interleukin-8 and Carotid-Artery-Diseases

Intensive statin therapy has been shown to improve prognosis in patients with coronary heart disease (CHD). It is unknown whether such benefit is mediated through the reduction of atherosclerotic plaque burden.. To examine the efficacy of high-dose atorvastatin in the reduction of carotid intimal-medial thickness (IMT) and inflammatory markers in patients with CHD.. Randomised trial.. Single centre.. 112 patients with angiographic evidence of CHD.. A high dose (80 mg daily) or low dose (10 mg daily) of atorvastatin was given for 26 weeks.. Carotid IMT, C-reactive protein (CRP) and proinflammatory cytokine levels were assessed before and after therapy.. The carotid IMT was reduced significantly in the high-dose group (left: mean (SD), 1.24 (0.48) vs 1.15 (0.35) mm, p = 0.02; right: 1.12 (0.41) vs 1.01 (0.26) mm, p = 0.01), but was unchanged in the low-dose group (left: 1.25 (0.55) vs 1.20 (0.51) mm, p = NS; right: 1.18 (0.54) vs 1.15 (0.41) mm, p = NS). The CRP levels were reduced only in the high-dose group (from 3.92 (6.59) to 1.35 (1.83) mg/l, p = 0.01), but not in the low-dose group (from 2.25 (1.84) to 3.36 (6.15) mg/l, p = NS). A modest correlation was observed between the changes in carotid IMT and CRP (r = 0.21, p = 0.03).. In patients with CHD, intensive atorvastatin therapy results in regression of carotid atherosclerotic disease, which is associated with reduction in CRP levels. On the other hand, a low-dose regimen only prevents progression of the disease.

Topics: Aged; Atorvastatin; C-Reactive Protein; Carotid Arteries; Carotid Artery Diseases; Coronary Disease; Double-Blind Method; Drug Administration Schedule; Female; Follow-Up Studies; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Interleukin-18; Interleukin-6; Interleukin-8; Lipids; Male; Middle Aged; Pyrroles; Tumor Necrosis Factor-alpha; Tunica Intima; Tunica Media

The 5-year recurrence risk after ischaemic stroke and transient ischaemic attack (TIA) is 25-30%. Although inflammation may be a target for prevention trials, the contribution of plaque inflammation to acute cerebrovascular events remains unclear. We investigated the association of acute inflammatory cytokines and high-sensitivity C-reactive protein (CRP) with recently symptomatic carotid atherosclerosis in a prospective cohort study.. Blood and Imaging markers of TIA BIO-TIA) is a multicentre prospective study of imaging and inflammatory markers in patients with TIA. Exclusion criteria were infection and other co-morbid illnesses associated with inflammation. CRP and serum cytokines (interleukin [IL]-6, IL-1β, IL-8, IL-10, IL-12, interferon-γ [IFN-γ] and tumour necrosis factor-α [TNF-α]) were measured. All patients had carotid imaging.. Two hundred and thirty-eight TIA cases and 64 controls (TIA mimics) were included. Forty-nine (20.6%) cases had symptomatic internal carotid artery stenosis. Pro-inflammatory cytokine levels increased in a dose-dependent manner across controls, TIA without carotid stenosis (CS), and TIA with CS (IL-1β, ptrend = 0.03; IL-6, ptrend < 0.0001; IL-8, ptrend = 0.01; interferon (IFN)-γ, ptrend = 0.005; TNF-α, ptrend = 0.003). Results were unchanged when DWI-positive cases were excluded. On multivariable linear regression, only age (p = 0.01) and CS (p = 0.04) independently predicted log-IL-6. On multivariable Cox regression, CRP was the only independent predictor of 90-day stroke recurrence (adjusted hazard ratio per 1-unit increase 1.03 [95% CI: 1.01-1.05], p = 0.003).. Symptomatic carotid atherosclerosis was associated with elevated cytokines in TIA patients after controlling for other sources of inflammation. High-sensitivity CRP was associated with recurrent ischaemic stroke at 90 days. These findings implicate acute plaque inflammation in the pathogenesis of cerebral thromboembolism and support a rationale for randomized trials of anti-inflammatory therapy for stroke patients, who were excluded from coronary trials.

Topics: Brain Ischemia; Carotid Artery Diseases; Carotid Stenosis; Clinical Trials as Topic; Cytokines; Humans; Inflammation; Interleukin-6; Interleukin-8; Ischemic Attack, Transient; Ischemic Stroke; Plaque, Atherosclerotic; Prospective Studies; Stroke; Tumor Necrosis Factor-alpha

