Coaction of hepatic thioredoxin and glutathione systems in iron overload-induced oxidative stress

Diffractaic acid exerts anti-cancer effects on hepatocellular carcinoma HepG2 cells by inducing apoptosis and suppressing migration through targeting thioredoxin reductase 1

Hepatocellular carcinoma (HCC) represents one of the most common malignant tumors worldwide. Due to the limited number of available drugs and their side effects, the development of new chemotherapeutic strategies for HCC treatment has become increasingly important. This study is aimed at investigating whether diffractaic acid (DA), one of the secondary metabolites of lichen, exhibits a potential anticancer effect on HepG2 cells and whether its anticancer effect is mediated by inhibition of thioredoxin reductase 1 (TRXR1), which is a target of chemotherapeutic strategies due to overexpression in tumor cells including HCC. XTT assay results showed that DA exhibited strong cytotoxicity on HepG2 cells with an IC50 value of 78.07 µg/mL at 48 h. Flow cytometric analysis results revealed that DA displayed late apoptotic and necrotic effects on HepG2 cells. Consistent with these findings, real-time PCR results showed that DA did not alter the BAX/BCL2 ratio in HepG2 cells but upregulated the P53 gene. Moreover, the wound healing assay results revealed a strong anti-migratory effect of DA in HepG2 cells. Real-time PCR and Western blot analyses demonstrated that DA increased TRXR1 gene and protein expression levels, whereas enzyme activity studies disclosed that DA inhibited TRXR1. These findings suggest that DA has an anticancer effect on HepG2 cells by targeting the enzymatic inhibition of TRXR1. In conclusion, DA as a TRXR1 inhibitor can be considered an effective chemotherapeutic agent which may be a useful lead compound for the treatment of HCC.

Research advances on molecular mechanism and natural product therapy of iron metabolism in heart failure

The progression of heart failure (HF) is complex and involves multiple regulatory pathways. Iron ions play a crucial supportive role as a cofactor for important proteins such as hemoglobin, myoglobin, oxidative respiratory chain, and DNA synthetase, in the myocardial energy metabolism process. In recent years, numerous studies have shown that HF is associated with iron dysmetabolism, and deficiencies in iron and overload of iron can both lead to the development of various myocarditis diseases, which ultimately progress to HF. Iron toxicity and iron metabolism may be key targets for the diagnosis, treatment, and prevention of HF. Some iron chelators (such as desferrioxamine), antioxidants (such as ascorbate), Fer-1, and molecules that regulate iron levels (such as lactoferrin) have been shown to be effective in treating HF and protecting the myocardium in multiple studies. Additionally, certain natural compounds can play a significant role by mediating the imbalance of iron-related signaling pathways and expression levels. Therefore, this review not only summarizes the basic processes of iron metabolism in the body and the mechanisms by which they play a role in HF, with the aim of providing new clues and considerations for the treatment of HF, but also summarizes recent studies on natural chemical components that involve ferroptosis and its role in HF pathology, as well as the mechanisms by which naturally occurring products regulate ferroptosis in HF, with the aim of providing reference information for the development of new ferroptosis inhibitors and lead compounds for the treatment of HF in the future.

Antiproliferative, antimigratory, and apoptotic effects of diffractaic and vulpinic acids as thioredoxin reductase 1 inhibitors on cervical cancer

