The role of iron and reactive oxygen species in cell death. Nat Chem Biol. 2014;10:9-17. [PMID: 24346035 DOI: 10.1038/nchembio.1416]

Therapeutic types and advantages of functionalized nanoparticles in inducing ferroptosis in cancer therapy

BACKGROUND

The clinical efficacy of cancer treatment protocols remains unsatisfactory; however, the emergence of ferroptosis-driven therapy strategies has renewed hope for tumor treatment, owing to their remarkable tumor suppression effects. Biologically based small-molecule inducers are used in conventional method to induce ferroptosis. Nevertheless, some molecular drugs have limited solubility, poor ability to target cells, and fast metabolism, which hinder their ability to induce ferroptosis over a prolonged period. Fortunately, further investigations of ferroptosis and the development of nanotechnology have demonstrated that nanoparticles (NPs) are more efficient in inducing ferroptosis than drugs alone, which opens up new perspectives for cancer therapy.

OBJECTIVE

In order to organize a profile of recent advance in NPs for inducing ferroptosis in cancer therapy, and NPs were comprehensively classified in a new light.Materials and methods: We comprehensively searched the databases such as PubMed and Embase. The time limit for searching was from the establishment of the database to 2023.11. All literatures were related to "ferroptosis", "nanoparticles", "nanodelivery systems", "tumors", "cancer".

RESULTS

We summarized and classified the available NPs from a new perspective. The NPs were classified into six categories based on their properties: (1) iron oxide NPs (2) iron - based conversion NPs (3) core-shell structure (4) organic framework (5) silica NPs (6) lipoprotein NPs. According to the therapeutic types of NPs, they can be divided into categories: (1) NPs induced ferroptosis-related immunotherapy (2) NPs loaded with drugs (3) targeted therapy of NPs (4) multidrug resistance therapy (5) gene therapy with NPs (6) energy conversion therapy.

CONCLUSIONS

The insights gained from this review can provide ideas for the development of original NPs and nanodelivery systems, pave the way for related nanomaterials application in clinical cancer therapy, and advance the application and development of nanotechnology in the medical field.

Imbalanced and Unchecked: The Role of Metal Dyshomeostasis in Driving COPD Progression

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterized by persistent inflammation and oxidative stress, which ultimately leads to progressive restriction of airflow. Extensive research findings have cogently suggested that the dysregulation of essential transition metal ions, notably iron, copper, and zinc, stands as a critical nexus in the perpetuation of inflammatory processes and oxidative damage within the lungs of COPD patients. Unraveling the intricate interplay between metal homeostasis, oxidative stress, and inflammatory signaling is of paramount importance in unraveling the intricacies of COPD pathogenesis. This comprehensive review aims to examine the current literature on the sources, regulation, and mechanisms by which metal dyshomeostasis contributes to COPD progression. We specifically focus on iron, copper, and zinc, given their well-characterized roles in orchestrating cytokine production, immune cell function, antioxidant depletion, and matrix remodeling. Despite the limited number of clinical trials investigating metal modulation in COPD, the advent of emerging methodologies tailored to monitor metal fluxes and gauge responses to chelation and supplementation hold great promise in unlocking the potential of metal-based interventions. We conclude that targeted restoration of metal homeostasis represents a promising frontier for ameliorating pathological processes driving COPD progression.

Autophagy-dependent ferroptosis may play a critical role in early stages of diabetic retinopathy

Diabetic retinopathy (DR), as one of the most common and significant microvascular complications of diabetes mellitus (DM), continues to elude effective targeted treatment for vision loss despite ongoing enrichment of the under-standing of its pathogenic mechanisms from perspectives such as inflammation and oxidative stress. Recent studies have indicated that characteristic neuroglial degeneration induced by DM occurs before the onset of apparent microvascular lesions. In order to comprehensively grasp the early-stage pathological changes of DR, the retinal neurovascular unit (NVU) will become a crucial focal point for future research into the occurrence and progression of DR. Based on existing evidence, ferroptosis, a form of cell death regulated by processes like fer-ritinophagy and chaperone-mediated autophagy, mediates apoptosis in retinal NVU components, including pericytes and ganglion cells. Autophagy-dependent ferroptosis-related factors, including BECN1 and FABP4, may serve as both biomarkers for DR occurrence and development and potentially crucial targets for future effective DR treatments. The aforementioned findings present novel perspectives for comprehending the mechanisms underlying the early-stage pathological alterations in DR and open up innovative avenues for investigating supplementary therapeutic strategies.

Dihydroartemisinin enhances the radiosensitivity of breast cancer by targeting ferroptosis signaling pathway through hsa_circ_0001610

OBJECTIVE

This study aimed to elucidate how DHA enhances the radiosensitivity of BC and to explain its potential mechanisms of action.

METHODS

The circular structure of hsa_circ_0001610 was confirmed by Sanger sequencing, RNase R treatment, RT-PCR analysis using gDNA or cDNA. Cellular localization of hsa_circ_0001610 and microRNA-139-5p (miR-139-5p) was detected by fluorescence in situ hybridization. Cell counting kit-8 assay, wound healing and colony formation tests for assessing cell proliferation, while flow cytometry was utilized to estimate cell cycle progression and apoptosis. Reactive oxygen species and malondialdehyde experiments were conducted to validate ferroptosis of BC cells. The expression of ncRNAs and mRNAs was quantified via qRT-PCR, and protein expression was analyzed using Western blot. The effects of hsa_circ_0001610 and DHA on radiosensitivity of BC in vivo were studied by establishing BC mice model.

RESULTS

In vivo and in vitro experimental results indicate that DHA promotes ferroptosis of BC cells at least partly by inhibiting hsa_circ_0001610/miR-139-5p/SLC7A11 pathway, thereby enhancing the radiosensitivity of BC cells.

CONCLUSIONS

Our findings showed that DHA can induce ferroptosis of BC cells by down-regulation of hsa_circ_0001610, thus enhancing radiosensitivity, suggesting a promising therapeutic strategy for enhancing BC radiosensitivity that is worthy of further exploration.

Ferroptosis in the neurovascular unit after spinal cord injury

The mechanisms of secondary injury following spinal cord injury are complicated. The role of ferroptosis, which is a newly discovered form of regulated cell death in the neurovascular unit(NVU), is increasingly important. Ferroptosis inhibitors have been shown to improve neurovascular homeostasis and attenuate secondary spinal cord injury(SCI). This review focuses on the mechanisms of ferroptosis in NVU cells and NVU-targeted therapeutic strategies according to the stages of SCI, and analyzes possible future research directions.

Synthesis, anticancer activity and mechanism of action of Fe(III) complexes

To inhibit the growth and metastasis of triple-negative breast cancer (TNBC), two Fe(III) thiosemicarbazone complexes (Fe1 and Fe2) were designed and synthesized. The structures of the Fe(III) complexes were characterized by single crystal X-ray diffraction. The antiproliferative activity of Fe1 and Fe2 against four cancer lines (MDA-MB-231, T98G, HepG2, 143B) and human renal proximal tubular epithelial cell line (HK-2) was evaluated by MTT assay. Among all cells, Fe2 showed significant cytotoxicity to TNBC cells (MDA-MB-231), with an IC50 value of 12.38 μM. Furthermore, Fe2 showed less toxicity to HK-2 cells. The two Fe(III) complexes can produce excess of reactive oxygen species, decrease of mitochondrial membrane potential, and induce DNA damage, then lead to apoptosis of MDA-MB-231 cells. In addition, Fe1 and Fe2 can also inhibit migration and invasion of MDA-MB-231 cells. This study provides guidance for the development of metal complexes that inhibit the growth and metastasis of TNBC.

Constructing Electron-Rich Ru Clusters on Non-Stoichiometric Copper Hydroxide for Superior Biocatalytic ROS Scavenging to Treat Inflammatory Spinal Cord Injury

Traumatic spinal cord injury (SCI) represents a complex neuropathological challenge that significantly impacts the well-being of affected individuals. The quest for efficacious antioxidant and anti-inflammatory therapies is both a compelling necessity and a formidable challenge. Here, in this work, the innovative synthesis of electron-rich Ru clusters on non-stoichiometric copper hydroxide that contain oxygen vacancy defects (Ru/def-Cu(OH)2), which can function as a biocatalytic reactive oxygen species (ROS) scavenger for efficiently suppressing the inflammatory cascade reactions and modulating the endogenous microenvironments in SCI, is introduced. The studies reveal that the unique oxygen vacancies promote electron redistribution and amplify electron accumulation at Ru clusters, thus enhancing the catalytic activity of Ru/def-Cu(OH)2 in multielectron reactions involving oxygen-containing intermediates. These advancements endow the Ru/def-Cu(OH)2 with the capacity to mitigate ROS-mediated neuronal death and to foster a reparative microenvironment by dampening inflammatory macrophage responses, meanwhile concurrently stimulating the activity of neural stem cells, anti-inflammatory macrophages, and oligodendrocytes. Consequently, this results in a robust reparative effect on traumatic SCI. It is posited that the synthesized Ru/def-Cu(OH)2 exhibits unprecedented biocatalytic properties, offering a promising strategy to develop ROS-scavenging and anti-inflammatory materials for the management of traumatic SCI and a spectrum of other diseases associated with oxidative stress.

