Antonio López Farré

Proteomic approach to identify changes in protein expression modified by 17β-oestradiol in bovine vascular smooth muscle cells

The aim of the present study was to use proteomics to analyse modifications in the level of expression of different proteins in BVSMCs (bovine vascular smooth muscle cells) incubated in the absence and presence of 17beta-oestradiol. By using two-dimensional electrophoresis with a pH range of 4-7, we identified several areas on the gels in which the level of expression of proteins were different between control BVSMCs and cells incubated for 24 h with 17beta-oestradiol. Changes in several isoforms of alpha-enolase, HSP60 (heat-shock protein 60), vimentin and PDI (protein disulphide-isomerase) were observed in BVSMCs. The expression of alpha-enolase isoform 1 was enhanced after 17beta-oestradiol treatment. The expression of HSP60 isoform 3, vimentin isoforms 2 and 3 and caldesmon was reduced by 17beta-oestradiol. Finally, the expression of PDI isoforms was reduced by 17beta-oestradiol. In summary, 17beta-oestradiol modified the expression of isoforms of proteins associated with smooth muscle cell proliferation (alpha-enolase, vimentin and HSP-60), cell contraction (vimentin and caldesmon) and cell redox modulation (PDI). These findings confirm that 17beta-oestradiol may modulate a wide range of signalling pathways in vascular smooth muscle cells.

Efectos antitrombóticos y antiinflamatorios de los ácidos grasos omega-3

Los ácidos grasos poliinsaturados de la dieta pueden clasificarse en dos tipos: ácidos grasos omega-3 (n-3) y ácidos grasos omega-6 (n-6). Los ácidos grasos n-3 se metabolizan en el organismo dando lugar a diferentes ácidos grasos n-3, y los de un mayor interés desde el punto de vista cardiovascular son los de cadena larga (PUFA n-3). Tres mecanismos principales parecen estar involucrados en el efecto protector cardiovascular de los ácidos grasos n-3: su efecto antiinflamatorio, su efecto antitrombótico y su acción antiarrítmica. En cuanto a su efecto antitrombótico, hay datos experimentales que indican que la ingesta de ácidos grasos omega-3 tiene un efecto antitrombótico principalmente mediado por una reducción en la formación de tromboxano. Se disponde de datos sobre su efecto antiinflamatorio que demuestran la reducción en la expresión de proteínas de adhesión. Sin embargo, en los estudios de intervención dietética en humanos estos 2 efectos no se repiten de forma consistente en todos los estudios publicados. En esta revisión se analizan los diferentes mecanismos de acción antitrombótica y antiinflamatoria de los ácidos grasos omega-3.

Impact of Clopidogrel and Aspirin Treatment on the Expression of Proteins in Platelets from Type-2 Diabetic Patients with Stable Coronary Ischemia

The purpose of this study was to compare the effect of dual antiplatelet therapy [clopidogrel + aspirin (ASA)] with respect to ASA on the protein expression of platelets from controlled type-2 diabetic patients with stable coronary ischemia. Patients had been taking ASA (100 mg day) and they were randomized to receive (n = 29) or not (n = 28) 75 mg day clopidogrel for 12 ± 2 weeks in a blind form. Protein expression was analyzed by two-dimensional electrophoresis and mass spectrometry. The protein expression of a limited number of proteins such as actin-binding protein isotypes 2 and 5, lactate dehydrogenase, serotransferrin isotype 4, protein disulfide isomerase-A3 isotype 1, fibrinogen beta chain isotype 5, Ras-related protein Rab-7b isotypes 1 and 6, and immunoglobulin heavy chain was changed after dual antiplatelet therapy. Plasma level of platelet factor 4 (PF4), an in vivo marker of platelet activity, was not different between both groups. These changes suggest lower platelet reactivity after dual antiplatelet therapy in the studied patients. However, the variation in platelet proteome was lower than it would be initially expected, taking into account the apparent clinical beneficial effects of dual antiplatelet therapy. PF4 plasma level was not further decreased in the platelets treated for a longer time than 9-12 months with ASA + clopidogrel, as compared with ASA alone.

Old and new molecular mechanisms associated with platelet resistance to antithrombotics.

ABSTRACTCurrent available data show that about 5 to 40% of coronary patients treated with conventional doses of antithrombotic drugs do not display adequate antiplatelet response. Nowadays, aspirin remains the main antiplatelet therapy. However, a significant number of patients show platelet resistance to aspirin therapy, and recurrent thrombotic events occur. Combined antithrombotic therapies with thienopyridines, such as clopidogrel have been used to resolve this problem. However, clopidogrel treatment has been also associated with wide response variability, and non-responsiveness to clopidogrel also occurs in some patients. Therefore, the main question arising about the antithrombotic therapy is why particular patients do not benefit from the therapy and how they might be identified to improve their treatment. Different hypotheses have been suggested, including genetic factors, platelet heterogeneity, non-compliance and others. However, it is probably that many molecular mechanisms involved in platelet resistance to antithrombotic therapies still remains unknown. New technologies, such as proteomics and genetic, are beginning to show new unknown biological biomarkers and molecular mechanisms which may be associated with platelet antithrombotic drug resistance.

