YTHDF2 Promotes Cardiac Ferroptosis via Degradation of SLC7A11 in Cardiac Ischemia-Reperfusion Injury

Biological function of RNA-binding proteins in myocardial infarction: a potential emerging therapeutic limelight

Myocardial infarction (MI) is currently one of the most fatal cardiovascular diseases worldwide. The screening, treatment, and prognosis of MI are top priorities for cardiovascular centers globally due to its characteristic occult onset, high lethality, and poor prognosis. MI is caused by coronary artery occlusion induced by coronary atherosclerotic plaque blockage or other factors, leading to ischemic necrosis and apoptosis of cardiomyocytes. Although significant advancements have been made in the study of cardiomyocytes at the cellular and molecular levels, RNA-binding proteins (RBPs) have not been extensively explored in the context of MI. RBPs, as key regulators coordinating cell differentiation and tissue homeostasis, exhibit specific functions in gene transcription, RNA modification and processing, and post-transcriptional gene expression. By binding to their target RNA, RBPs coordinate various RNA dynamics, including cellular metabolism, subcellular localization, and translation efficiency, thereby controlling the expression of encoded proteins. Classical RBPs, including HuR, hnRNPs, and RBM family molecules, have been identified as critical regulators in myocardial hypoxia, oxidative stress, pro-inflammatory responses, and fibrotic repair. These RBPs exert their effects by modulating key pathophysiological pathways in MI, thereby influencing specific cardiac outcomes. Additionally, specific RBPs, such as QKI and fused in sarcoma (FUS), are implicated in the apoptotic pathways activated during MI. This apoptotic pathway represents a significant molecular phenotype in MI, offering novel perspectives and insights for mitigating cardiomyocyte apoptosis and attenuating the progression of MI. Therefore, this review systematically summarizes the role of RBPs in the main pathophysiological stages of MI and explores their potential therapeutic prospects.

Knockdown of YTHDF2 mitigates OGD-induced microglial inflammation by preventing m6A-dependent PARP14 degradation

Neuroinflammation is a key pathological factor in ischemic brain diseases, contributing to the initiation and progression of these conditions. The function of the m6A reader protein YTHDF2 in regulating neuroinflammation across various neurological contexts. To elucidate the role and regulatory mechanism of YTHDF2 in inflammation under ischemic-like conditions, this study employed an in vitro model, exposing microglia to oxygen-glucose deprivation (OGD) to mimic the stress environment. And through YTHDF2 knockdown, we investigated its effect on OGD-induced inflammation. The results demonstrated that YTHDF2 knockdown significantly suppressed the expression of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), in OGD-treated microglia. Mechanistic analysis revealed that YTHDF2 interacts with Parp14 mRNA under OGD conditions, reducing its RNA stability via m6A-dependent mechanisms, which in turn decreases Poly (ADP-ribose) polymerase family, member 14 (PARP14) protein expression. Additionally, YTHDF2 knockdown after OGD promoted a PARP14-driven phenotypic switch in microglia from the pro-inflammatory M1 state to the anti-inflammatory M2 state, resulting in diminished inflammation. These findings offer new insights into the regulatory function of YTHDF2 in OGD-induced microglial inflammation and propose m6A modification as a potential therapeutic target for alleviating neuroinflammation.

Enhancement of YTHDF2 plays a protective role in acute IRI models through downregulation of TUG1 expression

As one of the major causes of acute kidney injury, renal ischemia-reperfusion is a common health problem in a series of clinical situations, including renal transplantation. Although the mechanisms of renal IRI have been widely investigated, effective strategies are still in lacking for its prevention and treatment. In previous study, we found that the down-regulation of taurine upregulated gene 1, a long non-coding RNA (lncRNA TUG1), markedly alleviated renal IRI through mitigating the cell inflammation and apoptosis. At meanwhile, YTHDF2, an RNA methylation reading protein, was identified as a vital player in IRI of distinct organs, however, not reported in kidney. We then conducted the current study on the function of YTHDF2 in renal IRI and its regulatory role to TUG1. Based on renal IRI models in vitro and in vivo, dramatical down-regulation of YTHDF2 was presented. Subsequently, exogenous perturbation of YTHDF2 was conducted and its protective effects on cell apoptosis were demonstrated in acute IRI exogenous. Furthermore, with the same model, it was indicated that YTHDF2 protein negative regulated TUG1 RNA via direction interaction. Since then, YTHDF2 was proved as a potential protector of renal IRI through restraining of TUG1. In further speculation, induction of YTHDF2 in IRI will possibly become a possible strategy to combat the pathological process post renal transplantation or other clinical conditions.

