Acetylation Is Crucial for p53-Mediated Ferroptosis and Tumor Suppression

The role of ferroptosis in Alzheimer's disease: Mechanisms and therapeutic potential (Review)

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by insidious onset and progressive symptom deterioration. It extends beyond a simple aging process, involving irreversible and progressive neurological degeneration that impairs brain function through multiple etiologies. Iron dysregulation is implicated in the pathophysiology of AD; however, the precise mechanisms remain unclear. Additionally, vitamin E and selenium are key in regulating ferroptosis through their antioxidant properties. The present review examined the mechanistic pathways by which ferroptosis contributes to AD, the regulatory roles of vitamin E, selenium, ferrostatin‑1, N‑acetylcysteine and curcumin, and their potential as therapeutic agents to mitigate neurodegeneration.

Ferroptosis: A Targetable Vulnerability for Melanoma Treatment

Melanoma is a devastating form of skin cancer characterized by a high mutational burden, limited treatment success, and dismal prognosis. Although immunotherapy and targeted therapies have significantly revolutionized melanoma treatment, the majority of patients fail to achieve durable responses, highlighting the urgent need for novel therapeutic strategies. Ferroptosis, an iron-dependent form of regulated cell death driven by the overwhelming accumulation of lipid peroxides, has emerged as a promising therapeutic approach in preclinical melanoma models. A deeper understanding of the ferroptosis landscape in melanoma based on its biology characteristics, including phenotypic plasticity, metabolic state, genomic alterations, and epigenetic changes, as well as the complex role and mechanisms of ferroptosis in immune cells could provide a foundation for developing effective treatments. In this review, we outline the molecular mechanisms of ferroptosis, decipher the role of melanoma biology in ferroptosis regulation, reveal the therapeutic potential of ferroptosis in melanoma, and discuss the pressing questions that should guide future investigations into ferroptosis in melanoma.

Ferroptosis: the potential key roles in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive interstitial lung disease characterized by recurrent injury to alveolar epithelial cells, epithelial-mesenchymal transition, and fibroblast activation, which leads to excessive deposition of extracellular matrix (ECM) proteins. However, effective preventative and therapeutic interventions are currently lacking. Ferroptosis, a unique form of iron-dependent lipid peroxidation-induced cell death, exhibits distinct morphological, physiological, and biochemical features compared to traditional programmed cell death. Recent studies have revealed a close relationship between iron homeostasis and the pathogenesis of pulmonary interstitial fibrosis. Ferroptosis exacerbates tissue damage and plays a crucial role in regulating tissue repair and the pathological processes involved. It leads to recurrent epithelial injury, where dysregulated epithelial cells undergo epithelial-mesenchymal transition via multiple signaling pathways, resulting in the excessive release of cytokines and growth factors. This dysregulated environment promotes the activation of pulmonary fibroblasts, ultimately culminating in pulmonary fibrosis. This review summarizes the latest advancements in ferroptosis research and its role in the pathogenesis and treatment of IPF, highlighting the significant potential of targeting ferroptosis for IPF management. Importantly, despite the rapid developments in this emerging research field, ferroptosis studies continue to face several challenges and issues. This review also aims to propose solutions to these challenges and discusses key concepts and pressing questions for the future exploration of ferroptosis.

p53-regulated non-apoptotic cell death pathways and their relevance in cancer and other diseases

Programmed cell death is a mechanism that is crucial for numerous physiological and pathological processes. Whereas p53-mediated apoptosis is a major cell death pathway in cancer, accumulating evidence indicates that p53 also has crucial roles in controlling different non-apoptotic cell death (NACD) pathways, including ferroptosis, necroptosis, pyroptosis, autophagy-dependent cell death, entotic cell death, parthanatos and paraptosis, and may regulate PANoptosis, cuproptosis and disulfidptosis. Notably, the function of p53 in these NACDs substantially contributes to its biological effects, particularly in cancer development and other pathological processes. In this Review, we discuss recent advances in understanding the roles and underlying mechanisms of p53-mediated NACDs, focusing on ferroptosis, necroptosis and pyroptosis. We discuss the complex and distinct physiological settings in which NACDs are regulated by p53, and potential targeting of p53-regulated NACDs for the treatment of cancer and other human diseases. Finally, we highlight several important questions concerning p53-regulated NACDs that warrant further investigation.

Epigenetic regulation of iron metabolism and ferroptosis in Parkinson's disease: Identifying novel epigenetic targets

Parkinson's disease (PD) is a neurodegenerative disease, and emerging evidence has shown that iron deposition, ferroptosis and epigenetic modifications are implicated in the pathogenesis of PD. However, the interplay among these factors in PD has not been fully understood. In this review, we provide an overview of the current research progress on iron metabolism, ferroptosis and epigenetic alterations associated with PD. Furthermore, we present new frontiers concerning various epigenetic modifications related to iron metabolism and ferroptosis that might contribute to the pathology of PD. Notably, epigenetic modifications of iron metabolism and ferroptosis as both diagnostic and therapeutic targets in PD have been discussed. This opens new avenues for the regulation of iron homeostasis and ferroptosis in PD from epigenetic perspectives, and provides evidence for their potential implications in the diagnosis and treatment of PD.

Nanomaterial-Triggered Ferroptosis and Cuproptosis in Cancer Therapy

Cancer remains one of the leading causes of the death of individuals globally. Conventional treatment techniques like chemotherapy and radiation often suffer various drawbacks like toxicity and drug resistance. The study of cell death has been predominantly focused on classical forms like apoptosis, but the role of metal ions in governing controlled cell death is a fascinating and less explored area. Metal-mediated controlled cell death is a process where metal triggers cell death via a unique mechanism. Nanomaterial-based strategies have gained attention for their ability to deliver precise therapeutic agents while also triggering Regulated Cell Death (RCD) mechanisms in cancer cells. The recently discovered metal-mediated controlled cell death techniques like cuproptosis and ferroptosis can be used in cancer treatment as they can be used selectively for the treatment of drug-resistant cancer. Nano material-based delivery system can also be used for the precise delivery of the drug to the targeted sites. In this review, we have given some idea about the mechanism of metal-mediated controlled cell death techniques (ferroptosis and cuproptosis) and how we can initiate controlled cell deaths using nanomaterials for cancer treatment.

Emerging insights into the role of microRNAs regulation of ferroptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major type of liver cancer and an important cause of cancer death. It has been reported that the hepatocyte death plays an important role in HCC. Ferroptosis is an iron-dependent programmed cell death characterized by the accumulation of free iron and lipid peroxidation. A series of studies have shown that ferroptosis contributes to the occurrence and development of HCC. MicroRNAs (miRNAs) are non-coding RNAs with a length of approximately 222 nt. In recent years, miRNAs have been shown to participate in regulating ferroptosis to play a vital role in HCC, but the related mechanisms are not fully understood. This review summarized the current understanding of ferroptosis, as well as the biogenesis and function of miRNAs, and focused on the role of miRNAs regulation of ferroptosis in HCC, with the hope of providing new targets and ideas for the treatment of HCC.

Important molecular mechanisms in ferroptosis

Ferroptosis is a type of cell death that is caused by the oxidation of lipids and is dependent on the presence of iron. It was first characterized by Brent R. Stockwell in 2012, and since then, research in the field of ferroptosis has rapidly expanded. The process of ferroptosis-induced cell death is genetically, biochemically, and morphologically distinct from other forms of cellular death, such as apoptosis, necroptosis, and non-programmed cell death. Extensive research has been devoted to comprehending the intricate process of ferroptosis and the various factors that contribute to it. While the majority of these studies have focused on examining the effects of lipid metabolism and mitochondria on ferroptosis, recent findings have highlighted the significant involvement of signaling pathways and associated proteins, including Nrf2, P53, and YAP/TAZ, in this process. This review provides a concise summary of the crucial signaling pathways associated with ferroptosis based on relevant studies. It also elaborates on the drugs that have been employed in recent years to treat ferroptosis-related diseases by targeting the relevant signaling pathways. The established and potential therapeutic targets for ferroptosis-related diseases, such as cancer and ischemic heart disease, are systematically addressed.

