Regulation Of Ferroptosis Research Articles

A lipid droplet-targeting fluorescence probe for monitoring of lipid peroxidation in ferroptosis and non-alcoholic fatty liver disease

Ferroptosis is a new regulated cell death process executed by lipid peroxidation (LPO) of polyunsaturated fatty acids. Lipid droplets (LDs), as an important organelle for lipid storage and metabolism, are probably a major site of LPO and play critical roles in the regulation of ferroptosis. However, the detailed study on LPO in LDs has not been carried out because of the lack of LD-targeting tools for the in situ monitoring of LPO. Herein, the first LD-targeting LPO fluorescence probe (LD-LPO) has been developed. LD-LPO exhibits a rapid and selective fluorescence enhancement at 518 nm, which is unaffected by highly destructive reactive oxygen species (e.g., hydroxyl radical) and environmental factor changes (e.g., polarity and viscosity). LD-LPO is capable of targeting LDs and visualizing LPO within LDs in situ during erastin- or (1S,3R)-RSL3 (RSL3)-induced ferroptosis. Moreover, LD-LPO has also been used to image LPO in the ferroptosis-associated non-alcoholic fatty liver disease (NAFLD), and to evaluate the medicine treatment of NAFLD with saroglitazar, demonstrating its utility for monitoring LPO levels in biosystems. The favorable analytical and imaging performance of LD-LPO may allow its application in more ferroptosis-associated physiological and pathological processes.

New Treatment Modalities for Colorectal Cancer Through Simultaneous Suppression of FSP1 and GPX4.

Ferroptosis is a nonapoptotic type of cell death that is dependent on iron and involves the accumulation of reactive oxygen species. Ferroptosis suppressor protein 1 (FSP1) and glutathione peroxidase 4 (GPX4) are ferroptosis regulators that inhibit ferroptosis through independent pathways. This study assessed the prognostic value of GPX4 and FSP1 expression in colorectal cancer (CRC). We also examined the effects of FSP1 and GPX4 inhibition on cell survival of CRC cells. This study included 206 surgical specimens from Stage II or III CRC patients. FSP1 and GPX4 expression was analyzed immunohistochemically, and the association of their expression levels with clinical outcome was evaluated. We also examined the effects of FSP1 and GPX4 inhibitors on the cell proliferative capacity of CRC cell lines. Overall survival and recurrence-free survival were reduced in patients with high expression of FSP1 or GPX4, and those with both GPX4 and FSP1 expression showed worse prognosis. Positivity of both FSP1 and GPX4 was an independent poor prognostic factor for CRC patients. In CRC cells, the combination of GPX4 and FSP1 inhibitors led to more effective cell death than either inhibitor alone. High expression of both GPX4 and FSP1 is a significant poor prognostic factor for CRC. Simultaneous inhibition of GPX4 and FSP1 to induce ferroptosis may be a novel therapeutic strategy in CRC.

Biomaterial-Mediated Metabolic Regulation of Ferroptosis for Cancer Immunotherapy.

Ferroptosis is a lipid peroxidation-driven cell death route and has attracted enormous interest for cancer therapy. Distinct from other forms of regulated cell death, its process is involved with multiple metabolic pathways including lipids, bioenergetics, iron, and so on, which influence cancer cell ferroptosis sensitivity and communication with the immune cells in the tumor microenvironment. Development of novel technologies for harnessing the ferroptosis-associated metabolic regulatory network would profoundly improve our understanding of the immune responses and enhance the efficacy of ferroptosis-dependent immunotherapy. Interestingly, the recent advances in bio-derived material-based therapeutic platforms offer novel opportunities to therapeutically modulate tumor metabolism through the insitu delivery of molecular or material cues, which not only allows the tumor-specific elicitation of ferroptosis but also holds promise to maximize their immunostimulatory impact. In this review, we will first dissect the crosstalk between tumor metabolism and ferroptosis and its impact on the immune regulation in the tumor microenvironment, followed by the comprehensive analysis on the recent progress in biomaterial-based metabolic regulatory strategies for evoking ferroptosis-mediated antitumor immunity. A perspective section is also provided to discuss the challenges in metabolism-regulating biomaterials for ferroptosis-immunotherapy. We envision that this review may provide new insights for improving tumor immunotherapeutic efficacy in the clinic.

