The Molecular Mechanisms of Regulating Oxidative Stress-Induced Ferroptosis and Therapeutic Strategy in Tumors

Lipoxygenases at the Intersection of Infection and Carcinogenesis

The persisting presence of opportunistic pathogens like Pseudomonas aeruginosa poses a significant threat to many immunocompromised cancer patients with pulmonary infections. This review highlights the complexity of interactions in the host's defensive eicosanoid signaling network and its hijacking by pathogenic bacteria to their own advantage. Human lipoxygenases (ALOXs) and their mouse counterparts are integral elements of the innate immune system, mostly operating in the pro-inflammatory mode. Taking into account the indispensable role of inflammation in carcinogenesis, lipoxygenases have counteracting roles in this process. In addition to describing the structure-function of lipoxygenases in this review, we discuss their roles in such critical processes as cancer cell signaling, metastases, death of cancer and immune cells through ferroptosis, as well as the roles of ALOXs in carcinogenesis promoted by pathogenic infections. Finally, we discuss perspectives of novel oncotherapeutic approaches to harness lipoxygenase signaling in tumors.

Interference with MTHFD2 induces ferroptosis in ovarian cancer cells through ERK signaling to suppress tumor malignant progression

Ovarian cancer (OC) is a deadliest gynecological cancer with the highest mortality rate. Methylenetetrahydrofolate dehydrogenase 2 (MTHFD2), a crucial tumor-promoting factor, is over-expressed in several malignancies including OC. The present study aimed to explore the role and mechanisms of MTHFD2 in OC malignant progression. Thus, cell proliferation, cycling, apoptosis, migration, and invasion were evaluated by CCK-8 assay, EdU assay, flow cytometry, wound healing, transwell assay and western blotting. Additionally, glycolysis was assessed by measuring the level of glucose and lactate production, as well as the expressions of GLUT1, HK2 and PKM2. Then the expression of ferroptosis-related proteins and ERK signaling was detected using western blotting. Ferroptosis was detected through the measurement of iron level, GSH, MDA and ROS activities. The results revealed that MTHFD2 was highly expressed in OC cells. Besides, interference with MTHFD2 induced ferroptosis, promoted ROS accumulation, destroyed mitochondrial function, reduced ATP content and inhibited glycolysis in OC cells. Subsequently, we further found that interference with MTHFD2 affected mitochondrial function and glycolysis in OC cells through ERK signaling. Moreover, interference with MTHFD2 affected ferroptosis to inhibit the malignant progression of OC cells. Collectively, our present study disclosed that interference with MTHFD2 induced ferroptosis in OC to inhibit tumor malignant progression through regulating ERK signaling.

TRAIL predisposes non-small cell lung cancer to ferroptosis by regulating ASK-1/JNK1 pathway

OBJECTIVE

Our current study aimed to assess the relationship between TNF-related apoptosis-inducing ligand (TRAIL) and ferroptosis in non-small cell lung cancer (NSCLC) development.

METHODS

The expression of TRAIL was detected by western blot, RT-qRCR and immunohistochemistry. The viability of NSCLC cells was analyzed by CCK-8 kit. The migration and invasion of NSCLC cells were detected by wound healing assay and transwell assay, respectively. Labile iron pool (LIP) was detected based on the calcein-acetoxymethyl ester method. Ferrous iron (Fe2+) and iron levels were assessed by detection kits. The levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were measured using corresponding detection kits. Mice tumor xenograft models were used for the in vivo research.

RESULTS

The expression of TRAIL was reduced in H1299, NCL-H1395, and A549 cells compared with BEAS-2B cells. The up-regulation of TRAIL expression significantly reduced cell viability, invasion, and migration of H1299 and A549 cells. TRAIL reduced the expression of ferroptosis-related genes (FTH1, GPX4, and SLC7A11), increased the levels of LIP, iron, and Fe2+, and promoted lipid peroxidation, thereby predisposing NSCLC cells to ferroptosis. TRAIL up-regulated the expression of phosphate modification of ASK-1 and JNK. ASKI-1 inhibitor GS-4977 attenuated the effects of TRAIL on the viability, migration, invasion, and ferroptosis of H1299 cells. Furthermore, TRAIL further suppressed tumor growth and ferroptosis in mice tumor xenograft models.

CONCLUSION

We indicated that overexpression of TRAIL induced ferroptosis in NSCLC cells and exerted anti-tumor effects. Mechanistically, TRAIL promoted ferroptosis by the activation of the ASK-1/JNK1 pathway. Our results may provide new therapeutic strategies for NSCLC.

Synergistic effect of PS-MPs and Cd on male reproductive toxicity: Ferroptosis via Keap1-Nrf2 pathway

It has been wildly reported that microplastics (MPs) can adsorb heavy metals and act as carriers for their transport into organisms. However, the combined toxicity of MPs and heavy metals remains poorly studied. In this study, we established single or co-exposure (i.e. complex/combined exposure) mice models to investigate the combined toxicity of MPs and cadmium (Cd) on male reproduction. The complexation of MPs and Cd enhanced the bioavailability of Cd, while the combination of MPs and Cd exerted synergistic effect. Ultimately, the co-exposure was reported to enhance the reproduction toxicity by single exposure, which reflected in testicular structure, spermatogenesis and sex hormone synthesis. More in-depth mechanistic investigation suggested that MPs and Cd synergistically inhibited the Keap1-Nrf2 pathway and its downstream genes, induced lipid peroxidation and ferroptosis, ultimately caused damage to reproductive structures and functions. Our results highlighted the synergistic effect of MPs and Cd on the reproductive toxicity in male mammals for the first time, which also provided valuable insights into the combined toxicity mechanisms of MPs and other pollutants.

Isoquercitrin promotes ferroptosis and oxidative stress in nasopharyngeal carcinoma via the AMPK/NF-κB pathway

Isoquercitrin has been discovered with various biological properties, including anticancer, anti-inflammation, antioxidation, and neuroprotection. The aim of this study is to explore the efficacy of isoquercitrin in nasopharyngeal carcinoma (NPC) and to disclose its potential regulating mechanisms. CNE1 and HNE1 cells were treated with various concentrations of isoquercitrin. Ferrostatin-1 (Fer-1, a ferroptosis inhibitor) and alpha-lipoic acid (ALA, an activator of the AMP-activated protein kinase [AMPK] pathway) treatments were conducted to verify the effects of isoquercitrin, respectively. Cell viability, proliferation, reactive oxygen species (ROS) generation, and lipid peroxidation were determined, respectively. GPX4 expression and ferroptosis- and pathway-related protein expression were measured. A xenograft tumor model was constructed by subcutaneously inoculating CNE1 cells into the middle groin of each mouse. We found that the IC50 values of CNE1 and HNE1 cells were 392.45 and 411.38 μM, respectively. CNE1 and HNE1 viability and proliferation were both markedly reduced with the increasing concentration of isoquercitrin. ROS generation and lipid peroxidation were both enhanced with declined ferroptosis-related markers under isoquercitrin treatment. The nuclear factor kappa B (NF-κB) pathway, the AMPK pathway, and the interleukin (IL)-1β expression were all markedly suppressed by isoquercitrin. Moreover, isoquercitrin restrained the tumor growth and enhanced lipid peroxidation and ferroptosis in vivo. Interestingly, both Fer-1 and ALA treatments distinctly offset isoquercitrin-induced effects in vitro and in vivo. These findings indicated that isoquercitrin might enhance oxidative stress and ferroptosis in NPC via AMPK/NF-κB p65 inhibition.

Liproxstatin-1 alleviates ferroptosis in sevoflurane anesthesia-induced cognitive deficits of aged mice: The role oxidative stress

In this study, we aimed to validate the hypothesis that the interplay between sevoflurane, oxidative stress and ferroptosis is crucial for the pathogenesis of sevoflurane-induced cognitive impairment in aged individuals. The mice with sevoflurane-induced cognitive impairment were used to explore the effects of sevoflurane on oxidative stress, iron homeostasis, and cognitive function in aged mice. Iron content and oxidative stress markers were analyzed in hippocampal tissue homogenates using specific assays. Additionally, the levels of iron death-related markers (Fth1 and Gpx4) were assessed by real-time PCR and Western blotting. Morris Water Maze and novel object recognition (NOR) tests were conducted to evaluate cognitive function. Sevoflurane exposure in aged mice resulted in a significant increase in iron overloading in the hippocampus, followed by a subsequent stabilization. Oxidative stress levels were elevated in the hippocampal tissue of sevoflurane-exposed mice, and a significant correlation was observed between iron death and oxidative stress. Liproxstatin-1, a ferroptosis inhibitor, effectively ameliorated the decline in memory and learning abilities induced by sevoflurane anesthesia. Liproxstatin-1 treatment reduced iron overload and oxidative stress in the hippocampal tissue of aged mice. The expression of Fth1 and Gpx4, iron death-related markers, was downregulated following Liproxstatin-1 intervention. Our findings suggest that sevoflurane anesthesia disrupts iron homeostasis, leading to increased oxidative stress and cognitive impairment in aged mice. These results highlight the potential of targeting iron-mediated processes to mitigate sevoflurane-induced cognitive impairment in the aging population.

Ammidin ameliorates myocardial hypoxia/reoxygenation injury by inhibiting the ACSL4/AMPK/mTOR-mediated ferroptosis pathway

OBJECTIVE

The aim of the present study was to investigate the therapeutic effect of ammidin on hypoxia/reoxygenation (H/R) injury in primary neonatal rat cardiomyocytes by observing the role of ferroptosis in the process of H/R injury, and to verify its target and regulatory signaling pathways.