Ferroptosis contributes to immunosuppression

As a novel form of cell death, ferroptosis is mainly regulated by the accumulation of soluble iron ions in the cytoplasm and the production of lipid peroxides and is closely associated with several diseases, including acute kidney injury, ischemic reperfusion injury, neurodegenerative diseases, and cancer. The term "immunosuppression" refers to various factors that can directly harm immune cells' structure and function and affect the synthesis, release, and biological activity of immune molecules, leading to the insufficient response of the immune system to antigen production, failure to successfully resist the invasion of foreign pathogens, and even organ damage and metabolic disorders. An immunosuppressive phase commonly occurs in the progression of many ferroptosis-related diseases, and ferroptosis can directly inhibit immune cell function. However, the relationship between ferroptosis and immunosuppression has not yet been published due to their complicated interactions in various diseases. Therefore, this review deeply discusses the contribution of ferroptosis to immunosuppression in specific cases. In addition to offering new therapeutic targets for ferroptosis-related diseases, the findings will help clarify the issues on how ferroptosis contributes to immunosuppression.

Ferroptosis and its relationship with cancer

Marked by iron buildup and lipid peroxidation, ferroptosis is a relatively new regulatory cell death (RCD) pathway. Many diseases like cancer, myocardial ischemia-reperfusion injury (MIRI), neurological disorders and acute renal failure (AKI) are corelated with ferroptosis. The main molecular processes of ferroptosis discovered yet will be presented here, along with the approaches in which it interacts with tumour-associated signaling pathways and its uses in systemic therapy, radiation therapy, and immunotherapy managing tumors.

Ferroptosis-related signaling pathways in cancer drug resistance

Ferroptosis is an iron-dependent form of programmed cell death induced by lipid peroxidation. This process is regulated by signaling pathways associated with redox balance, iron metabolism, and lipid metabolism. Cancer cells' increased iron demand makes them especially susceptible to ferroptosis, significantly influencing cancer development, therapeutic response, and metastasis. Recent findings indicate that cancer cells can evade ferroptosis by downregulating key signaling pathways related to this process, contributing to drug resistance. This underscores the possibility of modulating ferroptosis as an approach to counteract drug resistance and enhance therapeutic efficacy. This review outlines the signaling pathways involved in ferroptosis and their interactions with cancer-related signaling pathways. We also highlight the current understanding of ferroptosis in cancer drug resistance, offering insights into how targeting ferroptosis can provide novel therapeutic approaches for drug-resistant cancers. Finally, we explore the potential of ferroptosis-inducing compounds and examine the challenges and opportunities for drug development in this evolving field.

AZD1775 synergizes with SLC7A11 inhibition to promote ferroptosis

Tumor suppressor p53-mediated cell cycle arrest and DNA damage repair may exert cytoprotective effects against cancer therapies, including WEE1 inhibition. Considering that p53 activation can also lead to multiple types of cell death, the role of this tumor suppressor in WEE1 inhibitor-based therapies remains disputed. In this study, we reported that nucleolar stress-mediated p53 activation enhanced the WEE1 inhibitor AZD1775-induced ferroptosis to suppress lung cancer growth. Our findings showed that AZD1775 promoted ferroptosis by blocking cystine uptake, an action similar to that of Erastin. Meanwhile, inhibition of WEE1 by the WEE1 inhibitors or siRNAs induced compensatory upregulation of SLC7A11, which conferred resistance to ferroptosis. Mechanistically, AZD1775 prevented the enrichment of H3K9me3, a histone marker of transcriptional repression, on the SLC7A11 promoter by repressing the expression of the histone methyltransferase SETDB1, thereby enhancing NRF2-mediated SLC7A11 transcription. This finding was also validated using the H3K9me3 inhibitor BRD4770. Remarkably, we found that the nucleolar stress-inducing agent Actinomycin D (Act. D) inhibited SLC7A11 expression by activating p53, thus augmenting AZD1775-induced ferroptosis. Moreover, the combination of AZD1775 and Act. D synergistically suppressed wild-type p53-harboring lung cancer cell growth both in vitro and in vivo. Altogether, our study demonstrates that AZD1775 promotes ferroptosis by targeting cystine uptake but also mediates the adaptive activation of SLC7A11 through the WEE1-SETDB1 cascade and NRF2-induced transcription, and inhibition of SLC7A11 by Act. D boosts the anti-tumor efficacy of AZD1775 by enhancing ferroptosis in cancers with wild-type p53.

Anti-oxidants as therapeutic agents for oxidative stress associated pathologies: future challenges and opportunities

Free radicals have been implicated in the pathogenesis of cancer along with cardiovascular, neurodegenerative, pulmonary and inflammatory disorders. Further, the relationship between oxidative stress and disease is distinctively established. Clinical trials using anti-oxidants for the prevention of disease progression have indicated some beneficial effects. However, these trials failed to establish anti-oxidants as therapeutic agents due to lack of efficacy. This is attributed to the fact that living systems are under dynamic redox control wherein their redox behavior is compartmentalized and simple aggregation of redox couples, distributed throughout the system, is of miniscule importance while determining their overall redox state. Further, free radical metabolism is intriguingly complex as they play plural roles segregated in a spatio-temporal manner. Depending on quality, quantity and site of generation, free radicals exhibit beneficial or harmful effects. Use of nonspecific, non-targeted, general ROS scavengers lead to systemic elimination of all types of ROS and interferes in cellular signaling. Failure of anti-oxidants to act as therapeutic agents lies in this oversimplification of extremely dynamic cellular redox environment as a static and non-compartmentalized redox state. Rather than generalizing the term "oxidative stress" if we can identify the "type of oxidative stress" in different types of diseases, a targeted and more specific anti-oxidant therapy may be developed. In this review, we discuss the concept of redox dynamics, role and type of oxidative stress in disease conditions, and current status of anti-oxidants as therapeutic agents. Further, we probe the possibility of developing novel, targeted and efficacious anti-oxidants with drug-like properties.

RRFERV stabilizes TEAD1 expression to mediate nasopharyngeal cancer radiation resistance rendering tumor cells vulnerable to ferroptosis

BACKGROUND

Long noncoding RNAs (lncRNAs) regulate various essential biological processes, including cell proliferation, differentiation, apoptosis, migration, and invasion. However, in nasopharyngeal carcinoma (NPC), the clinical significance and mechanisms of lncRNAs in malignant progression are unknown.

METHODS

RNA sequencing and bioinformatic analysis were used to determine the potential function of RRFERV (radiation-resistant but ferroptosis-vulnerable), and its biological effects were investigated using in vitro and in vivo experiments. Western blotting, quantitative real-time reverse transcription PCR, RNA immunoprecipitation (RIP) assays, and flow cytometry detected RRFERV expression. Ferroptosis and lipid peroxidation were added to evaluate the relationship between it and radiotherapy resistance.

RESULTS

LncRNA-RRFERV was both highly expressed in NPC tissues and radiation-resistant cells. RRFERV is associated with poor clinical outcomes of NPC patients and stabilizes TEAD1 by competitive binding with microRNA-615-5p and microRNA-1293. RRFERV-TEAD1 signaling axis leads to malignant progression and radiotherapy resistance of NPC. Furthermore, we observed that NPC radiotherapy-resistance cells exist in a fragile oxidative stress equilibrium, which makes them more sensitive to ferroptosis inducers. Surprisingly, we found that RRFERV-TEAD1 signaling axis also plays a key role in mediating the lipid peroxidation levels of NPC radiotherapy-resistance cells through transcriptional activation of ACSL4/TFRC.

CONCLUSIONS

RRFERV serves as an independent prognostic factor in NPC. During the malignant progression of NPC caused by high expression of RRFERV, ferroptosis can be induced to effectively kill cancer cells and reverse the radiotherapy resistance of NPC cells, suggesting a potential treatment approach for recurrent and refractory NPC.

The molecular and metabolic landscape of ferroptosis in respiratory diseases: Pharmacological aspects

Ferroptosis is a form of cell death that occurs when there is an excess of reactive oxygen species (ROS), lipid peroxidation, and iron accumulation. The precise regulation of metabolic pathways, including iron, lipid, and amino acid metabolism, is crucial for cell survival. This type of cell death, which is associated with oxidative stress, is controlled by a complex network of signaling molecules and pathways. It is also implicated in various respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), lung cancer, pulmonary fibrosis (PF), and the coronavirus disease 2019 (COVID-19). To combat drug resistance, it is important to identify appropriate biological markers and treatment targets, as well as intervene in respiratory disorders to either induce or prevent ferroptosis. The focus is on the role of ferroptosis in the development of respiratory diseases and the potential of targeting ferroptosis for prevention and treatment. The review also explores the interaction between immune cell ferroptosis and inflammatory mediators in respiratory diseases, aiming to provide more effective strategies for managing cellular ferroptosis and respiratory disorders.