Biochanin A inhibits excitotoxicity-triggered ferroptosis in hippocampal neurons

Excitatory neurotransmitter-induced neuronal ferroptosis has been implicated in multiple neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Although there are several reports pertaining to the pharmacological activities of biochanin A, the effects of this isoflavone on excitotoxicity-triggered neuronal ferroptosis remain unclear. In this study, we demonstrate that biochanin A inhibits ferroptosis of mouse hippocampal neurons induced by glutamate or the glutamate analog, kainic acid. Biochanin A significantly inhibited accumulation of intracellular iron and lipid peroxidation in glutamate- or kainic acid-treated mouse hippocampal neurons. Furthermore, biochanin A regulated the level of glutathione peroxidase 4, a master regulator of ferroptosis, by modulating its autophagy-dependent degradation. We observed that biochanin A reduced the glutamate-induced accumulation of intracellular iron by regulating expression of iron metabolism-related proteins including ferroportin-1, divalent metal transferase 1, and transferrin receptor 1. Taken together, these results indicate that biochanin A effectively inhibits hippocampal neuronal death triggered by glutamate or kainic acid. Our study is the first to report that biochanin A has therapeutic potential for the treatment of diseases associated with hippocampal neuronal death, particularly ferroptosis induced by excitatory neurotransmitter.

MicroRNA-mediated regulation of Ferroptosis: Implications for disease pathogenesis and therapeutic interventions

MicroRNA-mediated regulation of Ferroptosis: Implications for disease pathogenesis and therapeutic interventions

Critical role of non-coding RNA-mediated ferroptosis in urologic malignancies.

Urologic malignancies, characterized by their high aggressiveness and metastatic potential, pose a significant public health challenge globally. Ferroptosis, a novel mode of cell death, typically arises from intracellular iron ion overload and the accumulation of lipid peroxides. This process has been shown to play a crucial regulatory role in various pathological conditions, particularly in cancer, including urologic cancers. However, the comprehensive regulatory mechanisms underlying ferroptosis remain poorly understood, which somewhat limits its broader application in cancer therapy. Non-coding RNAs (ncRNAs), which encompass microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), are non-coding transcripts that play pivotal roles in various physiological processes, such as proliferation, differentiation, apoptosis, and cell cycle regulation, by modulating the expression of target genes. The biological functions and potential regulatory mechanisms of ncRNAs in the context of cancer-related ferroptosis have been partially elucidated. Research indicates that ncRNAs can influence the progression of urologic cancers by affecting cell proliferation, migration, and drug resistance through the regulation of ferroptosis. Consequently, this review aims to clarify the functions and mechanisms of the ncRNA-ferroptosis axis in urologic cancers and to evaluate the clinical significance of ferroptosis-related ncRNAs, thereby providing new insights into cancer biology and therapeutic strategies that may ultimately benefit a diverse range of cancer patients.

CHAC1: a master regulator of oxidative stress and ferroptosis in human diseases and cancers.

CHAC1, an essential regulator of oxidative stress and ferroptosis, is increasingly recognized for its significant roles in these cellular processes and its impact on various human diseases and cancers. This review aims to provide a comprehensive overview of CHAC1's molecular functions, regulatory mechanisms, and effects in different pathological contexts. Specifically, the study objectives are to elucidate the biochemical pathways involving CHAC1, explore its regulatory network, and discuss its implications in disease progression and potential therapeutic strategies. As a γ-glutamyl cyclotransferase, CHAC1 degrades glutathione, affecting calcium signaling and mitochondrial function. Its regulation involves transcription factors like ATF4 and ATF3, which control CHAC1 mRNA expression. CHAC1 is crucial for maintaining redox balance and regulating cell death pathways in cancer. Its elevated levels are associated with poor prognosis in many cancers, indicating its potential as a biomarker and therapeutic target. Additionally, CHAC1 influences non-cancerous diseases such as neurodegenerative and cardiovascular disorders. Therapeutically, targeting CHAC1 could increase cancer cell sensitivity to ferroptosis, aiding in overcoming resistance to standard treatments. This review compiles current knowledge and recent discoveries, emphasizing CHAC1's vital role in human diseases and its potential in diagnostic and therapeutic applications.

