Iron Chaperone Poly rC Binding Protein 1 Protects Mouse Liver From Lipid Peroxidation and Steatosis

Expression of transferrin receptor/TFRC protein in bladder cancer cell T24 and its role in inducing iron death in bladder cancer

Bladder cancer (BC) is a very common malignant tumor in the urinary system. However, the incidence rate, recurrence rate, progression rate and metastasis rate of bladder cancer are still very high, leading to poor long-term prognosis of patients. This study was to investigate the expression of transferrin receptor/TFRC protein in bladder cancer tissue and its role in inducing iron death of T24 human bladder cancer cells. Based on the intersection of 259 FerrDb genes in the iron death database with GSE13507 and GSE13167 data sets, 54 genes related to iron death in bladder cancer were obtained. Analyzing 54 genes, KEGG enrichment analysis showed that the pathways involved were mainly focused on iron death, autophagy, and tumor center carbon metabolism. GO analysis found that the molecular functions mainly gather in ubiquitin like protein ligase binding, ubiquitin protein ligase binding, and antioxidant activity. In the cellular components, it is mainly distributed in pigment granules, melanosomes, and the basal lateral plasma membrane. In biological processes, it is enriched in nutrient level responses, responses to extracellular stimuli, and cellular redox homeostasis. Screen out the top 10 core genes. The 10 core genes are SLC2A1, TFRC, EGFR, KRAS, CAV1, HSPA5, NFE2L2, VEGFA, PIK3CA, and HRAS. Finally, TFRC was selected as the research object. TCGA analysis showed that the expression level in bladder cancer tissue was higher than that in normal tissue, and the difference was statistically significant (P < 0.001). Conclusion (1) TFRC is highly expressed in many kinds of tumors, and it is more highly expressed in bladder cancer than in normal bladder tissue. (2) TFRC has certain diagnostic and prognostic value in bladder cancer. (3) Erastin, an iron death inducer, induced the iron death of T24 human bladder cancer cells, knocked down the expression of TFRC in T24 human bladder cancer cells, and preliminarily verified that silencing TFRC could inhibit the iron death of T24 human bladder cancer cells.

A promising new approach to cancer therapy: Manipulate ferroptosis by hijacking endogenous iron

Ferroptosis, a form of regulated cell death characterized by iron-dependent phospholipid peroxidation, has emerged as a focal point in the field of cancer therapy. Compared with other cell death modes such as apoptosis and necrosis, ferroptosis exhibits many distinct characteristics in the molecular mechanisms and cell morphology, offering a promising avenue for combating cancers that are resistant to conventional therapeutic modalities. In light of the serious side effects associated with current Fenton-modulating ferroptosis therapies utilizing exogenous iron-based inorganic nanomaterials, hijacking endogenous iron could serve as an effective alternative strategy to trigger ferroptosis through targeting cellular iron regulatory mechanisms. A better understanding of the underlying iron regulatory mechanism in the process of ferroptosis has shed light on the current findings of endogenous ferroptosis-based nanomedicine strategies for cancer therapy. Here in this review article, we provide a comprehensive discussion on the regulatory network of iron metabolism and its pivotal role in ferroptosis, and present recent updates on the application of nanoparticles endowed with the ability to hijack endogenous iron for ferroptosis. We envision that the insights in the study may expedite the development and translation of endogenous ferroptosis-based nanomedicines for effective cancer treatment.

Macrophage iron dyshomeostasis promotes aging-related renal fibrosis

Renal aging, marked by the accumulation of senescent cells and chronic low-grade inflammation, leads to renal interstitial fibrosis and impaired function. In this study, we investigate the role of macrophages, a key regulator of inflammation, in renal aging by analyzing kidney single-cell RNA sequencing data of C57BL/6J mice from 8 weeks to 24 months. Our findings elucidate the dynamic changes in the proportion of kidney cell types during renal aging and reveal that increased macrophage infiltration contributes to chronic low-grade inflammation, with these macrophages exhibiting senescence and activation of ferroptosis signaling. CellChat analysis indicates enhanced communications between macrophages and tubular cells during aging. Suppressing ferroptosis alleviates macrophage-mediated tubular partial epithelial-mesenchymal transition in vitro, thereby mitigating the expression of fibrosis-related genes. Using SCENIC analysis, we infer Stat1 as a key age-related transcription factor promoting iron dyshomeostasis and ferroptosis in macrophages by regulating the expression of Pcbp1, an iron chaperone protein that inhibits ferroptosis. Furthermore, through virtual screening and molecular docking from a library of anti-aging compounds, we construct a docking model targeting Pcbp1, which indicates that the natural small molecule compound Rutin can suppress macrophage senescence and ferroptosis by preserving Pcbp1. In summary, our study underscores the crucial role of macrophage iron dyshomeostasis and ferroptosis in renal aging. Our results also suggest Pcbp1 as an intervention target in aging-related renal fibrosis and highlight Rutin as a potential therapeutic agent in mitigating age-related renal chronic low-grade inflammation and fibrosis.

Exocarpium Citri Grandis ameliorates LPS-induced acute lung injury by suppressing inflammation, NLRP3 inflammasome, and ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Exocarpium Citri Grandis (ECG), the epicarp of C. grandis 'Tomentosa' which is also known as Hua-Ju-Hong in China, has been widely used for thousands of years to treat inflammatory lung disorders such as asthma, and cough as well as dispelling phlegm. However, its underlying pharmacological mechanisms in acute lung injury (ALI) remain unclear.

AIM OF THE STUDY

To explore the therapeutic effect of ECG on ALI and reveal the potential mechanisms based on experimental techniques in vivo and in vitro.

MATERIALS AND METHODS

Lipopolysaccharides (LPS) induced ALI in mice and induced RAW 264.7 cell inflammatory model were established to investigate the pharmacodynamics of ECG. ELISA kits, commercial kits, Western Blot, qPCR, Hematoxylin and Eosin (H&E) staining, immunohistochemistry, and immunofluorescence technologies were used to evaluate the pharmacological mechanisms of ECG in ameliorating ALI.

RESULTS

ECG significantly attenuated pulmonary edema in LPS-stimulated mice and decreased the levels of IL1β, IL6, and TNF-α in serum and BALF, reduced MDA and iron concentration as well as increased SOD and GSH levels in lung tissues, and also decreased the ROS level in BALF and Lung tissue. Further pharmacological mechanism studies showed that ECG significantly inhibited mRNA expression of inflammatory signaling factors and chemokines, and down-regulated the expression of TLR4, MyD88, NF-κB p65, NF-κB p-p65 (S536), COX2, iNOS, Txnip, NLRP3, ASC, Caspase-1, JAK1, p-JAK1 (Y1022), JAK2, STAT1, p-STAT1 (S727), STAT3, p-STAT3 (Y705), STAT4, p-STAT4 (Y693), and Keap1, and also up-regulated the expression of Trx-1, Nrf2, HO-1, NQO1, GPX4, PCBP1, and SLC40A1. In the LPS-induced RAW264.7 cell inflammatory model, ECG showed similar results to animal experiments.

CONCLUSIONS

Our results showed that ECG alleviated ALI by inhibiting TLR4/MyD88/NF-κB p65 and JAK/STAT signaling pathway-mediated inflammatory response, Txnip/NLRP3 signaling pathway-mediated inflammasome activation, and regulating Nrf2/GPX4 axis-mediated ferroptosis. Our findings provide an experimental basis for the application of ECG.

