Ferroptosis turns 10: Emerging mechanisms, physiological functions, and therapeutic applications

Kaempferol protects against doxorubicin-induced myocardial damage by inhibiting mitochondrial ROS-dependent ferroptosis

BACKGROUND

Doxorubicin (DOX), a widely used chemotherapeutic agent, is limited in clinical application due to its dose-dependent cardiotoxicity. Therefore, it is crucial to explore alternative therapeutic molecules or drugs for mitigating DOX-induced cardiomyopathy (DIC). In this study aimed to explore underlying mechanisms of the cardioprotective effects of Kaempferol (KP) against DIC.

METHODS

H9c2 cell-based DIC model were established to explore the pharmacological mechanism. The levels of mitochondrial membrane potential, mitochondrial ROS, mitochondrial Fe2+ and lipid peroxidation were detected using JC-1, TMRE, Mito-SOX, Mito-Ferro Green and C11-BODIPY 581/591 probes. Furthermore, Western blot analysis measured the expression of key regulatory proteins, and NRF2-targeting siRNA was transfected into H9c2 cells. The nuclear translocation of NRF2 was assessed by immunofluorescence.

RESULTS

Data revealed that KP mitigated DOX-induced mitochondrial damage and ferroptosis via reducing membrane potential, mitochondrial ROS/Fe²+, and regulating lipid metabolism. Mechanistically, Western blot analysis revealed that KP inhibited DOX-induced ferroptosis by activating NRF2/SLC7A11/GPX4 axis. Moreover, KP promoted the accumulation and nuclear translocation of NRF2 protein.

CONCLUSION

These findings demonstrated that KP protected against DOX-induced myocardial damage by inhibiting mitochondrial ROS-dependent ferroptosis. This provides novel insights into KP as a promising drug candidate for cardioprotection.

Integrated transcriptome profiling and in vitro analysis reveals MLN4924's role in inducing ferroptosis in acute myeloid leukemia

OBJECTIVES

While ferroptosis induction emerges as a therapeutic strategy for solid tumors, its role in acute myeloid leukemia (AML) remains unexplored. This study aimed to investigate the role of MLN4924 in modulating ferroptosis and its molecular targets in AML.

METHODS

Transcriptome sequencing and bioinformatics analyses were performed to identify MLN4924 potential targets in ferroptosis. First, ferroptosis-related phenotypic assays were conducted, including assays of reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and Fe2+ levels. Second, cell viability assays were carried out with the combination of MLN4924 and ferroptosis inducers (Erastin, Sorafenib). Third, rescue experiments were used the ferroptosis inhibitor Ferrostatin-1 after MLN4924 treatment. In vivo efficacy was evaluated in NOD/SCID mice bearing AML xenografts treated with MLN4924, followed by tumor tissue analysis of GSH and Fe2+ levels, immunohistochemistry (IHC), and Western blotting for SLC7A11/GPX4 axis components.

RESULTS

Transcriptome sequencing and bioinformatics analyses identified SLC7A11 and GPX4 as key MLN4924 target genes, both of which are glutathione-related proteins. MLN4924 significantly suppressed SLC7A11 and GPX4 expression, decreased GSH activity, and increased ROS, Fe2+, and MDA levels. Ferroptosis inducers (Erastin, Sorafenib) further enhanced the antileukemic activity of MLN4924, and ferroptosis inhibitor Ferrostatin-1 partially reversed this toxicity. In vivo, MLN4924 reduced tumor burden, accompanied by SLC7A11/GPX4 downregulation and Fe2+ accumulation in xenografts.

CONCLUSION

This study provides the first evidence that MLN4924 triggers ferroptosis in AML by inhibiting the SLC7A11/GPX4 axis. These findings establish MLN4924 as a ferroptosis sensitizer through synergistic effects with ferroptosis inducers, supporting its therapeutic potential in AML.

High resolution two photon fluorescence probe monitoring ClO- based on anion exchange for the synergistic ROS and ferroptosis activated by thermal energy

Ferroptosis, closely correlated with hypochlorite (ClO-), is an emerging form of iron-dependent cell death. Exploring the ClO- content in living cells will help to further reveal the biological function of ferroptosis. In this work, we have developed a two-photon excited fluorescent probe (CMI-ClO) which can detect the ClO- changes during ferroptosis. CMI-ClO can specifically response to ClO- by exchanging with I-. The multiple reactive oxygen species (ROS) are produced simultaneously in the ClO- identification process. More significantly, CMI-ClO produces ROS through thermal energy, breaking the limitation of light trigged conventional photosensitizers. CMI-ClO can achieve high resolution tracking of ferroptosis under NIR II excitation, where ROS and ferroptosis combine to cause mitochondrial damage and cell death. This work provides a synergistic strategy for enhancing ROS and ferroptosis therapy.

Design, synthesis and biological evaluation of triazolothiadiazole derivatives as FSP1 inhibitors for sensitizing cancer cells to ferroptosis

Ferroptosis suppressor protein 1 (FSP1) is a recently identified ferroptosis suppressor that functions independently of the glutathione peroxidase reductase 4 (GPX4)-mediated pathway. Mechanistically, FSP1 mitigates ferroptosis by catalyzing the reduction of ubiquinone to ubiquinol and vitamin K (VK) to hydroquinone, thereby reducing lethal lipid peroxidation through the neutralization of free radicals. In this study, we designed and synthesized 32 compounds to systematically explore their structure-activity relationship (SAR) with the aim of identifying potent and novel FSP1 inhibitors. Among these, compound 39, a triazolothiadiazole derivative, exhibited the most significant inhibitory activity against FSP1, with an IC50 value of 35 nM. In vitro cellular assays demonstrated that compound 39 markedly enhanced RSL3-induced lipid peroxide (LPO) accumulation and sensitized cancer cells from diverse tissue origins to RSL3-induced ferroptosis. Furthermore, by exploiting the FSP1-mediated reduction of VK, compound 39 effectively augmented ferroptosis in HT1080 cells pretreated with RSL3 and VK through its potent inhibition of FSP1 activity. To the best of our knowledge, this study represents the first pharmacochemical investigation dedicated to the systematic design and synthesis of FSP1 inhibitors. Collectively, our findings underscore the profound impact of compound 39 on tumor ferroptosis, providing a promising foundation for the development of FSP1 inhibitors as potential therapeutic agents in cancer treatment.

Selective and iron-independent ferroptosis in cancer cells induced by manipulation of mitochondrial fatty acid oxidation

Despite the promise of ferroptosis in cancer therapy, selectively inducing robust ferroptosis in cancer cells remains a significant challenge. In this study, manipulation of fatty acids β-oxidation (FAO) by combination of mild photodynamic therapy (PDT) and inhibition of triglycerides (TGs) synthesis was found to induce robust and iron-independent ferroptosis in cancer cells with dysregulated lipid metabolism for the first time. To achieve that, TGs synthesis inhibitor of xanthohumol (Xan) and FAO initiator of tetrakis (4-carboxyphenyl) porphyrin (TCPP) were co-delivered by a nanoplexes composed of pH-responsive amphiphilic lipopeptide C18-pHis10 and DSPE-PEG2000. TCPP was found to rapidly increase the intracellular ROS under laser irradiation without inducing antioxidant response and apoptosis, activating the AMPK in cancer cells and accelerating mitochondrial FAO. Xan fueled the mitochondrial FAO with substrates by suppressing the conversion of fatty acids (FAs) to TGs. This also led to augmented intracellular polyunsaturated fatty acids (PUFAs) and PUFAs-phospholipids levels, increasing the intrinsic susceptibility of cancer cells to lipid peroxidization. As a result, the excessive ROS generated from the sustained mitochondrial FAO caused remarkably lipid peroxidation and ultimately ferroptosis. Collectively, our study provides a new approach to selectively induce iron-independent ferroptosis in cancer cells by taking advantage of dysregulated lipid metabolism.

Oxidative complexity: The role of ROS in the tumor environment and therapeutic implications

Reactive oxygen species (ROS) constitutes a group of reactive molecules that play a critical role in biological processes. Varying ROS levels have been frequently observed in cancer cells and the tumor microenvironment (TME). The role of ROS displays significant complexity in cancer development and therapy. Elevated ROS levels can induce metabolic reprogramming and promote the proliferation, invasion, and metastasis of cancer cells, resulting in cancer progression. However, excessive ROS accumulation leads to the occurrence of apoptosis, pyroptosis, necroptosis, and ferroptosis in cancer cells, which restrains tumor development. In the TME, ROS frequently promotes angiogenesis and remodels the extracellular matrix (ECM) by enhancing the differentiation of cancer-associated fibroblasts (CAFs), thereby supporting tumor growth. Concurrently, high ROS levels favour immunosuppressive cells, including M2-polarized macrophages, and regulatory T cells (Tregs), while impairing the antitumor capabilities of T cells. In the aspect of cancer therapy, it is overly simplistic to merely combine chemoradiotherapy with antioxidants as a therapeutic strategy. Instead, highlighting targeted therapies that modulate ROS is essential, given their inherent complexity. Fortunately, a variety of innovative treatments have emerged, including nanodrug delivery systems (NDDS), proteolysis-targeting chimeras (PROTAC), and adoptive cell therapy (ADT), which not only exhibit synergistic effects with immune checkpoint therapy (ICT), but also enhance the antitumor capabilities of the TME. In this paper, we elucidate the mechanism of ROS production, enumerate the role of ROS in cancer development and the TME, and discuss advancements in ROS-targeted cancer therapeutics.

Metal ions-induced programmed cell death: how does oxidative stress regulate cell death?