Ferroptosis: mechanisms and therapeutic targets

Ferroptosis is a nonapoptotic form of cell death characterized by iron-dependent lipid peroxidation in membrane phospholipids. Since its identification in 2012, extensive research has unveiled its involvement in the pathophysiology of numerous diseases, including cancers, neurodegenerative disorders, organ injuries, infectious diseases, autoimmune conditions, metabolic disorders, and skin diseases. Oxidizable lipids, overload iron, and compromised antioxidant systems are known as critical prerequisites for driving overwhelming lipid peroxidation, ultimately leading to plasma membrane rupture and ferroptotic cell death. However, the precise regulatory networks governing ferroptosis and ferroptosis-targeted therapy in these diseases remain largely undefined, hindering the development of pharmacological agonists and antagonists. In this review, we first elucidate core mechanisms of ferroptosis and summarize its epigenetic modifications (e.g., histone modifications, DNA methylation, noncoding RNAs, and N6-methyladenosine modification) and nonepigenetic modifications (e.g., genetic mutations, transcriptional regulation, and posttranslational modifications). We then discuss the association between ferroptosis and disease pathogenesis and explore therapeutic approaches for targeting ferroptosis. We also introduce potential clinical monitoring strategies for ferroptosis. Finally, we put forward several unresolved issues in which progress is needed to better understand ferroptosis. We hope this review will offer promise for the clinical application of ferroptosis-targeted therapies in the context of human health and disease.

Ferroptosis: A new way to intervene in the game between Mycobacterium tuberculosis and macrophages

Mycobacterium tuberculosis (Mtb), the main pathogen responsible for the high mortality and morbidity of tuberculosis (TB) worldwide, primarily targets and invades macrophages. Infected macrophages activate a series of immune mechanisms to clear Mtb, however, Mtb evades host immune surveillance through subtle immune escape strategies to create a microenvironment conducive to its own proliferation, growth, and dissemination, while inducing immune cell death. The course of TB is strongly correlated with the form of cell death, including apoptosis, pyroptosis, and necrosis. Recent studies have revealed that ferroptosis, a novel type of programmed cell death characterized by iron-dependent lipid peroxidation, is closely linked to the regulatory mechanisms of TB. The central role of ferroptosis in the pathologic process of TB is increasingly becoming a focal point for exploring new therapeutic targets in this field. This paper will delve into the dynamic game between Mtb and host immune cells, especially the role of ferroptosis in the pathogenesis of TB. At the same time, this paper will analyze the regulatory pathways of ferroptosis and provide unique insights and innovative perspectives for TB therapeutic strategies based on the ferroptosis mechanism. This study not only expands the theoretical basis of TB treatment, but also points out the direction of future drug development, providing new possibilities for overcoming this global health problem.

Identification of new hub- ferroptosis-related genes in Lupus Nephritis

Background: Lupus Nephritis (LN) is the primary causation of kidney injury in systemic lupus erythematosus (SLE). Ferroptosis is a programmed cell death. Therefore, understanding the crosstalk between LN and ferroptosis is still a significant challenge. Methods: We obtained the expression profile of LN kidney biopsy samples from the Gene Expression Omnibus database and utilised the R-project software to identify differentially expressed genes (DEGs). Then, we conducted a functional correlation analysis. Ferroptosis-related genes (FRGs) and differentially expressed genes (DEGs) crossover to select FRGs with LN. Afterwards, we used CIBERSORT to assess the infiltration of immune cells in both LN tissues and healthy control samples. Finally, we performed immunohistochemistry on LN human renal tissue. Results: 10619 DEGs screened from the LN biopsy tissue were identified. 22 hub-ferroptosis-related genes with LN (FRGs-LN) were screened out. The CIBERSORT findings revealed that there were significant statistical differences in immune cells between healthy control samples and LN tissues. Immunohistochemistry further demonstrated a significant difference in HRAS, TFRC, ATM, and SRC expression in renal tissue between normal and control groups. Conclusion: We developed a signature that allowed us to identify 22 new biomarkers associated with FRGs-LN. These findings suggest new insights into the pathology and therapeutic potential of LN ferroptosis inhibitors and iron chelators.

Bronchopulmonary dysplasia: analysis and validation of ferroptosis-related diagnostic biomarkers and immune cell infiltration features

BACKGROUND

Early and precise diagnosis of bronchopulmonary dysplasia (BPD) is essential to improve the prognosis of preterm infants with BPD. Studying ferroptosis-related genes for diagnostic markers of BPD was the objective of this study.

METHODS

Using the GEO database and the FerrDb database, we obtained the GSE32472 dataset and screened the ferroptosis-related differentially expressed mRNAs (FRDE-mRNAs). By using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG), possible biological functions and pathways were identified for FRDE-mRNAs. Three machine learning algorithms (LASSO, SVM-RFE, Random Forest) were used to recognize hub genes, as well as CIBERSORT for exploring the immune landscape of BPD and controls. Functional predictions for hub genes were made using single-gene gene set enrichment analysis (GSEA).

RESULTS

Twenty three FRDE-mRNAs were obtained and were mainly involved in autophagy, fatty acid metabolism and ferroptosis. The four hub genes (LPIN1, ACADSB, WIPI1 and SLC7A11) screened were utilized to construct a diagnostic nomogram. The receiver operating characteristic (ROC) curves and calibration curves demonstrateld that the nomogram exhibited good predictive performance. Eight types of immune cell markers differed significantly between BPD and controls.

CONCLUSION

We developed a diagnostic model for BPD, which could facilitate the early diagnosis and timely intervention of BPD.

IMPACT

The role of ferroptosis in bronchopulmonary dysplasia is rarely reported. The ferroptosis-related genes (LPIN1, ACADSB, WIPI1 and SLC7A11) we identified could serve as early diagnostic biomarkers for BPD. Immune cell infiltration features in BPD and signaling pathways associated with marker genes give new insight into the disease process and provide a basis for further research.

The Emerging Roles of Hydrogen Sulfide in Ferroptosis

Significance: Ferroptosis, a form of regulated cell death characterized by a large amount of lipid peroxidation-mediated membrane damage, joins the evolution of multisystem diseases, for instance, neurodegenerative diseases, chronic obstructive pulmonary disease, acute respiratory distress syndrome, osteoporosis, osteoarthritis, and so forth. Since being identified as the third gasotransmitter in living organisms, the intricate role of hydrogen sulfide (H2S) in ferroptosis has emerged at the forefront of research. Recent Advances: Novel targets in the relevant metabolic pathways have been found, including transferrin receptor 1, cystine/glutamate antiporter, and others, coupled with the exploration of new signaling pathways, particularly the p53 signaling pathway, the nitric oxide/nuclear factor erythroid 2-related factor 2 signaling pathway, and so on. Many diseases such as emphysema and airway inflammation, myocardial diseases, endothelial dysfunction in aging arteries, and traumatic brain injury have recently been found to be alleviated directly by H2S inhibition of ferroptosis. Safe, effective, and tolerable novel H2S donors have been developed and have shown promising results in phase I clinical trials. Critical Issues: Complicated cross talk between the ferroptosis signaling pathway and oncogenic factors results in the risk of cancer when inhibiting ferroptosis. Notably, targeted delivery of H2S is still a challenging task. Future Directions: Discovering more reliable and stable novel H2S donors and achieving their targeted delivery will enable further clinical trials for diseases associated with ferroptosis inhibition by H2S, determining their safety, efficacy, and tolerance. Antioxid. Redox Signal. 41, 1150-1172.

2-hydroxy-3-methyl anthraquinone promotes apoptosis and inhibits invasion of human hepatocellular carcinoma cells by targeting nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-1/cellular tumor antigen p53 signaling pathway

OBJECTIVE

To investigate the anti-liver cancer effect of 2-hydroxy-3-methyl anthraquinone (HMA) and the specific mechanism based on nicotinamide adenine dinucleotide-dependent protein deacetylase sirtuin-1 (SIRT1)/cellular tumor antigen p53 (p53) pathway.