Cervical cancer is among the most frequently observed cancer types in females. New therapeutic targets are needed because of the side impacts of existing cancer drugs and the inadequacy of treatment methods. Thioredoxin reductase 1 (TrxR1) is often overexpressed in many cancer cells, and targeting TrxR1 has become an attractive target for cancer therapy. This study investigated the anticancer impacts of diffractaic and vulpinic acids, lichen secondary metabolites, on the cervical cancer HeLa cell line. XTT findings demonstrated showed that diffractaic and vulpinic acids suppressed the proliferation of HeLa cells in a dose- and time-dependent manner and IC50 values were 22.52 μg/ml and 66.53 μg/ml at 48 h, respectively. Each of these lichen metabolites significantly suppressed migration. Diffractaic acid showed an increase in both the BAX/BCL2 ratio by qPCR analysis and the apoptotic cell population via flow cytometry analysis on HeLa cells. Concerning vulpinic acid, although it decreased the BAX/BCL2 ratio in this cells, it increased apoptotic cells according to the flow cytometry analysis results. Diffractaic and vulpinic acids significantly suppressed TrxR1 enzyme activity rather than the gene and protein expression levels in HeLa cells. This research demonstrated for the first time, that targeting TrxR1 with diffractaic and vulpinic acids was an effective therapeutic strategy for treating cervical cancer.

Resveratrol Attenuates Sepsis-Induced Cardiomyopathy in Rats through Anti-Ferroptosis via the Sirt1/Nrf2 Pathway

Background: Sepsis-induced cardiomyopathy (SIC) is a severe myocardial dysfunction secondary to septicemia. It is a major concern owing to the high mortality and morbidity, which are greatly influenced by ferroptosis. Resveratrol (RSV) is a naturally existing agonist of the silent information regulator 1 (Sirt1). It has cardioprotective effects against sepsis-induced myocardial injury, However, the detailed mechanism is unknown.Methods: In this study, cecal ligation and puncture (CLP)-induced septic rats were employed to assess the changes in ferroptosis with RSV administration. According to the different treatments the rats were divided into the following groups: (1) the Sham, (2) CLP, (3) CLP + RSV at various doses (10, 30, and 50 mg/kg), and (4) CLP + Fer-1(a ferroptotic inhibitor) groups. After 24 h, the structure and function of the cardiac system in rats were evaluated, and mitochondrial morphology, ferroptosis-related biomarkers, and the levels of Sirt1/Nrf2 were assessed.Results: The rats that underwent CLP had suffered cardiac dysfunction, accompanied with myocardial damage, impaired mitochondria, elevated lipid peroxidation, and reduced Sirt1/Nrf2 expression in the myocardium. High-dose RSV successfully improved heart function, reversing the abnormalities in a dose-dependent manner. We then used EX527, a selective Sirt1 inhibitor, to further identify the intermediate signaling targets of RSV that regulate ferroptosis. EX527 diminished the curative effects of high-doses RSV.Conclusions: Summarily, our findings suggest a novel mechanism of RSV in reducing SIC: ferroptosis inhibition via upregulation of Sirt1/Nrf2 signaling pathways. This may be an effective therapeutic approach against organ failure in sepsis, particularly SIC.

Diffractaic acid exhibits thioredoxin reductase 1 inhibition in lung cancer A549 cells

Lung cancer is the leading cause of cancer-related deaths all over the world. Therefore, it has gained importance in the development of new chemotherapeutic strategies to identify anticancer agents with low side effects, reliable, high anticancer potential, and specific to lung cancer cells. Thioredoxin reductase 1 (TrxR1) is an important therapeutic target for lung cancer treatment because of its overexpression in tumor cells. Here, we aimed to examine the anticancer effect of diffractaic acid, a lichen secondary metabolite, in A549 cells by comparing it with the commercial chemotherapeutic drug carboplatin and also to investigate whether the anticancer effect of diffractaic acid occurs via TrxR1-targeting. The IC50 value of diffractaic acid on A549 cells was determined as 46.37 μg/mL at 48 h, and diffractaic acid had stronger cytotoxicity than carboplatin in A549 cells. qPCR results revealed that diffractaic acid promoted the intrinsic apoptotic pathway through the upregulation of the BAX/BCL2 ratio and P53 gene in A549 cells, which is consistent with the flow cytometry results. Furthermore, migration analysis results indicated that diffractaic acid impressively suppressed the migration of A549 cells. While the enzymatic activity of TrxR1 was inhibited by diffractaic acid in A549 cells, no changes were seen in the quantitative expression levels of gene and protein. These findings provide fundamental data on the anticancer effect of diffractaic acid on A549 cells targeting TrxR1 activity, suggesting that it could be considered a chemotherapeutic agent for lung cancer therapy.

