Ethyl carbamate triggers ferroptosis in liver through inhibiting GSH synthesis and suppressing Nrf2 activation

SNORA56-mediated pseudouridylation of 28 S rRNA inhibits ferroptosis and promotes colorectal cancer proliferation by enhancing GCLC translation

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies and is characterized by reprogrammed metabolism. Ferroptosis, a programmed cell death dependent on iron, has emerged as a promising strategy for CRC treatment. Although small nucleolar RNAs are extensively involved in carcinogenesis, it is unclear if they regulate ferroptosis during CRC pathogenesis.

METHODS

The dysregulated snoRNAs were identified using published sequencing data of CRC tissues. The expression of the candidate snoRNAs, host gene and target gene were assessed by real-time quantitative PCR (RT-qPCR), fluorescence in situ hybridization (FISH), immunohistochemistry (IHC) and western blots. The biological function of critical molecules was investigated using in vitro and in vivo strategies including Cell Counting Kit-8 (CCK8), colony formation assay, flow cytometry, Fe2+/Fe3+, GSH/GSSG and the xenograft mice models. The ribosomal activities were determined by polysome profiling and O-propargyl-puromycin (OP-Puro) assay. The proteomics was conducted to clarify the downstream targets and the underlying mechanisms were validated by IHC, Pearson correlation analysis, protein stability and rescue assays. The clinical significance of the snoRNA was explored using the Cox proportional hazard model, receiver operating characteristic (ROC) and survival analysis.

RESULTS

Here, we investigated the SNORA56, which was elevated in CRC tissues and plasma, and correlated with CRC prognosis. SNORA56 deficiency in CRC impaired proliferation and triggered ferroptosis, resulting in reduced tumorigenesis. Mechanistically, SNORA56 mediated the pseudouridylation of 28 S rRNA at the U1664 site and promoted the translation of the catalytic subunit of glutamate cysteine ligase (GCLC), an indispensable rate-limiting enzyme in the biosynthesis of glutathione, which can inhibit ferroptosis by suppressing lipid peroxidation.

CONCLUSIONS

Therefore, the SNORA56/28S rRNA/GCLC axis stimulates CRC progression by inhibiting the accumulation of cellular peroxides, and it may provide biomarker and therapeutic applications in CRC.

Tussilagone inhibits osteoclastogenesis by modulating mitochondrial function and ROS production involved Nrf2 activation

Reactive Oxygen Species (ROS) play an essential role in the pathogenesis of osteoporosis mainly characterized by excessive osteoclasts (OCs) activity. OCs are rich in mitochondria for energy support, which is a major source of total ROS. Tussilagone (TSG), a natural Sesquiterpenes from the flower of Tussilago farfara, has plentiful beneficial pharmacological characteristics with anti-inflammatory and anti-oxidative activity, but its effects and mechanism in osteopathology are still unclear. In our study, we investigated the regulation of ROS generated from the mitochondria in OCs. We found that TSG inhibited OCs differentiation and bone resorption without any cytotoxicity. Mechanistically, TSG reduced RANKL-mediated total ROS level by down-regulating intracellular ROS production and mitochondrial function, leading to the suppression of NFATc1 transcription. We also found that nuclear factor erythroid 2-related factor 2 (Nrf2) could enhance ROS scavenging enzymes in response to RANKL-induced oxidative stress. Furthermore, TSG up-regulated the expression of Nrf2 by inhibiting its proteosomal degradation. Interestingly, Nrf2 deficiency reversed the suppressive effect of TSG on mitochondrial activity and ROS signaling in OCs. Consistent with this finding, TSG attenuated post-ovariectomy (OVX)- and lipopolysaccharide (LPS) induced bone loss by ameliorating osteoclastogenesis. Taken together, TSG has an anti-bone resorptive effect by modulating mitochondrial function and ROS production involved Nrf2 activation.

Qi-Shen-Tang alleviates retinitis pigmentosa by inhibiting ferroptotic features via the NRF2/GPX4 signaling pathway

Ferroptosis has been observed during retinal photoreceptor cell death, suggesting that it plays a role in retinitis pigmentosa (RP) pathogenesis. Qi-Shen-Tang (QST) is a combination of two traditional Chinese medicines used for the treatment of ophthalmic diseases; however, its mechanism of action in RP and ferroptosis remains unclear. Therefore, this study aimed to explore the effect and potential molecular mechanisms of QST on RP. QST significantly improved tissue morphology and function of the retina in the RP model mice. A significant increase in retinal blood flow and normalization of the fundus structure were observed in mice in the treatment group. After QST treatment, the level of iron and the production of malondialdehyde decreased significantly; the levels of superoxide dismutase and glutathione increased significantly; and the protein expression of glutathione peroxidase 4 (GPX4), glutathione synthetase, solute carrier family 7 member 11, and nuclear factor erythroid 2-related factor 2 (NRF2) increased significantly. The molecular docking results demonstrated potential interactions between the small molecules of QST and the key proteins of NRF2/GPX4 signaling pathway. Our results indicate that QST may inhibit ferroptosis by inhibiting the NRF2/GPX4 signaling pathway, thereby reducing RP-induced damage to retinal tissue.

