Emerging Mechanisms and Disease Implications of Ferroptosis: Potential Applications of Natural Products

Exploring ferroptosis and miRNAs: implications for cancer modulation and therapy

Ferroptosis is a novel, iron-dependent form of non-apoptotic cell death characterized by the accumulation of lipid reactive oxygen species (ROS) and mitochondrial shrinkage. It is closely associated with the onset and progression of various diseases, especially cancer, at all stages, making it a key focus of research for developing therapeutic strategies. Numerous studies have explored the role of microRNAs (miRNAs) in regulating ferroptosis by modulating the expression of critical genes involved in iron metabolism and lipid peroxidation. Due to their diversity, unique properties, and dynamic expression patterns in diseases, exosomal miRNAs are emerging as promising biomarkers. Exosomes act as biological messengers, delivering miRNAs to target cells through specific internalization, thus influencing the ferroptosis response in recipient cells. This review summarizes the roles of miRNAs, with particular focus on exosomal miRNAs, in ferroptosis and their implications for cancer pathology. By examining the molecular mechanisms of miRNAs, we aim to provide valuable insights into potential therapeutic approaches.

Chemical Constituents of Deep-Sea Derived Fungus Pseudogymnoascus hyalinus and Their Ferroptosis Inhibitory Activity

Four new polyketides including one indanone (1), one isobenzofuranone (2), and two naphthoquinones (3 and 4) were isolated from the deep-sea-derived fungus Pseudogymnoascus hyalinus, along with 20 known compounds (5-24). The structures of new compounds were established by comprehensive analyses of their 1D and 2D NMR, HRESIMS, as well as TD-DFT-ECD. Compounds 5, 6, and 10 displayed potent inhibitory effects against RSL3 induced ferroptosis with EC50 values of 4.74, 1.55, and 3.72 µM, respectively.

Chemical Constituents of the Deep-Sea-Derived Penicillium citrinum W22 and Their Ferroptosis Inhibitory Activity

One new monomeric citrinin analog (1) and 42 known compounds (2-43) were isolated from Penicillium citrinum W22. The structure of 1 was determined by detailed analysis of the 1D and 2D nuclear magnetic resonance (NMR), HRESIMS, and time-dependent density functional theory (TD-DFT)-based electronic circular dichroism (ECD) calculation. Penicitrinol A (2) and methyl 2-(2-acetyl-3,5-dihydroxy-4,6-dimethylphenyl) acetate (11) significantly inhibited renin-angiotensin system-selective lethal 3 (RSL3)-induced ferroptosis with half maximal effective concentration (EC50) values of 1.6 and 34.0 µM, respectively.

Targeting ferroptosis for the treatment of female reproductive system disorders

Ferroptosis, a regulated form of cell death driven by iron-dependent lipid peroxidation, has emerged as a critical factor in female reproductive health and has been implicated in disorders such as polycystic ovary syndrome, premature ovarian insufficiency, endometriosis, and ovarian cancer. This review explores the intricate molecular mechanisms underlying ferroptosis, emphasizing its reliance on iron metabolism and oxidative stress, which disrupt key processes in reproductive tissues, including granulosa cell function, folliculogenesis, and embryo implantation. Increasing evidence linking ferroptosis to these conditions offers new therapeutic opportunities, with iron chelators, lipid peroxidation inhibitors, and antioxidants showing the potential to alleviate reproductive dysfunction by modulating ferroptotic pathways. In ovarian cancer, ferroptosis inducers combined with conventional cancer therapies, such as chemotherapy, provide promising strategies to overcome drug resistance. This review synthesizes current knowledge on ferroptosis and highlights its importance as a therapeutic target in reproductive health, emphasizing the need for further research to refine and expand treatment options, evaluate their applicability in clinical settings, and explore their role in fertility preservation. By advancing our understanding of ferroptosis regulation, these therapeutic approaches could lead to novel treatments for reproductive disorders and cancers, offering new hope for improving outcomes in women's health and cancer therapy.

Natural Polyphenol-Mediated Inhibition of Ferroptosis Alleviates Oxidative Damage and Inflammation in Acute Liver Injury

Acetaminophen (APAP) overdose has long been recognized as the main cause of drug-induced liver injury (DILI), characterized by glutathione (GSH) depletion and reactive oxygen species (ROS) accumulation, leading to ferroptosis and inflammatory responses. There is an urgent need for liver-protective agents to combat ferroptosis, modulate oxidative stress, and ameliorate inflammation. Catechin, a well-known polyphenol compound, has been shown to have antioxidant potential. However, its protective role on APAP-induced liver injury (AILI) has not been elucidated. In this study, we evaluated the modulating effects of catechin on AILI and observed that catechin attenuated liver injury by reducing inflammation. Mechanistically, catechin alleviated hepatic oxidative stress by inhibiting ROS accumulation, malondialdehyde (MDA) production, and GSH depletion. Furthermore, catechin, as a hepatic injury reparative agent, could counteract APAP-induced hepatocyte ferroptosis by activating the xCT/GPX4 pathway, and is expected to be a novel natural inhibitor of ferroptosis. Additionally, the transcriptomic results indicated that the inhibition of Stat1 by catechin is important for the management of AILI. Inhibition of signal transducer and activator of transcription 1 (STAT1) expression, achieved through the use of the STAT1 inhibitor fludarabine in vivo and small interfering RNA (siRNA) in vitro, was confirmed to attenuate APAP-induced ferroptosis. In conclusion, the present study identified a novel natural drug inhibitor of ferroptosis and revealed its mechanism of action to inhibit ferroptosis, regulate oxidative stress, and ameliorate inflammation in AILI. This further provides new insights into the novel natural ferroptosis inhibitors for the treatment of ROS-related inflammatory diseases.

Chemical Constituents of the Deep-sea Derived Fungus Purpureocillium lilacinum XIA-9

Two new sphingosine derivatives (1 and 2), two new vicinal diol analogs (3 and 4), one new diol analog (5), one new fatty acid (9), together with 19 known compounds (6-8, 10-24), were isolated from Purpureocillium lilacinum XIA-9. Their structures were determined by detailed analysis of the 1D and 2D NMR, HRESIMS, and optical rotatory data. Fusarubin 3-methyl ether (17) exhibited potent inhibition on RSL3 induced ferroptosis with the EC50 value of 0.1 μM.

Potential role and therapeutic implications of glutathione peroxidase 4 in the treatment of Alzheimer's disease

Alzheimer's disease is an age-related neurodegenerative disorder with a complex and incompletely understood pathogenesis. Despite extensive research, a cure for Alzheimer's disease has not yet been found. Oxidative stress mediates excessive oxidative responses, and its involvement in Alzheimer's disease pathogenesis as a primary or secondary pathological event is widely accepted. As a member of the selenium-containing antioxidant enzyme family, glutathione peroxidase 4 reduces esterified phospholipid hydroperoxides to maintain cellular redox homeostasis. With the discovery of ferroptosis, the central role of glutathione peroxidase 4 in anti-lipid peroxidation in several diseases, including Alzheimer's disease, has received widespread attention. Increasing evidence suggests that glutathione peroxidase 4 expression is inhibited in the Alzheimer's disease brain, resulting in oxidative stress, inflammation, ferroptosis, and apoptosis, which are closely associated with pathological damage in Alzheimer's disease. Several therapeutic approaches, such as small molecule drugs, natural plant products, and non-pharmacological treatments, ameliorate pathological damage and cognitive function in Alzheimer's disease by promoting glutathione peroxidase 4 expression and enhancing glutathione peroxidase 4 activity. Therefore, glutathione peroxidase 4 upregulation may be a promising strategy for the treatment of Alzheimer's disease. This review provides an overview of the gene structure, biological functions, and regulatory mechanisms of glutathione peroxidase 4, a discussion on the important role of glutathione peroxidase 4 in pathological events closely related to Alzheimer's disease, and a summary of the advances in small-molecule drugs, natural plant products, and non-pharmacological therapies targeting glutathione peroxidase 4 for the treatment of Alzheimer's disease. Most prior studies on this subject used animal models, and relevant clinical studies are lacking. Future clinical trials are required to validate the therapeutic effects of strategies targeting glutathione peroxidase 4 in the treatment of Alzheimer's disease.