METHODS

The network pharmacology analysis was used to predict the biological processes, core targets and related signaling pathways of Angelica dahurica in the treatment of ferroptosis. Cell viability was assessed using live cell imaging and cell counting kit-8. Lactate dehydrogenase (LDH), reactive oxygen species (ROS) production, and malondialdehyde (MDA), superoxide dismutase (SOD) and mitochondrial membrane potential (MMP) content were determined to assess the level of ferroptosis. Western blotting was performed to measure protein expression.

RESULTS

Network pharmacology predicted that Acyl-CoA synthetase long chain family member 4 (ACSL4) was highly associated with myocardial H/R injury in the intersection of Angelica dahurica and ferroptosis. The top three active components of Angelica dahurica were found to be mandenol, alloisoimperatorin and ammidin, among which ammidin was found to have the strongest binding to the target proteins of the ACSL4/AMPK/mTOR pathway. H/R reduced the viability of cardiomyocytes, while the inhibition of ferroptosis by ferrostatin-1 alleviated the H/R-induced inhibition of cardiomyocyte viability. This was evidenced by the increased cell viability, SOD release, MMP level and glutathione peroxidase 4 (GPX4) protein expression, as well as the decreased LDH and MDA release and ROS production and ACSL4 protein expression (P < 0.05). To verify the existence of ferroptosis in myocardial hypoxia/reoxygenation injury. In addition, ammidin increased cell viability and GPX4 protein expression (P < 0.05), decreased ROS generation, and MDA and MTT expression (P < 0.05), then inhibited ferroptosis, and finally alleviated myocardial H/R injury by regulating the ACSL4/AMPK signaling pathway.

CONCLUSIONS

Network pharmacology was used to predict the correlation between ammidin and ferroptosis following myocardial H/R injury. It was demonstrated that ammidin may regulate ferroptosis by inhibiting the ACSL4/AMPK/mTOR signaling pathway and reduce H/R injury in cardiomyocytes.

Identification of a novel ferroptosis-related gene signature associated with retinal degeneration induced by light damage in mice

Background

Neurodegenerative retinal diseases such as retinitis pigmentosa are serious disorders that may cause irreversible visual impairment. Ferroptosis is a novel type of programmed cell death, and the involvement of ferroptosis in retinal degeneration is still unclear. This study aimed to investigate the related ferroptosis genes in a mice model of retinal degeneration induced by light damage.

Methods

A public dataset of GSE10528 deriving from the Gene Expression Omnibus database was analyzed to identify the differentially expressed genes (DEGs). Gene set enrichment analysis between light damage and control group was conducted. The differentially expressed ferroptosis-related genes (DE-FRGs) were subsequently identified by intersecting the DEGs with a ferroptosis genes dataset retrieved from the FerrDb database. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were further performed using the DE-FRGs. A protein-protein interaction (PPI) network was constructed to identify hub ferroptosis-related genes (HFRGs). The microRNAs (miRNAs)-HFRGs, transcription factors (TFs)-HFRGs networks as well as target drugs potentially interacting with HFRGs were analyzed utilizing bioinformatics algorithms.

Results

A total of 932 DEGs were identified between the light damage and control group. Among these, 25 genes were associated with ferroptosis. GO and KEGG analyses revealed that these DE-FRGs were mainly enriched in apoptotic signaling pathway, response to oxidative stress and autophagy, ferroptosis, necroptosis and cytosolic DNA-sensing pathway. Through PPI network analysis, six hub ferroptosis-related genes (Jun, Stat3, Hmox1, Atf3, Hspa5 and Ripk1) were ultimately identified. All of them were upregulated in light damage retinas, as verified by the GSE146176 dataset. Bioinformatics analyses predicated that 116 miRNAs, 23 TFs and several potential therapeutic compounds might interact with the identified HFRGs.

Conclusion

Our study may provide novel potential biomarkers, therapeutic targets and new insights into the ferroptosis landscape in retinal neurodegenerative diseases.

Nrf2--a hidden bridge linking cancer stem cells to ferroptosis

Cancer stem cells (CSCs), a small population of stem cells existing in cancer cells, are considered as the "culprits" of tumor recurrence, metastasis, and drug resistance. Ferroptosis is a promising new lead in anti-cancer therapy. Because of unique metabolic characteristics, CSCs' growth is more dependent on the iron and lipid than ordinary cancer cells. When the metabolism of iron/lipid is disordered, that is, imbalanced redox homeostasis, CSCs are more susceptible to ferroptosis. The expression of Nuclear factor E2-related factor 2 (Nrf2), a molecule playing a major regulatory role in redox homeostasis, determines whether the cells are under oxidative stress and ferroptosis occurs. Nrf2 expression level is higher in CSCs, indicating stronger dependence on Nrf2. Here we expound the unique biological and metabolic characteristics of CSCs, explore the mechanism of inducing ferroptosis by targeting Nrf2, thus providing promising new targets for eliminating aggressive tumors and achieving the goal of curing tumors.

SLC35F2-SYVN1-TRIM59 axis critically regulates ferroptosis of pancreatic cancer cells by inhibiting endogenous p53

Pancreatic cancer cells undergo intricate metabolic reprogramming to sustain their survival and proliferation. p53 exhibits a dual role in tumor cell ferroptosis. However, the precise role and mechanisms underlying wild-type p53 activation in promoting ferroptosis in pancreatic cancer cells remain obscure. In this study, we applied bioinformatics tools and performed an analysis of clinical tissue sample databases and observed a significantly upregulated expression of solute carrier family 35 member F2 (SLC35F2) in pancreatic cancer tissues. Our clinical investigations indicated that elevated SLC35F expression was related to adverse survival outcomes. Through multi-omics analyses, we discerned that SLC35F2 influences the transcriptome and inhibits ferroptosis in pancreatic cancer cells. Moreover, our findings reveal the pivotal involvement of p53 in mediating SLC35F2-mediated ferroptosis, both in vitro and in vivo. SLC35F2 inhibits ferroptosis by facilitating TRIM59-mediated p53 degradation. Further mechanistic investigations demonstrated that SLC35F2 competitively interacts with the E3 ubiquitin ligase SYVN1 of TRIM59, thereby stabilizing TRIM59 expression and consequentially promoting p53 degradation. Utilizing protein 3D structure analysis and drug screening, we identified irinotecan hydrochloride and lapatinib ditosylate as compounds targeting SLC35F2, augmenting the antitumor effect of imidazole ketone erastin (IKE) in a wild-type p53 patient-derived xenograft (PDX) model. However, in the p53 mutant PDX model, irinotecan hydrochloride and lapatinib ditosylate did not alter the sensitivity of the tumor xenograft model to IKE-triggered ferroptosis. In summary, our work establishes a novel mechanism wherein the SLC35F2-SYVN1-TRIM59 axis critically regulates ferroptosis of pancreatic cancer cells by inhibiting endogenous p53. Thus, SLC35F2 emerges as a promising therapeutic target for treating pancreatic cancer.

Exogenous spermidine alleviates diabetic cardiomyopathy via suppressing reactive oxygen species, endoplasmic reticulum stress, and Pannexin-1-mediated ferroptosis

Diabetic cardiomyopathy (DCM) is a serious complication and death cause of diabetes mellitus (DM). Recent cardiology studies suggest that spermidine (SPD) has cardioprotective effects. Here, we verified the hypothesis of SPD's protective effects on DCM. Therefore, db/db mice and primary neonatal mouse cardiomyocytes were used to observe the effects of SPD. Immunoblotting showed that ornithine decarboxylase (ODC) and SPD/spermine N1-acetyltransferase (SSAT) were downregulated and upregulated in the myocardium of db/db mice, respectively. We found that diabetic mice showed cardiac dysfunction in 12 weeks. Conversely, exogenous SPD could improve cardiac functions and reduce the deposition of collagens, myocardial damage, reactive oxygen species (ROS) levels, and endoplasmic reticulum stress (ERS) in diabetic mouse hearts. Our results also demonstrated that cardiomyocytes displayed ferroptosis and then activated Pannexin-1 expression, which resulted in the increase of the extracellular adenosine triphosphate (ATP). Subsequently, increased ATP as a paracrine molecule combined to purinergic receptor P2X7 to activate ERK1/2 signaling pathway in cardiomyocytes and activated NCOA4-mediated ferroptinophagy to promote lipid peroxidation and ferroptosis. Interestingly, SPD could reverse these molecular processes. Our findings indicate an important new mechanism for DCM and suggest that SPD has potential applicability to protect against deterioration of cardiac function with DCM.

Vitamin A and vitamin D3 protect the visual apparatus during the development of dopamine-2 receptor knockout mouse model of Parkinsonism

OBJECTIVES

Dopamine-related movement disorders are associated with a loss of visual acuity. Studies have shown that chemical stimulation of the vitamin D3 receptor (VDR) ameliorates movement disorders; however, the chemical stimulation is not effective when there is a deficiency of vitamin A in the cells. In the study, we examine the role of VDR and its interplay with vitamin A in impaired visual function in the dopamine deficit model.

METHODS

Thirty (30) male mice with an average weight of 26 g ± (2) were divided into six group (NS,-D2,-D2 + VD D2 + VD, -D2 + VA, -D2 + (VD + VA) and -D2 + D2 groups). Dopamine deficit models of movement disorders were created using 15 mg/kg of haloperidol (-D2) injected intraperitoneally daily for 21 days. In the -D2 + (VD + VA) group, 800 IU/day of vitamin D3 (VD) and 1000 IU/day of vitamin A were concurrently used, while in the -D2 + D2 group, bromocriptine (+D2) was used as the standard treatment of the model. At the end of the treatment phase, the animals were subjected to visual water box test for visual acuity. The level of oxidative stress was measured using Superoxide dismutase (SOD) and malondialdehyde (MDA) in the retina and visual cortex. The level of cytotoxicity in these tissues was measured using Lactate dehydrogenase (LDH) assay, while the structural integrity of these tissues was assessed using a light microscope by assessing slide mounted sections that were stained with haematoxylin and eosin.