Brusatol induces ferroptosis in oesophageal squamous cell carcinoma by repressing GSH synthesis and increasing the labile iron pool via inhibition of the NRF2 pathway

Brusatol (Bru), a bioactive compound found in Brucea sumatrana, exerts antitumour effects on several malignancies. However, the role and molecular mechanism of Bru in squamous cell carcinoma of the oesophagus (ESCC) remain unclear. Here, we found that Bru decreased the survival of ESCC cells. Subsequently, the ferroptosis inhibitors, deferoxamine and liproxstatin-1, rescued Bru-induced cell death, indicating that ferroptosis plays a major role in Bru-induced cell death. Furthermore, Bru promoted lipid peroxidation, glutathione (GSH) depletion, and ferrous iron overload in vitro. Consistent with these in vitro results, Bru significantly inhibited tumour growth in KYSE150 xenograft nude mice by triggering ferroptosis. Mechanistically, nuclear factor E2-related factor 2 (NRF2) inactivation via increased ubiquitin-proteasome degradation was found to be a vital determinant of ferroptosis induced by Bru. Notably, Bru significantly decreases GSH synthesis, iron storage, and efflux by downregulating the expression of NRF2 target genes (glutamate-cysteine ligase catalytic subunit (GCLC), solute carrier family 7 member 11 (SLC7A11), ferritin heavy chain 1 (FTH1), and solute carrier family 40 member 1 (SLC40A1)), resulting in the accumulation of lethal lipid-based reactive oxygen species (ROS) and intracellular enrichment of chelated iron. Taken together, our findings indicate that ferroptosis is a novel mechanism underlying Bru-induced antitumour activity and will hopefully provide a valuable compound for ESCC treatment.

Exogenous H2S initiating Nrf2/GPx4/GSH pathway through promoting Syvn1-Keap1 interaction in diabetic hearts

Excessive ROS accumulation contributes to cardiac injury in type 2 diabetes mellitus. Hydrogen sulfide (H2S) is a vital endogenous gasotransmitter to alleviate cardiac damage in diabetic cardiomyopathy (DCM). However, the underlying mechanisms remain unclear. In this study, we investigated the effects of NaHS administration in db/db mice via intraperitoneal injection for 20 weeks and the treatment of high glucose (HG), palmitate (PA) and NaHS in HL-1 cardiomyocytes for 48 h, respectively. H2S levels were decreased in hearts of db/db mice and HL-1 cardiomyocytes exposed to HG and PA, which were restored by NaHS. Exogenous H2S activated the nuclear factor erythroid 2-related factor 2 (Nrf2)/glutathione peroxidase 4 (GPx4)/glutathione (GSH) pathway, suppressed ferroptosis and mitigated mitochondrial apoptosis in db/db mice. However, these effects were abrogated after Nrf2 knockdown. NaHS treatment elevated the ubiquitination level of Kelch-like ECH-associated protein (Keap1) by preserving its E3 ligase synoviolin (Syvn1), resulting in Nrf2 nuclear translocation. H2S facilitated the sulfhydration of Syvn1-cys115 site, a post-translational modification. Transfecting Syvn1 C115A in cardiomyocytes exposed to HG and PA partially attenuated the effects of NaHS on Nrf2 and cell death. Our findings suggest that exogenous H2S regulates Nrf2/GPx4/GSH pathway by promoting the Syvn1-Keap1 interaction to reduce ferroptosis and mitochondrial apoptosis in DCM.

Mechanisms and regulations of ferroptosis

Regulation of cell mortality for disease treatment has been the focus of research. Ferroptosis is an iron-dependent regulated cell death whose mechanism has been extensively studied since its discovery. A large number of studies have shown that regulation of ferroptosis brings new strategies for the treatment of various benign and malignant diseases. Iron excess and lipid peroxidation are its primary metabolic features. Therefore, genes involved in iron metabolism and lipid metabolism can regulate iron overload and lipid peroxidation through direct or indirect pathways, thereby regulating ferroptosis. In addition, glutathione (GSH) is the body's primary non-enzymatic antioxidants and plays a pivotal role in the struggle against lipid peroxidation. GSH functions as an auxiliary substance for glutathione peroxidase 4 (GPX4) to convert toxic lipid peroxides to their corresponding alcohols. Here, we reviewed the researches on the mechanism of ferroptosis in recent years, and comprehensively analyzed the mechanism and regulatory process of ferroptosis from iron metabolism and lipid metabolism, and then described in detail the metabolism of GPX4 and the main non-enzymatic antioxidant GSH in vivo.

Coordination-driven FBXW7 DNAzyme-Fe nanoassembly enables a binary switch of breast cancer cell cycle checkpoint responses for enhanced ferroptosis-radiotherapy

Radiotherapy is a mainstream modality for breast cancer treatment that employs ionizing radiation (IR) to damage tumor cell DNA and elevate ROS stress, which demonstrates multiple clinically-favorable advantages including localized treatment and low invasiveness. However, breast cancer cells may activate the p53-mediated cell cycle regulation in response to radiotherapy to repair IR-induced cellular damage and facilitate post-treatment survival. F-Box and WD Repeat Domain Containing 7 (FBXW7) is a promoter of p53 degradation and critical nexus of cell proliferation and survival events. Herein, we engineered a cooperative radio-ferroptosis-stimulatory nanomedicine through coordination-driven self-assembly between ferroptosis-inducing Fe2+ ions and FBXW7-inhibiting DNAzymes and further modification of tumor-targeting dopamine-modified hyaluronic acid (HA). The nanoassembly could be selectively internalized by breast cancer cells and disintegrated in lysosomes to release the therapeutic payload. DNAzyme readily abolishes FBXW7 expression and stabilizes phosphorylated p53 to cause irreversible G2 phase arrest for amplifying post-IR tumor cell apoptosis. Meanwhile, the p53 stabilization also inhibits the SLC7A11-cystine-GSH axis, which combines with the IR-upregulated ROS levels to amplify Fe2+-mediated ferroptotic damage. The DNAzyme-Fe-HA nanoassembly could thus systematically boost the tumor cell damaging effects of IR, presenting a simple and effective approach to augment the response of breast cancer to radiotherapy. STATEMENT OF SIGNIFICANCE: To overcome the intrinsic radioresistance in breast cancer, we prepared co-assembly of Fe2+ and FBXW7-targeted DNAzymes and modified surface with dopamine conjugated hyaluronic acid (HA), which enabled tumor-specific FBXW7-targeted gene therapy and ferroptosis therapy in IR-treated breast cancers. The nanoassembly could be activated in acidic condition to release the therapeutic contents. Specifically, the DNAzymes could selectively degrade FBXW7 mRNA in breast cancer cells to simultaneously induce accumulation of p53 and retardation of NHEJ repair, eventually inducing irreversible cell cycle arrest to promote apoptosis. The p53 stabilization would also inhibit the SLC7A11/GSH/GPX4 axis to enhance Fe2+ mediated ferroptosis. These merits could act in a cooperative manner to induce pronounced tumor inhibitory effect, offering new approaches for tumor radiosensitization in the clinics.