Bee Pollen Potential to Modulate Ferroptosis: Phytochemical Insights for Age-Related Diseases

Bee pollen (BP) is one of the richest known natural resources of micronutrients and bioactive phytochemicals. Some captivating bioactivities of BP compounds, although being largely investigated for the latter as individual molecules, remain very scarcely investigated or completely uninvestigated in bee pollen as a whole product. Among the most intriguing of these bioactivities, we identified ferroptosis as a major one. Ferroptosis, a recently discovered form of cell death (connecting oxidative stress and inflammation), is a complex pathophysiological process and one of the most crucial and perplexing events in current challenging human diseases such as cancer, neurodegeneration, and general aging diseases. Many BP compounds were found to intricately modulate ferroptosis depending on the cellular context by inducing this cell death mechanism in malignant cells and preventing it in non-malignant cells. Since research in both fields, i.e., BP and ferroptosis, is still recent, we deemed it necessary to undertake this review to figure out the extent of BP potential in modulating ferroptosis mechanisms. Our research proved that a wide range of BP compounds (polyphenols, phenolamides, carotenoids, vitamins, minerals, and others) substantially modulate diverse ferroptosis mechanisms. Accordingly, these phytochemicals and nutrients showed interesting potential in preclinical studies to lead to ferroptosis-mediated outcomes in important pathophysiological processes, including many aging-related disorders. One of the most paramount challenges that remain to be resolved is to determine how different BP compounds act on ferroptosis in different biological and pathophysiological contexts, either through synergistic or antagonistic behaviors. We hope that our current work constitutes a valuable incentive for future investigations in this promising and very relevant research avenue.

Asiatic acid ameliorates doxorubicin-induced cardiotoxicity by promoting FPN-mediated iron export and inhibiting ferroptosis

Doxorubicin (DOX), a common chemotherapeutic agent in cancer therapy, is accompanied by pronounced cardiotoxicity. Ferroptosis has been implicated in the pathogenesis and therapeutics of DOX-induced cardiotoxicity (DIC). Asiatic acid (AA), a pentacyclic triterpene from the Chinese medicinal herb Centella asiatica, displays antioxidant, anti-inflammatory, and antiapoptotic activities. In this study, we investigated the beneficial effects of AA against DOX-induced ferroptosis and cardiotoxicity and the underlying mechanisms. A chronic DIC model was established by challenging mice with DOX (5 mg/kg, i.p.) once per week for 4 weeks. Concurrent with DOX insult, the mice were administered AA (25 mg·kg-1·d-1, i.g.). Cardiac function and mechanical properties of isolated cardiomyocytes were evaluated at the end of treatment. We showed that AA administration preserved cardiac function, significantly reduced cardiac injury, and improved cardiomyocyte contractile function in DIC mice. The beneficial effects of AA were causally linked to the inhibition of DOX-induced ferroptosis both in vivo and in vitro. We revealed that AA attenuated DOX-induced iron accumulation in HL-1 cells by increasing FPN-mediated iron export, in a Nrf2-dependent manner. AA upregulated Nrf2 expression and promoted Nrf2 nuclear translocation in DOX-treated HL-1 cells. Moreover, AA-offered benefits against DOX-induced cardiac dysfunction and ferroptosis were abolished by Nrf2 inhibitor ML385 (30 mg·kg-1·d-1, i.p.) administrated 30 min before AA in DIC mice. Our data favor that AA promotes FPN-mediated iron export to inhibit iron overload and ferroptosis in DIC, suggesting its therapeutic potential in the treatment of DIC.

Antioxidant-mediated suppression of ferroptosis in Pyricularia oryzae: a novel approach to rice blast management for sustainable rice production

Ferroptosis, an iron-dependent form of regulated cell death, has recently emerged as a crucial process in the pathogenesis of Pyricularia oryzae, the causal agent of the devastating rice blast disease, which causes billions of dollars in annual losses. This mini review explores the potential of antioxidants in suppressing ferroptosis in P. oryzae to promote sustainable rice production, with significant implications for global food security and nutrition. We critically analyze the current literature on the mechanisms of ferroptosis in P. oryzae, including iron metabolism and lipid peroxidation, the role of different antioxidants in inhibiting this cell death pathway, and the potential applications of antioxidant-based strategies for the management of rice blast disease. Recent discoveries, such as the efficacy of the natural flavonoid tangeretin in inhibiting fungal ferroptosis by interfering with the accumulation of iron and reactive oxygen species, highlight the promise of natural and nature-inspired compounds for disease management. The use of antioxidants to modulate ferroptosis in P. oryzae offers several advantages over traditional fungicide-based approaches, including improved safety, sustainability, and potential nutritional benefits through antioxidant-enriched rice varieties. However, challenges such as optimizing delivery methods, managing potential resistance, and ensuring efficacy under different environmental conditions need to be addressed. To achieve these goals, future research should focus on identifying the most effective antioxidant compounds, exploring synergistic combinations, and developing sustainable application methods.

Analyzing the role of ferroptosis in ribosome-related bone marrow failure disorders: From pathophysiology to potential pharmacological exploitation

Within the last decade, the scientific community has witnessed the importance of ferroptosis as a novel cascade of molecular events leading to cellular decisions of death distinct from apoptosis and other known forms of cell death. Notably, such non- apoptotic and iron-dependent regulated cell death has been found to be intricately linked to several physiological processes as well as to the pathogenesis of various diseases. To this end, recent data support the notion that a potential molecular connection between ferroptosis and inherited bone marrow failure (IBMF) in individuals with ribosomopathies may exist. In this review, we suggest that in ribosome-related IBMFs the identified mutations in ribosomal proteins lead to changes in the ribosome composition of the hematopoietic progenitors, changes that seem to affect ribosomal function, thus enhancing the expression of some mRNAs subgroups while reducing the expression of others. These events lead to an imbalance inside the cell as some molecular pathways are promoted while others are inhibited. This disturbance is accompanied by ROS production and lipid peroxidation, while an additional finding in most of them is iron accumulation. Once lipid peroxidation and iron accumulation are the two main characteristics of ferroptosis, it is possible that this mechanism plays a key role in the manifestation of IBMF in this type of disease. If this molecular mechanism is further confirmed, new pharmacological targets such as ferroptosis inhibitors that are already exploited for the treatment of other diseases, could be utilized to improve the treatment of ribosomopathies.

