Genetic inflammatory factors predict restenosis after percutaneous coronary interventions

Association of Endothelial Nitric Oxide Synthase and Angiotensin-Converting Enzyme Genes Polymorphism With In-Sent Restenosis of Bare Metal Stents vs Drug-Eluting Stents in Egyptians

Despite its unequivocal superiority compared with balloon angioplasty, coronary stenting did not abolish restenosis. We aimed to evaluate the associations between a common single nucleotide polymorphism occurring in endothelial nitric oxide synthase (eNOS) and angiotensin-converting enzyme (ACE) genes and the risk of in-stent restenosis (ISR) of bare metal stents vs drug-eluting stents (BMS vs DES) implanted in Egyptian patients. Two hundred patients who had coronary stenting were divided into group I (n = 98) who received a BMS and group II (n = 102) who received a DES. eNOS and ACE genes polymorphism were analyzed by polymerase chain reaction (PCR). We found that the GA and AA genotypes of the eNOS gene were associated with the ISR with both BMS and DES. However, the ACE gene was not associated with ISR. We concluded that eNOS gene polymorphism is associated with ISR. Hypertension, stent length, and AA genotype of the eNOS gene were found to be independent predictors of the occurrence of ISR after both BMS and DES use.

Pathogenesis and Clinical Significance of In-Stent Restenosis in Patients with Diabetes

Diabetes mellitus (DM) is a strong risk factor for the development of cardiovascular diseases such as coronary heart disease, cerebrovascular disease, and peripheral arterial disease (PAD). In the population of people living with DM, PAD is characterised by multi-level atherosclerotic lesions as well as greater involvement of the arteries below the knee. DM is also a factor that significantly increases the risk of lower limb amputation. Percutaneous balloon angioplasty with or without stent implantation is an important method of the treatment for atherosclerotic cardiovascular diseases, but restenosis is a factor limiting its long-term effectiveness. The pathogenesis of atherosclerosis in the course of DM differs slightly from that in the general population. In the population of people living with DM, more attention is drawn to such factors as inflammation, endothelial dysfunction, platelet dysfunction, blood rheological properties, hypercoagulability, and additional factors stimulating vascular smooth muscle cell proliferation. DM is a risk factor for restenosis. The purpose of this paper is to provide a review of the literature and to present the most important information on the current state of knowledge on mechanisms and the clinical significance of restenosis and in-stent restenosis in patients with DM, especially in association with the endovascular treatment of PAD. The role of such processes as inflammation, neointimal hyperplasia and neoatherosclerosis, allergy, resistance to antimitotic drugs used for coating stents and balloons, genetic factors, and technical and mechanical factors are discussed. The information on restenosis collected in this publication may be helpful in planning further research in this field, which may contribute to the formulation of more and more precise recommendations for the clinical practice.

Proinflammatory protein signatures in cryptogenic and large artery atherosclerosis stroke

Objectives

The cause of ischemic stroke remains unknown, cryptogenic, in 25% of young and middle‐aged patients. We hypothesized that if atherosclerosis is prominent in cryptogenic stroke, it would have a similar proinflammatory protein signature as large artery atherosclerosis (LAA) stroke.

Materials & Methods

Blood was collected in the acute phase and after 3 months from cryptogenic (n = 162) and LAA (n = 73) stroke patients aged 18–69 years and once from age‐matched controls (n = 235). Cryptogenic stroke was divided into Framingham Risk Score (FRS) quartiles to compare low and high risk of atherosclerosis. Plasma concentrations of 25 proteins were analyzed using a Luminex multiplex assay. The discriminating properties were assessed with discriminant analysis and C‐statistics.

Results

We identified proteins that separated cryptogenic and LAA stroke from controls (area under the curves, AUCs ≥ 0.85). For both subtypes, RANTES, IL‐4, and IFN‐γ contributed the most at both time points. These associations were independent of risk factors of atherosclerosis. We also identified proteins that separated cryptogenic strokes in the lowest quartile of FRS from those in the highest, and from LAA stroke (AUCs ≥ 0.76), and here eotaxin and MCP‐1 contributed the most.

Conclusions

The protein signature separating cases from controls was different from the signature separating cryptogenic stroke with low risk of atherosclerosis from those with high risk and from LAA stroke. This suggests that increased RANTES, IL‐4, and IFN‐γ in stroke may not be primarily related to atherosclerosis, whereas increased eotaxin and MCP‐1 in cryptogenic stroke may be markers of occult atherosclerosis as the underlying cause.

Circulating level of microRNA-142-5p is a potential biomarker for predicting in-stent restenosis: a case-control study

Background

Patients who receive percutaneous coronary intervention (PCI) have different chances of developing in-stent restenosis (ISR). To date, no predictable biomarker can be applied in the clinic. MicroRNAs (miRNAs or miRs) play critical roles in transcription regulation, and their circulating levels were reported to have potential as clinical biomarkers.

Methods

In total, 93 coronary stent-implanted patients without pregnancy, liver or renal dysfunction, malignancy, hemophilia, or autoimmune diseases were recruited in this clinical study. All recruited participants were divided into an ISR group (n = 45) and a non-ISR group (n = 48) based on their restenotic status as confirmed by cardiologists at the first follow-up visit (6 months after surgery). Blood samples of all participants were harvested to measure circulating levels of miRNA candidates (miR-132, miR-142-5p, miR-15b, miR-24-2, and miR-424) to evaluate whether these circulating miRNAs can be applied as predictive biomarkers of ISR.

Results

Our data indicated that circulating levels of miR-142-5p were significantly higher in the ISR population, and results from the receiver operating characteristic (ROC) curve analysis also demonstrated superior discriminatory ability of miR-142-5p in predicting patients’ restenotic status. In addition, circulating levels of miR-15b, miR-24-2, and miR-424 had differential expressions in participants with diabetes, hyperlipidemia, and hypertension, respectively.

Conclusions

The current study revealed that the circulating level of miR-142-5p has potential application as a clinical biomarker for predicting the development of ISR in stent-implanted patients.

P300/CBP Associated Factor (PCAF) Deficiency Enhances Diet-Induced Atherosclerosis in ApoE3*Leiden Mice via Systemic Inhibition of Regulatory T Cells

Background: Inflammatory stimuli induced by NF-kB drive atherosclerotic lesion formation. The epigenetic P300/CBP associated factor (PCAF) post-transcriptionally acetylates FoxP3, which is required for regulatory T-cell (Treg) differentiation and immune modulation. We hypothesize that PCAF deficiency affects atherosclerosis via regulation of regulatory Tregs.

