Targeting ferroptosis and ferritinophagy: new targets for cardiovascular diseases / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Cardiovascular diseases (CVDs) are a leading factor driving mortality worldwide. Iron, an essential trace mineral, is important in numerous biological processes, and its role in CVDs has raised broad discussion for decades. Iron-mediated cell death, namely ferroptosis, has attracted much attention due to its critical role in cardiomyocyte damage and CVDs. Furthermore, ferritinophagy is the upstream mechanism that induces ferroptosis, and is closely related to CVDs. This review aims to delineate the processes and mechanisms of ferroptosis and ferritinophagy, and the regulatory pathways and molecular targets involved in ferritinophagy, and to determine their roles in CVDs. Furthermore, we discuss the possibility of targeting ferritinophagy-induced ferroptosis modulators for treating CVDs. Collectively, this review offers some new insights into the pathology of CVDs and identifies possible therapeutic targets.

Inductores de ferroptosis para el tratamiento del cáncer / Ferroptosis Inducers for Cancer Treatment

Introducción: La ferroptosis es un proceso no apoptótico de muerte celular regulada que depende de la presencia de iones hierro en el medio intracelular. Se caracterizada por la acumulación de especies reactivas de lípidos oxidados y radicales libres en las membranas celulares. Los inductores e inhibidores de este proceso inciden de manera circunstancial en él, con cuya respuesta celular se trabaja en función de elaborar modelos para el tratamiento del cáncer. Objetivo: Profundizar en el proceso de ferroptosis con un enfoque hacia los inductores e inhibidores, el establecimiento de modelos biofisicoquímicos y las estrategias terapéuticas para el tratamiento del cáncer. Métodos: Se realizó una revisión de los estudios más significativos sobre el tema, publicados en la Web of Science, PubMed, EBSCO, y Scopus. Resultados: Gracias al novedoso descubrimiento de la ferroptosis como impulsor de la muerte de células tumorales para tratar el cáncer, se han comenzado a desarrollar modelos teóricos que simulan el comportamiento de estas células y la complejidad en sistemas biológicos; que permiten encontrar procedimientos alternativos y menos invasivos contra esta y otras enfermedades. Conclusiones: Los inductores e inhibidores tienen una función primordial a la hora de predecir la influencia en la sensibilidad a la ferroptosis; por lo que se indagó en los mecanismos de funcionamiento de estos, que facilitará la forma de inducir en mayor o menor grado la muerte celular y disminuir la población de células cancerígenas(AU)

Introduction: Ferroptosis is a non-apoptotic process of regulated cell death that depends on the presence of iron ions in the intracellular medium. It is characterized by the accumulation of reactive species of oxidized lipids and free radicals in cell membranes. The inducers and inhibitors of this process circumstantially affect it, whose cellular response is used to develop models for cancer treatment. Objective: To deepen the ferroptosis process focusing on inducers and inhibitors, the establishment of biophysiochemical models and therapeutic strategies for cancer treatment. Methods: A review was carried out of the most significant studies on the subject, published in the Web of Science, PubMed, EBSCO and Scopus. Results: Thanks to the novel discovery of ferroptosis as a conductor of tumor cell death to treat cancer, theoretical models have begun to be developed that simulate the behavior of these cells and the complexity in biological systems; that allow finding alternative and less invasive procedures against this and other diseases. Conclusions: Inductors and inhibitors have a primary role in predicting the influence on sensitivity to ferroptosis; therefore, the mechanisms of operation of these were investigated, which will facilitate the way to induce cell death to a greater or lesser degree and reduce the population of cancer cells(AU)

Astragaloside IV alleviates stroke-triggered early brain injury by modulating neuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway

Purpose: Stroke is an acute cerebrovascular disease. Astragaloside IV (AS-IV) is an active ingredient extracted from Astragalus membranaceus with an established therapeutic effect on central nervous system diseases. This study examined the neuroprotective properties and possible mechanisms of AS-IV in stroke-triggered early brain injury (EBI) in a rat transient middle cerebral artery occlusion (MCAO) model. Methods: The neurological scores and brain water content were analyzed. 2,3,5-triphenyl tetrazolium chloride (TTC) staining was utilized to determine the infarct volume, neuroinflammatory cytokine levels, and ferroptosis-related genes and proteins, and neuronal damage and molecular mechanisms were evaluated by terminal deoxynucleotidyl transferase dutp nickend labeling (TUNEL) staining, western blotting, and real-time polymerase chain reaction. Results: AS-IV administration decreased the infarct volume, brain edema, neurological deficits, and inflammatory cytokines TNF-α, interleukin-1ß (IL-1ß), IL-6, and NF-κB, increased the levels of SLC7A11 and glutathione peroxidase 4 (GPX4), decreased lipid reactive oxygen species (ROS) levels, and prevented neuronal ferroptosis. Meanwhile, AS-IV triggered the Nrf2/HO-1 signaling pathway and alleviated ferroptosis due to the induction of stroke. Conclusion: Hence, the findings of this research illustrate that AS-IV administration can improve delayed ischemic neurological deficits and decrease neuronal death by modulating nuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway.

Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction / 南方医科大学学报

OBJECTIVE@#To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.@*METHODS@#A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe2+, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.@*RESULTS@#The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe2+ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).@*CONCLUSION@#SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Ferroptosis in acute leukemia / 中华医学杂志(英文版)

Ferroptosis is an iron-dependent cell death pathway that is different from apoptosis, pyroptosis, and necrosis. The main characteristics of ferroptosis are the Fenton reaction mediated by intracellular free divalent iron ions, lipid peroxidation of cell membrane lipids, and inhibition of the anti-lipid peroxidation activity of intracellular glutathione peroxidase 4 (GPX4). Recent studies have shown that ferroptosis can be involved in the pathological processes of many disorders, such as ischemia-reperfusion injury, nervous system diseases, and blood diseases. However, the specific mechanisms by which ferroptosis participates in the occurrence and development of acute leukemia still need to be more fully and deeply studied. This article reviews the characteristics of ferroptosis and the regulatory mechanisms promoting or inhibiting ferroptosis. More importantly, it further discusses the role of ferroptosis in acute leukemia and predicts a change in treatment strategy brought about by increased knowledge of the role of ferroptosis in acute leukemia.

Omics Analysis of Ferroptosis and Establishment of Prognostic Model for multiple myeloma Patients / 中国实验血液学杂志

OBJECTIVE@#To explore the role of ferroptosis-related genes in multiple myeloma(MM) through TCGA database and FerrDb, and build a prognostic model of ferroptosis-related genes for MM patients.@*METHODS@#Using the TCGA database containing clinical information and gene expression profile data of 764 patients with MM and the FerrDb database including ferroptosis-related genes, the differentially expressed ferroptosis-related genes were screened by wilcox.test function. The prognostic model of ferroptosis-related genes was established by Lasso regression, and the Kaplan-Meier survival curve was drawn. Then COX regression analysis was used to screen independent prognostic factors. Finally, the differential genes between high-risk and low-risk patients were screened, and enrichment analysis was used to explore the mechanism of the relationship between ferroptosis and prognosis in MM.@*RESULTS@#36 differential genes related to ferroptosis were screened out from bone marrow samples of 764 MM patients and 4 normal people, including 12 up-regulated genes and 24 down-regulated genes. Six prognosis-related genes (GCLM, GLS2, SLC7A11, AIFM2, ACO1, G6PD) were screened out by Lasso regression and the prognostic model with ferroptosis-related genes of MM was established. Kaplan-Meier survival curve analysis showed that the survival rate between high risk group and low risk group was significantly different(P<0.01). Univariate COX regression analysis showed that age, sex, ISS stage and risk score were significantly correlated with overall survival of MM patients(P<0.05), while multivariate COX regression analysis showed that age, ISS stage and risk score were independent prognostic indicators for MM patients (P<0.05). GO and KEGG enrichment analysis showed that the ferroptosis-related genes was mainly related to neutrophil degranulation and migration, cytokine activity and regulation, cell component, antigen processing and presentation, complement and coagulation cascades, haematopoietic cell lineage and so on, which may affect the prognosis of patients.@*CONCLUSION@#Ferroptosis-related genes change significantly during the pathogenesis of MM. The prognostic model of ferroptosis-related genes can be used to predict the survival of MM patients, but the mechanism of the potential function of ferroptosis-related genes needs to be confirmed by further clinical studies.

