Ferritinophagy is involved in the zinc oxide nanoparticles-induced ferroptosis of vascular endothelial cells

Linking homocysteine and ferroptosis in cardiovascular disease: insights and implications

Homocysteine (Hcy) is a metabolic intermediate product derived from methionine. Hyperhomocysteinemia is a condition associated with various diseases. Hcy is recognized as a risk factor for cardiovascular disease (CVD). Ferroptosis, a novel form of cell death, is primarily characterized by substantial iron accumulation and lipid peroxidation. Recent research indicates a close association between ferroptosis and the pathophysiological processes of tumors, neurological diseases, CVD, and other ailments. However, limited research has been conducted on the impact of Hcy on ferroptosis. Therefore, this paper aimed to investigate the potential roles and mechanisms of homocysteine and ferroptosis in the context of cardiovascular disease. By conducting comprehensive literature research and analysis, we aimed to summarize recent advancements in understanding the effects of homocysteine on ferroptosis in cardiovascular diseases. This research contributes to a profound understanding of this critical domain.

Mechanistic insights into zinc oxide nanoparticles induced embryotoxicity via H3K9me3 modulation

The widespread application of nanoparticles (NPs) in various fields has raised health concerns, especially in reproductive health. Our research has shown zinc oxide nanoparticles (ZnONPs) exhibit the most significant toxicity to pre-implantation embryos in mice compared to other common NPs. In patients undergoing assisted reproduction technology (ART), a significant negative correlation was observed between Zn concentration and clinical outcomes. Therefore, this study explores the impact of ZnONPs exposure on pre-implantation embryonic development and its underlying mechanisms. We revealed that both in vivo and in vitro exposure to ZnONPs impairs pre-implantation embryonic development. Moreover, ZnONPs were found to reduce the pluripotency of mouse embryonic stem cells (mESCs), as evidenced by teratoma and diploid chimera assays. Employing multi-omics approaches, including RNA-Seq, CUT&Tag, and ATAC-seq, the embryotoxicity mechanisms of ZnONPs were elucidated. The findings indicate that ZnONPs elevate H3K9me3 levels, leading to increased heterochromatin and consequent inhibition of gene expression related to development and pluripotency. Notably, Chaetocin, a H3K9me3 inhibitor, sucessfully reversed the embryotoxicity effects induced by ZnONPs. Additionally, the direct interaction between ZnONPs and H3K9me3 was verified through pull-down and immunoprecipitation assays. Collectively, these findings offer new insights into the epigenetic mechanisms of ZnONPs toxicity, enhancing our understanding of their impact on human reproductive health.

Synthesis and biological evaluation of ferrostatin-based diamide derivatives as new ferroptosis inhibitors

Ferroptosis, a distinct type of cell death caused by iron and lipid peroxidation, has been associated with several diseases, including cardiovascular disorders. Ferrostatin-1 (Fer-1) is a known ferroptosis inhibitor, but its clinical application is limited by low efficacy and stability. In the present study, a series of Fer-1-based diamide derivatives was synthesized and evaluated to enhance ferroptosis inhibition and in vitro metabolic stability. The synthesized compounds were tested for their protective effects against Erastin-induced injury in human vascular endothelial cells (HUVECs). Among the derivatives, compound 36 exhibited the most potent anti-ferroptosis activity with an EC50 value of 0.58 ± 0.02 µM. Remarkably, compound 36 also demonstrated superior stability in both microsomal (human and mouse) and mouse plasma assays. These findings indicated ferroptosis inhibitor 36 as a promising hit for further developing potential therapeutic drug candidates in cardiovascular diseases.

Molecular mechanisms of zinc oxide nanoparticles neurotoxicity

Zinc oxide nanoparticles (ZnONPs) are widely used in industry and biomedicine. A growing body of evidence demonstrates that ZnONPs exposure may possess toxic effects to a variety of tissues, including brain. Therefore, the objective of the present review was to summarize existing evidence on neurotoxic effects of ZnONPs and discuss the underlying molecular mechanisms. The existing laboratory data demonstrate that both in laboratory rodents and other animals ZnONPs exposure results in a significant accumulation of Zn in brain and nervous tissues, especially following long-term exposure. As a result, overexposure to ZnONPs causes oxidative stress and cell death, both in neurons and glial cells, by induction of apoptosis, necrosis and ferroptosis. In addition, ZnONPs may induce neuroinflammation through the activation of nuclear factor kappa B (NF-κB), extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), and lipoxygenase (LOX) signaling pathways. ZnONPs exposure is associated with altered cholinergic, dopaminergic, serotoninergic, as well as glutamatergic and γ-aminobutyric acid (GABA)-ergic neurotransmission, thus contributing to impaired neuronal signal transduction. Cytoskeletal alterations, as well as impaired autophagy and mitophagy also contribute to ZnONPs-induced brain damage. It has been posited that some of the adverse effects of ZnONPs in brain are mediated by altered microRNA expression and dysregulation of gut-brain axis. Furthermore, in vivo studies have demonstrated that ZnONPs exposure induced anxiety, motor and cognitive deficits, as well as adverse neurodevelopmental outcome. At the same time, the relevance of ZnONPs-induced neurotoxicity and its contribution to pathogenesis of neurological diseases in humans are still unclear. Further studies aimed at estimation of hazards of ZnONPs to human brain health and the underlying molecular mechanisms are warranted.

Targeting selective autophagy and beyond: From underlying mechanisms to potential therapies

BACKGROUND

Autophagy is an evolutionarily conserved turnover process for intracellular substances in eukaryotes, relying on lysosomal (in animals) or vacuolar (in yeast and plants) mechanisms. In the past two decades, emerging evidence suggests that, under specific conditions, autophagy can target particular macromolecules or organelles for degradation, a process termed selective autophagy. Recently, accumulating studies have demonstrated that the abnormality of selective autophagy is closely associated with the occurrence and progression of many human diseases, including neurodegenerative diseases, cancers, metabolic diseases, and cardiovascular diseases.

AIM OF REVIEW

This review aims at systematically and comprehensively introducing selective autophagy and its role in various diseases, while unravelling the molecular mechanisms of selective autophagy. By providing a theoretical basis for the development of related small-molecule drugs as well as treating related human diseases, this review seeks to contribute to the understanding of selective autophagy and its therapeutic potential.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we systematically introduce and dissect the major categories of selective autophagy that have been discovered. We also focus on recent advances in understanding the molecular mechanisms underlying both classical and non-classical selective autophagy. Moreover, the current situation of small-molecule drugs targeting different types of selective autophagy is further summarized, providing valuable insights into the discovery of more candidate small-molecule drugs targeting selective autophagy in the future. On the other hand, we also reveal clinically relevant implementations that are potentially related to selective autophagy, such as predictive approaches and treatments tailored to individual patients.

Hypoxia and aging: molecular mechanisms, diseases, and therapeutic targets

Aging is a complex biological process characterized by the gradual decline of cellular functions, increased susceptibility to diseases, and impaired stress responses. Hypoxia, defined as reduced oxygen availability, is a critical factor that influences aging through molecular pathways involving hypoxia-inducible factors (HIFs), oxidative stress, inflammation, and epigenetic modifications. This review explores the interconnected roles of hypoxia in aging, highlighting how hypoxic conditions exacerbate cellular damage, promote senescence, and contribute to age-related pathologies, including cardiovascular diseases, neurodegenerative disorders, cancer, metabolic dysfunctions, and pulmonary conditions. By examining the molecular mechanisms linking hypoxia to aging, we identify key pathways that serve as potential therapeutic targets. Emerging interventions such as HIF modulators, antioxidants, senolytics, and lifestyle modifications hold promise in mitigating the adverse effects of hypoxia on aging tissues. However, challenges such as the heterogeneity of aging, lack of reliable biomarkers, and safety concerns regarding hypoxia-targeted therapies remain. This review emphasizes the need for personalized approaches and advanced technologies to develop effective antiaging interventions. By integrating current knowledge, this review provides a comprehensive framework that underscores the importance of targeting hypoxia-induced pathways to enhance healthy aging and reduce the burden of age-related diseases.

Sodium citrate targeting Ca2+/CAMKK2 pathway exhibits anti-tumor activity through inducing apoptosis and ferroptosis in ovarian cancer

INTRODUCTION

Ovarian cancer (OC) is known for its high mortality rate. Although sodium citrate has anti-tumor effects in various cancers, its effect and mechanism in OC remain unclear.

OBJECTIVES

To analyze the inhibitory effect of sodium citrate on ovarian cancer cells and the underlying mechanism.

METHODS

Cell apoptosis was examined by TUNEL staining, flow cytometry, and ferroptosis was examined intracellular Fe2+, MDA, LPO assays, respectively. Cell metabolism was examined by OCR and ECAR measurements. Immunoblotting and immunoprecipitation were used to elucidate the mechanism.

