Catechol-O-methyltransferase promoter hypomethylation is associated with the risk of coronary heart disease

Sex Differences in Opioid Response Linked to OPRM1 and COMT genes DNA Methylation/Genotypes Changes in Patients with Chronic Pain

Analgesic-response variability in chronic noncancer pain (CNCP) has been reported due to several biological and environmental factors. This study was undertaken to explore sex differences linked to OPRM1 and COMT DNA methylation changes and genetic variants in analgesic response. A retrospective study with 250 real-world CNCP outpatients was performed in which data from demographic, clinical, and pharmacological variables were collected. DNA methylation levels (CpG island) were evaluated by pyrosequencing, and their interaction with the OPRM1 (A118G) and COMT (G472A) gene polymorphisms was studied. A priori-planned statistical analyses were conducted to compare responses between females and males. Sex-differential OPRM1 DNA methylation was observed to be linked to lower opioid use disorder (OUD) cases for females (p = 0.006). Patients with lower OPRM1 DNA methylation and the presence of the mutant G-allele reduced opioid dose requirements (p = 0.001), equal for both sexes. Moreover, COMT DNA methylation levels were negatively related to pain relief (p = 0.020), quality of life (p = 0.046), and some adverse events (probability > 90%) such as constipation, insomnia, or nervousness. Females were, significantly, 5 years older with high anxiety levels and a different side-effects distribution than males. The analyses demonstrated significant differences between females and males related to OPRM1 signalling efficiency and OUD, with a genetic-epigenetic interaction in opioid requirements. These findings support the importance of sex as a biological variable to be factored into chronic pain-management studies.

Radiation-induced cardiovascular disease: an overlooked role for DNA methylation?

Radiotherapy in cancer treatment involves the use of ionizing radiation for cancer cell killing. Although radiotherapy has shown significant improvements on cancer recurrence and mortality, several radiation-induced adverse effects have been documented. Of these adverse effects, radiation-induced cardiovascular disease (CVD) is particularly prominent among patients receiving mediastinal radiotherapy, such as breast cancer and Hodgkin's lymphoma patients. A number of mechanisms of radiation-induced CVD pathogenesis have been proposed such as endothelial inflammatory activation, premature endothelial senescence, increased ROS and mitochondrial dysfunction. However, current research seems to point to a so-far unexamined and potentially novel involvement of epigenetics in radiation-induced CVD pathogenesis. Firstly, epigenetic mechanisms have been implicated in CVD pathophysiology. In addition, several studies have shown that ionizing radiation can cause epigenetic modifications, especially DNA methylation alterations. As a result, this review aims to provide a summary of the current literature linking DNA methylation to radiation-induced CVD and thereby explore DNA methylation as a possible contributor to radiation-induced CVD pathogenesis.

Aberrant DNA methylation and miRNAs in coronary artery diseases and stroke: a systematic review

Coronary artery disease (CAD) and ischemic stroke are the two most predominant forms of cardiovascular diseases (CVDs) caused by genetic, epigenetic and environmental risk factors. Although studies on the impact of 'epigenetics' in CVDs is not new, its effects are increasingly being realized as a key regulatory determinant that may drive predisposition, pathophysiology and therapeutic outcome. The most widely studied epigenetic risk factors are regulated by DNA methylation and miRNA expression. To keep pace with growing developments and discoveries, a comprehensive review was performed using Pubmed, Science Direct and Scopus databases to highlight the role of DNA methylation and miRNAs in CAD and stroke subjects. Network analysis was performed using ClueGO software and miRTargetLink database. We identified 32 studies of DNA methylation on CAD and stroke, of which, 6 studies showed differences in global DNA methylation, 10 studies reported the genome-wide difference in DNA methylation and 16 studies demonstrated altered DNA methylation at 14 candidate loci. The network analysis showed positive regulation of nitric oxide biosynthetic process, homocysteine metabolic process and negative regulation of lipid storage. About, 155 miRNAs were associated with CAD, stroke and related phenotypes in 83 studies. Interestingly, mir-223 hypomethylation and altered expression were associated with cerebral infarction and stroke. The target prediction for 18 common miRNAs between CAD and stroke showed strong interaction with SP3 and SP1 genes. This systematic review addresses the present knowledge on DNA methylation and miRNAs in CAD and stroke, whose abnormal regulation has been implicated in etiology or progression of the diseases.