METHODS

Cell counting kit-8 method was used to observe the effect of HMA on the activity of human hepatocellular carcinoma cells (HepG2) cells. At 72 h and 80 μL HMA, the apoptosis rate of HepG2 cells in each group was measured by flow cytometry. Transwell was used to assay for cell invasion. The protein expression levels of SIRT1, p53, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), caspase-9 (CASP9) and caspase-3 (CASP3) were detected by Western Blot.

RESULTS

HMA significantly inhibited the proliferation of HepG2 cells, The half inhibiting concentration (IC50) of the HMA at 24, 48 and 72 h were examined and it were 126.3, 98.6, and 80.55 μM, respectively. Compared with the control group, the apoptosis rate of HMA, Selisistat (EX527), and HMA+ EX527 groups enhanced, while the apoptosis rate of SRT1720 diminished, demonstrating that inhibition of SIRT1 can lead to apoptosis of HepG2 cells. HMA+ EX527 group had the highest apoptosis rate, the lowest expression of SIRT1 and Bcl-2, and the highest expression of p53, Bax, CASP9 and CASP3. The number of invasions of HepG2 was significantly reduced after HMA and EX527 intervened. Western blot shows HMA could inhibit SIRT1, promote the expression of p53, and decrease the ratio of Bcl-2/Bax.

CONCLUSIONS

HMA induced apoptosis in HepG2 cells, while inhibiting proliferation and invasion. The mechanism of HMA against HCC may be related to the SIRT1/p53 pathway.

NEDD4L contributes to ferroptosis and cell growth inhibition in esophageal squamous cell carcinoma by facilitating xCT ubiquitination

The oncogene xCT plays an indispensable role in tumor growth by protecting cancer cells from oxidative stress and ferroptosis. Emerging evidence indicated xCT function is tightly controlled by posttranslational modifications, especially ubiquitination. However, it still remains unclear what specific regulatory mechanism of xCT by ubiquitin ligases in human cancers. Here, we reported that NEDD4L, an E3 ubiquitin ligases, inhibited esophageal squamous cell carcinoma (ESCC) tumor growth and facilitated ferroptosis by ubiquitination of xCT. NEDD4L expression was declined in ESCC and was associated with tumor invasion, lymph node metastasis and distant metastasis. Silencing NEDD4L triggered ESCC tumor growth. Meanwhile, knock down of NEDD4L prevented the accumulation of ROS, elevated the level of GSH, reduced the content of MDA in ESCC cells, thereby inhibiting ferroptosis. Mechanistically, NEDD4L directly bound to the ∆CT domain of xCT through its WW and HECT domain. More importantly, NEDD4L promoted xCT degradation by facilitating its polyubiquitination in ESCC cells. Collectively, these findings suggest that NEDD4L is crucial in governing the stability of xCT and mediating ferroptosis in ESCC.

FXR deficiency induced ferroptosis via modulation of the CBP-dependent p53 acetylation to suppress breast cancer growth and metastasis

Farnesoid X receptor (NR1H4/FXR) functions as a scavenger of lipid peroxide products and drives the proliferation and metastasis of various cancers. However, the underlying molecular mechanisms remain poorly understood. In our study, we found that the expression levels of FXR, vimentin and SLC7A11 were significantly higher in breast cancer tissues, particularly in metastatic cancer tissues compared to non-metastatic ones. Furthermore, the increased FXR expression was positively correlated with vimentin and SLC7A11 in clinical tumor specimens. In addition, a high level of FXR correlated with poor prognosis in patients with breast cancer. Both Z-Guggulsterone (Z-GS), as a pharmacological inhibitor of FXR, and silencing FXR curbed proliferation and migration of breast cancer cells by promoting ferroptosis. Notably, our results showed that FXR competitively bound to CREB-binding protein (CBP) to suppress the interaction between p53 and CBP in the nucleus, and thus prevented p53 acetylation at lys382, which was essential for upregulating the expression of SLC7A11. Conversely, FXR knockdown increased the interaction between p53 and CBP and promoted p53 acetylation, which ultimately led to facilitating ferroptosis in breast cancer cells. More importantly, we also found that Z-GS inhibited TGF-β1-induced tumor growth and metastasis of breast cancer primarily through ferroptosis via regulating CBP-dependent p53 acetylation in nude mice. In conclusion, the FXR was first reported as a tumor promoter that enhanced the proliferation and metastasis of breast cancer cells through regulating CBP-dependent p53 K382 acetylation. It proposes that FXR may serve as a potential therapeutic target for the treatment of breast cancer.

Ferroptosis in Cancer: Epigenetic Control and Therapeutic Opportunities

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, has emerged as a critical pathway in cancer biology. This review delves into the epigenetic mechanisms that modulate ferroptosis in cancer cells, focusing on how DNA methylation, histone modifications, and non-coding RNAs influence the expression and function of essential genes involved in this process. By unraveling the complex interplay between these epigenetic mechanisms and ferroptosis, the article sheds light on novel gene targets and functional insights that could pave the way for innovative cancer treatments to enhance therapeutic efficacy and overcome resistance in cancer therapy.

xCT as a Predictor for Survival in a Population-Based Cohort of Head and Neck Squamous Cell Carcinoma

BACKGROUND

xCT, also known as SLC7A11 (solute carrier Family 7 Member 11), is a cystine/glutamate antiporter protein that mediates regulated cell death and antioxidant defense. The aim of this study was to investigate the effect of xCT on the outcome of patients diagnosed with new head and neck squamous cell carcinoma (HNSCC).

METHODS

This retrospective cohort study utilized a population-based dataset, comprising all patients (n = 1033) diagnosed with new HNSCC during 2005-2015 in a population of 697,000 people. All patients (n = 585) with a tumor tissue sample available for immunohistochemical (IHC) staining were included. The follow-up rates were 97% and 81% at 3 and 5 years, respectively. Also, the specificity of the anti-xCT antibody was validated.

RESULTS

The expression level and prognostic significance of xCT were strongly dependent on tumor location. In oropharyngeal squamous cell carcinoma (OPSCC) patients, xCT expression was a significant prognostic factor for 5-year overall survival (OAS) (HR: 2.71; 95% CI 1.67-4.39; p < 0.001), disease-specific survival (DSS) (HR: 2.58; 95% CI 1.47-4.54; p = 0.001), and disease-free survival (DFS) (HR: 2.69; 95% CI 1.55-4.64; p < 0.001). Five-year survival rates for OPSCC patients with high and low levels of xCT were OAS 34% versus 62%; DSS 51% versus 73%; DFS 43% versus 73%, respectively. According to a multivariate model adjusted for age, T-class, nodal positivity, and tobacco consumption, xCT was an independent prognostic factor for 3-year survival, in which it outperformed p16 IHC. Similar associations were not observed in squamous cell carcinomas of oral cavity or larynx. Regarding treatment modalities, xCT was most predictive in HNSCC patients who received radiotherapy.

CONCLUSIONS

High xCT expression was associated with poor prognosis in OPSCC. Our findings suggest that joint analysis of xCT and p16 may add significant value in OPSCC treatment stratification.

The intricate interplay between ferroptosis and efferocytosis in cancer: unraveling novel insights and therapeutic opportunities

The complex interplay between ferroptosis and efferocytosis in cancer has attracted significant interest recently. Efferocytosis, the process of eliminating apoptotic cells, is essential for preserving tissue homeostasis and reducing inflammation. However, dysregulation of efferocytosis can have profound effects on cancer. Apoptotic cells accumulate because of impaired efferocytosis, which triggers chronic inflammation and the release of pro-inflammatory chemicals. Surprisingly, accumulating evidence suggests that dysregulation of ferroptosis- a form of controlled cell death characterized by lipid peroxidation and the buildup iron-dependent reactive oxygen species (ROS)-can influence efferocytic activities within the tumor microenvironment. Dysfunctional iron metabolism and increased lipid peroxidation, are associated with ferroptosis, resulting in inadequate apoptotic cell clearance. Conversely, apoptotic cells can activate ferroptotic pathways, increasing oxidative stress and inducing cell death in cancer cells. This reciprocal interaction emphasizes the complex relationship between efferocytosis and ferroptosis in cancer biology. Understanding and managing the delicate balance between cell clearance and cell death pathways holds significant therapeutic potential in cancer treatment. Targeting the efferocytosis and ferroptosis pathways may offer new opportunities for improving tumor clearance, reducing inflammation, and sensitizing cancer cells to therapeutic interventions. Further research into the interaction between efferocytosis and ferroptosis in cancer will provide valuable insights for the development of novel therapies aimed at restoring tissue homeostasis and improving patient outcomes.