Intracellular C5aR1 inhibits ferroptosis in glioblastoma through METTL3-dependent m6A methylation of GPX4

Glioblastoma (GBM) is the most common primary intracranial malignant tumor. Recent literature suggests that induction of programmed death has become a mainstream cancer treatment strategy, with ferroptosis being the most widely studied mode. Complement C5a receptor 1 (C5aR1) is associated with both tumorigenesis and tumor-related immunity. However, knowledge regarding the role of C5aR1 in GBM progression is limited. In the present study, we observed significant upregulation of C5aR1 in glioma tissue. In addition, C5aR1 expression was found to be closely associated with patient prognosis and survival. Subsequent experimental verification demonstrated that C5aR1 promoted the progression of GBM mainly by suppressing ferroptosis induction, inhibiting the accumulation of lipid peroxides, and stabilizing the expression of the core antiferroptotic factor glutathione peroxidase 4 (GPX4). Aberrant N6-methyladenosine (m6A) modification of GPX4 mRNA contributes significantly to epigenetic tumorigenesis, and here, we report that selective methyltransferase-like 3 (METTL3)-dependent m6A methylation of GPX4 plays a key role in C5AR1 knockdown-induced ferroptosis induction. Mechanistically, ERK1/2 signaling pathway activation increases the METTL3 protein abundance in GBM cells. This activation then increases the stability of METTL3-mediated m6A modifications on GPX4, enabling it to fulfill its transcriptional function. More importantly, in an intracranial xenograft mouse model, PMX205, a C5aR1 inhibitor, promoted alterations in ferroptosis in GBM cells and inhibited GBM progression. In conclusion, our findings suggest that C5aR1 inhibits ferroptosis in GBM cells and promotes MettL3-dependent GPX4 expression through ERK1/2, thereby promoting glioma progression. Our study reveals a novel mechanism by which the intracellular complement receptor C5aR1 suppresses ferroptosis induction and promotes GBM progression. These findings may facilitate the identification of a potential therapeutic target for glioma.

Iron accumulation/overload and Alzheimer's disease risk factors in the precuneus region: A comprehensive narrative review

Alzheimer's disease (AD) is a neurodegenerative disease that is characterized by amyloid plaques, neurofibrillary tangles, and neuronal loss. Early cerebral and body iron dysregulation and accumulation interact with AD pathology, particularly in the precuneus, a crucial functional hub in cognitive functions. Quantitative susceptibility mapping (QSM), a novel post-processing approach, provides insights into tissue iron levels and cerebral oxygen metabolism and reveals abnormal iron accumulation early in AD. Increased iron deposition in the precuneus can lead to oxidative stress, neuroinflammation, and accelerated neurodegeneration. Metabolic disorders (diabetes, non-alcoholic fatty liver disease (NAFLD), and obesity), genetic factors, and small vessel pathology contribute to abnormal iron accumulation in the precuneus. Therefore, in line with the growing body of literature in the precuneus region of patients with AD, QSM as a neuroimaging method could serve as a non-invasive biomarker to track disease progression, complement other imaging modalities, and aid in early AD diagnosis and monitoring.

Natural products targeting ferroptosis pathways in cancer therapy (Review)

Ferroptosis inducers (FIN) have a key role in cancer therapy and provide novel and innovative treatment strategies. Although many researchers have performed FIN screening of synthetic compounds, studies on the identification of FIN from natural products are limited, particularly in the field of drug development and combination therapy. In this review, this gap was addressed by comprehensively summarizing recent studies on ferroptosis. The causes of ferroptosis were categorized into driving and defensive factors, elucidating key pathways and targets. Next, through summarizing research on natural products that induce ferroptosis, the study elaborated in detail on the natural products that have FIN functions. Their discovery and development were also described and insight for clinical drug development was provided. In addition, the mechanisms of action were analyzed and potential combination therapies, resistance reversal and structural enhancements were presented. By highlighting the potential of natural products in inducing ferroptosis for cancer treatment, this review may serve as a reference for utilizing these compounds against cancer. It not only showed the significance of natural products but may also promote further investigation into their therapeutic effects, thus encouraging research in this field.

GOLPH3 inhibits erastin-induced ferroptosis in colorectal cancer cells

Ferroptosis is a novel form of programmed cell death and is considered to be a druggable target for colorectal cancer (CRC) therapy. However, the role of ferroptosis in CRC and its underlying mechanism are not fully understood. In the present study we found that a protein enriched in the Golgi apparatus, Golgi phosphoprotein 3 (GOLPH3), was overexpressed in human CRC tissue and in several CRC cell lines. The expression of GOLPH3 was significantly correlated with the expression of ferroptosis-related genes in CRC. The overexpression of GOLPH3 in Erastin-induced Caco-2 CRC cells reduced ferroptotic phenotypes, whereas the knockdown of GOLPH3 potentiated ferroptosis in HT-29 CRC cells. GOLPH3 induced the expression of prohibitin-1 (PHB1) and prohibitin-2 (PHB2), which also inhibited ferroptosis in Erastin-treated CRC cells. Moreover, GOLPH3 interacted with PHB2 and nuclear factor erythroid 2-related factor 2 (NRF2) in Caco-2 cells. These observations indicate that GOLPH3 is a negative regulator of ferroptosis in CRC cells. GOLPH3 protects these cells from ferroptosis by inducing the expression of PHB1 and PHB2, and by interacting with PHB2 and NRF2.

Ferroptosis-Regulated Natural Products and miRNAs and Their Potential Targeting to Ferroptosis and Exosome Biogenesis

Ferroptosis, which comprises iron-dependent cell death, is crucial in cancer and non-cancer treatments. Exosomes, the extracellular vesicles, may deliver biomolecules to regulate disease progression. The interplay between ferroptosis and exosomes may modulate cancer development but is rarely investigated in natural product treatments and their modulating miRNAs. This review focuses on the ferroptosis-modulating effects of natural products and miRNAs concerning their participation in ferroptosis and exosome biogenesis (secretion and assembly)-related targets in cancer and non-cancer cells. Natural products and miRNAs with ferroptosis-modulating effects were retrieved and organized. Next, a literature search established the connection of a panel of ferroptosis-modulating genes to these ferroptosis-associated natural products. Moreover, ferroptosis-associated miRNAs were inputted into the miRNA database (miRDB) to bioinformatically search the potential targets for the modulation of ferroptosis and exosome biogenesis. Finally, the literature search provided a connection between ferroptosis-modulating miRNAs and natural products. Consequently, the connections from ferroptosis-miRNA-exosome biogenesis to natural product-based anticancer treatments are well-organized. This review sheds light on the research directions for integrating miRNAs and exosome biogenesis into the ferroptosis-modulating therapeutic effects of natural products on cancer and non-cancer diseases.

Anti-necroptosis and anti-ferroptosis compounds from the Deep-Sea-Derived fungus Aspergillus sp. MCCC 3A00392

Eight undescribed (1-8) and 46 known compounds (9-54) were isolated from the deep-sea-derived Aspergillus sp. MCCC 3A00392. Compounds 1-3 were three novel oxoindolo diterpenoids, 4-6 were three bisabolane sesquiterpenoids, while 7 and 8 were two monocyclic cyclopropanes. Their structures were established by exhaustive analyses of the HRESIMS, NMR, and theoretical calculations of the NMR data and ECD spectra. Compounds 10, 33, 38, and 39 were able to inhibit tumor necrosis factor (TNF)-induced necroptosis in murine L929 cell lines. Functional experiments verified that compounds 10 and 39 inhibited necroptosis by downregulating the phosphorylation of RIPK3 and MLKL. Moreover, compound 39 also reduced the phosphorylation of RIPK1. Compounds 10, 33, and 34 displayed potent inhibitory activities against RSL-3 induced ferroptosis with the EC50 value of 3.0 μM, 0.4 μM, and 0.1 μM, respectively. Compound 10 inhibited ferroptosis by the downregulation of HMOX1, while compounds 33 and 34 inhibited ferroptosis through regulation of NRF2/SLC7A11/GCLM axis. However, these compounds only showed weak effect in either the necroptosis or ferroptosis relative mouse disease models. Further studies of pharmacokinetics and pharmacodynamics might improve their in vivo bioactivities.

