FTO ameliorates doxorubicin-induced cardiotoxicity by inhibiting ferroptosis via P53-P21/Nrf2 activation in a HuR-dependent m6A manner

Epithelial-mesenchymal transition promotes metabolic reprogramming to suppress ferroptosis

Epithelial-mesenchymal transition (EMT) is a cellular de-differentiation process that provides cells with the increased plasticity and stem cell-like traits required during embryonic development, tissue remodeling, wound healing and metastasis. Morphologically, EMT confers tumor cells with fibroblast-like properties that lead to the rearrangement of cytoskeleton (loss of stiffness) and decrease of membrane rigidity by incorporating high level of poly-unsaturated fatty acids (PUFA) in their phospholipid membrane. Although large amounts of PUFA in membrane reduces rigidity and offers capabilities for tumor cells with the unbridled ability to stretch, bend and twist in metastasis, these PUFA are highly susceptible to lipid peroxidation, which leads to the breakdown of membrane integrity and, ultimately results in ferroptosis. To escape the ferroptotic risk, EMT also triggers the rewiring of metabolic program, particularly in lipid metabolism, to enforce the epigenetic regulation of EMT and mitigate the potential damages from ferroptosis. Thus, the interplay among EMT, lipid metabolism, and ferroptosis highlights a new layer of intricated regulation in cancer biology and metastasis. Here we summarize the latest findings and discuss these mutual interactions. Finally, we provide perspectives of how these interplays contribute to cellular plasticity and ferroptosis resistance in metastatic tumor cells that can be explored for innovative therapeutic interventions.

H 2 protects H9c2 cells from hypoxia/reoxygenation injury by inhibiting the Wnt/CX3CR1 signaling pathway

Myocardial ischemia‒reperfusion injury is a severe cardiovascular disease, and its treatment and prevention are crucial for improving patient prognosis and reducing the economic burden. This study aimed to explore the impact of hydrogen (H 2 ) on hypoxia/reoxygenation (H/R) injury in H9c2 cells (derived from rat embryonic heart tissue) induced by hydrogen peroxide (H 2 O 2 ) and to elucidate its underlying mechanism. An H/R injury model was established in H9c2 cells via exposure to 15 μM H 2 O 2 for 3 hours, followed by incubation in a 5% CO 2 atmosphere at 37°C for 24 hours. Then, the cells were treated with H 2 (50%) for 6, 12 or 24 hours. The results demonstrated that H9c2 cells exposed to H 2 O 2 and subjected to H/R injury presented a marked decrease in the cell survival rate, accompanied by severe morphological alterations, such as curling and wrinkling, and elevated lactate dehydrogenase levels. Notably, H 2 mitigated H/R injury induced by H 2 O 2 in a time-dependent manner, improving the morphological damage observed in H9c2 cells and decreasing lactate dehydrogenase levels. Compared with the model group, treatment with H 2 increased the activities of antioxidant enzymes, including catalase, superoxide dismutase, and glutathione peroxidase, while concurrently reducing the level of malondialdehyde, an indicator of cellular damage. Furthermore, H 2 treatment downregulated the expression of inflammatory cytokines and inflammatory-related factors, specifically interleukin-6, high-mobility group box 1, tumor necrosis factor-alpha, and Toll-like receptor 4, in H9c2 cells post-H/R injury. Furthermore, H 2 treatment resulted in a marked decrease in the expression levels of proteins associated with the Wnt/C-X3-C-motif receptor 1 signaling pathway, such as β-catenin, glycogen synthase kinase-3 beta, adenomatous polyposis coli, and Wnt and C-X3-C-motif receptor 1. This observation suggests a potential mechanism for its protective effects against H/R injury. Therefore, H 2 exerts a protective effect against H/R injury in H9c2 cells induced by H 2 O 2 , potentially by inhibiting the activated Wnt/C-X3-C-motif receptor 1 signaling pathway. This inhibition, in turn, prevents the generation of oxidative stress, inflammatory cytokines, and inflammation-associated factors.

Protein Kinase C Epsilon Overexpression Protects the Heart Against Doxorubicin-Induced Cardiotoxicity Via Activating SIRT1

