T lymphocytes from human atherosclerotic plaques recognize oxidized low density lipoprotein.

Atherosclerosis, an underlying cause of myocardial infarction, stroke, and other cardiovascular diseases, consists of focal plaques characterized by cholesterol deposition, fibrosis, and inflammation. The presence of activated T lymphocytes and macrophages and high expression of HLA class II molecules are indicative of a local immunologic activation in the atherosclerotic plaque, but the antigen(s) involved has not yet been identified. We established T-cell clones from human atherosclerotic plaques using polyclonal mitogens as stimuli and exposed the clones to potential antigens in the presence of autologous monocytes as antigen-presenting cells. Four of the 27 CD4+ clones responded to oxidized low density lipoprotein (oxLDL) by proliferation and cytokine secretion; this response was dependent on autologous antigen-presenting cells and restricted by HLA-DR. All clones that responded to oxLDL secreted interferon gamma upon activation, but only one produced interleukin 4, suggesting that the response to oxLDL results in immune activation and inflammation but may not be a strong stimulus to antibody production. No significant response to oxLDL could be detected in CD4+ T-cell clones derived from the peripheral blood of the same individuals. Together, the present data suggest that the inflammatory infiltrate in the atherosclerotic plaque is involved in a T-cell-dependent, autoimmune response to oxLDL.

The role of monocytes in atherosclerotic coronary artery disease

Inflammation plays a key role in the pathogenesis of atherosclerosis. The more we discover about the molecular pathways involved in atherosclerosis, the more we perceive the importance of monocytes in this process. Circulating monocytes are components of innate immunity, and many pro-inflammatory cytokines and adhesion molecules facilitate their adhesion and migration to the vascular endothelial wall. In addition to the accumulation of lipids and formation of atherogenic 'foam' cells, monocytes may promote atherosclerotic plaque growth by production of inflammatory cytokines, matrix metalloproteinases, and reactive oxidative species. However, the contribution of monocytes to atherogenesis is not only limited to tissue destruction. Monocyte subsets are also involved in intraplaque angiogenesis and tissue reparative processes. The aim of this overview is to discuss the mechanisms of monocyte activation, the pivotal role and importance of activated monocytes in atherosclerotic coronary artery disease, their implication in the development of acute coronary events, and their potential in cardiovascular reparative processes such angiogenesis.

Anticorpos contra LDL-ox e síndrome coronariana aguda

FUNDAMENTO: A oxidação da lipoproteína de baixa densidade (LDL-ox) induz à formação de epítopos imunogênicos na molécula. A presença de autoanticorpos contra a LDL-ox tem sido demonstrada no soro de pacientes com doença arterial coronariana (DAC). Contudo, o papel desses autoanticorpos na fisiopatologia das síndromes coronarianas agudas (SCA) e o seu significado clínico permanecem indefinidos. OBJETIVO: Avaliar a associação entre autoanticorpos contra a LDL-ox e SCA. MÉTODOS: Os títulos de imunoglobulina G autoanticorpos contra a LDL-ox por cobre (antiLDL-ox) e contra o peptídeo sintético D derivado da apolipoproteína B (antipeptD) foram determinados por ensaio imunoenzimático (ELISA) em 90 pacientes, nas primeiras 12h de SCA (casos) e em 90 pacientes com DAC crônica (controles). RESULTADOS: Os resultados mostraram que os títulos de antiLDL-ox foram significativamente mais elevados (p = 0,017) nos casos (0,40 ± 0,22), do que nos controles (0,33 ± 0,23). Por outro lado, os títulos de antipeptD foram significativamente menores (p < 0,01) nos casos (0,28 ± 0,23) do que nos controles (0,45 ± 0,30). A diferença dos títulos de ambos anticorpos entre os dois grupos estudados foi independente de idade, sexo, hipertensão arterial, diabete melito, dislipidemia, índice de massa corporal, tabagismo, perfil lipídico, uso de estatinas e história familiar de DAC. CONCLUSÃO: Os resultados mostraram que os títulos de antiLDL-ox foram significativamente mais elevados nos pacientes com síndrome coronariana aguda quando comparados aos pacientes com doença arterial coronariana e podem estar associados à instabilidade da placa aterosclerótica.

The Role of Black Rice (Oryza sativa L.) in the Control of Hypercholesterolemia in Rats

Cardiovascular disease is a serious public health problem; it is the first cause of death in Brazil and in developed countries. Thus, it is essential to search for alternative sources such as some functional foods to prevent and control the risks of this disease. The purpose of this study was to evaluate the lipidemic parameters in hypercholesterolemic rats fed diets containing black rice variety IAC 600 or unrefined rice. Adult male Wistar rats (Rattus norvegicus var. albinos) were used, weighing about 200-220 g. The animals were divided into four groups: the first received a control casein diet, the second received hypercholesterolemic diet, and the other two groups, after induction of hypercholesterolemia, received the test diets, the first containing 20% black rice and the second 20% unrefined, for 30 days. It was observed that diet containing black rice reduced the level of plasma cholesterol, triglycerides, and low-density lipoprotein. For high-density lipoprotein values, the diet that provided an increase in the levels was the black rice. The diet containing black rice was more effective in controlling the lipidemia in rats compared with the whole rice diet.