Vitamin E/Coenzyme Q-Dependent "Free Radical Reductases": Redox Regulators in Ferroptosis

Significance: Lipid peroxidation and its products, oxygenated polyunsaturated lipids, act as essential signals coordinating metabolism and physiology and can be deleterious to membranes when they accumulate in excessive amounts. Recent Advances: There is an emerging understanding that regulation of polyunsaturated fatty acid (PUFA) phospholipid peroxidation, particularly of PUFA-phosphatidylethanolamine, is important in a newly discovered type of regulated cell death, ferroptosis. Among the most recently described regulatory mechanisms is the ferroptosis suppressor protein, which controls the peroxidation process due to its ability to reduce coenzyme Q (CoQ). Critical Issues: In this study, we reviewed the most recent data in the context of the concept of free radical reductases formulated in the 1980-1990s and focused on enzymatic mechanisms of CoQ reduction in different membranes (e.g., mitochondrial, endoplasmic reticulum, and plasma membrane electron transporters) as well as TCA cycle components and cytosolic reductases capable of recycling the high antioxidant efficiency of the CoQ/vitamin E system. Future Directions: We highlight the importance of individual components of the free radical reductase network in regulating the ferroptotic program and defining the sensitivity/tolerance of cells to ferroptotic death. Complete deciphering of the interactive complexity of this system may be important for designing effective antiferroptotic modalities. Antioxid. Redox Signal. 40, 317-328.

Ferroptosis: a new mechanism of traditional Chinese medicine for cancer treatment

Ferroptosis, distinct from apoptosis, is a novel cellular death pathway characterized by the build-up of lipid peroxidation and reactive oxygen species (ROS) derived from lipids within cells. Recent studies demonstrated the efficacy of ferroptosis inducers in targeting malignant cells, thereby establishing a promising avenue for combating cancer. Traditional Chinese medicine (TCM) has a long history of use and is widely used in cancer treatment. TCM takes a holistic approach, viewing the patient as a system and utilizing herbal formulas to address complex diseases such as cancer. Recent TCM studies have elucidated the molecular mechanisms underlying ferroptosis induction during cancer treatment. These studies have identified numerous plant metabolites and derivatives that target multiple pathways and molecular targets. TCM can induce ferroptosis in tumor cells through various regulatory mechanisms, such as amino acid, iron, and lipid metabolism pathways, which may provide novel therapeutic strategies for apoptosis-resistant cancer treatment. TCM also influence anticancer immunotherapy via ferroptosis. This review comprehensively elucidates the molecular mechanisms underlying ferroptosis, highlights the pivotal regulatory genes involved in orchestrating this process, evaluates the advancements made in TCM research pertaining to ferroptosis, and provides theoretical insights into the induction of ferroptosis in tumors using botanical drugs.

Novel 3-hydroxypyridin-4(1H)-One derivatives as ferroptosis inhibitors with iron-chelating and reactive oxygen species scavenging activities and therapeutic effect in cisplatin-induced cytotoxicity

Recent advances in understanding the role of iron and ROS in cell death suggest new therapeutic avenues to treat organ damage including acute kidney injury (AKI). Inhibiting ferroptosis was expected to have great potential for the treatment of this disease. Ferroptosis is characterized by iron-dependent lipid peroxidation and currently, a majority of reported ferroptosis inhibitors belong to either radical-trapping antioxidants or iron chelators. However, clinically used iron chelators such as deferoxamine and deferiprone have limited efficacy against ferroptosis (generally with EC50 > 100 μM), despite their proven safety. Herein, we present the rational design of novel ferroptosis inhibitors by incorporating the naturally occurring cinnamic acid scaffold and the 3-hydroxypyridin-4(1H)-one iron-chelating pharmacophore. Through ABTS˙+ radical-scavenging assay, oxygen radical absorbance capacity (ORAC) measurement, Fe3+ affinity evaluation, and anti-erastin-induced HT22 cell ferroptosis assays, we identified compound 9c as the most prospective ferroptosis inhibitor (ABTS˙+, IC50 = 4.35 ± 0.05 μM; ORCA = 23.79 ± 0.56 TE; pFe3+ = 18.59; EC50 = 14.89 ± 0.08 μM, respectively). Notably, 9c dose-dependently alleviated cell death in cisplatin-induced AKI model. Our results provide insight into the development of new ferroptosis inhibitors through rational incorporation of pharmacophores from existing ferroptosis inhibitors, and compound 9c could be a promising lead compound worth further investigation.

Targeting epigenetic and posttranslational modifications regulating ferroptosis for the treatment of diseases

Ferroptosis, a unique modality of cell death with mechanistic and morphological differences from other cell death modes, plays a pivotal role in regulating tumorigenesis and offers a new opportunity for modulating anticancer drug resistance. Aberrant epigenetic modifications and posttranslational modifications (PTMs) promote anticancer drug resistance, cancer progression, and metastasis. Accumulating studies indicate that epigenetic modifications can transcriptionally and translationally determine cancer cell vulnerability to ferroptosis and that ferroptosis functions as a driver in nervous system diseases (NSDs), cardiovascular diseases (CVDs), liver diseases, lung diseases, and kidney diseases. In this review, we first summarize the core molecular mechanisms of ferroptosis. Then, the roles of epigenetic processes, including histone PTMs, DNA methylation, and noncoding RNA regulation and PTMs, such as phosphorylation, ubiquitination, SUMOylation, acetylation, methylation, and ADP-ribosylation, are concisely discussed. The roles of epigenetic modifications and PTMs in ferroptosis regulation in the genesis of diseases, including cancers, NSD, CVDs, liver diseases, lung diseases, and kidney diseases, as well as the application of epigenetic and PTM modulators in the therapy of these diseases, are then discussed in detail. Elucidating the mechanisms of ferroptosis regulation mediated by epigenetic modifications and PTMs in cancer and other diseases will facilitate the development of promising combination therapeutic regimens containing epigenetic or PTM-targeting agents and ferroptosis inducers that can be used to overcome chemotherapeutic resistance in cancer and could be used to prevent other diseases. In addition, these mechanisms highlight potential therapeutic approaches to overcome chemoresistance in cancer or halt the genesis of other diseases.

Ferroptosis: Emerging Role in Diseases and Potential Implication of Bioactive Compounds

Ferroptosis is a form of cell death that is distinguished from other types of death for its peculiar characteristics of death regulated by iron accumulation, increase in ROS, and lipid peroxidation. In the past few years, experimental evidence has correlated ferroptosis with various pathological processes including neurodegenerative and cardiovascular diseases. Ferroptosis also is involved in several types of cancer because it has been shown to induce tumor cell death. In particular, the pharmacological induction of ferroptosis, contributing to the inhibition of the proliferative process, provides new ideas for the pharmacological treatment of cancer. Emerging evidence suggests that certain mechanisms including the Xc- system, GPx4, and iron chelators play a key role in the regulation of ferroptosis and can be used to block the progression of many diseases. This review summarizes current knowledge on the mechanism of ferroptosis and the latest advances in its multiple regulatory pathways, underlining ferroptosis' involvement in the diseases. Finally, we focused on several types of ferroptosis inducers and inhibitors, evaluating their impact on the cell death principal targets to provide new perspectives in the treatment of the diseases and a potential pharmacological development of new clinical therapies.

