Serum glycoproteins and severity of coronary atherosclerosis

The Search for Associations of Serum Proteins with the Presence of Unstable Atherosclerotic Plaque in Coronary Atherosclerosis

To study the associations of blood proteins with the presence of unstable atherosclerotic plaques in the arteries of patients with coronary atherosclerosis using quantitative proteomics. The studies involved two groups of men with coronary atherosclerosis (group 1 (St) had only stable atherosclerotic plaques; group 2 (Ns) had only unstable atherosclerotic plaques, according to histological analysis of tissue samples); the average age of patients was 57.95 ± 7.22. Protein concentrations in serum samples were determined using the PeptiQuant Plus Proteomics Kit. The identification of protein fractions was carried out by monitoring multiple reactions on a Q-TRAP 6500 mass spectrometer combined with a liquid chromatograph. Mass spectrometric identification revealed in serum samples from patients with unstable atherosclerotic plaques a reduced concentration of proteins in the blood: α-1-acid glycoprotein, α-1-antichymotrypsin, α-1-antitrypsin, ceruloplasmin, hemopexin, haptoglobin, apolipoprotein B-100, apolipoprotein L1, afamin and complement component (C3, C7, C9). Moreover, at the same time a high concentration complements factor H and attractin. The differences were considered significant at p < 0.05. It was found that the instability of atherosclerotic plaques is associated with the concentration of proteins: afamin, attractin, components of the complement system, hemopexin and haptoglobin. The data of our study showed the association of some blood proteins with the instability of atherosclerotic plaques in coronary atherosclerosis. Their potential role in the development of this disease and the possibility of using the studied proteins as biomarkers requires further research.

Platelet-released extracellular vesicles: the effects of thrombin activation

Platelets exert fundamental roles in thrombosis, inflammation, and angiogenesis, contributing to different pathologies from cardiovascular diseases to cancer. We previously reported that platelets release extracellular vesicles (pEVs) which contribute to thrombus formation. However, pEV composition remains poorly defined. Indeed, pEV quality and type, rather than quantity, may be relevant in intravascular cross-talk with either circulating or vascular cells. We aimed to define the phenotypic characteristics of pEVs released spontaneously and those induced by thrombin activation to better understand their role in disease dissemination. pEVs obtained from washed platelets from healthy donor blood were characterized by flow cytometry. pEVs from thrombin-activated platelets (T-pEVs) showed higher levels of P-selectin and active form of glycoprotein IIb/IIIa than baseline non-activated platelets (B-pEVs). Following mass spectrometry-based differential proteomic analysis, significant changes in the abundance of proteins secreted in T-pEVs compared to B-pEVs were found. These differential proteins were involved in coagulation, adhesion, cytoskeleton, signal transduction, metabolism, and vesicle-mediated transport. Interestingly, release of proteins relevant for cell adhesion, intrinsic pathway coagulation, and platelet activation signalling was significantly modified by thrombin stimulation. A novel pEV-associated protein (protocadherin-α4) was found to be significantly reduced in T-pEVs showing a shift towards increased expression in the membranes of activated platelets. In summary, platelet activation induced by thrombin triggers the shedding of pEVs with a complex proteomic pattern rich in procoagulant and proadhesive proteins. Crosstalk with other vascular and blood cells in a paracrine regulatory mode could extend the prothrombotic signalling as well as promote proteostasic changes in other cellular types.

Molecular Functions of Ceruloplasmin in Metabolic Disease Pathology

Ceruloplasmin (CP) is a multicopper oxidase and antioxidant that is mainly produced in the liver. CP not only plays a crucial role in the metabolic balance of copper and iron through its oxidase function but also exhibits antioxidant activity. In addition, CP is an acute-phase protein. In addition to being associated with aceruloplasminemia and neurodegenerative diseases such as Wilson's disease, Alzheimer's disease, and Parkinson's disease, CP also plays an important role in metabolic diseases, which are caused by metabolic disorders and vigorous metabolism, mainly including diabetes, obesity, hyperlipidemia, etc. Based on the physiological functions of CP, we provide an overview of the association of type 2 diabetes, obesity, hyperlipidemia, coronary heart disease, CP oxidative stress, inflammation, and metabolism of copper and iron. Studies have shown that metabolic diseases are closely related to systemic inflammation, oxidative stress, and disorders of copper and iron metabolism. Therefore, we conclude that CP, which can reduce the formation of free radicals in tissues, can be induced during inflammation and infection, and can correct the metabolic disorder of copper and iron, has protective and diagnostic effects on metabolic diseases.

Interactive effects of interferon-gamma functional single nucleotid polymorphism (+874 T/A) with cardiovascular risk factors in coronary heart disease and early myocardial infarction risk

Atherosclerosis is an inflammatory disease characterized by extensive lipid accumulation in the artery wall. Throughout the atherosclerotic process, interferon-gamma (IFN-γ), which is an important pro-inflammatory cytokine, plays a central role in atherosclerotic plaque instability and the occurrence of myocardial infarction (MI). In this study, we aimed to investigate the relationship between IFN-γ +874 T/A (rs2430561) polymorphism and coronary heart disease (CHD) as well as its effects on MI and CHD. Three hundred and ninety patients with CHD (229 with MI, 161 without MI) and 233 healthy controls were screened by the amplification refractory mutation system (ARMS) PCR method for IFN-γ +874 T/A polymorphism. For MI risk, early adult age was important risk factors and the risk was increased with IFN-γ +874 T/A polymorphism. IFN-γ T allele was significantly increased in the CHD patients with age≤45 (p = 0.048) and patients with history of MI (p = 0.007). As IFN-γ is an inflammatory cytokine with an emerging role in the atherosclerotic process, it was suggested that inhibition of IFN-γ activity could be a therapeutic strategy to stabilize human atherosclerotic plaque. Our findings support the association between MI risk and IFN-γ +874 T/A polymorphism in the Turkish population, particularly by increasing the level of IFN-γ in young patients, thereby causing rupture of vulnerable plaques in atherosclerotic lesions. Identification of the IFN-γ +874 T/A gene variants as risk factors for early CHD and MI development may be a practical biomarker to guide the MI risk process and determine the ideal therapeutic approach.

Ceruloplasmin and Coronary Heart Disease-A Systematic Review

Several studies indicate that oxidative stress might play a central role in the initiation and maintenance of cardiovascular diseases. It remains unclear whether ceruloplasmin acts as a passive marker of inflammation or as a causal mediator. To better understand the impact of ceruloplasmin blood levels on the risk of cardiovascular disease, and paying special attention to coronary heart disease, we conducted a search on the two most commonly used electronic databases (Medline via PubMed and EMBASE) to analyze current assessment using observational studies in the general adult population. Each study was quality rated using criteria developed by the US Preventive Services Task Force. Most of 18 eligible studies reviewed support a direct relationship between ceruloplasmin elevated levels and incidence of coronary heart disease. Our results highlight the importance of promoting clinical trials that determine the functions of ceruloplasmin as a mediator in the development of coronary heart disease and evaluate whether the treatment of elevated ceruloplasmin levels has a role in the prognosis or prevention of this condition.

Increased Pro-Thrombotic Platelet Activity Associated with Thrombin/PAR1-Dependent Pathway Disorder in Patients with Secondary Progressive Multiple Sclerosis

Epidemiological studies confirm the high risk of ischemic events in multiple sclerosis (MS) that are associated with increased pro-thrombotic activity of blood platelets. The most potent physiological platelet agonist is thrombin, which activates platelets via cleavage of specific protease-activated receptors (PARs). Our current study is aimed to determine the potential genetics and proteomic abnormalities of PAR1 in both platelets and megakaryocytes, which may have thromboembolic consequences in the course of MS. The obtained results were correlated with the expression level of platelet and megakaryocyte transcripts for APOA1 and A2M genes encoding atherosclerosis biomarkers: apolipoprotein A1 (ApoA1) and α-2-macroglobulin (α2M), respectively. Moreover, PAR1 functionality in MS platelets was assessed by flow cytometry, determining the level of platelet–platelet and platelet–leukocyte aggregates, platelet microparticles and surface expression of P-selectin. As a PAR1 agonist, the synthetic TRAP-6 peptide was used, which made it possible to achieve platelet activation in whole blood without triggering clotting. Comparative analyses showed an elevated level of platelet activation markers in the blood of MS patients compared to controls. The mRNA expression of gene coding α2M was upregulated, whilst ApoA1 was down-regulated, both in platelets and megakaryocytes from MS patients. Furthermore, we observed an increase in both mRNA expression and surface density of PAR1 in platelets and megakaryocytes in MS compared to controls. Both the level of platelet activation markers and PAR1 expression showed a high correlation with the expression of transcripts for APOA1 and A2M genes.

