Optimizing cardiac ischemic preconditioning and postconditioning via epitranscriptional regulation

LncRNA UCA1 enhances NRF2 expression through the m6A pathway to mitigate oxidative stress and ferroptosis in aging cardiomyocytes

To explore the regulatory mechanism of lncRNA UCA1 and NRF2 in cardiomyocyte aging. In this study, we explored how lncRNA UCA1 regulates NRF2 and its effect on cardiomyocyte aging. H9c2 cardiomyocytes were cultured and treated with H2O2 to simulate cardiomyocyte aging in vitro. The expression levels of lncRNA UCA1 and NRF2 in cells were detected using qRT-PCR. Cell viability was assessed using the CCK8 assay, and cell aging was detected via Sa-β-gal staining. The levels of oxidative stress markers (SOD, MDA, ROS) and the expressions of ferroptosis-related proteins (ACSL4, TFR1, FTH1, GPX4) were measured. The regulatory mechanism between UCA1 and NRF2 was investigated using RIP-qPCR. Additionally, changes in m6A modification levels and the expression of m6A modification-related proteins in cells after UCA1 overexpression were analyzed by western blot. Our results indicate that H2O2 treatment significantly downregulated the expression of lncRNA UCA1 and NRF2. UCA1 overexpression promoted H9c2 cell proliferation, inhibited cell aging, increased SOD activity and the expression of FTH1 and GPX4 proteins, and decreased MDA and ROS content as well as ACSL4 and TFR1 protein expression. RIP-qPCR verified that UCA1 can promote the expression of NRF2 in cells. Overexpression of UCA1 significantly increased the expression of the demethylase FTO, leading to a reduction in m6A modification levels. Furthermore, there was significant enrichment between FTO and NRF2, and overexpression of FTO improved the expression of NRF2 protein in cells. Taken together, lncRNA UCA1 inhibits oxidative stress and ferroptosis, thereby preventing cardiomyocyte aging. This protective effect is likely mediated by increasing the expression of demethylase FTO and reducing m6A modification, which promotes the expression of NRF2.

m6A epitranscriptomic modification of inflammation in cardiovascular disease

Cardiovascular disease is currently the number one cause of death endangering human health. There is currently a large body of research showing that the development of cardiovascular disease and its complications is often accompanied by inflammatory processes. In recent years, epitranscriptional modifications have been shown to be involved in regulating the pathophysiological development of inflammation in cardiovascular diseases, with 6-methyladenine being one of the most common RNA transcriptional modifications. In this review, we link different cardiovascular diseases, including atherosclerosis, heart failure, myocardial infarction, and myocardial ischemia-reperfusion, with inflammation and describe the regulatory processes involved in RNA methylation. Advances in RNA methylation research have revealed the close relationship between the regulation of transcriptome modifications and inflammation in cardiovascular diseases and brought potential therapeutic targets for disease diagnosis and treatment. At the same time, we also discussed different cell aspects. In addition, in the article we also describe the different application aspects and clinical pathways of RNA methylation therapy. In summary, this article reviews the mechanism, regulation and disease treatment effects of m6A modification on inflammation and inflammatory cells in cardiovascular diseases in recent years. We will discuss issues facing the field and new opportunities that may be the focus of future research.

A review on the role of RNA methylation in aging-related diseases

Senescence is the underlying mechanism of organism aging and is robustly regulated at the post-transcriptional level. This regulation involves the chemical modifications, of which the RNA methylation is the most common. Recently, a rapidly growing number of studies have demonstrated that methylation is relevant to aging and aging-associated diseases. Owing to the rapid development of detection methods, the understanding on RNA methylation has gone deeper. In this review, we summarize the current understanding on the influence of RNA modification on cellular senescence, with a focus on mRNA methylation in aging-related diseases, and discuss the emerging potential of RNA modification in diagnosis and therapy.

