Autophagy-Dependent Ferroptosis: Machinery and Regulation

Pyroptosis, ferroptosis, and autophagy in spinal cord injury: regulatory mechanisms and therapeutic targets

Regulated cell death is a form of cell death that is actively controlled by biomolecules. Several studies have shown that regulated cell death plays a key role after spinal cord injury. Pyroptosis and ferroptosis are newly discovered types of regulated cell deaths that have been shown to exacerbate inflammation and lead to cell death in damaged spinal cords. Autophagy, a complex form of cell death that is interconnected with various regulated cell death mechanisms, has garnered significant attention in the study of spinal cord injury. This injury triggers not only cell death but also cellular survival responses. Multiple signaling pathways play pivotal roles in influencing the processes of both deterioration and repair in spinal cord injury by regulating pyroptosis, ferroptosis, and autophagy. Therefore, this review aims to comprehensively examine the mechanisms underlying regulated cell deaths, the signaling pathways that modulate these mechanisms, and the potential therapeutic targets for spinal cord injury. Our analysis suggests that targeting the common regulatory signaling pathways of different regulated cell deaths could be a promising strategy to promote cell survival and enhance the repair of spinal cord injury. Moreover, a holistic approach that incorporates multiple regulated cell deaths and their regulatory pathways presents a promising multi-target therapeutic strategy for the management of spinal cord injury.

A novel way of regression of pregnant corpus luteum during parturition in mice: The ferroptosis associated with NCOA4-mediated ferritinophagy

Numerous studies have shown that inappropriate regression of corpus luteum would lead to adverse pregnancy outcomes during gestation. However, the detailed mechanisms and types of programmed cell death involved in the regression of pregnant corpus luteum are largely unknown. Here, we investigated whether ferroptosis and ferritinophagy were involved in luteal regression during parturition in mice and related mechanisms. The results showed that ferroptosis and ferritinophagy were both involved in luteal regression during mice peri-parturition in vivo. Erastin (ferroptosis agonist) treatment significantly accelerated luteal regression and induced premature labor in pregnant mice. PGF2α treatment induced the ferroptosis and ferritinophagy of luteal cells in vitro. Nevertheless, inhibition or promotion of ferroptosis significantly altered the states of PGF2α-induced luteal cell viability and ferroptosis. Furthermore, inhibition of autophagy (3-methyladenine co-treatment) alleviated PGF2α-induced ferritinophagy and ferroptosis of luteal cells, and knockdown of NCOA4 reduced the degradation of FTH1 and the level of ferroptosis of luteal cells induced by PGF2α. In summary, our current data demonstrated that the ferroptosis associated with NCOA4-mediated ferritinophagy was a novel way of luteal regression during peri-parturition in mice. Targeting ferroptosis in the corpus luteum may be a therapeutic strategy for preventing luteal insufficiency in the future.

The cGAS-STING-mediated ROS and ferroptosis are involved in manganese neurotoxicity

Manganese (Mn) has been characterized as an environmental pollutant. Excessive releases of Mn due to human activities have increased Mn levels in the environment over the years, posing a threat to human health and the environment. Long-term exposure to high concentrations of Mn can induce neurotoxicity. Therefore, toxicological studies on Mn are of paramount importance. Mn induces oxidative stress through affecting the level of reactive oxygen species (ROS), and the overabundance of ROS further triggers ferroptosis. Additionally, Mn2+ was found to be a novel activator of the cyclic guanosine-adenosine synthase (cGAS)-stimulator of interferon genes (STING) pathway in the innate immune system. Thus, we speculate that Mn exposure may promote ROS production by activating the cGAS-STING pathway, which further induces oxidative stress and ferroptosis, and ultimately triggers Mn neurotoxicity. This review discusses the mechanism between Mn-induced oxidative stress and ferroptosis via activation of the cGAS-STING pathway, which may offer a prospective direction for future in-depth studies on the mechanism of Mn neurotoxicity.

Crosstalk between autophagy and other forms of programmed cell death

Cell death occurs continuously throughout individual development. By removing damaged or senescent cells, cell death not only facilitates morphogenesis during the developmental process, but also contributes to maintaining homeostasis after birth. In addition, cell death reduces the spread of pathogens by eliminating infected cells. Cell death is categorized into two main forms: necrosis and programmed cell death. Programmed cell death encompasses several types, including autophagy, pyroptosis, apoptosis, necroptosis, ferroptosis, and PANoptosis. Autophagy, a mechanism of cell death that maintains cellular equilibrium via the breakdown and reutilization of proteins and organelles, is implicated in regulating almost all forms of cell death in pathological contexts. Notably, necroptosis, ferroptosis, and PANoptosis are directly classified as autophagy-mediated cell death. Therefore, regulating autophagy presents a therapeutic approach for treating diseases such as inflammation and tumors that arise from abnormalities in other forms of programmed cell death. This review focuses on the crosstalk between autophagy and other programmed cell death modalities, providing new perspectives for clinical interventions in inflammatory and neoplastic diseases.

Baicalin plays a protective role by regulating ferroptosis in multiple diseases

Ferroptosis is a new kind of cell death discovered in recent years, usually accompanied by a large number of lipid peroxidation and iron accumulation in the process of cell death. Ferroptosis has been proven to play an important role in various diseases, including ischemic reperfusion injury, cancer, and neurodegeneration. Therefore, the regulation of ferroptosis will have a vital impact on the occurrence and development of diseases. Baicalin is a flavonoid compound extracted and isolated from the dried roots of Scutellaria baicalensis Georgi, a plant in the family Lamiaceae. It has various biological activities such as antioxidant, anti-proliferative, anti-inflammatory, anti-thrombotic, and regulates apoptosis and ferroptosis. Recently, increasing evidence indicates that baicalin regulation of ferroptosis is involved in multiple diseases. However, the relevant mechanisms are not yet fully understood. Here, we summarized the role of baicalin regulation of ferroptosis in different kinds of diseases, and conducted an in-depth analysis of the relevant mechanisms, hoping to provide the theoretical references for future related researches.

Mechanism and molecular targets of Euphorbia fischeriana Steud root extract in hepatocellular carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Euphorbia fischeriana Steud. (E. fischeriana) root is a well-known traditional Chinese medicine used in the treatment of skin ulceration, lymph node tuberculosis and tumors. However, its antitumor activity against HCC and the underlying molecular mechanisms remain to be further elucidated.

AIM OF THE STUDY

The study aimed to investigate the anti-hepatocarcinogenic effects of E. fischeriana root, specifically its impact on NCOA4-mediated ferritinophagy, and to elucidate the related molecular mechanisms in HCC.

METHODS

LC-MS was used to analyze the comprehensive chemical composition of E. fischeriana root extract. Through network pharmacology, transcriptomics, molecular docking, and molecular dynamics simulations, we investigated the potential mechanisms underlying the effects of E. fischeriana root extract on HCC. Finally, in vitro and in vivo experiments were performed to validate these mechanisms.

RESULTS

Through mass spectrometry analysis and drug-likeness screening, 93 active compounds were identified. Based on network pharmacology and transcriptomic analyses, we hypothesized that the PI3K/AKT pathway and its downstream signaling involving autophagy and ferroptosis are crucial pathways affected by E. fischeriana root extract. In vitro experiments demonstrated that E. fischeriana root extract inhibits proliferation, promotes apoptosis, triggers ferritinophagy and induces ferroptosis in HCC cells. In vivo studies further validated significant anti-HCC effects of E. fischeriana root extract.

CONCLUSIONS

Based on these findings, we propose that E. fischeriana root extract exerts its anti-HCC effects by targeting the PI3K/AKT pathway to regulate NCOA4-mediated ferritinophagy, thereby inducing ferroptosis. These results highlight E. fischeriana root extract as a promising therapeutic candidate for HCC.

Complexin 2 contributes to the protective effect of NAD+ on neuronal survival following neonatal hypoxia-ischemia

Nicotinamide adenine dinucleotide (NAD) is a key coenzyme involved in cell metabolism associated with aging, cancer, neurodegenerative diseases and metabolic disorders. We recently showed that NAD+ therapy significantly improved neurobehavioral outcomes in neonatal mice after hypoxia-ischemia (HI), and bioinformatics analysis revealed that the expression of complexin 2 (CPLX2) in the injured cerebral cortex was significantly decreased 24 h after HI injury but could be reversed by NAD+ intervention. In this study we explored the role of CPLX2 in the survival and function of neonatal hypoxic-ischemic cortical neurons. HI models were established by permanent ligation of the left common carotid artery in mice. CPLX2-knockdown lentiviral vector was injected intraventricularly on postnatal day 1 (P1); CPLX2 knockout mice were also used. NAD+ (5 mg·kg-1·d-1, i.p.) was administered before HI surgery, thereafter once a day until sampling. We showed that NAD+ administration significantly ameliorated the morphological damages and neurobehavioral defects, and elevated the seizure thresholds in HI mice. All the beneficial effects of NAD+ were abolished by CPLX2 knockdown or knockout. In HT22 neuronal cells subjected to OGD/R, pretreated with NAD+ (100 μM) for 12 h significantly increased the cell viability, decreased the LDH levels, and inhibited the ferroptosis evidenced by the changes in redox-related parameters including concentrations of Fe2+, GSH, MDA, H2O2 as well as the expression of GPX4 and SLC7A11. CPLX2 knockdown in HT22 neuronal cells blocked the protective effects of NAD+ as in HI mice, whereas CPLX2 overexpression enhanced the inhibitory effects of NAD+ on ferroptosis in HT22 neuronal cells.