High-molecular-weight kininogen and the intrinsic coagulation pathway in patients with de novo acute myocardial infarction

After an acute ischaemic event serum proteins may change reflecting the ischaemic damage. Proteomic studies could provide new insights into potential biomarkers in the evolution of ischaemic syndromes. In this study we have investigated the coordinated changes in coagulation-related proteins in the evolution after an acute myocardial infarction (AMI). Serum proteome (2D-electrophoresis and MALDI-TOF/ TOF) of AMI-patients within the first 6 hours after event onset (admission-time) and 3 days after were compared to controls. Systems biology and bioinformatic analysis were performed to identify the differentially expressed canonical pathways. In silico analysis of differential proteins revealed changes in the intrinsic coagulation pathway in the early phase post-AMI. The two identified high-molecular weight kininogen (HMWK) clusters were inversely correlated in AMI patients at admission, being the intensity of the low-molecular-weight form inversely related to myocardial necrosis (p<0.05). Factor XI (FXI) levels were decreased in AMI patients at admission and normalised 3 days after (p<0.05). There was an early increase in fibrinogen gamma and D-dimer at admission, followed by a decrease in fibrinogen turnover 3 days after (p<0.05). The influence of elapsed time of ischaemia on fibrinogen distribution changes was validated in coronary thrombi retrieved by thromboaspiration. In conclusion, our results demonstrate an active exchange between HMWK forms and a decrease in FXI indicative of intrinsic pathway activation, together with an increase in fibrinogen gamma turnover and D-dimer formation in the early phase post-AMI. Moreover, coronary thrombi showed a dynamic evolution in fibrinogen composition depending on the duration of ischaemia influencing serum fibrinogen-related products content.

Orosomucoid, Carotid Plaque, and Incidence of Stroke

Background and Purpose—

Orosomucoid (α-1-acid glycoprotein) is an acute-phase protein that has been implicated in anti-inflammatory, immunomodulating, and angiogenic pathways. Orosomucoid has also been associated with coronary disease and stroke. The relationship between orosomucoid, carotid plaque, and stroke incidence were explored in this study.

Methods—

Plasma levels of orosomucoid were assessed in 4285 subjects (39.8% men; mean age 57.5±5.9 years) without cardiovascular disease, who participated in the Malmö Diet and Cancer Study, between 1991 and 1994. The right carotid artery was examined for plaque using B-mode ultrasound examination. Incidence of stroke was followed up during a median follow-up time of 17.7 years.

Results—

Carotid plaque was present in 43.5% at baseline. Orosomucoid was significantly higher in subjects with carotid plaque (mean±SD: 0.72±0.22 versus 0.69±0.20 g/L; P <0.001). A total of 234 subjects were diagnosed with ischemic stroke during follow-up. Orosomucoid was associated with ischemic stroke after adjustment for risk factors, with hazard ratio 1.48 (95% confidence interval, 1.02–2.16) comparing the third versus first tertile. In subjects with plaque and belonging to the top tertile of orosomucoid, the hazard ratio was 2.07 (95% confidence interval, 1.38–3.11) compared with those without plaque and with orosomucoid in the first and second tertiles, after adjustment for C-reactive protein and other risk factors.

Conclusions—

Elevated levels of orosomucoid are associated with increased occurrence of carotid plaque and increased incidence of ischemic stroke. The combination of high orosomucoid and carotid plaque substantially increase the risk of stroke.

Time course of various cell origin circulating microparticles in ST-segment elevation myocardial infarction patients undergoing percutaneous transluminal coronary intervention

The present study aimed to investigate the time course of changes in microparticles (MPs) in patients with ST-segment elevation myocardial infarction (STEMI) that underwent percutaneous transluminal coronary intervention (PCI). A total of 24 STEMI patients undergoing primary PCI were enrolled, and circulating MPs were detected immediately prior to and after PCI, and at 4, 24 and 48 h post-PCI. Standard Megamix beads, based measurement protocols, were employed to measure MPs of different cell origin, including endothelial MPs (EMPs), platelet MPs (PMPs) and leukocyte-derived MPs (LMPs), which were identified by CD144, CD41 and CD45, respectively. The results indicated that PMP levels were evidently elevated immediately after PCI, and reached a maximum level at 48 h. In addition, LMP and EMP levels were significantly decreased immediately after the PCI, and then increased gradually with time. The total quantity of the three aforementioned MP types increased gradually at 48 h following PCI. Furthermore, coronary angiographic Gensini scores were significantly positively correlated with the level of PMPs (r2=0.42; P=0.0006). Log-normalized high sensitivity-C-reactive-protein was also significantly correlated with LMPs (r2=0.86; P<0.01). In conclusion, the time course of the changes in circulating MPs of different cell origin, provided information on possible functions of different MPs in STEMI.

Plasma α1-antitrypsin: a neglected predictor of angiographic severity in patients with stable angina pectoris

Background:

As an acute phase protein, α1-antitrypsin (AAT) has been extensively studied in acute coronary syndrome, but it is unclear whether a relationship exists between AAT and stable angina pectoris (SAP). The purpose of the present study was to investigate the association between AAT plasma levels and SAP.

Methods:

Overall, 103 SAP patients diagnosed by coronary angiography and clinical manifestations and 118 control subjects matched for age and gender were enrolled in this case-control study. Plasma levels of AAT, high-sensitivity C-reactive protein (hsCRP), lipid profiles and other clinical parameters were assayed for all participants. The severity of coronary lesions was evaluated based on the Gensini score (GS) assessed by coronary angiography.

Results:

Positively correlated with the GS (r = 0.564, P < 0.001), the plasma AAT level in the SAP group was significantly higher than that in the control group (142.08 ± 19.61 mg/dl vs. 125.50 ± 19.67 mg/dl, P < 0.001). The plasma AAT level was an independent predictor for both SAP (odds ratio [OR] = 1.037, 95% confidence interval [CI]: 1.020–1.054, P < 0.001) and a high GS (OR = 1.087, 95% CI: 1.051–1.124, P < 0.001) in a multivariate logistic regression model. In the receiver operating characteristic curve analysis, plasma AAT level was found to have a larger area under the curve (AUC) for predicting a high GS (AUC = 0.858, 95% CI: 0.788–0.929, P < 0.001) than that of hsCRP (AUC = 0.665, 95% CI: 0.557–0.773, P = 0.006; Z = 2.9363, P < 0.001), with an optimal cut-off value of 137.85 mg/dl (sensitivity: 94.3%, specificity: 68.2%).

Conclusions:

Plasma AAT levels correlate with both the presence and severity of coronary stenosis in patients with SAP, suggesting that it could be a potential predictive marker of severe stenosis in SAP patients.

Effect of 6-month caloric restriction on Cu bound to ceruloplasmin in adult overweight subjects

In a randomized clinical trial of calorie restriction (CR), we demonstrated that important cardiovascular disease (CVD) biomarkers were favorably influenced by CR alone and in conjunction with physical exercise. The aim of this study was to examine the effects of CR with or without exercise on copper bound to ceruloplasmin (CuCp), a well-known biomarker for CVD, in overweight men and women enrolled in the CALERIE phase 1 study. Forty-six individuals were randomized to one of four groups for 6 months: control, healthy weight maintenance; CR, 25% CR from baseline energy requirements; CR+exercise, 12.5% CR and 12.5% through aerobic exercise; and low-calorie diet, low-calorie diet until 15% reduction in body weight followed by weight maintenance diet. CuCp was determined in fasting blood samples by a high-performance liquid chromatography-inductively coupled plasma mass spectrometry methodology and compared with changes in body composition and markers of CVD. After 6 months, CR combined with exercise induced a decrease in plasma concentration of CuCp. CuCp was inversely correlated with insulin sensitivity at baseline and after 6 months of intervention. A cluster analysis showed that the percent change of weight after 6 months of intervention was the most important variable that could discriminate the intervention groups. The percent change of CuCp was the only other variable selected by the analysis. Decreased CuCp in overweight subjects by CR combined with exercise suggests a positive effect of this intervention on metabolic health. Further studies to explain the relationship between weight loss and CuCp and its relevance for cardiovascular health are needed.

