GPX4 at the Crossroads of Lipid Homeostasis and Ferroptosis

Induction of ferroptosis and apoptosis in endometrial cancer cells by dihydroisotanshinone I

Danshen, also known as Salvia miltiorrhiza, is a medicinal herb used in traditional Chinese medicine. Its potential impact on endometrial cancer has not been thoroughly investigated. This study aimed to examine the effect of dihydroisotanshinone I (DT), a compound found in Danshen, on the viability of ARK1 and ARK2 endometrial cancer cells and its mechanisms. The results showed that 10 μM DT inhibited cell viability of ARK1 and ARK2 cells by inducing apoptosis and ferroptosis, which was achieved by blocking the expression of GPX4. In vivo experiments using a xenograft nude mouse model indicated that DT treatment significantly reduced tumor volume without causing any adverse effects. These findings suggest that DT may be a potential therapeutic agent for inhibiting endometrial cancer cell viability, but further research is needed to confirm these results.

Targeting fatty acid uptake and metabolism in cancer cells: A promising strategy for cancer treatment

Despite scientific development, cancer is still a fatal disease. The development of cancer is thought to be significantly influenced by fatty acids. Several mechanisms that control fatty acid absorption and metabolism are reported to be altered in cancer cells to support their survival. Cancer cells can use de novo synthesis or uptake of extracellular fatty acid if one method is restricted. This factor makes it more difficult to target one pathway while failing to treat the disease properly. Side effects may also arise if several inhibitors simultaneously target many targets. If a viable inhibitor could work on several routes, the number of negative effects might be reduced. Comparative investigations against cell viability have found several potent natural and manmade substances. In this review, we discuss the complex roles that fatty acids play in the development of tumors and the progression of cancer, newly discovered and potentially effective natural and synthetic compounds that block the uptake and metabolism of fatty acids, the adverse side effects that can occur when multiple inhibitors are used to treat cancer, and emerging therapeutic approaches.

Rhein attenuates cerebral ischemia-reperfusion injury via inhibition of ferroptosis through NRF2/SLC7A11/GPX4 pathway

BACKGROUND

Ischemic stroke, a major cause of death and disability worldwide, results from reduced blood flow to the brain, leading to irreversible neuronal damage. Recent evidence suggests that ferroptosis, a form of regulated cell death, plays a critical role in the pathogenesis of ischemic stroke. Rhein, a natural anthraquinone compound, has demonstrated neuroprotective effects; However, its role in ferroptosis and the underlying mechanisms remain unclear. Here, we investigated the protective effects of Rhein against ischemia/reperfusion (I/R) injury in a rat model of middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cells. Rhein treatment dose-dependently ameliorated neurological deficits, reduced infarct volume, and attenuated blood-brain barrier (BBB) disruption in the MCAO model. Furthermore, Rhein suppressed oxidative stress, intracellular ROS generation, and ferroptosis-related protein expression in both in vivo and in vitro models. Mechanistically, Rhein protected against OGD/R-induced HT22 cell injury by regulating the NRF2/SLC7A11/GPX4 signaling pathway. This effect was abolished upon NRF2 inhibition, suggesting that Rhein's neuroprotective action is NRF2-dependent. Molecular docking and microscale thermophoresis analyses further supported the direct interaction between Rhein and the ferroptosis-related protein NRF2. Collectively, our findings reveal that Rhein confers neuroprotection against cerebral I/R injury by inhibiting ferroptosis via the NRF2/SLC7A11/GPX4 axis, providing a potential therapeutic avenue for ischemic stroke.

AIMS

To investigate the neuroprotective effects of Rhein, a natural anthraquinone compound, against ischemia/reperfusion (I/R) injury and elucidate the underlying mechanisms involving ferroptosis and the NRF2/SLC7A11/GPX4 pathway.

METHODS

A rat model of middle cerebral artery occlusion (MCAO) was employed for in vivo assessments, while oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cells were used as an in vitro model. Comprehensive analyses, including neurological score assessment, triphenyl tetrazolium chloride staining, Evans Blue leakage assay, intracellular ROS detection, MTT assay, dual-luciferase reporter assay, oxidative stress and Fe2+ content assessment, immunofluorescence, Western blot, flow cytometry, molecular docking, and microscale thermophoresis, were performed to evaluate the effects of Rhein on I/R injury and ferroptosis.

RESULTS

Rhein conferred dose-dependent neuroprotection against cerebral I/R injury, reducing infarct volume and blood-brain barrier (BBB) disruption in the MCAO model. In both in vivo and in vitro models, Rhein suppressed oxidative stress, intracellular ROS generation, and ferroptosis-related protein expression. Furthermore, Rhein protected HT22 cells from OGD/R-induced injury by regulating the NRF2/SLC7A11/GPX4 signaling pathway, with NRF2 inhibition abolishing these therapeutic effects. Molecular docking and microscale thermophoresis analyses supported a direct interaction between Rhein and NRF2, a ferroptosis-related protein.

CONCLUSION

Rhein attenuates cerebral I/R injury by inhibiting ferroptosis via the NRF2/SLC7A11/GPX4 axis, highlighting its potential as a therapeutic agent for ischemic stroke.

The role of ferroptosis in diabetic cardiovascular diseases and the intervention of active ingredients of traditional Chinese medicine

Cardiovascular diseases (CVDs), encompassing ischaemic heart disease, cardiomyopathy, and heart failure, among others, are the most prevalent complications of diabetes and the leading cause of mortality in patients with diabetes. Cell death modalities, including apoptosis, necroptosis, and pyroptosis, have been demonstrated to be involved in the pathogenesis of CVDs. As research progresses, accumulating evidence also suggests the involvement of ferroptosis, a novel form of cell death, in the pathogenesis of CVDs. Ferroptosis, characterised by iron-dependent lipid peroxidation, which culminates in membrane rupture, may present new therapeutic targets for diabetes-related cardiovascular complications. Current treatments for CVDs, such as antihypertensive, anticoagulant, lipid-lowering, and plaque-stabilising drugs, may cause severe side effects with long-term use. Traditional Chinese medicine, with its broad range of activities and minimal side effects, is widely used in China. Numerous studies have shown that active components of Chinese medicine, such as alkaloids, polyphenols, and saponins, can prevent CVDs by regulating ferroptosis. This review summarises the recent findings on the regulatory mechanisms of active components of Chinese medicine against ferroptosis in CVDs, aiming to provide new directions and a scientific basis for targeting ferroptosis for the prevention and treatment of diabetic CVDs.

TMT and PRM Based Quantitative Proteomics to Explore the Protective Role and Mechanism of Iristectorin B in Stroke

Stroke is a serious disease caused by the rupture or blockage of the cerebrovascular system. Its pathogenesis is complex and involves multiple mechanisms. Iristectorin B is a natural isoflavone that has certain anti stroke effects. In this study, an in vitro stroke injury model of glyoxylate deprivation was established using PC12 cells, which was used to evaluate the anti-stroke activity of Iristectorin B in ejecta stem. The results showed that Iristectorin B, a natural isoflavone derived from Dried Shoot, significantly reduced the damage to PC12 cells caused by oxygen glucose deprivation/reoxygenation, decreased apoptosis, enhanced cell survival and reduced Ca2+, LDH and ROS levels. The results showed that Iristectorin B had a significant protective effect on Na2S2O4-injured PC12 cells, and the mechanism may be related to the protective effect of neurons in the brain. After protein extraction and various analyses were performed, a series of cutting-edge technologies were organically combined to study the quantitative proteome of each group. Differential proteins were then analyzed. According to the protein screening principle, ferroptosis-related proteins were most closely associated with stroke. The differential proteins associated with ferroptosis screened were SLC3A2, TFR1 and HMOX1, with HMOX1 being the most significantly elevated and reduced via dosing. Iristectorin B may act as a protective agent against stroke by regulating ferroptosis, and SLC3A2, TFR1 and HMOX1 may serve as potential diagnostic biomarkers for stroke, providing additional evidence to support the importance of ferroptosis in stroke.