Zooming in and out of ferroptosis in human disease / 医学前沿

Ferroptosis is defined as an iron-dependent regulated form of cell death driven by lipid peroxidation. In the past decade, it has been implicated in the pathogenesis of various diseases that together involve almost every organ of the body, including various cancers, neurodegenerative diseases, cardiovascular diseases, lung diseases, liver diseases, kidney diseases, endocrine metabolic diseases, iron-overload-related diseases, orthopedic diseases and autoimmune diseases. Understanding the underlying molecular mechanisms of ferroptosis and its regulatory pathways could provide additional strategies for the management of these disease conditions. Indeed, there are an expanding number of studies suggesting that ferroptosis serves as a bona-fide target for the prevention and treatment of these diseases in relevant pre-clinical models. In this review, we summarize the progress in the research into ferroptosis and its regulatory mechanisms in human disease, while providing evidence in support of ferroptosis as a target for the treatment of these diseases. We also discuss our perspectives on the future directions in the targeting of ferroptosis in human disease.

Alda-1 alleviates brain injury after cardiopulmonary resuscitation by regulating acyl-CoA synthetase long-chain family member 4/glutathione peroxidase 4 pathway-mediated ferroptosis in swine / 中华危重病急救医学

OBJECTIVE@#To investigate whether the acetaldehyde dehydrogenase 2 specific activator, Alda-1, can alleviate brain injury after cardiopulmonary resuscitation (CPR) by inhibiting cell ferroptosis mediated by acyl-CoA synthetase long-chain family member 4/glutathione peroxidase 4 (ACSL4/GPx4) pathway in swine.@*METHODS@#Twenty-two conventional healthy male white swine were divided into Sham group (n = 6), CPR model group (n = 8), and Alda-1 intervention group (CPR+Alda-1 group, n = 8) using a random number table. The swine model of CPR was reproduced by 8 minutes of cardiac arrest induced by ventricular fibrillation through electrical stimulation in the right ventricle followed by 8 minutes of CPR. The Sham group only experienced general preparation. A dose of 0.88 mg/kg of Alda-1 was intravenously injected at 5 minutes after resuscitation in the CPR+Alda-1 group. The same volume of saline was infused in the Sham and CPR model groups. Blood samples were collected from the femoral vein before modeling and 1, 2, 4, 24 hours after resuscitation, and the serum levels of neuron specific enolase (NSE) and S100 β protein were determined by enzyme-linked immunosorbent assay (ELISA). At 24 hours after resuscitation, the status of neurologic function was evaluated by neurological deficit score (NDS). Thereafter, the animals were sacrificed, and brain cortex was harvested to measure iron deposition by Prussian blue staining, malondialdehyde (MDA) and glutathione (GSH) contents by colorimetry, and ACSL4 and GPx4 protein expressions by Western blotting.@*RESULTS@#Compared with the Sham group, the serum levels of NSE and S100β after resuscitation were gradually increased over time, and the NDS score was significantly increased, brain cortical iron deposition and MDA content were significantly increased, GSH content and GPx4 protein expression in brain cortical were significantly decreased, and ACSL4 protein expression was significantly increased at 24 hours after resuscitation in the CPR model and CPR+Alda-1 groups, which indicated that cell ferroptosis occurred in the brain cortex, and the ACSL4/GPx4 pathway participated in this process of cell ferroptosis. Compared with the CPR model group, the serum levels of NSE and S100 β starting 2 hours after resuscitation were significantly decreased in the CPR+Alda-1 group [NSE (μg/L): 24.1±2.4 vs. 28.2±2.1, S100 β (ng/L): 2 279±169 vs. 2 620±241, both P < 0.05]; at 24 hours after resuscitation, the NDS score and brain cortical iron deposition and MDA content were significantly decreased [NDS score: 120±44 vs. 207±68, iron deposition: (2.61±0.36)% vs. (6.31±1.66)%, MDA (μmol/g): 2.93±0.30 vs. 3.68±0.29, all P < 0.05], brain cortical GSH content and GPx4 expression in brain cortical was significantly increased [GSH (mg/g): 4.59±0.63 vs. 3.51±0.56, GPx4 protein (GPx4/GAPDH): 0.54±0.14 vs. 0.21±0.08, both P < 0.05], and ACSL4 protein expression was significantly decreased (ACSL4/GAPDH: 0.46±0.08 vs. 0.85±0.13, P < 0.05), which indicated that Alda-1 might alleviate brain cortical cell ferroptosis through regulating ACSL4/GPx4 pathway.@*CONCLUSIONS@#Alda-1 can reduce brain injury after CPR in swine, which may be related to the inhibition of ACSL4/GPx4 pathway mediated ferroptosis.

