Background-Cytochrome P450 (CYP) 2J2 is expressed in the vascular endothelium and metabolizes arachidonic acid to biologically active epoxyeicosatrienoic acids (EETs). The EETs are potent endogenous vasodilators and inhibitors of vascular inflammation. However, it is not known whether genetic polymorphisms of CYP2J2 are associated with increased cardiovascular risks. Methods and Results-All 9 exons of the CYP2J2 gene and its proximal promoter were sequenced in 132 patients to identify potential variants. Functional consequence of a single nucleotide polymorphism (SNP) in the promoter of CYP2J2 was further evaluated by use of transcription factor-binding and reporter assays. A total of 17 polymorphisms were identified. One of the most relevant polymorphisms in terms of frequency and functional importance is located at Ϫ50 (G-50T) in the proximal promoter of CYP2J2. Screening of 289 patients with coronary artery disease and 255 control subjects revealed 77 individuals with the G-50T SNP (17.3% of coronary artery disease patients, 10.6% of control subjects; Pϭ0.026). The association of the G-50T polymorphism remained significant after adjustment for age, gender, and conventional cardiovascular risk factors (OR, 2.23; 95% CI, 1.04 to 4.79). The G-50T mutation resulted in the loss of binding of the Sp1 transcription factor to the CYP2J2 promoter and resulted in a 48.1Ϯ2.4% decrease in CYP2J2 promoter activity (PϽ0.01). Plasma concentrations of stable EET metabolites were significantly lower in individuals with the G-50T SNP. Conclusions-A functionally relevant polymorphism of the CYP2J2 gene is independently associated with an increased risk of coronary artery disease.
Osteoprotegerin (OPG) antagonizes receptor activator of nuclear factor-kappaB ligand (RANKL), the principal regulator of osteoclasts. Of note, OPG-deficient mice display osteoporosis and arterial calcification. Recently, OPG gene polymorphisms have been associated with osteoporosis and early predictors of cardiovascular disease. In this study, we examined OPG gene polymorphisms in 468 men who had absence of coronary artery disease (CAD) or single-, double-, or triple-vessel disease on coronary angiography. Denaturing gradient gel electrophoresis followed by DNA sequencing revealed nucleotide substitutions 149 T-->C, 163 A-->G, 209 G-->A, 245 T-->G, 950 T-->C (all promoter), 1181 G-->C (exon 1), and 6890 A-->C (intron 4), respectively. Although single polymorphisms were not associated with CAD, linkage of polymorphisms 950 and 1181 revealed that haplotypes were overrepresented in men with CAD (chi(2) = 17.05; P = 0.03) with an increased risk of CAD in carriers of genotypes 950 TC/1181 GC and 950 CC/1181 CC (odds ratio, 1.67; 95% confidence interval, 1.02-2.72; P = 0.04). Furthermore, serum OPG levels were correlated with the presence of a C allele at position 950 (P = 0.02). In summary, linkage of genetic variations of the OPG gene at positions 950 and 1181 may confer an increased risk of CAD in Caucasian men.
Cardiac side effects of the cytostatic agent 5-fluorouracil (5-FU) have an incidence of 1.2-7.6%. Potentially, arrhythmias, myocardial infarction and sudden cardiac death could occur. Life-threatening cardiotoxicity is rarely observed with a frequency <1%. Cardiotoxicity of 5-FU seems to differ from well known effects of other cytostatics, e.g., anthracyclines. Myocardial ischemia was suggested as potential mechanism due to occasionally observed ECG alterations during 5-FU administration. Experimental studies revealed potential mechanisms of cardiotoxicity ranging from direct toxic effects on vascular endothelium involving endothelial NO synthase leading to coronary spasms and endothelium independent vasoconstriction via protein kinase C. In addition, rheological side effects have to be considered. Coronary artery disease is judged to increase the risk of cardiac side effects. Despite lack of prospective trials, verapamil type calcium antagonists as well as nitrates seem to be useful for treatment of 5-FU induced coronary spasms. In addition, modification of the cytostatic regimen has to be considered in patients who had been symptomatic. It could be assumed that 5-FU toxicity is reversible in the majority of cases when acute complications, e.g., arrhythmias, are resolved.
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