Selenium Supplementation Improved Cardiac Functions by Suppressing DNMT2-Mediated GPX1 Promoter DNA Methylation in AGE-Induced Heart Failure

RNA sequencing comparing centenarian and middle-aged women lymphoblastoid cell lines identifies age-related dysregulated expression of genes encoding selenoproteins, heat shock proteins, CD99, and BID

Women typically live longer than men, and constitute the majority of centenarians. We applied RNA-sequencing (RNA-seq) of blood-derived lymphoblastoid cell lines (LCLs) from women aged 60-80 years and centenarians (100-105 years), validated the RNA-seq findings by real-time PCR, and additionally measured the differentially expressed genes in LCLs from young women aged 20-35 years. Top RNA-seq genes with differential expression between the age groups included three selenoproteins (GPX1, SELENOW, SELENOH) and three heat shock proteins (HSPA6, HSPA1A, HSPA1B), with the highest expression in LCLs from young women, indicating that young women are better protected from oxidative stress. The expression of two additional genes, BID encoding BH3-interacting domain death agonist and CD99 encoding CD99 antigen, showed unique age dependence, with similar expression levels in young and centenarian women while exhibiting higher and lower expression levels, respectively, in LCLs from women aged 60-80 years compared with the two other age groups. This age-related differential expression of BID and CD99 suggests elevated inflammation susceptibility in middle-aged women compared with either young or centenarian women. Our findings, once validated with human peripheral blood mononuclear cells and further cell types, may lead to novel healthy aging diagnostics and therapeutics.

Melatonin alleviates aging-related heart failure through melatonin receptor 1A/B knockout in mice

Age-related cardiovascular diseases continue to be important issues that contribute to the societal burden. Unveiling the molecular mechanisms underlying age-related cardiovascular diseases provides novel opportunities to delay aging and facilitate early disease diagnosis and treatment. This study utilized knockout mice lacking melatonin receptors type 1A (MT1) and 1B (MT2). Ultrasonography, pathological staining, and transcriptomics were used to investigate the role of MT1/2 in the hearts of aging mice. Knockout of both receptors decreased ejection fraction and exacerbated fibrosis, inflammation, oxidative stress, and apoptosis levels in aging mice. Our findings indicated that the cardiac function of MT1 knockout mice was more severely affected than that of MT2 knockout mice. Additionally, we observed that intraperitoneal administration of melatonin (20 mg/kg/day for 90 days) ameliorated abnormal cardiac function in aging mice. However, the absence of MT1/2 resulted in the inability of melatonin to improve cardiac function. Our study, utilizing an aging polymerase chain reaction assay and cell experiments, revealed that melatonin receptors potentially influence cardiac function in aging mice through their effects on leukocyte differentiation antigen 14 (CD14) expression. Consequently, melatonin receptors, particularly MT1, are key contributors to cardiac aging, and therapeutic interventions targeting this receptor are promising for delaying the progression of cardiac aging.

Evaluating the link between DIO3-FA27 promoter methylation, biochemical indices, and heart failure progression

BACKGROUND

Heart failure (HF) is a disease that poses a serious threat to individual health, and DNA methylation is an important mechanism in epigenetics, and its role in the occurrence and development of the disease has attracted more and more attention. The aim of this study was to evaluate the link between iodothyronine deiodinase 3 promoter region fragment FA27 (DIO3-FA27) methylation levels, biochemical indices, and HF.

RESULTS

The methylation levels of DIO3-FA27_CpG_11.12 and DIO3-FA27_CpG_23.24 significantly differed in HF patients with different degrees. Multivariate logistic regression analysis indicated that the relative HF risk in the third and fourth quartiles of activated partial thromboplastin time and fibrin degradation products. The results of the restricted cubic spline model showed that the methylation levels of DIO3-FA 27_CpG_11.12 and DIO3-FA 27_CpG_23.24 were associated with coagulation indicators, liver function, renal function, and blood routine.

CONCLUSIONS

Based on the differential analysis of CpG methylation levels based on DIO3-FA27, it was found that biochemical indicators combined with DIO3-FA27 promoter DNA methylation levels could increase the risk of worsening the severity classification of HF patients, which provided a solid foundation and new insights for the study of epigenetic regulation mechanisms in patients with HF.