Doxorubicin (DOX)-induced cardiotoxicity (DIC) is known to be associated with reduction of cardiac protein kinase C epsilon (PKC-ε). PKC-ε promotes cell survival and protects hearts against various stresses. However, it is unclear whether or not the reduction in cardiac PKC-ε expression plays a causal role in DIC and in particular the potential underlying mechanism whereby PKC-ε may protect against DIC. C57BL/6 mice (8-10-week-old) were either treated with DOX administered intraperitoneally for a duration of 4 weeks to produce cardiotoxicity, or untreated in which mice received the same volume of saline. In vitro, neonatal rat ventricle cardiomyocytes were exposed to DOX for 24 h in the absence or presence of adenovirus overexpressing PKC-ε. Cardiomyocytes in a subgroup were treated with sirtuin-1 (SIRT1) selective inhibitor Ex527. Four weeks after DOX, cardiac contractile function was decreased concomitant with increased serum CK-MB and LDH levels as well as increases in Bax-to-Bcl-2 ratio and Cleaved Caspase 3 proteins expression, while PKC-ε and Sirt1 protein expressions were significantly decreased. In vitro, DOX reduced cardiomyocyte PKC-ε and SIRT1 protein expression, decreased cardiomyocyte viability, and increased LDH release with concomitant increases in oxidative stress and apoptosis. These changes were attenuated by overexpression of PKC-ε. IP study showed that PKC-ε could directly or indirectly bind SIRT1 in cardiomyocytes, and the protect effects of PKC-ε were further canceled by SIRT1 inhibition. In conclusion, activating SIRT1 may represent a major mechanism whereby PKC-ε protects the heart against DOX-induced cell apoptosis and oxidative stress.

Human antigen R -mediated autophagy-related gene 3 methylation enhances autophagy-driven ferroptosis in Crohn's disease colitis

BACKGROUND AND AIMS

Crohn's disease (CD) is a chronic inflammatory disorder that can affect any part of the gastrointestinal tract, with the exact etiology remaining unclear. Recent studies have implicated the role of human antigen R (HuR) in the pathogenesis of various inflammatory diseases, including CD. However, the role of HuR in the modulation of CD remains underexplored. Therefore, this study aimed to investigate the mechanistic involvement of HuR in CD.

METHODS

We established colitis models using human intestinal epithelial cells and lipopolysaccharide and dextran sulfate sodium-induced mice. Additionally, by knocking out HuR in both cell and animal models, we validated the role of HuR in autophagy and ferroptosis. The role of HuR in regulating ferroptosis accompanied by autophagy activation in CD was detected using ELISA, flow cytometry, immunofluorescence, transmission electron microscopy, Western blot, and RT-qPCR. The demethylation level of ATG3 and the stability of ATG3 mRNA regulated by HuR were detected using immunofluorescence, RIP, and MeRIP-qPCR. The effect of HuR on DSS-induced colitis was evaluated using DAI score, H&E staining, TUNEL staining, and immunohistochemistry.

RESULTS

The results show that HuR expression is significantly increased in CD colonic inflammation. Compared with the control group, the model group mice exhibited decreased levels of lipid peroxidation markers glutathione and superoxide dismutase, elevated malondialdehyde and reactive oxygen species levels, and reduced expression of iron-related proteins glutathione peroxidase 4, ferritin heavy chain protein 1, and solute carrier family 7 member 11. Additionally, the expression of autophagy-related proteins microtubule-associated protein 1 A/1B-light chain 3, beclin-1, and autophagy related 3 (ATG3) was upregulated, while p62 expression was downregulated. In both in vitro and in vivo models, HuR knockout reversed these changes induced by lipopolysaccharide and dextran sulfate sodium, concomitant with improved tissue pathology. Mechanistically, HuR enhances autophagy-mediated ferroptosis in CD colonic inflammation by regulating ATG3 methylation and mRNA stability.

CONCLUSION

HuR accelerates colonic inflammation in CD by regulating ATG3 methylation, which enhances autophagy-mediated ferroptosis. Knockout of HuR alleviates Crohn's colitis. This finding provides a potential therapeutic target for the treatment of CD.

Activation of sigma 1 receptor attenuates doxorubicin-induced cardiotoxicity by alleviating oxidative stress, mitochondria dysfunction, ER stress-related apoptosis, and autophagy impairment

The cardiotoxic effects of doxorubicin (DOX) are a significant clinical challenge. This study explored the mechanisms underlying the cardioprotective effects of fluvoxamine (FLU) in DOX-induced cardiotoxicity. In vitro and in vivo models of DOX-induced cardiotoxicity were established using H9c2 cardiomyocytes and BALB/c mice, respectively. The cardioprotective effects of FLU were evaluated using echocardiography, electrocardiography, HE staining, myocardial injury indicators, immunohistochemical staining, immunofluorescence staining, and western blotting. Small interfering RNA (siRNA) targeting the sigma-1 receptor (Sig1R), the Sig1R inhibitor haloperidol (HALO), and the nuclear factor erythroid 2-related factor 2 inhibitor ML385 were used to verify the mechanism of FLU in H9c2 cells, and molecular docking was performed to compare the binding affinities of DOX and FLU to Sig1R. DOX treatment significantly decreased Sig1R expression, leading to cardiac dysfunction, endoplasmic reticulum stress, apoptosis, impaired autophagy, oxidative stress, and mitochondrial dysfunction. Treatment with FLU mitigated these effects. Molecular docking simulations revealed that FLU showed better binding affinity for Sig1R than DOX. Moreover, the beneficial effects of FLU in DOX-induced cardiotoxicity were reduced in the presence of HALO, ML385, or Sig1R siRNA. Our study indicates that FLU effectively reduces DOX-induced cardiotoxicity by activating Sig1R, highlighting its potential as a therapeutic agent against chemotherapy-induced cardiotoxicity.