RESULTS

This study suggested that sodium citrate not only promoted ovarian cancer cell apoptosis but also triggeredferroptosis, manifested as elevated levels of Fe2+, LPO, MDA andlipid ROS production. On one hand, sodium citrate treatment led to a decrease of Ca2+ content in the cytosol by chelatingCa2+, which further inhibited the Ca2+/CAMKK2/AKT/mTOR signaling, thereby suppressing HIF1α-dependent glycolysis pathway and inducing cell apoptosis. On the other hand, the chelation of Ca2+ by sodium citrate resulted in inactivation of CAMKK2 and AMPK, leading to increase of NCOA4-mediated ferritinophagy, causing increased intracellular Fe2+ levels. More importantly, the inhibition of Ca2+/CAMKK2/AMPK signaling pathway reduced the activity of the MCU and Ca2+ concentration within the mitochondria, resulting in an increase in mitochondrial ROS. Additionally, metabolomic analysis indicated that sodium citrate treatment significantly increased de novo lipid synthesis. Altogether, these factors contributed to ferroptosis. As expected, Ca2+ supplementation successfully reversed the cell death and decreased tumor growth induced by sodium citrate. Inspiringly, it was found that coadministration of sodium citrate increased the sensitivity of OC cells to chemo-drugs.

CONCLUSION

These results revealed that the sodium citrate exerted its anti-cancer activity by inhibiting Ca2+/CAMKK2-dependent cell apoptosis and ferroptosis. Sodium citrate will hopefully serve as a prospective compound for OC treatment and for improvingthe efficacy of chemo-drugs.

Ferritinophagy is involved in hexavalent chromium-induced ferroptosis in Sertoli cells

Hexavalent chromium [Cr(VI)] has significant adverse effects on the environment and human health, particularly on the male reproductive system. Previously, we observed ferroptosis and autophagy in rat testicular injury induced by Cr(VI). In the present study, we focused on the association between ferroptosis and autophagy in mouse Sertoli cells (TM4) exposed to concentrations of 2.5 μМ, 5 μМ, and 10 μМ Cr(VI). Cr(VI) exposure altered mitochondrial ultrastructure; increased intracellular iron, malondialdehyde, and reactive oxygen species (ROS) levels; decreased glutathione content; increased TfR1 protein expression; and decreased GPX4, FPN1, and SLC7A11 protein expression, ultimately resulting in ferroptosis. Additionally, we observed ferritinophagy, increased expression of BECLIN1, LC3B, and NCOA4, and decreased expression of FTH1 and P62. Inhibition of autophagy and ferritinophagy via 3-MA and small interfering RNA (siRNA)-mediated silencing of NCOA4 ameliorated changes in ferritinophagy- and ferroptosis-associated protein expression, and reduced ROS levels. Rats exposed to Cr(VI) exhibited atrophy of testicular seminiferous tubules, a reduction in germ and Sertoli cells, and the occurrence of ferritinophagy and ferroptosis in cells of the rat testes. These results indicate that ferroptosis, triggered by NCOA4-mediated ferritinophagy, is one of the mechanisms that contribute to Cr(VI)-induced damage in Sertoli cells.

Silica nanoparticles induce liver lipid metabolism disorder via ACSL4-mediated ferroptosis

The disease burden of non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. Emerging evidence has revealed that silica nanoparticles (SiNPs) could disorder the liver lipid metabolism and cause hepatotoxicity, but the underlying mechanism remains unknown. The purpose of this study is to elucidate the molecular mechanism of hepatic lipid metabolism disorder caused by SiNPs, and to reveal the role of ferroptosis in SiNPs-induced hepatotoxicity. To explore the phenotypic changes in liver, the wild-type C57BL/6J mice were exposed to different doses of SiNPs (5, 10, 20 mg/kg·bw) with or without melatonin (20 mg/kg·bw). SiNPs accelerated hepatic oxidative stress and promoted pathological injury and lipid accumulation, resulting in NAFLD development. Melatonin significantly inhibited the oxidative damage caused by SiNPs. Then, the hepatocytes were treated with SiNPs, the ferroptosis inducer and inhibitor, respectively. In vitro, SiNPs (25 μg/mL) generated mitochondrial and intracellular Fe2+ accumulation and lipid peroxidation repair ability impairment, decreased the activity of GPX4 through ACSL4/p38 MAPK signaling pathway, resulting in ferroptosis of hepatocytes. Notably, Erastin (the ferroptosis activator, 5 μM) increased the sensitivity of hepatocytes to ferroptosis. Ferrostatin-1 (Fer-1, the ferroptosis inhibitor, 5 μM) restored GPX4 activity and protected against deterioration of lipid hydroperoxides (LOOHs) to salvage SiNPs-induced cytotoxicity. Finally, the liver tissue conditional ACSL4 knockout (cKO) mice and ACSL4-KO hepatocytes were adopted to further identify the role of the ACSL4-mediated ferroptosis on SiNPs-induced NAFLD development. The results displayed ACSL4 knockout could down-regulate the lipid peroxidation and ferroptosis, ultimately rescuing the progression of NAFLD. In summary, our data indicated that ACSL4/p38 MAPK/GPX4-mediated ferroptosis was a novel and critical mechanism of SiNPs-induced NAFLD.

Coke oven emissions exacerbate allergic asthma by promoting ferroptosis in airway epithelial cells

Epidemiological studies have shown that coke oven emissions (COEs) affect the deterioration of asthma, but has not been proven by experimental results. In this study, we found for the first time that COEs exacerbate allergen house dust mite (HDM)-induced allergic asthma in the mouse model. The findings reveal that airway inflammation, airway remodeling and allergic reaction were aggravated in the COE + HDM combined exposure group compared with the individual exposure group. Mechanism studies indicated higher levels of iron and MDA in the COE + HDM combined exposure group, along with increased expression of Ptgs2 and reduced GPX4 expression. Iron chelator deferoxamine (DFO) effectively inhibited ferroptosis induced by COE synergistically with HDM in vitro. Further studies highlighted the role of ferritinophagy in the COE + HDM-induced ferroptosis. 3-methyladenine (3-MA) could inhibit ferroptosis in the COE + HDM exposure group. Interestingly, we injected DFO intraperitoneally into mice in the combined exposure group and found DFO could significantly inhibit the COE-exacerbated ferroptosis and allergic asthma. Our findings link ferroptosis with COE-exacerbated allergic asthma, implying that ferroptosis may have important therapeutic potential for asthma in patients with occupational exposure of COE.

Chronic microcystin-leucine-arginine exposure induces osteoporosis by breaking the balance of osteoblasts and osteoclasts

Microcystin-leucine-arginine (MC-LR) produced by cyanobacterial harmful algal blooms are hazardous materials. However, the toxicity and mechanisms of continuous exposure to MC-LR on the occurrence of osteoporosis remains poorly documented. In this study, to mimic the chronic influences of MC-LR on the bone tissues in humans, an animal model was constructed in which mice were treated with MC-LR through drinking water at an environmentally relevant level (1-30 μg/L) for 6 months. MC-LR was enriched in the skeletal system, leading to the destruction of bone microstructure, the decrease of bone trabecular number, the reduction of osteoblasts, the enhanced content of lipid droplets, and the activation of osteoclasts, which is the characteristic of osteoporosis. Herein, we revealed ferroptosis is a vital mechanism of osteoblast death in mouse models of MC-LR. MC-LR exposure activates AMPK/ULK1 signaling, further promotes ferritin selective autophagy, causes free iron release and lipid peroxidation deposition, and eventually leads to ferroptosis of osteoblasts. Importantly, the use of AMPK or ferroptosis inhibitors in vivo markedly reduced MC-LR-induced osteoblast death and impaired osteogenic differentiation. Interestingly, MC-LR exposure promotes iron uptake in bone marrow macrophages through the TF-TFR1 pathway, leading to its transformation to TRAP-positive pre-osteoclast cells, thereby promoting bone resorption. Overall, our data innovatively revealed the core mechanism of MC-LR-induced osteoporosis, providing the bi-directional regulation of MC-LR on osteoblast-osteoclast from the perspective of iron homeostasis imbalance.

Examining the Influence of Zinc Oxide Nanoparticles and Bulk Zinc Oxide on Rat Brain Functions: a Comprehensive Neurobehavioral, Antioxidant, Gene Expression, and Histopathological Investigation

The study aimed to assess the impact of zinc oxide nanoparticles (ZnONPs) on rats' neurobehavior compared to bulk zinc oxide (BZnO). Thirty male Sprague-Dawley rats were randomly assigned to five groups. The control group received Tween 80 (10%), while the ZnONP groups were given ZnONPs at 5 and 10 mg/kg body weight dosages, and the bulk zinc oxide (BZnO) groups received BZnO at the same dosages. Behavioral observations, neurobehavioral examinations, and assessments of brain tissue oxidative markers, neurotransmitter levels, and histopathological changes were performed. The results indicated that ZnONP at a dosage of 5 mg/kg improved general behavior, locomotor activity, memory, and recognition and reduced fearfulness in rats. Conversely, the higher dosage of 10 mg/kg and the bulk form had adverse effects on general behavior, locomotor activity, and learning ability, with the bulk form demonstrating the most severe impact-znONP-5 treatment increased antioxidant enzyme levels and decreased inflammatory markers. BZnO-5 exhibited lower oxidative stress markers, although still higher than BZnO-10. Furthermore, ZnONP-5 and BZnO-5 increased neurotransmitter levels compared to higher dosages. ZnONP-5 upregulated the expression of brain-derived neurotrophic factor (BDNF) mRNA, while BZnO-5 showed increased BDNF mRNA expression and decreased expression of genes related to apoptosis and inflammation. In summary, ZnONPs at 5 mg/kg demonstrated positive effects on rat brain function and behavior, while higher dosages and the bulk form had detrimental effects. In conclusion, the studies emphasized the importance of further assessing various doses and forms of zinc oxide on brain health, highlighting the significance of dosage considerations when using nanomaterials.

