Increased levels of monocyte-related cytokines in patients with unstable angina

Preliminary Pilot Study of Combined Effects of Physical Activity and Achievement of LDL-Cholesterol Target on Coronary Plaque Volume Changes in Patients with Acute Coronary Syndrome

BACKGROUND

We investigated the combined effects of physical activity (PA) and aggressive low-density lipoprotein cholesterol (LDL-C) reduction on the changes in coronary plaque volume (PV) in patients with acute coronary syndrome (ACS) using volumetric intravascular ultrasound (IVUS) analysis.

METHODS

We retrospectively analyzed data from two different prospective clinical trials that involved 101 ACS patients who underwent percutaneous coronary intervention (PCI) and assessed the non-culprit sites of PCI lesions using IVUS at baseline and at the follow-up. After PCI, all the patients participated in early phase II comprehensive cardiac rehabilitation. Patients were divided into four groups based on whether the average daily step count, measured using a pedometer, was 7000 steps of more and whether the follow-up LDL-C level was <70 mg/dL. At the time of follow-up, we examined the correlation of changes in the PV with LDL-C and PA.

RESULTS

The baseline characteristics of the four study groups were comparable. At the follow-up, plaque regression in both the achievement group (PA and LDL-C reduction) was higher than that in the other three groups. In addition, plaque reduction independently correlated with increased PA and reduction in LDL-C level.

CONCLUSIONS

Combined therapy of intensive PA and achievement of LDL-C target retarded coronary PV in patients with ACS.

Impact of Physical Activity on Coronary Plaque Volume and Components in Acute Coronary Syndrome Patients After Early Phase II Cardiac Rehabilitation

BACKGROUND

Cardiac rehabilitation (CR) is an established multidisciplinary secondary preventive program. We investigated the effects of CR involving intensive physical activity (PA) on coronary plaque volume and components in patients with acute coronary syndrome (ACS).Methods and Results:We enrolled 32 consecutive patients with ACS in early phase II CR and randomly assigned them to an intensive CR group (n=18; CR participation ≥twice/week, daily PA ≥9,000 steps) or a standard CR group (n=14; CR participation ≥once/2weeks, daily PA ≥6,000 steps). Serial integrated backscatter intravascular ultrasound was performed for non-culprit lesions at baseline and after 8 months. Baseline clinical data were identical between the 2 groups. Unexpectedly, CR participation and PA did not differ significantly between the 2 groups, and there was no significant difference in plaque volume (PV) or components between the 2 groups. Subsequently, we classified the patients into 2 groups according to median PA (7,000 steps). There were significant differences in percent change of PV and of lipid volume between these 2 groups. In addition, these changes were negatively and independently correlated with PA.

CONCLUSIONS

No significant difference was observed in PV or components between the intensive CR and the standard CR groups. Intensive PA, however, may retard coronary PV and ameliorate lipid component in patients with ACS participating in late phase II CR.

An Evidence-Based Meta-Analysis on the Roles of Functional Interleukin-6 Polymorphisms in Coronary Artery Disease

Recently, the relationship between functional interleukin-6 (IL-6) polymorphisms and coronary artery disease (CAD) was extensively studied, with controversial findings. Therefore, we conducted this meta-analysis to better elucidate the relationship between these polymorphisms and the risk of CAD. A total of 57 case-control studies were finally included. The overall analyses showed that IL-6 -174G>C and -572G>C polymorphisms were significantly associated with the risk of CAD, the C allele of -174G>C (G versus C, odds ratio [OR] = 0.82, confidence interval [95% CI] = 0.75-0.89) and -572G>C polymorphisms (G versus C, OR = 0.82, 95% CI = 0.74-0.92) conferred an increased susceptibility to CAD. Further subgroup analyses yielded similar positive results for -174G>C polymorphism in Asian and Caucasian populations, and for -572G>C polymorphism in Asian and African populations. In conclusion, our findings suggest that IL-6 -174G>C and -572G>C polymorphisms may serve as potential genetic markers of CAD.

Dual Effect of IL-6 -174 G/C Polymorphism and Promoter Methylation in the Risk of Coronary Artery Disease Among South Indians

Inflammation plays an important role in the pathogenesis of atherosclerosis and coronary syndromes; moreover, various lines of evidence suggest that genetic factors do contribute to the risk of coronary artery disease (CAD). The proinflammatory cytokine IL-6 is a central mediator of inflammation associated with CAD. The present study is aimed to investigate the association of single nucleotide polymorphism in the promoter region of the IL-6 gene (-174 G > C) and methylation with the susceptibility of CAD. Genotyping of IL-6 -174 G/C polymorphism was performed by PCR-RFLP. Methylation-specific PCR method was used to study the IL-6 gene promoter methylation. Analysis of 470 subjects (265 CAD patients and 205 controls) showed association of the -174 G/C variant with the CAD risk in dominant model (OR 1.58, 95% CI, 1.024-2.23, P = 0.04). Further, the analysis of the distribution of genotypes and alleles of -174 G > C polymorphism according to clinical features of CAD, revealed significant association of genotype and allele (OR 1.86, 95% CI 1.18-2.84 P = 0.01, and OR 1.71, 95% CI 1.09-2.23 P = 0.02 respectively) with diabetes, and we found no association with hypertension (OR 0.95, 95% CI 0.57-1.59, P = 0.8). We also analyzed the methylation status of IL-6 promoter region between cases and controls showed significant hypo methylation in CAD subjects (OR 2.36, 95% CI 1.51-4.259, P = 0.006). Additionally, GC, CC genotypes and C allele carriers show hypomethylation in CAD cases compared to controls (54.58 vs. 76.85%, 29.83 vs. 40% respectively). In conclusion, the promoter polymorphism -174 G/C is associated with CAD risk and further carriers of 'C' allele at -174 locus showed significant hypo methylation which could contribute to increased risk of CAD. The present study highlights the association of allele and genotypes with differential DNA methylation of CpG islands in the IL-6 promoter region which may affect IL-6 gene regulation.

Cytokines and MicroRNA in Coronary Artery Disease

Cardiovascular disease (CVD) is a major health problem globally. The high incidence and case fatality of CVD are, to a large extent, a consequence of its late diagnosis and lack of highly sensitive and specific markers. Only a very small number of biomarkers, such as troponin, detect late disease. There is some evidence of an association and dysregulation between specific cytokines in the pathogenesis of CVD. These molecules are involved in inflammatory and immune mechanisms associated with atherogenesis. Several molecular/cellular pathways that include STAT, MAPK, and SMAD are modulated by cytokines. Against this background, microRNAs (miRNAs) are a class of noncoding RNAs with important roles in pathological events, leading to atherosclerotic CVD. It has been shown that the latter could affect cytokine production and contribute to progression of atherosclerotic CVD. Moreover, modulation of miRNAs appears to inhibit cardiomyocyte apoptosis, attenuate infarct size, and reduce cardiac dysfunction. This review highlights several recent preclinical and clinical studies on the role of cytokines in CVD, novel miRNA-based therapeutic approaches for therapeutic intervention, and potential circulating cytokines that have promise as biomarkers in CVD.