A review on the research progress of traditional Chinese medicine with anti-cancer effect targeting ferroptosis

Ferroptosis is a non-apoptotic form of regulated cell death characterized by iron-dependent lipid peroxidation. It can be triggered by various mechanisms, including the glutathione peroxidase 4 (GPX4)-glutathione (GSH) axis, iron metabolism, lipid metabolism, the GTP cyclohydrolase 1 (GCH1)-tetrahydrobiopterin (BH4) pathway, and the ferroptosis suppressor protein 1 (FSP1)-coenzyme Q10 axis. The redox balance is disrupted when ferroptosis occurs in cells, which is fatal to cancer cells. Additionally, some tumor-associated genes are involved in ferroptosis. Hence, targeting ferroptosis might be an effective strategy for treating cancer. Several small-molecule compounds exhibit anti-tumor effects through ferroptosis, including sorafenib and altretamine, which induce ferroptosis by inhibiting System-Xc and GPX4 respectively, but many problems, such as poor druggability, still exist. Some studies have shown that many traditional Chinese medicine (TCM) induce ferroptosis by inhibiting GPX4, solute carrier family 7 member 11 (SLC7A11), and nuclear factor (erythroid-derived 2)-like 2 (Nrf2), or by increasing the expression of Acyl-CoA synthetase long-chain family member 4 (ACSL4), transferrin (TF), and transferrin receptor 1 (TFR1). These changes can lead to the lysosomal degradation of ferritin, accumulation of iron, lipid peroxidation and the production of reactive oxygen species (ROS), which in turn can promote anti-tumor activities or synergistic effects with chemotherapeutic drugs. In this study, we elucidated the underlying mechanisms of ferroptosis, and the anti-tumor pharmacology of TCM targeting ferroptosis including prescriptions, Chinese herbs, extracts, and natural compounds. Our findings might act as valuable reference for research on anti-tumor drugs targeting ferroptosis, especially those drugs developed from TCM.

Mechanisms and regulations of ferroptosis

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

Transcriptomic profiling of human granulosa cells between women with advanced maternal age with different ovarian reserve

BACKGROUND

Age-related diminished ovarian reserve (DOR) is not absolute. Some advanced maternal age (AMA) still have normal ovarian reserve (NOR) and often show better pregnancy outcomes. Exploring the transcriptomic profile of granulosa cells (GCs) in AMA could lead to new ideas for mitigating age-related diminished ovarian reserve.

AIM

This study aimed to analyze the transcriptomic profile of GCs in AMA with different ovarian reserve.

RESULTS

In total, 6273 statistically significant differential expression genes (DEGs) (|log2fc|> 1, q < 0.05) were screened from the two groups, among which 3436 genes were upregulated, and 2837 genes were downregulated in the DOR group. Through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, the potential functions of dysregulated genes in AMA with DOR or NOR were predicted. The GO enrichment analysis revealed that the DEGs were mainly enriched in obsolete oxidation-reduction process, mitochondrion, metal ion binding, ATP binding, etc. The KEGG pathway enrichment analysis revealed that the above-mentioned DEGs were mainly enriched in ferroptosis, regulation of actin cytoskeleton, oxidative phosphorylation, etc. Meanwhile, verification of the mRNA expression levels of DEGs revealed the possible involvement of "ferroptosis" in age-related diminished ovarian reserve.

CONCLUSIONS

From a new clinical perspective, we presented the first data showing the transcriptomic profile in GCs between AMA with different ovarian reserve. At the same time, we identified the role of ferroptosis in the GCs of AMA, providing a new biological basis for studying ovarian aging and improving pregnancy outcomes of AMA.

IRF1 suppresses colon cancer proliferation by reducing SPI1-mediated transcriptional activation of GPX4 and promoting ferroptosis

IRF1 is a tumor suppressor gene in colon cancer. This study aimed to explore the potential regulation of IRF1 on the ferroptosis of colon cancer and the mechanisms underlying its regulation of GPX4 transcription. IRF1 interacting transcription factors regulating GPX4 transcription were predicted and validated. The role of the IRF1/SPI1-GPX4 axis on the ferroptosis of colon cancer cells was explored. Results showed that IRF1 overexpression reduced GPX4 transcription, increased reactive oxygen species (ROS) and lipid ROS accumulation, and enhanced erastin-induced colon cancer cell growth in vitro and in vivo. SPI1 could directly bind to the GPX4 promoter (-414 to -409) and activate its transcription. IRF1 could bind to SPI1 and suppress its transcriptional activating effects on GPX4 expression. SPI1 overexpression reduced ROS and lipid ROS accumulation and increased colon cancer cell viability and colony formation upon erastin induction. These trends were reversed by IRF1 overexpression. In conclusion, this study revealed a novel oncogenic mechanism of SPI1 by reducing erastin-induced ferroptosis in colon cancer. IRF1 interacts with SPI1 and suppresses its transcriptional activating effect on GPX4 expression. Through this mechanism, IRF1 can enhance erastin-induced ferroptosis of colon cancer. The IRF1/SPI1-GPX4 axis might play a crucial role in modulating ferroptosis in colon cancer and might serve as a potential therapeutic target in the future.

Curcumin reverses erastin-induced chondrocyte ferroptosis by upregulating Nrf2

Osteoarthritis (OA) is associated with ferroptosis, a newly discovered form of programmed cell death associated with lipid peroxidation. Curcumin, the main monomer component in turmeric rhizomes, possesses antioxidant and anti-ferroptosis properties, but its effect on ferroptosis in chondrocytes of OA is unknown. This study aimed to investigate the protective effect and potential mechanism of curcumin on chondrocytes induced by erastin, a ferroptosis inducer. CCK-8 assays were used to assess cell viability in mouse primary chondrocytes treated with 3.33 μM erastin alone or in combination with different doses of curcumin. Various parameters were detected, including LDH, SOD, GSH-PX, MDA, ROS and Fe2+ contents. The ferroptosis-related proteins, such as SLC7A11, GPX4, TFR1, ACSL4, and FTH1, were examined using immunofluorescence and western blotting. Nrf2 was knocked down using siRNA to explore the molecular mechanism through which curcumin protects chondrocytes from erastin-induced ferroptosis. In a mouse model of knee ferroptosis induced by intracavity injection of 10 μL erastin (5 mg/mL), HE staining, Safranin O-Fast Green staining, and immunohistochemistry were employed to evaluate articular cartilage injury. The results demonstrated that erastin significantly suppressed the expression of SOD, GSH-PX, SLC7A11, GPX4, and FTH1 while upregulating the levels of LDH, MDA, ROS, ACSL4, and TFR1 in chondrocytes. Moreover, erastin-induced chondrocyte ferroptosis, lipid ROS, and Fe2+ production were reversed by curcumin. Additionally, curcumin significantly upregulated the expression level of the Nrf2 gene and protein. Silencing Nrf2 reversed the protective effect of curcumin on erastin-induced chondrocyte ferroptosis. In animal experiments, silencing Nrf2 counteracted the impact and damage of curcumin on erastin-induced ferroptosis of cartilage tissue in vivo, leading to significant inhibition of OA progression. Taken together, these findings suggest that curcumin can inhibit chondrocyte ferroptosis by activating the Nrf2 signaling pathway, providing further insight into the regulatory mechanism of curcumin in OA and supporting its potential therapeutic use in OA treatment.

Broadening horizons: The role of ferroptosis in myocardial ischemia-reperfusion injury

Ferroptosis is a novel type of regulated cell death (RCD) discovered in recent years, where abnormal intracellular iron accumulation leads to the onset of lipid peroxidation, which further leads to the disruption of intracellular redox homeostasis and triggers cell death. Iron accumulation with lipid peroxidation is considered a hallmark of ferroptosis that distinguishes it from other RCDs. Myocardial ischemia-reperfusion injury (MIRI) is a process of increased myocardial cell injury that occurs during coronary reperfusion after myocardial ischemia and is associated with high post-infarction mortality. Multiple experiments have shown that ferroptosis plays an important role in MIRI pathophysiology. This review systematically summarized the latest research progress on the mechanisms of ferroptosis. Then we report the possible link between the occurrence of MIRI and ferroptosis in cardiomyocytes. Finally, we discuss and analyze the related drugs that target ferroptosis to attenuate MIRI and its action targets, and point out the shortcomings of the current state of relevant research and possible future research directions. It is hoped to provide a new avenue for improving the prognosis of the acute coronary syndrome.

Therapeutic inhibition of ferroptosis in neurodegenerative disease

Iron accumulation has been associated with the etiology and progression of multiple neurodegenerative diseases (NDDs). The exact role of iron in these diseases is not fully understood, but an iron-dependent form of regulated cell death called ferroptosis could be key. Although there is substantial preclinical and clinical evidence that ferroptosis plays a role in NDD, there are still questions regarding how to target ferroptosis therapeutically, including which proteins to target, identification of clinically relevant biomarkers, and which patients might benefit most. Clinical trials of iron- and ferroptosis-targeted therapies are beginning to provide some answers, but there is growing interest in developing new ferroptosis inhibitors. We describe newly identified ferroptosis targets, opportunities, and challenges in NDD, as well as key considerations for progressing new therapeutics to the clinic.

Role of ferroptosis in effects of anesthetics on multiple organ diseases: A literature review

Anesthesiologists are often faced with patients combined with a series of organ injuries, such as acute lung injury, myocardial ischemia-reperfusion injury, and neurodegenerative diseases. With the in-depth study of these diseases, we are more aware of the choice and rational use of anesthetics for the prognosis of these patients. Ferroptosis is a new type of programmed cell death. This unique pattern of cell death, driven by an imbalance between oxides and antioxidants, is regulated by multiple cellular metabolic events, including redox homeostasis, iron handling, mitochondrial activity, and lipids peroxidation. Numerous studies confirmed that anesthetics modulate ferroptosis by interfering its machineries such as cystine-import-glutathione-glutathione peroxidase 4 axis, Heme oxygenase 1, nuclear factor erythroid 2-related factor 2, and iron homeostasis system. In this literature review, we systemically illustrated possible involvement of ferroptosis in effects of anesthetics and adjuvant drugs on multiple organ diseases, hoping our work may serve as a basis for further studies on regulating ferroptosis through anesthetics related pharmacological modulation and promoting the rational use of anesthetics.

