ACSL4-Mediated Ferroptosis and Its Potential Role in Central Nervous System Diseases and Injuries

Ferroptosis meets microRNAs: A new frontier in anti-cancer therapy

Ferroptosis is an iron-dependent lipid peroxidation-mediated cell death. It is distinct from other types of cellular death and is recognized as a potential target for cancer therapy. This review discusses the mechanisms of ferroptosis, including its induction and inhibition pathways, its role in lipid metabolism, and its connection to various signaling pathways. We also explored the relationship between microRNAs and ferroptosis, highlighting the potential role of miRNAs targeting genes involved in ferroptosis. Role of miRNAs in metabolic reprogramming during carcinogenesis is well documented. We have discussed the role of miRNAs regulating expression of genes involved in iron metabolism, lipid metabolism, and redox metabolism which are associated with regulation of ferroptosis. In conclusion, we addressed various opportunities and challenges identified in ferroptosis research and its clinical implementation stressing the necessity of customized treatment plans based on each patient's unique vulnerability to the disease. Our article provides a complete overview of microRNAs and ferroptosis, with possible implications for cancer therapy.

The ameliorative effects of melatonin against BDE-47-induced hippocampal neuronal ferroptosis and cognitive dysfunction through Nrf2-Chaperone-mediated autophagy of ACSL4 degradation

Recent studies demonstrate that lipid peroxidation-induced ferroptosis participates in 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-evoked neurotoxicity and cognitive dysfunction. Melatonin has been indicated to confer neuroprotection against brain diseases via its potent anti-ferroptotic effects. Therefore, this study aims to explore whether melatonin can mitigate BDE-47-elicited cognitive impairment via suppressing ferroptosis, and further delineate the underlying mechanisms. Our results found that melatonin administration effectively inhibited BDE-47-induced ferroptosis in mice hippocampi and murine hippocampal neuronal HT-22 cells. Acyl-CoA synthetase long-chain family member 4 (ACSL4), a key lipid metabolism enzyme dictating ferroptosis sensitivity, accompanied by higher MDA and lipid reactive oxygen species (ROS), was remarkably increased under BDE-47 stress, while melatonin supplementation could suppress the elevated ACSL4 in vivo and in vitro. Furthermore, melatonin facilitated lysosomal ACSL4 degradation through enhancing lysosome-associated membrane protein type 2a (LAMP2a) expression and chaperone-mediated autophagy (CMA) activity, while LAMP2a knockdown abrogated the positive effects of melatonin on ACSL4 elimination in BDE-47-treated HT-22 cells. Moreover, nuclear factor erythroid 2-related factor 2 (Nrf2) activation by melatonin contributed to LAMP2a upregulation and CMA of ACSL4 and subsequent neuronal ferroptosis. Importantly, melatonin, CMA activator CA77.1, and ACSL4 inhibitor rosiglitazone (RSG) administration substantially attenuated neuronal/synaptic injury and cognitive deficits following BDE-47 exposure. Taken together, these findings revealed that melatonin could prevent BDE-47-provoked ferroptosis in the hippocampal neurons and mitigate cognitive dysfunction by facilitating ACSL4 degradation via Nrf2-chaperone-mediated autophagy. Therefore, melatonin might be a potential candidate for treating BDE-47-elicited neurotoxicity and neurobehavioral disorder.

Arsenic induces ferroptosis in HTR-8/SVneo cells and placental damage

Placenta ferroptosis has been proven to be associated with a variety of adverse pregnancy outcomes. Arsenic, a conventional metal noxious substance, has garnered considerable attention due to traversing the placental barrier. How arsenic induces placental ferroptosis and reproductive developmental toxicities remains largely unknown. Herein, we investigated the impact of sodium arsenite (As (III)) on iron homeostasis in the placenta through both in vivo and in vitro experiments by using HTR-8/SVneo cells and ICR pregnant mice. As (III) up-regulated the expression of genes or proteins associated with iron uptake (TFRC, DMT1), iron storage (FTH, FTL), ferritin autophagy (NCOA4), and heme degradation (HO-1), and induced cell iron overload. Additionally, accumulation of the lipid hydroperoxide malondialdehyde within cells was triggered by As (III) through inhibition of the Nrf2/GPX4 signal pathway, which resulted in cellular ferroptosis. Fer-1 effectively alleviated the suppression of GPX4 induced by As (III), reduced the accumulation of intracellular lipid peroxidation product MDA, and mitigated cellular ferroptosis. As (III) affected the iron homeostasis, as evidenced by the abnormal iron accumulation in the placenta. Placental structural abnormalities and hemorrhage may be the reason for As (III) causing placental injury and subsequent poor pregnancy outcomes. This study provides new insights into understanding the mechanisms by which As (III) produces placental damage and possible fetal developmental toxicity.

Solanum torvum induces ferroptosis to suppress hepatocellular carcinoma

ETHNOPHARMACOLOGICAL RELEVANCE

Solanum torvum Sw. (ST) is used to clear heat toxins, promote blood circulation, and alleviate blood stasis. Therefore, this plant has traditionally been used as an ethnomedicine for common cold, chronic gastritis, and tumors.

AIM OF THE STUDY

This study aimed to elucidate the mechanism by which ST induces ferroptosis in hepatocellular carcinoma (HCC), the combination effect with lenvatinib, and the impact on lenvatinib-resistant cells.

MATERIALS AND METHODS

Cell viability assays were performed using different hepatoma cell lines treated with ST. Lipid peroxidation and iron assays were performed using flow cytometry. Molecules involved in the ferroptosis pathway were detected by Western blotting. Finally, a lenvatinib-resistant cell line was established to evaluate the antiproliferative effects of ST.