Multiple roles of p53 in cancer development: Regulation of tumor microenvironment, m6A modification and diverse cell death mechanisms

BACKGROUND

The protein p53, encoded by the most frequently mutated gene TP53 in human cancers, has diverse functions in tumor suppression. As a best known transcription factor, p53 can regulate various fundamental cellular responses, ranging from the cell-cycle arrest, DNA repair, senescence to the programmed cell death (PCD), which includes autophagy, apoptosis, ferroptosis, cuproptosis, pyroptosis and disulfidoptosis. Accumulating evidence has indicated that the tumor microenvironment (TME), N6-methyladenosine (m6A) modification and diverse PCD are important for the progression, proliferation and metastases of cancers.

AIM OF REVIEW

This paper aims to systematically and comprehensively summarize the multiple roles of p53 in the development of cancers from the regulation of TME, m6A Modification and diverse PCD.

KEY SCIENTIFIC CONCEPTS OF REVIEW

TME, a crucial local homeostasis environment, influences every step of tumorigenesis and metastasis. m6A, the most prevalent and abundant endogenous modification in eukaryotic RNAs, plays an essential role in various biological processes, containing the progression of cancers. Additionally, PCD is an evolutionarily conserved mechanism of cell suicide and a common process in living organisms. Some forms of PCD contribute to the occurrence and development of cancer. However, the complex roles of p53 within the TME, m6A modification and diverse PCD mechanisms are still not completely understood. Presently, the function roles of p53 including the wild-type and mutant p53 in different context are summarized. Additionally, the interaction between the cancer immunity, cancer cell death and RNA m6A methylation and the p53 regulation during the development and progress of cancers were discussed. Moreover, the key molecular mechanisms by which p53 participates in the regulation of TME, m6A and diverse PCD are also explored. All the findings will facilitate the development of novel therapeutic approaches.

Paeoniflorin suppresses ferroptosis after traumatic brain injury by antagonizing P53 acetylation

BACKGROUND

Traumatic brain injury (TBI) could induce multiple forms of cell death, ferroptosis, a novel form of cell death distinct from apoptosis and autophagy, plays an important role in disease progression in TBI. Therapies targeting ferroptosis are beneficial for recovery from TBI. Paeoniflorin (Pae) is a water-soluble monoterpene glycoside and the active ingredient of Paeonia lactiflora pall. It has been shown to exert anti-inflammatory and antioxidant effects. However The effects and mechanisms of paeoniflorin on secondary injury after TBI are unknown.

PURPOSE

To investigate the mechanism by which Pae regulates ferroptosis after TBI.

METHODS

The TBI mouse model and cortical primary neurons were utilized to study the protective effect of paeoniflorin on the brain tissue after TBI. The neuronal cell ferroptosis model was established by treating cortical primary neurons with erastin. Liproxstatin-1(Lip-1) was used as a positive control drug. Immunofluorescence staining, Nissl staining, biochemical analyses, pharmacological analyses, and western blot were used to evaluate the effects of paeoniflorin on TBI.

RESULTS

Pae significantly ameliorated neuronal damage after TBI, inhibited mitochondrial damage, increased glutathione peroxidase 4 (GPX4) activity, decreased malondialdehyde (MDA) production, restored neurological function and inhibited cerebral edema. Pae promotes the degradation of P53 in the form of proteasome, promotes its ubiquitination, and reduces the stability of P53 by inhibiting its acetylation, thus alleviating the P53-mediated inhibition of cystine/glutamate antiporter solute carrier family 7 member 11 (SLC7A11) by P53.

CONCLUSION

Pae inhibits ferroptosis by promoting P53 ubiquitination out of the nucleus, inhibiting P53 acetylation, and modulating the SLC7A11-GPX4 pathway.

Iron chelators as mitophagy agents: Potential and limitations

Mitochondrial autophagy (mitophagy) is very important process for the maintenance of cellular homeostasis, functionality and survival. Its dysregulation is associated with high risk and progression numerous serious diseases (e.g., oncological, neurodegenerative and cardiovascular ones). Therefore, targeting mitophagy mechanisms is very hot topic in the biological and medicinal research. The interrelationships between the regulation of mitophagy and iron homeostasis are now becoming apparent. In short, mitochondria are central point for the regulation of iron homeostasis, but change in intracellular cheatable iron level can induce/repress mitophagy. In this review, relationships between iron homeostasis and mitophagy are thoroughly discussed and described. Also, therapeutic applicability of mitophagy chelators in the context of individual diseases is comprehensively and critically evaluated.

Ferroptosis and its Potential Determinant Role in Myocardial Susceptibility to Ischemia/Reperfusion Injury in Diabetes

Myocardial ischemia/reperfusion injury (MIRI) is a major cause of cardiac death particularly in patients with diabetes. When the coronary artery is partially or completely blocked, restoration of blood perfusion can normally be achieved within a certain time due to the development of advanced techniques such as percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) surgery. However, cardiac tissue injury may aggravate progressively even after the ischemic myocardium is restored to normal perfusion. MIRI is often associated with various forms of cell death, including apoptosis, autophagy, programmed necrosis, pyroptosis, and ferroptosis, among others. Ferroptosis is known as iron-dependent cell death that is distinct from other programmed modes of cell death. Ferroptosis is under constitutive control by glutathione peroxidase 4 (GPX4), and the reduction of GPX4 may result in ferroptosis even if iron homeostasis is physiologically maintained. The essences of ferroptosis are substantial iron accumulation and lipid peroxidation that trigger cell death. Under impaired antioxidant system, cellular reactive oxygen species (ROS) accumulation leads to lipid peroxidation which consequently results in ferroptosis. Ferroptosis shares a few common features with several types of cell death and interplays with various forms of cell death such as autophagy and apoptosis in the development of cardiovascular diseases. More and more recent studies have demonstrated that ferroptosis plays an important role in MIRI. However, few studies have addressed the relative importance of ferroptosis in MIRI relative to other forms of cell deaths. In this review, we summarized the basic aspects and advances regarding the molecular pathogenesis of ferroptosis, evaluated its role in MIRI, and propose that the levels of ferroptosis may function as a major determinant of myocardial susceptibility to ischemia/reperfusion injury (IRI) in general and of the enhanced vulnerability to MIRI specifically in diabetes.

Functional Investigations of p53 Acetylation Enabled by Heterobifunctional Molecules

Post-translational modifications (PTMs) dynamically regulate the critical stress response and tumor suppressive functions of p53. Among these, acetylation events mediated by multiple acetyltransferases lead to differential target gene activation and subsequent cell fate. However, our understanding of these events is incomplete due to, in part, the inability to selectively and dynamically control p53 acetylation. We recently developed a heterobifunctional small molecule system, AceTAG, to direct the acetyltransferase p300/CBP for targeted protein acetylation in cells. Here, we expand AceTAG to leverage the acetyltransferase PCAF/GCN5 and apply these tools to investigate the functional consequences of targeted p53 acetylation in human cancer cells. We demonstrate that the recruitment of p300/CBP or PCAF/GCN5 to p53 results in distinct acetylation events and differentiated transcriptional activities. Further, we show that chemically induced acetylation of multiple hotspot p53 mutants results in increased stabilization and enhancement of transcriptional activity. Collectively, these studies demonstrate the utility of AceTAG for functional investigations of protein acetylation.