Metabolomic profiling reveals the mechanisms underlying the nephrotoxicity of methotrexate in children with acute lymphoblastic leukemia

BACKGROUND

Methotrexate is widely recommended as a first-line treatment for the intensive systemic and consolidation phases of childhood acute lymphoblastic leukemia. However, methotrexate-induced nephrotoxicity is a severe adverse reaction, of which the mechanisms remain unclear.

METHODS

An untargeted metabolomics analysis of serum from childhood acute lymphoblastic leukemia patients with delayed methotrexate excretion, with or without acute kidney injury, was performed to identify altered metabolites and metabolic pathways. An independent external validation cohort and in vitro HK-2 cell assays further verified the candidate metabolites, and explored the mechanisms underlying the nephrotoxicity of methotrexate.

RESULTS

Four metabolites showed significant differences between normal excretion and delayed excretion, seven metabolites reflected the differences between groups with or without acute kidney injury, and six pathways were finally enriched. In particular, oxidized glutathione was confirmed as a candidate metabolite involved in the toxicity of methotrexate. We further explored the role of glutathione deprivation-induced ferroptosis on methotrexate cytotoxicity, and it was found that methotrexate overload significantly reduced cell viability, triggered reactive oxygen species and intracellular Fe2+ accumulation, and altered the expression of ferroptosis-related proteins in HK-2 cells. These methotrexate-induced changes were alleviated or reversed by the administration of a ferroptosis inhibitor, further suggesting that ferroptosis promoted methotrexate-induced cytotoxicity in HK-2 cells.

CONCLUSIONS

Our findings revealed complex metabolomic profiles and provided novel insights into the mechanism by which ferroptosis contributes to the nephrotoxic effects of methotrexate.

The Interplay between Mitochondrial Dysfunction and Ferroptosis during Ischemia-Associated Central Nervous System Diseases

Cerebral ischemia, a leading cause of disability and mortality worldwide, triggers a cascade of molecular and cellular pathologies linked to several central nervous system (CNS) disorders. These disorders primarily encompass ischemic stroke, Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, and other CNS conditions. Despite substantial progress in understanding and treating the underlying pathological processes in various neurological diseases, there is still a notable absence of effective therapeutic approaches aimed specifically at mitigating the damage caused by these illnesses. Remarkably, ischemia causes severe damage to cells in ischemia-associated CNS diseases. Cerebral ischemia initiates oxygen and glucose deprivation, which subsequently promotes mitochondrial dysfunction, including mitochondrial permeability transition pore (MPTP) opening, mitophagy dysfunction, and excessive mitochondrial fission, triggering various forms of cell death such as autophagy, apoptosis, as well as ferroptosis. Ferroptosis, a novel type of regulated cell death (RCD), is characterized by iron-dependent accumulation of lethal reactive oxygen species (ROS) and lipid peroxidation. Mitochondrial dysfunction and ferroptosis both play critical roles in the pathogenic progression of ischemia-associated CNS diseases. In recent years, growing evidence has indicated that mitochondrial dysfunction interplays with ferroptosis to aggravate cerebral ischemia injury. However, the potential connections between mitochondrial dysfunction and ferroptosis in cerebral ischemia have not yet been clarified. Thus, we analyzed the underlying mechanism between mitochondrial dysfunction and ferroptosis in ischemia-associated CNS diseases. We also discovered that GSH depletion and GPX4 inactivation cause lipoxygenase activation and calcium influx following cerebral ischemia injury, resulting in MPTP opening and mitochondrial dysfunction. Additionally, dysfunction in mitochondrial electron transport and an imbalanced fusion-to-fission ratio can lead to the accumulation of ROS and iron overload, which further contribute to the occurrence of ferroptosis. This creates a vicious cycle that continuously worsens cerebral ischemia injury. In this study, our focus is on exploring the interplay between mitochondrial dysfunction and ferroptosis, which may offer new insights into potential therapeutic approaches for the treatment of ischemia-associated CNS diseases.

Emerging significance and therapeutic targets of ferroptosis: a potential avenue for human kidney diseases

Kidney diseases remain one of the leading causes of human death and have placed a heavy burden on the medical system. Regulated cell death contributes to the pathology of a plethora of renal diseases. Recently, with in-depth studies into kidney diseases and cell death, a new iron-dependent cell death modality, known as ferroptosis, has been identified and has attracted considerable attention among researchers in the pathogenesis of kidney diseases and therapeutics to treat them. The majority of studies suggest that ferroptosis plays an important role in the pathologies of multiple kidney diseases, such as acute kidney injury (AKI), chronic kidney disease, and renal cell carcinoma. In this review, we summarize recently identified regulatory molecular mechanisms of ferroptosis, discuss ferroptosis pathways and mechanisms of action in various kidney diseases, and describe the protective effect of ferroptosis inhibitors against kidney diseases, especially AKI. By summarizing the prominent roles of ferroptosis in different kidney diseases and the progress made in studying ferroptosis, we provide new directions and strategies for future research on kidney diseases. In summary, ferroptotic factors are potential targets for therapeutic intervention to alleviate different kidney diseases, and targeting them may lead to new treatments for patients with kidney diseases.

The Emerging Roles of Ferroptosis in Pathophysiology and Treatment of Acute Lung Injury

Ferroptosis, a programmed cell death discovered in recent years, is an iron-dependent lipid peroxidation accumulation. Unlike other modes of cell death (autophagy, necroptosis, pyroptosis, cuproptosis, etc.), ferroptosis has unique morphological characteristics and plays an important role in a variety of diseases. In recent years, there has been great progress in the study of ferroptosis. Studies have found that ferroptosis is associated with acute lung injury (ALI), a condition with a high mortality rate and limited treatment options. This paper summarizes the mechanism of ferroptosis from the perspectives of iron metabolism, lipid metabolism, amino acid metabolism, and glutathione metabolism. It also discusses the research progress of ferroptosis in ALI in order to find new directions for the prevention and treatment of this condition.

Effects of Nitro-Oxidative Stress on Biomolecules: Part 1-Non-Reactive Molecular Dynamics Simulations

Plasma medicine, or the biomedical application of cold atmospheric plasma (CAP), is an expanding field within plasma research. CAP has demonstrated remarkable versatility in diverse biological applications, including cancer treatment, wound healing, microorganism inactivation, and skin disease therapy. However, the precise mechanisms underlying the effects of CAP remain incompletely understood. The therapeutic effects of CAP are largely attributed to the generation of reactive oxygen and nitrogen species (RONS), which play a crucial role in the biological responses induced by CAP. Specifically, RONS produced during CAP treatment have the ability to chemically modify cell membranes and membrane proteins, causing nitro-oxidative stress, thereby leading to changes in membrane permeability and disruption of cellular processes. To gain atomic-level insights into these interactions, non-reactive molecular dynamics (MD) simulations have emerged as a valuable tool. These simulations facilitate the examination of larger-scale system dynamics, including protein-protein and protein-membrane interactions. In this comprehensive review, we focus on the applications of non-reactive MD simulations in studying the effects of CAP on cellular components and interactions at the atomic level, providing a detailed overview of the potential of CAP in medicine. We also review the results of other MD studies that are not related to plasma medicine but explore the effects of nitro-oxidative stress on cellular components and are therefore important for a broader understanding of the underlying processes.

Inhibition of ACSL4 ameliorates tubular ferroptotic cell death and protects against fibrotic kidney disease

Ferroptosis is a recently recognized form of regulated cell death, characterized by iron-dependent accumulation of lipid peroxidation. Ample evidence has depicted that ferroptosis plays an essential role in the cause or consequence of human diseases, including cancer, neurodegenerative disease and acute kidney injury. However, the exact role and underlying mechanism of ferroptosis in fibrotic kidney remain unknown. Acyl-CoA synthetase long-chain family member 4 (ACSL4) has been demonstrated as an essential component in ferroptosis execution by shaping lipid composition. In this study, we aim to discuss the potential role and underlying mechanism of ACSL4-mediated ferroptosis of tubular epithelial cells (TECs) during renal fibrosis. The unbiased gene expression studies showed that ACSL4 expression was tightly associated with decreased renal function and the progression of renal fibrosis. To explore the role of ACSL4 in fibrotic kidney, ACSL4 specific inhibitor rosiglitazone (ROSI) was used to disturb the high expression of ACSL4 in TECs induced by TGF-β, unilateral ureteral obstruction (UUO) and fatty acid (FA)-modeled mice in vivo, and ACSL4 siRNA was used to knockdown ACSL4 in TGF-β-induced HK2 cells in vitro. The results demonstrated that inhibition and knockdown of ACSL4 effectively attenuated the occurrence of ferroptosis in TECs and alleviated the interstitial fibrotic response. In addition, the expression of various profibrotic cytokines all decreased after ROSI-treated in vivo and in vitro. Further investigation showed that inhibition of ACSL4 obviously attenuates the progression of renal fibrosis by reducing the proferroptotic precursors arachidonic acid- and adrenic acid- containing phosphatidylethanolamine (AA-PE and AdA-PE). In conclusion, these results suggest ACSL4 is essential for tubular ferroptotic death during kidney fibrosis development and ACSL4 inhibition is a viable therapeutic approach to preventing fibrotic kidney diseases.