LC-MS untargeted metabolomics reveals metabolic disturbance and ferroptosis in MWCNTs-induced hepatotoxicity of Cyprinus carpio

In recent years, there is a great concern about the potential adverse effects of carbon nanotubes (CNTs) on the aquatic systems due to their increasingly extensive application. In this study, juvenile Cyprinus carpio were exposed to multi-walled CNTs (MWCNTs) at concentrations of 0, 0.25, and 2.5 mg L-1 for 28 days. Then, oxidative stress indicators and metabolite profile of the livers were assessed. Results showed the significant increase of malondialdehyde (MDA) content and decrease of glutathione (GSH) activities in fish treated with 2.5 mg L-1 MWCNTs. LC-MS untargeted metabolomics demonstrated that 406 and 274 metabolites in fish treated with 2.5 mg L-1 MWCNTs were significantly up- and down-regulated, respectively. KEGG functional annotation analysis showed the disturbance of amino acid metabolism, lipid metabolism, and nucleotide metabolism. In addition, ferroptosis signaling pathway was detected. Therefore, iron content analysis and quantitative real-time RT-PCR assay were performed furtherly to validate the contribution of ferroptosis to MWCNTs-induced hepatotoxicity. The iron content increased significantly and the mRNA levels of ferroptosis-related genes including STEAP3, ACSL4, NCOA4, TFR1, NRF2, SLC3A2, SLC7A11, GPX4, and FPN1 were also obviously changed. Taken together, our study suggested that MWCNTs exposure-induced ferroptosis were associated with iron overload and lipid peroxidation via NRF2/SLC7A11/GSH/GPX4 axis. Our findings provide essential information to understand the mechanism of CNTs-induced hepatotoxicity in fish and explore potential biomarkers.

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.

DEHP regulates ferritinophagy to promote testicular ferroptosis via suppressing SIRT1/PGC-1α pathway

To increase elasticity and flexibility, di-2-ethylhexyl phthalate (DEHP) is used in a variety of industrial products, but excessive exposure to it can pose a threat to human health. In epidemiological studies of population exposure to DEHP, attention has been paid to damage to the male reproductive system. However, the toxicological mechanism of DEHP regarding testicular injury is not well understood. We used Western blot analysis, transmission electron microscopy, fluorescence staining, transient transfection and assay kit to detect relevant indicators, and the results were as follows: After DEHP exposure, the expression levels of ACSL4, COX2, TF, FTH1, LC3, AMPK, p-AMPK, ULK1, p-ULK1, serum iron, tissue iron and MDA in the exposure group were significantly increased. The expression levels of GPX4, NCOA4, p62, SIRT1, and PGC-1α, as well as the contents of GSH and ATP, decreased. Electron microscopy showed that more autophagosomes were observed. Our findings suggest that exposure to DEHP induced ferritinophagy and ferroptosis in the testis. In vitro, the promoting effect of ferritinophagy on ferroptosis was verified by applying the autophagy inhibitor (3-MA) and si-NCOA4. Moreover, Mono-(2-ethylhexyl) phthalate (MEHP) inhibited the mitochondrial regulatory protein SIRT1/PGC-1α, leading to mitochondrial dysfunction. Changes in mitochondrial reactive oxygen species (MtROS) and energy over-activated AMPK/ULK1 autophagy pathway, and then promoted ferritinophagy, which increased the sensitivity of TM4 cells to ferroptosis. This research offers a theoretical framework for the prevention and management of DEHP-induced harm.

Genome-wide DNA methylation sequencing reveals the involvement of ferroptosis in hepatotoxicity induced by dietary exposure to food-grade titanium dioxide

BACKGROUND

Following the announcement by the European Food Safety Authority that the food additive titanium dioxide (E 171) is unsafe for human consumption, and the subsequent ban by the European Commission, concerns have intensified over the potential risks E 171 poses to human vital organs. The liver is the main organ for food-grade nanoparticle metabolism. It is increasingly being found that epigenetic changes may play an important role in nanomaterial-induced hepatotoxicity. However, the profound effects of E 171 on the liver, especially at the epigenetic level, remain largely unknown.

METHODS

Mice were exposed orally to human-relevant doses of two types of E 171 mixed in diet for 28 and/or 84 days. Conventional toxicology and global DNA methylation analyses were performed to assess E 171-induced hepatotoxicity and epigenetic changes. Whole genome bisulfite sequencing and further ferroptosis protein detection were used to reveal E 171-induced changes in liver methylation profiles and toxic mechanisms.

RESULTS

Exposed to E 171 for 28 and/or 84 days resulted in reduced global DNA methylation and hydroxymethylation in the liver of mice. E 171 exposure for 84 days elicited inflammation and damage in the mouse liver, whereas 28-day exposure did not. Whole-genome DNA methylation sequencing disclosed substantial methylation alterations at the CG and non-CG sites of the liver DNA in mice exposed to E 171 for 84 days. Mechanistic analysis of the DNA methylation alterations indicated that ferroptosis contributed to the liver toxicity induced by E 171. E 171-induced DNA methylation changes triggered NCOA4-mediated ferritinophagy, attenuated the protein levels of GPX4, FTH1, and FTL in the liver, and thereby caused ferroptosis.

CONCLUSIONS

Long-term oral exposure to E 171 triggers hepatotoxicity and induces methylation changes in both CG and non-CG sites of liver DNA. These epigenetic alterations activate ferroptosis in the liver through NCOA4-mediated ferritinophagy, highlighting the role of DNA methylation and ferroptosis in the potential toxicity caused by E 171 in vivo.

Evaluation of ferroptosis-based anti-leukemic activities of ZnO nanoparticles synthesized by a green route against Pre-B acute lymphoblastic leukemia cells (Nalm-6 and REH)

Background

Our research presents an efficient and practical method for producing Zinc Oxide nanoparticles (ZnO NPs), which have anti-leukemic effects based on ferroptosis.

Methods

The black cardamom extract was employed as a capping and reducing agent for the green synthesis. The NPs have been characterized via scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. Additionally, leukemic and normal cells were exposed to ZnO NPs (25, 50, 75, 100, 150, 200, and 300 μg/mL) for 24 and 48 h. The cell vitality was then measured using the MTT test. Moreover, ferroptosis indicators were assessed via commercial testing kits, and finally, qRT-PCR and flow cytometry were used to measure gene expression and cell death.

Results

The findings displayed that green synthesized ZnO NPs reduced the survival of leukemic cells, with IC50 values of 150.89 μg/ml for Nalm-6 and 101.31 μg/ml for REH cells after 48 h. The ZnO NPs increased ferroptosis by significantly increasing MDA, intracellular iron, ACSL4, ALOX15, and p53 mRNA expressions while significantly decreasing GSH and GPx activity levels and SLC7A11 and GPx4 mRNA expressions. On the other hand, ZnO NPs exhibited no toxicity toward normal cells.

Conclusions

The research suggests that ZnO NPs synthesized using the green approach can induce ferroptosis in leukemic cells by disrupting redox homeostasis and increasing intracellular iron levels, potentially enhancing the benefits of anti-leukemic therapies in the future.

Zinc oxide nanoparticles disrupt the mammary epithelial barrier via Z-DNA binding protein 1-triggered PANoptosis

Lactation women, a highly concerned demographic in society, face health risks that deserve attention. Zinc oxide nanoparticles (ZnO NPs) are widely utilized in food and daily products due to their excellent physicochemical properties, leading to the potential exposure of lactating women to ZnO NPs. Hence, assessing the potential risks associated with ZnO NP exposure during lactation is critical. While studies have confirmed that exposure to ZnO NPs during lactation can induce toxic responses in multiple organs through blood circulation, the effects of lactational exposure on mammary tissue remain unclear. This research investigated the impairment of mammary tissue induced by ZnO NPs and its potential mechanisms. Through administering multiple injections of ZnO NPs into the tail vein of lactating ICR mice, our study revealed that ZnO NPs can deposit in the mammary tissues, downregulating key components of mammary epithelial barrier such as ZO-1, occludin, and claudin-3. In vivo, we also found that ZnO NPs can simultaneously induce apoptosis, necroptosis, and pyroptosis, called PANoptosis. Additionally, using EpH4-Ev cells to simulate an in vitro mammary epithelial barrier model, we observed that ZnO NPs effectively disrupted the integrity of mammary epithelial barrier and induced PANoptosis. Furthermore, we confirmed that PANoptosis was responsible for the mammary epithelial barrier disruption induced by ZnO NPs. Moreover, we identified that ZBP1 was the primary mechanism of ZnO NPs inducing PANoptosis. These discoveries are designed to enhance our comprehension of the mechanisms underlying mammary epithelial barrier disruption caused by ZnO NPs, and we aim to highlight the potential hazards associated with daily usage and therapeutic exposure to ZnO NPs during lactation.