RESULTS

A significant decline in time taken to reach the escape platform in the visual water box test was observed in the -D2 (p<0.005) and -D2 + D2 (p<0.05) group. In the retina and the visual cortex, a significant increase in LDH, MDA and the density of degenerating neurons was observed in the -D2 and -D2 + D2 groups. LDH level in the retina was also found to be significantly increased in (-D2 + VD, -D2 + VA, -D2 + (VD + VA). A Significant decrease in SOD was found in the retina and visual cortex of -D2 and -D2 + D2 group. In the histology of the retina, thinning of the retina, retinal fold, distortion and retinal detachment were all seen in the -D2 group. These structural alterations were not seen in other groups. Histological hallmarks of degeneration were observed in the visual cortex of the mice from the -D2 (p<0.001), -D2 + D2 (p<0.005) and -D2 + VD (p<0.05) groups only.

CONCLUSIONS

Dopamine-deficient models of movement disorders are associated with loss of visual functions, especially due to thinning of the retina, retinal fold, retinal detachment, and neurodegeneration in the visual cortex. Supplementation during the development of the model with vitamin D3 and vitamin A prevented the deterioration of the retina and visual cortex by reducing the degree of oxidative stress and cytotoxicity.

NeuroD4 converts glioblastoma cells into neuron-like cells through the SLC7A11-GSH-GPX4 antioxidant axis

Cell fate and proliferation ability can be transformed through reprogramming technology. Reprogramming glioblastoma cells into neuron-like cells holds great promise for glioblastoma treatment, as it induces their terminal differentiation. NeuroD4 (Neuronal Differentiation 4) is a crucial transcription factor in neuronal development and has the potential to convert astrocytes into functional neurons. In this study, we exclusively employed NeuroD4 to reprogram glioblastoma cells into neuron-like cells. In vivo, the reprogrammed glioblastoma cells demonstrated terminal differentiation, inhibited proliferation, and exited the cell cycle. Additionally, NeuroD4 virus-infected xenografts exhibited smaller sizes compared to the GFP group, and tumor-bearing mice in the GFP+NeuroD4 group experienced prolonged survival. Mechanistically, NeuroD4 overexpression significantly reduced the expression of SLC7A11 and Glutathione peroxidase 4 (GPX4). The ferroptosis inhibitor ferrostatin-1 effectively blocked the NeuroD4-mediated process of neuron reprogramming in glioblastoma. To summarize, our study demonstrates that NeuroD4 overexpression can reprogram glioblastoma cells into neuron-like cells through the SLC7A11-GSH-GPX4 signaling pathway, thus offering a potential novel therapeutic approach for glioblastoma.

Micronutrients/miRs/ATP networking in mitochondria: Clinical intervention with ferroptosis, cuproptosis, and calcium burden

The mitochondrial electron transport chain (mtETC) requires mainly coenzyme Q10 (CoQ10), copper (Cu2+), calcium (Ca2+), and iron (Fe2+) ions for efficient ATP production. According to cross-sectional research, up to 50% of patients with micronutrient imbalances have been linked to oxidative stress, mitochondrial dysfunction, reduced ATP production, and the prognosis of various diseases. The condition of ferroptosis, which is caused by the downregulation of CoQ10 and the activation of non-coding micro RNAs (miRs), is strongly linked to free radical accumulation, cancer, and neurodegenerative diseases. The entry of micronutrients into the mitochondrial matrix depends upon the higher threshold level of mitochondrial membrane potential (ΔΨm), and high cytosolic micronutrients. The elevated micronutrient in the mitochondrial matrix causes the utilization of all ATP, leading to a drop in ATP levels. Mitochondrial calcium uniporter (MCU) and Na+/Ca2+ exchanger (NCX) play a major role in Ca2+ influx in the mitochondrial matrix. The mitochondrial Ca2+ overload is regulated by specific miRs such as miR1, miR7, miR25, miR145, miR138, and miR214, thereby reducing apoptosis and improving ATP production. Cuproptosis is primarily brought on by increased Cu+ build-up and mitochondrial proteotoxic stress, mediated by ferredoxin-1 (FDX1) and long non-coding RNAs. Cu importers (SLC31A1) and exporters (ATP7B) influence intracellular Cu2+ levels to control cuproptosis. According to literature reviews, very few randomized micronutrient interventions have been carried out, despite the identification of a high prevalence of micronutrient deficiencies. In this review, we concentrated on essential micronutrients and specific miRs associated with ATP production that balance oxidative stress in mitochondria.

Mitochondrial Regulation of Ferroptosis in Cancer Therapy

Ferroptosis, characterized by glutamate overload, glutathione depletion, and cysteine/cystine deprivation during iron- and oxidative-damage-dependent cell death, is a particular mode of regulated cell death. It is expected to effectively treat cancer through its tumor-suppressor function, as mitochondria are the intracellular energy factory and a binding site of reactive oxygen species production, closely related to ferroptosis. This review summarizes relevant research on the mechanisms of ferroptosis, highlights mitochondria's role in it, and collects and classifies the inducers of ferroptosis. A deeper understanding of the relationship between ferroptosis and mitochondrial function may provide new strategies for tumor treatment and drug development based on ferroptosis.

Berberine modulates gut microbiota to attenuate cerebral ferroptosis induced by ischemia-reperfusion in mice

Ferroptosis was reported to be involved in cerebral ischemia-reperfusion injury (CIRI), on which the effects of berberine (BBR) remain unclear. Moreover, based on the critical role of gut microbiota in pleiotropic actions of BBR, we hypothesized that BBR can suppress CIRI-induced ferroptosis by modulating the gut microbiota. In this study, the results showed that BBR obviously attenuated the behavioral deficits of CIRI mice, accompanied with the improved survival rate and neuron damages, as phenocopied by dirty cage experiment. The typical morphological changes in ferroptotic cells and biomarkers of ferroptosis were attenuated in BBR- and its fecal microbiota-treated mice, accompanied by reduced malondialdehyde and reactive oxygen species, and the increased glutathione (GSH). BBR was found to alter the gut microbiota of CIRI mice with decreased abundance of Muribaculaceae, Erysipelotrichaceae, Helicobacteraceae, Streptococcaceae and Tannerellaceae, but elevated Bacteroidaceae and Enterobacteriaceae. KEGG analysis based on the 16S rRNA results indicated that multiple metabolic pathways including ferroptosis and GSH metabolism, were altered by BBR. Oppositely, the antibiotics administration counteracted the protective properties of BBR. Summarily, this study revealed the therapeutic potential of BBR on CIRI via inhibiting neuronal ferroptosis, in which upregulated glutathione peroxidase 1 (GPX1) was possibly involved. Moreover, the BBR-modulated gut microbiota was shown to play the critical role in the underlying mechanism.

Anomanolide C suppresses tumor progression and metastasis by ubiquitinating GPX4-driven autophagy-dependent ferroptosis in triple negative breast cancer

Anomanolide C (AC), a natural withanolide isolated from Tubocapsicum anomalum, has been reported to have exhibits remarkable anti-tumour activities in several types of human cancers, particularly triple-negative breast cancer (TNBC). However, its intricate mechanisms still remain need to be clarified. Here, we evaluated whether AC could inhibit cell proliferation and the role of AC in ferroptosis induction and autophagy activation. Subsequently, the anti-migration potential of AC was found via autophagy-dependent ferroptosis. Additionally, we found that AC reduced the expression of GPX4 by ubiquitination and inhibited TNBC proliferation and metastasis in vitro and in vivo. Moreover, we demonstrated that AC induced autophagy-dependent ferroptosis, and led to Fe²⁺ accumulation via ubiquitinating GPX4. Moreover, AC was shown to induce autophagy-dependent ferroptosis as well as to inhibit TNBC proliferation and migration via GPX4 ubiquitination. Together, these results demonstrated that AC inhibited the progression and metastasis of TNBC by inducing autophagy-dependent ferroptosis via ubiquitinating GPX4, which might shed light on exploiting AC as a new drug candidate for the future TNBC therapy.

Total Flavonoids of Rhizoma Drynariae Mitigates Aflatoxin B1-Induced Liver Toxicity in Chickens via Microbiota-Gut-Liver Axis Interaction Mechanisms

Aflatoxin B1 (AFB1) is a common mycotoxin that widely occurs in feed and has severe hepatotoxic effects both in humans and animals. Total flavonoids of Rhizoma Drynaria (TFRD), a traditional Chinese medicinal herb, have multiple biological activities and potential hepatoprotective activity. This study investigated the protective effects and potential mechanisms of TFRD against AFB1-induced liver injury. The results revealed that supplementation with TFRD markedly lessened broiler intestinal permeability by increasing the expression of intestinal tight junction proteins, as well as correcting the changes in gut microbiota and liver damage induced by AFB1. Metabolomics analysis revealed that the alterations in plasma metabolites, especially taurolithocholic acid, were significantly improved by TFRD treatment in AFB1-exposed chickens. In addition, these metabolites were closely associated with [Ruminococcus], ACC, and GPX1, indicating that AFB1 may cause liver injury by inducing bile acid metabolism involving the microbiota–gut–liver axis. We further found that TFRD treatment markedly suppressed oxidative stress and hepatic lipid deposition, increased plasma glutathione (GSH) concentrations, and reversed hepatic ferroptosis gene expression. Collectively, these findings indicate that ferroptosis might contribute to the hepatotoxicity of AFB1-exposed chickens through the microbiota–gut–liver axis interaction mechanisms; furthermore, TFRD was confirmed as an herbal extract that could potentially antagonize mycotoxins detrimental effects.

