DNA methyltransferase 1 (DNMT1) suppresses mitophagy and aggravates heart failure via the microRNA-152-3p/ETS1/RhoH axis

Epigenetic modifications and emerging therapeutic targets in cardiovascular aging and diseases

The complex mechanisms underlying the development of cardiovascular diseases remain not fully elucidated. Epigenetics, which modulates gene expression without DNA sequence changes, is shedding light on these mechanisms and their heritable effects. This review focus on epigenetic regulation in cardiovascular aging and diseases, detailing specific epigenetic enzymes such as DNA methyltransferases (DNMTs), histone acetyltransferases (HATs), and histone deacetylases (HDACs), which serve as writers or erasers that modify the epigenetic landscape. We also discuss the readers of these modifications, such as the 5-methylcytosine binding domain proteins, and the erasers ten-eleven translocation (TET) proteins. The emerging role of RNA methylation, particularly N6-methyladenosine (m6A), in cardiovascular pathogenesis is also discussed. We summarize potential therapeutic targets, such as key enzymes and their inhibitors, including DNMT inhibitors like 5-azacytidine and decitabine, HDAC inhibitors like belinostat and givinotide, some of which have been approved by the FDA for various malignancies, suggesting their potential in treating cardiovascular diseases. Furthermore, we highlight the role of novel histone modifications and their associated enzymes, which are emerging as potential therapeutic targets in cardiovascular diseases. Thus, by incorporating the recent studies involving patients with cardiovascular aging and diseases, we aim to provide a more detailed and updated review that reflects the advancements in the field of epigenetic modification in cardiovascular diseases.

Epigenetic regulation of sex dimorphism in cardiovascular health

Cardiovascular diseases (CVDs) remain the leading cause of morbidity and mortality, affecting people of all races, ages, and sexes. Substantial sex dimorphism exists in the prevalence, manifestation, and outcomes of CVDs. Understanding the role of sex hormones as well as sex-hormone-independent epigenetic mechanisms could play a crucial role in developing effective and sex-specific cardiovascular therapeutics. Existing research highlights significant disparities in sex hormones, epigenetic regulators, and gene expression related to cardiac health, emphasizing the need for a nuanced understanding of these variations between men and women. Despite these differences, current treatment approaches for CVDs often lack sex-specific considerations. A pivotal shift toward personalized medicine, informed by comprehensive insights into sex-specific DNA methylation, histone modifications, and non-coding RNA dynamics, holds the potential to revolutionize CVD management. By understanding sex-specific epigenetic complexities, independent of sex hormone influence, future cardiovascular research can be tailored to achieve effective diagnostic and therapeutic interventions for both men and women. This review summarizes the current knowledge and gaps in epigenetic mechanisms and sex dimorphism implicated in CVDs.

The potential of RNA methylation in the treatment of cardiovascular diseases

RNA methylation has emerged as a dynamic regulatory mechanism that impacts gene expression and protein synthesis. Among the known RNA methylation modifications, N6-methyladenosine (m6A), 5-methylcytosine (m5C), 3-methylcytosine (m3C), and N7-methylguanosine (m7G) have been studied extensively. In particular, m6A is the most abundant RNA modification and has attracted significant attention due to its potential effect on multiple biological processes. Recent studies have demonstrated that RNA methylation plays an important role in the development and progression of cardiovascular disease (CVD). To identify key pathogenic genes of CVD and potential therapeutic targets, we reviewed several common RNA methylation and summarized the research progress of RNA methylation in diverse CVDs, intending to inspire effective treatment strategies.