Genetic polymorphisms of interleukin-6 gene and susceptibility to coronary artery disease in Chinese population: Evidence based on 4582 subjects

The aim of this study was to explore whether interleukin-6 (IL-6) gene (-174 G/C and -572 C/G) polymorphisms are associated with susceptibility to coronary artery disease (CAD) risk in Chinese population. All the statistical tests were performed using Stata version 11.0. Twelve articles involving 16 studies were included in this meta-analysis, covering a total of 2309 CAD cases and 2273 controls. For IL-6 gene -572 C/G polymorphism, the results showed evidence for significant association between IL-6 gene -572 C/G polymorphism and CAD risk (for G allele vs. C allele: OR=1.48, 95% CI=1.26-1.74, p<0.001; for G/G vs. C/C: OR=2.60, 95% CI=1.54-4.39, p<0.001; for G/G vs. G/C+C/C: OR=2.15, 95% CI=1.35-3.42, p=0.001; for G/G+G/C vs. C/C: OR=1.55, 95% CI=1.29-1.85, p<0.001). However, for IL-6 gene -174 G/C polymorphism, no significant association was found between this variation and CAD risk. In summary, our meta-analysis showed evidence that IL-6 gene -572 C/G polymorphism may be a risk factor for CAD susceptibility. For IL-6 gene -174 G/C polymorphism, no significant association was found between this variation and CAD risk.

Genetic relationship between serum pregnancy-associated plasma protein-A gene polymorphism and ischemic cerebrovascular disease in a Northern Han Chinese population

The present study recruited 193 patients with ischemic cerebrovascular disease from Inpatient and Outpatient Departments at the Affiliated Hospital of Qingdao University Medical College, China from August 2008 to May 2010, as well as 120 healthy volunteers from the Medical Examination Center at the Affiliated Hospital of Qingdao University Medical College, China, who served as controls for this study. Patients and control subjects were from the Han population in northern China. Enzyme- linked immunosorbent assay analysis revealed increased levels of serum pregnancy-associated plasma protein-A (PAPP-A) in ischemic cerebrovascular disease patients compared with healthy controls. In addition, the patients exhibited greater frequency of genotype CC and C alleles in a missense A/C (Tyr/Ser) polymorphism (dbSNP: rs7020782) of exon 14 in the PAPP-A gene. Multiple-factor logistic regression analysis on correction of age, gender, history of smoking, hypertension, diabetes mellitus, hypercholesteremia, and ischemic stroke family history showed that the risk for ischemic cerebrovascular disease in the population without the A allele at the A/C genetic locus in exon 14 of the PAPP-A was 2-folds greater than the population expressing the A allele. These experimental findings suggested that ischemic cerebrovascular disease correlated with the C allele in exon 14 of PAPP-A. In addition, the A allele is likely a protective gene; individuals carrying the A allele were less prone to ischemic cerebrovascular disease compared with individuals without the A allele.

Effects of Calcium Fructoborate on Levels of C-Reactive Protein, Total Cholesterol, Low-Density Lipoprotein, Triglycerides, IL-1β, IL-6, and MCP-1: a Double-blind, Placebo-controlled Clinical Study

Calcium fructoborate (CFB) has been reported as supporting healthy inflammatory response. In this study, we assess the effects of CFB on blood parameters and proinflammatory cytokines in healthy subjects. This was a randomized, double-blinded, placebo-controlled trial. Participants received placebo or CFB at a dose of 112 mg/day (CFB-1) or 56 mg/day (CFB-2) for 30 days. Glucose, total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), C-reactive protein (CRP), homocysteine, interleukin 1 beta (IL-1β), IL-6, and monocyte chemoattractant protein-1 (MCP-1) were determined before and after supplementation. CFB-1 showed a reduction in blood levels of CRP by 31.3 % compared to baseline. CFB-1 and CFB-2 reduced LDL levels by 9.8 and 9.4 %, respectively. CFB-1 decreased blood homocysteine by 5.5 % compared with baseline, whereas CFB-2 did not have a significant effect. Blood levels of TG were reduced by 9.1 and 8.8 % for CFB-1 and CFB-2, respectively. Use of both CFB-1 and CFB-2 resulted in significantly reduced IL-6 levels, when compared within and between groups. IL-1β was reduced by 29.2 % in the CFB-1 group. Finally, CFB-1 and CFB-2 reduced MCP-1 by 31 and 26 %, respectively. Our data indicate that 30-day supplementation with 112 mg/day CFB (CFB-1) resulted in a significant reduction of LDL, TG, TC, IL-1β, IL-6, MCP-1, and CRP. HDL levels were increased, when compared to baseline and placebo. These results suggest that CFB might provide beneficial support to healthy cardiovascular systems by positively affecting these blood markers (ClinicalTrials.gov, ISRCTN90543844; May 24, 2012 ( http://www.controlled-trials.com/ISRCTN90543844 )).

Protein-protein interaction network and mechanism analysis in ischemic stroke

Ischemic stroke is a leading cause of mortality and permanent disability, with enormous financial repercussions on health systems worldwide. Ischemic brain injury results from a complex sequence of pathophysiological events that evolve over time. In order to examine the molecular mechanisms underlying middle cerebral artery occlusion (MCAO)-induced ischemic stroke, the GSE35338 affymetrix microarray data was obtained from the Gene Expression Omnibus database and the differentially expressed genes (DEGs) between samples from patients with MCAO-induced ischemic stroke and sham controls at various time points were identified. Furthermore, protein-protein interaction (PPI) networks were constructed by mapping the DEGs into PPI data to identify the pathways that these DEGS are involved in. The results revealed that the expression of 438 DEGs, which are mainly involved in cell death, oxidant reduction, cell cycle and cell-cell signaling, were altered in MCAO samples. The nodes of CXC motif chemokine 10 (CXCL10) and interleukin-6 (IL-6) were large, with degrees of >20. In conclusion, the results suggest that CXCL10 and IL-6 have important roles in the occurrence and progression of MCAO-induced ischemic stroke.

Clinical utility of novel biomarkers for cardiovascular disease risk stratification

Over the past few decades, a number of coronary artery disease (CAD) and cardiovascular disease (CVD) risk factors have been identified. The predictive power of "conventional" risk factors have been validated by observational, prospective and intervention studies. Nevertheless, all attempts to exactly predict the individual risk for CAD have failed, biased by a large number of incorrectly risk-classified subjects. To improve cardiovascular (CV) risk prediction, a large number of genetic and/or non-genetic biomarkers have been discovered and tested against the "classical" risk factors for their power to predict CV risk. Only few of them had a significant improvement over the predictive models. In this paper, the most investigated biomarkers will be discussed and the evidence of their use as predictors of CV will be questioned.

Impact of MCP-1 and CCR-2 gene polymorphisms on coronary artery disease susceptibility

Coronary artery disease (CAD) was the second leading cause of death during the last 3 years in Taiwan. Smooth muscle cells, monocytes/macrophages, and endothelial cells produce monocyte chemoattractant protein-1 (MCP-1) within atherosclerotic plaques following binding to the chemokine receptor-2 (CCR-2). Previous studies have well-documented the association between MCP-1 expression and susceptibility to, or clinicopathological features, of CAD. This study investigated the relationships between MCP-1-2518A/G and CCR-2-V64I genetic polymorphisms and CAD in the Taiwanese population. A total of 608 subjects, including 392 non-CAD controls and 216 patients with CAD, were recruited and subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to evaluate the effects of these two polymorphic variants on CAD. Results indicated a significant association between MCP-1 -2548 gene polymorphism and susceptibility to CAD. GG genotypes (OR = 1.629; 95 % CI = 1.003-2.644), or individuals with at least one G allele (OR = 1.511; 95 % CI = 1.006-2.270), had a higher risk of CAD as compared with AA genotypes. Results also revealed that subjects with at least one A allele of the V64I CCR2 gene polymorphism had significantly increased risk of CAD. G allele in MCP-1-2518 might contribute to higher prevalence of atrial fibrillation in CAD patients (OR = 4.254; p < 0.05). In conclusion, MCP-1-2518G and CCR-2 64I gene polymorphisms represent important factors in determining susceptibility to CAD, and the contribution of MCP-1-2518G could be through effects on atrial fibrillation in CAD patients.

