The multifaceted role of ferroptosis in liver disease

SUGP2 p.(Arg639Gln) variant is involved in the pathogenesis of hemochromatosis via the CIRBP/BMPER signaling pathway

Pathogenic variants in HFE and non-HFE genes have been identified in hemochromatosis in different patient populations, but there are still a certain number of patients with unexplained primary iron overload. We recently identified in Chinese patients a recurrent p.(Arg639Gln) variant in SURP and G-patch domain containing 2 (SUGP2), a potential mRNA splicing-related factor. However, the target gene of SUGP2 and affected iron-regulating pathway remains unknown. We aimed to investigate the pathogenicity and underlying mechanism of this variant in hemochromatosis. RNA-seq analysis revealed that SUGP2 knockdown caused abnormal alternative splicing of CIRBP pre-mRNA, resulting in an increased normal splicing form of CIRBP V1, which in turn increased the expression of BMPER by enhancing its mRNA stability and translation. Furthermore, RNA-protein pull-down and RNA immunoprecipitation assays revealed that SUGP2 inhibited splicing of CIRBP pre-mRNA by a splice site variant at CIRBP c.492 and was more susceptible to CIRBP c.492 C/C genotype. Cells transfected with SUGP2 p.(Arg639Gln) vector showed up-regulation of CIRBP V1 and BMPER expression and down-regulation of pSMAD1/5 and HAMP expression. CRISPR-Cas9 mediated SUGP2 p.(Arg622Gln) knock-in mice showed increased iron accumulation in the liver, higher total serum iron, and decreased serum hepcidin level. A total of 10 of 54 patients with hemochromatosis (18.5%) harbored the SUGP2 p.(Arg639Gln) variant and carried CIRBP c.492 C/C genotype, and had increased BMPER expression in the liver. Altogether, the SUGP2 p.(Arg639Gln) variant down-regulates hepcidin expression through the SUGP2/CIRBP/BMPER axis, which may represent a novel pathogenic factor for hemochromatosis.

Arsenic-Induced Ferroptosis in Chicken Hepatocytes via the Mitochondrial ROS Pathway

Arsenic has been shown to be highly toxic and can cause liver damage. Previous studies have shown that arsenic causes severe liver damage and induces accumulation of reactive oxygen species (ROS). This study aimed to investigate the effects of ferroptosis on the liver in arsenic trioxide (ATO) and to explore the underlying mechanisms. We confirmed the hepatotoxic effects of arsenic by in vivo and in vitro experiments. After 28 days of administration of arsenic trioxide (4-mg/kg, 8-mg/kg) by gavage, chickens exhibited body weight loss and liver damage in a dose-dependent manner. In addition, in vivo and in vitro western blot and real-time fluorescence quantitative PCR analyses simultaneously indicated that ferroptosis might be the main pathway of arsenic-induced liver injury. Finally, Mito-TEMPO effectively eliminated the ROS accumulation in mitochondria, significantly attenuating the process of cellular ferroptosis. In summary, the hepatotoxic effects of arsenic are related to ferroptosis, and the hepatic ferroptosis process of arsenic is regulated by mitochondrial ROS (MtROS). Our study reveals new mechanisms of arsenic toxicity to the liver, which may deepen our understanding of arsenic toxicology.

Discovery of a NCOA4 Degrader for Labile Iron-Dependent Ferroptosis Inhibition

Ferroptosis, a distinctive form of programmed cell death, has been implicated in numerous pathological conditions, and its inhibition is considered a promising therapeutic strategy. Currently, there is a scarcity of efficient antagonists for directly regulating intracellular ferrous iron. Ferritinophagy, an essential process for supplying intracellular labile iron, relies on nuclear receptor coactivator 4 (NCOA4), a selective autophagy receptor for the ferritin iron storage complex, thus playing a pivotal role in ferritinophagy. In this study, we reported a novel von Hippel-Lindau-based NCOA4 degrader, V3, as a potent ferroptosis inhibitor with an intracellular ferrous iron inhibition mechanism. V3 significantly reduced NCOA4 levels and downregulated intracellular ferrous iron (Fe2+) levels, thereby effectively suppressing ferroptosis induced by multiple pathways within cells and alleviating liver damage. This research presents a chemical knockdown tool targeting NCOA4 for further exploration into intracellular ferrous iron in ferroptosis, offering a promising therapeutic avenue for ferroptosis-related acute liver injury.

Integrative analysis of ferroptosis-related genes reveals that ABHD12 is a novel prognostic biomarker and facilitates hepatocellular carcinoma tumorigenesis

Hepatocellular carcinoma (HCC) is a highly heterogeneous disease, making the prognostic prediction challenging. Ferroptosis, an iron-dependent form of cell death, is a key regulator in the initiation, progression, and metastasis of HCC. However, the expression and function of ferroptosis-related genes (FRGs) in HCC remained largely unclear. In this study, we analyzed TCGA datasets and identified 58 survival-related deferentially expressed FRGs (DE-FRGs). Then, based on the results of LASSO analysis, we developed a novel prognostic model based on 12 survival-related DE-FRGs. Survival assays indicated a strong prognostic ability of this new model in predicting clinical prognosis of HCC patients. In addition, we conducted an exploration of molecular subtypes related to HCC and delved into the associated immune characteristics and gene expression patterns. Among the 12 survival-related DE-FRGs, our attention focused on ABHD12 (abhydrolase domain containing 12) which was highly expressed in HCC and associated with advanced clinical stages. Multivariate assays confirmed that ABHD12 was a significant prognostic factor for HCC patients. Immune analysis revealed that ABHD12 may play an important role in tumor microenvironment. Finally, we performed RT-PCR and confirmed that ABHD12 was highly expressed in HCC cells. Functional experiments revealed that ABHD12 knockdown may suppress the proliferation and migration of HCC cells. These findings emphasized the significance of ABHD12 as a potential prognostic marker for HCC and its crucial role in the field of tumor biology. Additionally, the study introduces a novel survival model that holds promise for enhancing prognostic predictions in HCC patients. Overall, this research provided valuable insights for a deeper comprehension of the complexity of HCC and the development of personalized treatment strategies.

Preventive effects of lactoferrin on acute alcohol-induced liver injury via iron chelation and regulation of iron metabolism

Lactoferrin is widely found in milk and has the ability to bind iron. Previous studies have reported that lactoferrin was effective in the prevention and treatment of acute alcohol-induced liver injury (AALI). Ferroptosis is a recently discovered cell death and is involved in the development of AALI. However, the potential role of lactoferrin in acute alcohol-induced ferroptosis is still unclear. In this study, we observed that lactoferrin (10, 20, and 40 μg/mL) significantly mitigated alcohol (300 mM)-induced injury in vitro. Additionally, lactoferrin (100 and 200 mg/kg BW) significantly alleviated alcohol (4.8 g/kg BW)-induced injury in vivo. Our results showed that lactoferrin inhibited alcohol-induced upregulation of the ferroptosis marker protein ACSL4 and downregulation of GPX4. Meanwhile, lactoferrin treatment successfully reversed the elevated malondialdehyde (MDA) levels and the reduced glutathione (GSH) levels caused by alcohol treatment. These results may indicate that lactoferrin significantly decreased ferroptosis in vivo and in vitro. Lactoferrin has the potential to chelate iron, and our results showed that lactoferrin (20 μg/mL) significantly reduced iron ions and the expression of the ferritin heavy chain (FTH) under FeCl3 (100 μM) treatment. It was demonstrated that lactoferrin had a significant iron-chelating effect and reduced iron overload caused by FeCl3 in AML12 cells. Next, we examined iron content and the expression of iron metabolism marker proteins transferrin receptor (TFR), divalent metal transporter 1 (DMT1), FTH, and ferroportin (FPN). Our results showed that lactoferrin alleviated iron overload induced by acute alcohol. The expression of TFR and DMT1 was downregulated, and FPN and FTH were upregulated after lactoferrin treatment in vivo and in vitro. Above all, the study suggested that lactoferrin can alleviate AALI by mitigating acute alcohol-induced ferroptosis. Lactoferrin may offer new strategies for the prevention or treatment of AALI.

Oxidative Stress-Mediated Programmed Cell Death: a Potential Therapy Target for Atherosclerosis

Nowadays, as a type of orderly and active death determined by genes, programmed cell death (PCD), including apoptosis, pyroptosis, ferroptosis, and necroptosis, has attracted much attention owing to its participation in numerous chronic cardiovascular diseases, especially atherosclerosis (AS), a canonical chronic inflammatory disease featured by lipid metabolism disturbance. Abundant researches have reported that PCD under distinct internal conditions fulfills different roles of atherosclerotic pathological processes, including lipid core expansion, leukocyte adhesion, and infiltration. Noteworthy, emerging evidence recently has also suggested that oxidative stress (OS), an imbalance of antioxidants and oxygen free radicals, has the potential to mediate PCD occurrence via multiple ways, including oxidization and deubiquitination. Interestingly, more recently, several studies have proposed that the mediating mechanisms could effect on the atherosclerotic initiation and progression significantly from variable aspects, so it is of great clinical importance to clarify how OS-mediated PCD and AS interact. Herein, with the aim of summarizing potential and sufficient atherosclerotic therapy targets, we seek to provide extensive analysis of the specific regulatory mechanisms of PCD mediated by OS and their multifaceted effects on the entire pathological atherosclerotic progression.