Mechanism of action of miR-15a-5p and miR-152-3p in paraquat-induced pulmonary fibrosis through Wnt/β-catenin signaling mediation

Background

miRNAs are small, conserved, single-stranded non-coding RNA that are typically transported by exosomes for their functional roles. The therapeutic potential of exosomal miRNAs has been explored in various diseases including breast cancer, pancreatic cancer, cholangiocarcinoma, skin diseases, Alzheimer's disease, stroke, and glioma. Pathophysiological processes such as cellular inflammation, apoptosis, necrosis, immune dysfunction, and oxidative stress are closely associated with miRNAs. Internal and external factors such as tissue ischemia, hypoxia, pathogen infection, and endotoxin exposure can trigger these reactions and are linked to miRNAs. Paraquat-induced fibrosis is a protracted process that may not manifest immediately after injury but develops during bodily recovery, providing insights into potential miRNA intervention treatments.

Rationale

These findings could potentially be applied for further pharmaceutical research and clinical therapy of paraquat-induced pulmonary fibrosis, and are likely to be of great interest to clinicians involved in lung fibrosis research.

Methodology

Through a literature review, we identified an association between miR-15a-5p and miR-152-3p and their involvement in the Wnt signaling pathway. This allowed us to deduce the molecular mechanisms underlying regulatory interactions involved in paraquat-induced lung fibrosis.

Results

miR-15a-5p and miR-152-3p play roles in body repair processes, and pulmonary fibrosis can be considered a form of reparative response by the body. Although the initial purpose of fibrotic repair is to restore normal body function, excessive tissue fibrosis, unlike scar formation following external skin trauma, can significantly and adversely affect the body. Modulating the Wnt/β-catenin signaling pathway is beneficial in alleviating tissue fibrosis in various diseases.

Conclusions

In this study, we delineate the association between miR-15a-5p and miR-152-3p and the Wnt/β-catenin signaling pathway, presenting a novel concept for addressing paraquat-induced pulmonary fibrosis.

The role and mechanism of epigenetics in anticancer drug-induced cardiotoxicity

Cardiovascular disease is the main factor contributing to the global burden of diseases, and the cardiotoxicity caused by anticancer drugs is an essential component that cannot be ignored. With the development of anticancer drugs, the survival period of cancer patients is prolonged; however, the cardiotoxicity caused by anticancer drugs is becoming increasingly prominent. Currently, cardiovascular disease has emerged as the second leading cause of mortality among long-term cancer survivors. Anticancer drug-induced cardiotoxicity has become a frontier and hot topic. The discovery of epigenetics has given the possibility of environmental changes in gene expression, protein synthesis, and traits. It has been found that epigenetics plays a pivotal role in promoting cardiovascular diseases, such as heart failure, coronary heart disease, and hypertension. In recent years, increasing studies have underscored the crucial roles played by epigenetics in anticancer drug-induced cardiotoxicity. Here, we provide a comprehensive overview of the role and mechanisms of epigenetics in anticancer drug-induced cardiotoxicity.

Molecular mechanisms in regulation of autophagy and apoptosis in view of epigenetic regulation of genes and involvement of liquid-liquid phase separation

Cellular physiology is critically regulated by multiple signaling nexuses, among which cell death mechanisms play crucial roles in controlling the homeostatic landscape at the tissue level within an organism. Apoptosis, also known as programmed cell death, can be induced by external and internal stimuli directing the cells to commit suicide in unfavourable conditions. In contrast, stress conditions like nutrient deprivation, infection and hypoxia trigger autophagy, which is lysosome-mediated processing of damaged cellular organelle for recycling of the degraded products, including amino acids. Apparently, apoptosis and autophagy both are catabolic and tumor-suppressive pathways; apoptosis is essential during development and cancer cell death, while autophagy promotes cell survival under stress. Moreover, autophagy plays dual role during cancer development and progression by facilitating the survival of cancer cells under stressed conditions and inducing death in extreme adversity. Despite having two different molecular mechanisms, both apoptosis and autophagy are interconnected by several crosslinking intermediates. Epigenetic modifications, such as DNA methylation, post-translational modification of histone tails, and miRNA play a pivotal role in regulating genes involved in both autophagy and apoptosis. Both autophagic and apoptotic genes can undergo various epigenetic modifications and promote or inhibit these processes under normal and cancerous conditions. Epigenetic modifiers are uniquely important in controlling the signaling pathways regulating autophagy and apoptosis. Therefore, these epigenetic modifiers of both autophagic and apoptotic genes can act as novel therapeutic targets against cancers. Additionally, liquid-liquid phase separation (LLPS) also modulates the aggregation of misfolded proteins and provokes autophagy in the cytosolic environment. This review deals with the molecular mechanisms of both autophagy and apoptosis including crosstalk between them; emphasizing epigenetic regulation, involvement of LLPS therein, and possible therapeutic approaches against cancers.

