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Background and aims Patients with rheumatic diseases have an increased risk of atherosclerosis with up-regulated serum amyloid A (SAA), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), which were reported to activate human coronary artery endothelial cells (HCAEC). We aimed to investigate the effects of TNF-α inhibitor infliximab and anti-infliximab antibodies on the TNF-α/IL-1β/SAA activated HCAEC. Methods HCAEC were incubated with TNF-α, IL-1β, SAA, infliximab, anti-infliximab antibodies and their combinations. The protein levels of pro- and anti-atherogenic analytes were measured in supernatants using ELISA and multiplex assays, while mRNA expression was determined by RT-PCR. Anti-infliximab antibodies were purified from sera samples by affinity chromatography. Results IL-6, IL-8, GM-CSF and GRO-α were synergistically up-regulated in triple stimulation with TNF-α, IL-1β and SAA, while their levels in solely SAA- or TNF-α-stimulated HCAEC did not increase. IL-1Ra, IL-1α, VCAM-1, MCP-1, IL-10 and IL-17A were increased, but no synergistic responses were observed in triple stimulation. Infliximab was effective in lowering the synergistic effect of IL-6, IL-8, GM-CSF and GRO-α in triple stimulation, while anti-infliximab antibodies restored the levels. The changes were confirmed at the mRNA expression level for IL-6, IL-8 and GM-CSF. Conclusions Triple stimulation with TNF-α, IL-1β and SAA synergistically elevated IL-6, IL-8, GM-CSF and GRO-α release in supernatants of HCAEC, with infliximab substantially inhibiting their levels. An isolated, enriched fraction of polyclonal anti-infliximab antibodies was capable of neutralizing infliximab, in the presence of TNF-α/IL-1β/SAA. The long-term presence of anti-infliximab antibodies in the circulation of patients with chronic rheumatic diseases is potentially important for promoting the atherosclerotic process.

Objective The nitroxide compound TEMPOL (4-hydroxy-2,2,6,6-tetramethylpiperidine- N -oxyl radical) has been shown to prevent obesity-induced changes in adipokines in cell and animal systems. In this study we investigated whether supplementation with TEMPOL inhibits inflammation and atherosclerosis in apoE −/− mice fed a high fat diet (HFD). Methods ApoE −/− mice were fed for 12 weeks on standard chow diet or a high-fat diet. Half the mice were supplemented with 10 mg/g TEMPOL in their food. Plasma samples were analysed for triglycerides, cholesterol, low- and high-density lipoprotein cholesterol, inflammatory cytokines and markers (interleukin-6, IL-6; monocyte-chemotactic protein, MCP-1; myeloperoxidase, MPO; serum amyloid A, SAA; adiponectin; leptin). Plaques in the aortic sinus were analysed for area, and content of collagen, lipid, macrophages and smooth muscle cells. Results High fat feeding resulted in marked increases in body mass and plasma lipid levels. Dietary TEMPOL decreased both parameters. In the high-fat-fed mice significant elevations in plasma lipid levels and the inflammatory markers IL-6, MCP-1, MPO, SAA were detected, along with an increase in leptin and a decrease in adiponectin. TEMPOL supplementation reversed these effects. When compared to HFD-fed mice, TEMPOL supplementation increased plaque collagen content, decreased lipid content and increased macrophage numbers. Conclusions These data indicate that in a well-established model of obesity-associated hyperlipidaemia and atherosclerosis, TEMPOL had a significant impact on body mass, atherosclerosis, hyperlipidaemia and inflammation. TEMPOL may therefore be of value in suppressing obesity, metabolic disorders and increasing atherosclerotic plaque stability.

Objective: Previous studies investigating flavanol-rich foods provide indications for potential cardioprotective effects of these foods, but the effects of individual flavanols remain unclear. We investigated whether the flavanol epicatechin can reduce diet-induced atherosclerosis, with particular emphasis on the cardiovascular risk factors dyslipidaemia and inflammation. Methods: ApoE*3-Leiden mice were fed a cholesterol-containing atherogenic diet with or without epicatechin (0.1% w/w) to study effects on early- and late-stage atherosclerosis (8w and 20w). Invivo effects of epicatechin on diet-induced inflammation were studied in human-CRP transgenic mice and NFκB-luciferase reporter mice. Results: Epicatechin attenuated atherosclerotic lesion area in ApoE*3-Leiden mice by 27%, without affecting plasma lipids. This anti-atherogenic effect of epicatechin was specific to the severe lesion types, with no effect on mild lesions. Epicatechin mitigated diet-induced increases in plasma SAA (in ApoE*3-Leiden mice) and plasma human-CRP (in human-CRP transgenic mice). Microarray analysis of aortic gene expression revealed an attenuating effect of epicatechin on several diet-induced pro-atherogenic inflammatory processes in the aorta (e.g. chemotaxis of cells, matrix remodelling), regulated by NFκB. These findings were confirmed immunohistochemically by reduced lesional neutrophil content in HCE, and by inhibition of diet-induced NFκB activity in epicatechin-treated NFκB-luciferase reporter mice. Conclusion: Epicatechin attenuates development of atherosclerosis and impairs lesion progression from mild to severe lesions in absence of an effect on dyslipidaemia. The observed reduction of circulating inflammatory risk factors by epicatechin (e.g. SAA, human-CRP), as well as its local anti-inflammatory activity in the vessel wall, provide a rationale for epicatechin's anti-atherogenic effects. © 2014 Elsevier Ireland Ltd.

Serum amyloid A (SAA) is an acute phase response protein and has apolipoprotein properties. Since type 2 diabetes is associated with chronic subclinical inflammation, the objective of this study is to investigate the changes in SAA level in type 2 diabetic patients and to evaluate the relationship between SAA and the capacity of serum to induce cellular cholesterol efflux via the two known cholesterol transporters, scavenger receptor class B type I (SR-BI) and ATP-binding cassette transporter G1 (ABCG1).264 patients with type 2 diabetes mellitus (42% with normoalbuminuria, 30% microalbuminuria, and 28% proteinuria) and 275 non-diabetic controls were recruited. SAA was measured by ELISA. SR-BI and ABCG1-mediated cholesterol efflux to serum were determined by measuring the transfer of [(3)H]cholesterol from Fu5AH rat hepatoma cells expressing SR-BI and from human ABCG1-transfected CHO-K1 cells to the medium containing the tested serum respectively.SAA was significantly increased in diabetic patients with incipient or overt nephropathy. Both SR-BI and ABCG1-mediated cholesterol efflux to serum were significantly impaired in all three groups of diabetic patients (p0.01). SAA inversely correlated with SR-BI-mediated cholesterol efflux (r = -0.36, p0.01) but did not correlate with ABCG1-mediated cholesterol efflux. Stepwise linear regression analysis showed that HDL, the presence or absence of diabetes, and log(SAA) were significant independent determinants of SR-BI-mediated cholesterol efflux to serum.SAA was increased in type 2 diabetic patients with incipient or overt nephropathy, and SAA was associated with impairment of SR-BI-mediated cholesterol efflux to serum.