Ferroptosis: a new target for hepatic ischemia-reperfusion injury?

Ischemia-reperfusion injury (IRI) can seriously affect graft survival and prognosis and is an unavoidable event during liver transplantation. Ferroptosis is a novel iron-dependent form of cell death characterized by iron accumulation and overwhelming lipid peroxidation; it differs morphologically, genetically, and biochemically from other well-known cell death types (autophagy, necrosis, and apoptosis). Accumulating evidence has shown that ferroptosis is involved in the pathogenesis of hepatic IRI, and targeting ferroptosis may be a promising therapeutic approach. Here, we review the pathways and phenomena involved in ferroptosis, explore the associations and implications of ferroptosis and hepatic IRI, and discuss possible strategies for modulating ferroptosis to alleviate the hepatic IRI.

Antimony trioxide nanoparticles promote ferroptosis in developing zebrafish (Danio rerio) by disrupting iron homeostasis

The widespread use of antimony trioxide (ATO) and ATO nanoparticles (nATO) has led to increasing ecological and health risks. However, there is relatively insufficient research on the aquatic ecotoxicology of nATO. This study revealed that nATO affects the development of zebrafish embryos and mainly induces ferroptosis through the dissolution of Sb(III). The size of nATO ranged from 50 to 250 nm, and it generated free radicals in water. It can be ingested and accumulate in zebrafish larvae and affects normal development. Compared with those in the control group, the levels of reactive oxygen species (ROS), cell apoptosis, mitochondrial damage and iron content in the group exposed to high concentrations of nATO were increased. The transcriptomics results indicated that nATO significantly altered the expression levels of key genes related to glutathione metabolism and ferroptosis. Quantitative polymerase chain reaction consistently demonstrated the reliability of the transcriptome data and revealed that nATO induced ferroptosis by disrupting iron homeostasis and the key factor is the dissolution of Sb(III). Furthermore, ferrostatin-1, an inhibitor of ferroptosis, decreased the levels of ROS, apoptosis and mitochondrial damage induced by nATO, which further prove that nATO can promote ferroptosis. This work deepens the understanding of the ecological toxicological effects of nATO in aquatic environments and its mechanisms, which is highly important for the development of antimony management strategies.

Ferroptosis is involved in Staphylococcus aureus-induced mastitis through autophagy activation by endoplasmic reticulum stress

Cell death caused by severe Staphylococcus aureus (S. aureus) infection is a fatal threat to humans and animals. However, whether ferroptosis, an iron-dependent form of cell death, is involved in S. aureus-induced cell death and its role in S. aureus-induced diseases are unclear. Using a mouse mastitis model and mammary epithelial cells (MMECs), we investigated the role of ferroptosis in the pathogenesis of S. aureus infection. The results revealed that S. aureus-induced ferroptosis in vivo and in vitro as demonstrated by dose-dependent increases in cell death; the level of malondialdehyde (MDA), the final product of lipid peroxidation; and dose-dependent decrease the production of the antioxidant glutathione (GSH). Treatment with typical inhibitors of ferroptosis, including ferrostatin-1 (Fer-1) and deferiprone (DFO), significantly inhibited S. aureus-induced death in MMECs. Mechanistically, treatment with S. aureus activated the protein kinase RNA-like ER kinase (PERK)-eukaryotic initiation factor 2, α subunit (eIF2α)-activating transcription factor 4 (ATF4)-C/EBP homologous protein (CHOP) pathway, which subsequently upregulated autophagy and promoted S. aureus-induced ferroptosis. The activation of autophagy degraded ferritin, resulting in iron dysregulation and ferroptosis. In addition, we found that excessive reactive oxygen species (ROS) production induced ferroptosis and activated endoplasmic reticulum (ER) stress, manifesting as elevated p-PERK-p-eIF2α-ATF4-CHOP pathway protein levels. Collectively, our findings indicate that ferroptosis is involved in S. aureus-induced mastitis via ER stress-mediated autophagy activation, implying a potential strategy for the prevention of S. aureus-associated diseases by targeting ferroptosis. In conclusion, the ROS-ER stress-autophagy axis is involved in regulating S. aureus-induced ferroptosis in MMECs. These findings not only provide a new potential mechanism for mastitis induced by S. aureus but also provide a basis for the treatment of other ferroptotic-related diseases.

Discovery of New Phenyltetrazolium Derivatives as Ferroptosis Inhibitors for Treating Ischemic Stroke: An Example Development from Free Radical Scavengers

Ferroptosis is a promising therapeutic target for injury-related diseases, yet diversity in ferroptosis inhibitors remains limited. In this study, initial structure optimization led us to focus on the bond dissociation enthalpy (BDE) of the N-H bond and the residency time of radical scavengers in a phospholipid bilayer, which may play an important role in ferroptosis inhibition potency. This led to the discovery of compound D1, exhibiting potent ferroptosis inhibition, high radical scavenging, and moderate membrane permeability. D1 demonstrated significant neuroprotection in an oxygen glucose deprivation/reoxygenation (OGD/R) model and reduced infarct volume in an in vivo stroke model upon intravenous treatment. Further screening based on this strategy identified NecroX-7 and Eriodictyol-7-O-glucoside as novel ferroptosis inhibitors with highly polar structural characteristics. This approach bridges the gap between free radical scavengers and ferroptosis inhibitors, providing a foundation for research and insights into novel ferroptosis inhibitor development.

BACH1 inhibits senescence, obesity, and short lifespan by ferroptotic FGF21 secretion

Ferroptosis is a type of regulated cell death characterized by iron-dependent lipid peroxidation. A model cell system is constructed to induce ferroptosis by re-expressing the transcription factor BACH1, a potent ferroptosis inducer, in immortalized mouse embryonic fibroblasts (iMEFs). The transfer of the culture supernatant from ferroptotic iMEFs activates the proliferation of hepatoma cells and other fibroblasts and suppresses cellular senescence-like features. The BACH1-dependent secretion of the longevity factor FGF21 is increased in ferroptotic iMEFs. The anti-senescent effects of the culture supernatant from these iMEFs are abrogated by Fgf21 knockout. BACH1 activates the transcription of Fgf21 by promoting ferroptotic stress and increases FGF21 protein expression by suppressing its autophagic degradation through transcriptional Sqstm1 and Lamp2 repression. The BACH1-induced ferroptotic FGF21 secretion suppresses obesity in high-fat diet-fed mice and the short lifespan of progeria mice. The inhibition of these aging-related phenotypes can be physiologically significant regarding ferroptosis.

The emerging roles of hydrogen sulfide in ferroptosis

SIGNIFICANCE

Ferroptosis, a form of regulated cell death characterized by a large amount of lipid peroxidation-mediated membrane damage, joins the evolution of multisystem diseases. For instance, neurodegenerative diseases, chronic obstructive pulmonary disease and acute respiratory distress syndrome, osteoporosis and osteoarthritis, and so on. Since being identified as the third gasotransmitter in living organisms, the intricate role of hydrogen sulfide (H2S) in ferroptosis has emerged at the forefront of research.

RECENT ADVANCES

The discovery of novel targets in the relevant metabolic pathways, including transferrin receptor 1, cystine/glutamate antiporter, and others, coupled with the exploration of new signaling pathways, particularly the p53 signaling pathway and the nitric oxide / nuclear factor erythroid 2-related factor 2 signaling pathway, and so on. Many diseases such as emphysema and airway inflammation, myocardial diseases, endothelial dysfunction in aging arteries, and traumatic brain injury have recently been found to be alleviated directly by H2S inhibition of ferroptosis. Safe, effective, and tolerable novel H2S donors have been developed and have shown promising results in phase I clinical trials.

CRITICAL ISSUES

Complicated crosstalk between ferroptosis signaling pathway and oncogenic factors results in the risk of cancer when inhibiting ferroptosis. Notably, targeted delivery of H2S is still a challenging task.

FUTURE DIRECTIONS

Discovering more reliable and stable novel H2S donors and achieving their targeted delivery will enable further clinical trials for diseases associated with ferroptosis inhibition by H2S, determining their safety, efficacy, and tolerance.

Inhibition of ethanol-induced eNAMPT secretion attenuates liver ferroptosis through BAT-Liver communication

BACKGROUND & AIMS

Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) has long been recognized as an adipokine. However, the exact role of eNAMPT in alcoholic liver disease (ALD) and its relevance to brown adipose tissue (BAT) remain largely unknown. This study aimed to evaluate the impact of eNAMPT on liver function and the underlying mechanisms involved in BAT-Liver communication.

METHODS

Serum eNAMPT levels were detected in the serum of both ALD patients and mice. Chronic and binge ethanol feeding was used to induce alcoholic liver injury in mice. An eNAMPT antibody, a coculture model of brown adipocytes and hepatocytes, and BAT-specific Nampt knockdown mice were used to investigate the role of eNAMPT in ALD.