The Hepatic Antioxidant System Damage Induced with the Cafeteria (CAF) Diet Is Largely Counteracted Using SCD Probiotics during Development of Male Wistar Rats

The cafeteria (CAF) diet, reflective of predominant Western dietary behaviors, is implicated in hastening weight gain, subsequently resulting in health complications such as obesity, diabetes, and cancer. To this end, it is vital to notice the deleterious consequences of the CAF regimen prior to the onset of complications, which is fundamental for early intervention in the context of numerous diseases. Probiotic-derived postbiotic metabolites have gained attention for their antioxidative properties, offering a potential countermeasure against oxidative stress. This research sought to discern the protective efficacy of SCD Probiotics against liver glutathione system damage arising from the CAF diet during developmental phases. Male Wistar rats, from weaning on day 21 to day 56, were categorized into four groups: a control on a conventional diet; a group on a standard diet enriched with SCD Probiotics; a mixed-diet group comprising both CAF and standard feed; and a combination diet group supplemented with SCD Probiotics. Through the application of real-time PCR, enzyme activity assessments, and quantitative metabolite analyses, our findings highlight the CAF diet's adverse influence on the liver's antioxidant defenses via shifts in gene expression. Yet, the inclusion of SCD Probiotics mostly ameliorated these harmful effects. Remarkably, the positive regulatory influence of SCD Probiotics on the liver's antioxidant system was consistently observed, independent of the CAF diet's presence.

Haloxyfop-P-methyl induces immunotoxicity and glucose metabolism disorders and affects the Nrf2/ARE pathway mediated antioxidant system in Chiromantes dehaani

Haloxyfop-P-methyl is used extensively in agricultural production, and its metabolites in soil have potentially toxic effects on aquatic ecosystems. In this study, we explored the toxicity of haloxyfop-P-methyl on Chiromantes dehaani. The results of the 21-day toxicity test showed that haloxyfop-P-methyl decreased the weight gain (WG), specific growth rate (SGR) and hepatosomatic index (HSI). In glucose metabolism, haloxyfop-P-methyl reduced pyruvate, lactate, lactate dehydrogenase and succinate dehydrogenase, but enhanced glucose-6-phosphate dehydrogenase and hexokinase. Furthermore, expression of glucose metabolism-related genes was upregulated. We cloned the full-length CdG6PDH gene, which contains a 1587 bp ORF that encoded a 528 amino acid polypeptide. In antioxidant system, haloxyfop-P-methyl increased glutathione, thioredoxin reductase and thioredoxin peroxidase activities and activated the Nrf2/ARE pathway through upregulation of ERK, JNK, PKC and Nrf2. In immunity, low concentrations haloxyfop-P-methyl, or short-term exposure, upregulated the expression of immune-related genes and enhanced immune-related enzymes activity, while high concentrations or long-term exposure inhibited immune function. In summary, haloxyfop-P-methyl inhibited the growth performance, disrupted glucose metabolism, activated the antioxidant system, and led to immunotoxicity. The results deepen our understanding of the toxicity mechanism of haloxyfop-P-methyl and provide basic biological data for the comprehensive assessment of the risk of haloxyfop-P-methyl to the environment and humans.

Sesamol Mitigates Chronic Iron Overload-Induced Cognitive Impairment and Systemic Inflammation via IL-6 and DMT1 Regulation

SCOPE

Excessive iron contributes to oxidative damage and cognitive decline in Alzheimer's disease. Sesamol, a compound in sesame oil that exhibits both anti-inflammatory and neuroprotective properties, is examined in this study for its ability to alleviate cognitive impairments in iron overload mice model.