A comprehensive review of m6 A methylation in coronary heart disease

The morbidity and mortality rates of coronary heart disease (CHD) are high worldwide. The primary pathological changes in CHD involve stenosis and ischemia caused by coronary atherosclerosis (AS). Extensive research on the pathogenesis of AS has revealed chronic immunoinflammatory processes and cell proliferation in all layers of coronary vessels, including endothelial cells (ECs), vascular smooth muscle cells, and macrophages. m6 A methylation is a common posttranscriptional modification of RNA that is coordinated by a variety of regulators (writers, readers, erasers) to maintain the functional stability of modified mRNAs and ncRNAs. In recent years, there has been increasing focus on the involvement of m6 A methylation in the incidence and progression of CHD, which starts with atherosclerotic plaque formation, leads to myocardial ischemia, and ultimately results in the occurrence of myocardial infarction (MI). m6 A regulators modulate relevant signaling pathways to participate in the inflammatory response, programmed death of cardiomyocytes, and fibrosis. Therefore, diagnostic models based on m6 A profiling are helpful for the early detection of CHD, and m6 A methylation shows promise as a sensitive target for new drugs to treat CHD in the future.

Different types of cell death and their interactions in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (I/R) injury is a multifaceted process observed in patients with coronary artery disease when blood flow is restored to the heart tissue following ischemia-induced damage. Cardiomyocyte cell death, particularly through apoptosis, necroptosis, autophagy, pyroptosis, and ferroptosis, is pivotal in myocardial I/R injury. Preventing cell death during the process of I/R is vital for improving ischemic cardiomyopathy. These multiple forms of cell death can occur simultaneously, interact with each other, and contribute to the complexity of myocardial I/R injury. In this review, we aim to provide a comprehensive summary of the key molecular mechanisms and regulatory patterns involved in these five types of cell death in myocardial I/R injury. We will also discuss the crosstalk and intricate interactions among these mechanisms, highlighting the interplay between different types of cell death. Furthermore, we will explore specific molecules or targets that participate in different cell death pathways and elucidate their mechanisms of action. It is important to note that manipulating the molecules or targets involved in distinct cell death processes may have a significant impact on reducing myocardial I/R injury. By enhancing researchers' understanding of the mechanisms and interactions among different types of cell death in myocardial I/R injury, this review aims to pave the way for the development of novel interventions for cardio-protection in patients affected by myocardial I/R injury.

ZHX2 inhibits diabetes-induced liver injury and ferroptosis by epigenetic silence of YTHDF2

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a common complication of type 2 diabetes mellitus (DM). The transcription factor zinc fingers and homeoboxes 2 (ZHX2) has been implicated in the pathogenesis of chronic liver diseases, yet its precise role and underlying mechanism in DM-induced hepatic injury remain poorly elucidated.

METHODS

To investigate this, we used a high-fat diet (HFD) and streptozotocin (STZ) administration to create a DM model in mice, while high glucose (HG) exposure was used to simulate DM in vitro. Through various experiments such as luciferase reporter assay, chromatin immunoprecipitation, RNA immunoprecipitation, and rescue experiments, we aimed to uncover the mechanisms involving ZHX2.