Reconstituted Extracellular Vesicles from Human Platelets Decrease Viral Myocarditis in Mice

Patients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease-specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human-platelet-derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)-like module-containing mucin-like hormone receptor-like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll-like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL-1β), transforming growth factor-beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7-9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T-cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

Ginsenoside Rb2 improves heart failure by down-regulating miR-216a-5p to promote autophagy and inhibit apoptosis and oxidative stress

BACKGROUND

Ginsenoside Rb2 is beneficial in cardiovascular disease treatment, yet its role in heart failure (HF) is obscure. This study aimed to investigate the effect and mechanism of ginsenoside Rb2 on HF.

METHODS

The left anterior descending branch-ligated HF rat model and oxygen-glucose deprivation/reoxygenation (OGD/R) H9c2 cell model were constructed. Ginsenoside Rb2 were applied for intervention. Heart function indexes, miR-216a-5p expression, autophagy, oxidative stress, apoptosis, cell morphology, and proliferation were detected to explore the effect of ginsenoside Rb2 on HF. Overexpression of miR-216a-5p was employed to explore the specific mechanism of ginsenoside Rb2 on HF.

RESULTS

Ginsenoside Rb2 improved the heart function of HF rats, including the reduction of heart rate, LVEDP, and heart weight/body weight ratio, and the increase of LVSP, +dP/dtmax, -dP/dtmax, LVEF, and LVFS. It also down-regulated miR-216a-5p expression and enhanced OGD/R-induced cardiomyocyte viability. Ginsenoside Rb2 up-regulated Bcl2, LC3B II/I, and Beclin1, and down-regulated Bax, Caspase-3, and p62 in the myocardium of HF rats and OGD/R-induced H9c2 cells. Moreover, ginsenoside Rb2 increased the levels of SOD and CAT, but decreased the levels of MDA and ROS in the myocardium of HF rats and OGD/R-induced H9c2 cells. However, overexpression of miR-216a-5p promoted the apoptosis and oxidative stress of cardiomyocytes and inhibited autophagy, thus reversing the therapeutic effect of ginsenoside Rb2 on HF in vivo and in vitro.

CONCLUSION

Ginsenoside Rb2 demonstrated potential as a therapeutic intervention for HF by enhancing autophagy and reducing apoptosis and oxidative stress through miR-216a-5p downregulation. Further research could explore its application in clinical trials and investigate the complex mechanism networks underlying its effects.

Inhibiting mir-34a-5p regulates doxorubicin-induced autophagy disorder and alleviates myocardial pyroptosis by targeting Sirt3-AMPK pathway

Doxorubicin (DOX) is a commonly used chemotherapy drug widely applied in various cancers such as breast cancer, leukemia, and sarcomas. However, its usage is limited by cardiotoxicity. Additionally, the cardiac toxicity of DOX accumulates with dose and duration, making it imperative to identify therapeutic targets for DOX-induced cardiomyopathy (DIC). It has been reported that miRNAs are involved in the progression of DIC. Mir-34a-5p has been identified as an early diagnostic marker for DIC. While studies have shown the involvement of mir-34a-5p in DIC apoptosis, it has not been validated in animal models, nor has the potential improvement of DIC by inhibiting mir-34a-5p been confirmed. Autophagy and pyroptosis are key factors in the development of DIC and can serve as therapeutic targets for its treatment. In this study, we found that mir-34a-5p was upregulated in the heart after DOX treatment and that the inhibition of mir-34-5p reduced autophagy and pyroptosis in DIC. We also found that the inhibition of mir-34a-5p inhibited pyroptosis by regulating autophagy and reducing mitochondrial reactive oxygen species. Moreover, we identified Sirtuin3 (Sirt3) as a target gene of mir-34a-5p using a double-luciferase reporter assay. overexpression Sirt3 reduced pyroptosis by alleviating autophagy. Our research findings suggest that inhibiting mir-34a-5p has a beneficial role in alleviating autophagy and pyroptosis in DIC. This provides therapeutic prospects for treating DIC.