The melatonin-FTO-ATF4 signaling pathway protects granulosa cells from cisplatin-induced chemotherapeutic toxicity by suppressing ferroptosis

PURPOSE

In cisplatin-induced premature ovarian failure (POF) mice, granulosa cells showed a high level of ferroptosis. Previous research has indicated that the fat mass and obesity-associated protein/activating transcription factor 4 (FTO/ATF4) axis was involved in the regulation of ferroptosis. The purpose of this study was to explore the role of the FTO/ATF4 axis in cisplatin-induced ferroptosis in granulosa cell.

METHODS

The extent of ferroptosis was assessed by transmission electron microscopy (TEM) and ROS, GPX, GSH, and MDA assays. Western blotting was used to evaluate the protein expression levels of ferroptosis-related molecules. Ferroptosis activator and inhibitor were also used.

RESULTS

We found that ferroptosis increased in a concentration-dependent manner in cisplatin-induced injured granulosa cells, accompanied by the downregulation of FTO. In addition, gain- and loss-of-function studies showed that FTO affects ferroptosis in injured cells by regulating ATF4 expression. Ferrostatin-1 inhibited the effect of FTO downregulation on injured granulosa cells ferroptosis, and erastin reversed the protective effect of FTO on ferroptosis in injured granulosa cells. Finally, melatonin was used, and we found that melatonin reduced ferroptosis in cisplatin-induced injured granulosa cells by upregulating FTO expression.

CONCLUSION

Our study demonstrated that cisplatin induced granulosa cell ferroptosis by downregulating the expression of FTO. ATF4 was identified as a downstream target of FTO, and overexpression of ATF4 reversed the effects of decreased FTO on ferroptosis. Additionally, melatonin mitigates the cytotoxic effects of cisplatin by upregulating FTO expression. The melatonin-FTO-ATF4 signaling pathway plays a vital role in the treatment of cisplatin-induced POF.

Dynamic death decisions: How mitochondrial dynamics shape cellular commitment to apoptosis and ferroptosis

The incorporation of mitochondria into early eukaryotes established organelle-based biochemistry and enabled metazoan development. Diverse mitochondrial biochemistry is essential for life, and its homeostatic control via mitochondrial dynamics supports organelle quality and function. Mitochondrial crosstalk with numerous regulated cell death (RCD) pathways controls the decision to die. In this review, we will focus on apoptosis and ferroptosis, two distinct forms of RCD that utilize divergent signaling to kill a targeted cell. We will highlight how proteins and processes involved in mitochondrial dynamics maintain biochemically diverse subcellular compartments to support apoptosis and ferroptosis machinery, as well as unite disparate RCD pathways through dual control of organelle biochemistry and the decision to die.

Reduced microRNA-744 expression in mast cell-derived exosomes triggers epithelial cell ferroptosis in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a critical disorder characterized by immune-related damage to epithelial cells; however, its underlying mechanism remains elusive. This study investigated the effects of alterations in microRNA (miRNA) expression in mast cell-derived exosomes on human bronchial epithelial (HBE) cells and ARDS development in cellular and mouse models challenged with lipopolysaccharide. Lipopolysaccharide-treated mast cell-derived exosomes reduced glutathione peroxidase 4 (GPX4) expression and increased long-chain acyl-CoA synthetase 4 (ACSL4), 15-lipoxygenase (ALOX15), and inflammatory mediator levels in HBE cells. miRNA sequencing revealed a reduction in mast cell-derived exosomal miR-744 levels, which was associated with the regulation of ACSL4, ALOX15, and GPX4 expression. This downregulation of exosomal miR-744 expression reduced miR-744 levels and promoted ferroptosis in HBE cells, whereas the experimental upregulation of miR-744 reversed these adverse effects. Down-regulation of miR-744 induced the expression of markers for ferroptosis and inflammation in HBE cells and promoted pulmonary ferroptosis, inflammation, and injury in LPS-stimulated mice. In vivo, treatment with ACSL4, ALOX15, and GPX4 inhibitors mitigated these effects, and experimental miR-744 expression rescued the lipopolysaccharide-induced changes in HBE cells and mouse lungs. Notably, miR-744 levels were reduced in the plasma and exosomes of patients with ARDS. We concluded that decreased mast cell-derived exosomal miR-744 levels trigger epithelial cell ferroptosis, promoting lung inflammation and damage in ARDS. This study provides new mechanistic insights into the development and sustained pulmonary damage associated with ARDS and highlights potential therapeutic strategies.

Brain Iron in signature regions relating to cognitive aging in older adults: the Taizhou Imaging Study

BACKGROUND

Recent magnetic resonance imaging (MRI) studies have established that brain iron accumulation might accelerate cognitive decline in Alzheimer's disease (AD) patients. Both normal aging and AD are associated with cerebral atrophy in specific regions. However, no studies have investigated aging- and AD-selective iron deposition-related cognitive changes during normal aging. Here, we applied quantitative susceptibility mapping (QSM) to detect iron levels in cortical signature regions and assessed the relationships among iron, atrophy, and cognitive changes in older adults.

METHODS

In this Taizhou Imaging Study, 770 older adults (mean age 62.0 ± 4.93 years, 57.5% women) underwent brain MRI to measure brain iron and atrophy, of whom 219 underwent neuropsychological tests nearly every 12 months for up to a mean follow-up of 2.68 years. Global cognition was assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Domain-specific cognitive scores were obtained from MoCA subscore components. Regional analyses were performed for cortical regions and 2 signature regions where atrophy affected by aging and AD only: Aging (AG) -specific and AD signature meta-ROIs. The QSM and cortical morphometry means of the above ROIs were also computed.

RESULTS

Significant associations were found between QSM levels and cognitive scores. In particular, after adjusting for cortical thickness of regions of interest (ROIs), participants in the upper tertile of the cortical and AG-specific signature QSM exhibited worse ZMMSE than did those in the lower tertile [β = -0.104, p = 0.026;β = -0.118, p = 0.021, respectively]. Longitudinal analysis suggested that QSM values in all ROIs might predict decline in ZMoCA and key domains such as attention and visuospatial function (all p < 0.05). Furthermore, iron levels were negatively correlated with classic MRI markers of cortical atrophy (cortical thickness, gray matter volume, and local gyrification index) in total, AG-specific signature and AD signature regions (all p < 0.05).

CONCLUSION

AG- and AD-selective iron deposition was associated with atrophy and cognitive decline in elderly people, highlighting its potential as a neuroimaging marker for cognitive aging.

Research Progress on Ferroptosis in Multiple Myeloma

OPINION STATEMENT

Multiple myeloma (MM) is the second most common hematological malignant (HM) tumor, and a large proportion of patients still suffer from treatment failure and a poor prognosis despite the use of some newly approved drugs, a deeper understanding of the underlying mechanism is still needed. Ferroptosis is a new form of programmed cell death (PCD) that is different from other traditional forms of cell death such as apoptosis, necrosis and autophagy. With the continuous deepening of research on ferroptosis, ferroptosis has been found to be closely related to MM. This article reviews the regulatory mechanism of ferroptosis and research progress on ferroptosis in MM, providing a new theoretical basis and strategies for the diagnosis and treatment of MM.

Cancer cell membrane-camouflaged curcumin nanoparticles trigger ferroptosis for accurate gastric cancer therapy

Curcumin (CUR) is a hydrophobic polyphenol with considerable antitumor efficiency, but its clinical application is limited because of its poor solubility and low stability in aqueous solution and lack of targeting in vivo. Herein, we fabricated a tumor-targeting drug delivery system by loading CUR and cloaking homologous cancer cell membrane (CM) onto mesoporous silica NPs (MSN-CUR@CM). Characterization analysis showed that MSN-CUR@CM with a size of approximately 70 nm showed high water solubility and biocompatibility. Besides, MSN-CUR@CM exhibited tumor-targeting and excellent anti-gastric cancer efficiency both in vitro and in vivo owing to the cellular self-recognition of CM. In the established xenograft tumor nude mouse model, it was still significantly drug accumulated at the tumor site 72 h post administration. In addition, the mean tumor volume and weight of the MSN-CUR@CM group were was 3.97 and 7.47 times smaller than those of the CUR group. Ferroptosis, a type of non-apoptotic regulated cell death accompanied by iron-dependent lipid peroxidation, was triggered by MSN-CUR@CM. Further analysis demonstrated that MSN-CUR@CUR upregulated heme oxygenase (HO)-1 levels whereas it downregulated the expression of glutathione peroxidase 4 (GPX4) in SGC7901 cells in vitro, indicating that the canonical and noncanonical ferroptosis pathways were regulated by MSN-CUR@CM. In conclusion, our study demonstrated that MSN-CUR@CM with high water solubility, biocompatibility, and tumor-targeting properties inhibited gastric cancer both in vitro and in vivo by triggering ferroptosis and provided an admirable cancer therapy efficacy.