METHODS AND RESULTS

An iron overload model is established by intraperitoneally injecting dextran iron (250 mg kg-1 body weight) twice a week for 6 weeks, while sesamol (100 mg kg-1 body weight) is administered daily for the same length of time. The results demonstrate that sesamol protects spatial working memory and learning ability in iron overload mice, and inhibits neuronal loss and brain atrophy induced by iron overload. Moreover, sesamol significantly decreases interleukin-6 and malondialdehyde, and increases glutathione peroxidase 4 in the brains of iron overload mice. Additionally, sesamol maintains iron homeostasis in the brain by regulating the expressions of transferrin receptors, divalent metal transporter 1, and hepcidin, and reducing iron accumulation. Furthermore, sesamol suppresses disturbed systemic iron homeostasis and inflammation, particularly liver interleukin-6 expression.

CONCLUSION

These findings suggest that sesamol may be effective in mitigating neuroinflammatory responses and cognitive impairments induced by iron overload, potentially through its involvement in mediating the liver-brain axis.

Effect of evernic acid on human breast cancer MCF-7 and MDA-MB-453 cell lines via thioredoxin reductase 1: A molecular approach

Thioredoxin reductase 1 (TrxR1) has emerged as an important target for anticancer drug development due to its overexpression in many human tumors including breast cancer. Due to the serious side effects of currently used commercial anticancer drugs, new natural compounds with very few side effects and high efficacy are of great importance in cancer treatment. Lichen secondary metabolites, known as natural compounds, have diverse biological properties, including antioxidant and anticancer activities. Herein, we aimed to determine the potential antiproliferative, antimigratory, and apoptotic effects of evernic acid, a lichen secondary metabolite, on breast cancer MCF-7 and MDA-MB-453 cell lines and afterward to investigate whether its anticancer effect is exerted by TrxR1-targeting. The cytotoxicity results indicated that evernic acid suppressed the proliferation of MCF-7 and MDA-MB-453 cells in a dose-dependent manner and the IC₅₀ values were calculated as 33.79 and 121.40 μg/mL, respectively. Migration assay results revealed the notable antimigratory ability of evernic acid against both cell types. The expression of apoptotic markers Bcl2 associated X, apoptosis regulator, Bcl2 apoptosis regulator, and tumor protein p53 by quantitative real-time polymerase chain reaction and western blot analysis showed that evernic acid did not induce apoptosis in both cell lines, consistent with flow cytometry results. Evernic acid showed its anticancer effect via inhibiting TrxR1 enzyme activity rather than mRNA and protein expression levels in both cell lines. In conclusion, these findings suggest that evernic acid has the potential to be evaluated as a therapeutic agent in breast cancer treatment.

Comparison of the efficacy of the mouse hepatic and renal antioxidant systems against inflammation-induced oxidative stress

This study was conducted to compare the efficacy of the mouse hepatic and renal antioxidant systems against inflammation-induced oxidative stress. Increased Il-1 and Il-6 expressions, markers of inflammation, were represented by inflammation models in mouse liver and kidney tissues injected intraperitoneally with LPS. After establishing the model, the GSH level and the GSH/GSSG ratio, which are oxidative stress markers, were investigated in both tissues treated with LPS and the control group. The expression of Trx1, TrxR, and Txnip genes increased in the liver tissues of LPS-treated mice. In the kidney tissue, while Trx1 expression decreased, no change was observed in TrxR1 expression, and Txnip expression increased. In the kidneys, TRXR1 and GR activities decreased, whereas GPx activity increased. In both tissues, the TRXR1 protein expression decreased significantly, while TXNIP expression increased. In conclusion, different behaviors of antioxidant system members were observed during acute inflammation in both tissues. Additionally, it can be said that the kidney tissue is more sensitive and takes earlier measures than the liver tissue against cellular damage caused by inflammation and inflammation-induced oxidative stress.