Programmed Release METTL3-14 Inhibitor Microneedle Protects Myocardial Function by Reducing Drp1 m6A Modification-Mediated Mitochondrial Fission

M6A modification is an RNA-important processing event mediated by methyltransferases METTL3 and METTL14 and the demethylases. M6A dynamic changes after myocardial infarction (MI), involved in the massive loss of cardiomyocytes due to hypoxia, as well as the recruitment and activation of myofibroblasts. Balanced mitochondrial fusion and fission are essential to maintain intracardiac homeostasis and reduce poststress myocardial remodeling. Double-layer programmed drug release microneedle (DPDMN) breaks the limitations of existing therapeutic interventions in one period or one type of cells, and multitargeted cellular combination has more potential in MI therapy. By employing hypoxia-ischemic and TGF-β1-induced fibrosis cell models, we found that METTL3-14 inhibition effectively decreased cardiomyocyte death through the reduction of mitochondrial fragmentation and inhibiting myofibrillar transformation. DPDMN treatment of MI in rat models showed improved cardiac function and decreased infarct size and fibrosis level, demonstrating its superior effectiveness. The DPDMN delivers METTL3 inhibitor swiftly in the early phase to rescue dying cardiomyocytes and slowly in the late phase to achieve long-term suppression of fibroblast over proliferation, collagen synthesis, and deposition. RIP assay and mechanistic investigation confirmed that METTL3 inhibition reduced the translation efficiency of Drp1 mRNA by 5'UTR m6A modification, thus decreasing the Drp1 protein level and mitochondrial fragment after hypoxic-ischemic injury. This project investigated the efficacy of DPDMNs-loaded METTL3 inhibitor in MI treatment and the downstream signaling pathway proteins, providing an experimental foundation for the translation of the utility, safety, and versatility of microneedle drug delivery for MI into clinical applications.

RNA methylation in vascular disease: a systematic review

Despite the rise in morbidity and mortality associated with vascular diseases, the underlying pathophysiological molecular mechanisms are still unclear. RNA N6-methyladenosine modification, as the most common cellular mechanism of RNA regulation, participates in a variety of biological functions and plays an important role in epigenetics. A large amount of evidence shows that RNA N6-methyladenosine modifications play a key role in the morbidity caused by vascular diseases. Further research on the relationship between RNA N6-methyladenosine modifications and vascular diseases is necessary to understand disease mechanisms at the gene level and to provide new tools for diagnosis and treatment. In this study, we summarize the currently available data on RNA N6-methyladenosine modifications in vascular diseases, addressing four aspects: the cellular regulatory system of N6-methyladenosine methylation, N6-methyladenosine modifications in risk factors for vascular disease, N6-methyladenosine modifications in vascular diseases, and techniques for the detection of N6-methyladenosine-methylated RNA.

Emerging Roles and Mechanism of m6A Methylation in Cardiometabolic Diseases

Cardiometabolic diseases (CMDs) are currently the leading cause of death and disability worldwide, and their underlying regulatory mechanisms remain largely unknown. N6-methyladenosine (m6A) methylation, the most common and abundant epigenetic modification of eukaryotic mRNA, is regulated by m6A methyltransferase, demethylase, and the m6A binding protein, which affect the transcription, cleavage, translation, and degradation of target mRNA. m6A methylation plays a vital role in the physiological and pathological processes of CMDs. In this review, we summarize the role played by m6A methylation in CMDs, including obesity, hypertension, pulmonary hypertension, ischemic heart disease, myocardial hypertrophy, heart failure, and atherosclerosis. We also describe mechanisms that potentially involve the participation of m6A methylation, such as those driving calcium homeostasis, circadian rhythm, lipid metabolism, autophagy, macrophage response, and inflammation. m6A methylation and its regulators are expected to be targets for the treatment of CMDs.

Amelioration of acute myocardial infarction injury through targeted ferritin nanocages loaded with an ALKBH5 inhibitor

The roles of m⁶A RNA methylation and mitochondrial metabolism in acute myocardial infarction (AMI) remain unclear. In this study, we demonstrated that m⁶A RNA methylation affected ischemia/reperfusion (I/R) injury in AMI through the "Erasers" protein ALKBH5-related metabolic reprogramming, characterized by the inhibition of enzyme activities of the tricarboxylic acid cycle; moreover, a surface-modified bioengineered ferritin nanocage was obtained from Archaeoglobus fulgidus, with a chimeric structure containing 8 lysine residues, SpyTag/SpyCatcher, and the C1q ligand Scarf1, which could disassemble and self-assemble in neutral solutions according to different Mg²⁺ concentrations. The surface-modified bioengineered ferritin nanocage targeted the dying cells in the infarct area under the guidance of Scarf1. These cells were then phagocytosed through recognition of their TfR1 receptor. Lysosomal escape was achieved through the 8 lysine residues on the nanocage, and the nanocage disassembled based on the differences in intracellular and extracellular Mg²⁺ concentrations. Finally, the ALKBH5 inhibitor IOX1 was loaded onto the ferritin nanocage and used in the AMI model, and it was found to effectively improve cardiac function. These results provide a potential strategy for the treatment of AMI in the future. STATEMENT OF SIGNIFICANCE: In acute myocardial infarction (AMI) induced by ischemia/reperfusion injury, m⁶A RNA methylation aggravates the injury through the "Erasers" protein ALKBH5-related metabolic reprogramming. To achieve precise treatment, genetic engineering-based recombinant expression technology was used to obtain a ferritin from Archaeoglobus fulgidus. The obtained ferritin was designated as HAfFtO, and it can disassemble and self-assemble in a neutral solution under different Mg²⁺ concentrations and achieve lysosomal escape. Three G4S linkers were used to connect SpyTag with HAfFtO to synthesize HAfFtO-ST and recombination Scarf1 containing SpyCatcher structure, namely SC-Sf. According to the SpyTag/SpyCatcher technique, HAfFtO-ST and SC-Sf can form a gentle and firm combination, namely HSSS. The ALKBH5 inhibitor IOX1 was loaded on HSSS to form HSSS-I. HSSS-I effectively improved the cardiac function and decreased the infarct size in AMI.