Plasma albumin and platelet function: relevance to atherogenesis and thrombosis

Two papers published in this journal(1,2) during the past year remind us that plasma albumin concentrations can influence platelet function. These publications, together with epidemiological evidence showing that low plasma concentrations of albumin predict mortality from cardiovascular disease(3,4) have prompted this review.

Novel proteins associated with risk for coronary heart disease or stroke among postmenopausal women identified by in-depth plasma proteome profiling

Background

Coronary heart disease (CHD) and stroke were key outcomes in the Women's Health Initiative (WHI) randomized trials of postmenopausal estrogen and estrogen plus progestin therapy. We recently reported a large number of changes in blood protein concentrations in the first year following randomization in these trials using an in-depth quantitative proteomics approach. However, even though many affected proteins are in pathways relevant to the observed clinical effects, the relationships of these proteins to CHD and stroke risk among postmenopausal women remains substantially unknown.

Methods

The same in-depth proteomics platform was applied to plasma samples, obtained at enrollment in the WHI Observational Study, from 800 women who developed CHD and 800 women who developed stroke during cohort follow-up, and from 1-1 matched controls. A plasma pooling strategy, followed by extensive fractionation prior to mass spectrometry, was used to identify proteins related to disease incidence, and the overlap of these proteins with those affected by hormone therapy was examined. Replication studies, using enzyme-linked-immunosorbent assay (ELISA), were carried out in the WHI hormone therapy trial cohorts.

Results

Case versus control concentration differences were suggested for 37 proteins (nominal P < 0.05) for CHD, with three proteins, beta-2 microglobulin (B2M), alpha-1-acid glycoprotein 1 (ORM1), and insulin-like growth factor binding protein acid labile subunit (IGFALS) having a false discovery rate < 0.05. Corresponding numbers for stroke were 47 proteins with nominal P < 0.05, three of which, apolipoprotein A-II precursor (APOA2), peptidyl-prolyl isomerase A (PPIA), and insulin-like growth factor binding protein 4 (IGFBP4), have a false discovery rate < 0.05. Other proteins involved in insulin-like growth factor signaling were also highly ranked. The associations of B2M with CHD (P < 0.001) and IGFBP4 with stroke (P = 0.005) were confirmed using ELISA in replication studies, and changes in these proteins following the initiation of hormone therapy use were shown to have potential to help explain hormone therapy effects on those diseases.

Conclusions

In-depth proteomic discovery analysis of prediagnostic plasma samples identified B2M and IGFBP4 as risk markers for CHD and stroke respectively, and provided a number of candidate markers of disease risk and candidate mediators of hormone therapy effects on CHD and stroke.

Clinical Trials Registration

ClinicalTrials.gov identifier: NCT00000611

Association of inflammatory markers with angiographic severity and extent of coronary artery disease

Inflammatory processes play a pivotal role in the pathogenesis of atherosclerosis and mediate many of the stages of atheroma development, from initial leukocyte recruitment to eventual rupture of the unstable atherosclerotic plaque. Several systemic inflammatory markers reflect different degrees of inflammation and have been indicated as independent risk factors in cardiovascular disease, especially in unstable coronary syndromes. However, whether elevated levels of circulating inflammatory markers play a role in the extent and severity of atherosclerosis remains controversial. The present review summarizes our current understanding of the relationship between inflammatory markers and the presence and extent of coronary atherosclerosis, in order to assess the potential utility of these markers in identifying patients with higher levels of atherosclerotic burden.

Diabetic dyslipidemia and exercise alter the plasma low-density lipoproteome in Yucatan pigs

Although low-density lipoprotein (LDL) plays a predominant role in atherogenesis, the low-density lipoproteome has not been fully characterized. Moreover, alterations from a Western diet, diabetes, and physical inactivity on this proteome have yet to be determined. Accordingly, relative quantification was determined in LDL proteins from male Yucatan diabetic dyslipidemic (DD) swine in the early stages of atherosclerosis compared to healthy control (C) and non-diabetic hyperlipidemic (H) swine. Importantly, coronary vascular dysfunction was prevented by aerobic exercise training in these animals (DDX) without altering total LDL concentration. Using 2-DE, Western blot, label-free quantitative MS, and selected reaction monitoring, alterations in the abundance of apolipoproteins A-I, B, C-III, D, E, and J and noncovalently associated proteins were determined in LDL isolated using fast protein liquid chromatography. At least 28 unique proteins, many of which were novel, were identified with high confidence. An apolipoprotein E isoform demonstrated stronger correlation to disease (percent of coronary artery segments with intimal thickening) than some traditional risk factors (total cholesterol, LDL cholesterol, and LDL/HDL cholesterol). Taken together, this work identifies new possible biomarkers, potential therapeutic targets for atherosclerosis, and generates new hypotheses regarding the role of LDL in atherogenesis.

Inflammatory cytokine gene variants in coronary artery disease patients in Greece

OBJECTIVE

Abundant evidence supports the central role of inflammatory cytokines in immune responses mediating the pathogenesis of atherosclerosis, coronary artery disease, and its complications, such as myocardial infarction and unstable angina.

METHODS

We investigated the association of genetic polymorphisms of the inflammatory cytokines, IL-10, TGF-beta1, IFN-gamma, IL-6, and TNF-alpha with the clinical presentation of coronary artery disease in 26 patients with stable angina, 45 patients with unstable angina and 58 patients who had experienced nonfatal myocardial infarction. Genotyping was performed by the sequence-specific primer polymerase chain reaction method.

RESULTS

A significant difference in the frequencies of -174G/C IL-6 alleles was observed, with the low in-vitro producing -174*C allele predominating in patients with myocardial infarction, compared with stable angina and unstable angina patients, after the analysis of genotypes (P=0.024 and 0.022, respectively), phenotypes [P=0.0099, odds ratio (OR)=0.271, 95% confidence interval (CI)=0.1012-0.7292; P=0.03, OR=0.40, respectively] and haplotypes (P=0.007, OR=3.028, 95% CI=1.347-6.806; P=0.0096, OR=2.368, 95% CI=1.262-4.444; respectively). In addition, a predominance of the -1082ACC/ATA IL-10 genotype in the myocardial infarction group compared with the unstable angina group and the -874 A/A IFN-gamma genotype in the stable angina group compared with the unstable angina and the myocardial infarction group, was found. No significant differences in the distribution of genotypes, phenotypes and haplotypes in the three study groups, for the TNF-alpha-308 A/G and TGF-beta1-codon 25 G/C, codon 10 T/C polymorphisms were detected.

CONCLUSION

Our data provide evidence that the IL-6-174G/C polymorphism may be involved in the pathogenesis of coronary artery disease, contributing to genetic susceptibility for myocardial infarction.

High-density lipoprotein cholesterol, C-reactive protein, and prevalence and severity of coronary artery disease in 5641 consecutive patients undergoing coronary angiography

BACKGROUND

Although high-density lipoprotein cholesterol (HDL-C) and C-reactive protein (CRP) are well-established predictors for future cardiovascular events, little information is available regarding their correlation with the prevalence and severity of angiographically evaluated coronary artery disease (CAD).

MATERIAL AND METHODS

Five thousand six hundred forty-one consecutive patients undergoing coronary angiography for the evaluation of CAD were analysed. Cardiovascular risk factors were assessed by routine blood chemistry and questionnaire. CAD severity was graded by visual estimation of lumen diameter stenosis with significant stenoses defined as lumen diameter reduction of >or= 70%. Coronary angiograms were graded as one-, two- or three-vessel disease, as nonsignificant CAD (lumen irregularities < 70%) or non-CAD.

RESULTS

HDL-C (60.3 +/- 18.5 vs. 51.9 +/- 15.3 mg dL(-1); P < 0.001) was higher and CRP was lower (0.65 +/- 1.68 vs. 1.02 +/- 2.38 mg dL(-1); P < 0.001) in non-CAD (n = 1517) compared to overall CAD patients (n = 4124). CAD patients were older (65.2 +/- 10.5 years vs. 59.9 +/- 11.4 years), more often diabetics (19.2% vs. 10.6%) and hypertensives (79.2% vs. 66.0%) and included more smokers (18.8% vs. 16.5%) (all P < 0.005). Low-density lipoprotein cholesterol (124.5 +/- 38.3 vs. 126.0 +/- 36.3 mg dL(-1); P = NS) was similar in overall CAD and non-CAD patients with more statin users (43.4% vs. 27.9%; P < 0.001) among CAD patients. Comparing non-CAD with different CAD severities using analysis of variance, results did not change substantially. In a multivariate analysis, HDL-C and CRP remained independently associated with the prevalence of CAD. In addition, HDL-C is also a potent predictor for the severity of CAD.