HDAC3 aberration-incurred GPX4 suppression drives renal ferroptosis and AKI-CKD progression

Acute kidney injury (AKI) progression to chronic kidney disease (CKD) represents a unique renal disease setting characterized by early renal cellular injury and regulated cell death, and later renal fibrosis, of which the critical role and nature of ferroptosis are only partially understood. Here, we report that renal tubular epithelial ferroptosis caused by HDAC3 (histone deacetylase 3) aberration and the resultant GPX4 suppression drives AKI-CKD progression. In mouse models of AKI-CKD transition induced by nephrotoxic aristolochic acid (AA) and folic acid (FA), renal tubular epithelial ferroptosis occurred early that coincided with preferential HDAC3 elevation and marked suppression of a core anti-ferroptosis enzyme GPX4 (glutathione peroxidase 4). Intriguingly, genetic Hdac3 knockout or administration of a HDAC3-selective inhibitor RGFP966 effectively mitigated the GPX4 suppression, ferroptosis and the fibrosis-associated renal functional loss. In cultured tubular epithelial cells, HDAC3 over-expression or inhibition inversely affected GPX4 abundances. Further analysis revealed that Gpx4 promoter contains a typical binding motif of transcription factor KLF5 (Kruppel-like factor 5). HDAC3 and KLF5 inducibly associated and bound to Gpx4 promoter upon AA treatment, leading to local histone hypoacetylation and GPX4 transactivation inhibition, which was blocked by RGFP966 and a KLF5 inhibitor ML264, respectively, suggesting that KLF5 co-regulated the HDAC3-incurred Gpx4 transcription inhibition. More importantly, in AKI-CKD mice receiving a GPX4 inactivator RSL3, the anti-ferroptosis and renoprotective effects of RGFP966 were largely abrogated, indicating that GPX4 is an essential downstream mediator of the HDAC3 aberration and renal ferroptosis during AKI-CKD transition. Together, our study identified a critical epigenetic pathway of ferroptosis during AKI-CKD transition and suggested that the strategies preserving GPX4 by HDAC3 inhibition are potentially effective to reduce renal ferroptosis and slow AKI-CKD progression.

Natural product piperlongumine inhibits proliferation of oral squamous carcinoma cells by inducing ferroptosis and inhibiting intracellular antioxidant capacity

Background

As a new form of cell death, ferroptosis has been shown to have inhibitory effects on a variety of tumor cells except oral squamous cell carcinoma (OSCC). There were few investigations on the effects and molecular mechanisms of piperlongumine (PL, a ferroptosis inducer) and CB-839 (a GLS1 inhibitor which promotes ferroptosis) on OSCC cells. This article assesses the anticancer effect and mechanism of PL as well as combined with CB-839.

Methods

OSCC cells were treated with specified concentration of PL alone or with ferroptosis inhibitor Ferrostatin-1 (Fer-1) and antioxidant N-Acetylcysteine (NAC) to assess their effects on biological characteristics such as cell proliferation, cell death and intracellular ferroptosis related pathways. Also, cells were treated with PL combined with CB-839 to evaluate the synergistic effect of CB-839 on PL's anticancer effects.

Results

The results showed that the proliferation rate of PL-treated OSCC cells were decreased in a dose- and time-dependent manner. PL can induce OSCC cells apoptosis. Lipid peroxidation (LPO) and intracellular reactive oxygen species (ROS) were accumulated after PL treatment. We found some protein changes significantly such as the expression of DMT1 increased, and the expression of FTH1, SLC7A11 and GPX4 decreased. In addition, the anti-proliferation effect of PL can be reversed by Fer-1 and NAC and the level of LPO and ROS was decreased accordingly. Importantly, we found that PL and CB-839 in combination could decrease the cell viability and the LPO level synergistically, accompanied by a large consumption of glutathione (GSH). These evidences prove that PL can induce ferroptosis of OSCC cells, which can be enhanced by CB-839.

Conclusions

Our study suggested that the nature product PL can induce the ferroptotic death of OSCC cells, which is further enhanced when combined with CB-839. The synergistic anticancer effect of these two may prove new strategy for OSCC treatment.

The role of cell death in SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), showing high infectiousness, resulted in an ongoing pandemic termed coronavirus disease 2019 (COVID-19). COVID-19 cases often experience acute respiratory distress syndrome, which has caused millions of deaths. Apart from triggering inflammatory and immune responses, many viral infections can cause programmed cell death in infected cells. Cell death mechanisms have a vital role in maintaining a suitable environment to achieve normal cell functionality. Nonetheless, these processes are dysregulated, potentially contributing to disease pathogenesis. Over the past decades, multiple cell death pathways are becoming better understood. Growing evidence suggests that the induction of cell death by the coronavirus may significantly contributes to viral infection and pathogenicity. However, the interaction of SARS-CoV-2 with cell death, together with its associated mechanisms, is yet to be elucidated. In this review, we summarize the existing evidence concerning the molecular modulation of cell death in SARS-CoV-2 infection as well as viral-host interactions, which may shed new light on antiviral therapy against SARS-CoV-2.

Ferroptosis and EMT: key targets for combating cancer progression and therapy resistance

Iron-dependent lipid peroxidation causes ferroptosis, a form of regulated cell death. Crucial steps in the formation of ferroptosis include the accumulation of ferrous ions (Fe2+) and lipid peroxidation, of which are controlled by glutathione peroxidase 4 (GPX4). Its crucial role in stopping the spread of cancer has been shown by numerous studies undertaken in the last ten years. Epithelial-mesenchymal transition (EMT) is the process by which epithelial cells acquire mesenchymal characteristics. EMT is connected to carcinogenesis, invasiveness, metastasis, and therapeutic resistance in cancer. It is controlled by a range of internal and external signals and changes the phenotype from epithelial to mesenchymal like. Studies have shown that mesenchymal cancer cells tend to be more ferroptotic than their epithelial counterparts. Drug-resistant cancer cells are more easily killed by inducers of ferroptosis when they undergo EMT. Therefore, understanding the interaction between ferroptosis and EMT will help identify novel cancer treatment targets. In-depth discussion is given to the regulation of ferroptosis, the potential application of EMT in the treatment of cancer, and the relationships between ferroptosis, EMT, and signaling pathways associated with tumors. Invasion, metastasis, and inflammation in cancer all include ferroptosis and EMT. The goal of this review is to provide suggestions for future research and practical guidance for applying ferroptosis and EMT in clinical practice.

Pharmacological Inhibition of Ferroptosis as a Therapeutic Target for Neurodegenerative Diseases and Strokes

Emerging evidence suggests that ferroptosis, a unique regulated cell death modality that is morphologically and mechanistically different from other forms of cell death, plays a vital role in the pathophysiological process of neurodegenerative diseases, and strokes. Accumulating evidence supports ferroptosis as a critical factor of neurodegenerative diseases and strokes, and pharmacological inhibition of ferroptosis as a therapeutic target for these diseases. In this review article, the core mechanisms of ferroptosis are overviewed and the roles of ferroptosis in neurodegenerative diseases and strokes are described. Finally, the emerging findings in treating neurodegenerative diseases and strokes through pharmacological inhibition of ferroptosis are described. This review demonstrates that pharmacological inhibition of ferroptosis by bioactive small-molecule compounds (ferroptosis inhibitors) could be effective for treatments of these diseases, and highlights a potential promising therapeutic avenue that could be used to prevent neurodegenerative diseases and strokes. This review article will shed light on developing novel therapeutic regimens by pharmacological inhibition of ferroptosis to slow down the progression of these diseases in the future.