Insights into DNMT1 and programmed cell death in diseases

DNMT1 (DNA methyltransferase 1) is the predominant member of the DNMT family and the most abundant DNMT in various cell types. It functions as a maintenance DNMT and is involved in various diseases, including cancer and nervous system diseases. Programmed cell death (PCD) is a fundamental mechanism that regulates cell proliferation and maintains the development and homeostasis of multicellular organisms. DNMT1 plays a regulatory role in various types of PCD, including apoptosis, autophagy, necroptosis, ferroptosis, and others. DNMT1 is closely associated with the development of various diseases by regulating key genes and pathways involved in PCD, including caspase 3/7 activities in apoptosis, Beclin 1, LC3, and some autophagy-related proteins in autophagy, glutathione peroxidase 4 (GPX4) and nuclear receptor coactivator 4 (NCOA4) in ferroptosis, and receptor-interacting protein kinase 1-receptor-interacting protein kinase 3-mixed lineage kinase domain-like protein (RIPK1-RIPK3-MLKL) in necroptosis. Our study summarizes the regulatory relationship between DNMT1 and different types of PCD in various diseases and discusses the potential of DNMT1 as a common regulatory hub in multiple types of PCD, offering a perspective for therapeutic approaches in disease.

The Role of Clonal Hematopoiesis of Indeterminant Potential and DNA (Cytosine-5)-Methyltransferase Dysregulation in Pulmonary Arterial Hypertension and Other Cardiovascular Diseases

DNA methylation is an epigenetic mechanism that regulates gene expression without altering gene sequences in health and disease. DNA methyltransferases (DNMTs) are enzymes responsible for DNA methylation, and their dysregulation is both a pathogenic mechanism of disease and a therapeutic target. DNMTs change gene expression by methylating CpG islands within exonic and intergenic DNA regions, which typically reduces gene transcription. Initially, mutations in the DNMT genes and pathologic DNMT protein expression were found to cause hematologic diseases, like myeloproliferative disease and acute myeloid leukemia, but recently they have been shown to promote cardiovascular diseases, including coronary artery disease and pulmonary hypertension. We reviewed the regulation and functions of DNMTs, with an emphasis on somatic mutations in DNMT3A, a common cause of clonal hematopoiesis of indeterminant potential (CHIP) that may also be involved in the development of pulmonary arterial hypertension (PAH). Accumulation of somatic mutations in DNMT3A and other CHIP genes in hematopoietic cells and cardiovascular tissues creates an inflammatory environment that promotes cardiopulmonary diseases, even in the absence of hematologic disease. This review summarized the current understanding of the roles of DNMTs in maintenance and de novo methylation that contribute to the pathogenesis of cardiovascular diseases, including PAH.

SGLT2 inhibitors: role in protective reprogramming of cardiac nutrient transport and metabolism