CONCLUSIONS

In this large consecutive patient cohort, HDL-C and CRP are independently associated with the prevalence of CAD. In this analysis, HDL-C is an even stronger predictor for CAD than some other major classical risk factors.

Lipid peroxidation and the levels of antioxidant enzymes in coronary artery disease

Coronary Artery Disease is the major cause of mortality and morbidity worldwide. Traditional risk factors account for only half of the morbidity and mortality from coronary artery disease. There is substantial evidence that oxidative stress plays the major role in the atherosclerotic process. The present study was undertaken to evaluate the level of lipid peroxidation (by measuring malondialdehyde) and antioxidant enzymes (ceruloplasmin, glutathione, superoxide dismutase) in coronary artery disease. Serum malondialdehyde levels and serum ceruloplasmin levels were significantly raised in all the subgroups of study group as compared to control group (p<0.001). Whole blood glutathione levels and hemolysate superoxide dismutase activity was significantly decreased in all the subgroups of study group as compared to control group (p<0.001). Above results suggests that the patients of coronary artery disease show increased oxidative stress and decreased levels of antioxidant enzymes. So it is recommended that the management protocol for coronary artery disease patients should include antioxidant supplementation along with simultaneous lowering of lipid peroxidation.

Association between inflammation, lipid and hemostatic factors in patients with stable angina

INTRODUCTION

Dyslipidemia and thrombotic processes are both clearly involved in atherogenesis and its secondary complications. Moreover, inflammation has also been shown to play an important role in the pathophysiology of atherosclerosis. Our objective was to determine the association between inflammation, lipids and thrombosis in a group of patients with stable angina.

PATIENTS AND METHODS

295 patients (217 males and 78 females) with a mean age of 65.69+/-11.24 years. Levels of C-reactive protein, total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, lipoprotein(a), apolipoproteins A1 and B100, fibrinogen and D-dimer were determined for each.

RESULTS

Arithmetic and geometric means of C-reactive protein in the sample were 10.7 and 1.4 mg/l, respectively. Distributing the sample by quartiles of C-reactive protein, we found a positive correlation between C-reactive protein, fibrinogen and D-dimer levels (p<0.000), and an inverse correlation for HDL cholesterol and apolipoprotein A1 (p<0.000). In multivariate analysis, fibrinogen (p<0.000) and D-dimer (p<0.01) levels were independently associated with high levels of C-reactive protein. Of the lipid factors, only apolipoprotein A1 (p<0.000) was independently and inversely associated with high levels of C-reactive protein.

CONCLUSIONS

These data confirm the association between prothrombotic and inflammatory states and suggest the anti-inflammatory effect of apolipoprotein A1.

C-reactive protein as a marker for active coronary artery disease in patients with chest pain in the emergency room

BACKGROUND

Markers of inflammation, such as C-reactive protein (CRP), were found to be related to risk for cardiovascular disease (CVD) events in patients with angina pectoris. In addition, recent studies have shown that, in the case of atherosclerosis, increased CRP concentration reflects the inflammatory condition of the vascular wall.

HYPOTHESIS

The study was undertaken to determine whether CRP levels in individuals with chest pain attending the emergency room (ER) may be used as a marker of active CVD.

METHODS

Serum CRP level was measured in 226 of 326 consecutive patients (128 men, 98 women; mean age 61.3 +/- 5.9 years; range 19-87 years) referred to the ER with chest pain. The decision whether to admit orrelease the subjects was determined without taking the CRP level into account. Follow-up was then performed for 1 year.

RESULTS

Eighty-four patients were admitted to the hospital. Of these, 9 with acute coronary syndrome (ACS) had very high levels of CRP (25-40 mg/l), 35 had had an acute coronary event within the preceding 3 months, with levels of CRP 14-20 mg/l. Only eight patients with nonsignificant CVD had elevated CRP levels. Twenty-eight subjects who were released from the ER had elevated CRP levels (7-14 mg/l); 8 of these, in addition to 4 subjects with normal CRP levels, had a late coronary event.

CONCLUSION

This study indicates that in patients referred to the ER with chest pain and no other indication for hospitalization, a normal level of CRP suggests safe release. Most hospitalized patients with normal CRP will not have acute coronary syndrome. Patients who will develop early coronary events have very high CRP levels. High serum CRP level, after excluding other inflammatory sources, was proven to be a sensitive diagnostic and prognostic marker for significant coronary disease.

Total and differential leukocytes counts, but not hsCRP, ESR, and five fractioned serum proteins have significant potency to predict stable coronary artery disease

BACKGROUND

The role and diagnostic value of markers of inflammation is well recognized in acute coronary syndromes but it is uncertain in patients with stable coronary artery disease (CAD). This study was done to investigate the association of markers of inflammation with the occurrence and severity of CAD and to evaluate their predictive values.

METHODS

Markers of inflammation, electrophoresis serum protein fractions, serum (apo)lipoproteins and classical risk factors were determined in 270 angiographically documented subjects. The subjects were classified as CAD cases and controls according to angiography. The severity of CAD was scored on the basis of the number and extent of lesions.

RESULTS

The counts of total leukocytes (7.14+/-1.86 cell/nl vs. 6.58+/-1.62, p<or=0.02), neutrophils (3.95+/-1.42 vs. 3.59+/-1.07, p<or=0.05) and eosinophils (0.25+/-0.28 vs. 0.19+/-0.24, p<or=0.03) were increased significantly, whereas the concentrations of high-sensitivity C-reactive protein (hsCRP, 2.03 (0.0-32.0) mg/l vs.1.72 (0.09-11.36), p<or=0.07) changed modestly in CAD patients relative to controls. There were no significant differences in the counts of monocytes and lymphocytes and the concentrations of erythrocyte sedimentation rate (ESR) and any five fractions of serum proteins between two groups. The counts of total leukocytes, neutrophils and eosinophils, but not hsCRP and ESR exhibited significant associations with the severity of CAD. In univariate logistic regression analysis, leukocytes count associated significantly (OR=1.97, p<or=0.01) whereas hsCRP modestly (OR=1.76, p<or=0.06) with the occurrence of CAD. The association was lessened by diabetes mellitus in multivariable adjustment. Receiver operating characteristic (ROC) analysis showed that, only total leukocyte and differential counts had significant potency to predict CAD (area under curve, AUC=0.60+/-0.04, p<or=0.02).

CONCLUSIONS

The total leukocytes count and its subgroups are associated with the presence and severity of CAD, but the associations were not independent. The efficiency was questioned for hsCRP, ESR and five fractioned serum proteins to identify stable CAD.

Relationship Between C-Reactive Protein and Subclinical Atherosclerosis

Background— Elevated levels of C-reactive protein (CRP) are associated with increased risk for incident cardiovascular events on the basis of observations from several prospective epidemiological studies. However, less is known regarding the relationship between CRP levels and atherosclerotic burden.

Methods and Results— We measured CRP in 3373 subjects 30 to 65 years of age who were participating in the Dallas Heart Study, a multiethnic, population-based, probability sample. Electron-beam CT scans were used to measure coronary artery calcification (CAC) in 2726 of these subjects, and MRI was used to measure aortic plaque in 2393. CRP levels were associated with most traditional cardiovascular risk factors. Subjects with CAC had higher median CRP levels than those without CAC (men: median, 2.4 versus 1.8 mg/L, P <0.001; women: median, 5.2 versus 3.6 mg/L, P <0.001), and there was a modest trend toward increasing CRP levels with increased CAC levels in men ( P for trend=0.003) but not in women ( P for trend=0.08). Male subjects with aortic plaque also had higher CRP levels than those without (median, 2.3 versus 1.8; P <0.001). In multivariate analysis adjusted for traditional cardiovascular risk factors, body mass index, and estrogen and statin medication use, the associations between CRP levels and CAC and CRP levels and aortic plaque were no longer statistically significant.

Conclusions— In a large, population-based sample, subjects with higher CRP levels had a modest increase in the prevalence of subclinical atherosclerosis, but this association was not independent of traditional cardiovascular risk factors. CRP is a poor predictor of atherosclerotic burden.