Protective Effects of 3'-Epilutein and 3'-Oxolutein against Glutamate-Induced Neuronal Damage

Dietary lutein can be naturally metabolized to 3'-epilutein and 3'-oxolutein in the human body. The epimerization of lutein can happen in acidic pH, and through cooking, 3'-epilutein can be the product of the direct oxidation of lutein in the retina, which is also present in human serum. The 3'-oxolutein is the main oxidation product of lutein. Thus, the allylic oxidation of dietary lutein can result in the formation of 3'-oxolutein, which may undergo reduction either to revert to dietary lutein or epimerize to form 3'-epilutein. We focused on the effects of 3'-epilutein and 3'-oxolutein itself and on glutamate-induced neurotoxicity on SH-SY5Y human neuroblastoma cells to identify the possible alterations in oxidative stress, inflammation, antioxidant capacity, and iron metabolism that affect neurological function. ROS measurements were performed in the differently treated cells. The inflammatory state of cells was followed by TNFα, IL-6, and IL-8 cytokine ELISA measurements. The antioxidant status of the cells was determined by the total antioxidant capacity kit assay. The alterations of genes related to ferroptosis and lipid peroxidation were followed by gene expression measurements; then, thiol measurements were performed. Lutein metabolites 3'-epilutein and 3'-oxolutein differently modulated the effect of glutamate on ROS, inflammation, ferroptosis-related iron metabolism, and lipid peroxidation in SH-SY5Y cells. Our results revealed the antioxidant and anti-inflammatory features of 3'-epilutein and 3'-oxolutein as possible protective agents against glutamate-induced oxidative stress in SH-SY5Y cells, with greater efficacy in the case of 3'-epilutein.

Molecular Mechanisms of Ferroptosis and Updates of Ferroptosis Studies in Cancers and Leukemia

Ferroptosis is a mode of cell death regulated by iron-dependent lipid peroxidation. Growing evidence suggests ferroptosis induction as a novel anti-cancer modality that could potentially overcome therapy resistance in cancers. The molecular mechanisms involved in the regulation of ferroptosis are complex and highly dependent on context. Therefore, a comprehensive understanding of its execution and protection machinery in each tumor type is necessary for the implementation of this unique cell death mode to target individual cancers. Since most of the current evidence for ferroptosis regulation mechanisms is based on solid cancer studies, the knowledge of ferroptosis with regard to leukemia is largely lacking. In this review, we summarize the current understanding of ferroptosis-regulating mechanisms with respect to the metabolism of phospholipids and iron as well as major anti-oxidative pathways that protect cells from ferroptosis. We also highlight the diverse impact of p53, a master regulator of cell death and cellular metabolic processes, on the regulation of ferroptosis. Lastly, we discuss recent ferroptosis studies in leukemia and provide a future perspective for the development of promising anti-leukemia therapies implementing ferroptosis induction.

Ferroptosis in lung cancer: a novel pathway regulating cell death and a promising target for drug therapy

Lung cancer is a common malignant tumor that occurs in the human body and poses a serious threat to human health and quality of life. The existing treatment methods mainly include surgical treatment, chemotherapy, and radiotherapy. However, due to the strong metastatic characteristics of lung cancer and the emergence of related drug resistance and radiation resistance, the overall survival rate of lung cancer patients is not ideal. There is an urgent need to develop new treatment strategies or new effective drugs to treat lung cancer. Ferroptosis, a novel type of programmed cell death, is different from the traditional cell death pathways such as apoptosis, necrosis, pyroptosis and so on. It is caused by the increase of iron-dependent reactive oxygen species due to intracellular iron overload, which leads to the accumulation of lipid peroxides, thus inducing cell membrane oxidative damage, affecting the normal life process of cells, and finally promoting the process of ferroptosis. The regulation of ferroptosis is closely related to the normal physiological process of cells, and it involves iron metabolism, lipid metabolism, and the balance between oxygen-free radical reaction and lipid peroxidation. A large number of studies have confirmed that ferroptosis is a result of the combined action of the cellular oxidation/antioxidant system and cell membrane damage/repair, which has great potential application in tumor therapy. Therefore, this review aims to explore potential therapeutic targets for ferroptosis in lung cancer by clarifying the regulatory pathway of ferroptosis. Based on the study of ferroptosis, the regulation mechanism of ferroptosis in lung cancer was understood and the existing chemical drugs and natural compounds targeting ferroptosis in lung cancer were summarized, with the aim of providing new ideas for the treatment of lung cancer. In addition, it also provides the basis for the discovery and clinical application of chemical drugs and natural compounds targeting ferroptosis to effectively treat lung cancer.

Astragaloside IV alleviates stroke-triggered early brain injury by modulating neuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway

PURPOSE

Stroke is an acute cerebrovascular disease. Astragaloside IV (AS-IV) is an active ingredient extracted from Astragalus membranaceus with an established therapeutic effect on central nervous system diseases. This study examined the neuroprotective properties and possible mechanisms of AS-IV in stroke-triggered early brain injury (EBI) in a rat transient middle cerebral artery occlusion (MCAO) model.

METHODS

The neurological scores and brain water content were analyzed. 2,3,5-triphenyl tetrazolium chloride (TTC) staining was utilized to determine the infarct volume, neuroinflammatory cytokine levels, and ferroptosis-related genes and proteins, and neuronal damage and molecular mechanisms were evaluated by terminal deoxynucleotidyl transferase dutp nick-end labeling (TUNEL) staining, western blotting, and real-time polymerase chain reaction.

RESULTS

AS-IV administration decreased the infarct volume, brain edema, neurological deficits, and inflammatory cytokines TNF-α, interleukin-1β (IL-1β), IL-6, and NF-κB, increased the levels of SLC7A11 and glutathione peroxidase 4 (GPX4), decreased lipid reactive oxygen species (ROS) levels, and prevented neuronal ferroptosis. Meanwhile, AS-IV triggered the Nrf2/HO-1 signaling pathway and alleviated ferroptosis due to the induction of stroke.

CONCLUSIONS

Hence, the findings of this research illustrate that AS-IV administration can improve delayed ischemic neurological deficits and decrease neuronal death by modulating nuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway.

Links between Vitamin K, Ferroptosis and SARS-CoV-2 Infection

Ferroptosis is a recently discovered form of programmed cell death. It is characterized by the accumulation of iron and lipid hydroperoxides in cells. Vitamin K is known to have antioxidant properties and plays a role in reducing oxidative stress, particularly in lipid cell membranes. Vitamin K reduces the level of reactive oxygen species by modulating the expression of antioxidant enzymes. Additionally, vitamin K decreases inflammation and potentially prevents ferroptosis. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leading to coronavirus disease 2019 (COVID-19) is associated with oxidant–antioxidant imbalance. Studies have shown that intensified ferroptosis occurs in various tissues and cells affected by COVID-19. Vitamin K supplementation during SARS-CoV-2 infection may have a positive effect on reducing the severity of the disease. Preliminary research suggests that vitamin K may reduce lipid peroxidation and inhibit ferroptosis, potentially contributing to its therapeutic effects in COVID-19 patients. The links between ferroptosis, vitamin K, and SARS-CoV-2 infection require further investigation, particularly in the context of developing potential treatment strategies for COVID-19.