Method: ApoE3^*Leiden (n = 13) and ApoE3^*LeidenxPCAF^−/− (n = 13) were fed a high-fat diet (HFD) containing 1.25% cholesterol. Systemic FoxP3⁺ T cells were measured every 4 weeks by flow cytometry (n = 6). After 5-months of HFD, mice were euthanized, and hearts and blood were collected. IL-6 and TNFα concentrations were measured in plasma to identify systemic inflammatory responses. Compositional and morphometrical analyses were performed on the atherosclerotic lesions in the aortic sinuses.

Results: After 5 months of HFD, plasma cholesterol concentrations were not different for ApoE3^*LeidenxPCAF^−/− compared to ApoE3^*Leiden mice. Expression of FoxP3 by systemic CD4⁺ T cells decreased 1.8 fold in ApoE3^*LeidenxPCAF^−/− after 5 months HFD and remained significantly reduced after 5 months of HFD. Systemic TNFα and IL-6 concentrations were comparable, whereas the atherosclerotic lesion size in ApoE3^*LeidenxPCAF^−/− mice was increased by 28% compared to ApoE3^*Leiden mice. In atherosclerotic lesions, no differences were observed in macrophage differentiation or VSMC content, although a small increase in collagen was identified.

Conclusion: Our data show that PCAF deficiency resulted in a decrease in circulatory FoxP3⁺ regulatory T cells and ameliorated atherosclerotic lesions with no differences in systemic inflammation or macrophage differentiation in the atherosclerotic lesions. This suggests that PCAF regulates atherosclerosis via modulation of FoxP3⁺ regulatory T cell differentiation.

Mechanisms of drug-eluting stent restenosis

Drug-eluting stents (DES) were developed to overcome in-stent restenosis (ISR), which has long been considered the main complication limiting the long-term efficacy of coronary stenting. New-generation DES which composed of advanced stent design with and without specific biocompatible polymer contributes a reduction of the incidence of ISR to rate ranging from 5 to 10%. The precise reasons of DES restenosis are still controversial and not fully understood. Angiographic and coronary images at the index procedure, systemic status of patients, medications, and intracoronary imaging at ISR site are all considered to find the possible mechanisms of DES restenosis. Multiple biological, genetic, mechanical, and technical factors might intricately contribute to DES restenosis. Biological and genetic factors of ISR are not able to be sufficiently modified by the current medical approaches. Tailored treatments avoiding mechanical and technical factors of ISR are required to reduce DES restenosis. Elucidation of DES restenosis leads to further improvement in the current DES system and finds the optimal approach to treat DES restenosis. The possible mechanisms of DES restenosis are discussed in this review.

The association between genetic polymorphisms of the interleukin-10, tumor necrosis factor-alpha, and annexin A5 gene loci and restenosis after percutaneous coronary angioplasty and stenting

BACKGROUND

Advances in the technology for percutaneous coronary angioplasty, such as coated stents, have reduced its complications, but restenosis remains an important clinical problem. The factors associated with an increased risk of restenosis include diabetes mellitus and multiple coronary artery disease. It is also possible that genetic factors play a role in restenosis although there are little data on this. We have investigated the association of three genetic markers of genes involved in inflammation leading to restenosis.

MATERIALS AND METHODS

In this case-control study, 306 unrelated Iranian patients who were thought to have restenosis on clinical grounds were investigated. Based on the results of angiography, 104 patients were found to have >50% stenosis within an implanted stent, and these were allocated to the in-stent restenosis (ISR) group; 202 patients with no in-stent stenosis or stenosis ≤50% were allocated to the non-ISR (NISR) group. Demographic data were collected from medical records. Biochemical parameters were measured using routine methods. Genotypes of the interleukin-10 (IL-10), annexin A5 (AnxA5), and tumor necrosis factor-alpha (TNFα) loci were determined using real-time polymerase chain reaction and a high-resolution melting assay.

RESULTS

Fasting blood glucose, serum triglycerides, and serum high-sensitivity C-reactive protein (hs-CRP) concentrations were higher in the ISR group than in the NISR group (P < 0.05), and a history of diabetes mellitus was significantly related to the presence of restenosis (P < 0.001). There were no significant differences in the frequency of the genetic polymorphisms of IL-10, AnxA5, and TNFα genes and the presence of ISR.

CONCLUSION

After adjustment for clinical variables, the genetic polymorphisms at the IL-10, TNFα, and ANXA5 gene loci do not appear to be risk factors for >50% ISR in our population. However, our data suggested a significant association between diabetes mellitus, serum hs-CRP, stent type, and restenosis.

Stabilisation of atherosclerotic plaques

Plaque rupture and subsequent thrombotic occlusion of the coronary artery account for as many as three quarters of myocardial infarctions. The concept of plaque stabilisation emerged about 20 years ago to explain the discrepancy between the reduction of cardiovascular events in patients receiving lipid lowering therapy and the small decrease seen in angiographic evaluation of atherosclerosis. Since then, the concept of a vulnerable plaque has received a lot of attention in basic and clinical research leading to a better understanding of the pathophysiology of the vulnerable plaque and acute coronary syndromes. From pathological and clinical observations, plaques that have recently ruptured have thin fibrous caps, large lipid cores, exhibit outward remodelling and invasion by vasa vasorum. Ruptured plaques are also focally inflamed and this may be a common denominator of the other pathological features. Plaques with similar characteristics, but which have not yet ruptured, are believed to be vulnerable to rupture. Experimental studies strongly support the validity of anti-inflammatory approaches to promote plaque stability. Unfortunately, reliable non-invasive methods for imaging and detection of such plaques are not yet readily available. There is a strong biological basis and supportive clinical evidence that low-density lipoprotein lowering with statins is useful for the stabilisation of vulnerable plaques. There is also some clinical evidence for the usefulness of antiplatelet agents, beta blockers and renin-angiotensin-aldosterone system inhibitors for plaque stabilisation. Determining the causes of plaque rupture and designing diagnostics and interventions to prevent them are urgent priorities for current basic and clinical research in cardiovascular area.

The epigenetic factor PCAF regulates vascular inflammation and is essential for intimal hyperplasia development

Objective

Genetic P300/CBP-associated factor (PCAF) variation affects restenosis-risk in patients. PCAF has lysine acetyltransferase activity and promotes nuclear factor kappa-beta (NFκB)-mediated inflammation, which drives post-interventional intimal hyperplasia development. We studied the contributing role of PCAF in post-interventional intimal hyperplasia.