RESULTS

Our findings revealed that ZHX2 was lower and YTHDF2 was higher in the livers of DM mice and HG-induced Huh7 cells. ZHX2 overexpression rescued DM-induced liver injury. ZHX2 overexpression also reversed DM-induced hepatic ferroptosis in vivo and in vitro. Mechanistically, YTHDF2 recognized m6A-modified ZHX2 mRNA and promoted its degradation. In turn, ZHX2 inhibited the transcription of YTHDF2 by binding to its promoter region. Knockdown of ZHX2 led to increased ferroptosis in Huh7 cells through activating YTHDF2-induced GPX4 and SLC7A11 degradation.

CONCLUSION

These findings highlight the involvement of the ZHX2-YTHDF2-ferroptosis pathway in DM-induced liver injury and suggest that targeting this pathway may hold therapeutic potential for improving such injuries.

Bioinformatics analysis of ferroptosis-related hub genes and immunoinfiltration in myocardial ischemia/reperfusion following heart transplantation

BACKGROUND

Ischemia/reperfusion (I/R) is an inevitable pathophysiological process during heart transplantation, and ferroptosis is an important pathogenic mechanism. Unlike other modes of cell death, ferroptosis depends on the accumulation of iron within the cell and the oxidative degradation of polyunsaturated fatty acids. Dysregulation of this pathway has been linked to the progression of multiple pathological conditions, making it an attractive target for therapeutic intervention. Therefore, this study aims to explore the effect of ferroptosis on I/R during heart transplantation.

METHODS

GEO2R was applied to identify differentially expressed genes (DEGs) obtained from GSE50884 data, which was involved in I/R and heart transplantation. And ferroptosis-related DEGs (FRDEGs) were screened by venn diagram with ferroptosis-related genes downloaded from FerDb database. FRDEGs was enriched and analyzed by GO and KEGG, and hub genes related to ferroptosis were screened by Cytoscape software and database STRING. Additionally, considering the relationship between ferroptosis and immunity, CIBERSORTx was to analyze the infiltration of 22 kinds of immune cells in I/R during heart transplantation, and the correlation between each immune cell and the expression of FRDEGs was also discussed. Finally, the mouse model of heart transplantation with I/R was constructed, and the hub genes was verified by RT-qPCR and western blot.

RESULTS

12 FRDEGs were identified out of 327 DEGs in GSE50844, which were mainly involved in ferroptosis and other pathways. Three hub genes (SLC7A11, PSAT1, ASNS) were obtained by the degree algorithm of cytohubba plug-in. Immunoinfiltration analysis showed that 16 of 22 immune cells changed, and the immune score of heart transplantation with I/R was higher than that without I/R. In addition, hub genes exhibited significant correlation with Eosinophils, NK cells resting, Dendritic cells resting, NK cells activated and T cells CD4 memory activated. We verified the expression of SLC7A11, PSAT1 and ASNS was higher than that in normal tissues using RT-qPCR and western blot in mouse models of heart transplantation with I/R, companied by ferroptosis aggravated is involved.

CONCLUSIONS

In short, ferroptosis is involved in I/R injury during heart transplantation, which is related to immune cell infiltration. Three hub genes (SLC7A11, PSAT1 and ASNS) identified in this study provide therapeutic targets for ameliorating I/R injury in heart transplantation.

The Role of Methylation in Ferroptosis

Methylation modification is a crucial epigenetic alteration encompassing RNA methylation, DNA methylation, and histone methylation. Ferroptosis represents a newly discovered form of programmed cell death (PCD) in 2012, which is characterized by iron-dependent lipid peroxidation. The comprehensive investigation of ferroptosis is therefore imperative for a more profound comprehension of the pathological and pathophysiological mechanisms implicated in a wide array of diseases. Researches show that methylation modifications can exert either promotive or inhibitory effects on cell ferroptosis. Consequently, this review offers a comprehensive overview of the pivotal role played by methylation in ferroptosis, elucidating its associated factors and underlying mechanisms.