Novel druggable mechanism of Parkinson's disease: Potential therapeutics and underlying pathogenesis based on ferroptosis

Genetics, age, environmental factors, and oxidative stress have all been implicated in the development of Parkinson's disease (PD); however, a complete understanding of its pathology remains elusive. At present, there is no cure for PD, and currently available therapeutics are insufficient to meet patient needs. Ferroptosis, a distinctive iron-dependent cell death mode characterized by lipid peroxidation and oxidative stress, has pathophysiological features similar to those of PD, including iron accumulation, reactive oxygen species-induced oxidative damage, and mitochondrial dysfunction. Ferroptosis has been identified as a specific pathway of neuronal death and is closely related to the pathogenesis of PD. Despite the similarities in the biological targets involved in PD pathogenesis and ferroptosis, the relationship between novel targets in PD and ferroptosis has been neglected in the literature. In this review, the mechanism of ferroptosis is discussed, and the potential therapeutic targets implicated in both PD and ferroptosis are compared. Furthermore, the anti-PD effects of several ferroptosis inhibitors, as well as clinical studies thereof, and the identification of novel lead compounds for the treatment of PD and the inhibition of ferroptosis are reviewed. It is hoped that this review can promote research to further elucidate the relationship between ferroptosis and PD and provide new strategies for the development of novel ferroptosis-targeting PD therapy.

Molecular Mechanisms of Nemorosone-Induced Ferroptosis in Cancer Cells

Ferroptosis is an iron-dependent cell death-driven by excessive peroxidation of polyunsaturated fatty acids (PUFAs) of membranes. A growing body of evidence suggests the induction of ferroptosis as a cutting-edge strategy in cancer treatment research. Despite the essential role of mitochondria in cellular metabolism, bioenergetics, and cell death, their function in ferroptosis is still poorly understood. Recently, mitochondria were elucidated as an important component in cysteine-deprivation-induced (CDI) ferroptosis, which provides novel targets in the search for new ferroptosis-inducing compounds (FINs). Here, we identified the natural mitochondrial uncoupler nemorosone as a ferroptosis inducer in cancer cells. Interestingly, nemorosone triggers ferroptosis by a double-edged mechanism. In addition to decreasing the glutathione (GSH) levels by blocking the System xc cystine/glutamate antiporter (SLC7A11), nemorosone increases the intracellular labile Fe²⁺ pool via heme oxygenase-1 (HMOX1) induction. Interestingly, a structural variant of nemorosone (O-methylated nemorosone), having lost the capacity to uncouple mitochondrial respiration, does not trigger cell death anymore, suggesting that the mitochondrial bioenergetic disruption via mitochondrial uncoupling is necessary for nemorosone-induced ferroptosis. Our results open novel opportunities for cancer cell killing by mitochondrial uncoupling-induced ferroptosis.

Neuroprotective Potentials of Flavonoids: Experimental Studies and Mechanisms of Action

Neurological and neurodegenerative diseases, particularly those related to aging, are on the rise, but drug therapies are rarely curative. Functional disorders and the organic degeneration of nervous tissue often have complex causes, in which phenomena of oxidative stress, inflammation and cytotoxicity are intertwined. For these reasons, the search for natural substances that can slow down or counteract these pathologies has increased rapidly over the last two decades. In this paper, studies on the neuroprotective effects of flavonoids (especially the two most widely used, hesperidin and quercetin) on animal models of depression, neurotoxicity, Alzheimer's disease (AD) and Parkinson's disease are reviewed. The literature on these topics amounts to a few hundred publications on in vitro and in vivo models (notably in rodents) and provides us with a very detailed picture of the action mechanisms and targets of these substances. These include the decrease in enzymes that produce reactive oxygen and ferroptosis, the inhibition of mono-amine oxidases, the stimulation of the Nrf2/ARE system, the induction of brain-derived neurotrophic factor production and, in the case of AD, the prevention of amyloid-beta aggregation. The inhibition of neuroinflammatory processes has been documented as a decrease in cytokine formation (mainly TNF-alpha and IL-1beta) by microglia and astrocytes, by modulating a number of regulatory proteins such as Nf-kB and NLRP3/inflammasome. Although clinical trials on humans are still scarce, preclinical studies allow us to consider hesperidin, quercetin, and other flavonoids as very interesting and safe dietary molecules to be further investigated as complementary treatments in order to prevent neurodegenerative diseases or to moderate their deleterious effects.

Identification and validation of ferroptosis-related gene signature in intervertebral disc degeneration

Lower back pain (LBP) is a leading cause of disability in the elderly and intervertebral disc degeneration (IDD) is the major contributor to LBP. Ferroptosis is a newly discovered programmed cell death, characterized by iron-dependent lethal lipid peroxidation. Growing evidence has shown that ferroptosis plays important roles in various human diseases. However, the underlying mechanism of ferroptosis in IDD remains elusive. This study is aimed to uncover the key roles of ferroptosis in the pathogenesis and progression of IDD comprehensively. To investigate the ferroptosis related differentially expressed genes (FRDEGs) in IDD, we analyzed the microarray data from the Gene Expression Omnibus (GEO) database. Then we performed functional enrichment analysis and protein-protein interaction (PPI) network analysis, and screened out the hub FRDEGs. To further evaluate the predictive value of these hub FRDEGs, we performed ROC analysis based on the GSE124272 dataset. A total of 80 FRDEGs were identified, including 20 downregulated and 60 upregulated FRDEGs. The FRDEGs were primarily involved in the biological processes of response to chemical, and response to stress. KEGG pathway enrichment analysis showed that the FRDEGs were mainly involved in ferroptosis, TNF signaling pathway, HIF-1 signaling pathway, NOD-like receptor signaling pathway, and IL-17 signaling pathway. Ten hub OSRDEGs were obtained according to the PPI analysis, including HMOX1, KEAP1, MAPK1, HSPA5, TXNRD1, IL6, PPARA, JUN, HIF1A, DUSP1. The ROC analysis and RT-qPCR validation results suggested that most of the hub FRDEGs might be potential signature genes for IDD. This study reveals that ferroptosis might provide promising strategy for the diagnosis and treatment of IDD.

Fascaplysin Induces Apoptosis and Ferroptosis, and Enhances Anti-PD-1 Immunotherapy in Non-Small Cell Lung Cancer (NSCLC) by Promoting PD-L1 Expression

Fascaplysin is a natural product isolated from sponges with a wide range of anticancer activities. However, the mechanism of fascaplysin against NSCLC has not been clearly studied. In this study, fascaplysin was found to inhibit migration by regulating the wnt/β-catenin signaling pathway and reversing the epithelial-mesenchymal transition phenotype. Further research showed that the anti-NSCLC effect of fascaplysin was mainly through the induction of ferroptosis and apoptosis. Fascaplysin-induced ferroptosis in lung cancer cells, evidenced by increased levels of ROS and Fe2+ and downregulation of ferroptosis-associated protein and endoplasmic reticulum stress, was involved in fascaplysin-induced ferroptosis. In addition, ROS was found to mediate fascaplysin-induced apoptosis. Fascaplysin significantly upregulated the expression of PD-L1 in lung cancer cells, and enhanced anti-PD-1 antitumor efficacy in a syngeneic mouse model. Therefore, these results suggest that fascaplysin exerts anticancer effects by inducing apoptosis and ferroptosis in vitro, and improving the sensitivity of anti-PD-1 immunotherapy in vivo. Fascaplysin is a promising compound for the treatment of NSCLC.