Methods and results

PCAF contribution to inflammation and intimal hyperplasia was assessed in leukocytes, macrophages and vascular smooth muscle cells (vSMCs) in vitro and in a mouse model for intimal hyperplasia, in which a cuff is placed around the femoral artery. PCAF deficiency downregulate CCL2, IL-6 and TNF-alpha expression, as demonstrated on cultured vSMCs, leukocytes and macrophages. PCAF KO mice showed a 71.8% reduction of vSMC-rich intimal hyperplasia, a 73.4% reduction of intima/media ratio and a 63.7% reduction of luminal stenosis after femoral artery cuff placement compared to wild type (WT) mice. The association of PCAF and vascular inflammation was further investigated using the potent natural PCAF inhibitor garcinol. Garcinol treatment reduced CCL2 and TNF-alpha expression, as demonstrated on cultured vSMCs and leukocytes.

To assess the effect of garcinol treatment on vascular inflammation we used hypercholesterolemic ApoE*3-Leiden mice. After cuff placement, garcinol treatment resulted in reduced arterial leukocyte and macrophage adherence and infiltration after three days compared to untreated animals.

Conclusions

These results identify a vital role for the lysine acetyltransferase PCAF in the regulation of local inflammation after arterial injury and likely the subsequent vSMC proliferation, responsible for intimal hyperplasia.

β2-Adrenergic receptor gene polymorphisms in the relapse of myasthenia gravis with thymus abnormality

BACKGROUND

The role of β2-adrenergic receptor (β2-AR) in the relapse of myasthenia gravis (MG) associated with thymus abnormality has not been fully identified.

METHODS

Using polymerase chain reaction and gene sequencing method, we investigated the relationship of β2-AR gene polymorphisms with different thymus pathology in MG patients. The role of β2-AR gene polymorphisms in the relapse of MG was further investigated.

RESULTS

Age of onset (p = 0.034), the onset symptom of ocular MG (OMG; p = 0.023), the first symptom of OMG second generalization (p = 0.040) were different in MG with thymoma from those in MG with normal thymus or thymus hyperplasia. Gene polymorphisms of β2-AR on positions 16 and 27 showed no significant difference between relapsed and non-relapsed MG patients with thymus abnormality (thymus hyperplasia: position 16, p = 0.792; position 27, p = 0.664; thymoma: position 16, p = 0.226; position 27, p = 0.615). However, genotypes distribution on position 27 among MG patients with three thymus histology was significantly different (χ² = 8.153, p = 0.041). Furthermore, glucocorticoid can decrease relapse of MG with thymus hyperplasia (p = 0.021).

CONCLUSIONS

MG patients with thymus abnormality differ from MG patients with normal thymus in age of onset, the onset symptom of OMG and the first symptom of OMG second generalization. β2-AR gene polymorphisms had no relationship with the relapse of MG with thymus abnormality. Gene polymorphism of β2-AR on position 27 was associated with different thymus histology of MG. Glucocorticoid was able to reduce the risk of relapse of MG with thymus hyperplasia.

Vein graft failure: from pathophysiology to clinical outcomes

Occlusive arterial disease is a leading cause of morbidity and mortality worldwide. Aside from balloon angioplasty, bypass graft surgery is the most commonly performed revascularization technique for occlusive arterial disease. Coronary artery bypass graft surgery is performed in patients with left main coronary artery disease and three-vessel coronary disease, whereas peripheral artery bypass graft surgery is used to treat patients with late-stage peripheral artery occlusive disease. The great saphenous veins are commonly used conduits for surgical revascularization; however, they are associated with a high failure rate. Therefore, preservation of vein graft patency is essential for long-term surgical success. With the exception of 'no-touch' techniques and lipid-lowering and antiplatelet (aspirin) therapy, no intervention has hitherto unequivocally proven to be clinically effective in preventing vein graft failure. In this Review, we describe both preclinical and clinical studies evaluating the pathophysiology underlying vein graft failure, and the latest therapeutic options to improve patency for both coronary and peripheral grafts.

Genetics of coronary artery disease and myocardial infarction

Atherosclerotic coronary artery disease (CAD) comprises a broad spectrum of clinical entities that include asymptomatic subclinical atherosclerosis and its clinical complications, such as angina pectoris, myocardial infarction (MI) and sudden cardiac death. CAD continues to be the leading cause of death in industrialized society. The long-recognized familial clustering of CAD suggests that genetics plays a central role in its development, with the heritability of CAD and MI estimated at approximately 50% to 60%. Understanding the genetic architecture of CAD and MI has proven to be difficult and costly due to the heterogeneity of clinical CAD and the underlying multi-decade complex pathophysiological processes that involve both genetic and environmental interactions. This review describes the clinical heterogeneity of CAD and MI to clarify the disease spectrum in genetic studies, provides a brief overview of the historical understanding and estimation of the heritability of CAD and MI, recounts major gene discoveries of potential causal mutations in familial CAD and MI, summarizes CAD and MI-associated genetic variants identified using candidate gene approaches and genome-wide association studies (GWAS), and summarizes the current status of the construction and validations of genetic risk scores for lifetime risk prediction and guidance for preventive strategies. Potential protective genetic factors against the development of CAD and MI are also discussed. Finally, GWAS have identified multiple genetic factors associated with an increased risk of in-stent restenosis following stent placement for obstructive CAD. This review will also address genetic factors associated with in-stent restenosis, which may ultimately guide clinical decision-making regarding revascularization strategies for patients with CAD and MI.

Effect of pioglitazone on in-stent restenosis after coronary drug-eluting stent implantation: a meta-analysis of randomized controlled trials

BACKGROUND

In-stent restenosis (ISR) remains a common life-threatening complication and some studies have shown that pioglitazone can reduce the incidence of ISR in patients with drug-eluting stents (DES) implantation. We conducted a meta-analysis to assess the effect of pioglitazone in preventing ISR after DES implantation.

METHODS

Randomized controlled trials (RCTs) investigating the effects of pioglitazone for ISR after DES implantation were identified by systematic searches of multiple online databases and manual searches of related reference lists of identified trials through May 2014. The primary endpoint was the rate of ISR. Secondary endpoints included minimum lumen diameter, percentage stenosis of stented vessels, late loss, in-stent neointimal volume, target vessel revascularization (TVR), target lesion revascularization, myocardial infarction, stent thrombosis and death.