Background: High density lipoproteins (HDL) contain paraoxonase-1 (PON-1), which has strong anti-oxidative properties. Apolipoprotein E (apoE) may enhance PON-1 activity in vitro, but the extent to which PON-1 activity is determined by circulating apoE levels is unknown. Here we determined relationships of serum PON-1 activity with apoE in subjects without and with metabolic syndrome (MetS).Methods: We measured PON-1 activity (arylesterase activity), plasma apoE and serum amyloid A (SAA) in 93 subjects without and in 75 subjects with MetS (25 and 54 subjects with Type 2 diabetes mellitus (T2DM), respectively; p Results: PON-1 activity was lower in MetS (p Conclusion: Higher apoE levels may confer higher PON-1 activity. The relationship of PON-I activity with total plasma apoE is apparently abrogated in MetS. (C) 2013 Elsevier Ireland Ltd. All rights reserved.

Objectives Although lipoprotein-associated phospholipase A 2 (Lp-PLA 2 ) has been regarded as a biomarker and a causative agent for acute coronary events recently, the mechanism of the regulation of Lp-PLA 2 has not been fully elucidated yet. This study was aimed to investigate the influence of serum amyloid A (SAA) on the expression of Lp-PLA 2 in THP-1 cells and ApoE-deficient (ApoE −/− ) mice. Methods THP-1 cells were stimulated by SAA and the mRNA and protein expression of Lp-PLA 2 was detected. ApoE −/− mice were intravenously injected with murine SAA1 lentivirus. Formyl peptide receptor like-1 (FPRL1) agonist (WKYMVm) and inhibitor (WRW 4 ), mitogen-activated protein kinases (MAPKs) inhibitors, and peroxisome proliferator-activated receptor-γ (PPAR-γ) agonist and inhibitor were used to investigate the mechanism of regulation of Lp-PLA 2 . Results Recombinant SAA up-regulated Lp-PLA 2 expression in a dose and time-dependent manner in THP-1 cells. Immunohistochemical analysis of aortic root of ApoE −/− mice also demonstrated that the expression of Lp-PLA 2 was up-regulated significantly with SAA treatment. WRW 4 decreased SAA-induced Lp-PLA 2 production; while WKYMVm could induce Lp-PLA 2 expression. ERK1/2, JNK1/2, and p38 inhibition reduced SAA-induced Lp-PLA 2 production. Furthermore, the results suggested the activation of PPAR-γ played a crucial role in this process. Conclusion These results demonstrate that SAA up-regulates Lp-PLA 2 production significantly via a FPRL1/MAPKs./PPAR-γ signaling pathway.

Objective To identify protein biomarkers in order to classify ischemic stroke subtypes using proteomic analysis and immunoenzymatic tools for clinical validation. Methods and results We performed a proteomic analysis in serum samples of 24 patients with ischemic stroke (12 atherothrombotic patients and 12 cardioembolic patients). In this study, based on two-dimensional electrophoresis and mass spectrometry we found four spots whose expression intensity was at least four times stronger in atherothrombotic patients than in cardioembolic patients. These spots were identified as haptoglobin related protein, serum amyloid A (two spots) and haptoglobin α chain. We validated the possible value of haptoglobin and serum amyloid A in a larger series of patients (n = 262) with ischemic stroke using ELISA techniques. Haptoglobin levels >1040 μg/mL identified atherothrombotic patients with 95% sensitivity and 88% specificity whereas serum amyloid A levels >160 μg/mL identified atherothrombotic patients with 91% sensitivity and 83% specificity. Conclusions Haptoglobin and serum amyloid A are useful biomarkers for atherothrombotic ischemic stroke diagnosis confirmation.

Background The putative association between the novel oxidized low-density lipoprotein markers, serum amyloid A-LDL (SAA-LDL) and α1-antitrypsin-LDL (AT-LDL), and obesity and the metabolic syndrome (MetS) has not been previously studied. In the present report, we investigated the levels of SAA-LDL and AT-LDL in relation to the components of the MetS. We also assessed the effect of weight reduction therapy on serum SAA-LDL and AT-LDL levels among obese subjects. Methods The study population included 421 obese Japanese outpatients (185 men and 236 women, mean age: 51.1 years) enrolled in the multicenter Japan Obesity and Metabolic Syndrome Study (JOMS). The novel oxidized low-density lipoprotein markers, serum SAA-LDL and AT-LDL, were measured in all participants. Results Circulating SAA-LDL levels were independently associated with the presence and the number of components of the MetS. SAA-LDL levels were also significantly and independently correlated with high-sensitivity C-reactive protein. Notably, successful weight reduction resulted in a significant decrease in circulating SAA-LDL concentrations. Levels of AT-LDL were not associated with the MetS. Conclusions We documented, for the first time, that serum SAA-LDL levels correlate positively with the number of components of the MetS and weight reduction. Whether SAA-LDL may be involved in the pathophysiology of MetS and atherosclerosis deserves further investigation.

Much experimental evidence supports a protective role of dietary flavonoids against cardiovascular diseases. The aim of the present study was to investigate the anti-atherosclerotic effects of catechin supplemented in the diet of apoE deficient mice at a low nutritional level and to explore the mechanisms of action by a transcriptomic approach. After 6 weeks of supplementation, atherosclerotic lesions were assessed by histomorphometry and several markers of lipid, inflammation and oxidative stress status were evaluated. Analysis of the global gene expression in the aorta was carried out using pangenomic arrays. Catechin supplementation reduced the mean atherosclerotic lesion area by 32% but had no effect on total cholesterol and triacylglycerol levels in the plasma and the liver. The plasma antioxidant capacity (FRAP) and inflammatory status (serum amyloid A) were unchanged. The expression of 450 genes was significantly modified by catechin supplementation. Some of the most significantly down-regulated genes included genes coding for adhesion molecules such as CD34 and PSGL-1 known to play a key role in leukocyte adhesion to the endothelium. Other genes involved in energy metabolism, lipid metabolism and lipids trafficking such as FABP4, LPL and SCARA5 were down-regulated and may contribute to the atheroprotective effect of catechin. This work shows that transcriptomic allows characterizing the biological effects of low doses of flavonoids where common markers were not significantly affected.