Ferroptosis: Biology and Role in Gastrointestinal Disease

Ferroptosis is a form of nonapoptotic cell death that involves iron-dependent phospholipid peroxidation induced by accumulation of reactive oxygen species, and results in plasma membrane damage and the release of damage-associated molecular patterns. Ferroptosis has been implicated in aging and immunity, as well as disease states including intestinal and liver conditions and cancer. To date, several ferroptosis-associated genes and pathways have been implicated in liver disease. Although ferroptotic cell death is associated with dysfunction of the intestinal epithelium, the underlying molecular basis is poorly understood. As the mechanisms regulating ferroptosis become further elucidated, there is clear potential to use ferroptosis to achieve therapeutic benefit.

Protocol for deep mining the correlation between acute pancreatitis and ferroptosis using the MIMIC-III database and STATA software

The limitations associated with distinguishing serum Fe2+ and Fe3+ hinder the widespread application of ferroptosis, beyond laboratory settings. Here, we present a protocol for deep mining the correlation between acute pancreatitis and ferroptosis using the MIMIC-III database and STATA software. We describe steps for using Cox regression, decision curve analysis (DCA), and receiver operating characteristic (ROC) approaches to establish the relationship between them and determine the relevant factors. This protocol has potential application in establishing novel research models that integrate both fundamental and clinical methodologies. For complete details on the use and execution of this protocol, please refer to Yueling Deng et al.1.

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.

Polycytosine RNA-binding protein 1 regulates osteoblast function via a ferroptosis pathway in type 2 diabetic osteoporosis

BACKGROUND

Recently, type 2 diabetic osteoporosis (T2DOP) has become a research hotspot for the complications of diabetes, but the specific mechanism of its occurrence and development remains unknown. Ferroptosis caused by iron overload is con-sidered an important cause of T2DOP. Polycytosine RNA-binding protein 1 (PCBP1), an iron ion chaperone, is considered a protector of ferroptosis.

AIM

To investigate the existence of ferroptosis and specific role of PCBP1 in the development of type 2 diabetes.

METHODS

A cell counting kit-8 assay was used to detect changes in osteoblast viability under high glucose (HG) and/or ferroptosis inhibitors at different concentrations and times. Transmission electron microscopy was used to examine the morphological changes in the mitochondria of osteoblasts under HG, and western blotting was used to detect the expression levels of PCBP1, ferritin, and the ferroptosis-related protein glutathione peroxidase 4 (GPX4). A lentivirus silenced and overexpressed PCBP1. Western blotting was used to detect the expression levels of the osteoblast functional proteins osteoprotegerin (OPG) and osteocalcin (OCN), whereas flow cytometry was used to detect changes in reactive oxygen species (ROS) levels in each group.

RESULTS

Under HG, the viability of osteoblasts was considerably decreased, the number of mitochondria undergoing atrophy was considerably increased, PCBP1 and ferritin expression levels were increased, and GPX4 expression was decreased. Western blotting results demonstrated that infection with lentivirus overexpressing PCBP1, increased the expression levels of ferritin, GPX4, OPG, and OCN, compared with the HG group. Flow cytometry results showed a reduction in ROS, and an opposite result was obtained after silencing PCBP1.

CONCLUSION

PCBP1 may protect osteoblasts and reduce the harm caused by ferroptosis by promoting ferritin expression under a HG environment. Moreover, PCBP1 may be a potential therapeutic target for T2DOP.

Small-Molecule Fluorescent Probes for Binding- and Activity-Based Sensing of Redox-Active Biological Metals

Although transition metals constitute less than 0.1% of the total mass within a human body, they have a substantial impact on fundamental biological processes across all kingdoms of life. Indeed, these nutrients play crucial roles in the physiological functions of enzymes, with the redox properties of many of these metals being essential to their activity. At the same time, imbalances in transition metal pools can be detrimental to health. Modern analytical techniques are helping to illuminate the workings of metal homeostasis at a molecular and atomic level, their spatial localization in real time, and the implications of metal dysregulation in disease pathogenesis. Fluorescence microscopy has proven to be one of the most promising non-invasive methods for studying metal pools in biological samples. The accuracy and sensitivity of bioimaging experiments are predominantly determined by the fluorescent metal-responsive sensor, highlighting the importance of rational probe design for such measurements. This review covers activity- and binding-based fluorescent metal sensors that have been applied to cellular studies. We focus on the essential redox-active metals: iron, copper, manganese, cobalt, chromium, and nickel. We aim to encourage further targeted efforts in developing innovative approaches to understanding the biological chemistry of redox-active metals.

Ferroptosis and its role in gastric and colorectal cancers

Ferroptosis is a novel mechanism of programmed cell death, characterized by intracellular iron overload, intensified lipid peroxidation, and abnormal accumulation of reactive oxygen species, which ultimately resulting in cell membrane impairment and demise. Research has revealed that cancer cells exhibit a greater demand for iron compared to normal cells, indicating a potential susceptibility of cancer cells to ferroptosis. Stomach and colorectal cancers are common gastrointestinal malignancies, and their elevated occurrence and mortality rates render them a global health concern. Despite significant advancements in medical treatments, certain unfavorable consequences and drug resistance persist. Consequently, directing attention towards the phenomenon of ferroptosis in gastric and colorectal cancers holds promise for enhancing therapeutic efficacy. This review aims to elucidate the intricate cellular metabolism associated with ferroptosis, encompassing lipid and amino acid metabolism, as well as iron metabolic processes. Furthermore, the significance of ferroptosis in the context of gastric and colorectal cancer is thoroughly examined and discussed.

A Systematic Review of Statins for the Treatment of Nonalcoholic Steatohepatitis: Safety, Efficacy, and Mechanism of Action

Nonalcoholic fatty liver disease (NAFLD) is the liver component of a cluster of conditions, while its subtype, nonalcoholic steatohepatitis (NASH), emerges as a potentially progressive liver disorder that harbors the risk of evolving into cirrhosis and culminating in hepatocellular carcinoma (HCC). NASH and cardiovascular disease (CVD) have common risk factors, but compared to liver-related causes, the most common cause of death in NASH patients is CVD. Within the pharmacological armamentarium, statins, celebrated for their lipid-modulating prowess, have now garnered attention for their expansive therapeutic potential in NASH. Evidence from a plethora of studies suggests that statins not only manifest anti-inflammatory and antifibrotic properties but also impart a multifaceted beneficial impact on hepatic health. In this review, we used "statin", "NAFLD", "NASH", and "CVD" as the major keywords and conducted a literature search using the PubMed and Web of Science databases to determine the safety and efficacy of statins in patients and animals with NASH and NAFLD, and the mechanism of statin therapy for NASH. Simultaneously, we reviewed the important role of the intestinal microbiota in statin therapy for NASH, as it is hoped that statins will provide new insights into modulating the harmful inflammatory microbiota in the gut and reducing systemic inflammation in NASH patients.

Emerging role of ferroptosis in metabolic dysfunction-associated steatotic liver disease: revisiting hepatic lipid peroxidation

Metabolic dysfunction-associated steatohepatitis (MASH) is characterised by cell death of parenchymal liver cells which interact with their microenvironment to drive disease activity and liver fibrosis. The identification of the major death type could pave the way towards pharmacotherapy for MASH. To date, increasing evidence suggest a type of regulated cell death, named ferroptosis, which occurs through iron-catalysed peroxidation of polyunsaturated fatty acids (PUFA) in membrane phospholipids. Lipid peroxidation enjoys renewed interest in the light of ferroptosis, as druggable target in MASH. This review recapitulates the molecular mechanisms of ferroptosis in liver physiology, evidence for ferroptosis in human MASH and critically appraises the results of ferroptosis targeting in preclinical MASH models. Rewiring of redox, iron and PUFA metabolism in MASH creates a proferroptotic environment involved in MASH-related hepatocellular carcinoma (HCC) development. Ferroptosis induction might be a promising novel approach to eradicate HCC, while its inhibition might ameliorate MASH disease progression.