RESULTS

Five studies, comprising 255 pioglitazone-treated patients and 245 controls, were identified in the current meta-analysis. Pioglitazone did not significantly reduce the rate of ISR (P = 0.20) with low heterogeneity (I2 = 13.3%, P = 0.32). For the secondary outcomes, pioglitazone did not substantially affect the pooled estimates of these endpoints except late loss (P = 0.01) and TVR (P = 0.04).

CONCLUSIONS

The limited evidence indicates that pioglitazone does not demonstrate markedly beneficial effect in patients subjected to coronary DES implantation. However, the results should be interpreted with care given the small sample size. Further large-scale RCTs are needed.

Potassium concentration on admission is an independent risk factor for target lesion revascularization in acute myocardial infarction

Background. Acute myocardial infarction (AMI) is accompanied by excessive production of catecholamines, which is characterized by a hypokalemic dip. A polymorphism of the adrenergic receptor has also been reported to be associated with target lesion revascularization (TLR) after coronary intervention. Subjects and Methods. We enrolled 276 consecutive patients with AMI within 24 hours of symptom onset, who underwent emergency coronary intervention using bare metal stents and had examinations over a 5–10-month follow-up period. The patients were divided into tertiles based on their serum potassium level on admission (low K, <3.9; mid K, ≥3.9, <4.3; and high K, ≥4.3). Results. Sixty-four TLRs were observed in the study. Increased potassium concentration was associated significantly with TLR. Patients in the high K group were about two and a half times more likely to have a TLR after AMI compared to those in the low K group. Multiple logistic analysis showed that potassium level on admission was an independent risk factor for TLR (odds ratio 1.69; confidence interval 1.04 to 2.74; P = 0.036). Conclusions. These findings indicated that increased potassium levels on admission might predict TLRs in AMI patients treated with bare metal stents.

Pathway analysis using genome-wide association study data for coronary restenosis--a potential role for the PARVB gene

Background

Coronary restenosis after percutaneous coronary intervention (PCI) still remains a significant limitation of the procedure. The causative mechanisms of restenosis have not yet been fully identified. The goal of the current study was to perform gene-set analysis of biological pathways related to inflammation, proliferation, vascular function and transcriptional regulation on coronary restenosis to identify novel genes and pathways related to this condition.

Methods

The GENetic DEterminants of Restenosis (GENDER) databank contains genotypic data of 556,099SNPs of 295 cases with restenosis and 571 matched controls. Fifty-four pathways, related to known restenosis-related processes, were selected. Gene-set analysis was performed using PLINK, GRASS and ALIGATOR software. Pathways with a p<0.01 were fine-mapped and significantly associated SNPs were analyzed in an independent replication cohort.

Results

Six pathways (cell-extracellular matrix (ECM) interactions pathway, IL2 signaling pathway, IL6 signaling pathway, platelet derived growth factor pathway, vitamin D receptor pathway and the mitochondria pathway) were significantly associated in one or two of the software packages. Two SNPs in the cell-ECM interactions pathway were replicated in an independent restenosis cohort. No replication was obtained for the other pathways.

Conclusion

With these results we demonstrate a potential role of the cell-ECM interactions pathway in the development of coronary restenosis. These findings contribute to the increasing knowledge of the genetic etiology of restenosis formation and could serve as a hypothesis-generating effort for further functional studies.

TLR accessory molecule RP105 (CD180) is involved in post-interventional vascular remodeling and soluble RP105 modulates neointima formation

Background

RP105 (CD180) is TLR4 homologue lacking the intracellular TLR4 signaling domain and acts a TLR accessory molecule and physiological inhibitor of TLR4-signaling. The role of RP105 in vascular remodeling, in particular post-interventional remodeling is unknown.

Methods and Results

TLR4 and RP105 are expressed on vascular smooth muscle cells (VSMC) as well as in the media of murine femoral artery segments as detected by qPCR and immunohistochemistry. Furthermore, the response to the TLR4 ligand LPS was stronger in VSMC from RP105^−/− mice resulting in a higher proliferation rate. In RP105^−/− mice femoral artery cuff placement resulted in an increase in neointima formation as compared to WT mice (4982±974 µm² vs.1947±278 µm²,p = 0.0014). Local LPS application augmented neointima formation in both groups, but in RP105^−/− mice this effect was more pronounced (10316±1243 µm² vs.4208±555 µm²,p = 0.0002), suggesting a functional role for RP105. For additional functional studies, the extracellular domain of murine RP105 was expressed with or without its adaptor protein MD1 and purified. SEC-MALSanalysis showed a functional 2∶2 homodimer formation of the RP105-MD1 complex. This protein complex was able to block the TLR4 response in whole blood ex-vivo. In vivo gene transfer of plasmid vectors encoding the extracellular part of RP105 and its adaptor protein MD1 were performed to initiate a stable endogenous soluble protein production. Expression of soluble RP105-MD1 resulted in a significant reduction in neointima formation in hypercholesterolemic mice (2500±573 vs.6581±1894 µm²,p<0.05), whereas expression of the single factors RP105 or MD1 had no effect.

Conclusion

RP105 is a potent inhibitor of post-interventional neointima formation.

Systematic testing of literature reported genetic variation associated with coronary restenosis: results of the GENDER Study

Background

Coronary restenosis after percutaneous coronary intervention still remains a significant problem, despite all medical advances. Unraveling the mechanisms leading to restenosis development remains challenging. Many studies have identified genetic markers associated with restenosis, but consistent replication of the reported markers is scarce. The aim of the current study was to analyze the joined effect of previously in literature reported candidate genes for restenosis in the GENetic DEterminants of Restenosis (GENDER) databank.

Methodology/Principal Findings

Candidate genes were selected using a MEDLINE search including the terms ‘genetic polymorphism’ and ‘coronary restenosis’. The final set included 36 genes. Subsequently, all single nucleotide polymorphisms (SNPs) in the genomic region of these genes were analyzed in GENDER using set-based analysis in PLINK. The GENDER databank contains genotypic data of 2,571,586 SNPs of 295 cases with restenosis and 571 matched controls. The set, including all 36 literature reported genes, was, indeed, significantly associated with restenosis, p = 0.024 in the GENDER study. Subsequent analyses of the individual genes demonstrated that the observed association of the complete set was determined by 6 of the 36 genes.