Aims Elevated serum amyloid A (SAA) levels, like C-reactive protein (CRP), predict coronary events. Both induce monocyte tissue factor (TF), and peripheral blood mononuclear cells (PBMC) from patients with coronary artery disease (CAD) express higher TF in response to CRP. This study examined SAA induction of TF and tumour necrosis factor-α (TNF) in PBMC from patients with CAD and in monocytoid THP-1 cells. Methods and results PBMC from 26 males with CAD (15 stable angina, SA, and 11 acute coronary syndromes, ACS) and 14 male controls were stimulated with SAA. SAA promoted up to six-fold increase in TF activity (recalcification assay) on PBMC from patients, associated with elevated TF mRNA and protein. PBMC responded optimally when monocytes were adherent. Unlike CRP, SAA induced TF and TNF in THP-1 cells. SAA-induced TNF was dose-dependently inhibited by HDL. PBMC from patients with ACS expressed more basal TF (257.4 ± 46.8 mU/106 PBMC vs. 131.0 ± 12.5 mU/106 PBMC, P = 0.003), and greater SAA-induced TF than cells from controls, whereas no difference was found between SA and controls (ACS 2246 ± 493, SA 1364 ± 206, controls 1091 ± 113 mU/106 PBMC, with SAA 250 ng/mL, P = 0.002 ACS vs. controls across the dose range). Importantly, SAA-induced TNF levels (ELISA) were much higher in patients with ACS than SA or controls (ACS 211 ± 41, SA 108 ± 16, controls 73 ± 11 pg/mL, with SAA 250 ng/mL, P = 0.001 ACS vs. controls or P = 0.013 ACS vs. SA across the dose range). SAA-induced TF and TNF correlated positively with serum SAA levels in CAD, but not controls. Conclusions SAA is a prothrombotic and proinflammatory mediator in ACS which may contribute to atherogenesis and its complications.

Objective: To investigate the relationship between plasmaHDLat admission and the extent of the inflammatory response during anST-elevation myocardial infarction (STEMI), and to analyse structural HDL changes during STEMI as related to the extent of inflammation. Methods and results: CRP and IL-6 were monitored for 96 h in 45 patients with STEMI. Plasma apoA-II and LpA-I:A-II levels at admission, but not HDL cholesterol or other HDL-related biomarkers, were associated with the extent of the inflammatory response during STEMI, as indicated by the positive correlations with CRP AUC (apoA-II: F = 7.44, p = 0.009; LpA-I:A-II: F = 14.29, p < 0.001), and IL-6 AUC (apoAII: F = 6.98, p = 0.012; LpA-I:A-II: F = 6.67, p = 0.013). By multivariate analysis the plasma LpA-I:A-II level at admission was a powerful independent predictor of the inflammatory response, evaluated either as CRP AUC (F = 22.30, p < 0.001), or IL-6 AUC (F = 6.92, p = 0.012). During STEMI, the plasma concentration of LpA-I:A-II, but not LpA-I particles decreased, HDL became larger and progressively enriched in serum amyloid A; these changes occurred only in patients with a significant inflammatory response. Conclusion: An elevated plasma concentration of LpA-I:A-II particles was an independent predictor of a more severe inflammatory response in patients with STEMI.

Increased levels of acute phase proteins (APP) in serum are associated with vulnerability of atherosclerotic plaques and acute manifestations of coronary heart disease (CHD). APP have been viewed as indexes of active vascular inflammation or as mediators of atherothrombosis. In the present study we tested the hypothesis that individuals who develop stable or unstable forms of CHD might have different innate responses to an inflammatory stimulus. We compared changes in plasma C-reactive protein (CRP) and serum amyloid A (SAA) concentrations 48 h after a standardized inflammatory stimulus (adjuvanted influenza vaccination) in patients with quiescent CHD that had been manifested at onset as inducible myocardial ischemia (Group 1, n=26) or as acute coronary syndromes (ACS) (Group 2, n=34). Selected patients were free from inflammatory or other conditions that might affect the immune response. CRP concentration increased significantly after vaccination in both groups (Group 1: 0.47 [0.21-0.86] to 0.56 [0.32-1.17]mg/L, p=0.005; Group 2: 0.64 [0.21-1.09] to 0.75 [0.33-1.48]mg/L, p=0.003), without significant differences between groups in absolute or percentage changes. By contrast, SAA did not change after vaccination in Group 1 (14.4 [8.9-19.5] to 14.8 [10.3-18.8]mg/L, p=0.88) but increased significantly in Group 2 (16.9 [10.0-21.5] to 19.2 [11.3-29.1]mg/L, p=0.002), with significant differences between the groups in absolute and percentage terms (p=0.015 and 0.019, respectively). Changes in CRP and SAA, both absolute and percentage, were significantly correlated in Group 2 (r=0.60 and 0.66, both p0.001). The responsiveness of plasma SAA to an inflammatory stimulus in Group 2 alone suggests a pro-inflammatory status in patients prone to acute coronary syndrome but not in those with inducible myocardial ischemia.