Calcium/Calmodulin-Dependent Protein Kinase II β Regulates Autophagy Dependent Ferroptosis of Neurons after Cerebral Ischemic Injury by Activating the AREG/JUN/ELAVL1 Pathway

Ferroptosis is an iron-dependent regulatory cell death characterized by lipid peroxidation. The molecular mechanism of calcium/calmodulin-dependent protein kinase II β (CAMK2B) affecting cerebral ischemic injury through autophagy-dependent ferroptosis is still unclear. Here, we aimed to study the regulatory effect of CAMK2B on autophagy-dependent ferroptosis and its effect on cerebral ischemic injury. We found that CAMK2B was significantly upregulated in oxygen and glucose deprivation/recovery (OGD/R)-induced PC12 cells and primary hippocampal neurons. CAMK2B knockdown inhibited OGD/R-induced autophagy-dependent ferroptosis in PC12 cells and primary hippocampal neurons. In addition, CAMK2B was co-localized with amphiregulin (AREG) in PC12 cells, and overexpression of AREG reversed the effect of CAMK2B knockdown on OGD/R-induced autophagy-dependent ferroptosis in PC12 cells and primary hippocampal neurons. Further molecular mechanism studies showed that AREG enhanced the transcriptional activation of embryonic lethal abnormal vision-like 1 (ELAVL1) through Jun Proto-Oncogene (c-Jun), thereby inducing autophagy-dependent ferroptosis in PC12 cells and primary hippocampal neurons. Moreover, CAMK2B was significantly upregulated in the ipsilateral penumbra neurons of cerebral ischemia-reperfusion (I/R) mice, and the level of autophagy-dependent ferroptosis was increased in the brain tissue of I/R mice. Knockdown of CAMK2B alleviated neuronal damage by inhibiting autophagy-dependent ferroptosis in the brain tissue of model mice. This study suggests that CAMK2B plays a key role in regulating neuronal autophagy-dependent ferroptosis, and CAMK2B may be a potential target for the treatment of cerebral I/R injury.

The long noncoding RNA APR attenuates PPRV infection-induced accumulation of intracellular iron to inhibit membrane lipid peroxidation and viral replication

Peste des petits ruminants virus (PPRV) is an important pathogen that has long been a significant threat to small ruminant productivity worldwide. Iron metabolism is vital to the host and the pathogen. However, the mechanism underlying host-PPRV interactions from the perspective of iron metabolism and iron-mediated membrane lipid peroxidation has not been reported thus far. In this study, we identified a novel host long-noncoding RNA (lncRNA), APR, that impairs PPRV infectivity by sponging miR-3955-5p, a negative microRNA (miRNA) that directly targets the gene encoding the ferritin-heavy chain 1 (FTH1) protein. Importantly, we demonstrated that PPRV infection causes aberrant cellular iron accumulation by increasing transferrin receptor (TFRC) expression and that iron accumulation induces reticulophagy and ferroptosis, which benefits PPRV replication. Moreover, PPRV infection enhanced the localization of cellular iron on the endoplasmic reticulum (ER) and caused ER membrane damage by promoting excess lipid peroxidation to induce reticulophagy. Interestingly, APR decreased PPRV infection-induced accumulation of intracellular Fe2+ via miR-3955-5p/FTH1 axis and ultimately inhibited reticulophagy and ferroptosis. Additionally, our results indicate that interferon regulatory factor 1 promotes APR transcription by positively regulating APR promoter activity after PPRV infection. Taken together, our findings revealed a new pattern of PPRV-host interactions, involving noncoding RNA regulation, iron metabolism, and iron-related membrane lipid peroxidation, which is critical for understanding the host defense against PPRV infection and the pathogenesis of PPRV.IMPORTANCEMany viruses have been demonstrated to engage in iron metabolism to facilitate their replication and pathogenesis. However, the mechanism by which PPRV interacts with host cells from the perspective of iron metabolism, or iron-mediated membrane lipid peroxidation, has not yet been reported. Our data provide the first direct evidence that PPRV infection induces aberrant iron accumulation to promote viral replication and reveal a novel host lncRNA, APR, as a regulator of iron accumulation by promoting FTH1 protein expression. In this study, PPRV infection increased cellular iron accumulation by increasing TFRC expression, and more importantly, iron overload increased viral infectivity as well as promoted ER membrane lipid peroxidation by enhancing the localization of cellular iron on the ER and ultimately induced ferroptosis and reticulophagy. Furthermore, a host factor, the lncRNA APR, was found to decrease cellular iron accumulation by sponging miR-3955-5p, which directly targets the gene encoding the FTH1 protein, thereby attenuating PPRV infection-induced ferroptosis and reticulophagy and inhibiting PPRV infection. Taken together, the results of the present study provide new insight into our understanding of host-PPRV interaction and pathogenesis from the perspective of iron metabolism and reveal potential targets for therapeutics against PPRV infection.

Pharmacological targeting of the mitochondrial phosphatase PTPMT1 sensitizes hepatocellular carcinoma to ferroptosis

Protein tyrosine phosphatase mitochondrial 1 (PTPMT1), is a member of the protein tyrosine phosphatase superfamily localized on the mitochondrial inner membrane, and regulates the biosynthesis of cardiolipin. Given the important position of PTPMT1 in mitochondrial function and metabolism, pharmacological targeting of PTPMT1 is considered a promising manner in disease treatments. In this study, we mainly investigated the role of PTPMT1 in hepatocellular carcinoma (HCC) ferroptosis, a new type of cell death accompanied by significant iron accumulation and lipid peroxidation. Herein, the pharmacological inhibition of PTPMT1 was induced by alexidine dihydrochloride (AD, a dibiguanide compound). Human HCC cell lines with PTPMT1 knockout and PTPMT1 overexpression were established using CRISPR/Cas9 and lentiviral transduction methods, respectively. The position of PTPMT1 in regulating HCC ferroptosis was evaluated in vitro and in vivo. Our results indicated that pharmacological inhibition of PTPMT1, facilitated by AD treatment, heightens the susceptibility of HCC to cystine deprivation-ferroptosis, and AD treatment promoted the conversion from ferritin-bound Fe3+ to free Fe2+, which contributed to the labile iron pool in cytoplasm. Meanwhile, pharmacological inhibition of PTPMT1 also induced the formation of both swollen mitochondria and donut mitochondria, and enhanced the metabolism process form succinate to fumarate in mitochondrial tricarboxylic acid (TCA) cycle, which increased the sensitivity of HCC cells to cystine deprivation-induced ferroptosis. In total, our work reveals the close association of PTPMT1 with cysteine deprivation-induced ferroptosis, providing a novel insight into chemotherapy strategies against human HCC.

Microplastics exacerbate ferroptosis via mitochondrial reactive oxygen species-mediated autophagy in chronic obstructive pulmonary disease

Microplastics (MPs) induce mitochondrial dysfunction and iron accumulation, contributing to mitochondrial macroautophagy/autophagy and ferroptosis, which has increased susceptibility to the exacerbation of chronic obstructive pulmonary disease (COPD); however, the underlying mechanism remains unclear. We demonstrated that MPs intensified inflammation in COPD by enhancing autophagy-dependent ferroptosis (ADF) in vitro and in vivo. In the lung tissues of patients with COPD, the concentrations of MPs, especially polystyrene microplastics (PS-MPs), were significantly higher than that of the control group, as detected by pyrolysis gas chromatography mass spectrometry (Py-GCMS), with increased iron accumulation. The exposure to PS-MPs, 2 μm in size, resulted in their being deposited in the lungs of COPD model mice detected by optical in vivo imaging, and observed in bronchial epithelial cells traced by GFP-labeled PS-MPs. There were mitochondrial impairments accompanied by mitochondrial reactive oxygen species (mito-ROS) overproduction and significantly increased levels of lysosome biogenesis and acidification in pDHBE cells with PS-MP stimulation, triggering occurrence of ferritinophagy and enhancing ADF in COPD, which triggered acute exacerbation of COPD (AECOPD). Reestablishing autophagy-dependent ferroptosis via mitochondria-specific ROS scavenging or ferroptosis inhibition alleviated excessive inflammation and ameliorated AECOPD induced by PS-MPs. Collectively, our data initially revealed that MPs exacerbate ferroptosis via mito-ROS-mediated autophagy in COPD, which sheds light on further hazard assessments of MPs on human respiratory health and potential therapeutic agents for patients with COPD.Abbreviations: ADF: autophagy-dependent ferroptosis; AECOPD: acute exacerbation of chronic obstructive pulmonary disease; Cchord: static compliance; COPD: chronic obstructive pulmonary disease; CQ: chloroquine; CS: cigarette smoke; DEGs: differentially expressed genes; Fer-1: ferrostatin-1; FEV 0.1: forced expiratory volume in first 100 ms; FVC: forced vital capacity; GSH: glutathione; HE: hematoxylin and eosin; IL1B/IL-1β: interleukin 1 beta; IL6: interleukin 6; MDA: malondialdehyde; Mito-ROS: mitochondrial reactive oxygen species; MMA: methyl methacrylate; MMF: maximal mid-expiratory flow curve; MMP: mitochondrial membrane potential; MOI: multiplicity of infection; MPs: microplastics; MV: minute volume; PA: polyamide; PBS: phosphate-buffered saline; PC: polycarbonate; pDHBE: primary human bronchial epithelial cell from COPD patients; PET: polyethylene terephthalate; PIF: peak inspiratory flow; PLA: polylactic acid; pNHBE: primary normal human bronchial epithelial cell; PS-MPs: polystyrene microplastics; PVA: polyvinyl acetate; PVC: polyvinyl chloride; Py-GCMS: pyrolysis gas chromatography mass spectrometry; SEM: scanning electron microscopy; Te: expiratory times; Ti: inspiratory times; TNF/TNF-α: tumor necrosis factor.