Neutrophil gelatinase-associated lipocalin (NGAL), a protein found in activated neutrophils, is expressed in kidney tubule cells in response to noxious stimuli, and is thus recognized as a marker of acute kidney injury. Recent studies have suggested that NGAL could also have pathophysiological importance in cardiovascular diseases. The aim of the present study was to examine NGAL expression in human carotid endarterectomy tissues ex vivo as well as the effects of NGAL in the main cell types involved in atherogenesis, namely in human macrophages, endothelial cells, and smooth muscle cells in vitro.. NGAL protein was analyzed in human endarterectomy samples from patients with asymptomatic and symptomatic carotid stenosis by immunofluorescence, and NGAL mRNA expression was detected using RealTime-PCR. Human monocyte derived macrophages (MDM), human coronary artery smooth muscle cells (HCASMC), and human umbilical vein endothelial cells (HUVEC) were treated with recombinant human (rh) NGAL at different concentrations. Interleukin (IL)-6, IL-8, and monocyte chemo-attractant protein-1 (MCP-1) were determined by specific enzyme linked immunosorbent assays (ELISAs) in culture supernatants of such treated cells.. Expression of NGAL protein was demonstrated by macrophages, smooth muscle cells, and endothelial cells in human carotid atherosclerotic tissue. NGAL mRNA expression was detected at a higher rate in atherosclerotic tissue of patients with symptomatic carotid stenosis (in 70%; n = 19) compared with asymptomatic patients (in 37%; n = 20, p < .001). Treatment of MDM, HCASMC, and HUVEC with rhNGAL led to a significant (p < 0.05) and concentration dependent increase of pro-inflammatory cytokines IL-6, IL-8, and MCP-1 in all cell types analyzed.. By induction of pro-inflammatory mediators in human macrophages, smooth muscle cells and endothelial cells, NGAL, which is predominantly expressed in atherosclerotic plaques of symptomatic patients, could be involved in creating the local and systemic pro-inflammatory environment characteristic for atherosclerosis.

Topics: Carotid Artery Diseases; Chemokine CCL2; Dose-Response Relationship, Drug; Endothelial Cells; Fluorescent Antibody Technique; Humans; In Vitro Techniques; Inflammation; Interleukin-6; Interleukin-8; Lipocalin-2; Macrophages; Muscle, Smooth, Vascular; Real-Time Polymerase Chain Reaction

Polymorphonuclear neutrophils (PMN) in atherosclerotic plaques have been identified only recently, and their contribution to plaque development is not yet fully understood. In this study, production of elastase, interleukin (IL)-8 and vascular endothelial growth factor (VEGF) by PMN was investigated in subjects with carotid stenosis undergoing carotid endarterectomy (CEA).. The study enrolled 50 patients (Pts) and 10 healthy subjects (HS). Circulating PMN (cPMN) isolated from venous blood (in both Pts and HS) and from plaques (pPMN, in Pts) were cultured, alone or with 0.1 μM fMLP. Elastase, IL-8 and VEGF mRNA were analyzed by real-time PCR. In CEA specimens, PMN were localized by immunohistochemistry.. In both Pts cPMN and pPMN, IL-8 mRNA was higher at rest but lower after fMLP (P<0.01 vs HS), and VEGF mRNA was higher both at rest and after fMLP (P<0.01 vs HS), while elastase mRNA was not significantly different. On the contrary, protein production was always higher in cPMN of HS with respect to values measured in cells of Pts. In CEA specimens, CD66b+ cells localized to areas with massive plaque formation close to neovessels. Pts with soft and mix plaques, as defined by computed tomography, did not differ in cPMN or pPMN IL-8, VEGF or elastase mRNA, or in intraplaque CD66b+ cell density. However, Pts with soft plaques had higher white blood cell count due to increased PMN.. In Pts with carotid plaques, both circulating and intraplaque PMN produce IL-8, VEGF and elastase, which are crucial for plaque development and progression. These findings suggest mechanistic explanations to the reported correlation between PMN count and cardiovascular mortality in carotid ATH.

Topics: Aged; Antigens, CD; Carotid Artery Diseases; Cell Adhesion Molecules; Cell Movement; Female; Gene Expression Regulation; Humans; Immunohistochemistry; Interleukin-8; Male; Neutrophils; Pancreatic Elastase; Plaque, Atherosclerotic; Real-Time Polymerase Chain Reaction; Vascular Endothelial Growth Factor A

Platelets foster an inflammatory environment that influences atherosclerotic lesion progression and facilitates plaque rupture, in addition to their role in acute thrombus formation. The route of entry of platelets into the atherosclerotic plaque and their exact location inside the plaque are however not completely understood.. 188 carotid plaques were examined for the presence of platelets using immunohistochemistry (CD42b), and 76/188 (40.4%) were platelet positive. Platelets were observed in intraplaque hemorrhages, around plaque microvessels, mostly without leakage of erythrocytes; and in mural thrombi. Platelet positive staining was associated with a higher plaque microvessel density, and elevated plaque-levels of interleukin-8.. Due to their short life span, platelets reflect recent bleeding. It can be hypothesized that platelets might serve as a marker for leaky microvessels inside atherosclerotic plaques that are at risk for development, or progression of plaque hemorrhage.