Association between interleukin-6 gene -174 G/C polymorphism and the risk of coronary heart disease: a meta-analysis of 20 studies including 9619 cases and 10,919 controls

Interleukin-6 (IL-6) gene -174 G/C polymorphism has been reported to be associated with coronary heart disease (CHD), but the results remain inconclusive. The present meta-analysis was therefore designed to clarify these controversies. This meta-analysis was performed by searching PubMed, Embase and Web of Science databases. A total of 20 studies including 9619 CHD cases and 10,919 controls were combined showing no evidence of association between IL-6 gene -174 G/C polymorphism and CHD risk (for C/C+C/G vs. G/G: OR=1.10, 95% CI=0.99-1.22, p=0.07; for C/C vs. C/G+G/G: OR=1.08, 95% CI=0.93-1.24, p=0.33; for C/C vs. G/G: OR=1.16, 95% CI=0.97-1.39, p=0.11; for C allele vs. G allele: OR=1.10, 95% CI=1.00-1.21, p=0.06). Moreover, we also did not find significant association between IL-6 gene -174 G/C polymorphism and myocardial infarction (MI) risk. However, in the subgroup analysis by ethnicity, significant association was found among Asians (for C/C+C/G vs. G/G: OR=1.35, 95% CI=1.05-1.63, p=0.02). In summary, the present meta-analysis suggests that IL-6 gene -174 G/C polymorphism is associated with increased CHD risk among Asians. However, due to the small subjects included in the subgroup analysis of Asians, the results should be interpreted with caution.

Roles of IL-6-gp130 Signaling in Vascular Inflammation

Interleukin-6 (IL-6) is a well-established, independent indicator of multiple distinct types of cardiovascular disease and all-cause mortality. In this review, we present current understanding of the multiple roles that IL-6 and its signaling pathways through glycoprotein 130 (gp130) play in cardiovascular homeostasis. IL-6 is highly inducible in vascular tissues through the actions of the angiotensin II (Ang II) peptide, where it acts in a paracrine manner to signal through two distinct mechanisms, the first being a classic membrane receptor initiated pathway and the second, a trans-signaling pathway, being able to induce responses even in tissues lacking the IL-6 receptor. Recent advances and new concepts in how its intracellular signaling pathways operate via the Janus kinase (JAK)-Signal Transducer and Activator of Transcription (STAT) are described. IL-6 has diverse actions in multiple cell types of cardiovascular importance, including endothelial cells, monocytes, platelets, hepatocytes and adipocytes. We discuss central roles of IL-6 in endothelial dysfunction, cellular inflammation by affecting monocyte activation/differentiation, cellular cytoprotective functions from reactive oxygen species (ROS) stress, modulation of pro-coagulant state, myocardial growth control, and its implications in metabolic control and insulin resistance. These multiple actions indicate that IL-6 is not merely a passive biomarker, but actively modulates adaptive and pathological responses to cardiovascular stress.

Synthetic peptide fragment (65-76) of monocyte chemotactic protein-1 (MCP-1) inhibits MCP-1 binding to heparin and possesses anti-inflammatory activity in stable angina patients after coronary stenting

OBJECTIVE AND DESIGN

The peptide from C-terminal domain of MCP-1 (Ingramon) has been shown to inhibit monocyte migration and possess anti-inflammatory activity in animal models of inflammation and post-angioplasty restenosis. Here, we investigate the effect of Ingramon treatment on blood levels of acute-phase reactants and chemokines in patients after coronary stenting and the mechanisms of Ingramon anti-inflammatory activity.

SUBJECTS

Eighty-seven patients with ischemic heart disease (IHD) who faced the necessity of coronary angiography (CA) were enrolled. In 67 patients, one-stage coronary stenting was performed; 33 of them were treated with Ingramon in addition to standard therapy. Twenty patients underwent CA only.

METHODS

High-sensitivity C-reactive protein (hsCRP) and fibrinogen blood levels were detected routinely. The chemokine concentration in plasma was measured by enzyme-linked immunosorbent assay (ELISA) or cytometric bead array-based immunoassay. Intracellular Ca(2+) levels and cell surface integrin exposure were assayed by flow cytometry. MCP-1 dimerization was studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). MCP-1-heparin binding was assessed with a biosensor and ELISA.

RESULTS AND CONCLUSIONS

Ingramon treatment was accompanied by less pronounced elevation of hsCRP and fibrinogen levels and decreased MCP-1 concentration in plasma in patients after coronary stenting. Ingramon had no effect on MCP-1 interaction with cell receptors or MCP-1 dimerization, but inhibited MCP-1 binding to heparin. The anti-inflammatory activity of the peptide may be mediated by an impaired chemokine interaction with glycosaminoglycans.

The role of macrophage colony-stimulating factor in patients with acute myocardial infarction: a pilot study

We assessed whether macrophage colony-stimulating factor (M-CSF) levels are associated with left ventricular systolic dysfunction (LVSD) in patients with acute myocardial infarction (AMI). We studied 56 patients with AMI (mean age: 67 ± 12 years) and identified those with clinical (Killip class >II) or echocardiographic signs (ejection fraction ≤45%) of LVSD. We evaluated the established cardiovascular risk factors and measured several cardiovascular biomarkers, including M-CSF. Serum M-CSF concentrations (pg/mL) were significantly increased in patients with both clinical and echocardiographic signs of LVSD (460 ± 265 vs 290 ± 210, P = .0103 and 493 ± 299 vs 287 ± 174, P = .0028, respectively). We found a significant inverse association between M-CSF and ejection fraction (r = -.351, P = .0079). Logistic regression analysis revealed that, among all evaluated clinical and biochemical parameters, the stronger predictor of LVSD was M-CSF (odds ratios 2.1, 95% confidence interval 1.1-2.9, P = .0168). This is the first study reporting plasma M-CSF levels as independent determinants of low LV ejection fraction and clinical LV dysfunction in patients with AMI.

Inflammatory cytokines imbalance in the very early phase of acute coronary syndrome: correlations with angiographic findings and in-hospital events

The aim of this study is to investigate the release of some inflammatory cytokines (Cks) during the very early phase (first 24 h) of acute coronary syndrome (ACS). Twenty-six consecutive subjects admitted to coronary care unit with ACS underwent serial blood sampling in order to evaluate concentrations of interleukin (IL)-2, IL-10, IL-18, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ. Blood samples were taken within 6 h after onset of chest pain (T₀), at 12 h (T₁), and at 24 h (T₂). Patients were thus divided into four groups comparing pro-inflammatory Ck release (IL-2, TNF-α, and IFN-γ) and anti-inflammatory activity (IL-10). Clinical features, risk factors, incidence of adverse events, and coronary angiography findings were compared with Ck activation. Ck levels were significantly increased if compared with baseline. Subjects with marked inflammatory response showed a higher incidence of left anterior descending coronary disease (IL-2, p < 0.001; TNF-α and IFN-γ, p < 0.05) and more often incurred early complications (IL-2, p < 0.05; IFN-γ, p < 0.001). A correlation was detectable between IL-18 levels and myocardial enzyme release (creatine kinase, r = 0.47; lactate dehydrogenase, r = 0.54; troponin I, r = 0.58; p < 0.05). TNF-α levels were associated with a worse prognosis at follow-up (Log rank, p < 0.05). A Ck activation characterizes the early phase of ACS. Early inflammatory reaction seems to correlate with coronary disease and adverse events.