Natural products protect against spinal cord injury by inhibiting ferroptosis: a literature review

Spinal cord injury (SCI) is a severe traumatic condition that frequently results in various neurological disabilities, including significant sensory, motor, and autonomic dysfunctions. Ferroptosis, a recently identified non-apoptotic form of cell death, is characterized by the accumulation of reactive oxygen species (ROS), intracellular iron overload, and lipid peroxidation, ultimately culminating in cell death. Recent studies have demonstrated that ferroptosis plays a critical role in the pathophysiology of SCI, contributing significantly to neural cell demise. Three key cellular enzymatic antioxidants such as glutathione peroxidase 4 (GPX4), ferroptosis suppressor protein 1 (FSP1), and dihydroorotate dehydrogenase (DHODH), have been elucidated as crucial components in the defense against ferroptosis. Natural products, which are bioactive compounds mostly derived from plants, have garnered considerable attention for their potential therapeutic effects. Numerous studies have reported that several natural products can effectively mitigate neural cell death and alleviate SCI symptoms. This review summarizes fifteen natural products containing (-)-Epigallocatechin-3-gallate (EGCG), Proanthocyanidin, Carnosic acid, Astragaloside IV, Trehalose, 8-gingerol, Quercetin, Resveratrol, Albiflorin, Alpha-tocopherol, Celastrol, Hispolon, Dendrobium Nobile Polysaccharide, Silibinin, and Tetramethylpyrazine that have shown promise in treating SCI by inhibiting ferroptosis. Additionally, this review provides an overview of the mechanisms involved in these studies and proposes several perspectives to guide future research directions.

Nuclear receptor coactive 4-mediated ferritinophagy: a key role of heavy metals toxicity

Nuclear receptor coactive 4 (NCOA4) is a specific receptor for ferritinophagy, transporting ferritin to lysosomal degradation, releasing free iron, and excessive iron levels may lead to cellular redox imbalance, contributing to cell death, predominantly ferroptosis. NCOA4 is regulated by a variety of transcriptional, post-transcriptional, translational, and post-translational modifications. Targeted modulation of NCOA4-mediated ferritinophagy has been successfully used as a therapeutic strategy in several disease models. Recent evidences have elucidated that ferritinophagy and ferroptosis played a major role in heavy metals toxicity. In this review, we explored the regulatory mechanism of NCOA4 as the sole receptor for ferritinophagy from multiple perspectives based on previous studies. The significant role of ferritinophagy-mediated ferroptosis in heavy metals toxicity was discussed in detail, emphasizing the great potential of NCOA4 as a target for heavy metals toxicity.

Targeting ferroptosis for the treatment of female reproductive system disorders

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

Nestin Regulates Autophagy-Dependent Ferroptosis Mediated Skeletal Muscle Atrophy by Ubiquitinating MAP 1LC3B

BACKGROUND

Programmed cell death plays a critical role in skeletal muscle atrophy. Ferroptosis, an iron-dependent form of programmed cell death driven by lipid peroxidation, has been implicated in various diseases, but its role in skeletal muscle atrophy remains unclear.

METHODS

Ferroptosis in skeletal muscle atrophy was investigated using two models: dexamethasone (Dex)-induced atrophy (n = 6 independent cell cultures per group) and simulated microgravity (n = 6 mice per group). Conditional Nestin knockout (KO) mice were generated using CRISPR/Cas9 (n = 6-8 mice per group), with wild-type (WT) controls (n = 6-8). Phenotypic analyses included histopathology (HE staining), functional assessments (muscle strength, weight analysis, treadmill), and dystrophy evaluation (dystrophin staining). Molecular analyses involved flow cytometry, ELISA, transmission electron microscopy, PI staining, and IP/MS to delineate Nestin-regulated ferroptosis pathways in skeletal muscle atrophy.

RESULTS

Ferroptosis was significantly activated in both atrophy models, with a 2.5-fold increase in lipid peroxidation (p < 0.01), a 2-fold accumulation of Fe2+ (p < 0.01) and a 50% reduction in Nestin expression (p < 0.001). Nestin KO mice exhibited exacerbated muscle atrophy, showing a 40% decrease in muscle weight (p < 0.01) and a 30% reduction in muscle strength (p < 0.05) compared to WT mice. Nestin overexpression mitigated Dex-induced ferroptosis, reducing lipid peroxidation by 40%, decreasing Fe2+ accumulation by 50% (p < 0.01), and improving muscle function by 30% (p < 0.05). Mechanistically, Nestin interacted with MAP 1LC3B (LC3B) to catalyse LC3B polyubiquitination at lysine-51, reducing LC3B availability for autophagy and inhibiting autophagy flux by 60% (p < 0.01), leading to a 50% reduction in ferroptosis (p < 0.001).

CONCLUSIONS

Our study identifies Nestin as a critical regulator of ferroptosis-autophagy crosstalk in skeletal muscle atrophy. Targeting Nestin-LC3B ubiquitination may offer novel therapeutic strategies for preventing muscle wasting in diseases such as cachexia and sarcopenia.

Warm-ischemia and cold storage induced modulation of ferroptosis observed in human hearts donated after circulatory death and brain death

We investigated ferroptosis, a type of programmed cell death mechanism, in human hearts donated after brain death (DBD) and those donated after circulatory death (DCD), focusing on warm ischemia time (WIT) and cold storage. A total of 24 hearts were procured, with six from the DBD group and 18 from the DCD group. The DCD group was divided into three subgroups, each containing six hearts, based on different WITs of 20, 40, and 60 min. All procured hearts were placed in cold storage for up to 6 h. Left ventricular biopsies were performed at 0, 2, 4, and 6 h. We measured ferroptosis regulators [glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long chain family member 4 (ACSL4), and transferrin receptor], iron content (Fe2+ and Fe3+), and lipid peroxidation (malondialdehyde, MDA) in the cardiac tissue. Modulation of ferroptosis was observed in both DBD and DCD hearts. Warm ischemia injury increased myocardial vulnerability to ferroptotic cell death. For DBD hearts, up to 6 h of cold storage increases cardiac levels of MDA, iron content, and ACSL4, thereby increasing vulnerability to ferroptotic cell death. In contrast, for DCD hearts with a WIT of 40 min or more, warm ischemia injury was identified as the primary factor contributing to increased myocardial susceptibility to ferroptotic cell death. Ferroptosis may serve as a promising target to optimize cold preservation for DBD hearts. For DCD hearts, strategies to inhibit ferroptosis should focus on the early warm ischemia phase to assess donor heart quality and suitability for transplantation.NEW & NOTEWORTHY The first human heart research explored the effects of ischemia on the myocardial ferroptotic cell death mechanism. Prolonged cold storage increases the susceptibility of DBD hearts to ferroptotic cell death. In contrast, warm ischemic injury appears to be the main factor leading to the vulnerability of DCD heart ferroptosis. Targeting ferroptosis could be beneficial in optimizing cold preservation for DBD hearts. However, for DCD hearts, interventions should focus on the early phase of warm ischemia.

Mechanistic study of METTL3 inducing ferroptosis to promote cervical cancer progression through mediating m6A modification of COTE-1

Cervical Cancer (CC) is one of the leading causes of tumor-related deaths among women worldwide, and the mechanisms underlying the anti-ferroptosis of CC cells are still unclear. Methyltransferase like 3 (METTL3) is widely expressed various types of tissues and plays a crucial role in tumorigenesis in part by mediating cell death. However, its regulatory function in CC progression and especially the underlying mechanisms have not been fully elucidated. This study aims to explore the role of METTL3 in the ferroptosis of CC cells. Mechanistically, by MeRIP-seq, we identified COTE-1 as a target of METTL3 mediated m6A modification, and revealed that METTL3-mediated COTE-1 expression was dependent on the m6A reader-dependent manner. Functionally, in vitro and in vivo experiments that METTL3 promotes proliferation and metastasis of CC cells by regulating COTE-1 expression. In addition, the study verified the effect of the METTL3/COTE-1 axis on autophagy-dependent ferroptosis. In summary, METTL3 influences CC progression by mediating COTE-1 to influence autophagy-dependent ferroptosis, representing a potential therapeutic approach for treating CC.

The role of ACSL4 in stroke: mechanisms and potential therapeutic target

Stroke, as a neurological disorder with a poor overall prognosis, has long plagued the patients. Current stroke therapy lacks effective treatments. Ferroptosis has emerged as a prominent subject of discourse across various maladies in recent years. As an emerging therapeutic target, notwithstanding its initial identification in tumor cells associated with brain diseases, it has lately been recognized as a pivotal factor in the pathological progression of stroke. Acyl-CoA synthetase long-chain family member 4 (ACSL4) is a potential target and biomarker of catalytic unsaturated fatty acids mediating ferroptosis in stroke. Specifically, the upregulation of ACSL4 leads to heightened accumulation of lipid peroxidation products and reactive oxygen species (ROS), thereby exacerbating the progression of ferroptosis in neuronal cells. ACSL4 is present in various tissues and involved in multiple pathways of ferroptosis. At present, the pharmacological mechanisms of targeting ACSL4 to inhibit ferroptosis have been found in many drugs, but the molecular mechanisms of targeting ACSL4 are still in the exploratory stage. This paper introduces the physiopathological mechanism of ACSL4 and the current status of the research involved in ferroptosis crosstalk and epigenetics, and summarizes the application status of ACSL4 in modern pharmacology research, and discusses the potential application value of ACSL4 in the field of stroke.

WGCNA and ferroptosis genes in OSCC: unraveling prognostic biomarkers and therapeutic targets

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the predominant type of oral cancer, with over 370,000 new cases and approximately 170,000 deaths annually worldwide. Despite therapeutic advancements, OSCC mortality rates have been increasing, underscoring the need for improved prognostic models and therapeutic targets.