Celastrol alleviated acute kidney injury by inhibition of ferroptosis through Nrf2/GPX4 pathway

Ferroptosis is an important pathological process in acute kidney injury (AKI) which could lead to chronic kidney disease (CKD) and end-stage renal disease (ESRD). As an active ingredient of Chinese medicine Tripterygium wilfordii, celastrol has been reported to alleviate inflammation and preclinical studies have confirmed its anticancer effect. In the present study, we investigated the renal protective effects of celastrol against cisplatin induced AKI. Mice were administrated cisplatin by intraperitoneal injection and we found that celastrol reduced serum levels of BUN and creatinine, inhibited renal dysfunction, inflammation and oxidative stress. In addition, renal iron accumulation and ferroptosis were significantly reduced by celastrol treatment. Further mechanistic analyses suggested that Nrf2 is essential for celastrol upregulated GPX4 to alleviate ferroptosis and reduction of LDH release, intracellular iron accumulation and lipid peroxidation. These findings expand the potential uses of celastrol for treatment of various kinds of AKI associated with ferroptosis.

Bone-targeting exosome nanoparticles activate Keap1 / Nrf2 / GPX4 signaling pathway to induce ferroptosis in osteosarcoma cells

BACKGROUND

In recent years, the development of BMSCs-derived exosomes (EXO) for the treatment of osteosarcoma (OS) is a safe and promising modality for OS treatment, which can effectively deliver drugs to tumor cells in vivo. However, the differences in the drugs carried, and the binding of EXOs to other organs limit their therapeutic efficacy. Therefore, improving the OS-targeting ability of BMSCs EXOs and developing new drugs is crucial for the clinical application of targeted therapy for OS.

RESULTS

In this study, we constructed a potential therapeutic nano platform by modifying BMSCs EXOs using the bone-targeting peptide SDSSD and encapsulated capreomycin (CAP) within a shell. These constructed nanoparticles (NPs) showed the ability of homologous targeting and bone-targeting exosomes (BT-EXO) significantly promotes cellular endocytosis in vitro and tumor accumulation in vivo. Furthermore, our results revealed that the constructed NPs induced ferroptosis in OS cells by prompting excessive accumulation of reactive oxygen species (ROS), Fe2+ aggregation, and lipid peroxidation and further identified the potential anticancer molecular mechanism of ferroptosis as transduced by the Keap1/Nrf2/GPX4 signaling pathway. Also, these constructed NP-directed ferroptosis showed significant inhibition of tumor growth in vivo with no significant side effects.

CONCLUSION

These results suggest that these constructed NPs have superior anticancer activity in mouse models of OS in vitro and in vivo, providing a new and promising strategy for combining ferroptosis-based chemotherapy with targeted therapy for OS.

The gut metabolite 3-hydroxyphenylacetic acid rejuvenates spermatogenic dysfunction in aged mice through GPX4-mediated ferroptosis

BACKGROUND

Aging-related fertility decline is a prevalent concern globally. Male reproductive system aging is mainly characterized by a decrease in sperm quality and fertility. While it is known that intestinal physiology changes with age and that microbiota is shaped by physiology, the underlying mechanism of how the microbiota affects male reproductive aging is still largely unexplored.

RESULTS

Here, we utilized fecal microbiota transplantation (FMT) to exchange the fecal microbiota between young and old mice. Cecal shotgun metagenomics and metabolomics were used to identify differences in gut microbiota composition and metabolic regulation during aging. Our results demonstrated that FMT from young to old mice alleviated aging-associated spermatogenic dysfunction through an unexpected mechanism mediated by a gut bacteria-derived metabolite, 3-hydroxyphenylacetic acid (3-HPAA). 3-HPAA treatment resulted in an improvement of spermatogenesis in old mice. RNA sequencing analysis, qRT-PCR and Western blot revealed that 3-HPAA induced an upregulation of GPX4, thereby restraining ferroptosis and restoring spermatogenesis. These findings were further confirmed by in vitro induction of ferroptosis and inhibition of GPX4 expression.

CONCLUSIONS

Our results demonstrate that the microbiome-derived metabolite, 3-HPAA, facilitates spermatogenesis of old mice through a ferroptosis-mediated mechanism. Overall, these findings provide a novel mechanism of dysregulated spermatogenesis of old mice, and suggest that 3-HPAA could be a potential therapy for fertility decline of aging males in clinical practice. Video Abstract.