We evaluated whether high circulating levels of serum amyloid A (SAA), fibrinogen, interleukin-6 (IL-6) or leukocytes count (LC), can provide any additional predictive value over that provided by hs C-reactive protein (hs-CRP) for the incidence of 5-year cardiovascular mortality, in 458 and 476 consecutive patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndromes (NSTE-ACS), respectively. By 5 years the incidence of cardiovascular mortality was 37.3% and 35.5% in patients with STEMI and NSTE-ACS, respectively. Each of the study inflammatory biomarkers conferred independent to clinical risk predictors (and to cardiac troponin I) long-term prognostic information (all p

Background There is substantial evidence that cerebral ischaemia triggers an inflammatory response. We examined the short-term prognostic value on mortality of C-reactive protein (CRP), interleukin-6 (IL-6) and serum amyloid A (SAA) in patients with ischaemic stroke. Methods We recruited 203 consecutive patients, under the age of 66 years (mean age = 54.2 ± 8.1 years, men = 132) who admitted to the Neurology Department with the diagnosis of non-haemorrhagic stroke. Patients in atrial fibrillation or with evidence of inflammatory or malignant disease were excluded. The diagnosis was confirmed with a computed tomography or magnetic resonance imaging of the brain within 24 h of admission. CRP, IL-6 and SAA levels were determined within 12 h from admission. Results Fourteen (6.9%) patients died during hospitalization. Serum concentrations of CRP, IL-6 and SAA were significantly higher in patients who died compared with those who survived and were independently associated with early death, after adjusting for various confounding factors. For one unit increase in IL-6, CRP and SAA there was an 18%, 14% and 9% higher risk of dying during hospitalization, respectively. Comparisons of the areas under the ROC curve showed that IL-6 had the best predictive ability. Age-adjusted cut-off point analysis showed that IL-6 levels >13 pg/ml were the optimal point that discriminated those who died from the rest of the patients (sensitivity = 85% and specificity = 93%). Conclusions We demonstrated that in-hospital mortality in ischaemic stroke is associated with an exacerbation of inflammatory response as it is reflected by the higher serum levels of IL-6, CRP and SAA. From the inflammatory markers high IL-6 levels had the strongest independent predictive value for in-hospital mortality.

We evaluated the association of obesity with various markers of chronic inflammation, in a population-based sample of 3,042 adults.During 2001-2002, we randomly enrolled 1,514 men (18-87 years old) and 1,528 women (18-89 years old), from the Attica area, Greece; the sampling was stratified by the age-sex distribution of the region (census 2001). Among several variables, we also measured various inflammatory markers (C-reactive protein, tumor necrosis factor alpha, amyloid A, white blood cells and interleukin-6) and anthropometric variables (weight, height, waist and hip circumferences). Central fat was defined as waist-to-hip ratioor=0.95 in men andor=0.8 in women, while obesity as body mass index (BMI)29.9 kg/m(2).Central fat prevailed in 36% of men and 43% of women (p0.001), while obesity prevailed in 20% of men and 15% of women, respectively. Compared to participants with normal body fat distribution, those with central fat exhibited 53% higher C-reactive protein levels, 30% higher tumor necrosis factor, alpha levels, 26% higher amyloid A levels, 17% higher white blood cell counts and 42% higher interleukin-6 levels (all p0.05). We observed that all inflammation markers were related to BMI (index for obesity), waist and to waist-to-hip ratio (indices for central fat), in both genders. Moreover, the models that included waist or waist-to-hip ratio as independent variable had higher explanatory ability (i.e. R(2)) than the models included BMI, especially in women, even after adjusting for age and various other potential confounders.Our results suggest a relationship between central adiposity and inflammation process, irrespective of age and other potential confounders. This association was more prominent than the relationship between total obesity and inflammation. It could be hypothesized that a disproportionate accumulation of visceral fat mass could be partially associated with increased coronary risk, through inflammation process.

Background: Although some reports have indicated that acute phase proteins such as C-reactive protein (CRP) and serum amyloid A (SAA) can predict the prognosis in patients with acute coronary syndrome, the value of these markers in patients with stable coronary artery disease (CAD) still remains obscure. Therefore, our aim was to determine the prognostic value of inflammatory markers in patients with stable coronary artery disease. Methods and results: We conducted a prospective cohort study in 140 consecutive patients with stable coronary artery disease who had at least one coronary stenosis more than 50% in diameter seen on diagnostic coronary angiography (CAG). We determined serum levels of the SAA/LDL complex as a new marker in addition to CRP and SAA. Serum levels of the SAA/LDL complex were measured by a sandwich enzyme-linked immunosorbent assay (ELISA). End-points were defined as cardiac death, myocardial infarction, cerebral infarction, and coronary revascularization. End-point events occurred in 21 patients (2 death from myocardial infarction, 2 cerebral infarction, and 17 revascularization). Age (year) (OR=1.14, CI: 1.05–1.25), diabetes mellitus (OR=3.50, CI: 1.08–11.40), triglyceride (10mg/dl) (OR=1.12, CI: 1.01–1.23) and SAA/LDL complex (10μg/ml) (OR=2.32, CI: 1.05–4.70) were independently related to the events. A reconstitution experiment suggested that the SAA/LDL complex is derived by oxidative interaction between SAA and lipoproteins. Conclusions: The SAA/LDL complex reflects intravascular inflammation directly and can be a new marker more sensitive than CRP or SAA for prediction of prognosis in patients with stable coronary artery disease.

Estrogen replacement therapy (ERT) has been found to be associated with increased cardiovascular risk in the first year after initiation of ERT. We compared the effects of oral and transdermal estradiol (E2) replacement therapy on markers of inflammation, coagulation and fibrinolysis in a randomized double-blind trial. Forty-three healthy women were randomized 6 weeks after surgically induced menopause to receive treatment with either oral or transdermal E2 over a period of 28 weeks. At baseline and after 28 weeks, levels of serum lipids and lipoproteins, and markers of coagulation, fibrinolysis and inflammation were determined. Among fibrinolytic parameters, oral E2 shortened euglobulin clot lysis time (P

Background Inflammation plays an important role in the pathogenesis of coronary artery disease. We examined whether dietary supplementation with alpha-linolenic acid (ALA, 18:3n-3) affects the levels of inflammatory markers in dyslipidaemic patients. Methods We recruited 76 male dyslipidaemic patients (mean age=51+/-8 years) following a typical Greek diet. They were randomly assigned either to 15 ml of linseed oil (rich in ALA) per day (n=50) or to 15 ml of safflower oil (rich in linoleic acid (LA, 18:2n-6)) per day (n=26). The ratio of n-6:n-3 in linseed oil supplemented group was 1.3:1 and in safflower oil supplemented group 13.2:1. Dietary intervention lasted for 3 months. Blood lipids and C-reactive protein (CRP), serum amyloid A (SAA), and interleukin-6 (IL-6) levels were determined prior and after intervention. CRP and SAA were measured by nephelometry and IL-6 by immunoassay. Results Dietary supplementation with ALA decreased significantly CRP, SAA and IL-6 levels. The median decrease of CRP was 38% (1.24 vs. 0.93 mg/l, P=0.0008), of SAA 23.1% (3.24 vs. 2.39 mg/l, P=0.0001) and of IL-6 10.5% (2.18 vs. 1.7 pg/ml, P=0.01). The decrease of inflammatory markers was independent of lipid changes. Dietary supplementation with LA did not affect significantly CRP, SAA and IL-6 concentrations but decreased cholesterol levels. Conclusions Dietary supplementation with ALA for 3 months decreases significantly CRP, SAA and IL-6 levels in dyslipidaemic patients. This anti-inflammatory effect may provide a possible additional mechanism for the beneficial effect of plant n-3 polyunsaturated fatty acids in primary and secondary prevention of coronary artery disease.