Levosimendan Reverses Cardiac Malfunction and Cardiomyocyte Ferroptosis During Heart Failure with Preserved Ejection Fraction via Connexin 43 Signaling Activation

PURPOSE

In recent decades, the occurrence of heart failure with preserved ejection fraction (HFpEF) has outweighed that of heart failure with reduced ejection fraction by degrees, but few drugs have been demonstrated to improve long-term clinical outcomes in patients with HFpEF. Levosimendan, a calcium-sensitizing cardiotonic agent, improves decompensated heart failure clinically. However, the anti-HFpEF activities of levosimendan and underlying molecular mechanisms are unclear.

METHODS

In this study, a double-hit HFpEF C57BL/6N mouse model was established, and levosimendan (3 mg/kg/week) was administered to HFpEF mice aged 13 to 17 weeks. Different biological experimental techniques were used to verify the protective effects of levosimendan against HFpEF.

RESULTS

After four weeks of drug treatment, left ventricular diastolic dysfunction, cardiac hypertrophy, pulmonary congestion, and exercise exhaustion were significantly alleviated. Junction proteins in the endothelial barrier and between cardiomyocytes were also improved by levosimendan. Among the gap junction channel proteins, connexin 43, which was especially highly expressed in cardiomyocytes, mediated mitochondrial protection. Furthermore, levosimendan reversed mitochondrial malfunction in HFpEF mice, as evidenced by increased mitofilin and decreased ROS, superoxide anion, NOX4, and cytochrome C levels. Interestingly, after levosimendan administration, myocardial tissue from HFpEF mice showed restricted ferroptosis, indicated by an increased GSH/GSSG ratio; upregulated GPX4, xCT, and FSP-1 expression; and reduced intracellular ferrous ion, MDA, and 4-HNE levels.

CONCLUSION

Regular long-term levosimendan administration can benefit cardiac function in a mouse model of HFpEF with metabolic syndromes (namely, obesity and hypertension) by activating connexin 43-mediated mitochondrial protection and sequential ferroptosis inhibition in cardiomyocytes.

Emerging therapeutics agents and recent advances in drug repurposing for Alzheimer's disease

Alzheimer's disease (AD) is a multivariate and diversified disease and affects the most sensitive areas of the brain, the cerebral cortex, and the hippocampus. AD is a progressive age-related neurodegenerative disease most often associated with memory deficits and cognition that get more worsen over time. The central theory on the pathophysiological hallmark features of AD is characterized by the accumulation of amyloid β (Aβ) peptides, also associated with tau proteins (τ) dysfunctioning which leads to distorted microtubular structure, affects the cholinergic system, and mitochondrial biogenesis. This review emphasizes how simple it is to find novel treatments for AD and focuses on several recently developed medications through repurposing that can speed up traditional drug development.

A bioinspired polydopamine-FeS nanocomposite with high antimicrobial efficiency via NIR-mediated Fenton reaction

Ferrous and sulfur ions are essential elements for the human body, which play an active role in maintaining the body's normal physiology. Meanwhile, mussel-inspired polydopamine (PDA) possesses good hydrophilicity and biocompatibility. In the present work, ferrous sulfide embedded into polydopamine nanoparticles (PDA@FeS NPs) was designed and synthesized via a simple predoping polymerization-coprecipitation strategy and the intelligent PDA matrix successfully prevented the oxidation and agglomeration of FeS nanoparticles. Importantly, there was an obvious synergistic enhancement of the photothermal effect between polydopamine and ferrous sulfide. The PDA@FeS NPs exhibited excellent photothermal antibacterial effects against both E. coli and S. aureus. The near-infrared (NIR) light-mediated release of ferrous ions could reach about 26.5% under weakly acidic conditions, further triggering the Fenton reaction to produce toxic hydroxyl radicals (·OH) in the presence of hydrogen peroxide. The antibacterial mechanism could be attributed to cell membrane damage and cellular content leakage with the synergistic effect of PTT and CDT. This study highlighted the germicidal efficacy of PDA@FeS NPs and provided a new strategy for designing and developing next-generation antibacterial platforms.

Metformin improves polycystic ovary syndrome in mice by inhibiting ovarian ferroptosis

BACKGROUND AND OBJECTIVE

PCOS is a common metabolic disorder in women of reproductive age, which pathogenesis is very complex. The role of ferroptosis in PCOS is a novel finding, and the mechanistic studies are not clear. Metformin is a commonly used drug of PCOS but few studies on whether metformin can improve the follicle development and ovarian function in PCOS. We aims to use PCOS mouse model to study the effect of metformin on PCOS based on the ovarian function and explored the regulation of metformin in PCOS mice by intervening in ferroptosis pathway.

MATERIALS AND METHODS

C57 BL/6J female mice aged 4-5 weeks were purchased and gavaged with letrozole (1 mg/kg/day) combined with high-fat diet for 21days to establish PCOS model, and control group was set up. After modeling, the mice were divided into PCOS model group and metformin treatment group (Met) (n=6).The Met group were gavaged metformin (200 mg/kg/day) for 28 days. The body weight, estrous cycle, glucose tolerance test (OGTT)and insulin resistance test (ITT) were monitored. Then, The mice were euthanized to collect serum and ovaries. Elisa was used to detect changes in related serum hormones (E2, LH, FSH, TP). Ovaries used for molecular biology experiments to detect changes in GPX4, SIRT3, AMPK/p-AMPK, and mTOR/p-mTOR by Western blot and qPCR.

RESULTS

Compared with the model group mice, body weight was significantly reduced, and their estrous cycle was restored in Met group. The results of OGTT and ITT showed an improvment of glucose tolerance and insulin resistance. Morphological results showed that after metformin treatment, polycystic lesions in ovaries were reduced, the ovarian function was restored, and the expressions of SIRT3 and GPX4 were elevated. WB results demonstrated that the expressions of p-mTOR and p-AMPK in ovaries were significantly reduced in Model group, but reversed in MET group.

CONCLUSION

Our study confirmed metformin could not only improve body weight and metabolism disorders, but also improve ovarian dysfunction in PCOS mice.In addition, we explored metformin could regulate ferroptosis to improve PCOS via the SIRT3/AMPK/mTOR pathway. Our study complements the mechanisms by which metformin improves PCOS.

CHAC1 exacerbates LPS-induced ferroptosis and apoptosis in HK-2 cells by promoting oxidative stress

BACKGROUND

Sepsis-induced acute kidney injury (AKI) is a singularly grievous and life-threatening syndrome. Its pathogenesis is closely related to inflammatory response, apoptosis, oxidative stress, and ferroptosis. Cation transport regulator-like protein 1 (CHAC1), as a proapoptic factor, may be involved in apoptosis, oxidative stress, and ferroptosis. This study aimed to explore the role of CHAC1 in the lipopolysaccharide (LPS)-induced the human renal proximal tubular epithelial (HK-2) cells.

METHODS

HK-2 cells were challenged with LPS to construct a model of sepsis-induced AKI in vitro. The role of CHAC1 in the LPS-induced HK-2 cells was explored using Western blot assay, cell counting kit-8 (CCK-8), flow cytometry, and colorimetric assays. Additionally, N-acetyl cysteine (NAC) was incubated with HK-2 cells to define deeply the relation between oxidative stress and apoptosis or ferroptosis.

RESULTS

The expression of CHAC1 was enhanced in the kidney tissues of mice with sepsis--induced multiple organ dysfunction syndrome (MODS), through the Gene Expression Omnibus database (GSE60088 microarray dataset), and in the LPS-induced HK-2 cells. The cell viability was significantly reduced by LPS treatment, which was at least partly restored by the transfection of siCHAC1#1 and siCHAC1#2 but not siNC. In addition, down-regulation of CHAC1 counteracted the LPS-induced reactive oxygen species level and malonaldehyde concentrations while restored the LPS-induced glutathione concentrations. Meanwhile, interference of CHAC1 neutralized LPS-induced apoptosis rate, and the relative level of cleaved poly(ADP-ribose) polymerase (PARP)/PARP, and cleaved caspase-3/caspase-3. In addition, silencing of CHAC1 recovered the LPS-induced enhanced protein level of glutathione peroxidase 4 (GPx4) whereas antagonized the LPS-induced relative protein level of ACSL4 and that of iron. Moreover, application of NAC inverted the effect of CHAC1 on apoptosis and ferroptosis in HK-2 cells.

CONCLUSION

CHAC1 exacerbated ferroptosis and apoptosis by enhancing oxidative stress in LPS-induced HK-2 cells.

WTAP-mediated m6A modification on circCMTM3 inhibits hepatocellular carcinoma ferroptosis by recruiting IGF2BP1 to increase PARK7 stability

BACKGROUND

Hepatocellular carcinoma (HCC) has poor prognosis and high mortality. CircCMTM3 was significantly up-regulated in HCC. However, the mechanism of circCMTM3 in HCC is not full elucidated.

METHODS

The expression level of circCMTM3, PARK7, GPX4, and Ki67 in HCC cells and tissues were quantified by qRT-PCR, IHC, and Western blotting. The level of GSH, total iron, Fe²⁺, and MDA were detected by their kits. CCK-8 and flow cytometry analysis were used to evaluated cell proliferation and lipid ROS level, respectively. m6A level of circCMTM3 was assessed by MeRIP-PCR. RNA pulldown, RIP, and FISH detected the interaction between circCMTM3, WTAP, and PARK7. Tumor xenograft model was constructed to validate the function of cicrCMTM3 and WTAP.