METHODS

We integrated transcriptomic and clinical survival data from the TCGA-OSCC dataset to identify ferroptosis-related prognostic genes. Using weighted gene co-expression network analysis (WGCNA), we selected genes associated with OSCC prognosis and applied Lasso regression analysis to pinpoint key genes. A prognostic model was constructed and validated through survival analysis and receiver operating characteristic (ROC) curve analysis.

RESULTS

WGCNA identified modules significantly correlated with ferroptosis, yielding 321 genes associated with OSCC prognosis. Univariate Cox analysis identified 13 genes affecting OSCC prognosis. Lasso regression and multivariate Cox regression narrowed down the gene set to a final set of 7 genes, which were used to construct the risk model. The model stratified patients into high- and low-risk groups with significant survival differences (P < 0.001). The model's predictive accuracy was validated, with AUC values ranging from 0.565 to 0.733 for 1-, 3-, and 5-year survival predictions. Immune-related analysis revealed that low-risk patients exhibited higher immune cell infiltration and were more likely to benefit from immunotherapy.

CONCLUSION

Our study presents a novel prognostic model for OSCC patients based on ferroptosis-related genes, which not only predicts survival but also identifies potential therapeutic targets. The model's predictive accuracy and clinical relevance were validated, offering a new strategy for OSCC treatment.

ESR1-dependent suppression of LCN2 transcription reverses autophagy-linked ferroptosis and enhances sorafenib sensitivity in hepatocellular carcinoma

Sorafenib resistance is a significant hurdle in the treatment landscape of hepatocellular carcinoma (HCC). Lipocalin 2 (LCN2), a secretory glycoprotein that transports lipophilic molecules across cell membranes, is thought to affect the s therapeutic efficacy of sorafenib. Despite its importance, the detailed regulatory pathways involving LCN2 are still being deciphered. We probed the correlation between LCN2 expression and sorafenib resistance in HCC cells. Through the modulation of LCN2 levels, we investigated its role in cell proliferation, apoptosis, and its regulatory effects on autophagy-driven ferroptosis. With the aid of hTFtarget and JASPAR databases, ESR1 was pinpointed as a transcriptional inhibitor of LCN2. The impact of the ESR1-LCN2 axis on sorafenib resistance in HCC was then examined in vitro and validated in a xenograft tumor mouse model. In HCC cells, elevated LCN2 levels were found to be associated with resistance to sorafenib. Depletion of LCN2 resulted in attenuated HCC cell growth and elevated rates of apoptosis and ferroptosis. Overexpression of LCN2 had the opposite effect, promoting cell proliferation and suppressing cell death pathways, a response that could be overridden by autophagy agonists. ESR1 suppressed LCN2 transcription, which in turn activated autophagy-mediated ferroptosis, mitigating sorafenib tolerance in HCC and enhancing the therapeutic index. ESR1 targets LCN2 transcription to initiate autophagy-driven ferroptosis, thereby reducing sorafenib resistance in HCC cells.

Research progress of ferroptosis pathway and its related molecular ubiquitination modification in liver cancer

As a new type of programmed cell death, ferroptosis is characterized by iron metabolism disorder and reactive oxygen species (ROS) accumulation, and is involved in regulating the occurrence and development of cancer cells. Especially in the field of liver cancer treatment, ferroptosis shows great potential because it can induce tumor cell death. Ubiquitination is a process of protein post-translational modification, which can affect the stability of proteins and regulate the progress of ferroptosis. This article reviews the research progress of ubiquitination modification of molecules related to ferroptosis pathway in the regulation of liver cancer, providing a new strategy for the treatment of liver cancer.

Nrf2 ameliorates defective autophagic processes and thereby inhibits ferroptosis in acute pancreatitis by suppressing Beclin1-Slc7a11 complex formation

Ferroptosis is a mode of programmed cell death that plays an important role in an increasing number of diseases. Recently, ferroptosis was found to be involved in the pathology of acute pancreatitis (AP). We determined that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a pivotal role in the ferroptosis process in AP. By inhibiting Nrf2 expression, the death of acinar cells in AP can be increased. Therefore, to help treat AP to a certain extent, we analyzed the effects of astaxanthin and found that it can activate Nrf2 and reduce the pathological process of AP. The activation of Nrf2 improves defective autophagy in AP and inhibits ferroptosis in acinar cells. Specifically, Nrf2 can promote the expression of Gpx4 and ferritin, and can inhibit the formation of Beclin-Slc7a11 complex by improving autophagy, thereby increasing the membrane expression of Slc7a11. Slc7a11/Gpx4 is an important anti-ferroptosis pathway; Slc7a11 can promote the synthesis of glutathione, while Gpx4 can utilize glutathione to exert antioxidative effects. Thus, we demonstrated that Nrf2 activation not only ameliorated defective autophagy at the time of AP but also promoted membrane expression of Slc7a11 to inhibit ferroptosis in acinar cells, thereby alleviating AP.

Glutathione-scavenging natural-derived ferroptotic nano-amplifiers strengthen tumor therapy through aggravating iron overload and lipid peroxidation

Nanomedicine-driven ferroptosis has emerged as a promising tumor treatment strategy through delivering exogenous iron and aggravating the lethal accumulation of lipid peroxides (LPO). However, the compensatory mechanisms of ferroptosis defense systems in cancer cells compromise the therapeutic efficacy and lead to potential side effects. Herein, a highly effective ferroptotic nano-amplifier is designed to synergistically promote ferroptosis via increasing intracellular labile iron, exacerbating lipid peroxidation and overcoming the defense system. Briefly, a natural-derived amphiphilic polymer composing of chondroitin sulfate (CS), arachidonic acid (AA) and a redox-sensitive linker, cystamine (CYS) is constructed to self-assemble as a GSH-responsive nanodrug delivery system for loading bioactive ingredient Polyphyllin I (PPI) and ferric ion (Fe3+). This nanodrug (CSAA/Fe@PPI) can scavenge the aberrant intracellular GSH via CYS linker, accompanied with the degradation of CSAA/Fe@PPI and the release of PPI, AA and Fe3+. On one hand, the intracellular labile iron level is significantly elevated due to the exogenous delivery of Fe3+ and PPI-induced ferritinophagy. On the other hand, ROS burst and the supplement of AA initiate and propagate the lipid peroxidation chain reaction. Meanwhile, the depletion of intracellular GSH suppresses the GPX4 activity, further strengthening the lethal accumulation of LPO. Consequently, the ferroptotic antitumor efficacy is remarkably improved by systemically aggravating iron overload and lipid peroxidation. Therefore, our study presents an effective strategy to improve ferroptosis-based anti-cancer treatment through multiple intervention routes.

Autophagy induced by mechanical stress sensitizes cells to ferroptosis by NCOA4-FTH1 axis

Ferroptosis is an iron-dependent regulated form of cell death implicated in various diseases, including cancers, with its progression influenced by iron-dependent peroxidation of phospholipids and dysregulation of the redox system. Whereas the extracellular matrix of tumors provides mechanical cues influencing tumor initiation and progression, its impact on ferroptosis and its mechanisms remains largely unexplored. In this study, we reveal that heightened mechanical tension sensitizes cells to ferroptosis, whereas decreased mechanics confers resistance. Mechanistically, reduced mechanical tension reduces intracellular free iron levels by enhancing FTH1 protein expression. Additionally, low mechanics significantly diminishes NCOA4, pivotal in mediating FTH1 phase separation-induced ferritinophagy. Targeting NCOA4 effectively rescues ferroptosis susceptibility under low mechanical tension through modulation of FTH1 phase separation-driven autophagy. In conclusion, our findings demonstrate that mechanics regulates iron metabolism via NCOA4-FTH1 phase separation-mediated autophagy, thereby influencing ferroptosis sensitivity and offering promising therapeutic avenues for future exploration.Abbreviations: ACO1: aconitase 1; ATG5: autophagy related 5; DMSO: dimethyl sulfoxide; EGFP: enhanced green fluorescent protein; FACS: fluorescence-activated cell sorting; FER-1: ferrostatin-1; FTH1: ferritin heavy chain 1; FTL: ferritin light chain; GPX4: glutathione peroxidase 4; IR: ionizing radiation; IREB2: iron responsive element binding protein 2; NCOA4: nuclear receptor coactivator 4; NFE2L2: NFE2 like bZIP transcription factor 2; NOPP: norepinephrine; PBS: phosphate-buffered saline; PI: propidium iodide; RSL3: (1S,3 R)-RSL3; TCGA: The Cancer Genome Atlas; WWTR1: WW domain containing transcription regulator 1; YAP1: Yes1 associated transcriptional regulator.

Disorders of Iron Metabolism: A "Sharp Edge" of Deoxynivalenol-Induced Hepatotoxicity

BACKGROUND/OBJECTIVES

Deoxynivalenol (DON), known as vomitoxin, is one of the most common mycotoxins produced by Fusarium graminearum, with high detection rates in feed worldwide. Ferroptosis is a novel mode of cell death characterized by lipid peroxidation and the accumulation of reactive oxygen species. Although it has been demonstrated that DON can induce ferroptosis in the liver, the specific mechanisms and pathways are still unknown. The aim of this experiment was to investigate that DON can induce iron metabolism disorders in the livers of mice, thereby triggering ferroptosis and causing toxic damage to the liver.

METHODS

Male C57 mice were treated with DON at a 5 mg/kg BW concentration as an in vivo model. After sampling, organ coefficient monitoring, liver function test, histopathological analysis, liver Fe2+ content test, and oxidative stress-related indexes were performed. The mRNA and protein expression of Nrf2 and its downstream genes were also detected using a series of methods including quantitative real-time PCR, immunofluorescence double-labeling, and Western blotting analysis.