AIG1 protects against doxorubicin-induced cardiomyocyte ferroptosis and cardiotoxicity by promoting ubiquitination-mediated p53 degradation

Background: Doxorubicin (DOX) is a widely employed chemotherapeutic drug, while its clinical use is limited by the lethal cardiotoxicity. Previous studies highlighted the critical role of cardiomyocyte ferroptosis in the pathogenesis of DOX-induced cardiotoxicity (DIC). Androgen-induced gene 1 (AIG1) is perceived as a key regulator of oxidative stress-mediated cell death. Nonetheless, it remains elusive whether AIG1 is involved in the progression of DOX-induced cardiomyocyte ferroptosis and cardiotoxicity. Methods: C57BL/6 male mice were repeatedly administrated with DOX at an accumulative dosage of 20 mg/kg to establish a chronic DIC model. Global AIG1 knockout mice and AAV9-mediated cardiac-specific AIG1 knockdown or overexpression mice were utilized to evaluate the precise role of AIG1 in DIC. Additionally, the effects of AIG1 on cardiomyocyte ferroptosis were further investigated following DOX stimulation. Results: Ferroptosis played a pivotal role in DIC in both in vivo and in vitro settings. DOX exposure significantly reduced AIG1 expression levels in cardiomyocytes. Global AIG1 knockout or cardiac-specific AIG1 knockdown mice exhibited deteriorated cardiac function, adverse cardiac remodeling following DOX insult. Moreover, AIG1 deficiency aggravated DOX-evoked ferroptosis and oxidative stress in cardiomyocytes, whereas cardiac-specific overexpression of AIG1 conferred the protective effects manifested by the inhibition of cardiomyocyte ferroptosis and improvements in cardiac performance and remodeling under DOX challenge. Mechanistically, AIG1 directly interacted with the Pirh2 E3 ubiquitin ligase to promote the ubiquitination of p53, a key protein governing ferroptosis during DIC, thereby accelerating its degradation. Cardiac-specific Pirh2 knockdown markedly exacerbated DOX-induced ferroptosis by enhancing p53 activity in cardiomyocytes. Furthermore, the pharmacological administration of a highly selective p53 inhibitor PFT-α effectively ameliorated DIC in mice by inhibiting cardiomyocyte ferroptosis and substantially abrogated the deleterious cardiac effects associated with AIG knockout under DOX challenge. Conclusion: Our findings defined the critical cardioprotective role of AIG1 in DIC by alleviating cardiomyocyte ferroptosis in a Pirh2/p53 axis-dependent manner. Targeting the novelly identified AIG1-Pirh2-p53 signaling axis presents a promising approach to prevent DIC.

FTO-mediated Nrf2 demethylation alleviates high glucose-induced oxidative stress and apoptosis in retinal pigment epithelial cells

BACKGROUND

N6-methyladenosine (m6A) modification contributes to the development of diabetic retinopathy (DR). This study aimed to reveal the role and downstream regulatory signaling of an m6A demethylase fat mass and obesity-associated gene (FTO) in high glucose-induced damage of retinal pigment epithelial cells.

METHODS AND RESULTS

By stimulating ARPE-19 cells with different concentrations of glucose (0 mM-50 mM), we observed that FTO expression was significantly downregulated, while m6A modification level was upregulated in a glucose concentration-dependent manner in ARPE-19 cells. Then, ARPE-19 cells were transfected with FTO knockdown or overexpression vector, and administrated with high glucose (25mM) to perform functional verification experiments. FTO overexpression recovered cell viability, inhibited cell apoptosis, elevated GSH/GSSG ratio, but reduced MDA and ROS levels in high glucose-induced cells, while FTO knockdown further exacerbated high glucose-triggered oxidative stress and apoptotic cell death. Additionally, FTO overexpression upregulated the expression of NF-E2-related factor 2 (Nrf2) and activated the antioxidant heme oxygenase 1 (HO-1) signal through m6A demethylation on Nrf2 in high glucose-treated ARPE-19 cells. Finally, we proved that knockdown of Nrf2 or HO-1 reversed the protective effects of FTO overexpression on high glucose-treated ARPE-19 cells.

CONCLUSION

Altogether, the study demonstrated that FTO ameliorates high glucose-triggered oxidative stress and cell apoptosis through activating the Nrf2/HO-1 signaling pathway in an m6A-dependent manner.