A guideline on the molecular ecosystem regulating ferroptosis

Ferroptosis, an intricately regulated form of cell death characterized by uncontrolled lipid peroxidation, has garnered substantial interest since this term was first coined in 2012. Recent years have witnessed remarkable progress in elucidating the detailed molecular mechanisms that govern ferroptosis induction and defence, with particular emphasis on the roles of heterogeneity and plasticity. In this Review, we discuss the molecular ecosystem of ferroptosis, with implications that may inform and enable safe and effective therapeutic strategies across a broad spectrum of diseases.

Mechanisms controlling cellular and systemic iron homeostasis

In mammals, hundreds of proteins use iron in a multitude of cellular functions, including vital processes such as mitochondrial respiration, gene regulation and DNA synthesis or repair. Highly orchestrated regulatory systems control cellular and systemic iron fluxes ensuring sufficient iron delivery to target proteins is maintained, while limiting its potentially deleterious effects in iron-mediated oxidative cell damage and ferroptosis. In this Review, we discuss how cells acquire, traffick and export iron and how stored iron is mobilized for iron-sulfur cluster and haem biogenesis. Furthermore, we describe how these cellular processes are fine-tuned by the combination of various sensory and regulatory systems, such as the iron-regulatory protein (IRP)-iron-responsive element (IRE) network, the nuclear receptor co-activator 4 (NCOA4)-mediated ferritinophagy pathway, the prolyl hydroxylase domain (PHD)-hypoxia-inducible factor (HIF) axis or the nuclear factor erythroid 2-related factor 2 (NRF2) regulatory hub. We further describe how these pathways interact with systemic iron homeostasis control through the hepcidin-ferroportin axis to ensure appropriate iron fluxes. This knowledge is key for the identification of novel therapeutic opportunities to prevent diseases of cellular and/or systemic iron mismanagement.

Targeting ferroptosis and ferritinophagy: new targets for cardiovascular diseases

Cardiovascular diseases (CVDs) are a leading factor driving mortality worldwide. Iron, an essential trace mineral, is important in numerous biological processes, and its role in CVDs has raised broad discussion for decades. Iron-mediated cell death, namely ferroptosis, has attracted much attention due to its critical role in cardiomyocyte damage and CVDs. Furthermore, ferritinophagy is the upstream mechanism that induces ferroptosis, and is closely related to CVDs. This review aims to delineate the processes and mechanisms of ferroptosis and ferritinophagy, and the regulatory pathways and molecular targets involved in ferritinophagy, and to determine their roles in CVDs. Furthermore, we discuss the possibility of targeting ferritinophagy-induced ferroptosis modulators for treating CVDs. Collectively, this review offers some new insights into the pathology of CVDs and identifies possible therapeutic targets.

Ferroptosis in the ageing retina: A malevolent fire of diabetic retinopathy

Ageing retina is prone to ferroptosis due to the iron accumulation and impaired efficiency of intracellular antioxidant defense system. Ferroptosis acts as a cell death modality that is characterized by the iron-dependent accumulation of lipid peroxidation. Ferroptosis is distinctively different from other types of regulated cell death (RCD) at the morphological, biochemical, and genetic levels. Diabetic retinopathy (DR) is a common microvascular complication of diabetes. Its prevalence and severity increase progressively with age. Recent reports have shown that ferroptosis is implicated in the pathophysiology of DR. Under hyperglycemia condition, the endothelial cell and retinal pigment epithelium (RPE) cell will undergo ferroptosis, which contributes to the increased vascular permeability and the disrupted blood retinal barrier (BRB). The underlying etiology of DR can be attributed to the impaired BRB integrity and subsequent damages of the neurovascular units. In the absence of timely intervention, the compromised BRB can ultimately cause profound visual impairments. In particular, the ageing retina is vulnerable to ferroptosis, and hyperglycemia will accelerate the progression of this pathological process. In this article, we discuss the contributory role of ferroptosis in DR pathogenesis, and summarize recent therapeutic trials that targeting the ferroptosis. Further study on the ferroptosis mediated damage would enrich our knowledge of DR pathology, and promote the development of clinical treatment for this degenerative retinopathy.

Molecular mechanisms of ferroptosis and its roles in leukemia

Cell death is a complex process required to maintain homeostasis and occurs when cells are damage or reach end of life. As research progresses, it is apparent that necrosis and apoptosis do not fully explain the whole phenomenon of cell death. Therefore, new death modalities such as autophagic cell death, and ferroptosis have been proposed. In recent years, ferroptosis, a new type of non-apoptotic cell death characterized by iron-dependent lipid peroxidation and reactive oxygen species (ROS) accumulation, has been receiving increasing attention. Ferroptosis can be involved in the pathological processes of many disorders, such as ischemia-reperfusion injury, nervous system diseases, and blood diseases. However, the specific mechanisms by which ferroptosis participates in the occurrence and development of leukemia still need to be more fully and deeply studied. In this review, we present the research progress on the mechanism of ferroptosis and its role in leukemia, to provide new theoretical basis and strategies for the diagnosis and treatment of clinical hematological diseases.

Ironing out the details: ferroptosis and its relevance to diabetic cardiomyopathy

Ferroptosis is a newly identified myocardial cell death mechanism driven by iron-dependent lipid peroxidation. The presence of elevated intramyocardial lipid levels and excessive iron in patients with diabetes suggest a predominant role of ferroptosis in diabetic cardiomyopathy. As myocardial cell death is a precursor of heart failure, and intensive glycemic control cannot abate the increased risk of heart failure in patients with diabetes, targeting myocardial cell death via ferroptosis is a promising therapeutic avenue to prevent and/or treat diabetic cardiomyopathy. This review provides updated and comprehensive molecular mechanisms underpinning ferroptosis, clarifies several misconceptions about ferroptosis, emphasizes the importance of ferroptosis in diabetes-induced myocardial cell death, and offers valuable approaches to evaluate and target ferroptosis in the diabetic heart. Furthermore, basic concepts and ideas presented in this review, including glutathione peroxidase-4-independent and mitochondrial mechanisms of ferroptosis, are also important for investigating ferroptosis in other diabetic organs, as well as nondiabetic and metabolically compromised hearts.

In vivo bioluminescence imaging of labile iron in xenograft models and liver using FeAL-1, an iron-activatable form of D-luciferin

Dysregulated iron homeostasis underlies diverse pathologies, from ischemia-reperfusion injury to epithelial-mesenchymal transition and drug-tolerant "persister" cancer cell states. Here, we introduce ferrous iron-activatable luciferin-1 (FeAL-1), a small-molecule probe for bioluminescent imaging of the labile iron pool (LIP) in luciferase-expressing cells and animals. We find that FeAL-1 detects LIP fluctuations in cells after iron supplementation, depletion, or treatment with hepcidin, the master regulator of systemic iron in mammalian physiology. Utilizing FeAL-1 and a dual-luciferase reporter system, we quantify LIP in mouse liver and three different orthotopic pancreatic ductal adenocarcinoma tumors. We observed up to a 10-fold increase in FeAL-1 bioluminescent signal in xenograft tumors as compared to healthy liver, the major organ of iron storage in mammals. Treating mice with hepcidin further elevated hepatic LIP, as predicted. These studies reveal a therapeutic index between tumoral and hepatic LIP and suggest an approach to sensitize tumors toward LIP-activated therapeutics.