Conclusion

Despite overt inconsistencies in literature, with regard to individual candidate gene studies, this is the first study demonstrating that the joint effect of all these genes together, indeed, is associated with restenosis.

The A to G polymorphism at -1082 of the interleukin-10 gene is rare in the Han Chinese population

Interleukin-10 (IL-10) is a multifunctional anti-inflammatory cytokine involved in various physiological and pathophysiological processes including cardiovascular disease. It has been reported that 50-75% of the variation in IL-10 production is genetically controlled. In the present study, the IL-10 -1082A/G (rs1800896) polymorphism was detected in 174 coronary artery disease (CAD) patients confirmed by selective coronary angiography and 176 age and gender-matched controls from the Jiangsu area (East China). The majority of the subjects (93.14%) carried the AA wild-type genotype, whereas only 0.29% carried the GG genotype. Our results suggest that IL-10 -1082A/G is rare and unlikely to be a significant contributory to disease susceptibility in the Han Chinese population.

On the epigenetics of vascular regulation and disease

Consolidated knowledge is accumulating as to the role of epigenetic regulatory mechanisms in the physiology of vascular development and vascular tone as well as in the pathogenesis of cardiovascular disease. The modulation of gene expression through modification of the epigenome by structural changes of the chromatin architecture without alterations of the associated genomic DNA sequence is part of the cellular response to environmental changes. Such environmental conditions, which are finally being translated into adaptations of the cardiovascular system, also comprise pathological conditions such as atherosclerosis or myocardial infarction. This review summarizes recent findings on the epigenetics of vascular regulation and disease and presents nutritional and pharmacological approaches as novel epigenetic strategies in the prevention and treatment of cardiovascular disease.

Annexin A5 prevents post-interventional accelerated atherosclerosis development in a dose-dependent fashion in mice

BACKGROUND

Activated cells in atherosclerotic lesions expose phosphatidylserine (PS) on their surface. Annexin A5 (AnxA5) binds to PS and is used for imaging atherosclerotic lesions. Recently, AnxA5 was shown to inhibit vascular inflammatory processes after vein grafting. Here, we report a therapeutic role for AnxA5 in post-interventional vascular remodeling in a mouse model mimicking percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Associations between the rs4833229 (OR = 1.29 (CI 95%), p(allelic) = 0.011) and rs6830321 (OR = 1.35 (CI 95%), p(allelic) = 0.003) SNPs in the AnxA5 gene and increased restenosis-risk in patients undergoing PCI were found in the GENDER study. To evaluate AnxA5 effects on post-interventional vascular remodeling and accelerated atherosclerosis development in vivo, hypercholesterolemic ApoE(-/-) mice underwent femoral arterial cuff placement to induce intimal thickening. Dose-dependent effects were investigated after 3 days (effects on inflammation and leukocyte recruitment) or 14 days (effects on remodeling) after cuff placement. Systemically administered AnxA5 in doses of 0.1, 0.3 and 1.0mg/kg compared to vehicle reduced early leukocyte and macrophage adherence up to 48.3% (p = 0.001) and diminished atherosclerosis development by 71.2% (p = 0.012) with a reduction in macrophage/foam cell presence. Moreover, it reduced the expression of the endoplasmic reticulum stress marker GRP78/BiP, indicating lower inflammatory activity of the cells present.

CONCLUSIONS

AnxA5 SNPs could serve as markers for restenosis after PCI and AnxA5 therapeutically prevents vascular remodeling in a dose-dependent fashion, together indicating clinical potential for AnxA5 against post-interventional remodeling.

Do statins have a role in reduction/prevention of post-PCI restenosis?

The pathophysiology of post-PCI restenosis involves neointimal formation that consists of three phases: thrombosis (within 24 h), recruitment (3-8 days), and proliferation, which starts on day 8 of PCI. Various factors suggested to be predictors/risks for restenosis include C-reactive protein (CRP), inflammatory mediators (cytokines and adhesion molecules), oxygen radicals, advanced glycation end products (AGEs) and their receptors (RAGE), and soluble RAGE (sRAGE). The earlier noted factors produce thrombogenesis, vascular smooth muscle cell proliferation, and extracellular matrix formation. Statins have pleiotropic effects. Besides lowering serum cholesterol, they have various other biological effects including antiinflammatory, antithrombotic, CRP-lowering, antioxidant, antimitotic, and inhibition of smooth muscle cell proliferation. They inhibit matrix metalloproteinase and cyclooxygenase-2, lower AGEs, decrease expression of RAGE and increase levels of serum sRAGE. They also increase the synthesis of nitric oxide (NO) by increasing endothelial NO synthase expression and activity. Preprocedural statin therapy is known to reduce peri- and post-PCI myonecrosis and reduce the need for repeat revascularization. There is evidence that statin-eluting stents inhibit in-stent restenosis in animal models. It is concluded that because of the above attributes of statins, they are suitable candidates for reduction of post-PCI restenosis and post-PCI myonecrosis. The future directions for the use of statins in reduction of post-PCI restenosis and myonecrosis have been discussed.

Restenosis after PCI. Part 1: pathophysiology and risk factors

Restenosis is a complex disease for which the pathophysiological mechanisms have not yet been fully elucidated, but are thought to include inflammation, proliferation, and matrix remodeling. Over the years, many predictive clinical, biological, (epi)genetic, lesion-related, and procedural risk factors for restenosis have been identified. These factors are not only useful in risk stratification of patients, they also contribute to our understanding of this condition. Furthermore, these factors provide evidence on which to base treatment tailored to the individual and aid in the development of novel therapeutic modalities. In this Review, we will evaluate the available evidence on the pathophysiological mechanisms of restenosis and provide an overview of the various risk factors, together with the possible clinical application of this knowledge.

