Haplotypes and haplotype-pairs of IL-1 beta and IL-6 genes and risk of non fatal myocardial infarction in the Western New York Acute MI Study

Prazosin protects myocardial cells against anoxia-reoxygenation injury via the extracellular signal‑regulated kinase signaling pathway

Ischemic heart disease (including coronary arterial atherosclerosis, or vascular cavity stenosis or occlusion) remains the leading cause of disease-associated mortality worldwide. Prazosin, a receptor blocker of postsynaptic adrenaline, is essential in expanding peripheral arteries, which decreases peripheral vascular resistance, and regulates anti-hypertensive action. However, the mechanisms underlying the effects of prazosin have not been fully elucidated. The aim of the present study was to investigate the protective effects of prazosin on myocardial cells against anoxia-reoxygenation injury in a mouse model. The regulatory effects of prazosin on blood lipid levels and blood pressure were investigated in experimental mice. Furthermore, inflammation responses and oxidative stress in myocardial cells were analyzed in mice treated with prazosin. Apoptotic myocardial cells were investigated in experimental mice treated with prazosin. In addition, apoptotic gene expression levels were evaluated in myocardial cells. Extracellular signal-regulated kinase (ERK) expression and phosphorylation was investigated in myocardial cells in mice with anoxia-reoxygenation injury following prazosin treatment. The activity and expression levels of nuclear factor of activated T cells (NF-AT), activator protein 1 (AP-1) and necrosis factor (NF)-κB were observed in myocardial cells. Furthermore, histological analyses were performed to investigate the benefits of prazosin treatment on anoxia-reoxygenation injury. The results of the present study identified that prazosin decreased the expression levels of inflammatory factors, interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-10 and IL-1 in the serum of mice exhibiting hypoxia/reoxygenation injury. Oxidative stress was observed to be improved and the apoptosis rate was decreased in myocardial cells in anoxia-reoxygenation injury model mice treated with prazosin. ERK expression and phosphorylation was upregulated, and expression levels of NF-AT, AP-1 and NF-κB were downregulated in the myocardial cells of mice treated with prazosin. Blood lipid levels and blood pressure of the anoxia-reoxygenation injury model mice were markedly improved following treatment with prazosin. Histological analysis indicated that the area, circumference fragmentation and segmentation of myocardial cells were significantly improved following prazosin treatment. Thus, these results indicate that prazosin treatment decreases inflammation responses, oxidative stress, and apoptosis of myocardial cells via regulation of the ERK signaling pathway. The findings indicate that prazosin may present as a potential therapeutic agent for the treatment of hypoxia/reoxygenation injury.

Shared polymorphisms and modifiable behavior factors for myocardial infarction and high cholesterol in a retrospective population study

Genetic and environmental (behavior, clinical, and demographic) factors are associated with increased risks of both myocardial infarction (MI) and high cholesterol (HC). It is known that HC is major risk factor that may cause MI. However, whether there are common single nucleotide polymorphism (SNPs) associated with both MI and HC is not firmly established, and whether there are modulate and modified effects (interactions of genetic and known environmental factors) on either HC or MI, and whether these joint effects improve the predictions of MI, is understudied.The purpose of this study is to identify novel shared SNPs and modifiable environmental factors on MI and HC. We assess whether SNPs from a metabolic pathway related to MI may relate to HC; whether there are moderate effects among SNPs, lifestyle (smoke and drinking), HC, and MI after controlling other factors [gender, body mass index (BMI), and hypertension (HTN)]; and evaluate prediction power of the joint and modulate genetic and environmental factors influencing the MI and HC.This is a retrospective study with residents of Erie and Niagara counties in New York with a history of MI or with no history of MI. The data set includes environmental variables (demographic, clinical, lifestyle). Thirty-one tagSNPs from a metabolic pathway related to MI are genotyped. Generalized linear models (GLMs) with imputation-based analysis are conducted for examining the common effects of tagSNPs and environmental exposures and their interactions on having a history of HC or MI.MI, BMI, and HTN are significant risk factors for HC. HC shows the strongest effect on risk of MI in addition to HTN; gender and smoking status while drinking status shows protective effect on MI. rs16944 (gene IL-1β) and rs17222772 (gene ALOX) increase the risks of HC, while rs17231896 (gene CETP) has protective effects on HC either with or without the clinical, behavioral, demographic factors with different effect sizes that may indicate the existence of moderate or modifiable effects. Further analysis with the inclusions of gene-gene and gene-environmental interactions shows interactions between rs17231896 (CETP) and rs17222772 (ALOX); rs17231896 (CETP) and gender. rs17237890 (CETP) and rs2070744 (NOS3) are found to be significantly associated with risks of MI adjusted by both SNPs and environmental factors. After multiple testing adjustments, these effects diminished as expected. In addition, an interaction between drinking and smoking status is significant. Overall, the prediction power in successfully classifying MI status is increased to 80% with inclusions of all significant tagSNPs and environmental factors and their interactions compared with environmental factors only (72%).Having a history of either HC or MI has significant effects on each other in both directions, in addition to HTN and gender. Genes/SNPs identified from this analysis that are associated with HC may be potentially linked to MI, which could be further examined and validated through haplotype-pairs analysis with appropriate population stratification corrections, and function/pathway regulation analysis to eliminate the limitations of the current analysis.