RESULTS

ST ethanol extract inhibited the growth of various hepatoma cell lines. A significant reduction in glutathione peroxidase 4 (GPX4) expression was observed following ST treatment, which was accompanied by increased lipid peroxidation and Fe2+ accumulation. ST induced ferroptosis mainly through heme oxygenase-1 (HO-1) expression. HO-1 knockdown reduced ST-induced lipid peroxidation and reversed GPX4 suppression. Acyl-CoA synthetase long-chain family member 4 (ACSL4) also participated in ST-induced ferroptosis. ST and lenvatinib combination showed an additive effect, and ST retained its potential anti-HCC efficacy in a lenvatinib-resistant cell line.

CONCLUSION

This study demonstrated that the ethanol extract of ST inhibits hepatoma cell growth by inducing ferroptosis. ST displayed an additive effect with lenvatinib in Hep 3B cells and showed remarkable anti-HCC activity in lenvatinib-resistant Hep 3B cells. Collectively, the study shows that ST might have the potential to reduce lenvatinib use in clinical practice and salvage cases of lenvatinib resistance.

Chicoric acid acts as an ALOX15 inhibitor to prevent ferroptosis in asthma

BACKGROUND

Chicoric acid (CA) is a crucial immunologically active compound found in chicory and echinacea, possessing a range of biological activities. Ferroptosis, a type of iron-dependent cell death induced by lipid peroxidation, plays a key role in the development and advancement of asthma. Targeting ferroptosis could be a potential therapeutic strategy for treating asthma.

PURPOSE

The purpose of this study was to explore the screening of ALOX15, a pivotal target of ferroptosis in asthma, and potential therapeutic agents, as well as to investigate the promising potential of CA as an ALOX15 inhibitor for modulating ferroptosis in asthma.

METHODS

Through high-throughput data processing of bronchial epithelial RNA from asthma patients using bioinformatics and machine learning, the key target of ferroptosis in asthma, ALOX15, was identified. An inhibitor of ALOX15 was then obtained through high-throughput molecular docking and molecular dynamics simulation tests. In vitro experiments were conducted using a 16HBE cell model induced by house dust mite (HDM) and lipopolysaccharide (LPS), which were treated with the ALOX15 inhibitor (PD146176), CA treatment, or ALOX15 knockdown. In vivo experiments were also carried out using a mouse model induced by HDM and LPS.

RESULTS

The composite model of ALOX15 and CA in molecular dynamics simulations shows good stability and flexibility. Network pharmacological analysis reveals that CA regulates ferroptosis through ALOX15 in treating asthma. In vitro studies show that ALOX15 is highly expressed in HDM and LPS treatments, while CA inhibits HDM and LPS-induced ferroptosis in 16HBE cells by reducing ALOX15 expression. Knockdown of ALOX15 has the opposite effect. Metabolomics analysis identifies key compounds associated with ferroptosis, including L-Targinine, eicosapentaenoic acid, 16-hydroxy hexadecanoic acid, and succinic acid. In vivo experiments demonstrate that CA suppresses ALOX15 expression, inhibits ferroptosis, and improves asthma symptoms in mice.

CONCLUSION

Our research initially identified CA as a promising asthma treatment that effectively blocks ferroptosis by specifically targeting ALOX15. This study not only highlights CA as a potential therapeutic agent for asthma but also introduces novel targets and treatment options for this condition, along with innovative approaches for utilizing natural compounds to target diseases associated with ferroptosis.

Role of Hippo/ACSL4 axis in ferroptosis-induced pericyte loss and vascular dysfunction in sepsis

Sepsis is a critical condition characterized by a systemic inflammatory response to infection, often leading to severe vascular dysfunction and high mortality. One of the hallmarks of vascular dysfunction in sepsis is increased vascular permeability and the loss of pericytes, which are essential for maintaining vascular integrity. Despite the significance of pericyte loss in sepsis, the primary type of cell death responsible and the underlying molecular mechanisms remain incompletely understood. This study aims to elucidate these mechanisms by focusing on ferroptosis, a form of programmed cell death, and its regulation through the Hippo/ACSL4 axis. Our research confirmed significant pericyte loss in patients with sepsis. Through advanced single-cell analysis and proteomics, ferroptosis was identified as a key differentiating cell death type between sepsis and sham samples. Further metabolomics analysis revealed that Acyl-CoA Synthetase Long-Chain Family Member 4 (ACSL4) plays a pivotal role in the ferroptosis of pericytes during sepsis. In vitro experiments demonstrated that downregulation of ACSL4 effectively reduced lipopolysaccharide (LPS)-induced lipid peroxidation, restored pericyte viability, and improved endothelial permeability. In vivo studies with pericyte-specific ACSL4 knockout mice showed a marked decrease in pericyte loss and enhanced vascular barrier function following sepsis induction. To translate these findings into potential therapeutic strategies, we developed pericyte-targeting liposomes encapsulating ACSL4 shRNA adenovirus. These liposomes successfully restored pulmonary vascular barrier function and significantly reduced pericyte loss in septic conditions. The results of this study underscore the crucial role of ACSL4 in mediating ferroptosis in pericytes and highlight the therapeutic potential of targeting ACSL4 to mitigate vascular dysfunction in sepsis.