Promoted coagulant activity and disrupted blood-brain barrier depending on phosphatidylserine externalization of red blood cells exposed to ZnO nanoparticles

Zinc oxide nanoparticles (ZnO-NPs) are nanomaterials mainly produced and used worldwide. They translocate to circulatory systems from various exposure routes. While blood and endothelial cells are persistently exposed to circulating ZnO-NPs, the potential risks posed by ZnO-NPs to the cardiovascular system are largely unknown. Our study identified the potential risk of thrombosis and disturbance of the blood-brain barrier (BBB) by coagulant activity on red blood cells (RBCs) caused by ZnO-NPs. ZnO-NPs promoted the externalization of phosphatidylserine and the generation of microvesicles through an imbalance of intracellular mechanisms regulating procoagulant activity in human RBCs. The coagulation cascade leading to thrombin generation was promoted in ZnO-NPs-treated human RBCs. Combined with human RBCs, ZnO-NPs caused coagulant activity on isolated rat RBCs and rat venous thrombosis models. We identified the erythrophagocytosis of RBCs into brain endothelial cells via increased PS exposure induced by ZnO-NPs. Excessive erythrophagocytosis contributes to disrupting the BBB function of endothelial cells. ZnO-NPs increased the procoagulant activity of RBCs, causing venous thrombosis. Excessive erythrophagocytosis through ZnO-NPs-treated RBCs resulted in the dysfunction of BBB. Our study will help elucidate the potential risk ZnO-NPs exert on the cardiovascular system.

Ferroptosis at the nexus of metabolism and metabolic diseases

Ferroptosis, an iron-dependent form of regulated cell death, is emerging as a crucial regulator of human physiology and pathology. Increasing evidence showcases a reciprocal relationship between ferroptosis and dysregulated metabolism, propagating a pathogenic vicious cycle that exacerbates pathology and human diseases, particularly metabolic disorders. Consequently, there is a rapidly growing interest in developing ferroptosis-based therapeutics. Therefore, a comprehensive understanding of the intricate interplay between ferroptosis and metabolism could provide an invaluable resource for mechanistic insight and therapeutic development. In this review, we summarize the important metabolic substances and associated pathways in ferroptosis initiation and progression, outline the cascade responses of ferroptosis in disease development, overview the roles and mechanisms of ferroptosis in metabolic diseases, introduce the methods for ferroptosis detection, and discuss the therapeutic perspectives of ferroptosis, which collectively aim to illustrate a comprehensive view of ferroptosis in basic, translational, and clinical science.

Autophagy aggravates multi-walled carbon nanotube-induced ferroptosis by suppressing PGC-1 dependent-mitochondrial biogenesis in lung epithelial cells

Multi-walled carbon nanotube (MWCNT) induced respiratory toxicity has become a growing concern, with ferroptosis emerging as a novel mechanism implicated in various respiratory diseases. However, whether ferroptosis is involved in MWCNT-elicited lung injury and the underlying molecular mechanisms warrant further exploration. In this study, we found that MWCNT-induced ferroptosis is autophagy-dependent, contributing to its cellular toxicity. Inhibiting of autophagy by pharmacological inhibitors 3-MA or ATG5 gene knockdown significantly attenuated MWCNT-induced ferroptosis, concomitant with rescued mitochondrial biogenesis. Rapamycin, the autophagy agonist, exacerbated the mitochondrial damage and MWCNT-induced ferroptosis. Moreover, lentivirus-mediated overexpression of PGC-1α inhibited ferroptosis, while inhibition of PGC-1α aggravated ferroptosis. In summary, our study unveils ferroptosis as a novel mechanism underlying MWCNT-induced respiratory toxicity, with autophagy promoting MWCNT-induced ferroptosis by hindering PGC-1α-dependent mitochondrial biogenesis.

CircFAM188A Regulates Autophagy via miR-670-3p and ULK1 in Epithelial Ovarian Carcinoma

BACKGROUND AND AIMS

CircRNAs and autophagy are closely involved in the physiological and pathological processes of ovarian cancer; however, their exact mechanisms are still undetermined. This investigation aimed to elucidate the function and associated pathways of circFAM188A, which modulates proliferation, autophagy, and invasion in ovarian cancer (EOC).

METHODS

The expression of circFAM188A in the tissues of EOC patients was assessed via RT-PCR. To elucidate proliferation, invasion, and autophagy in the tumor cells, Transwell, 5-ethynyl-2'-deoxyuridine (EdU), and mRFP-GFP-LC3 reporter assays were conducted. The binding sites between circ-FAM188A and the miR-670-3p, miR-670-3p and YY1 were predicted using bioinformatics and verified by dual-luciferase reporter assays. Pulldown assays demonstrated binding between ULK1 and circ-FAM188A. ULK1 was found to be crucial in the initial stage of autophagy. Moreover, an in vivo xenograft model was established by subcutaneous injection of nude mice with EOC cells.

RESULT

Expression of circ-FAM188A was increased in EOC tissues relative to normal ovarian tissues and circ-FAM188A overexpression promoted proliferation, invasion, and autophagy; these effects were reversed by circ-FAM188A silencing. miR-670-3p and circ-FAM188A co-localized in the cytoplasm. circ-FAM188A enhanced YY1 expression by sponging miR-670-3p and was also shown to interact with ULK1.

CONCLUSION

It is thus suggested that circ-FAM188A modulates autophagy by sponging miR-670-3p as well as interacting with ULK1.

The romantic history of signaling pathway discovery in cell death: an updated review

Cell death is a fundamental physiological process in all living organisms. Processes such as embryonic development, organ formation, tissue growth, organismal immunity, and drug response are accompanied by cell death. In recent years with the development of electron microscopy as well as biological techniques, especially the discovery of novel death modes such as ferroptosis, cuprotosis, alkaliptosis, oxeiptosis, and disulfidptosis, researchers have been promoted to have a deeper understanding of cell death modes. In this systematic review, we examined the current understanding of modes of cell death, including the recently discovered novel death modes. Our analysis highlights the common and unique pathways of these death modes, as well as their impact on surrounding cells and the organism as a whole. Our aim was to provide a comprehensive overview of the current state of research on cell death, with a focus on identifying gaps in our knowledge and opportunities for future investigation. We also presented a new insight for macroscopic intracellular survival patterns, namely that intracellular molecular homeostasis is central to the balance of different cell death modes, and this viewpoint can be well justified by the signaling crosstalk of different death modes. These concepts can facilitate the future research about cell death in clinical diagnosis, drug development, and therapeutic modalities.

Avicularin Attenuated Lead-Induced Ferroptosis, Neuroinflammation, and Memory Impairment in Mice

Lead (Pb) is a common environmental neurotoxicant that results in abnormal neurobehavior and impaired memory. Avicularin (AVL), the main dietary flavonoid found in several plants and fruits, exhibits neuroprotective and hepatoprotective properties. In the present study, the effects of AVL on Pb-induced neurotoxicity were evaluated using ICR mice to investigate the molecular mechanisms behind its protective effects. Our study has demonstrated that AVL treatment significantly ameliorated memory impairment induced by lead (Pb). Furthermore, AVL mitigated Pb-triggered neuroinflammation, ferroptosis, and oxidative stress. The inhibition of Pb-induced oxidative stress in the brain by AVL was evidenced by the reduction in malondialdehyde (MDA) levels and the enhancement of glutathione (GSH) and glutathione peroxidase (GPx) activities. Additionally, in the context of lead-induced neurotoxicity, AVL mitigated ferroptosis by increasing the expression of GPX4 and reducing ferrous iron levels (Fe2+). AVL increased the activities of glycogenolysis rate-limiting enzymes HK, PK, and PYG. Additionally, AVL downregulated TNF-α and IL-1β expression while concurrently enhancing the activations of AMPK, Nrf2, HO-1, NQO1, PSD-95, SNAP-25, CaMKII, and CREB in the brains of mice. The findings from this study suggest that AVL mitigates the memory impairment induced by Pb, which is associated with the AMPK/Nrf2 pathway and ferroptosis.

tRF-Gly-GCC in Atretic Follicles Promotes Ferroptosis in Granulosa Cells by Down-Regulating MAPK1

Follicle development refers to the process in which the follicles in the ovary gradually develop from the primary stage to a mature state, and most primary follicles fail to develop normally, without forming a dense granular cell layer and cell wall, which is identified as atretic follicles. Granulosa cells assist follicle development by producing hormones and providing support, and interference in the interaction between granulosa cells and oocytes may lead to the formation of atretic follicles. Ferroptosis, as a non-apoptotic form of death, is caused by cells accumulating lethal levels of iron-dependent phospholipid peroxides. Healthy follicles ranging from 4 to 5 mm were randomly divided into two groups: a control group (DMSO) and treatment group (10 uM of ferroptosis inducer erastin). Each group was sequenced after three repeated cultures for 24 h. We found that ferroptosis was associated with atretic follicles and that the in vitro treatment of healthy follicles with the ferroptosis inducer erastin produced a phenotype similar to that of atretic follicles. Overall, our study elucidates that tRF-1:30-Gly-GCC-2 is involved in the apoptosis and ferroptosis of GCs. Mechanistically, tRF-1:30-Gly-GCC-2 inhibits granulosa cell proliferation and promotes ferroptosis by inhibiting Mitogen-activated protein kinase 1 (MAPK1). tRF-1:30-Gly-GCC-2 may be a novel molecular target for improving the development of atretic follicles in ovarian dysfunction. In conclusion, our study provides a new perspective on the pathogenesis of granulosa cell dysfunction and follicular atresia.