Depletion of Tip60/Kat5 affects the hepatic antioxidant system in mice

Tat-interactive protein 60 kDa (TIP60, also known as lysine acetyltransferase 5 [KAT5]) is a member of the MYST protein family with histone acetyltransferase activity. Recent studies have reported that TIP60 has multiple functions in many signal transduction mechanisms, especially p53-mediated apoptosis. Although the activation of apoptosis signaling pathways requires the presence of cellular reactive oxygen species (ROS) at a certain level, an imbalance between the production and consumption of ROS in cells results in oxidative stress (OS). In this study, we investigated for the first time how the absence of the Tip60 gene in the liver affects gene expression, enzyme activity, and protein expression of the hepatic antioxidant members localized in the cytoplasm, including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), and glutathione S-transferase (GST). First, we successfully generated liver-specific Tip60 knockout mice (mutants) using Cre/LoxP recombination. The reduced glutathione level and nicotinamide adenine dinucleotide phosphate oxidase 4 (Nox4) expression, a marker of OS, increased significantly in the Tip60 mutant liver. Gene expression, activity, and protein expression of the enzymatic antioxidant system, including SOD, CAT, GR, GPx, and GST were investigated in mutants and control groups. Despite a significant correlation between the gene, enzyme activity, and protein content for CAT and GR, this was not true for SOD and GPx. The overall results suggest that TIP60 acts on the hepatic antioxidant system both at the gene and protein levels, but the actual effect of the deletion of Tip60 is observed at the protein level, especially for SOD and GPx.

Tip60/Kat5 may be a novel candidate histone acetyltransferase for the regulation of liver iron localization via acetylation

Hepcidin (HAMP), an iron regulatory hormone synthesized by liver hepatocytes, works together with ferritin (FTH) and ferroportin (FPN) in regulating the storage, transport, and utilization of iron in the cell. Epigenetic mechanisms, especially acetylation, also play an important role in the regulation of iron metabolism. However, a target protein has not been mentioned yet. With this preliminary study, we investigated the effect of histone acetyltransferase TIP60 on the expression of HAMP, FTH, and FPN. In addition, how the depletion of Tip60, which regulates the circadian system, affects the daily expression of Hamp was examined at six Zeitgeber time (ZT) points. For this purpose, liver-specific Tip60 knockout mice (mutant) were produced with tamoxifen-inducible Cre/lox recombination and an iron overload model in mice was generated. While HAMP and FTH expressions decreased, FPN expression increased in the mutant group. Interestingly, there was no change in the iron content. A significant increase was observed in the expressions of HAMP, FTH, and FPN and total liver iron content in the liver tissue of the iron overload group. Since intracellular iron concentration is involved in regulating the circadian clock, temporal expression of Hamp was investigated in control and mutant groups at six ZT points. In the control group, Hamp accumulated in a circadian manner with maximal and minimal levels reaching around ZT16 and ZT8, respectively. In the mutant group, there was a significant reduction in Hamp expression in the light phase ZT0 and ZT4 and in the dark phase ZT16. These data are the first findings demonstrating a possible relationship between Tip60 and iron metabolism.

Food-derived bioactive oligopeptide iron complexes ameliorate iron deficiency anemia and offspring development in pregnant rats