Analyzing the role of ferroptosis in ribosome-related bone marrow failure disorders: From pathophysiology to potential pharmacological exploitation

Within the last decade, the scientific community has witnessed the importance of ferroptosis as a novel cascade of molecular events leading to cellular decisions of death distinct from apoptosis and other known forms of cell death. Notably, such non- apoptotic and iron-dependent regulated cell death has been found to be intricately linked to several physiological processes as well as to the pathogenesis of various diseases. To this end, recent data support the notion that a potential molecular connection between ferroptosis and inherited bone marrow failure (IBMF) in individuals with ribosomopathies may exist. In this review, we suggest that in ribosome-related IBMFs the identified mutations in ribosomal proteins lead to changes in the ribosome composition of the hematopoietic progenitors, changes that seem to affect ribosomal function, thus enhancing the expression of some mRNAs subgroups while reducing the expression of others. These events lead to an imbalance inside the cell as some molecular pathways are promoted while others are inhibited. This disturbance is accompanied by ROS production and lipid peroxidation, while an additional finding in most of them is iron accumulation. Once lipid peroxidation and iron accumulation are the two main characteristics of ferroptosis, it is possible that this mechanism plays a key role in the manifestation of IBMF in this type of disease. If this molecular mechanism is further confirmed, new pharmacological targets such as ferroptosis inhibitors that are already exploited for the treatment of other diseases, could be utilized to improve the treatment of ribosomopathies.

Melatonin Attenuates Ferritinophagy/Ferroptosis by Acting on Autophagy in the Liver of an Autistic Mouse Model BTBR T+Itpr3tf/J

Autism spectrum disorders (ASDs) are a pool of neurodevelopment disorders in which social impairment is the main symptom. Presently, there are no definitive medications to cure the symptoms but the therapeutic strategies that are taken ameliorate them. The purpose of this study was to investigate the effects of melatonin (MLT) in treating ASDs using an autistic mouse model BTBR T+Itpr3tf/J (BTBR). We evaluated the hepatic cytoarchitecture and some markers of autophagy, ferritinophagy/ferroptosis, in BTBR mice treated and not-treated with MLT. The hepatic morphology and the autophagy and ferritinophagy/ferroptosis pathways were analyzed by histological, immunohistochemical, and Western blotting techniques. We studied p62 and microtubule-associated protein 1 light chain 3 B (LC3B) for evaluating the autophagy; nuclear receptor co-activator 4 (NCOA4) and long-chain-coenzyme synthase (ACSL4) for monitoring ferritinophagy/ferroptosis. The liver of BTBR mice revealed that the hepatocytes showed many cytoplasmic inclusions recognized as Mallory-Denk bodies (MDBs); the expression and levels of p62 and LC3B were downregulated, whereas ACSL4 and NCOA4 were upregulated, as compared to control animals. MLT administration to BTBR mice ameliorated liver damage and reduced the impairment of autophagy and ferritinophagy/ferroptosis. In conclusion, we observed that MLT alleviates liver damage in BTBR mice by improving the degradation of intracellular MDBs, promoting autophagy, and suppressing ferritinophagy/ferroptosis.

The Role of Fatty Acid Metabolism, the Related Potential Biomarkers, and Targeted Therapeutic Strategies in Gastrointestinal Cancers

Gastrointestinal cancer has emerged as a significant global health concern due to its high incidence and mortality, limited effectiveness of early detection, suboptimal treatment outcomes, and poor prognosis. Metabolic reprogramming is a prominent feature of cancer, and fatty acid metabolism assumes a pivotal role in bridging glucose metabolism and lipid metabolism. Fatty acids play important roles in cellular structural composition, energy supply, signal transduction, and other lipid-related processes. Changes in the levels of fatty acid metabolite may indicate the malignant transformation of gastrointestinal cells, which have an impact on the prognosis of patients and can be used as a marker to monitor the efficacy of anticancer therapy. Therefore, targeting key enzymes involved in fatty acid metabolism, either as monotherapy or in combination with other agents, is a promising strategy for anticancer treatment. This article reviews the potential mechanisms of fatty acid metabolism disorders in the occurrence and development of gastrointestinal tumors, and summarizes the related potential biomarkers and anticancer strategies.

Exploring the therapeutic potential of rabdoternin E in lung cancer treatment: Targeting the ROS/p38 MAPK/JNK signaling pathway

Lung cancer has the highest incidence and mortality rates of all cancer types in China and therefore represents a serious threat to human health. In the present study, the mechanism of rabdoternin E against the proliferation of the lung cancer cell line A549 was explored. It was found that rabdoternin E caused the accumulation of large amounts of reactive oxygen species (ROS), promoted cell S phase arrest by reducing the expression of CDK2 and cyclin A2, induced apoptosis by increasing the Bax/Bcl‑2 ratio and promoted the phosphorylation of proteins in the ROS/p38 MAPK/JNK signaling pathway, which is associated with apoptosis and ferroptosis. In addition, it was also found that Z‑VAD‑FMK (an apoptosis inhibitor), ferrostatin‑1 (ferroptosis inhibitor) and N‑acetylcysteine (a ROS inhibitor) could partially or greatly reverse the cytotoxicity of rabdoternin E to A549 cells. Similarly, NAC (N‑acetylcysteine) treatment notably inhibited the rabdoternin E‑stimulated p38 MAPK and JNK activation. Furthermore, in vivo experiments in mice revealed that Rabdoternin E markedly reduced tumor volume and weight and regulated the expression levels of apoptosis and ferroptosis‑related proteins (including Ki67, Bcl‑2, Bax, glutathione peroxidase 4, solute carrier family 7 member 11 and transferrin) in the tumor tissues of mice. Histopathological observation confirmed that the number of tumor cells decreased markedly after administration of rabdoternin E. Taken together, rabdoternin E induced apoptosis and ferroptosis of A549 cells by activating the ROS/p38 MAPK/JNK signaling pathway. Therefore, the results of the present study showed that rabdoternin E is not toxic to MCF‑7 cells (normal lung cells), had no significant effect on body weight and was effective and therefore may be a novel therapeutic treatment for lung cancer.