Activation of protein kinase B rescues against thapsigargin-elicited cardiac dysfunction through regulation of NADPH oxidase and ferroptosis

Endoplasmic reticulum (ER) stress is a known contributor to cardiac remodeling and contractile dysfunction. Although NADPH oxidase has been implicated in ER stress-induced organ damage, its specific role in myocardial complications resulting from ER stress remains unclear. This study aimed to investigate the possible involvement of NADPH oxidase in ER stress-induced myocardial abnormalities and to evaluate the impact of Akt constitutive activation on these myocardial defects. Mice with cardiac-specific overexpression of active mutant of Akt (Myr-Akt) and their wild-type (WT) littermates were treated with ER stress instigator thapsigargin (1 mg/kg, i. p. 72 hrs) before evaluating myocardial morphology and function. Our results noted that thapsigargin significantly impaired echocardiographic parameters and cell shortening indices, including elevated LVESD, decreased ejection fraction, fractional shortening, peak shortening, electrically-stimulated intracellular Ca2+ release, and cardiomyocyte survival. These functional deteriorations were accompanied by upregulation of NADPH oxidase, O2− production, mitochondrial damage, carbonyl formation, lipid peroxidation, apoptosis, and interstitial fibrosis, with unchanged myocardial size. Constitutive Akt hyperactivation did not generate any response on myocardial morphology and function, although it greatly suppressed or nullified thapsigargin-induced myocardial remodeling and dysfunction. Thapsigargin also triggered dephosphorylation of Akt and its downstream signal GSK3β, along with development of ferroptosis, all of which were nullified by Akt hyperactivation. In vitro studies further revealed that thapsigargin provoked cardiomyocyte mechanical anomalies and lipid peroxidation, similar to in vivo results. These effects were reverted by inhibitors of NADPH oxidase and ferroptosis (apocynin and LIP1). Collectively, our data denote an important protective role for Akt hyperactivation in thapsigargin-evoked myocardial anomalies, likely through NADPH oxidase-mediated regulation of ferroptosis.

Low Iron Diet Improves Clinical Arthritis in the Mouse Model of Collagen-Induced Arthritis.

Background: In response to inflammation, the absorption of nutritional iron is restricted. Since the pathophysiological significance of the presence and uptake of iron in chronic inflammation is still unknown, we tested the effect of a low iron diet on the clinical course of arthritis in the mouse model of collagen-induced arthritis (CIA). Methods: Six- to eight-week-old male DBA/1 mice were fed either a normal (51 mg/kg) or a low iron diet (5 mg/kg) starting four weeks before the first immunization. From day 4 after the second collagen booster made on day 25, the development of arthritis was regularly monitored until the end of the experiment (day 34), using a standard clinical arthritis score. Concentrations of mouse anti-bovine and anti-mouse collagen type 2 IgG antibodies were measured by ELISA; blood cell counts were performed and mediators of inflammation, tissue matrix degradation, oxygenation and oxidative stress were measured in the mouse sera of both diet groups at the end of the experiment by bead-based multiplex assay. Fe2+, Fe3+, oxidized and reduced glutathione (GSH and GSSG) and malondialdehyde (MDA) were quantified in whole paw tissue by ELISA. Quantitative PCR was performed in the tissues for glutathione peroxidase 4 and other key regulator genes of iron metabolism and ferroptosis. We used nonparametric tests to compare cross-sectional data. Nonlinear regression models were used for longitudinal data of the arthritis scores. Results: Mice fed a low iron diet showed a significantly less severe course of arthritis compared to mice fed a normal iron diet (p < 0.001). The immune response against bovine and mouse type 2 collagen did not differ between the two diet groups. Mice fed a low iron diet exhibited significantly lower serum levels of tissue inhibitor of metalloproteinase-1 (TIMP-1), a central regulator of inflammation and tissue matrix degradation (p < 0.05). In addition, a low iron diet led to a significant reduction in red blood cell indices, indicating restricted iron uptake and latent iron deficiency, but had no effect on hemoglobin concentrations or red blood cell counts. There were no differences between the dietary groups in Fe2+ or Fe3+ content in the paws. Based on calculation of the GSH/GSSG ratio and high MDA levels, high oxidative stress and lipid peroxidation were likewise detected in the paws of both diet groups of mice. Consequently, no differences associated with gene expression of key regulators of iron metabolism and ferroptosis could be detected between the paws of both diet groups. Conclusions: Restricted dietary iron intake alleviates immune-mediated inflammation in CIA without causing anemia. This finding suggests a promising option for dietary treatment of arthritis in inflammation. The underlying mechanism causing reduced arthritis may be linked to the complex regulatory network of TIMP-1 and appears to be independent from the local iron levels, oxidative stress and ferroptosis in the synovial tissues.