In recent years, the mechanisms of ferroptosis and cuproptosis, two novel modes of cell death, have been elucidated and have attracted much attention. Ferroptosis is dependent on the metabolic disruption of iron ions and lipid peroxidation, whereas cuproptosis is closely related to intracellular accumulation of copper ions, aggregation of lipoylated proteins and damage to FeS cluster proteins. In particular, oxidative stress plays an important role in both types of cell death. During ferroptosis, the central role of oxidative stress is reflected in the overproduction of reactive oxygen species (ROS) and lipid peroxidation of the cell membrane. Recent studies have revealed that ROS can propagate over long distances across cells in the form of trigger waves, triggering large-scale ferroptosis. In embryonic development, different regional redox states can limit the long-distance propagation of ferroptosis waves, which is critical for muscle remodeling and tissue formation during development. In cuproptosis, processes such as copper ions accumulation, tricarboxylic acid (TCA) cycle blockade, and reduced level of FeS cluster proteins are closely associated with oxidative stress. In addition, there is a close link between oxidative stress and death induced by other metal ions (Ca2+, Zn2+, etc.). In this paper, we review the role of oxidative stress in ferroptosis and cuproptosis and the related research progress to provide new ideas for understanding the mechanism of cell death and the occurrence and treatment of related diseases.

Ferroptosis targeting offers a therapeutic target for septic cardiomyopathy

Sepsis-induced cardiac dysfunction, usually termed sepsis-induced cardiomyopathy or septic cardiomyopathy(SCM), is developed in approximately 70 % of the patients with sepsis, making it is a major concern for sepsis patients. However, the pathogenesis of SCM remain incompletely understood. Ferroptosis, a newly identified mechanism of regulated cell death, characterized by a decline in antioxidant capacity, iron accumulation, and lipid peroxidation(LPO), is involved in sepsis and SCM. Moreover, ferroptosis inhibitors confer a novel therapeutic regimen in SCM. In this Review, we first summarizes the core mechanism of ferroptosis, with an emphasis on how best to interpret ferroptosis leads to the genesis of SCM. We then highlights our focus on the emerging different types of therapeutic ferroptosis inhibitors and summarizes their pharmacological beneficial effect to treat SCM. This review highlights a novel potential therapeutic strategy for SCM by pharmacologically inhibiting ferroptosis.

Neuronal regulated cell death in aging-related neurodegenerative diseases: key pathways and therapeutic potentials

Regulated cell death (such as apoptosis, necroptosis, pyroptosis, autophagy, cuproptosis, ferroptosis, disulfidptosis) involves complex signaling pathways and molecular effectors, and has been proven to be an important regulatory mechanism for regulating neuronal aging and death. However, excessive activation of regulated cell death may lead to the progression of aging-related diseases. This review summarizes recent advances in the understanding of seven forms of regulated cell death in age-related diseases. Notably, the newly identified ferroptosis and cuproptosis have been implicated in the risk of cognitive impairment and neurodegenerative diseases. These forms of cell death exacerbate disease progression by promoting inflammation, oxidative stress, and pathological protein aggregation. The review also provides an overview of key signaling pathways and crosstalk mechanisms among these regulated cell death forms, with a focus on ferroptosis, cuproptosis, and disulfidptosis. For instance, FDX1 directly induces cuproptosis by regulating copper ion valency and dihydrolipoamide S-acetyltransferase aggregation, while copper mediates glutathione peroxidase 4 degradation, enhancing ferroptosis sensitivity. Additionally, inhibiting the Xc- transport system to prevent ferroptosis can increase disulfide formation and shift the NADP + /NADPH ratio, transitioning ferroptosis to disulfidptosis. These insights help to uncover the potential connections among these novel regulated cell death forms and differentiate them from traditional regulated cell death mechanisms. In conclusion, identifying key targets and their crosstalk points among various regulated cell death pathways may aid in developing specific biomarkers to reverse the aging clock and treat age-related neurodegenerative conditions.

Grx2 maintains GSH/GSSG homeostasis to enhance GPX4-mediated ferroptosis defense in UVB irradiation induced cataract

PURPOSE

Ultraviolet B (UVB) irradiation induces cataract pathogenesis, and Glutaredoxin 2 (Grx2) deficiency causes the early onset of UVB-induced cataracts. Several researchers have shown that, apart from apoptosis and pyroptosis, UVB irradiation also can induce cell ferroptosis. We explored the role of ferroptosis caused by UVB irradiation in human lens epithelial cells (HLECs) and clarified how Grx2 protects against UVB-induced cataracts.

METHODS

HLE-B3 cells and mice lenses were treated with DMSO or ferroptosis inhibitors after various doses of UVB irradiation. Cell morphology and ultrastructure were observed by optical microscope and transmission electron microscopy. Lens opacity was observed ex vivo using an optical microscope and in vivo using a slit lamp. The lipid peroxidation level was measured by C11-BODIPY probe and 4-HNE (the lipid peroxidation marker) protein expression. Cell viability was determined using the CCK-8 kit and propodium iodide (PI) immunofluorescence. Grx2 KO and KI mice, Grx2 silencing and Grx2 overexpression in HLE-B3 cell lines were used for in vivo and in vitro experiments respectively.

RESULTS

UVB-caused HLE-B3 cells death, lens opacity and lipid peroxidation could be mitigated by ferroptosis inhibitors. Grx2 KO mice accelerate the appearance of lens opacity induced by UVB. Meanwhile, Grx2 silencing enhanced HLECs lipid peroxidation susceptibility, downregulated the GSH level, shrunk mitochondria, and reduced the number of cristae. Grx2 overexpression had opposite effects.

CONCLUSIONS

Ferroptosis appears involved in UVB-induced HLECs damage. Inhibiting ferroptosis prevented UVB-induced cataracts. Grx2 strengthens resistance to ferroptosis induced by UVB irradiation through maintaining HLEC cellular GSH/GSSG homeostasis.

The interplay of sleep deprivation, ferroptosis, and BACH1 in cardiovascular disease pathogenesis

BACKGROUND AND OBJECTIVE

Sleep deprivation (SD) can induce cardiac dysfunction, myocardial injury, and sudden death. The purpose of this study is to investigate whether the mechanism of sleep deprivation induced myocardial injury is related to abnormal expression of BACH1 and ferroptosis of myocardial cells.

METHODS

Thirty-six male C57BL/6 J mice were used in the study. Twenty-four were exposed to SD through a modified multiple platform water method, while twelve served as controls. Cardiac function was assessed by small animal ultrasound super-resolution microimager and morphology by H&E staining. Ferroptosis model was established in H9c2 cardiomyocytes by Erastin. Biochemical assays measured key markers in serum and cell supernatants. TEM and flow cytometry evaluated mitochondrial changes and ROS levels. Western blot analyzed the expression of BACH1 and ferroptosis-related proteins.

RESULTS

Sleep deprivation caused increased heart rate (644 ± 30 bpm) and impaired cardiac function (EF 88.29 ± 3.97 %, FS 60.27 ± 2.70 %, LVIDd 3.14 ± 0.16 mm, LVIDs 1.30 ± 0.18 mm) in mice. It induced cardiomyocyte and mitochondrial damage, resulting in oxidative stress (MDA 7.16 ± 0.39 nmol/mg prot, GSH 33.88 ± 1.41 μg/mL, SOD 56.12 ± 1.44 U/mL, LDH 702.24 ± 33.48 U/L) and elevated CK levels (43.78 ± 2.30 U/mL). The expression of ANP, BACH1, and ferroptosis-related proteins (TFRC, SLC7A11, GPX4, NQO1, and HO-1) was altered. We observed aberrant oxidative stress indicators and expression of BACH1 and ferroptosis-related proteins in an Erastin-induced H9c2 cardiomyocytes model.

CONCLUSIONS

Sleep deprivation promotes BACH1 through ferroptosis and leads to myocardial injury, thereby revealing potential therapeutic targets for CVDs.

F-box only protein 10 protects against kidney tubulointerstitial fibrosis by inhibiting ACSL4-mediated lipid peroxidation and ferroptosis

Renal tubular epithelial cell ferroptosis is significantly linked to kidney tubulointerstitial fibrosis, a critical pathological condition in chronic kidney disease. F-box only protein 10 (FBXO10), a newly identified ferroptosis-regulating gene, plays a role in various pathological contexts; however, its involvement in kidney tubulointerstitial fibrosis is not yet fully understood. This research sought to investigate whether FBXO10 regulates ferroptosis in kidney tubular epithelial cells and its relationship with kidney tubulointerstitial fibrosis in both animal and cellular models. We observed a significant decrease in FBXO10 levels in mice with unilateral ureteral obstruction (UUO) and HK-2 cells exposed to TGF-β1. FBXO10 overexpression inhibited the EMT process and counteracted the typical ferroptosis features evoked by TGF-β1 or erastin in HK-2 cells. Compared with those in wild-type (WT) mice, kidney injury, inflammation, and fibrosis are exacerbated in FBXO10-knockout (KO) mice, with elevated ferroptosis levels. Conversely, FBXO10 overexpression reversed these symptoms, alleviating kidney fibrosis and ferroptosis in both WT and FBXO10 KO mice with UUO. Mechanistically, FBXO10 directly interacted with ACSL4 and promoted its ubiquitination and degradation. Overexpression of ACSL4 reversed the inhibitory effect of FBXO10 overexpression on TGF-β1-induced ferroptotic death and fibrosis in HK-2 cells. In summary, FBXO10 mitigates ferroptosis in renal tubular epithelial cells by inhibiting ACSL4-mediated lipid peroxidation, thereby hindering the progression of kidney tubulointerstitial fibrosis. FBXO10 is proposed as a promising target for treating kidney disorders related to tubulointerstitial fibrosis.