Ferroptosis, autophagy, tumor and immunity

Ferroptosis was first proposed in 2012, a new form of cell death. Autophagy plays a crucial role in cell clearance and maintaining homeostasis. Autophagy is involved in the initial step of ferroptosis under the action of histone elements such as NCOA4, RAB7A, and BECN1. Ferroptosis and autophagy are involved in tumor progression, treatment, and drug resistance in the tumor microenvironment. In this review, we described the mechanisms of ferroptosis, autophagy, and tumor and immunotherapy, respectively, and emphasized the relationship between autophagy-related ferroptosis and tumor.

Functional significance of cholesterol metabolism in cancer: from threat to treatment

Cholesterol is an essential structural component of membranes that contributes to membrane integrity and fluidity. Cholesterol homeostasis plays a critical role in the maintenance of cellular activities. Recently, increasing evidence has indicated that cholesterol is a major determinant by modulating cell signaling events governing the hallmarks of cancer. Numerous studies have shown the functional significance of cholesterol metabolism in tumorigenesis, cancer progression and metastasis through its regulatory effects on the immune response, ferroptosis, autophagy, cell stemness, and the DNA damage response. Here, we summarize recent literature describing cholesterol metabolism in cancer cells, including the cholesterol metabolism pathways and the mutual regulatory mechanisms involved in cancer progression and cholesterol metabolism. We also discuss various drugs targeting cholesterol metabolism to suggest new strategies for cancer treatment.

Effects of amygdalin on ferroptosis and oxidative stress in diabetic retinopathy progression via the NRF2/ARE signaling pathway

Oxidative stress has been involved in the pathogenesis of diabetic retinopathy (DR). Amygdalin is an effective component of bitter almond that exhibits excellent antioxidant properties. We explored the effects of amygdalin on ferroptosis and oxidative stress in high-glucose (HG)-stimulated human retinal endothelial cells (HRECs) via the NRF2/ARE pathway. HG-stimulated HRECs were used to establish a DR model. Cell viability was evaluated using the MTT assay. The release of lactate dehydrogenase was used to evaluate cell toxicity. The protein levels of NRF2, NQO1, and HO-1 were detected using western blotting. The GSH, GSSG, GPX4, SOD, CAT, MDA, and Fe2+ levels in the HRECs were also detected. Flow cytometry was used to detect reactive oxygen species (ROS) using a fluorescent probe. Immunofluorescence staining was performed to detect NRF2 expression. The results revealed that HG stimulation decreased the levels of GSH, GPX4, SOD, and CAT but increased those of MDA, ROS, GSSG, and Fe2+ in HRECs. Ferrostatin-1 treatment reversed the effects of HG stimulation, whereas erastin aggravated these effects. Amygdalin treatment relieved HG-induced injury in HRECs. Amygdalin treatment promoted the nuclear transport of NRF2 in HG-stimulated HRECs. NQO1 and HO-1 levels were upregulated in HG-stimulated HRECs after amygdalin treatment. An inhibitor of NRF2 reversed the effects of amygdalin. Therefore, amygdalin treatment inhibited ferroptosis and oxidative stress in HG-stimulated HRECs by activating the NRF2/ARE signaling pathway.

San-Huang-Yi-Shen capsule ameliorates diabetic nephropathy in mice through inhibiting ferroptosis

Diabetic nephropathy (DN) is one of the main complications of diabetes. However, effective therapy to block or slow down the progression of DN is still lacking. San-Huang-Yi-Shen capsule (SHYS) has been shown to significantly improve renal function and delay the progression of DN. However, the mechanism of SHYS on DN is still unclear. In this study, we established a mouse model of DN. Then, we investigated the anti-ferroptotic effects of SHYS including the reduction of iron overload and the activation of cystine/GSH/GPX4 axis. Finally, we used a GPX4 inhibitor (RSL3) and ferroptosis inhibitor (ferrostatin-1) to determine whether SHYS ameliorates DN through inhibiting ferroptosis. The results showed that SHYS treatment was effective for mice with DN in terms of improving renal function, and reducing inflammation and oxidative stress. Besides, SHYS treatment reduced iron overload and upregulated the expression of cystine/GSH/GPX4 axis-related factors in kidney. Moreover, SHYS exhibited similar therapeutic effect on DN as ferrostatin-1, RSL3 could abolish the therapeutic and anti- ferroptotic effects of SHYS on DN. In conclusion, SHYS can be used to treat mice with DN. Furthermore, SHYS could inhibit ferroptosis in DN through reducing iron overload and upregulating the expression of cystine/GSH/GPX4 axis.

Carnosine alleviates kidney tubular epithelial injury by targeting NRF2 mediated ferroptosis in diabetic nephropathy

Diabetic nephropathy (DN) can promote the occurrence of end-stage renal disease (ESRD). The injury of renal tubular epithelial cells is a significant reason for the occurrence of ESRD. A recent research demonstrated that ferroptosis was associated with renal tubular injury in DN. Ferroptosis is a kind of cell death brought on by the buildup of iron ions and lipid peroxidation brought on by ROS. Because carnosine (CAR) is a scavenger of iron ions and reactive oxygen species, we investigated whether CAR can improve DN by regulating ferroptosis. The results show that both CAR and Fer-1 significantly reduced kidney damage and inhibited ferroptosis in STZ mice. In addition, ferroptosis caused by HG or erastin (an inducer of ferroptosis) in human kidney tubular epithelial cell (HK2) was also rescued by CAR treatment. It was discovered that the protective effect of CAR against HG-induced ferroptosis was abolished when NRF2 was specifically knocked down in HK2 cells.

Ferroptosis in the colon epithelial cells as a therapeutic target for ulcerative colitis

BACKGROUND

Ferroptosis, a type of programmed cell death triggered by oxidative stress, was suspected to play a role in ulcerative colitis. Indigo naturalis is highly effective against ulcerative colitis, but its mechanism is unclear. This study found that indigo naturalis treatment suppressed ferroptosis.

METHODS

We analyzed 770 mRNA expressions of patients with ulcerative colitis. Suppression of ferroptosis by indigo naturalis treatment was shown using a cell death assay. Malondialdehyde levels and reactive oxygen species were analyzed in CaCo-2 cells treated with indigo naturalis. Glutathione metabolism was shown by metabolomic analysis. Extraction of the ingredients indigo naturalis from the rectal mucosa was performed using liquid chromatograph-mass spectrometry.

RESULTS

Gene expression profiling showed that indigo naturalis treatment increased antioxidant genes in the mucosa of patients with ulcerative colitis. In vitro analysis showed that nuclear factor erythroid-2-related factor 2-related antioxidant gene expression was upregulated by indigo naturalis. Indigo naturalis treatment rendered cells resistant to ferroptosis. Metabolomic analysis suggested that an increase in reduced glutathione by indigo naturalis. The protein expression of CYP1A1 and GPX4 was increased in the rectum by treatment with indigo naturalis. The main ingredients of indigo naturalis, indirubin and indigo inhibited ferroptosis. Indirubin was detected in the rectal mucosa of patients with ulcerative colitis who were treated with indigo naturalis.

CONCLUSIONS

Suppression of ferroptosis by indigo naturalis in the intestinal epithelium could be therapeutic target for ulcerative colitis. The main active ingredient of indigo naturalis may be indirubin.

ACSL4 promotes ferroptosis and M1 macrophage polarization to regulate the tumorigenesis of nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a head and neck malignant tumor with a high incidence and recurrence rate. The crosstalk between ferroptosis and tumor-associated macrophages (TAMs) is thought to have major implications in interfering with cancers. We intended to explore the effect of acyl-CoA synthetase long-chain family member 4 (ACSL4) on the pathogenesis of NPC via ferroptosis and TAMs.

METHODS

Differential genes in NPC patients were analyzed using publicly available databases, and the ferroptosis-related gene ACSL4 was identified. Expression of ACSL4 in NPC cell lines and xenografted mice was examined. Colony formation, cell proliferation, migration, and invasion were assessed. The abundance of epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin, and Vimentin) was confirmed. Lipid peroxidation levels and related markers were measured. Clophosome was administered to determine the role of TAMs in NPC mice.

