F2RL3

Abstract: The association between cigarette smoking and inflammation is well known However, the biological mechanisms behind the association are not fully understood, particularly the role of DNA methylation, which is known to be affected by smoking Using 2-step epigenetic Mendelian randomization, we investigated the role of DNA methylation in the association between cigarette smoking and inflammation In 822 African Americans from the Genetic Epidemiology Network of Arteriopathy, phase 2 (Jackson, Mississippi; 2000-2005), study population, we examined the association of cigarette smoking with DNA methylation using single nucleotide polymorphisms identified in previous genome-wide association studies of cigarette smoking We then investigated the association of DNA methylation with levels of inflammatory markers using cis-methylation quantitative trait loci single nucleotide polymorphisms We found that current smoking status was associated with the DNA methylation levels (M values) of cg03636183 in the coagulation factor II (thrombin) receptor-like 3 gene (F2RL3) (M = -064, 95% confidence interval (CI): -084, -045) and of cg19859270 in the G protein-coupled receptor 15 gene (GPR15) (M = -021, 95% CI: -027, -015) The DNA methylation levels of cg03636183 in F2RL3 were associated with interleukin-18 concentration (-011 pg/mL, 95% CI: -019, -004) These combined negative effects suggest that cigarette smoking increases interleukin-18 levels through the decrease in DNA methylation levels of cg03636183 in F2RL3

Abstract: The aim of this work was to investigate the correlation between methylation of F2RL3 gene and coronary heart disease (CHD) with or without hypertension, secondary cardiovascular events and mortality. Sixty patients with CHD who underwent a cardiovascular rehabilitation program were recruited. Group A included 30 patients with hypertension and CHD, and group B included 30 patients with non-hypertensive CHD, followed-up for more than 8 years. F2RL3 gene methylation was characterized by Sequenom matrix assisted laser desorption ionization time flight mass spectrometry. The correlation between methylation of the F2RL3 gene, hypertension and secondary cardiovascular events and all-cause mortality was analyzed by multivariate Cox, regression models that estimated confounders to control risk ratios. The results showed that during the follow-up, 3 patients in Group A developed non-fatal stroke, 2 patients died of cardiovascular disease, 1 patient died of other causes, and 4 patients in Group B developed non-fatal myocardial infarction. After adjusting for known prognostic factors, Cox model analysis showed that methylation of F2RL3 gene was closely related to hypertension and mortality. After F2RL3 included in the regression model, the correlation between hypertension and all prognostic outcomes increased. In conclusion, the methylation of F2RL3 can affect the prognosis of different types of acute coronary syndrome and is closely related to mortality.

Abstract: Protease-activated receptor 4 (PAR4) is a potent thrombin receptor. Epigenetic control of the F2RL3 locus (which encodes for PAR4) via DNA methylation is associated with both smoking and cardiovascular disease. We examined the association between DNA hypomethylation at F2RL3 and risk of cardiovascular disease, focusing on acute myocardial infarction (AMI) (n=853/2,352 cases/controls). We used in vitro cell models to dissect the role of DNA methylation in regulating expression of F2RL3. We investigated the interplay between F2RL3 DNA methylation and platelet function in human (n=41). Lastly, we used Mendelian randomization to unify observational and functional work by assessing evidence for causal relationships using data from UK Biobank (n=407,141) and CARDIoGRAMplusC4D (n=184,305). Observationally, one standard deviation (SD) decrease in DNA methylation at F2RL3 was associated with a 25% increase in the odds of AMI. In vitro, short-term exposure of cells to cigarette smoke reduced F2RL3 DNA methylation and increased gene expression. Transcriptional assays flagged a role for a CEBP recognition sequence in modulating the enhancer activity of F2RL3 exon 2. Lower DNA methylation at F2RL3 was associated with increased platelet reactivity in human. The estimated casual odds ratio of ischaemic heart disease was 1.03 (95% CI: 1.00, 1.07) per 1 SD decrease in F2RL3 DNA. In conclusion, we show that DNA methylation-dependent platelet activation is part of a complex system of features contributing to cardiovascular health. Tailoring therapeutic intervention to new knowledge of F2RL3/PAR4 function should be explored to ameliorate the detrimental effects of this risk factor on cardiovascular health.

Abstract: Aims In a recent genome-wide study, cytosine bases in the F2RL3 gene, which codes for a protein relevant for cardiovascular physiology, were discovered to be hypomethylated in smokers. We aimed to determine the clinical importance of methylation at the F2RL3 locus. Methods and results In the KAROLA prospective cohort study, 1206 participants of inpatient cardiovascular rehabilitation programmes after experiencing an acute coronary syndrome, myocardial infarction, or coronary intervention were recruited in two clinics in Germany. Active follow-up was conducted over 8 years. Methylation at loci in F2RL3 was characterized by Sequenom matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Associations of methylation and smoking with secondary cardiovascular events, and cause-specific and all-cause mortality were examined by multiple Cox's regression estimating confounder-controlled hazard ratios. A total of 49 non-fatal myocardial infarctions, 41 non-fatal strokes, 64 cardiovascular deaths, and 50 deaths due to other causes were observed. In Cox's models controlling for established prognostic factors, F2RL3 methylation was strongly associated with mortality. Adjusted hazard ratios (95% confidence intervals) for death from cardiovascular, non-cardiovascular, or any cause were 2.32 (0.97–5.58), 5.16 (1.81–14.7), and 3.19 (1.64–6.21) in subjects in the lowest quartile of methylation in comparison to the highest quartile. In contrast, no association was seen with the combined secondary event outcome. The strong association of smoking with all outcomes was markedly attenuated when F2RL3 was included in the regression models. Conclusion The results seem to indicate methylation in F2RL3 to be a potential mediator of the detrimental impact of smoking and to be strongly related to mortality among patients with stable coronary heart disease. Multidisciplinary research efforts are needed to unravel prognostic, preventive, and therapeutic potentials of these pronounced associations.