N6-methyladenosine (m6A) RNA methylation is an emerging area of epigenetics, which is a reversible and dynamic modification mediating by ‘writers’ (methylase, adding methyl groups, METTL3, METTL14, and WTAP), ‘erasers’ (demethylase, deleting methyl groups, FTO and ALKBH5), and ‘readers’ (YTHDF1-3, YTHDC1 and YTHDC2). Recent studies in human, animal models and cell levels have disclosed a critical role of m6A modification in regulating the homeostasis of metabolic processes and cardiovascular function. Evidence from these studies identify m6A as a candidate of biomarker and therapeutic target for metabolic abnormality and cardiovascular diseases (CVD). Comprehensive understanding of the complexity of m6A regulation in metabolic diseases and CVD will be helpful for us to understand the pathogenesis of CVD. In this review, we discuss the regulatory role of m6A in metabolic abnormality and CVD. We will emphasize the clinical relevance of m6A dysregulation in CVD.

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Background: Post-ischemic angiogenesis is critical for blood flow recovery and ischemic tissue repair. N6-methyladenosine (m6A) plays essential roles in numerous biological processes. However, the impact and connected mechanism of m6A on post-ischemic angiogenesis are not fully understood. Methods: AlkB homolog 5 (ALKBH5) was screened out among several methyltransferases and demethylases involved in dynamic m6A regulation. Cardiac microvascular endothelial cells (CMECs) angiogenesis and WNT family member 5A (WNT5A) stability were analyzed upon ALKBH5 overexpression with adenovirus or knockdown with small interfering RNAs in vitro. The blood flow recovery, capillary, and small artery densities were evaluated in adeno-associated virus (AAV)-ALKBH5 overexpression or ALKBH5 knockout (KO) mice in a hind-limb ischemia model. The same experiments were conducted to explore the translational value of transient silencing of ALKBH5 with adenovirus. Results: ALKBH5 was significantly upregulated in hypoxic CMECs and led to a global decrease of m6A level. ALKBH5 overexpression further reduced m6A level in normoxic and hypoxic CMECs, impaired proliferation, migration, and tube formation only in hypoxic CMECs. Conversely, ALKBH5 knockdown preserved m6A levels and promoted angiogenic phenotypes in hypoxic but not in normoxic CMECs. Mechanistically, ALKBH5 regulated WNT5A expression through post-transcriptional mRNA modulation in an m6A-dependent manner, which decreased its stability and subsequently impeded angiogenesis in hypoxic CMECs. Furthermore, ALKBH5 overexpression hindered blood flow

Background: Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous disease, in which its pathogenesis is very complex and far from defined. Here, we explored the N6-methyladenosine (m6A) RNA methylation alteration in patients with HFpEF and mouse model of HFpEF.Methods: In this case–control study, peripheral blood mononuclear cells (PBMCs) were separated from peripheral blood samples obtained from 16 HFpEF patients and 24 healthy controls. The change of m6A regulators was detected by quantitative real-time PCR (RT-PCR). A “two-hit” mouse model of HFpEF was induced by a high-fat diet and drinking water with 0.5 g/L of Nω-nitro-l-arginine methyl ester (L-NAME). MeRIP-seq was used to map transcriptome-wide m6A in control mice and HFpEF mice, and the gene expression was high-throughput detected by RNA-seq.Results: The expression of m6A writers METTL3, METTL4, and KIAA1429; m6A eraser FTO; and reader YTHDF2 was up-regulated in HFpEF patients, compared with health controls. Furthermore, the expression of FTO was also elevated in HFpEF mice. A total of 661 m6A peaks were significantly changed by MeRIP-seq. Gene Ontology (GO) analysis revealed that protein folding, ubiquitin-dependent ERAD pathway, and positive regulation of RNA polymerase II were the three most significantly altered biological processes in HFpEF. The pathways including proteasome, protein processing in the endoplasmic reticulum, and PI3K-Akt signaling pathway were significantly changed in HFpEF by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.Conclusions: The expression pattern of m6A regulators and m6A landscape is changed in HFpEF. This uncovers a new transcription-independent mechanism of translation regulation. Therefore, our data suggest that the modulation of epitranscriptomic processes, such as m6A methylation, might be an interesting target for therapeutic interventions.