We studied the value of serum amyloid A (SAA), a first-class acute-phase protein, as a marker for coronary heart disease (CHD) in a middle-aged male population. In a working population of 16307 men (age, 35-59 years), 446 cases had a history of CHD or prominent Q:QS waves on electrocardiogram. For each case, two matched controls were investigated. SAA, measured by immunonephelometry, was correlated with other acute-phase proteins, cardiovascular risk factors, and infectious serology markers. SAA concentrations were significantly higher in the cases than in controls (P

Objective Interleukin (IL)-6 is a key modulator of the acute phase response (APR), and while both are implicated in atherosclerosis, the pathological role of specific IL-6 signalling cascades is ill-defined. Since IL-6 employs the cytokine receptor gp130 to primarily activate the STAT3 pathway, here we evaluate whether gp130-dependent STAT3 activation modulates atherosclerosis. Methods High-fat diet-induced atherosclerosis was established in ApoE −/− mice crossed with gp130 F/F knock-in mice displaying elevated gp130-dependent STAT3 activation and production of the APR protein, serum amyloid A (SAA). Also generated were gp130 F/F : Stat3 −/+ : ApoE −/− mice displaying genetically-normalised STAT3 activation and SAA levels, and bone marrow chimeras involving ApoE −/− and gp130 F/F : ApoE −/− mice. At 10 weeks post high-fat diet, aortic atherosclerotic lesions, including the presence of CD68 + macrophages, and plasma lipid and SAA profiles, were assessed. Results Aortic plaque development and plasma triglyceride levels in gp130 F/F : ApoE −/− mice were significantly reduced (3-fold, P ApoE −/− littermates. By contrast, in gp130 F/F : ApoE −/− mice, atherosclerotic plaques contained augmented CD68 + macrophage infiltrates, and plasma SAA levels were elevated, compared to ApoE −/− mice. Atherosclerotic lesion development and plasma triglyceride levels in gp130 F/F : ApoE −/− and gp130 F/F : Stat3 −/+ : ApoE −/− mice were comparable, despite a significant ( P gp130 F/F : Stat3 −/+ : ApoE −/− mice. Aortic plaque development and plasma triglyceride levels were comparable in ApoE −/− mice reconstituted with gp130 F/F : ApoE −/− (ApoE F/F:ApoE ) or ApoE −/− (ApoE ApoE ) bone marrow cells. Conclusions Deregulation of gp130/STAT3 signalling augments the APR and macrophage infiltration during atherosclerosis without impacting on the development of aortic plaques.

Recent data suggest that infections, inflammation and the immune system are involved in the process of atherosclerosis. The aim of the present study was to analyze the association of coronary heart disease (CHD) with three inflammation markers, C-reactive protein (CRP), serum amyloid-A (SAA) and plasma fibrinogen. The cross-sectional study included 1400 men aged 45-74 years, who participated in a cardiovascular risk factor survey in Finland in 1997. Participants with prevalent CHD had markedly higher CRP, SAA and fibrinogen levels than participants without CHD. In logistic regression models, the age, smoking, serum cholesterol and systolic blood pressure adjusted odds ratios (2nd, 3rd and 4th quartile as compared with the 1st quartile) of CHD increased gradually with increasing quartile of CRP (1.90, 2.27, 2.64), SAA (1.68, 1.83, 2.41), and fibrinogen (1.60, 1.95, 2.14). The associations weakened somewhat after further adjustment for indicators of obesity, particularly waist hip-ratio. CRP, SAA and fibrinogen levels were markedly lower among CHD patients using cholesterol-lowering medication as compared to non-users. In conclusion, CRP, SAA and fibrinogen, which are markers of inflammation, were positively and significantly associated with prevalent CHD. Central obesity needs to be considered as a confounding factor in the observed associations. These findings support the hypothesis that cholesterol-lowering drugs have an anti-inflammatory effect.

In reverse cholesterol transport, plasma phospholipid transfer protein (PLTP) converts high density lipoprotein(3) (HDL(3)) into two new subpopulations, HDL(2)-like particles and prebeta-HDL. During the acute-phase reaction (APR), serum amyloid A (SAA) becomes the predominant apolipoprotein on HDL. Displacement of apo A-I by SAA and subsequent remodeling of HDL during the APR impairs cholesterol efflux from peripheral tissues, and might thereby change substrate properties of HDL for lipid transfer proteins. Therefore, the aim of this work was to study the properties of SAA-containing HDL in PLTP-mediated conversion. Enrichment of HDL by SAA was performed in vitro and in vivo and the SAA content in HDL varied between 32 and 58 mass%. These HDLs were incubated with PLTP, and the conversion products were analyzed for their size, composition, mobility in agarose gels, and apo A-I degradation. Despite decreased apo A-I concentrations, PLTP facilitated the conversion of acute-phase HDL (AP-HDL) more effectively than the conversion of native HDL(3), and large fusion particles with diameters of 10.5, 12.0, and 13.8 nm were generated. The ability of PLTP to release prebeta from AP-HDL was more profound than from native HDL(3). Prebeta-HDL formed contained fragmented apo A-I with a molecular mass of about 23 kDa. The present findings suggest that PLTP-mediated conversion of AP-HDL is not impaired, indicating that the production of prebeta-HDL is functional during the ARP. However, PLTP-mediated in vitro degradation of apo A-I in AP-HDL was more effective than that of native HDL, which may be associated with a faster catabolism of inflammatory HDL.