Mitochondrial aldehyde dehydrogenase 2 alleviates septic liver injury by inhibiting ferroptosis in mouse model / 中华危重病急救医学

OBJECTIVE@#To observe the ferroptosis triggered by in different pathways during cecal ligation and puncture (CLP)-induced liver injury in septic mice, and to investigate whether mitochondrial aldehyde dehydrogenase 2 (ALDH2) can alleviate sepsis-induced liver injury by inhibiting ferroptosis.@*METHODS@#Sixty 8-week-old male C57BL/6J mice were randomly divided into sham operation group (Sham group), CLP group, ferroptosis inhibitor ferrostain-1 (Fer-1) group, ALDH2-specific agonist Alda-1 group, iron chelator deferasirox Fe3+ chelate (DXZ) group and dimethyl sulfoxide (DMSO) group, with 10 mice in each group. The septic liver injury was induced by CLP in mice model. In the Sham group, only laparotomy was performed without ligation and puncture of the cecum. 10 mL/kg 5% DMSO, 5 mg/kg Fer-1, 50 mg/kg DXZ and 10 mg/kg Alda-1 were injected intraperitoneally 1 hour before CLP in the DMSO, Fer-1, DXZ and Alda-1 groups respectively. At 24 hours after operation, eyeball blood and liver tissue were collected from anesthetized mice. The hepatic structure and inflammatory infiltration were observed by hematoxylin-eosin (HE) staining. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in serum, the levels of hepatic malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen species (ROS) were detected. Western blotting was used to detect the protein expressions of ALDH2, ferroptosis-related proteins glutathione peroxidase 4 (GPX4), ferroptosis suppressor protein 1 (FSP1) and transferrin receptor 1 (TFR1) in liver tissue.@*RESULTS@#Compared with Sham group, the mice in CLP group showed varying degrees of congestion, disorganized hepatocyte arrangement, inflammatory cell infiltration at 24 hours after operation. Compared with the CLP group, the mice in the Fer-1 group, DXZ group and Alda-1 group liver morphology, liver injury and inflammatory cell infiltration was improved. Compared with Sham group, the serum levels of ALT and AST, the contents of MDA and ROS, and the expression of TFR1 protein in CLP group were significantly increased, while the activity of SOD and the expressions of ALDH2, GPX4 and FSP1 protein in CLP group were significantly decreased. Compared with CLP group, serum ALT and AST levels in Fer-1, DXZ and Alda-1 groups were significantly decreased [ALT (U/L): 45.76±10.81, 37.30±2.98, 36.40±12.75 vs. 73.06±12.20, AST (U/L): 61.57±2.69, 52.41±6.92, 56.05±8.29 vs. 81.59±5.46, all P < 0.05], and the contents of MDA, ROS and TFR1 protein expression in liver tissue were significantly decreased [MDA (μmol/L): 0.60±0.10, 0.57±0.18, 0.83±0.39 vs. 1.61±0.30, ROS (fluorescence intensity): 270.34±9.64, 276.02±62.33, 262.05±18.55 vs. 455.38±36.07, TFR1/GAPDH: 0.90±0.04, 1.01±0.09, 0.55±0.08 vs. 1.18±0.06, all P < 0.05], and the SOD activity and ALDH2, GPX4 and FSP1 protein expressions in liver tissue were significantly increased [SOD (kU/g): 88.77±8.20, 88.37±4.47, 93.43±7.24 vs. 50.27±3.57, ALDH2/GAPDH: 1.10±0.15, 1.02±0.07, 1.14±0.07 vs. 0.70±0.04, GPX4/GAPDH: 1.02±0.12, 0.99±0.08, 1.05±0.19 vs. 0.71±0.10, FSP1/GAPDH: 1.06±0.24, 1.02±0.08, 0.93±0.09 vs. 0.66±0.03, all P < 0.05]. There was no significant difference in the parameters between DMSO group and CLP group.@*CONCLUSIONS@#Both GPX4 and FSP1 mediated ferroptosis are involved in liver injury in septic mice. Activation of ALDH2 and inhibition of ferroptosis can alleviatehepatic injury. ALDH2 may play a protective role by regulating FSP1 and GPX4 mediated ferroptosis.