Role of Histiocyte-Derived frHMGB1 as a Facilitator in Noncanonical Pyroptosis of Monocytes/Macrophages in Lethal Sepsis

In this study, we investigated the role of the noncanonical pyroptosis pathway in the progression of lethal sepsis. Our findings emphasize the significance of noncanonical pyroptosis in monocytes/macrophages for the survival of septic mice. We observed that inhibiting pyroptosis alone significantly improved the survival rate of septic mice and that the HMGB1 A box effectively suppressed this noncanonical pyroptosis, thereby enhancing the survival of septic mice. Additionally, our cell in vitro experiments unveiled that frHMGB1, originating from lipopolysaccharide-carrying histiocytes, entered macrophages via RAGE, resulting in the direct activation of caspase 11 and the induction of noncanonical pyroptosis. Notably, A box's competitive binding with lipopolysaccharide impeded its entry into the cell cytosol. These findings reveal potential therapeutic strategies for slowing the progression of lethal sepsis by modulating the noncanonical pyroptosis pathway.

Nanomedicines Targeting Ferroptosis to Treat Stress-Related Diseases

Ferroptosis, a unique form of regulated cell death driven by iron-dependent lethal lipid peroxidation, is implicated in various stress-related diseases like neurodegeneration, vasculopathy, and metabolic disturbance. Stress-related diseases encompass widespread medical disorders that are influenced or exacerbated by stress. These stressors can manifest in various organ or tissue systems and have significant implications for human overall health. Understanding ferroptosis in these diseases offers insights for therapeutic strategies targeting relevant pathways. This review explores ferroptosis mechanisms, its role in pathophysiology, its connection to stress-related diseases, and the potential of ferroptosis-targeted nanomedicines in treating conditions. This monograph also delves into the engineering of ferroptosis-targeted nanomedicines for tackling stress-related diseases, including cancer, cardia-cerebrovascular, neurodegenerative, metabolic and inflammatory diseases. Anyhow, nanotherapy targeting ferroptosis holds promise by both promoting and suppressing ferroptosis for managing stress-related diseases.

Hepcidin depending on astrocytic NEO1 ameliorates blood-brain barrier dysfunction after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) significantly compromises the blood-brain barrier (BBB) and impairs patient recovery. This study elucidates the critical role of astrocytic Neogenin-1 (NEO1) in BBB integrity post-SAH and examines the regulatory effects of hepcidin on endothelial cell (EC) function amid NEO1-mediated disruptions in iron homeostasis. Proteomic analyses of cerebrospinal fluid (CSF) from SAH patients revealed a substantial decrease in NEO1 expression, identifying it as a key factor in BBB integrity. 111 CSF proteins were significantly reduced in early SAH stages (days 1-3), with NEO1 among the most significantly altered. This dysregulation was linked to poorer patient outcomes, as indicated by a negative correlation between NEO1 levels and Modified Rankin Scale scores six months post-SAH (R = -0.4743, P < 0.0001). Experimental models further highlighted the importance of NEO1: SAH model and NEO1GFAP-Cre mice exhibited exacerbated EC dysfunction and increased BBB permeability, evidenced by significant Evans Blue retention and dextran leakage in the parietal cortex, effects that were mitigated by hepcidin administration. Our findings highlight the complex interplay between astrocytic signaling and endothelial function in SAH pathophysiology. The loss of astrocytic NEO1 led to increased EC proliferation and altered BBB structure, as confirmed by transmission electron microscopy and immunostaining for PECAM-1, indicating heightened blood vessel density in the affected cortex. Hepcidin treatment effectively reversed the EC dysfunction and BBB disruption in both NEO1-cKO mice and the SAH model, highlighting its potential as a therapeutic agent to enhance recovery and improve prognosis following SAH.

Reactive oxygen species regulation by NCF1 governs ferroptosis susceptibility of Kupffer cells to MASH

Impaired self-renewal of Kupffer cells (KCs) leads to inflammation in metabolic dysfunction-associated steatohepatitis (MASH). Here, we identify neutrophil cytosolic factor 1 (NCF1) as a critical regulator of iron homeostasis in KCs. NCF1 is upregulated in liver macrophages and dendritic cells in humans with metabolic dysfunction-associated steatotic liver disease and in MASH mice. Macrophage NCF1, but not dendritic cell NCF1, triggers KC iron overload, ferroptosis, and monocyte-derived macrophage infiltration, thus aggravating MASH progression. Mechanistically, elevated oxidized phospholipids induced by macrophage NCF1 promote Toll-like receptor (TLR4)-dependent hepatocyte hepcidin production, leading to increased KC iron deposition and subsequent KC ferroptosis. Importantly, the human low-functional polymorphic variant NCF190H alleviates KC ferroptosis and MASH in mice. In conclusion, macrophage NCF1 impairs iron homeostasis in KCs by oxidizing phospholipids, triggering hepatocyte hepcidin release and KC ferroptosis in MASH, highlighting NCF1 as a therapeutic target for improving KC fate and limiting MASH progression.

Ferritinophagy and Ferroptosis in Cerebral Ischemia Reperfusion Injury

Cerebral ischemia-reperfusion injury (CIRI) is the second leading cause of death worldwide, posing a huge risk to human life and health. Therefore, investigating the pathogenesis underlying CIRI and developing effective treatments are essential. Ferroptosis is an iron-dependent mode of cell death, which is caused by disorders in iron metabolism and lipid peroxidation. Previous studies demonstrated that ferroptosis is also a form of autophagic cell death, and nuclear receptor coactivator 4(NCOA4) mediated ferritinophagy was found to regulate ferroptosis by interfering with iron metabolism. Ferritinophagy and ferroptosis are important pathogenic mechanisms in CIRI. This review mainly summarizes the link and regulation between ferritinophagy and ferroptosis and further discusses their mechanisms in CIRI. In addition, the potential treatment methods targeting ferritinophagy and ferroptosis for CIRI are presented, providing new ideas for the prevention and treatment of clinical CIRI in the future.

Environmentally relevant levels of Cd and Mo coexposure induces ferroptosis and excess ferritinophagy through AMPK/mTOR axis in duck myocardium

Cadmium (Cd) and excess molybdenum (Mo) are multiorgan toxic, but the detrimental impacts of Cd and/or Mo on poultry have not been fully clarified. Thence, a 16-week sub-chronic toxic experiment was executed with ducks to assess the toxicity of Cd and/or Mo. Our data substantiated that Cd and Mo coexposure evidently reduced GSH-Px, GSH, T-SOD, and CAT activities and elevated H2O2 and MDA concentrations in myocardium. What is more, the study suggested that Cd and Mo united exposure synergistically elevated Fe2+ content in myocardium and activated AMPK/mTOR axis, then induced ferroptosis by obviously upregulating ACSL4, PTGS2, and TFRC expression levels and downregulating SLC7A11, GPX4, FPN1, FTL1, and FTH1 expression levels. Additionally, Cd and Mo coexposure further caused excessive ferritinophagy by observably increasing autophagosomes, the colocalization of endogenous FTH1 and LC3, ATG5, ATG7, LC3II/LC3I, NCOA4, and FTH1 expression levels. In brief, this study for the first time substantiated that Cd and Mo united exposure synergistically induced ferroptosis and excess ferritinophagy by AMPK/mTOR axis, finally augmenting myocardium injure in ducks, which will offer an additional view on united toxicity between two heavy metals on poultry.

Human umbilical cord mesenchymal stem cells alleviate chemotherapy-induced premature ovarian insufficiency mouse model by suppressing ferritinophagy-mediated ferroptosis in granulosa cells

Primary ovarian insufficiency (POI) in younger women (under 40) manifests as irregular periods, high follicle-stimulating hormone (FSH), and low estradiol (E2), often triggered by chemotherapy. Though mesenchymal stem cell (MSC) therapy shows promise in treating POI, its exact mechanism remains unclear. This study reveals that human umbilical cord-derived MSCs (hUC-MSCs) can protect ovarian granulosa cells (GCs) from cyclophosphamide (CTX)-induced ferroptosis, a form of cell death driven by iron accumulation. CTX, commonly used to induce POI animal model, triggered ferroptosis in GCs, while hUC-MSCs treatment mitigated this effect, both in vivo and in vitro. Further investigations using ferroptosis and autophagy inhibitors suggest that hUC-MSCs act by suppressing ferroptosis in GCs. Interestingly, hUC-MSCs activate a protective antioxidant pathway in GCs via NRF2, a stress-response regulator. Overall, our findings suggest that hUC-MSCs improve ovarian function in CTX-induced POI by reducing ferroptosis in GCs. This study not only clarifies the mechanism behind the benefits of hUC-MSCs but also strengthens the case for their clinical use in treating POI. Additionally, it opens up a new avenue for protecting ovaries from chemotherapy-induced damage by regulating ferroptosis.

Autophagy-mediated ferroptosis is involved in development of severe acute pancreatitis

BACKGROUND

Ferroptosis is a newly recognized form of regulatory cell death characterized by severe lipid peroxidation triggered by iron overload and the production of reactive oxygen species (ROS). However, the role of ferroptosis in severe acute pancreatitis(SAP) has not been fully elucidated.

