PET imaging, using the bone tracer Na18F, allows the non-invasive location of atherosclerotic plaques that are at risk of rupture. However, the spatial resolution of PET is only 4-5 mm, limiting the mechanistic information this technique can provide. In this thesis, the use of fluorescence and Raman imaging to elucidate the mechanism of micro-calcification within atherosclerotic plaques has been investigated. A number of fluorescent probes to detect fluoride and calcium have been synthesised. One of the fluoride probes has been shown to be selective for fluoride however, the concentration of fluoride required to activate the probe is order of magnitudes higher than the amount of Na18F used for PET imaging making it problematic to use for future studies. On the other hand, a calcium probe has been shown to: selectively bind to hydroxyapatite (HAP); permit visualisation and quantification of HAP in both vascular and bone cell models; and effectively stain cultured aortic sections and whole mouse aorta for OPT imaging. Building on these preliminary data, fluorescence imaging and immunohistochemistry (IHC) imaging of both healthy and atherosclerotic tissue that were previously subjected to PET imaging, were successfully carried out showing the ability of the probe to detect HAP in human vascular tissue. IHC staining for Osteoprotegerin (OPG) and Osteopontin (OPN), two bone proteins recently detected in vascular tissue, showed the co-localization of OPG with the probe. Conversely, the OPN was shown to localize in areas surrounding high OPG and probe signal. To determine the exact composition of vascular calcification, Raman spectroscopy was also used. It is believed that the biosynthetic pathway to HAP passes through a series of transitional states; each of these has different structural characteristics which can be studied using Raman spectroscopy. In particular, HAP has a strong characteristic Raman peak at 960 cm-1. An increase in HAP concentration has been detected by Raman in both calcified cell models and aortic sections. When human vascular tissue was analysed, an additional peak at 973 cm-1 was present suggesting the presence of whitlockite (WTK) in this tissue as well as HAP.

Orientador: Maria Aparecida Neves Jardini / Coorientador: Antônio Martins Figueiredo / Banca: José Benedito Oliveira Amorim / Banca: Milton Santamaria Júnior / Resumo: A Doença Periodontal (DP) e o Diabetes Mellitus tipo 2 (DM2) apresentam a mesma etiopatogênese inflamatória e demonstram uma relação bidirecional, pois DM2 afeta a severidade da DP, e esta pode contribuir para a carga inflamatória total do indivíduo, influenciando a evolução do DM2. O objetivo do presente estudo foi avaliar os fatores de risco para o desenvolvimento de aterosclerose em pacientes portadores de DM2, com e sem periodontite crônica. Foram analisados 48 pacientes, os quais foram divididos em 2 grupos: Teste (pacientes diabéticos com periodontite crônica) e Controle (pacientes diabéticos sem periodontite crônica). O grupo teste foi tratado com debridamento periodontal e o grupo controle recebeu profilaxia supragengival. Ambos os grupos receberam controle de placa a cada 3 meses. No baseline e 6 meses após o tratamento, foi realizada tomada dos parâmetros clínicos periodontais (IP, IG, PS, RG e NIC) e coleta de sangue para avaliação dos marcadores séricos inflamatórios (oxLDL, CT, TG, LDL, HDL, glicose, HbA1c, PCRus, leucócitos e neutrófilos). Os parâmetros periodontais mostraram melhora significativa (p<0,05) no grupo teste, exceto RG. IP e IG também diminuíram significativamente no grupo controle após 6 meses. CT e HbA1c apresentaram taxas significativamente maiores no grupo teste, em comparação com o grupo controle. As taxas de PCR-us e HbA1c diminuíram significativamente no grupo teste após a terapia periodontal. A contagem de leucócitos mostrou uma diminuição r... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Periodontal Disease (DP) and Type 2 Diabetes Mellitus (DM2) present the same inflammatory etiopathogenesis and demonstrate a bidirectional relationship, since DM2 affects the severity of PD, and this may contribute to the individual's total inflammatory load, influencing the evolution of DM2. The objective of the present study was to evaluate the risk factors for the development of atherosclerosis in patients with T2DM, with and without chronic periodontitis. We analyzed 48 patients, who were divided into 2 groups: Test (diabetic patients with chronic periodontitis) and Control (diabetic patients without chronic periodontitis). The test group was treated with periodontal debridement and the control group received supragingival prophylaxis. Both groups received plaque control every 3 months. Periodontal clinical parameters (IP, IG, PS, RG and NIC) and collection of blood for evaluation of serum inflammatory markers (oxLDL, CT, TG, LDL, HDL, glucose, HbA1c, hs-CRP, leukocytes and neutrophils). The periodontal parameters showed significant improvement (p <0.05) in the test group, except for RG. IP and IG also decreased significantly in the control group after 6 months. CT and HbA1c presented significantly higher rates in the test group compared to the control group. Rates of Hs-1c and HbA1c decreased significantly in the test group after periodontal therapy. The leukocyte count showed a significant decrease in the control group during the study time. Periodontal therapy promotes... (Complete abstract click electronic access below) / Mestre