The role of glutathione peroxidase 4 in neuronal ferroptosis and its therapeutic potential in ischemic and hemorrhagic stroke

Ferroptosis is a type of cell death that depends on iron and is driven by lipid peroxidation, playing a crucial role in neuronal death during stroke. A central element in this process is the inactivation of glutathione peroxidase 4 (GPx4), an antioxidant enzyme that helps maintain redox balance by reducing lipid hydroperoxides. This review examines the critical function of GPx4 in controlling neuronal ferroptosis following ischemic and hemorrhagic stroke. We explore the mechanisms through which GPx4 becomes inactivated in various stroke subtypes. In strokes, excess glutamate depletes glutathione (GSH) and products of hemoglobin breakdown overwhelm GPx4. Studies using genetic models with GPx4 deficiency underscore its vital role in maintaining neuronal survival and function. We also consider new therapeutic approaches to enhance GPx4 activity, including novel small molecule activators, adjustments in GSH metabolism, and selenium supplementation. Additionally, we outline the potential benefits of combining these GPx4-focused strategies with other anti-ferroptotic methods like iron chelation and lipoxygenase inhibition for enhanced neuroprotection. Furthermore, we highlight the significance of understanding the timing of GPx4 inactivation during stroke progression to design effective therapeutic interventions.

Loss of AR-regulated AFF3 contributes to prostate cancer progression and reduces ferroptosis sensitivity by downregulating ACSL4 based on single-cell sequencing analysis

Prostate cancer (PCa) is one of the most common cancers affecting the health of men worldwide. Castration-resistant prostate cancer (CRPC), the advanced and refractory phase of prostate cancer, has multiple mechanisms of resistance to androgen deprivation therapy (ADT) such as AR mutations, aberrant androgen synthase, and abnormal expression of AR-related genes. Based on the research of the AR pathway, new drugs for the treatment of CRPC have been developed in clinical practice, such as Abiraterone and enzalutamide. However, many areas in this pathway are still worth exploring. In this study, single-cell sequencing analysis was utilized to scrutinize significant genes in the androgen receptor (AR) pathway related to CRPC. Our analysis of single-cell sequencing combined with bulk-cell sequencing revealed a substantial downregulation of AR-regulated AFF3 in CRPC. Overexpression of AFF3 restricted the proliferation and migration of prostate cancer cells whilst also increasing their sensitivity towards enzalutamide, while knockdown of AFF3 had the opposite effect. To elucidate the mechanism of tumor inhibition by AFF3, we applied GSVA and GSEA to investigate the metabolic pathways related to AFF3 and revealed that AFF3 had an impact on fatty acids metabolism and ferroptosis through the regulation of ACSL4 protein expression. Based on correlation analysis and flow cytometry, we can speculate that AFF3 can impact the sensitivity of the CRPC cell lines to the ferroptosis inducer (RSL3) by regulating ACSL4. Therefore, our findings may provide new insights into the mechanisms of drug resistance in CRPC, and AFF3 may serve as a novel prognostic biomarker in prostate cancer.

Emerging insights: miRNA modulation of ferroptosis pathways in lung cancer

The newly discovered programmed iron-dependent necrosis, ferroptosis, is a novel pathway that is controlled by iron-dependent lipid peroxidation and cellular redox changes. It can be triggered intrinsically by low antioxidant enzyme activity or extrinsically by blocking amino acid transporters or activating iron transporters. The induction of ferroptosis involves the activation of specific proteins, suppression of transporters, and increased endoplasmic reticulum (ER) stress (a condition in which the ER, a crucial organelle involved in protein folding and processing, becomes overwhelmed by an accumulation of misfolded or unfolded proteins. This situation disrupts the normal functioning of the ER, leading to a cellular stress response known as the unfolded protein response), leading to lipid peroxidation byproduct accumulation and toxic reactive oxygen species (ROS), which are highly reactive molecules derived from diatomic oxygen and include various forms such as superoxide (O₂⁻), hydroxyl radicals (•OH), and hydrogen peroxide (H₂O₂). Ferroptosis is closely associated with signaling molecules in lung cancer, including epidermal growth factor receptor (EGFR), mitogen-activated protein kinase (MAPK), hypoxia-inducible factor 1-alpha (HIF-1α), and P53, and is regulated by epigenetic factors such as microRNAs (miRNAs). miRNAs are small non-coding RNA molecules that regulate gene expression by binding to target messenger RNAs (mRNAs), leading to translational repression or degradation. Several miRNAs have been found to modulate ferroptosis by targeting key genes involved in iron metabolism, lipid peroxidation, and antioxidant defense pathways. The research on ferroptosis has expanded to target its role in lung cancer treatment and resistance prevention. This review encapsulates the significance of ferroptosis in lung cancer. Understanding the mechanisms and implications of ferroptosis in lung cancer cells may lead to targeted therapies exploiting cancer cell vulnerabilities to ferroptosis Also, improving treatment outcomes, and overcoming resistance.

