Association between plasma monocyte chemoattractant protein-1 levels and the extent of atherosclerotic peripheral artery disease

Genetic influence on femoral plaque and its relationship with carotid plaque: an international twin study

To disentangle genetic and environmental influences on the development of femoral plaques using a population of adult twins. To evaluate the potential role of shared genetic and environmental factors in the co-occurrence of femoral and carotid plaques. The sample included 566 twins belonging to 164 monozygotic (MZ) and 119 dizygotic (DZ) twin pairs, who underwent peripheral arterial assessment by B-mode ultrasound in different centers. The variance in femoral plaques onset was due to genetic factors and the remaining 50% was explained by common (15%) and unique (35%) environmental factors. Findings on sidedness and number of femoral plaques indicated that also these traits were mainly under genetic control. No effect of common environment was found on plaques composition, and variability of this trait was explained by genetics (64%) and unique environment (36%). Covariation between the liabilities to carotid and femoral plaques was mainly attributed to shared genes (77%), with the remaining 23% explained by individual-specific environmental factors shared by the two districts. Inter-individual differences in plaque onset as well as in their number, sidedness and composition are mainly genetic in origin. The results on the cooccurrence of carotid and femoral plaque underline the genetic role in atherogenesis.

Immunohistochemical analysis of paraoxonases and chemokines in arteries of patients with peripheral artery disease

Oxidative damage to lipids and lipoproteins is implicated in the development of atherosclerotic vascular diseases, including peripheral artery disease (PAD). The paraoxonases (PON) are a group of antioxidant enzymes, termed PON1, PON2, and PON3 that protect lipoproteins and cells from peroxidation and, as such, may be involved in protection against the atherosclerosis process. PON1 inhibits the production of chemokine (C–C motif) ligand 2 (CCL2) in endothelial cells incubated with oxidized lipoproteins. PON1 and CCL2 are ubiquitously distributed in tissues, and this suggests a joint localization and combined systemic effect. The aim of the present study has been to analyze the quantitative immunohistochemical localization of PON1, PON3, CCL2 and CCL2 receptors in a series of patients with severe PAD. Portions of femoral and/or popliteal arteries from 66 patients with PAD were obtained during surgical procedures for infra-inguinal limb revascularization. We used eight normal arteries from donors as controls. PON1 and PON3, CCL2 and the chemokine-binding protein 2, and Duffy antigen/chemokine receptor, were increased in PAD patients. There were no significant changes in C–C chemokine receptor type 2. Our findings suggest that paraoxonases and chemokines play an important role in the development and progression of atherosclerosis in peripheral artery disease.

Ultrasensitive electrochemical immunosensor based on orderly oriented conductive wires for the detection of human monocyte chemotactic protein-1 in serum

For the first time, a simple, ultrasensitive and label-free electrochemical monocyte chemotactic protein-1 (MCP-1) immunosensor based on orderly oriented conductive wires has been developed. A conductive wire, which is similar to an electron-conducting tunnel, was designed with Au nanoparticles (AuNPs) joined to Au@Pt core-shell microspheres via a cysteamine (CA) crosslinker. To enhance the sensitivity of the immunosensor, Au nanoparticles were electrodeposited onto the gold electrode, and CA was self-assembled via strong Au-S covalent bonds, providing an appropriate surface and promoting electron transfer. Next, Au@Pt core-shell microspheres with large surface area were grafted onto the modified electrode to immobilize more MCP-1 antibodies. MCP-1 is an initiating factor and biomarker of atherosclerotic diseases. Under optimal experimental conditions, differential pulse voltammetry (DPV) current changes were used to detect MCP-1 with a broad linear range of 0.09-360 pg mL(-1) and a low detection limit of 0.03 pg mL(-1) (S/N=3). The proposed immunosensor exhibited good selectivity, reproducibility and reusability. When applied to spiked serum samples, the data for the developed immunosensor were in agreement with an enzyme linked immunosorbent assay, suggesting that the electrochemical immunosensor would be suitable for practical detection.

Understanding the role of circulating chemokine (C-C motif) ligand 2 in patients with chronic ischemia threatening the lower extremities

The role of chemokine (C-C motif) ligand 2 (CCL2) in peripheral artery disease is unclear. We measured the difference between serum and plasma levels of CCL2 in patients with chronic ischemia threatening the lower extremities following the observation that atypical chemokine receptors in blood and tissue cells may prevent CCL2 from entering the circulation and consequently modulate its function of attracting monocytes to the site of lesion. To identify the influence of CCL2, we compared the patients' values to those in bio-banked samples from a control population. Further, we explored the association with the Asp42Gly polymorphism (rs12075) in Duffy antigen chemokine receptor; one of these atypical chemokine receptors. When possible, we evaluated in surgically excised normal and affected arteries the calcium burden as well as the expression of CCL2 and related receptors reflecting the inflammatory status. Our findings indicate that circulating CCL2 was significantly associated with the severity and presence of the disease (OR 0.966, 95% CI 0.944 to 0.988, p = 0.003). Circulating CCL2 was dependent on the rs12075 genotype (AA>AG>GG), which, probably, indicates a higher expression of chemokine receptor in the arteries of AA subjects. The associations with genetic variants and the over-expression of atypical chemokine receptors in diseased arteries may have potential implications and our data indicate that CCL2 may represent a previously unrecognized factor that needs to be considered in the screening of patients with risk factors for peripheral artery disease.