Genetic epidemiological studies of longevity-associated mitochondrial DNA 5178 C/A polymorphism

Mitochondrial DNA 5178 cytosine/adenine (Mt5178 C/A) polymorphism is associated with longevity in the Japanese population, and the Mt5178A genotype may confer antiatherogenic advantages. Individuals with the Mt5178A genotype may be more resistant to adult-onset diseases, such as myocardial infarction, cerebrovascular diseases and type 2 diabetes, than those with the Mt5178C genotype. Moreover, Mt5178 C/A polymorphism has been reported to be associated with blood pressure, serum lipid levels, hematological parameters, intraocular pressure, serum protein fraction levels and serum electrolyte levels in healthy Japanese individuals. Differences in the influence of habitual drinking or habitual smoking on health status between the Mt5178C genotype and the Mt5178A genotype have been reported. The individual modification of drinking habits or smoking habits based on the genotyping of Mt5178 C/A may promote improved health and lead to the establishment of personalized prevention strategies for adult-onset diseases.

Reference maps of mouse serum acute-phase proteins: Changes with LPS-induced inflammation and apolipoprotein A-I and A-II transgenes

We present reference maps of the mouse serum proteome (run under reducing and non-reducing conditions), from control animals, from mice injected with lipopolysaccharide (LPS) to induce systemic inflammation, and from mice transgenic for human apolipoproteins A-I and A-II. Seventy-seven spots/spot chains from the reducing gels were identified by HPLC MS/MS, representing 28 distinct proteins, including a species-specific protease inhibitor, contrapsin, and high levels of carboxylesterase. The concentrations of acute-phase reactants were monitored for 96 h after LPS challenge. The greatest changes (four-fold 48 h after LPS administration) were observed for haptoglobin and hemopexin. Orosomucoid/alpha(1)-acid glycoprotein and apolipoprotein A-I increased steadily, to 50-60% above baseline at 96 h from stimulation. In mice transgenic for human apolipoprotein A-I the levels of expression of orosomucoid/alpha(1)-acid glycoprotein, alpha(1)-macroglobulin, esterase, kininogen and contrapsin were altered compared to knockout mice lacking apolipoprotein A-I. In contrast, except for the presence of apolipoprotein A-II, no statistically significant difference was observed in mice transgenic for human apolipoprotein A-II.

Relationship among pregnancy associated plasma protein-A levels, clinical characteristics, and coronary artery disease extent in patients with chronic stable angina pectoris

AIMS

To assess, in chronic stable angina (CSA) patients, the relationship among clinical characteristics and cardiovascular risk factors, extent of coronary artery disease (CAD), and pregnancy-associated plasma protein-A (PAPP-A) levels.

METHODS AND RESULTS

We studied 643 CSA patients (63+/-10 years, 482 men) undergoing diagnostic coronary angiography; 97 with angiographically normal coronary arteries or <50% stenosis, 127 with single vessel disease (VD), and 419 with multi-VD. Patients' age, gender, cardiovascular risk factors, body mass index, history of previous myocardial infarction, angina class, left ventricular ejection fraction (LVEF), and treatment were assessed at study entry. PAPP-A levels (mIU/L) were higher in men than in women (6.2+/-2.4 vs. 5.2+/-1.8; P<0.001) and in hypertensive vs. normotensive patients (6.4+/-2.8 vs. 5.8+/-2.1; P=0.01). PAPP-A correlated directly with age (r=0.19, P<0.001) and inversely with LVEF (r=-0.11, P=0.01). Patients with multivessel disease (VD) had higher PAPP-A levels (6.45+/-2.58) than those with single-VD (5.49+/-1.54, P<0.001) or normal coronaries (4.62+/-1.17, P<0.001). Male gender, age, history of a previous MI, hypercholesterolaemia, and PAPP-A levels were independent predictors for the presence of CAD.

CONCLUSION

In CSA patients PAPP-A levels correlate with age, male gender, hypertension, and CAD extent. In the present study, PAPP-A was an independent predictor for the presence and extent of CAD.

C-reactive protein, atherosclerosis and kidney function in hypertensive patients

Previous studies have shown a relationship between coronary or carotid atherosclerosis and C-reactive protein (CRP) concentrations. In the present investigation, we evaluated the relationship between high-sensitivity CRP (hsCRP) concentrations and the presence of atherosclerotic lesions in the renal arteries and/or abdominal aorta. In 95 hypertensive patients who underwent intra-arterial DSA on suspicion of renovascular disease, blood was sampled during the procedure for measurement of hsCRP. The presence of atherosclerotic lesions was assessed at the level of the renal arteries and the abdominal aorta. Haemodynamically significant renal artery stenosis was diagnosed when 50% or more stenosis was observed. Patients with fibromuscular disease (n = 8) or incomplete data (n = 4) were excluded from analysis. The results revealed that the median hsCRP concentrations were significantly higher among the 57 patients with atherosclerosis of the aorta and/or renal arteries compared to those in the 26 patients without any angiographic lesions (4.6 vs 1.7 mg/l; P < 0.005). Moreover, in patients with renal artery stenosis, levels of hsCRP were higher when the degree of stenosis exceeded 50%. However, the association between hsCRP and the presence of atherosclerosis appeared to be confounded by serum creatinine, creatinine clearance, age and gender. In the whole group a significant inverse relationship was found between creatinine clearance and hsCRP (P < 0.05). In conclusion, hsCRP concentrations are related to atherosclerotic lesions in the renal arteries and the abdominal aorta. While this supports the view that atherosclerotic renal artery stenosis is part of a systemic inflammatory vascular disease, increased concentrations of CRP may also coincide with decreased renal function.

Anatomy of coronary disease in diabetic patients: an explanation for poorer outcomes after percutaneous coronary intervention and potential target for intervention

There are over 1.3 million known diabetic patients in the UK and a similar number who have the disease undiagnosed. Over 90% have non-insulin dependent diabetes mellitus usually characterised by insulin resistance and adult onset. Over half of all diabetic patients die of coronary disease and account for over a fifth of percutaneous coronary intervention (PCI) revascularisation procedures. Despite recent therapeutic advances such as new antiplatelet treatments and drug eluting stents, outcomes for diabetic patients after PCI are still significantly worse than for non-diabetic patients. This article summarises what is known about the pattern and severity of diabetic coronary disease, what mechanisms are responsible for these differences, and whether this information can help explain the poorer prognosis for these patients after PCI and form the basis of interventions to improve outcome.

Longevity-associated mitochondrial DNA 5178 A/C polymorphism influences effects of cigarette smoking on serum protein fraction levels in Japanese men

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is reportedly associated with longevity and susceptibility to age-related diseases in Japanese individuals. We previously reported an association between mt5178 A/C polymorphism and serum protein fraction levels in healthy Japanese women. An association between habitual smoking and serum protein fraction levels has also been reported previously. The aim of this study was to examine whether mt5178 A/C polymorphism influenced the effects of habitual smoking on serum protein fraction levels in 321 healthy Japanese men. In mt5178C genotype men, alpha-1 and alpha-2 globulin levels were higher in smokers than in nonsmokers (P<0.001, and P=0.002, respectively). The influence of smoking on these globulin levels depended on cigarette consumption. However, in mt5178A genotype men, no significant difference was observed in alpha-1 or alpha-2 globulin levels between smokers and nonsmokers. These results suggest that longevity-associated mt5178 A/C polymorphism may influence the effects of cigarette smoking on serum protein fraction levels in healthy Japanese men.

Omega-3 fatty acids in inflammation and autoimmune diseases

Among the fatty acids, it is the omega-3 polyunsaturated fatty acids (PUFA) which possess the most potent immunomodulatory activities, and among the omega-3 PUFA, those from fish oil-eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)--are more biologically potent than alpha-linolenic acid (ALA). Some of the effects of omega-3 PUFA are brought about by modulation of the amount and types of eicosanoids made, and other effects are elicited by eicosanoid-independent mechanisms, including actions upon intracellular signaling pathways, transcription factor activity and gene expression. Animal experiments and clinical intervention studies indicate that omega-3 fatty acids have anti-inflammatory properties and, therefore, might be useful in the management of inflammatory and autoimmune diseases. Coronary heart disease, major depression, aging and cancer are characterized by an increased level of interleukin 1 (IL-1), a proinflammatory cytokine. Similarly, arthritis, Crohn's disease, ulcerative colitis and lupus erythematosis are autoimmune diseases characterized by a high level of IL-1 and the proinflammatory leukotriene LTB(4) produced by omega-6 fatty acids. There have been a number of clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis, Crohn's disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches. Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and a lowered use of anti-inflammatory drugs.