Picropodophyllin induces ferroptosis via blockage of AKT/NRF2/SLC7A11 and AKT/NRF2/SLC40A1 axes in hepatocellular carcinoma as a natural IGF1R inhibitor

BACKGROUND

Ferroptosis represents a distinct form of regulated cell death characterized by intracellular iron overload and extensive lipid peroxidation. Targeting ferroptosis-related signaling pathways and inducing ferroptosis have emerged as promising therapeutic strategies for hepatocellular carcinoma (HCC). Recent studies have highlighted the involvement of insulin-like growth factor 1 receptor (IGF1R) signaling in cancer progression and antioxidant defense mechanisms. Picropodophyllin (PPP), a natural IGF1R inhibitor isolated from Dysosma versipellis, exhibits anticancer effects against several solid tumors. However, the impact of PPP on ferroptosis in HCC and the underlying molecular mechanisms remain unclear.

PURPOSE

The current study aims to evaluate the anti-tumor effects of PPP on HCC progression in vitro and in vivo, and to investigate the actions and mechanisms of PPP as a novel ferroptosis inducer.

METHODS

Clinical sample from HCC patients were applied to analyze the correlation of IGF1R with malignancy of HCC. Docking simulations, molecular dynamics simulation and cellular thermal shift assay were performed to verify the interaction between PPP and IGF1R. CCK-8 cell viability assay, colony formation, Calcein-AM/PI staining, wound healing and transwell assays were conducted to determine the effects of PPP on cell viability, proliferation, migration and invasion. Intracellular Fe2+, GSH, MDA and lipid ROS levels were measured to evaluate the degree of ferroptosis induced by PPP. GO functional annotation and KEGG enrichment analysis, quantitative real-time PCR, western blot and immunofluorescence (IF) assay were performed to investigate the mechanisms underlying the action of PPP. Nude mice xenograft model and immunohistochemistry (IHC) assay were utilized to observe the impact of PPP on tumor growth in vivo.

RESULTS

Upregulation of IGF1R were confirmed to positively correlated with malignant progression of HCC and PPP were verified to act as a specific inhibitor of IGF1R in HCC. PPP exhibited dose-dependent anti-proliferative and anti-metastasis effects on HCC cells, and inhibited HCC growth in a subcutaneous xenograft murine model. Meanwhile, PPP remarkably increased intracellular Fe2+, lipid ROS and MDA levels, but decreased ROS scavenger GSH content and glutathione peroxidase 4 (GPX4) activity significantly, which suggested that PPP stimulated ferroptosis relying on iron-dependent lipid peroxidation. The ferroptosis inhibitor deferoxamine mesylate (DFO) nearly abolished the anti-cancer and ferroptosis-inducing effects of PPP both in vitro and in vivo. Mechanistically, PPP inhibited the phosphorylation of IGF1R, PI3K and AKT, thus suppressed the protein stability of NRF2 by facilitating ubiquitination, and consequently decreased expression of its target gene SLC7A11 and SLC40A1.

CONCLUSION

The natural IGF1R inhibitor PPP induced ferroptosis through blockage of PI3K/AKT/NRF2 signaling pathway and subsequent inhibition of downstream gene expression of SLC7A11 and SLC40A1 in hepatocellular carcinoma. Consequently, our findings provide a novel action and mechanism of PPP, as well as offer innovative and promising ferroptosis-inducing agents for the clinical treatment of HCC.

Netrin-1 binding to UNC5b improves post-stroke neuronal ferroptosis via AMPK-BACH1 pathway

Ferroptosis contributes to neuronal destruction after ischemic stroke which may be improved by inhibiting BTB domain and CNC homolog 1 (BACH1), a recently recognized ferroptosis facilitator. Axon guidance molecule netrin-1 (Ntn1) functions in neuroprotection against ischemic insult by engaging into its receptor of uncoordinated-5 homolog B (UNC5b) via adenosine 5'-monophosphate-activated protein kinase (AMPK), which potentially binds to BACH1. Whether Ntn1/UNC5b regulates post-stroke ferroptosis through AMPK-BACH1 pathway remains unclear. Ntn1 supplementation and UNC5b knockdown by siRNA were performed in photo-thrombosis stroke mice and oxygen-glucose deprivation-treated HT22 neurons. AMPK inhibitor BAY3827 and BACH1 activator Leptomycin B (LMB) were administrated. Ferroptosis was determined by ferroptosis-associated proteins (FSP1, GPX4 and ACSL4), Fe2+, malondialdehyde and mitochondrial morphology. BACH1 and p-AMPK/AMPK as well as the interaction between them were examined by Western blot and co-immunoprecipitation. Neuronal ferroptosis and the protein levels of BACH1 and p-AMPK were increased after photo-thrombosis and oxygen-glucose deprivation. Ntn1 supplementation or UNC5b knockdown relieved neuronal ferroptosis and neurological impairment with downregulated BACH1 and upregulated p-AMPK, nonetheless, UNC5b knockdown prevented the beneficial role of Ntn1. Both BAY3827 and LMB could reverse the change of ferroptosis caused by Ntn1 where BAY3827 inhibited the effects of Ntn1 to p-AMPK and BACH1 while LMB only inhibited the effect of Ntn1 to BACH1 without p-AMPK, suggesting BACH1 was regulated by AMPK. Co-immunoprecipitation verified that AMPK could physically bind to BACH1. Our results demonstrate UNC5b-evoked neuronal ferroptosis post stroke, and favor that Ntn1 improves post-stroke ferroptosis by its interaction with UNC5b via the AMPK-BACH1 pathway.

Cryptotanshinone promotes ferroptosis in glioblastoma via KEAP1/NRF2/HMOX1 signaling pathway

Glioblastoma multiforme (GBM) is a common and highly malignant brain tumor characterized by heterogeneity, invasiveness, and resistance to therapy. Inducing ferroptosis in GBM represents a promising therapeutic strategy that inhibits angiogenesis. Natural ingredients in anti-tumor adjuvants are increasingly reported to promote cell death with fewer side effects. Salvia miltiorrhiza Bunge has been widely proven to have significant anti-tumor activity, but its mechanism remains unclear and not deeply understood. This study aimed to investigate the mechanisms by which the compound cryptotanshinone (CTS) induces cell death in glioblastoma (GBM). Our findings revealed that cryptotanshinone, a lipophilic compound, exhibited the most significant anti-tumor activity against GBM. We observed that cryptotanshinone triggered ferroptosis in GBM cells both in vitro and in vivo. RNA sequencing analysis (RNA-seq) revealed that cryptotanshinone led to the upregulation of heme oxygenase 1 (HMOX1), a key protein that facilitates the release of iron ions, which is essential for the induction of ferroptosis. Knocking down HMOX1 could restore ferrous ion levels and Glutathione peroxidase 4 (GPX4) expression to antagonize GBM ferroptosis induced by cryptotanshinone. An in vivo study also showed that cryptotanshinone inhibited GBM growth and upregulated HMOX1 expression without significant side effects. Mechanistically, we found that cryptotanshinone, acting as a protein-protein interaction (PPI) inhibitor of nuclear factor erythroid 2-related factor 2 (NRF2) and Kelch-like ECH-associated protein 1 (KEAP1), promoted the dissociation of NRF2 from KEAP1, enhancing NRF2 nuclear translocation and the transcription of HMOX1. Together, our results revealed that cryptotanshinone is a novel ferroptosis inducer for GBM treatment.

Platelet-rich plasma inhibits ferroptosis and inflammation to alleviate frozen shoulder via activating the CST1/GPX4 signaling pathway

Platelet-rich plasma (PRP) has been shown to be beneficial to frozen shoulder (FS), but the mechanism of PRP's intervention in FS is still incomplete. Ferroptosis and inflammation are important pathological factors of cartilage injury, but their role in FS has not been explored. In vivo, we found that PRP treatment significantly enhanced the joint range of motion and mitigated joint histopathological damage in FS rats. Notably, levels of iron ions, the ferroptosis marker prostaglandin-endoperoxide synthase 2 (PTGS2), reactive oxygen species (ROS), malondialdehyde (MDA), and pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) in the cartilage tissue of PRP-treated rats were significantly reduced. Conversely, levels of superoxide dismutase (SOD) and glutathione (GSH) were markedly increased. In vitro experiments revealed that PRP effectively countered the IL-1β-induced suppression of chondrocyte proliferation while also reducing levels of ferroptosis and inflammation. Furthermore, the CST1/GPX4 pathway was suppressed in the FS environment, while it has the potential to be activated by PRP. Importantly, silencing CST1 negated the therapeutic effects of PRP on IL-1β-treated chondrocytes and FS rats. In summary, we found that PRP alleviated the progression of FS by inhibiting ferroptosis and the inflammatory response by activating the CST1/GPX4 signaling pathway.

Natural products and ferroptosis: A novel approach for heart failure management

BACKGROUND

The discovery of ferroptosis has brought a revolutionary breakthrough in heart failure treatment, and natural products, as a significant source of drug discovery, are gradually demonstrating their extraordinary potential in regulating ferroptosis and alleviating heart failure symptoms. In addition to chemically synthesized small molecule compounds, natural products have attracted attention as an important source for discovering compounds that target ferroptosis in treating heart failure.

PURPOSE

Systematically summarize and analyze the research progress on improving heart failure through natural products' modulation of the ferroptosis pathway.

METHODS

By comprehensively searching authoritative databases like PubMed, Web of Science, and China National Knowledge Infrastructure with keywords such as "heart failure", "cardiovascular disease", "heart disease", "ferroptosis", "natural products", "active compounds", "traditional Chinese medicine formulas", "traditional Chinese medicine", and "acupuncture", we aim to systematically review the mechanism of ferroptosis and its link with heart failure. We also want to explore natural small-molecule compounds, traditional Chinese medicine formulas, and acupuncture therapies that can inhibit ferroptosis to improve heart failure.