A genome-wide association study identifies a region at chromosome 12 as a potential susceptibility locus for restenosis after percutaneous coronary intervention

Percutaneous coronary intervention (PCI) has become an effective therapy to treat obstructive coronary artery diseases (CAD). However, one of the major drawbacks of PCI is the occurrence of restenosis in 5-25% of all initially treated patients. Restenosis is defined as the re-narrowing of the lumen of the blood vessel, resulting in renewed symptoms and the need for repeated intervention. To identify genetic variants that are associated with restenosis, a genome-wide association study (GWAS) was conducted in 295 patients who developed restenosis (cases) and 571 who did not (controls) from the GENetic Determinants of Restenosis (GENDER) study. Analysis of ~550 000 single nucleotide polymorphisms (SNPs) in GENDER was followed by a replication phase in three independent case-control populations (533 cases and 3067 controls). A potential susceptibility locus for restenosis at chromosome 12, including rs10861032 (P(combined) = 1.11 × 10(-7)) and rs9804922 (P(combined) = 1.45 × 10(-6)), was identified in the GWAS and replication phase. In addition, both SNPs were also associated with coronary events (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023) in a trial based cohort set of elderly patients with (enhanced risk of) CAD (PROSPER) and all-cause mortality in PROSPER (rs10861032, P(additive) = 0.007; rs9804922, P(additive) = 0.013) and GENDER (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023). Further analysis suggests that this locus could be involved in regulatory functions.

Toll-like receptor 4 gene polymorphisms show no association with the risk of clinical or angiographic restenosis after percutaneous coronary intervention

OBJECTIVE

Restenosis after percutaneous coronary intervention (PCI) remains an issue even in the drug-eluting stent era. Genetic polymorphisms may provide insight in the pathogenesis of restenosis and may help in the stratification of patients at risk for restenosis. The aim of this study was to examine whether polymorphisms at the toll-like receptor 4 (TLR4) locus, that are associated with impaired innate immune system and with an increased risk of cardiovascular events, were associated with clinical and/or angiographic restenosis after PCI.

METHODS

The GENetic Determinants of Restenosis (GENDER) project was a prospective, multicenter study that enrolled 3146 consecutive patients after successful PCI. Frequencies of the TLR4 896A/G (Asp299Gly; rs4986790) and 1196C/T (Thr399Ile; rs4986791) polymorphisms and haplotypes were assessed. Patients were followed up for 1 year and in a subgroup of 406 patients angiographic follow-up was obtained.

RESULTS

We included a total of 2682 patients that underwent successful PCI. There was no association between genotypes and the risk of target vessel revascularization at 1-year or late luminal loss at 6-months angiographic follow-up (P=0.53 and 0.44, respectively). Absence of association with target lesion revascularization and late luminal loss was replicated in the GEnetic risk factors for In-Stent Hyperplasia study Amsterdam (GEISHA) cohort study of 674 patients and in a subgroup of 550 patients with angiographic follow-up available (P=0.26, and 0.86, respectively). Moreover, in both the studies, no significant differences between haplotypes A/C and G/T were observed for target vessel revascularization at late luminal loss.

CONCLUSION

Although inflammation has been implicated in the pathophysiology of restenosis, the 896A/G and 1196C/T polymorphisms or haplotypes based on these polymorphisms at the TLR4 locus are not associated with an increased risk of target vessel revascularization or angiographic restenosis after PCI. These polymorphisms are not useful for pre-PCI identification of patients at risk for restenosis.

The evolving role of inflammatory biomarkers in risk assessment after stent implantation

The main adverse reactions to coronary stents are in-stent restenosis (ISR) and stent thrombosis. Along with procedural factors, individual susceptibility to these events plays an important role. In particular, inflammatory status, as assessed by C-reactive protein levels, predicts the risk of ISR after bare-metal stent implantation, although it does not predict the risk of stent thrombosis. Conversely, C-reactive protein levels fail to predict the risk of ISR after drug-eluting stent (DES) implantation, although they appear to predict the risk of stent thrombosis. Of note, DES have abated ISR rates occurring in the classical 1-year window, but new concern is emerging regarding late restenosis and thrombosis. The pathogenesis of these late events seems to be related to delayed healing and allergic reactions to polymers, a process in which eosinophils seem to play an important role by enhancing restenosis and thrombosis. The identification of high-risk individuals based on biomarker assessment may be important for the management of patients receiving stent implantation. In this report, we review the evolving role of inflammatory biomarkers in predicting the risk of ISR and stent thrombosis.

The 5352 A allele of the pro-inflammatory caspase-1 gene predicts late-acquired stent malapposition in STEMI patients treated with sirolimus stents

Late-acquired stent malapposition (LASM) is a common finding after sirolimus-eluting stent (SES) implantation and may be the cause for late stent thrombosis. Inflammation may play a pivotal role in LASM just as it plays in stent restenosis. We have therefore investigated seven polymorphisms involved in inflammatory processes, related in previous reports to restenosis, on the risk of LASM in SES patients. Patients with ST-elevation myocardial infarction who underwent SES implantation and had intravascular ultrasonography (IVUS) data available for both immediate post-intervention and 9-month follow-up were included in the present study. In total, 104 patients from the MISSION! Intervention Study were genotyped for the caspase-1 5352 G/A, eotaxin 1382 A/G, CD14 260 A/G, colony stimulating factor 2 1943 C/T, IL10 -1117 C/T, IL10 4251 C/T, and the tumor necrosis factor alpha 1211 C/T polymorphisms. LASM occurred in 26/104 (25%) of patients. We found a significantly higher risk for LASM in patients carrying the caspase-1 (CASP1) 5352 A allele (RR = 2.32; 95% CI 1.22-4.42). In addition, mean neointimal growth was significantly lower in patients carrying this LASM risk allele (1.6 vs. 4.1%, p = 0.014). The other six polymorphisms related to inflammation were not significantly related to the risk of LASM. In conclusion, carriers of the 5352 A allele in the caspase-1 gene are at increased risk of developing LASM after SES implantation. If this is confirmed in larger studies, then screening for this polymorphism in patients undergoing percutaneous coronary interventions could eventually help cardiologists to better select between commercially available stents.

Genomics of cardiovascular disease

As the leading cause of death worldwide and a major cause of disability, cardiovascular disease remains a central focus of basic research, pharmacological treatment, surgical interventions, and long-term care. Inherited, monogenic syndromes have provided insight into pathophysiological mechanisms across the range of cardiovascular diseases. With the advent of post-Human Genome Project resources and technology, there has been a flood of research aimed at genome-wide predisposition markers, pharmacogenetics, and genomic signatures in complex cardiovascular disorders. Genomic research has both further elucidated the impact of genes previously identified in cardiovascular disease development and progression and discovered genomic regions as yet unknown to be associated with cardiovascular outcomes. The promise of personalized medicine lies in combining this genetic information with other biomarkers to tailor preventive and therapeutic strategies to individual patients for effective management, fewer adverse events, and preventive care.