Inflammatory response to coronary stent implantation in patients with unstable angina

Previous evidence has shown that coronary angioplasty leads to the release of inflammatory mediators. In this study, we sought to characterize the systemic inflammatory response after coronary stent implantation in patients with unstable angina by measuring different protein markers. Peripheral blood samples were taken before and 24 h, 48 h, and 7 days after successful coronary stenting in 58 patients. Several markers of acute-phase response were determined: C-reactive protein (CRP), alpha2-macroglobulin, haptoglobin, acid alpha1-glycoprotein, prealbumin and albumin. Besides, proinflammatory cytokines (tumor necrosis factor-alpha, IL-6, IL-8) and the anti-inflammatory cytokine IL-10 were also measured. We have found that coronary angioplasty with stent implantation produces a systemic inflammatory response with a rise in inflammation markers concentration. CRP plasma levels declined 1 week after the intervention, but the other marker levels were even higher after 7 days. IL-6 was the only cytokine whose plasma levels significantly increased in peripheral blood after stenting, with a rise after 24 h, maintained after 48 h, and decreased to near-basal levels after 1 week. There was a good correlation between CRP and IL-6 plasma levels (r=0.5, p<0.001). IL-10 levels were slightly decreased after 24 h. Although no significant differences in the means at different time points were found, there was a decrease in IL-10 in most patients 24 h after the intervention. These results indicate that coronary stent implantation induces a systemic inflammatory reaction, with a temporal increase in the concentration of the inflammation markers, especially CRP and IL-6. Since these markers had been previously used as prognostic markers, this needs to be taken into account in patients undergoing stent implantation.

[Interleukin-10 and coronary disease]

Understanding of the pathophysiology of atherosclerosis has changed markedly over the past few decades. It is now widely accepted that inflammation plays a fundamental role in the genesis and development of atherosclerosis. Inflammatory mechanisms also appear to determine clinical presentation and disease outcome. Atherosclerotic lesions have high concentrations of inflammatory cells (T lymphocytes and activated macrophages) as well as an abundance of pro-inflammatory cytokines [interleukin (IL)-1, IL-6, IL-8, interferon-gamma, tumor necrosis factor-alpha, etc.] that modulate local inflammatory responses. These may also alter plaque stability and facilitate the development of acute cardiovascular events. The role of anti-inflammatory cytokines in this context remains to be studied. IL-10 is an anti-inflammatory cytokine synthesised by T-lymphocytes and macrophages and has other anti-inflammatory effects. IL-10 expression within human atherosclerotic plaques has been demonstrated and animal experiments have shown that low levels of IL-10 lead to the development of extensive and unstable atherosclerotic lesions. Currently available evidence suggests a potential protective role for IL-10 in atherosclerosis. This new perspective on coronary disease as a chronic inflammatory process may open new avenues for the management of ischemic heart disease.

Different associations of C-reactive protein, fibrinogen and C3 with traditional risk factors in middle-aged men

BACKGROUND

Some acute phase proteins are associated with both ischemic events and traditional risk factors. Since they are strongly interrelated, each of them partly reflects the characteristics of other proteins. This study was carried out to ascertain the specific preferential associations of some acute phase proteins with traditional risk factors for atherosclerotic disease.

METHODS

High-sensitivity C-reactive protein, fibrinogen and C3-complement were assessed in 288 unselected men aged 55-64 years. Three multiple linear regression analyses were performed, in which each of the three acute phase proteins was considered the dependent variable of both traditional risk factors and the other two proteins.

RESULTS

The three acute phase proteins strongly correlated with each other. Moreover, C-reactive protein was independently associated with triglycerides (P<0.0001), age (P=0.0130), body mass index (P=0.0179), and acute (P=0.0280) and chronic (P=0.0582) inflammations (R2=0.17). Fibrinogen was associated with alcohol consumption (inversely, P=0.0001) and smoking (P=0.0598) (R2=0.06). Finally, C3 was associated with insulin (P<0.0001), cholesterol (P=0.0001), sedentarity (P=0.0028), glucose (P=0.0077), and systolic blood pressure (P=0.0124) (R2=0.28).

CONCLUSIONS

When simultaneously studied in multivariate analysis, acute phase proteins have different preferential associations with traditional risk factors, a probable consequence of their involvement in different cellular activations and metabolic processes.

Elevated C-reactive protein constitutes an independent predictor of advanced carotid plaques in dyslipidemic subjects

Inflammation plays a key role in the physiopathology of atherosclerosis. C-reactive protein (CRP) has been found to predict cardiac events in healthy subjects and in patients with coronary heart disease. However, the relationship between CRP and subclinical atherosclerosis is not well established. We examined the potential relationship between CRP and common carotid artery intima-media thickness and carotid plaques in dyslipidemic subjects. Dyslipidemic patients (n=1051) were recruited for the study. All patients had a complete clinical examination and systematically underwent ultrasonographic evaluation of the extracranial carotid arteries on a duplex system. The serum concentration of CRP was measured by using a sensitive immunoradiometric assay. In a univariate model, a strong positive relationship was found between CRP and the severity of carotid stenosis (P<0.0001). In multivariate analysis, the association between CRP and the degree of carotid atherosclerosis remained significant for advanced plaques (P=0.0007) in male subjects only. Significant correlations were found between CRP and body mass index (P<0.0001) and between CRP and other markers associated with the metabolic syndrome. In this large dyslipidemic population, elevated CRP is an independent predictor of advanced carotid plaques in male subjects. Body mass index and other markers of the metabolic syndrome (HDL cholesterol, triglycerides, diabetes, and high blood pressure) are significant determinants of CRP levels in this population.

C-terminal fragment of alpha1-antitrypsin activates human monocytes to a pro-inflammatory state through interactions with the CD36 scavenger receptor and LDL receptor

Monocyte scavenger receptor, CD36 has been implicated in the pathogenesis of atherosclerosis as a major oxidised LDL receptor mediating lipid accumulation and foam cell formation. Previously, we found that treatment of monocyte cultures with the carboxyl terminal fragment of alpha1-antitrypsin (C-36) increases lipid binding and uptake, induces LDL receptor mRNA and CD36 receptor protein expression, and also significantly increases production of pro-inflammatory molecules. To assess the role of the CD36 receptor in proatherogenic monocyte activation by the C-36 fragment, we tested whether specific anti-CD36 receptor antibodies would block the effects of C-36 on monocyte activation. We find that pre-incubation of cells with anti-LDL and anti-CD36 receptor antibodies (10 microg/ml) blocks binding of 125I-C-36 by about 50%. Similarly, cells pre-incubated with oxidised LDL or native LDL at concentrations from 2.5 to 10 microg/ml showed a loss of 125I-C-36 binding (up to 49 and 57%) and uptake (up to 47 and 59.8%), respectively. In parallel experiments, monocytes were first incubated for 1 or 6 h with anti-CD36 antibodies (10 microg/ml) prior to adding C-36 peptide. Anti-CD36 antibodies suppressed C-36-induced production of gelatinase B, monocyte chemoattractant protein-1, interleukin-6 and cellular oxygen consumption to control levels, whereas levels of TNFalpha were unaffected. In contrast, saturation of LDL receptors with excess of anti-LDL (20 microg/ml) significantly inhibited C-36 induced TNFalpha levels. Results indicate that the C-36 peptide binds to both LDL and CD36 scavenger receptors which involves selective upregulation of pro-inflammatory molecules and activation of the respiratory burst in human monocytes. This also supports important roles for CD36 and LDL receptors in atherogenesis and suggests that blockade of CD36 receptor can be protective in pro-inflammatory activation of human monocytes.

Human alpha-1-glycoprotein and its interactions with drugs

For about half a century, the binding of drugs to plasma albumin, the "silent receptor," has been recognized as one of the major determinants of drug action, distribution, and disposition. In the last decade, the binding of drugs, especially but not exclusively basic entities, to another plasma protein, alpha 1-acid glycoprotein (AAG), has increasingly become important in this regard. The present review points out that hundreds of drugs with diverse structures bind to this glycoprotein. Although plasma concentration of AAG is much lower than that of albumin, AAG can become the major drug binding macromolecule in plasma with significant clinical implications. Also, briefly reviewed are the physiological, pathological, and genetic factors that influence binding, the role of AAG in drug-drug interactions, especially the displacement of drugs and endogenous substances from AAG binding sites, and pharmacokinetic and clinical consequences of such interactions. It can be predicted that in the future, rapid automatic methods to measure binding to albumin and/or AAG will routinely be used in drug development and in clinical practice to predict and/or guide therapy.