Metabolic dysfunction-associated steatotic liver disease: ferroptosis related mechanisms and potential drugs

Metabolic dysfunction-associated steatotic liver disease (MASLD) is considered a "multisystem" disease that simultaneously suffers from metabolic diseases and hepatic steatosis. Some may develop into liver fibrosis, cirrhosis, and even hepatocellular carcinoma. Given the close connection between metabolic diseases and fatty liver, it is urgent to identify drugs that can control metabolic diseases and fatty liver as a whole and delay disease progression. Ferroptosis, characterized by iron overload and lipid peroxidation resulting from abnormal iron metabolism, is a programmed cell death mechanism. It is an important pathogenic mechanism in metabolic diseases or fatty liver, and may become a key direction for improving MASLD. In this article, we have summarized the physiological and pathological mechanisms of iron metabolism and ferroptosis, as well as the connections established between metabolic diseases and fatty liver through ferroptosis. We have also summarized MASLD therapeutic drugs and potential active substances targeting ferroptosis, in order to provide readers with new insights. At the same time, in future clinical trials involving subjects with MASLD (especially with the intervention of the therapeutic drugs), the detection of serum iron metabolism levels and ferroptosis markers in patients should be increased to further explore the efficacy of potential drugs on ferroptosis.

The iron chaperone poly(rC)-binding protein 1 regulates iron efflux through intestinal ferroportin in mice

Iron is an essential nutrient required by all cells but used primarily for red blood cell production. Because humans have no effective mechanism for ridding the body of excess iron, the absorption of dietary iron must be precisely regulated. The critical site of regulation is the transfer of iron from the absorptive enterocyte to the portal circulation via the sole iron efflux transporter, ferroportin. Here, we report that poly(rC)-binding protein 1 (PCBP1), the major cytosolic iron chaperone, is necessary for the regulation of iron flux through ferroportin in the intestine of mice. Mice lacking PCBP1 in the intestinal epithelium exhibit low levels of enterocyte iron, poor retention of dietary iron in enterocyte ferritin, and excess efflux of iron through ferroportin. Excess iron efflux occurred despite lower levels of ferroportin protein in enterocytes and upregulation of the iron regulatory hormone hepcidin. PCBP1 deletion and the resulting unregulated dietary iron absorption led to poor growth, severe anemia on a low-iron diet, and liver oxidative stress with iron loading on a high-iron diet. Ex vivo culture of PCBP1-depleted enteroids demonstrated no defects in hepcidin-mediated ferroportin turnover. However, measurement of kinetically labile iron pools in enteroids competent or blocked for iron efflux indicated that PCBP1 functioned to bind and retain cytosolic iron and limit its availability for ferroportin-mediated efflux. Thus, PCBP1 coordinates enterocyte iron and reduces the concentration of unchaperoned "free" iron to a low level that is necessary for hepcidin-mediated regulation of ferroportin activity.

Cross-species comparison illuminates the importance of iron homeostasis for splenic anti-immunosenescence

Although immunosenescence may result in increased morbidity and mortality, many mammals have evolved effective immune coping strategies to extend their lifespans. Thus, the immune systems of long-lived mammals present unique models to study healthy longevity. To identify the molecular clues of anti-immunosenescence, we first built high-quality reference genome for a long-lived myotis bat, and then compared three long-lived mammals (i.e., bat, naked mole rat, and human) versus the short-lived mammal, mouse, in splenic immune cells at single-cell resolution. A close relationship between B:T cell ratio and immunosenescence was detected, as B:T cell ratio was much higher in mouse than long-lived mammals and significantly increased during aging. Importantly, we identified several iron-related genes that could resist immunosenescence changes, especially the iron chaperon, PCBP1, which was upregulated in long-lived mammals but dramatically downregulated during aging in all splenic immune cell types. Supportively, immune cells of mouse spleens contained more free iron than those of bat spleens, suggesting higher level of ROS-induced damage in mouse. PCBP1 downregulation during aging was also detected in hepatic but not pulmonary immune cells, which is consistent with the crucial roles of spleen and liver in organismal iron recycling. Furthermore, PCBP1 perturbation in immune cell lines would result in cellular iron dyshomeostasis and senescence. Finally, we identified two transcription factors that could regulate PCBP1 during aging. Together, our findings highlight the importance of iron homeostasis in splenic anti-immunosenescence, and provide unique insight for improving human healthspan.

Serum iron fluctuations link ferroptosis process with mortality and prognosis of acute pancreatitis

Recently, the existence of ferroptosis has been confirmed in chronic pancreatitis. However, its role in acute pancreatitis (AP) process, especially in critical status, has not yet been mentioned. To verify this hypothesis, we included 873 AP patients (training set) and 1,188 NAFLD patients (internal validation set) selected from MIMIC-III (Medical Information Mark for Intensive Care) database and 218 AP patients (external validation set) in Linshui County People's Hospital ICU data. We analyzed the correlation between mortality and ferroptosis associating factors (such as serum iron, ALP, lactate, etc.) in them through regression analysis. In addition, to test the significance of these factors, the nomogram, AUC, and DCA analysis were applied. The results showed that serum iron, IBC, ALP, and lactate (p < 0.05) were independent factors for the mortality and prognosis of these patients. These correlations suggest ferroptosis and follow-up cell programmed death may own an important clinical interference significance among this population.

Ferroptosis: An Emerging Target for Bladder Cancer Therapy

Bladder cancer (BC), as one of the main urological cancers in the world, possesses the abilities of multiple-drug resistance and metastasis. However, there remains a significant gap in the understanding and advancement of prognosis and therapeutic strategies for BC. Ferroptosis, a novel type of iron-dependent regulated cell death, depends on lipid peroxidation, which has been proven to have a strong correlation with the development and treatment of BC. Its mechanism mainly includes three pathways, namely, lipid peroxidation, the antioxidant system, and the iron overload pathway. In this review, we reviewed the mechanism of ferroptosis, along with the related therapeutic targets and drugs for BC, as it might become a new anticancer treatment in the future.

Mechanisms and regulations of ferroptosis

Regulation of cell mortality for disease treatment has been the focus of research. Ferroptosis is an iron-dependent regulated cell death whose mechanism has been extensively studied since its discovery. A large number of studies have shown that regulation of ferroptosis brings new strategies for the treatment of various benign and malignant diseases. Iron excess and lipid peroxidation are its primary metabolic features. Therefore, genes involved in iron metabolism and lipid metabolism can regulate iron overload and lipid peroxidation through direct or indirect pathways, thereby regulating ferroptosis. In addition, glutathione (GSH) is the body's primary non-enzymatic antioxidants and plays a pivotal role in the struggle against lipid peroxidation. GSH functions as an auxiliary substance for glutathione peroxidase 4 (GPX4) to convert toxic lipid peroxides to their corresponding alcohols. Here, we reviewed the researches on the mechanism of ferroptosis in recent years, and comprehensively analyzed the mechanism and regulatory process of ferroptosis from iron metabolism and lipid metabolism, and then described in detail the metabolism of GPX4 and the main non-enzymatic antioxidant GSH in vivo.

