Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-08-31T17:28:06Z No. of bitstreams: 1 Thassila Nogueira Pitanga Efeito das micropartículas....pdf: 1105021 bytes, checksum: 9c6f0280b9ffe2b38105f8844c3a2b0f (MD5) / Made available in DSpace on 2012-08-31T17:28:06Z (GMT). No. of bitstreams: 1 Thassila Nogueira Pitanga Efeito das micropartículas....pdf: 1105021 bytes, checksum: 9c6f0280b9ffe2b38105f8844c3a2b0f (MD5) Previous issue date: 2011 / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil / Micropartículas (MPs) são vesículas liberadas da membrana plasmática após ativação celular ou fases iniciais de apoptose. MPs de neutrófilos (NMPs) apresentam em suas membranas diferentes proteínas com diferentes funções e diretamente relacionadas com seus efeitos biológicos, tais como mediadores inflamatórios (integrinas e L-selectina) e mieloperoxidase (MPO). A MPO é uma enzima catiônica, presente nos grânulos azurófilos de neutrófilos e monócitos, responsável pela formação de espécies reativas de oxigênio (ROS). Na presença de peróxido de hidrogênio (H2O2), a enzima catalisa a oxidação de íons cloro com a formação de ácido hipocloroso (HOCl). MPs de diversas origens parecem afetar a função vascular por mecanismos dependentes do estresse oxidativo. No presente trabalho investigamos o possível papel de NMPs na lesão de células endoteliais vasculares in vitro. NMPs foram produzidas por ativação de polimorfonucleares (PMNs) humanos com ionóforo de cálcio e caracterizadas por microscopia eletrônica de transmissão e varredura como estruturas delimitadas por bicamada lipídica e com diâmetro menor do que 1 m. A presença da MPO foi confirmada por citometria de fluxo, utilizando o anticorpo anti-MPO, e pela atividade enzimática detectada por quimioluminescência de HOCl, uma ROS catalisada unicamente pela MPO. A adição de azida, inibidor de peroxidases, ou de taurina, “scavanger” de HOCl, inibiu ou reduziu a atividade enzimática, respectivamente. Identificamos moléculas expressas na superfície das NMPs (CD62L, CD66b, CD45, CD95 e fosfatidilserina). A atividade de MPO foi observada após incubação das células endoteliais vasculares in vitro com NMPs, sugerindo que estas apresentam um potencial de carrear a MPO para a superfície endotelial vascular. A exposição de células endoteliais a NMPs induziu alterações morfológicas e perda da integridade da membrana celular, analisadas, respectivamente, por microscópio de contraste de fase e microscopia de fluorescência. Nossos resultados sugerem que NMPs atuam como carreadoras de MPO para a superfície de células endoteliais vasculares e induzem lesão destas células em um mecanismo dependente de MPO, sugerindo sua participação no desenvolvimento das complicações cardiovasculares. / Microparticles (MPs) are vesicles released from the plasma membrane after cell activation or early stages of apoptosis. In its membranes, neutrophil MPs (NMPs) present different proteins with different functions, directly associated with the cell’s biological activities, such as inflammatory mediation via integrins, L-selectin and myeloperoxidase (MPO). MPO is a cationic enzyme found in the azurophilic granules of neutrophils and monocytes that produces reactive oxygen species (ROS). In the presence of hydrogen peroxide (H2O2) it catalyzes the oxidation of chlorine ions with the formation of hypochlorous acid (HOCl). MPs from different sources seem to affect vascular function through oxidative stress dependent mechanisms. In this study we investigated the possible role of NMP in vascular endothelial cell injury in vitro. NMPs were produced by activation of human polymorphonuclear (PMN) cells with calcium ionophore and characterized as structures bounded by lipid bilayer and with less than 1 m diameter by transmission and scanning electron microscopy. MPO presence was confirmed by flow cytometry using anti-MPO antibody, and the enzyme activity detected by chemiluminescence of HOCl, a ROS catalyzed solely by the MPO. The addition of azide, peroxidase inhibitor, or taurine, HOCl scavanger, inhibited and reduced enzymatic activity, respectively. We identified molecules expressed on the NMPs surface (CD62L, CD66b, CD45, CD95 and phosphatidylserine). MPO activity was observed after incubation of vascular endothelial cells in vitro with NMPs, suggesting that they have the potential to carry MPO to the vascular endothelial surface. Exposure of endothelial cells to NMPs induced morphological changes and loss of cell membrane integrity, which were evaluated, respectively, by phase contrast microscopy and fluorescence microscopy. Our findings suggest that NMPs act as carriers of MPO to the surface of vascular endothelial cells and induce damage to these cells with an MPO-dependent mechanism, suggesting its participation in the development of cardiovascular complications.

This diploma thesis consists of two parts - the theoretical and the practical one. The theoretical part is divided into several chapters; the first three are focused on the main information about atherosclerosis such as its definition, predilection areas, process of atherosclerotic changes, the most important risk factors and its clinical consequences. The following chapter introduces the essential measures used in cardiovascular disease prevention. The last chapter deals with education and also describes education for cardiovascular disease prevention. The practical part is dedicated to the assessment of knowledge about the appropriate composition of diet in patients with cardiovascular disease risk factors. The research part was carried out on grounds of the quantitative survey through a questionnaire, which was completed by patients of the Centre for the Prevention of Cardiovascular Disease of the General Teaching Hospital in Prague in the course of three months - from 1st November 2017 to 31st January 2018. There are one main and two partial aims to the study; the main aim was to determine knowledge about the appropriate composition of diet in patients. This aim was accomplished, patients were successful in some knowledge questions, but only a small number of them knew the right answer to...