LncRNA MIR210HG promotes phenotype switching of pulmonary arterial smooth muscle cells through autophagy-dependent ferroptosis pathway

Hypoxic pulmonary hypertension (HPH) is a pathophysiological syndrome in which pulmonary vascular pressure increases under hypoxic stimulation and there is an urgent need to develop emerging therapies for the treatment of HPH. LncRNA MIR210HG is a long non-coding RNA closely related to hypoxia and has been widely reported in a variety of tumor diseases. But its mechanism in hypoxic pulmonary hypertension is not clear. In this study, we identified for the first time the potential effect of MIR210HG on disease progression in HPH. Furthermore, we investigated the underlying mechanism through which elevated levels of MIR210HG promotes the transition from a contractile phenotype to a synthetic phenotype in PASMCs under hypoxia via activation of autophagy-dependent ferroptosis pathway. While overexpression of HIF-2α in PASMCs under hypoxia significantly reversed the phenotypic changes induced by MIR210HG knockdown. We further investigated the potential positive regulatory relationship between STAT3 and the transcription of MIR210HG in PASMCs under hypoxic conditions. In addition, we established both in vivo and in vitro models of HPH to validate the differential expression of specific markers associated with hypoxia. Our findings suggest a potential mechanism of LncRNA MIR210HG in the progression of HPH and offer potential targets for disease intervention and treatment.

Synthesis of reduced graphene oxide supported FeCu and its environmental applications

A significant share of wastewater produced during different processes is released to the surroundings without further treatment. Therefore, polluted water sources are triggering diseases like typhoid. To avoid this, various techniques have been developed for the removal of contaminants from the water. Iron-copper bimetallic nanoparticles (NPs) supported on the reduced graphene oxide (rGOFeCu) were prepared which showed excellent antibacterial activity, efficient dechlorination of 1,1,1-trichloroethane (TCA), and removal of methylene blue (MB). The characterization of prepared nanocomposites was done by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Iron-based bimetallic NPs supported on the graphene were successfully synthesized as confirmed by TEM. Iron has a strong antibacterial effect on microorganisms, especially bacteria. We conducted the antibacterial activity of different compositions of nanocomposite toward Escherichia coli to understand the efficacy of prepared nanocomposites. In the same time and concentration conditions, rGOFeCu showed the best antibacterial activity, as compared to the graphene-based iron. Results show that the excellent antibacterial activity was exhibited by using rGO-Fe95Cu05 within two hours. More than 98% of cell inhibition was observed. The further increase in copper loading has no major effect on antibacterial activity. rGO-Fe95Cu05 exhibited excellent removal efficiency of TCA (99%) within 30 min as compared to other compositions of FeCu. It was found that rGO-Fe95Cu05 exhibited excellent removal efficiency against degradation of methylene blue (MB) through activation of sodium percarbonate (SPC). The results indicated that more than 99% of MB was removed within 15 min. The rGOFeCu represented a great potential material for antibacterial activity towards E. coli and remediation of other pollutants in the wastewater such as TCA and removal of MB.

White light increases anticancer effectiveness of iridium(III) complexes toward lung cancer A549 cells

Anticancer activity has been extensively studies. In this article, three ligands 2-(6-bromobenzo[d][1,3]dioxol-5-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (BDIP), 2-(7-methoxybenzo[d][1,3]dioxol-5-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (MDIP), 2-(6-nitrobenzo[d][1,3]dioxol-5-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (NDIP) and their iridium(III) complexes: [Ir(ppy)2(BDIP)](PF6) (ppy = deprotonated 2-phenylpyridine, 3a), [Ir(ppy)2(MDIP)](PF6) (3b) and [Ir(ppy)2(NDIP)](PF6) (3c) were synthesized. The cytotoxicity of 3a, 3b, 3c against Huh7, A549, BEL-7402, HepG2, HeLa, and non-cancer NIH3T3 was tested using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. The results obtained from the MTT test stated clearly that these complexes demonstrated moderate or non-cytotoxicity toward Huh7, BEL-7402, HepG2 and HeLa except A549 cells. To improve the anticancer efficacy, we used white light to irradiate the mixture of cells and complexes for 30 min, the anticancer activity of the complexes was greatly enhanced. Particularly, 3a and 3b exhibited heightened capability to inhibit A549 cells proliferation with IC50 (half maximal inhibitory concentration) values of 0.7 ± 0.3 μM and 1.8 ± 0.1 μM, respectively. Cellular uptake has shown that 3a and 3b can be accumulated in the cytoplasm. Wound healing and colony forming showed that 3a and 3b significantly hinder the cell migration and growth in the S phase. The complexes open mitochondrial permeability transition pore (MPTP) channel and cause the decrease of membrane potential, release of cytochrome C, activation of caspase 3, and finally lead to apoptosis. In addition, 3a and 3b cause autophagy, increase the lipid peroxidation and lead to ferroptosis. Also, 3a and 3b increase the expression of calreticulin (CRT), high mobility group box 1 (HMGB1), heat shock protein 70 (HSP70), thereby inducing immunogenic cell death.

Glutathione-Disrupting Nanotherapeutics Potentiate Ferroptosis for Treating Luminal Androgen Receptor-Positive Triple-Negative Breast Cancer

The refractory luminal androgen receptor (LAR) subtype of triple-negative breast cancer (TNBC) patients is challenged by significant resistance to neoadjuvant chemotherapy and increased immunosuppression. Regarding the distinct upregulation of glutathione (GSH) and glutathione peroxidase 4 (GPX4) in LAR TNBC tumors, we herein designed a GSH-depleting phospholipid derivative (BPP) and propose a BPP-based nanotherapeutics of RSL-3 (GDNS), aiming to deplete intracellular GSH and repress GPX4 activity, thereby potentiating ferroptosis for treating LAR-subtype TNBC. GDNS treatment drastically downregulated the expression of GSH and GPX4, resulting in a 33.88-fold enhancement of lipid peroxidation and significant relief of immunosuppression in the 4T1 TNBC model. Moreover, GDNS and its combination with antibody against programed cell death protein 1 (antiPD-1) retarded tumor growth and produced 2.83-fold prolongation of survival in the LAR-positive TNBC model. Therefore, the GSH-disrupting GDNS represents an encouraging strategy to potentiate ferroptosis for treating refractory LAR-subtype TNBC.

Applications of pyroptosis activators in tumor immunotherapy

Contemporary progress in tumor immunotherapy has solidified its role as an effective approach in combating cancer. Nonetheless, the prevalent "immune cold" state within the tumor microenvironment poses a substantial barrier to its efficacy. Addressing this, pyroptosis-a gasdermin-mediated programmed cell death characterized by its inflammatory profile-emerges as a crucial mechanism. It catalyzes the release of vast quantities of pro-inflammatory cytokines and immunogens, potentially transforming immunosuppressive "cold" tumors into reactive "hot" ones. Herein, we will initially present an overview of pyroptosis as a distinct form of cell death, along with its molecular mechanisms. Subsequently, we will focus on introducing how pyroptosis activators are utilized in the field of tumor immunotherapy. Insights gained from applications of pyroptosis activators in tumor immunotherapy could lead to the development of safe and efficient pyroptosis activators, significantly enriching the arsenal for tumor immunotherapy.

Hesperetin alleviates aflatoxin B1 induced liver toxicity in mice: Modulating lipid peroxidation and ferritin autophagy

One of the ways Aflatoxin B1 damages the liver is through ferroptosis. Ferroptosis is characterized by the build-up of lipid peroxides and reactive oxygen species (ROS) due to an excess of iron. Dietary supplements have emerged as a promising strategy for treating ferroptosis in the liver. The flavonoid component hesperetin, which is mostly present in citrus fruits, has a number of pharmacological actions, such as those against liver fibrosis, cancer, and hyperglycemia. However, hesperetin's effects and mechanisms against hepatic ferroptosis are still unknown. In this study, 24 male C57BL/6 J mice were randomly assigned to CON, AFB1 (0.45 mg/kg/day), and AFB1+ hesperetin treatment groups (40 mg/kg/day). The results showed that hesperetin improved the structural damage of the mouse liver, down-regulated inflammatory factors (Cxcl1, Cxcl2, CD80, and F4/80), and alleviated liver fibrosis induced by aflatoxin B1. Hesperetin reduced hepatic lipid peroxidation induced by iron accumulation by up-regulating the levels of antioxidant enzymes (GPX4, GSH-Px, CAT, and T-AOC). It is worth noting that hesperetin not only improved lipid peroxidation but also maintained the dynamic balance of iron ions by reducing ferritin autophagy. Mechanistically, hesperetin's ability to regulate ferritin autophagy mostly depends on the PI3K/AKT/mTOR/ULK1 pathway. In AFB1-induced HepG2 cells, the addition of PI3K inhibitor (LY294002) and AKT inhibitor (Miransertib) confirmed that hesperetin regulated the PI3K/AKT/mTOR/ULK1 pathway to inhibit ferritin autophagy and reduced the degradation of ferritin in lysosomes. In summary, our results suggest that hesperetin not only regulates the antioxidant system but also inhibits AFB1-induced ferritin hyperautophagy, thereby reducing the accumulation of iron ions to mitigate lipid peroxidation. This work provides a fresh perspective on the mechanism behind hesperetin and AFB1-induced liver damage in mice.