High white blood cell count and low estimated glomerular filtration rate are independently associated with serum level of monocyte chemoattractant protein-1 in a general population

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) plays a role in cardiovascular disease (CVD) and renal injury. Recent clinical studies have suggested that circulating levels of MCP-1 could be a biomarker of atherosclerosis and future cardiovascular events in humans. Because chronic kidney disease (CKD) is one of the risk factors of CVD, it is conceivable that elevated MCP-1 levels may link the increased risk of CVD in CKD patients. However, as far as we know, in addition to well-known traditional risk factors for atherosclerosis, whether renal dysfunction could be independently associated with the elevation of MCP-1 levels in a general population remains unknown. Therefore, we examined here which anthropometric and metabolic variables, including renal function, could be independent correlates of circulating levels of MCP-1 in a general population.

HYPOTHESIS

We hypothesized that renal function was one of the independent correlates of serum MCP-1 levels.

METHODS

A total of 860 Japanese residents (318 males and 542 females, mean age 65.4 ± 9.8 years) in a small fishing community underwent a complete history and physical examination with determination of blood chemistries, including serum levels of MCP-1.

RESULTS

Mean MCP-1 levels were 281.4 pg/mL. Multiple stepwise regression analyses revealed that male sex (P<0.0001), age (P=0.03), estimated glomerular filtration rate (eGFR) (P<0.0001, inversely), and white blood cell count (P=0.037) were independently associated with MCP-1 levels.

CONCLUSIONS

The present study demonstrated for the first time that other than white blood cell count, eGFR was an independent correlate of serum levels of MCP-1 in a Japanese general population. Elevated MCP-1 levels may partly explain the increased risk of CVD in CKD patients.

-174G>C interleukin-6 gene polymorphism in Tunisian patients with coronary artery disease

BACKGROUND AND OBJECTIVES

A state of low-grade inflammation accompanies the pathogenesis of atherosclerotic events. Interleukin-6 (IL-6) is a pleotropic pro-inflammatory cytokine that modulates the development of acute coronary syndromes (ACSs), partly by destabilizing coronary atherosclerotic plaques. We have examined the contribution of the -174G>C IL-6 promoter variant on the risk of coronary artery disease (CAD) among Tunisians.

PATIENTS AND METHODS

Study subjects included 418 CAD patients and 406 age- and sex-matched controls. IL-6 genotyping was done by PCR-restriction fragment length polymorphism.

RESULTS

The frequency of the -174C allele (mutant) was lower in Tunisians than in Europeans, and the distribution of -174 G>C genotypes was similar between CAD patients and control subjects. Moreover, compared to GG genotype carriers, -174C allele carriage did not increase the CAD relative risk (odds ratio and 95% confidence interval=1.09 and 0.80-1.49), which remained nonsignificant after adjusting for traditional risk factors for CAD (age, smoking, hypertension, diabetes and obesity).

CONCLUSION

The -174G>C IL-6 promoter variant is not associated with an increased risk of CAD among Tunisians.

Differential regulation of immune responses and macrophage/neuron interactions in the dorsal root ganglion in young and adult rats following nerve injury

BACKGROUND

Neuropathic pain is an apparently spontaneous experience triggered by abnormal physiology of the peripheral or central nervous system, which evolves with time. Neuropathic pain arising from peripheral nerve injury is characterized by a combination of spontaneous pain, hyperalgesia and allodynia. There is no evidence of this type of pain in human infants or rat pups; brachial plexus avulsion, which causes intense neuropathic pain in adults, is not painful when the injury is sustained at birth. Since infants are capable of nociception from before birth and display both acute and chronic inflammatory pain behaviour from an early neonatal age, it appears that the mechanisms underlying neuropathic pain are differentially regulated over a prolonged postnatal period.

RESULTS

We have performed a microarray analysis of the rat L4/L5 dorsal root ganglia (DRG), 7 days post spared nerve injury, a model of neuropathic pain. Genes that are regulated in adult rats displaying neuropathic behaviour were compared to those regulated in young rats (10 days old) that did not show the same neuropathic behaviour. The results show a set of genes, differentially regulated in the adult DRG, that are principally involved in immune system modulation. A functional consequence of this different immune response to injury is that resident macrophages cluster around the large A sensory neuron bodies in the adult DRG seven days post injury, whereas the macrophages in young DRG remain scattered evenly throughout the ganglion, as in controls.

CONCLUSIONS

The results show, for the first time, a major difference in the neuroimmune response to nerve injury in the dorsal root ganglion of young and adult rats. Differential analysis reveals a new set of immune related genes in the ganglia, that are differentially regulated in adult neuropathic pain, and that are consistent with the selective activation of macrophages around adult, but not young large A sensory neurons post injury. These differences may contribute to the reduced incidence of neuropathic pain in infants.

Non-traditional biomarkers of atherosclerosis in stable and unstable coronary artery disease, do they differ?

BACKGROUND

Biomarkers of atherosclerosis are emerging as a potential tool for assessment of coronary artery disease (CAD) patients. As acute coronary syndrome (ACS), and stable CAD are distinguished in their pathophysiology it is conceivable that they are also characterized by different biomarkers of atherosclerosis.

METHODS

We systematically reviewed the literature for clinical studies of several non-traditional biomarkers of atherosclerosis reflecting various pathophysiological processes, namely macrophage-activity, oxidative-stress, tissue remodeling, and thrombosis in ACS and stable CAD to determine whether circulating biomarkers are differently expressed/predict outcome in these two clinical conditions.

RESULTS

Macrophage-activity (monocyte chemoattractant protein-1, neopterin), tissue-remodeling (matrix metalloproteinase-9) and thrombosis (tissue-factor) related biomarkers were consistently elevated in ACS compared to stable CAD, in accordance with the pathophysiological role of these mediators in plaque rupture, characterizing ACS. Thus, these biomarkers may be applicable for diagnosis of ACS. Additionally, neopterin was consistently shown to predict outcome in both stable and ACS patients and myeloperoxidase was strongly shown to predict outcome in ACS, implying for their potential role in risk stratification of these patients.

CONCLUSIONS

As ACS and stable CAD are characterized by different pathophysiological processes, it appears that the biomarkers that are associated with them are differently expressed in these two clinical conditions

Interleukin-6 −174G/C Polymorphism and Ischemic Stroke

Background and Purpose— Interleukin-6 (IL-6) is associated with atherosclerotic disease and is also a key mediator in the inflammatory response to cerebral ischemia. Although the IL-6 −174G/C promoter polymorphism has been associated with carotid artery atherosclerosis and coronary heart disease, its relation to ischemic stroke is unclear. This review summarizes the current literature and discusses methodological considerations for future studies.

Methods— Electronic searches were conducted in the PubMed MEDLINE, Scopus, and ISI Web of Science databases. Two investigators independently reviewed all abstracts to identify studies examining the association between the IL-6 −174G/C polymorphism and ischemic cerebrovascular events.

Results— Twelve relevant publications were identified. Three reported on a subset of patients from a later publication, leaving 9 independent studies. Two studies found an association between ischemic stroke and the G allele or GG genotype, whereas 4 found an association with the C allele or CC genotype. One study found the CC genotype to be significantly less frequent in retinal artery occlusion patients. Two studies found no association between the −174G/C polymorphism and stroke.

Conclusions— Studies investigating stroke and the −174G/C polymorphism report conflicting results, which may reflect the complex physiology of IL-6 and true differences between stroke subtypes and populations. However, interpretation of published results is hindered by methodological limitations, and greater rigor and consistency in future studies will help unravel the relationship between the −174G/C polymorphism and stroke.