Metal ion interference therapy: metal-based nanomaterial-mediated mechanisms and strategies to boost intracellular "ion overload" for cancer treatment

Metal ion interference therapy (MIIT) has emerged as a promising approach in the field of nanomedicine for combatting cancer. With advancements in nanotechnology and tumor targeting-related strategies, sophisticated nanoplatforms have emerged to facilitate efficient MIIT in xenografted mouse models. However, the diverse range of metal ions and the intricacies of cellular metabolism have presented challenges in fully understanding this therapeutic approach, thereby impeding its progress. Thus, to address these issues, various amplification strategies focusing on ionic homeostasis and cancer cell metabolism have been devised to enhance MIIT efficacy. In this review, the remarkable progress in Fe, Cu, Ca, and Zn ion interference nanomedicines and understanding their intrinsic mechanism is summarized with particular emphasis on the types of amplification strategies employed to strengthen MIIT. The aim is to inspire an in-depth understanding of MIIT and provide guidance and ideas for the construction of more powerful nanoplatforms. Finally, the related challenges and prospects of this emerging treatment are discussed to pave the way for the next generation of cancer treatments and achieve the desired efficacy in patients.

p53 lysine-lactylated modification contributes to lipopolysaccharide-induced proinflammatory activation in BV2 cell under hypoxic conditions

p53 has diversity functions in regulation of transcription, cell proliferation, cancer metastasis, etc. Recent studies have shown that p53 and nuclear factor-κB (NF-κB) co-regulate proinflammatory responses in macrophages. However, the role of p53 lysine lactylation (p53Kla) in mediating proinflammatory phenotypes in microglia under hypoxic conditions remains unclear. In the current study, we investigated the proinflammatory activation exacerbated by hypoxia and the levels of p53Kla in microglial cells. BV2 cells, an immortalized mouse microglia cell line, were divided into control, lipopolysaccharide (LPS)-induced, hypoxia (Hy), and LPS-Hy groups. The protein expression levels of p53 and p53Kla and the activation of microglia were compared among the four groups. Sodium oxamate and mutant p53 plasmids were transfected into BV2 cells to detect the effect of p53Kla on microglial proinflammatory activation. LPS-Hy stimulation significantly upregulated p53Kla levels in both the nucleus and the cytoplasm of BV2 cells. In contrast, the p53 protein levels were downregulated. LPS-Hy stimulation upregulated phosphorylated p65 protein levels in nuclear and activated the NF-κB pathway in BV2 cells, resulting in increased expression of pro-inflammatory cytokines (iNOS, IL6, IL1β, TNFα), enhanced cell viability, and concomitantly, increased cytotoxicity. In conclusion, p53 lysine-lactylated modification contributes to LPS-induced proinflammatory activation in BV2 cells under hypoxia through NF-κB pathway and inhibition of lactate production may alleviate neuroinflammatory injury.

Protein modification and degradation in ferroptosis

Ferroptosis is a form of iron-related oxidative cell death governed by an integrated redox system, encompassing pro-oxidative proteins and antioxidative proteins. These proteins undergo precise control through diverse post-translational modifications, including ubiquitination, phosphorylation, acetylation, O-GlcNAcylation, SUMOylation, methylation, N-myristoylation, palmitoylation, and oxidative modification. These modifications play pivotal roles in regulating protein stability, activity, localization, and interactions, ultimately influencing both the buildup of iron and lipid peroxidation. In mammalian cells, regulators of ferroptosis typically undergo degradation via two principal pathways: the ubiquitin-proteasome system, which handles the majority of protein degradation, and autophagy, primarily targeting long-lived or aggregated proteins. This comprehensive review aims to summarize recent advances in the post-translational modification and degradation of proteins linked to ferroptosis. It also discusses strategies for modulating ferroptosis through protein modification and degradation systems, providing new insights into potential therapeutic applications for both cancer and non-neoplastic diseases.

Ferroptosis in health and disease

Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells' susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.

Design, Synthesis, and Evaluation of p53Y220C Acetylation Targeting Chimeras (AceTACs)

The well-known tumor suppressor p53 is mutated in approximately half of all cancers. The Y220C mutation is one of the major p53 hotspot mutations. Several small-molecule stabilizers of p53Y220C have been developed. We recently developed a new technology for inducing targeted protein acetylation, termed acetylation targeting chimera (AceTAC), and the first p53Y220C AceTAC that effectively acetylated p53Y220C at lysine 382. Here, we report structure-activity relationship (SAR) studies of p53Y220C AceTACs, which led to the discovery of a novel p53Y220C AceTAC, compound 11 (MS182). 11 effectively acetylated p53Y220C at lysine 382 in a time- and concentration-dependent manner via inducing the ternary complex formation between p300/CBP acetyltransferase and p53Y220C. 11 was more effective than the parent p53Y220C stabilizer in suppressing the proliferation and clonogenicity in cancer cells harboring the p53Y200C mutation and was bioavailable in mice. Overall, 11 is a potentially valuable chemical tool to investigate the role of p53Y220C acetylation in cancer.

A New Ferroptosis-Related Long Non-Coding RNA Risk Model Predicts the Prognosis of Patients With Papillary Thyroid Cancer

Background

Ferroptosis is a novel form of regulated cell death that involves in cancer progression. However, the role of ferroptosis-related long non-coding RNAs (lncRNAs) in papillary thyroid cancer (PTC) remains to be elucidated. The purpose of this paper was to clarify the prognostic value of ferroptosis-related lncRNAs in PTC.

Methods

The transcriptome data and clinical information were downloaded from The Cancer Genome Atlas (TCGA) database. The correlation between ferroptosis-related genes (FRGs) and lncRNA was determined using Pearson correlation analysis. Multivariate Cox regression model (P < 0.01) was performed to establish a ferroptosis-related lncRNAs risk model. Kaplan-Meier survival analysis, receiver operating characteristic (ROC) curves, risk curve and nomograms were then performed to assess the accuracy and clinical applicability of prognostic models. The correlations between the prognosis model and clinicopathological variables, immune and m6A were analyzed. Finally, in vitro assays were performed to verify the role of LINC00900, LINC01614 and PARAL1 on the proliferation, migration and invasion in TPC-1 and BCPAP cells, as well as the relationship between three lncRNAs and ferroptosis.

Results

A five-ferroptosis-related lncRNAs (PARAL1, LINC00900, DPH6-DT, LINC01614, LPP-AS2) risk model was constructed. Based on the risk score, samples were divided into the high- and low-risk groups. Patients in the low-risk group had better prognosis than those in high-risk group. Compared to traditional clinicopathological features, risk score was more accurate in predicting prognosis in patients with PTC. Additionally, the difference of immune cell, function and checkpoints was observed between two groups. Moreover, experiments showed that LINC00900 promoted the proliferation, migration and invasion in TPC-1 and BCPAP cells, while LINC01614 and PARAL1 revealed opposite effects, all of which were related to ferroptosis.

Conclusions

In summary, we identified a five-ferroptosis-related lncRNAs risk model to predict the prognosis of PTC. Furthermore, our study also revealed that LINC00900 functioned as a tumor suppressor lncRNA, LINC01614 and PARAL1 as an oncogenic lncRNA in PTC.

Ferrostatin-1 specifically targets mitochondrial iron-sulfur clusters and aconitase to improve cardiac function in Sirtuin 3 cardiomyocyte knockout mice

AIMS

Ferroptosis is a form of iron-regulated cell death implicated in ischemic heart disease. Our previous study revealed that Sirtuin 3 (SIRT3) is associated with ferroptosis and cardiac fibrosis. In this study, we tested whether the knockout of SIRT3 in cardiomyocytes (SIRT3cKO) promotes mitochondrial ferroptosis and whether the blockade of ferroptosis would ameliorate mitochondrial dysfunction.

METHODS AND RESULTS

Mitochondrial and cytosolic fractions were isolated from the ventricles of mice. Cytosolic and mitochondrial ferroptosis were analyzed by comparison to SIRT3loxp mice. An echocardiography study showed that SIRT3cKO mice developed heart failure as evidenced by a reduction of EF% and FS% compared to SIRT3loxp mice. Comparison of mitochondrial and cytosolic fractions of SIRT3cKO and SIRT3loxp mice revealed that, upon loss of SIRT3, mitochondrial, but not cytosolic, total lysine acetylation was significantly increased. Similarly, acetylated p53 was significantly upregulated only in the mitochondria. These data demonstrate that SIRT3 is the primary mitochondrial deacetylase. Most importantly, loss of SIRT3 resulted in significant reductions of frataxin, aconitase, and glutathione peroxidase 4 (GPX4) in the mitochondria. This was accompanied by a significant increase in levels of mitochondrial 4-hydroxynonenal. Treatment of SIRT3cKO mice with the ferroptosis inhibitor ferrostatin-1 (Fer-1) for 14 days significantly improved preexisting heart failure. Mechanistically, Fer-1 treatment significantly increased GPX4 and aconitase expression/activity, increased mitochondrial iron‑sulfur clusters, and improved mitochondrial membrane potential and Complex IV activity.