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce heart failure events by direct action on the failing heart that is independent of changes in renal tubular function. In the failing heart, nutrient transport into cardiomyocytes is increased, but nutrient utilization is impaired, leading to deficient ATP production and the cytosolic accumulation of deleterious glucose and lipid by-products. These by-products trigger downregulation of cytoprotective nutrient-deprivation pathways, thereby promoting cellular stress and undermining cellular survival. SGLT2 inhibitors restore cellular homeostasis through three complementary mechanisms: they might bind directly to nutrient-deprivation and nutrient-surplus sensors to promote their cytoprotective actions; they can increase the synthesis of ATP by promoting mitochondrial health (mediated by increasing autophagic flux) and potentially by alleviating the cytosolic deficiency in ferrous iron; and they might directly inhibit glucose transporter type 1, thereby diminishing the cytosolic accumulation of toxic metabolic by-products and promoting the oxidation of long-chain fatty acids. The increase in autophagic flux mediated by SGLT2 inhibitors also promotes the clearance of harmful glucose and lipid by-products and the disposal of dysfunctional mitochondria, allowing for mitochondrial renewal through mitochondrial biogenesis. This Review describes the orchestrated interplay between nutrient transport and metabolism and nutrient-deprivation and nutrient-surplus signalling, to explain how SGLT2 inhibitors reverse the profound nutrient, metabolic and cellular abnormalities observed in heart failure, thereby restoring the myocardium to a healthy molecular and cellular phenotype.

Advances in epigenetic modifications of autophagic process in pulmonary hypertension

Pulmonary hypertension is characterized by pulmonary arterial remodeling that results in increased pulmonary vascular resistance, right ventricular failure, and premature death. It is a threat to public health globally. Autophagy, as a highly conserved self-digestion process, plays crucial roles with autophagy-related (ATG) proteins in various diseases. The components of autophagy in the cytoplasm have been studied for decades and multiple studies have provided evidence of the importance of autophagic dysfunction in pulmonary hypertension. The status of autophagy plays a dynamic suppressive or promotive role in different contexts and stages of pulmonary hypertension development. Although the components of autophagy have been well studied, the molecular basis for the epigenetic regulation of autophagy is less understood and has drawn increasing attention in recent years. Epigenetic mechanisms include histone modifications, chromatin modifications, DNA methylation, RNA alternative splicing, and non-coding RNAs, which control gene activity and the development of an organism. In this review, we summarize the current research progress on epigenetic modifications in the autophagic process, which have the potential to be crucial and powerful therapeutic targets against the autophagic process in pulmonary hypertension development.

MicroRNA in the Diagnosis and Treatment of Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is widely applied to the treatment of cancer; however, DOX-induced cardiotoxicity (DIC) limits its clinical therapeutic utility. However, it is difficult to monitor and detect DIC at an early stage using conventional detection methods. Thus, sensitive, accurate, and specific methods of diagnosis and treatment are important in clinical practice. MicroRNAs (miRNAs) belong to non-coding RNAs (ncRNAs) and are stable and easy to detect. Moreover, miRNAs are expected to become biomarkers and therapeutic targets for DIC; thus, there are currently many studies focusing on the role of miRNAs in DIC. In this review, we list the prominent studies on the diagnosis and treatment of miRNAs in DIC, explore the feasibility and difficulties of using miRNAs as diagnostic biomarkers and therapeutic targets, and provide recommendations for future research.

ELF1 suppresses autophagy to reduce cisplatin resistance via the miR-152-3p/NCAM1/ERK axis in lung cancer cells