RESULTS

In this review, we not only trace the evolution of the concept of ferroptosis and clearly distinguish it from other forms of cell death but also establish a comprehensive theoretical framework encompassing core mechanisms such as iron overload and system xc-/GSH/GPX4 imbalance, along with multiple auxiliary pathways. On this basis, we innovatively link ferroptosis with various types of heart failure, covering classic heart failure types and extending our research to pre-heart failure conditions such as arrhythmia and aortic aneurysm, providing new insights for early intervention in heart failure. Importantly, this article systematically integrates multiple strategies of natural products for interfering with ferroptosis, ranging from monomeric compounds and bioactive components to crude extracts and further to traditional Chinese medicine formulae. In addition, non-pharmacological means such as acupuncture are also included.

CONCLUSION

This study fills the gap in the systematic description of the relationship between ferroptosis and heart failure and the therapeutic strategies of natural products, aiming to provide patients with more diverse treatment options and promote the development of the heart failure treatment field.

The cardiac glycoside periplocymarin sensitizes gastric cancer to ferroptosis via the ATP1A1-Src-YAP/TAZ-TFRC axis

BACKGROUND

Targeting ferroptosis vulnerabilities in tumors has become an increasingly promising therapeutic strategy. While the regulatory effects of natural products on ferroptosis are progressively being elucidated, the role of cardiac glycosides in modulating ferroptosis remains poorly understood.

PURPOSE

This study aims to investigate the ferroptosis-sensitizing effects of periplocymarin (PPM), a cardiac glycoside derived from the traditional plant Periploca sepium, and to elucidate the underlying molecular mechanisms.

METHODS

The effects of PPM on ferroptosis regulation were comprehensively assessed through functional assays, followed by sequencing analysis to identify associated signaling pathways. Subsequent mechanistic validation experiments were conducted to confirm the upstream and downstream regulatory components involved in this ferroptosis-modulating axis.

RESULTS

PPM induced slow and mild apoptosis in gastric cancer cells through the inhibition of glycolysis. However, when combined with ferroptosis inducers, it promoted rapid and robust ferroptosis. In vivo, PPM sensitized gastric cancer xenografts to cisplatin-induced ferroptosis with no observable cardiotoxicity or renal impairment. Mechanistically, PPM targeted the α1 subunit of the Na+/K+-ATPase (ATP1A1), leading to the activation of Src, which subsequently induced tyrosine phosphorylation of YAP/TAZ in a Hippo-independent manner, promoting their nuclear translocation. The YAP/TAZ-TEAD transcriptional complex directly bound to the TFRC promoter region between nucleotides 401-409 upstream of the transcription start site, thereby activating TFRC transcription. This resulted in increased iron influx, elevated lipid peroxidation, and heightened sensitivity to ferroptosis. Notably, ATP1A1 was essential for ferroptosis resistance, as its knockdown mimicked the sensitizing effect of PPM on ferroptosis. Moreover, the oncogenic Src-YAP/TAZ-TFRC axis may have represented a ferroptosis vulnerability and a potential biomarker in ferroptosis therapy for cancer. Importantly, other cardiac glycosides targeting Na+/K+-ATPase, such as digitoxin and bufalin, also enhanced ferroptosis sensitivity in gastric cancer cells through activation of YAP/TAZ signaling.

CONCLUSION

Our findings establish the cardiac glycoside PPM as a novel ferroptosis sensitizer that targets ATP1A1 to activate the Src-YAP/TAZ-TFRC axis, providing mechanistic insights for repurposing cardiac glycosides as ferroptosis modulators in precision combinatorial cancer therapy.

Induction of Ferroptosis by Shikonin in Gastric Cancer via the DLEU1/mTOR/GPX4 Axis

Gastric cancer (GC) is the most prevalent cancer in Asia. Shikonin, one of the ingredients extracted from the roots of Lithospermum erythrorhizon, has been proven to be a necrosis inducer and has an antitumour effect on many cancers. We explored the mechanism of the antitumour effect of shikonin in GC. CCK8 and clonogenic assays were used to determine the effect of shikonin on the proliferation of GC cell lines. Shikonin could induce reactive oxygen species (ROS), lipid ROS, intracellular ferrous iron (Fe2+), and malondialdehyde (MDA) in GC. We also found that shikonin decreased the expression of GPX4 by suppressing GPX4 synthesis and decreasing ferritin. Furthermore, long noncoding RNA deleted in lymphocytic leukaemia 1 (DLEU1) is an oncogene in GC, and shikonin decreased DLEU1 expression in GC cells. Overexpression of DLEU1 eliminated the anticancer effect of shikonin. Mechanistically, shikonin might decrease GPX4 levels by inhibiting the DLEU1/mTOR pathway. DLEU1 was sponged with miR-9-3p, which also regulated mTOR and GPX4. A xenograft tumour model of GC was established, and shikonin treatment inhibited cell proliferation and induced ferroptosis. In conclusion, shikonin exerts its antitumour effects on GC by triggering ferroptosis, and the DLEU1/mTOR/GPX4 axis may play an essential role in shikonin-induced ferroptosis. Therefore, our findings provide a potential lead compound for treating GC.

A novel integrated diagnostic and therapeutic ferroptosis inhibitor based on a phenothiazine scaffold with ROS-Responsive strategy

Ferroptosis is a newly discovered form of cell death that is closely related to the occurrence of various diseases, such as neurodegenerative diseases, cardiovascular and cerebrovascular ischemic damage, and organ fibrosis. Therefore, the discovery of new active compounds with ferroptosis inhibitory activity is regarded as a new strategy for the clinical treatment of these diseases. In this study, a multifunctional prodrug molecule PNX-B2 with a phenoxazine structure was designed based on the oxidative microenvironment characteristic of ferroptosis. PNX-B2 can recognize the ferroptosis-associated oxidative conditions and simultaneously release compounds with ferroptosis-inhibitory activity. Moreover, it integrates diagnostic and therapeutic functions and offers a fluorescent indication of the ferroptosis microenvironment. PNX-B2 has demonstrated excellent ferroptosis-inhibitory activity with an EC50 value of 1.7 nM. This intelligent multifunctional compound shows great potential as a novel clinical agent for ferroptosis inhibition and presents broad prospects for future development.

Berberine alleviates tendinopathy by suppressing the cGAS-STING pathway and Relieving ferroptosis

Berberine, a key bioactive component of Coptis rhizome, has been extensively studied for its therapeutic effects on various diseases. This research aimed to investigate the potential benefits of berberine in treating tendinopathy and to elucidate the underlying mechanisms through animal and laboratory studies. Our findings indicated that berberine effectively treated type I collagenase-induced tendinopathy in rats, confirmed by cellular-level validation. At the molecular level, berberine reduced the activation of the cGAS-STING signaling pathway and decreased the accumulation of malondialdehyde (MDA) and reactive oxygen species (ROS) in both animal models and cell cultures. Additionally, berberine upregulated the expression of glutathione (GSH) and glutathione peroxidase 4 (GPX4) in tissues. These results suggested that berberine alleviated ferroptosis via the cGAS-STING pathway, thus exerting therapeutic effects on tendinopathy. To validate these findings further, we administered the ferroptosis inducer Imidazole Ketone Erastin (IKE) to evaluate the effects of berberine. IKE significantly diminished the therapeutic effects of berberine on tendinopathy, as indicated by the previously mentioned markers. Thus, berberine mitigated ferroptosis by inhibiting the cGAS-STING pathway, highlighting its potential in managing tendinopathy.

Sevoflurane exposure triggers ferroptosis of neuronal cells initiated by the activation of ATM/p53 in the neonatal mouse brain via JNK/p38 MAPK-mediated oxidative DNA damage

Neuronal death has long been regarded as a pivotal pathological factor in the developmental neurotoxicity caused by the volatile anesthetic sevoflurane in the neonatal brain, but the detailed mechanism remains controversial. Ferroptosis is a novel type of regulated cell death driven by excess lipid peroxidation secondary to intracellular iron overload, and it is implicated in the pathogenesis of various neurological disorders. Acting as a death messenger, p53 is primarily activated by ATM during DNA damage and mediates various forms of cell death, including apoptosis, autophagy, and ferroptosis. JNK/p38 MAPK are important stress-responsive pathways that can exacerbate intracellular ROS production, thereby linking DNA damage to many pathological conditions such as neurodegeneration and ischemic injury. In our present study, we demonstrated that sevoflurane exposure-induced neuronal death was correlated with intracellular iron overload and lipid peroxidation in HT22 cells, primary hippocampal neurons, and the hippocampi of neonatal mice, consistent with the hallmarks of ferroptosis. Furthermore, we found that sevoflurane-induced neuronal ferroptosis was associated with ATM/p53 activation in response to DNA damage. Additionally, sevoflurane exposure caused JNK/p38 MAPK activation followed by intracellular ROS accumulation, ultimately leading to DNA damage. Mechanistically, ATM/p53 contributed to ferroptosis caused by sevoflurane via two pathways: (1) enhancing iron uptake (upregulating TFR and downregulating FPN) and (2) promoting lipid peroxidation through NOX4, ALOX12, ALOX15 activation and SLC7A11 suppression. Collectively, these findings demonstrated that sevoflurane exposure induced ferroptosis of neuronal cells in the neonatal brain, triggered by ATM/p53 activation via JNK/p38 MAPK-mediated ROS accumulation and subsequent DNA damage.