Topics: Aged; Biomarkers; Blood Platelets; Capillary Permeability; Carotid Arteries; Carotid Artery Diseases; Disease Progression; Female; Hemorrhage; Humans; Immunohistochemistry; Interleukin-8; Male; Microvessels; Middle Aged; Plaque, Atherosclerotic; Platelet Glycoprotein GPIb-IX Complex; Rupture, Spontaneous

The aim of our study was to assess the impact of increased iron stores on the presence of asymptomatic atherosclerosis in a cohort of healthy men. We anticipated that higher iron stores would be associated with higher soluble cluster of differentiation 163 (sCD163) concentrations, elevated markers of oxidative stress, inflammation and higher common carotid intima-media thickness, independently of traditional risk factors of atherosclerosis.. In this cross-sectional study that included 72 healthy men, we measured the ultrasonography of common carotid intima-media thickness (IACC), the ratio of plasma-circulating transferrin receptors concentration to plasma ferritin concentration, certain inflammatory and oxidative stress markers, insulin sensitivity, plasma lipids and markers of endothelial dysfunction.. The plasma-circulating transferrin receptor concentration to plasma ferritin concentration ratio (TfR/F) showed significant association with IACC (r=-0·310, P=0·008 vs. r=0·295, P=0·012). Multivariate analysis confirmed that the correlation of TfR/F with IACC is independent of traditional risk factors of atherosclerosis. The TfR/F ratio correlated with other indicators of atherosclerotic process fibrinogen (r=-0·292, P=0·013), von Willebrand factor (vWf; r=0·284, P=0·017), sCD163 (r=0·239, P=0·043) and IL-8 (r=0·233, P=0·049). In multivariate analysis, TfR/F independently correlated with haemoglobin (β=-0·220, P=0·047), fibrinogen (β=-0·290, P=0·009), IL-8 (β=0·227, P=0·039) and sCD163 (β=0·244, P=0·025); however, when vWf was added, significant independent correlation was seen only with fibrinogen (β=-0·301, P=0·007) and IL-8 (β=0·219, P=0·047). In addition, we demonstrated the independent correlation of sCD163 with vWf (β=0·240, P=0·040).. Our study showed a clear association of body iron stores expressed by the TfR/F ratio with asymptomatic carotid atherosclerosis. TfR/F further exhibited an independent positive correlation with fibrinogen and a negative correlation with sCD163 and IL-8.

Topics: Adult; Biomarkers; Carotid Artery Diseases; Carotid Intima-Media Thickness; Cohort Studies; Cross-Sectional Studies; Endothelium, Vascular; Ferritins; Fibrinogen; Humans; Interleukin-8; Iron; Male; Middle Aged; Multivariate Analysis; Oxidative Stress; Receptors, Transferrin; Risk Factors; von Willebrand Factor

The innate immune response elicited by activation of TLRs (Toll-like receptors) plays an important role in the pathogenesis of atherosclerosis. We hypothesized that cardiovascular risk factors are associated with the activation status of the innate immune system. We therefore assessed the responsiveness of TLRs on circulating cells in two groups of patients with established atherosclerosis and related this to the presence of cardiovascular risk factors. TNF (tumour necrosis factor)-α release induced by TLR2 and TLR4 activation was measured in patients with established coronary [PCI (percutaneous coronary intervention) study, n=78] or carotid artery disease [CEA (carotid endarterectomy) study, n=104], by stimulating whole blood samples with lipopolysaccharide (TLR4 ligand) and Pam3CSK4 [tripalmitoylcysteinylseryl-(lysyl)4; TLR2 ligand]. As an early activation marker, CD11b expression was measured by flow cytometry on CD14+ cells. Obesity was the 'only' risk factor that correlated with the TLR response. In both studies, obese patients had significantly higher TNF-α levels after stimulation of TLR2 compared with non-obese patients [16.9 (7.7-49.4) compared with 7.5 (1.5-19.2) pg/ml (P=0.008) in coronary artery disease and 14.6 (8.1-28.4) compared with 9.5 (6.1-15.7) pg/ml (P=0.015) in carotid artery disease; values are medians (interquartile range)]. Similar results were obtained following TLR4 stimulation. The enhanced inflammatory state in obese patients was also confirmed by a significant increased expression of the activation marker CD11b on circulating monocytes. In conclusion, obesity is associated with an enhanced TLR response in patients suffering from established atherosclerotic disease.

Topics: Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Atherosclerosis; Carotid Artery Diseases; CD11b Antigen; Cohort Studies; Coronary Artery Disease; Endarterectomy, Carotid; Female; Humans; Interleukin-6; Interleukin-8; Male; Middle Aged; Obesity; Risk Factors; Toll-Like Receptor 2; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Subendothelial deposited low-density lipoprotein particles are a known inflammatory factor in atherosclerosis. However, the causal components derived from low-density lipoprotein are still poorly defined. Apolipoprotein B100 (ApoB100) is the unexchangeable protein component of low-density lipoprotein, and the progression of atherosclerosis is associated with immune responses to ApoB100-derived peptides. In this study, we analyzed the proinflammatory activity of ApoB100 peptides in atherosclerosis.. By screening a peptide library of ApoB100, we identified a distinct native peptide referred to as ApoB100 danger-associated signal 1 (ApoBDS-1), which shows sequence-specific bioactivity in stimulation of interleukin-8, CCL2, and interleukin-6. ApoBDS-1 activates mitogen-activated protein kinase and calcium signaling, thereby effecting the expression of interleukin-8 in innate immune cells. Ex vivo stimulation of carotid plaques with ApoBDS-1 enhances interleukin-8 and prostaglandin E₂ release. Furthermore, we demonstrated that ApoBDS-1-positive peptide fragments are present in atherosclerotic lesions using immunoassays and that low-molecular-weight fractions isolated from plaque show ApoBDS-1 activity inducing interleukin-8 production.. Our data show that ApoBDS-1 is a previously unrecognized peptide with robust proinflammatory activity, contributing to the disease-promoting effects of low-density lipoprotein in the pathogenesis of atherosclerosis.