Rosiglitazone retards the progression of iron overload-induced osteoarthritis by impeding chondrocyte ferroptosis

Ferroptosis is implicated in several diseases, including iron overload-induced osteoarthritis (IOOA), which is marked by oxidative stress, iron imbalance, and lipid peroxidation. Given rosiglitazone's (RSG) ability to inhibit lipid peroxidation and ferroptosis, this study aims to assess its therapeutic potential for treating IOOA. Our in vitro results show that RSG targets acyl-CoA synthetase long-chain family member 4 to mitigate impairments induced by interleukin-1 beta and ferric ammonium citrate, including cell apoptosis, senescence, inflammatory responses, extracellular matrix degradation, and ferroptosis. RSG reduced intracellular iron content, alleviated oxidative stress and lipid peroxidation, mitigated damage to membrane-bound organelles, and enhanced glucose transport. Additionally, pre-treatment with RSG imparted anti-ferroptotic properties to chondrocytes. In vivo, RSG alleviated cartilage degradation, inflammatory responses, and ferroptosis in mice with IOOA. In conclusion, RSG exhibits chondroprotective and anti-ferroptotic effects by suppressing lipid peroxidation and restoring iron homeostasis, highlighting its potential for treating IOOA.

Mechanisms of ferroptosis and the relationship between ferroptosis and ER stress after JEV and HSV infection

Ferroptosis is a novel form of programmed cell death, which is different from apoptosis, pyroptosis and autophagy in morphology and biochemistry. Ferroptosis is characterized by condensed mitochondrial membrane densities, vanished of mitochondria crista and outer membrane rupture in morphology, and the accumulation of intracellular iron, lipid peroxidation (LPO), decrease of GSH and inhibition of GPX4 in biochemistry. Japanese encephalitis virus (JEV) and Herpes simplex virus (HSV) are both common neurotropic viruses that can cause neurological disorders, such as severe encephalitis. JEV and HSV have been demonstrated to be able to induce ferroptosis. This process is closely related to the inhibition of the GSH-GPX4 system, ACSL4 phosphorylation, and Nrf2 ubiquitination. In this review, we summarized the mechanisms by which JEV and HSV induced ferroptosis in the current study. In addition, we found a strong relationship between endoplasmic reticulum (ER) stress and ferroptosis, and we therefore speculated that sustained ER stress might be a prerequisite for ferroptosis in JEV and HSV-induced diseases.

Ferroptosis in radiation-induced brain injury: roles and clinical implications

Radiation-induced brain injury (RBI) presents a significant challenge for patients undergoing radiation therapy for head, neck, and intracranial tumors. This review aims to elucidate the role of ferroptosis in RBI and its therapeutic implications. Specifically, we explore how ferroptosis can enhance the sensitivity of tumor cells to radiation while also examining strategies to mitigate radiation-induced damage to normal brain tissues. By investigating the mechanisms through which radiation increases cellular reactive oxygen species (ROS) and initiates ferroptosis, we aim to develop targeted therapeutic strategies that maximize treatment efficacy and minimize neurotoxicity. The review highlights key regulatory factors in the ferroptosis pathway, including glutathione peroxidase 4 (GPX4), cystine/glutamate antiporter system Xc- (System Xc-), nuclear factor erythroid 2-related factor 2 (NRF2), Acyl-CoA synthetase long-chain family member 4 (ACSL4), and others, and their interactions in the context of RBI. Furthermore, we discuss the clinical implications of modulating ferroptosis in radiation therapy, emphasizing the potential for selective induction of ferroptosis in tumor cells and inhibition in healthy cells. The development of advanced diagnostic tools and therapeutic strategies targeting ferroptosis offers a promising avenue for enhancing the safety and efficacy of radiation therapy, underscoring the need for further research in this burgeoning field.

Evaluation of Known Markers of Ferroptosis in Semen of Patients with Different Reproductive Pathologies and Fertile Men

This study aims to investigate the role of ferroptosis, an iron-dependent form of regulated cell death, in male infertility. The motivation behind this research stems from the increasing recognition of oxidative stress and iron metabolism dysregulation as critical factors in male reproductive health. In this study, 28 infertile patients (grouped by the presence of urogenital infections or varicocele) and 19 fertile men were selected. Spermiograms were performed by light microscopy (WHO, 2021). Testosterone, ferritin, transferrin-bound iron, transferrin, and F2-isoprostanes (F2-IsoPs) were detected in seminal plasma. Glutathione peroxidase 4 (GPX4) and acyl coenzyme A synthetase long chain family member 4 (ACSL4) were also assessed in sperm cells using enzyme-linked immunosorbent assays (ELISA). All the variables were correlated (statistically significant Spearman's rank correlations) in the whole population, and then the comparison between variables of the different groups of men were carried out. Seminal ferritin and transferrin positively correlated with seminal F2-IsoPs, which had positive correlations with ACSL4 detected in sperm cells. Ferritin and ACSL4 negatively correlated with the seminal parameters. No correlation was detected for GPX4. Comparing the variables in the three examined groups, elevated levels of ACSL4 were observed in infertile patients with urogenital infections and varicocele; GPX4 levels were similar in the three groups. These results suggested a mechanism of ferroptosis, identified by increased ACSL4 levels and the occurrence of lipid peroxidation. Such events appear to be GPX4-independent in reproductive pathologies such as varicocele and urogenital infections.