Regional uterine contractility differences during pregnancy: The role of hypoxia and ferroptosis in vitro

Regional variations in uterine contractility during pregnancy have been well-documented. However, the molecular mechanisms underlying these differences remain unclear. To address this, isotonic contraction experiments were conducted on pregnant rat uteri, revealing significantly lower contractility on the placenta-attached side compared to the non-attached side. Interestingly, lactic acid accumulation was higher in the placenta-attached tissue, suggesting metabolic differences between these regions. Muscle contraction requires substantial energy, with adenosine triphosphate (ATP) serving as the direct source of energy, which is predominantly supplied by mitochondria, the cellular energy production centers. Mitochondrial energy generation relies heavily on oxygen availability. To explore the impact of oxygen conditions on uterine smooth muscle cell (USMC) contraction, we cultured these cells under hypoxic conditions. Hypoxia was found to reduce cell contraction and disrupt mitochondrial integrity. Specifically, mitochondria exhibited shrinkage and deformation, characterized by reduced cristae and a collapse of the mitochondrial membrane potential. These structural and functional changes align with hallmarks of ferroptosis. Furthermore, hypoxia stimulated the translocation of dynamic related protein 1 (Drp1) to mitochondria, a process linked to mitochondrial fragmentation. Ferroptosis was downregulated when Drp1 activity was inhibited, highlighting its regulatory role in this process. Collectively, these findings demonstrate that hypoxia induced-ferroptosis impairs mitochondria, leading to reduced energy production and cell viability. This ultimately decreases the contractility of pregnant USMC, providing new insights into the molecular mechanisms underlying regional differences in uterine contractility during pregnancy.

Dictamnine alleviates DSS-induced colitis mice by inhibiting ferroptosis of enterocytes via activating Nrf2-Gpx4 signaling pathway

BACKGROUND

The treatment of ulcerative colitis (UC) remains a huge challenge worldwide. Dictamnine is a natural product derived from Dictamnus dasycarpus Turcz. root bark and possesses multi-pharmacological properties, including anti-inflammation effects. However, its protective effect on UC and its underlying mechanisms are unknown.

PURPOSE

Here we explored the protective effect and underlying mechanism of dictamnine against dextran sulfate sodium (DSS)-induced colitis in mice.

METHODS

The experimental colitis was established by adding 3% DSS on drinking water of mice and the effects of dictamnine (10, 20, 40 mg/kg, p.o, once a day by 10 days) in colon tissues was analyzed. NCM460 cell was induced by RSL3 to detect the effect of dictamnine on ferroptosis and the underlying mechanism. Pathological damage was determined by H&E. Indicators related to intestinal permeability were detected by FITC and immunofluorescence. Cytokines levels (TNF-α、IL-1β and IL-6), antioxidant enzymes activities (MDA and GSH), the level of Fe2+ Cytokines levels and Gpx4 activity were detected by ELISA. Finally, the activation of nuclear factor erythroid 2-like 2 (Nrf2) was detected to explore the mechanism.

RESULTS

The results indicated that dictamnine significantly attenuated DSS-induced colon pathological damage, intestinal barrier, cytokines levels, and increased the antioxidant enzymes activities. Moreover, dictamnine attenuated ferroptosis in DSS-induced colon injury and upregulated Gpx4 expression in DSS-induced mice. Mechanistic experiments revealed that dictamnine activated Nrf2 in mice.

CONCLUSION

Taken together, this study evaluates that dictamnine alleviates DSS-induced colitis mice by inhibiting ferroptosis of enterocytes and its protective effects are associated with activating the Nrf2-Gpx4 signaling pathway.

Endoplasmic reticulum-mitochondria contacts are prime hotspots of phospholipid peroxidation driving ferroptosis

The peroxidation of membrane phospholipids (PLs) is a hallmark of ferroptosis. The endoplasmic reticulum and mitochondria have been implicated in ferroptosis, but whether intracellular PL peroxidation ensues at their contact sites (endoplasmic reticulum-mitochondria contact sites, EMCSs) is unknown. Using super-resolution live imaging, we charted the spatiotemporal events triggered by ferroptosis at the interorganelle level. Here we show that EMCSs expand minutes after localized PL peroxides are formed and secondarily spread to mitochondria, promoting mitochondrial reactive oxygen species and fission. Oxidative lipidomics unravels that EMCSs host distinct proferroptotic polyunsaturated-PLs, including doubly proferroptotic polyunsaturated-acylated PLs, demonstrating their high propensity to undergo PL peroxidation. Endoplasmic reticulum-mitochondria untethering blunts PL peroxidation and ferroptosis, while EMCS stabilization enhances them. Consistently, distancing EMCSs protects the ferroptosis-susceptible triple-negative breast cancer subtype, harbouring high EMCS-related gene expression and basal PL peroxide levels. Conversely, in insensitive triple-negative breast cancer subtypes, bolstering EMCSs sensitizes them to ferroptosis. Our data unveil endoplasmic reticulum-mitochondria appositions as initial hubs of PL peroxide formation and posit that empowering EMCSs endorses ferroptosis in cancer cells.

Roflumilast inhibits neuronal ferroptosis via AMPK/Nrf2/HO-1 signaling and promotes motor function recovery after spinal cord injury in rats

Spinal cord injury (SCI) is a serious central nervous system disease. Ferroptosis is one of the major causes of spinal cord neurological loss, and targeting ferroptosis is a promising therapeutic strategy. Roflumilast has shown promising applications in the treatment of neurological diseases due to its potent anti-inflammatory and anti-oxidative stress effects. This study aimed to investigate whether roflumilast could inhibit neuronal ferroptosis to improve motor function after SCI in rats. In vitro experiments, we found that roflumilast significantly increased cell survival in an in vitro ferroptosis model, improved mitochondrial function, reduced intracellular iron, reactive oxygen species (ROS), and lipid peroxides accumulation as well as the expression of the pro-ferroptosis proteins, long-chain acyl-coenzyme A synthase 4 (ACSL4), and prostaglandin-endoperoxide synthase 2 (PTGS2), and increased the expression of ferroptosis-inhibitory protein glutathione peroxidase 4 (GPX4), and ferritin heavy chain 1 (FTH1) expression. Mechanistically, these protective effects were achieved by activating AMP-dependent protein kinase (AMPK)/nuclear factor E2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling and were attenuated when AMPK signaling was blocked. In vivo experiments, roflumilast attenuated spinal cord tissue damage, increased the number of motor neuron survivors, and improved motor function after SCI in rats. Overall, activation of AMPK/Nrf2/HO-1 signaling by roflumilast attenuated neuronal ferroptosis and improved motor function after SCI in rats.

1,25(OH)2D3 Ameliorates DSS-induced Intestinal Ferroptosis through the SIRT3-SOD2-mtROS Pathway

Ferroptosis has been shown to play a significant role in the pathogenesis of ulcerative colitis (UC). This study investigated the effects of 1,25(OH)2D3 supplementation on ferroptosis in dextran sulfate sodium (DSS)-evoked colitis. Intestinal VDR was reduced in UC patients. Accordingly, GPX4 was downregulated and ACSL4 was upregulated in the intestine of UC patients. Animal experiments indicated that vitamin D deficiency exacerbated DSS-induced intestinal ferroptosis in mice. Conversely, pretreatment with 1,25(OH)2D3 alleviated DSS-induced ferroptosis in mouse intestine. Similarly, 1,25(OH)2D3 supplementation inhibited DSS-induced ferroptosis in HT-29 cells. Furthermore, we found decreased intestinal SIRT3 protein and increased acetylated superoxide dismutase 2 (Ac-SOD2) in UC patients. Pretreatment with 1,25(OH)2D3 attenuated DSS-induced downregulation of SIRT3 and acetylation of SOD2 in both mouse intestine and HT-29 cells. Moreover, 1,25(OH)2D3 pretreatment inhibited mitochondrial reactive oxygen species (mtROS) in DSS-treated HT-29 cells. Finally, transfection with SIRT3 siRNA antagonized the protective effect of 1,25(OH)2D3 on ferroptosis in DSS-treated HT-29 cells. Overall, our results suggest that 1,25(OH)2D3 alleviates DSS-induced intestinal ferroptosis via the SIRT3-SOD2-mtROS pathway, further supporting the potential use of 1,25(OH)2D3 supplementation in UC treatment.

Ferroptosis-related LncRNAs in diseases

Ferroptosis is a form of regulated cell death (RCD) caused by the accumulation of intracellular iron and lipids and is involved in many pathological processes, including neurodegenerative and cardiovascular diseases, and cancer. Long non-coding RNAs (lncRNAs), RNA molecules exceeding 200 nt in length that do not possess protein coding function can interfere with ferroptosis by binding ferroptosis-related miRNAs or proteins. Recently, ferroptosis-related lncRNAs (FRlncRNAs) have been identified in cancer and non-malignant disease models, including inprediction of drug resistance, intra-tumoral immune infiltration, metabolic reprogramming and mutation landscape. Here, we review FRlncRNAs in cancer and non-malignant diseases, from prognosis to treatment.