RESULTS

DON can cause damage to the liver of a mouse. Specifically, we found that mouse livers in the DON group exhibited pathological damage in cell necrosis, inflammatory infiltration, cytoplasmic vacuolization, elevated relative liver weight, and significant changes in liver function indexes. Meanwhile, the substantial reduction in the levels of glutathione (GSH), catalase (CAT), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC) in the DON group indicated that DON also caused oxidative stress in the liver. Notably, DON exposure increased the levels of Fe2+ and Malondialdehyde (MDA) in the liver, which provides strong evidence for the occurrence of iron metabolism and ferroptosis disorders. Most importantly, mRNA and protein expression of Nrf2, an important pathway for iron metabolism and ferroptosis, along with its downstream genes, heme oxygenase (HO-1), quinone oxidoreductase (NQO1), glutathione peroxidase (GPX4), and solute carrier gene (SLC7a11), were significantly inhibited in the DON group.

CONCLUSIONS

Based on our results, the Nrf2 pathway is closely associated with DON-induced iron metabolism disorders and ferroptosis in mouse livers, suggesting that maintaining hepatic iron homeostasis and activating the Nrf2 pathway may be a potential target for mitigating DON hepatotoxicity in the future.

NGR-Modified CAF-Derived exos Targeting Tumor Vasculature to Induce Ferroptosis and Overcome Chemoresistance in Osteosarcoma

Osteosarcoma (OS) chemoresistance presents a significant clinical challenge. This study aims to investigate the potential of using tumor vascular-targeting peptide NGR-modified cancer-associated fibroblasts (CAFs)-derived exosomes (exos) to deliver circ_0004872-encoded small peptides promoting autophagy-dependent ferroptosis to reverse chemoresistance in OS. Through combined single-cell transcriptome analysis and high-throughput sequencing, it identified circ_0004872 associated with chemoresistance. Subsequent experiments demonstrated that the small peptide encoded by this Circular RNA (circRNA) can effectively reverse chemoresistance by enhancing OS cell sensitivity to chemotherapy via the mechanism of promoting autophagy-dependent ferroptosis. Moreover, in vitro and in vivo results confirmed the efficient delivery of NGR-modified CAFs-derived exo-packaged circ_0004872-109aa to tumor cells, thereby improving targeted therapy efficacy. This study not only offers a novel strategy to overcome chemoresistance in OS but also highlights the potential application value of utilizing exos for drug delivery.

Histone lysine crotonylation accelerates ACSL4-mediated ferroptosis of keratinocytes via modulating autophagy in diabetic wound healing

Dysfunction of keratinocytes affects diabetic wound healing, but underlying mechanisms have not been understood. This study examines crotonylation's role in ferroptosis and autophagy in keratinocytes, particularly regarding ACSL4, using STZ-induced diabetic rats and high glucose-exposed keratinocytes to assess these processes. The ACSL4 knockdown was achieved using adenovirus in wounds to examine the impact of ferroptosis modulation on healing diabetic wounds. MB-3 was utilized to block the H3K27 crotonylation (H3K27cr) in order to clarify the regulatory function of crotonylation in both autophagy and ferroptosis. In STZ-induced diabetic skin and high glucose-exposed keratinocytes, ferroptosis mediated by ACSL4 and suppression of autophagic flux were demonstrated. Moreover, the downregulation of ACSL4 triggered ferroptosis in adjacent wounds of diabetic rats and improved wound healing. The degradation of ACSL4 may be observed via the autophagy-lysosome pathway in keratinocytes. Downregulation of SQSTM1 in diabetic keratinocytes leads to autophagy inhibition and modulates the protein level of ACSL4. Mechanistically, total crotonylation levels and H3K27cr were remarkably elevated in the skin and keratinocytes of diabetic rats; blocking high glucose-induced H3K27cr with MB-3 can enhance SQSTM1 transcription and expression while promoting autophagy and reducing ACSL4-induced ferroptosis in keratinocytes. Therefore, H3K27cr influences autophagy by adjusting SQSTM1 to facilitate ACSL4-triggered ferroptosis in diabetic keratinocytes. This study clarifies the relationships between acylation modifications, autophagy, and ferroptosis, while also offering mechanistic insights and potential therapeutic targets for issues associated with diabetic wound healing.

Hydrogen Sulfide Inhibits Ferritinophagy-Mediated Ferroptosis in the Hippocampus of Rotenone-Exposed Rats

ABSTRACT

Our previous research has established that hydrogen sulfide (H 2 S) exerts an antagonistic effect against the hippocampal neurotoxicity induced by Rotenone (ROT). However, the underlying mechanisms are so far poorly understood. Substantial evidence corroborates the involvement of ferroptosis in ROT-induced neurotoxicity. To elucidate the protective mechanism of H 2 S against ROT-induced hippocampal neurotoxicity, this study explores its regulatory role in ferroptosis and its underlying mechanisms. We used Fluoro-Jade B staining to detect dead neurons. The levels of ferrous ions and glutathione (GSH) were measured by a kit. The ferroptosis-related proteins, including light-chain subunit (xCT), GSH peroxidase 4(GPX4), ferroptosis marker acyl-CoA synthetase long-chain family member 4(ACSL4), and ferritinophagy-related protein, including ferritin heavy chain 1 (FTH1), sequestosome 1 (p62), ferritinophagy markers autophagosome marker light-chain I/II (LC3I/II), and nuclear receptor coactivator 4 (NCOA4), were measured by Western blot. Our findings indicate that H 2 S reduces hippocampal neuron deaths in ROT-exposed rats. Meanwhile, H 2 S reverses the downregulations of xCT and GPX4, and the upregulations of ferrous ion and ACSL4 in the hippocampus induced by ROT. Furthermore, H 2 S reverses the upregulations of LC3I/II and NCOA4, and the downregulations of P62 and FTH1. Based on these findings, we concluded that the protective role of H 2 S against ROT-induced hippocampal neuronal death involves inhibiting ferroptosis triggered by ferritinophagy.

Inhibition of ferroptosis protects intrahepatic bile duct cells against ischemia-reperfusion and bile salt toxicity

Ischemia-reperfusion injury (IRI) and bile salt toxicity are significant contributors to post-transplant cholangiopathy. Ferroptosis appears to play a critical role in intrahepatic bile duct injury induced by ischemia-reperfusion (I/R) and bile salt toxicity. Our study aimed to elucidate the role of ferroptosis in bile duct injuries and its potential as a therapeutic target for liver diseases. Mouse models of liver ischemia-reperfusion (I/R) and α-naphthyl isocyanate (ANIT)-induced liver cholestasis were employed to investigate the role of ferroptosis in intrahepatic bile duct injury in vivo. Hypoxia-reoxygenation (H/R) and bile salt treatment models were utilized to simulate the post-transplant bile duct injury process in vitro. In mouse models of liver I/R and cholestasis, we observed a downregulation of glutathione peroxidase 4 (GPX4) and an upregulation of lipid peroxidation levels in bile duct cells. Furthermore, the ferroptosis inhibitor Liproxstatin-1 (Lip-1) significantly attenuated intrahepatic bile duct injuries. Ferroptosis inhibitors alleviated cell death and lipid peroxide accumulation in human intrahepatic biliary epithelial cells (HiBECs) subjected to H/R or glycochenodeoxycholate (GCDCA) treatment. GCDCA treatment led to ferroptosis in HiBECs along with ferritin degradation. Inhibition of autophagy alleviated GCDCA-induced bile duct cell death. Our study suggested that ferroptosis played an important role of in the intrahepatic bile duct injury during I/R or cholestasis.

Hydrogen Sulfide Sustained Release Donor Alleviates Spinal Cord Ischemia-Reperfusion-Induced Neuron Death by Inhibiting Ferritinophagy-Mediated Ferroptosis

AIMS

Spinal cord ischemia-reperfusion injury (SCIRI) is a disastrous complication that cannot be completely prevented in thoracoabdominal aneurysm surgery, leading to sensory and motor dysfunction and even paraparesis, causing tremendous socioeconomic burden. Ferritinophagy is a form of autophagic ferroptosis, which is a contributor to SCIRI. Hydrogen sulfide (H2S) has been reported to be neuroprotective in various diseases. However, it remains unclear whether H2S alleviates SCIRI-induced neural death via regulating ferritinophagy-mediated ferroptosis. The aim of this study was to explore their relationship and interaction in SCIRI.

RESULTS

The results demonstrate that Nissl bodies and motor function were obviously lost in SCIRI rats. Meanwhile, SCIRI led to a significant increase in DHE-positive neurons, TUNEL-positive neurons, LC3-positive neurons, and ferritin-positive neurons, downregulation of GPx4, Slc7a11, p62, and ferritin expression, and upregulation of LC3 II/I and NCOA4 expression. Additionally, there was upregulation of the level of MDA, GSH, and Fe2+. Finally, we found that H2S could significantly relieve neuronal death and loss of motor function in SCIRI rats by inhibiting ferritinophagy and ferroptosis.

CONCLUSION

Ferroptosis and ferritinophagy play a crucial role in the etiopathogenesis of SCIRI, and H2S exerts neuroprotection by inhibiting ferritinophagy-mediated ferroptosis.