A aterosclerose e suas doenças associadas constituem a principal causa de morte no Brasil. Aterosclerose é uma doença inflamatória crônica que atinge a parede das artérias causando bloqueio das mesmas o que eventualmente pode produzir infarto do miocárdio ou acidente vascular cerebral (AVC). A periodontite é uma enfermidade inflamatória causada pelos subprodutos tóxicos que as bactérias produzem quando se colonizam na placa bacteriana. Essa doença é comum em pacientes HIV positivos e o uso de terapia anti-retroviral altamente ativa (HAART) utilizada nesses pacientes ocasiona efeitos adversos, como a lipodistrofia, fato este que pode apressar o ciclo da aterogênese. Assim, existe uma relação entre a presença da aterosclerose e da doença periodontal em pacientes HIV positivos. No entanto, essa relação é pouco estudada na literatura e é o objetivo desse estudo que avaliou 31 pacientes portadores do HIV com diagnóstico de periodontite crônica e 38 pacientes HIV positivos sem periodontite. Ambos os grupos utilizavam a HAART. Nesses pacientes foi avaliado o perfil lipídico (colesterol total, HDL-C, triglicérides, LDL-C), a expressão de anticorpos anti-oxLDL, as concentrações de citocinas séricas (TNF-, IL-1, IL-6 e IL-10) e os dados do hemograma completo, antes e 12 meses após o tratamento periodontal. Os resultados indicaram que os indivíduos com periodontite crônica quando comparados com o grupo controle apresentam níveis plasmáticos aumentados de leucócitos e neutrófilos; e após o tratamento periodontal, as concentrações plasmáticas de TNF-, IL-1 e IgG diminuíram. Assim, vimos que alguns dos marcadores de risco para doenças cardiovasculares diminuem após um plano de reabilitação oral visando o tratamento da doença periodontal em pacientes HIV positivos. Conseqüentemente, sugerimos que a periodontite pode ser um fator de risco para o desenvolvimento da aterosclerose nesses pacientes. / Atherosclerosis and its associated diseases are the leading cause of death in Brazil. Atherosclerosis is a chronic inflammatory disease that affects the wall of the arteries causing blockage that eventually leads to myocardial infarction or stroke. Periodontitis is an inflammatory disease caused by toxic byproducts produced by bacteria that colonize the oral plaque. HIV positive patients commonly present periodontal diseases and the highly active anti-retroviral therapy (HAART) used in these patients lead to side effects such as lipodystrophy which in turn, can speed up the cycle of atherogenesis. Therefore, there is an occult association between the presence of atherosclerosis and periodontal diseases in these patients. However, this correlation is rarely investigated in the literature and was the objective of this study that analysed 30 HIV positive patients with and 39 HIV positive patients without periodontal disease. All the participants were under HAART. Herein we analysed the lipid profile (total cholesterol, HDL-C, triglycerides, LDL-C), the expression of antioxLDL, concentrations of serum cytokines (TNF-, IL-1, IL-6 and IL-10) and full blood test before and 12 months after periodontal treatment. The results showed that individuals with chronic periodontitis presented increased plasmatic levels of leukocytes and neutrophils and after the periodontal treatment, plasmatic levels of TNF-, IL-1 and IgG decreased. Thus, we showed that some of the risk markers for cardiovascular diseases decrease after oral rehabilitation aiming treatment of periodontal disease in HIV positive patients. Therefore, we suggest that periodontites can be a risk factor for the development of atherosclerosis in these patients.

A síndrome dos ovários policísticos (SOP) e a obesidade estão associadas ao aumento do risco cardiovascular, mas não está estabelecido se tal aumento é determinado por estas condições propriamente ditas ou pelos fatores de risco cardiometabólicos a elas associados. Objetivo: determinar, em mulheres jovens e sem fatores de risco cardiometabólicos, a influência da SOP e da obesidade sobre parâmetros vasculares relacionados ao processo de aterogênese. Métodos: foram estudadas pacientes com SOP, subdivididas em portadoras de índice de massa corpórea (IMC) normal e obesas, as quais foram comparadas a mulheres sem SOP (grupo controle) pareadas para o IMC. Foram excluídas participantes tabagistas, com distúrbios do metabolismo da glicose, hipertensão arterial, LDL-C 160 mg/dL e triglicérides 250 mg/dL. Foram avaliados parâmetros clínicos, laboratoriais (perfis hormonal e metabólico) e vasculares [espessura íntimamédia da artéria carótida comum (EIM-ACC), complacência da artéria carótida comum (CP-ACC) e função endotelial da artéria braquial (DMF)], os quais foram avaliados de maneira não-invasiva através de imagens ultrasonográficas de alta-resolução. Para determinar a influência da SOP e da obesidade sobre tais parâmetros, foram formados grupos de acordo com a presença ou ausência de tais condições: grupo SOP vs grupo Controle, independentemente do IMC; grupo IMC normal vs grupo Obesidade, independentemente da presença da SOP. Resultados: Foram selecionadas 25 pacientes com SOP, sendo 10 com IMC normal (34,0 ± 3,2 kg/m2) e 15 obesas (22,4 ± 2,1 kg/m2) e 23 mulheres controles (12 com IMC normal e 11 obesas). As médias de testosterona livre das pacientes com SOP foram significativamente superiores às médias das mulheres controles, independentemente do IMC. As médias do HOMA-IR e da área sob a curva de insulina das pacientes obesas com SOP foram significativamente superiores às observadas nas pacientes com SOP portadoras de IMC normal e mulheres controles. A média da EIM-ACC das pacientes obesas com SOP foi significativamente superior à das mulheres controles com IMC normal (50,0 ± 4,0 vs 47,0 ± 3,0 mm.10-2; p<0,05). As médias da CP-ACC e da DMF foram semelhantes entre pacientes com SOP e mulheres controles, independentemente do IMC. Para avaliar a influência da SOP e da obesidade, as comparações foram, respectivamente: grupo SOP (n=25) vs grupo Controle (n=23); grupo IMC normal (n=22) vs grupo Obesidade (n=26). A faixa etária global foi de 26,0 ± 4,7 anos. Tanto a SOP quanto a obesidade influenciaram os parâmetros de resistência insulínica. A média da EIM-ACC foi maior no grupo SOP do que no grupo Controle (49,1 ± 1,0 vs 47,2 ± 1,0 mm.10-2; p<0,05) e semelhante entre os grupos IMC normal e Obesidade (49,1 ± 1,0 vs 47,3 ± 1,0 mm.10-2; NS). Não foi observada influência da SOP ou da obesidade na CP-ACC e na DMF. Os parâmetros vasculares estudados não se correlacionaram com as outras variáveis analisadas entre as pacientes com SOP e entre as mulheres controles. Conclusão: Em mulheres jovens e sem fatores de risco cardiometabólicos, a presença da SOP teve influência no aumento da EIM-ACC. Assim, a EIMACC pode ser o marcador inicial do processo de aterogênese nesse grupo de pacientes / Polycystic ovary syndrome (PCOS) and obesity are related to the increase in cardiovascular risk, but it is still not known if such risk is due to these conditions themselves or to the cardiometabolic risk factors associated with them. Objective: determine, in young women without cardiometabolic risk factors, the influence of PCOS as well as obesity on vascular parameters related to the process of atherogenesis. Methods: We studied patients with PCOS, subdivided in patients with normal body mass index (BMI) and obeses, who were compared with women without PCOS (control group) pairwise matched for BMI. We excluded smoking subjects, subjects with glucose metabolism disturbances, with arterial hypertension, LDC -L 160 mg/dl and with triglycerides 250 mg/dl. We evaluated clinical, laboratory (hormonal and metabolic profiles) and vascular parameters [common carotidy artery intima-media thickness (CCA-IMT), compliance of commom carotid artery (CP-CCA) and endothelium function of the braquial artery (FMD)], through a non-invasive method using high resolution ultrasound imaging. In order to determine the influence of PCOS and obesity on such parameters, groups were formed according to the presence or absence of such conditions: PCOS group vs Control group, independently of BMI; normal BMI group vs obesity group, independently of PCOS presence. Results: Twenty-five patients with PCOS were selected, being 10 with normal BMI (34.0 ± 3.2 kg/m²), 15 obeses (22.4 ± 2.1 kg/m²) and 23 control women (12 with normal BMI and 11 obeses). The mean values of free testosterone in PCOS patients were significantly higher than the means in controls, independently of BMI. The means of HOMA-IR and the area under the insulin curve in obese PCOS patients were significantly higher than the ones observed in PCOS patients with normal BMI and controls. The means of CCA-IMT in obese PCOS patients was significantly higher than in controls with normal BMI (50.0 ± 4.0 vs 47.0 ± 3.0 mm.10-2; p<0.05). The means of CP-CCA and FMD were similar between PCOS patients and controls, independently of BMI. To evaluate the influence of PCOS and obesity, the comparisons were respectively: PCOS group (n=25) vs Control group (n=23); normal BMI group (n=22) vs Obesity group (n=26). Global age range was 26.0 ± 4.7 years. PCOS as well as obesity influenced the insulin resistance parameters. The means of CCA-IMT was higher in PCOS group than in Control group (49.1 ± 1.0 vs 47.2 ± 1.0 mm.10-2; p<0.05) and similar between normal BMI and Obesity groups (49.1 ± 1.0 vs 47.3 ± 1.0 mm 10-2; NS). It was not observed any influence of PCOS or obesity in CP-CCA and in FMD. The vascular parameters studied did not correlate with the other variables analized between PCOS patients and controls. Conclusions: In young women without cardiometabolic risk factors, the presence of PCOS had influence on the increase of CCA-IMT. Thus, CCA-IMT might be the initial marker of the atherogenic process in this group of patients

Vários estudos que tentam compreender a gênese da aterosclerose têm demonstrado evidências que a oxLDL é peça importante para o desenvolvimento da doença, tornando-a um importante marcador. Os objetivos deste trabalho foram propor um novo imunossensor empregando anticorpos monoclonais anti-oxLDL e desenvolver um processo inovador de obtenção de anticorpos plásticos anti-oxLDL. Para construção do imunossensor, a região Fc do anticorpo foi ligada ao eletrodo de trabalho do dispositivo AuSPE (Screen-Printed Gold Electrodes), utilizando cisteamina. Posteriormente, foi adicionado BSA como bloqueador de possíveis regiões livres. Após o bloqueio, o imunossensor foi testado com oxLDL e outros antígenos, como forma de garantir a especificidade. Em relação aos anticorpos plásticos, chamados MAPS, estes foram desenvolvidos contruindo uma camada impressa de forma invertida ao anticorpo plástico SPAN, referência deste trabalho. Após obtenção dos MAPSs, estes passaram por diversos testes, similar ao imunossensor. Os resultados demonstraram excelente sensibilidade e especificidade às moléculas de oxLDL com detecção em tempo real em ambas as metodologias. / Increased levels of plasma oxLDL are associated with atherosclerosis, and the subsequent development of severe cardiovascular diseases that are today a major cause of death in modern countries. It is therefore important to find a reliable and fast assay to determine oxLDL. A new Immunosensor employing three monoclonal antibodies against oxLDL and a backside protein-surface imprinting process are proposed in this work. To generate the Immunosensor the mAbs were set-up by cysteamine on a gold layer of a disposable screen-printed electrode. BSA was immobilized further as bloker. All steps were followed by various characterization techniques such as electrochemical impedance spectroscopy and square wave voltammetry. To generate specific synthetic antibody materials, called MAPS, these were developed with a backside protein-surface imprinting process of the plastic antibody SPAN, the reference of the work. The devices were successfully applied to determine the oxLDL fraction in real serum, without prior dilution or necessary chemical treatment. Overall, these were promising results with the possibility to apply on the practical use of clinical.