Topics: Apolipoprotein B-100; Atherosclerosis; Calcium; Carotid Artery Diseases; Chemokine CCL2; Humans; Immunity, Innate; Interleukin-6; Interleukin-8; Mitogen-Activated Protein Kinase Kinases; Peptides; Plaque, Atherosclerotic; Signal Transduction

Both inflammatory markers and carotid intima-media thickness (IMT) are associated with future cardiovascular disease (CVD). We investigated whether inflammatory markers can be predictors for incident CVD independent of carotid IMT in atherosclerotic high-risk patients and evaluated the joint effect of inflammatory markers and IMT in CVD prediction.. We performed a prospective cohort study of 770 patients who had one or more atherosclerotic risk factors. Serum high-sensitive C-reactive protein (hsCRP), interleukin (IL)-6, IL-18, and carotid IMT were assessed at baseline and the incidence of CVD was determined.. During 4.3 years of mean follow-up, CVD occurred in 104 patients (14%). In univariate analyses, higher levels of hsCRP, IL-6, and IL-18 were significantly related to an increased risk of CVD. However, only IL-6, but not hsCRP or IL-18, was associated with incident CVD after adjustment for conventional risk factors and carotid IMT (hazard ratio of upper half to lower half, 1.87; 95% confidence interval, 1.20-2.93). Measuring IL-6 level in combination with carotid IMT improves the prediction of incident CVD.. Elevated IL-6 is associated with the risk of CVD independently of carotid IMT in atherosclerotic high-risk patients.

Topics: Aged; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Carotid Arteries; Carotid Artery Diseases; Chi-Square Distribution; Disease-Free Survival; Female; Humans; Incidence; Inflammation; Inflammation Mediators; Interleukin-6; Interleukin-8; Japan; Kaplan-Meier Estimate; Male; Middle Aged; Proportional Hazards Models; Prospective Studies; Risk Assessment; Risk Factors; Time Factors; Tunica Intima; Tunica Media; Ultrasonography; Up-Regulation

To score the number of plaque neutrophils and relate the score to plaque morphology and inflammatory status.. Neutrophils are inflammatory cells with tissue destruction capabilities that have been found at the site of an atherosclerotic plaque rupture or erosion. Poor evidence exists for neutrophil infiltration in human carotid atherosclerotic plaques, and its association with plaque morphology has not yet been described. A set of 355 human carotid plaques was stained for the neutrophil marker CD66b. High neutrophil numbers were found in plaques with a large lipid core, high macrophage numbers, and low collagen amount and smooth muscle cell numbers. High neutrophil numbers were associated with high interleukin 8 (P<0.001) and matrix metalloproteases 8 (P=0.005) and 9 (P<0.001) plaque levels. High microvessel density within plaques was correlated with high neutrophil numbers (P=0.01). In addition, low numbers of neutrophils were associated with female sex and use of beta-blockers.. For the first time to our knowledge, these results show that neutrophil numbers are strongly associated with the histopathologic features of rupture-prone atherosclerotic lesions and suggest a role for neutrophils in plaque destabilization.

Topics: Adrenergic beta-Antagonists; Aged; Aged, 80 and over; Antigens, CD; Biomarkers; Carotid Arteries; Carotid Artery Diseases; Cell Adhesion Molecules; Collagen; Disease Progression; Female; GPI-Linked Proteins; Humans; Immunohistochemistry; Interleukin-8; Leukocyte Count; Lipids; Logistic Models; Macrophages; Male; Matrix Metalloproteinase 8; Matrix Metalloproteinase 9; Microvessels; Middle Aged; Myocytes, Smooth Muscle; Netherlands; Neutrophil Infiltration; Neutrophils; Odds Ratio; Risk Assessment; Risk Factors; Rupture; Severity of Illness Index; Sex Factors; Up-Regulation

To validate the hypothesis that the toxic heavy metal lead (Pb) may be linked to cardiovascular diseases via the initiation of atherosclerosis, in vivo and in vitro studies were conducted.. During the human study part of this project, serum Pb levels of healthy young women were correlated to carotid intima-media thickness. Multivariate logistic regression analyses showed that increased serum Pb levels were significantly associated with an increased intima-media thickness (P=0.01; odds ratio per SD unit, 1.6 [95% CI, 1.1 to 2.4]). In vitro, Pb induced an increase in interleukin 8 production and secretion by vascular endothelial cells. Nuclear factor erythroid 2-related factor-2 is the crucial transcription factor involved in Pb-induced upregulation of interleukin 8. Endothelial cell-secreted interleukin 8 triggered intimal invasion of smooth muscle cells and enhanced intimal thickening in an arterial organ culture model. This phenomenon was further enhanced by Pb-increased elastin synthesis of smooth muscle cells.. Our data support the hypothesis that Pb is a novel, independent, and significant risk factor for intimal hyperplasia.