Chondrocyte Ferritinophagy as a Molecular Mechanism of Arthritis-A Narrative Review

Osteoarthritis (OA) is a prevalent joint disease affecting orthopedic patients. Its incidence is steadily increasing, causing great economic hardship for individuals and society as a whole. OA is connected with risk factors such as genetics, obesity, and joint diseases; yet, its pathophysiology is still largely understood. At present, several cell death pathways govern the initiation and advancement of OA. It has been discovered that the onset and progression of OA are strongly associated with pyroptosis, senescence, apoptosis, ferroptosis, and autophagy. Ferroptosis and autophagy have not been well studied in OA, and elucidating their molecular mechanisms in chondrocytes is important for the diagnosis of OA. For this reason, we aim was reviewed recent national and international developments and provided an initial understanding of the molecular pathways underlying autophagy and ferroptosis in OA. We determined the reference period to be the last five years by searching for the keywords "osteoarthritis, mechanical stress, Pizeo1, ferroptosis, autophagy, ferritin autophagy" in the three databases of PUBMED, Web of Science, Google Scholar. We then screened irrelevant literature by reading the abstracts. Ferroptosis is a type of programmed cell death that is dependent on reactive oxygen species and Fe2+. It is primarily caused by processes linked to amino acid metabolism, lipid peroxidation, and iron metabolism. Furthermore, Piezoelectric mechanically sensitive ion channel assembly 1 (PIEZO1), which is triggered by mechanical stress, has been revealed to be intimately associated with ferroptosis events. It was found that mechanical injury triggers changes in the intracellular environment of articular chondrocytes (e.g., elevated levels of oxidative stress and increased inflammation) through PIEZO1, ultimately leading to iron death in chondrocytes. Therefore, we believe that PIEZO1 is a key initiator protein of iron death in chondrocytes. Widely present in eukaryotic cells, autophagy is a lysosome-dependent, evolutionarily conserved catabolic process that carries misfolded proteins, damaged organelles, and other macromolecules to lysosomes for breakdown and recycling. Throughout OA, autophagy is activated to differing degrees, indicating that autophagy may play a role in the development of OA. According to recent research, autophagy is a major factor in the process that leads cells to ferroptosis. Despite the notion of ferritinophagy being put forth, not much research has been done to clarify the connection between ferroptosis and autophagy in OA.

Iron metabolism and the tumor microenvironment: A new perspective on cancer intervention and therapy (Review)

Iron metabolism plays a crucial role in the tumor microenvironment, influencing various aspects of cancer cell biology and tumor progression. This review discusses the regulatory mechanisms of iron metabolism within the tumor microenvironment and highlights how tumor cells and associated stromal cells manage iron uptake, accumulation and regulation. The sources of iron within tumors and the biological importance of ferroptosis in cancer were explored, focusing on its mechanisms, biological effects and, in particular, its tumor‑suppressive properties. Furthermore, the protective strategies employed by cancer cells to evade ferroptosis were examined. This review also delves into the intricate relationship between iron metabolism and immune modulation within the tumor microenvironment, detailing the impact on tumor‑associated immune cells and immune evasion. The interplay between ferroptosis and immunotherapy is discussed and potential strategies to enhance cancer immunotherapy by modulating iron metabolism are presented. Finally, the current ferroptosis‑based cancer therapeutic approaches were summarized and future directions for therapies that target iron metabolism were proposed.

Novel Cell Models to Study Myelin and Microglia Interactions

Multiple sclerosis (MS) is characterized by demyelination and neuroinflammation, with oxidative stress playing a pivotal role in lesion pathology. This study aimed to investigate the differential cellular responses to myelin debris under varying oxidative states. Myelin oxidation was induced using a Cu-peroxide system, confirmed by elevated TBARS levels and autofluorescence. BV-2 microglia viability remained unaffected by myelin exposure. However, oxidized myelin significantly altered oxidative stress markers, autophagy, and iron metabolism, as evidenced by changes in Sod2, Tfr1, p62, and P-Erk/Erk ratios. Morphological analyses revealed time- and dose-dependent differences in myelin processing, with oxidized myelin leading to distinct phagosome dynamics. Complementary studies using induced microglia-like cells (iMG)-a primary cell culture-confirmed the feasibility of employing oxidized microglia to study microglia activity. The use of iMGs provides a model closer to patient physiology, offering the potential to evaluate individual cellular responses to oxidative damage. This approach could be instrumental in identifying personalized therapeutic strategies by assessing patient-specific microglial behavior in response to myelin debris. These findings highlight the impact of myelin oxidative status on microglial function, advancing the understanding of oxidative stress in MS and paving the way for personalized medicine applications in neuroinflammation.

Attenuated growth factor signaling during cell death initiation sensitizes membranes towards peroxidation

Cell death programs such as apoptosis and ferroptosis are associated with aberrant redox homeostasis linked to lipid metabolism and membrane function. Evidence for cross-talk between these programs is emerging. Here, we show that cytotoxic stress channels polyunsaturated fatty acids via lysophospholipid acyltransferase 12 into phospholipids that become susceptible to peroxidation under additional redox stress. This reprogramming is associated with altered acyl-CoA synthetase isoenzyme expression and caused by a decrease in growth factor receptor tyrosine kinase (RTK)-phosphatidylinositol-3-kinase signaling, resulting in suppressed fatty acid biosynthesis, for specific stressors via impaired Akt-SREBP1 activation. The reduced availability of de novo synthesized fatty acids favors the channeling of polyunsaturated fatty acids into phospholipids. Growth factor withdrawal by serum starvation mimics this phenotype, whereas RTK ligands counteract it. We conclude that attenuated RTK signaling during cell death initiation increases cells' susceptibility to oxidative membrane damage at the interface of apoptosis and alternative cell death programs.

RORA Regulates Autophagy in Hair Follicle Stem Cells by Upregulating the Expression Level of the Sqstm1 Gene

The hair coat is an adaptive evolutionary trait unique to mammals, aiding them in adapting to complex environmental challenges. Although some of the factors involved in regulating hair follicle development have been characterized, further in-depth research is still needed. Retinoic acid receptor-related orphan receptor alpha (RORA), as a member of the nuclear receptor family, is highly involved in the regulation of cellular states. Previous studies have shown that autophagy plays a significant role in hair follicle development. This study uses rat hair follicle stem cells (HFSCs) as a model to analyze the impact of RORA on the autophagy levels of HFSCs. Upon activation of RORA, autophagy indicators such as the LC3-II/LC3-I ratio and MDC staining significantly increased, suggesting an elevated level of autophagy in HFSCs. Following treatment with chloroquine, the LC3-II/LC3-I ratio, as well as the expression levels of BECN1 protein and SQSTM1 protein, were markedly elevated in the cells, indicating that the autophagic flux was unobstructed and ruling out the possibility that RORA activation impeded autophagy. Additionally, the level of the Sqstm1 gene increased markedly after RORA activation promoted autophagy in the cells. We found that RORA regulates the transcription level of Sqstm1 by binding to its promoter region. We believe that RORA activation significantly promotes the level of autophagy, particularly selective autophagy, in HFSCs, suggesting that RORA has the potential to become a new target for research on hair follicle development. This research provides a theoretical foundation for studies on hair follicle development and also offers new insights for the treatment of diseases such as alopecia.

The Role of Ferroptosis and Cuproptosis in Tuberculosis Pathogenesis: Implications for Therapeutic Strategies

Tuberculosis (TB) caused by Mycobacterium tuberculosis (M.tb) remains a global health crisis, with over 10 million people affected annually. Despite advancements in treatment, M.tb has developed mechanisms to evade host immune responses, complicating efforts to eradicate the disease. Two emerging cell death pathways, ferroptosis and cuproptosis, have been linked to TB pathogenesis. Ferroptosis, an iron-dependent form of cell death, is driven by lipid peroxidation and reactive oxygen species (ROS) accumulation. This process can limit M.tb replication by depleting intracellular iron and inducing macrophage necrosis. However, excessive ferroptosis may lead to tissue damage and aid bacterial dissemination. Cuproptosis, triggered by copper accumulation, disrupts mitochondrial metabolism, leading to protein aggregation and cell death. M.tb exploits both iron and copper metabolism to survive within macrophages, manipulating these processes to resist oxidative stress and immune responses. This review examines the roles of ferroptosis and cuproptosis in TB, discussing how M.tb manipulates these pathways for survival. While therapeutic strategies targeting these processes, such as ferroptosis inducers (Erastin, RSL3) and inhibitors (Ferrostatin-1) and copper ionophores (Disulfiram, Elesclomol) and chelators, show promise, the limited understanding of these pathways and potential off-target effects remains a significant challenge. Further exploration of these pathways may provide insights into the development of targeted therapies aimed at controlling M.tb infection while minimizing host tissue damage. By elucidating the complex interactions between ferroptosis, cuproptosis, and TB, future therapies could better address bacterial resistance and improve clinical outcomes.

Intricating connections: the role of ferroptosis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease with multiple tissue damage. However, the pathology remains elusive, and effective treatments are lacking. Multiple types of programmed cell death (PCD) implicated in SLE progression have recently been identified. Although ferroptosis, an iron-dependent form of cell death, has numerous pathophysiological features similar to those of SLE, such as intracellular iron accumulation, mitochondrial dysfunction, lipid metabolism disorders and concentration of damage associated-molecular patterns (DAMPs), only a few reports have demonstrated that ferroptosis is involved in SLE progression and that the role of ferroptosis in SLE pathogenesis continues to be neglected. Therefore, this review elucidates the potential intricate relationship between SLE and ferroptosis to provide a reliable theoretical basis for further research on ferroptosis in the pathogenesis of SLE.