MDH2 Promotes Hepatocellular Carcinoma Growth Through Ferroptosis Evasion via Stabilizing GPX4.

The crosstalk between tumor progression and ferroptosis is largely unknown. Here, we identify malate dehydrogenase 2 (MDH2) as a key regulator of ferroptosis. MDH2 deficiency inhibits the growth of hepatocellular carcinoma (HCC) cells and enhances their sensitivity to ferroptosis induced by RAS-selective lethal 3 (RSL3), a compound known to cause ferroptosis. MDH2 knock-down enhances RSL3-induced intracellular reactive oxygen species, free iron ions and lipid per-oxides levels, leading to HCC ferroptotic cell death which is rescued by ferrostatin-1 and iron chelator deferiprone. Importantly, the inhibition of HCC cell growth caused by MDH2 deficiency is partially rescued by ferroptosis blockade. Mechanistically, MDH2 resists RSL3-induced ferroptosis sensitivity dependent on glutathione peroxidase 4 (GPX4), an enzyme responsible for scavenging lipid peroxides, which is stabilized by MDH2 in HCC. The protein expressions of MDH2 and GPX4 are positively correlated with each other in HCC cell lines. Furthermore, through our UALCAN website analysis, we found that MDH2 and GPX4 are highly expressed in HCC samples. These findings reveal a critical mechanism by which HCC evades ferroptosis via MDH2-mediated stabilization of GPX4 to promote tumor progression and underscore the potential of MDH2 inhibition in combi-nation with ferroptosis inducers for the treatment of HCC.

Ferroptosis: A key regulator and potential target for tissue injury.

The maintenance of iron homeostasis is essential for proper body function. A growing body of evidence suggests that iron imbalance is the common denominator in many tissue injuries, including acute, chronic, and reperfusion injuries. Ferroptosis, a novel form of programmed cell death due to metabolic abnormalities, has become increasingly recognized as an important process mediating the pathogenesis and progression of numerous tissue injuries, including cerebral, myocardial, lung, liver, kidney, and intestinal injuries. Therefore, a thorough understanding of the mechanisms involved in the regulation of ferroptosis might contribute to improvements in disease management. In this review, we summarize the importance of ferroptosis in various tissue injuries, discuss the potential targets of ferroptosis in the treatment of tissue injuries, and describe the current limitations and future directions of these novel treatment targets.

Identification of a Novel Signature Based on Ferritinophagy-Related Genes to Predict Prognosis in Lung Adenocarcinoma: Focus on AHNAK2

Background: Lung adenocarcinoma (LUAD) accounts for over 40% of all non-small cell lung cancer (NSCLC) cases and continues to be difficult to treat despite advancements in diagnostics and therapies. Ferritinophagy, a newly recognized autophagy process linked to ferroptosis, has been associated with LUAD development. Recent studies have shown a dysregulation of genes related to ferritinophagy in LUAD, indicating its potential as a therapeutic target. Methods: We constructed a predictive model using seven genes associated with ferritinophagy. The model’s accuracy was evaluated across three independent gene expression datasets. We analyzed the biological functions, immune environment, mutations, and drug sensitivities in groups with high and low risk. Utilizing a single-cell sequencing (scRNA-seq) dataset, we confirmed the expression of the model genes and identified a subtype of epithelial cells expressing AHNAK2. We further investigated the impact of the ferritinophagy-related gene AHNAK2 on LUAD cell proliferation, invasion, migration, and ferroptosis in vitro. Results: Our prediction model, comprising seven genes (AHNAK2, ARNTL2, CD27, LTB, SLC15A1, SLC2A1, and SYT1), has shown potential in predicting the prognosis of individuals diagnosed with LUAD. Notably, AHNAK2 impedes ferroptosis, promoting LUAD progression in vitro. Conclusions: Our research suggests that ferritinophagy-associated genes are promising prognostic markers for LUAD and lay the groundwork for further exploration of ferritinophagy’s role in LUAD. Furthermore, we present AHNAK2 as a novel regulator of ferroptosis, which requires further investigation to understand its mechanism.