Pro-inflammatory interleukin-1 genotypes potentiate the risk of coronary artery disease and cardiovascular events mediated by oxidized phospholipids and lipoprotein(a)

OBJECTIVES

The aim of this study was to assess the influence of pro-inflammatory interleukin (IL)-1 genotype status on the risk for coronary artery disease (CAD), defined as >50% diameter stenosis, and cardiovascular events mediated by oxidized phospholipids (OxPLs) and lipoprotein (Lp) (a).

BACKGROUND

OxPLs are pro-inflammatory, circulate on Lp(a), and mediate CAD. Genetic variations in the IL-1 region are associated with increased inflammatory mediators.

METHODS

IL-1 genotypes, OxPL on apolipoprotein B-100 (OxPL/apoB), and Lp(a) levels were measured in 499 patients undergoing coronary angiography. The composite genotype termed IL-1(+) was defined by 3 single-nucleotide polymorphisms in the IL-1 gene cluster associated with higher levels of pro-inflammatory cytokines. All other IL-1 genotypes were termed IL-1(-).

RESULTS

Among IL-1(+) patients, the highest quartile of OxPL/apoB was significantly associated with a higher risk for CAD compared with the lowest quartile (odds ratio [OR]: 2.84; p = 0.001). This effect was accentuated in patients age ≤60 years (OR: 7.03; p < 0.001). In IL-1(-) patients, OxPL/apoB levels showed no association with CAD. The interaction was significant for OxPL/apoB (OR: 1.99; p = 0.004) and Lp(a) (OR: 1.96; p < 0.001) in the IL-1(+) group versus the IL-1(-) group in patients age ≤60 years but not in those age >60 years. In IL-1(+) patients age ≤60 years, after adjustment for established risk factors, high-sensitivity C-reactive protein, and Lp(a), OxPL/apoB remained an independent predictor of CAD. IL-1(+) patients above the median OxPL/apoB presented to the cardiac catheterization laboratory a mean of 3.9 years earlier (p = 0.002) and had worse 4-year event-free survival (death, myocardial infarction, stroke, and need for revascularization) compared with other groups (p = 0.006).

CONCLUSIONS

Our study suggests that IL-1 genotype status can stratify population risk for CAD and cardiovascular events mediated by OxPL. These data suggest a clinically relevant biological link between pro-inflammatory IL-1 genotype, oxidation of phospholipids, Lp(a), and genetic predisposition to CAD and cardiovascular events.

Common polymorphisms in the interleukin-6 gene and myocardial infarction risk: a meta-analysis

BACKGROUND

Interleukin-6 (IL-6) plays a critical role in the development and progression of cardiovascular disease. Emerging evidence suggests that two common polymorphisms (-174 G/C and -572 G/C) in the IL-6 gene might have an impact on an individual's susceptibility to myocardial infarction (MI), but individually published results are inconclusive. This meta-analysis aimed to derive a more precise estimation of the relationship between IL-6 -174 G/C and -572 G/C polymorphisms and MI risk.

METHOD

An extensive literary search for relevant studies was conducted in PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, China BioMedicine (CBM), and China National Knowledge Infrastructure (CNKI) databases from their inception through August 1st, 2013. A meta-analysis was then performed using the STATA 12.0 software. The crude odds ratios (OR) with 95% confidence intervals (CI) were calculated.

RESULTS

Eleven case-control studies were included with a total of 10,252 subjects, including 5429 MI patients and 4823 healthy controls. Our meta-analysis results indicated that IL-6 -174 G/C polymorphism may increase the risk of MI (C allele vs. G allele: OR=1.07, 95% CI: 1.01-1.14, p=0.018; GC+CC vs. GG: OR=1.14, 95% CI: 1.04-1.24, p=0.003; respectively). However, our results showed no significant association between IL-6 -572 G/C polymorphism and MI risk (C allele vs. G allele: OR=0.88, 95% CI: 0.75-1.03, p=0.098; GC+CC vs. GG: OR=0.87, 95% CI: 0.70-1.07, p=0.173; respectively). No publication bias was detected in this meta-analysis.

CONCLUSION

The current meta-analysis suggests that IL-6 -174 G/C polymorphism may contribute to MI susceptibility. Thus, detection of IL-6 -174 G/C polymorphisms may be a promising biomarker for the early detection of MI. However, IL-6 -572 G/C polymorphism may not associate with the risk of MI.