Ferroptosis of Endothelial Cells in Vascular Diseases

Endothelial cells (ECs) line the inner surface of blood vessels and play a substantial role in vascular biology. Endothelial dysfunction (ED) is strongly correlated with the initiation and progression of many vascular diseases. Regulated cell death, such as ferroptosis, is one of the multiple mechanisms that lead to ED. Ferroptosis is an iron-dependent programmed cell death associated with various vascular diseases, such as cardiovascular, cerebrovascular, and pulmonary vascular diseases. This review summarized ferroptosis of ECs in vascular diseases and discussed potential therapeutic strategies for treating ferroptosis of ECs. In addition to lipid peroxidation inhibitors and iron chelators, a growing body of evidence showed that clinical drugs, natural products, and intervention of noncoding RNAs may also inhibit ferroptosis of ECs.

Vicious cycle of lipid peroxidation and iron accumulation in neurodegeneration

Lipid peroxidation and iron accumulation are closely associated with neurodegenerative diseases, such as Alzheimer's, Parkinson's, and Huntington's diseases, or neurodegeneration with brain iron accumulation disorders. Mitochondrial dysfunction, lipofuscin accumulation, autophagy disruption, and ferroptosis have been implicated as the critical pathomechanisms of lipid peroxidation and iron accumulation in these disorders. Currently, the connection between lipid peroxidation and iron accumulation and the initial cause or consequence in neurodegeneration processes is unclear. In this review, we have compiled the known mechanisms by which lipid peroxidation triggers iron accumulation and lipofuscin formation, and the effect of iron overload on lipid peroxidation and cellular function. The vicious cycle established between both pathological alterations may lead to the development of neurodegeneration. Therefore, the investigation of these mechanisms is essential for exploring therapeutic strategies to restrict neurodegeneration. In addition, we discuss the interplay between lipid peroxidation and iron accumulation in neurodegeneration, particularly in PLA2G6-associated neurodegeneration, a rare neurodegenerative disease with autosomal recessive inheritance, which belongs to the group of neurodegeneration with brain iron accumulation disorders.

Astragaloside IV attenuates ferroptosis after subarachnoid hemorrhage via Nrf2/HO-1 signaling pathway

Subarachnoid hemorrhage (SAH) is a severe type of stroke featuring exceptionally high rate of morbidity and mortality due to the lack of effective management. Ferroptosis can be defined as a novel iron-dependent programmed cell death in contrast to classical apoptosis and necrosis. Astragaloside IV (AS-IV) is an active ingredient extracted from Astragalus membranaceus with established therapeutic effect on CNS diseases. However, the exact role of ferroptosis in Astragaloside IV-mediated neuroprotection after SAH is yet to be demonstrated. In the present study, the SAH model of SD male rats with endovascular perforation was used to gauge the neuroprotective effect of AS-IV on SAH-induced early brain injury (EBI) and to clarify the potential molecular mechanism. We found that the induction of SAH reduced the levels of SLC7A11 and glutathione peroxidase 4 (GPX4) in the brain, exacerbated iron accumulation, enhanced lipid reactive oxygen species (ROS) level, and stimulated neuronal ferroptosis. However, the administration of AS-IV and the ferroptosis inhibitor Ferrostatin-1 (Fer-1) enhanced the antioxidant capacity after SAH and suppressed the accumulation of lipid peroxides. Meanwhile, AS-IV triggered Nrf2/HO-1 signaling pathway and alleviated ferroptosis due to the induction of SAH. The Nrf2 inhibitor ML385 blocked the beneficial effects of neuroprotection. These results consistently suggest that ferroptosis is profoundly implicated in facilitating EBI in SAH, and that AS-IV thwarts the process of ferroptosis in SAH by activating Nrf2/HO-1 pathway.

Emerging role of ferroptosis in glioblastoma: Therapeutic opportunities and challenges

Glioblastoma (GBM) is the most common malignant craniocerebral tumor. The treatment of this cancer is difficult due to its high heterogeneity and immunosuppressive microenvironment. Ferroptosis is a newly found non-apoptotic regulatory cell death process that plays a vital role in a variety of brain diseases, including cerebral hemorrhage, neurodegenerative diseases, and primary or metastatic brain tumors. Recent studies have shown that targeting ferroptosis can be an effective strategy to overcome resistance to tumor therapy and immune escape mechanisms. This suggests that combining ferroptosis-based therapies with other treatments may be an effective strategy to improve the treatment of GBM. Here, we critically reviewed existing studies on the effect of ferroptosis on GBM therapies such as chemotherapy, radiotherapy, immunotherapy, and targeted therapy. In particular, this review discussed the potential of ferroptosis inducers to reverse drug resistance and enhance the sensitivity of conventional cancer therapy in combination with ferroptosis. Finally, we highlighted the therapeutic opportunities and challenges facing the clinical application of ferroptosis-based therapies in GBM. The data generated here provide new insights and directions for future research on the significance of ferroptosis-based therapies in GBM.

Seco-Lupane Triterpene Derivatives Induce Ferroptosis through GPX4/ACSL4 Axis and Target Cyclin D1 to Block the Cell Cycle

In this study, 70 new seco-lupane triterpene derivatives were designed, synthesized, and characterized, and their in vitro anticancer activities were evaluated. Structure-activity relationship studies showed that most compounds inhibited the growth of a variety of tumor cells in vitro. With the extension of alkyl chains, the activity of azole compounds gradually increased while that of indole compounds first increased and then decreased. Moreover, all indole derivatives showed stronger anticancer activity than azole derivatives. In addition, compound 21 showed the strongest inhibitory effect on HepG2 cells with an IC₅₀ value of 0.97 μM. Mechanistic studies showed that compound 21 coregulates the cell death process by inducing ferroptosis and regulating the cell cycle. In conclusion, compound 21 can be used as a ferroptosis inducer and cycle blocker to regulate the HepG2 death process, and it has the potential to become an effective new drug for the treatment of hepatocellular carcinoma.

Heme Oxygenase Modulation Drives Ferroptosis in TNBC Cells

The term ferroptosis refers to a peculiar type of programmed cell death (PCD) mainly characterized by extensive iron-dependent lipid peroxidation. Recently, ferroptosis has been suggested as a potential new strategy for the treatment of several cancers, including breast cancer (BC). In particular, among the BC subtypes, triple negative breast cancer (TNBC) is considered the most aggressive, and conventional drugs fail to provide long-term efficacy. In this context, our study's purpose was to investigate the mechanism of ferroptosis in breast cancer cell lines and reveal the significance of heme oxygenase (HO) modulation in the process, providing new biochemical approaches. HO's effect on BC was evaluated by MTT tests, gene silencing, Western blot analysis, and measurement of reactive oxygen species (ROS), glutathione (GSH) and lipid hydroperoxide (LOOH) levels. In order to assess HO's implication, different approaches were exploited, using two distinct HO-1 inducers (hemin and curcumin), a well-known HO inhibitor (SnMP) and a selective HO-2 inhibitor. The data obtained showed HO's contribution to the onset of ferroptosis; in particular, HO-1 induction seemed to accelerate the process. Moreover, our results suggest a potential role of HO-2 in erastin-induced ferroptosis. In view of the above, HO modulation in ferroptosis can offer a novel approach for breast cancer treatment.