Topics: Adolescent; Carotid Artery Diseases; Cell Movement; Cell Proliferation; Cells, Cultured; Dose-Response Relationship, Drug; Elastin; Endothelial Cells; Female; Heat-Shock Proteins; Humans; Hyperplasia; Interleukin-8; Lead; Logistic Models; Mammary Arteries; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; NF-E2-Related Factor 2; Odds Ratio; Organ Culture Techniques; Radial Artery; Risk Assessment; Risk Factors; Severity of Illness Index; Time Factors; Tunica Intima; Ultrasonography; Up-Regulation; Young Adult

Inflammation is a key mechanism in human atherosclerotic plaque vulnerability and disruption. The objective was to determine the differential gene expression of pro- and anti-inflammatory factors in the fibrous cap and shoulder region of noncalcified and calcified carotid endarterectomy plaques.. Thirty carotid endarterectomy plaques were classified as type Va (noncalcified, n = 15) and type Vb (calcified, n = 15) in accordance with the American Heart Association consensus. Using laser capture microdissection, fibrous cap and shoulder regions were excised from frozen sections. Gene expression of pro- [interleukin 1 (IL-1), IL-8 and monocyte chemoattractant protein 1 (MCP-1)] and anti-inflammatory (IL-10) factors, and bone formation (bone morphogenetic protein 6 and osteocalcin) mediators were quantitated by real-time PCR. Protein levels were determined using Western blotting.. Mean percent carotid stenosis and calcification area were 79 and 5% in Va-plaques (40% symptomatic) and 77 and 42% in Vb-plaques (20% symptomatic). Macrophages infiltrating the region of the fibrous cap and the shoulder were more numerous in non-calcified plaques compared with calcified plaques (p < 0.01]. mRNA expression of MCP-1 and IL-8, and protein levels of IL-8 were also greater in Va plaques compared to Vb plaques (p < 0.05). Protein levels and mRNA expression of osteocalcin were greater in Vb compared to Va plaques (p < 0.05).. Fibrous cap inflammation is more likely to occur in noncalcified than in calcified plaques. These findings suggest that carotid atherosclerotic plaque calcification is a structural marker of plaque stability.

Topics: Aged; Aged, 80 and over; Biomarkers; Bone Morphogenetic Protein 6; Calcinosis; Carotid Artery Diseases; Carotid Stenosis; Cell Movement; Chemokine CCL2; Cytokines; Endarterectomy, Carotid; Gene Expression Regulation; Humans; Interleukin-10; Interleukin-1beta; Interleukin-8; Macrophages; Middle Aged; Osteocalcin; Retrospective Studies; RNA, Messenger

The molecular regulation for the transition from stable to vulnerable plaque remains to be elucidated. Heme oxygenase 1 (HO-1) and its metabolites have been implicated in the cytoprotective defense against oxidative injury in atherogenesis. In this study, we sought to assess the role of HO-1 in the progression toward plaque instability in carotid artery disease in patients and in a murine model of vulnerable plaque development.. Atherectomy biopsy from 112 patients with clinical carotid artery disease was collected and stratified according to characteristics of plaque vulnerability. HO-1 expression correlated closely with features of vulnerable human atheromatous plaque (P<0.005), including macrophage and lipid accumulation, and was inversely correlated with intraplaque vascular smooth muscle cells and collagen deposition. HO-1 expression levels correlated with the plaque destabilizing factors matrix metalloproteinase-9, interleukin-8, and interleukin-6. Likewise, in a vulnerable plaque model using apolipoprotein E(-/-) mice, HO-1 expression was upregulated in vulnerable versus stable lesions. HO-1 induction by cobalt protoporphyrin impeded lesion progression into vulnerable plaques, indicated by a reduction in necrotic core size and intraplaque lipid accumulation, whereas cap thickness and vascular smooth muscle cells were increased. In contrast, inhibition of HO-1 by zinc protoporphyrin augmented plaque vulnerability. Plaque stabilizing was prominent after adenoviral transduction of HO-1 compared with sham virus-treated animals, providing proof that the observed effects on plaque vulnerability were HO-1 specific.. Here we demonstrate in a well-defined patient group and a murine vulnerable plaque model that HO-1 induction reverses plaque progression from a vulnerable plaque to a more stable phenotype as part of a compensatory atheroprotective response.