Application of a novel RNA-protein interaction assay to develop inhibitors blocking RNA-binding of the HuR protein

RNA-protein interactions play an important regulatory role in several biological processes. For example, the RNA-binding protein HuR (human antigen R) binds to its target mRNAs and regulates their translation, stability, and subcellular localization. HuR is involved in the pathogenic processes of various diseases. Thus, small molecules blocking RNA-binding of HuR may be useful in a variety of diseases. Previously, we identified STK018404 as a small molecule targeting the HuR-RNA interaction. Based on this study we identified optimized compounds by exploiting combined structure-based and ligand-based computational approaches. To test a series of these compounds, we developed a novel readout system for the HuR-RNA interaction. Traditional methods to detect RNA-protein interaction come with some disadvantages: they require significant reagent optimization and may be difficult to optimize for weakly expressed RNA molecules. The readout often requires amplification. Thus, these methods are not well suited for quantitative analysis of RNA-protein interactions. To achieve an easy-to-perform, rapid, and robust detection of RNA-protein binding, we applied a split luciferase reporter system, to detect the interaction between HuR and its target RNA. We expressed one luciferase fragment as a fusion protein with HuR. The second luciferase fragment was Streptavidin-coated and coupled to a biotinylated RNA-oligo comprising an AU-rich HuR-binding element. The binding between HuR and its target RNA-oligo then allowed reconstitution of the functional luciferase that was detectable by luminescence. Using the split luciferase reporter system, we present here a series of optimized compounds that we developed.

Bisphenol F induces spermatogenic cell ferroptosis via FTO-mediated m6A regulation of FTH1

Bisphenol F (BPF) has become a new risk factor for male semen quality, but its specific mechanism is still unclear. Therefore, this study explored the potential mechanism of BPF affecting male semen quality from the perspective of ferroptosis and m6A RNA methylation. In vivo experiments showed that BPF destroyed the structure of seminiferous tubules, reduced the layers of spermatogenic cells, and reduced semen quality in mice. Moreover, BPF reduced cell viability and induced ferroptosis in GC-2 cells in vitro. Meanwhile, BPF inhibited the expression of fat mass and obesity-associated gene (FTO). Therefore, we constructed differential expression model of FTO and detected key indicators of ferroptosis such as Fe2+, malondialdehyde, and lipid peroxide. The results found that FTO was important in inhibiting BPF-induced ferroptosis in GC-2 cells. Mechanistically, we found that the m6A modification level on ferritin heavy chain 1 (FTH1) mRNA increased after interfering with FTO by MeRIP assay. Moreover, the RIP assay showed that both YTH N6-methyladenosine RNA binding protein F1 (YTHDF1) and YTH N6-methyladenosine RNA binding protein F2 (YTHDF2) could bind FTH1 mRNA to regulate its expression. This study suggests that FTO regulates the expression of FTH1 in YTHDF1 and YTHDF2 dependent manner and mediates ferroptosis in spermatogenic cells, thus alleviating the reproductive damage induced by BPF.

Iron homeostasis and ferroptosis in muscle diseases and disorders: mechanisms and therapeutic prospects

The muscular system plays a critical role in the human body by governing skeletal movement, cardiovascular function, and the activities of digestive organs. Additionally, muscle tissues serve an endocrine function by secreting myogenic cytokines, thereby regulating metabolism throughout the entire body. Maintaining muscle function requires iron homeostasis. Recent studies suggest that disruptions in iron metabolism and ferroptosis, a form of iron-dependent cell death, are essential contributors to the progression of a wide range of muscle diseases and disorders, including sarcopenia, cardiomyopathy, and amyotrophic lateral sclerosis. Thus, a comprehensive overview of the mechanisms regulating iron metabolism and ferroptosis in these conditions is crucial for identifying potential therapeutic targets and developing new strategies for disease treatment and/or prevention. This review aims to summarize recent advances in understanding the molecular mechanisms underlying ferroptosis in the context of muscle injury, as well as associated muscle diseases and disorders. Moreover, we discuss potential targets within the ferroptosis pathway and possible strategies for managing muscle disorders. Finally, we shed new light on current limitations and future prospects for therapeutic interventions targeting ferroptosis.

The Emerging Role of m6A and Programmed Cell Death in Cardiovascular Diseases

N6-methyladenosine (m6A) is the most prevalent internal chemical modification in eukaryotic messenger RNA (mRNA), significantly impacting its lifecycle through dynamic and reversible processes involving methyltransferase, demethylase, and binding proteins. These processes regulate mRNA stability, splicing, nuclear export, translation, and degradation. Programmed cell death (PCD), a tightly controlled process encompassing apoptosis, pyroptosis, ferroptosis, autophagy, and necroptosis, plays a crucial role in maintaining cellular homeostasis, tissue development, and function. Recently, m6A modification has emerged as a significant research area due to its role in regulating PCD and its implications in cardiovascular diseases (CVDs). In this review, we delve into the intricate relationship between various PCD types and m6A modification, emphasizing their pivotal roles in the initiation and progression of CVDs such as myocardial ischemia-reperfusion (I/R), atherosclerosis (AS), pulmonary hypertension (PH), cardiomyopathy, doxorubicin (Dox)-induced cardiotoxicity (DIC), heart failure (HF), and myocardial infarction (MI). Our findings underscore the potential of elucidating the roles of m6A and PCD in CVD to pave new pathways for prevention and treatment strategies.