RESULTS

Serum eNAMPT levels are elevated in ALD patients and are significantly positively correlated with the liver injury index. In ALD mice, neutralizing eNAMPT reduced the elevated levels of circulating eNAMPT induced by ethanol and attenuated liver injury. In vitro experiments revealed that eNAMPT induced hepatocyte ferroptosis through the TLR4-dependent mitochondrial ROS-induced ferritinophagy pathway. Furthermore, ethanol stimulated eNAMPT secretion from brown adipocytes but not from other adipocytes. In the coculture model, ethanol-induced release of eNAMPT from brown adipocytes promoted hepatocyte ferroptosis. In BAT-specific Nampt-knockdown mice, ethanol-induced eNAMPT secretion was significantly reduced, and alcoholic liver injury were attenuated. These effects can be reversed by intraperitoneal injection of eNAMPT.

CONCLUSION

Inhibition of ethanol-induced eNAMPT secretion from BAT attenuates liver injury and ferroptosis. Our study reveals a previously uncharacterized critical role of eNAMPT-mediated BAT-Liver communication in ALD and highlights its potential as a therapeutic target.

Integrating Network Pharmacology with in vitro Experiments to Validate the Efficacy of Celastrol Against Hepatocellular Carcinoma Through Ferroptosis

Background

As a traditional Chinese medicine monomer derived from Tripterygium wilfordii Hook.f. with potential anticancer activity, celastrol can induce ferroptosis in hepatic stellate cells and inhibit their activation to alleviate liver fibrosis. Activation of ferroptosis can effectively inhibit Hepatocellular carcinoma (HCC). Whether celastrol inhibits HCC by inducing ferroptosis remains to be studied.

Purpose

To explore the potential targets of celastrol against HCC through ferroptosis based on network pharmacology and to verify the anticancer effect of celastrol on HepG2 cells.

Methods

We collected celastrol targets, HCC, and ferroptosis-related genes through online databases, and got their intersection targets. Subsequently, we obtained a protein-protein interaction (PPI) network, and performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to gain key genes for further study. They were verified in vitro and were performed molecular docking. The changes in cell proliferation and ferroptosis characteristics of HepG2 cells after celastrol treatment were detected.

Results

31 core target genes were screened for PPI network and enrichment analysis. The most significantly related KEGG pathway was chemical carcinogenesis-reactive oxygen species. The mRNA and protein levels of GSTM1 were significantly decreased after celastrol treatment. Molecular docking demonstrated the interaction between celastrol and GSTM1. Ferroptosis was induced and cell proliferation was inhibited by celastrol in HCC cells.

Conclusion

Celastrol induces ferroptosis in HCC via regulating GSTM1 expression and may serve as a novel therapeutic compound with clinical potential in HCC treatment.

LACTB suppresses liver cancer progression through regulation of ferroptosis

Ferroptosis, driven by iron-dependent phospholipid peroxidation, is emerging as an intrinsic cancer defense mechanism. However, the regulatory networks involved in ferroptosis remain largely unknown. Here, we found that serine beta-lactamase-like protein (LACTB) inhibits liver cancer progression by regulating ferroptosis. LACTB is downregulated in liver cancer, and the ectopic expression of LACTB markedly inhibits cell viability, colony formation, and tumour growth. LACTB knockout exerts the opposite effects. Further investigation revealed that LACTB blocks HSPA8 transcription in a p53-dependent manner, resulting in the elevation of NCOA4-mediated ferritinophagy and inhibition of SLC7A11/GSH/GPX4 signalling, thereby triggering ferroptosis and suppressing liver cancer progression. Liver cancer cells with an endogenous mutation of p53 binding site in the HSPA8 promoter exhibited increased resistance to ferroptosis inducers, and the ferroptosis-promoting effect of LACTB was significantly weakened in these mutant cells. Importantly, LACTB is identified as a downstream target of lenvatinib, and adeno-associated virus-mediated overexpression and knockdown of LACTB notably enhance and attenuate the anti-tumour efficacy of lenvatinib in vivo, respectively. Taken together, our study reveals a novel action of LACTB and provides potential therapeutic strategies for enhancing the efficacy of lenvatinib in liver cancer.

Hepatoprotective potential of four fruit extracts rich in different structural flavonoids against alcohol-induced liver injury via gut microbiota-liver axis

Alcoholic liver injury (ALI) accounts for a major share of the global burden of non-viral liver disease. In the absence of specialized medications, research on using fruit flavonoids as a treatment is gaining momentum. This study investigated the hepatoprotective effects of four fruits rich in structurally diverse flavonoids: ougan (Citrus reticulata cv. Suavissima, OG), mulberry (Morus alba L., MB), apple (Malus × domestica Borkh., AP), and turnjujube (Hovenia dulcis Thunnb., TJ). A total of one flavanone glycoside, three polymethoxyflavones, two anthocyanins, one flavonol glycoside, and one dihydroflavonol were identified through UPLC analysis. In an acute ethanol-induced ALI mouse model, C57BL/6J mice were supplemented with 200 mg/kg·BW/day of different fruit extracts for three weeks. Our results showed that the four extracts exhibited promising benefits in improving lipid metabolism disorders, iron overload, and oxidative stress. RT-PCR and Western blot tests suggested that the potential mechanism may partially be attributed to the activation of the NRF2-mediated antioxidant response and the inhibition of ferroptosis pathways. Furthermore, fruit extracts administration demonstrated a specific regulatory role in intestinal microecology, with increases in beneficial bacteria such as Dubosiella, Lactobacillus, and Bifidobacterium. Spearman correlation analysis revealed strong links between intestinal flora, lipid metabolism, and iron homeostasis, implying that the fruit extracts mitigated ALI via the gut microbiota-liver axis. In vitro experiments reaffirmed the activity against ethanol-induced oxidative damage and highlighted the positive effects of flavonoid components. These findings endorse the prospective application of OG, MB, AP, and TJ as dietary supplements or novel treatments for ALI.

Ferroptosis crosstalk in anti-tumor immunotherapy: molecular mechanisms, tumor microenvironment, application prospects

Immunotherapies for cancer, specifically immune checkpoint inhibition (ICI), have shown potential in reactivating the body's immune response against tumors. However, there are challenges to overcome in addressing drug resistance and improving the effectiveness of these treatments. Recent research has highlighted the relationship between ferroptosis and the immune system within immune cells and the tumor microenvironment (TME), suggesting that combining targeted ferroptosis with immunotherapy could enhance anti-tumor effects. This review explores the potential of using immunotherapy to target ferroptosis either alone or in conjunction with other therapies like immune checkpoint blockade (ICB) therapy, radiotherapy, and nanomedicine synergistic treatments. It also delves into the roles of different immune cell types in promoting anti-tumor immune responses through ferroptosis. Together, these findings provide a comprehensive understanding of synergistic immunotherapy focused on ferroptosis and offer innovative strategies for cancer treatment.

Toxicity and related molecular mechanisms of Sb(III) in the embryos and larvae of zebrafish (Danio rerio)

Antimony (Sb) pollution poses a severe threat to humans and ecosystems due to the extensive use of Sb in various fields. However, little is known about the toxic effects of Sb and its aquatic ecotoxicological mechanism. This study aimed to reveal the toxicity and related molecular mechanisms of trivalent Sb (Sb(III)) in zebrafish embryos/larvae. Sb(III) accumulated in larvae, which correlated with the exposure concentration. Although no significant lethal or teratogenic effects were observed, normal growth and development were affected. Exposure to 10 or 20 mg/L Sb(III) increased the levels of reactive oxygen species in the larvae while enhancing catalase activity and increasing cell apoptosis. Transcriptomic analysis revealed that Sb(III) promoted glutathione metabolism and the ferroptosis pathway. In addition, symptoms associated with ferroptosis, including mitochondrial damage, biochemical levels of related molecules and increased tissue iron content, were detected. Quantitative polymerase chain reaction (qPCR) analyses further confirmed that Sb(III) significantly altered the transcription levels of genes related to the ferroptosis pathway by disrupting iron homeostasis. Furthermore, ferrostatin-1 (Fer-1) mitigated the toxic effects induced by Sb(III) in zebrafish. Our research fills the gap in the literature on the toxicity and mechanism of Sb(III) in aquatic organisms, which is highly important for understanding the ecological risks associated with Sb.