Background: This study aimed to verify the effect of soluble guanylate cyclase (sGC) stimulator vericiguat on myocardial ischemia-reperfusion injury and explore its mechanism.Methods: A myocardial ischemia-reperfusion injury model of mice was established and intravenous administration was performed 2 minutes before reperfusion. Triphenyltetrazolium chloride (TTC) staining and echocardiography were used to verify the effect of vericiguat on myocardial ischemia-reperfusion injury in the infarct area, and immunofluorescence was used to observe myocardial pathological changes at different time points after reperfusion. Quantitative proteomics was conducted to analysis the main differentially expressed proteins after drug intervention. The distribution of endothelial cells and sGC after myocardial ischemia-reperfusion injury in mice was observed by immunofluorescence. RNA sequencing of endothelial cells was used to search for differentially expressed molecules. Thioflavin-S staining was used to observe the effect of vericiguat on improving the nonrecurrence phenomenon and reducing the infarct size after reperfusion.Results: The effect of the sGC stimulator vericiguat on myocardial ischemia-reperfusion injury was verified, and myocardial microcirculation significantly increased after drug intervention. Quantitative proteomics found that the protein expression of myocardial tissue in the ischemia-reperfusion area was not significantly different in the drug intervention group, except for increased adenosine triphosphate (ATP) activity. Vericiguat, nitroglycerin, and nitrite did not directly affect apoptosis or cell viability. RNA sequencing of human umbilical vein endothelial cells screened the upregulated antioxidant response.Conclusions: SGC stimulator vericiguat ameliorated myocardial ischemia-reperfusion injury through indirect pathways of improving microcirculation.

Background Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a key enzyme in alcohol metabolism. The ALDH2*2 mutations are found in approximately 45% of East Asians, with 40% being heterozygous (HE) ALDH2*1/*2 and 5% homozygous (HO) ALDH2*2/*2. Studies have shown that HO mice lack cardioprotective effects induced by moderate alcohol consumption. However, the impact of moderate alcohol consumption on cardiac function in HE mice is unknown. Methods In this study, HO, HE, and wild‐type (WT) mice were subjected to a 6‐week moderate alcohol drinking protocol, following which myocardial tissue and cardiomyocytes of the mice were extracted. Results We found that moderate alcohol exposure did not increase mortality, myocardial fibrosis, apoptosis, or inflammation in HE mice, which differs from the effects observed in HO mice. After exposure to the 6‐week alcohol drinking protocol, there was impaired cardiac function, cardiomyocyte contractility, and intracellular Ca2+ homeostasis and mitochondrial function in both HE and HO mice as compared to WT mice. Moreover, these animals showed overt oxidative stress production and increased levels of the activated forms of calmodulin‐dependent protein kinase II (CaMKII) and ryanodine receptor type 2 (RYR2) phosphorylation protein. Conclusion We found that moderate alcohol exposure impaired cardiac function in HE mice, possibly by increasing reactive oxygen species (ROS)/CaMKII/RYR2‐mediated Ca2+ handling abnormalities. Hence, we advocate that people with ALDH2*1/*2 genotypes rigorously avoid alcohol consumption to prevent potential cardiovascular harm induced by moderate alcohol consumption.

Exercise has long been recognized as a beneficial living style for cardiovascular health. It has been applied to be a central component of cardiac rehabilitation for patients with chronic heart failure (CHF), coronary heart disease (CHD), post-acute coronary syndrome (ACS) or primary percutaneous coronary intervention (PCI), post cardiac surgery or transplantation. Although the effect of exercise is multifactorial, in this review, we focus on the specific contribution of regular exercise on the heart and vascular system. We will summarize the known result of clinical findings and possible mechanisms of chronic exercise on the cardiovascular system.