Endothelial cell iron overload and ferroptosis mediate thrombosis and inflammation through the miR-32-5p/neurofibromin 2 pathway

Thromboangiitis obliterans (TAO) is characterized by progressive inflammatory vasculopathy featuring thrombotic occlusion. Aberrant thrombosis induces endothelial damage through pathological clotting, while iron may act as a pro-oxidant cofactor. However, the function and mechanism of iron in TAO pathogenesis and endothelial damage remain to be elucidated. In the current study, the iron status and key lipid peroxidation markers (MDA, 4HNE, and ACSL4) were evaluated in patients with TAO and the sodium laurate-induced rat model. The CCK-8 assay, immunofluorescence, western blot, qPCR, and transmission electron microscopy were employed to detect iron overload and ferroptosis in vascular endothelial cells. In addition, bioinformatics analysis, luciferase reporter gene assay, qPCR, and western blot were used to confirm the miR-32-5p/Neurofibromin-2 (NF2) pathway in vitro. The therapeutic feasibility was validated by deferoxamine and Ferrostatin-1 treatment in vivo. The results showed iron overload and increased TFR1 expression in the vessel lesions of patients with TAO, as well as significant increases in MDA, 4HNE, and ACSL4. Serum from patients with TAO increased intracellular iron and lipid peroxidation and decreased the viability of HUVECs in vitro. Mechanism studies indicated that exosomal miR-32-5p increased in patients with TAO and could target and decrease the expression of NF2, which then decreased the phosphorylation of YAP at Ser109 and Ser217 sites. Then the NF2-targeted genes TFR1 and ACSL4 were upregulated. Finally, deferoxamine and Ferrostatin-1 treatment relieved the disease score, inflammation, and ferroptosis in vivo. This study newly demonstrates that iron overload and ferroptosis are key risk factors in patients with TAO and that the exosomal miR-32-5p/NF2 pathway may play an important role in TAO pathogenesis.

Disrupting the immune homeostasis: the emerging role of macrophage ferroptosis in autoimmune diseases

Autoimmune diseases are a class of chronic disorders characterized by the aberrant activation of the immune system, where macrophages play a central role in regulating immune responses during disease onset and progression. Ferroptosis, a form of iron-dependent programmed cell death, has recently attracted significant interest due to its involvement in various pathological conditions. In macrophages, ferroptosis not only compromises cell viability but also disrupts immune homeostasis by promoting pro-inflammatory responses and suppressing anti-inflammatory pathways, thereby intensifying inflammation and exacerbating disease severity. While substantial progress has been made in elucidating macrophage ferroptosis in atherosclerosis and oncology, its precise mechanistic role in autoimmune diseases remains largely unexplored. This review systematically summarizes the molecular mechanisms of macrophage ferroptosis and its regulatory effects on immune homeostasis, with particular emphasis on its role in autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), multiple sclerosis (MS), and systemic sclerosis (SSc). Furthermore, we discuss potential therapeutic targets related to macrophage ferroptosis in these conditions. By integrating current knowledge, this review aims to provide a theoretical framework and novel perspectives for developing innovative therapeutic strategies targeting autoimmune diseases.

Identification of imidazo[1,2-a]pyridine-3-amine as a novel drug-like scaffold for efficious ferroptosis inhibition in vivo

Ferroptosis has emerged as a promising therapeutic approach for a wide range of diseases. However, limited chemical diversity and poor drug-like profiles have hindered the development of effective ferroptosis inhibitors for clinical use. Herein, we identified drug-like imidazo[1,2-a]pyridine-3-amine derivatives as innovative ferroptosis inhibitors for injury-related diseases by drug scaffold repositioning strategy. Our findings established that the selected compounds exhibited high radical scavenging and effective membrane retention, thereby leading to significant suppression of lipid peroxidation and ferroptosis at nanomolar concentrations. Notably, compound C18, with low cytotoxicity and favorable pharmacokinetics properties, demonstrated remarkable in vivo neuroprotection against ischemic brain injury in mice. In conclusion, our investigations not only engender potent ferroptosis inhibitors with novel structural characteristics that warrant further development, but also serve as a valuable case study for drug repurposing in the discovery of additional ferroptosis inhibitors.

The role of ferroptosis in breast cancer: Tumor progression, immune microenvironment interactions and therapeutic interventions

Ferroptosis represents a distinctive and distinct form of regulated cellular death, which is driven by the accumulation of lipid peroxidation. It is distinguished by altered redox lipid metabolism and is linked to a spectrum of cellular activities, including cancer. In breast cancer (BC), with triple negative breast cancer (TNBC) being an iron-and lipid-rich tumor, inducing ferroptosis was thought to be a novel approach to killing breast tumor cells. However, in the recent past, a novel conceptual framework has emerged which posits that in addition to the promotion of tumor cell death, ferritin deposition has a potent immunosuppressive effect on the tumor immune microenvironment (TIME) via the influence on both innate and adaptive immune responses. TIME of BC includes various cell populations from both the innate and adaptive immune systems. In this review, the internal association between iron homeostasis and the progression of ferroptosis, along with the common inducers and protectors of ferroptosis in BC, are discussed in detail. Furthermore, a comprehensive analysis is conducted on the dual role of ferroptosis in immune cells and proto-oncogenic functions, along with an evaluation of the potential applications of immunogenic cell death-targeted immunotherapy in TIME of BC. It is anticipated that our review will inform future research endeavors that seek to integrate ferroptosis and immunotherapy in the management of BC.

USP5 Stabilizes IKBKG Through Deubiquitination to Suppress Ferroptosis and Promote Growth in Non-small Cell Lung Cancer

Ferroptosis, a distinctive modality of cell mortality, has emerged as a critical regulator in non-small cell lung cancer (NSCLC). The deubiquitinating enzyme USP5 has established an oncogenic role in NSCLC. However, its biological relevance in NSCLC cell ferroptosis is currently unexplored. Expression analysis was performed by quantitative PCR (qPCR), immunohistochemistry (IHC) and immunoblotting. Animal xenograft studies were used to detect USP5's role in tumor growth. Cell proliferation, colony formation and apoptotic ratio were assessed by CCK-8, colony formation and flow cytometry assays, respectively. Cell ferroptosis was evaluated by gauging ROS, MDA, GSH, SOD, and Fe2+ contents. The USP5/IKBKG relationship and the ubiquitinated IKBKG were evaluated by Co-IP experiments. USP5 expression was elevated in human NSCLC. USP5 depletion suppressed NSCLC cell in vitro and in vivo growth and enhanced cell apoptosis. Moreover, USP5 depletion induced ferroptosis in NSCLC cell lines. Mechanistically, USP5 could enhance the stability of IKBKG protein through deubiquitination. Re-expression of IKBKG partially but significantly abolished USP5 depletion-mediated anti-growth and pro-ferroptosis effects in NSCLC cells. Our study demonstrates that USP5 suppresses ferroptosis and enhances growth in NSCLC cells by stabilizing IKBKG protein through deubiquitination. Targeting USP5 expression is an encouraging strategy to block NSCLC progression.

Crosstalk between ferroptosis and endoplasmic reticulum stress: A potential target for ovarian cancer therapy (Review)

Ferroptosis is a unique mode of cell death driven by iron‑dependent phospholipid peroxidation, and its mechanism primarily involves disturbances in iron metabolism, imbalances in the lipid antioxidant system and accumulation of lipid peroxides. Protein processing, modification and folding in the endoplasmic reticulum (ER) are closely related regulatory processes that determine cell function, fate and survival. The uncontrolled proliferative capacity of malignant cells generates an unfavorable microenvironment characterized by high metabolic demand, hypoxia, nutrient deprivation and acidosis, which promotes the accumulation of misfolded or unfolded proteins in the ER, leading to ER stress (ERS). Ferroptosis and ERS share common pathways in several diseases, and the two interact to affect cell survival and death. Additionally, cell death pathways are not linear signaling cascades, and different pathways of cell death may be interrelated at multiple levels. Ferroptosis and ERS in ovarian cancer (OC) have attracted increasing research interest; however, both are discussed separately regarding OC. The present review aims to summarize the associations and potential links between ferroptosis and ERS, aiming to provide research references for the development of therapeutic approaches for the management of OC.

Anion exchange regulated charge separation engineering in bismuth nanoflowers for sonocatalytic radio-immunotherapy

Ultrasound and X-ray are considered potential options in cancer therapy due to their superior tissue penetration capabilities. Developing effective radiosensitizers is crucial for advancing cancer treatment as they enhance the effectiveness of radiation and sonodynamic therapies while minimizing their side effects. This study aimed to design a degradable bismuth-based heterojunction BiF3-Bi2O3-x:Sx-PEG (BFOSP) radiosensitizer using anion-exchange-regulated charge separation engineering. The heterojunction regulated the bandgap, improved charge carrier mobility, and enhanced reactive oxygen species generation efficiency by introducing O and S anions, enhancing the synergistic effects of sonodynamic therapy and radiotherapy. Sonodynamic therapy reduces the required radiotherapy dose, thus improving the synergistic therapeutic efficacy while enhancing treatment safety. The degradation and oxidative stress effects of BFOSP further disrupted redox balance in the tumor microenvironment while inducing tumor cell apoptosis, ferroptosis, and immunogenic cell death, activating systemic immune responses. This study introduces a reasonable design strategy for degradable radiosensitizers, offering a promising approach to improving synergy and advancing comprehensive cancer therapy.

CBX3 promotes multidrug resistance by suppressing ferroptosis in colorectal carcinoma via the CUL3/NRF2/GPX2 axis

Chemoresistance poses a significant challenge in colorectal cancer (CRC) treatment. However, the mechanisms underlying chemoresistance remain unclear. CBX3 promoted proliferation and metastasis in CRC. However, the role and mechanism of CBX3 in chemoresistance remain unknown. Therefore, we aimed to investigate the effects and mechanisms of CBX3 on multidrug resistance in CRC. Our studies showed that higher levels of CBX3 expression were associated with poor survival, especially in groups with progression following chemotherapy. CBX3 overexpression increased Irinotecan and Oxaliplatin resistance, whereas CBX3 knockdown suppressed multidrug resistance in CRC cells. Additionally, CBX3 inhibited ferroptosis associated with multidrug resistance, and the ferroptosis activators prevented CBX3 overexpression-mediated cell survival. RNA sequencing revealed that the NRF2-signaling pathway was involved in this process. CBX3-upregulated NRF2 protein expression by directly binding to the promoter of Cullin3 (CUL3) to suppress CUL3 transcription and CUL3-mediated NRF2 degradation. Moreover, Glutathione Peroxidase 2 (GPX2) was downstream of the CBX3-NRF2 pathway in CRC chemoresistance. ML385, an NRF2 inhibitor, suppressed GPX2 expression, and increased ferroptosis in PDX models. Our study identified CBX3/NRF2/GPX2 axis may be a novel signaling pathway that mediates multidrug resistance in CRC. This study proposes developing novel strategies for cancer treatment to overcome drug resistance in the future.