Quantitative trait locus analysis of neointimal formation in an intercross between C57BL/6 and C3H/HeJ apolipoprotein E-deficient mice

BACKGROUND

Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit marked differences in neointimal formation after arterial injury when deficient in apolipoprotein E (apoE(-/-)) and fed a Western diet. Quantitative trait locus (QTL) analysis was performed on an intercross between B6.apoE(-/-) and C3H.apoE(-/-) mice to determine genetic factors contributing to the phenotype.

METHODS AND RESULTS

Female B6.apoE(-/-) mice were crossed with male C3H.apoE(-/-) mice to generate F(1)s, which were intercrossed to generate 204 male F(2) progeny. At 10 weeks of age, F(2)s underwent endothelium denudation injury to the left common carotid artery. Mice were fed a Western diet for 1 week before and 4 weeks after injury and analyzed for neointimal lesion size, plasma lipid and MCP-1 levels. One significant QTL, named Nih1 (61cM, LOD score: 5.02), on chromosome 12 and a suggestive locus on chromosome 13 (35cM, LOD: 2.67) were identified to influence lesion size. One significant QTL on distal chromosome 1 accounted for major variations in plasma non-HDL cholesterol and triglyceride levels. Four suggestive QTLs on chromosomes 1, 2, and 3 were detected for circulating MCP-1 levels. No correlations were observed between neointimal lesion size and plasma lipid levels or between lesion size and plasma MCP-1 levels.

CONCLUSIONS

Neointimal formation is controlled by genetic factors independent of those affecting plasma lipid levels and circulating MCP-1 levels in the B6 and C3H mouse model.

Predictive value of C-reactive protein after drug-eluting stent implantation

During the last few decades, with the evolution of techniques and materials and the increasing experience of operators, percutaneous coronary interventions (PCI) have become an equally efficient alternative to coronary artery bypass grafts for the treatment of most coronary stenoses. Bare-metal stent implantation represented a major step forward, compared with plain old balloon angioplasty (POBA), by improving the immediate angiographic success. However, the incidence of in-stent restenosis (ISR) remained unacceptably high. Development of the drug-eluting stent (DES) significantly improved the outcome of PCI by dramatically abating the rate of ISR and reducing the incidence of target lesion revascularization. However, ISR has not been eliminated and the persistence of metal vessel scaffolding also raises concern regarding the occurrence of late or very late stent thrombosis. POBA and stent implantation have been shown to induce a local and systemic inflammatory response, whose magnitude is associated with worse clinical outcome, and they increase the risk of ISR. C-reactive protein, a marker of systemic inflammation, has been demonstrated to predict clinical and angiographic outcome after POBA or bare-metal stent implantation. However, conflicting data regarding the prognostic value of C-reactive protein following DES implantation are available. In this paper, we review the literature regarding the clinical and pathophysiological association between inflammation and prognosis after DES implantation and suggest some possible therapeutic approaches to reduce inflammatory burden with the aim to improve clinical and angiographic outcome after PCI.

Epigenetics in atherosclerosis and inflammation

Atherosclerosis is a multifactorial disease with a severe burden on western society. Recent insights into the pathogenesis of atherosclerosis underscore the importance of chronic inflammation in both the initiation and progression of vascular remodelling. Expression of immunoregulatory molecules by vascular wall components within the atherosclerotic lesions is accordingly thought to contribute to the ongoing inflammatory process. Besides gene regulatory proteins (transcription factors), epigenetic mechanisms also play an essential and fundamental role in the transcriptional control of gene expression. These epigenetic mechanisms change the accessibility of chromatin by DNA methylation and histone modifications. Epigenetic modulators are thus critically involved in the regulation of vascular, immune and tissue-specific gene expression within the atherosclerotic lesion. Importantly, epigenetic processes are reversible and may provide an excellent therapeutic target. The concept of epigenetic regulation is gradually being recognized as an important factor in the pathogenesis of atherosclerosis. Recent research provides an essential link between inflammation and reprogramming of the epigenome. In this review we therefore discuss the basis of epigenetic regulation – and the contribution thereof in the regulation of inflammatory processes in general and during atherosclerosis in particular. Moreover we highlight potential therapeutic interventions based on epigenetic mechanisms.

Inflammation and apoptosis genes and the risk of restenosis after percutaneous coronary intervention

OBJECTIVES

Genetic factors appear to be important in the development of restenosis after percutaneous coronary intervention, as well as in the process of inflammation, a pivotal factor in restenosis. Caspase-1, interleukin-1-receptor and protein tyrosine phosphatase nonreceptor type 22 are important mediators in the inflammatory response and caspase-1 also in apoptosis. Therefore, we examined whether polymorphisms in these candidate genes are related to the risk of developing restenosis after percutaneous coronary intervention.

METHODS

The GENetic DEterminants of Restenosis-project is a multicenter prospective follow-up study. The 5352G/A (L235L) caspase-1-polymorphism, the 7464C/G (A124G) interleukin-1r-polymorphism and the 1858C/T (R620W) protein tyrosine phosphatase nonreceptor type 22-polymorphism were genotyped. To examine the functional effect of the caspase-1 polymorphism, mature plasma interleukin-1beta levels were measured by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated whole blood from a subpopulation of patients.

RESULTS

A total of 3104 patients, age 62.1+/-10.7 years, were included after successful percutaneous coronary intervention. A significant association between the 5352AA genotype of the caspase-1 gene and target vessel revascularization (relative risk 2.2, 95% confidence interval 1.32-3.76) was observed after correcting for clinical variables. Angiographic analysis of a subgroup of patients (N=478) also showed an increased risk for developing restenosis for patients having the 5352GA/AA genotype (P=0.001). The results were corroborated, although they were not statistically significant, by somewhat higher mature interleukin-1beta levels in patients with the 5352AA genotype.

CONCLUSIONS

The present study shows that patients with the 5352AA genotype in the caspase-1 gene are at increased risk of developing restenosis. If confirmed by other studies, screening patients for this genotype can lead to better risk stratification and provide indications for improving individual treatment; for instance, by providing a new target for drug-eluting stents.

p27kip1-838C>A single nucleotide polymorphism is associated with restenosis risk after coronary stenting and modulates p27kip1 promoter activity

BACKGROUND

The cyclin-dependent kinase inhibitor p27(kip1) is a key regulator of smooth muscle cell and leukocyte proliferation in vascular disease, including in-stent restenosis. We therefore hypothesized that common genetic variations or single nucleotide polymorphisms in p27(kip1) may serve as a useful tool in risk stratification for in-stent restenosis.