Targeting ferroptosis: a promising approach for treating lung carcinoma

Lung carcinoma incidence and fatality rates remain among the highest on a global scale. The efficacy of targeted therapies and immunotherapies is commonly compromised by the emergence of drug resistance and other factors, resulting in a lack of durable therapeutic benefits. Ferroptosis, a distinct pattern of cell death marked by the buildup of iron-dependent lipid peroxides, has been shown to be a novel and potentially more effective treatment for lung carcinoma. However, the mechanism and regulatory network of ferroptosis are exceptionally complex, and many unanswered questions remain. In addition, research on ferroptosis in the diagnosis and treatment of lung cancer has been growing exponentially. Therefore, it is necessary to provide a thorough summary of the latest advancements in the field of ferroptosis. Here, we comprehensively analyze the mechanisms underlying the preconditions of ferroptosis, the defense system, and the associated molecular networks. The potential strategies of ferroptosis in the treatment of lung carcinoma are also highlighted. Targeting ferroptosis improves tumor cell drug resistance and enhances the effectiveness of targeted drugs and immunotherapies. These findings may shed fresh light on the diagnosis and management of lung carcinoma, as well as the development of drugs related to ferroptosis.

Early detection of anthracycline-induced cardiotoxicity

Although anthracyclines are important anticancer agents, their use is limited due to various adverse effects, particularly cardiac toxicity. Mechanisms underlying anthracycline-induced cardiotoxicity (AIC) are complex. Given the irreplaceable role of anthracyclines in treatment of malignancies and other serious diseases, early monitoring of AIC is paramount. In recent years, multiple studies have investigated various biomarkers for early detection of AIC. Currently, the two most common are cardiac troponin and B-type natriuretic peptide. In addition, a range of other molecules, including RNAs, myeloperoxidase (MPO), C-reactive protein (CRP), various genes, and others, also play roles in AIC prediction. Unfortunately, current research indicates a need to validate their sensitivity and specificity of these biomarkers especially in large study populations. In this review, we summarize the mechanisms and potential biomarkers of AIC, although some remain preliminary.

Epigenetic regulation and post-translational modifications of ferroptosis-related factors in cardiovascular diseases

As an important element of the human body, iron participates in numerous physiological and biochemical reactions. In the past decade, ferroptosis (a form of iron-dependent regulated cell death) has been reported to contribute to the pathogenesis and progression of various diseases. The stability of iron in cardiomyocytes is crucial for the maintenance of normal physiological cardiac activity. Ferroptosis has been detected in many cardiovascular diseases (CVDs), including coronary heart disease, myocardial ischemia-reperfusion injury, heart failure, and chemotherapy-induced myocardial damage. In cardiomyocytes, epigenetic regulation and post-translational modifications regulate the expression of ferroptosis-related factors, maintain iron homeostasis, and participate in the progression of CVDs. Currently, there is no detailed mechanism to explain the relationship between epigenetic regulation and ferroptosis in CVDs. In this review, we provide an initial summary of the core mechanisms of ferroptosis in cardiomyocytes, with first focus on the epigenetic regulation and expression of ferroptosis-related factors in the context of common cardiovascular diseases. We anticipate that the new insights into the pathogenesis of CVDs provided here will inspire the development of clinical interventions to specifically target the active sites of these factors, reducing the harmfulness of ferroptosis to human health.

N6-methyladenosine modification of SPOP relieves ferroptosis and diabetic cardiomyopathy by enhancing ubiquitination of VDAC3

Understanding the pathogenesis of diabetic cardiomyopathy (DCM), a common microvascular complication affecting the heart, is crucial for identifying new therapeutic targets and intervention strategies for DCM. Our study revealed a significant downregulation in Speckle-type POZ protein (SPOP) expression in DCM, while the overexpression of SPOP improved DCM-induced myocardial dysfunction, injury, fibrosis, hypertrophy, and ferroptosis. Mechanistically, SPOP facilitated the degradation of voltage-dependent anion channel 3 (VDAC3) by enhancing its ubiquitination. M6A demethylase AlkB homolog 5 (ALKBH5) reduced the mRNA stability of SPOP by decreasing m6A modification in its 3'UTR. The m6A reader insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) enhanced the stability of SPOP mRNA through recognition of m6A-modified SPOP 3'UTR. Furthermore, ALKBH5 promoted ferroptosis by inhibiting SPOP-induced VDAC3 degradation, while IGF2BP2 inhibited ferroptosis via activation of SPOP-induced VDAC3 degradation in high glucose-treated neonatal mouse ventricular cardiomyocytes (NMVCs). Overall, our study has unveiled a novel role of SPOP in the pathogenesis of ferroptosis and DCM, thereby significantly advancing our understanding of the involvement of ferroptosis during the progression of DCM. Moreover, this discovery offers promising potential therapeutic interventions targeting DCM.