Disulfidptosis: A new type of cell death

Disulfidptosis is a novel form of cell death that is distinguishable from established programmed cell death pathways such as apoptosis, pyroptosis, autophagy, ferroptosis, and oxeiptosis. This process is characterized by the rapid depletion of nicotinamide adenine dinucleotide phosphate (NADPH) in cells and high expression of solute carrier family 7 member 11 (SLC7A11) during glucose starvation, resulting in abnormal cystine accumulation, which subsequently induces andabnormal disulfide bond formation in actin cytoskeleton proteins, culminating in actin network collapse and disulfidptosis. This review aimed to summarize the underlying mechanisms, influencing factors, comparisons with traditional cell death pathways, associations with related diseases, application prospects, and future research directions related to disulfidptosis.

GDF15 restrains myocardial ischemia-reperfusion injury through inhibiting GPX4 mediated ferroptosis

BACKGROUND

Growth and differentiation factor 15 (GDF15) has been proved to regulate the process of Myocardial ischemia-reperfusion injury (MIRI), which is a serious complication of reperfusion therapy. The present study aimed to explore if GDF15 could regulate the MIRI-induced ferroptosis.

METHOD

MIRI animal model was established by ligating the left anterior descending coronary artery. Oxygen-glucose deprivation/reoxygenation (OGD/R) cell model was established to imitate MIRI in vitro. The indicators of ferroptosis including mitochondrial damage, GPX4, FACL4, XCT4, and oxidative stress markers were evaluated.

RESULTS

Overexpression of GDF15 greatly inhibited MIRI, improved cardiac function, alleviated MIRI-induced ferroptosis. pc-DNA-GDF15 significantly inhibited the oxidative stress condition and inflammation response. The OGD/R-induced ferroptosis was also inhibited by pc-DNA-GDF15.

CONCLUSION

We proved that the MIRI-induced ferroptosis could by inhibited by pc-DNA-GDF15 through evaluating mitochondrial damage, MDA, GSH, and GSSG. Our research provides a new insight for the prevention and treatment of MIRI, and a new understanding for the mechanism of MIRI-induced ferroptosis.

Dexmedetomidine alleviates ferroptosis following hepatic ischemia-reperfusion injury by upregulating Nrf2/GPx4-dependent antioxidant responses

Hepatic ischemia-reperfusion injury (HIRI) adversely affects liver transplant and resection outcomes. Recently, ferroptosis has been associated with HIRI. Dexmedetomidine (Dex), a potent sedative with anti-inflammatory, antioxidant, and anti-apoptotic properties, protects organs from hypoxic or ischemia-reperfusion (I/R) injuries. However, the mechanisms underlying this protective effect against I/R-induced liver injury remain unclear. This study evaluated the effect of Dex on HIRI in mouse models and the oxygen-glucose deprivation/reperfusion (OGD/R) AML12 cell model. We examined ferroptosis-related markers, including Fe2+ levels, reactive oxygen species (ROS) content, mitochondrial morphology, GPX4 protein expression, 4-hydroxynonenal (4-HNE), and Nrf2. The Nrf2 inhibitor ML385 was used in combination with Dex to treat HIRI mice and OGD/R-induced cellular models to explore the pathways by which Dex counteracts ferroptosis. Our results showed that Dex treatment significantly ameliorated OGD/R-induced ferroptosis in AML12 cells, including reduced Fe2+, ROS, malondialdehyde (MDA), and 4-HNE levels. Dex also ameliorated liver tissue damage and reduced serum AST, ALT, and inflammatory factor levels in HIRI mice. Additionally, Dex increased the levels of GSH, an antioxidative stress marker, and GPX4 expression in HIRI mice. Mechanistically, Nrf2 expression and nuclear translocation were significantly inhibited in both HIRI mice and OGD/R-treated AML12 cells. Dex treatment also restored the I/R-induced inhibition of Nrf2 expression and nuclear translocation. ML385 significantly inhibited Dex-promoted Nrf2 nuclear aggregation with Gpx4 protein expression, hindering the efficacy of Dex. In conclusion, Dex ameliorates ferroptosis in HIRI by positively regulating the Nrf2/GPx4 axis, potentially presenting a therapeutic avenue for addressing HIRI.