A male-specific association between AGTR1 hypermethylation and coronary heart disease

The AGTR1 gene encodes angiotensin II receptor type 1, which is involved in cardiovascular diseases such as coronary heart disease (CHD). In the current study, we analyzed AGTR1 promoter methylation level in a Han Chinese population by SYBR green-based quantitative methylation-specific PCR (qMSP). We collected blood samples from 761 CHD patients and 398 non-CHD controls at the Ningbo First Hospital. A data mining analysis was also performed to explore the association between AGTR1 methylation and AGTR1 gene expression, using datasets from the cBioPortal for Cancer Genomics and the Gene Expression Omnibus (GEO) database. Our results showed a significantly higher percentage of methylated reference (PMR) of AGTR1 in male CHD patients compared with male non-CHD controls (median PMR: 2.12% vs. 0.59%, p = 0.037). The data mining analysis showed that AGTR1 expression was significantly increased in human hepatoma HepG2 cells treated with the demethylation agent 5-aza-2’-deoxycytidine (fold = 3.12, p = 0.009). Further data mining analysis using the cholangiocarcinoma (TCGA, PanCancer Atlas) data indicated an inverse association between AGTR1 methylation and AGTR1 expression (r = -0.595, p = 1.29E-04). Overall, our results suggest that AGTR1 methylation is involved in the regulation of AGTR1 gene expression and that AGTR1 hypermethylation is associated with CHD in males. These findings may provide new clues about the pathogenesis of CHD.

Gout in males: a possible role for COMT hypomethylation

OBJECTIVE

Gout is a common inflammatory disease, and the prevalence of gout in men is significantly higher than in women. Catechol-O-methyltransferase (COMT) regulates dopamine activity and metabolism, thereby participating in the uric acid metabolism, which in turn affects the occurrence of gout. Our study aimed to investigate the association between COMT methylation and gout in men.

METHODS

This study involved 57 male gout patients and 103 age-matched healthy men. We used quantitative methylation-specific polymerase chain reaction (qMSP) to determine DNA methylation levels in the blood. The COMT methylation level was represented by the percentage of methylation reference (PMR).

RESULTS

Our results showed that COMT methylation levels were significantly lower in gout patients than in the control group (median PMR 9.50 vs 31.34, p = 3E-5). The area under the curve (AUC) was 0.701 (95% CI 0.611-0.790, p = 2.7E-5) with a sensitivity of 68% and a specificity of 68.4%.

CONCLUSION

Our study found that there was a significant correlation between COMT hypomethylation and the risk of gout in males, and this provides an epigenetic mechanism of COMT in gout. COMT hypomethylation might be used as a potential diagnostic biomarker for gout in the future.

Association between DNA methylation and coronary heart disease or other atherosclerotic events: A systematic review

BACKGROUND AND AIMS

The aim of this study was to perform a systematic review of the association between DNA methylation and coronary heart disease (CHD) or related atherosclerotic traits.

METHODS

A systematic review was designed. The condition of interest was DNA methylation, and the outcome was CHD or other atherosclerosis-related traits. Three DNA methylation approaches were considered: global methylation, candidate-gene, and epigenome-wide association studies (EWAS). A functional analysis was undertaken using the Ingenuity Pathway Analysis software.

RESULTS

In total, 51 articles were included in the analysis: 12 global methylation, 34 candidate-gene and 11 EWAS, with six studies using more than one approach. The results of the global methylation studies were inconsistent. The candidate-gene results were consistent for some genes, suggesting that hypermethylation in ESRα, ABCG1 and FOXP3 and hypomethylation in IL-6 were associated with CHD. The EWAS identified 84 genes showing differential methylation associated with CHD in more than one study. The probability of these findings was <1.37·10^-5. One third of these genes have been related to obesity in genome-wide association studies. The functional analysis identified several diseases and functions related to these set of genes: inflammatory, metabolic and cardiovascular disease.

CONCLUSIONS

Global DNA methylation seems to be not associated with CHD. The evidence from candidate-gene studies was limited. The EWAS identified a set of 84 genes highlighting the relevance of obesity, inflammation, lipid and carbohydrate metabolism in CHD. This set of genes could be prioritized in future studies assessing the role of DNA methylation in CHD.