Bcl-2 in endothelial cells is increased by vitamin E and alpha-lipoic acid supplementation but not exercise training

Atherosclerotic plaque contains apoptotic endothelial cells with oxidative stress implicated in this process. Vitamin E and a-lipoic acid are a potent antioxidant combination with the potential to prevent endothelial apoptosis. Regular exercise is known to increase myocardial protection, however, little research has investigated the effects of exercise on the endothelium. The purpose of these studies was to investigate the effects of antioxidant supplementation and/or exercise training on proteins that regulate apoptosis in endothelial cells. Male rats received a control or antioxidant-supplemented diet (vitamin E and alpha-lipoic acid) and were assigned to sedentary or exercise-trained groups for 14 weeks. Left ventricular endothelial cells (LVECs) were isolated and levels of the anti-apoptotic protein Bcl-2 and the pro-apoptotic protein Bax were measured. Antioxidant supplementation caused a fourfold increase in Bcl-2 (P < 0.05) with no change in Bax (P > 0.05). Bcl-2:Bax was increased sixfold with antioxidant supplementation compared to non-supplemented animals (P < 0.05). Exercise training had no significant effect on Bcl-2, Bax or Bcl-2:Bax either alone or combined with antioxidant supplementation (P > 0.05) compared to non-supplemented animals. However, Bax was significantly lower (P < 0.05) in the supplemented trained group compared to non-supplemented trained animals. Cultured bovine endothelial cells incubated for 24 h with vitamin E and/or a-lipoic acid showed the combination of the two antioxidants increased Bcl-2 to a greater extent than cells incubated with the vehicle alone. In summary, vitamin E and a-lipoic acid increase endothelial cell Bcl-2, which may provide increased protection against apoptosis. (c) 2005 Elsevier Ltd. All rights reserved

Azithromycin does not prevent six-month myointimal proliferation but attenuates the transient systemic inflammation occurring after coronary stenting

Stent implantation produces a systemic increase of inflammatory markers that correlates with Chlamydophila pneumoniae infection in atherosclerotic plaque. We performed a clinical intervention study to investigate the effect of antibiotic treatment on 6-month follow-up angiographic minimal luminal diameter after stenting. Ninety patients were randomly assigned to oral azithromycin or placebo in a double-blinded and randomized fashion. Medication was initiated 2 weeks before a pre-scheduled stenting procedure and maintained 12 weeks thereafter. Angiographic outcomes were evaluated by a six-month follow-up angiography and laboratorial parameters were accessed by blood sampling 2 weeks before stenting, within the first 24 h after procedure and additional samples after four weeks and 6 months. Minimal luminal diameter (1.76 +/- A 0.56 mm Vs. 1.70 +/- A 0.86 mm; P = 0.7), restenosis rate, diameter stenosis, late loss, and binary restenosis rates were comparable in placebo and azithromycin group in the 6 months follow-up. Serum levels of C-reactive protein presented a three fold significant increase in the control group one day after stenting but did not change in the azithromycin group (8.5 [3.0;16.4] Vs. 2.9 [1.7;6.6]-median [25;75 percentile] P < 0.01). Azithromycin does not improve late angiographic outcomes but attenuates the elevation of C-reactive protein levels after stenting, indicating an anti-inflammatory effect.

Repeated three-dimensional magnetic resonance imaging of atherosclerosis development in innominate arteries of low-density lipoprotein receptor-knockout mice

Background-In vivo methods to evaluate the size and composition of atherosclerotic lesions in animal models of atherosclerosis would assist in the testing of antiatherosclerotic drugs. We have developed an MRI method of detecting atherosclerotic plaque in the major vessels at the base of the heart in low-density lipoprotein (LDL) receptor-knockout (LDLR-/-) mice on a high-fat diet. Methods and Results-Three-dimensional fast spin-echo magnetic resonance images were acquired at 7 T by use of cardiac and respiratory triggering, with approximate to140-mum isotropic resolution, over 30 minutes. Comparison of normal and fat-suppressed images from female LDLR-/- mice I week before and 8 and 12 weeks after the transfer to a high-fat diet allowed visualization and quantification of plaque development in the innominate artery in vivo. Plaque mean cross-sectional area was significantly greater at week 12 in the LDLR-/- mice (0.14+/-0.086 mm(2) [mean+/-SD]) than in wild-type control mice on a normal diet (0.017+/-0.031 mm(2), p

Expression of Heparan Sulphate N-deacetylase/N-sulphotransferase by Vascular Smooth Muscle Cells

Heparan sulphate is an important mediator in determining vascular smooth muscle cell (SMC) phenotype. The sulphation pattern of the heparan sulphate chains is critical to their function. We have examined the initial step in the biosynthesis of the sulphated domains mediated by the enzyme heparan sulphate N-deacetylase/N-sulphotransferase (NDST). Rabbit aortic SMC in primary culture exhibited NDST enzyme activity and expressed NDST-1 in their Golgi apparatus, with maximal expression in SMC 2 days after dispersal in primary culture confirmed by Western blot analysis. Endothelial cells, macrophages and fibroblasts expressed NDST-1 but had generally less intense staining than SMC, although SMC expression decreased with culture. The uninjured rat aorta also showed widespread expression of NDST-1. After balloon de-endothelialisation, NDST-1 could not be detected in SMC of the neointima in the early stages of neointimal formation, but was re-expressed at later time points (after 12 weeks). In human coronary arteries, SMC of the media and the diffuse intimal thickening expressed NDST-1, while SMC in the atherosclerotic plaque were negative for NDST-1. We conclude that SMC may regulate their heparan sulphate sulphation at the level of expression of the enzyme heparan sulphate NDST in a manner related to their phenotypic state.