Intricate effects of post-translational modifications in liver cancer: mechanisms to clinical applications

Liver cancer is a significant global health challenge, with hepatocellular carcinoma (HCC) being the most prevalent form, characterized by high incidence and mortality rates. Despite advances in targeted therapies and immunotherapies, the prognosis for advanced liver cancer remains poor. This underscores the urgent need for a deeper understanding of the molecular mechanisms underlying HCC to enable early detection and the development of novel therapeutic strategies. Post-translational modifications (PTMs) are crucial regulatory mechanisms in cellular biology, affecting protein functionality, interactions, and localization. These modifications, including phosphorylation, acetylation, methylation, ubiquitination, and glycosylation, occur after protein synthesis and play vital roles in various cellular processes. Recent advances in proteomics and molecular biology have highlighted the complex networks of PTMs, emphasizing their critical role in maintaining cellular homeostasis and disease pathogenesis. Dysregulation of PTMs has been associated with several malignant cellular processes in HCC, such as altered cell proliferation, migration, immune evasion, and metabolic reprogramming, contributing to tumor growth and metastasis. This review aims to provide a comprehensive understanding of the pathological mechanisms and clinical implications of various PTMs in liver cancer. By exploring the multifaceted interactions of PTMs and their impact on liver cancer progression, we highlight the potential of PTMs as biomarkers and therapeutic targets. The significance of this review lies in its potential to inform the development of novel therapeutic approaches and improve prognostic tools for early intervention in the fight against liver cancer.

Association of Obstructive Sleep Apnea with Nonalcoholic Fatty Liver Disease: Evidence, Mechanism, and Treatment

Obstructive sleep apnea (OSA), a common sleep-disordered breathing condition, is characterized by intermittent hypoxia (IH) and sleep fragmentation and has been implicated in the pathogenesis and severity of nonalcoholic fatty liver disease (NAFLD). Abnormal molecular changes mediated by IH, such as high expression of hypoxia-inducible factors, are reportedly involved in abnormal pathophysiological states, including insulin resistance, abnormal lipid metabolism, cell death, and inflammation, which mediate the development of NAFLD. However, the relationship between IH and NAFLD remains to be fully elucidated. In this review, we discuss the clinical correlation between OSA and NAFLD, focusing on the molecular mechanisms of IH in NAFLD progression. We meticulously summarize clinical studies evaluating the therapeutic efficacy of continuous positive airway pressure treatment for NAFLD in OSA. Additionally, we compile potential molecular biomarkers for the co-occurrence of OSA and NAFLD. Finally, we discuss the current research progress and challenges in the field of OSA and NAFLD and propose future directions and prospects.

Unveiling the role of ferroptosis in the progression from NAFLD to NASH: recent advances in mechanistic understanding

Non-alcoholic fatty liver disease (NAFLD) is a prevalent and significant global public health issue. Nonalcoholic steatohepatitis (NASH) represents an advanced stage of NAFLD in terms of pathology. However, the intricate mechanisms underlying the progression from NAFLD to NASH remain elusive. Ferroptosis, characterized by iron-dependent cell death and distinguished from other forms of cell death based on morphological, biochemical, and genetic criteria, has emerged as a potential participant with a pivotal role in driving NAFLD progression. Nevertheless, its precise mechanism remains poorly elucidated. In this review article, we comprehensively summarize the pathogenesis of NAFLD/NASH and ferroptosis while highlighting recent advances in understanding the mechanistic involvement of ferroptosis in NAFLD/NASH.

Apomorphine Suppresses the Progression of Steatohepatitis by Inhibiting Ferroptosis

The role of ferroptosis in steatohepatitis development is largely unknown. We investigated (1) whether hepatocyte ferroptosis occurs in a gene-modified steatohepatitis model without modifying dietary components, (2) whether ferroptosis occurs at an early stage of steatohepatitis, and (3) whether apomorphine, recently reported as a ferroptosis inhibitor, can ameliorate steatohepatitis. Hepatocyte-specific PTEN KO mice were used. Huh 7 and primary cultured hepatocytes isolated from the mice were used in this study. The number of dead cells increased in 10-week-old PTEN KO mice. This cell death was suppressed by the administration of ferroptosis inhibitor ferrostatin-1 for 2 weeks. Apomorphine also ameliorated the severity of steatohepatitis. Treatment with ferroptosis inhibitors, including apomorphine, decreases the level of lipid peroxidase. Apomorphine suppressed cell death induced by RSL-3 (a ferroptosis inducer), which was not suppressed by apoptosis or necroptosis inhibitors. Apomorphine showed a radical trapping capacity with much more potent activity than ferrostatin-1 and Trolox, a soluble form of vitamin E. In addition, apomorphine activated nrf2 and its downstream genes, including HO-1 and xCT. In conclusion, ferroptosis occurs in steatohepatitis from an early stage in PTEN KO mice. In addition, apomorphine ameliorates the severity of steatohepatitis by inhibiting ferroptosis.

Polyacrylic Acid-Coated Selenium-Doped Carbon Dots Inhibit Ferroptosis to Alleviate Chemotherapy-Associated Acute Kidney Injury

Cisplatin-associated acute kidney injury (AKI) is a severe clinical syndrome that significantly restricts the chemotherapeutic application of cisplatin in cancer patients. Ferroptosis, a newly characterized programmed cell death driven by the lethal accumulation of lipid peroxidation, is widely reported to be involved in the pathogenesis of cisplatin-associated AKI. Targeted inhibition of ferroptosis holds great promise for developing novel therapeutics to alleviate AKI. Unfortunately, current ferroptosis inhibitors possess low bioavailability or perform non-specific accumulation in the body, making them inefficient in alleviating cisplatin-associated AKI or inadvertently reducing the anti-tumor efficacy of cisplatin, thus not suitable for clinical application. In this study, a novel selenium nanomaterial, polyacrylic acid-coated selenium-doped carbon dots (SeCD), is rationally developed. SeCD exhibits high biocompatibility and specifically accumulates in the kidney. Administration of SeCD effectively scavenges broad-spectrum reactive oxygen species and significantly facilitates GPX4 expression by releasing selenium, resulting in strong mitigation of ferroptosis in renal tubular epithelial cells and substantial alleviation of cisplatin-associated AKI, without compromising the chemotherapeutic efficacy of cisplatin. This study highlights a novel and promising therapeutic approach for the clinical prevention of AKI in cancer patients undergoing cisplatin chemotherapy.

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.

N6-methyladenosine (m6A) reader YTHDF2 accelerates endothelial cells ferroptosis in cerebrovascular atherosclerosis

Cerebrovascular diseases have extreme high mortality and disability rate worldwide, and endothelial cells injury-induced atherosclerosis acts as the main cause of cerebrovascular disease. Ferroptosis is a novel type of programmed cell death depending on iron-lipid peroxidation. Recent studies have revealed that ferroptosis might promote the progression of atherosclerosis (AS). Here, this research aimed to investigate the function and its profound mechanism on vascular endothelial cells in atherosclerosis. Research results revealed that YTHDF2 expression up-regulated in ox-LDL treated human umbilical vein endothelial cells (HUVECs). Gain/loss functional assays indicated that YTHDF2 overexpression inhibited HUVECs' proliferation and accelerated the ferroptosis in ox-LDL-administered HUVECs. Meanwhile, YTHDF2 silencing promoted cell proliferation and reduced the ferroptosis in ox-LDL-administered HUVECs. Mechanistically, in silico analysis suggested that there were potential m6A-modified sites on SLC7A11 mRNA, and YTHDF2 could bind with SLC7A11 mRNA via m6A-dependent manner. YTHDF2 promoted the degradation of SLC7A11 mRNA, thereby reducing its mRNA stability. Taken together, these findings suggest that YTHDF2 accelerates endothelial cells ferroptosis in cerebrovascular atherosclerosis, helping us enhance our comprehension on cerebrovascular disease pathological physiology.

Cadmium aggravates liver injury by activating ferroptosis and neutrophil extracellular traps formation in Nile tilapia (Oreochromis niloticus)

Cadmium (Cd) is a pervasive environmental contaminant and a significant risk factor for liver injury. The present study was undertaken to evaluate the involvement of ferroptosis and neutrophil extracellular traps (NETs) in Cd-induced liver injury in Nile tilapia (Oreochromis niloticus), and to explore its underlying mechanism. Cd-induced liver injury was associated with increased total iron, malondialdehyde (MDA), and Acyl-CoA synthetase long-chain family member 4 (ACSL4), together with reduced levels of glutathione, glutathione peroxidase-4a (Gpx4a), and solute carrier family 7 member 11 (SLC7A11), which are all hallmarks of ferroptosis. Moreover, liver hyperemia, neutrophil infiltration, increased inflammatory factors and myeloperoxidase, as well as elevated serum DNA content in Cd-stimulated Nile tilapia suggested that a considerable number of neutrophils were recruited to the liver. Furtherly, in vitro experiments demonstrated that Cd induced the formation of NETs, and the possible mechanism was related to the generation of reactive oxygen species and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, along with the P38 and extracellular regulated protein kinase (ERK) signaling pathways. We concluded that ferroptosis and NETs are the critical mechanisms contributing to Cd-induced liver injury in Nile tilapia. These findings will contribute to Cd toxicological studies in aquatic animals.

Astragaloside IV ameliorates cisplatin-induced liver injury by modulating ferroptosis-dependent pathways

ETHNOPHARMACOLOGICAL RELEVANCE

The use of antineoplastic drugs, such as cisplatin, in clinical practice can cause adverse effects in patients, such as liver injury, which limits their long-term use. Therefore, there is an urgent need to develop alternative therapeutic strategies or drugs to minimize cisplatin-induced liver injury. Huangqi, the root of Astragalus membranaceus, is extensively used in traditional Chinese medicine (TCM) and has been employed in treating diverse liver injuries. Astragalus membranaceus contains several bioactive constituents, including triterpenoid saponins, one of which, astragaloside IV (ASIV), has been reported to have anti-inflammatory and antioxidant stress properties. However, its potential in ameliorating cisplatin-induced liver injury has not been explored.