Serum amyloid A (SAA) is an acute phase protein whose expression increases markedly during bacterial infection, tissue damage, and inflammation. The potential beneficial roles of SAA include its involvement in the reverse cholesterol transport and possibly extracellular lipid deposition at sites of inflammation and tissue repair. It is an attractive therapeutic target for the treatment of atherosclerosis. Peroxisome proliferator-activated receptor γ (PPARγ) plays a major regulatory role in adipogenesis, and the expression of genes involved in lipid metabolism. Activation of PPARγ leads to multiple changes in gene expression, some of which are believed to be atherogenic while others are antiatherogenic. In this study, we demonstrated that SAA upregulated COX-2 expression and induced PPARγ activity through NF-кB pathway. The effect of SAA on NF-кB activity is mediated by FPRL-1 and TLR4.

Serum amyloid A (SAA) proteins comprise a family of apolipoproteins coded for by at least three genes with allelic variation and a high degree of homology between species. The synthesis of certain members of the family is greatly increased in inflammation. However, SAA is not often used as an acute-phase marker despite being at least as sensitive as C-reactive protein. SAA proteins can be considered as apolipoproteins since they associate with plasma lipoproteins mainly within the high density range, perhaps through amphipathic alpha-helical structure. It is not known why certain subjects expressing SAA develop secondary systemic amyloidosis. There is still no specific function attributed to SAA; however, a popular hypothesis suggests that SAA may modulate metabolism of high density lipoproteins (HDL). This may impede the protective function of HDL against the development of atherosclerosis. The potential significance of the association between SAA and lipoproteins needs further evaluation.

Acute-phase Serum Amyloid A (ASAA) is a novel pro-inflammatory adipokine, increased in obese, insulin resistant subjects. Polycystic ovary syndrome (PCOS) is associated with inflammation and atherosclerosis. We assessed sera, adipose tissue (AT) mRNA and protein levels of ASAA of PCOS women and matched controls. Ex vivo regulation of AT ASAA by d-glucose, effects of metformin treatment on circulating ASAA in PCOS subjects and effects of sera from normal and PCOS subjects (before and after metformin) on ASAA production (THP-1 macrophages) were also studied.Circulating ASAA (ELISA), subcutaneous and omental AT ASAA mRNA (RT-PCR) and protein (western blotting) were significantly higher in PCOS women (P0.05). In AT explants, glucose significantly increased ASAA production and secretion (P0.05, P0.01). Furthermore, ASAA production (THP-1 macrophages) was significantly greater by sera from PCOS women compared to controls (P0.01). ASAA protein production was significantly decreased by sera from PCOS women following 6 months of metformin treatment (P0.05). After 6 months of metformin treatment, there was a significant decrease in circulating ASAA (P0.05). Importantly, changes in intima media thickness were predictive of changes in circulating ASAA (P=0.034).Serum and AT ASAA are increased in PCOS women and are elevated by glucose. Metformin treatment decreases serum ASAA in these women. An adipose tissue-monocyte axis may be pivotal in the pathogenesis of inflammation and atherosclerosis. ASAA may be a valuable diagnostic marker in the management of dysmetabolic states including PCOS.

Objectives Serum amyloid A (SAA) is a biomarker of inflammation. Elevated blood levels in cardiovascular disease and local deposition in atheroma implies a role of SAA as a mediator rather than just a marker of inflammation. This study explored SAA-induced cytokine production and secretion by mononuclear cells. Methods and results RT-PCR showed that SAA time-dependently induced cytokine mRNAs in peripheral blood mononuclear cells (PBMC) and THP-1 monocytoid cells, and dramatically increased IL-1β, MCP-1, IL-6, IL-8, IL-10, GM-CSF, TNF, and MIP-1α secretion by PBMC to levels 28 to 25,000 fold above baseline, as measured with Bio-Plex kits; monocytes were the principle source. SAA induction of cytokines in monocyte-derived macrophages (MDM) was significantly higher than from monocytes from the same donors. SAA time-dependently induced transient and significant upregulation of NF-κB1 mRNA; inhibitor studies indicate that activation of NF-κB through the ERK1/2, p38 and JNK MAPKs and the PI3K pathway was involved. PBMC from 10 patients with coronary artery disease (CAD) spontaneously secreted higher levels of IL-6 and MIP-1α after 24 h incubation than PBMC from normal controls, whereas SAA-induced levels of all cytokines were similar to controls. Aortic and coronary sinus sampling in 23 CAD patients indicated significant SAA release into the coronary circulation, not evident in 11 controls. Conclusions SAA can increase monocyte and macrophage cytokine production, possibly at sites of atherosclerosis, thereby contributing to the pro-inflammatory state in coronary artery disease.

Objective The transcription factors, peroxisome proliferator-activated receptors (PPAR) alpha (α) and gamma (γ), which are involved in lipid and glucose homeostasis, also exert modulatory actions on vascular cells where they exhibit anti-inflammatory and anti-proliferative properties. Hence, PPAR agonists potentially can affect atherogenesis both via metabolic effects and direct effects on the vessel wall. We tested whether the dual PPAR-α/γ agonist, tesaglitazar (TZ), would reduce atherosclerosis in a non-diabetic, atherosclerosis-prone mouse model, independent of effects on plasma lipids. Methods and results Low-density lipoprotein receptor deficient (LDLr−/−) mice were fed a Western type diet consisting of 21% butterfat and 0.15% cholesterol, with or without TZ 0.5 μmol/kg of diet, for 12 weeks. TZ reduced atherosclerosis in the female, but not male, LDLr−/− mice without affecting cholesterol and triglyceride levels, HDL binding to biglycan, or the inflammatory markers serum amyloid A (SAA) and serum amyloid P (SAP). TZ also decreased adiposity in both genders. Conclusions TZ reduced atherosclerosis in the female LDLr−/− mice via lipid-independent mechanisms, probably at least in part by direct actions on the vessels. The body weight changes in these mice are different from the effects of dual PPAR agonists seen in humans.