Oral rapamycin attenuates atherosclerosis without affecting the arterial responsiveness of resistance vessels in apolipoprotein E-deficient mice

The objective of the present study was to assess the effects of the immunosuppressant rapamycin (Rapamune®, Sirolimus) on both resistance vessel responsiveness and atherosclerosis in apolipoprotein E-deficient 8-week-old male mice fed a normal rodent diet. Norepinephrine (NE)-induced vasoconstriction, acetylcholine (ACh)- and sodium nitroprusside (SNP)-induced vasorelaxation of isolated mesenteric bed, and atherosclerotic lesions were evaluated. After 12 weeks of orally administered rapamycin (5 mg·kg-1·day-1, N = 9) and compared with untreated (control, N = 9) animals, rapamycin treatment did not modify either NE-induced vasoconstriction (maximal response: 114 ± 4 vs 124 ± 10 mmHg, respectively) or ACh- (maximal response: 51 ± 8 vs 53 ± 5%, respectively) and SNP-induced vasorelaxation (maximal response: 73 ± 6 vs 74 ± 6%, respectively) of the isolated vascular mesenteric bed. Despite increased total cholesterol in treated mice (982 ± 59 vs 722 ± 49 mg/dL, P < 0.01), lipid deposition on the aorta wall vessel was significantly less in rapamycin-treated animals (37 ± 12 vs 68 ± 8 µm2 x 103). These results indicate that orally administered rapamycin is effective in attenuating the progression of atherosclerotic plaque without affecting the responsiveness of resistance vessels, supporting the idea that this immunosuppressant agent might be of potential benefit against atherosclerosis in patients undergoing therapy.

Expressão de Aterosclerose Sub-Clínica para Diferentes Factores de Risco Cardiovasculares em Populações Jovens

INTRODUCTION: Carotid intima-media thickness (cIMT) is considered an early marker for atherosclerosis, but there are few studies on the expression of this marker in younger populations. OBJECTIVES: To evaluate cIMT in younge patients (aged 30-50 years) and its expression according to cardiovascular risk factors. METHODS: We analyzed individuals admitted for an invasive cardiac procedure. Normal cIMT was defined as < 0.90 mm, thickened as 0.90-1.50 mm and atherosclerotic plaque as > 1.50 mm. Lipid profile, anthropometric parameters, fasting blood glucose and estimated GFR were also determined. RESULTS: A total of 106 patients were included (59% male), with a mean age of 43 +/- 5 years, 36% with hypertension, 22% smokers, 32% with known hyperlipidemia, 16% with diabetes, 39% under statin therapy and 40% with metabolic syndrome (AHA/NHLBI definition). Mean cIMT was 0.69 +/- 0.26 mm, and was normal in 74% of the patients, thickened in 20% and with atherosclerotic plaques in 6%. cIMT correlated directly with age (r = 0.26, p = 0.007), log fasting glucose (r = 0.21, p = 0.04), and log triglycerides (r = 0.24, p = 0.017), and tended to correlate with the number of components of metabolic syndrome (r = 0.17, p = 0.08). However, on multivariate analysis, only age remained as an independent predictor (r = 0.29, p = 0.005). Diabetic patients had greater cIMT (0.81 +/- 0.22 vs. 0.67 +/- 0.26 mm, p = 0.039) and there was a trend for greater cIMT in those with metabolic syndrome (0.75 +/- 0.29 vs. 0.66 +/- 0.23 mm, p = 0.09). There were no differences for the other risk factors, A higher number of risk factors in a single patient showed a trend for increased cIMT (p = 0.083) CONCLUSIONS: Age is the only independent determinant of cIMT in a young population. Diabetic patients have greater cIMT and a trend was seen in those with metabolic syndrome, possibly influenced by its relation with diabetes, one of the components of the metabolic syndrome.

Marcadores inflamatórios de instabilidade da placa aterosclerótica coronária : caraterização e potencial utilização clínica