The peptide analogue of MCP-1 65-76 sequence is an inhibitor of inflammation

Inflammation plays an important role in vessel wall remodeling that occurs in atherosclerosis and postangioplasty restenosis. Monocytic chemoattractant protein-1 (MCP-1) is one of the main attractors of monocytes and some lymphocyte subsets to the damaged vessel. The aims of the study were to confirm MCP-1 participation in the development of acute coronary syndromes, to produce the potential MCP-1 peptide antagonist, and to investigate its effects in vitro and in vivo in different animal models of inflammation. MCP-1 plasma concentration was measured by ELISA (enzyme-linked immunosorbent assay). Chemokine receptor expression by cells isolated from human atherosclerotic lesions was assessed by direct immunofluorescence and flow cytometry. MCP-1 sequence was analyzed with Peptide Companion software and peptides were synthesized using Fmoc strategy. The peptide resistance to degradation was checked by 1H-NMR spectroscopy. The peptide effect on MCP-1-stimulated cell migration was studied in Boyden chamber and in mouse air pouch model, and its influence on lipopolysaccharide (LPS)-induced inflammatory cell recruitment was investigated in models of subcutaneous inflammation in rats and nonhuman primates. We revealed nearly a 2-fold increase of MCP-1 plasma level in patients with unstable angina in comparison with patients with stable angina. The atherosclerotic plaque specimens obtained from patients with unstable angina contained a significant amount of chemokine receptor-expressing leukocytes. Peptide from MCP-1 C-terminal 65-76 sequence (peptide X) inhibited MCP-1-stimulated monocytic cell migration in vitro and in vivo. Peptide X labeled with 99mTc accumulated specifically at sites of inflammation in rats. Peptide X administrated i.m and i.v. suppressed monocyte and granulocyte recruitment induced by subcutaneous injection of LPS in the back of rats and non-human primates. Our data demonstrate that MCP-1-mediated chemotaxis could be responsible for atherosclerotic plaque "destabilization". Peptide X may represent a new class of anti-inflammatory drugs to be used in cardiology.

Acute effect of standard heparin versus low molecular weight heparin on oxidative stress and inflammation in hemodialysis patients

OBJECTIVE

Atherosclerotic cardiovascular diseases caused by traditional and non-traditional risk factors are the most common cause of morbidity and mortality in hemodialysis patients. Recently, much interest has been focused on non-traditional factors, such as oxidative stress, inflammation, and endothelial dysfunction. Hemodialysis patients are not only exposed to oxidative stress but also to inflammation. Although anticoagulants are the most frequently used drugs in hemodialysis patients, their effect upon oxidative stress and inflammation in dialysis patients are still unknown.

METHODS

Thirty-three hemodialysis patients were randomized into three groups. Group 1 received standard heparin while group 2 received low molecular weight heparin during the dialysis therapy. Group 3 (control group) did not receive any anticoagulant agent. Investigators were blinded to the therapy. Serum concentrations of oxidative stress and inflammation markers, including C-reactive protein, tumor necrosis factor alpha, superoxide dismutase, and malondialdehyde, were measured before and after dialysis session.

RESULTS

The oxidative stress and inflammation markers were significantly increased in groups 1 and 3 (p < 0.05 for each) compared to their baseline values. In contrast, baseline and end-treatment values of the oxidative stress and inflammation markers were comparable in the group 2 (p > 0.05).

CONCLUSION

These findings indicate that the type of anticoagulants may take a role in the acute effect of hemodialysis upon oxidative stress and inflammation markers. A comparison of the groups revealed that low molecular weight heparin decreased the oxidative stress and inflammation, whereas standard heparin increased the oxidative stress and inflammation. Low molecular weight heparin appears to have an additive benefit for hemodialysis patients.

Local Activation of Interleukin 6 Signaling Is Associated With Arteriovenous Fistula Stenosis in Hemodialysis Patients

BACKGROUND

Vascular access failure is the main cause of morbidity in hemodialysis patients. Stenosis of the arteriovenous fistula (AVF) is similar histologically to atherosclerosis. Recent studies showed that interleukin 6 (IL-6) has a key role in the pathogenesis of atherosclerosis by binding 2 specific receptors, gp80 and gp130. When activated, gp130 interacts with a tyrosine kinase, Janus kinase (JAK2), which then activates a transcription factor, signal transducers and activators of transcription (STAT3), directly turning on several proinflammatory genes. The aim of this study is to evaluate gp130 expression and JAK2/STAT3 activation within stenotic AVFs.

METHODS

44 patients undergoing surgery for AVF creation were enrolled; 10 of them had AVF failure with histologically proven AVF stenosis (wall-lumen ratio > 1). A venous fragment of the AVFs was collected during creation and revision of the vascular access. gp130 and gp80 expression, as well as JAK/STAT activation, were evaluated by means of confocal microscopy. Peripheral-blood mononuclear cells were isolated at the time of AVF creation and revision.

RESULTS

gp130 protein expression, barely detectable in native AVFs, was strikingly increased within the venous branch of stenotic AVFs. The signaling subunit of the IL-6 receptor broadly colocalized with gp80, the IL-6-binding subunit. gp130-expressing cells were mainly CD34(+), suggesting that this receptor is expressed primarily by neovasculature endothelial cells. At the same time, a significant increase in phosphorylation of JAK2/STAT3 was observed in endothelial cells of stenotic AVFs. Interestingly, peripheral-blood mononuclear cells isolated at the time of AVF failure presented strikingly greater IL-6 expression compared with dialysis age-matched controls.

CONCLUSION

IL-6 receptor activation may have a role in the pathogenesis of AVF failure in hemodialysis patients and may represent a potential therapeutic target in this setting.

Monocyte chemoattractant protein-1 and coronary artery disease

The designation of atherosclerosis as a chronic inflammatory process represents an exciting and logical paradigm shift for cardiologists. Monocyte chemoattractant protein-1 (MCP-1) plays an important role in the recruitment and activation of monocytes and thus in the development of atherosclerosis. Enhanced MCP-1 expression has been detected in macrophages, endothelial cells, and vascular smooth muscle cells in the atheromatous plaque. Activation of macrophages by MCP-1 also appears to be involved in the vulnerability of the plaque. Indeed, circulating MCP-1 levels are elevated in patients with acute myocardial infarction and in those with unstable angina, but not in patients with stable angina. Production of MCP-1 and macrophage accumulation are also observed after coronary angioplasty or grafting, indicating that MCP-1 expression may be related not only to instability of atheromatous plaques, but also to the formation of restenotic lesions. The development of therapeutic drugs for atherosclerosis targeted specially against MCP-1 may be useful in the prevention of plaque formation and future myocardial infarction.

Chemokines in Children With Heterozygous Familiar Hypercholesterolemia

OBJECTIVE

Increasing data support the involvement of chemokines in atherogenesis. However, although several studies have shown increased chemokine levels in adult patients, the literature is virtually devoid of data on chemokines in children with hypercholesterolemia.

METHODS AND RESULTS

We examined the gene expression of chemokines in peripheral blood mononuclear cells (PBMCs) from clinically healthy children with and without heterozygous familial hypercholesterolemia (FH). Our main findings were: (1) compared with healthy controls, PBMCs from FH children showed significantly higher mRNA levels of RANTES, but not of the other examined chemokines; (2) an opposite pattern was seen in adult FH subjects, with markedly enhanced expression of macrophage inflammatory peptide-1alpha, but not of RANTES; (3) this increased gene expression of RANTES in PBMCs from FH children seemed to reflect enhanced RANTES expression in monocytes but not in T cells; (4) FH children also had raised serum levels of neopterin, additionally suggesting monocyte/macrophage activation in these children; and (5) PBMCs from both FH children and controls showed enhanced release of interleukin 8 on RANTES stimulation in vitro.