O aumento da morbimortalidade cardiovascular nos indivíduos com doença arterial periférica (DAP) e claudicação intermitente (CI) se associa a alterações hemodinâmicas, autonômicas, endoteliais, inflamatórias e de estresse oxidativo, que são inerentes ao desenvolvimento da própria doença. O treinamento de caminhada (TC) pode atenuar os processos fisiopatológicos que cursam com a doença, o que precisa ser melhor investigado. Por outro lado, a execução da caminhada até a dor máxima nesses indivíduos provoca episódios de isquemia, que geram alterações nesses processos e promovem sobrecarga cardiovascular. É possível que o TC possa atenuar essas respostas após o esforço máximo, o que também foi pouco investigado. Dessa forma, o objetivo do presente estudo foi verificar, em indivíduos com DAP e CI, o efeito de um TC sobre a função e regulação cardiovasculares, bem como sobre marcadores locais (músculo) e sistêmicos (sangue) de função endotelial, estresse oxidativo e inflamação, avaliados em repouso e após uma caminhada até a dor máxima de claudicação. Para tanto, 32 homens com DAP e CI foram divididos aleatoriamente em dois grupos: TC (n = 16, 2 sessões/sem, 15 séries de 2 min de caminhada na frequência cardíaca do limiar de dor intercaladas com 2 min de pausa passiva) e controle (CO, n =16, 2 sessões/semana, 30 min alongamento). No início e ao final do estudo, os indivíduos realizaram uma caminhada máxima e as seguintes avaliações foram realizadas pré e pós-caminhada: função cardiovascular (pressão arterial - PA, frequência cardíaca - FC, duplo produto - DP); regulação autonômica cardiovascular (variabilidade da FC e da PA e sensibilidade barorreflexa - SBR); função endotelial (óxido nítrico sanguíneo - NO e óxido nítrico sintase muscular - eNOS); estresse oxidativo (catalase - CAT, superóxido dismutase - SOD, peroxidação lipídica - LPO no sangue e no músculo); e inflamação (interleucina-6 - IL-6, proteína C-reativa - PCr, fator de necrose tumoral alfa - TNF-alfa, moléculas de adesão intercelular - ICAM, moléculas de adesão vascular - VCAM no sangue e no músculo). Os dados foram avaliados pela ANOVA de 2 fatores, empregando-se o teste de post-hoc de Newman-Keuls e adotando-se P<0,05 como significante. No repouso, o TC diminuiu a sobrecarga cardiovascular (PA sistólica, PA média, FC e DP) e o balanço simpatovagal cardíaco; aumentou a SBR, a biodisponibilidade de NO, a eNOS e a defesa antioxidante (SOD e CAT no sangue; SOD no músculo), além de reduzir o perfil inflamatório (PCr, ICAM e VCAM no sangue; IL-6 e PCr no músculo) (todos, p<0,05). Em relação à resposta à caminhada máxima, o TC: 1) não modificou o aumento da sobrecarga cardiovascular ao esforço, mas diminuiu a sobrecarga absoluta após o exercício (PA sistólica, PA média e DP); 2) diminuiu a resposta do NO sanguíneo e da eNOS muscular, sem alterar os valores absolutos atingidos após o exercício; 3) não modificou a resposta e os valores absolutos pós-exercício da capacidade antioxidante (SOD e CAT) e do estresse oxidativo (LPO) sistêmicos e locais, mas impediu o aumento da LPO pós-exercício observado no grupo CO; e 4) aumentou a resposta inflamatória sistêmica e local ao exercício (TNF-alfa, ICAM e VCAM no sangue e IL-6, PCr e VCAM no músculo) com manutenção da inflamação sistêmica pós-exercício e redução da inflamação local (VCAM). Em conclusão, em homens com DAP e CI, o TC melhora a modulação autonômica e a função cardiovascular, aumenta a biodisponibilidade de NO e diminui o estresse oxidativo e a inflamação tanto sistêmicos quanto locais. Além disso, o TC, de modo geral, não altera ou mesmo reduz as respostas desses marcadores após uma caminhada até a dor máxima de claudicação / The increase in cardiovascular morbimortality in individuals with peripheral artery disease (PAD) and intermittent claudication (IC) is associated with alterations in cardiovascular function, cardiac autonomic modulation, endothelial function, oxidative stress and inflammation, which are processes inherent to the disease development. Walking training (WT) may attenuate these pathophysiological processes, however, knowledge about these effects of WT is scarce and controversial. On the other hand, in these individuals, a bout of walking promotes ischemic episodes that may exacerbate these processes, leading to cardiovascular overload. WT might attenuate these post-walking responses; however, these effects were also poorly studied. Thus, the aim of the present study was to evaluate, in individuals with PAD and IC, the effects of WT on cardiovascular autonomic modulation and function as well as on blood and muscle markers of endothelial function, oxidative stress and inflammation assessed at rest and after a walking until maximal leg pain. Thirty-two men with PAD and IC were randomly allocated in two groups: WT (n = 16, 2 sessions/week, 15 bouts of 2 min walking at an intensity corresponding to the heart rate of the pain threshold interspersed with 2 min of passive pause) and control (CO, n =16, 2 sessions/week, 30 min of stretching). At the beginning and end of the study, the subjects underwent a maximal walking and the following evaluations were