This study aimed to investigate anemia treatment and other potential effects of two food-derived bioactive oligopeptide iron complexes on pregnant rats with iron deficiency anemia (IDA) and their offspring. Rats with IDA were established with a low iron diet and then mated. There were one control group and seven randomly assigned groups of pregnant rats with IDA: Control group [Control, 40 ppm ferrous sulfate (FeSO₄)]; IDA model group (ID, 4 ppm FeSO₄), three high-iron groups (H-FeSO₄, 400 ppm FeSO₄; MCOP-Fe, 400 ppm marine fish oligopeptide iron complex; WCOP-Fe, 400 ppm whey protein oligopeptide iron complex) and three low-iron groups (L-FeSO₄, 40 ppm FeSO₄; MOP-Fe, 40 ppm marine fish oligopeptide iron complex; WOP-Fe, 40 ppm whey protein oligopeptide iron complex). Rats in each group were fed the corresponding special diet during pregnancy until the day of delivery. After different doses of iron supplement, serum hemoglobin, iron, and ferritin levels in rats with IDA were significantly increased to normal levels (P < 0.05). Serum iron levels were significantly lower in two food-derived bioactive oligopeptide low-iron complex groups than in the low FeSO₄ group (P<0.05). Liver malondialdehyde levels were significantly increased in the three high-iron groups compared with the other five groups (P < 0.05), and hemosiderin deposition was observed in liver tissue, indicating that the iron dose was overloaded and aggravated the peroxidative damage in pregnant rats. Liver inflammation was reduced in the three low-iron groups. Tumor necrosis factor α secretion was significantly decreased in all groups with supplemented oligopeptide (P < 0.05), with the concentration of tumor necrosis factor α declining to normal levels in the two whey protein oligopeptide iron complex groups. In the marine fish oligopeptide iron complex groups, body length, tail length, and weight of offspring were significantly increased (P < 0.05) and reached normal levels. Therefore, food-derived bioactive oligopeptide (derived from marine fish skin and milk) iron complexes may be an effective type of iron supplement for pregnancy to improve anemia, as well as reduce the side effects of iron overload, and improve the growth and nutritional status of offspring.

Role of ferroptosis-related genes in coronary atherosclerosis and identification of key genes: integration of bioinformatics analysis and experimental validation

Background

Coronary atherosclerosis (CA) is the most common type of atherosclerosis. However, the inherent pathogenesis and mechanisms of CA are unclear, and the relationship with ferroptosis-related genes (FRGs) has not been reported. The purpose of this study was to use bioinformatics techniques to evaluate potential therapeutic targets for CA.Please provide the given name for author “Dingshun”.Please provide the given name for author “Dingshun”.

Methods

First, the GSE132651 dataset was acquired from the Gene Expression Omnibus database. Gene Ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and Protein–Protein interaction network were successively conducted. Next, overlapping genes between hub genes and CA genes were found. FRGs were found when comparing the CA group with the normal group. The correlation between overlapping genes and FRGs was further analyzed. At last, we performed Elisa to validate the expression of these genes in human blood specimens. Mice aortic tissues were used for western blot to detect the expression of proteins.

Results

Based on the GSE132651 dataset, 102 differentially expressed genes were identified. Five overlapping genes between hub genes and CA genes were found (CCNA2, RRM2, PBK, PCNA, CDK1). TFRC and GPX4 were found to be FRGs. TFRC was positively correlated with CCNA2, PBK, PCNA, CDK1, RRM2, with CDK1 being the strongest correlation. GPX4 was negatively correlated with these genes, among which CCNA2 was the strongest correlation. The ELISA results showed that CCNA2, CDK1, and TFRC expression were markedly increased in serum of the CA samples compared with controls, while GPX4 expression was markedly decreased in the CA samples. The western blot results show that GPX4 expression was lower in the model group, TFRC, CDK1, and CCNA2 protein expression were high in the model group.

Conclusions

Ferroptosis-related genes GPX4 and TFRC were closely correlated with the identified overlapping genes CCNA2 and CDK1, which may serve as targeted therapies for the treatment of CA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02747-x.