Neuregulin-1 reduces Doxorubicin-induced cardiotoxicity by upregulating YAP to inhibit senescence

The cardiotoxicity of Doxorubicin (Dox) limits its clinical application, creating an urgent need to investigate its underlying mechanism and develop effective therapies. Senescence plays an important role in Dox-induced cardiotoxicity (DIC). Recently, Neuregulin-1 (NRG1) was found to regulate Yes-associated protein (YAP), which was reported to inhibit senescence, suggesting that NRG1 might be used to treat DIC by inhibiting senescence through YAP regulation. We examined the changes and regulatory roles of YAP and senescence in Dox cardiotoxicity and whether NRG1 could reduce DIC in chronic DIC mice and Dox-treated H9c2 cells. Our study revealed that sustained small doses of Dox impaired cardiac function and H9c2 cell viability, induced myocardial senescence, and inhibited YAP expression. Conversely, high levels of YAP inhibited Dox-induced senescence in H9c2 cells, indicating that Dox promotes myocardial senescence by inhibiting YAP. In addition, we found that exogenous NRG1 inhibited the phosphorylation of LATS1 and MST1, thereby inhibiting YAP phosphorylation and promote the nuclear translocation of YAP, inhibiting senescence and attenuating Dox-induced cardiotoxicity. YAP knockdown or inhibition of YAP binding to TEA domain transcription factor protein （TEAD）blocks the protective effects of NRG1. In conclusion, our study suggests that Dox-induced myocardial senescence through YAP inhibition is one of the pathological mechanisms of its cardiotoxicity. Additionally, NRG1 reduces DIC by upregulating YAP to inhibit senescence.

FTO in health and disease

Fat mass and obesity-associated (FTO) protein, a key enzyme integral to the dynamic regulation of epitranscriptomic modifications in RNAs, significantly influences crucial RNA lifecycle processes, including splicing, export, decay, and translation. The role of FTO in altering the epitranscriptome manifests across a spectrum of physiological and pathological conditions. This review aims to consolidate current understanding regarding the implications of FTO in health and disease, with a special emphasis on its involvement in obesity and non-communicable diseases associated with obesity, such as diabetes, cardiovascular disease, and cancer. It also summarizes the established molecules with FTO-inhibiting activity. Given the extensive impact of FTO on both physiology and pathophysiology, this overview provides illustrative insights into its roles, rather than an exhaustive account. A proper understanding of FTO function in human diseases could lead to new treatment approaches, potentially unlocking novel avenues for addressing both metabolic disorders and malignancies. The evolving insights into FTO's regulatory mechanisms hold great promise for future advancements in disease treatment and prevention.

Histone deacetylase 9 promotes osteogenic trans-differentiation of vascular smooth muscle cells via ferroptosis in chronic kidney disease vascular calcification

Vascular calcification, a common complication of chronic kidney disease (CKD), remains an unmet therapeutic challenge. The trans-differentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells is crucial in the pathogenesis of vascular calcification in CKD. Despite ferroptosis promotes vascular calcification in CKD, the upstream or downstream regulatory mechanisms involved remains unclear. In this study, we aimed to investigate the regulatory mechanism involved in ferroptosis in CKD vascular calcification. Transcriptome sequencing revealed a potential relationship between HDAC9 and ferroptosis in CKD vascular calcification. Subsequently, we observed increased expression of HDAC9 in calcified arteries of patients undergoing hemodialysis and in a rat model of CKD. We further demonstrated that knockout of HDAC9 attenuates osteogenic trans-differentiation and ferroptosis in VSMCs stimulated by high calcium and phosphorus. In addition, RSL3 exacerbated ferroptosis and osteogenic trans-differentiation of VSMCs exposed to high levels of calcium and phosphorus, and these effects were suppressed to some extent by HDAC9 knockout. In summary, our findings suggest that HDAC9 promotes VSMCs osteogenic trans-differentiation involving ferroptosis, providing new insights for the therapy of CKD vascular calcification.

WTAP weakens oxaliplatin chemosensitivity of colorectal cancer by preventing PANoptosis

As the most abundant post-transcriptional modification in eukaryotes, N6-methyladenosine (m6A) plays a crucial role in cancer cell proliferation, invasion and chemoresistance. However, its specific effects on chemosensitivity to oxaliplatin-based regimens and the impact of these drugs on m6A methylation levels in colorectal cancer (CRC) remain largely unexplored. In this study, we demonstrated that the m6A methyltransferase Wilms tumor 1-associating protein (WTAP) weakens oxaliplatin chemosensitivity in HCT116 and DLD1 cells. Mechanistically, oxaliplatin treatment upregulated WTAP expression, preventing multiple forms of cell death simultaneously, a process known as PANoptosis, by decreasing intracellular oxidative stress through maintaining the expression of nuclear factor erythroid-2-related factor 2 (NRF2), a major antioxidant response element, in an m6A-dependent manner. In addition, high WTAP expression in CRC patients is associated with a poor prognosis and reduced benefit from standard chemotherapy by clinical data analysis of The Cancer Genome Atlas (TCGA) database and patient cohort study. These findings suggest that targeting WTAP-NRF2-PANoptosis axis could enhance the antitumor efficacy of oxaliplatin-based chemotherapy in CRC treatment.