Background Tea consumption has been inversely related to the risk of cardiovascular disease, but the mechanism behind this cardioprotective role is not fully understood. In vitro and animal model studies suggest an anti-oxidative and/or anti-inflammatory role. We aimed at investigating the association between tea drinking and indicators of low-grade inflammation in humans. Methods We used observational data from 1031 healthy men participating in a larger cross-sectional study (BELSTRESS). Tea consumption was determined according to a semi-quantitative food frequency questionnaire. Blood samples were analysed for C-reactive protein (CRP), serum amyloid A (SAA), serum haptoglobin and plasma fibrinogen. Results Of all participants, 22% consumed tea regularly while 10% drank more than two cups per day. Tea drinkers were less obese, smoked less and drank less alcohol and coffee. CRP, SAA and haptoglobin were significantly associated with tea consumption, the effect being graded for SAA. Multivariate analysis did confirm the independence of the observed beneficial role of tea drinking. Fibrinogen levels were however not different between habitual tea consumers and non-consumers. Coffee drinking proved unrelated to chronic inflammation. Conclusion Tea drinking might be of interest in reducing the inflammatory process underlying cardiovascular disease. In light of the fact that tea is the most consumed beverage in the world after water, our findings might be of importance from a public health perspective.

Human growth hormone (GH) excess is linked to increased cardiovascular morbidity and mortality. However, little is known about the effect of GH excess on atherosclerosis. We developed a new mouse model to assess the hypothesis that GH overexpression accelerates atherosclerotic lesion formation. apoE −/− mice were crossed with bovine GH (bGH) transgenic mice to yield apoE −/− mice overexpressing bGH (apoE −/− /bGH). The mice were fed either standard or Western diet. At 22 weeks, atherosclerotic lesion area of thoracic aorta was larger in apoE −/− /bGH mice compared with littermate apoE −/− mice fed either diet (standard: +161±50%, Western: +430±134%). Aortic sinus lesions were more severe in apoE −/− /bGH mice fed standard diet compared with littermate apoE −/− mice. apoE −/− /bGH mice had lower (VLDL+LDL)/HDL ratios compared with littermate apoE −/− mice, while systolic blood pressure was higher in apoE −/− /bGH mice, irrespective of diet. The levels of serum amyloid A and hepatic CRP mRNA were higher in apoE −/− /bGH mice than in littermate apoE −/− mice. In conclusion, this study shows that excess GH augments the development of atherosclerosis in apoE −/− mice. The mechanisms could be direct effects of GH on cellular processes in the vessel wall or the result of concomitant processes such as hypertension or a general inflammatory state.

We evaluated the possible association of the serum levels of C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen, and cardiac troponin I (cTnI) with the presence of complex angiographic characteristics throughout the coronary artery tree in 519 consecutive patients with non-ST-elevation acute myocardial infarction (NSTEMI). Blood samples were obtained in the first 12h of NSTEMI invasion and all patients underwent in-hospital coronary angiography. Coronary lesions were classified as complex lesion (CL) or non-CL according to Ambrose criteria. Serum levels of CRP (p0.001), SAA (p0.001), or fibrinogen (p=0.001), but not of cTnI (p=0.9), were significantly related to the presence of multiple (or =2) CLs. On the contrary, serum levels of cTnI (p0.001), but not of CRP (p=0.5), SAA (p=0.9), or fibrinogen (p=0.9), were significantly associated with the severity of coronary artery disease. The results of the present study suggest that elevated levels of inflammatory biomarkers are associated with a generalized activation of coronary artery tree while elevated cTnI levels are associated with the severity of coronary artery disease in the setting of NSTEMI. It seems that inflammatory biomarkers and cTnI reflect different aspect of the process involved in unstable coronary artery disease.

It has been suggested that low-grade systemic inflammation is associated with obesity and that this association might be modified by sex.We performed a cross-sectional analysis among 641 men and 597 women aged 55-74 years who participated in the population-based KORA Survey 2000, conducted in the area of Augsburg, Germany. Measures of both total (fat mass, body mass index) and abdominal adiposity (waist circumference (WC), waist to hip ratio (WHR)) were highly correlated with markers of systemic inflammation (C-reactive protein (CRP), serum amyloid A (SAA), fibrinogen (FIB), interleukin-6 (IL-6)) in men and in women. Significant associations persisted when the effect of lifestyle factors was taken into account. In multivariable linear regression analysis, a considerably higher percentage of variability in inflammatory markers was explained by body composition in women compared to men. Furthermore, the relevance of single body composition variables varied by sex. In women, fat mass in % explained the highest percentage of the variability of circulating acute-phase proteins (18.2% for CRP, 7.2% for SAA, 6.1% for FIB, all p-values0.001), whereas in men, WHR explained the highest percentage of the variability (6.2% for CRP, 2.3% for SAA, 1.8% for FIB, all p-values0.001). For IL-6, WC explained the highest percentage of the variability in women (3.7%, p0.001) and in men (1.8%, p0.001).Adiposity is strongly associated with low-grade systemic inflammation in men and in women but the association is considerably stronger in women, especially for CRP. Thus, weight reduction as a means to prevent a state of subclinical inflammation might be particularly effective in women.

Numerous animal studies have reported that garlic can protect against atherosclerosis. However, a comparable number of studies do not support this observation. This contradiction may result from differences in study design, use of different animal models, and use of different garlic formulations and preparations. Here, we investigated the effect of the chemically well-characterized and production-controlled garlic powder printanor on atherosclerosis in the APOE*3-Leiden transgenic mouse, a mouse model well suited for evaluating anti-atherosclerotic properties of drugs and food components under human-like conditions. APOE*3-Leiden mice were fed a Western diet supplemented with either 5 or 50 g kg −1 printanor. As a reference, the commercially available fermented garlic kyolic was included (1.6 g kg −1 diet). Treatment with printanor demonstrated reduced body weight, coinciding with increased feces production and fecal fatty acids excretion. Printanor and kyolic treatment did not affect plasma lipids, markers of inflammation (serum amyloid A, serum-soluble intercellular adhesion molecule-1, and blood-leukocytes tumor necrosis factor- (TNF) production) and vascular activation (plasma von Willebrand factor (vWF)). As analyzed after 28 weeks of treatment, printanor and kyolic did not affect atherosclerotic lesion type, area or composition. Under conditions relevant to the human situation, the well-characterized and production-controlled garlic powder printanor does not display hypolipidemic, anti-inflammatory or anti-atherosclerotic properties. © 2004 Elsevier Ireland Ltd. All rights reserved.