RESUMO:Introdução: Reviu-se o conhecimento epidemiológico, fisiopatológico e clínico atual sobre a doença coronária, da sua génese até ao evento agudo, o Enfarte Agudo do Miocárdio (EAM). Valorizou-se, em especial, a teoria inflamatória da aterosclerose, que foi objeto de grandes desenvolvimentos na última década. Marcadores de instabilidade da placa aterosclerótica coronária: Aprofundou-se o conhecimento da placa aterosclerótica coronária instável. Descreveram-se detalhadamente os biomarcadores clínicos e laboratoriais associados à instabilidade da placa, com particular ênfase nos mecanismos inflamatórios. Objetivos:Estão divididos em dois pontos fundamentais:(1) Estudar em doentes com EAM a relação existente entre as moléculas inflamatórias: Interleucina-6 (IL-6), Fator de Necrose Tumoral-α (TNF-α) e Metaloproteinase de Matriz-3 (MMP3), não usados em contexto clínico, com um marcador inflamatório já em uso clínico: a Proteína C-Reativa ultrassensível (hs-CRP). Avaliar a relação de todas as moléculas inflamatórias com um biomarcador de lesão miocárdica: a Troponina Cardíaca I (cTnI). (2) Avaliar, no mesmo contexto de EAM, a Resposta de Fase Aguda (RFA) . Pretende-se demonstrar o impacto deste fenómeno, com repercussão clínica generalizada, no perfil lipídico e nos biomarcadores inflamatórios dos doentes. Métodos:(1) Estudo observacional prospetivo de doentes admitidos consecutivamente por EAM (grupo EAM) numa única unidade coronária, após exclusão de trauma ou infeção. Doseamento no sangue periférico, na admissão, de IL-6, TNF-α, MMP3, hs-CRP e cTnI. Este último biomarcador foi valorizado também nos valores séricos obtidos 6-9 horas depois. Procedeu-se a correlação linear (coeficiente de Pearson, de Rho-Spearman e determinação do R2) entre os 3 marcadores estudados com os valores de hs-CRP e de cTnI (valores da admissão e 6 a 9 horas após). Efetuou-se o cálculo dos coeficientes de regressão linear múltipla entre cTnI da admissão e cTnI 6-9h após, com o conjunto dos fatores inflamatórios estudados. (2) Estudo caso-controlo entre o grupo EAM e uma população aleatória de doentes seguidos em consulta de cardiologia, após exclusão de eventos cardiovasculares de qualquer território (grupo controlo) e também sem infeção ou trauma. Foram doseados os mesmos marcadores inflamatórios no grupo controlo e no grupo EAM. Nos dois grupos dosearam-se, ainda, as lipoproteínas: Colesterol total (CT), Colesterol HDL (HDLc), com as suas subfrações 2 e 3 (HDL 2 e HDL3), Colesterol LDL oxidado (LDLox),Triglicéridos (TG), Lipoproteína (a) [Lp(a)], Apolipoproteína A1 (ApoA1), Apolipoproteína B (ApoB) e Apolipoproteína E (ApoE). Definiram-se, em cada grupo, os dados demográficos, fatores de risco clássicos, terapêutica cardiovascular e o uso de anti-inflamatórios. Procedeu-se a análise multivariada em relação aos dados demográficos, fatores de risco e à terapêutica basal. Compararam-se as distribuições destas mesmas caraterísticas entre os dois grupos, assim como os valores séricos respetivos para as lipoproteínas estudadas. Procedeu-se à correlação entre as moléculas inflamatórias e as lipoproteínas, para todos os doentes estudados. Encontraram-se os coeficientes de regressão linear múltipla entre cada marcador inflamatório e o conjunto das moléculas lipídicas, por grupo. Finalmente, efetuou-se a comparação estatística entre os marcadores inflamatórios do grupo controlo e os marcadores inflamatórios do grupo EAM. Resultados: (1) Correlações encontradas, respetivamente, Pearson, Rho-Spearman e regressão-R2: IL-6/hs-CRP 0,549, p<0,001; 0,429, p=0,001; 0,302, p<0,001; MMP 3/hsCRP 0,325, p=0,014; 0,171, p=0,202; 0,106, p=0,014; TNF-α/hs-CRP 0,261, p=0,050; 0,315, p=0,017; 0,068, p=0.050; IL-6/cTnI admissão 0,486, p<0,001; 0,483, p<0,001; 0,236, p<0,001; MMP3/cTnI admissão 0,218, p=0,103; 0,146, p=0,278; 0,048, p=0,103; TNF-α/cTnI admissão 0,444, p=0,001; 0,380, p=0,004; 0,197, p=0,001; IL-6/cTnI 6-9h 0,676, p<0,001; 0,623, p<0,001; 0,456, p<0,01; MMP3/cTnI 6-9h 0,524, p=0,001; 0,149, p=0,270; 0,275, p<0,001; TNF-α/cTnI 6-9h 0,428, p=0,001, 0,452, p<0,001, 0,183, p<0,001. A regressão linear múltipla cTnI admissão/marcadores inflamatórios produziu: (R=0,638, R2=0,407) p<0,001 e cTnI 6-9h/marcadores inflamatórios (R=0,780, R2=0,609) p<0,001. (2) Significância da análise multivariada para idade (p=0,029), IMC>30 (p=0.070), AAS (p=0,040) e grupo (p=0,002). Diferenças importantes entre as distribuições dos dados basais entre os dois grupos (grupo controlo vs EAM): idade (47,95±11,55 vs 68,53±2,70 anos) p<0.001; sexo feminino (18,18 vs 22,80%) p=0,076; diabetes mellitus (9,09% vs 36,84%) p=0,012; AAS (18,18 vs 66,66%) p<0,001; clopidogrel (4,54% vs 66,66%) p=0,033; estatinas (31,81% vs 66,14%) p=0,078; beta-bloqueadores (18,18% vs 56,14%) p=0,011; anti-inflamatórios (4,54% vs 33,33%) p=0,009. Resultados da comparação entre os dois grupos quanto ao padrão lipídico (média±dp ou mediana/intervalo interquartil, grupo controlo vs EAM): CT (208,45±35,03 vs 171,05±41,63 mg/dl) p<0,001; HDLc (51,50/18,25 vs 42,00/16,00 mg/dl) p=0,007; HDL2 (8,50/3,25 vs 10,00/6,00 mg/dl) p=0,292; HDL3 (41,75±9,82 vs 31,75±9,41 mg/dl) p<0,001; LDLox (70,00/22,0 vs 43,50/21,00 U/L) p<0,001; TG (120,00/112,50 vs 107,00/86,00 mg/dl) p=0,527; Lp(a) (0,51/0,73 vs 0,51/0,50 g/L) p=0,854; ApoA1 (1,38±0,63 vs 1,19±0,21 g/L) p=0,002; ApoB (0,96±0,19 vs 0,78±0,28 g/L) p=0,004; ApoE (38,50/10,00 vs 38,00/17,00 mg/L) p=0,574. Nas correlações lineares entre as variáveis inflamatórias e as variáveis lipídicas para todos os doentes, encontrámos uma relação negativa entre IL-6 e CT, HDLc, HDL3, LDLox, ApoA1 e ApoB. A regressão múltipla marcadores inflamatórios/perfil lipídico (grupo controlo) foi: hs-CRP (R=0,883, R2=0,780) p=0,022; IL-6 (R=0,911, R2=0,830) p=0,007; MMP3 (R=0,498, R2=0,248) p=0,943; TNF-α (R=0,680, R2=0,462) p=0,524. A regressão múltipla marcadores inflamatórios/perfil lipídico (grupo EAM) foi: hs-CRP (R=0,647, R2=0,418) p=0,004; IL-6 (R=0,544, R2=0,300), p=0,073; MMP3 (R=0,539, R2=0,290) p=0,089; TNF-α (R=0,595; R2=0,354) p=0,022. Da comparação entre os marcadores inflamatórios dos dois grupos resultou (mediana/intervalo interquartil, grupo controlo vs EAM): hs-CRP (0,19/0,27 vs 0,42/2,53 mg/dl) p=0,001, IL-6 (4,90/5,48 vs 13,07/26,41 pg/ml) p<0,001, MMP3 (19,70/13,70 vs 10,10/10,40 ng/ml) p<0,001;TNF-α (8,67/6,71 vs 8,26/7,80 pg/dl) p=0,805. Conclusões: (1) Nos doentes com EAM, existe correlação entre as moléculas inflamatórias IL-6, MMP3 e TNF-α, quer com o marcador inflamatório hs-CRP, quer com o marcador de lesão miocárdica cTnI. Esta correlação reforça-se para os valores de cTnI 6-9 horas após admissão, especialmente na correlação múltipla com o grupo dos quatro marcadores inflamatórios. (2) IL-6 está inversamente ligada às lipoproteínas de colesterol; hs-CRP e IL-6 têm excelentes correlações com o perfil lipídico valorizado no seu conjunto. No grupo EAM encontram-se níveis séricos mais reduzidos para as lipoproteínas de colesterol. Para TNF-α não foram encontradas diferenças significativas entre os grupos, as quais foram observadas para a IL-6 e hs-CRP (mais elevadas no grupo EAM). Os valores de MMP3 no grupo controlo estão mais elevados. ABSTRACT: 0,524, p=0,001; 0,149, p=0,270; 0,275, p<0,001; TNF-α/cTnI 6-9h 0,428, p=0,001, 0,452, p<0,001, 0,183, p<0,001. A regressão linear múltipla cTnI admissão/marcadores inflamatórios produziu: (R=0,638, R2=0,407) p<0,001 e cTnI 6-9h/marcadores inflamatórios (R=0,780, R2=0,609) p<0,001. (2) Significância da análise multivariada para idade (p=0,029), IMC>30 (p=0.070), AAS (p=0,040) e grupo (p=0,002). Diferenças importantes entre as distribuições dos dados basais entre os dois grupos (grupo controlo vs EAM): idade (47,95±11,55 vs 68,53±2,70 anos) p<0.001; sexo feminino (18,18 vs 22,80%) p=0,076; diabetes mellitus (9,09% vs 36,84%) p=0,012; AAS (18,18 vs 66,66%) p<0,001; clopidogrel (4,54% vs 66,66%) p=0,033; estatinas (31,81% vs 66,14%) p=0,078; beta-bloqueadores (18,18% vs 56,14%) p=0,011; anti-inflamatórios (4,54% vs 33,33%) p=0,009. Resultados da comparação entre os dois grupos quanto ao padrão lipídico (média±dp ou mediana/intervalo interquartil, grupo controlo vs EAM): CT (208,45±35,03 vs 171,05±41,63 mg/dl) p<0,001; HDLc (51,50/18,25 vs 42,00/16,00 mg/dl) p=0,007; HDL2 (8,50/3,25 vs 10,00/6,00 mg/dl) p=0,292; HDL3 (41,75±9,82 vs 31,75±9,41 mg/dl) p<0,001; LDLox (70,00/22,0 vs 43,50/21,00 U/L) p<0,001; TG (120,00/112,50 vs 107,00/86,00 mg/dl) p=0,527; Lp(a) (0,51/0,73 vs 0,51/0,50 g/L) p=0,854; ApoA1 (1,38±0,63 vs 1,19±0,21 g/L) p=0,002; ApoB (0,96±0,19 vs 0,78±0,28 g/L) p=0,004; ApoE (38,50/10,00 vs 38,00/17,00 