CDKN1A promotes Cis-induced AKI by inducing cytoplasmic ROS production and ferroptosis

BACKGROUND AND OBJECTIVE

This study focuses on investigating the role of CDKN1A in cisplatin-induced AKI (acute kidney injury, AKI) and its potential as a biomarker for early diagnosis and therapeutic intervention by integrating bioinformatics analysis, machine learning, and experimental validation.

METHODS

We analyzed the GSE85957 dataset to find genes that changed between control and cisplatin-treated rats. Using bioinformatics and machine learning, we found 13 important genes related to ferroptosis and the P53 pathway. The key gene, CDKN1A, was identified using various algorithms. We then tested how reducing CDKN1A in human kidney cells affected cell health, ROS, and iron levels. We also checked how CDKN1A changes the levels of proteins linked to ferroptosis using Q-PCR and Western Blot.

RESULTS

CDKN1A was found to negatively regulate the G1/S phase transition and was associated with ferroptosis in p53 signaling. Experiments in human renal tubular epithelial cells (HK-2) and rat NRK-52E cells showed that CDKN1A knockdown mitigated cisplatin-induced cell injury by reducing oxidative stress and ferroptosis.

CONCLUSION

Our integrated approach identified CDKN1A as a biomarker for cisplatin-induced AKI. Its regulation could be key in AKI pathogenesis, offering new therapeutic insights and aiding in early diagnosis and intervention.

MG53 inhibits ferroptosis by targeting the p53/SLC7A11/GPX4 pathway to alleviate doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an anthracycline medication that is commonly used to treat solid tumors. However, DOX has limited clinical efficacy due to known cardiotoxicity. Ferroptosis is involved in DOX-induced cardiotoxicity (DIC). Although mitsugumin-53 (MG53) has cardioprotective effects and is expected to attenuate myocardial ischemic injury, its ability to inhibit DOX-induced ferroptosis has not been extensively studied. This research aims to investigate the pathophysiological impact of MG53 on DOX induced ferroptosis. Here, MG53 levels were evaluated in relation to the extent of ferroptosis by establishing in vivo and in vitro DIC mouse models. Additionally, myocardial specific MG53 overexpressing mice were used to study the effect of MG53 on cardiac function in DIC mice. The study found that the MG53 expression decreased in DOX treated mouse hearts or cardiomyocytes. However, MG53-overexpressing improved cardiac function in the DIC model and effectively reduced myocardial ferroptosis by increasing solute carrier family 7 member 11 (SLC7A11) and Glutathione peroxidase 4 (GPX4) levels, which were decreased by DOX. Mechanistically, MG53 binds to tumor suppressor 53 (p53) to regulate its ubiquitination and degradation. Ferroptosis induced by DOX was prevented by either MG53 overexpression or p53 knockdown in cardiomyocytes. The modulation of the p53/SLC7A11/GPX4 pathway by overexpression of MG53 can alleviate DOX induced ferroptosis. The study indicates that MG53 can provide protection against DIC by increasing p53 ubiquitination. These results highlight the previously unidentified role of MG53 in inhibiting ferroptosis to prevent DIC.

Epigenetic regulation of diverse regulated cell death modalities in cardiovascular disease: Insights into necroptosis, pyroptosis, ferroptosis, and cuproptosis

Cell death constitutes a critical component of the pathophysiology of cardiovascular diseases. A growing array of non-apoptotic forms of regulated cell death (RCD)-such as necroptosis, ferroptosis, pyroptosis, and cuproptosis-has been identified and is intimately linked to various cardiovascular conditions. These forms of RCD are governed by genetically programmed mechanisms within the cell, with epigenetic modifications being a common and crucial regulatory method. Such modifications include DNA methylation, RNA methylation, histone methylation, histone acetylation, and non-coding RNAs. This review recaps the roles of DNA methylation, RNA methylation, histone modifications, and non-coding RNAs in cardiovascular diseases, as well as the mechanisms by which epigenetic modifications regulate key proteins involved in cell death. Furthermore, we systematically catalog the existing epigenetic pharmacological agents targeting novel forms of RCD and their mechanisms of action in cardiovascular diseases. This article aims to underscore the pivotal role of epigenetic modifications in precisely regulating specific pathways of novel RCD in cardiovascular diseases, thus offering potential new therapeutic avenues that may prove more effective and safer than traditional treatments.

