No association of nineteen COX-2 gene variants to preclinical markers of atherosclerosis The Cardiovascular Risk in Young Finns Study

Identification and functional characterisation of DNA methylation differences between East- and West-originating Finns

Eastern and Western Finns show a striking difference in coronary heart disease-related mortality; genetics is a known contributor for this discrepancy. Here, we discuss the potential role of DNA methylation in mediating the discrepancy in cardiometabolic disease-risk phenotypes between the sub-populations. We used data from the Young Finns Study (n = 969) to compare the genome-wide DNA methylation levels of East- and West-originating Finns. We identified 21 differentially methylated loci (FDR < 0.05; Δβ >2.5%) and 7 regions (smoothed FDR < 0.05; CpGs ≥ 5). Methylation at all loci and regions associates with genetic variants (p < 5 × 10-8). Independently of genetics, methylation at 11 loci and 4 regions associates with transcript expression, including genes encoding zinc finger proteins. Similarly, methylation at 5 loci and 4 regions associates with cardiometabolic disease-risk phenotypes including triglycerides, glucose, cholesterol, as well as insulin treatment. This analysis was also performed in LURIC (n = 2371), a German cardiovascular patient cohort, and results replicated for the association of methylation at cg26740318 and DMR_11p15 with diabetes-related phenotypes and methylation at DMR_22q13 with triglyceride levels. Our results indicate that DNA methylation differences between East and West Finns may have a functional role in mediating the cardiometabolic disease discrepancy between the sub-populations.

Methylation status of nc886 epiallele reflects periconceptional conditions and is associated with glucose metabolism through nc886 RNAs

BACKGROUND

Non-coding RNA 886 (nc886) is coded from a maternally inherited metastable epiallele. We set out to investigate the determinants and dynamics of the methylation pattern at the nc886 epiallele and how this methylation status associates with nc886 RNA expression. Furthermore, we investigated the associations between the nc886 methylation status or the levels of nc886 RNAs and metabolic traits in the YFS and KORA cohorts. The association between nc886 epiallele methylation and RNA expression was also validated in induced pluripotent stem cell (iPSC) lines.

RESULTS

We confirm that the methylation status of the nc886 epiallele is mostly binomial, with individuals displaying either a non- or hemi-methylated status, but we also describe intermediately and close to fully methylated individuals. We show that an individual's methylation status is associated with the mother's age and socioeconomic status, but not with the individual's own genetics. Once established, the methylation status of the nc886 epiallele remains stable for at least 25 years. This methylation status is strongly associated with the levels of nc886 non-coding RNAs in serum, blood, and iPSC lines. In addition, nc886 methylation status associates with glucose and insulin levels during adolescence but not with the indicators of glucose metabolism or the incidence of type 2 diabetes in adulthood. However, the nc886-3p RNA levels also associate with glucose metabolism in adulthood.

CONCLUSIONS

These results indicate that nc886 metastable epiallele methylation is tuned by the periconceptional conditions and it associates with glucose metabolism through the expression of the ncRNAs coded in the epiallele region.

Methylation status of nc886 epiallele reflects periconceptional conditions and is associated with glucose metabolism through nc886 RNAs

BACKGROUND

Non-coding RNA 886 (nc886) is coded from a maternally inherited metastable epiallele. We set out to investigate the determinants and dynamics of the methylation pattern at the nc886 epiallele and how this methylation status associates with nc886 RNA expression. Furthermore, we investigated the associations between the nc886 methylation status or the levels of nc886 RNAs and metabolic traits in the YFS and KORA cohorts. The association between nc886 epiallele methylation and RNA expression was also validated in induced pluripotent stem cell (iPSC) lines.