Activation of Yes-associated protein (YAP) improves mouse acute liver failure by alleviating ferroptosis / 细胞与分子免疫学杂志

Objective To investigate the effects of YAP on the occurrence and progression of acute liver failure by regulating the ferroptosis pathway and its underlying mechanism. Methods A total of 20 8-week-old C57BL/6 mice were randomly divided into four groups: a control group, an acute liver failure model group, a YAP agonist XMU-MP-1 treatment group and a YAP inhibitor verteporfin treatment group, five mice for each group. HE staining was used to observe the pathological changes of hepatic inflammation and necrosis. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were detected by liver biochemistry. Iron (Fe), malondialdehyde (MDA), glutathione (GSH) determination kits were used to measure their levels in liver tissues of each group. The changes of hepatocyte mitochondrial in each group were observed by electron microscopy. Real time PCR and Western blot analysis were used to detect the mRNA and protein expressions of YAP, glutathione peroxidase 4 (GPX4) and 5-lipoxygenase (5-LOX). Results Compared with the control group, mice in the acute liver failure model group and the YAP inhibitor verteporfin treatment group showed severe liver tissue congestion with inflammatory cell infiltration and structural damage to hepatic lobules. Liver injury was alleviated in the XMU-MP-1 treatment group. With the occurrence of liver failure, plasma ALT and AST levels significantly increased, and liver function was improved in XMU-MP-1 treatment group. Electron microscopy showed that mitochondria in hepatocytes of mice with liver failure became smaller and bilayer membrane density increased, while mitochondria changes in the XMU-MP-1 group were alleviated. In addition, the acute liver failure model group showed an increase in Fe and MDA contents, decreased protein expressions of GPX4, and enhanced expression of 5-LOX, suggesting that ferroptosis was involved in acute liver failure in C57BL/6 mice. Ferroptosis was inhibited by activation of YAP. Conclusion Activation of YAP may ameliorate liver injury by inhibiting ferroptosis.

Novel perspective in transplantation therapy of mesenchymal stem cells: targeting the ferroptosis pathway / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Ex vivo culture-amplified mesenchymal stem cells (MSCs) have been studied because of their capacity for healing tissue injury. MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells, but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period. Hence, strategies to increase the efficacy of MSC treatment are urgently needed. Iron overload, reactive oxygen species deposition, and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs, thereby hastening cell death. Notably, oxidative stress (OS) and deficient antioxidant defense induced by iron overload can result in ferroptosis. Ferroptosis may inhibit cell survival after MSC transplantation, thereby reducing clinical efficacy. In this review, we explore the role of ferroptosis in MSC performance. Given that little research has focused on ferroptosis in transplanted MSCs, further study is urgently needed to enhance the in vivo implantation, function, and duration of MSCs.

Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats / 中国中药杂志

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

Bisphenol A induces testicular oxidative stress in mice leading to ferroptosis / 亚洲男科学杂志(英文版)

Bisphenol A is a common environmental factor and endocrine disruptor that exerts a negative impact on male reproductive ability. By exploring bisphenol A-induced testicular cell death using the Institute of Cancer Research (ICR) mouse model, we found that a ferroptosis phenomenon may exist. Mice were divided into six groups and administered different doses of bisphenol A via intragastric gavage once daily for 45 consecutive days. Serum was then collected to determine the levels of superoxide dismutase and malondialdehyde. Epididymal sperm was also collected for semen analysis, and testicular tissue was collected for ferritin content determination, electron microscope observation of mitochondrial morphology, immunohistochemistry, real-time quantitative polymerase chain reaction, and western blot analysis. Exposure to bisphenol A was found to decrease sperm quality and cause oxidative damage, iron accumulation, and mitochondrial damage in the testes of mice. In addition, bisphenol A was confirmed to affect the expression of the ferroptosis-related genes, glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), cyclooxygenase 2 (COX2), and acyl-CoA synthetase 4 (ACSL4) in mouse testicular tissues. Accordingly, we speculate that bisphenol A induces oxidative stress, which leads to the ferroptosis of testicular cells. Overall, the inhibition of ferroptosis may be a potential strategy to reduce male reproductive toxicity caused by bisphenol A.

Acyl-CoA synthase ACSL4: an essential target in ferroptosis and fatty acid metabolism / 中华医学杂志(英文版)

Long-chain acyl-coenzyme A (CoA) synthase 4 (ACSL4) is an enzyme that esterifies CoA into specific polyunsaturated fatty acids, such as arachidonic acid and adrenic acid. Based on accumulated evidence, the ACSL4-catalyzed biosynthesis of arachidonoyl-CoA contributes to the execution of ferroptosis by triggering phospholipid peroxidation. Ferroptosis is a type of programmed cell death caused by iron-dependent peroxidation of lipids; ACSL4 and glutathione peroxidase 4 positively and negatively regulate ferroptosis, respectively. In addition, ACSL4 is an essential regulator of fatty acid (FA) metabolism. ACSL4 remodels the phospholipid composition of cell membranes, regulates steroidogenesis, and balances eicosanoid biosynthesis. In addition, ACSL4-mediated metabolic reprogramming and antitumor immunity have attracted much attention in cancer biology. Because it facilitates the cross-talk between ferroptosis and FA metabolism, ACSL4 is also a research hotspot in metabolic diseases and ischemia/reperfusion injuries. In this review, we focus on the structure, biological function, and unique role of ASCL4 in various human diseases. Finally, we propose that ACSL4 might be a potential therapeutic target.