FTO alleviated ferroptosis in septic cardiomyopathy via mediating the m6A modification of BACH1

Sepsis is a global health challenge that results in systemic inflammation, oxidative stress, and multi-organ dysfunction, with the heart being particularly susceptible. This study aimed to elucidate the effect of FTO, a key regulator in m6A methylation in septic cardiomyopathy, and its potential therapeutic implications. Cellular and animal models of septic myocardial injury were established. Moreover, it was revealed that ferroptosis, which is a form of programmed necrosis occurring with iron dependence, was activated within cardiomyocytes during septic conditions. The overexpression of FTO-suppressed ferroptosis alleviated heart inflammation and dysfunction and improved survival rates in vivo. However, the protective effects of FTO were attenuated by the overexpression of BACH1, which is a molecule negatively correlated with FTO. Mechanistically, FTO modulated the m6A modification of BACH1, suggesting a complex interplay in the regulation of cardiomyocyte damage and sepsis. Our findings reveal the potential of targeting the FTO/BACH1 axis and ferroptosis inhibitors as therapeutic strategies for sepsis-induced cardiac injuries.

Role of M6a Methylation in Myocardial Ischemia-Reperfusion Injury and Doxorubicin-Induced Cardiotoxicity

Cardiovascular disease remains the leading cause of death worldwide, with acute myocardial infarction and anticancer drug-induced cardiotoxicity being the significant factors. The most effective treatment for acute myocardial infarction is rapid restoration of coronary blood flow by thrombolytic therapy or percutaneous coronary intervention. However, myocardial ischemia-reperfusion injury (MI/RI) after reperfusion therapy is common in acute myocardial infarction, thus affecting the prognosis of patients with acute myocardial infarction. There is no effective treatment for MI/RI. Anthracyclines such as Doxorubicin (DOX) have limited clinical use due to their cardiotoxicity, and the mechanism of DOX-induced cardiac injury is complex and not yet fully understood. N6-methyladenosine (m6A) plays a crucial role in many biological processes. Emerging evidence suggests that m6A methylation plays a critical regulatory role in MI/RI and DOX-induced cardiotoxicity (DIC), suggesting that m6A may serve as a novel biomarker and therapeutic target for MI/RI and DIC. M6A methylation may mediate the pathophysiological processes of MI/RI and DIC by regulating cellular autophagy, apoptosis, oxidative stress, and inflammatory response. In this paper, we first focus on the relationship between m6A methylation and MI/RI, then further elucidate that m6A methylation may mediate the pathophysiological process of MI/RI through the regulation of cellular autophagy, apoptosis, oxidative stress, and inflammatory response. Finally, briefly outline the roles played by m6A in DIC, which will provide a new methodology and direction for the research and treatment of MI/RI and DIC.

Medicinal chemistry aspects of fat mass and obesity associated protein: structure, function and inhibitors

Adiposity and obesity-related proteins (FTO), the earliest identified mRNA N6-methyladenosine (m6A) demethylases, are known to play crucial roles in several biological processes. Therefore, FTO is a promising target for anticancer treatment. Understanding the biological functions and regulatory mechanisms of FTO targets can serve as guidelines for drug development. Despite significant efforts to develop FTO inhibitors, no specific small-molecule inhibitors have entered clinical trials so far. In this manuscript, we review the relationship between FTO and various cancers, the small-molecule inhibitors developed against FTO targets from the perspective of medicinal chemistry and other fields, and describe their structural optimization process and structure-activity relationship, providing clues for their future development direction.

Protective Role of Dioscin against Doxorubicin-Induced Chronic Cardiotoxicity: Insights from Nrf2-GPX4 Axis-Mediated Cardiac Ferroptosis

Recent evidence suggests that ferroptosis, an iron-facilitated cell death with excessive lipid peroxidation, is a critical mechanism underlying doxorubicin (DOX)-induced cardiotoxicity (DIC). Although dioscin has been reported to improve acute DIC, direct evidence is lacking to clarify the role of dioscin in chronic DIC and its potential mechanism in cardiac ferroptosis. In this study, we used chronic DIC rat models and H9c2 cells to investigate the potential of dioscin to mitigate DIC by inhibiting ferroptosis. Our results suggest that dioscin significantly improves chronic DIC-induced cardiac dysfunction. Meanwhile, it significantly inhibited DOX-induced ferroptosis by reducing Fe2+ and lipid peroxidation accumulation, maintaining mitochondrial integrity, increasing glutathione peroxidase 4 (GPX4) expression, and decreasing acyl-CoA synthetase long-chain family 4 (ACSL4) expression. Through transcriptomic analysis and subsequent validation, we found that the anti-ferroptotic effects of dioscin are achieved by regulating the nuclear factor-erythroid 2-related factor 2 (Nrf2)/GPX4 axis and Nrf2 downstream iron metabolism genes. Dioscin further downregulates nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) and upregulates expression of frataxin (FXN) and ATP-binding cassette B8 (ABCB8) to limit mitochondrial Fe2+ and lipid peroxide accumulation. However, Nrf2 inhibition diminishes the anti-ferroptotic effects of dioscin, leading to decreased GPX4 expression and increased lipid peroxidation. This study is a compelling demonstration that dioscin can effectively reduce DIC by inhibiting ferroptosis, which is dependent on the Nrf2/GPX4 pathway modulation.