Effects of ferritin iron loading, subunit composition, and the NCOA4-iron sulfur cluster on ferritin-NCOA4 interactions: An isothermal titration calorimetry study

Ferritin is a 24-mer protein nanocage that stores iron and regulates intracellular iron homeostasis. The nuclear receptor coactivator-4 (NCOA4) binds specifically to ferritin H subunits and facilitates the autophagic trafficking of ferritin to the lysosome for degradation and iron release. Using isothermal titration calorimetry (ITC), we studied the thermodynamics of the interactions between ferritin and the soluble fragment of NCOA4 (residues 383-522), focusing on the effects of the recently identified FeS cluster bound to NCOA4, ferritin subunit composition, and ferritin-iron loading. Our findings show that in the presence of the FeS cluster, the binding is driven by a more favorable enthalpy change and a decrease in entropy change, indicating a key role for the FeS cluster in the structural organization and stability of the complex. The ferritin iron core further enhances this association, increasing binding enthalpy and stabilizing the NCOA4-ferritin complex. The ferritin subunit composition primarily affects binding stoichiometry of the reaction based on the number of H subunits in the ferritin H/L oligomer. Our results demonstrate that both the FeS cluster and the ferritin iron core significantly affect the binding thermodynamics of the NCOA4-ferritin interactions, suggesting regulatory roles for the FeS cluster and ferritin iron content in ferritinophagy.

Association between the pre-transplantation serum ferritin level and outcomes of hematopoietic stem cell transplantation: A systematic review and meta-analysis

Background

Iron overload, as indicated by evaluated serum ferritin (SF) level, occurs commonly in patients with hematological diseases. To evaluate the association between pre-transplant SF level and outcomes of hematopoietic stem cell transplantation (HSCT), we performed this systematic review and meta-analysis.

Methods

PubMed, Embase, Web of Science and the Cochrane Library electronic database were searched from inception to August 2023, and 56 studies with 14149 patients were found to be eligible.

Results

An elevated pre-transplantation SF level was associated with inferior overall survival (hazard ratio [HR],1.77; 95 % confidence interval [CI],1.61-1.96) and disease-free survival (HR, 1.86; 95 % CI, 1.58-2.19), and increased risk of non-relapse mortality (HR, 1.73; 95 % CI, 1.49-2.02), and relapse (HR, 1.46; 95 % CI, 1.29-1.65). However, no meaningful association was observed between SF levels and acute graft-versus-host disease (GVHD) (risk ratio [RR], 1.09; 95 % CI, 0.96-1.24), or chronic GVHD (RR, 0.95; 95 % CI, 0.79-1.16). Furthermore, an elevated pre-transplantation SF level was associated with a higher risk of fungal infection (RR, 1.56; 95 % CI, 1.16-2.10), but not with bacterial infection (RR, 1.09; 95 % CI, 0.80-1.50). Moreover, an elevated pre-transplantation SF level was related to a higher risk of death due to relapse/disease progression (RR, 1.72; 95 % CI, 1.33-2.23) and infection (RR, 2.21; 95 % CI, 1.55-3.15), but not death due to GVHD (RR, 1.18; 95 % CI, 0.79-1.77).

Conclusions

A higher pre-transplantation SF level was significantly associated with a higher risk of relapse/disease progression and infections, which contributed to worse survival in patients undergoing HSCT. In particular, a higher SF level was related to a higher risk of fungal infection, indicating that patients with a higher pre-transplantation SF level require more attention regarding the risk of fungal infection after HSCT.

Singlet oxygen-mediated photochemical cross-linking of an engineered fluorescent flavoprotein iLOV

Genetically-encoded photoactive proteins are integral tools in modern biochemical and molecular biological research. Within this tool box, truncated variants of the phototropin 2 light-oxygen-voltage (LOV) flavoprotein have been developed to photochemically generate singlet oxygen (1O2) in vitro and in vivo, yet the effect of 1O2 on these genetically encoded photosensitizers remains underexplored. In this study, we demonstrate that the "improved" LOV (iLOV) flavoprotein is capable of photochemical 1O2 generation. Once generated, 1O2 induces protein oligomerization via covalent cross-linking. The molecular targets of protein oligomerization by cross-linking are not endogenous tryptophans or tyrosines, but rather primarily histidines. Substitution of surface-exposed histidines for serine or glycine residues effectively eliminates protein cross-linking. When used in biochemical applications, such protein-protein cross-links may interfere with native biological responses to 1O2, which can be ameliorated by substitution of the surface exposed histidines of iLOV or other 1O2-generating flavoproteins.

ASIC1a regulates ferroptosis in hepatic stellate cells via the Hippo/Yap-1 pathway in liver fibrosis

BACKGROUND

Liver fibrosis is a sustained process of liver tissue damage and repair caused by various physiological and pathological factors, with the activation and proliferation of hepatic stellate cells being central. Therefore, understanding and clarifying the relevant mechanisms of hepatic stellate cell activation and death is of great clinical significance for the treatment of liver fibrosis diseases.

METHODS

In vivo, recombinant adeno-associated virus was used to infect the liver of experimental mice, overexpressing ASIC1a, and based on this, a liver fibrosis model treated with sorafenib was constructed. In vitro, using RNA plasmid technology to transfect HSC-T6 cells, ASIC1a was overexpressed or silenced in the cells, and on this basis, PDGF-BB and Sorafenib were used to stimulate HSC-T6 cells, causing activated HSC-T6 to undergo ferroptosis.

RESULTS

The ferroptosis inducers Sorafenib and erastin can induce ferroptosis in HSCs, effectively inhibiting or reversing the progression of liver fibrosis. We found that the expression level of ASIC1a was significantly reduced in the livers of mice with liver fibrosis treated with Sorafenib. After treatment with an adeno-associated virus overexpressing ASIC1a, the therapeutic effect of Sorafenib was inhibited, and the level of ferroptosis induced by Sorafenib was also inhibited. The induction of ferroptosis in hepatic stellate cells in vitro depends on the presence of ASIC1a. By further exploring the potential mechanism, we observed that the overexpression of ASIC1a can promote an increase in YAP nuclear translocation, thereby regulating the activity of Hippo/YAP pathway signaling. After treatment with Sorafenib, the influx of Ca2+ significantly increased when ASIC1a was overexpressed, and BAPTA-AM intervention eliminated the intracellular Ca2+ accumulation induced by ASIC1a overexpression.

CONCLUSIONS

This indicated that the activation of YAP depends on the calcium ion influx induced by ASIC1a, which regulates ferroptosis in hepatic stellate cells by regulating the calcium ion-dependent Hippo/YAP pathway.

Diosgenin ameliorating non-alcoholic fatty liver disease via Nrf2-mediated regulation of oxidative stress and ferroptosis

AIM

This study aimed to investigate the mechanisms through which diosgenin inhibits the pathogenesis of non-alcoholic fatty liver disease, focusing particularly on ferroptosis-related pathways and its reliance on nuclear factor erythroid 2-related factor 2.

MATERIALS AND METHODS

Using a rat model, we showed diosgenin's efficacy in reducing lipid deposition throughout the body and examined its impact on ferroptosis-related gene expression in vivo. Moreover, in vitro experiments using human hepatocellular liver carcinoma cell line cells were conducted to assess oxidative stress and ferroptosis levels.

RESULTS

Diosgenin decreased lipid accumulation and steatosis; lowered serum levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol, glutamic pyruvic transaminase and glutamic oxaloacetic transaminase; reduced interleukin-1β and tumour necrosis factor-α; diosgenin decreased malondialdehyde levels; and increased serum superoxide dismutase levels in a rat model of high-fat diet-induced non-alcoholic fatty liver disease. Diosgenin upregulated the expression of nuclear factor erythroid 2-related factor 2 and its downstream ferroptosis-related genes to inhibit ferroptosis in the livers of rats with non-alcoholic fatty liver disease. Diosgenin decreased reactive oxygen species levels and enhanced the expression of ferroptosis-related genes in human hepatocellular liver carcinoma cells induced by free fatty acids, with its effects being dependent on nuclear factor erythroid 2-related factor 2.

CONCLUSIONS

This study highlights the potential of diosgenin from Dioscoreaceae plants in mitigating oxidative stress and ferroptosis levels through nuclear factor erythroid 2-related factor 2 regulation, offering novel insights into the treatment of non-alcoholic fatty liver disease and other metabolic disorders through traditional Chinese medicine.

Augmented the sensitivity of photothermal-ferroptosis therapy in triple-negative breast cancer through mitochondria-targeted nanoreactor

Ferroptosis primarily relies on reactive oxygen (ROS) production and lipid peroxide (LPO) accumulation, which opens up new opportunities for tumor therapy. However, a standalone ferroptosis process is insufficient in inhibiting tumor progression. Unlike previously reported Fe-based nanomaterials, we have engineered a novel nanoreactor named IR780/Ce@EGCG/APT, which uses metal-polyphenols network (Ce@EGCG) based on rare-earth cerium and epigallocatechin gallate (EGCG) to encapsulate IR780 and modified with the aptamer (AS1411). The intricately designed nanoreactor is specifically taken up by tumor cells, releasing Ce3+, EGCG, and IR780. On the one hand, Ce3+ triggers ROS production via a Fenton-like reaction, inducing ferroptosis in tumor cells. On the other hand, IR780 accumulates in mitochondria and disrupts mitochondrial function upon laser irradiation, leading to tumor cell apoptosis. EGCG serves as a sensitizer, simultaneously enhancing the sensitivity of tumor cells to ferroptosis and photothermal therapy. After a single dose and three times of 808 nm laser irradiation for treatment, it has been observed that the nanoreactor induces dendritic cells (DCs) maturation, facilitates cytotoxic T lymphocyte infiltration, improves immunosuppressive microenvironment, activates the systemic immune system, and generates long-term immune memory.