AIM OF THE STUDY

The objective of this study was to examine the mechanism by which ASIV protects against cisplatin-induced liver injury.

MATERIALS AND METHODS

This study established a model of cisplatin-induced liver injury in mice, followed by treatment with various doses of astragaloside IV (40 mg/kg, 80 mg/kg). In addition, a model of hepatocyte ferroptosis in AML-12 cells was established using RSL3. The mechanism of action of astragaloside IV was investigated using a range of methods, including Western blot assay, qPCR, immunofluorescence, histochemistry, molecular docking, and high-content imaging system.

RESULTS

The findings suggested a significant improvement in hepatic injury, inflammation and oxidative stress phenotypes with the administration of ASIV. Furthermore, network pharmacological analyses provided evidence that a major pathway for ASIV to attenuate cisplatin-induced hepatic injury entailed the cell death cascade pathway. It was observed that ASIV effectively inhibited ferroptosis both in vivo and in vitro. Subsequent experimental outcomes provided further validation of ASIV's ability to hinder ferroptosis through the inhibition of PPARα/FSP1 signaling pathway. The current findings suggest that ASIV could function as a promising phytotherapy composition to alleviate cisplatin-induced liver injury.

CONCLUSIONS

The current findings suggest that astragaloside IV could function as a promising phytotherapy composition to alleviate cisplatin-induced liver injury.

Emerging roles of ferroptosis in pulmonary fibrosis: current perspectives, opportunities and challenges

Pulmonary fibrosis (PF) is a chronic interstitial lung disorder characterized by abnormal myofibroblast activation, accumulation of extracellular matrix (ECM), and thickening of fibrotic alveolar walls, resulting in deteriorated lung function. PF is initiated by dysregulated wound healing processes triggered by factors such as excessive inflammation, oxidative stress, and coronavirus disease (COVID-19). Despite advancements in understanding the disease's pathogenesis, effective preventive and therapeutic interventions are currently lacking. Ferroptosis, an iron-dependent regulated cell death (RCD) mechanism involving lipid peroxidation and glutathione (GSH) depletion, exhibits unique features distinct from other RCD forms (e.g., apoptosis, necrosis, and pyroptosis). Imbalance between reactive oxygen species (ROS) production and detoxification leads to ferroptosis, causing cellular dysfunction through lipid peroxidation, protein modifications, and DNA damage. Emerging evidence points to the crucial role of ferroptosis in PF progression, driving macrophage polarization, fibroblast proliferation, and ECM deposition, ultimately contributing to alveolar cell death and lung tissue scarring. This review provides a comprehensive overview of the latest findings on the involvement and signaling mechanisms of ferroptosis in PF pathogenesis, emphasizing potential novel anti-fibrotic therapeutic approaches targeting ferroptosis for PF management.

Interaction between α-Synuclein and Bioactive Lipids: Neurodegeneration, Disease Biomarkers and Emerging Therapies

The present review provides a comprehensive examination of the intricate dynamics between α-synuclein, a protein crucially involved in the pathogenesis of several neurodegenerative diseases, including Parkinson's disease and multiple system atrophy, and endogenously-produced bioactive lipids, which play a pivotal role in neuroinflammation and neurodegeneration. The interaction of α-synuclein with bioactive lipids is emerging as a critical factor in the development and progression of neurodegenerative and neuroinflammatory diseases, offering new insights into disease mechanisms and novel perspectives in the identification of potential biomarkers and therapeutic targets. We delve into the molecular pathways through which α-synuclein interacts with biological membranes and bioactive lipids, influencing the aggregation of α-synuclein and triggering neuroinflammatory responses, highlighting the potential of bioactive lipids as biomarkers for early disease detection and progression monitoring. Moreover, we explore innovative therapeutic strategies aimed at modulating the interaction between α-synuclein and bioactive lipids, including the development of small molecules and nutritional interventions. Finally, the review addresses the significance of the gut-to-brain axis in mediating the effects of bioactive lipids on α-synuclein pathology and discusses the role of altered gut lipid metabolism and microbiota composition in neuroinflammation and neurodegeneration. The present review aims to underscore the potential of targeting α-synuclein-lipid interactions as a multifaceted approach for the detection and treatment of neurodegenerative and neuroinflammatory diseases.

Mendelian Randomization Analysis of Systemic Iron Status and Risk of Different Types of Kidney Disease

With rapid increases in incidence, diverse subtypes, and complicated etiologies, kidney disease remains a global public health problem. Iron, as an essential trace element, has pleiotropic effects on renal function and the progression of kidney diseases. A two-sample Mendelian randomization (MR) analysis was implemented to determine the potential causal effects between systemic iron status on different kidney diseases. Systemic iron status was represented by four iron-related biomarkers: serum iron, ferritin, transferrin saturation (TfSat), and total iron binding capacity (TIBC). For systemic iron status, 163,511, 246,139, 131,471, and 135,430 individuals were included in the genome-wide association study (GWAS) of serum iron, ferritin, TfSat, and TIBC, respectively. For kidney diseases, 653,143 individuals (15,658 cases and 637,485 controls), 657,076 individuals (8160 cases and 648,916 controls), and 659,320 individuals (10,404 cases and 648,916 controls) were included for immunoglobulin A nephropathy (IgAN), acute kidney disease (AKD), and chronic kidney disease (CKD), respectively. Our MR results showed that increased serum iron [odds ratio (OR): 1.10; 95% confidence interval (95% CI): 1.04, 1.16; p < 0.0042], ferritin (OR: 1.30; 95% CI: 1.14, 1.48; p < 0.0042), and TfSat (OR: 1.07; 95% CI: 1.04, 1.11; p < 0.0042)] and decreased TIBC (OR: 0.92; 95% CI: 0.88, 0.97; p < 0.0042) were associated with elevated IgAN risk. However, no significant associations were found between systemic iron status and AKD or CKD. In our MR study, the genetic evidence supports elevated systemic iron status as a causal effect on IgAN, which suggests a potential protective effect of iron chelation on IgAN patients.

New Insight into Neuropathic Pain: The Relationship between α7nAChR, Ferroptosis, and Neuroinflammation

Neuropathic pain, which refers to pain caused by a lesion or disease of the somatosensory system, represents a wide variety of peripheral or central disorders. Treating neuropathic pain is quite demanding, primarily because of its intricate underlying etiological mechanisms. The central nervous system relies on microglia to maintain balance, as they are associated with serving primary immune responses in the brain next to cell communication. Ferroptosis, driven by phospholipid peroxidation and regulated by iron, is a vital mechanism of cell death regulation. Neuroinflammation can be triggered by ferroptosis in microglia, which contributes to the release of inflammatory cytokines. Conversely, neuroinflammation can induce iron accumulation in microglia, resulting in microglial ferroptosis. Accumulating evidence suggests that neuroinflammation, characterized by glial cell activation and the release of inflammatory substances, significantly exacerbates the development of neuropathic pain. By inhibiting microglial ferroptosis, it may be possible to prevent neuroinflammation and subsequently alleviate neuropathic pain. The activation of the homopentameric α7 subtype of the neuronal nicotinic acetylcholine receptor (α7nAChR) has the potential to suppress microglial activation, transitioning M1 microglia to an M2 phenotype, facilitating the release of anti-inflammatory factors, and ultimately reducing neuropathic pain. Recent years have witnessed a growing recognition of the regulatory role of α7nAChR in ferroptosis, which could be a potential target for treating neuropathic pain. This review summarizes the mechanisms related to α7nAChR and the progress of ferroptosis in neuropathic pain according to recent research. Such an exploration will help to elucidate the relationship between α7nAChR, ferroptosis, and neuroinflammation and provide new insights into neuropathic pain management.

Exploration and Validation of Ferroptosis-Associated Genes in ADAR1 Deletion-Induced NAFLD through RNA-seq Analysis

BACKGROUND

Ferroptosis, characterized by excessive iron ions and lipid peroxides accumulation, contributes to Nonalcoholic Fatty Liver Disease (NAFLD) development. The role of ADAR1, crucial for lipid metabolism and immune regulation, in ferroptosis-related NAFLD remains unexplored.

METHODS

In this study, we analyzed the expression of ADAR1 in NAFLD patients using the GSE66676 database. Subsequently, We investigated the effects of ADAR1 knockdown on mitochondrial membrane potential (MMP), Fe2+ levels, oxidation products, and ferroptosis in NAFLD cells through in vitro and in vivo experiments. Additionally, RNA-seq analysis was performed following ADAR1 depletion in an NAFLD cell model. Overlapping and ferroptosis-related genes were identified using a Venn diagram, while Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted as well. Furthermore, a protein-protein interaction (PPI) network was constructed to identify hub genes associated with ferroptosis.