Studies have been conducted to determine whether the ability of high density lipoproteins (HDL) to inhibit the cytokine-induced expression of vascular cell adhesion molecule-1 (VCAM-1) in endothelial cells is altered by the presence in HDL of the acute phase reactant, serum amyloid-A (SAA). Preparations of HDL(3) were isolated on two separate occasions from the plasma of each of 19 patients: the first was collected before and the second 3 days after undergoing coronary artery bypass graft surgery. Whereas the preoperative HDL(3) sample contained no SAA, in the postoperative sample SAA accounted for an average of 42% of the HDL(3) protein. The preoperative HDL(3) and postoperative, SAA-enriched HDL(3) were identical in terms of their ability to inhibit the tumour necrosis factor-alpha (TNF-alpha)-induced expression of VCAM-1 in human umbilical vein endothelial cells (HUVECs). To assess the effect of having an even greater SAA enrichment of HDL(3), samples of HDL(3) were incubated with purified SAA, which displaced almost all of the apoAI and about 40% of the apoAII from the HDL(3). This in vitro SAA-enriched HDL(3) inhibited the TNF-alpha-induced expression of VCAM-1 in HUVECs in a concentration dependent manner, which was identical to that of the unmodified HDL(3). The presence of SAA did not alter the cell-surface binding of HDL(3) to endothelial cells. It has been concluded that the presence of SAA in HDL has no effect on the ability of these lipoproteins either to inhibit the expression of VCAM-1 in endothelial cells or to bind to proteins on the endothelial cell surface.

We have previously observed low levels of high density lipoprotein (HDL) cholesterol in active sarcoidosis. The aim of this study was to analyze the role of serum amyloid A (SAA) on this lipid disorder.Eighty five untreated sarcoid patients, 40 with active disease and 45 with inactive disease, were recruited. Sarcoidosis activity was evaluated by means of clinical, chest X-ray, gallium-67 scan, serum angiotensin converting enzyme (peptidyl-dipeptidase A) values, and pulmonary function tests. Analysis of lipoprotein metabolism included: serum cholesterol, low density lipoprotein (LDL)-cholesterol, HDL-cholesterol, HDL(2)-cholesterol, HDL(3)-cholesterol, apolipoprotein A-I (apo A-I), apolipoprotein B (apo B), and triglyceride concentrations. Serum amyloid A protein and lecithin-cholesterol acyltransferase (LCAT) activity were measured.In active sarcoidosis we found significantly reduced levels of HDL-cholesterol (1.17+/-0.36 vs. 1. 44+/-0.39 mmol/l, P=0.002), HDL(3)-cholesterol (0.78+/-0.23 vs. 1. 02+/-0.21 mmol/l, P0.0001), and apo A-I (1.36+/-0.29 vs. 1.61+/-0. 27 g/l, P0.0001) and significantly increased levels of triglyceride (1.51+/-0.64 vs. 1.03+/-0.46 mmol/l, P0.0001), and apo B (1.14+/-0. 25 vs. 0.99+/-0.27 g/l, P=0.012) versus inactive sarcoidosis. Serum amyloid A concentrations were significantly increased in the patients with active disease (155.45+/-154.01 mg/ml) compared to the inactive sarcoid patients (89.70+/-65.36 mg/ml) (P=0.011). There were no significant differences in cholesterol, LDL-cholesterol, HDL(2)-cholesterol or LCAT values between groups. Multivariate logistic regression analysis showed that HDL-cholesterol (regression coefficient b=-1.96; S.E.=0.87; P=0.02) and SAA (regression coefficient b=0.01; S.E.=0.004; P=0.01) were the two variables independently associated with disease activity. Moreover, a significant negative correlation was observed between SAA levels and both HDL-cholesterol (r=-0.39; P=0.01) and apo A-I (r=-0.35; P=0.03) levels, in the active sarcoid group. Conversely, no correlation was found in the inactive sarcoid group.The low HDL-cholesterol and apo A-I concentrations seen in active sarcoid patients are associated with a significant increase of SAA levels. We suggest that the displacement of apo A-I by SAA on HDL accounts for the lower level of HDL-cholesterol seen in active sarcoidosis.

There is mounting evidence that inflammation plays a role in the development of coronary heart disease (CHD). Observations have been made linking the presence of infections in the vessel wall with atherosclerosis, and epidemiological data also implicate infection in remote sites in the aetiology of CHD. In this article we propose a key role for the proinflammatory cytokine interleukin-6 (IL-6) in several mechanisms that contribute to the development of CHD. IL-6 is a powerful inducer of the hepatic acute phase response. Elevated concentrations of acute phase reactants, such as C-reactive protein (CRP), are found in patients with acute coronary syndromes, and predict future risk in apparently healthy subjects. The acute phase reaction is associated with elevated levels of fibrinogen, a strong risk factor for CHD, with autocrine and paracrine activation of monocytes by IL-6 in the vessel wall contributing to the deposition of fibrinogen. The acute phase response is associated with increased blood viscosity, platelet number and activity. Furthermore, raised serum amyloid A lowers HDL-cholesterol levels. IL-6 decreases lipoprotein lipase (LPL) activity and monomeric LPL levels in plasma, which increases macrophage uptake of lipids. In fatty streaks and in the atheromatous 'cap' and 'shoulder' regions, macrophage foam cells and smooth muscle cells (SMC) express IL-6, suggesting a role for this cytokine along with interleukin-1 (IL-1) and tumour necrosis factor-alpha (TNF-alpha), in the progression of atherosclerosis. Both these cytokines induce the release of IL-6 from several cell types, including SMC. During vascular injury SMC are exposed to platelets or their products, and cytokine production by SMC further contributes to vascular damage. Furthermore, circulating IL-6 stimulates the hypothalamic-pituitary-adrenal (HPA) axis, activation of which is associated with central obesity, hypertension and insulin resistance. Thus we propose a role for IL-6 in the pathogenesis of CHD through a combination of autocrine, paracrine and endocrine mechanisms. This hypothesis lends itself to testing using interventions to influence IL-6 secretion and actions.

Fig. 3. Detection of apoproteins in complexes by Western blotting. (a) Apoprotein staining of the VLDL (lane 1) of coronary atherosclerosis patients with low levels of SAA/LDL, and the SAA-unbound VLDL (lane 2) and SAA/VLDL (lane 3) of coronary atherosclerosis patients. (b) Apoprotein staining of the LDL (lane 1) of coronary atherosclerosis patients with low levels of SAA/LDL, and the SAA-unbound LDL (lane 2) and SAA/LDL (lane 3) of coronary atherosclerosis patients.