done pre and post-exercise: cardiovascular function (blood pressure - BP, heart rate - HR, rate pressure product - RPP); cardiovascular autonomic modulation (HR and BP variabilities and baroreflex sensitivity - BRS); endothelial function (blood nitric oxide - NO and muscle nitric oxide synthase - eNOS); oxidative stress (catalase - CAT, superoxide dismutase - SOD, lipid peroxidation - LPO measured in blood and muscle); and inflammation (interleukin-6 - IL-6, C-reactive protein - CRP, tumor necrosis factor alpha - TNF-alpha, intercellular adhesion molecules - ICAM, vascular adhesion molecules - VCAM measured in blood and muscle). Data were evaluated by 2-way ANOVA, and Newman-Keuls test was used as a post-hoc. P <0.05 was set as significant. At rest, WT decreased cardiovascular overload (systolic BP, mean BP, HR and RPP) and sympathovagal balance; increased BRS, blood NO, muscle eNOS and antioxidant defence (blood SOD and CAT, and muscle SOD), besides decreasing inflammatory markers (blood CRP, ICAM and VCAM and muscle IL-6 and CRP). Concerning the response after maximal walking, WT: 1) did not change cardiovascular overload increase after the effort, but reduced the absolute post-exercise overload (systolic BP, mean BP and RPP); 2) decreased blood NO and muscle eNOS responses without changing the absolute values achieved after the exercise; 3) did not change systemic and local antioxidant (SOD and CAT) and oxidative stress (LPO) responses as well as post-exercise absolute values; but mitigated the increase in postexercise oxidative stress observed in the CO group; and 4) increased systemic and local inflammatory responses (blood TNF-alpha, ICAM e VCAM and muscle IL-6, PCr e VCAM), but did not change post-exercise absolute systemic inflammation and decreased post-exercise absolute local inflammation (VCAM). In conclusion, in men with PAD and IC, WT improves cardiovascular function and autonomic modulation, increases NO bioavailability and decreases systemic and local oxidative stress and inflammation. In addition, in general, WT does not alter or even reduces these processes responses after a walking until maximal claudication pain

Doenças cardiovasculares podem ocasionar manifestações clínicas graves como infarto agudo do miocárdio e acidentes vasculares trombóticos, constituindo a principal causa de morte no mundo, fato esse que desperta grande interesse da indústria farmacêutica. As causas normalmente estão relacionadas à elevação dos níveis de colesterol e à agregação plaquetária, que acarretam eventos vaso-oclusivos. Entre as alternativas terapêuticas para o controle e prevenção das doenças cardiovasculares podem-se destacar os inibidores da 3-hidroxi-3-metilglutaril coenzima-A redutase (HMG-CoA redutase), popularmente conhecidos como estatinas. A rosuvastatina merece destaque nessa classe de fármacos, devido à maior seletividade e potência na redução dos níveis de colesterol LDL. O ácido acetilsalicílico, antiinflamatório não-esteróide, também representa uma importante alternativa terapêutica para prevenção de doenças cardiovasculares, devido à sua ampla aceitação como inibidor da agregação plaquetária. Considerando seus mecanismos de ação, estatinas e ácido acetilsalicílico podem ser usados em conjunto para a prevenção de doenças cardiovasculares. Face ao exposto e tendo-se em vista a importância dos dendrímeros como transportadores de fármacos na latenciação, o presente trabalho teve como objetivo desenvolver o pró-fármaco dendrimérico potencialmente ativo em doenças cardiovasculares contendo rosuvastatina e ácido acetisalicílico. Diversas metodologias de síntese foram realizadas na tentativa de obtenção do pró-fármaco dendrimérico composto por mio-inositol ou etilenoglicol como foco central, ácido L(-)-málico e etilenoglicol como espaçantes e rosuvastatina e ácido acetilsalicílico como compostos bioativos. Parte dos intermediários propostos foi sintetizada e purificada com sucesso. As maiores dificuldades encontradas foram a purificação dos compostos e a hidrólise seletiva da proteção do ácido málico protegido. Adicionalmente, realizaram-se estudos computacionais para prever a liberação dos fármacos do pró-fármaco dendrimérico. / Cardiovascular diseases can lead to several clinical manifestations such as myocardial infarction and stroke. Those diseases represent the main cause of death globally and this fact triggers a great interest from the pharmaceutical industries. The causes are usually related to high cholesterol levels and platelet aggregation, which are responsible for the vaso-occlusive events. Among the available drug therapy for control and prevention of cardiovascular diseases, the inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase), popularly known as statins, can be highlighted. Rosuvastatin deserves mention in this class of drugs due to its greater selectivity and potency in reducing the levels of LDL cholesterol. Aspirin, a nonsteroidal anti-inflammatory, also represents an important drug therapy for treatment and prevention of cardiovascular diseases, due to its widespread acceptance as a platelet aggregation inhibitor. Considering their