Isoliquiritigenin induces HMOX1 and GPX4-mediated ferroptosis in gallbladder cancer cells / 中华医学杂志(英文版)

BACKGROUND@#Gallbladder cancer (GBC) is the most common malignant tumor of biliary tract. Isoliquiritigenin (ISL) is a natural compound with chalcone structure extracted from the roots of licorice and other plants. Relevant studies have shown that ISL has a strong anti-tumor ability in various types of tumors. However, the research of ISL against GBC has not been reported, which needs to be further investigated.@*METHODS@#The effects of ISL against GBC cells in vitro and in vivo were characterized by cytotoxicity test, RNA-sequencing, quantitative real-time polymerase chain reaction, reactive oxygen species (ROS) detection, lipid peroxidation detection, ferrous ion detection, glutathione disulphide/glutathione (GSSG/GSH) detection, lentivirus transfection, nude mice tumorigenesis experiment and immunohistochemistry.@*RESULTS@#ISL significantly inhibited the proliferation of GBC cells in vitro . The results of transcriptome sequencing and bioinformatics analysis showed that ferroptosis was the main pathway of ISL inhibiting the proliferation of GBC, and HMOX1 and GPX4 were the key molecules of ISL-induced ferroptosis. Knockdown of HMOX1 or overexpression of GPX4 can reduce the sensitivity of GBC cells to ISL-induced ferroptosis and significantly restore the viability of GBC cells. Moreover, ISL significantly reversed the iron content, ROS level, lipid peroxidation level and GSSG/GSH ratio of GBC cells. Finally, ISL significantly inhibited the growth of GBC in vivo and regulated the ferroptosis of GBC by mediating HMOX1 and GPX4 .@*CONCLUSION@#ISL induced ferroptosis in GBC mainly by activating p62-Keap1-Nrf2-HMOX1 signaling pathway and down-regulating GPX4 in vitro and in vivo . This evidence may provide a new direction for the treatment of GBC.

Research Progress of Nrf2 and Ferroptosis in Tumor Drug Resistance / 中国肺癌杂志

Lung cancer is one of the most common cancers in the world, and its treatment strategy is mainly surgery combined with radiotherapy and chemotherapy. However, long-term chemotherapy will result in drug resistance, which is also one of the difficulties in the treatment of lung cancer. Ferroptosis is an iron-dependent and lipid peroxidation-driven non-apoptotic cell death cascade, occurring when there is an imbalance of redox homeostasis in the cell. Nuclear factor erythroid 2-related factor 2 (Nrf2) is key for cellular antioxidant responses. Numerous studies suggest that Nrf2 assumes an extremely important role in regulation of ferroptosis, for its various functions in iron, lipid, and amino acid metabolism, and so on. In this review, a brief overview of the research progress of ferroptosis over the past decade will be presented. In particular, the mechanism of ferroptosis and the regulation of ferroptosis by Nrf2 will be discussed, as well as the role of the Nrf2 pathway and ferroptosis in tumor drug resistance, which will provide new research directions for the treatment of drug-resistant lung cancer patients.
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Mechanism of miR-186-5p Regulating PRKAA2 to Promote Ferroptosis in Lung Adenocarcinoma Cells / 中国肺癌杂志