FGF2 Rescued Cisplatin-Injured Granulosa Cells through the NRF2-Autophagy Pathway

Premature ovarian failure (POF) is a complicated disorder related to the apoptosis of granulosa cells. The incidence of chemotherapy-associated POF is rising dramatically owing to the increasing proportion of cancer in adolescents. According to previous studies, oxidative stress caused by chemotherapeutic agents plays an important role in the development of POF. However, the exact effects of nuclear factor-erythroid 2-related factor2 (NRF2), a pivotal anti-oxidative factor, are still unknown in chemotherapy-associated POF. Firstly, we manipulated NRF2 expressions on a genetic or pharmaceutical level in cisplatin-injured granulosa cell models. The results indicate that the increasing NRF2 in cisplatin-injured cells was just compensatory and not enough to resist the accumulated stress. Upregulation of NRF2 could protect granulosa cells against cisplatin via elevating autophagic level by using an autophagic activator (rapamycin) and inhibitor (chloroquine). Additionally, exogenous FGF2 exerted a protective role by increasing NRF2 expression and promoting its nuclear translocation. Meanwhile, the results in cisplatin-POF mice models were consistent with what was found in injured cells. In conclusion, our research proved that FGF2 rescued cisplatin-injured granulosa cells through the NRF2-autophagy pathway and might provide a possible alternative treatment choice by targeting NRF2 for POF patients who are intolerant or unsuitable to FGF2.

lncRNA HOTAIR promotes ROS generation and NLRP3 inflammasome activation by inhibiting Nrf2 in diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a microvascular complication associated with damage to the retina due to inflammation induced by high glucose. Activation of the NLRP3 inflammasome plays a critical role in DR and its prevention is beneficial to patients. However, the regulation of long non-coding RNA (lncRNA) in NLRP3 inflammasome activation of DR is incompletely understood. So, this study aimed to uncover the functional and regulatory mechanism of the lncRNA HOTAIR in NLRP3 inflammasome activation in Dr.

METHODS

The vitreous humor was collected from the patients and detected the inflammatory and oxidative stress makers. Human retinal endothelial cells (HRECs) were cultured and stimulated in low D-glucose (5 mmol/L) or high D-glucose (20 mmol/L). Additionally, HRECs were knocked down HOTAIR with a si-RNA. Then, the NLRP3 inflammasome activation was analyzed by western blotting and pyroptosis cell imaging. The ROS was measured by specific probe. The activation of Nrf2 measured by Immunofluorescent staining. The interaction between HOTAIR and Nrf2 was evaluated by co-immunoprecipitation and RNA immunoprecipitation.

RESULTS

The expression of HOTAIR was significantly increased in the vitreous of patients with DR and in HRECs stimulated with high glucose. Furthermore, HOTAIR knockdown relieved NLRP3 inflammasome activation. More specifically, HOTAIR knockdown suppressed the expression of NLRP3, pro-caspase-1, and pro-IL-1β, as well as IL-1β maturation and pyroptosis. HOTAIR knockdown also interfered with the ROS generation induced by high glucose. Moreover, HOTAIR promoted the interaction between Nrf2 and Keap1 by binding and inactivating Nrf2.

CONCLUSION

The lncRNA HOTAIR promotes NLRP3 inflammasome activation and ROS generation by inhibiting Nrf2 in Dr.

Metabolite Neu5Ac triggers SLC3A2 degradation promoting vascular endothelial ferroptosis and aggravates atherosclerosis progression in ApoE-/-mice

Background: Atherosclerosis (AS) is still the major cause of cardiovascular disease (CVD) as well as stroke. Endothelial metabolic disorder has been found to be activated and then promote endothelial cells (ECs) injury, which is regarded to initiate AS progression. N-acetylneuraminic acid (Neu5Ac), a metabolite produced by hexosamine-sialic acid pathway branching from glucose metabolism, was presented as a notable biomarker of CVD and is positively correlated with ECs function. However, few studies explain whether Neu5Ac regulate AS progression by affecting EC function as well as its involved mechanisms are still unknown. Methods: Here, we mimicked an animal model in ApoE-/- mice which displaying similar plasma Neu5Ac levels with AS model to investigate its effect on AS progression. Results: We found that Neu5Ac exacerbated plaques area and increased lipids in plasma in absence of HFD feeding, and ECs inflammatory injury was supposed as the triggering factor upon Neu5Ac treatment with increasing expression of IL-1β, ICAM-1, and promoting ability of monocyte adhesion to ECs. Mechanistic studies showed that Neu5Ac facilitated SLC3A2 binding to ubiquitin and then triggered P62 mediated degradation, further leading to accumulation of lipid peroxidation in ECs. Fer-1 could inhibit ECs injury and reverse AS progression induced by Neu5Ac in ApoE-/- mice. Interestingly, mitochondrial dysfunction was also partly participated in ECs injury after Neu5Ac treatment and been reversed by Fer-1. Conclusions: Together, our study unveils a new mechanism by which evaluated metabolite Neu5Ac could promote SLC3A2 associated endothelial ferroptosis to activate ECs injury and AS plaque progression, thus providing a new insight into the role of Neu5Ac-ferroptosis pathway in AS. Also, our research revealed that pharmacological inhibition of ferroptosis may provide a novel therapeutic strategy for premature AS.

Programmed Cell Death in Liver Fibrosis

Programmed cell death (PCD) is a comprehensive term that encompasses various forms of cell death, such as apoptosis, necroptosis, pyroptosis, ferroptosis, and autophagy, which play a crucial role in the pathogenesis of liver fibrosis. PCD facilitates the elimination of aberrant cells, particularly activated hepatic stellate cells (HSCs), which are the primary producers of extracellular matrix (ECM). The removal of HSCs may impede ECM synthesis, thereby mitigating liver fibrosis. As such, PCD has emerged as a promising therapeutic target for the development of novel drugs to treat liver fibrosis. Numerous studies have been conducted to investigate the underlying mechanisms of PCD in the elimination of activated HSCs and other aberrant liver cells in fibrotic liver tissue, including hepatocytes, hepatic sinusoid endothelial cells (LSECs), and Kupffer cells (KCs). The induction of PCD, the interplay between different forms of PCD, and the potential harm or benefit of PCD in liver fibrosis are topics of ongoing research. Evidences suggest that PCD is a complex process with dual effects on liver fibrosis. The purpose of this review is to summarize the most recent advances in PCD and liver fibrosis research.