Macrophage metabolism in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and its inflammatory and often progressive subtype nonalcoholic steatohepatitis (NASH), have emerged as significant contributors to hepatic morbidity worldwide. The pathophysiology of NAFLD/NASH is multifaceted, variable, and remains incompletely understood. The pivotal role of liver-resident and recruited macrophages in the pathogenesis of NAFLD and NASH is widely acknowledged as a crucial factor in innate immunity. The remarkable plasticity of macrophages enables them to assume diverse activation and polarization states, dictated by their immunometabolism microenvironment and functional requirements. Recent studies in the field of immunometabolism have elucidated that alterations in the metabolic profile of macrophages can profoundly influence their activation state and functionality, thereby influencing various pathological processes. This review primarily focuses on elucidating the polarization and activation states of macrophages, highlighting the correlation between their metabolic characteristics and the transition from pro-inflammatory to anti-inflammatory phenotypes. Additionally, we explore the potential of targeting macrophage metabolism as a promising therapeutic approach for the management of NAFLD/NASH.

The Regulation of Ferroptosis by Noncoding RNAs

As a novel form of regulated cell death, ferroptosis is characterized by intracellular iron and lipid peroxide accumulation, which is different from other regulated cell death forms morphologically, biochemically, and immunologically. Ferroptosis is regulated by iron metabolism, lipid metabolism, and antioxidant defense systems as well as various transcription factors and related signal pathways. Emerging evidence has highlighted that ferroptosis is associated with many physiological and pathological processes, including cancer, neurodegeneration diseases, cardiovascular diseases, and ischemia/reperfusion injury. Noncoding RNAs are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that noncoding RNAs, especially miRNAs, lncRNAs, and circRNAs, can interfere with the progression of ferroptosis by modulating ferroptosis-related genes or proteins directly or indirectly. In this review, we summarize the basic mechanisms and regulations of ferroptosis and focus on the recent studies on the mechanism for different types of ncRNAs to regulate ferroptosis in different physiological and pathological conditions, which will deepen our understanding of ferroptosis regulation by noncoding RNAs and provide new insights into employing noncoding RNAs in ferroptosis-associated therapeutic strategies.

Ferroptosis Nanomedicine: Clinical Challenges and Opportunities for Modulating Tumor Metabolic and Immunological Landscape

Ferroptosis, a type of regulated cell death driven by iron-dependent phospholipid peroxidation, has captured much attention in the field of nanomedicine since it was coined in 2012. Compared with other regulated cell death modes such as apoptosis and pyroptosis, ferroptosis has many distinct features in the molecular mechanisms and cellular morphology, representing a promising strategy for treating cancers that are resistant to conventional therapeutic modalities. Moreover, recent insights collectively reveal that ferroptosis is tightly connected to the maintenance of the tumor immune microenvironment (TIME), suggesting the potential application of ferroptosis therapies for evoking robust antitumor immunity. From a biochemical perspective, ferroptosis is intricately regulated by multiple cellular metabolic pathways, including iron metabolism, lipid metabolism, redox metabolism, etc., highlighting the importance to elucidate the relationship between tumor metabolism and ferroptosis for developing antitumor therapies. In this review, we provide a comprehensive discussion on the current understanding of ferroptosis-inducing mechanisms and thoroughly discuss the relationship between ferroptosis and various metabolic traits of tumors, which offer promising opportunities for direct tumor inhibition through a nanointegrated approach. Extending from the complex impact of ferroptosis on TIME, we also discussed those important considerations in the development of ferroptosis-based immunotherapy, highlighting the challenges and strategies to enhance the ferroptosis-enabled immunostimulatory effects while avoiding potential side effects. We envision that the insights in this study may facilitate the development and translation of ferroptosis-based nanomedicines for tumor treatment.

Vitamin E Induces Liver Iron Depletion and Alters Iron Regulation in Mice

BACKGROUND

Vitamin E (vit E) is an essential nutrient that functions as a lipophilic antioxidant and is used clinically to treat nonalcoholic fatty liver disease, where it suppresses oxidative damage and impedes the progression of steatosis and fibrosis. Mice lacking a critical liver iron-trafficking protein also manifest steatosis because of iron-mediated oxidative damage and are protected from liver disease by oral vit E supplements.

OBJECTIVES

We aimed to examine the role of dietary vit E supplementation in modulating iron-sensing regulatory systems and nonheme iron levels in mouse liver.

METHODS

C57Bl/6 male mice, aged 6 wk, were fed purified diets containing normal amounts of iron and either control (45 mg/kg) or elevated (450 mg/kg) levels of 2R-α-tocopherol (vit E) for 18 d. Mouse plasma and liver were analyzed for nonheme iron, levels and activity of iron homeostatic proteins, and markers of oxidative stress. We compared means ± SD for iron and oxidative stress parameters between mice fed the control diet and those fed the vit E diet.

RESULTS

The Vit E-fed mice exhibited lower levels of liver nonheme iron (38% reduction, P < 0.0001) and ferritin (74% reduction, P < 0.01) than control-fed mice. The levels of liver mRNA for transferrin receptor 1 and divalent metal transporter 1 were reduced to 42% and 57% of the control, respectively. The mRNA levels for targets of nuclear factor erythroid 2-related factor (Nrf2), a major regulator of the oxidative stress response and iron-responsive genes, were also suppressed in vit E livers. Hepcidin, an iron regulatory hormone, levels were lower in the plasma (P < 0.05), and ferroportin (FPN), the iron exporter regulated by hepcidin, was expressed at higher levels in the liver (P < 0.05).

CONCLUSIONS

Oral vit E supplementation in mice can lead to depletion of liver iron stores by suppressing the iron- and redox-sensing transcription factor Nrf2, leading to enhanced iron efflux through liver FPN. Iron depletion may indirectly enhance the antioxidative effects of vit E.

Ferroptosis as an emerging therapeutic target in liver diseases

Ferroptosis is an iron-dependently nonapoptotic cell death characterized by excessive accumulation of lipid peroxides and cellular iron metabolism disturbances. Impaired iron homeostasis and dysregulation of metabolic pathways are contributors to ferroptosis. As a major metabolic hub, the liver synthesizes and transports plasma proteins and endogenous fatty acids. Also, it acts as the primary location of iron storage for hepcidin generation and secretion. To date, although the intricate correlation between ferroptosis and liver disorders needs to be better defined, there is no doubt that ferroptosis participates in the pathogenesis of liver diseases. Accordingly, pharmacological induction and inhibition of ferroptosis show significant potential for the treatment of hepatic disorders involved in lipid peroxidation. In this review, we outline the prominent features, molecular mechanisms, and modulatory networks of ferroptosis and its physiopathologic functions in the progression of liver diseases. Further, this review summarizes the underlying mechanisms by which ferroptosis inducers and inhibitors ameliorate liver diseases. It is noteworthy that natural active ingredients show efficacy in preclinical liver disease models by regulating ferroptosis. Finally, we analyze crucial concepts and urgent issues concerning ferroptosis as a novel therapeutic target in the diagnosis and therapy of liver diseases.