METHODS

We established four severe acute pancreatitis models of rats including the sham control group, the SAP group, the Fer -1-treated SAP (SAP + Fer-1) group, the 3-MA-treated SAP (SAP + 3-MA) group. The SAP group was induced by retrograde injection of sodium taurocholate into the pancreatic duct. The other two groups were intraperitoneally injected with ferroptosis inhibitor (Fer-1) and autophagy inhibitor (3-MA), respectively. The model of severe acute pancreatitis with amylase crest-related inflammatory factors was successfully established. Then we detected ferroptosis (GPX4, SLC7A1 etc.) and autophagy-related factors (LC3II, p62 ect.) to further clarify the relationship between ferroptosis and autophagy.

RESULTS

Our study found that ferroptosis occurs during the development of SAP, such as iron and lipid peroxidation in pancreatic tissues, decreased levels of reduced glutathione peroxidase 4 (GPX 4) and glutathione (GSH), and increased malondialdehyde(MDA) and significant mitochondrial damage. In addition, ferroptosis related proteins such as GPX4, solute carrier family 7 member 11(SLC7A11) and ferritin heavy chain 1(FTH1) were significantly decreased. Next, the pathogenesis of ferroptosis in SAP was studied. First, treatment with the ferroptosis inhibitor ferrostatin-1(Fer-1) significantly alleviated ferroptosis in SAP. Interestingly, autophagy occurs during the pathogenesis of SAP, and autophagy promotes the occurrence of ferroptosis in SAP. Moreover, 3-methyladenine (3-MA) inhibition of autophagy can significantly reduce iron overload and ferroptosis in SAP.

CONCLUSIONS

Our results suggest that ferroptosis is a novel pathogenesis of SAP and is dependent on autophagy. This study provides a new theoretical basis for the study of SAP.

Analysis of mechanism, therapeutic strategies, and potential natural compounds against atherosclerosis by targeting iron overload-induced oxidative stress

Ferroptosis is a novel form of cell demise characterized primarily by the reduction of trivalent iron to divalent iron, leading to the release of reactive oxygen species (ROS) and consequent induction of intense oxidative stress. In atherosclerosis (AS), highly accumulated lipids are modified by ROS to promote the formation of lipid peroxides, further amplifying cellular oxidative stress damage to influence all stages of atherosclerotic development. Macrophages are regarded as pivotal executors in the progression of AS and the handling of iron, thus targeting macrophage iron metabolism holds significant guiding implications for exploring potential therapeutic strategies against AS. In this comprehensive review, we elucidate the potential interplay among iron overload, inflammation, and lipid dysregulation, summarizing the potential mechanisms underlying the suppression of AS by alleviating iron overload. Furthermore, the application of Traditional Chinese Medicine (TCM) is increasingly widespread. Based on extant research and the pharmacological foundations of active compounds of TCM, we propose alternative therapeutic agents for AS in the context of iron overload, aiming to diversify the therapeutic avenues.

Selenium nanoparticles alleviate renal ischemia/reperfusion injury by inhibiting ferritinophagy via the XBP1/NCOA4 pathway

Acute kidney injury (AKI) is closely related to lysosomal dysfunction and ferroptosis in renal tubular epithelial cells (TECs), for which effective treatments are urgently needed. Although selenium nanoparticles (SeNPs) have emerged as promising candidates for AKI therapy, their underlying mechanisms have not been fully elucidated. Here, we investigated the effect of SeNPs on hypoxia/reoxygenation (H/R)-induced ferroptosis and lysosomal dysfunction in TECs in vitro and evaluated their efficacy in a murine model of ischemia/reperfusion (I/R)-AKI. We observed that H/R-induced ferroptosis was accompanied by lysosomal Fe2+ accumulation and dysfunction in TECs, which was ameliorated by SeNPs administration. Furthermore, SeNPs protected C57BL/6 mice against I/R-induced inflammation and ferroptosis. Mechanistically, we found that lysosomal Fe2+ accumulation and ferroptosis were associated with the excessive activation of NCOA4-mediated ferritinophagy, a process mitigated by SeNPs through the upregulation of X-box binding protein 1 (XBP1). Downregulation of XBP1 promoted ferritinophagy and partially counteracted the protective effects of SeNPs on ferroptosis inhibition in TECs. Overall, our findings revealed a novel role for SeNPs in modulating ferritinophagy, thereby improving lysosomal function and attenuating ferroptosis of TECs in I/R-AKI. These results provide evidence for the potential application of SeNPs as therapeutic agents for the prevention and treatment of AKI.

Defective ferritinophagy and imbalanced iron metabolism in PBDE-47-triggered neuronal ferroptosis and salvage by Canolol

The brominated flame retardant 2,2',4,4'-tetrabromodiphenyl ether (PBDE-47) is a ubiquitous environmental pollutant that causes neurotoxicity. However, incomplete understanding of the underlying mechanisms has hampered the development of effective intervention strategies. Oxidative stress and related cell death are the modes of action for PBDE-47 neurotoxicity, which are also the characteristics of ferroptosis. Nonetheless, the role of ferroptosis in PBDE-47-induced neurotoxicity remains unclear. In the present study, we found that PBDE-47 triggered ferroptosis in neuron-like PC12 cells, as evidenced by intracellular iron overload, lipid peroxidation, and mitochondrial damage. This was confirmed by ferroptosis inhibitors including the lipid reactive oxygen species scavenger ferrostatin-1 and iron chelator deferoxamine mesylate. Mechanistically, PBDE-47 impaired ferritinophagy by disrupting nuclear receptor coactivator 4-mediated lysosomal degradation of the iron storage protein ferritin. Moreover, PBDE-47 disturbed iron metabolism by increasing cellular iron import via upregulation of transferrin receptor 1 and decreasing cellular iron export via downregulation of ferroportin 1 (FPN1). Intriguingly, rescuing lysosomal function by overexpressing cathepsin B (CatB) mitigated PBDE-47-induced ferroptosis by partially restoring dysfunctional ferritinophagy and enhancing iron excretion via the upregulation of FPN1. However, FPN1 knockdown reversed the beneficial effects of CatB overexpression on the PBDE-47-induced iron overload. Finally, network pharmacology integrated with experimental validation revealed that Canolol, the main phenolic compound in canola oil, protected against PBDE-47-evoked iron overload, resulting in ferroptosis by restoring defective ferritinophagy and improving abnormal iron metabolism via lowering iron uptake and facilitating iron excretion. Overall, these data suggest that ferroptosis is a novel mechanism of PBDE-47-induced neuronal death and that manipulation of ferritinophagy and iron metabolism via Canolol represents a promising therapeutic strategy.

ZnO NPs induce miR-342-5p mediated ferroptosis of spermatocytes through the NF-κB pathway in mice

BACKGROUND

Zinc oxide nanoparticle (ZnO NP) is one of the metal nanomaterials with extensive use in many fields such as feed additive and textile, which is an emerging threat to human health due to widely distributed in the environment. Thus, there is an urgent need to understand the toxic effects associated with ZnO NPs. Although previous studies have found accumulation of ZnO NPs in testis, the molecular mechanism of ZnO NPs dominated a decline in male fertility have not been elucidated.

RESULTS

We reported that ZnO NPs exposure caused testicular dysfunction and identified spermatocytes as the primary damaged site induced by ZnO NPs. ZnO NPs led to the dysfunction of spermatocytes, including impaired cell proliferation and mitochondrial damage. In addition, we found that ZnO NPs induced ferroptosis of spermatocytes through the increase of intracellular chelatable iron content and lipid peroxidation level. Moreover, the transcriptome analysis of testis indicated that ZnO NPs weakened the expression of miR-342-5p, which can target Erc1 to block the NF-κB pathway. Eventually, ferroptosis of spermatocytes was ameliorated by suppressing the expression of Erc1.

CONCLUSIONS

The present study reveals a novel mechanism in that miR-342-5p targeted Erc1 to activate NF-κB signaling pathway is required for ZnO NPs-induced ferroptosis, and provide potential targets for further research on the prevention and treatment of male reproductive disorders related to ZnO NPs.

The emerging role of nuclear receptor coactivator 4 in health and disease: a novel bridge between iron metabolism and immunity

Nuclear receptor coactivator 4 (NCOA4) has recently been recognized as a selective cargo receptor of ferritinophagy participating in ferroptosis. However, NCOA4 is also a coactivator that modulates the transcriptional activity of many vital nuclear receptors. Recent novel studies have documented the role of NCOA4 in healthy and pathogenic conditions via its modulation of iron- and non-iron-dependent metabolic pathways. NCOA4 exhibits non-ferritinophagic and iron-independent features such as promoting tumorigenesis and erythropoiesis, immunomodulation, regulating autophagy, and participating in DNA replication and mitosis. Full-length human-NCOA4 is composed of 614 amino acids, of which the N-terminal (1-237) contains nuclear-receptor-binding domains, while the C-terminal (238-614) principally contains a ferritin-binding domain. The exploration of the protein structure of NCOA4 suggests that NCOA4 possesses additional significant and complex functions based on its structural domains. Intriguingly, another three isoforms of NCOA4 that are produced by alternative splicing have been identified, which may also display disparate activities in physiological and pathological processes. Thus, NCOA4 has become an important bridge that encompasses interactions between immunity and metabolism. In this review, we outline the latest advances in the important regulating mechanisms underlying NCOA4 actions in health and disease conditions, providing insights into potential therapeutic interventions.