FSP1 confers ferroptosis resistance in KEAP1 mutant non-small cell lung carcinoma in NRF2-dependent and -independent manner

Ferroptosis, a type of cell death induced by lipid peroxidation, has emerged as a novel anti-cancer strategy. Cancer cells frequently acquire resistance to ferroptosis. However, the underlying mechanisms are poorly understood. To address this issue, we conducted a thorough investigation of the genomic and transcriptomic data derived from hundreds of human cancer cell lines and primary tissue samples, with a particular focus on non-small cell lung carcinoma (NSCLC). It was observed that mutations in Kelch-like ECH-associated protein 1 (KEAP1) and subsequent nuclear factor erythroid 2-related factor 2 (NRF2, also known as NFE2L2) activation are strongly associated with ferroptosis resistance in NSCLC. Additionally, AIFM2 gene, which encodes ferroptosis suppressor protein 1 (FSP1), was identified as the gene most significantly correlated with ferroptosis resistance, followed by multiple NRF2 targets. We found that inhibition of NRF2 alone was not sufficient to reduce FSP1 protein levels and promote ferroptosis, whereas FSP1 inhibition effectively sensitized KEAP1-mutant NSCLC cells to ferroptosis. Furthermore, we found that combined inhibition of FSP1 and NRF2 induced ferroptosis more intensely. Our findings imply that FSP1 is a crucial suppressor of ferroptosis whose expression is partially dependent on NRF2 and that synergistically targeting both FSP1 and NRF2 may be a promising strategy for overcoming ferroptosis resistance in cancer.

A Nationwide Survey and Risk Assessment of Ethyl Carbamate Exposure Due to Daily Intake of Alcoholic Beverages in the Chinese General Population

Ethyl carbamate (EC) is carcinogenic, and, in China, oral intake of EC mainly occurs as a result of the consumption of alcoholic beverages. To obtain the latest EC intake and risk analysis results for the general population in China, the China National Center for Food Safety Risk Assessment (CFSA) conducted the sixth total diet study (TDS) as a platform to analyze EC contents and exposure due to the intake of alcoholic beverages. A total of 100 sites in 24 provinces were involved in the collection and preparation of alcohol mixture samples for the sixth TDS. There were 261 different types of alcohol collected across the country, based on local dietary menus and consumption survey results. Ultimately, each province prepared a mixed sample by mixing their respective samples according to the percentage of local consumption. The EC levels of these twenty-four mixed samples were determined using our well-validated gas chromatography-mass spectrometry (GC-MS) method. The values ranged from 1.0 μg/kg to 33.8 μg/kg, with 10.1 μg/kg being the mean. China's EC daily intake ranged from 0.001 ng/kg bw/d to 24.56 ng/kg bw/d, with a mean of 3.23 ng/kg bw/d. According to the margin of exposure (MOE), virtually safe dose (VSD), and T25 risk assessments of the carcinogenicity of EC, the mean lifetime cancer risk for the Chinese population was 9.8 × 104, 1.5 × 10-7, and 8.6 × 10-8, respectively. These data show that the carcinogenicity of EC in the general Chinese population due to alcoholic intake is essentially minimal.

Salidroside ameliorates acetaminophen-induced acute liver injury through the inhibition of endoplasmic reticulum stress-mediated ferroptosis by activating the AMPK/SIRT1 pathway

Acetaminophen (APAP) overdose has long been considered a major cause of drug-induced liver injury. Ferroptosis is a type of programmed cell death mediated by iron-dependent lipid peroxidation. Endoplasmic reticulum (ER) stress is a systemic response triggered by the accumulation of unfolded or misfolded proteins in the ER. Ferroptosis and ER stress have been proven to contribute to the progression of APAP-induced acute liver injury (ALI). It was reported that salidroside protects against APAP-induced ALI, but the potential mechanism remain unknown. In this study, male C57BL/6 J mice were intraperitoneally (i.p.) injected APAP (500 mg/kg) to induce an ALI model. Salidroside was i.p. injected at a dose of 100 mg/kg 2 h prior to APAP administration. Mice were sacrificed 12 h after APAP injection and the liver and serum of the mice were obtained for histological and biochemistry analysis. AML12 cells were used in in vitro assays. The results indicated that salidroside mitigated glutathione degradation via inhibiting cation transport regulator homolog 1 (CHAC1) to attenuate ferroptosis, and simultaneously suppressing PERK-eIF2α-ATF4 axis-mediated ER stress, thus alleviating APAP-induced ALI. However, PERK activator CCT020312 and overexpression of ATF4 inhibited the protective function of salidroside on CHAC1-mediated ferroptosis. Besides this, activation of the AMPK/SIRT1 signaling pathway by salidroside was demonstrated to have a protective effect against APAP-induced ALI. Interestingly, selective inhibition of SIRT1 ameliorated the protective effects of salidroside on ER stress and ferroptosis. Overall, salidroside plays a significant part in the mitigation of APAP-induced ALI by activating the AMPK/SIRT1 signaling to inhibit ER stress-mediated ferroptosis in the ATF4-CHAC1 axis.

Special issue: molecular nutrition and chronic diseases

"Let food be thy medicine and medicine be thy food"-the ancient adage proposed by Greek philosopher Hippocrates of Kos thousands of years ago already acknowledged the importance of the beneficial and health-promoting effects of food nutrients on the body (Mafra et al., 2021). Recent epidemiological and large-scale community studies have also reported that unhealthy diets or eating habits may contribute heavily to the burden of chronic, non-communicable diseases, such as obesity, type 2 diabetes mellitus (T2DM), hypertension, cardiovascular disease (CVD), cancer, neurodegenerative diseases, arthritis, chronic kidney disease (CKD), and chronic obstructive pulmonary disease (COPD) (Jayedi et al., 2020; Gao et al., 2022). Emerging evidence highlights that a diet rich in fruits and vegetables can prevent various chronic diseases (Chen et al., 2022). Food bioactive compounds including vitamins, phytochemicals, and dietary fibers are responsible for these nutraceutical benefits (Boeing et al., 2012). Recently, phytochemicals such as polyphenols, phytosterols, and carotenoids have gained increasing attention due to their potential health benefits to alleviate chronic diseases (van Breda and de Kok, 2018). Understanding the role of phytochemicals in health promotion and preventing chronic diseases can inform dietary recommendations and the development of functional foods. Therefore, it is crucial to investigate the health benefits of phytochemicals derived from commonly consumed foods for the prevention and management of chronic diseases.