RESULTS

We found the expression level of ADAR1 was downregulated in NAFLD patients and 22 ferroptosis-associated genes were differentially expressed in a NAFLD cell model upon ADAR1 knockdown. Based on PPI network, we identified NOS2, PTGS2, NOX4, ALB, IL6, and CCL5 as the central genes related to ferroptosis. ADAR1 deletion-related NAFLD was found to be involved in the ferroptosis signaling pathway. NOS2, PTGS2, ALB, and IL6 can serve as potential biomarkers. These findings offer new insights and expanded targets for NAFLD prevention and treatment.

CONCLUSION

These findings provide new strategies and potential targets for preventing and treating NAFLD. NOS2, PTGS2, ALB, and IL6 may serve as biomarkers for ADAR1 deletion-related NAFLD, which could help for developing its new diagnostic and therapeutic strategies.

Si-Wu-Tang alleviates metabolic dysfunction-associated fatty liver disease by inhibiting ACSL4-mediated arachidonic acid metabolism and ferroptosis in MCD diet-fed mice

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a prevalent chronic liver disease worldwide. Si-Wu-Tang (SWT), a traditional Chinese medicine decoction has shown therapeutic effects on various liver diseases. However, the hepatoprotective effects and underlying mechanism of SWT on MAFLD remain unclear.

METHODS

First, a methionine-choline-deficient (MCD) diet-fed mice model was used and lipidomic analysis and transcriptomic analysis were performed. The contents of total iron ions, ferrous ions, and lipid peroxidation were detected and Prussian blue staining was performed to confirm the protective effects of SWT against ferroptosis. Finally, chemical characterization and network pharmacological analysis were employed to identify the potential active ingredients.

RESULTS

Serological and hepatic histopathological findings indicated SWT's discernible therapeutic impact on MCD diet-induced MAFLD. Lipidomic analysis revealed that SWT improved intrahepatic lipid accumulation by inhibiting TG synthesis and promoting TG transport. Transcriptomic analysis suggested that SWT ameliorated abnormal FA metabolism by inhibiting FA synthesis and promoting FA β-oxidation. Then, ferroptosis phenotype experiments revealed that SWT could effectively impede hepatocyte ferroptosis, which was induced by long-chain acyl-CoA synthetase 4 (ACSL4)-mediated esterification of arachidonic acid (AA). Finally, chemical characterization and network pharmacological analysis identified that paeoniflorin and other active ingredients might be responsible for the regulative effects against ferroptosis and MAFLD.

CONCLUSION

In conclusion, our study revealed the intricate mechanism through which SWT improved MCD diet-induced MAFLD by targeting FA metabolism and ferroptosis in hepatocytes, thus offering a novel therapeutic approach for the treatment of MAFLD and its complications.

FTO deficiency in older livers exacerbates ferroptosis during ischaemia/reperfusion injury by upregulating ACSL4 and TFRC

Older livers are more prone to hepatic ischaemia/reperfusion injury (HIRI), which severely limits their utilization in liver transplantation. The potential mechanism remains unclear. Here, we demonstrate older livers exhibit increased ferroptosis during HIRI. Inhibiting ferroptosis significantly attenuates older HIRI phenotypes. Mass spectrometry reveals that fat mass and obesity-associated gene (FTO) expression is downregulated in older livers, especially during HIRI. Overexpressing FTO improves older HIRI phenotypes by inhibiting ferroptosis. Mechanistically, acyl-CoA synthetase long chain family 4 (ACSL4) and transferrin receptor protein 1 (TFRC), two key positive contributors to ferroptosis, are FTO targets. For ameliorative effect, FTO requires the inhibition of Acsl4 and Tfrc mRNA stability in a m6A-dependent manner. Furthermore, we demonstrate nicotinamide mononucleotide can upregulate FTO demethylase activity, suppressing ferroptosis and decreasing older HIRI. Collectively, these findings reveal an FTO-ACSL4/TFRC regulatory pathway that contributes to the pathogenesis of older HIRI, providing insight into the clinical translation of strategies related to the demethylase activity of FTO to improve graft function after older donor liver transplantation.

Iron metabolism and ferroptosis in nonalcoholic fatty liver disease: what is our next step?

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with increasing prevalence worldwide. NAFLD could develop from simple hepatic steatosis to nonalcoholic steatohepatitis (NASH), NASH-related fibrosis, cirrhosis, and even hepatocellular carcinoma. However, the mechanism of NAFLD development has not yet been fully defined. Recently, emerging evidence shows that the dysregulated iron metabolism marked by elevated serum ferritin, and ferroptosis are involved in the NAFLD. Understanding iron metabolism and ferroptosis can shed light on the mechanisms of NAFLD development. Here, we summarized studies on iron metabolism and the ferroptosis process involved in NAFLD development to highlight potential medications and therapies for treating NAFLD.

Regulation and targeting of SREBP-1 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an increasing burden on global public health and is associated with enhanced lipogenesis, fatty acid uptake, and lipid metabolic reprogramming. De novo lipogenesis is under the control of the transcription factor sterol regulatory element-binding protein 1 (SREBP-1) and essentially contributes to HCC progression. Here, we summarize the current knowledge on the regulation of SREBP-1 isoforms in HCC based on cellular, animal, and clinical data. Specifically, we (i) address the overarching mechanisms for regulating SREBP-1 transcription, proteolytic processing, nuclear stability, and transactivation and (ii) critically discuss their impact on HCC, taking into account (iii) insights from pharmacological approaches. Emphasis is placed on cross-talk with the phosphatidylinositol-3-kinase (PI3K)-protein kinase B (Akt)-mechanistic target of rapamycin (mTOR) axis, AMP-activated protein kinase (AMPK), protein kinase A (PKA), and other kinases that directly phosphorylate SREBP-1; transcription factors, such as liver X receptor (LXR), peroxisome proliferator-activated receptors (PPARs), proliferator-activated receptor γ co-activator 1 (PGC-1), signal transducers and activators of transcription (STATs), and Myc; epigenetic mechanisms; post-translational modifications of SREBP-1; and SREBP-1-regulatory metabolites such as oxysterols and polyunsaturated fatty acids. By carefully scrutinizing the role of SREBP-1 in HCC development, progression, metastasis, and therapy resistance, we shed light on the potential of SREBP-1-targeting strategies in HCC prevention and treatment.

Exacerbated ischemia-reperfusion injury in fatty livers is mediated by lipid peroxidation stress and ferroptosis

BACKGROUND

Ischemia-reperfusion injury is a common problem in liver surgery and transplantation. Although ischemia-reperfusion injury is known to be more pronounced in fatty livers, the underlying mechanisms for this difference remain poorly understood. We hypothesized that ferroptosis plays a significant role in fatty liver ischemia-reperfusion injury due to increased lipid peroxidation in the presence of stored iron in the fatty liver. To test this hypothesis, the ferroptosis pathway was evaluated in a murine fatty liver ischemia-reperfusion injury model.

METHODS

C57BL6 mice were fed with a normal diet or a high fat, high sucrose diet for 12 weeks. At 22 weeks of age, liver ischemia-reperfusion injury was induced through partial (70%) hepatic pedicle clamping for 60 minutes, followed by 24 hours of reperfusion before tissue harvest. Acyl-coenzyme A synthetase long-chain family member 4 and 4-hydroxynonenal were quantified in the liver tissues. In separate experiments, liproxstatin-1 or vehicle control was administered for 7 consecutive days before liver ischemia-reperfusion injury.

RESULTS

Exacerbated ischemia-reperfusion injury was observed in the livers of high fat, high sucrose diet fed mice. High fat, high sucrose diet + ischemia-reperfusion injury (HDF+IRI) livers had a significantly greater abundance of acyl-coenzyme A synthetase long-chain family member 4 and 4-hydroxynonenal compared with normal diet + ischemia-reperfusion injury (ND+IRI) livers or sham fatty livers, which indicated an increase of ferroptosis. HFD fed animals receiving liproxstatin-1 injections had a significant reduction in serum aspartate transaminase and alanine transaminase after ischemia-reperfusion injury, consistent with attenuation of ischemia-reperfusion injury in the liver.

CONCLUSION

Ferroptosis plays a significant role in ischemia-reperfusion injury in fatty livers. Inhibiting ferroptotic pathways in the liver may serve as a novel therapeutic strategy to protect the fatty liver in the setting of ischemia-reperfusion injury.