Mechanistic elucidation of ferroptosis and ferritinophagy: implications for advancing our understanding of arthritis

In recent years, the emerging phenomenon of ferroptosis has garnered significant attention as a distinctive mode of programmed cell death. Distinguished by its reliance on iron and dependence on reactive oxygen species (ROS), ferroptosis has emerged as a subject of extensive investigation. Mechanistically, this intricate process involves perturbations in iron homeostasis, dampening of system Xc-activity, morphological dynamics within mitochondria, and the onset of lipid peroxidation. Additionally, the concomitant phenomenon of ferritinophagy, the autophagic degradation of ferritin, assumes a pivotal role by facilitating the liberation of iron ions from ferritin, thereby advancing the progression of ferroptosis. This discussion thoroughly examines the detailed cell structures and basic processes behind ferroptosis and ferritinophagy. Moreover, it scrutinizes the intricate web of regulators that orchestrate these processes and examines their intricate interplay within the context of joint disorders. Against the backdrop of an annual increase in cases of osteoarthritis, rheumatoid arthritis, and gout, these narrative sheds light on the intriguing crossroads of pathophysiology by dissecting the intricate interrelationships between joint diseases, ferroptosis, and ferritinophagy. The newfound insights contribute fresh perspectives and promising therapeutic avenues, potentially revolutionizing the landscape of joint disease management.

Regulating NCOA4-Mediated Ferritinophagy for Therapeutic Intervention in Cerebral Ischemia-Reperfusion Injury

Ischemic stroke presents a global health challenge, necessitating an in-depth comprehension of its pathophysiology and therapeutic strategies. While reperfusion therapy salvages brain tissue, it also triggers detrimental cerebral ischemia-reperfusion injury (CIRI). In our investigation, we observed the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy in an oxygen-glucose deprivation/reoxygenation (OGD/R) model using HT22 cells (P < 0.05). This activation contributed to oxidative stress (P < 0.05), enhanced autophagy (P < 0.05) and cell death (P < 0.05) during CIRI. Silencing NCOA4 effectively mitigated OGD/R-induced damage (P < 0.05). These findings suggested that targeting NCOA4-mediated ferritinophagy held promise for preventing and treating CIRI. Subsequently, we substantiated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway effectively regulated the NCOA4-mediated ferritinophagy, by applying the cGAS inhibitor RU.521 and performing NCOA4 overexpression (P < 0.05). Suppressing the cGAS-STING pathway efficiently curtailed ferritinophagy (P < 0.05), oxidative stress (P < 0.05), and cell damage (P < 0.05) of CIRI, while NCOA4 overexpression could alleviate this effect (P < 0.05). Finally, we elucidated the specific molecular mechanism underlying the protective effect of the iron chelator deferoxamine (DFO) on CIRI. Our findings revealed that DFO alleviated hypoxia-reoxygenation injury in HT22 cells through inhibiting NCOA4-mediated ferritinophagy and reducing ferrous ion levels (P < 0.05). However, the protective effects of DFO were counteracted by cGAS overexpression (P < 0.05). In summary, our results indicated that the activation of the cGAS-STING pathway intensified cerebral damage during CIRI by inducing NCOA4-mediated ferritinophagy. Administering the iron chelator DFO effectively attenuated NCOA4-induced ferritinophagy, thereby alleviating CIRI. Nevertheless, the role of the cGAS-STING pathway in CIRI regulation likely involves intricate mechanisms, necessitating further validation in subsequent investigations.

PEDF and 34-mer peptide inhibit cardiac microvascular endothelial cell ferroptosis via Nrf2/HO-1 signalling in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) represents a critical pathology in acute myocardial infarction (AMI), which is characterized by high mortality and morbidity. Cardiac microvascular dysfunction contributes to MIRI, potentially culminating in heart failure (HF). Pigment epithelium-derived factor (PEDF), which belongs to the non-inhibitory serpin family, exhibits several physiological effects, including anti-angiogenesis, anti-inflammatory and antioxidant properties. Our study aims to explore the impact of PEDF and its functional peptide 34-mer on both cardiac microvascular perfusion in MIRI rats and human cardiac microvascular endothelial cells (HCMECs) injury under hypoxia reoxygenation (HR). It has been shown that MIRI is accompanied by ferroptosis in HCMECs. Furthermore, we investigated the effect of PEDF and its 34-mer, particularly regarding the Nrf2/HO-1 signalling pathway. Our results demonstrated that PEDF 34-mer significantly ameliorated cardiac microvascular dysfunction following MIRI. Additionally, they exhibited a notable suppression of ferroptosis in HCMECs, and these effects were mediated through activation of Nrf2/HO-1 signalling. These findings highlight the therapeutic potential of PEDF and 34-mer in alleviating microvascular dysfunction and MIRI. By enhancing cardiac microvascular perfusion and mitigating endothelial ferroptosis, PEDF and its derivative peptide represent promising candidates for the treatment of AMI.

Targeting ferroptosis in neuroimmune and neurodegenerative disorders for the development of novel therapeutics

Neuroimmune and neurodegenerative ailments impose a substantial societal burden. Neuroimmune disorders involve the intricate regulatory interactions between the immune system and the central nervous system. Prominent examples of neuroimmune disorders encompass multiple sclerosis and neuromyelitis optica. Neurodegenerative diseases result from neuronal degeneration or demyelination in the brain or spinal cord, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. The precise underlying pathogenesis of these conditions remains incompletely understood. Ferroptosis, a programmed form of cell death characterised by lipid peroxidation and iron overload, plays a pivotal role in neuroimmune and neurodegenerative diseases. In this review, we provide a detailed overview of ferroptosis, its mechanisms, pathways, and regulation during the progression of neuroimmune and neurodegenerative diseases. Furthermore, we summarise the impact of ferroptosis on neuroimmune-related cells (T cells, B cells, neutrophils, and macrophages) and neural cells (glial cells and neurons). Finally, we explore the potential therapeutic implications of ferroptosis inhibitors in diverse neuroimmune and neurodegenerative diseases.

ISRIB improves white matter injury following TBI by inhibiting NCOA4-mediated ferritinophagy

Traumatic brain injury (TBI) often results in persistent neurological dysfunction, which is closely associated with white matter injury. The mechanisms underlying white matter injury after TBI remain unclear. Ferritinophagy is a selective autophagic process that degrades ferritin and releases free iron, which may cause ferroptosis. Although ferroptosis has been demonstrated to be involved in TBI, it is unclear whether ferritinophagy triggers ferroptosis in TBI. Integrated stress response inhibitor (ISRIB) has neuroprotective properties. However, the effect of ISRIB on white matter after TBI remains uncertain. We aimed to investigate whether ferritinophagy was involved in white matter injury following TBI and whether ISRIB can mitigate white matter injury after TBI by inhibiting ferritinophagy. In this study, controlled cortical impact (CCI) was performed on rats to establish the TBI model. Ferritinophagy was measured by assessing the levels of nuclear receptor coactivator 4 (NCOA4), which regulates ferritinophagy, ferritin heavy chain 1(FTH1), LC3, ATG5, and FTH1 colocalization with LC3 in the white matter. Increased NCOA4 and decreased FTH1 were detected in our study. FTH1 colocalization with LC3 enhanced in the white matter after TBI, indicating that ferritinophagy was activated. Immunofluorescence co-localization results also suggested that ferritinophagy occurred in neurons and oligodendrocytes after TBI. Furthermore, ferroptosis was assessed by determining free iron content, MDA content, GSH content, and Perl's staining. The results showed that ferroptosis was suppressed by NCOA4 knockdown via shNCOA4 lentivirus infection, indicating that ferroptosis in TBI is triggered by ferritinophagy. Besides, NCOA4 deletion notably improved white matter injury following TBI, implying that ferritinophagy contributed to white matter injury. ISRIB treatment reduced the occurrence of ferritinophagy in neurons and oligodendrocytes, attenuated ferritinophagy-induced ferroptosis, and alleviated white matter injury. These findings suggest that NCOA4-mediated ferritinophagy is a critical mechanism underlying white matter injury after TBI. ISRIB holds promise as a therapeutic agent for this condition.

Targeted ferritinophagy in gastrointestinal cancer: from molecular mechanisms to implications

Gastrointestinal cancer is a significant global health burden, necessitating the development of novel therapeutic strategies. Emerging evidence has highlighted the potential of targeting ferritinophagy as a promising approach for the treatment of gastrointestinal cancer. Ferritinophagy is a form of selective autophagy that is mediated by the nuclear receptor coactivator 4 (NCOA4). This process plays a crucial role in regulating cellular iron homeostasis and has been implicated in various pathological conditions, including cancer. This review discusses the molecular mechanisms underlying ferritinophagy and its relevance to gastrointestinal cancer. Furthermore, we highlight the potential therapeutic implications of targeting ferritinophagy in gastrointestinal cancer. Several approaches have been proposed to modulate ferritinophagy, including small molecule inhibitors and immunotherapeutic strategies. We discuss the advantages and challenges associated with these therapeutic interventions and provide insights into their potential clinical applications.