RESULTS

Low levels of ACSL4 were observed in NPC patients and CNE-2 and 5-8F cells. Erastin (a ferroptosis inducer) and ACSL4 increased lipid peroxidation, decreased cell viability, colony formation, cell proliferation, migration and invasion, and inhibited EMT. Moreover, Erastin and ACSL4 promoted M2 to M1 macrophage polarization. The effects of erastin and ACSL4 were additive. Ferrostatin-1, an inhibitor of ferroptosis, exerted the opposite effect and reversed the beneficial effects of ACSL4 overexpression. In xenograft mice, ACSL4 and clophosome hindered the growth of NPC, and extra clophosome slightly enhanced the antitumor effect of ACSL4.

CONCLUSION

Our findings indicated that ACSL4 inhibited the pathogenesis of NPC, at least through crosstalk between ferroptosis and macrophages, providing potential direction for NPC therapy.

Mechanisms of ferroptosis regulating oxidative stress and energy metabolism in myocardial ischemia-reperfusion injury and a novel perspective of natural plant active ingredients for its treatment

Acute myocardial infarction remains the leading cause of death in humans. Timely restoration of blood perfusion to ischemic myocardium remains the most effective strategy in the treatment of acute myocardial infarction, which can significantly reduce morbidity and mortality. However, after restoration of blood flow and reperfusion, myocardial injury will aggravate and induce apoptosis of cardiomyocytes, a process called myocardial ischemia-reperfusion injury. Studies have shown that the loss and death of cardiomyocytes caused by oxidative stress, iron load, increased lipid peroxidation, inflammation and mitochondrial dysfunction, etc., are involved in myocardial ischemia-reperfusion injury. In recent years, with the in-depth research on the pathology of myocardial ischemia-reperfusion injury, people have gradually realized that there is a new form of cell death in the pathological process of myocardial ischemia-reperfusion injury, namely ferroptosis. A number of studies have found that in the myocardial tissue of patients with acute myocardial infarction, there are pathological changes closely related to ferroptosis, such as iron metabolism disorder, lipid peroxidation, and increased reactive oxygen species free radicals. Natural plant products such as resveratrol, baicalin, cyanidin-3-O-glucoside, naringenin, and astragaloside IV can also exert therapeutic effects by correcting the imbalance of these ferroptosis-related factors and expression levels. Combining with our previous studies, this review summarizes the regulatory mechanism of natural plant products intervening ferroptosis in myocardial ischemia-reperfusion injury in recent years, in order to provide reference information for the development of targeted ferroptosis inhibitor drugs for the treatment of cardiovascular diseases.

In vitro siRNA-mediated GPX4 and AKT1 silencing in oxaliplatin resistance cancer cells induces ferroptosis and apoptosis

Oxaliplatin is a member of platinum-based chemotherapy drugs frequently used in colorectal cancer (CRC). However, resistance to oxaliplatin causes tumor progression and metastasis. Akt1 and Gpx4 are essential regulator genes of apoptosis and ferroptosis pathways. Inhibition of these genes might eradicate oxaliplatin resistance in resistant CRC cells. We compared two cell death strategies to reverse drug resistance in Caco-2 and HT-29 oxaliplatin-resistant cell lines. We used the AKT1-specific siRNA to induce apoptosis. Also, GPX4-specific siRNA and FIN56 were utilized to generate ferroptosis. The effect of these treatments was assessed by reactive oxygen species (ROS) formation, cell viability, and protein expression level assays. Besides, the expression of GPX4, CoQ10, and NRF2 was assessed in both cell lines after treatments. Correctly measuring the expression of these responsible genes and proteins confirms the occurrence of different types of cell death. In addition, the ability of Akt1/ GPX4 siRNA in resensitizing HT-29 and Caco-2 oxaliplatin resistance cells was evaluated. Our finding showed that the upregulation of GPX4/siRNA caused a reduction in GPX4 and CoQ10 expressions in both cell lines. However, the expression level of NRF2 showed the same level in our cell lines, so we observed a downregulation of NRF2 in resistant CRC cell lines. Cell viability assay indicated that induction of ferroptosis by GPX4/siRNA or FIN56 and apoptosis by Akt1/siRNA in resistant cell lines could reverse the oxaliplatin resistance. We concluded that downregulation of Akt1 or Gpx4 could increase the efficacy of oxaliplatin to overcome the resistance compared to FIN56.

Glutathione Peroxidase gpx1 to gpx8 Genes Expression in Experimental Brain Tumors Reveals Gender-Dependent Patterns

Extensive research efforts in the field of brain tumor studies have led to the reclassification of tumors by the World Health Organization (WHO) and the identification of various molecular subtypes, aimed at enhancing diagnosis and treatment strategies. However, the quest for biomarkers that can provide a deeper understanding of tumor development mechanisms, particularly in the case of gliomas, remains imperative due to their persistently incurable nature. Oxidative stress has been widely recognized as a key mechanism contributing to the formation and progression of malignant tumors, with imbalances in antioxidant defense systems being one of the underlying causes for the excess production of reactive oxygen species (ROS) implicated in tumor initiation. In this study, we investigated the gene expression patterns of the eight known isoforms of glutathione peroxidase (GPx) in brain tissue obtained from male and female control rats, as well as rats with transplacental ethyl nitrosourea (ENU)-induced brain tumors. Employing the delta-delta Ct method for RT-PCR, we observed minimal expression levels of gpx2, gpx5, gpx6, and gpx7 in the brain tissue from the healthy control animals, while gpx3 and gpx8 exhibited moderate expression levels. Notably, gpx1 and gpx4 displayed the highest expression levels. Gender differences were not observed in the expression profiles of these isoforms in the control animals. Conversely, the tumor tissue exhibited elevated relative expression levels in all isoforms, except for gpx4, which remained unchanged, and gpx5, which exhibited alterations solely in female animals. Moreover, except for gpx1, which displayed no gender differences, the relative expression values of gpx2, gpx3, gpx6, gpx7, and gpx8 were significantly higher in the male animals compared to their female counterparts. Hence, the analysis of glutathione peroxidase isoforms may serve as a valuable approach for discerning the behavior of brain tumors in clinical settings.

Exosomal ACADM sensitizes gemcitabine-resistance through modulating fatty acid metabolism and ferroptosis in pancreatic cancer

This study aimed to evaluate the potential of exosomes from cancer cells to predict chemoresistance in pancreatic cancer (PC) and explore the molecular mechanisms through RNA-sequencing and mass spectrometry. We sought to understand the connection between the exosomal Medium-chain acyl-CoA dehydrogenase (ACADM) level and the reaction to gemcitabine in vivo and in patients with PC. We employed loss-of-function, gain-of-function, metabolome mass spectrometry, and xenograft models to investigate the effect of exosomal ACADM in chemoresistance in PC. Our results showed that the molecules involved in lipid metabolism in exosomes vary between PC cells with different gemcitabine sensitivity. Exosomal ACADM (Exo-ACADM) was strongly correlated with gemcitabine sensitivity in vivo, which can be used as a predictor for postoperative gemcitabine chemosensitivity in pancreatic patients. Moreover, ACADM was found to regulate the gemcitabine response by affecting ferroptosis through Glutathione peroxidase 4 (GPX4) and mevalonate pathways. It was also observed that ACADM increased the consumption of unsaturated fatty acids and decreased intracellular lipid peroxides and reactive oxygen species (ROS) levels. In conclusion, this research suggests that Exo-ACADM may be a viable biomarker for predicting the responsiveness of patients to chemotherapy.

Ferroptosis Nanomedicine: Clinical Challenges and Opportunities for Modulating Tumor Metabolic and Immunological Landscape

Ferroptosis, a type of regulated cell death driven by iron-dependent phospholipid peroxidation, has captured much attention in the field of nanomedicine since it was coined in 2012. Compared with other regulated cell death modes such as apoptosis and pyroptosis, ferroptosis has many distinct features in the molecular mechanisms and cellular morphology, representing a promising strategy for treating cancers that are resistant to conventional therapeutic modalities. Moreover, recent insights collectively reveal that ferroptosis is tightly connected to the maintenance of the tumor immune microenvironment (TIME), suggesting the potential application of ferroptosis therapies for evoking robust antitumor immunity. From a biochemical perspective, ferroptosis is intricately regulated by multiple cellular metabolic pathways, including iron metabolism, lipid metabolism, redox metabolism, etc., highlighting the importance to elucidate the relationship between tumor metabolism and ferroptosis for developing antitumor therapies. In this review, we provide a comprehensive discussion on the current understanding of ferroptosis-inducing mechanisms and thoroughly discuss the relationship between ferroptosis and various metabolic traits of tumors, which offer promising opportunities for direct tumor inhibition through a nanointegrated approach. Extending from the complex impact of ferroptosis on TIME, we also discussed those important considerations in the development of ferroptosis-based immunotherapy, highlighting the challenges and strategies to enhance the ferroptosis-enabled immunostimulatory effects while avoiding potential side effects. We envision that the insights in this study may facilitate the development and translation of ferroptosis-based nanomedicines for tumor treatment.