Epigenetics in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a critical complication that poses a significant threat to the health of patients with diabetes. The intricate pathological mechanisms of DCM cause diastolic dysfunction, followed by impaired systolic function in the late stages. Accumulating researches have revealed the association between DCM and various epigenetic regulatory mechanisms, including DNA methylation, histone modifications, non-coding RNAs, and other epigenetic molecules. Recently, a profound understanding of epigenetics in the pathophysiology of DCM has been broadened owing to advanced high-throughput technologies, which assist in developing potential therapeutic strategies. In this review, we briefly introduce the epigenetics regulation and update the relevant progress in DCM. We propose the role of epigenetic factors and non-coding RNAs (ncRNAs) as potential biomarkers and drugs in DCM diagnosis and treatment, providing a new perspective and understanding of epigenomics in DCM.

Diabetic Retinopathy and Regulation of Mitochondrial Glutathione-Glutathione Peroxidase Axis in Hyperhomocysteinemia

Diabetic patients have elevated homocysteine levels, and hyperhomocysteinemia is shown to exacerbate mitochondrial damage, which plays a central role in diabetic retinopathy. Glutathione peroxidases (GPx) catalyze hydrogen peroxide (H2O2) reduction using glutathione (GSH) as a cofactor. GSH and GPx are mainly cytosolic but are also present in the mitochondria to neutralize H2O2 produced by superoxide dismutase, and in diabetes, they are downregulated. Hyperhomocysteinemia also disrupts the balance between S-adenosyl-L-homocysteine and S-adenosylmethionine (SAM); SAM is also a methyl donor for DNA methylation. The aim of this study was to investigate the role of homocysteine in mitochondrial GSH-GPx1 regulation in diabetic retinopathy. Human retinal endothelial cells in 20 mM D-glucose + high homocysteine were analyzed for ROS, GSH and GPx in the mitochondria, and SAM levels and GPx1 promoter DNA methylation were also studied (5-methylcytosine and MS-PCR). The results were confirmed in the retina from streptozotocin-induced hyperhomocysteinemic (cystathionine-β-synthase-deficient) diabetic mice. High homocysteine exacerbated the glucose-induced decrease in GSH levels and GPx activity in the mitochondria and the downregulation of GPx1 transcripts and further increased SAM levels and GPx1 promoter DNA methylation. Similar results were obtained in a hyperglycemic-hyperhomocysteinemic mouse model. Thus, elevated homocysteine in diabetes hypermethylates GPx1 promoter, thus decreasing the mitochondrial GPx/GSH pool and exacerbating mitochondrial damage. Modulating hyperhomocysteinemia could be a potential therapeutic avenue to target mitochondrial dysfunction in diabetic retinopathy.

An Updated Review on the Significance of DNA and Protein Methyltransferases and De-methylases in Human Diseases: From Molecular Mechanism to Novel Therapeutic Approaches

Epigenetic mechanisms are crucial in regulating gene expression. These mechanisms include DNA methylation and histone modifications, like methylation, acetylation, and phosphorylation. DNA methylation is associated with gene expression suppression; however, histone methylation can stimulate or repress gene expression depending on the methylation pattern of lysine or arginine residues on histones. These modifications are key factors in mediating the environmental effect on gene expression regulation. Therefore, their aberrant activity is associated with the development of various diseases. The current study aimed to review the significance of DNA and histone methyltransferases and demethylases in developing various conditions, like cardiovascular diseases, myopathies, diabetes, obesity, osteoporosis, cancer, aging, and central nervous system conditions. A better understanding of the epigenetic roles in developing diseases can pave the way for developing novel therapeutic approaches for affected patients.

Inflammation in Heart Failure-Future Perspectives

Chronic heart failure is a terminal point of a vast majority of cardiac or extracardiac causes affecting around 1-2% of the global population and more than 10% of the people above the age of 65. Inflammation is persistently associated with chronic diseases, contributing in many cases to the progression of disease. Even in a low inflammatory state, past studies raised the question of whether inflammation is a constant condition, or if it is, rather, triggered in different amounts, according to the phenotype of heart failure. By evaluating the results of clinical studies which focused on proinflammatory cytokines, this review aims to identify the ones that are independent risk factors for heart failure decompensation or cardiovascular death. This review assessed the current evidence concerning the inflammatory activation cascade, but also future possible targets for inflammatory response modulation, which can further impact the course of heart failure.