High Iron Exposure from the Fetal Stage to Adulthood in Mice Alters Lipid Metabolism

Iron supplementation is recommended during pregnancy and fetal growth. However, excess iron exposure may increase the risk of abnormal fetal development. We investigated the potential side effects of high iron levels in fetuses and through their adult life. C57BL/6J pregnant mice from 2 weeks of gestation and their offspring until 30 weeks were fed a control (CTRL, FeSO₄ 0 g/1 kg) or high iron (HFe, FeSO₄ 9.9 g/1 kg) diets. HFe group showed higher iron accumulation in the liver with increased hepcidin, reduced TfR1/2 mRNAs, and lowered ferritin heavy chain (FTH) proteins in both liver and adipose tissues despite iron loading. HFe decreased body weight, fat weight, adipocyte size, and triglyceride levels in the blood and fat, along with downregulation of lipogenesis genes, including PPARγ, C/EBPα, SREBP1c, FASN, and SCD1, and fatty acid uptake and oxidation genes, such as CD36 and PPARα. UCP2, adiponectin, and mRNA levels of antioxidant genes such as GPX4, HO-1, and NQO1 were increased in the HFe group, while total glutathione was reduced. We conclude that prolonged exposure to high iron from the fetal stage to adulthood may decrease fat accumulation by altering ferritin expression, adipocyte differentiation, and triglyceride metabolism, resulting in an alteration in normal growth.

Apigenin ameliorates di(2-ethylhexyl) phthalate-induced ferroptosis: The activation of glutathione peroxidase 4 and suppression of iron intake

Di(2-ethylhexyl) phthalate (DEHP) is a widely artificial persistent organic pollutant, the contamination of which infiltrates daily human life from many aspects, imperceptibly causing damage to multiple organs in the body, including the liver. Apigenin (APG) is widely distributed in vegetables and fruits and can relieve or prevent the injuries caused by exogenous chemicals through various pharmacological effects, such as antioxidant effects. To investigate the mechanism of DEHP-induced liver injury and the antagonistic effects of APG, we treated AML12 cells with 1 mM DEHP and/or APG. Ultrastructural morphology analysis indicated that DEHP induced typical ferroptosis-like damage. In addition, we found that DEHP exposure induced ferroptosis by enhancing reactive oxygen species (ROS) levels, disrupting iron homeostasis and lipid peroxidation, and regulating the expression of ferroptosis-related genes. Notably, supplementation with APG significantly inhibited these abnormal changes, and molecular docking further showed evidence of the activating effects of APG ligand on glutathione peroxidase 4 (GPX4). These results demonstrated that the protective effects of APG on DEHP-induced ferroptosis were achieved by activating GPX4 and suppressing intracellular iron accumulation. This information not only adds to DEHP toxicological data but also provides a basis for the practical application of APG.

Steel wools microfibers causes iron overload and induces biochemical changes in Gallus gallus domesticus chicks (Galliformes: Phasianidae)

Steel wool (SW) has a broad-spectrum of applicability, particularly as abrasives, cleaning household utensils and surfaces in general. However, when present in the natural environment, they can be ingested by animals, such as birds, and may represent a risk to the survival of individuals. Accordingly, in this study, we attempted the hypothesis that the ingestion of SW microfibers (SWMs) by Gallus gallus domesticus chicks (model system used) alters growth/development, induces redox imbalance and cholinesterasic effect, as well as promotes iron overload in different organs. For this, the animals received SWMs twice (within a 24-h interval) in an amount corresponding to 12% of their total stomach volume. At the end of the experiment, we observed less weight gain and less head growth, increased production of hydrogen peroxide (in the brain, liver, crop, and gizzard), nitrite (liver, crop, proventriculus and gizzard), malondialdehyde (brain, liver, muscle, proventriculus, and gizzard), along with increased superoxide dismutase activity in the liver, muscle and crop of animals exposed to SWMs. Such results were associated with iron overload observed in different organs, especially in liver, crop, and gizzard. Furthermore, we evidenced an anti-cholinesterasic effect in birds that ingested the SWMs, marked by a reduction in the acetylcholinesterase activity (in brain). Thus, our study sheds light on the (eco)toxicological potential of SWMs in avifauna, conceding us to associate their ingestion (despite ephemeral and occasional) with damage to the health of individuals, requiring a greater attention spotted to disposal of these materials in ecosystems.