Biodegradable copper-doped calcium phosphate nanoplatform enables tumor microenvironment modulations for amplified ferroptosis in cervical carcinoma treatment

As a recently discovered form of regulated cell death, ferroptosis has attracted much attention in the field cancer therapy. However, achieving considerably enhanced efficacy is often restricted by the overexpression of endogenous glutathione (GSH) in tumor microenvironment (TME). In this work, we report a ferroptosis-inducing strategy of GSH depletion and reactive oxygen species (ROS) generation based on a biodegradable copper-doped calcium phosphate (CaP) with L-buthionine sulfoximine (BSO) loading (denoted as BSO@CuCaP-LOD, BCCL). BCCL was conducted by a biomineralization approach using lactate oxidases (LOD) as a bio-template to obtain Cu-doped CaP nanoparticles. Then, BSO was loaded to form BCCL nanoparticles with pH-responsive biodegradability to endow controlled release of Cu2+ and BSO in response to acidic TME. Benefiting from the catalytic performance of LOD, BCCL efficiently depletes the level of lactate in tumor, which can generate endogenous H2O2 for subsequent Fenton-like reaction. The Cu2+ and BSO intracellular GSH depletion followed by GSH-mediated Cu2+/Cu+ conversion, leading to the inhibition of glutathione peroxidase 4 (GPX4) and generation of •OH radicals via Cu+-mediated Fenton-like reaction. BCCL confers enhanced ferroptosis induction via intracellular LOD-induced H2O2 production, BSO-mediated GSH depletion, and Cu+-mediated ROS generation, leading to cause effective ferroptotic cell damage. As verified by in vitro and in vivo assays, the designed BCCL nanoplatform is highly biocompatible and exhibits superior anticancer therapy on uterine cervical carcinoma U14 tumor xenografts. This study, therefore, provides a biocompatible therapeutic platform that modulating the TME to enable intensive ROS generating efficacy and GSH depleting performance, as well as provides an innovative paradigm for achieving effective ferroptosis-based cancer therapy.

COPS5 Triggers Ferroptosis Defense by Stabilizing MK2 in Hepatocellular Carcinoma

Sorafenib, which is proven to serve as a potent ferroptosis inducer, is used as a first-line treatment for patients with advanced hepatocellular carcinoma (HCC), but it has limited clinical benefits, mainly due to drug resistance. Herein, using genome-wide CRISPR/Cas9 knockout screening and multiple functional studies, this work identifies COP9 signalosome subunit 5 (COPS5) as a driver of sorafenib resistance and a suppressor of ferroptosis in HCC. Consistently, the amplification and overexpression of COPS5 are frequently observed in clinical HCC samples, which are associated with poor patient prognosis and might predict patient response to sorafenib therapy. Mechanistically, COPS5 stabilized mitogen-activated protein kinase 2 (MK2) through deubiquitination and, in turn, induced the activation of heat shock protein beta-1 (HSPB1), a ferroptosis repressor, thereby protecting HCC cells from ferroptosis and consequently leading to sorafenib resistance and tumor progression, while its own expression could be induced by sorafenib treatment via activating transcription factor 4 (ATF4)-activated transcription. Furthermore, pharmacological inhibition of COPS5/MK2 synergize with sorafenib to induce ferroptosis and suppress HCC progression. This data reveals the crucial role of COPS5 in triggering ferroptosis defense and sorafenib resistance through the activation of the MK2-HSPB1 axis in HCC and highlights the potential of targeting COPS5/MK2 combined with sorafenib as a promising strategy for treating HCC.

Asparagine alleviates naphthalene-induced lens opacity by suppressing ferroptosis

Cataract, with lens opacity as its feature, often cause vision loss. The main clinical treatment is lens replacement surgery, which usually works well for most of the patients, but not for all. And researching drugs to delay or treat cataracts is also very important socially and scientifically. This study explored the effect of asparagine (Asn) on cataracts. In vivo, a naphthalene-induced cataract model in rats was set up, focusing on lens opacity. In vitro, SRA01/04 cells or cultured lenses were treated with the naphthalene metabolite 1,2-dihydroxynaphthalene (1,2-DHN) to study cellular mechanisms. The results showed that Asn effectively reduced lens opacity in rats with naphthalene-induced cataracts. In vitro experiments revealed that the ATF3/GPX4 signaling pathway is involved in the mechanism by which asparagine inhibits ferroptosis in lens epithelial cells induced by 1,2-DHN, playing a crucial role in this process. When given orally, Asn could cut down the accumulation of ferrous ions caused by naphthalene, stop the production of reactive oxygen species (ROS) and malondialdehyde (MDA), and ease the depletion of glutathione (GSH). In short, our findings suggest that Asn can protect against naphthalene-induced cataracts by reducing ferroptosis. This new discovery surely creates new research directions and strategies for future cataract prevention and treatment.

Endothelial but not systemic ferroptosis inhibition protects from antineutrophil cytoplasmic antibody-induced crescentic glomerulonephritis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are systemic autoimmune diseases featuring small blood vessel inflammation and organ damage, including necrotizing crescentic glomerulonephritis (NCGN). Persistent vascular inflammation leads to endothelial and kidney cell necrosis. Ferroptosis is a regulated cell death pathway executed by reactive oxygen species and iron-dependent lipid peroxidation culminating in cell membrane rupture. Here we show that ANCA-activated neutrophils induced endothelial cell (EC) death in vitro that was prevented by ferroptosis inhibition with Ferrostatin-1, Liproxstatin-1 and small inhibiting RNA against the enzyme AcylCoA Synthetase Long Chain Family Member 4 (ACSL4). In contrast, neither necroptosis nor apoptosis inhibition affected EC death. Moreover, both ferroptosis inhibitors alleviated lipid peroxide accumulation in EC. Increased lipid peroxidation was detected in kidney sections of AAV mice by immunohistochemistry. We generated MPO-/- ACSL4flox Tie2-Cre+ mice lacking ACSL4 specifically in EC (ACSL4ΔEC) to study the significance of endothelial ferroptosis in vivo. ACSL4ΔEC chimeric mice, but not control mice (ACSL4WT), were protected from NCGN in an MPO-AAV bone-marrow transplantation model. These data establish that EC ferroptosis contributes to ANCA-induced glomerulonephritis. However, systemic pharmacological ferroptosis inhibition with Ferrostatin-1 or Liproxstatin-1 did not protect from NCGN in a murine AAV model. Ferrostatin-1 treatment both directly activated T-cell proliferation and indirectly myeloid-mediated T-cell proliferation and polarization in vitro. Conceivably, both effects may cancel the beneficial effect of endothelial ferroptosis inhibition. Mechanistically, we describe the importance of EC ferroptosis for the development of AAV. However, the lack of protection with systemic pharmacological ferroptosis inhibition should discourage clinicians from evaluating this treatment strategy in clinical AAV studies.

Acyl-CoA thioesterase 8 induces gemcitabine resistance via regulation of lipid metabolism and antiferroptotic activity in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) comprises a group of highly malignant tumors of the pancreas. Metabolic reprogramming in tumors plays a pivotal role in promoting cancer progression. However, little is known about the metabolic alterations in tumors that drive cancer drug resistance in patients with PDAC. Here, we identified acyl-CoA thioesterase 8 (ACOT8) as a key player in driving PDAC gemcitabine (GEM) resistance. The expression of ACOT8 is significantly upregulated in GEM-resistant PDAC tissues and is closely associated with poor survival in patients with PDAC. Gain- and loss-of-function studies have shown that ACOT8 drives PDAC GEM resistance both in vitro and in vivo. Mechanistically, ACOT8 regulates cellular cholesterol ester (CE) levels, decreases the levels of phosphatidylethanolamines (PEs) that bind to polyunsaturated fatty acids and promote peroxisome activation. The knockdown of ACOT8 promotes ferroptosis and increases the chemosensitivity of tumors to GEM by inducing ferroptosis-associated pathway activation in PDAC cell lines. The combination of orlistat, an ACOT8 inhibitor, and GEM significantly inhibited tumor growth in PDAC organoid and mouse models. This study reveals the biological importance of ACOT8 and provides a potential combination therapy for treating patients with advanced GEM-resistant PDAC.

Protein kinase A regulates ferroptosis by controlling GPX4 m6A modification through phosphorylation of ALKBH5

GPX4-dependent ferroptosis has emerged as a therapeutic strategy for cancer treatment. Here, we demonstrated that protein kinase A (PKA) participates in the regulation of ferroptosis by controlling the m6A modification of GPX4 in an ALKBH5-dependent manner. Notably, we identified ALKBH5, an m6A demethylase, as a novel target of PKA, which drives phosphorylation-dependent degradation of ALKBH5 protein. Moreover, the deletion of ALKBH5 represses ferroptotic cell death by maintaining GPX4 m6A modification and stability. Thus, by regulating ALKBH5-dependent GPX4 stability, PKA acts as a key regulator of ferroptosis. Our study unveils the involvement of PKA in m6A modification, which could control GPX4-dependent ferroptosis and tumor progression.