RESULTS

CircCMTM3 and WTAP were enhanced in HCC tissues and cells. Knockdown of WTAP inhibited m6A modification of circCMTM3, which promoted HCC ferroptosis. circCMTM3 silencing suppressed the expression and stability of PARK7 through binding with IGF2BP1 in HCC cells, which finally induced ferroptosis. In vivo studies demonstrated that silencing WTAP and circCMTM3 suppressed tumor growth and promoted HCC ferroptosis in nude mice by regulating PARK7 signaling.

CONCLUSION

CircCMTM3 promoted the carcinogenesis through inhibiting ferroptosis by recruiting IGF2BP1 to increase PARK7 stability in HCC, suggesting that cicrCMTM3 may be an important marker for HCC treatment.

Quercetin inhibits the progression of endometrial HEC-1-A cells by regulating ferroptosis—a preliminary study

BACKGROUND

Endometrial carcinoma (EC) is one of the most common female reproductive system tumors, which seriously threatens women's health. This preliminary study aimed to investigate the effects of quercetin on the EC cells and explore the potential mechanism.

METHODS

In this study, the effects of quercetin on endometrial cancer HEC-1-A cells were studied by a series of cell biological methods, including CCK-8 detection of cell activity, Western blotting of ferroptosis-related proteins, apoptosis detection, reactive oxygen species (ROS) detection and other detections.

RESULTS

Our results showed that quercetin inhibited the proliferation and migration of EC cells, induced cell apoptosis, and affected the cell cycle. Furthermore, the anti-tumor effect of quercetin was related to the induction of ferroptosis in the EC cells.

CONCLUSIONS

Our study shows quercetin may exert anti-tumor effects, which may be related to the regulation of ferroptosis. Our study provides evidence for the future treatment of EC with small molecule drugs.

Xiaojianzhong decoction attenuates gastric mucosal injury by activating the p62/Keap1/Nrf2 signaling pathway to inhibit ferroptosis

Gastric mucosal injury is the initial stage of the occurrence and development of gastric diseases. Oxidative stress and ferroptosis caused by the imbalance of redox and iron dynamics in gastric mucosal epithelial cells are present throughout the occurrence and development of gastric mucosal injury. Therefore, the inhibition of oxidative stress and ferroptosis is a potential target for the treatment of the gastric mucosal injury. Xiaojianzhong decoction (XJZ), which consists of six Chinese herbal medicines and extracts, is used for the treatment of diseases related to gastrointestinal mucosal injury; however, its specific mechanism of action has yet to be clarified. In this study, we clarified the protective effect of XJZ on gastric mucosa and revealed its underlying mechanism. We established a gastric mucosal injury model using aspirin and administered XJZ. Furthermore, we systematically evaluated the mucosal injury and examined the expression of genes related to oxidative stress, ferroptosis, and inflammation. The study found that XJZ significantly counteracted aspirin-induced gastric mucosal injury and inhibited oxidative stress and ferroptosis in mice. Upon examining SQSTM1/p62(p62)/Kelch-like ECH-associated protein 1 (Keap1)/Nuclear Factor erythroid 2-Related Factor 2 (Nrf2), a well-known signaling pathway involved in the regulation of oxidative stress and ferroptosis, we found that its activation was significantly inhibited by aspirin treatment and that this signaling pathway was activated after XJZ intervention. Our study suggests that XJZ may inhibit aspirin induced oxidative stress and ferroptosis via the p62/Keap1/Nrf2 signaling pathway, thereby attenuating gastric mucosal injury.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

The anti-alcoholism drug disulfiram effectively ameliorates ulcerative colitis through suppressing oxidative stresses-associated pyroptotic cell death and cellular inflammation in colonic cells

BACKGROUND

Oxidative stress, cell pyroptosis and inflammation are considered as important pathogenic factors for ulcerative colitis (UC) development, and the traditional anti-alcoholism drug disulfiram (DSF) has recently been reported to exert its regulating effects on all the above cellular functions, which makes DSF as ideal therapeutic agent for UC treatment, but this issue has not been fully studied.

METHODS

Dextran sulfate sodium (DSS)-induced animal models in C57BL/6J mice and lipopolysaccharide (LPS)-induced cellular models in colonic cell lines (HT-29 and Caco-2) for UC were respectively established. Cytokine secretion was determined by ELISA. Cell viability and proliferation were evaluated by MTT assay and EdU assay. Real-Time qPCR, Western Blot, immunofluorescent staining assay and immunohistochemistry (IHC) were employed to evaluate gene expressions. The correlations of the genes in the clinical tissues were analyzed by using the Pearson Correlation analysis.

RESULTS

DSF restrained oxidative stress, pyroptotic cell death and cellular inflammation in UC models in vitro and in vivo, and elimination of Reactive Oxygen Species (ROS) by N-acetyl-l-cysteine (NAC) rescued cell viability in LPS-treated colonic cells (HT-29 and Caco-2). Further experiments suggested that a glycogen synthase kinase-3β (GSK-3β)/Nrf2/NLRP3 signaling cascade played critical role in this process. Mechanistically, DSF downregulated GSK-3β and NLRP3, whereas upregulated Nrf2 in LPS-treated colonic cells. Also, the regulating effects of DSF on Nrf2 and NLRP3 were abrogated by upregulating GSK-3β. Moreover, upregulation of GSK-3β abolished the protective effects of DSF on LPS-treated colonic cells.

CONCLUSIONS

Taken together, data of this study indicated that DSF restrained oxidative damages-related pyroptotic cell death and inflammation via regulating the GSK-3β/Nrf2/NLRP3 pathway, leading to the suppression of LPS-induced UC development.

GPX4 suppresses ferroptosis to promote malignant progression of endometrial carcinoma via transcriptional activation by ELK1

Background

Glutathione Peroxidase 4 (GPX4) is a key protein that inhibits ferroptosis. However, its biological regulation and mechanism in endometrial cancer (EC) have not been reported in detail.

Methods

The expression of GPX4 in EC tissues was determined by TCGA databases, qRT-PCR, Western blot, and immunohistochemistry (IHC). The effects of GPX4 on EC cell proliferation, migration, apoptosis, and tumorigenesis were studied in vivo and in vitro. In addition, ETS Transcription Factor ELK1 (ELK1) was identified by bioinformatics methods, dual-luciferase reporter assay, and chromatin immunoprecipitation (ChIP). Pearson correlation analysis was used to evaluate the association between ELK1 and GPX4 expression.

Results

The expression of GPX4 was significantly up-regulated in EC tissues and cell lines. Silencing GPX4 significantly inhibited the proliferation, migration ability, induced apoptosis, and arrested the cell cycle of Ishikawa and KLE cells. Knockdown of GPX4 accumulated intracellular ferrous iron and ROS, disrupted MMP, and increased MDA levels. The xenograft tumor model also showed that GPX4 knockdown markedly reduced tumor growth in mice. Mechanically, ELK1 could bind to the promoter of GPX4 to promote its transcription. In addition, the expression of ELK1 in EC was positively correlated with GPX4. Rescue experiments confirmed that GPX4 knockdown could reverse the strengthens of cell proliferation and migration ability and the lower level of Fe²⁺ and MDA caused by upregulating ELK1.

Conclusion

The results of the present study suggest that ELK1 / GPX4 axis plays an important role in the progress of EC by promoting the malignant biological behavior and inducing ferroptosis of EC cells, which provides evidence for investigating the potential therapeutic strategies of endometrial cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09986-3.

From Iron Metabolism to Ferroptosis: Pathologic Changes in Coronary Heart Disease

Coronary heart disease (CHD) is closely related to oxidative stress and inflammatory response and is the most common cardiovascular disease (CVD). Iron is an essential mineral that participates in many physiological and biochemical reactions in the human body. Meanwhile, on the negative side, iron has an active redox capacity, which leads to the accumulation of reactive oxygen species (ROS) and lipid peroxidation. There is growing evidence that disordered iron metabolism is involved in CHD's pathological progression. And the result of disordered iron metabolism is associated with iron overload-induced programmed cell death, often called ferroptosis. That features iron-dependent lipid peroxidation. Ferroptosis may play a crucial role in the development of CHD, and targeting ferroptosis may be a promising option for treating CHD. Here, we review the mechanisms of iron metabolism in cardiomyocytes (CMs) and explain the correlation between iron metabolism and ferroptosis. Meanwhile, we highlight the specific roles of iron metabolism and ferroptosis in the main pathological progression of CHD.

Targeting Ferroptosis as a Novel Approach to Alleviate Aortic Dissection

A variety of programmed cell death types have been shown to participate in the loss of smooth muscle cells (SMCs) during the development of aortic dissection (AD), but it is still largely unclear whether ferroptosis is involved in the development of AD. In the present study, we found that the expression of key ferroptosis regulatory proteins, solute carrier family 7 member 11 (SLC7A11), ferroptosis suppressor protein 1 (FSP1) and glutathione peroxidase 4 (GPX4) were downregulated in aortas of Stanford type A AD (TAAD) patients, and liproxstatin-1, a specific inhibitor of ferroptosis, obviously abolished the β-aminopropionitrile (BAPN)-induced development and rupture of AD in mice. Furthermore, the expression of methyltransferase-like 3 (METTL3), a major methyltransferase of RNA m⁶A, was remarkably upregulated in the aortas of TAAD patients, and the protein levels of METTL3 were negatively correlated with SLC7A11 and FSP1 levels in human aortas. Overexpression of METTL3 in human aortic SMCs (HASMCs) inhibited, while METTL3 knockdown promoted SLC7A11 and FSP1 expression. More importantly, overexpression of METTL3 facilitated imidazole ketone erastin- and cystine deprivation-induced ferroptosis, while knockdown of METTL3 repressed ferroptosis of HASMCs. Overexpression of either SLC7A11 or FSP1 largely abrogated the effect of METTL3 on HASMC ferroptosis. Therefore, we have revealed that ferroptosis is a critical cause of AD in both humans and mice and that METTL3 promotes ferroptosis of HASMCs by inhibiting the expression of SLC7A11 and FSP1. Thus, targeting ferroptosis or m⁶A RNA methylation is a potential novel strategy for the treatment of AD.