E3 ubiquitin ligase CHIP interacts with transferrin receptor 1 for degradation and promotes cell proliferation through inhibiting ferroptosis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the major form of liver malignancy with high incidence and mortality. Identifying novel biomarkers and understanding regulatory mechanisms underlying the development and progression of HCC are critical for improving diagnosis, treatment and patient outcomes. Carboxyl terminus of Hsc-70-interacting protein (CHIP) is a well-described U-box-type E3 ubiquitin ligase which promotes the ubiquitination and degradation of numerous tumor-associated proteins. Recent studies have shown that CHIP can play as a tumor-suppressor gene or an oncogene in different kinds of malignancies. To date, the function and mechanism of CHIP in hepatocellular carcinoma remains largely unknown. Based on TCGA data, we found that compared with high CHIP expression, the overall survival of HCC patients with low expression of CHIP was better. In addition, CHIP overexpression markedly enhanced HCC cell proliferation and colony formation. Conversely, knockdown of CHIP restrained the proliferation and colony formation of HCC cells. Meanwhile, knockdown of CHIP decreased mitochondrial cristae or ruptured outer mitochondrial membrane, promoted the accumulation of Fe2+ and ferroptosis of HCC cells. Further research for the first time confirmed that CHIP interacts and degrades transferrin receptor 1 (TfR1) by ubiquitin-proteasome pathway, which leads to the inhibition of ferroptosis and promotes the proliferation of HCC cells. The analysis of proteomics data from CPTAC revealed a negative correlation between CHIP and TfR1 protein expression levels in HCC. These findings indicate that CHIP acts as a negative modulator of ferroptosis and functions as an oncogene in HCC.

FAdV-4-induced ferroptosis affects fat metabolism in LMH cells

Ferroptosis is a form of controlled cell death that was first described relatively recently and that is dependent on the formation and accumulation of lipid free radicals through an iron-mediated mechanism. A growing body of evidence supports the close relationship between pathogenic infections and ferroptotic cell death, particularly for viral infections. Ferroptosis is also closely tied to the pathogenic development of hepatic steatosis and other forms of liver disease. Fowl adenovirus serotype 4 (FAdV-4) is a hepatotropic aviadenovirus causing hydropericardium syndrome (HPS) that is capable of impacting fat metabolism. However, it remains uncertain as to what role, if any, ferroptotic death plays in the context of FAdV-4 infection. Here, FAdV-4 was found to promote ferroptosis via the p53-SLC7A11-GPX4 axis, while ferrostain-1 was capable of inhibiting this FAdV-4-mediated ferroptotic death through marked reductions in lipid peroxidation. The incidence of FAdV-4-induced fatty liver was also found to be associated with the activation of ferroptotic activity. Together, these results offer novel insights regarding potential approaches to treating HPS.

Metabolomics reveals ascorbic acid inhibits ferroptosis in hepatocytes and boosts the effectiveness of anti-PD1 immunotherapy in hepatocellular carcinoma

BACKGROUND

Immunotherapy combined with molecular targeted therapy is increasingly popular in patients with advanced hepatocellular carcinoma (HCC). However, immune-related adverse events(irAEs) brought on by immunotherapy increase the likelihood of side effects, thus it is important to look into ways to address this issue.

METHODS

Different metabolite patterns were established by analyzing metabolomics data in liver tissue samples from 10 patients(divided into severe and mild liver injury) before and after immuno-targeted therapy. After establishing a subcutaneous tumor model of HCC, the mice were divided into PBS group, ascorbic acid(AA) group, and anti-PD1 + tyrosine kinase inhibitor (TKI) group, anti-PD1 + TKI + AA group. Liver tissue were stained with hematoxylin-eosin staining(HE) and the content of aspartate transaminase (AST) and alanine transaminase(ALT) in blood were determined. The mechanism was confirmed by western blotting, mass cytometry, and other techniques.

RESULTS

Through metabolomics analysis, AA was significantly reduced in the sample of patients with severe liver injury caused by immuno-targeted therapy compared to patients with mild liver injury. The addition of AA in vivo experiments demonstrated a reduction in liver injury in mice. In the liver tissues of the anti-PD1 + TKI + AA group, the protein expressions of SLC7A11,GPX4 and the level of glutathione(GSH) were found to be higher compared to the anti-PD1 + TKI group. Mass cytometry analysis revealed a significant increase in the CD11b+CD44+ PD-L1+ cell population in the AA group when compared to the PBS group.

CONCLUSIONS

AA could reduce liver injury by preventing hepatocyte SLC7A11/GPX4 ferroptosis and improve the immunotherapy effect of anti-PD1 by boosting CD11b+CD44+PD-L1+cell population in HCC.

Ferroptosis in health and disease

Ferroptosis is a pervasive non-apoptotic form of cell death highly relevant in various degenerative diseases and malignancies. The hallmark of ferroptosis is uncontrolled and overwhelming peroxidation of polyunsaturated fatty acids contained in membrane phospholipids, which eventually leads to rupture of the plasma membrane. Ferroptosis is unique in that it is essentially a spontaneous, uncatalyzed chemical process based on perturbed iron and redox homeostasis contributing to the cell death process, but that it is nonetheless modulated by many metabolic nodes that impinge on the cells' susceptibility to ferroptosis. Among the various nodes affecting ferroptosis sensitivity, several have emerged as promising candidates for pharmacological intervention, rendering ferroptosis-related proteins attractive targets for the treatment of numerous currently incurable diseases. Herein, the current members of a Germany-wide research consortium focusing on ferroptosis research, as well as key external experts in ferroptosis who have made seminal contributions to this rapidly growing and exciting field of research, have gathered to provide a comprehensive, state-of-the-art review on ferroptosis. Specific topics include: basic mechanisms, in vivo relevance, specialized methodologies, chemical and pharmacological tools, and the potential contribution of ferroptosis to disease etiopathology and progression. We hope that this article will not only provide established scientists and newcomers to the field with an overview of the multiple facets of ferroptosis, but also encourage additional efforts to characterize further molecular pathways modulating ferroptosis, with the ultimate goal to develop novel pharmacotherapies to tackle the various diseases associated with - or caused by - ferroptosis.

Ferroptosis and hepatocellular carcinoma: the emerging role of lncRNAs

Hepatocellular carcinoma is the most common form of primary liver cancer and poses a significant challenge to the medical community because of its high mortality rate. In recent years, ferroptosis, a unique form of cell death, has garnered widespread attention. Ferroptosis, which is characterized by iron-dependent lipid peroxidation and mitochondrial alterations, is closely associated with the pathological processes of various diseases, including hepatocellular carcinoma. Long non-coding RNAs (lncRNAs), are a type of functional RNA, and play crucial regulatory roles in a variety of biological processes. In this manuscript, we review the regulatory roles of lncRNAs in the key aspects of ferroptosis, and summarize the research progress on ferroptosis-related lncRNAs in hepatocellular carcinoma.

Impacts of small-molecule STAT3 inhibitor SC-43 on toxicity, global proteomics and metabolomics of HepG2 cells

OBJECTIVE

In this study, we aimed to investigate the cytotoxicity and potential mechanisms of SC-43 by analyzing the global proteomics and metabolomics of HepG2 cells exposed to SC-43.

METHODS

The effect of SC-43 on cell viability was evaluated through CCK-8 assay. Proteomics and metabolomics studies were performed on HepG2 cells exposed to SC-43, and the functions of differentially expressed proteins and metabolites were categorized. Drug affinity responsive target stability (DARTS) was utilized to identify the potential binding proteins of SC-43 in HepG2 cells. Finally, based on the KEGG pathway database, the co-regulatory mechanism of SC-43 on HepG2 cells was elucidated by conducting a joint pathway analysis on the differentially expressed proteins and metabolites using the MetaboAnalyst 5.0 platform.

RESULTS

Liver cell viability is significantly impaired by continuous exposure to high concentrations of SC-43. Forty-eight dysregulated proteins (27 upregulated, 21 downregulated) were identified by proteomics analysis, and 184 dysregulated metabolites (65 upregulated, 119 downregulated) were determined by metabolomics in HepG2 cells exposed to SC-43 exposure compared with the control. A joint pathway analysis of proteomics and metabolomics data using the MetaboAnalyst 5.0 platform supported the close correlation between SC-43 toxicity toward HepG2 and the disturbances in pyrimidine metabolism, ferroptosis, mismatch repair, and ABC transporters. Specifically, SC-43 significantly affected the expression of several proteins and metabolites correlated with the above-mentioned functional pathways, such as uridine 5'-monophosphate, uridine, 3'-CMP, glutathione, γ-Glutamylcysteine, TF, MSH2, RPA1, RFC3, TAP1, and glycerol. The differential proteins suggested by the joint analysis were further selected for ELISA validation. The data showed that the RPA1 and TAP1 protein levels significantly increased in HepG2 cells exposed to SC-43 compared to the control group. The results of ELISA and joint analysis were basically in agreement. Notably, DARTS and biochemical analysis indicated that SART3 might be a potential target for SC-43 toxicity in HepG2 cells.

CONCLUSION

In summary, prolonged exposure of liver cells to high concentrations of SC-43 can result in significant damage. Based on a multi-omics analysis, we identified proteins and metabolites associated with SC-43-induced hepatocellular injury and clarified the underlying mechanism, providing new insights into the toxic mechanism of SC-43.