CONCLUSIONS

Our findings support a role of inflammation also in the early stages of atherogenesis possibly involving monocyte-derived RANTES as an important mediator.

Different effects of simvastatin and losartan on cytokine levels in coronary artery disease

BACKGROUND AND OBJECTIVE

Use of HMG-CoA reductase inhibitors (statins) and angiotensin II type 1 (AT(1)) receptor antagonists reduces the incidence of cardiovascular events. The cytokines macrophage colony-stimulating factor (M-CSF) and transforming growth factor (TGF)-beta may exert proatherogenic and antiatherogenic effects, respectively. In this study, we examined whether treatment with a statin or an AT(1) receptor antagonist alters M-CSF and TGF-beta levels in patients with coronary artery disease.

METHODS

Twenty-seven consecutive patients with coronary artery disease were randomly assigned to the following three treatment groups for 8 weeks: simvastatin 5 mg/day (n = 10); losartan 50 mg/day (n = 9); or control (usual treatment; n = 8). Blood samples were collected before and after treatment.

RESULTS

Clinical characteristics and baseline cytokine levels were comparable among the three groups. Serum levels of M-CSF were significantly decreased only in the simvastatin group (from 403 +/- 71 to 303 +/- 116 pg/mL; p = 0.009). Plasma levels of TGF-beta were significantly increased only in the losartan group (from 5.01 +/- 1.13 to 7.50 +/- 3.83 ng/mL; p = 0.021). Simvastatin decreased serum M-CSF levels independently of changes in total cholesterol or low-density lipoprotein-cholesterol.

CONCLUSIONS

The results of this study indicate that simvastatin decreases serum levels of M-CSF while losartan increases plasma levels of TGF-beta, suggesting that the two drugs may have different anti-atherosclerotic properties.

Characterization of the expression of TLR2 (toll-like receptor 2) and TLR4 on circulating monocytes in coronary artery disease

TLRs are receptors involved in the recognition of pathogens by the innate immune system, and TLR2 and TLR4 play important roles in the activation of monocytes. A total of 105 consecutive patients who underwent coronary angiography comprised of 46 with stable effort angina (SA), 41 with unstable angina (UA), and 18 with no significant CAD (CNT) were enrolled. The baseline expression levels of TLR2 and TLR4 on monocytes in peripheral blood mononuclear cells (PBMCs) were determined by flow-cytometric analysis. Since TLR2 expression has been reported to be regulated by TLR4 signaling, we cultured PBMCs with or without lipopolysaccharide (LPS, 1 microg/ml). At baseline, TLR4 levels (mean of fluorescence intensity ) in SA (145 +/- 58, p < 0.05) and UA (164 +/- 65, p < 0.01) were higher than those in CNT (107 +/- 37). As for TLR2, levels were higher in UA (108 +/- 36, p < 0.05) than in SA (94 +/- 18) and CNT (87 +/- 22). After stimulation with LPS, TLR2 levels increased in SA but decreased in UA. In conclusions, TLR4 levels increased in both SA and UA. Monocytes in UA were characterized by elevated TLR2 levels and unresponsiveness of the TLR2 levels to TLR4 stimulation.

Monocyte chemoattractant protein-1 and recurrent cardiovascular events in patients with stable coronary heart disease

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) participates in the recruitment of mononuclear cells to the vessel wall.

HYPOTHESIS

The aim of the study was to evaluate the potential association between serum concentration of MCP-1 and risk of future cardiovascular events in patients with chronic coronary heart disease.

METHODS

A nested case control design was used. Baseline serum samples were taken from patients with coronary heart disease who were enrolled in a secondary prevention study. The MCP-1 levels were measured in those patients who had recurrent cardiovascular events during follow-up (n = 233) and compared with levels in age- and gender-matched controls.

RESULTS

There were no differences in serum MCP-1 levels between cases and controls. The relative odds of a recurrent cardiovascular event for each 1 standard deviation difference in MCP-1 serum concentration (160 pg/ml) was 1.19 (95% confidence interval, 0.95-1.45). No increase in the relative odds for recurrent cardiovascular events was observed per increasing tertiles of MCP-1 concentrations.

CONCLUSION

Elevated MCP-1 levels are not associated with long-term risk of cardiovascular events in patients with stable coronary disease.

TNF-α −308G/A and IL-6 −174 G/C polymorphisms in the Turkish pediatric stroke patients

INTRODUCTION

Introduction: Stroke is an important cause of mortality and morbidity in the pediatric age group. There is increasing evidence on the role of proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in the occurrence and outcome of stroke. These proinflammatory cytokines carry functional polymorphisms (IL-6 -174 G/C and TNF-alpha -308 G/A) in their promoter regions, affecting their transcription rate and plasma cytokine levels. The aim of this study was to investigate the association of these polymorphisms with the occurrence of stroke in the Turkish pediatric stroke patients.

MATERIAL AND METHODS

Eighty six arterial stroke patients (aged between 0 and 14) and 83 healthy unrelated adult controls without personal or family history of stroke were investigated by PCR and restriction endonuclease analysis for IL-6 -174 G/C and TNF-alpha -308 G/A polymorphisms.

RESULTS

The allele distribution, allele frequencies, and combined distribution of genotypes for both polymorphisms did not differ significantly between control and patient groups.

CONCLUSIONS

The two polymorphisms did not associate with the occurrence of stroke in our study group.

Prognostic usefulness of plasma monocyte/macrophage and T-lymphocyte activation markers in patients with acute coronary syndromes

Macrophages and T lymphocytes accumulate and are activated in atherosclerotic plaques. We tested the hypothesis that plasma levels of the monocyte/macrophage and T-lymphocyte activation markers, monocyte chemoattractant protein-1 (MCP-1) and soluble interleukin-2 receptor (sIL-2r), respectively, can be used in acute coronary syndrome classification and risk prediction. Blood samples were collected at hospital admissions of 183 patients who had ischemic chest pain. Of these, 59 had acute myocardial infarction, 60 had unstable angina, and 64 had angina pectoris. No significant differences in the levels or proportions of subjects with increased levels of MCP-1 or sIL-2r were found across groups. During a mean follow-up of 13 months, 117 patients (64%) had a study end point (i.e., cardiac death, recurrent myocardial infarction, unstable angina, or revascularization). Increased levels (above median) of MCP-1 and sIL-2r were associated with increased risk, with odds ratios of 1.85 (95% confidence interval 0.92 to 3.73, p = 0.08) and 2.34 (95% confidence interval 1.16 to 4.71, p <0.02), respectively. In summary, in this unselected patient population with a very high rate of coronary events during follow-up, increased plasma levels of MCP-1 and sIL-2r were helpful for predicting new coronary events.

Raised concentrations of macrophage colony stimulating factor in severe unstable angina beyond the acute phase are strongly predictive of long term outcome

OBJECTIVE

To evaluate the long term prognostic value of macrophage colony stimulating factor (MCSF), interleukin-6 (IL-6), and tumour necrosis factor alpha (TNFalpha) measured in serum six weeks after the occurrence of unstable angina.

SUBJECTS

119 consecutive patients, mean (SD) age 58 (10) years, with severe unstable angina (Braunwald class IIIb); controls were 96 subjects of similar age and sex distribution.