Conformational properties of serine proteinase inhibitors (serpins) confer multiple pathophysiological roles

Serine proteinase inhibitors (Serpins) are irreversible suicide inhibitors of proteases that regulate diverse physiological processes such as coagulation, fibrinolysis, complement activation, angiogenesis, apoptosis, inflammation, neoplasia and viral pathogenesis. The molecular structure and physical properties of serpins permit these proteins to adopt a number of variant conformations under physiological conditions including the native inhibitory form and several inactive, non-inhibitory forms, such as complexes with protease or other ligands, cleaved, polymerised and oxidised. Alterations of a serpin which affect its structure and/or secretion and thus reduce its functional levels may result in pathology. Serpin dysfunction has been implicated in thrombosis, emphysema, liver cirrhosis, immune hypersensitivity and mental disorders. The loss of inhibitory activity of serpins necessarily results in an imbalance between proteases and their inhibitors, but it may also have other physiological effects through the generation of abnormal concentrations of modified, non-inhibitory forms of serpins. Although these forms of inhibitory serpins are detected in tissues and fluids recovered from inflammatory sites, the important questions of which conditions result in generation of different molecular forms of serpins, what biological function these forms have, and which of them are directly linked to pathologies and/or may be useful markers for characterisation of disease states, remain to be answered. Elucidation of the biological activities of non-inhibitory forms of serpins may provide useful insights into the pathogenesis of diseases and suggest new therapeutic strategies.

Increased Acute Phase Reactants are Associated with Levels of Lipoproteins and Increased Carotid Plaque Volume

OBJECTIVES

to test the hypotheses that increased acute phase reactants predict elevated levels of lipoproteins and increased plaque volume as well as echolucency of carotid plaques.

MATERIALS AND METHODS

the study included 258 patients with >or =50% carotid artery stenosis. Acute phase reactants (orosomucoid, C-reactive protein (CRP)) were measured in the fasting state, and ultracentrifugated lipoproteins before and after a standardised fat load test. Echogenicity of carotid plaques was detected using high-resolution B-mode ultrasound and computer-assisted image processing. A subgroup of 81 patients underwent carotid endarterectomy.

RESULTS

on linear regression analysis orosomucoid levels were positively associated with fasting and postprandial levels of all triglyceride-rich lipoproteins, and negatively associated with HDL cholesterol (p -values <0.0001); results for CRP were less pronounced. Orosomucoid and CRP both predicted the presence of an increased carotid plaque volume on univariate analysis (p =0.01 and p =0.02). Finally, orosomucoid was negatively associated with echolucency of carotid plaques ( p =0.05).

CONCLUSIONS

elevated levels of acute phase reactants are strongly associated with elevated levels of triglyceride-rich lipoproteins, increased plaque volume, and borderline significantly associated with echolucency of carotid plaques. Elevated acute phase reactants possibly predict severity of atherosclerosis, and presence of lipid-rich, rupture-prone plaques.

Is ceruloplasmin an important catalyst for S-nitrosothiol generation in hypercholesterolemia?

Nitric oxide (NO) reacts with thiol-containing biomolecules to form S-nitrosothiols (RSNOs). RSNOs are considered as NO reservoirs as they generate NO by homolytic cleavage. Ceruloplasmin has recently been suggested to have a potent catalytic activity towards RSNO production. Considering that NO activity is impaired in hypercholesterolemia and that RSNOs may act as important NO donors, we investigated the relation between concentrations of ceruloplasmin and RSNOs in plasma of hypercholesterolemic (HC) patients compared to normolipidemic (N) controls. Concentrations of ceruloplasmin (0.36 +/- 0.07 x 0.49 +/- 0.11 mg/dl, N x HC), nitrate (19.10 +/- 12.03 x 40.19 +/- 18.70 microM, N x HC), RSNOs (0.25 +/- 0.20 x 0.54 +/- 0.26 microM, N x HC), nitrated LDL (19.51 +/- 6.98 x 35.29 +/- 17.57 nM nitro-BSA equivalents, N x HC), and cholesteryl ester-derived hydroxy/hydroperoxides (CEOOH, 0.19 +/- 0.06 x 1.46 +/- 0.97 microM) were increased in plasma of HC as compared to N. No difference was found for nitrite levels between the two groups (1.01 +/- 0.53 x 1.02 +/- 0.33 microM, N x HC). The concentrations of RSNOs, nitrate, and nitrated LDL were positively correlated to those of total cholesterol, LDL cholesterol, and apoB. Ceruloplasmin levels were directly correlated to apoB and apoE concentrations. Data suggest that: (i) ceruloplasmin may have a role in the enhancement of RSNOs found in hypercholesterolemia; (ii) the lower NO bioactivity associated with hypercholesterolemia is not related to a RSNOs paucity or a defective NO release from RSNOs; and (iii) the increased nitrotyrosine levels found in hypercholesterolemia indicate that superoxide radicals contribute to inactivation of NO, directly generated by NO synthase or originated by RSNO decomposition.

Role of novel markers of inflammation in patients with stable coronary heart disease

The role of novel markers of inflammation in patients with coronary heart disease (CHD) is still unclear. We conducted a case-control study to assess the association between various markers of inflammation and the presence and severity of chronic stable CHD. We included 312 clinically stable patients with angiographically documented CHD, aged 40 to 68 years. Voluntary blood donors (n = 479) matched for age and gender served as controls. High-sensitivity C-reactive protein, serum amyloid A, plasminogen activator inhibitor-1 activity, von Willebrand factor, fibrinogen, plasma viscosity, albumin, and neutrophils were determined. The severity of CHD was evaluated by 3 coronary scoring systems: the clinical 1- to 3-vessel disease score, the American Heart Association extension score (1 to 15 segments), and the Gensini score. All markers of inflammation were highly significantly elevated (all p <0.005) in patients with stable CHD compared with controls. After multivariable adjustment by means of logistic regression analysis, the association between CHD and fibrinogen, plasma viscosity, von Willebrand factor, and plasminogen activator inhibitor-1 activity remained substantial, whereas it decreased in high-sensitivity C-reactive protein, serum amyloid A, and neutrophils. The combination of > or = 2 markers of inflammation was associated with a strongly increased risk of CHD. No association between markers of inflammation and any of the coronary scores applied was found. These results document an independent association between most of the markers of inflammation and chronic CHD, even in clinically stable patients. The combination of several of these biochemical markers, i.e., the determination of an "inflammatory risk profile," may be useful to further stratify cardiovascular risk.

Stromelysin-1 and interleukin-6 gene promoter polymorphisms are determinants of asymptomatic carotid artery atherosclerosis

The functional 5A/6A polymorphism of the stromelysin-1 promoter has been implicated as a potential genetic marker for the progression of angiographically determined atherosclerosis in patients with coronary artery disease. Recently, a novel interleukin-6 (IL-6) gene functional G/C polymorphism at -174 in the promoter has also been reported. In this study, we analyzed the relation of these two polymorphisms with carotid artery atherosclerosis in 109 randomly selected, middle-aged men without exercise-induced ischemia. Atherosclerosis was quantified as intima-media thickness (IMT) by high-resolution ultrasonography. Univariately, stromelysin genotype was significantly (P:=0.015) associated with IMT, and this relation remained (P:=0.033) after adjustments for age, cardiorespiratory fitness, body mass index, smoking, LDL cholesterol, and systolic blood pressure and for sonographers. The 5A/6A polymorphism independently explained 7% of the variance in carotid bifurcation IMT. The IL-6 polymorphism was also significantly associated (P:=0. 036) with increased IMT, with men homozygous for the G allele having IMT that was 11% greater than men homozygous for the C allele. Men who were homozygous for both the 6A and G alleles had an covariate adjusted IMT that was 36% greater than men who were homozygous for neither allele (P:<0.003). These data suggest that genetic factors that predispose to reduced matrix remodeling (stromelysin 6A allele) and to increased inflammation (IL-6 G allele) combine to increase susceptibility for intima-media thickening in the carotid bifurcation, a predilection site for atherosclerosis.