Topics: Aged; Animals; Apolipoproteins E; Carotid Artery Diseases; Collagen; Disease Models, Animal; Disease Progression; Female; Heme Oxygenase-1; Humans; Hyperlipidemias; Interleukin-6; Interleukin-8; Macrophages; Male; Matrix Metalloproteinase 9; Mice; Mice, Mutant Strains; Middle Aged; Muscle, Smooth, Vascular; Thrombosis; Transfection

Caveolin-1 (Cav-1) is a regulatory protein of the arterial wall, but its role in human atherosclerosis remains unknown. We have studied the relationships between Cav-1 abundance, atherosclerotic plaque characteristics and clinical manisfestations of atherosclerotic disease.We determined Cav-1 expression by western blotting in atherosclerotic plaques harvested from 378 subjects that underwent carotid endarterectomy. Cav-1 levels were significantly lower in carotid plaques than non-atherosclerotic vascular specimens. Low Cav-1 expression was associated with features of plaque instability such as large lipid core, thrombus formation, macrophage infiltration, high IL-6, IL-8 levels and elevated MMP-9 activity. Clinically, a down-regulation of Cav-1 was observed in plaques obtained from men, patients with a history of myocardial infarction and restenotic lesions. Cav-1 levels above the median were associated with absence of new vascular events within 30 days after surgery [0% vs. 4%] and a trend towards lower incidence of new cardiovascular events during longer follow-up. Consistent with these clinical data, Cav-1 null mice revealed elevated intimal hyperplasia response following arterial injury that was significantly attenuated after MMP inhibition. Recombinant peptides mimicking Cav-1 scaffolding domain (Cavtratin) reduced gelatinase activity in cultured porcine arteries and impaired MMP-9 activity and COX-2 in LPS-challenged macrophages. Administration of Cavtratin strongly impaired flow-induced expansive remodeling in mice. This is the first study that identifies Cav-1 as a novel potential stabilizing factor in human atherosclerosis. Our findings support the hypothesis that local down-regulation of Cav-1 in atherosclerotic lesions contributes to plaque formation and/or instability accelerating the occurrence of adverse clinical outcomes. Therefore, given the large number of patients studied, we believe that Cav-1 may be considered as a novel target in the prevention of human atherosclerotic disease and the loss of Cav-1 may be a novel biomarker of vulnerable plaque with prognostic value.

Topics: Aged; Animals; Atherosclerosis; Carotid Artery Diseases; Caveolin 1; Follow-Up Studies; Humans; Immunohistochemistry; Interleukin-6; Interleukin-8; Male; Matrix Metalloproteinase 9; Mice

Atherosclerosis is potentiated by stimulation of Toll-like receptors (TLRs), which serve to detect pathogen associated molecular patterns (PAMPs). However little is known of which PAMPs may be present in atheroma, or capable of stimulating inflammatory signalling in vascular cells.. DNA extracted from human carotid atheroma samples was amplified and sequenced using broad-range 16S gene specific primers to establish historical exposure to bacterial PAMPs. Responsiveness of primary human arterial and venous endothelial and smooth muscle cells to PAMPs specific for each of the TLRs was assessed by measurement of interleukin-8 secretion and E-selectin expression.. Extracts of atheromatous tissue stimulated little or no signalling in TLR-transfected HEK-293 cells. However, sequencing of bacterial DNA amplified from carotid atheroma revealed the presence of DNA from 17 different bacterial genera, suggesting historical exposure to bacterial lipopeptide, lipopolysaccharide and flagellin. All cells examined were responsive to the ligands of TLR3 and TLR4, poly inosine:cytosine and lipopolysaccharide. Arterial cells were responsive to a wider range of PAMPs than venous cells, being additionally responsive to bacterial flagellin and unmethylated cytosine-phosphate-guanosine DNA motifs, the ligands of TLR5 and TLR9, respectively. Cells were generally unresponsive towards the ligands of human TLR7 and TLR8, loxoribine and single stranded RNA. Only coronary artery endothelial cells expressed TLR2 mRNA and responded to the TLR2 ligand Pam(3)CSK(4).. Vascular cells are responsive to a relatively diverse range of TLR ligands and may be exposed, at least transiently, to ligands of TLR2, TLR4, TLR5 and TLR9 during the development of carotid atheroma.

Topics: Antigens, Bacterial; Biomarkers; Carotid Artery Diseases; Cell Line; DNA Primers; DNA, Bacterial; E-Selectin; Endothelial Cells; Humans; Interleukin-8; Ligands; Myocytes, Smooth Muscle; Reverse Transcriptase Polymerase Chain Reaction; Sequence Analysis, DNA; Toll-Like Receptor 2; Toll-Like Receptor 4; Toll-Like Receptor 5; Toll-Like Receptor 9; Toll-Like Receptors; Transfection

MIAMI was a prospective multicenter clinical study designed to investigate the relationship between changes in carotid intima-media thickness (C-IMT) and those in the levels of circulating markers of inflammation, thrombosis and endothelial dysfunction. The study was performed in a group of stable coronary patients treated for two years with a moderate dosage of atorvastatin (20mg/day). In this paper the cross-sectional relationship between C-IMT and the same circulating markers of inflammation, thrombosis and endothelial dysfunction measured at baseline was investigated.. Eighty-five subjects that had not used statins for at least two months were enrolled in the study. At time of enrollment, the levels of vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin, interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-alpha, high-sensitivity C-reactive protein (hs-CRP), tissue factor (TF), tissue factor pathway inhibitor (TFPI), von Willebrand factor (vWF), fibrinogen, total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL), and triglycerides were measured, in parallel with C-IMT assessment.. In cross-sectional analyses, markers of endothelial perturbation (i.e. E-selectin) and TFPI were more strongly correlated with arherosclerotic burden than markers of inflammation. The baseline picture in this study indicates that E-selectin and TFPI are linked with atherosclerotic burden.