DESIGN

MCSF, IL-6, and TNFalpha were measured on admission, at discharge, and six weeks later, and the patients were followed for two years. Clinical end points were: cardiac death, readmission for acute coronary syndromes, and revascularisation.

SETTING

District general hospital.

RESULTS

113 patients completed follow up, during which two died of non-cardiac causes. Of the remaining 111 patients, 39 (35.1%) had a cardiac event (two deaths, 15 revascularisations, and 22 readmissions for acute coronary syndromes). MCSF and IL-6 concentrations at six weeks were higher in patients with cardiac events than in those without (424 v 306 pg/ml, p = 0.0008, and 6.6 v 4.5 pg/ml, p = 0.01, respectively). Cytokine concentrations at six weeks were also significantly higher than in the control group. Logistic regression analysis showed that MCSF concentrations were the only independent predictors of future events, with an adjusted odds ratio for events of 4.1 (95% confidence interval 1.1 to 14.8; p = 0.03). The two year survival free of cardiac events was significantly lower in patients with MCSF concentrations in the highest tertile (values > or = 468 pg/ml) than in those with values < 468 pg/ml.

CONCLUSIONS

Increased MCSF concentrations beyond the acute phase are strongly predictive of long term outcome in patients with severe unstable angina.

Plasma Concentrations of Monocyte Chemoattractant Protein 1 (MCP-1) and Neopterin in the Coronary Circulation of Patients With Coronary Artery Disease-Association With the Severity of Coronary Atherosclerosis-

BACKGROUND

The dynamics of MCP-1 and neopterin and the relation between their concentrations in coronary circulation and the severity of coronary atherosclerosis were evaluated in patients with stable coronary artery disease (CAD).

METHODS AND RESULTS

Blood samples were obtained from the aortic root (Ao) and coronary sinus (CS) of 78 patients who underwent coronary angiography. Plasma MCP-1 and neopterin concentrations were measured using an enzyme-linked immunosorbent assay method and the CS-Ao differences were calculated. The severity of coronary heart disease (CHD) was evaluated in 52 patients who had no history of coronary angioplasty, using 3 coronary scoring systems: the clinical 1- to 3-vessel disease score, the American Heart Association extension score (1-15 segments), and the Gensini score. The plasma MCP-1 and neopterin concentrations increased significantly with age. The CS-Ao differences for neopterin showed weak, but significant, positive correlation with the Gensini score (r=0.347, p=0.013). There were no correlations among the MCP-1 concentrations in the Ao or CS, or in the CS-Ao difference, with the severity of CHD.

CONCLUSIONS

The results indicate that neopterin is a useful marker of the severity of coronary atherosclerosis in patients with stable CAD, acting as an index of the activity of monocytes/macrophages.

Atorvastatin reduces plasma MCP-1 in patients with acute coronary syndrome

BACKGROUND

The monocyte chemoattractant protein-1 (MCP-1) is a chemokine responsible for the recruitment of monocytes to sites of inflammation. MCP-1 may play critical roles in plaque instability. Anti-inflammation may be one benefit of statin drugs in acute coronary syndrome (ACS). We investigated the effects of atorvastatin therapy on plasma MCP-1 concentrations and production of MCP-1 released by peripheral blood monocytes from ACS patients.

METHODS

Forty patients with ACS were randomly separated into two groups, those receiving conventional therapy (Group A, n=20), and conventional therapy+atorvastatin (10 mg/day, Group B, n=20). The study the effects of atorvastatin on secretion and expression of MCP-1, human peripheral blood monocytes from healthy donors were incubated with atorvastatin (0.1-10 micromol/l) for up to 24 h in vitro. MCP-1 concentrations in plasma and monocytes culture supernatants were measured by enzyme-linked immunosorbent assays (ELISA). MCP-1 expression was measured by RT-PCR.

RESULTS

Plasma concentrations of MCP-1 were significantly lower after 4 weeks therapy in both groups of patients [Group A from 97.4 (50.1-164) to 72.6 (36.3-156) pg/ml, Group B from 101 (60-178) to 45 (29-91) pg/ml, (P<0.05, respectively)]. Compared with conventional therapy alone, atorvastatin significantly further reduced plasma MCP-1 concentrations. There was no significant correlation between the degree of changes in plasma MCP-1 and LDL-C. In vitro, atorvastatin inhibits production of MCP-1 up to 73%, in a concentration-dependent manner, and suppressed MCP-1 expression in peripheral blood monocytes.

CONCLUSIONS

Atorvastatin reduced plasma MCP-1 concentrations in patients with ACS. These effects may explain some clinical benefits of statins in the treatment of these patients.

Increased levels of pregnancy-associated plasma protein-A in patients with hypercholesterolemia: the effect of atorvastatin treatment

BACKGROUND

Serum levels of pregnancy-associated plasma protein-A (PAPP-A) have recently been linked to plaque instability and are increased in acute coronary syndromes. The relation between PAPP-A levels and coronary risk factors, namely blood lipids, has not been studied to date. We have therefore investigated whether serum PAPP-A levels are increased in asymptomatic hypercholesterolemic subjects and whether PAPP-A levels are influenced by atorvastatin therapy.

METHODS

We examined 27 subjects with isolated hypercholesterolemia free of manifest vascular disease and 29 age-matched healthy control subjects. Patients were examined at baseline and after 10 weeks of atorvastatin treatment (20 mg/d).

RESULTS

In untreated hypercholesterolemic subjects, PAPP-A levels were significantly higher than in control subjects (8.02 +/- 1.86 mU/L vs 6.50 +/- 2.54 mU/L, P =.018). There was no correlation between PAPP-A levels and serum lipid levels. Atorvastatin treatment reduced total and LDL-cholesterol by 31% and 40%, respectively. Despite this profound lipid lowering, there was no significant change in the serum PAPP-A levels.

CONCLUSIONS

PAPP-A levels are elevated in hypercholesterolemic subjects without clinical signs of atherosclerosis. PAPP-A may therefore not only reflect plaque instability but also serve as a marker of total atherosclerotic burden in asymptomatic subjects with hyperlipidemia. However, PAPP-A levels are not influenced by atorvastatin treatment.

Serum concentrations of vascular endothelial growth factor and monocyte-colony stimulating factor in peripheral arterial disease

Vascular endothelial growth factor (VEGF) strongly promotes angiogenesis, and monocyte-colony stimulating factor (M-CSF) regulates the differentiation, proliferation, and survival of monocytes. Both VEGF and M-CSF are expressed in atherosclerotic lesions. The present study was performed to clarify the role of VEGF and M-CSF in the development of peripheral artery disease (PAD). The serum VEGF and M-CSF concentrations were determined in patients with arteriosclerosis obliterans (ASO) and thromboangitis obliterans (TAO). In both patient groups the serum VEGF concentrations were significantly higher than those in the control subjects. In contrast, the serum M-CSF concentrations in the ASO patients were significantly higher than those in both the TAO patients and control subjects, but there were no differences in the M-CSF concentrations between the TAO patients and control subjects. There was no correlation between the serum concentrations of VEGF and M-CSF. In conclusion, the serum VEGF concentration was increased in ASO and TAO patients, but increased concentration of M-CSF was seen only in ASO patients. These results may reflect a difference between ASO and TAO in disease pathogenesis.