METHODS AND RESULTS

Three single nucleotide polymorphisms concerning the p27(kip1) gene (-838C>A, rs36228499; -79C>T, rs34330; +326G>T, rs2066827) were determined in a cohort of 715 patients undergoing coronary angioplasty and stent placement. We discovered that the p27(kip1)-838C>A single nucleotide polymorphism is associated with clinical in-stent restenosis; the -838AA genotype decreases the risk of target vessel revascularization (hazard ratio, 0.28; 95% confidence interval, 0.10 to 0.77). This finding was replicated in another cohort study of 2309 patients (hazard ratio, 0.61; 95% confidence interval, 0.40 to 0.93). No association was detected between this end point and the p27(kip1)-79C>T and +326G>T single nucleotide polymorphisms. We subsequently studied the functional importance of the -838C>A single nucleotide polymorphism and detected a 20-fold increased basal p27(kip1) transcriptional activity of the -838A allele containing promoter.

CONCLUSIONS

Patients with the p27(kip1)-838AA genotype have a decreased risk of in-stent restenosis corresponding with enhanced promoter activity of the -838A allele of this cell-cycle inhibitor, which may explain decreased smooth muscle cell proliferation.

A genome wide association analysis in the GENDER study

Percutaneous coronary intervention (PCI) has become an effective therapy to treat coronary artery diseases. However, one of the major drawbacks of PCI is the occurrence of restenosis in 8 to 40% of all treated patients. The GENetic Determinants of Restenosis (GENDER) project was designed to study the association between genetic polymorphisims and clinical restenosis. The discovery of genetic variants associated to the occurrence of restenosis after PCI may provide a more tailored therapy and may serve as rationale for new antirestenotic therapies. So far, several candidate gene approaches had already been performed in the GENDER samples but a Genome Wide Association Scan (GWAS) was still lacking. Here, we present preliminary results from the GWAS we are currently carrying out in the GENDER population. (Neth Heart J 2009;17:262-4.).

Phosphodiesterase 4D and 5-lipoxygenase activating protein genes and risk of ischemic stroke in Sardinians

Genetic factors contribute to the risk of ischemic stroke (IS). The phosphodiesterase-4D (PDE4D) and the 5-lipoxygenase activating protein (ALOX5AP) genes were identified as contributors to stroke in an Icelandic population. In an attempt to better define the contributory role of PDE4D and ALOX5AP genes to the risk of IS in humans, we carried out the present association study in a well-characterized, earlier published, genetically homogenous population from the island of Sardinia, Italy. In this cohort, including 294 cases and 235 controls, age, hypertension, hypercholesterolemia, and atrial fibrillation represent risk factors for IS. The PDE4D gene was evaluated by four single nucleotide polymorphisms (SNP32, SNP45, SNP83, SNP87) and by the microsatellite AC008818-1; the ALOX5AP gene was characterized by three SNPs (SG13S32, SG13S89, ALO2A). The results of our study provide no evidence of association between any single PDE4D and ALOX5AP gene variant with the risk of IS in the Sardinian cohort. Haplotype analysis, including that constructed with allele 0 of microsatellite AC008818-1 and SNP45 of the PDE4D gene, was also negative. In conclusion, we found no evidence of association between PDE4D and ALOX5AP genes and the risk of IS in a genetically homogenous population from Sardinia.

The critical role of the intrinsic VSMC proliferation and death programs in injury-induced neointimal hyperplasia

Postangioplasty and in-stent restenosis remain ominous problems in percutaneous coronary intervention where good animal models of restenosis proneness and resistance are needed. We accidentally discovered that the carotid arteries (CAs) of the Harlan and Sasco substrains of Sprague-Dawley rats display drastically different restenosis phenotypes following balloon-induced endothelial denudation. When subjected to balloon injury, Sasco CAs exhibited significantly larger neointimal mass than did Harlan CAs at both days 14 and 32, as evidenced by a higher intima-to-media ratio and a greater number of intimal cells in Sasco CAs. This was due to a greater cell proliferation and to a less vigorous apoptosis of Sasco neointima, as assessed by 5-bromo-2'-deoxyuridine and terminal deoxynucleotidyl transferase-deoxyuridine nick-end labeling staining, respectively. At a cellular level, whereas vascular smooth muscle cells (VSMCs) isolated from Sasco and Harlan CAs were identical in morphology and in propensity to migrate, Sasco VSMCs proliferated more robustly and died far less, suggesting that under the exact same microenvironment, Sasco and Harlan VSMCs respond to growth and noxious stimuli in a drastically different fashion and that Sasco's significantly more robust neointimal proliferation after vascular injury in vivo can be accounted for by these intrinsic differences in VSMCs of these substrains in vitro. Sasco and Harlan Sprague-Dawley rats as well as VSMCs from these rats will prove to be powerful tools to study genes involved in the pathogenesis of restenosis.

Innate immunity has a dual effect on vascular healing: suppression and aggravation of neointimal formation and remodeling post-endotoxin challenge

BACKGROUND

Inflammation is important to vascular repair following injury, modulating neointimal proliferation and remodeling. Previously, we have shown that a low-intensity inflammatory response aggravates neointimal formation following balloon and stent injury. The present study examined whether modulation of the extent and timing of nonspecific inflammation mediates the local vascular response in an additive unidirectional or rather a bidirectional fashion.

METHODS AND RESULTS

Rabbits subjected to denudation and balloon injury of the iliac artery were treated with low (1 microg/kg) or high (100 microg/kg) doses of bacterial endotoxin (LPS) immediately after injury, or with early high-dose LPS administered 3 days prior to injury (preconditioning). Neointimal formation at 28 days was significantly increased in the low-dose group (0.537+/-0.059 mm(2)) as compared with controls (0.3+/-0.03 mm(2)). High-dose LPS did not significantly affect neointimal formation while early high dose significantly reduced neointima (0.296+/-0.033 and 0.194+/-0.025 mm(2), respectively, n=12-14/group). Arterial wall and systemically circulating interleukin-1 beta levels, and monocyte CD14 activation correlated with neointimal formation. Vascular remodeling was accelerated in animals treated with low- or high-dose LPS while not affected in the preconditioned group. Remodeling index inversely correlated with arterial matrix metalloproteinase-2 levels 6 days after injury.

CONCLUSIONS

The extent and timing of nonspecific inflammation that is concurrent with vascular injury can determine different and opposite vascular repair patterns.