mg/L) p=0,574. Nas correlações lineares entre as variáveis inflamatórias e as variáveis lipídicas para todos os doentes, encontrámos uma relação negativa entre IL-6 e CT, HDLc, HDL3, LDLox, ApoA1 e ApoB. A regressão múltipla marcadores inflamatórios/perfil lipídico (grupo controlo) foi: hs-CRP (R=0,883, R2=0,780) p=0,022; IL-6 (R=0,911, R2=0,830) p=0,007; MMP3 (R=0,498, R2=0,248) p=0,943; TNF-α (R=0,680, R2=0,462) p=0,524. A regressão múltipla marcadores inflamatórios/perfil lipídico (grupo EAM) foi: hs-CRP (R=0,647, R2=0,418) p=0,004; IL-6 (R=0,544, R2=0,300), p=0,073; MMP3 (R=0,539, R2=0,290) p=0,089; TNF-α (R=0,595; R2=0,354) p=0,022. Da comparação entre os marcadores inflamatórios dos dois grupos resultou (mediana/intervalo interquartil, grupo controlo vs EAM): hs-CRP (0,19/0,27 vs 0,42/2,53 mg/dl) p=0,001, IL-6 (4,90/5,48 vs 13,07/26,41 pg/ml) p<0,001, MMP3 (19,70/13,70 vs 10,10/10,40 ng/ml) p<0,001;TNF-α (8,67/6,71 vs 8,26/7,80 pg/dl) p=0,805. Conclusões: (1) Nos doentes com EAM, existe correlação entre as moléculas inflamatórias IL-6, MMP3 e TNF-α, quer com o marcador inflamatório hs-CRP, quer com o marcador de lesão miocárdica cTnI. Esta correlação reforça-se para os valores de cTnI 6-9 horas após admissão, especialmente na correlação múltipla com o grupo dos quatro marcadores inflamatórios. (2) IL-6 está inversamente ligada às lipoproteínas de colesterol; hs-CRP e IL-6 têm excelentes correlações com o perfil lipídico valorizado no seu conjunto. No grupo EAM encontram-se níveis séricos mais reduzidos para as lipoproteínas de colesterol. Para TNF-α não foram encontradas diferenças significativas entre os grupos, as quais foram observadas para a IL-6 e hs-CRP (mais elevadas no grupo EAM). Os valores de MMP3 no grupo controlo estão mais elevados. ------------- ABSTRACT: Introduction: We reviewed the epidemiology, pathophysiology and current clinical knowledge about coronary heart disease, from its genesis to the acute myocardial infarction (AMI). The inflammatory theory for atherosclerosis, which has undergone considerable development in the last decade, was especially detailed. Markers of coronary atherosclerotic vulnerable plaque: The clinical and laboratory biomarkers associated with the unstable coronary atherosclerotic plaque vulnerable plaque are detailed. An emphasis was placed on the inflammatory mechanisms. Objectives: They are divided into two fundamental points: (1) To study in AMI patients, the relationship between the inflammatory molecules: Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF-α) and Matrix metalloproteinase-3 (MMP3), unused in the clinical setting, with an inflammatory marker in clinical use: ultrasensitive C-reactive protein (hs-CRP), as well as a biomarker of myocardial injury: cardiac troponin I (cTnI). (2) To study, in the context of AMI, the Acute Phase Response (APR). We intend to demonstrate the impact of that clinical relevant phenomenon in the lipid profile and inflammatory biomarkers of our patients. Methods: (1) Prospective observational study of patients consecutively admitted for AMI (AMI group) in a single coronary care unit, after exclusion of trauma or infection. A peripheral assay at admission for IL-6, TNF-α, MMP3, hs-CRP and cTnI was performed. The latter was also valued in assays obtained 6-9 hours after admission. Linear correlation (Pearson's correlation coefficient, Spearman Rho's correlation coefficient and R2 regression) was performed between the three markers studied and the values of hs-CRP and cTnI (on admission and 6-9 hours after admission). Multiple linear regression was also obtained between cTnI on admission and 6-9h after, with all the inflammatory markers studied. (2) Case-control study between the AMI group and a random population of patients from an outpatient cardiology setting (control group). Cardiovascular events of any kind and infection or trauma were excluded in this group. The same inflammatory molecules were assayed in control and AMI groups. The following lipoproteins were also assayed: total cholesterol (TC), HDL cholesterol (HDLc) and subfractions 2 and 3 (HDL2 and HDL 3), oxidized LDL cholesterol (oxLDL), Triglycerides (TG), Lipoprotein (a) [Lp(a)], Apolipoprotein A1 (apoA1), Apolipoprotein B (ApoB) and Apolipoprotein E (ApoE). Demographics, classical risk factors, cardiovascular therapy and the use of anti-inflammatory drugs were appreciated in each group. The authors conducted a multivariate analysis with respect to demographics, risk factors and baseline therapy. The distribution of the same baseline characteristics was compared between the two groups, as well as the lipoprotein serum values. A correlation was performed between each inflammatory molecule and each of the lipoproteins, for all the patients studied. Multiple linear regression was determined between each inflammatory marker and all the lipid molecules per group. Finally, the statistical comparison between the inflammatory markers in the two groups was performed. Results: (1) The correlation coefficients recorded, respectively, Pearson, Spearman's Rho and regression-R2, were: IL-6/hs-CRP 0.549, p <0.001; 0.429, p=0.001; 0.302, p <0.001; MMP 3/hsCRP 0.325, p=0.014; 0.171, p=0.202; 0.106, p=0.014; TNF-α/hs-CRP 0.261, p=0.050; 0.315, p=0.017; 0.068, p=0.050; IL-6/admission cTnI 0.486, p<0.001; 0.483, p<0.001; 0.236, p<0.001; MMP3/admission cTnI 0.218, p=0.103; 0.146, p=0.278; 0.048, p=0.103; TNF-α/admission cTnI 0.444, p=0.001; 0.380, p=0.004; 0.197, p=0.001; IL-6/6-9 h cTnI 0.676, p<0.001; 0.149, p<0.001; 0.456, p <0.01; MMP3/6-9h cTnI 0.428, p=0.001; 0.149, p<0.001; 0.183, p=0.001; TNF-α/6-9 h cTnI 0.676, p<0,001; 0.452, p<0.001; 0.183, p<0,001. The multiple linear regression admission cTnI/inflammatory markers produced: (R=0.638, R2=0.407) p<0.001 and 6-9 h cTnI/inflammatory markers (R=0.780, R2=0.609) p<0.001. (2) Significances of the multivariate analysis were found for age (p=0.029), IMC>30 (p=0.070), Aspirin (p=0.040) and group (p=0.002). Important differences between the baseline data of the two groups (control group vs AMI): age (47.95 ± 11.55 vs 68.53±12.70 years) p<0.001; gender (18.18 vs 22.80%) p=0.076; diabetes mellitus (9.09% vs 36. 84%) p=0.012; Aspirin (18.18 vs. 66.66%) p<0.001; Clopidogrel (4, 54% vs 66.66%) p=0.033; Statins, 31.81% vs 66.14%, p=0.078, beta-blockers 18.18% vs 56.14%, p=0.011; anti-inflammatory drugs (4.54% vs 33.33%) p=0.009. Significant differences in the lipid pattern of the two groups (mean±SD or median/interquartile range, control group vs AMI): TC (208.45±35.03 vs 171.05±41.63 mg/dl) p<0.001; HDLc (51.50/18.25 vs 42.00/16.00 mg/dl) p=0.007; HDL2 (8.50/3.25 vs 10.00/6.00 mg/dl) p=0.292; HDL3 (41.75±9.82 vs 31.75±9.82 mg/dl) p<0.01; oxLDL (70.00/22.0 vs 43.50/21.00 U/L) p <0.001; TG (120.00/112.50 vs 107.00/86.00 mg/dl) p=0.527; Lp(a) (0.51/0.73 vs 0,51/0.50 g/L) p=0.854; apoA1 (1.38±0.63 vs 1.19±0.21 g/L) p=0.002; ApoB (0.96± 0.39 vs 0.78±0.28 g/L) p=0.004; ApoE (38.50/10,00 vs 38.00 /17,00 mg/L) p=0.574. In the linear correlations between inflammatory variables and lipid variables for all patients, we found a negative relationship between IL-6 and TC, HDLc, HDL3, ApoA1 and ApoB. The multiple linear regression inflammatory markers/lipid profile (control group) was: hs-CRP (R= 0.883, R2=0.780) p=0.022; IL6 (R=0.911, R2=0.830) p=0.007; MMP3 (R=0.498, R2=0.248) p=0.943; TNF-α (R=0.680, R2=0.462) p=0.524. For the linear regression inflammatory markers/lipid profile (AMI group) we found: hs-CRP (R=0.647, R2=0.418) p=0.004; IL-6 (R=0.544, R2=0.300) p=0.073; MMP3 (R=0.539, R2 =0.290) p=0.089; TNF-α (R=0.595, R2=0.354) p=0.022. The comparison between inflammatory markers in both groups (median/interquartile range, control group vs AMI) resulted as: hs-CRP (0.19/0.27 vs 0.42/2.53 mg/dl) p=0.001; IL-6 (4.90/5.48 vs 13.07/26.41 pg/ml) p<0.001; MMP3 (19.70/13.70 vs 10.10/10.40 ng/ml) p<0.001; TNF-α (8.67/6.71 vs 8.26/7.80 pg/dl) p=0.805. Conclusions: (1) In AMI patients there is a correlation between the inflammatory molecules IL-6, TNF-α and MMP3 with both the inflammatory marker hs-CRP and the ischemic marker cTnI. This correlation is strengthened for the cTnI at 6-9h post admission, particularly in the multiple linear regression to the four inflammatory markers studied. (2) IL-6 correlates negatively with the cholesterol lipoproteins. Hs-CRP and IL-6 are strongly correlated to the whole lipoprotein profile. AMI patients display reduced serum lipid levels. For the marker TNF-α no significant differences were found between groups, which were observed for IL-6 and hs-CRP (higher in the AMI group). MMP3 values are higher in the control group.