Nanodrug delivery systems targeting ferroptosis as an innovative therapeutic approach for Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a chronic inflammatory disease characterized by joint inflammation, progressive cartilage degradation, and bone erosion. Recent research has implicated ferroptosis not only in autoimmune hepatitis but also in the pathogenesis and progression of autoimmune disorders like RA. Consequently, numerous therapeutic strategies have begun to target the ferroptosis pathway, particularly in the design and development of nanodrug delivery systems (NDDSs). While previous reviews have comprehensively discussed the mechanisms of ferroptosis, related signaling pathways, and NDDS materials, recent studies have further elucidated the interplay between ferroptosis and various metabolic pathways, providing a robust theoretical basis for the design of NDDS-based ferroptosis strategies. This review focuses on investigating the role of ferroptosis in the development of RA, aiming to elucidate how targeting ferroptosis can offer novel therapeutic concepts and potential treatments for RA patients. Specifically, it summarizes the design strategies of ferroptosis-based NDDSs via different pathways and highlights the feasibility of RA treatment regimens based on the ferroptosis mechanism. Furthermore, the review critically discusses the current limitations of NDDSs and offers perspectives on future research directions in this field.

Noscapine derivative 428 suppresses ferroptosis through targeting GPX4

Inhibiting ferroptosis represents a promising strategy to combat ferroptosis-related diseases. Here we show that 428, a selenide-containing noscapine derivative, effectively inhibits ferroptosis in various cell lines by enhancing the stability and activity of GPX4. TRIM41 was identified as a novel E3 ubiquitin ligase of GPX4 and 428 was demonstrated to bind to the selenocysteine residue Sec46 of GPX4 via the formation of a transient and reversible Se-Se bond, thereby blocking the interaction between GPX4 and TRIM41, stabilizing GPX4 and enhancing its activity. This unique dynamic covalent binding mode was preliminarily validated by structure-activity relationship analysis and molecular docking studies. Importantly, we demonstrated that 428 treatment alleviates bleomycin-induced pulmonary fibrosis in vivo by inhibiting ferroptosis. Overall, our studies identified a novel stabilizer and activator of GPX4, offering a potential therapeutic approach for the treatment of ferroptosis-related diseases and uncovering a new mechanism for regulating GPX4 degradation.

Integrated hepatic ferroptosis gene signature dictates pathogenic features of ferroptosis

BACKGROUND

Ferroptosis, a distinctive form of cell death induced by iron-dependent lipid peroxidation, is implicated in various biological processes, including liver diseases. Establishing an iron overload-induced ferroptosis model and identifying hepatic gene signatures associated with ferroptosis are crucial for understanding its role in liver pathogenesis.

METHODS

F-box and leucine-rich repeat protein 5 (FBXL5) is a substrate-recognition component of the SCF E3 ligase complex that restricts intracellular iron levels. In this study, we used liver-specific Fbxl5-null mice to establish an iron overload-induced ferroptosis model. Transcriptome analysis identified genes involved in hepatic ferroptosis. Integrating these gene signatures with another ferroptosis model enabled the assessment of ferroptosis-related pathology in murine liver injury models and in 174 patients undergoing liver resection surgery.

RESULTS

Iron overload induced severe liver damage in liver-specific Fbxl5-null mice, characterized by elevated liver enzymes, histopathological changes, and lipid peroxidation. Transcriptome analysis revealed a distinct set of genes associated with hepatic ferroptosis response. Generating a gene signature for evaluating ferroptosis enhanced the understanding of ferroptosis-related pathologies in liver diseases. Iron overload exacerbated liver damage in murine ischemia-reperfusion injury models via ferroptosis induction. In human patients, elevated serum iron levels correlated with sustained postoperative liver damage, indicating heightened susceptibility to ferroptosis.

CONCLUSIONS

Here, a murine model of iron overload-induced hepatic ferroptosis was established, and a gene signature indicative of hepatic ferroptosis response in both mice and humans was identified. These findings underscore the role of ferroptosis in liver injury progression and suggest potential therapeutic targets for liver disease intervention.

Novel pH-responsive lipid nanoparticles deliver UA-mediated mitophagy and ferroptosis for osteoarthritis treatment

Synovial inflammation plays a crucial role in osteoarthritis (OA) development, leading to chronic inflammation and cartilage destruction. Although targeting synovitis can alleviate OA, clinical outcomes have been disappointing due to poor drug targeting and joint cavity heterogeneity. This study presents pH-responsive lipid nanoparticles (LNPs@UA), loaded with Urolithin A (UA), as a potential OA treatment. LNPs@UA showed uniform particle size, low zeta potential, and effective mitochondria-targeting and pH-responsive capabilities. In vitro, LNPs@UA reduced reactive oxygen species (ROS), pro-inflammatory factors (IL-1β, IL-6, TNF-α), and promoted M2 macrophage polarization. It improved mitochondrial structure, enhanced autophagy, and inhibited ferroptosis. In vivo, LNPs@UA alleviated OA progression in an ACLT-induced OA mouse model. Transcriptomic analysis revealed inhibition of NF-κB signaling and activation of repair pathways. These results suggest LNPs@UA could offer a promising therapeutic approach for OA.

Cobalt carbonate nanorods enhance chemotherapy via neutralization of acidic tumor microenvironment and generation of carbonate radical anions for necrosis

One of the hallmarks of cancer is the acidic extracellular space surrounding the tumor, which is linked to metabolic reprogramming and the use of glycolysis. Additionally, the acidic tumor microenvironment (TME) establishes a physiological barrier called "ion trapping" and significantly lowers the ability of cells to absorb weak-base chemotherapy agents. Although CO32- containing agents and nanoformulations could effectively neutralize the tumor acidity, the CO32- based therapeutic effect was insufficiently investigated. Herein, we fabricated cobalt carbonate (CoCO3) nanorods as drug carriers with acidity-responsive dissociation and acidity neutralization properties for the loading of hydrophobic and weak-basic drugs, evodiamine (EVO). After effective surface modification, CoCO3-PEG-EVO could effectively accumulate in the tumor and inhibit the growth of the tumor. On the one hand, acidity neutralization of CoCO3-PEG-EVO could lead to the ion trapping overcome and cellular uptake of EVO enhancement for effective cancer cell apoptosis. On the other hand, the high level of H2O2 in the tumor and HCO3- from dissociated CoCO3-PEG-EVO could cause the generation of CO3·- through a Fenton-like reaction while not hydroxyl radical (·OH) for cancer cell necrosis. Our results thus point to a potent yet easily prepared CoCO3 nanosystem (CoCO3-PEG-EVO) to induce cancer cell death, and because of its well-defined composition and excellent biocompatibility, it may be used in clinical settings in the future.

4, 9-dihydroxy-α-lapachone as a potent antiproliferation agent for triple-negative breast cancer via ferroptosis

Triple-negative breast cancer (TNBC) is the most aggressive and malignant breast cancer. Ferroptosis is an oxidative, iron-dependent form of regulated cell death. Ferroptosis-targeted therapies is a promising approach to improving treatment outcomes of TNBC. Combining death pathway inhibitors with relevant indices for ferroptosis and LipROS, this study uncovered that a natural product of 4, 9-dihydroxy-α-lapachone (DLN) from Catalpa bungei "jinsi" exhibited in vitro and in vivo inhibitory activity against TNBC via ferroptosis. The molecular mechanism is an activation of the FTH1 led to iron overload, and then inhibition of cysteine-glutamate antiporter (system Xc-) and GPX4, which further sensitized TNBC cells to ferroptosis. This study clarified the pathway of DLN-induced cell death in TNBC treatment and exhibited its potential as therapeutic agent for TNBC.

Protein S-glutathionylation confers cellular resistance to ferroptosis induced by glutathione depletion

Ferroptosis is one of the most critical biological consequences of glutathione depletion. Excessive oxidative stress, indicated by an elevated oxidized glutathione (GSSG)/reduced glutathione (GSH) ratio, is recognized as a key driver of ferroptosis. However, in glutathione depletion-induced ferroptosis, a marked decrease in total glutathione levels (including both GSH and GSSG) is frequently observed, yet its significance remains understudied. Protein S-glutathionylation (protein-SSG) levels are closely linked to the redox state and cellular glutathione pools including GSH and GSSG. To date, the role of protein-SSG during cell ferroptosis induced by glutathione depletion remains poorly understood. Here, we demonstrated that upregulation of CHAC1, a glutathione-degrading enzyme, acted as a key regulator of protein-SSG formation and exacerbated glutathione depletion-induced ferroptosis. This effect was observed in both in vitro and in vivo models, including erastin-induced ferroptosis across multiple cell lines and acetaminophen overdose-triggered ferroptosis in hepatocytes. Deficiency of CHAC1 resulted in increased glutathione pools, enhanced protein-SSG, improved liver function, and attenuation of hepatocyte ferroptosis upon acetaminophen challenge. These protective effects were reversed by CHAC1 overexpression. Using quantitative redox proteomics, we identified glutathione pool-sensitive S-glutathionylated proteins. As an important example, we discovered that ADP-ribosylation factor 6 (ARF6) was regulated by S-glutathionylation during glutathione depletion-induced ferroptosis. Our findings revealed that CHAC1 upregulation reduced the S-glutathionylation of ARF6, resulting in decreased ARF6 levels in lysosomes. This, in turn, enhanced the localization of the transferrin receptor (TFRC) on the cell membrane and increased transferrin uptake, ultimately compromising the protective role of ARF6 in ferroptosis induced by glutathione depletion. Targeting TFRC using GalNAc-siTfrc mitigated acetaminophen-induced liver injury in vivo. In conclusion, our study provide evidence that availability of glutathione pools affects protein S-glutathionylation and regulates protein functions to influence the process of ferroptosis, which opens an avenue to understanding the cell ferroptosis induced by glutathione depletion.

Ferroptosis: A Targetable Vulnerability for Melanoma Treatment

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