RESULTS

We confirm that the methylation status of the nc886 epiallele is mostly binomial, with individuals displaying either a non- or hemi-methylated status, but we also describe intermediately and close to fully methylated individuals. We show that an individual's methylation status is associated with the mother's age and socioeconomic status, but not with the individual's own genetics. Once established, the methylation status of the nc886 epiallele remains stable for at least 25 years. This methylation status is strongly associated with the levels of nc886 non-coding RNAs in serum, blood, and iPSC lines. In addition, nc886 methylation status associates with glucose and insulin levels during adolescence but not with the indicators of glucose metabolism or the incidence of type 2 diabetes in adulthood. However, the nc886-3p RNA levels also associate with glucose metabolism in adulthood.

CONCLUSIONS

These results indicate that nc886 metastable epiallele methylation is tuned by the periconceptional conditions and it associates with glucose metabolism through the expression of the ncRNAs coded in the epiallele region.

Use of genetic data to guide therapy in arterial disease

There is considerable interindividual variation in the response to antiplatelet and anticoagulant therapies. It has been proposed that this variability in drug response may be attributable to genetic variants. Thus, pharmacogenetics may help to accurately predict response to cardiovascular disease (CVD) therapies in order to maximize drug efficacy, minimize drug toxicity, and to tailor personalized care for these patients. Although the clinical utility of pharmacogenetics is promising, its adoption in clinical practice has been slow. This resistance may stem from sometimes conflicting findings among pharmacogenetic studies. Thus, this review focuses on the genetic determinants of commonly used platelet antagonists and anticoagulants including aspirin, clopidogrel, dabigatran, and warfarin. We also explore the clinical translation of pharmacogenetics in the management of patients with CVD.

Pharmacogenomics of cyclooxygenases

Cyclooxygenases (COX-1 and COX-2) are key enzymes in several physiopathological processes. Many adverse drugs reactions to NSAIDs are attributable to COX-inhibition. The genes coding for these enzymes (PTGS1 and PTGS2) are highly variable, and variations in these genes may underlie the risk of developing, or the clinical evolution of, several diseases and adverse drug reactions. We analyze major variations in the PTGS1 and PTGS2 genes, allele frequencies, functional consequences and population genetics. The most salient clinical associations of PTGS gene variations are related to colorectal cancer and stroke. In many studies, the SNPs interact with NSAIDs use, dietary or environmental factors. We provide an up-to-date catalog of PTGS clinical associations based on case–control studies and genome-wide association studies, and future research suggestions.

Association of cyclooxygenase-2 genetic variant with cardiovascular disease

AIM

A genetic variant (rs20417) of the PTGS2 gene, encoding for COX-2, has been associated with decreased COX-2 activity and a decreased risk of cardiovascular disease (CVD). However, this genetic association and the role of COX-2 in CVD remain controversial.

METHODS AND RESULTS

The association of rs20417 with CVD was prospectively explored in 49 232 subjects (ACTIVE-A, CURE, epiDREAM/DREAM, ONTARGET, RE-LY, and WGHS) and the effect of potentially modifiable risk factors on the genetic association was further explored in 9363 INTERHEART participants. The effect of rs20417 on urinary thromboxane and prostacyclin metabolite concentrations was measured in 117 healthy individuals. Carriage of the rs20417 minor allele was associated with a decreased risk of major CVD outcomes (OR = 0.78, 95% CI: 0.70-0.87; P = 1.2 × 10(-5)). The genetic effect was significantly stronger in aspirin users (OR: 0.74, 95% CI: 0.64-0.84; P = 1.20 × 10(-5)) than non-users (OR: 0.87, 95% CI: 0.72-1.06; P = 0.16) (interaction P-value: 0.0041). Among patients with previous coronary artery disease (CAD), rs20417 carriers had a stronger protective effect on risk of major adverse events when compared with individuals without previous CAD (interaction P-value: 0.015). Carriers had significantly lower urinary levels of thromboxane (P = 0.01) and prostacyclin (P = 0.01) metabolites when compared with non-carriers.

CONCLUSION

The rs20417 polymorphism is associated with a reduced risk of major cardiovascular events and lower levels of thromboxane and prostacyclin. Our results suggest that a genetic decrease in COX-2 activity may be beneficial with respect to CVD risk, especially, in higher risk patients on aspirin.