Natural history of stenosis in the iliac arteries in patients with intermittent claudication undergoing clinical treatment

PURPOSE: Inspite of the long experience with the treatment of intermittent claudication, little is known about the natural history of stenotic lesions in the iliac segment. With the advent of endovascular treatment, this knowledge has become important. METHODS: Fifty-two stenosis, diagnosed using arteriography, in 38 claudicant patients were analyzed. After a minimum time interval of 6 months, a magnetic resonance angiography was performed to determine whether there was arterial occlusion. The primary factors that could influence the progression of a stenosis were analyzed, such as risk factors (smoking, hypertension, diabetes, sex, and age), compliance with clinical treatment, initial degree of stenosis, site of the stenosis, and length of follow-up. RESULTS: The average length of follow-up was 39 months. From the 52 lesions analyzed, 13 (25%) evolved to occlusion. When occlusion occurred, there was clinical deterioration in 63.2% of cases. This association was statistically significant (P = .002). There was no statistically significant association of the progression of the lesion with the degree or site of stenosis, compliance with treatment, or length of follow-up. Patients who evolved to occlusion were younger (P = .02). The logistic regression model showed that the determinant factors for clinical deterioration were arterial occlusion and noncompliance with clinical treatment. CONCLUSIONS: The progression of a stenosis to occlusion, which occurred in 25% of the cases, caused clinical deterioration. Clinical treatment was important, but it did not forestall the arterial occlusion. Prevention of occlusion could be achieved by early endovascular intervention or with the development of drugs that might stabilize the atherosclerotic plaque.