Inhibition of the renin-angiotensin system: no effect on circulating macrophage colony-stimulating factor levels in acute myocardial infarction

Macrophage colony-stimulating factor, which induces proliferation and differentiation, and activation of monocytes and macrophages, plays an important role in the vulnerability of atheromatous plaques as well as the formation of atherosclerotic lesions. We measured serum concentrations of macrophage colony-stimulating factor in patients with acute myocardial infarction and also investigated the effects of early administration of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker on circulating macrophage colony-stimulating factor levels in these patients. The patients were divided randomly into 3 therapeutic groups; perindopril, candesartan, and control (without perindopril and candesartan) groups, and the drugs were administered within 24 to 36 hours after the onset of acute myocardial infarction. Serum macrophage colony-stimulating factor concentrations in acute myocardial infarction patients at the time of admission were significantly higher than those in healthy control subjects. The macrophage colony-stimulating factor levels in the patients decreased gradually after admission, but remained significantly higher than those in control subjects for 14 days. There were no significant differences in serum macrophage colony-stimulating factor levels among the 3 therapeutic groups during this study period. In conclusion, circulating macrophage colony-stimulating factor levels are elevated during the course of acute myocardial infarction, and inhibition of the renin-angiotensin system by angiotensin-converting enzyme inhibitor or angiotensin receptor blocker does not affect these levels.

Synergistic effect of -174 G/C polymorphism of the interleukin-6 gene promoter and 469 E/K polymorphism of the intercellular adhesion molecule-1 gene in Italian patients with history of ischemic stroke

BACKGROUND AND PURPOSE

Interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) are involved in the pathogenetic mechanisms responsible for several ischemic cardiovascular disorders, including cerebral ischemia. IL-6 and ICAM-1 plasma levels and/or function may be genetically influenced. We sought to evaluate distribution and reciprocal interaction of IL-6 G/C gene promoter polymorphism and ICAM-1 E/K gene polymorphism in Italian patients with history of ischemic stroke.

METHODS

One hundred nineteen patients with history of ischemic stroke and 133 age- and sex-matched controls were studied. IL-6 and ICAM-1 genotypes were evaluated by polymerase chain reaction and restriction enzyme analysis.

RESULTS

The GG genotype of -174 IL-6 G/C gene polymorphism was significantly associated with history of ischemic stroke at both univariate (P<0.0001) and multivariate analysis (odds ratio [OR], 8.6; P<0.0001). Additionally, the EE genotype of ICAM-1 E/K gene polymorphism was significantly more common in the group of patients with history of ischemic stroke (P=0.003) and was an independent variable associated with stroke history (OR, 4.0; P=0.002). Interestingly, a further increased risk of stroke was found in subjects who concomitantly carry the IL-6 GG and ICAM-1 EE genotypes (IL-6 GG/ICAM-1 EE double-homozygous subjects) (OR, 10.1; P=0.004).

CONCLUSIONS

There is a synergistic effect of IL-6 G/C and ICAM-1 E/K gene polymorphisms in patients with stroke history. Reciprocal interactions between genotypes may contribute in determining the risk profile for cardiovascular diseases and may merit further investigation as potential therapeutic targets.

Insulin resistance and adiposity correlate with acute-phase reaction and soluble cell adhesion molecules in type 2 diabetes

OBJECTIVE

To investigate the relationship of inflammation and endothelial activation with insulin resistance and adiposity in type 2 diabetes.

METHODS AND RESULTS

Hundred and thirty-four (45 female) type 2 diabetic subjects aged 50-75 in the Fenofibrate Intervention and Event Lowering in Diabetes Study in Helsinki were examined before fenofibrate intervention. Fasting levels of circulating intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) (vascular cell adhesion molecule), ultra-sensitive C-reactive protein (CRP), human serum amyloid A (hSAA), interleukin-6 (IL-6), macrophage colony-stimulating factor (M-CSF), secretory phospholipase A(2) IIA (PLA(2)), total, HDL and LDL cholesterol, triglycerides, P-glucose, HbA1c, and serum free insulin were determined. Insulin resistance was assessed by the homeostasis model. HOMA IR correlated significantly with all measures of adiposity and markers of inflammation and endothelial dysfunction. BMI was significantly associated with inflammation and endothelial activation, but with neither lipoproteins nor glycaemic control. After controlling for age, gender and BMI, HbA1c correlated significantly with CRP, hSAA, ICAM-1, E-selectin, and HOMA IR. HDL cholesterol correlated inversely with IL-6, M-CSF, E-selectin, and HOMA IR. HbA1c, phospholipase A(2), VCAM-1, and HDL cholesterol remained independent determinants of HOMA IR in the linear regression analysis controlled for age, gender, and BMI.

CONCLUSION

Endothelial activation and acute-phase reaction correlate with insulin resistance and obesity in type 2 diabetic patients.

Intravenous prostaglandin E1 reduces monocyte chemoattractant protein-1 levels in peripheral arterial obstructive disease

OBJECTIVES

Blood monocytes are the precursors of the lipid-laden foam cells that are the hallmark of early atherosclerotic lesions, and monocyte chemoattractant protein-1 (MCP-1) plays important roles in their recruitment to the vessel wall. In this study, we measured serum levels of MCP-1 in patients with peripheral arterial obstructive disease (PAOD) and investigated whether intravenous prostaglandin E1 (PGE1) treatment, which produces clinical benefits in PAOD, might decrease such levels.

METHODS

Eight patients with PAOD at Fontaine stage II to IV were treated with a daily intravenous infusion of 10 microg of PGE1 for 7 consecutive days. Blood samples before and after 7-day PGE1 treatment were used for assays of MCP-1, interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP), von Willebrand factor (vWF), and endothelin-1 (ET-1).

RESULTS

Serum MCP-1 levels in patients with PAOD were significantly higher than those in healthy control subjects (263.8 +/- 52.8 vs 136.5 +/- 15.0 pg/mL, P =.002). PGE1 administration for 7 days resulted in a significant decrease in the MCP-1 level, from 263.8 +/- 52.8 to 196.1 +/- 25.5 pg/mL (P =.02), whereas levels of IL-6, hs-CRP, and ET-1 and the activity of vWF were not affected.

CONCLUSIONS

Serum MCP-1 levels were elevated in patients with PAOD, indicating the involvement of activation of monocytes in the pathogenesis of this disorder. Parenteral administration of PGE1 appeared to decrease circulating MCP-1 levels, which might lead to the suppression of the development of atherosclerotic lesions in patients with PAOD.

Effects of obstructive sleep apnea on circulating ICAM-1, IL-8, and MCP-1

Obstructive sleep apnea syndrome (OSAS) is one of the most important risk factors of cardiovascular disorders. In the treatment of OSAS, nasal continuous positive airway pressure (nCPAP) has been widely used and found to be effective. In the present study, we hypothesized that the hypoxic stress caused by obstructive sleep apnea would increase circulating intercellular adhesion molecule-1 (ICAM-1), interleukin-8 (IL-8), and monocyte chemoattractant protein-1 (MCP-1) in untreated OSAS patients compared with an age-matched control group. In addition, we hypothesized that nCPAP may decrease OSAS-induced hypoxic stress and mediators. To examine these hypotheses, we measured circulating ICAM-1 and IL-8 before and after nCPAP therapy in OSAS patients. We observed that nCPAP decreased apnea, desaturation, and the circulating ICAM-1 and IL-8 levels in OSAS patients. The circulating levels of ICAM-1, IL-8, and MCP-1 in untreated OSAS patients were significantly greater than those in the controls. These observations suggest that nCPAP therapy could reduce OSAS-induced hypoxia and generation of inflammatory mediators. Treatment of OSAS using nCPAP can be, therefore, a potential approach to decrease risk of the progression of OSAS-associated disorders.