Ferroptosis participates in neuron damage in experimental cerebral malaria and is partially induced by activated CD8+ T cells

Cerebral malaria is the most serious complication of malaria infection, with 26% of surviving children having neurological sequelae, which may be caused by neuron damage, but the mechanism is not clear. Ferroptosis has been reported to play an important role in neuron damage in several nervous system diseases. However, the occurrence of ferroptosis in experimental cerebral malaria (ECM) pathogenesis is still unknown. In this study, we firstly detected increased levels of malondialdehyde (MDA) and iron, which are indicators of ferroptosis, in the cerebrum of ECM mice. Some important regulators of ferroptosis, including upregulated expression of transferrin receptor 1 (TfR1) and acyl-CoA synthetase long-chain family member 4 (ACSL4), and downregulation of glutathione peroxidase 4 (GPX4) levels, were also confirmed in ECM mice. Consistently, neuron damage, which was detected in the cerebrum of ECM mice, was positively correlated with reduced GPX4 expression and furtherly rescued by administration of the ferroptosis inhibitor ferrostatin-1 (Fer-1). In addition, primary neurons were damaged by activated CD8⁺ T cells, an effect that was also partially rescued by Fer-1 on amyloid precursor protein expression and mitochondrial membrane potential levels in vitro. Activated CD8⁺ T cells were also shown to infiltrate the cerebrum of ECM mice and upregulate TfR1 expression in primary neurons, which may be an important event for inducing ferroptosis in ECM. Altogether, we show that ferroptosis contributes to neuron damage in ECM pathogenesis, and activated CD8⁺ T cells may be important inducers of neuronal ferroptosis. Hence, targeting ferroptosis may be a promising adjuvant therapeutic strategy for neurological sequelae in patients with cerebral malaria.

Identification of ferroptosis-related genes for overall survival prediction in hepatocellular carcinoma

Ferroptosis is a novel type of cell death depending on iron and is strongly related to the development of tumors. Hepatocellular carcinoma (HCC) is a malignancy with high incidence. Despite some reports demonstrating the relation between ferroptosis-related genes and HCC, more details have not been excavated. In the present study, we collected and analyzed HCC patients' datasets from the TCGA-LIHC project and ICGC portal, respectively. Through the bioinformatic methods, we screened 126 differentially expressed genes. Then a prognostic model was established with four genes (GPX2, MT3, PRDX1, and SRXN1). PRDX1 is the hub gene of the prognosis model and has a high expression in hepatocellular carcinoma tumor tissue and cell lines. We further found that silencing PRDX1 increased the accumulation of ferrous ions and lipid peroxidation accumulation in HEPG2 cells and promoted ferroptosis in hepatocellular carcinoma. In conclusion, the study demonstrated the four-gene signature can be used to predict HCC prognosis. It also revealed the potential function of the ferroptosis-related gene PRDX1 in HCC, which can be a biomarker of the prediction for HCC outcome.

Synergistic Microbicidal Effect of AUR and PEITC Against Staphylococcus aureus Skin Infection

Given the increasing prevalence of Staphylococcus aureus antibiotic resistance, there is an urgent need to repurpose approved drugs with known pharmacology and toxicology as an alternative therapeutic strategy. We have reported that the sustained monotherapy of auranofin (AUR) inevitably resulted in reduced susceptibility or even the emergence of resistance to AUR in S. aureus. However, whether drug combination could increase antibacterial activity while preventing AUR resistance is still unknown. Here, we focused on the important role of AUR combined with phenethyl isothiocyanate (PEITC) in skin infection and determined the synergistic antimicrobial effect on S. aureus by using checkerboard assays and time-kill kinetics analysis. This synergistic antimicrobial activity correlated with increased reactive oxygen species (ROS) generation, disruption of bacterial cell structure, and inhibition of biofilm formation. We also showed that AUR synergized with PEITC effectively restored the susceptibility to AUR via regulating thioredoxin reductase (TrxR) and rescued mice from subcutaneous abscesses through eliminating S. aureus pathogens, including methicillin-resistant S. aureus (MRSA). Collectively, our study indicated that the AUR and PEITC combination had a synergistic antimicrobial impact on S. aureus in vitro and in vivo. These results suggest that AUR and PEITC treatment may be a promising option for S. aureus infection.

Prospective Application of Ferroptosis in Hypoxic Cells for Tumor Radiotherapy

Radiation therapy plays an increasingly important role in cancer treatment. It can inhibit the progression of various cancers through radiation-induced DNA breakage and reactive oxygen species (ROS) overload. Unfortunately, solid tumors, such as breast and lung cancer, often develop a hypoxic microenvironment due to insufficient blood supply and rapid tumor proliferation, thereby affecting the effectiveness of radiation therapy. Restraining hypoxia and improving the curative effect of radiotherapy have become difficult problems. Ferroptosis is a new type of cell death caused by lipid peroxidation due to iron metabolism disorders and ROS accumulation. It plays an important role in both hypoxia and radiotherapy and can enhance the radiosensitivity of hypoxic tumor cells by amplifying oxidative stress or inhibiting antioxidant regulation. In this review, we summarize the internal relationship and related mechanisms between ferroptosis and hypoxia, thus exploring the possibility of inducing ferroptosis to improve the prognosis of hypoxic tumors.

Geniposide Possesses the Protective Effect on Myocardial Injury by Inhibiting Oxidative Stress and Ferroptosis via Activation of the Grsf1/GPx4 Axis

Reactive oxygen species (ROS) produced in the ischemic myocardium can induce cardiomyocyte injury and death, resulting in cardiac remodeling. Ferroptosis, known as a newly type of cell death caused by iron-dependent oxidative stress, which is an essential death mechanism in cardiomyocytes. However, it is unclear whether oxidative stress products can further induce ferroptosis and aggravate cardiomyocyte injury. Geniposide (GEN), a major active component of Gardenia jasminoides J. Ellis, possesses the natural antioxidant activity and cardioprotective effect. Herein, we evaluated the role of ferroptosis in myocardial oxidative injury and the protective effect of GEN on myocardial ferroptosis. We first detected iron overload, massive ROS, and lipid peroxidation in ferric ammonium citrate (FAC)-treated cardiomyocytes, which were typical characteristics of ferroptosis. The iron overload-induced oxidative stress and ferroptosis aggravated cardiomyocyte injury, which were significantly alleviated by GEN treatment. Similar phenotypic changes of ferroptosis were consistently discovered in hydrogen peroxide (H₂O₂)-induced cells, which were reversed by GEN treatment as well. Interestingly, the RNA-binding protein Grsf1, which directly upregulated Gpx4 at the translational level, was activated by GEN following myocardial oxidative injury. The specific knockdown of Grsf1 increased their sensitivity to ferroptosis and weakened the cardioprotective effect of GEN in H₂O₂-treated cardiomyocytes. Moreover, GEN treatment reduced iron overload and lipid peroxidation in myocardial infarction (MI) rats, thereby fighting against the cardiac ischemic injury. Collectively, our study revealed the pathogenesis of oxidative stress and ferroptosis associated with myocardial ischemia, and indicated the antioxidant and anti-ferroptosis effects of GEN on preventing myocardial injury by activating the Grsf1/GPx4 axis, serving as a potential therapeutic target.

Targeting cellular energy metabolism- mediated ferroptosis by small molecule compounds for colorectal cancer therapy

Alterations in cellular energy metabolism, including glycolysis, glutamine and lipid metabolism that affects ferroptosis in the tumour microenvironment (TME), play a critical role in the development and progression of colorectal cancer (CRC) and offer evolutionary advantages to tumour cells and even enhance their aggressive phenotype. This review summarises the findings on the dysregulated energy metabolism pathways, including lipid and fatty acid metabolism especially for regulating the ferroptosis in TME. Moreover, the cellular energy metabolism and tumour ferroptosis to be regulated by small molecule compounds, which targeting the different aspects of metabolic pathways of energy production as well as metabolic enzymes that connect with the tumour cell growth and ferroptosis in CRC are also discussed. In this review, we will provide a comprehensive summary on small molecule compounds regulatory function of different energy metabolic routes on ferroptosis in tumour cells and discuss those metabolic vulnerabilities for the development of potential ferroptosis-based tumour therapies for colorectal cancer.

Iron Transporters and Ferroptosis in Malignant Brain Tumors

Malignant brain tumors represent approximately 1.5% of all malignant tumors. The survival rate among patients is relatively low and the mortality rate of pediatric brain tumors ranks first among all childhood malignant tumors. At present malignant brain tumors remain incurable. Although some tumors can be treated with surgery and chemotherapy, new treatment strategies are urgent owing to the poor clinical prognosis. Iron is an essential trace element in many biological processes of the human body. Iron transporters play a crucial role in iron absorption and transport. Ferroptosis, an iron-dependent form of nonapoptotic cell death, is characterized by the accumulation of lipid peroxidation products and lethal reactive oxygen species (ROS) derived from iron metabolism. Recently, compelling evidence has shown that inducing ferroptosis of tumor cells is a potential therapeutic strategy. In this review, we will briefly describe the significant regulatory factors of ferroptosis, iron, its absorption and transport under physiological conditions, especially the function of iron transporters. Then we will summarize the relevant mechanisms of ferroptosis and its role in malignant brain tumors, wherein the role of transporters is not to be ignored. Finally, we will introduce the current research progress in the treatment of malignant brain tumors by inducing ferroptosis in order to explain the current biological principles of potential treatment targets and treatment strategies for malignant brain tumors.