Topics: Atorvastatin; Biomarkers; C-Reactive Protein; Carotid Artery Diseases; Cholesterol; E-Selectin; Endothelium, Vascular; Female; Fibrinogen; Heptanoic Acids; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-6; Interleukin-8; Lipoproteins; Male; Middle Aged; Prospective Studies; Pyrroles; Thromboplastin; Triglycerides; Tumor Necrosis Factor-alpha; Tunica Intima; Vascular Cell Adhesion Molecule-1; von Willebrand Factor

Although the participation of inflammation in atherogenesis is widely recognized, the identification of the different components has not been clarified. In particular, the role of inflammation in plaque destabilization is not fully understood.. Our main findings were as follows: (1) In a microarray experiment, we identified visfatin, one of the most recently identified adipokines, as a gene that was markedly enhanced in carotid plaques from symptomatic compared with plaques from asymptomatic individuals. This finding was confirmed when carotid plaques from 7 patients with asymptomatic and 14 patients with symptomatic lesions were examined with real-time reverse transcription polymerase chain reaction. (2) Immunohistochemistry showed that visfatin was localized in areas that were rich in lipid-loaded macrophages. (3) The relationship between visfatin and unstable lesions was also found in patients with coronary artery disease, demonstrating a strong visfatin immunostaining in lipid-rich regions within the material obtained at the site of plaque rupture in patients with acute myocardial infarction. (4) Both oxidized low-density lipoprotein and tumor necrosis factor-alpha increased visfatin expression in THP-1 monocytes, with a particularly enhancing effect when these stimuli were combined. (5) Visfatin increased matrix metalloproteinase-9 activity in THP-1 monocytes and tumor necrosis factor-alpha and interleukin-8 levels in peripheral blood mononuclear cells. Both of these effects were abolished when insulin receptor signaling was blocked.. Our findings suggest that visfatin should be regarded as an inflammatory mediator, localized to foam cell macrophages within unstable atherosclerotic lesions, that potentially plays a role in plaque destabilization.

Topics: Aged; Angina, Unstable; Atherosclerosis; Carotid Artery Diseases; Cell Line; Coronary Artery Disease; Cytokines; Female; Gene Expression Regulation; Humans; Immunohistochemistry; Inflammation; Interleukin-8; Macrophages; Male; Matrix Metalloproteinase 9; Middle Aged; Monocytes; Nicotinamide Phosphoribosyltransferase; Tumor Necrosis Factor-alpha

Interleukin (IL)-18 is a novel proinflammatory cytokine that plays a central role in innate and acquired immunity, making it a likely inflammatory candidate in atherosclerosis. We investigated whether circulating IL-18 levels were associated with subclinical atherosclerosis in a community population. Carotid intimal medial thickness (IMT) and carotid plaques were assessed in a cross-sectional study of 1111 randomly selected community subjects, aged 27-77 years. Baseline levels of IL-18, IL-6, high sensitive CRP (hsCRP), fibrinogen and white cell counts were measured along with conventional cardiovascular risk factors. Men had higher mean IL-18 levels than women (P<0.0001). Spearman rank correlations (r(s)) showed that IL-18 was weakly correlated with all inflammatory markers in the whole population (r(s) between 0.11 and 0.23, all P<0.001). IL-18 was also correlated with conventional risk factors including waist-hip ratio, BMI, blood pressure, triglycerides, HDL (inversely) and pack-years smoking (r(s) between 0.18 and 0.39, all P<0.001) but not with LDL-cholesterol. Independent predictors of IL-18 concentrations were waist-hip ratio, HDL, IL-6, hsCRP and hypertension. There was a positive univariate association of IL-18 levels with carotid IMT (P<0.001) and plaque prevalence (P<0.001) but no residual association after adjustment for conventional risk factors (both P>0.05). In a cross-sectional community population, IL-18 levels were related to traditional risk factors and inflammatory markers but were not independently associated with subclinical carotid atherosclerosis.