Epigenetics of methylation modifications in diabetic cardiomyopathy

Type 2 diabetes is one of the most common metabolic diseases with complications including diabetic cardiomyopathy and atherosclerotic cardiovascular disease. Recently, a growing body of research has revealed that the complex interplay between epigenetic changes and the environmental factors may significantly contribute to the pathogenesis of cardiovascular complications secondary to diabetes. Methylation modifications, including DNA methylation and histone methylation among others, are important in developing diabetic cardiomyopathy. Here we summarized the literatures of studies focusing on the role of DNA methylation, and histone modifications in microvascular complications of diabetes and discussed the mechanism underlying these disorders, to provide the guidance for future research toward an integrated pathophysiology and novel therapeutic strategies to treat or prevent this frequent pathological condition.

The roles and mechanisms of epigenetic regulation in pathological myocardial remodeling

Pathological myocardial remodeling was still one of the leading causes of death worldwide with an unmet therapeutic need. A growing number of researchers have addressed the role of epigenome changes in cardiovascular diseases, paving the way for the clinical application of novel cardiovascular-related epigenetic targets in the future. In this review, we summarized the emerged advances of epigenetic regulation, including DNA methylation, Histone posttranslational modification, Adenosine disodium triphosphate (ATP)-dependent chromatin remodeling, Non-coding RNA, and RNA modification, in pathological myocardial remodeling. Also, we provided an overview of the mechanisms that potentially involve the participation of these epigenetic regulation.

DNA Methylation of Patatin-Like Phospholipase Domain-Containing Protein 6 Gene Contributes to the Risk of Intracranial Aneurysm in Males

Objective: This study is aimed to investigate the contribution of patatin-like phospholipase domain-containing protein 6 (PNPLA6) DNA methylation to the risk of intracranial aneurysm (IA) in the Han Chinese population.

Methods: A total of 96 age- and sex-matched participants were recruited to evaluate PNPLA6 methylation via bisulfite pyrosequencing. The PNPLA6 mRNA expression in the plasma was determined using real-time quantitative reverse transcription-polymerase chain reaction. Human primary artery smooth muscle cells (HPCASMC) were used for the in vitro function study.

Results: PNPLA6 methylation was significantly higher in patients with IA than in healthy controls (p < 0.01). Sex group analysis showed that this correlation appeared in the male group (p < 0.01) but not in the female group (p > 0.05). PNPLA6 methylation was significantly associated with age in all participants (r = 0.306, p = 0.003) and in the control group (r = 0.377, p = 0.008) but not in the IA group (r = 0.127, p = 0.402). Furthermore, the PNPLA6 mRNA expression significantly decreased in patients with IA than that in the controls (p = 0.016). PNPLA6 expression was significantly inversely correlated with elevated DNA methylation in participants (r = −0.825, p < 0.0001). In addition, PNPLA6 transcription was significantly enhanced following treatment with 5-aza-2’-deoxycytidine methylation inhibitor in HPCASMC.The receiver operating characteristic analyses of curves showed that the PNPLA6 mean methylation [area under the curve (AUC) = 0.74, p < 0.001] and mRNA expression (AUC = 0.86, p < 0.001) could have a diagnostic value for patients with IA.

Conclusion: Although future functional experiments are required to test our hypothesis, our study demonstrated that PNPLA6 methylation and mRNA expression were significantly associated with the risk of IA; thus, they show potential for use in the early diagnosis of IA.

Epigenetic regulation in cardiovascular disease: mechanisms and advances in clinical trials

Epigenetics is closely related to cardiovascular diseases. Genome-wide linkage and association analyses and candidate gene approaches illustrate the multigenic complexity of cardiovascular disease. Several epigenetic mechanisms, such as DNA methylation, histone modification, and noncoding RNA, which are of importance for cardiovascular disease development and regression. Targeting epigenetic key enzymes, especially the DNA methyltransferases, histone methyltransferases, histone acetylases, histone deacetylases and their regulated target genes, could represent an attractive new route for the diagnosis and treatment of cardiovascular diseases. Herein, we summarize the knowledge on epigenetic history and essential regulatory mechanisms in cardiovascular diseases. Furthermore, we discuss the preclinical studies and drugs that are targeted these epigenetic key enzymes for cardiovascular diseases therapy. Finally, we conclude the clinical trials that are going to target some of these processes.