BACKGROUND@#Lung adenocarcinoma (LUAD) is the most common type of non-small cell lung cancer, and any change of miRNAs expression will affect the degree of target regulation, thus affecting intracellular homeostasis. This study verified that miR-186-5p could inhibit the proliferation, migration and invasion of LUAD cells by regulating PRKAA2.@*METHODS@#Previous investigations found that the expression of miR-186-5p was markedly suppressed in LUAD. Bioinformatics method is used to predict the target protein related to ferroptosis downstream and inquire about its expression level in LUAD and its influence on the survival of patients. Double luciferase verified the binding site of PRKAA2 and miR-186-5p. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expression of PRKAA2. The effects of miR-186-5p of LUAD cells as well as the mechanism by which miR-186-5p inhibits Fer-1's sensitivity to ferroptosis were confirmed by EdU, Transwell, and scratch assays. The effect of miR-186-5p on the amount of reactive oxygen species (ROS) in LUAD cells was discovered using ROS experiment. Malondialdehyde (MDA) and glutathione (GSH) experiments were used to detect the effects of miR-186-5p and PRKAA2 on ferroptosis index of LUAD cells. The concentration of lipid ROS (L-ROS) in LUAD cells were measured using the L-ROS tests to determine the effects of miR-186-5p and PRKAA2.@*RESULTS@#The expression of PRKAA2 is up-regulated, and a high level of PRKAA2 expression was associated with a poor prognosis for patients with LUAD. Overexpression of miR-186-5p decreased the gene and protein expression of PRKAA2. By promoting ferroptosis, miR-186-5p overexpression prevented lung cancer cells from proliferating, invading, and migrating. ROS could be produced in higher amounts in LUAD cells due to miR-186-5p. Overexpression of miR-186-5p and knockdown PRKAA2 up-regulated MDA content and reduced GSH content in LUAD cells, respectively. miR-186-5p could increase the content of L-ROS and promote the ferroptosis sensitivity of LUAD cells by targeting PRKAA2.@*CONCLUSIONS@#miR-186-5p promotes ferroptosis of LUAD cells through targeted regulation of PRKAA2, thus inhibiting the proliferation, invasion and migration of LUAD.
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Pathogenesis of chronic heart failure in rats based on ferroptosis-mediated oxidative stress and intervention effect of Shenfu Injection / 中国中药杂志

This study aims to investigate the pathogenesis of chronic heart failure based on ferroptosis-mediated oxidative stress and predict the targets of Shenfu Injection in treating chronic heart failure. A rat model of chronic heart failure was established by the isoproterenol induction method. According to the random number table method, the modeled rats were assigned into three groups: a model group, a Shenfu Injection group, and a ferrostatin-1(ferroptosis inhibitor) group. In addition, a normal group was designed. After 15 days of intervention, the cardiac mass index and left ventricular mass index were determined. Echocardiography was employed to eva-luate the cardiac function. Hematoxylin-eosin staining and Masson staining were employed to reveal the pathological changes and fibrosis of the heart, and Prussian blue staining to detect the aggregation of iron ions in the myocardial tissue. Transmission electron microscopy was employed to observe the mitochondrion ultrastructure in the myocardial tissue. Colorimetry was adopted to measure the levels of iron metabolism, lipid peroxidation, and antioxidant indicators. Flow cytometry was employed to measure the content of lipid-reactive oxygen species(ROS) and the fluorescence intensity of ROS. Western blot and RT-qPCR were employed to determine the protein and mRNA levels, respectively, of ferroptosis-related factors in the myocardial tissue. The results showed that the rats in the model group had reduced cardiac function, elevated levels of total iron and Fe~(2+), lowered level of glutathione(GSH), increased malondialdehyde(MDA), decreased superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px), and rising levels of ROS and lipid-ROS. In addition, the model group showed fibrous tissue hyperplasia with inflammatory cell infiltration and myocardial fibrosis, iron ion aggregation, and characteristic mitochondrial changes specific for iron death. Moreover, the model group showcased upregulated protein and mRNA levels of p53 and COX2 and downregulated protein and mRNA levels of GPX4, FTH1, SLC7A11, and Nrf2 in the myocardial tissue. The intervention with Shenfu Injection significantly improved the cardiac function, recovered the iron metabolism, lipid peroxidation, and antioxidant indicators, decreased iron deposition, improved mitochondrial structure and function, and alleviated inflammatory cell infiltration and fibrosis. Furthermore, Shenfu Injection downregulated the mRNA and protein levels of p53 and COX2 and upregulated the mRNA and protein levels of GPX4, FTH1, SLC7A11, and Nrf2 in the myocardial tissue. Shenfu Injection can improve the cardiac function by regulating iron metabolism, inhibiting ferroptosis, and reducing oxidative stress injury.