Puerarin Ameliorates Ferroptosis in Neuronal Injury Through the PI3K/AKT Signaling Pathway

Ferroptosis plays an important role in the pathogenesis of neuronal damage, generally mediated by iron and lipid peroxidation. In the present study, we measured the protective effects of puerarin against corticosterone-induced neuronal injury via PI3K/AKT-mediated activation of nuclear factor erythroid 2-related factor 2 (Nrf2). After exposing corticosterone-treated PC12 cells to indicated compounds, we measured the key regulators of ferroptosis (ferritin, SLC7A11, and Ptgs2), ferroptosis events (levels of iron, ROS, MDA, and GSH), and the PI3K/AKT/Nrf2 axis. Corticosterone induced ferroptosis in PC12 cells, evidenced by reduced levels of ferritin, SLC7A11, and GSH and increased levels of iron, ROS, and MDA. These effects were reversed by inhibiting ferroptosis with ferrostatin-1. Puerarin-mediated activation of Nrf2 repressed ferroptosis in corticosterone-treated PC12 cells by upregulating ferritin and SLC7A11 expression. Moreover, the protective effects of puerarin on ferroptosis in corticosterone-treated cells relied on the activation of the PI3K/AKT pathway though the upregulation of nuclear Nrf2. These findings indicate that ferroptosis plays an essential role in corticosterone-induced neuronal damage, and puerarin protects against ferroptosis in corticosterone-treated cells via PI3K/AKT-mediated activation of Nrf2.

Ante-mortem glutathione peroxidase 4 inhibition by RSL3 affects post-mortem meat quality in broiler chickens

ABSTRACT 1. This study investigated the role of glutathione peroxidase 4 (GPX4), a key regulator of ferroptosis, a form of programmed cell death, in muscle biochemistry and meat quality, utilising broiler chickens whose ante-mortem GPX4 activity was inhibited pharmacologically. 2. Male broilers were divided into two groups, each receiving ante-mortem administration of the GPX4 inhibitor, Ras-selective lethal 3 (RSL3), or a vehicle only. After slaughter, breast muscles were collected and stored for 48 h. The expressions of ferroptosis-related genes, glutathione levels, pH, colour and water-holding capacity were evaluated at multiple time points during the storage period. 3. The RSL3 treatment decreased the expression of GPX4 and ferritin heavy chain 1, which are negative regulators of ferroptosis, while it increased the expression of a ferroptosis accelerator, acyl-CoA synthetase long chain family member 4. The ratio of reduced to oxidised glutathione was significantly decreased in the RSL3 group. The RSL3 treatment decelerated post-mortem pH decline and colour changes, such as a decrease in L* and an increase in a* were observed in the RSL3 group. In addition, the RSL3 group showed increased levels of water-holding capacity. 4. These findings suggested that ante-mortem GPX4 activity plays a role in determining meat quality, implying the possible involvement of ferroptosis in the mechanism by which skeletal muscle is converted after slaughter into meat that is eaten.

Regulation of renal ischemia-reperfusion injury and tubular epithelial cell ferroptosis by pparγ m6a methylation: mechanisms and therapeutic implications

This study aimed to elucidate the role and underlying mechanisms of Peroxisome proliferator-activated receptor gamma (PPARγ) and its m6A methylation in renal ischemia-reperfusion (I/R) injury and ferroptosis of tubular epithelial cells (TECs). High-throughput transcriptome sequencing was performed on renal tissue samples from I/R injury models and sham-operated mice, complemented by in vivo and in vitro experiments focusing on the PPARγ activator Rosiglitazone and the manipulation of METTL14 and IGF2BP2 expression. Key evaluations included renal injury assessment, ferroptosis indicator measurement, and m6A methylation analysis of PPARγ. Our findings highlight the critical role of the PPARγ pathway and ferroptosis in renal I/R injury, with Rosiglitazone ameliorating renal damage and TEC ferroptosis. METTL14-mediated m6A methylation of PPARγ, dependent on IGF2BP2, emerged as a pivotal regulator of PPARγ expression, renal injury, and ferroptosis. This study reveals that PPARγ m6A methylation, orchestrated by METTL14 through an IGF2BP2-dependent mechanism, plays a crucial role in mitigating renal I/R injury and TEC ferroptosis. These insights offer promising avenues for therapeutic strategies targeting acute kidney injury.