Oxaliplatin induces ferroptosis and oxidative stress in HT29 colorectal cancer cells by inhibiting the Nrf2 signaling pathway

Oxaliplatin is a third-generation platinum drug that is used as first-line chemotherapy for colorectal cancer (CRC). Ferroptosis has been demonstrated to induce cell death and oxidative stress in CRC. The aim of the present study was to investigate whether oxaliplatin could exert anticancer effects on CRC by promoting ferroptosis and oxidative stress. Cell viability and apoptosis were assessed by performing Cell Counting Kit-8 and TUNEL assays, respectively, in the presence or absence of the ferroptosis inducer, erastin. Western blotting was performed to detect the levels of certain nuclear factor erythroid 2-related factor 2 (Nrf2)-associated proteins in HT29 cells treated with oxaliplatin. Furthermore, after treating cells with the Nrf2 activator, NK-252, Fe²⁺ was detected in cells using a commercial kit. Ferroptosis-associated protein expression was also evaluated via western blotting. Additionally, ELISA was adopted to measure the levels of oxidative stress-related factors. Following the addition of erastin, iron ion content, ferroptosis-related protein expression and the levels of oxidative stress-related factors were assayed as described previously. The results of the present study demonstrated that oxaliplatin inhibited viability and the Nrf2 signaling pathway in CRC cells. In addition, oxaliplatin promoted ferroptosis and oxidative stress in CRC cells by inhibiting the Nrf2 signaling pathway. Treatment with oxaliplatin enhanced the effects of erastin on CRC cells by promoting ferroptosis and oxidative stress and inhibiting cell viability. In conclusion, oxaliplatin induced ferroptosis and oxidative stress in CRC cells by inhibiting the Nrf2 signaling pathway.

Cryptotanshinone Protects against PCOS-Induced Damage of Ovarian Tissue via Regulating Oxidative Stress, Mitochondrial Membrane Potential, Inflammation, and Apoptosis via Regulating Ferroptosis

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of childbearing age. Cryptotanshinone (CRY) has been shown to be effective in reversing reproductive disorders, but whether it can be used in the treatment of polycystic ovary syndrome remains unclear. We aimed to explore whether the mechanism of cryptotanshinone (CRY) in the treatment of polycystic ovary syndrome (PCOS) can be driven via regulating ferroptosis. A rat model of PCOS was established by daily injection of human chorionic gonadotropin and insulin for 22 days. An in vitro model of ischemia-reperfusion (IR) of granulosa cells was established. The in vitro and rat models of PCOS were subjected to different treatments including ferroptosis activators and inhibitors, CRY, and MAPK inhibitor. Oxidative stress was evaluated by measuring the activities of SOD, MDA, and GSH-PX. Total body weight and ovarian weight, as well as the levels of LH and the LH to FSH ratio, significantly increased in rats with PCOS, compared with controls. The expression of Bax was increased in PCOS tissues while PGC1α, NFR1, GPX4, catalase p-ERK, and Bcl-2 were all downregulated. Ferroptosis activator, erastin, had effects similar to those of PCOS while the contrary was found with CRY and ferroptosis inhibitor treatment groups. In vitro, CRY inhibited oxidative stress, MMP, and NF-κB and activated MAPK/ERK signaling by regulating ferroptosis. Overall, this study indicated that CRY protects against PCOS-induced damage of the ovarian tissue, via regulating oxidative stress, MMP, inflammation, and apoptosis via regulating ferroptosis.

Carboxymethylated pachyman induces ferroptosis in ovarian cancer by suppressing NRF1/HO‑1 signaling

Carboxymethylated pachyman (CMP) is characterized by immune regulatory, antitumor and antioxidant activities. However, whether CMP contributes to the treatment of ovarian cancer has yet to be explored. The role of CMP in ovarian cancer cell death was analyzed using CCK-8 and flow cytometry assays. The data showed that CMP induced ovarian cancer cell death in a dose-dependent manner. Furthermore, CMP-induced cell death could be largely reversed by preincubation with ferrostatin-1 (Fer-1) but not 3-methyladenine or necrostatin-1. Reverse transcription-quantitative PCR analysis indicated that CMP significantly increased prostaglandin-endoperoxide synthase 2 (PTGS2) and Chac glutathione specific γ-glutamylcyclotransferase 1 (CHAC1) mRNA levels, but preincubation with Fer-1 obviously reduced PTGS2 and CHAC1 mRNA levels in SKOV3 and Hey cells. The intracellular levels of superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA) and Fe²⁺ were then quantified The data showed that 100 and 200 µg/ml CMP enhanced the production of SOD, MDA and Fe²⁺ but decreased GSH levels in SKOV3 and HEY cells. These data indicated that CMP could induce ferroptosis in ovarian cancer cells. More importantly, in vitro and in vivo studies indicated that CMP significantly suppressed nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), cystine/glutamate antiporter system X(c)(−) (xCT) and glutathione peroxidase 4 (GPX4) expression in ovarian cancer cells and tumors. In conclusion, the present study showed novel data that CMP could induce ferroptotic death in ovarian cancer cells by suppressing Nrf2/HO-1/xCT/GPX4. All these findings indicate that CMP may have great potential in anti-ovarian cancer cell therapy by inducing ferroptosis.

The Potential Mechanisms by which Artemisinin and Its Derivatives Induce Ferroptosis in the Treatment of Cancer

Artemisinin (ART) is a bioactive molecule derived from the Chinese medicinal plant Artemisia annua (Asteraceae). ART and artemisinin derivatives (ARTs) have been effectively used for antimalaria treatment. The structure of ART is composed of a sesquiterpene lactone, including a peroxide internal bridge that is essential for its activity. In addition to their well-known antimalarial effects, ARTs have been shown recently to resist a wide range of tumors. The antineoplastic mechanisms of ART mainly include cell cycle inhibition, inhibition of tumor angiogenesis, DNA damage, and ferroptosis. In particular, ferroptosis is a novel nonapoptotic type of programmed cell death. However, the antitumor mechanisms of ARTs by regulating ferroptosis remain unclear. Through this review, we focus on the potential antitumor function of ARTs by acting on ferroptosis, including the regulation of iron metabolism, generation of reactive oxygen species (ROS), and activation of endoplasmic reticulum stress (ERS). This article systematically reviews the recent progress in ferroptosis research and provides a basis for ARTs as an anticancer drug in clinical practice.

Ferroptosis inhibitor ferrostatin‑1 alleviates homocysteine‑induced ovarian granulosa cell injury by regulating TET activity and DNA methylation

Polycystic ovary syndrome is one of the most common endocrine and metabolic gynecological disorders, of which dysfunction of ovarian granulosa cells is a key contributing factor. The aim of the present study was to explore the role of ferrostatin-1 (Fer-1), a ferroptosis inhibitor, in a cell injury model established by homocysteine (Hcy)-induced ovarian granulosa KGN cell line and the potential underlying mechanism. Cell viability was measured using Cell Counting Kit-8 assay in the presence or absence of Hcy and Fer-1. Cell apoptosis was assessed using TUNEL staining and the expression levels of apoptosis-related proteins were measured using western blotting. To explore the effects of Fer-1 on oxidative stress in Hcy-treated ovarian granulosa cells, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), lactate dehydrogenase (LDH) and glutathione (GSH) were measured using their corresponding kits. Furthermore, Fe²⁺ levels were assessed using Phen Green^™ SK labeling and western blotting was performed to measure the protein expression levels of ferroptosis-associated proteins GPX4, SLC7A11, ASCL4 and DMT1. Subsequently, DNA methylation and ten-eleven translocation (TET) 1/2 demethylase levels were also detected to evaluate the extent of overall DNA methylation in ovarian granulosa cells after Hcy treatment. The TET1/2 inhibitor Bobcat339 hydrochloride was applied to treat ovarian granulosa cells before evaluating the possible effects of Fer-1 on TET1/2 and DNA methylation. Fer-1 was found to markedly elevate ovarian granulosa cell viability following Hcy treatment. The apoptosis rate in Fer-1-treated groups was also markedly decreased, which was accompanied by downregulated Bax and cleaved caspase-3 expression and upregulated Bcl-2 protein expression. In addition, Fer-1 treatment reduced the levels of ROS, MDA and LDH whilst enhancing the levels of GSH. Fe²⁺ levels were significantly decreased following Fer-1 treatment, which also elevated glutathione peroxidase 4 expression whilst reducing solute carrier family 7 member 11, achaete-scute family BHLH transcription factor 4 and divalent metal transporter 1 protein expression. Fer-1 significantly inhibited DNA methylation and enhanced TET1/2 levels, which were reversed by treatment with Bobcat339 hydrochloride. Subsequent experiments on cell viability, oxidative stress, Fe²⁺ content, ferroptosis- and apoptosis-related proteins levels revealed that Bobcat339 hydrochloride reversed the effects of Fer-1 on ovarian granulosa Hcy-induced cell injury. These results suggest that Fer-1 may potentially protect ovarian granulosa cells against Hcy-induced injury by increasing TET levels and reducing DNA methylation.

Dihydroartemisinin and Artesunate Inhibit Aerobic Glycolysis via Suppressing c-Myc Signaling in non-small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) cells exhibit aberrant metabolism characterized by high glycolysis even in the presence of abundant oxygen. Inhibition of aerobic glycolysis remains challenging when identifying potential cancer-specific inhibitors while maintaining or even boosting the anti-cancer immunity. Artemisinin derivatives DHA and AS have shown excellent anti-tumor and immunoenhancing roles in numerous malignancies, but the molecular mechanism of DHA and AS in regulating cancer glucose metabolism is largely unknown. In this study, we proved that DHA and AS inhibit NSCLC growth via prohibiting cancer cell aerobic glycolysis through ERK/c-Myc pathway. First, we proved that DHA and AS have comparable anti-cancer growth roles in both NSCLC cell lines and mouse Lewis Lung Cancer model. Then, our data clearly showed that DHA and AS dose- and time-dependently reduce the uptake of glucose, the production of ATP, and the secretion of lactate, the expression of glucose transporter GLUT1 and two key glycolysis-related enzymes hexokinase and lactate dehydrogenase, as well as the level of c-Myc. Finally, we generated c-Myc^high stable-expressing NSCLC cell line and treated it with DHA or AS, respectively. Our data clearly showed that c-Myc overexpression can partially reverse the glycolysis-repressing role of DHA and AS which strongly supported our proposal that AS and DHA suppress aerobic glycolysis in a c-Myc-dependent manner in NSCLC cells. This study extends our knowledge of artemisinin derivatives in regulating tumor glucose metabolism and provides potential strategy in the therapy of lung cancer.

Ferroptosis Signaling and Regulators in Atherosclerosis

Atherosclerosis (AS) is a major cause of cardiovascular diseases such as coronary heart disease, heart failure and stroke. Abnormal lipid metabolism, oxidative stress and inflammation are the main features of AS. Ferroptosis is an iron-driven programmed cell death characterized by lipid peroxidation, which have been proved to participate in the development and progression of AS by different signal pathways. NRF2-Keap1 pathway decreases ferroptosis associated with AS by maintaining cellular iron homeostasis, increasing the production glutathione, GPX4 and NADPH. The p53 plays different roles in ferroptosis at different stages of AS in a transcription-dependent and transcription- independent manner. The Hippo pathway is involved in progression of AS, which has been proved the activation of ferroptosis. Other transcription factors, such as ATF3, ATF4, STAT3, also involved in the occurrence of ferroptosis and AS. Certain proteins or enzymes also have a regulatory role in AS and ferroptosis. In this paper, we review the mechanism of ferroptosis and its important role in AS in an attempt to find a new relationship between ferroptosis and AS and provide new ideas for the future treatment of AS.

Quantitative Proteomics Reveals That a Prognostic Signature of the Endometrium of the Polycystic Ovary Syndrome Women Based on Ferroptosis Proteins

OBJECTIVE

We aimed to study the relationship between ferroptosis proteins and reproductive outcomes of infertile patients with PCOS and construct the related prognostic model.

METHODS

These endometrium samples of the study were collected from 33 women with PCOS and 7 control women with successful pregnancies at the Reproductive Center of Lanzhou University Second Hospital, September 2019 to September 2020. The 40 patients' endometrium was identified the differentially expressed proteins (DEPs) using liquid chromatography tandem mass spectrometry. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and Gene Ontology (GO) showed that the DEPs related pathways and functions between PCOS and controls. Subsequently, univariate Cox regression analysis and Lasso regression were used to identifying independent prognostic ferroptosis proteins, which were utilized to establish a prognostic model. Then the performance of the prognostic model was evaluated by receiver operating characteristic curve (ROC) and decision curve analysis (DCA). Then clinical data and prognostic model were used to predict the reproductive outcomes of PCOS patients by constructing the nomograms. Finally, we performed the single sample gene set enrichment analysis (ssGSEA) to explore the correlation between risk scores and immune status.

RESULTS

A total of 5331 proteins were identified, 391 proteins were differentially expressed in the PCOS and controls. The KEGG analysis revealed that the ferroptosis pathway was significantly different between PCOS and controls. 5 ferroptosis proteins (GPX4, DPP4, G6PD, PCBP1, and PCBP2) prognostic model (FerSig) was constructed via Cox regression and Lasso regression. Patients were separated into high and low-risk groups according to the FerSig. Kaplan-Meier curve showed that patients in the low-risk group had much better reproductive outcomes than those in the high-risk group. The DCA showed that the risk score was an independent predictive factor for reproductive outcomes. Compared with clinical data, ROC curve analysis indicated the FerSig proteins as a potential diagnostic and prognostic factor in PCOS patients. Functional analysis revealed that the FerSig proteins and immune microenvironment were correlated to the prognosis of PCOS.

CONCLUSION

The prognostic model focused on the FerSig proteins could predict the reproductive outcomes of PCOS patients with decreased endometrial receptivity, and provided theoretical basis for individualized treatment.

The Emerging Role of Ferroptosis in Liver Diseases

Ferroptosis is a newly discovered type of cell death mediated by iron-dependent lipid peroxide. The disturbance of iron metabolism, imbalance of the amino acid antioxidant system, and lipid peroxide accumulation are considered distinct fingerprints of ferroptosis. The dysregulation of ferroptosis has been intensively studied in recent years due to its participation in various diseases, including cancer, kidney injury, and neurodegenerative diseases. Notably, increasing evidence indicates that ferroptosis plays different roles in a wide spectrum of liver diseases. On the one hand, inhibiting ferroptosis may counteract the pathophysiological progression of several liver diseases, such as alcoholic liver injury, nonalcoholic steatosis hepatitis and fibrosis. On the other hand, inducing ferroptosis may restrict the emergence of secondary resistance to current medicines, such as sorafenib, for hepatocellular carcinoma (HCC) therapy. Here, we summarize the biological characteristics and regulatory signalling pathways of ferroptosis involved in liver disease. The current available medical agents targeting ferroptosis, including inducers or inhibitors applied in liver diseases, are also reviewed. This work aims to provide new insight into the emerging role of pathogenesis and therapeutic approaches for liver diseases.

The non-canonical effects of heme oxygenase-1, a classical fighter against oxidative stress

The role of heme oxygenase-1 in resisting oxidative stress and cell protection has always been a hot research topic. With the continuous deepening of research, in addition to directly regulating redox by catalyzing the degradation of heme, HO-1 protein also participates in the gene expression level in a great diversity of methods, thereby initiating cell defense. Particularly the non-canonical nuclear-localized HO-1 and HO-1 protein interactions play the role of a warrior against oxidative stress. Besides, HO-1 may be a promising marker for disease prediction and detection in many clinical trials. Especially for malignant diseases, there may be new advances in the treatment of HO-1 by regulating abnormal ROS and metabolic signaling. The purpose of this review is to systematically sort out and describe several aspects of research to facilitate further detailed mechanism research and clinical application promotion in the future.

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The different subcellular localizations ofHO-1 implies that it has special functions.

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Nuclear HO-1 plays an indispensable role in gene regulation and other aspects.

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The interactions between HO-1 and others provide the possibility to participate in vital physiological processes.

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HO-1 may become a potential disease assessment marker.

Emerging role of ferroptosis in breast cancer: New dawn for overcoming tumor progression

Breast cancer has become a serious threat to women's health. Cancer progression is mainly derived from resistance to apoptosis induced by procedures or therapies. Therefore, new drugs or models that can overcome apoptosis resistance should be identified. Ferroptosis is a recently identified mode of cell death characterized by excess reactive oxygen species-induced lipid peroxidation. Since ferroptosis is distinct from apoptosis, necrosis and autophagy, its induction successfully eliminates cancer cells that are resistant to other modes of cell death. Therefore, ferroptosis may become a new direction around which to design breast cancer treatment. Unfortunately, the complete appearance of ferroptosis in breast cancer has not yet been fully elucidated. Furthermore, whether ferroptosis inducers can be used in combination with traditional anti- breast cancer drugs is still unknown. Moreover, a summary of ferroptosis in breast cancer progression and therapy is currently not available. In this review, we discuss the roles of ferroptosis-associated modulators glutathione, glutathione peroxidase 4, iron, nuclear factor erythroid-2 related factor-2, superoxide dismutases, lipoxygenase and coenzyme Q in breast cancer. Furthermore, we provide evidence that traditional drugs against breast cancer induce ferroptosis, and that ferroptosis inducers eliminate breast cancer cells. Finally, we put forward prospect of using ferroptosis inducers in breast cancer therapy, and predict possible obstacles and corresponding solutions. This review will deepen our understanding of the relationship between ferroptosis and breast cancer, and provide new insights into breast cancer-related therapeutic strategies.

The transcription factor BACH1 at the crossroads of cancer biology: From epithelial-mesenchymal transition to ferroptosis

The progression of cancer involves not only the gradual evolution of cells by mutations in DNA but also alterations in the gene expression induced by those mutations and input from the surrounding microenvironment. Such alterations contribute to cancer cells' abilities to reprogram metabolic pathways and undergo epithelial-to-mesenchymal transition (EMT), which facilitate the survival of cancer cells and their metastasis to other organs. Recently, BTB and CNC homology 1 (BACH1), a heme-regulated transcription factor that represses genes involved in iron and heme metabolism in normal cells, was shown to shape the metabolism and metastatic potential of cancer cells. The growing list of BACH1 target genes in cancer cells reveals that BACH1 promotes metastasis by regulating various sets of genes beyond iron metabolism. BACH1 represses the expression of genes that mediate cell–cell adhesion and oxidative phosphorylation but activates the expression of genes required for glycolysis, cell motility, and matrix protein degradation. Furthermore, BACH1 represses FOXA1 gene encoding an activator of epithelial genes and activates SNAI2 encoding a repressor of epithelial genes, forming a feedforward loop of EMT. By synthesizing these observations, we propose a “two-faced BACH1 model”, which accounts for the dynamic switching between metastasis and stress resistance along with cancer progression. We discuss here the possibility that BACH1-mediated promotion of cancer also brings increased sensitivity to iron-dependent cell death (ferroptosis) through crosstalk of BACH1 target genes, imposing programmed vulnerability upon cancer cells. We also discuss the future directions of this field, including the dynamics and plasticity of EMT.