PCBP1 protects bladder cancer cells from mitochondria injury and ferroptosis by inducing LACTB mRNA degradation

Although Poly C Binding Protein 1 (PCBP1) affects cellular ferroptosis and mitochondrial dysfunction, the mechanisms by which PCBP1 regulates bladder cancer (BC) cell functions are unknown. In this study, two BC cell lines (T24 and UMUC3) were treated with different doses of ferroptosis inducer erastin to analyze the effect of PCBP1. Online databases (RPISeq and CatRAPID) were used to predict the possible direct interaction between PCBP1 protein and serine β-lactamase-like protein (LACTB) mRNA, which was further validated via RNA pull-down, RNA immunoprecipitation, and luciferase reporter assays. Mitochondria injury and ferroptosis were evaluated using CCK-8 assay, TUNEL staining, flow cytometry, corresponding kits, and JC-1 staining. In vivo experiments were conducted using tumor xenograft models. Quantitative reverse-transcription polymerase chain reaction was used to detect transcript expression levels, while protein levels were analyzed using western blot and immunohistochemistry. PCBP1 expression was significantly upregulated in BC tissues and cell lines. Also, PCBP1 knockdown increased erastin-mediated ferroptosis in T24 and UMUC3 cells, while PCBP1 overexpression decreased erastin-mediated ferroptosis in T24 and UMUC3 cells. Mechanistic results showed that LACTB mRNA is a novel PCBP1-binding transcript. LACTB upregulation promoted erastin-induced ferroptosis and mitochondrial dysfunction. Furthermore, LACTB overexpression reversed PCBP1-mediated ferroptosis protection, including decreased ROS and enhanced mitochondrial function, which were further alleviated after phosphatidylserine decarboxylase (PISD) overexpression. Moreover, PCBP1 silencing significantly enhanced tumor inhibition effect of sulfasalazine in xenograft mice transplanted with T24 and UMUC3 cells, leading to LACTB upregulation and PISD downregulation. In conclusion, PCBP1 protects BC cells against mitochondria injury and ferroptosis via LACTB/PISD axis.

Zooming in and out of ferroptosis in human disease

Ferroptosis is defined as an iron-dependent regulated form of cell death driven by lipid peroxidation. In the past decade, it has been implicated in the pathogenesis of various diseases that together involve almost every organ of the body, including various cancers, neurodegenerative diseases, cardiovascular diseases, lung diseases, liver diseases, kidney diseases, endocrine metabolic diseases, iron-overload-related diseases, orthopedic diseases and autoimmune diseases. Understanding the underlying molecular mechanisms of ferroptosis and its regulatory pathways could provide additional strategies for the management of these disease conditions. Indeed, there are an expanding number of studies suggesting that ferroptosis serves as a bona-fide target for the prevention and treatment of these diseases in relevant pre-clinical models. In this review, we summarize the progress in the research into ferroptosis and its regulatory mechanisms in human disease, while providing evidence in support of ferroptosis as a target for the treatment of these diseases. We also discuss our perspectives on the future directions in the targeting of ferroptosis in human disease.

Ferroptotic mechanisms and therapeutic targeting of iron metabolism and lipid peroxidation in the kidney

Ferroptosis is a mechanism of regulated necrotic cell death characterized by iron-dependent, lipid peroxidation-driven membrane destruction that can be inhibited by glutathione peroxidase 4. Morphologically, it is characterized by cellular, organelle and cytoplasmic swelling and the loss of plasma membrane integrity, with the release of intracellular components. Ferroptosis is triggered in cells with dysregulated iron and thiol redox metabolism, whereby the initial robust but selective accumulation of hydroperoxy polyunsaturated fatty acid-containing phospholipids is further propagated through enzymatic and non-enzymatic secondary mechanisms, leading to formation of oxidatively truncated electrophilic species and their adducts with proteins. Thus, ferroptosis is dependent on the convergence of iron, thiol and lipid metabolic pathways. The kidney is particularly susceptible to redox imbalance. A growing body of evidence has linked ferroptosis to acute kidney injury in the context of diverse stimuli, such as ischaemia-reperfusion, sepsis or toxins, and to chronic kidney disease, suggesting that ferroptosis may represent a novel therapeutic target for kidney disease. However, further work is needed to address gaps in our understanding of the triggers, execution and spreading mechanisms of ferroptosis.

Borax regulates iron chaperone- and autophagy-mediated ferroptosis pathway in glioblastoma cells

Glioblastoma (GBM) is classified as a stage-IV glioma. Unfortunately, there are currently no curative treatments for GBM. Poly(rC)-binding protein 1 (PCBP1) is a cytosolic iron chaperone with diverse functions. PCBP1 is also known to regulate autophagy, but the role of PCBP1 in ferroptosis, iron-dependent cell death pathway, remains unrevealed in GBM cells. Here, we investigated the effects of borax, a boron compound, on the ferroptosis signaling pathway mediated by PCBP1 and autophagy. The study analyzed cell viability, proliferation, and cell cycle on U87-MG and HMC3 cells to investigate the effects of borax. After determining the cytotoxic concentrations of borax, morphological analyzes and measurement of PCBP1, Beclin1, malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase 4 (GPx4) and acyl-CoA synthetase long chain family member 4 (ACSL4) levels were performed. Finally, expression levels of PCBP1, Beclin1, GPx4 and ACSL4, and caspase-3/7 activity were determined. We found that borax reduced U87-MG cell viability in a concentration- and time-dependent manner. Additionally, borax altered cell proliferation and remarkably reduced S phase in the U87-MG cells and exhibited selectivity by having an opposite effect on normal cells (HMC3). According to DAPI staining, borax caused nuclear deficits in U87-MG cells. The result showed that borax in U87-MG cells induced reduction of the PCBP1, GSH, and GPx4 and enhancement of Beclin1, MDA, and ACSL4. Furthermore, borax triggered apoptosis by activating caspase 3/7 in U87-MG cells. Our study indicated that the borax has potential as an anticancer treatment for GBM via regulating PCBP1/Beclin1/GPx4/ACSL4 signaling pathways.

The crosslinks between ferroptosis and autophagy in asthma

Autophagy is an evolutionarily conserved cellular process capable of degrading various biological molecules and organelles via the lysosomal pathway. Ferroptosis is a type of oxidative stress-dependent regulated cell death associated with the iron accumulation and lipid peroxidation. The crosslinks between ferroptosis and autophagy have been focused on since the dependence of ferroptosis on autophagy was discovered. Although the research and theories on the relationship between autophagy and ferroptosis remain scattered and fragmented, the crosslinks between these two forms of regulated cell death are closely related to the treatment of various diseases. Thereof, asthma as a chronic inflammatory disease has a tight connection with the occurrence of ferroptosis and autophagy since the crosslinked signal pathways may be the crucial regulators or exactly regulated by cells and secretion in the immune system. In addition, non-immune cells associated with asthma are also closely related to autophagy and ferroptosis. Further studies of cross-linking asthma inflammation with crosslinked signaling pathways may provide us with several key molecules that regulate asthma through specific regulators. The crosslinks between autophagy and ferroptosis provide us with a new perspective to interpret and understand the manifestations of asthma, potential drug discovery targets, and new therapeutic options to effectively intervene in the imbalance caused by abnormal inflammation in asthma. Herein, we introduce the main molecular mechanisms of ferroptosis, autophagy, and asthma, describe the role of crosslinks between ferroptosis and autophagy in asthma based on their common regulatory cells or molecules, and discuss potential drug discovery targets and therapeutic applications in the context of immunomodulatory and symptom alleviation.