CONCLUSIONS

Inhibition of ferroptosis ameliorated cardiac dysfunction by specifically targeting mitochondrial aconitase and iron‑sulfur clusters. Blockade of mitochondrial ferroptosis may be a novel therapeutic target for mitochondrial cardiomyopathies.

Current Progress of Ferroptosis Study in Hepatocellular Carcinoma

Ferroptosis, an emerging type of programmed cell death, is initiated by iron-dependent and excessive ROS-mediated lipid peroxidation, which eventually leads to plasma membrane rupture and cell death. Many canonical signalling pathways and biological processes are involved in ferroptosis. Furthermore, cancer cells are more susceptible to ferroptosis due to the high load of ROS and unique metabolic characteristics, including iron requirements. Recent investigations have revealed that ferroptosis plays a crucial role in the progression of tumours, especially HCC. Specifically, the induction of ferroptosis can not only inhibit the growth of hepatoma cells, thereby reversing tumorigenesis, but also improves the efficacy of immunotherapy and enhances the antitumour immune response. Therefore, triggering ferroptosis has become a new therapeutic strategy for cancer therapy. In this review, we summarize the characteristics of ferroptosis based on its underlying mechanism and role in HCC and provide possible therapeutic applications.

Ferroptosis: a novel mechanism of cell death in ophthalmic conditions

Ferroptosis, a new type of programmed cell death proposed in recent years, is characterized mainly by reactive oxygen species and iron-mediated lipid peroxidation and differs from programmed cell death, such as apoptosis, necrosis, and autophagy. Ferroptosis is associated with a variety of physiological and pathophysiological processes. Recent studies have shown that ferroptosis can aggravate or reduce the occurrence and development of diseases by targeting metabolic pathways and signaling pathways in tumors, ischemic organ damage, and other degenerative diseases related to lipid peroxidation. Increasing evidence suggests that ferroptosis is closely linked to the onset and progression of various ophthalmic conditions, including corneal injury, glaucoma, age-related macular degeneration, diabetic retinopathy, retinal detachment, and retinoblastoma. Our review of the current research on ferroptosis in ophthalmic diseases reveals significant advancements in our understanding of the pathogenesis, aetiology, and treatment of these conditions.

Challenges of Regulated Cell Death: Implications for Therapy Resistance in Cancer

Regulated cell death, a regulatory form of cell demise, has been extensively studied in multicellular organisms. It plays a pivotal role in maintaining organismal homeostasis under normal and pathological conditions. Although alterations in various regulated cell death modes are hallmark features of tumorigenesis, they can have divergent effects on cancer cells. Consequently, there is a growing interest in targeting these mechanisms using small-molecule compounds for therapeutic purposes, with substantial progress observed across various human cancers. This review focuses on summarizing key signaling pathways associated with apoptotic and autophagy-dependent cell death. Additionally, it explores crucial pathways related to other regulated cell death modes in the context of cancer. The discussion delves into the current understanding of these processes and their implications in cancer treatment, aiming to illuminate novel strategies to combat therapy resistance and enhance overall cancer therapy.

Tumor suppressor Par-4 activates autophagy-dependent ferroptosis

Ferroptosis is a unique iron-dependent form of non-apoptotic cell death characterized by devastating lipid peroxidation. Whilst growing evidence suggests that ferroptosis is a type of autophagy-dependent cell death, the underlying molecular mechanisms regulating ferroptosis are largely unknown. In this study, through an unbiased RNA-sequencing screening, we demonstrate the activation of a multi-faceted tumor-suppressor protein Par-4/PAWR during ferroptosis. Functional studies reveal that genetic depletion of Par-4 effectively blocks ferroptosis, whereas Par-4 overexpression sensitizes cells to undergo ferroptosis. More importantly, we have determined that Par-4-triggered ferroptosis is mechanistically driven by the autophagic machinery. Upregulation of Par-4 promotes activation of ferritinophagy (autophagic degradation of ferritin) via the nuclear receptor co-activator 4 (NCOA4), resulting in excessive release of free labile iron and, hence, enhanced lipid peroxidation and ferroptosis. Inhibition of Par-4 dramatically suppresses the NCOA4-mediated ferritinophagy signaling axis. Our results also establish that Par-4 activation positively correlates with reactive oxygen species (ROS) production, which is critical for ferritinophagy-mediated ferroptosis. Furthermore, Par-4 knockdown effectively blocked ferroptosis-mediated tumor suppression in the mouse xenograft models. Collectively, these findings reveal that Par-4 has a crucial role in ferroptosis, which could be further exploited for cancer therapy.

Dihydroquercetin improves experimental acute liver failure by targeting ferroptosis and mitochondria-mediated apoptosis through the SIRT1/p53 axis

BACKGROUND

Ferroptosis and mitochondria-mediated apoptosis are both involved in the pathogenesis of acute liver failure (ALF). Ferroptosis-produced reactive oxygen species (ROS) trigger the chain oxidation of polyunsaturated phospholipids and promote mitochondrial apoptosis. Dihydroquercetin (DHQ) also plays an important protective role against liver injury.

PURPOSE

Here, we aimed to investigate the protective effects of DHQ on ALF. We also explored the underlying mechanism.

METHODS

We established a Lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced ALF mouse model and tumor necrosis factor-α (TNF-α)/D-Gal-induced ALF LO2 cell model. 2',7'-Dichlorofluorescein diacetate (DCFH-DA) and Dihydroethidium (DHE) were used to detect total ROS levels. Lipid ROS was assessed using C11-BODIPY flow cytometry. Lipid peroxidative products levels were detected using MDA ELISA assay and 4-hydroxynonenal (4-HNE) immunohistochemistry. QRT-PCR and western blots were used to test mRNA and protein expression levels, respectively. Cell viability was evaluated with CCK8 assay, and apoptosis was analyzed using flow cytometry.

RESULTS

DHQ treatment improved LPS/D-Gal-induced ALF, as well as TNF-α/D-Gal-induced reductions in LO2 viability and increased sirtuin 1 (SIRT1) expression. DHQ pretreatment also reduced the accumulation of ROS, reduced lipid peroxidation, elevated mitochondrial membrane potentials (ΔΨm), and decreased liver cell apoptosis both in vivo and in vitro. Additionally, the knockdown of SIRT1 and p53 activator (Tenovin-6) treatment reversed DHQ's inhibitory effects on ferroptosis and mitochondria-mediated apoptosis in vitro. DHQ enhanced p53 deacetylation by both up-regulating SIRT1 expression and directly bonding to SIRT1. We also found that Tenovin-6's stimulatory effects on ferroptosis and mitochondria-mediated apoptosis in the DHQ-treated LO2 ALF cell model were partially attenuated by overexpression of solute carrier family 7member 11 (SLC7A11), as well as by apoptotic protease activating factor 1 (Apaf-1) knockdown.

CONCLUSION

Our results suggest that DHQ alleviated ALF by inhibiting both ferroptosis and mitochondria-mediated apoptosis by regulating the SIRT1/p53 axis. Thus, DHQ may serve as a novel therapy for ALF.

A Deep Insight into Ferroptosis in Renal Disease: Facts and Perspectives

Background

Ferroptosis, a newly recognized form of programmed cell death, is distinguished by its reliance on reactive oxygen species and iron-mediated lipid peroxidation, setting it apart from established types like apoptosis, cell necrosis, and autophagy. Recent studies suggest its role in exacerbating or mitigating diseases by influencing metabolic and signaling pathways in conditions such as tumors and ischemic organ damage. Evidence also links ferroptosis to various kidney diseases, prompting a review of its research status and potential breakthroughs in understanding and treating these conditions.

Summary

In acute kidney disease (AKI), ferroptosis has been confirmed in animal kidneys after being induced by various factors such as renal ischemia-reperfusion and cisplatin, and glutathione peroxidase 4 (GPX4) is linked with AKI. Ferroptosis is associated with renal fibrosis in chronic kidney disease (CKD), TGF-β1 being crucial in this regard. In diabetic nephropathy (DN), high SLC7A11 and low nuclear receptor coactivator 4 (NCOA4) expressions are linked to disease progression. For polycystic kidney disease (PKD), ferroptosis promotes the disease by regulating ferroptosis in kidney tissue. Renal cell carcinoma (RCC) and lupus nephritis (LN) also have links to ferroptosis, with mtDNA and iron accumulation causing RCC and oxidative stress causing LN.