OsHRZ1 negatively regulates rice resistant to Magnaporthe oryzae infection by targeting OsVOZ2

Rice blast disease caused by Magnaporthe oryzae significantly reduces yield production. Blast resistance is closely associated with iron (Fe) status, but the mechanistic basis linking iron status to immune function in rice remains largely unknown. Here, iron-binding haemerythrin RING ubiquitin ligases OsHRZ1 was confirmed to play key roles in iron-mediated rice blast resistance. The expression of OsHRZ1 was suppressed by M. oryzae inoculation and high iron treatment. Both mutants of OsHRZ1 enhanced rice resistance to M. oryzae. OsPR1a was up-regulated in OsHRZ1 mutants. Yeast two-hybrid, bimolecular fluorescence complementation, and Co-IP assay results indicated that OsHRZ1 interacts with Vascular Plant One Zinc Finger 2 (OsVOZ2) in the nucleus. Additionally, the vitro ubiquitination assay indicated that OsHRZ1 can ubiquitinate OsVOZ2 and mediate the degradation of OsVOZ2. The mutants of OsVOZ2 showed reduced resistance to M. oryzae and down-regulated the expression of OsPR1a. Yeast one-hybrid, EMSA, and dual-luciferase reporter assay results indicated that OsVOZ2 directly binds to the promoter of OsPR1a, activating its expression. In summary, OsHRZ1 plays an important role in rice disease resistance by mediated degradation of OsVOZ2 thus shaping PR gene expression dynamics in rice cells. This highlights an important link between iron signaling and rice pathogen defenses.

Ferroptosis: a new mechanism of traditional Chinese medicine for treating hematologic malignancies

Ferroptosis is a recently identified form of cell death characterized by lipid peroxidation and elevated iron levels. It is closely associated with hematologic malignancies, including leukemia, multiple myeloma (MM), and myelodysplastic syndromes (MDS). Research indicates that ferroptosis could represent a novel therapeutic target for these hematologic malignancies. Furthermore, traditional Chinese medicine (TCM) has been shown to modulate hematologic malignancies through the ferroptosis pathway. This paper aims to elucidate the mechanisms underlying ferroptosis and summarize the current research advancements regarding ferroptosis in hematologic malignancies, as well as the role of traditional Chinese medicine in the prevention and treatment of ferroptosis, with the goal of enhancing treatment efficacy.

Silibinin attenuates ferroptosis in acute kidney injury by targeting FTH1

Acute kidney injury (AKI) is primarily caused by renal ischemia-reperfusion injury (IRI), which is one of the most prevalent triggers. Currently, preventive and therapeutic measures remain limited. Ferroptosis plays a significant role in the pathophysiological process of IRI-induced AKI and is considered a key target for improving its outcomes. Silibinin, a polyphenolic flavonoid, possesses diverse pharmacological properties and is widely used as an effective therapeutic agent for liver diseases. Recent studies have reported that silibinin may improves kidney diseases, though the underlying mechanism remain unclear. In this study, we investigated whether silibinin protects against IRI-induced AKI and explored its mechanism of action. Our findings indicated that pretreatment with silibinin alleviated renal dysfunction, pathological damage, and inflammation in IRI-AKI mice. Furthermore, the results demonstrated that silibinin inhibited ferroptosis both in vivo and in vitro. Proteome microarrays were used to identify silibinin's target, and our results revealed that silibinin binds to FTH1. This binding affinity was confirmed through molecular docking, SPRi, CETSA, and DARTS. Additionally, co-IP assays demonstrated that silibinin disrupted the NCOA4-FTH1 interaction, inhibiting ferritinophagy. Finally, the inhibitory effects of silibinin on ferroptosis were reversed by knocking down FTH1 in vitro. In conclusion, our study shows that silibinin effectively alleviates AKI by targeting FTH1 to reduce ferroptosis, suggesting that silibinin could be developed as a potential therapeutic agent for managing and treating AKI.

A BODIPY-Ferrocene Conjugate for the Combined Photodynamic Therapy and Chemodynamic Therapy with Improved Antitumor Efficiency

Photodynamic therapy (PDT) can destroy tumor cells by generating singlet oxygen (1O2) under light irradiation, which is limited by the hypoxia of the neoplastic tissue. Chemodynamic therapy (CDT) can produce toxic hydroxyl radical (⋅OH) to eradicate tumor cells by catalytic decomposition of endogenous hydrogen peroxide (H2O2), the therapeutic effect of which is highly dependent on the concentration of H2O2. Herein, we propose a BODIPY-ferrocene conjugate with a balanced 1O2 and ⋅OH generation capacity, which can serve as a high-efficiency antitumor agent by combining PDT and CDT. The ferrocene moieties endow the as-prepared conjugates with the ability of chemodynamic killing of tumor cells. Moreover, combined PDT/CDT therapy with improved antitumor efficiency can be realized after exposure to light irradiation. Compared with the monotherapy by PDT or CDT, the BODIPY-ferrocene conjugates can significantly increase the intracellular ROS levels of the tumor cells after light irradiation, thereby inducing the tumor cell apoptosis at low drug doses. In this way, a synergistic antitumor treatment is achieved by the combination of PDT and CDT.

CD44-hyaluronan mediating endocytosis of iron-platinum alloy nanoparticles induces ferroptotic cell death in mesenchymal-state lung cancer cells with tyrosine kinase inhibitor resistance

While tyrosine kinase inhibitor resistance in cancer is a critical issue in the medical field, it is important for clinical testing as well, since it affects the ultimate outcome of cancer therapy. Yet, no effective solutions have been implemented till date. Clinical observations after tyrosine kinase inhibitor treatment reveal that acquired resistance inevitably limits the curative effects of non-small cell lung cancer treatment because of mutations in the epidermal growth factor receptor gene, which are accompanied by epithelial-mesenchymal transition. Here, for the first time, we report that the transmembrane glycoprotein CD44, which is associated with epithelial-mesenchymal transition, chemoresistance, and cancer progression, mediates enhanced endocytosis of iron-platinum alloy nanoparticles (FePt NPs) in the mesenchymal-state gefitinib-resistant (GR+ and M6) cells, via the binding of the CD44 ligand, hyaluronan, to the surface-absorbed hyaluronan-binding protein 2. Upon treatment with FePt NPs, there was higher cellular uptake in mesenchymal-state GR+ and M6 cells, resulting from cell death through ferroptosis and mitochondrial dysfunction, as compared to that observed in the epithelial-state cells. Mechanistically, inactivation of dihydroorotate dehydrogenase elevated the production of mitochondrial lipid peroxidation, and enhanced the cell death in the epithelial-state HCC827 cells, thereby indicating its role in defense against FePt NPs-induced ferroptosis. Furthermore, induction of ferroptosis has been shown to specifically promote the cell death of drug-tolerant "persister" cells and reverse their resistance as well. Therefore, we concluded that FePt NPs preferentially target mesenchymal drug-tolerant "persister" cells and promote ferroptosis, to overcome their resistance. STATEMENT OF SIGNIFICANCE: In the present study, we identified FePt NPs as an innovative agent for cancer treatment, particularly in mesenchymal-state cells that exhibit TKI resistance. Mesenchymal-state cancer cells showed enhanced uptake of FePt NPs via CD44-HA-mediated endocytosis, accompanied by severe cell death and mitochondrial morphology alterations, in comparison to epithelial-state cells. We further elucidated the mechanism underlying FePt NPs-induced ferroptotic cell death as via a burst of mitochondrial LPO and DHODH protein inactivation. In addition, we found that FePt NPs inhibit tumor growth in TKI-resistant mesenchymal GR+ cell-bearing mice with better efficacy than the ferroptotic inducer RSL3. Our current findings on using FePt NPs to overcome TKI resistance through ferroptosis activation may offer a alternative strategy for improved cancer treatment.

Ferroptosis in Ischemic Stroke and Related Traditional Chinese Medicines

Stroke is a severe neurological disorder resulting from the rupture or blockage of blood vessels, leading to significant mortality and disability worldwide. Among the different types of stroke, ischemic stroke (IS) is the most prevalent, accounting for 70-80% of cases. Cell death following IS occurs through various mechanisms, including apoptosis, necrosis, and ferroptosis. Ferroptosis, a recently identified form of regulated cell death characterized by iron overload and lipid peroxidation, was first described by Dixon in 2012. Currently, the only approved pharmacological treatment for IS is recombinant tissue plasminogen activator (rt-PA), which is limited by a narrow therapeutic window and often results in suboptimal outcomes. Recent research has identified several traditional Chinese medicines (TCMs) that can inhibit ferroptosis, thereby mitigating the damage caused by IS. This review provides an overview of stroke, the role of ferroptosis in IS, and the potential of certain TCMs to inhibit ferroptosis and contribute to stroke treatment.