Plasma-derived extracellular vesicles prime alveolar macrophages for autophagy and ferroptosis in sepsis-induced acute lung injury

Sepsis-induced acute respiratory distress syndrome (ARDS) is a severe complication of sepsis and the leading cause of mortality. Although the role of alveolar macrophages (AMs) in stabilizing pulmonary homeostasis is well established, the effects of circulating extracellular vesicles (EVs) on AMs remain largely unknown. In this study, an investigation was conducted to map the miRNA and protein expression profiles of EVs derived from septic plasma. Notably, EV-based panels (miR-122-5p, miR-125b-5p, miR-223-3p, OLFM4, and LCN2) have been found to be associated with the severity or prognosis of sepsis, with promising AUC values. Moreover, the levels of LCN2, miR-122-5p, and miR-223-3p were identified as independent predictors of septic ARDS. The in vitro coculture results revealed that the effects of LPS-EVs from the plasma of sepsis-induced acute lung injury (ALI), which carry pro-inflammatory EVs, were partly mediated by miR-223-3p, as evidenced by the promotion of inflammation, autophagy and ferroptosis in AMs. Mechanistically, the upregulation of miR-223-3p in LPS-EVs triggers autophagy and ferroptosis in AMs by activating Hippo signaling via the targeting of MEF2C. In vivo, the inhibition of miR-223-3p effectively mitigated LPS-EV-induced inflammation and AM death in the lungs, as well as histological lesions. Overall, miR-223-3p in LPS-EVs contributes to sepsis-induced ALI by priming AMs for autophagy and ferroptosis through the MEF2C/Hippo signaling pathway. These findings suggest a novel mechanism of plasma-AM interaction in sepsis-induced ALI, offering a plausible strategy for assessing septic progression and treating lung injury.

The role of ferroptosis in acute kidney injury: mechanisms and potential therapeutic targets

Acute kidney injury (AKI) is one of the most common and severe clinical renal syndromes with high morbidity and mortality. Ferroptosis is a form of programmed cell death (PCD), is characterized by iron overload, reactive oxygen species accumulation, and lipid peroxidation. As ferroptosis has been increasingly studied in recent years, it is closely associated with the pathophysiological process of AKI and provides a target for the treatment of AKI. This review offers a comprehensive overview of the regulatory mechanisms of ferroptosis, summarizes its role in various AKI models, and explores its interaction with other forms of cell death, it also presents research on ferroptosis in AKI progression to other diseases. Additionally, the review highlights methods for detecting and assessing AKI through the lens of ferroptosis and describes potential inhibitors of ferroptosis for AKI treatment. Finally, the review presents a perspective on the future of clinical AKI treatment, aiming to stimulate further research on ferroptosis in AKI.

Programmed cell death in nasopharyngeal carcinoma: Mechanisms and therapeutic targets

Programmed cell death is a type of autonomic and orderly cell death mode controlled by genes that maintain homeostasis and growth. Tumor is a typical manifestation of an imbalance in environmental homeostasis in the human body. Currently, several tumor treatments are designed to trigger the death of tumor cells. Nasopharyngeal carcinoma is one of the most common malignant tumors in China. It displays obvious regional and ethnic differences in its incidence, being typically high in the south and low in the north of China. Nasopharyngeal carcinoma is currently considered to be a polygenic inherited disease and is often mediated by the interaction between multiple genes or between genes and the environment. Apoptosis has long been considered the key to tumor treatment, while other cell death pathways have often been overlooked. The current study provides an overview of the relationship among apoptosis, autophagy, pyroptosis, necroptosis, ferroptosis, and nasopharyngeal carcinoma, and the regulatory pathways of nasopharyngeal carcinoma based on five cell death modes were synthesized from the view of molecule. We hope this review will help explore additional, novel programmed cell death targets for the treatment of nasopharyngeal carcinoma and thus promote in-depth research.

Targeting ferroptosis in gastrointestinal tumors: Interplay of iron-dependent cell death and autophagy

Ferroptosis is a regulated cell death mechanism distinct from apoptosis, autophagy, and necroptosis, marked by iron accumulation and lipid peroxidation. Since its identification in 2012, it has developed into a potential therapeutic target, especially concerning GI disorders like PC, HCC, GC, and CRC. This interest arises from the distinctive role of ferroptosis in the progression of diseases, presenting a new avenue for treatment where existing therapies fall short. Recent studies emphasize the promise of focusing on ferroptosis to fight GI cancers, showcasing its unique pathophysiological mechanisms compared to other types of cell death. By comprehending how ferroptosis aids in the onset and advancement of GI diseases, scientists aim to discover novel drug targets and treatment approaches. Investigating ferroptosis in gastrointestinal disorders reveals exciting possibilities for novel therapies, potentially revolutionizing cancer treatment and providing renewed hope for individuals affected by these tumors.

The protective role of baicalin regulation of autophagy in cancers

Autophagy is a conservative process of self degradation, in which abnormal organelles, proteins and other macromolecules are encapsulated and transferred to lysosomes for subsequent degradation. It maintains the intracellular balance, and responds to cellular conditions such as hunger or stress. To date, there are mainly three types of autophagy: macroautophagy, microautophagy and chaperone-mediated autophagy. Autophagy plays a key role in regulating multiple physiological and pathological processes, such as cell metabolism, development, energy homeostasis, cell death and hunger adaptation, and so on. Increasing evidence indicates that autophagy dysfunction participates in many kinds of cancers, such as liver cancer, pancreatic cancer, prostate cancer, and so on. However, the relevant mechanisms are not yet fully understood. Baicalin is a natural flavonoid compound extracted from the traditional Chinese medicine Scutellaria baicalensis. The research has shown that after oral or intravenous administration of baicalin, it is delivered to various organs through the systemic circulation, with the highest volume in the kidneys and lungs. More and more evidence suggests that baicalin has antioxidant, anticancer, anti-inflammatory, anti-apoptotic, immunomodulatory and antiviral effects. Therefore, baicalin plays an important role in various diseases, such as cancers, lung diseases, liver diseases, cardiovascular diseases, ans so on. However, the relevant mechanisms have not yet been fully clear. Recently, increasing evidence indicates that baicalin participates in different cancer by regulating autophagy. Herein, we reviewed the current knowledge about the role and mechanism of baicalin regulation of autophagy in multiple types of cancers to lay the theoretical foundation for future related researches.

Caspase family in autoimmune diseases

Programmed cell death (PCD) plays a crucial role in maintaining tissue homeostasis, with its primary forms including apoptosis, pyroptosis, and necroptosis. The caspase family is central to these processes, and its complex functions across different cell death pathways and other non-cell death roles have been closely linked to the pathogenesis of autoimmune diseases. This article provides a comprehensive review of the role of the caspase family in autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), and multiple sclerosis (MS). It particularly emphasizes the intricate functions of caspases within various cell death pathways and their potential as therapeutic targets, thereby offering innovative insights and a thorough discussion in this field. In terms of therapy, strategies targeting caspases hold significant promise. We emphasize the importance of a holistic understanding of caspases in the overall concept of cell death, exploring their unique functions and interrelationships across multiple cell death pathways, including apoptosis, pyroptosis, necroptosis, and PANoptosis. This approach transcends the limitations of previous studies that focused on singular cell death pathways. Additionally, caspases play a key role in non-cell death functions, such as immune cell activation, cytokine processing, inflammation regulation, and tissue repair, thereby opening new avenues for the treatment of autoimmune diseases. Regulating caspase activity holds the potential to restore immune balance in autoimmune diseases. Potential therapeutic approaches include small molecule inhibitors (both reversible and irreversible), biological agents (such as monoclonal antibodies), and gene therapies. However, achieving specific modulation of caspases to avoid interference with normal physiological functions remains a major challenge. Future research must delve deeper into the regulatory mechanisms of caspases and their associated complexes linked to PANoptosis to facilitate precision medicine. In summary, this article offers a comprehensive and in-depth analysis, providing a novel perspective on the complex roles of caspases in autoimmune diseases, with the potential to catalyze breakthroughs in understanding disease mechanisms and developing therapeutic strategies.

XueBiJing injection improves the symptoms of sepsis-induced acute lung injury by mitigating oxidative stress and ferroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

XBJ injection is approved by the China Food and Drug Administration for the adjunctive treatment of sepsis, and it is derived from the traditional Chinese medicine (TCM) prescription XuefuZhuyu Decoction. It consists of five Chinese herbal extracts: Carthamus tinctorius, Paeonia lactiflora, Salvia miltiorrhiza, Conioselinum anthriscoides 'Chuanxiong' and Angelica sinensis.

AIM OF THE STUDY

The purpose of this study was to explore the relationship between ferroptosis and acute septic lung injury, and to evaluate the improvement effect of XBJ injection on acute lung injury in sepsis.

MATERIALS AND METHODS

Acute lung injury was induced in rats by cecum ligation and puncture, and these rats were treated with XBJ injection. Oxidative stress and inflammation levels were assessed in serum and lung tissue, and tissue samples were collected for histological and protein analyses. To illustrate the mechanism of the improvement effect of XBJ on acute lung injury in sepsis, serum lipidomics was carried out to investigate whether XBJ prevents oxidative stress-induced lipid metabolism disorders. Furthermore, protein expression of ferroptosis-related genes was also examined.

RESULTS

XBJ was shown to be effective in alleviating sepsis-induced ALI. XBJ also improves sepsis-induced acute lung injury by reducing lipid peroxidation and inflammation and modulating ferroptosis pathways. Specifically, compared with the sham group, XBJ downregulated the levels of Fe2+, MDA and GSSG, and reversed the decrease in the levels of GSH and GSH/GSSH in lung tissue. Metabolic pathways such as glycerophospholipid metabolism, phospholipid metabolism, and lipid metabolism associated with ferroptosis were obtained by lipidomic analysis of differential lipid metabolite enrichment, suggesting that ferroptosis occurs in septic rats, and that XBJ inhibits ferroptosis and thereby improves sepsis-induced ALI. Furthermore, XBJ optimises iron metabolism and lipid oxide metabolism by regulating the expression of a series of proteins that are closely related to ferroptosis, such as GPX4, ACSL4, x-CT, and FTH1.