Ferroptosis mediates decabromodiphenyl ether-induced liver damage and inflammation

Decabromodiphenyl ether (BDE-209) is an environmental toxin. Increasing evidence showed that BDE-209 exposure induced liver injury, but the mechanism still remains unknown. The present study explored the effect and mechanism of ferroptosis on hepatotoxicity triggered by BDE-209 in vivo and in vitro. In vivo experiment, ICR mice were exposed to BDE-209 for 50 days, and then recovered for 50 days; HepG2 and L02 cells were treated with BDE-209 or/and ferrostatin-1 (Fer-1) for establishing in vitro model. In vivo, the results showed that BDE-209 accumulated in liver and induced liver damage, increased Fe²⁺ and MDA contents, and blocked the activation of SLC7A11/GSH/GPX4 pathway in liver; BDE-209 also activated IKK/IκB/NF-κB pathway and elevated inflammatory cytokines levels in liver after exposure for 50 days. After BDE-209 stopping exposure 50 days, the severity of liver damage, ferroptosis and inflammatory response were still higher than the corresponding control group. In vitro, ferroptosis inhibitor Fer-1 rescued ferroptotic damage and attenuated cell death in BDE-209-treated HepG2 and L02 cells. In addition, Fer-1 reversed the activation of IKK/IκB/NF-κB pathway and the increase of pro-inflammatory cytokines levels in BDE-209-treated HepG2 and L02 cells. Together, the above results suggested that BDE-209 induced tissue damage and inflammatory response by activating ferroptosis through increasing iron-dependent lipid peroxidation and blocking the activation of SLC7A11/GSH/GPX4 pathway in liver, indicating that ferroptosis is a potential mechanism for BDE-209-induced hepatotoxicity.

Natural Flavonoids and Ferroptosis: Potential Therapeutic Opportunities for Human Diseases

Flavonoids are a class of bioactive phytochemicals containing a core 2-phenylchromone skeleton and are widely found in fruits, vegetables, and herbs. Such natural compounds have gained significant attention due to their various health benefits. Ferroptosis is a recently discovered unique iron-dependent mode of cell death. Unlike traditional regulated cell death (RCD), ferroptosis is associated with excessive lipid peroxidation on cellular membranes. Accumulating evidence suggests that this form of RCD is involved in a variety of physiological and pathological processes. Notably, multiple flavonoids have been shown to be effective in preventing and treating diverse human diseases by regulating ferroptosis. In this review, we introduce the key molecular mechanisms of ferroptosis, including iron metabolism, lipid metabolism, and several major antioxidant systems. Additionally, we summarize the promising flavonoids targeting ferroptosis, which provides novel ideas for the management of diseases such as cancer, acute liver injury, neurodegenerative diseases, and ischemia/reperfusion (I/R) injury.

Dissecting the potential role of ferroptosis in liver diseases: an updated review

Ferroptosis is a novel form of cell death, manifested by iron-dependent, non-apoptotic manner resulting from the intracellular accumulation of large clusters of reactive oxygen species (ROS) and lipid peroxides due to abnormal iron metabolism. Since the liver is the main organ of human body for storing iron, it is essential to perform in-depth investigation on the role and mechanistic basis of ferroptosis in the context of divergent liver diseases. We previously summarized the emerging role of ferroptosis among various liver diseases, however, the past few years have been a surge in research establishing ferroptosis as the molecular basis or treatment option. This review article concentrated on the accumulating research progress of ferroptosis in a range of liver diseases such as acute liver injury/failure (ALI/ALF), immune-mediated hepatitis, alcoholic liver disease (ALD), nonalcoholic fatty liver disease and liver fibrosis. Ferroptosis may be a promising target for the prevention and treatment of various liver diseases, providing a strategy for exploring new therapeutic avenues for these entities.

Ferroptosis contribute to neonicotinoid imidacloprid-evoked pyroptosis by activating the HMGB1-RAGE/TLR4-NF-κB signaling pathway

Imidacloprid (IMI) is among the common neonicotinoid insecticides used in agriculture worldwide, posing a potential toxic threat to non-target animals and humans. Numerous studies have shown that ferroptosis is involved in the pathophysiological progression of renal diseases. However, it remains unclear whether ferroptosis is involved in IMI-induced nephrotoxicity. In the present study, we investigated the potential pathogenic role of ferroptosis in IMI-induced kidney damage in vivo. Transmission electron microscopy (TEM) showed that the mitochondrial crest of kidney cells significantly decreased following IMI exposure. Moreover, IMI exposure triggered ferroptosis and lipid peroxidation in the kidney. We confirmed that nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant capability was negatively correlated with the ferroptosis induced by IMI exposure. Importantly, we verified that NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3)-driven inflammation occurred in the kidneys following IMI exposure, but pretreatment with the ferroptosis inhibitor ferrostatin (Fer-1) blocked this phenomenon. Additionally, IMI exposure induced F4/80⁺ macrophages to accumulated in the proximal tubules of the kidneys, and also increased the protein expression of high-mobility group box 1 (HMGB1), receptor for advanced glycation end products (RAGE), receptor for advanced glycation end products (TLR4), and nuclear factor kappa-B (NF-κB). In contrast, inhibition of ferroptosis by Fer-1 blocked IMI-induced NLRP3 inflammasome activation, F4/80 positive macrophages, and the HMGB1-RAGE/TLR4 signaling pathway. To the best of our knowledge, this is the first study to reveal that IMI stress can induce Nrf2 inactivation, thereby triggering ferroptosis, causing an initial wave of death, and activating HMGB1-RAGE/TLR4 signaling, which promotes pyroptosis that perpetuates kidney dysfunction.