Deciphering heart failure: an integrated proteomic and transcriptomic approach with experimental validation.

This study analyzed transcriptomic and proteomic data to identify molecular changes during heart failure (HF). Additionally,we embarked on an exploration of the prospect of therapeutic intervention through the manipulation of proteins implicated in ferroptosis. Three publicly available microarray datasets (GSE135055, GSE147236, GSE161472) profiling left ventricular samples from HF patients and healthy controls were obtained. Differentially expressed genes were identified in each dataset and cross-analyzed to determine shared gene signatures. Enrichment analysis of Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and gene set enrichment analysis were performed. Differentially expressed proteins were obtained from published proteomic studies and integrated with the transcriptomic results. To validate findings, a HF mouse model was generated and ferroptosis-related proteins were evaluated. Additionally, the effect of suppression of ferroptosis on hypoxia-induced ischemia model in HL-1 cardiomyocytes was assessed by knocking down Acyl-CoA synthetase long-chain family member 4 (ACSL4) using small interfering RNA (siRNA).Cross-analysis of differentially expressed genes (DEGs) in the GSE135055, GSE147236 and GSE161472 datasets revealed 224 up-regulated and 187 down-regulated potential genes which showed high enrichment in immune, inflammatory and metabolic pathways. Notably, four proteins, among them ACSL4, displayed consistent alterations at both the transcriptional and protein levels. In the HF mouse model, ACSL4 exhibited an elevation, whereas negative regulators of ferroptosis witnessed a decrement. Subsequently, knockdown of ACSL4 in a hypoxia-induced ischemic HL-1 cardiomyocyte cell model upregulated the expression of ferroptosis inhibitory protein and decreased the levels of reactive oxygen species (ROS), malondialdehyde (MDA)., and free iron and increased cell viability. Comprehensive multi-omics analysis revealed that the expression of the molecular target ACSL4 was increased in HF. Targeting ACSL4 to inhibit ferroptosis may represent a novel therapeutic strategy for HF treatment.

The Protective Effects of Polygala tenuifolia and Tenuifolin on Corticosterone-Evoked Ferroptosis, Oxidative Stress, and Neuroinflammation: Insights from Molecular Dynamics Simulations and In Vitro Experiments.

Excessive stress is a well-established contributor to neurological damage, insomnia, and depression, imposing a significant burden on individuals and society. This underscores the urgent need for effective stress-relief strategies. The main purpose of this study was to explore the protective effects of Polygala tenuifolia (PT) and its bioactive compound, tenuifolin, against corticosterone-induced neurotoxicity, with a focus on ferroptosis, oxidative stress, and neuroinflammation. Both PT extracts and tenuifolin mitigated corticosterone-induced cellular damage. Tenuifolin reversed the corticosterone-induced dysregulation of ferroptosis-associated proteins, such as SLC7A11, GPX4, and Nrf2, leading to a marked reduction in ferroptosis levels. Molecular dynamics simulations revealed that corticosterone significantly altered the conformation and binding energy of the SLC7A11/SLC3A2 complex, critical for ferroptosis regulation. These changes were reversed by tenuifolin. Additionally, tenuifolin alleviated corticosterone-induced oxidative stress and neuroinflammation, both of which accelerated ferroptosis. In conclusion, these results indicate that tenuifolin attenuates corticosterone-induced neurotoxicity by modulating ferroptosis, oxidative stress, and neuroinflammation. This study provides a theoretical foundation for the application of PT and tenuifolin in stress-induced nerve damage.

Regulation Mechanisms of the Glutamate Transporter in the Response of Pacific Oyster upon High-Temperature Stress.