A cross-sectional analysis of candidate biomarkers of biological effect in smokers, never-smokers and ex-smokers

CONTEXT

Biomarkers of biological effect (BOBE) have been proposed as potential tools to assess tobacco product use, toxicity and disease risk.

OBJECTIVE

To determine if candidate BOBE can distinguish between smokers, never-smokers and former smokers.

METHODS

Biomarker levels were compared from 143 smokers, 61 never-smokers and 61 ex-smokers.

RESULTS

In total, 27 candidate biomarkers were assessed, 14 were significantly different between smokers and never-smokers (p < 0.01) and of these 14 biomarkers, 12 were able to distinguish between smokers and former smokers (p < 0.05), which indicates the potential for reversibility.

CONCLUSIONS

A total of 12 of 27 BOBE are potentially useful tools for future product assessment.

Hyperhomocysteinemia-Induced Monocyte Chemoattractant Protein-1 Promoter DNA Methylation by Nuclear Factor-κB/DNA Methyltransferase 1 in Apolipoprotein E-Deficient Mice

Hyperhomocysteinemia is considered to be a significant risk factor in atherosclerosis and plays an important role in it. The purpose of this study was to determine the molecular mechanism of blood monocyte chemoattractant protein-1 (MCP-1) promoter DNA hypomethylation in the formation of atherosclerosis induced by hyperhomocysteinemia, and to explore the effect of nuclear factor-κB (NF-κB)/DNA methyltransferase 1 (DNMT1) in this mechanism. The atherosclerotic effect of MCP-1 in apolipoprotein E–deficient (ApoE^−/−) and wild-type C57BL/6J mice was evaluated using atherosclerotic lesion area; serum NF-κB, MCP-1, and DNMT1 levels; and MCP-1 promoter DNA methylation expression. In vitro, the mechanism responsible for the effect of NF-κB/DNMT1 on foam cells was investigated by measuring NF-κB and DNMT1 levels to determine whether NF-κB/DNMT1 had an effect on gene expression. Compared with the control group, atherosclerotic lesions in ApoE^−/− mice fed a high methionine diet significantly increased, as did the expression of MCP-1. In vitro study showed that pyrrolidine dithiocarbamate treatment down-regulated levels of NF-κB and raised DNMT1 concentrations, confirming the effect of NF-κB/DNMT1 in the MCP-1 promoter DNA methylation process. In conclusion, our results suggest that through NF-κB/DNMT1, MCP-1 promoter DNA hypomethylation may play a key role in formation of atherosclerosis under hyperhomocysteinemia.

Phytochemicals: countering risk factors and pathological responses associated with ischaemia reperfusion injury

Plant derived non-nutritive molecules, known as phytochemicals, have been investigated for their ability to provide protection against inflammation. Emerging studies of several vasculopathies (e.g. atherosclerosis, hypertension) provide novel data to support these anti-inflammatory effects and offer evidence for involvement of host pathways. Fundamental mechanisms of action are common amongst these compounds, and furthermore, the administration of these phytochemicals activates host defence pathways innately present to protect cells from oxidative stress. This review will elucidate the real benefit of therapeutic intervention with these phytochemicals for vasculopathies, and associated ischaemia reperfusion injury in both the heart and brain.

Monocyte chemoattractant protein 1 is correlated with glycemic control and peripheral arterial disease in type 2 diabetic patients with metabolic syndrome

We evaluated the serum levels of monocyte chemoattractant protein 1 (MCP-1) and their association with peripheral arterial disease (PAD) in 199 patients with type 2 diabetes mellitus (T2DM) and metabolic syndrome ([MetS], group A) in comparison with 109 healthy controls (group B). In group A, MCP-1 levels were significantly (P < .001) higher than group B and exhibited a positive correlation with HbA1c (P < .001) and a negative correlation with ankle-brachial index (P < .001). In the same group, patients with PAD had significantly higher MCP-1 levels compared with those without PAD (P < .001). In conclusion, T2DM patients with MetS exhibit higher serum MCP-1 levels. The latter is associated with worse glycemic control and PAD. These results suggest a potential contributory role for MCP-1 in the pathogenesis of PAD in the presence of hyperglycemia and MetS in T2DM.