Deoxynivalenol induces testicular ferroptosis by regulating the Nrf2/System Xc-/GPX4 axis

Deoxynivalenol (DON) is the most common mycotoxin contaminant in food and feed. DON accumulation in food chain severely threatens human and animal health due to the toxic effects on the reproduction system. However, the underlying mechanism of DON on male reproductive dysfunction is still in debate and there is little information about whether DON triggers testicular ferroptosis. In this study, male C57BL/6 mice were divided into 4 groups and treated by oral gavage with 0, 0.5, 1.0, 2.0 mg/kg BW DON for 28 days. Firstly, we proved that male reproduction dysfunction was induced by DON through assessing testicular histopathology, serum testosterone level as well as blood-testis barrier integrity. Then, we verified ferroptosis occurred in DON-induced testicular dysfunction model through disrupting iron homeostasis, increasing lipid peroxidation and inhibiting system Xc^-/Gpx4 axis. Notably, the present data showed DON reduced antioxidant capacity via blocking Nrf2 pathway to lead to the further weakness of ferroptosis resistance. Altogether, these results indicated that DON caused mice testicular ferroptosis associated with inhibiting Nrf2/System Xc-/GPx4 axis, which provided that maintaining testicular iron homeostasis and activating Nrf2 pathway may be a potential target for alleviating testicular toxicity of DON in the future.

The advancements in targets for ferroptosis in liver diseases

Ferroptosis is a type of regulated cell death caused by iron overload and lipid peroxidation, and its core is an imbalance of redox reactions. Recent studies showed that ferroptosis played a dual role in liver diseases, that was, as a therapeutic target and a pathogenic factor. Therefore, herein, we summarized the role of ferroptosis in liver diseases, reviewed the part of available targets, such as drugs, small molecules, and nanomaterials, that acted on ferroptosis in liver diseases, and discussed the current challenges and prospects.

The role of ferroptosis mediated by Bmal1/Nrf2 in nicotine -induce injury of BTB integrity

Nicotine has shown the toxic effects on male reproductive system, and testicular damage is associated with ferroptosis, which is a non-apoptotic regulated cell death driven by iron-dependent lipid peroxidation. However, the role of nicotine on ferroptosis of testicular cells is largely elusive. In the present study, we showed that nicotine destroyed blood-testis barrier (BTB) by interfering with the circadian rhythm of BTB-related factors (ZO-1, N-Cad, Occludin and CX-43) and induced ferroptosis, as reflected via increased clock-control levels of lipid peroxide and decreased ferritin and GPX4, which involved in the circadian. Inhibition of ferroptosis with Fer-1 alleviated nicotine-induced injury of BTB and impaired sperm in vivo. Mechanically, we uncover that the core molecular clock protein, Bmal1, regulates the expression of Nrf2 via direct E-box binding to its promoter to regulate its activity, and nicotine decreases the transcription of Nrf2 through Bmal1 and inactivates Nrf2 pathway and its downstream antioxidant gene, which leads to the imbalance of redox state and ROS accumulation. Intriguingly, nicotine induced lipid peroxidation and subsequent ferroptosis by Bmal1-mediated Nrf2. In conclusion, our study reveals a clear role for the molecular clock in controlling Nrf2 in testis to mediate the ferroptosis induced by nicotine. These findings provide a potential mechanism to prevent smoking and/or cigarette smoke-induced male reproductive injury.

Glyphosate-triggered hepatocyte ferroptosis via suppressing Nrf2/GSH/GPX4 axis exacerbates hepatotoxicity

Glyphosate (GLY) exposure has been reported to damage organs in animals, in particular the liver, due to increased reactive oxygen species (ROS). Ferroptosis is defined as a new type of cell death that is characterized by the increase of ROS. The purpose of this study was to elucidate whether the relationship between ferroptosis and GLY-induced hepatotoxicity is of significance to enlarge the knowledge about GLY toxicity and consequences for human and animal health. To this end, in this study, we investigated the role of ferroptosis in GLY-induced hepatotoxicity both in vivo and in vitro. The results showed that GLY exposure triggered ferroptosis in L02 cells, but pretreatment with ferroptosis inhibitor ferrostatin (Fer-1) rescued ferroptosis-induced injury, thereby indicating that ferroptosis plays a key role in GLY-induced hepatotoxicity. Moreover, N-acetylcysteine, a glutathione (GSH) synthesis precursor, reversed GLY-triggered ferroptosis damage, thus indicating that GSH exhaustion may be a prerequisite for GLY-triggered hepatotoxicity. Mechanistically, GLY inhibited GSH biosynthesis via blocking the phosphorylation and nuclear translocation of Nrf2, which resulted in GSH depletion-induced hepatocyte ferroptosis. In a mouse model, GLY exposure triggered ferroptosis-induced liver damage, which can be rescued by pretreatment with Fer-1 or tBHQ (a specific agonist of Nrf2). To our knowledge, this is the first study to reveal that GLY-triggered hepatocyte ferroptosis via suppressing Nrf2/GSH/GPX4 axis exacerbates hepatotoxicity, which expands our knowledge about GLY toxicity in animal and human health.