Topics: Adult; Aged; Atherosclerosis; Biomarkers; C-Reactive Protein; Carotid Arteries; Carotid Artery Diseases; Cross-Sectional Studies; Disease Progression; Female; Fibrinogen; Humans; Interleukin-18; Interleukin-6; Interleukin-8; Male; Middle Aged; Population Surveillance; Prevalence; Risk Factors; Severity of Illness Index; Ultrasonography; Western Australia

Atherosclerotic carotid artery disease is responsible for a variety of clinical presentations, ranging from asymptomatic to cerebral ischemic events. Considering the upcoming use of noninvasive imaging modalities, plaque characteristics could serve as a marker in the selection of patients eligible for carotid endarterectomy (CEA). This would be more likely if characteristics corresponded with clinical manifestations and were predictive of future events. In this study, we hypothesized that plaque characteristics correlate with the clinical presentation of carotid artery disease.. We included 404 patients undergoing a carotid endarterectomy (CEA). Ipsilateral clinical symptoms and duplex measurements were recorded. Patients could be asymptomatic (23.5%) or symptomatic with stroke (26.5%), transient ischemic attack (TIA) (36.1%), or amaurosis fugax (AFX) (13.9%). Plaques were stained and semi-quantitatively analyzed for the presence of macrophages, smooth muscle cells, collagen, calcifications, and thrombus. Plaques were categorized in three phenotypes by their overall presentation and the amount of fat. In addition, plaque matrix metalloproteinase (MMP) activity and cytokines expressions were measured.. Fibrous, fibro-atheromatous, and atheromatous plaques were observed in 30.2%, 35.6%, and 34.2%, respectively. Atheromatous plaques were more prevalent in patients with stroke and TIA compared with asymptomatic patients or patients with AFX (P = .001). Collagen staining was less evident in patients with TIA and stroke compared with asymptomatic patients or patients with AFX (P < .001). Plaques of patients with TIA and stroke showed significantly higher activity levels of MMP-8 and MMP-9 and higher levels of interleukin-8 compared with asymptomatic and AFX patients.. Plaque phenotype of patients with TIA is comparable to that of patients with stroke; whereas, the plaque phenotype of patients with AFX resembles the plaque phenotype of asymptomatic patients. Follow-up studies should be encouraged to determine whether plaque characteristics visualized by imaging techniques might help to identify patients most likely to benefit from CEA.

Topics: Aged; Amaurosis Fugax; Angiography; Biomarkers; Carotid Artery Diseases; Female; Follow-Up Studies; Humans; Interleukin-8; Ischemic Attack, Transient; Magnetic Resonance Imaging; Male; Matrix Metalloproteinase 8; Matrix Metalloproteinase 9; Prospective Studies; Risk Factors; Severity of Illness Index; Stroke; Tomography, X-Ray Computed; Ultrasonography, Doppler

Chemokines such as monocyte chemoattractant protein (MCP) -1 and interleukin (IL)-8 are known to be involved in various processes in atherosclerosis such as plaque formation, plaque rupture, and thrombus formation. We investigated whether a new chemokine, Leukotactin (LKN)-1, is involved in atherosclerosis. We tested the expression of LKN-1 by immunohistochemical methods in carotid atherosclerotic plaque specimen. Induction of pro-inflammatory cytokines, transmigration, and tissue factor (TF) expression were tested in THP-1 cells and human peripheral blood monocytes treated with recombinant human LKN-1. Immunohistochemical analyses revealed that expression of LKN-1 occurs in regions of plaques rich in foam cells. In a Boyden chamber assay, THP-1 cells treated with 0.01--10 nM of LKN-1 transmigrated through gelatin coated filters in a dose dependent manner. LKN-1 also induced the transient expression of TNF-alpha, IL-8, and MCP-1 within 15 min of the treatment of the THP-1 cells. When peripheral blood monocytes were treated with LKN-1, expression levels of TF and TF-mediated procoagulating activity were induced in a time- and dose-dependent manner. These results raise the possibility that LKN-1 is another chemokine that is involved in the atherogenesis. LKN-1 may chemoattract immune cells into the plaque, induce pro-inflammatory cytokines, and produce thrombi by inducing TF expression.

Topics: Aged; Aged, 80 and over; Carotid Artery Diseases; Cells, Cultured; Chemokine CCL2; Chemokines, CC; Chemotaxis; Female; Flow Cytometry; Humans; Immunohistochemistry; Interleukin-8; Lymphocyte Activation; Male; Middle Aged; Monocytes; Sensitivity and Specificity; Thromboplastin

Interleukin (IL)-8 and vascular endothelial growth factor (VEGF) are important factors that induce the migration and proliferation of endothelial cells, increase the vascular permeability, and the modulate chemotaxis of monocytes. These molecules have been found in human atherosclerotic plaques. However, it is not clear whether the circulating levels of IL-8 and VEGF correlate with the extents of carotid stenosis. In this study, we investigated the relationship between circulating levels of IL-8 as well as VEGF and the extents of carotid stenosis. Sera from 41 patients with carotid stenosis were assessed for concentrations of IL-8 and VEGF by enzyme-linked immunosorbent assay. The degree of stenosis of extracranial carotid artery was calibrated by carotid B- mode ultrasonography. The serum concentration of IL-8 (r = -0.04733, p > 0.05) was not correlated with the degree of stenosis. However, the serum concentration of VEGF (r = 0.4974, p < 0.01) was significantly correlated with the degree of carotid stenosis. These findings suggest that increased serum level of VEGF might be a marker for higher degree of stenosis of extracranial carotid artery.

Topics: Adult; Aged; Carotid Artery Diseases; Carotid Stenosis; Disease Progression; Endothelial Growth Factors; Female; Humans; Interleukin-8; Lymphokines; Male; Middle Aged; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors