New genetic variants associated with major adverse cardiovascular events in patients with acute coronary syndromes and treated with clopidogrel and aspirin

The Physiological and Pathological Role of Acyl-CoA Oxidation

Fatty acid metabolism, including β-oxidation (βOX), plays an important role in human physiology and pathology. βOX is an essential process in the energy metabolism of most human cells. Moreover, βOX is also the source of acetyl-CoA, the substrate for (a) ketone bodies synthesis, (b) cholesterol synthesis, (c) phase II detoxication, (d) protein acetylation, and (d) the synthesis of many other compounds, including N-acetylglutamate-an important regulator of urea synthesis. This review describes the current knowledge on the importance of the mitochondrial and peroxisomal βOX in various organs, including the liver, heart, kidney, lung, gastrointestinal tract, peripheral white blood cells, and other cells. In addition, the diseases associated with a disturbance of fatty acid oxidation (FAO) in the liver, heart, kidney, lung, alimentary tract, and other organs or cells are presented. Special attention was paid to abnormalities of FAO in cancer cells and the diseases caused by mutations in gene-encoding enzymes involved in FAO. Finally, issues related to α- and ω- fatty acid oxidation are discussed.

Non-Random Enrichment of Single-Nucleotide Polymorphisms Associated with Clopidogrel Resistance within Risk Loci Linked to the Severity of Underlying Cardiovascular Diseases: The Role of Admixture

Cardiovascular disease (CVD) is one of the leading causes of death in Puerto Rico, where clopidogrel is commonly prescribed to prevent ischemic events. Genetic contributors to both a poor clopidogrel response and the severity of CVD have been identified mainly in Europeans. However, the non-random enrichment of single-nucleotide polymorphisms (SNPs) associated with clopidogrel resistance within risk loci linked to underlying CVDs, and the role of admixture, have yet to be tested. This study aimed to assess the possible interaction between genetic biomarkers linked to CVDs and those associated with clopidogrel resistance among admixed Caribbean Hispanics. We identified 50 SNPs significantly associated with CVDs in previous genome-wide association studies (GWASs). These SNPs were combined with another ten SNPs related to clopidogrel resistance in Caribbean Hispanics. We developed Python scripts to determine whether SNPs related to CVDs are in close proximity to those associated with the clopidogrel response. The average and individual local ancestry (LAI) within each locus were inferred, and 60 random SNPs with their corresponding LAIs were generated for enrichment estimation purposes. Our results showed no CVD-linked SNPs in close proximity to those associated with the clopidogrel response among Caribbean Hispanics. Consequently, no genetic loci with a dual predictive role for the risk of CVD severity and clopidogrel resistance were found in this population. Native American ancestry was the most enriched within the risk loci linked to CVDs in this population. The non-random enrichment of disease susceptibility loci with drug-response SNPs is a new frontier in Precision Medicine that needs further attention.

Characterization of Systemic and Culprit-Coronary Artery miR-483-5p Expression in Chronic CAD and Acute Myocardial Infarction Male Patients

Coronary artery disease (CAD) is the leading cause of mortality worldwide. In chronic and myocardial infarction (MI) states, aberrant levels of circulating microRNAs compromise gene expression and pathophysiology. We aimed to compare microRNA expression in chronic-CAD and acute-MI male patients in peripheral blood vasculature versus coronary arteries proximal to a culprit area. Blood from chronic-CAD, acute-MI with/out ST segment elevation (STEMI/NSTEMI, respectively), and control patients lacking previous CAD or having patent coronary arteries was collected during coronary catheterization from peripheral arteries and from proximal culprit coronary arteries aimed for the interventions. Random coronary arterial blood was collected from controls; RNA extraction, miRNA library preparation and Next Generation Sequencing followed. High concentrations of microRNA-483-5p (miR-483-5p) were noted as 'coronary arterial gradient' in culprit acute-MI versus chronic-CAD (p = 0.035) which were similar to controls versus chronic-CAD (p < 0.001). Meanwhile, peripheral miR-483-5p was downregulated in acute-MI and chronic-CAD, compared with controls (1.1 ± 2.2 vs. 2.6 ± 3.3, respectively, p < 0.005). A receiver operating characteristic curve analysis for miR483-5p association with chronic CAD demonstrated an area under the curve of 0.722 (p < 0.001) with 79% sensitivity and 70% specificity. Using in silico gene analysis, we detected miR-483-5p cardiac gene targets, responsible for inflammation (PLA2G5), oxidative stress (NUDT8, GRK2), apoptosis (DNAAF10), fibrosis (IQSEC2, ZMYM6, MYOM2), angiogenesis (HGSNAT, TIMP2) and wound healing (ADAMTS2). High miR-483-5p 'coronary arterial gradient' in acute-MI, unnoticed in chronic-CAD, suggests important local mechanisms for miR483-5p in CAD in response to local myocardial ischemia. MiR-483-5p may have an important role as a gene modulator for pathologic and tissue repair states, is a suggestive biomarker, and is a potential therapeutic target for acute and chronic cardiovascular disease.

COX-1, COX-2 and CYP2C19 variations may be related to cardiovascular events due to acetylsalicylic acid resistance

BACKGROUND

In some stent implanted patients, cardiovascular events (CE) may occur. Acetylsalicylic acid (ASA) is routinely administered to these patients in order to prevent the occurrence of CE. CE may be related to gene variations which cause ASA resistance (AR). Therefore, it was aimed to investigate the relationship between COX-1, COX-2, CYP2C9 and CYP2C19 variations with CE due to AR.

MATERIALS AND RESULTS

Seventy-four stent implanted patients, using 100 mg of ASA per day during five years were enrolled into the study. Following stent implantation, thirty-eight patients who had a CE within five years due to AR and 36 patients without CE were enrolled in patient and control group, respectively. AR was confirmed by platelet aggregation testing. After DNA isolation from blood; COX-1, COX-2, CYP2C19 and CYP2C9 variations were investigated with real-time polymerase chain reaction. At the end of this study, heterozygous genotype of COX-1 was found statistically high in patients whereas heterozygous genotype of CYP2C19*17 was found statistically high in controls. The presence of C and G allele in COX-1 and COX-2 were found statistically high in patients, respectively. The presence of T allele in CYP2C19*17 was found statistically high in controls. Heterozygous genotype of COX-1 variation was found statistically high in patients who have AR. Additionally heterozygous genotype of CYP2C19*17 was found statistically high in patients who have low thrombosis risk.

CONCLUSIONS

COX-1 and COX-2 gene mutations may increase the risk of CE due to AR whereas CYP2C19*17 may have a protective effect in this process.