Ferroptosis in radiation-induced brain injury: roles and clinical implications

Radiation-induced brain injury (RBI) presents a significant challenge for patients undergoing radiation therapy for head, neck, and intracranial tumors. This review aims to elucidate the role of ferroptosis in RBI and its therapeutic implications. Specifically, we explore how ferroptosis can enhance the sensitivity of tumor cells to radiation while also examining strategies to mitigate radiation-induced damage to normal brain tissues. By investigating the mechanisms through which radiation increases cellular reactive oxygen species (ROS) and initiates ferroptosis, we aim to develop targeted therapeutic strategies that maximize treatment efficacy and minimize neurotoxicity. The review highlights key regulatory factors in the ferroptosis pathway, including glutathione peroxidase 4 (GPX4), cystine/glutamate antiporter system Xc- (System Xc-), nuclear factor erythroid 2-related factor 2 (NRF2), Acyl-CoA synthetase long-chain family member 4 (ACSL4), and others, and their interactions in the context of RBI. Furthermore, we discuss the clinical implications of modulating ferroptosis in radiation therapy, emphasizing the potential for selective induction of ferroptosis in tumor cells and inhibition in healthy cells. The development of advanced diagnostic tools and therapeutic strategies targeting ferroptosis offers a promising avenue for enhancing the safety and efficacy of radiation therapy, underscoring the need for further research in this burgeoning field.

Implications of Iron in Ferroptosis, Necroptosis, and Pyroptosis as Potential Players in TBI Morbidity and Mortality

Iron is a critical transition metal required to sustain a healthy central nervous system. Iron is involved in metabolic reactions, enzymatic activity, myelinogenesis, and oxygen transport. However, in several pathological conditions such as cancer, neurodegeneration, and neurotrauma iron becomes elevated. Excessive iron can have deleterious effects leading to reactive oxygen species (ROS) via the Fenton reaction. Iron-derived ROS are known to drive several mechanisms such as cell death pathways including ferroptosis, necroptosis, and pyroptosis. Excessive iron present in the post-traumatic brain could trigger these harmful pathways potentiating the high rates of morbidity and mortality. In the present review, we will discuss how iron plays an intricate role in initiating ferroptosis, necroptosis, and pyroptosis, examine their potential link to traumatic brain injury morbidity and mortality, and suggest therapeutic targets.

METTL16-SENP3-LTF axis confers ferroptosis resistance and facilitates tumorigenesis in hepatocellular carcinoma

BACKGROUND

Ferroptosis, characterized by iron-dependent lipid peroxidation, emerges as a promising avenue for hepatocellular carcinoma (HCC) intervention due to its tumor susceptibility. RNA N6-methyladenosine (m6A) modification has been involved in several types of regulated cell death. However, the roles and molecular mechanisms of m6A-related regulators in HCC cell ferroptosis remain unclear.

METHODS

By examining a series of m6A modification enzymes upon ferroptosis induction or inhibition, we identified METTL16 as a novel ferroptotic repressor in HCC cells. The roles of METTL16 on ferroptosis and HCC development were investigated in multiple cell lines, human HCC organoids, subcutaneous xenografts and MYC/Trp53-/- HCC model in hepatocyte-specific Mettl16 knockout and overexpression mice. The underlying mechanism was elucidated with MeRIP/RIP-qPCR, luciferase assay, Co-IP assay and Mass Spectrometry. The clinical significance and relevance were evaluated in human samples.

RESULTS

High METTL16 expression confers ferroptosis resistance in HCC cells and mouse models, and promotes cell viability and tumor progression. Mechanistically, METTL16 collaborates with IGF2BP2 to modulate SENP3 mRNA stability in an m6A-dependent manner, and the latter impedes the proteasome-mediated ubiquitination degradation of Lactotransferrin (LTF) via de-SUMOylation. Elevated LTF expression facilitates the chelation of free iron and reduces liable iron pool level. SENP3 and LTF are implicated in METTL16-mediated HCC progression and anti-ferroptotic effects both in vivo and in vitro. Clinically, METTL16 and SENP3 expression were positively correlated, and high METTL16 and SENP3 expression predicts poor prognosis in human HCC samples.

CONCLUSIONS

Our study reveals a new METTL16-SENP3-LTF signaling axis regulating ferroptosis and driving HCC development. Targeting this axis is a promising strategy for sensitizing ferroptosis and against HCC.

Iron Overload Induces Hepatic Ferroptosis and Insulin Resistance by Inhibiting the Jak2/stat3/slc7a11 Signaling Pathway

Recent studies showed that patients with iron overload had increased risk of insulin resistance or diabetes. Ferroptosis is a new type of cell death mainly caused by iron-dependent oxidative damage. In the present study, we investigated potential mechanisms of iron overload induced hepatic ferroptosis and insulin resistance through in vivo and in vitro experiments. In vivo, the mice models of iron overload were established by intraperitoneal injection of iron dextran. The changes of body weight, serum ferritin and blood glucose were measured. Hematoxylin-eosin (HE) and Perl's stainings were used to observe the pathological changes and iron deposition in the liver of mice. In vitro, HepG2 cells were treated with ferric ammonium citrate (FAC, 9 mmol/L, 24 h) to establish the cell models of iron overload. The labile iron pool, cell viability, glucose consumption and glycogen contents were measured. The ultrastructure of mitochondria was observed by transmission electron microscope (TEM). The malondialdehyde (MDA) and glutathione (GSH) kits were used to detect lipid peroxidation in liver tissues of mice and HepG2 cells. RT-PCR and Western blot were used to detect the mRNA and protein expression levels of ferroptosis factors and JAK2/STAT3 signaling pathway. In this study, we used the iron chelator deferasirox in mice and HepG2 cells. Iron overload caused weight loss, elevated serum ferritin, fasting blood glucose, fasting insulin, HOMA-IR, impaired glucose tolerance, and decreased insulin sensitivity in mice. HE staining and Perls staining showed clumps of iron deposition in the liver of iron overload mice. Iron overload could reduce the glucose consumption, increase MDA contents of HepG2 cells, while reduce glycogen and GSH contents in liver tissues of mice and HepG2 cells. TEM showed deletion of mitochondrial ridge and rupture of outer membrane in HepG2 cells with iron overload. Iron chelator deferasirox could significantly improve the above indicators, which might be related to the activation of JAK2/STAT3/SLC7A11 signaling pathway and hepatic ferroptosis. Iron overload could induce hepatic ferroptosis and insulin resistance by inhibiting the JAK2/STAT3/SLC7A11 signaling pathway, and the iron chelator deferasirox might improve hepatic insulin resistance induced by iron overload.

Hindlimb immobilization induces insulin resistance and elevates mitochondrial ROS production in the hippocampus of female rats

Alzheimer's disease (AD) is the fifth leading cause of death in older adults, and treatment options are severely lacking. Recent findings demonstrate a strong relationship between skeletal muscle and cognitive function, with evidence supporting that muscle quality and cognitive function are positively correlated in older adults. Conversely, decreased muscle function is associated with a threefold increased risk of cognitive decline. Based on these observations, the purpose of this study was to investigate the negative effects of muscle disuse [via a model of hindlimb immobilization (HLI)] on hippocampal insulin sensitivity and mitochondrial function and identify the potential mechanisms involved. HLI for 10 days in 4-mo-old female Wistar rats resulted in the following novel findings: 1) hippocampal insulin resistance and deficits in whole body glucose homeostasis, 2) dramatically increased mitochondrial reactive oxygen species (ROS) production in the hippocampus, 3) elevated markers for amyloidogenic cleavage of amyloid precursor protein (APP) and tau protein in the hippocampus, 4) and reduced brain-derived neurotrophic factor (BDNF) expression. These findings were associated with global changes in iron homeostasis, with muscle disuse producing muscle iron accumulation in association with decreased serum and whole brain iron levels. We report the novel finding that muscle disuse alters brain iron homeostasis and reveal a strong negative correlation between muscle and brain iron content. Overall, HLI-induced muscle disuse has robust negative effects on hippocampal insulin sensitivity and ROS production in association with altered brain iron homeostasis. This work provides potential novel mechanisms that may help explain how loss of muscle function contributes to cognitive decline and AD risk.NEW & NOTEWORTHY Muscle disuse via hindlimb immobilization increased oxidative stress and insulin resistance in the hippocampus. These findings were in association with muscle iron overload in connection with iron dysregulation in the brain. Overall, our work identifies muscle disuse as a contributor to hippocampal dysfunction, potentially through an iron-based muscle-brain axis, highlighting iron dysregulation as a potential novel mechanism in the relationship between muscle health, cognitive function, and Alzheimer's disease risk.

Transcriptomics pave the way into mechanisms of cobalt and nickel toxicity: Nrf2-mediated cellular responses in liver carcinoma cells

Cobalt (Co) and Nickel (Ni) are used nowadays in various industrial applications like lithium-ion batteries, raising concerns about their environmental release and public health threats. Both metals are potentially carcinogenic and may cause neurological and cardiovascular dysfunctions, though underlying toxicity mechanisms have to be further elucidated. This study employs untargeted transcriptomics to analyze downstream cellular effects of individual and combined Co and Ni toxicity in human liver carcinoma cells (HepG2). The results reveal a synergistic effect of Co and Ni, leading to significantly higher number of differentially expressed genes (DEGs) compared to individual exposure. There was a clear enrichment of Nrf2 regulated genes linked to pathways such as glycolysis, iron and glutathione metabolism, and sphingolipid metabolism, confirmed by targeted analysis. Co and Ni exposure alone and combined caused nuclear Nrf2 translocation, while only combined exposure significantly affects iron and glutathione metabolism, evidenced by upregulation of HMOX-1 and iron storage protein FTL. Both metals impact sphingolipid metabolism, increasing dihydroceramide levels and decreasing ceramides, sphingosine and lactosylceramides, along with diacylglycerol accumulation. By combining transcriptomics and analytical methods, this study provides valuable insights into molecular mechanisms of Co and Ni toxicity, paving the way for further understanding of metal stress.