Tumor suppressor Par-4 activates autophagy-dependent ferroptosis

Ferroptosis is a unique iron-dependent form of non-apoptotic cell death characterized by devastating lipid peroxidation. Whilst growing evidence suggests that ferroptosis is a type of autophagy-dependent cell death, the underlying molecular mechanisms regulating ferroptosis are largely unknown. In this study, through an unbiased RNA-sequencing screening, we demonstrate the activation of a multi-faceted tumor-suppressor protein Par-4/PAWR during ferroptosis. Functional studies reveal that genetic depletion of Par-4 effectively blocks ferroptosis, whereas Par-4 overexpression sensitizes cells to undergo ferroptosis. More importantly, we have determined that Par-4-triggered ferroptosis is mechanistically driven by the autophagic machinery. Upregulation of Par-4 promotes activation of ferritinophagy (autophagic degradation of ferritin) via the nuclear receptor co-activator 4 (NCOA4), resulting in excessive release of free labile iron and, hence, enhanced lipid peroxidation and ferroptosis. Inhibition of Par-4 dramatically suppresses the NCOA4-mediated ferritinophagy signaling axis. Our results also establish that Par-4 activation positively correlates with reactive oxygen species (ROS) production, which is critical for ferritinophagy-mediated ferroptosis. Furthermore, Par-4 knockdown effectively blocked ferroptosis-mediated tumor suppression in the mouse xenograft models. Collectively, these findings reveal that Par-4 has a crucial role in ferroptosis, which could be further exploited for cancer therapy.

Ferroptosis: An important mechanism of disease mediated by the gut-liver-brain axis

AIMS

As a unique iron-dependent non-apoptotic cell death, Ferroptosis is involved in the pathogenesis and development of many human diseases and has become a research hotspot in recent years. However, the regulatory role of ferroptosis in the gut-liver-brain axis has not been elucidated. This paper summarizes the regulatory role of ferroptosis and provides theoretical basis for related research.

MATERIALS AND METHODS

We searched PubMed, CNKI and Wed of Science databases on ferroptosis mediated gut-liver-brain axis diseases, summarized the regulatory role of ferroptosis on organ axis, and explained the adverse effects of related regulatory effects on various diseases.

KEY FINDINGS

According to our summary, the main way in which ferroptosis mediates the gut-liver-brain axis is oxidative stress, and the key cross-talk of ferroptosis affecting signaling pathway network is Nrf2/HO-1. However, there were no specific marker between different organ axes mediate by ferroptosis.

SIGNIFICANCE

Our study illustrates the main ways and key cross-talk of ferroptosis mediating the gut-liver-brain axis, providing a basis for future research.

Nuciferine Protects Cochlear Hair Cells from Ferroptosis through Inhibiting NCOA4-Mediated Ferritinophagy

Cisplatin is a widely used antineoplastic drug for treating various types of cancers. However, it can cause severe side effects, such as bilateral and irreversible hearing loss, which significantly impacts quality of life. Ferroptosis, an iron-dependent form of programmed cell death, has been implicated in the pathogenesis of cisplatin-induced ototoxicity. Here, we investigated the effects of nuciferine, a natural active ingredient isolated from lotus species, on the ferroptosis of cochlear hair cells. Firstly, our results demonstrated that nuciferine can protect hair cells against RSL3-induced and cisplatin-induced damage. Secondly, nuciferine treatment reduced ferrous iron (Fe2+) overload in cochlear hair cells via inhibiting NCOA4-mediated ferritinophagy. Inhibition of ferritinophagy by knocking down Ncoa4 alleviated cisplatin-induced ototoxicity. Importantly, nuciferine treatment mitigated cochlear hair cell loss and damage to ribbon synapse, and improved mouse hearing function in an acute cisplatin-induced hearing loss model. Our findings highlight the role of NCOA4-mediated ferritinophagy in the pathogenesis of cisplatin-induced ototoxicity and provide evidence for nuciferine as a promising protective agent for treating cisplatin-induced hearing loss.

18β-Glycyrrhetinic acid protects against deoxynivalenol-induced liver injury via modulating ferritinophagy and mitochondrial quality control

Deoxynivalenol (DON), a widespread mycotoxin, represents a substantial public health hazard due to its propensity to contaminate agricultural produce, leading to both acute and chronic health issues in humans and animals upon consumption. The role of ferroptosis in DON-induced hepatic damage remains largely unexplored. This study investigates the impact of 18β-glycyrrhetinic acid (GA), a prominent constituent of glycyrrhiza, on DON hepatotoxicity and elucidates the underlying mechanisms. Our results indicate that GA effectively attenuates liver injury inflicted by DON. This was achieved by inhibiting nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy and ferroptosis, as well as by adjusting mitochondrial quality control (MQC). Specifically, GA curtails ferritinophagy by diminishing NCOA4 expression without affecting the autophagic flux. At a molecular level, GA binds to and stabilizes programmed cell death protein 4 (PDCD4), thereby inhibiting its ubiquitination and subsequent degradation. This stabilization of PDCD4 leads to the downregulation of NCOA4 via the JNK-Jun-NCOA4 axis. Knockdown of PDCD4 weakened GA's protective action against DON exposure. Furthermore, GA improved mitochondrial function and limited excessive mitophagy and mitochondrial division induced by DON. Disrupting GA's modulation of MQC nullified its anti-ferroptosis effects. Overall, GA offers protection against DON-induced ferroptosis by blocking ferritinophagy and managing MQC. ENVIRONMENTAL IMPLICATION: Food contamination from mycotoxins, is a problem for agricultural and food industries worldwide. Deoxynivalenol (DON), the most common mycotoxins in cereal commodities. A survey in 2023 showed that the positivity rate for DON contamination in food reached more than 70% globally. DON can damage the health of humans whether exposed to high doses for short periods of time or low doses for long periods of time. We have discovered 18β-Glycyrrhetinic acid (GA), a prominent constituent of glycyrrhiza. Liver damage caused by low-dose DON can be successfully treated with GA. This study will support the means of DON control, including antidotes.

From ferroptosis to cuproptosis, and calcicoptosis, to find more novel metals-mediated distinct form of regulated cell death

Regulated cell death (RCD), also known as programmed cell death (PCD), plays a critical role in various biological processes, such as tissue injury/repair, development, and homeostasis. Dysregulation of RCD pathways can lead to the development of many human diseases, such as cancer, neurodegenerative disorders, and cardiovascular diseases. Maintaining proper metal ion homeostasis is critical for human health. However, imbalances in metal levels within cells can result in cytotoxicity and cell death, leading to a variety of diseases and health problems. In recent years, new types of metal overload-induced cell death have been identified, including ferroptosis, cuproptosis, and calcicoptosis. This has prompted us to examine the three defined metal-dependent cell death types, and discuss other metals-induced ferroptosis, cuproptosis, and disrupted Ca2+ homeostasis, as well as the roles of Zn2+ in metals' homeostasis and related RCD. We have reviewed the connection between metals-induced RCD and various diseases, as well as the underlying mechanisms. We believe that further research in this area will lead to the discovery of novel types of metal-dependent RCD, a better understanding of the underlying mechanisms, and the development of new therapeutic strategies for human diseases.

International consensus guidelines for the definition, detection, and interpretation of autophagy-dependent ferroptosis

Macroautophagy/autophagy is a complex degradation process with a dual role in cell death that is influenced by the cell types that are involved and the stressors they are exposed to. Ferroptosis is an iron-dependent oxidative form of cell death characterized by unrestricted lipid peroxidation in the context of heterogeneous and plastic mechanisms. Recent studies have shed light on the involvement of specific types of autophagy (e.g. ferritinophagy, lipophagy, and clockophagy) in initiating or executing ferroptotic cell death through the selective degradation of anti-injury proteins or organelles. Conversely, other forms of selective autophagy (e.g. reticulophagy and lysophagy) enhance the cellular defense against ferroptotic damage. Dysregulated autophagy-dependent ferroptosis has implications for a diverse range of pathological conditions. This review aims to present an updated definition of autophagy-dependent ferroptosis, discuss influential substrates and receptors, outline experimental methods, and propose guidelines for interpreting the results.Abbreviation: 3-MA:3-methyladenine; 4HNE: 4-hydroxynonenal; ACD: accidentalcell death; ADF: autophagy-dependentferroptosis; ARE: antioxidant response element; BH2:dihydrobiopterin; BH4: tetrahydrobiopterin; BMDMs: bonemarrow-derived macrophages; CMA: chaperone-mediated autophagy; CQ:chloroquine; DAMPs: danger/damage-associated molecular patterns; EMT,epithelial-mesenchymal transition; EPR: electronparamagnetic resonance; ER, endoplasmic reticulum; FRET: Försterresonance energy transfer; GFP: green fluorescent protein;GSH: glutathione;IF: immunofluorescence; IHC: immunohistochemistry; IOP, intraocularpressure; IRI: ischemia-reperfusion injury; LAA: linoleamide alkyne;MDA: malondialdehyde; PGSK: Phen Green™ SK;RCD: regulatedcell death; PUFAs: polyunsaturated fatty acids; RFP: red fluorescentprotein;ROS: reactive oxygen species; TBA: thiobarbituricacid; TBARS: thiobarbituric acid reactive substances; TEM:transmission electron microscopy.