CONCLUSIONS

Our findings, initially, indicated that XBJ ameliorates sepsis-induced ALI by reducing oxidative stress and ferroptosis, revealing a previously unrecognised mechanism by which XBJ ameliorates sepsis-induced ALI.

The link between ferroptosis and autophagy in myocardial ischemia/reperfusion injury: new directions for therapy

Myocardial ischemia/reperfusion (I/R)-induced cell death, such as autophagy and ferroptosis, is a major contributor to cardiac injury. Regulating cell death may be key to mitigating myocardial ischemia/reperfusion injury (MI/RI). Autophagy is a crucial physiological process involving cellular self-digestion and compensation, responsible for degrading excess or malfunctioning long-lived proteins and organelles. During MI/RI, autophagy plays both "survival" and "death" roles. A growing body of research indicates that ferroptosis is a type of autophagy-dependent cell death. This article provides a comprehensive review of the functions of autophagy and ferroptosis in MI/RI, as well as the molecules mediating their interaction. Understanding the link between autophagy and ferroptosis may offer new therapeutic directions for MI/RI, bearing significant clinical implications.

Canagliflozin ameliorates ferritinophagy in HFpEF rats

Background

Recent studies have shown that sodium-glucose cotransporters-2 (SGLT2) inhibitors significantly improve major adverse cardiovascular events in heart failure with preserved ejection fraction (HFpEF) patients, but the exact mechanism is unknown. Ferritinophagy is a special form of selective autophagy that participates in ferroptosis. In this study, we aimed to investigate whether ferritinophagy was activated during the occurrence of HFpEF, and whether canagliflozin (CANA) could inhibite ferritinophagy.

Methods

We reared Dahl salt-sensitive (DSS) rats on a high-salt diet to construct a hypertensive HFpEF model, and simultaneously administered CANA intervention. Then we detected indicators related to ferritinophagy.

Results

The expression of nuclear receptor coactivator 4 (NCOA4), as well as microtubule-associated proteins light chain 3 (LC3), Bcl-2 interacting protein 1 (Beclin-1) and p62, were upregulated in HFpEF rats, accompanied by the downregulation of ferritin heavy chain 1 (FTH1), upregulation of mitochondrial iron transporter sideroflexin1 (SFXN1) and increased reactive oxygen species (ROS) production. Above changes were diminished by CANA.

CONCLUSION

Ferritinophagy is activated in HFpEF rats and then inhibited by CANA, leading to HFpEF benefits. The inhibition of ferritinophagy could provide new prospective targets for the prevention and treatment of HFpEF, and provide new ideas for investigating the mechanism of cardiovascular benefit of SGLT2 inhibitors.

Nrf2 inhibition and NCOA4-mediated ferritinophagy activation synergistically exacerbated S-3'-hydroxy-7', 2', 4'-trimethoxyisoxane induced ferroptosis in lung cancer cells

S-3'-hydroxy-7', 2', 4'-trimethoxyisoxane (ShtIX) is a novel isoflavane compound that exhibits significant anticancer activity against a variety of cancer cells. Our previous studies have confirmed that ShtIX induced ferroptosis by inhibiting Nr2/HO-1 pathway in non-small cell lung cancer (NSCLC) cells, both in vitro and vivo. Recent research has increasingly recognized ferroptosis as an autophagy-dependent form of cell death. However, it has not been previously explored whether ShtIX can activate autophagy during ferroptosis and its relationship with ferroptosis. In the present study, we discovered that ShtIX was able to trigger autophagy, and the activation of autophagy is essential for ShtIX-induced ferroptosis. These findings demonstrated that ShtIX induced an autophagy-dependent form of ferroptosis in NSCLC cells. Intriguingly, the autophagy triggered by ShtIX is independent of ferroptosis. Furthermore, our results indicated that ShtIX degraded ferritin through autophagy and promoted NCOA4-mediated ferritinophagy, which contributed significantly to ShtIX-induced ferroptosis in NSCLC cells. Additionally, the knockdown Nrf2 reinforced ShtIX-induced NCOA4-mediated ferritinophagy, while the inhibition of autophagy attenuated the suppressive effect of ShtIX on Nrf2 and HO-1. Taken together, our work uncovers a new mechanism by which ShtIX induced ferroptosis through inhibition the Nrf2 pathway and activation of NCOA4-mediated ferritinophagy in NSCLC cells. Targeting ferritinophagy to regulate ferroptosis offers a novel therapeutic strategy for the treatment of lung cancer with ShtIX.

siRNA-mediated inhibition of hTERT enhances the effects of curcumin in promoting cell death in precursor-B acute lymphoblastic leukemia cells: an in silico and in vitro study

This study investigates the interrelationship between human telomerase reverse transcriptase (hTERT) and ferroptosis in precursor-B (pre-B) acute lymphoblastic leukemia (ALL), specifically examining how hTERT modulation affects ferroptotic cell death pathways. Given that hTERT overexpression characterizes various cancer phenotypes and elevated telomerase activity is observed in early-stage and relapsed ALL, we investigated the molecular mechanisms linking hTERT regulation and ferroptosis in leukemia cells. The experimental design employed Nalm-6 and REH cell lines under three distinct conditions: curcumin treatment, hTERT siRNA knockdown, and their combination. Cell viability and proliferation were assessed via MTT and BrdU assays at 24- and 48-hour intervals post-treatment. Ferroptotic and oxidative markers were quantified using commercial assays, while cell death parameters and gene expression were evaluated through flow cytometry and qRT-PCR analyses. Molecular docking studies were performed to evaluate protein-ligand interactions. Results demonstrated that combined curcumin treatment and hTERT knockdown significantly enhanced cytotoxicity in Nalm-6 cells compared to individual interventions. This was characterized by the upregulation of ferroptosis promoters (lipid-ROS, Fe²⁺, ACSL4) and suppression of inhibitors (GSH, GPx, SLC7A11, GPx4). The response showed cell-line specificity, with Nalm-6 cells exhibiting enhanced ferroptotic sensitivity while REH cells underwent apoptotic cell death. Molecular docking revealed strong curcumin-protein interactions (∆G = -34.24 kcal/mol for hTERT). This study establishes hTERT as a critical regulator of ferroptotic cell death in pre-B ALL, operating through redox homeostasis, iron metabolism, and lipid peroxidation pathways. The cell-type-specific responses suggest promising therapeutic strategies through combined hTERT suppression and ferroptosis induction.

Melanoma bone metastasis-induced osteocyte ferroptosis via the HIF1α-HMOX1 axis

Osteocytes are the main cells in mineralized bone tissue. Elevated osteocyte apoptosis has been observed in lytic bone lesions of patients with multiple myeloma. However, their precise contribution to bone metastasis remains unclear. Here, we investigated the pathogenic mechanisms driving melanoma-induced osteocyte death. Both in vivo models and in vitro assays were combined with untargeted RNA sequencing approaches to explore the pathways governing melanoma-induced osteocyte death. We could show that ferroptosis is the primary mechanism behind osteocyte death in the context of melanoma bone metastasis. HMOX1 was identified as a crucial regulatory factor in this process, directly involved in inducing ferroptosis and affecting osteocyte viability. We uncover a non-canonical pathway that involves excessive autophagy-mediated ferritin degradation, highlighting the complex relationship between autophagy and ferroptosis in melanoma-induced osteocyte death. In addition, HIF1α pathway was shown as an upstream regulator, providing a potential target for modulating HMOX1 expression and influencing autophagy-dependent ferroptosis. In conclusion, our study provides insight into the pathogenic mechanisms of osteocyte death induced by melanoma bone metastasis, with a specific focus on ferroptosis and its regulation. This would enhance our comprehension of melanoma-induced osteocyte death.

Mechanisms of regulated cell death during plant infection by the rice blast fungus Magnaporthe oryzae

Fungi are the most important group of plant pathogens, responsible for many of the world's most devastating crop diseases. One of the reasons they are such successful pathogens is because several fungi have evolved the capacity to breach the tough outer cuticle of plants using specialized infection structures called appressoria. This is exemplified by the filamentous ascomycete fungus Magnaporthe oryzae, causal agent of rice blast, one of the most serious diseases affecting rice cultivation globally. M. oryzae develops a pressurized dome-shaped appressorium that uses mechanical force to rupture the rice leaf cuticle. Appressoria form in response to the hydrophobic leaf surface, which requires the Pmk1 MAP kinase signalling pathway, coupled to a series of cell-cycle checkpoints that are necessary for regulated cell death of the fungal conidium and development of a functionally competent appressorium. Conidial cell death requires autophagy, which occurs within each cell of the spore, and is regulated by components of the cargo-independent autophagy pathway. This results in trafficking of the contents of all three cells to the incipient appressorium, which develops enormous turgor of up to 8.0 MPa, due to glycerol accumulation, and differentiates a thickened, melanin-lined cell wall. The appressorium then re-polarizes, re-orienting the actin and microtubule cytoskeleton to enable development of a penetration peg in a perpendicular orientation, that ruptures the leaf surface using mechanical force. Re-polarization requires septin GTPases which form a ring structure at the base of the appressorium, which delineates the point of plant infection, and acts as a scaffold for actin re-localization, enhances cortical rigidity, and forms a lateral diffusion barrier to focus polarity determinants that regulate penetration peg formation. Here we review the mechanism of regulated cell death in M. oryzae, which requires autophagy but may also involve ferroptosis. We critically evaluate the role of regulated cell death in appressorium morphogenesis and examine how it is initiated and regulated, both temporally and spatially, during plant infection. We then use this synopsis to present a testable model for control of regulated cell death during appressorium-dependent plant infection by the blast fungus.