Ironing out the role of ferroptosis in immunity

Ferroptosis is a type of regulated cell death that drives the pathophysiology of many diseases. Oxidative stress is detectable in many types of regulated cell death, but only ferroptosis involves lipid peroxidation and iron dependency. Ferroptosis originates and propagates from several organelles, including the mitochondria, endoplasmic reticulum, Golgi, and lysosomes. Recent data have revealed that immune cells can both induce and undergo ferroptosis. A mechanistic understanding of how ferroptosis regulates immunity is critical to understanding how ferroptosis controls immune responses and how this is dysregulated in disease. Translationally, more work is needed to produce ferroptosis-modulating immunotherapeutics. This review focuses on the role of ferroptosis in immune-related diseases, including infection, autoimmune diseases, and cancer. We discuss how ferroptosis is regulated in immunity, how this regulation contributes to disease pathogenesis, and how targeting ferroptosis may lead to novel therapies.

circ_WASF2 regulates ferroptosis by miR-634/ GPX4 signaling in pancreatic cancer

PURPOSE

Pancreatic cancer (PC) is one of the most lethal malignant gastrointestinal tumors (GI) characterized by a poor prognosis. Ferroptosis is an emerging programmed cell death that plays an essential role in the progression of various cancers. Ferroptosis is driven by iron-dependent phospholipid peroxidation and is regulated by mitochondrial activity, lipid peroxidation, and reactive oxygen species (ROS). The function and mechanism of ferroptosis in PC need more research.

METHODS

The levels of circRNAs, miRNAs, and mRNAs were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Western blot was used for protein detection. CCK8 assays were used to detect cell proliferation. Cell death, lipid peroxidation, ROS, and Fe2+ were detected by indicted kits. Dual-luciferase reporter and RNA pull-down assays were conducted to confirm the interaction between circRNAs, miRNAs, and mRNAs.

RESULTS

In this research, we found that circular RNA hsa_circ_0000003(circ_WASF2) was upregulated in pancreatic cancer cells. The silence of circ_WASF2 inhibited cancer proliferation and increased cell death by increasing ferroptosis accompanied by up-regulation of lipid peroxidation, ROS, and Fe2+. Further studies showed that circ_WASF2 could attenuate ferroptosis by targeting miR-634 and the downstream glutathione peroxidase 4 (GPX4). GPX4 has been well-reported as a central factor in ferroptosis. Our research revealed a new pathway for regulating ferroptosis in PC.

CONCLUSION

In summary, we have determined that circ_WASF2/miR-634/GPX4 contributed to ferroptosis-induced cell death, and provided a possible therapeutic target in PC.

Long-term exposure to dietary emulsifier Tween 80 promotes liver lipid accumulation and induces different-grade inflammation in young and aged mice

With the advent of industrialization, there has been a substantial increase in the production and consumption of ultra-processed foods (UPFs). These processed foods often contain artificially synthesized additives, such as emulsifiers. Emulsifiers constitute approximately half of the total amount of food additives, with Tween 80 being a commonly used emulsifier in the food industry. Concurrently, China is undergoing significant demographic changes, transitioning into an aging society. Despite this demographic shift, there is insufficient research on the health implications of food emulsifiers, particularly on the elderly population. In this study, we present novel findings indicating that even at low concentrations, Tween 80 suppressed the viability of multiple cell types. Prolonged in vivo exposure to 1 % Tween 80 in drinking water induced liver lipid accumulation and insulin resistance in young adult mice under a regular chow diet. Intriguingly, in mice with high-fat diet (HFD) induced metabolic dysfunction-associated steatotic liver disease (MASLD), this inductive effect was masked. In aged mice, liver lipid accumulation was replicated under prolonged Tween 80 exposure. We further revealed that Tween 80 induced inflammation in both adult and aged mice, with a more pronounced inflammation in aged mice. In conclusion, our study provides compelling evidence that Tween 80 could contribute to a low-grade inflammation and liver lipid accumulation. These findings underscore the need for increasing attention regarding the consumption of UPFs with Tween 80 as the emulsifier, particularly in the elderly consumers.

HNRNPL facilitates ferroptosis in hepatocellular carcinoma cells by promoting S100A9 expression

OBJECTIVE

This study probed into the effect of HNRNPL on ferroptosis in hepatocellular carcinoma (HCC) cells and related molecular mechanisms.

METHODS

Expression patterns of HNRNPL, Recombinant S100 Calcium Binding Protein A9 (S100A9) were analyzed in HCC tissues or cells. Following transfection, HCC cell activity was analyzed, followed by detection of levels of ROS, iron content, LPO, MDA, and GSH as well as the expression of ferroptosis-related proteins. For molecular mechanism, RIP, RNA pull-down assay and actinomycin D assay were implemented to verify the binding relationship between HNRNPL and S100A9. Finally, in vivo nude mouse xenograft tumor experiments were performed for further validate the crucial role of HNENPL expression in HCC.

RESULTS

HNRNPL and S100A9 were significantly overexpressed in HCC. sh-HNRNPL treatment led to a significant decrease in cellular activity, GSH content, and expression of GPX4 and SLC7A11, and a significant increase in iron content, LPO level, MDA, ROS content, and expression of ACSL4 and TFR1. In addition, after sh-HNRNPL was combined with oe-S100A9 or Fer-1, a ferroptosis inhibitor, both oe-S100A9 and Fer-1 reversed the promotional effect of sh-HNRNPL on ferroptosis of HCC cells when sh-HNRNPL acted alone. Mechanically, HNRNPL promoted S100A9 mRNA stability and expression through RBP. Furthermore, low expression of HNRNPL in vivo delayed the growth of xenograft tumors and the expression of ferroptosis-related proteins.

CONCLUSION

HNRNPL promotes S100A9 mRNA stability and expression through RBP action, thereby promoting ferroptosis in HCC cells.

Ginsenoside Rb1 induces hepatic stellate cell ferroptosis to alleviate liver fibrosis via the BECN1/SLC7A11 axis

Liver fibrosis is primarily driven by the activation of hepatic stellate cells (HSCs), a process associated with ferroptosis. Ginsenoside Rb1 (GRb1), a major active component extracted from Panax ginseng, inhibits HSC activation. However, the potential role of GRb1 in mediating HSC ferroptosis remains unclear. This study examined the effect of GRb1 on liver fibrosis both in vivo and in vitro, using CCl4-induced liver fibrosis mouse model and primary HSCs, LX-2 cells. The findings revealed that GRb1 effectively inactivated HSCs in vitro, reducing alpha-smooth muscle actin (α-SMA) and Type I collagen (Col1A1) levels. Moreover, GRb1 significantly alleviated CCl4-induced liver fibrosis in vivo. From a mechanistic standpoint, the ferroptosis pathway appeared to be central to the antifibrotic effects of GRb1. Specifically, GRb1 promoted HSC ferroptosis both in vivo and in vitro, characterized by increased glutathione depletion, malondialdehyde production, iron overload, and accumulation of reactive oxygen species (ROS). Intriguingly, GRb1 increased Beclin 1 (BECN1) levels and decreased the System Xc-key subunit SLC7A11. Further experiments showed that BECN1 silencing inhibited GRb1-induced effects on HSC ferroptosis and mitigated the reduction of SLC7A11 caused by GRb1. Moreover, BECN1 could directly interact with SLC7A11, initiating HSC ferroptosis. In conclusion, the suppression of BECN1 counteracted the effects of GRb1 on HSC inactivation both in vivo and in vitro. Overall, this study highlights the novel role of GRb1 in inducing HSC ferroptosis and promoting HSC inactivation, at least partly through its modulation of BECN1 and SLC7A11.

GPX4, ferroptosis, and diseases

GPX4 (Glutathione peroxidase 4) serves as a crucial intracellular regulatory factor, participating in various physiological processes and playing a significant role in maintaining the redox homeostasis within the body. Ferroptosis, a form of iron-dependent non-apoptotic cell death, has gained considerable attention in recent years due to its involvement in multiple pathological processes. GPX4 is closely associated with ferroptosis and functions as the primary inhibitor of this process. Together, GPX4 and ferroptosis contribute to the pathophysiology of several diseases, including sepsis, nervous system diseases, ischemia reperfusion injury, cardiovascular diseases, and cancer. This review comprehensively explores the regulatory roles and impacts of GPX4 and ferroptosis in the development and progression of these diseases, with the aim of providing insights for identifying potential therapeutic strategies in the future.

Type 2 diabetic mellitus related osteoporosis: focusing on ferroptosis

With the aging global population, type 2 diabetes mellitus (T2DM) and osteoporosis(OP) are becoming increasingly prevalent. Diabetic osteoporosis (DOP) is a metabolic bone disorder characterized by abnormal bone tissue structure and reduced bone strength in patients with diabetes. Studies have revealed a close association among diabetes, increased fracture risk, and disturbances in iron metabolism. This review explores the concept of ferroptosis, a non-apoptotic cell death process dependent on intracellular iron, focusing on its role in DOP. Iron-dependent lipid peroxidation, particularly impacting pancreatic β-cells, osteoblasts (OBs) and osteoclasts (OCs), contributes to DOP. The intricate interplay between iron dysregulation, which comprises deficiency and overload, and DOP has been discussed, emphasizing how excessive iron accumulation triggers ferroptosis in DOP. This concise overview highlights the need to understand the complex relationship between T2DM and OP, particularly ferroptosis. This review aimed to elucidate the pathogenesis of ferroptosis in DOP and provide a prospective for future research targeting interventions in the field of ferroptosis.