Iron chelation mitigates mitochondrial dysfunction and oxidative stress by enhancing nrf2-mediated antioxidant responses in the renal cortex of a murine model of type 2 diabetes

Renal iron overload is a common complication of diabetes that leads to oxidative stress and mitochondrial dysfunction in the kidneys. This study investigated the effects of iron chelation using deferiprone on mitochondrial dysfunction and oxidative stress in the renal cortex of a murine model of type 2 diabetes. Diabetic rats were treated with deferiprone (50 mg/kg BW) for 16 weeks. Our results show that iron chelation with deferiprone significantly increased the nuclear accumulation of Nrf2, a transcription factor that regulates the expression of antioxidant enzymes. This led to enhanced antioxidant capacity, reduced production of reactive oxygen species, and improved mitochondrial bioenergetic function in diabetic rats. However, chronic iron chelation led to altered mitochondrial respiration and increased oxidative stress in non-diabetic rats. In conclusion, our findings suggest that iron chelation with deferiprone protects mitochondrial bioenergetics and mitigates oxidative stress in the renal cortex, involving the NRF2 pathway in type 2 diabetes.

Genetically Engineered Membrane-Coated Nanoparticles for Enhanced Prostate-Specific Membrane Antigen Targeting and Ferroptosis Treatment of Castration-Resistant Prostate Cancer

Conventional androgen deprivation therapy (ADT) targets the androgen receptor (AR) inhibiting prostate cancer (PCa) progression; however, it can eventually lead to recurrence as castration-resistant PCa (CRPC), which has high mortality rates and lacks effective treatment modalities. The study confirms the presence of high glutathione peroxidase 4 (GPX4) expression, a key regulator of ferroptosis (i.e., iron-dependent program cell death) in CRPC cells. Therefore, inducing ferroptosis in CRPC cells might be an effective therapeutic modality for CRPC. However, nonspecific uptake of ferroptosis inducers can result in undesirable cytotoxicity in major organs. Thus, to precisely induce ferroptosis in CRPC cells, a genetic engineering strategy is proposed to embed a prostate-specific membrane antigen (PSMA)-targeting antibody fragment (gy1) in the macrophage membrane, which is then coated onto mesoporous polydopamine (MPDA) nanoparticles to produce a biomimetic nanoplatform. The results indicate that the membrane-coated nanoparticles (MNPs) exhibit high specificity and affinity toward CRPC cells. On further encapsulation with the ferroptosis inducers RSL3 and iron ions, MPDA/Fe/RSL3@M-gy1 demonstrates superior synergistic effects in highly targeted ferroptosis therapy eliciting significant therapeutic efficacy against CRPC tumor growth and bone metastasis without increased cytotoxicity. In conclusion, a new therapeutic strategy is reported for the PSMA-specific, CRPC-targeting platform for ferroptosis induction with increased efficacy and safety.

BCAT1 alleviates early brain injury by inhibiting ferroptosis through PI3K/AKT/mTOR/GPX4 pathway after subarachnoid hemorrhage

Regulation of the redox system by branched-chain amino acid transferase 1 (BCAT1) is of great significance in the occurrence and development of diseases, but the relationship between BCAT1 and subarachnoid hemorrhage (SAH) is still unknown. Ferroptosis, featured by iron-dependent lipid peroxidation accompanied by the depletion of glutathione peroxidase 4 (GPX4), has been implicated in the pathological process of early brain injury after subarachnoid hemorrhage. This study established SAH model by endovascular perforation and adding oxyhemoglobin (Hb) to HT22 cells and delved into the mechanism of BCAT1 in SAH-induced ferroptotic neuronal cell death. It was found that SAH-induced neuronal ferroptosis could be inhibited by BCAT1 overexpression (OE) in rats and HT22 cells, and BCAT1 OE alleviated neurological deficits and cognitive dysfunction in rats after SAH. In addition, the effect of BCAT1 could be reversed by the Ly294002, a specific inhibitor of the PI3K pathway. In summary, our present study indicated that BCAT1 OE alleviated early brain injury EBI after SAH by inhibiting neuron ferroptosis via activation of PI3K/AKT/mTOR pathway and the elevation of GPX4. These results suggested that BCAT1 was a promising therapeutic target for subarachnoid hemorrhage.

Ironing out the details of ferroptosis

Ferroptosis, spurred by excess labile iron and lipid peroxidation, is implicated in various diseases. Advances have been made in comprehending the lipid-peroxidation side of ferroptosis, but the exact role of iron in driving ferroptosis remains unknown. Although iron overload is characterized in multiple disease states, the potential role of ferroptosis within them remains undefined. This overview focuses on the 'ferro' side of ferroptosis, highlighting iron dysregulation in human diseases and potential therapeutic strategies targeting iron regulation and metabolism.

The main molecular mechanisms of ferroptosis and its role in chronic kidney disease

The term ferroptosis, coined in 2012, has been widely applied in various disease research fields. Ferroptosis is a newly regulated form of cell death distinct from apoptosis, necrosis, and autophagy, the mechanisms of which have been extensively studied. Chronic kidney disease, characterized by renal dysfunction, is a common disease severely affecting human health, with its occurrence and development influenced by multiple factors and leading to dysfunction in multiple systems. It often lacks obvious clinical symptoms in the early stages, and thus, diagnosis is typically made in the later stages, complicating treatment. While research on ferroptosis and acute kidney injury has made continuous progress, studies on the association between ferroptosis and chronic kidney disease remain limited. This review aims to summarize chronic kidney disease, investigate the mechanism and regulation of ferroptosis, and attempt to elucidate the role of ferroptosis in the occurrence and development of chronic kidney disease.

Catalytic Nanoparticles in Biomedical Applications: Exploiting Advanced Nanozymes for Therapeutics and Diagnostics

Catalytic nanoparticles (CNPs) as heterogeneous catalyst reveals superior activity due to their physio-chemical features, such as high surface-to-volume ratio and unique optical, electric, and magnetic properties. The CNPs, based on their physio-chemical nature, can either increase the reactive oxygen species (ROS) level for tumor and antibacterial therapy or eliminate the ROS for cytoprotection, anti-inflammation, and anti-aging. In addition, the catalytic activity of nanozymes can specifically trigger a specific reaction accompanied by the optical feature change, presenting the feasibility of biosensor and bioimaging applications. Undoubtedly, CNPs play a pivotal role in pushing the evolution of technologies in medical and clinical fields, and advanced strategies and nanomaterials rely on the input of chemical experts to develop. Herein, a systematic and comprehensive review of the challenges and recent development of CNPs for biomedical applications is presented from the viewpoint of advanced nanomaterial with unique catalytic activity and additional functions. Furthermore, the biosafety issue of applying biodegradable and non-biodegradable nanozymes and future perspectives are critically discussed to guide a promising direction in developing span-new nanozymes and more intelligent strategies for overcoming the current clinical limitations.

Ferroptosis in liver diseases: Fundamental mechanism and clinical implications

This editorial discusses a recently published paper in the World Journal of Gastroenterology. Our research focuses on p53's regulatory mechanism for controlling ferroptosis, as well as the intricate connection between ferroptosis and liver diseases. Ferroptosis is a specific form of programmed cell death that is de-pendent on iron and displays unique features in terms of morphology, biology, and genetics, distinguishing it from other forms of cell death. Ferroptosis can affect the liver, which is a crucial organ responsible for iron storage and meta-bolism. Mounting evidence indicates a robust correlation between ferroptosis and the advancement of liver disorders. P53 has a dual effect on ferroptosis through various distinct signaling pathways. However, additional investigations are required to clarify the regulatory function of p53 metabolic targets in this complex association with ferroptosis. In the future, researchers should clarify the mechanisms by which ferroptosis and other forms of programmed cell death contribute to the progression of liver diseases. Identifying and controlling important regulatory factors associated with ferroptosis present a promising therapeutic strategy for liver disorders.

Exogenous iron caused osteocyte apoptosis, increased RANKL production, and stimulated bone resorption through oxidative stress in a murine model

Iron overload is a risk factor for osteoporosis due to its oxidative toxicity. Previous studies have demonstrated that an excessive amount of iron increases osteocyte apoptosis and receptor activator of nuclear factor κ-B ligand (RANKL) production, which stimulates osteoclast differentiation in vitro. However, the effects of exogenous iron supplementation-induced iron overload on osteocytes in vivo and its role in iron overload-induced bone loss are unknown. This work aimed to develop an iron overloaded murine model of C57BL/6 mice by intraperitoneal administration of iron dextran for two months. The iron levels in various organs, bone, and serum, as well as the microstructure and strength of bone, apoptosis of osteocytes, oxidative stress in bone tissue, and bone formation and resorption, were assessed. The results showed that 2 months of exogenous iron supplementation significantly increased iron levels in the liver, spleen, kidney, bone tissue, and serum. Iron overload negatively affected bone microstructure and strength. Osteocyte apoptosis and empty lacunae rate were elevated by exogenous iron. Iron overload upregulated RANKL expression but had no significant impact on osteoprotegerin (OPG) and sclerostin levels. Static and dynamic histologic analyses and serum biochemical assay showed that iron overload increased bone resorption without significantly affecting bone formation. Exogenous iron promoted oxidative stress in osteocytes in vivo and in vitro. Additional supplementation of iron chelator (deferoxamine) or N-acetyl-l-cysteine (NAC) partially alleviated bone loss, osteocyte apoptosis, osteoclast formation, and oxidative stress due to iron overload. These findings, in line with prior in vitro studies, suggest that exogenous iron supplementation induces osteoclastogenesis and osteoporosis by promoting osteocyte apoptosis and RANKL production via oxidative stress.

