de estenose coronária 50% foi moderada em ambos os grupos, sendo que um EC zero ou baixo não excluiu a ocorrência de estenose significativa, especialmente no grupo SCA / BACKGROUND: Multi-detector computed tomography angiography (MDCTA) has shown high accuracy to detect obstructive coronary luminal stenosis ( 50%) compared to invasive coronary angiography (ICA). Recently, this technology has been investigated in the evaluation of patients with low-risk acute chest pain. However, few studies investigated its diagnostic performance in higher-risk patients with suspected acute coronary syndrome (ACS). OBJECTIVES: To estimate the diagnostic accuracy of 64- row computed tomography angiography to detect significant coronary stenosis defined by ICA in a per-patient analysis and its ability to predict coronary revascularization in patients with suspected acute coronary syndrome and in those with chronic, stable coronary artery disease; to identify the prevalence and the diagnostic accuracy of coronary calcification to detect significant luminal stenosis in both groups. METHODS: Patients included in the international multicenter trial CorE64 were categorized as suspected ACS or non-ACS based on clinical data. A 64-row coronary MDCTA was performed before ICA and both exams were evaluated by blinded, independent core laboratories. RESULTS: From 291 patients with coronary calcium score (CCS) 600 included in the primary analysis, 80 were categorized as suspected ACS. The prevalence of obstructive coronary disease was 68% in suspected ACS and 52% in non-ACS group (p=0.015). Patient-based analysis showed an area under the receiver-operatingcharacteristic curve (AUC) for detecting coronary stenosis 50% of 0.95 (95% CI: 0.90-0.99) in ACS and 0.92 (95% CI: 0.89-0.96) in non-ACS group (p=0.44). After 30 days of follow-up, 98 patients were submitted to coronary revascularization (48 from the ACS and 50 from the non-ACS group). MDCTA was similar to ICA to predict coronary revascularization in both groups with AUC of 0.91 (95% CI: 0.83-0.99) for MDCTA versus 0.89 (95% CI: 0.80-0.98) for ICA in the ACS group (p=0.61) and 0.80 (95% CI: 0.74- 0.86) for MDCTA versus 0.79 (95% CI: 0.73-0.85) for ICA in non-ACS group (p=0.75). MDCTA was better to predict revascularization in ACS than in non- ACS group (p=0.035). In the suspected ACS group, 6 patients (7.5%) had no coronary calcification and coronary stenosis 50%, compared with 8 patients (3.8%) in the non-ACS group (p=0.22). Considering patients with zero or low (0 to 9) CCS, 12 (15%) in the ACS and 11 (5.2%) in the non-ACS group had significant coronary stenosis (p=0.012). The accuracy of CCS to detect obstructive coronary stenosis in the ACS and non-ACS groups were 0.73 (95% CI: 0.63-0.82) e 0.70 (95% CI: 0.64-0.76), p=0.75, and its negative predictive value in the suspected ACS group was lower than in non-ACS patients [0.63 (95% CI: 0.39-0.86) and 0.86 (95% CI: 0.77-0.95), respectively, p=0.038]. CONCLUSIONS: Coronary MDCTA diagnostic accuracy was high and comparable for both ACS and non-ACS patients. MDCTA predicted revascularization similarly to ICA and its prediction ability was significantly better in the ACS than in non-ACS group. The diagnostic accuracy of a positive CCS to detect luminal stenosis 50% was moderate in both groups and a zero or low CCS could not exclude reliably significant coronary stenosis, particularly in suspected ACS patients