Ferroptosis in non-alcoholic liver disease: Molecular mechanisms and therapeutic implications

Ferroptosis refers to a novel modality of regulated cell death characterized by excessive iron accumulation and overwhelming lipid peroxidation, which takes an important part in multiple pathological processes associated with cell death. Considering the crucial roles of the liver in iron and lipid metabolism and its predisposition to oxidative insults, more and more studies have been conducted to explore the relationship between ferroptosis and various liver disorders, including non-alcoholic fatty liver disease (NAFLD). With increased morbidity and high mortality rates, NAFLD has currently emerged as a global public health issue. However, the etiology of NAFLD is not fully understood. In recent years, an accumulating body of evidence have suggested that ferroptosis plays a pivotal role in the pathogenesis of NAFLD, but the precise mechanisms underlying how ferroptosis affects NAFLD still remain obscure. Here, we summarize the molecular mechanisms of ferroptosis and its complicated regulation systems, delineate the different effects that ferroptosis exerts in different stages of NAFLD, and discuss some potential effective therapies targeting ferroptosis for NAFLD treatment, which putatively points out a novel direction for NAFLD treatment.

Iron-tracking strategies: Chaperones capture iron in the cytosolic labile iron pool

Cells express hundreds of iron-dependent enzymes that rely on the iron cofactors heme, iron-sulfur clusters, and mono-or di-nuclear iron centers for activity. Cells require systems for both the assembly and the distribution of iron cofactors to their cognate enzymes. Proteins involved in the binding and trafficking of iron ions in the cytosol, called cytosolic iron chaperones, have been identified and characterized in mammalian cells. The first identified iron chaperone, poly C-binding protein 1 (PCBP1), has also been studied in mice using genetic models of conditional deletion in tissues specialized for iron handling. Studies of iron trafficking in mouse tissues have necessitated the development of new approaches, which have revealed new roles for PCBP1 in the management of cytosolic iron. These approaches can be applied to investigate use of other nutrient metals in mammals.

Targeting Iron Metabolism and Ferroptosis as Novel Therapeutic Approaches in Cardiovascular Diseases

Iron functions as an essential micronutrient and participates in normal physiological and biochemical processes in the cardiovascular system. Ferroptosis is a novel type of iron-dependent cell death driven by iron accumulation and lipid peroxidation, characterized by depletion of glutathione and suppression of glutathione peroxidase 4 (GPX4). Dysregulation of iron metabolism and ferroptosis have been implicated in the occurrence and development of cardiovascular diseases (CVDs), including hypertension, atherosclerosis, pulmonary hypertension, myocardial ischemia/reperfusion injury, cardiomyopathy, and heart failure. Iron chelators deferoxamine and dexrazoxane, and lipophilic antioxidants ferrostatin-1 and liproxstatin-1 have been revealed to abolish ferroptosis and suppress lipid peroxidation in atherosclerosis, cardiomyopathy, hypertension, and other CVDs. Notably, inhibition of ferroptosis by ferrostatin-1 has been demonstrated to alleviate cardiac impairments, fibrosis and pathological remodeling during hypertension by potentiating GPX4 signaling. Administration of deferoxamine improved myocardial ischemia/reperfusion injury by inhibiting lipid peroxidation. Several novel small molecules may be effective in the treatment of ferroptosis-mediated CVDs. In this article, we summarize the regulatory roles and underlying mechanisms of iron metabolism dysregulation and ferroptosis in the occurrence and development of CVDs. Targeting iron metabolism and ferroptosis are potential therapeutic strategies in the prevention and treatment of hypertension and other CVDs.

Inhibitory Effects of Esculetin on Liver Cancer Through Triggering NCOA4 Pathway-Mediation Ferritinophagy in vivo and in vitro

Objective

To explore the effects of Esculetin on liver cancer and explore potential mechanisms of Esculetin-inducing cells death.

Methods

Esculetin's effects on the proliferation, migration and apoptosis of HUH7 and HCCLM3 cells were detected by using CCK8, crystal violet staining, wound healing, Transwell^TM and Annexin V-FITC/PI. Flow cytometry, fluorescence staining, Western blot, T-AOC, DPPH radical scavenging assay, hydroxyl radical's inhibitory capability and GSH test were used to examine the esculetin's effects on the ROS level, the oxidation-related substances and proteins' expression in hepatoma cells. In vivo experiment was performed by xenograft model. Ferrostatin-1 was used to determine the death way of hepatoma cells induced by esculetin. Live cell probe, Western blot, Fe²⁺ content, MDA, HE staining, Prussian blue staining and immunohistochemistry were used to examine the ferritinophagy-related phenomenon induced by esculetin in hepatoma cells. The relationship between esculetin and NCOA4-mediated ferritinophagy was confirmed through gene silence and overexpression, immunofluorescence staining and Western blot.

Results

Esculetin suppressed the proliferation, migration and apoptosis of HUH7 and HCCLM3 cells significantly, influenced the oxidative stress level, altered the autophagy and iron metabolism levels in cells, and produced a ferritinophagy-related phenomena. Esculetin increased the levels of cellular lipid peroxidation and reactive oxygen species. In vivo, esculetin could decrease tumour volume, promote LC3 and NCOA4 expressions, suppresse hydroxyl radical's inhibiting capacity and GSH, increase Fe²⁺ and MDA levels, decrease antioxidant proteins expression in tumour tissue. In addition, Esculetin could also increase the iron deposition of tumour tissues, promote ferritinophagy, and induce tumours' ferroptosis.

Conclusion

Esculetin has an inhibitory effect on liver cancer in vivo and in vitro through triggering NCOA4 pathway-mediation ferritinophagy.

The initiator of neuroexcitotoxicity and ferroptosis in ischemic stroke: Glutamate accumulation

Glutamate plays an important role in excitotoxicity and ferroptosis. Excitotoxicity occurs through over-stimulation of glutamate receptors, specifically NMDAR, while in the non-receptor-mediated pathway, high glutamate concentrations reduce cystine uptake by inhibiting the System Xc-, leading to intracellular glutathione depletion and resulting in ROS accumulation, which contributes to increased lipid peroxidation, mitochondrial damage, and ultimately ferroptosis. Oxidative stress appears to crosstalk between excitotoxicity and ferroptosis, and it is essential to maintain glutamate homeostasis and inhibit oxidative stress responses in vivo. As researchers work to develop natural compounds to further investigate the complex mechanisms and regulatory functions of ferroptosis and excitotoxicity, new avenues will be available for the effective treatment of ischaemic stroke. Therefore, this paper provides a review of the molecular mechanisms and treatment of glutamate-mediated excitotoxicity and ferroptosis.

The molecular and metabolic landscape of iron and ferroptosis in cardiovascular disease

The maintenance of iron homeostasis is essential for proper cardiac function. A growing body of evidence suggests that iron imbalance is the common denominator in many subtypes of cardiovascular disease. In the past 10 years, ferroptosis, an iron-dependent form of regulated cell death, has become increasingly recognized as an important process that mediates the pathogenesis and progression of numerous cardiovascular diseases, including atherosclerosis, drug-induced heart failure, myocardial ischaemia-reperfusion injury, sepsis-induced cardiomyopathy, arrhythmia and diabetic cardiomyopathy. Therefore, a thorough understanding of the mechanisms involved in the regulation of iron metabolism and ferroptosis in cardiomyocytes might lead to improvements in disease management. In this Review, we summarize the relationship between the metabolic and molecular pathways of iron signalling and ferroptosis in the context of cardiovascular disease. We also discuss the potential targets of ferroptosis in the treatment of cardiovascular disease and describe the current limitations and future directions of these novel treatment targets.