Myocardial Bridges and their Relationship to the Anterior Interventricular Branch of the Left Coronary Artery

OBJECTIVE: To analyze the relationship between myocardial bridges and the anterior interventricular branch (anterior descending) of the left coronary artery. METHODS: The study was carried out with postmortem material, and methods of dissection and observation were used. We assessed the perimeter of the anterior interventricular branch of the left coronary artery using a pachymeter, calculated its proximal and distal diameters in relation to the myocardial bridge, and also its diameter under the myocardial bridge in 30 hearts. We also observed the position of the myocardial bridge in relation to the origin of the anterior interventricular branch. RESULTS: The diameters of the anterior interventricular branch were as follows: the mean proximal diameter was 2.76±0.76 mm; the mean diameter under the myocardial bridge was 2.08±0.54 mm; and the mean distal diameter was 1.98±0.59 mm. In 33.33% (10/30) of the cases, the diameter of the anterior interventricular branch under the myocardial bridge was lower than the diameter of the anterior interventricular branch distal to the myocardial bridge. In 3.33% (1/30) of the cases, an atherosclerotic plaque was found in the segment under the myocardial bridge. The myocardial bridge was located in the middle third of the anterior interventricular branch in 86.66% (26/30) of the cases. CONCLUSION: Myocardial bridges are more frequently found in the middle third of the anterior interventricular branch of the left coronary artery. The diameter of the anterior interventricular branch of the left coronary artery under the myocardial bridge may be smaller than after the bridge. Myocardial bridges may not provide protection against the formation of atherosclerotic plaque inside the anterior interventricular branch of the left coronary artery.