Key Messages

Ferroptosis is a newly identified form of programmed cell death that is associated with various diseases. It targets metabolic and signaling pathways and has been linked to kidney diseases such as AKI, CKD, PKD, DN, LN, and clear cell RCC. Understanding its role in these diseases could lead to breakthroughs in their pathogenesis, etiology, and treatment.

The positive feedback loop of the NAT10/Mybbp1a/p53 axis promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury

Ferroptosis is a nonapoptotic form of regulated cell death that has been reported to play a central role in cardiac ischemia‒reperfusion (I/R) injury. N-acetyltransferase 10 (NAT10) contributes to cardiomyocyte apoptosis by functioning as an RNA ac4c acetyltransferase, but its role in cardiomyocyte ferroptosis during I/R injury has not been determined. This study aimed to elucidate the role of NAT10 in cardiac ferroptosis as well as the underlying mechanism. The mRNA and protein levels of NAT10 were increased in mouse hearts after I/R and in cardiomyocytes that were exposed to hypoxia/reoxygenation. P53 acted as an endogenous activator of NAT10 during I/R in a transcription-dependent manner. Cardiac overexpression of NAT10 caused cardiomyocyte ferroptosis to exacerbate I/R injury, while cardiomyocyte-specific knockout of NAT10 or pharmacological inhibition of NAT10 with Remodelin had the opposite effects. The inhibition of cardiomyocyte ferroptosis by Fer-1 exerted superior cardioprotective effects against the NAT10-induced exacerbation of post-I/R cardiac damage than the inhibition of apoptosis by emricasan. Mechanistically, NAT10 induced the ac4C modification of Mybbp1a, increasing its stability, which in turn activated p53 and subsequently repressed the transcription of the anti-ferroptotic gene SLC7A11. Moreover, knockdown of Mybbp1a partially abolished the detrimental effects of NAT10 overexpression on cardiomyocyte ferroptosis and cardiac I/R injury. Collectively, our study revealed that p53 and NAT10 interdependently cooperate to form a positive feedback loop that promotes cardiomyocyte ferroptosis to exacerbate cardiac I/R injury, suggesting that targeting the NAT10/Mybbp1a/p53 axis may be a novel approach for treating cardiac I/R.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

Nicorandil Regulates Ferroptosis and Mitigates Septic Cardiomyopathy via TLR4/SLC7A11 Signaling Pathway

This study mainly explored the role of nicorandil in regulating ferroptosis and alleviating septic cardiomyopathy through toll-like receptor (TLR) 4/solute carrier family 7 member 11 (SLC7A11) signaling pathway. Twenty-four male SD rats were randomly divided into control, Nic (nicorandil), LPS (lipopolysaccharide), and LPS + Nic groups and given echocardiography. A detection kit was applied to measure the levels of lactic dehydrogenase (LDH), cardiac troponin I (cTnI), and creatine kinase-MB (CK-MB); HE staining and the levels of glutathione (GSH), malondialdehyde (MDA), total iron, and Fe2+ of myocardial tissues were detected. Moreover, the expression of TLR4 and SLC7A11 were measured by qRT-PCR and the proteins regulating ferroptosis (TLR4, SLC7A11, GPX4, ACSL4, DMT1, Fpn, and TfR1) were checked by western blot. Myocardial cells (H9C2) were induced with lipopolysaccharide (LPS) and transfected with si-TLR4 or SLC7A11-OE. Then, the viability, ferroptosis, and TLR4/SLC7A11 signaling pathway of cells were examined. Nicorandil could significantly increase left ventricular (LV) ejection fraction (LVEF) while reduce LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV). Also, it greatly reduced the levels of LDH, cTnI, and CK-MB; alleviated the pathological changes of myocardial injury; notably decreased MDA, total iron, and Fe2+ levels in myocardial tissues; and significantly increased GSH level. Besides, nicorandil obviously raised protein levels of GPX4, Fpn, and SLC7A11, and decreased protein levels of ACSL4, DMT1, TfR1, and TLR4. After knockdown of TLR4 or overexpression of SLC7A11, the inhibition effect of nicorandil on ferroptosis was strengthened in LPS-induced H9C2 cells. Therefore, nicorandil may regulate ferroptosis through TLR4/SLC7A11 signaling, thereby alleviating septic cardiomyopathy.

LncRNA RGMB-AS1 inhibits HMOX1 ubiquitination and NAA10 activation to induce ferroptosis in non-small cell lung cancer

Ferroptosis, an iron-dependent regulated cell death caused by excessive lipid peroxide accumulation, has emerged as a promising therapeutic target in various cancers, including non-small cell lung cancer (NSCLC). In this study, we identified the long non-coding RNA RGMB-AS1 as a key regulator of ferroptosis in NSCLC. Mechanistically, RGMB-AS1 interacted with heme oxygenase 1 (HMOX1) and prevented its ubiquitination by the E3 ligase TRC8, leading to increased HMOX1 stability and enhanced ferroptosis. Additionally, RGMB-AS1 bound to the 82-87 amino acid region of N-alpha-acetyltransferase 10 (NAA10), stimulating its acetyltransferase activity and promoting the conversion of acetyl-CoA to HMG-CoA, further contributing to ferroptosis. The RGMB-AS1-HMOX1 and RGMB-AS1-NAA10 axes synergistically inhibited NSCLC growth both in vitro and in vivo. Clinically, low RGMB-AS1 expression was associated with advanced tumor stage and poor overall survival in NSCLC patients. Furthermore, adeno-associated virus-mediated RGMB-AS1 overexpression significantly suppressed tumor growth in mouse xenograft models. Our findings uncover a novel lncRNA-mediated regulatory mechanism of ferroptosis and highlight the potential of RGMB-AS1 as a prognostic biomarker and therapeutic target in NSCLC.

SLC7A11 in hepatocellular carcinoma: potential mechanisms, regulation, and clinical significance

Exploring novel early detection biomarkers and developing more efficacious treatments remain pressing tasks in the current research landscape for hepatocellular carcinoma (HCC). Morphologically and molecularly separate from apoptosis, cell death, and autophagy, ferroptosis is a recently discovered, unique, controlled form of cell death. SLC7A11 (also known as xCT) represents a subunit of the cystine-glutamate antiporter (also known as system Xc(-)). A growing body of research suggests that induction of ferroptosis through SLC7A11 can effectively eliminate hepatocellular carcinoma (HCC) cells, particularly those exhibiting resistance to alternative forms of cell death. Thus, targeting ferroptosis via SLC7A11 may become a new direction for the design of therapeutic strategies for HCC. Although many research articles have investigated the possible roles of SLC7A11 in HCC, a study that summarizes the main findings, including the regulators and mechanisms of action of SLC7A11 in HCC is not available. Therefore, we present a comprehensive overview of the functions of ferroptosis, particularly SLC7A11, in the identification, development, and management of HCC in this review. In addition, we discuss how this knowledge can be translated into treatment by providing a systemic therapy in advanced HCC using sorafenib, the first-line drug targeting multiple kinases and SLC7A11. We further dissect the possible barriers as well as the corresponding solutions and provide insights on how to navigate effective treatment using this knowledge.

Oxidative Stress in Breast Cancer: A Biochemical Map of Reactive Oxygen Species Production

This review systematizes information about the metabolic features of breast cancer directly related to oxidative stress. It has been shown those redox changes occur at all levels and affect many regulatory systems in the human body. The features of the biochemical processes occurring in breast cancer are described, ranging from nonspecific, at first glance, and strictly biochemical to hormone-induced reactions, genetic and epigenetic regulation, which allows for a broader and deeper understanding of the principles of oncogenesis, as well as maintaining the viability of cancer cells in the mammary gland. Specific pathways of the activation of oxidative stress have been studied as a response to the overproduction of stress hormones and estrogens, and specific ways to reduce its negative impact have been described. The diversity of participants that trigger redox reactions from different sides is considered more fully: glycolytic activity in breast cancer, and the nature of consumption of amino acids and metals. The role of metals in oxidative stress is discussed in detail. They can act as both co-factors and direct participants in oxidative stress, since they are either a trigger mechanism for lipid peroxidation or capable of activating signaling pathways that affect tumorigenesis. Special attention has been paid to the genetic and epigenetic regulation of breast tumors. A complex cascade of mechanisms of epigenetic regulation is explained, which made it possible to reconsider the existing opinion about the triggers and pathways for launching the oncological process, the survival of cancer cells and their ability to localize.