Both Maternal High-Fat and Post-Weaning High-Carbohydrate Diets Increase Rates of Spontaneous Hepatocellular Carcinoma in Aged-Mouse Offspring

Both maternal obesity and postnatal consumption of obesogenic diets contribute to the development of metabolic dysfunction-associated steatotic liver disease (MASLD) and hepatocellular carcinoma (HCC). However, there is no consensus as to whether diets that are high in fat or carbohydrates/sugars differentially influence the development of HCC. Moreover, the long-term effects of prenatal HF exposure on HCC and whether this is influenced by postnatal diet has not yet been evaluated. C57BL/6 dams were fed either a low-fat, high-carbohydrate control (C) or low-carbohydrate, high-fat (HF) diet. At weaning, male and female offspring were fed the C or HF diet, generating four diet groups: C/C, C/HF, HF/C and HF/HF. Tissues were collected at 16 months of age and livers were assessed for MASLD and HCC. Glucose regulation and pancreatic morphology were also evaluated. Liver tissues were assessed for markers of glycolysis and fatty acid metabolism and validated using a human HCC bioinformatic database. Both C/HF and HF/HF mice developed obesity, hyperinsulinemia and a greater degree of MASLD than C/C and HF/C offspring. However, despite significant liver and pancreas pathology, C/HF mice had the lowest incidence of HCC while tumour burden was highest in HF/C male offspring. The molecular profile of HCC mouse samples suggested an upregulation of the pentose phosphate pathway and a downregulation of fatty acid synthesis and oxidation, which was largely validated in the human dataset. Both pre-weaning HF diet exposure and post-weaning consumption of a high-carbohydrate diet increased the risk of developing spontaneous HCC in aged mice. However, the influence of pre-weaning HF feeding on HCC development appeared to be stronger in the context of post-weaning obesity. As rates of maternal obesity continue to rise, this has implications for the future incidence of HCC and possible dietary manipulation of offspring carbohydrate intake to counteract this risk.

Tetramethylpyrazine alleviates ferroptosis and promotes functional recovery in spinal cord injury by regulating GPX4/ACSL4

OBJECTIVE

Tetramethylpyrazine (TMP) has been demonstrated to alleviate neuronal ferroptosis following spinal cord injury (SCI), thereby promoting neural repair. However, the precise underlying mechanisms remain elusive.

METHODS

The SCI model was established using a modified version of Allen's method. TMP (40, 80, 120, and 160 mg/kg) and ras-selective lethal 3 (RSL3) (5 mg/kg) were administered intraperitoneally once daily for 7 days. HE and Nissl staining were employed to examine histomorphology and neurons, respectively. Perls staining was used to identify the distribution of iron. A transmission electron microscope was used to observe the microcosmic morphology of mitochondria. Immunofluorescence staining and Western blot were used to analyze neuronal nuclear protein (NeuN) and glial fibrillary acidic protein (GFAP) surrounding injury sites. Additionally, glutathione peroxidase 4 (GPX4)/NeuN + cells and acyl-CoA synthetase long-chain family member 4 (ACSL4)/NeuN + cells were observed. RT-qPCR was conducted to examine the mRNA expression levels of GPX4 and ACSL4. ELISA were used to quantify the concentrations of GPX4, reactive oxygen species (ROS), L-glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD), and tissue iron.

RESULTS

TMP had an inhibitory effect on the concentrations of tissue iron, ROS, GSH, MDA, and SOD. TMP improved the microcosmic morphology of mitochondria and increased GPX4 level while decreasing that of ACSL4. TMP reduced lesion sizes, enhanced neuronal survival, and inhibited glial scar formation. However, the effect of TMP can be effectively reversed by RSL3.

CONCLUSION

TMP alleviates neuronal ferroptosis by regulating the GPX4/ACSL4 axis, thereby protecting the remaining neurons surrounding injury sites and reducing glial scar formation.

ALKBH5 targets ACSL4 mRNA stability to modulate ferroptosis in hyperbilirubinemia-induced brain damage

Bilirubin-induced brain damage is a serious clinical consequence of hyperbilirubinemia, yet the underlying molecular mechanisms remain largely unknown. Ferroptosis, an iron-dependent cell death, is characterized by iron overload and lipid peroxidation. Here, we report a novel regulatory mechanism of demethylase AlkB homolog 5 (ALKBH5) in acyl-coenzyme A synthetase long-chain family member 4 (ACSL4)-mediated ferroptosis in hyperbilirubinemia. Hyperdifferential PC12 cells and newborn Sprague-Dawley rats were used to establish in vitro and in vivo hyperbilirubinemia models, respectively. Proteomics, coupled with bioinformatics analysis, first suggested the important role of ferroptosis in hyperbilirubinemia-induced brain damage. In vitro experiments showed that ferroptosis is activated in hyperbilirubinemia, and ferroptosis inhibitors (desferrioxamine and ferrostatin-1) treatment effectively alleviates hyperbilirubinemia-induced oxidative damage. Notably, we observed that the ferroptosis in hyperbilirubinemia was regulated by m6A modification through the downregulation of ALKBH5 expression. MeRIP-seq and RIP-seq showed that ALKBH5 may trigger hyperbilirubinemia ferroptosis by stabilizing ACSL4 mRNA via m6A modification. Further, hyperbilirubinemia-induced oxidative damage was alleviated through ACSL4 genetic knockdown or rosiglitazone-mediated chemical repression but was exacerbated by ACSL4 overexpression. Mechanistically, ALKBH5 promotes ACSL4 mRNA stability and ferroptosis by combining the 669 and 2015 m6A modified sites within 3' UTR of ACSL4 mRNA. Our findings unveil a novel molecular mechanism of ferroptosis and suggest that m6A-dependent ferroptosis could be an underlying clinical target for the therapy of hyperbilirubinemia.