Exercice physique et athérosclérose : quels sont les mécanismes physiologiques et moléculaires de l'exercice qui préviennent et protègent de l'athérosclérose? : approche chez un modèle expérimental d'athérosclérose : la souris génétiquement dépourvue en apolipoprotéine E (apoE-/-)

RESUME : L'athérosclérose, pathologie inflammatoire artérielle chronique, est à l'origine de la plupart des maladies cardiovasculaires qui constituent l'une des premières causes de morbidité et mortalité en France. Les études observationnelles et expérimentales montrent que l'exercice physique prévient la mortalité cardiovasculaire. Cependant, les mécanismes précisant les bénéfices cliniques de l'exercice sur l'athérosclérose sont encore largement inconnus. Le but général de ce travail a donc été d'explorer, en utilisant un modèle expérimental d'athérosclérose, la souris hypercholestérolémique génétiquement dépourvue en apolipoprotéine E (apoE-/-), les mécanismes athéroprotecteurs de l'exercice. La dysfonction endothéliale, généralement associée aux facteurs de risque cardiovasculaire, serait l'une des étapes précoces majeures de l'athérogenèse. Elle est caractérisée par une diminution de la biodisponibilité en monoxyde d'azote (NO) avec la perte de ses propriétés vasculo-protectrices, ce qui favorise un climat pro-athérogène (stress oxydatif, adhésion et infiltration des cellules inflammatoires dans la paroi artérielle...) conduisant à la formation de la plaque athéromateuse. L'objectif de notre premier travail a donc été d'explorer les effets de l'exercice d'une part, sur le développement des plaques athéromateuses et d'autre part, sur la fonction endothéliale de la souris apoE-/-. Nos résultats montrent que l'exercice réduit significativement l'extension de l'athérosclérose et prévient la dysfonction endothéliale. L'explication pharmacologique montre que l'exercice stimule la fonction endothéliale via, notamment, une plus grande sensibilité des récepteurs endothéliaux muscariniques, ce qui active les événements signalétiques cellulaires récepteurs-dépendants à l'origine d'une bioactivité accrue de NO. Les complications cliniques graves de l'athérosclérose sont induites par la rupture de la plaque instable provoquant la formation d'un thrombus occlusif et l'ischémie du territoire tissulaire en aval. L'objectif de notre deuxième travail a été d'examiner l'effet de l'exercice sur la qualité/stabilité de la plaque. Nos résultats indiquent que l'exercice de longue durée stabilise la plaque en augmentant le nombre de cellules musculaires lisses et en diminuant le nombre de macrophages intra-plaques. Nos résultats montrent aussi que la phosphorylation de la eNOS (NO Synthase endothéliale) Akt-dépendante n'est pas le mécanisme moléculaire majeur à l'origine de ce bénéfice. Enfin, dans notre troisième travail, nous avons investigué l'effet de l'exercice sur le développement de la plaque vulnérable. Nos résultats montrent, chez un modèle murin de plaque instable (modèle d'hypertension rénovasculaire à rénine et angiotensine II élevés) que l'exercice prévient l'apparition de la plaque vulnérable indépendamment d'un effet hémodynamique. Ce bénéfice serait associé à une diminution de l'expression vasculaire des récepteurs AT1 de l'Angiotensine II. Nos résultats justifient l'importance de l'exercice comme outil préventif des maladies cardiovasculaires. ABSTRACT : Atherosclerosis, a chronic inflammatory disease, is one of the main causes of morbidity and mortality in France. Observational and experimental data indicate that regular physical exercise has a positive impact on cardiovascular mortality. However, the mechanisms by which exercise exerts clinical benefits on atherosclerosis are still unknown. The general aim of this work was to elucidate the anti-atherosclerotic effects of exercise, using a mouse model of atherosclerosis: the apolipoprotein E-deficient mice (apoE-/- mice). Endothelial dysfunction, generally associated with cardiovascular risk factors, has been recognized to be a major and early step in atherogenesis. Endothelial dysfunction is characterized by Nitric Oxide (NO) biodisponibility reduction with loss of NO-mediated vasculoprotective actions. This leads to vascular effects such as increased oxidative stress and increased adhesion of inflammatory cells into arterial wall thus playing a role in atherosclerotic plaque development. Therefore, one of the objective of our study was to explore the effects of exercise on atherosclerotic plaque extension and on endothelial function in apoE-/- mice. Results show that exercise significantly reduces plaque progression and prevents endothelial dysfunction. Pharmacological explanation indicates that exercise stimulates endothelial function by increasing muscarinic receptors sensitivity which in turn activates intracellular signalling receptor-dependent events leading to increased NO bioactivity. The clinical manifestations of atherosclerosis are the consequences of unstable plaque rupture with thrombus formation leading to tissue ischemia. The second aim of our work was to determine the effect of exercise on plaque stability. We demonstrate that long-term exercise stabilizes atherosclerotic plaques as shown by decreased macrophage and increased Smooth Muscle Cells plaque content. Our results also suggest that the Akt-dependent eNOS phosphorylation pathway is not the primary molecular mechanism mediating these beneficial effects. Finally, we assessed a putative beneficial effect of exercise on vulnerable plaque development. In a mouse model of Angiotensine II (Ang II)-mediated vulnerable atherosclerotic plaques, we provide fist evidence that exercise prevents atherosclerosis progression and plaque vulnerability. The beneficial effect of swimming was associated with decreased aortic Ang II AT1 receptor expression independently from any hemodynamic change. These findings suggest clinical benefit of exercise in terms of cardiovascular event protection.

Xanthine oxidase inhibition by febuxostat attenuates experimental atherosclerosis in mice.

Atherosclerosis is a chronic inflammatory disease due to lipid deposition in the arterial wall. Multiple mechanisms participate in the inflammatory process, including oxidative stress. Xanthine oxidase (XO) is a major source of reactive oxygen species (ROS) and has been linked to the pathogenesis of atherosclerosis, but the underlying mechanisms remain unclear. Here, we show enhanced XO expression in macrophages in the atherosclerotic plaque and in aortic endothelial cells in ApoE(-/-) mice, and that febuxostat, a highly potent XO inhibitor, suppressed plaque formation, reduced arterial ROS levels and improved endothelial dysfunction in ApoE(-/-) mice without affecting plasma cholesterol levels. In vitro, febuxostat inhibited cholesterol crystal-induced ROS formation and inflammatory cytokine release in murine macrophages. These results demonstrate that in the atherosclerotic plaque, XO-mediated ROS formation is pro-inflammatory and XO-inhibition by febuxostat is a potential therapy for atherosclerosis.