Shenqi Dihuang Decoction inhibits high-glucose induced ferroptosis of renal tubular epithelial cells via Nrf2/HO-1/GPX4 pathway / 中国中药杂志

This study aims to explore the effects of Shenqi Dihuang Decoction on high-glucose induced ferroptosis and the nuclear factor erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)/glutathione peroxidase 4(GPX4) axis in human renal tubular epithelial cells(HK-2) and to clarify the underlying mechanism. The cell injury model was established by exposing HK-2 to high glucose, and the Shenqi Dihuang Decoction-medicated serum was prepared. The optimal concentration and intervention time of Shenqi Dihuang Decoction were determined. HK-2 were divided into normal, high glucose, and low-, medium-, and high-dose Shenqi Dihuang Decoction groups. After interventions, the cell proliferation rate in each group was determined and the cell morphology and mitochondrial ultrastructure were observed. Then, the levels of intracellular reactive oxygen species(ROS), ferrous ion(Fe~(2+)), glutathione(GSH), and malondialdehyde(MDA) and the protein levels of Nrf2, HO-1, GPX4, and xCT were measured. The optimal concentration and intervention time of Shenqi Dihuang Decoction-medicated serum were determined to be 10% and 24 h, respectively. Compared with the high glucose group, high-dose Shenqi Dihuang Decoction promoted the proliferation of HK-2. The cells in the low-, medium-, and high-dose Shenqi Dihuang Decoction groups presented tight arrangement, an increased cell count, improved morphology from a spindle-fiber shape to a cobblestone shape, and improved morphology and structure of mitochondrial membrane and cristae, compared with those in the high glucose group. Meanwhile, all the doses of Shenqi Dihuang Decoction inhibited ROS elevation to mitigate the peroxidation damage, lowered the Fe~(2+) and MDA levels and elevated the GSH level to inhibit lipid peroxidation, and activated the antioxidant pathway to upregulate the protein levels of Nrf2, HO-1, xCT, and GPX4. In conclusion, Shenqi Dihuang Decoction-medicated serum can inhibit high-glucose induced ferroptosis of HK-2 in vitro, which involves the antioxidant effect and the activation of the Nrf2/HO-1/GPX4 pathway.

Leonurine inhibits ferroptosis in renal tubular epithelial cells by activating p62/Nrf2/HO-1 signaling pathway / 中国中药杂志

To investigate the protective effect and the potential mechanism of leonurine(Leo) against erastin-induced ferroptosis in human renal tubular epithelial cells(HK-2 cells), an in vitro erastin-induced ferroptosis model was constructed to detect the cell viability as well as the expressions of ferroptosis-related indexes and signaling pathway-related proteins. HK-2 cells were cultured in vitro, and the effects of Leo on the viability of HK-2 cells at 10, 20, 40, 60, 80 and 100 μmol·L~(-1) were examined by CCK-8 assay to determine the safe dose range of Leo administration. A ferroptosis cell model was induced by erastin, a common ferroptosis inducer, and the appropriate concentrations were screened. CCK-8 assay was used to detect the effects of Leo(20, 40, 80 μmol·L~(-1)) and positive drug ferrostatin-1(Fer-1, 1, 2 μmol·L~(-1)) on the viability of ferroptosis model cells, and the changes of cell morphology were observed by phase contrast microscopy. Then, the optimal concentration of Leo was obtained by Western blot for nuclear factor erythroid 2-related factor 2(Nrf2) activation, and transmission electron microscope was further used to detect the characteristic microscopic morphological changes during ferroptosis. Flow cytometry was performed to detect reactive oxygen species(ROS), and the level of glutathione(GSH) was measured using a GSH assay kit. The expressions of glutathione peroxidase 4(GPX4), p62, and heme oxygenase 1(HO-1) in each group were quantified by Western blot. RESULTS:: showed that Leo had no side effects on the viability of normal HK-2 cells in the concentration range of 10-100 μmol·L~(-1). The viability of HK-2 cells decreased as the concentration of erastin increased, and 5 μmol·L~(-1) erastin significantly induced ferroptosis in the cells. Compared with the model group, Leo dose-dependently increased cell via-bility and improved cell morphology, and 80 μmol·L~(-1) Leo promoted the translocation of Nrf2 from the cytoplasm to the nucleus. Further studies revealed that Leo remarkably alleviated the characteristic microstructural damage of ferroptosis cells caused by erastin, inhibited the release of intracellular ROS, elevated GSH and GPX4, promoted the nuclear translocation of Nrf2, and significantly upregulated the expression of p62 and HO-1 proteins. In conclusion, Leo exerted a protective effect on erastin-induced ferroptosis in HK-2 cells, which might be associated with its anti-oxidative stress by activating p62/Nrf2/HO-1 signaling pathway.