NAD(P)H-quinone oxidoreductase 1 induces complicated effects on mitochondrial dysfunction and ferroptosis in an expression level-dependent manner

NAD(P)H-quinone oxidoreductase 1 (NQO1) is an essential redox enzyme responsible for redox balance and energy metabolism. Despite of its importance, the brain contains high capacity of polyunsaturated fatty acids and maintains low levels of NQO1 expression. In this study, we examined how levels of NQO1 expression affects cell survival in response to toxic insults causing mitochondrial dysfunction and ferroptosis, and whether NQO1 has a potential as a biomarker in different stressed conditions. Following treatment with rotenone, overexpressed NQO1 in SH-SY5Y cells improved cell survival by reducing mitochondrial reductive stress via increased NAD+ supply without mitochondrial biogenesis. However, NQO1 overexpression boosted lipid peroxidation following treatment with RSL3 and erastin. A lipid droplet staining assay showed increased lipid droplets in cells overexpressing NQO1. In contrast, NQO1 knockdown protected cells against ferroptosis by increasing GPX4, xCT, and the GSH/GSSG system. Also, NQO1 knockdown showed lower iron contents and lipid droplets than non-transfectants and cells overexpressing NQO1, even though it could not attenuate cell death when exposed to rotenone. In summary, our study suggests that different NQO1 levels may have advantages and disadvantages depending on the surrounding environments. Thus, regulating NQO1 expression could be a potential supplementary tool when treating neuronal diseases.

E3 ligases and DUBs target ferroptosis: A potential therapeutic strategy for neurodegenerative diseases

Ferroptosis is a form of cell death mediated by iron and lipid peroxidation (LPO). Recent studies have provided compelling evidence to support the involvement of ferroptosis in the pathogenesis of various neurodegenerative diseases (NDDs), such as Alzheimer's disease (AD), Parkinson's disease (PD). Therefore, understanding the mechanisms that regulate ferroptosis in NDDs may improve disease management. Ferroptosis is regulated by multiple mechanisms, and different degradation pathways, including autophagy and the ubiquitinproteasome system (UPS), orchestrate the complex ferroptosis response by directly or indirectly regulating iron accumulation or lipid peroxidation. Ubiquitination plays a crucial role as a protein posttranslational modification in driving ferroptosis. Notably, E3 ubiquitin ligases (E3s) and deubiquitinating enzymes (DUBs) are key enzymes in the ubiquitin system, and their dysregulation is closely linked to the progression of NDDs. A growing body of evidence highlights the role of ubiquitin system enzymes in regulating ferroptosis sensitivity. However, reports on the interaction between ferroptosis and ubiquitin signaling in NDDs are scarce. In this review, we first provide a brief overview of the biological processes and roles of the UPS, summarize the core molecular mechanisms and potential biological functions of ferroptosis, and explore the pathophysiological relevance and therapeutic implications of ferroptosis in NDDs. In addition, reviewing the roles of E3s and DUBs in regulating ferroptosis in NDDs aims to provide new insights and strategies for the treatment of NDDs. These include E3- and DUB-targeted drugs and ferroptosis inhibitors, which can be used to prevent and ameliorate the progression of NDDs.

A New Perspective in the Treatment of Ischemic Stroke: Ferroptosis

Ischemic stroke is a common neurological disease. Currently, there are no Food and Drug Administration-approved drugs that can maximize the improvement in ischemic stroke-induced nerve damage. Hence, treating ischemic stroke remains a clinical challenge. Ferroptosis has been increasingly studied in recent years, and it is closely related to the pathophysiological process of ischemic stroke. Iron overload, reactive oxygen species accumulation, lipid peroxidation, and glutamate accumulation associated with ferroptosis are all present in ischemic stroke. This article focuses on describing the relationship between ferroptosis and ischemic stroke and summarizes the relevant substances that ameliorate ischemic stroke-induced neurological damage by inhibiting ferroptosis. Finally, the problems in the treatment of ischemic stroke targeting ferroptosis are discussed, hoping to provide a new direction for its treatment.

Sodium aescinate induces renal toxicity by promoting Nrf2/GPX4-mediated ferroptosis

Sodium aescinate (SA) is extracted from Aesculus wilsonii Rehd seeds and was first marketed as a medicament in German. With the wide application of SA in clinical practice, reports of adverse drug reactions and adverse events have gradually increased, including renal impairment. However, the pathogenic mechanisms of SA have not yet been fully elucidated. The toxic effects and underlying mechanisms of SA were explored in this study. Our data showed that SA significantly elevated the levels of blood urea nitrogen (BUN), serum creatinine (Scr) and Kidney injury molecule 1 (Kim-1), accompanied by pathologically significant changes in renal tissue. SA induced NRK-52E cell death and disrupted the integrity of the cell membrane. Moreover, SA caused significant reductions in FTH, Nrf2, xCT, GPX4, and FSP1 levels, but increased TFR1 and ACSL4 levels. SA decreased glutathione peroxidase (GPx), glutathione (GSH) and cysteine (Cys) levels, but improved Fe2+, malondialdehyde (MDA), reactive oxygen species (ROS) and lipid peroxidation levels, ultimately leading to the induction of ferroptosis. Importantly, inhibition of ferroptosis or activation of the Nrf2/GPX4 pathway prevented SA-induced nephrotoxicity. These findings indicated that SA induced oxidative damage and ferroptosis-mediated kidney injury by suppressing the Nrf2/GPX4 axis activity.

Antioxidant Systems as Modulators of Ferroptosis: Focus on Transcription Factors

Ferroptosis is a type of programmed cell death that differs from apoptosis, autophagy, and necrosis and is related to several physio-pathological processes, including tumorigenesis, neurodegeneration, senescence, blood diseases, kidney disorders, and ischemia-reperfusion injuries. Ferroptosis is linked to iron accumulation, eliciting dysfunction of antioxidant systems, which favor the production of lipid peroxides, cell membrane damage, and ultimately, cell death. Thus, signaling pathways evoking ferroptosis are strongly associated with those protecting cells against iron excess and/or lipid-derived ROS. Here, we discuss the interaction between the metabolic pathways of ferroptosis and antioxidant systems, with a particular focus on transcription factors implicated in the regulation of ferroptosis, either as triggers of lipid peroxidation or as ferroptosis antioxidant defense pathways.