mechanism of action, aspirin and statin can be used in association for prevention of cardiovascular diseases. This said and taken into account that dendrimers are important as carriers in prodrug design the purpose of this work was the synthesis of dendrimer prodrugs potentially active in cardiovascular diseases containing aspirin and rosuvastatin. Several synthetic methods have been used with the aim to synthesizing the dendrimer produgs composed of myo-inositol or ethyleneglycol as core, L-(-)-malic acid and ethyleneglycol as spacer groups and rosuvastatin and aspirin as bioactive compounds. Some of the proposed intermediates was synthesized and purified successfully. The main difficulties were purification of compounds and selectivy desprotection of protected malic acid. Additionally, computational studies were performed in order to predict the release of those drugs from dendrimer prodrugs

Estudos anteriores em nosso laboratório demonstraram que pacientes portadores de DAC apresentam diferenças no metabolismo do CL e CE de uma nanoemulsão artificial rica em colesterol (LDE), nos quais o CL apresentou maior remoção plasmática e depósito arterial. Dando continuidade a esta linha de pesquisa, neste trabalho foram avaliadas a cinética plasmática, representada pela taxa fracional de remoção (TFR), e a captação do 3H-colesterol livre (3H - CL) e 14C - colesterol esterificado (14C - CE) da LDE por segmentos arteriais e por órgãos de coelhos normais (n=17) e coelhos submetidos à indução de aterosclerose por dieta rica em colesterol (1%) (n=13). Além disso, avaliou-se a captação in vitro do 3H CL e do 14C CE da LDE por células endoteliais aórticas de coelhos. Por último, foi avaliada a influência da inibição da enzima lecitina-colesterol aciltransferase (LCAT), e indiretamente, a esterificação do CL em ratos normais (n=9) e tratados com diazepam (n=9). Em coelhos que receberam dieta normal, não houve diferença entre a remoção plasmática do 3H - CL e do 14C - CE. Em coelhos que desenvolveram hiperlipidemia e aterosclerose através de dieta rica em colesterol, o 3H - CL foi removido mais rapidamente da circulação do que o 14C - CE (p<0,05), entretanto houve maior captação de 14C - CE do que de 3H - CL no arco aórtico (p<0,05). Em ambos os grupos, os principais órgãos captadores de colesterol da LDE foram fígado, pulmão, adrenais e baço (p<0,05). Tanto a TRF quanto a captação hepática de 3H - CL e 14C - CE foram menores no grupo que recebeu a dieta rica em colesterol. Em células endoteliais aórticas de coelhos, a captação de 3H - CL foi maior que a de 14C CE independente da massa de LDE incubada (p<0,01). Em ratos, não houve diferença entre a captação das duas formas de colesterol da LDE pela aorta no grupo controle, entretanto, quando a atividade da LCAT foi diminuída pelo tratamento com diazepam, a captação arterial de 3H - CL foi maior do que a de 14C - CE (p< 0,01). A hiperlipidemia e distúrbios no processo de estabilização do colesterol, favorecem a dissociação entre o CL e o CE das lipoproteínas, e podem elevar o risco de desenvolvimento da aterosclerose, assim como agravar o processo de aterogênese. / I n previously studies, it was shown that free cholesterol (FC) and cholesterol ester (CE) of a cholesterol-rich nanoemulsion (LDE) behaves differently in patients with coronary artery disease (CAD). The FC plasma clearance and arterial deposition is greater than CE. In the present study we evaluate the plasma kinetics, estimated by the fractional clearance rate (FCR), and the tissue uptake of 3H-free cholesterol (3H FC) and of 14C cholesterol ester (14C - CE) of LDE by arterial segments and organs of rabbits with (n=13) and without atherosclerosis (n=17). Furthermore, it was evaluated the in vitro uptake of 3H FC and 14C - CE by rabbit aortic endothelial cells. Finally, it was evaluated the inhibition of the enzyme lecithin-cholesterol acyltransferase (LCAT), and indirectly, the FC esterification in rats non-treated (n=9) and treated with diazepam (n=9). In rabbits without atherosclerosis that received an standard diet there was no difference between the plasma clearance of 3H FC and 14C CE. In rabbits with hyperlipidemia and atherosclerosis induced by the cholesterol-rich diet the 3H - FC was removed faster than 14C - CE (p<0.05), however the arch aortic uptake of 14C CE was greater than of 3H - FC (0p<0.05). In both groups, liver, lungs, adrenals and spleen were the principal sites of LDE cholesterol uptake. The FCR and tissue uptake were smaller in rabbits with than those without atherosclerosis. In rabbit aortic endothelial cells the 3H - FC uptake was greater than 14C CE independently of incubated LDE mass (p<0.01). In control rats there was no difference on the arterial uptake of both cholesterol forms of LDE, but when the LCAT activity was diminished by the diazepam treatment, the arterial uptake of 3H FC were greater than 14C CE (p< 0.01). The hyperlipidemia and cholesterol stability alterations may lead to dissociation between lipoproteins FC and CE. This dissociation may increase the risk for atherosclerosis and likewise enhance the severity of atherosclerosis.