Plaqueta: fisiología de la activación y la inhibición

Las plaquetas tienen un papel fundamental tanto en la hemostasia como en la patogenia de la aterotrombosis. Despues de producirse la rotura de la placa de ateroma, diferentes proteinas se expresan en la plaqueta que interviene tanto en la union de la plaqueta a la pared vascular danada como en la interaccion con nuevas plaquetas y otras celulas sanguineas para formar el trombo final. Diferentes agonistas, entre ellos el difosfato de adenosina, el tromboxano A2 y la trombina, se sintetizan y se liberan para llamar a mas plaquetas a formar parte del trombo. Ademas, diferentes inhibidores endogenos de las plaquetas tratan de formar los agonistas plaquetarios anteriormente mencionados. Las plaquetas jovenes y las microparticulas derivadas de las plaquetas tambien participan en la formacion del trombo. Este articulo trata de revisar los mecanismos fisiologicos implicados en la activacion y la inactivacion plaquetarias.

Effects of hormones on platelet aggregation.

Abstract Platelets and their activation/inhibition mechanisms play a central role in haemostasis. It is well known agonists and antagonists of platelet activation; however, during the last years novel evidences of hormone effects on platelet activation have been reported. Platelet functionality may be modulated by the interaction between different hormones and their platelet receptors, contributing to sex differences in platelet function and even in platelet-mediated vascular damage. It has suggested aspects that apparently are well established should be reviewed. Hormones effects on platelet activity are included among them. This article tries to review knowledge about the involvement of hormones in platelet biology and activity.

Actual Pharmacological Treatment to Reduce Growth of Small Abdominal Aneurysm

Abdominal aortic aneurysm (AAA), defined as a permanent segmental dilatation of the abdominal aorta, is a pathology responsible for significant morbidity and mortality especially among adult population over 60 years of age. Indeed, AAA is one of the fifteen most frequent causes of death among men older than 55 years in Western societies (Lederle et al., 2000). However, despite of its importance, little is known about etiopathogenesis of AAA. The observation by non-invasive imaging methods of an abdominal aorta of 3 cm typically or large in maximal diameter is generally considered to indicate aneurysm formation (Lederle et al., 2000). Diagnosis is typically made by non-invasive imaging modalities such as ultrasound, computerized tomography scan or magnetic resonance imaging with formal aortic angiography utilized in special clinical scenarios. At present, surgical treatment, conventional or endovascular surgery of AAA are very effective to prevent AAA rupture in patients with large AAA, at least 5,5 cm in diameter, with high risk of rupture. However, despite AAA with diameter <5,5 cm (termed as small AAA) have a low risk of rupture there are non well-defined therapeutic strategies for them. Moreover, the group of patients with small AAA should wait expectantly for the aneurysm reaches the minimum size to undergo surgical treatment, living through those days with great anxiety. Many factors may contribute to AAA formation and rupture, there are mechanical and rupture factors among them. Indeed, ultrasound examination showed AAA in 5.8% of World War II amputees, compared with 1% of non-amputees related to asymmetrical flow pattern at the aortic bifurcation. Moreover, evidence of genetic predisposition to the development of AAA has been noteworthy with 19% of AAA patients reporting one or more first-degree relatives with an aneurysm. Therefore, it is important to understand and know the molecular mechanisms involved in AAA expansion and which pharmacological treatments may prevent and delay it.

Horizontes de la proteómica en el diagnóstico y el tratamiento de la enfermedad cardiovascular

La proteomica es una nueva tecnologia, incluso algunos la llegan a considerar como una nueva ciencia, que permite analizar la expresion de multiples proteinas a la vez en una unica muestra. La proteomica puede facilitarnos identificar nuevos biomarcadores utiles para el pronostico y el diagnostico de las enfermedades cardiovasculares. El analisis proteomico esta comenzando a dar resultados en el conocimiento de la aterosclerosis, isquemia miocardica o hipertrofia ventricular, entre otras enfermedades cardiovasculares. Una importante aplicacion de la proteomica es la farmacoproteomica, que trata de identificar biomarcadores que permitan predecir la respuesta farmacologica de un paciente. Ademas, mediante la farmacoproteomica tambien podemos identificar las variaciones en la expresion proteica asociada a un tratamiento farmacologico especifico, lo que facilitara conocer los efectos clase y pleiotropicos de los farmacos.