Identification of Novel Biomarkers for Alzheimer's Disease and Related Dementias Using Unbiased Plasma Proteomics

Alzheimer's disease (AD) and related dementias (ADRD) is a complex disease with multiple pathophysiological drivers that determine clinical symptomology and disease progression. These diseases develop insidiously over time, through many pathways and disease mechanisms and continue to have a huge societal impact for affected individuals and their families. While emerging blood-based biomarkers, such as plasma p-tau181 and p-tau217, accurately detect Alzheimer neuropthology and are associated with faster cognitive decline, the full extension of plasma proteomic changes in ADRD remains unknown. Earlier detection and better classification of the different subtypes may provide opportunities for earlier, more targeted interventions, and perhaps a higher likelihood of successful therapeutic development. In this study, we aim to leverage unbiased mass spectrometry proteomics to identify novel, blood-based biomarkers associated with cognitive decline. 1,786 plasma samples from 1,005 patients were collected over 12 years from partcipants in the Massachusetts Alzheimer's Disease Research Center Longitudinal Cohort Study. Patient metadata includes demographics, final diagnoses, and clinical dementia rating (CDR) scores taken concurrently. The Proteograph™ Product Suite (Seer, Inc.) and liquid-chromatography mass-spectrometry (LC-MS) analysis were used to process the plasma samples in this cohort and generate unbiased proteomics data. Data-independent acquisition (DIA) mass spectrometry results yielded 36,259 peptides and 4,007 protein groups. Linear mixed effects models revealed 138 differentially abundant proteins between AD and healthy controls. Machine learning classification models for AD diagnosis identified potential candidate biomarkers including MBP, BGLAP, and APoD. Cox regression models were created to determine the association of proteins with disease progression and suggest CLNS1A, CRISPLD2, and GOLPH3 as targets of further investigation as potential biomarkers. The Proteograph workflow provided deep, unbiased coverage of the plasma proteome at a speed that enabled a cohort study of almost 1,800 samples, which is the largest, deep, unbiased proteomics study of ADRD conducted to date.

m6A methylation-mediated PGC-1α contributes to ferroptosis via regulating GSTK1 in arsenic-induced hepatic insulin resistance

Arsenic exposure has been closely linked to hepatic insulin resistance (IR) and ferroptosis with the mechanism elusive. Peroxisome proliferator γ-activated receptor coactivator 1-α (PGC-1α) is essential for glucose metabolism as well as for the production of reactive oxygen species (ROS). However, it was unclear whether there is a regulatory connection between PGC-1α and ferroptosis. Besides, the definitive mechanism of arsenic-induced hepatic IR progression remains to be determined. Here, we found that hepatic insulin sensitivity impaired by sodium arsenite (NaAsO2) could be reversed by inhibiting ferroptosis. Mechanistically, we found that PGC-1α suppression inhibited the protein expression of glutathione s-transferase kappa 1 (GSTK1) via nuclear respiratory factor 1 (NRF1), thereby increasing ROS accumulation and promoting ferroptosis. Furthermore, we showed that NaAsO2 induced hepatic IR and ferroptosis via methyltransferase-like 14 (METTL14) and YTH domain-containing family protein 2 (YTHDF2)-mediated N6-methyladenosine (m6A) of PGC-1α mRNA. In conclusion, NaAsO2-mediated PGC-1α suppression was m6A methylation-dependent and induced ferroptosis via the PGC-1α/NRF1/GSTK1 pathway in hepatic IR. The data might provide insight into potential targets for diabetes prevention and treatment.

Ferroptosis contributes to hemolytic hyperbilirubinemia‑induced brain damage in vivo and in vitro

Ferroptosis is driven by iron‑dependent accumulation of lipid hydroperoxides, and hemolytic hyperbilirubinemia causes accumulation of unconjugated bilirubin and iron. The present study aimed to assess the role of ferroptosis in hemolytic hyperbilirubinemia‑induced brain damage (HHIBD). Rats were randomly divided into the control, phenylhydrazine (PHZ) and deferoxamine (DFO) + PHZ groups, with 12 rats in each group. Ferroptosis‑associated biochemical and protein indicators were measured in the brain tissue of rats. We also performed tandem mass tag‑labeled proteomic analysis. The levels of iron and malondialdehyde were significantly higher and levels of glutathione (GSH) and superoxide dismutase activity significantly lower in the brain tissues of the PHZ group compared with those in the control group. HHIBD also resulted in significant increases in the expression of the ferroptosis‑related proteins acyl‑CoA synthetase long‑chain family member 4, ferritin heavy chain 1 and transferrin receptor and divalent metal transporter 1, as well as a significant reduction in the expression of ferroptosis suppressor protein 1. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis demonstrated that the differentially expressed proteins of rat brain tissues between the control and PHZ groups were significantly involved in ferroptosis, GSH metabolism and fatty acid biosynthesis pathways. Pretreatment with DFO induced antioxidant activity and alleviated lipid peroxidation‑mediated HHIBD. In addition, PC12 cells treated with ferric ammonium citrate showed shrinking mitochondria, high mitochondrial membrane density, and increased lipid reactive oxygen species and intracellular ferrous iron, which were antagonized by pretreatment with ferrostatin‑1 or DFO, which was reversed by pretreatment with ferrostatin‑1 or DFO. The present study demonstrated that ferroptosis is involved in HHIBD and provided novel insights into candidate proteins that are potentially involved in ferroptosis in the brain during hemolytic hyperbilirubinemia.