Ferroptosis in pulmonary fibrosis: an emerging therapeutic target

In recent years, the role of ferroptosis in pulmonary fibrosis has garnered increasing interest as a potential therapeutic target. Pulmonary fibrosis is a pathological process characterized by the accumulation of extracellular matrix in affected lung tissues, and currently, there are no effective therapies for preventing or reversing the fibrotic lesions. Ferroptosis is a form of programmed cell death that is regulated by a network of enzymes and signaling pathways. Dysregulation of ferroptosis has been implicated in several diseases, including pulmonary fibrosis. The accumulation of lipid peroxides in the course of ferroptosis causes damage to cell membranes and other cellular components, leading ultimately to cell death. Relevant targets for therapeutic intervention in ferroptosis include key enzymes, such as glutathione peroxidase 4, transcription factors like nuclear factor erythroid 2-related factor 2, and iron chelation. This review provides an overview of the emerging role of ferroptosis in pulmonary fibrosis and highlights potential therapeutic targets in this pathway. Further research is needed to develop safe and effective approaches targeting ferroptosis in treatment of pulmonary fibrosis.

Selenium hyperaccumulator plant Cardamine enshiensis: from discovery to application

Selenium (Se) is an essential trace element for animals and humans. Se biofortification and Se functional agriculture are emerging strategies to satisfy the needs of people who are deficient in Se. With 200 km2 of Se-excess area, Enshi is known as the "world capital of Se." Cardamine enshiensis (C. enshiensis) is a Se hyperaccumulation plant discovered in the Se mine drainage area of Enshi. It is edible and has been approved by National Health Commission of the People's Republic of China as a new source of food, and the annual output value of the Se-rich industry in Enshi City exceeds 60 billion RMB. This review will mainly focus on the discovery and mechanism underlying Se tolerance and Se hyperaccumulation in C. enshiensis and highlight its potential utilization in Se biofortification agriculture, graziery, and human health.

Elevated phospholipid hydroperoxide glutathione peroxidase (GPX4) expression modulates oxylipin formation and inhibits age-related skeletal muscle atrophy and weakness

Our previous studies support a key role for mitochondrial lipid hydroperoxides as important contributors to denervation-related muscle atrophy, including muscle atrophy associated with aging. Phospholipid hydroperoxide glutathione peroxidase 4 (GPX4) is an essential antioxidant enzyme that directly reduces phospholipid hydroperoxides and we previously reported that denervation-induced muscle atrophy is blunted in a mouse model of GPX4 overexpression. Therefore, the goal of the present study was to determine whether GPX4 overexpression can reduce the age-related increase in mitochondrial hydroperoxides in skeletal muscle and ameliorate age-related muscle atrophy and weakness (sarcopenia). Male C57Bl6 WT and GPX4 transgenic (GPX4Tg) mice were studied at 3 to 5 and 23-29 months of age. Basal mitochondrial peroxide generation was reduced by 34% in muscle fibers from aged GPX4Tg compared to old WT mice. GPX4 overexpression also reduced levels of lipid peroxidation products: 4-HNE, MDA, and LOOHs by 38%, 32%, and 84% respectively in aged GPX4Tg mice compared to aged WT mice. Muscle mass was preserved in old GPX4 Tg mice by 11% and specific force generation was 21% higher in old GPX4Tg versus age matched male WT mice. Oxylipins from lipoxygenases (LOX) and cyclooxygenase (COX), as well as less abundant non-enzymatically generated isomers, were significantly reduced by GPX4 overexpression. The expression of cPLA2, 12/15-LOX and COX-2 were 1.9-, 10.5- and 3.4-fold greater in old versus young WT muscle respectively, and 12/15-LOX and COX-2 levels were reduced by 37% and 35%, respectively in muscle from old GPX4Tg mice. Our study suggests that lipid peroxidation products may play an important role in the development of sarcopenia, and their detoxification might be an effective intervention in preventing muscle atrophy.

Butylphthalide protects against ischemia-reperfusion injury in rats via reducing neuron ferroptosis and oxidative stress

Local ischemia in the cerebra leads to vascular injury and necrosis. Ferroptosis is involved in the pathophysiological process of many diseases and widely exists when ischemia-reperfusion injury occurs in many organs. The aim of this study was to evaluate the effect of Butylphthalide (NBP) on middle cerebral artery occlusion (MCAO) rats model-caused neuron injury. Sprague Dawley Rats were randomly allocated to receive sham and MCAO operation. NBP low-dose (40 mg/kg b.w), and high-dose (80 mg/kg b.w) were administrated in MACO rats. Results showed NBP improves infarct volume, attenuates neuronal apoptosis in the brain tissue of MCAO rats. The tumor necrosis factor (TNF-α), IL-6, and malondialdehyde (MDA) levels decreased after NBP administration, while the activity of superoxide dismutase (SOD) and the ratio of GSH/GSSG in MACO rats increased. MACO caused non-heme iron accumulation in the brain tissue and Perl's staining confirmed NBP attenuates ferroptosis in MACO rats. The protein expressions of SCL7A11 and glutathione peroxidase 4 (GPX4) decreased following MCAO, and NBP treatment subsequently increased the expression of SCL7A11 and GPX4. In vitro analysis in cortical neuron cells indicated that the GPX4 inhibitor reverses the inhibition of ferroptosis by NBP, which suggested that the SCL7A11/GPX4 pathway majorly contributed to the NBP ferroptosis protection effect.

Pharmacological Inhibition of Ferroptosis as a Therapeutic Target for Neurodegenerative Diseases and Strokes

Emerging evidence suggests that ferroptosis, a unique regulated cell death modality that is morphologically and mechanistically different from other forms of cell death, plays a vital role in the pathophysiological process of neurodegenerative diseases, and strokes. Accumulating evidence supports ferroptosis as a critical factor of neurodegenerative diseases and strokes, and pharmacological inhibition of ferroptosis as a therapeutic target for these diseases. In this review article, the core mechanisms of ferroptosis are overviewed and the roles of ferroptosis in neurodegenerative diseases and strokes are described. Finally, the emerging findings in treating neurodegenerative diseases and strokes through pharmacological inhibition of ferroptosis are described. This review demonstrates that pharmacological inhibition of ferroptosis by bioactive small-molecule compounds (ferroptosis inhibitors) could be effective for treatments of these diseases, and highlights a potential promising therapeutic avenue that could be used to prevent neurodegenerative diseases and strokes. This review article will shed light on developing novel therapeutic regimens by pharmacological inhibition of ferroptosis to slow down the progression of these diseases in the future.

Tumor-Associated Macrophages Regulating a Polymer Nanoplatform for Synergistic Treatment of Breast Tumors

Tumor-associated macrophages (TAMs) play a critical role in tumor progression and metastasis. Modulation of TAM polarization is one of the most effective strategies to change the immunosuppressive tumor microenvironment (TME). In this study, organic polymer nanoparticles (CPHT) were prepared using hyaluronic acid (HA)-conjugated disulfide-bonded polyethylene imide (PEIS) as a carrier through a self-assembly strategy. These nanoparticles were modified by transferrin (Tf) and loaded with chlorin e6 (Ce6). The results showed that CPHT had good dispersion with a particle size of about 30 nm. CPHT gradually disintegrated under the exposure with a high concentration of glutathione (GSH) in tumor cells, proving the possibility for the controlled release of Ce6 and photodynamic therapy. An in vitro test showed that the uptake of CPHT in tumor cells was mediated by both HA and Tf, indicating the active tumor-targeting capacity of CPHT. CPHT significantly downregulated the ratio of CD206/CD86 and triggered the upregulation of immune factors such as TNF-α and iNOS, suggesting the repolarization of TAMs. We also found that CPHT effectively induced ferroptosis in tumor cells through lipid peroxide accumulation, GSH depletion, and downregulation of lipid peroxidase (GPX4) expression. Animal experiments confirmed that CPHT not only effectively inhibited the growth of tumors in situ but also significantly decelerated the growth of the distal tumor. Elevated levels of CD86 and IFN-γ and decreased expression of CD206 were observed at the tumor sites post CPHT treatment. These results confirmed the value of CPHT as a multifunctional nanoplatform that can tune the TME and provide new hope for tumor treatment.

Ferroptosis as a potential target for cancer therapy

Ferroptosis is a recently discovered essential type of cell death that is mainly characterized by iron overload and lipid peroxidation. Emerging evidence suggests that ferroptosis is a double-edged sword in human cancer. However, the precise underlying molecular mechanisms and their differential roles in tumorigenesis are unclear. Therefore, in this review, we summarize and briefly present the key pathways of ferroptosis, paying special attention to the regulation of ferroptosis as well as its dual role as an oncogenic and as a tumor suppressor event in various human cancers. Moreover, multiple pharmacological ferroptosis activators are summarized, and the prospect of targeting ferroptosis in cancer therapy is further elucidated.