Glutamate transporters (GLTs) are integral to the glutamatergic system, modulating glutamate homeostasis to enhance resilience and resistance against environmental stress. There are six GLTs identified in the Pacific oyster (Crassostrea gigas), which were categorized into two subfamilies: excitatory amino acid transporters (CgEAATs) and vesicular glutamate transporters (CgVGLUTs). The CgEAATs harbor a GltP domain, while CgVGLUTs feature an MFS domain, both with conserved sequence and structural characteristics. The expression of CgGLTs is elevated during the planktonic larval stage compared to the fertilized egg stage and is constitutively expressed in various tissues of adult oysters, suggesting its critical role in both larval development and the physiological processes of adult oysters. Transcriptomic analysis revealed diverse expression patterns of GLTs in oyster gills after 7 days of high-temperature stress, with CgEAAT3 showing a significant upregulation. A KEGG pathway enrichment analysis identified glutathione metabolism and ferroptosis as prominently enriched pathways. At 48 h after high-temperature stress, the expression levels of Glutathione Peroxidase 4 (CgGPX4) and CgEAAT3, along with elevated Fe content in the gills, significantly increased. Moreover, the RNAi-mediated the inhibition of CgEAAT3 expression under high-temperature stress, resulting in a significant reduction in CgGPX4 expression and a further increase in Fe accumulation in oyster gills. These results indicate that CgEAAT3 contributes to the regulation of ferroptosis and redox homeostasis by modulating CgGPX4 expression. This study provides new insights into the adaptive mechanisms of bivalves to environmental stress.

Methionine-SAM metabolism-dependent ubiquinone synthesis is crucial for ROS accumulation in ferroptosis induction

Ferroptosis is a cell death modality in which iron-dependent lipid peroxides accumulate on cell membranes. Cysteine, a limiting substrate for the glutathione system that neutralizes lipid peroxidation and prevents ferroptosis, can be converted by cystine reduction or synthesized from methionine. However, accumulating evidence shows methionine-based cysteine synthesis fails to effectively rescue intracellular cysteine levels upon cystine deprivation and is unable to inhibit ferroptosis. Here, we report that methionine-based cysteine synthesis is tissue-specific. Unexpectedly, we find that rather than inhibiting ferroptosis, methionine in fact plays an essential role during cystine deprivation-induced ferroptosis. Methionine-derived S-adenosylmethionine (SAM) contributes to methylation-dependent ubiquinone synthesis, which leads to lipid peroxides accumulation and subsequent ferroptosis. Moreover, SAM supplementation synergizes with Imidazole Ketone Erastin in a tumor growth suppression mouse model. Inhibiting the enzyme that converts methionine to SAM protects heart tissue from Doxorubicin-induced and ferroptosis-driven cardiomyopathy. This study broadens our understanding about the intersection of amino acid metabolism and ferroptosis regulation, providing insight into the underlying mechanisms and suggesting the methionine-SAM axis is a promising therapeutic strategy to treat ferroptosis-related diseases.

HPV16 integration regulates ferroptosis resistance via the c-Myc/miR-142-5p/HOXA5/SLC7A11 axis during cervical carcinogenesis

BackgroundFerroptosis, a newly identified form of regulated cell death triggered by small molecules or specific conditions, plays a significant role in virus-associated carcinogenesis. However, whether tumours arising after high-risk HPV integration are associated with ferroptosis is unexplored and remains enigmatic.MethodsHigh-risk HPV16 integration was analysed by high­throughput viral integration detection (HIVID). Ferroptosis was induced by erastin, and the levels of ferroptosis were assessed through the measurement of lipid-reactive oxygen species (ROS), malondialdehyde (MDA), intracellular Fe2+ level and transmission electron microscopy (TEM). Additionally, clinical cervical specimens and an in vivo xenograft model were utilized for the study.ResultsExpression of HPV16 integration hot spot c-Myc negatively correlates with ferroptosis during the progression of cervical squamous cell carcinoma (CSCC). Further investigation revealed that the upregulated oncogene miR-142-5p in HPV16-integrated CSCC cells served as a critical downstream effector of c-Myc in its target network. Inhibiting miR-142-5p significantly decreased the ferroptosis-suppressing effect mediated by c-Myc. Through a combination of computational and experimental approaches, HOXA5 was identified as a key downstream target gene of miR-142-5p. Overexpression of miR-142-5p suppressed HOXA5 expression, leading to decreased accumulation of intracellular Fe2+ and lipid peroxides (ROS and MDA). HOXA5 increased the sensitivity of CSCC cells to erastin-induced ferroptosis via transcriptional downregulation of SLC7A11, a negative regulator of ferroptosis. Importantly, c-Myc knockdown increased the anti-tumour activity of erastin by promoting ferroptosis both in vitro and in vivo.ConclusionsCollectively, these data indicate that HPV16 integration hot spot c-Myc plays a novel and indispensable role in ferroptosis resistance by regulating the miR-142-5p/HOXA5/SLC7A11 signalling axis and suggest a potential therapeutic approach for HPV16 integration-related CSCC.