Nrf2 attenuates ferroptosis-mediated IIR-ALI by modulating TERT and SLC7A11

Acute lung injury (ALI) carries a mortality rate of ~50% and is a hot topic in the world of critical illness research. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical modulator of intracellular oxidative homeostasis and serves as an antioxidant. The Nrf2-related anti-oxidative stress is strongly associated with ferroptosis suppression. Meanwhile, telomerase reverse transcriptase (TERT), the catalytic portion of the telomerase protein, is reported to travel to the mitochondria to alleviate ROS. In our study, we found that TERT was significantly reduced in lung tissue of Nrf2^-/- mice in the model of intestinal ischemia/reperfusion-induced acute lung injury (IIR-ALI). In addition, MDA levels showed marked increase, whereas GSH and GPX4 levels fell drastically in ALI models. Moreover, typical-related structural changes were observed in the type II alveolar epithelial cells in the IIR model. We further employed the scanning transmission X-ray microscopy (STXM) to examine Fe levels and distribution within cells. Based on our observations, massive aggregates of Fe were found in the MLE-12 cells upon OGD/R (oxygen and glucose deprivation/reperfusion) induction. Additionally, Nrf2 silencing dramatically reduced TERT and SLC7A11 levels, and further exacerbated cellular injuries. In contrast, TERT-overexpressing cells exhibited marked elevation in SLC7A11 levels and thereby inhibited ferroptosis. Collectively, these data suggest that Nrf2 can negatively regulate ferroptosis via modulation of TERT and SLC7A11 levels. The conclusion from this study brings insight into new candidates that can be targeted in future IIR-ALI therapy.

An Original Ferroptosis-Related Gene Signature Effectively Predicts the Prognosis and Clinical Status for Colorectal Cancer Patients

Background

Colorectal cancer (CRC) is one of the most common malignant tumors in the world. Ferroptosis is a newly defined form of cell death, distinguished by different morphology, biochemistry, and genetics, and involved in CRC progression and treatment. This study aims to establish a predictive model to elucidate the relationship between ferroptosis and prognosis of CRC patients, to explore the potential value of ferroptosis in therapeutic options.

Methods

The ferroptosis-related genes were obtained from the GeneCards and FerrDb websites. The limma R package was used to screen the differential ferroptosis-related genes (DEGs) in CRC from The Cancer Genome Atlas (TCGA) dataset. The least absolute shrinkage and selection operator (LASSO) and multivariate Cox regressions were to establish the 10-gene prognostic signature. The survival and receiver operating characteristic (ROC) curves were illustrated to evaluate the predictive effect of the signature. Besides, independent prognostic factors, downstream functional enrichment, drug sensitivity, somatic mutation status, and immune feature were analyzed. Moreover, all these conclusions were verified by using multiple datasets in International Cancer Genome Consortium (ICGC) and Gene Expression Omnibus (GEO).

Results

Ten ferroptosis-related gene signature (TFAP2C, SLC39A8, NOS2, HAMP, GDF15, FDFT1, CDKN2A, ALOX12, AKR1C1, ATP6V1G2) was established to predict the prognosis of CRC patients by Lasso cox analysis, demonstrating a good performance on Receiver operating characteristic (ROC) and Kaplan–Meier (K–M) analyses. The CRC patients in the high- or low-risk group showed significantly different fractions of immune cells, such as macrophage cells and CD8+ T cells. Drug sensitivity and somatic mutation status like TP53 were also closely associated with the risk scores.

Conclusions

In this study, we identified a novel ferroptosis-related 10-gene signature, which could effectively predict the prognosis and survival time of CRC patients, and provide meaningful clinical implications for targeted therapy or immunotherapy. Targeting ferroptosis is a good therapeutic option for CRC patients. Further studies are needed to reveal the underlying mechanisms of ferroptosis in CRC.