Lipid Peroxidation and Iron Metabolism: Two Corner Stones in the Homeostasis Control of Ferroptosis

Regulated cell death (RCD) has a significant impact on development, tissue homeostasis, and the occurrence of various diseases. Among different forms of RCD, ferroptosis is considered as a type of reactive oxygen species (ROS)-dependent regulated necrosis. ROS can react with polyunsaturated fatty acids (PUFAs) of the lipid (L) membrane via the formation of a lipid radical L• and induce lipid peroxidation to form L-ROS. Ferroptosis is triggered by an imbalance between lipid hydroperoxide (LOOH) detoxification and iron-dependent L-ROS accumulation. Intracellular iron accumulation and lipid peroxidation are two central biochemical events leading to ferroptosis. Organelles, including mitochondria and lysosomes are involved in the regulation of iron metabolism and redox imbalance in ferroptosis. In this review, we will provide an overview of lipid peroxidation, as well as key components involved in the ferroptotic cascade. The main mechanism that reduces ROS is the redox ability of glutathione (GSH). GSH, a tripeptide that includes glutamic acid, cysteine, and glycine, acts as an antioxidant and is the substrate of glutathione peroxidase 4 (GPX4), which is then converted into oxidized glutathione (GSSG). Increasing the expression of GSH can inhibit ferroptosis. We highlight the role of the x_c^- GSH-GPX4 pathway as the main pathway to regulate ferroptosis. The system x_c^-, composed of subunit solute carrier family members (SLC7A11 and SLC3A2), mediates the exchange of cystine and glutamate across the plasma membrane to synthesize GSH. Accumulating evidence indicates that ferroptosis requires the autophagy machinery for its execution. Ferritinophagy is used to describe the removal of the major iron storage protein ferritin by the autophagy machinery. Nuclear receptor coactivator 4 (NCOA4) is a cytosolic autophagy receptor used to bind ferritin for subsequent degradation by ferritinophagy. During ferritinophagy, stored iron released becomes available for biosynthetic pathways. The dysfunctional ferroptotic response is implicated in a variety of pathological conditions. Ferroptosis inducers or inhibitors targeting redox- or iron metabolism-related proteins and signal transduction have been developed. The simultaneous detection of intracellular and extracellular markers may help diagnose and treat diseases related to ferroptotic damage.

α-Lipoic Acid Alleviated Fluoride-Induced Hepatocyte Injury via Inhibiting Ferroptosis

Fluoride is widely used in agricultural production and food packaging. Excessive fluoride in water and food is a serious threat to liver health. α-Lipoic acid, a natural free radical scavenger, has hepatoprotective properties. However, the protective effect of α-lipoic acid on fluorohepatotoxicity is uncertain. The aim of this study was to investigate the mechanism of ferroptosis in α-lipoic acid preventing fluoride-induced hepatotoxicity. Five-week-old ICR mice were treated with sodium fluoride (100 mg/L) and/or α-lipoic acid (200 mg/kg) for 9 weeks. The results showed that α-lipoic acid attenuated fluoride-induced damage to liver morphology and ultrastructure. Moreover, α-lipoic acid alleviated fluoride-induced iron accumulation, increased oxidative stress, and elevated lipid peroxidation in the liver. In addition, the mechanism study found that α-lipoic acid prevented fluoride-induced ferroptosis through the System Xc^-/GPX4 axis, lipid peroxidation axis, and iron metabolism axis, but it was interestingly not regulated by mitochondrial free radical axis in the hepatocytes. Altogether, this study indicated that α-lipoic acid prevents fluoride-induced liver injury by inhibiting ferroptosis, which has potential implications for the prevention and treatment of fluoride-induced liver injury.

Iron and liver cancer: an inseparable connection

Iron is an essential element for all organisms. Iron-containing proteins play critical roles in cellular functions. The biological importance of iron is largely attributable to its chemical properties as a transitional metal. However, an excess of 'free' reactive iron damages the macromolecular components of cells and cellular DNA through the production of harmful free radicals. On the contrary, most of the body's excess iron is stored in the liver. Not only hereditary haemochromatosis but also some liver diseases with mild-to-moderate hepatic iron accumulation, such as chronic hepatitis C, alcoholic liver disease and nonalcoholic steatohepatitis, are associated with a high risk for liver cancer development. These findings have attracted attention to the causative and promotive roles of iron in the development of liver cancer. In the last decade, accumulating evidence regarding molecules regulating iron metabolism or iron-related cell death programmes such as ferroptosis has shed light on the relationship between hepatic iron accumulation and hepatocarcinogenesis. In this review, we briefly present the current molecular understanding of iron regulation in the liver. Next, we describe the mechanisms underlying dysregulated iron metabolism depending on the aetiology of liver diseases. Finally, we discuss the causative and promotive roles of iron in cancer development.

Targeting Ferroptosis Holds Potential for Intervertebral Disc Degeneration Therapy

Intervertebral disc degeneration (IVDD) is a common pathological condition responsible for lower back pain, which can significantly increase economic and social burdens. Although considerable efforts have been made to identify potential mechanisms of disc degeneration, the treatment of IVDD is not satisfactory. Ferroptosis, a recently reported form of regulated cell death (RCD), is characterized by iron-dependent lipid peroxidation and has been demonstrated to be responsible for a variety of degenerative diseases. Accumulating evidence suggests that ferroptosis is implicated in IVDD by decreasing viability and increasing extracellular matrix degradation of nucleus pulposus cells, annulus fibrosus cells, or endplate chondrocytes. In this review, we summarize the literature regarding ferroptosis of intervertebral disc cells and discuss its molecular pathways and biomarkers for treating IVDD. Importantly, ferroptosis is verified as a promising therapeutic target for IVDD.

Bioactive Iridium Nanoclusters with Glutathione Depletion Ability for Enhanced Sonodynamic-Triggered Ferroptosis-Like Cancer Cell Death

Ferroptosis is a regulated form of necrotic cell death that involves the accumulation of lipid peroxide (LPO) species in an iron- and reactive oxygen species (ROS)-dependent manner. Previous investigations have reported that ferroptosis-based cancer therapy can overcome the limitations of traditional therapeutics targeting the apoptosis pathway. However, it is still challenging to enhance the antitumor efficacy of ferroptosis due to intrinsic cellular regulation. In this study, a ferroptosis-inducing agent, i.e., chlorin e6 (Ce6)-conjugated human serum albumin-iridium oxide (HSA-Ce6-IrO₂ , HCIr) nanoclusters, is developed to achieve sonodynamic therapy (SDT)-triggered ferroptosis-like cancer cell death. The sonosensitizing role of both Ce6 and IrO₂ within the HCIr nanoclusters exhibits highly efficient ¹ O₂ generation capacity upon ultrasound stimulation, which promotes the accumulation of LPO and subsequently induces ferroptosis. Meanwhile, the HCIr can deplete glutathione (GSH) by accelerating Ir (IV)-Ir (III) transition, which further suppresses the activity of glutathione peroxidase 4 (GPX4) to enhance the ferroptosis efficacy. Through in vitro and in vivo experiments, it is demonstrated that HCIr possesses tremendous capacity to reduce the intracellular GSH content, which enhances SDT-triggered ferroptosis-like cancer cell death. Thus, an iridium-nanoclusters-based ferroptosis-inducing agent is developed, providing a promising strategy for inducing ferroptosis-like cancer cell death.