The carboxyl-terminal fragment of alpha1-antitrypsin is present in atherosclerotic plaques and regulates inflammatory transcription factors in primary human monocytes

alpha1-Antitrypsin (AAT) serine proteinase inhibitor is found in most biological fluids, diffuses into most tissues, and is an important factor in controlling tissue damage by proteases in inflammatory diseases such as atherosclerosis. We have previously reported that the C-terminal fragment (C-36) generated during the cleavage of AAT by proteinases forms amyloid fibrils which have biological effects unrelated to precursor functions. Here we show that the C-36 fragment is present in atherosclerotic plaques, particularly within the fibrous cap at the base of the lipid core. We also found that human monocyte stimulation with C-36 fibrils led to a strong activation of both peroxisome proliferator-activated receptors alpha and gamma (PPARalpha and PPARgamma) at 1, 2, and 18 h of cell culture. A parallel increase in the intracellular lipid accumulation was also observed. Furthermore, stimulation of monocytes with C-36 for 18 h led to activator protein-1 (AP-1) and nuclear factor-kappaB (NF-kappaB) activation. These data for the first time demonstrate the peptide of AAT as a component of atherosclerotic plaques and as a novel activator of PPARalpha, PPARgamma, NF-kappaB, and AP-1 in cultured monocytes. Taken together, the effects of the peptide represent a new mechanism of monocyte activation that may be of importance not only in atherogenesis, but also in other inflammatory processes.

Serum C-reactive protein and self-reported stroke: findings from the Third National Health and Nutrition Examination Survey

C-reactive protein may predict the risk of coronary heart disease, but its association with stroke has not been well studied. We used data from the Third National Health and Nutrition Examination Survey, conducted from 1988 to 1994, to examine the association between serum C-reactive protein concentrations and self-reported past history of stroke among 8850 US men and women aged >/=40 years. The unadjusted geometric mean of C-reactive protein concentration was higher among participants with stroke than those without stroke (0. 45+/-0.02 versus 0.32+/-0.01, P<0.001). After adjusting for age, sex, race or ethnicity, education, smoking status, systolic blood pressure, serum cholesterol, high density lipoprotein cholesterol, history of diabetes mellitus, body mass index, and physical activity, the odds ratio for stroke among participants with C-reactive protein concentrations >/=0.55 mg/dL compared with participants with concentrations </=0.21 mg/dL was 1.71 (95% CI 1.11 to 2.64 [odds ratio per mg/dL 1.19, 95% CI 1.05 to 1.34]). These cross-sectional data support findings from other studies suggesting that C-reactive protein concentration may be a risk factor or marker for stroke in the US population.

Novel risk factors for atherosclerosis

In the past several years, evidence has accumulated that factors other than conventional risk factors may contribute to the development of atherosclerosis. Conventional risk factors predict less than one half of future cardiovascular events. Furthermore, conventional risk factors may not have the same causal effect in different ethnic groups in whom novel risk factors may have a role. These newer risk factors for atherosclerosis include homocysteine, fibrinogen, impaired fibrinolysis, increased platelet reactivity, hypercoagulability, lipoprotein(a), small dense low-density lipoprotein cholesterol, and inflammatory-infectious markers. Identification of other markers associated with an increased risk of atherosclerotic vascular disease may allow better insight into the pathobiology of atherosclerosis and facilitate the development of preventive and therapeutic measures. In this review, we discuss the evidence associating these factors in the pathogenesis of atherosclerosis, the mechanism of risk, and the clinical implications of this knowledge.

Activation of primary human monocytes by the oxidized form of alpha1-antitrypsin

The oxidation of methionine residues in many proteins, including the serine proteinase inhibitor alpha1-antitrypsin (AAT), can result in functional inactivation. In this study we investigated the pro-inflammatory properties of oxidized AAT (oxAAT), specifically its ability to activate human monocytes in culture. Monocytes stimulated with oxAAT at concentrations up to 0.2 mg/ml for 24 h showed significant elevation in monocyte chemoattractant protein-1, cytokine interleukin-6, and tumor necrosis factor-alpha expression and increased NADPH oxidase activity. Monocytes activated with oxAAT showed surprising effects on lipid metabolism. Expression of low density lipoprotein (LDL) receptors increased by up to 76% compared with controls but was not accompanied by any changes in (125)I-labeled LDL binding and, paradoxically, decreased LDL uptake, degradation, and intracellular cholesterol synthesis. oxAAT also down-regulated the scavenger receptor CD36, which takes up and is up-regulated by oxidized LDL and is down-regulated by cholesterol efflux. As a by-product of oxidative events accompanying inflammation, oxAAT has multiple effects on cytokine expression, generation of reactive oxygen species, and on intracellular lipid metabolism. The up-regulation of monocyte-derived reactive oxygen by oxAAT could potentially result in self-amplification of AAT oxidation and, thereby, the other effects deriving from it. This implies that there are as yet unidentified regulatory processes that control this cycle.

C-reactive protein (CRP) in cerebro-vascular events

BACKGROUND AND PURPOSE

C-reactive protein (CRP) is a useful prognostic factor in coronary heart disease. It has not been previously studied in acute cerebro-vascular events, which was the topic of the present study.

METHODS

Patients admitted to the hospital for an acute cerebro-vascular event were prospectively investigated. C-reactive protein was determined nephelometrically. Infection or inflammation were excluded clinically and with an erythrocyte sedimentation rate <30 mm/h. Computed tomography or nuclear magnetic resonance imaging of the brain was performed.

RESULTS

According to initial brain imaging and the clinical course the 138 patients were divided into five groups: 20 with transient ischemic attack, 20 with reversible neurological deficit lasting less than 2 weeks, 61 with completed stroke and restitution, 16 with stroke without restitution and 21 with cerebral hemorrhage. Median CRP values (range) were 3.2 (2.4-13.5), 3.3 (2.4-39.4), 4.2 (2.4-73. 4), 3.4 (3.2-44.0) and 3.5 (2.4-104.0 mg/l), respectively with no significant differences between groups in a non-parametric test (Kruskal-Wallis). Risk factors for vascular disease in general and stroke in particular had no visible influence on CRP levels. No relationship was found between time interval since onset of symptoms and CRP measurement, suggesting that an acute cerebro-vascular event has little influence on CRP values.

CONCLUSION

CRP is not a useful marker to predict the outcome of an acute cerebro-vascular event on hospital admission. This is in contrast to acute coronary events.

Copper-induced apoptosis and immediate early gene expression in macrophages

The death of macrophage-derived foam cells contributes to the formation of the lipid core in atherosclerotic lesions. Although the underlying mechanism is not yet clear, apoptosis has been shown to be responsible, at least in part, for the cell death of lipid-laden macrophages in atherosclerotic plaques. In the present study, we demonstrated that copper, in the presence of 8-hydroxyquinoline, was able to induce apoptosis of murine J774.A1 cells in culture. Ceruloplasmin exerts similar a effect, but not iron or hemin. Further experiments demonstrated that the expression of immediate early genes, including c-jun, c-fos and egr-1, was also induced by copper treatment in these cells, although only egr-1 mRNA was induced in a time- and dose-dependent manner. The antioxidant, N-acetylcysteine, exhibited remarkable inhibitory effect on the copper-induced apoptosis dose-dependently. Time course experiment revealed that prior treatment of cells with N-acetylcysteine is essential for the anti-apoptotic effect of this compound. Results also demonstrated that under the condition; in which N-acetylcysteine inhibited the copper-induced apoptosis, this antioxidant also abolished the gene expression of egr-1. Collectively, these results suggest that egr-1 gene expression is closely associated with the apoptosis induced by copper in macrophages.

Serum sialic acid and sialoglycoproteins in asymptomatic carotid artery atherosclerosis. ARIC Investigators. Atherosclerosis Risk in Communities

Serum total sialic acid (S-TSA) is a recently identified risk marker for atherosclerosis and cardiovascular mortality. The purpose of this study was to evaluate the influence of three sialic acid rich glycoproteins (orosomucoid, haptoglobin, and alpha1-antitrypsin) on the relationship between S-TSA and carotid atherosclerosis. The mean S-TSA was 0.045 g/l higher among cases than controls (P<0.001) in 310 45-64 year-old male and female pairs of carotid atherosclerosis cases and disease-free controls from the Atherosclerosis Risk in Communities (ARIC) Study. Also mean serum levels of the glycoproteins were significantly higher in cases compared to controls. In a conditional multiple logistic regression model with the glycoproteins as independent variables, orosomucoid was correlated most strongly with case control status. However, when incorporated into the mathematical model, S-TSA not only contributed additional information as to the risk of atherosclerosis; none of the three glycoproteins contributed further once S-TSA had been accounted for. Thus, some other source of serum sialic acid or variations in the degree of sialylation of glycoproteins may be essential for understanding the relation between S-TSA and atherosclerosis.