BNIP3-mediated mitophagy attenuates hypoxic-ischemic brain damage in neonatal rats by inhibiting ferroptosis through P62-KEAP1-NRF2 pathway activation to maintain iron and redox homeostasis

As a major contributor to neonatal death and neurological sequelae, hypoxic-ischemic encephalopathy (HIE) lacks a viable medication for treatment. Oxidative stress induced by hypoxic-ischemic brain damage (HIBD) predisposes neurons to ferroptosis due to the fact that neonates accumulate high levels of polyunsaturated fatty acids for their brain developmental needs but their antioxidant capacity is immature. Ferroptosis is a form of cell death caused by excessive accumulation of iron-dependent lipid peroxidation and is closely associated with mitochondria. Mitophagy is a type of mitochondrial quality control mechanism that degrades damaged mitochondria and maintains cellular homeostasis. In this study we employed mitophagy agonists and inhibitors to explore the mechanisms by which mitophagy exerted ferroptosis resistance in a neonatal rat HIE model. Seven-days-old neonatal rats were subjected to ligation of the right common carotid artery, followed by exposure to hypoxia for 2 h. The neonatal rats were treated with a mitophagy activator Tat-SPK2 peptide (0.5, 1 mg/kg, i.p.) 1 h before hypoxia, or in combination with mitochondrial division inhibitor-1 (Mdivi-1, 20 mg/kg, i.p.), and ferroptosis inhibitor Ferrostatin-1 (Fer-1) (2 mg/kg, i.p.) at the end of the hypoxia period. The regulation of ferroptosis by mitophagy was also investigated in primary cortical neurons or PC12 cells in vitro subjected to 4 or 6 h of OGD followed by 24 h of reperfusion. We showed that HIBD induced mitochondrial damage, ROS overproduction, intracellular iron accumulation, lipid peroxidation and ferroptosis, which were significantly reduced by the pretreatment with Tat-SPK2 peptide, and aggravated by the treatment with Mdivi-1 or BNIP3 knockdown. Ferroptosis inhibitors Fer-1 and deferoxamine B (DFO) reversed the accumulation of iron and lipid peroxides caused by Mdivi-1, hence reducing ferroptosis triggered by HI. We demonstrated that Tat-SPK2 peptide-activated BNIP3-mediated mitophagy did not alleviate neuronal ferroptosis through the GPX4-GSH pathway. BNIP3-mediated mitophagy drove the P62-KEAP1-NRF2 pathway, which conferred ferroptosis resistance by maintaining iron and redox homeostasis via the regulation of FTH1, HO-1, and DHODH/FSP1-CoQ10-NADH. This study may provide a new perspective and a therapeutic drug for the treatment of neonatal HIE.

Inhibition of IRP2-dependent reprogramming of iron metabolism suppresses tumor growth in colorectal cancer

BACKGROUND

Dysregulation of iron metabolism is implicated in malignant transformation, cancer progression, and therapeutic resistance. Here, we demonstrate that iron regulatory protein 2 (IRP2) preferentially regulates iron metabolism and promotes tumor growth in colorectal cancer (CRC).

METHODS

IRP2 knockdown and knockout cells were generated using RNA interference and clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 methodologies, respectively. Cell viability was evaluated using both CCK-8 assay and cell counting techniques. Furthermore, IRP2 inhibition was determined by surface plasmon resonance (SPR) and RNA immunoprecipitation (IP). The suppressive effects of IRP2 were also corroborated in both organoid and mouse xenograft models, providing a comprehensive validation of IRP2's role.

RESULTS

We have elucidated the role of IRP2 as a preferential regulator of iron metabolism, actively promoting tumorigenesis within CRC. Elevated levels of IRP2 expression in patient samples are correlated with diminished overall survival, thereby reinforcing its potential role as a prognostic biomarker. The functional suppression of IRP2 resulted in a pronounced delay in tumor growth. Building on this proof of concept, we have developed IRP2 inhibitors that significantly reduce IRP2 expression and hinder its interaction with iron-responsive elements in key iron-regulating proteins, such as ferritin heavy chain 1 (FTH1) and transferrin receptor (TFRC), culminating in iron depletion and a marked reduction in CRC cell proliferation. Furthermore, these inhibitors are shown to activate the AMPK-ULK1-Beclin1 signaling cascade, leading to cell death in CRC models.

CONCLUSIONS

Collectively, these findings highlight the therapeutic potential of targeting IRP2 to exploit the disruption of iron metabolism in CRC, presenting a strategic advancement in addressing a critical area of unmet clinical need.

Astaxanthin activated the SLC7A11/GPX4 pathway to inhibit ferroptosis and enhance autophagy, ameliorating dry eye disease

Dry eye disease (DED) is a common eye disease in clinical practice. The crucial pathogenesis of DED is that hyperosmolarity activates oxidative stress signaling pathways in corneal epithelial and immune cells and, thus, produces inflammatory molecules. The complex pathological changes in the dry eye still need to be elucidated to facilitate treatment. In this study, we found that astaxanthin (AST) can protect against DED through the SLC7A11/GPX4 pathway. After treatment with AST, the SLC7A11/GPX4 pathway was positively activated in DED both in vivo and in vitro, accompanied by enhanced autophagy and decreased ferroptosis. In hyperosmolarity-induced DED corneal epithelial cells, AST increased the expression of ferritin to promote iron storage and reduce Fe2+ overload. It increased glutathione (GSH) and GPX4, scavenged reactive oxygen species (ROS) and lipid peroxide, and rescued the mitochondrial structure to prevent ferroptosis. Furthermore, inhibition of ferroptosis by ferrostatin-1 (Fer-1), iron chelator deferoxamine mesylate (DFO), or AST could activate healthy autophagic flux. In addition, in a dry eye mouse model, AST upregulated SLC7A11 and GPX4 and inhibited ferroptosis. To summarize, we found that AST can ameliorate DED by reinforcing the SLC7A11/GPX4 pathway, which mainly affects oxidative stress, autophagy, and ferroptosis processes.

Targeting and activation of macrophages in leishmaniasis. A focus on iron oxide nanoparticles

Macrophages play a pivotal role as host cells for Leishmania parasites, displaying a notable functional adaptability ranging from the proinflammatory, leishmanicidal M1 phenotype to the anti-inflammatory, parasite-permissive M2 phenotype. While macrophages can potentially eradicate amastigotes through appropriate activation, Leishmania employs diverse strategies to thwart this activation and redirect macrophages toward an M2 phenotype, facilitating its survival and replication. Additionally, a competition for iron between the two entities exits, as iron is vital for both and is also implicated in macrophage defensive oxidative mechanisms and modulation of their phenotype. This review explores the intricate interplay between macrophages, Leishmania, and iron. We focus the attention on the potential of iron oxide nanoparticles (IONPs) as a sort of immunotherapy to treat some leishmaniasis forms by reprogramming Leishmania-permissive M2 macrophages into antimicrobial M1 macrophages. Through the specific targeting of iron in macrophages, the use of IONPs emerges as a promising strategy to finely tune the parasite-host interaction, endowing macrophages with an augmented antimicrobial arsenal capable of efficiently eliminating these intrusive microbes.

Seliciclib alleviates ulcerative colitis by inhibiting ferroptosis and improving intestinal inflammation

BACKGROUND

Ulcerative colitis (UC) is a chronic, recurrent, non-specific inflammatory disease, and the pathogenesis of the disease remains unclear. Ferroptosis is a form of programmed cell death characterized by the accumulation of iron-dependent lipid peroxides, which are simultaneously closely related to reactive oxygen species (ROS). Although seliciclib is highly effective against immune inflammation, its mechanism on colitis is unclear. This study demonstrated that seliciclib administration partially inhibited ferroptosis, alleviating symptoms and inflammation in experimental colitis.

METHODS

The mouse UC model was induced by 3.0 % dextran sodium sulfate (DSS) for 7 days and treated with seliciclib (10 mg/kg) for 5 days. In the in vitro model, LPS (100 μg/mL) was used for induction and seliciclib (10 μM) was applied for 2 h. Meanwhile, appropriate histopathology, inflammatory response, oxidative stress, and ferroptosis regulators were measured.

RESULTS

This study primarily investigated the role of seliciclib in regulating ferroptosis in UC. Bioinformatics analysis indicated that Dual oxidase 2 (DUOX2) may serve a role involved in the ferroptosis of UC. The experimental findings demonstrated that seliciclib alleviates symptoms and inflammation in DSS-induced UC mice and partially mitigates the occurrence of ferroptosis both in vivo and in vitro, possibly through the modulation of DUOX2.

CONCLUSIONS

Ferroptosis is strongly associated with the development of colitis, and seliciclib plays an essential role in ferroptosis and inflammation in UC. The suppression of ferroptosis in the intestinal epithelium could be a therapeutic approach for UC.