L’effet athéroprotecteur des Lipoprotéines de Haute Densité (HDL) est principalement attribué à leur rôle clé dans Transport Retour du Cholestérol (RCT), un processus par lequel le cholestérol excédentaire des cellules périphériques est capté par les particules HDL pour être amené au foie où il sera préférentiellement sécrété dans les voies biliaires, puis excrété dans les fèces. Deux voies indépendantes ont été identifiées comme étant impliquées dans l’endocytose hépatique du HDL. La première est la voie ecto-F1-ATPase/P2Y13 dans laquelle l’apoA-I (apolipoprotéine majoritaire des HDL) se lie à la F1-ATPase exprimé à la surface des hépatocytes (ecto-F1-ATPase) et stimule l’hydrolyse d’ATP en ADP. L’ADP ainsi généré active le récepteur purinergique P2Y13 pour stimuler l’endocytose de l’holoparticule HDL (protéines + lipides) via un troisième récepteur différent de SR-BI. Les souris invalidées pour P2Y13 présentent une diminution des sécrétions de lipides biliaires accompagnée d’une diminution du RCT des macrophages vers les fèces sous régime normolipidique. Un régime riche en cholestérol (1.25% cholestérol) accentue ce phénotype. La voie SR-BI, quant à elle, est responsable de la captation sélective du cholestérol estérifié des HDL par le foie. Les souris invalidées pour SR-BI spécifiquement au niveau du foie (SR-BI KOfoie) présentent une hypercholestérolémie principalement attribuée à une augmentation du HDL-C et développent des plaques d’athérosclérose sous régime hypercholestérolémique. Dans une étude récente, nous avons montré que l’invalidation de P2Y13 dans le modèle murin proathérogène apoE KO induit une augmentation du développement d’athérosclérose associée à une diminution des sécrétions de lipides biliaires et du RCT des macrophages vers les fèces. De plus, dans ces souris, l’expression hépatique transcriptionnelle et protéique de SR-BI étaient fortement augmentées par rapport aux souris apoE KO, suggérant qu’un possible mécanisme de compensation pourrait exister entre les récepteurs P2Y13 et SR-BI. L’objectif de ma thèse a été d’étudier la contribution respective des récepteur P2Y13 et SR-BI dans le métabolisme du HDL-C et le développement de l’athérosclérose. Nous avons croisé des souris P2Y13 KO avec des souris SR-BI KOfoie et nous avons obtenu des souris doublement invalidées (P2Y13 x SR-BIfoie dKO). Le phénotype métabolique des souris dKO a été étudié sous régime normolipidique et hypercholestérolémique et le développement d’athérosclérose sous régime hypercholestérolémique. Par rapport aux souris sauvages, les souris dKO sous régime normolipidique, présentent une augmentation du cholestérol plasmatique similaire à celle observée chez les souris SR-BI KOfoie, principalement imputable à une augmentation du HDL-C. Les souris dKO, mais pas les souris SR-BI KO, montrent une diminution des sécrétions de lipides biliaires comparable à celle observée chez les souris P2Y13 KO. Ce phénotype métabolique observé chez les souris dKO est accentué sous régime hypercholestérolémique et est associé à une augmentation des plaques d’athérosclérose par rapport aux souris SR-BI KOfoie. L’ensemble des résultats montrent que la délétion hépatique de SR-BI contribue essentiellement à une augmentation des taux plasmatiques de cholestérol, et plus particulièrement HDL-C. La délétion de P2Y13, quant à elle, n’induit aucune variation des lipides plasmatiques mais contribue principalement à une diminution des sécrétions de lipides biliaires qui contribue au développement de l’athérosclérose chez les souris invalidées pour SR-BI hépatique. Ces résultats soutiennent le concept selon lequel le flux de cholestérol transporté par les HDL des tissus périphériques vers le foie et les voies de sécrétions biliaires est plus important dans l’athéro-protection que la concentration plasmatique en HDL-C. L’activation du récepteur P2Y13 constitue une approche thérapeutique intéressante pour cibler les HDL contre le développement de l’athérosclérose. / The atheroprotective effect of High Density Lipoproteins (HDL) is mostly attributed to their central role in Reverse Cholesterol Transport (RCT), a process whereby excess cholesterol is taken up from peripheral cells to be processed into HDL particles, then later delivered to the liver where it is preferentially secreted into the bile, either as free cholesterol or after transformation into bile acids, to be further excreted into the feces. Two independent pathways have been identified as being involved in the hepatic HDL uptake. The first one involves the ecto-F1-ATPase/P2Y13 pathway. Briefly, apoA-I (main HDL apolipoprotein) binds to the F1-ATPase expressed ectopically at the surface of the hepatocyte (ecto-F1-ATPase) and stimulates hydrolysis of extracellular ATP into ADP. The generated ADP selectively activates the purinergic receptor P2Y13 