Potential regulatory role of epigenetic RNA methylation in cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide, especially in developing countries. To date, several approaches have been proposed for the prevention and treatment of CVDs. However, the increased risk of developing cardiovascular events that result in hospitalization has become a growing public health concern. The pathogenesis of CVDs has been analyzed from various perspectives. Recent data suggest that regulatory RNAs play a multidimensional role in the development of CVDs. Studies have identified several mRNA modifications that have contributed to the functional characterization of various cardiac diseases. RNA methylation, such as N6-methyladenosine, N1-methyladenosine, 5-methylcytosine, N7-methylguanosine, N4-acetylcytidine, and 2'-O-methylation are novel epigenetic modifications that affect the regulation of cell growth, immunity, DNA damage, calcium signaling, apoptosis, and aging in cardiomyocytes. In this review, we summarize the role of RNA methylation in the pathophysiology of CVDs and the potential of using epigenetics to treat such disorders.

YTHDC1 mitigates ischemic stroke by promoting Akt phosphorylation through destabilizing PTEN mRNA

YTH Domain Containing 1 (YTHDC1) is one of the m⁶A readers that is essential for oocyte development and tumor progression. The role of YTHDC1 in neuronal survival and ischemic stroke is unknown. Here, we found that YTHDC1 was unregulated in the early phase of ischemic stroke. Knockdown of YTHDC1 exacerbated ischemic brain injury and overexpression of YTHDC1 protected rats against brain injury. Mechanistically, YTHDC1 promoted PTEN mRNA degradation to increase Akt phosphorylation, thus facilitating neuronal survival in particular after ischemia. These data identify YTHDC1 as a novel regulator of neuronal survival and modulating m⁶A reader YTHDC1 may provide a potential therapeutic target for ischemic stroke.

m6A RNA Methylation in Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain the leading cause of death and disability worldwide, despite marked improvements in prevention, diagnosis, and early intervention. There is an urgent need to discover more effective therapeutic strategies, which would be facilitated by a more in-depth understanding of CVDs and their underlying molecular mechanisms. Recent advances in knowledge about epigenetic mechanisms, especially RNA methylation, have revealed a close relationship between epigenetic modifications and CVDs and have brought to potential novel targets for diagnosis and treatment. Here, we provide a review of recent studies exploring RNA N⁶-methyladenosine (m⁶A) modification, with particular emphasis on its role in CVDs, such as coronary heart disease, hypertension, cardiac hypertrophy, and heart failure. We also introduce the "life cycle" of m⁶A and its dominant function in several biological processes. Finally, we highlight the prospects of treatment based on interfering with m⁶A, which could have a transformative effect on clinical medicine.

The critical roles of m6A modification in metabolic abnormality and cardiovascular diseases

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.

N6-methyladenosine (m6A) methylation in ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is common during surgery and often results in organ dysfunction. The mechanisms of I/R injury are complex, diverse, and not well understood. RNA methylation is a novel epigenetic modification that is involved in the regulation of various biological processes, such as immunity, response to DNA damage, tumorigenesis, metastasis, stem cell renewal, fat differentiation, circadian rhythms, cell development and differentiation, and cell division. Research on RNA modifications, specifically N6-methyladenosine (m6A), have confirmed that they are involved in the regulation of organ I/R injury. In this review, we summarized current understanding of the regulatory roles and significance of m6A RNA methylation in I/R injury in different organs.