Resistance to chemotherapeutic drugs limits the efficacy of chemotherapy in non-small cell lung cancer (NSCLC). Autophagy is an essential mechanism which involves in drug resistance. Our previous research has revealed that miR-152-3p represses NSCLC progression. However, the mechanism of miR-152-3p in autophagy-mediated chemoresistance in NSCLC remains unclear. Cisplatin-resistant cell lines (A549/DDP and H446/DDP) were transfected with related vectors and subjected to cisplatin, autophagy inhibitor, activator, or extracellular signal-regulated kinase (ERK) activator. Flow cytometry, CCK8 and colony formation assays were performed for testing apoptosis and cell viability. The related RNAs or proteins were detected by qRT-PCR or Western blot. Chromatin immunoprecipitation, luciferase reporter assay or RNA immunoprecipitation were used for validating the interaction between miR-152-3p and ELF1 or NCAM1. Co-IP verified the binding between NCAM1 and ERK. The role of miR-152-3p in cisplatin resistance of NSCLC was also validated in vivo. The results showed that miR-152-3p and ELF1 were decreased in NSCLC tissues. miR-152-3p reversed cisplatin resistance by inhibiting autophagy through NCAM1. NCAM1 promoted autophagy through the ERK pathway and facilitated cisplatin resistance. ELF1 positively regulated miR-152-3p level by directly interacting with miR-152-3p promoter. miR-152-3p targeted NCAM1 to regulate NCAM1 level and then affected the binding of NCAM1 to ERK1/2. ELF1 inhibited autophagy and reversed cisplatin resistance through miR-152-3p/NCAM1. miR-152-3p inhibited autophagy and cisplatin resistance of xenograft tumor in mice. In conclusion, our study revealed that ELF1 inhibited autophagy to attenuate cisplatin resistance through the miR-152-3p/NCAM1/ERK pathway in H446/DDP and A549/DDP cells, suggesting a potential novel treatment strategy for NSCLC.

MicroRNAs in doxorubicin-induced cardiotoxicity: The DNA damage response

Doxorubicin (DOX) is a chemotherapeutic drug widely used for cancer treatment, but its use is limited by cardiotoxicity. Although free radicals from redox cycling and free cellular iron have been predominant as the suggested primary pathogenic mechanism, novel evidence has pointed to topoisomerase II inhibition and resultant genotoxic stress as the more fundamental mechanism. Recently, a growing list of microRNAs (miRNAs) has been implicated in DOX-induced cardiotoxicity (DIC). This review summarizes miRNAs reported in the recent literature in the context of DIC. A particular focus is given to miRNAs that regulate cellular responses downstream to DOX-induced DNA damage, especially p53 activation, pro-survival signaling pathway inhibition (e.g., AMPK, AKT, GATA-4, and sirtuin pathways), mitochondrial dysfunction, and ferroptosis. Since these pathways are potential targets for cardioprotection against DOX, an understanding of how miRNAs participate is necessary for developing future therapies.

Expression Profile of Inflammation Response Genes and Potential Regulatory Mechanisms in Dilated Cardiomyopathy

Background

The inflammatory response is important in dilated cardiomyopathy (DCM). However, the expression of inflammatory response genes (IRGs) and regulatory mechanisms in DCM has not been well characterized.

Methods

We analyzed 27,665 cells of single-cell RNA sequencing dataset of four DCM samples and two healthy controls (HC). IRGs among differentially expressed genes (DEGs) of active cell clusters were screened from the Molecular Signatures Database (MSigDB). The bulk sequencing dataset of 166 DCM patients and 166 HC was analyzed to explore the common IRGs. The biological functions of the IRGs were analyzed according to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. IRG-related transcription factors (TFs) were determined using the TRRUST database. The protein-protein interaction (PPI) network was constructed using the STRING database. Then, we established the noncoding RNA (ncRNA) regulatory network based on the StarBase database. Finally, the potential drugs that target IRGs were explored using the Drug Gene Interaction Database (DGIdb).

Results

The proportions of dendritic cells (DCs), B cells, NK cells, and T cells were increased in DCM patients, whereas monocytes were decreased. DCs expressed more IRGs in DCM. The GO and KEGG analyses indicated that the functional characteristics of active cells mainly focused on the immune response. Thirty-nine IRGs were commonly expressed among active cell cluster DEGs, bulk RNA DEGs, and inflammatory response-related genes. ETS1 plays an important role in regulation of IRG expression. The competing endogenous RNA regulatory network showed the relationship between ncRNA and IRGs. Sankey diagram showed that arachidonate 5-lipoxygenase (ALOX5) played a major role in regulation between TFs and potential drugs.

Conclusion

DCs infiltrate into the myocardium and contribute to the immune response in DCM. The transcription factor ETS1 plays an important role in regulation of IRGs. Moreover, ALOX5 may be a potential therapeutic target for DCM.