resulting in subsequent endocytosis of the HDL-holoparticle (i.e. protein and lipid moieties) through a low-affinity binding site distinct from SR-BI. Mice deficient for P2Y13 display decreased biliary lipids secretion associated to an impaired macrophage-to-feces RCT when fed a Chow Diet (CD), phenotype emphasized when fed a High Cholesterol Diet (HCD). Differently, the SR-BI pathway mediates selective HDL-cholesteryl ester uptake by the liver. Mice with liver-specific SR-BI deficiency (SR-BI-KOliver) display a hypercholesterolemia mainly due to an increase on HDL-C and develop atherosclerosis when fed a HCD. In a recent study, we showed that P2Y13 extinction in the pro-atherogenic mouse model apoE-KO resulted in an increase of atherosclerotic plaque development associated to a decreased biliary lipid secretion and macrophage-to-feces RCT. Moreover, in these mice, mRNA and protein level of hepatic SR-BI were consistently increased as compared to apoE KO mice, suggesting that a possible compensatory mechanism might exist between P2Y13 and SR-BI receptors. My thesis aimed to study the respective contribution of P2Y13 and hepatic SR-BI in HDL-C metabolism and atherosclerosis development. We crossbred P2Y13 KO with SR-BI KOliver mice and obtained double knockout mice (P2Y13 x SR-BIliver dKO). The phenotype of dKO mice was analysed with regards to HDL-C metabolism either on CD or after 20 weeks of HCD, and to atherosclerosis development on HCD. When fed a CD, dKO mice, showed an increase in plasma cholesterol compared to WT mice similar to that observed in SR-BI KOliver mice, mainly due to an increase in HDL-C. DKO, but not SR-BI KOliver mice, showed impaired biliary lipid secretion to the same extent than P2Y13 KO mice. HCD accentuated the metabolic phenotype of dKO mice, with an increase in atherosclerotic lipid lesions in dKO mice compared to SR-BI KOliver mice. The phenotypic features of P2Y13 x SR-BIliver dKO mice show that hepatic extinction of SR-BI essentially contributes to an increase of HDL-C levels. Conversely, P2Y13 extinction does not induce any change in plasma lipoprotein levels but mainly contributes to a decrease of hepato-biliary cholesterol secretions, which translates into an increased atherosclerosis development, on top of SR-BI hepatic extinction. These results support the concept that the dynamic flux of cholesterol transported by HDL from macrophage foam cells to the liver for further bile secretion is essential for athero-protection rather than steady-state HDL-C concentration. In the future of HDL-therapies, P2Y13 receptor activation constitutes an interesting therapeutic approach against atherosclerosis development.

ShcA (Src Homology and Collagen A) est une protéine adaptatrice qui se lie à la partie cytoplasmique de LRP1 (Low Density Lipoprotein-related receptor 1), un récepteur transmembranaire qui protège contre l'athérosclérose. La calcification vasculaire est une complication majeure de cette maladie et ses mécanismes ressemblent au processus d’ostéochondrogenèse. Nous avons étudié le rôle de ShcA endothélial dans la formation des lésions d’athérosclérose ainsi que les rôles de ShcA et LRP1 dans la chondrogenèse. ShcA endothélial participe à la formation des lésions d’athérosclérose in-vivo. En inhibant la NOS endothéliale et activant l’expression de ICAM-1 via ZEB1, ShcA favorise l’adhésion des monocytes. La suppression de ShcA dans les chondrocytes a conduit au développement de souris présentant un phénotype de nanisme par une inhibition de la différenciation hypertrophique des chondrocytes. Ceci conduit également à une diminution du développement de l’arthrose liée au vieillissement. La suppression de LRP1 dans les chondrocytes conduit également à un phénotype de nanisme chez la souris, mais par des mécanismes différents. / ShcA (Src Homology and Collagen A) is an adaptor protein that binds to the cytoplasmic tail of the Low Density Lipoprotein-related receptor1 (LRP1), a trans-membrane receptor that protects against atherosclerosis. Vascular calcification is a major complication of this disease and its mechanisms highly resemble the process of osteochondrogenesis. We studied the role of endothelial ShcA in atherosclerotic lesion formation as well as the roles of ShcA and LRP1 in chondogenesis. Endothelial ShcA participates in the formation of atherosclerotic lesions in-vivo. By inhibiting endothelial NOS and activating the expression of ICAM-1 via ZEB1, ShcA enhances monocyte adhesion. The deletion of ShcA in chondrocytes led to the development of mice with a dwarfism phenotype by inhibiting chondrocyte hypertrophic differentiation. This also led to a decrease in the development of age-related osteoarthritis. The deletion of LRP1 in chondrocytes also led to a dwarfism phenotype in our mouse model, but trough different mechanisms.