Intraperitoneal Injection of Human Ferritin Heavy Chain Attenuates the Atherosclerotic Process in APOE-Knockout Mice

Background: Iron overload can accelerate the accumulation of lipid oxides and contribute to the progression of atherosclerosis. Ferritin heavy chain (FT-H) exhibits oxidase activity, which inhibits the toxicity of ferrous ions and reduces oxidative damage. We investigated the effect of the intraperitoneal injection of FT-H on the progression of atherosclerosis in APOE-knockout mice (Apo-E^(-/-) mice). Methods: All mice were fed on a high-fat diet. After 10 weeks, the mice were divided into an injection group (n = 4) and a control group (n = 4). The injection group was injected intraperitoneally with FT-H (50 mg/kg, once a week), and the control group was treated with PBS buffer (at an equal volume to the injection group, once a week). After 10 weeks of intervention, MRI of the aortas was performed. Then, the animals were sacrificed, and tissues were taken. Hematoxylin-eosin (HE) staining was used for histomorphometry, Masson staining was used to quantify the collagen content in the arteries, Prussian blue staining was used to visualize iron deposition in the arteries, and MRI was used to analyze the structure of the aorta in vivo. Immunohistochemistry was performed to detect the expression of MCP-1, MMP-2, MMP-9, FT-H, FT-L, TfR1, NRF-2 and GPX-4. Results: The serological results showed that the injection group had lower levels of glucose (Glu), triacylglycerol (TG), cholesterol (CHO), low-density lipoprotein-C (LDL-C) and malondialdehyde (MDA) (p = 0.0058, p = 0.0098, p = 0.0019, p = 0.0368 and p = 0.0025, respectively), and their serum ferritin (SF) and superoxide dismutase (SOD) levels were higher (p = 0.0004 and p < 0.0001). The Masson staining and MRI results showed that the injection group had less collagen deposition (p = 0.0226), a larger arterial lumen area and arterial volume (p = 0.0006 and p = 0.0005), thinner arterial wall thickness (p = 0.0013) and a more stable arterial plaque structure (p < 0.0001). The immunohistochemical results showed reduced expression of FT-H, FT-L, TfR1, MMP-2, MMP-9, MCP-1 and NRF-2 in the injection group (p = 0.0054, p = 0.0242, p = 0.0221, p = 0.0477, p = 0.0131, p = 0.0435 and p = 0.0179). Prussian blue staining showed that the area of iron-positive areas in the aortic plaques of the control group was larger than that of injected group. The expression of GPX-4 was lower in the control group than in the injection group (p = 0.016). Conclusions: The intraperitoneal administration of FT-H to Apo-E^(-/-) mice resulted in lower blood glucose and lipid levels; reduced iron and iron metabolism protein deposition in the aorta; reduced indices of their ferroptosis, oxidation and inflammatory aggregation; and reduced collagen deposition in the aorta, which delayed the process of aortic atherosclerosis in mice.

Interaction mechanisms between autophagy and ferroptosis: Potential role in colorectal cancer

Colorectal cancer (CRC) is a common malignancy that has the second highest incidence and mortality rate. Although there are many personalized treatment options for CRC, the therapeutic effects are ultimately limited by drug resistance. Studies have aimed to block the initiation and progression of CRC by inducing cell death to overcome this obstacle. Substantial evidence has indicated that both autophagy and ferroptosis play important regulatory roles in CRC. Autophagy, a lysosome-dependent process by which cellular proteins and organelles are degraded, is the basic mechanism for maintaining cell homeostasis. The duality and complexity of autophagy in cancer therapy is a hot topic of discussion. Ferroptosis, a regulated cell death pathway, is associated with iron accumulation-induced lipid peroxidation. The activation of ferroptosis can suppress CRC proliferation, invasion and drug resistance. Furthermore, recent studies have suggested an interaction between autophagy and ferroptosis. Autophagy can selectively degrade certain cellular contents to provide raw materials for ferroptosis, ultimately achieving antitumor and anti-drug resistance. Therefore, exploring the interaction between autophagy and ferroptosis could reveal novel ideas for the treatment of CRC. In this review, we describe the mechanisms of autophagy and ferroptosis, focusing on their roles in CRC and the crosstalk between them.

Ferrostatin-1 alleviates the damage of C2C12 myoblast and mouse pelvic floor muscle induced by mechanical trauma

Ferroptosis is a special form of regulated cell death, which is reported to play an important role in a variety of traumatic diseases by promoting lipid peroxidation and devastating cell membrane structure. Pelvic floor dysfunction (PFD) is a kind of disease affecting the quality and health of many women's lives, which is closely related to the injury of the pelvic floor muscle. Clinical findings have discovered that there is anomalous oxidative damage to the pelvic floor muscle in women with PFD caused by mechanical trauma, but the specific mechanism is still unclear. In this study, we explored the role of ferroptosis-associated oxidative mechanisms in mechanical stretching-induced pelvic floor muscle injury, and whether obesity predisposed pelvic floor muscle to ferroptosis from mechanical injury. Our results, in vitro, showed that mechanical stretch could induce oxidative damage to myoblasts and trigger ferroptosis. In addition, glutathione peroxidase 4 (GPX4) down-regulation and 15-lipoxygenase 1(15LOX-1) up-regulation exhibited the same variational characteristics as ferroptosis, which was much more pronounced in palmitic acid (PA)-treated myoblasts. Furthermore, ferroptosis induced by mechanical stretch could be rescued by ferroptosis inhibitor (ferrostatin-1). More importantly, in vivo, we found that the mitochondria of pelvic floor muscle shrank, which were consistent with the mitochondrial morphology of ferroptosis, and GPX4 and 15LOX-1 showed the same change observed in cells. In conclusion, our data suggest ferroptosis is involved in the injury of the pelvic floor muscle caused by mechanical stretching, and provide a novel insight for PFD therapy.

Response of the Glutathione (GSH) Antioxidant Defense System to Oxidative Injury in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a neonatal intestinal disease associated with oxidative stress. The targets of peroxidation and the role of the innate intestinal epithelial antioxidant defense system are ill-defined. We hypothesized that oxidative stress in NEC correlates with oxidized GSH redox potentials, lipid peroxidation, and a dysfunctional antioxidant system. Methods: Intestinal samples from infants +/- NEC were generated into enteroids and incubated with lipopolysaccharide (LPS) and hypoxia to induce experimental NEC. HPLC assayed GSH redox potentials. Lipid peroxidation was measured by flow cytometry. Immunoblotting measured glutathione peroxidase 4 (Gpx4) expression. Results: GSH redox potentials were more oxidized in NEC intestinal tissue and enteroids as compared to controls. Lipid radicals in NEC-induced enteroids were significantly increased. Human intestinal tissue with active NEC and treated enteroid cultures revealed decreased levels of Gpx4. Conclusions: The ability of neonatal intestine to mitigate radical accumulation plays a role in its capacity to overcome oxidative stress. Accumulation of lipid radicals is confirmed after treatment of enteroids with NEC-triggering stimuli. Decreased Gpx4 diminishes a cell's ability to effectively neutralize lipid radicals. When lipid peroxidation overwhelms antioxidant machinery, cellular death ensues. Identification of the mechanisms behind GSH-dependent enzyme dysfunction in NEC may provide insights into strategies for reversing radical damage.

The Role of Ferroptosis in Placental-Related Diseases

Ferroptosis is a recently identified form of programmed cell death which is different from apoptosis, pyroptosis, necrosis, and autophagy. It is uniquely defined by redox-active iron-dependent hydroxy-peroxidation of polyunsaturated fatty acid (PUFA)-containing phospholipids and a loss of lipid peroxidation repair capacity. Ferroptosis has recently been implicated in multiple human diseases, such as tumors, ischemia-reperfusion injury, acute kidney injury, neurological diseases, and asthma among others. Intriguingly, ferroptosis is associated with placental physiology and trophoblast injury. Circumstances such as accumulation of lipid reactive oxygen species (ROS) due to hypoxia-reperfusion and anoxia-reoxygenation of trophoblast during placental development, the abundance of trophoblastic iron and PUFA, physiological uterine contractions, or pathological placental bed perfusion, cause placental trophoblasts' susceptibility to ferroptosis. Ferroptosis of trophoblast can cause placental dysfunction, which may be involved in the occurrence and development of placenta-related diseases such as gestational diabetes mellitus, preeclampsia, fetal growth restriction, preterm birth, and abortion. The regulatory mechanisms of trophoblastic ferroptosis still need to be explored further. Here, we summarize the latest progress in trophoblastic ferroptosis research on placental-related diseases, provide references for further understanding of its pathogenesis, and propose new strategies for the prevention and treatment of placental-related diseases.