Cross-talk between autophagy and ferroptosis contributes to the liver injury induced by fluoride via the mtROS-dependent pathway

Fluoride can induce hepatotoxicity, but the mechanisms responsible are yet to be investigated. This study sought to investigate the role and mechanism of mitochondrial reactive oxygen species (mtROS), autophagy, and ferroptosis in fluoride-induced hepatic injury with a focus on the role of mtROS-mediated cross-talk between autophagy and ferroptosis. To this end, an in vivo Sprague-Dawley rat model and in vitro BRL3A cells were exposed to sodium fluoride (NaF). The results revealed that NaF exposure diminished the mitochondrial membrane potential, increased mtROS production and TOMM20 expression, and induced autophagic flux blockage and ferroptosis in vivo and in vitro. Furthermore, the autophagy activator (RAPA) enhanced GPX4 expression while inhibiting ACSL4 expression, reduced the accumulation of ferrous ions in BRL3A cells, and restored lipid peroxidation levels, thus inhibiting ferroptosis. Fer-1, a ferritinase inhibitor, downregulated the expression of LC3-II and p62, increased the number of autolysosomes while decreasing the number of autophagosomes, and alleviated the blockage of autophagic flux by improving autophagic degradation. These results suggest the occurrence of a cross-talk between autophagy and ferroptosis. The mtROS inhibitor (Mito-TEMPO) could alleviate autophagic flux blockage and inhibit ferroptosis in NaF-induced liver injury. In addition, the cross-talk between NaF-induced autophagy and ferroptosis was dependent on the mtROS pathway.

Andrographolide promoted ferroptosis to repress the development of non-small cell lung cancer through activation of the mitochondrial dysfunction

BACKGROUND

Ferroptosis, a form of regulated cell death by lipid peroxidation, was currently considered as a key factor affecting the occurrence and progression in various cancers. Andrographolide (ADE), a major effective ingredient of Andrographis paniculate, has proven to have a substantial anti-tumor effect on multiple cancer types. However, the function and underlying mechanism of ADE in Non-Small Cell Lung Cancer remain unclear.

METHODS

CCK8 assay, colony-formation assay, flow cytometry, scratch test, transwell assay, western blotting, ferroptosis analysis and mitochondria analysis were performed to reveal the role and underlying mechanisms of ADE in NSCLC cell lines (H460 and H1650). In vivo, xenograft model and lung metastatic model were performed to verify the effect of ADE on the growth and metastasis of NSCLC.

RESULTS

In this present study, we demonstrated that treatment with ADE could inhibit cell growth and metastases through eliciting ferroptosis in vitro an in vivo. The IC50 of ADE in H460 and H1650 cells were 33.16 μM and 32.45 μM respectively. In Lewis xenografted animals, i.p. ADE repressed relative tumor growth (p < 0.01) and inhibited metastases (p < 0.01). Notably, the ferroptosis inhibitor Fer-1 abrogated the anti-tumor capacity of ADE. Induction of ferroptosis by ADE was confirmed by elevated levels of reactive oxygen sepsis (ROS), glutathione (GSH), malondialdehyde (MDA), intracellular iron content and lipid ROS reduced glutathione (GSH) accumulation (p < 0.01). Furthermore, ADE inhibited the expression of ferroptosis-related protein GPX4 and SLC7A11. Simultaneously, it also disclosed that ADE enhanced mitochondrial dysfunction, as evidenced by increased mitochondrial ROS release, mitochondrial membrane potential (MMP) depolarization, and decreased mitochondrial ATP. Most interestingly, Mito-TEMPO, a mitochondria-targeted antioxidant, rescued ADE-induced ferroptosis.

CONCLUSION

Our data validated that ADE treatment could restrain proliferation and metastases of NSCLC cells through induction of ferroptosis via potentiating mitochondrial dysfunction.

Ferroptosis and its role in skeletal muscle diseases

Ferroptosis is characterized by the accumulation of iron and lipid peroxidation products, which regulates physiological and pathological processes in numerous organs and tissues. A growing body of research suggests that ferroptosis is a key causative factor in a variety of skeletal muscle diseases, including sarcopenia, rhabdomyolysis, rhabdomyosarcoma, and exhaustive exercise-induced fatigue. However, the relationship between ferroptosis and various skeletal muscle diseases has not been investigated systematically. This review’s objective is to provide a comprehensive summary of the mechanisms and signaling factors that regulate ferroptosis, including lipid peroxidation, iron/heme, amino acid metabolism, and autophagy. In addition, we tease out the role of ferroptosis in the progression of different skeletal muscle diseases and ferroptosis as a potential target for the treatment of multiple skeletal muscle diseases. This review can provide valuable reference for the research on the pathogenesis of skeletal muscle diseases, as well as for clinical prevention and treatment.

Ferroptosis-Related Gene GCLC Is a Novel Prognostic Molecular and Correlates with Immune Infiltrates in Lung Adenocarcinoma

Ferroptosis, a newly discovered iron-dependent type of cell death, has been found to play a crucial role in the depression of tumorigenesis. However, the prognostic value of ferroptosis-related genes (FRGs) in lung adenocarcinoma (LUAD) remains to be further elucidated. Differential expression analysis and univariate Cox regression analysis were utilized in this study to search for FRGs that were associated with the prognosis of LUAD patients. The influences of candidate markers on LUAD cell proliferation, migration, and ferroptosis were evaluated by CCK8, colony formation, and functional experimental assays in association with ferroptosis. To predict the prognosis of LUAD patients, we constructed a predictive signature comprised of six FRGs. We discovered a critical gene (GCLC) after intersecting the prognostic analysis results of all aspects, and its high expression was associated with a bad prognosis in LUAD. Correlation research revealed that GCLC was related to a variety of clinical information from LUAD patients. At the same time, in the experimental verification, we found that GCLC expression was upregulated in LUAD cell lines, and silencing GCLC accelerated ferroptosis and decreased LUAD cell proliferation and invasion. Taken together, this study established a novel ferroptosis-related gene signature and discovered a crucial gene, GCLC, that might be a new prognostic biomarker of LUAD patients, as well as provide a potential therapeutic target for LUAD patients.