Emerging roles of ferroptosis-related miRNAs in tumor metastasis

Ferroptosis, a novel mode of cell death dependent on iron and reactive oxygen species, has been extensively explored during malignant tumors metastasis. Ferroptosis can interact with multiple components of the tumor microenvironment to regulate metastasis. These interactions generally include the following aspects: (1) Epithelial-mesenchymal transformation, which can help cancer cells increase their sensitivity to ferroptosis while they have multiple mechanisms to fight against it; (2) Disorder of iron metabolism in cancer stem cells which maintains their stem characteristics; (3) Polarization of M0 macrophages to M2. (4) The paradoxical effects of iron metabolism and CD8 + T cells induced by ferroptosis (5) Regulation of angiogenesis. In addition, ferroptosis can be regulated by miRNAs through the reprogramming of various intracellular metabolism processes, including the regulation of the glutathione- glutathione peroxidase 4 pathway, glutamic acid/cystine transport, iron metabolism, lipid metabolism, and oxidative stress. Therefore, there are many potential interactions between ferroptosis-related miRNAs and tumor metastasis, including interaction with cancer cells and immune cells, regulating cytokines, and angiogenesis. This review focuses on the role of ferroptosis-related miRNA in tumor metastasis, aiming to help readers understand their relationship and provide a new perspective on the potential treatment strategies of malignant tumors.

Ferroptosis and Traditional Chinese Medicine for Type 2 Diabetes Mellitus

Ferroptosis, an emerging form of regulated programmed cell death, has garnered significant attention in the past decade. It is characterized by the accumulation of lipid peroxides and subsequent damage to cellular membranes, which is dependent on iron. Ferroptosis has been implicated in the pathogenesis of various diseases, including tumors and diabetes mellitus. Traditional Chinese medicine (TCM) has unique advantages in preventing and treating type 2 diabetes mellitus (T2DM) due to its anti-inflammatory, antioxidant, immunomodulatory, and intestinal flora-regulating functions. Recent studies have determined that TCM may exert therapeutic effects on T2DM and its complications by modulating the ferroptosis-related pathways. Therefore, a comprehensive and systematic understanding of the role of ferroptosis in the pathogenesis and TCM treatment of T2DM is of great significance for developing therapeutic drugs for T2DM and enriching the spectrum of effective T2DM treatment with TCM. In this review, we review the concept, mechanism, and regulatory pathways of ferroptosis and the ferroptosis mechanism of action involved in the development of T2DM. Also, we develop a search strategy, establish strict inclusion and exclusion criteria, and summarize and analyze the application of the ferroptosis mechanism in TCM studies related to T2DM and its complications. Finally, we discuss the shortcomings of current studies and propose a future research focus.

Homocysteine induces ferroptosis in endothelial cells through the systemXc-/GPX4 signaling pathway

OBJECTIVES

To investigate whether ferroptosis is involved in HCY-induced endothelial injury and the possible mechanism of HCY-induced ferroptosis.

METHODS

EA. hy926 cells were cultured in vitro. Cells were intervened using HCY and Fer-1. The cells were divided into Control groups, HCY (4 mM), HCY (8 mM), HCY + Fer-1 (4 mM HCY + 0.5/2.5/5 µM Fer-1). CCK-8 assay was used to detect cell viability; Flow Cytometry was used to detect cellular Lip-ROS, TBA and Microplate assay was used to detect MDA&GSH, Western blot was used to detect the expression of ferroptosis-related proteins GPX4 and SLC7A11.

RESULTS

HCY can inhibited the proliferation of EA. hy926 cells in a time- and concentration-dependent manner; Fer-1 inhibits HCY-induced ferroptosis in EA.hy926 cells in a concentration-dependent manner; Compared with the control group, the cell viability and GSH content in the HCY group was significantly decreased (p < 0.05), and the Lip-ROS and MDA were significantly increased (p < 0.05); After co-culture of HCY and Fer-1, compared with the HCY (4 mM) group, the cell viability and GSH content in the co-culture group were significantly increased (p < 0.05), and the Lip-ROS and MDA were significantly decreased (p < 0.05) in a concentration-dependent manner; Western blotting results showed that the protein expression levels of ferroptosis-related proteins GPX4 and SLC7A11 in each experimental were significantly decreased after HCY treatment (p < 0.05), and Fer-1 could significantly reverse this effect.

CONCLUSIONS

(1) HCY can induce ferroptosis in vascular endothelial cells. (2) HCY may induce vascular endothelial cell ferroptosis through the system Xc-GSH-GPX4 signaling pathway.

Can pyroptosis be a new target in rheumatoid arthritis treatment?

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease of undefined etiology, with persistent synovial inflammation and destruction of articular cartilage and bone. Current clinical drugs for RA mainly include non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, disease modifying anti-rheumatic drugs (DMARDs) and so on, which can relieve patients' joint symptoms. If we want to have a complete cure for RA, there are still some limitations of these drugs. Therefore, we need to explore new mechanisms of RA to prevent and treat RA radically. Pyroptosis is a newly discovered programmed cell death (PCD) in recent years, which is characterized by the appearance of holes in cell membranes, cell swelling and rupture, and the release of intracellular pro-inflammatory factors into the extracellular space, resulting in a strong inflammatory response. The nature of pyroptosis is pro-inflammatory, and whether it is participating in the development of RA has attracted a wide interest among scholars. This review describes the discovery and mechanism of pyroptosis, the main therapeutic strategies for RA, and the role of pyroptosis in the mechanism of RA development. From the perspective of pyroptosis, the study of new mechanisms of RA may provide a potential target for the treatment of RA and the development of new drugs in the clinics.

Isoorientin reverses lung cancer drug resistance by promoting ferroptosis via the SIRT6/Nrf2/GPX4 signaling pathway

Cisplatin, or DDP, is a highly successful and well-known chemotherapy drug used to treat cancer. Acquired resistance to chemotherapy is a major clinical concern, yet the mechanisms of this resistance are still unknown. Ferroptosis is a type of cell death distinct from other forms, fueled by a buildup of iron-associated lipid reactive oxygen species (ROS). Gaining insight into the process of ferroptosis could lead to novel treatments for overcoming cancer resistance. In this study, the combination of isoorientin (IO) and DDP treatment resulted in a significant decrease in the viability of drug-resistant cells, a substantial increase in intracellular iron, malondialdehyde (MDA) and ROS concentrations, a notable decrease in glutathione concentration, and the occurrence of ferroptosis in cells, as revealed by in vitro and in vivo experiments. Additionally, there was a decrease in the expression of nuclear factor-erythroid factor 2-related factor 2 (Nrf2), glutathione peroxidase 4 (GPX4), and sirtuin 6 (SIRT6) proteins, and an increase in cellular ferroptosis. Isoorientin acts as a mediator to regulate cellular ferroptosis and reverse drug resistance in lung cancer cells by controlling the SIRT6/Nrf2/GPX4 signaling pathway. The findings of this study suggest that IO can promote ferroptosis and reverse drug resistance in lung cancer through the SIRT6/Nrf2/GPX4 signaling pathway, thus offering a theoretical basis for its potential clinical application.

Effects of Iron Nanoparticles Administration on Ischemia/Reperfusion Injury in Isolated Hearts of Male Wistar Rats

Iron is an essential mineral participating in numerous biological processes in the organism under physiological conditions. However, it may be also involved in the pathological mechanisms activated in various cardiovascular diseases including myocardial ischemia/reperfusion (I/R) injury, due to its involvement in reactive oxygen species (ROS) production. Furthermore, iron has been reported to participate in the mechanisms of iron-dependent cell death defined as "ferroptosis". On the other hand, iron may be also involved in the adaptive processes of ischemic preconditioning (IPC). This study aimed to elucidate whether small amounts of iron may modify the cardiac response to I/R in isolated perfused rat hearts and their protection by IPC. Pretreatment of the hearts with iron nanoparticles 15 min prior to sustained ischemia (iron preconditioning, Fe-PC) did not attenuate post-I/R contractile dysfunction. Recovery of left ventricular developed pressure (LVDP) was significantly improved only in the group with combined pretreatment with iron and IPC. Similarly, the rates of contraction and relaxation [+/-(dP/dt)max] were almost completely restored in the group preconditioned with a combination of iron and IPC but not with iron alone. In addition, the severity of reperfusion arrhythmias was reduced only in the iron+IPC group. No changes in protein levels of "survival" kinases of the RISK pathway (Reperfusion Injury Salvage Kinase) were found except for reduced caspase 3 levels in both preconditioned groups. The results indicate that a failure to precondition rat hearts with iron may be associated with the absent upregulation of RISK proteins and the pro-ferroptotic effect manifested by reduced glutathione peroxidase 4 (GPX4) levels. However, combination with IPC suppressed the negative effects of iron resulting in cardioprotection.