Dysregulation of Iron Homeostasis in the Central Nervous System and the Role of Ferroptosis in Neurodegenerative Disorders

Role of iron in brain development, aging, and neurodegenerative diseases

It is now understood that iron crosses the blood-brain barrier via a complex metabolic regulatory network and participates in diverse critical biological processes within the central nervous system, including oxygen transport, energy metabolism, and the synthesis and catabolism of myelin and neurotransmitters. During brain development, iron is distributed throughout the brain, playing a pivotal role in key processes such as neuronal development, myelination, and neurotransmitter synthesis. In physiological aging, iron can selectively accumulate in specific brain regions, impacting cognitive function and leading to intracellular redox imbalance, mitochondrial dysfunction, and lipid peroxidation, thereby accelerating aging and associated pathologies. Furthermore, brain iron accumulation may be a primary contributor to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Comprehending the role of iron in brain development, aging, and neurodegenerative diseases, utilizing iron-sensitive Magnetic Resonance Imaging (MRI) technology for timely detection or prediction of abnormal neurological states, and implementing appropriate interventions may be instrumental in preserving normal central nervous system function.

The cGAS-STING-mediated ROS and ferroptosis are involved in manganese neurotoxicity

Manganese (Mn) has been characterized as an environmental pollutant. Excessive releases of Mn due to human activities have increased Mn levels in the environment over the years, posing a threat to human health and the environment. Long-term exposure to high concentrations of Mn can induce neurotoxicity. Therefore, toxicological studies on Mn are of paramount importance. Mn induces oxidative stress through affecting the level of reactive oxygen species (ROS), and the overabundance of ROS further triggers ferroptosis. Additionally, Mn2+ was found to be a novel activator of the cyclic guanosine-adenosine synthase (cGAS)-stimulator of interferon genes (STING) pathway in the innate immune system. Thus, we speculate that Mn exposure may promote ROS production by activating the cGAS-STING pathway, which further induces oxidative stress and ferroptosis, and ultimately triggers Mn neurotoxicity. This review discusses the mechanism between Mn-induced oxidative stress and ferroptosis via activation of the cGAS-STING pathway, which may offer a prospective direction for future in-depth studies on the mechanism of Mn neurotoxicity.

Adiponectin ameliorates traumatic brain injury-induced ferroptosis through AMPK- ACC1 signaling pathway

Various forms of neuronal death contribute to neurological injury after traumatic brain injury (TBI), leading to irreversible neurological deficits. Among these, ferroptosis is a form of regulated cell death characterized by the accumulation of iron-dependent lipid hydroperoxides and induced by the incorporation of polyunsaturated fatty acids (PUFAs) into cellular membranes. Adiponectin (APN), a cytokine secreted by adipocytes, have showed neuroprotective effects by binding to adiponectin receptors (AdipoRs), which are widely expressed in the central nervous system. However, the role of APN-AdipoRs signaling in ferroptosis after TBI remains unexplored. Our clinical analysis revealed a significant correlation between serum levels of APN and 6-month outcomes of TBI patients. Subsequent studies confirmed that TBI-induced ferroptosis was more pronounced in APN knockout mice compared to wild-type mice, while additional APN receptor agonist (AdipoRon) treatment significantly mitigated TBI induced ferroptosis. Furthermore, AdipoR1 knockdown significantly diminished the protective effects of AdipoRon against erastin-induced ferroptosis in primary neurons. Correspondingly, in the neuron-specific AdipoR1 conditional knockout (AdipoR1CKO) mice, neurons were more susceptible to ferroptosis after TBI, leading to increased brain edema and lesion volume, and exacerbated neurological deficits. Mechanically, activation of APN-AdipoR1 signaling promoted adenosine monophosphate activated protein kinase (AMPK) -mediated phosphorylation of acetyl-CoA carboxylase-1 (ACC1), thus suppressed the PUFAs biosynthesis, which determines theferroptosissensitivity of neurons. Taken together, these findings provided compelling evidence for the protective role of APN-AdipoR1 signaling against TBI-induced ferroptosis by inhibiting AMPK-ACC1.

The role of microglia in neurodegenerative diseases: from the perspective of ferroptosis

Iron plays a pivotal role in numerous fundamental biological processes in the brain. Among the various cell types in the central nervous system, microglia are recognized as the most proficient cells in accumulating and storing iron. Nonetheless, iron overload can induce inflammatory phenotype of microglia, leading to the production of proinflammatory cytokines and contributing to neurodegeneration. A growing body of evidence shows that disturbances in iron homeostasis in microglia is associated with a range of neurodegenerative disorders. Recent research has revealed that microglia are highly sensitive to ferroptosis, a form of iron-dependent cell death. How iron overload influences microglial function? Whether disbiosis in iron metabolism and ferroptosis in microglia are involved in neurodegenerative disorders and the underlying mechanisms remain to be elucidated. In this review we focus on the recent advances in research on microglial iron metabolism as well as ferroptosis in microglia. Meanwhile, we provide a comprehensive overview of the involvement of microglial ferroptosis in neurodegenerative disorders from the perspective of crosstalk between microglia and neuron, with a focus on Alzheimer's disease and Parkinson's disease.

The interplay of iron, oxidative stress, and α-synuclein in Parkinson's disease progression

The irreversible degeneration of dopamine neurons induced by α-synuclein (α-syn) aggregation in the substantia nigra is the central pathological feature of Parkinson's disease (PD). Neuroimaging and pathological autopsy studies consistently confirm significant iron accumulation in the brain of PD patients, suggesting a critical role for iron in disease progression. Current research has established that iron overload induces ferroptosis in dopaminergic neurons, evidence indicates that the impact of iron on PD pathology extends beyond ferroptosis. Iron also plays a regulatory role in modulating α-syn, affecting its aggregation, spatial conformation, post-translational modifications, and mRNA stability. Iron-induced α-syn aggregation can contribute to dopaminergic neurodegeneration through additional mechanisms, potentially creating a feedback loop in which α-syn further enhances iron accumulation, thus perpetuating a vicious cycle of neurotoxicity. Given α-syn's intrinsically disordered structure, targeting iron metabolism presents a promising therapeutic strategy for PD. Therefore, the development of iron chelators, alone or in combination with other therapeutic drugs, may offer a beneficial approach to alleviating PD symptoms and slowing disease progression.

Ferroptosis targeting offers a therapeutic target for septic cardiomyopathy

Sepsis-induced cardiac dysfunction, usually termed sepsis-induced cardiomyopathy or septic cardiomyopathy(SCM), is developed in approximately 70 % of the patients with sepsis, making it is a major concern for sepsis patients. However, the pathogenesis of SCM remain incompletely understood. Ferroptosis, a newly identified mechanism of regulated cell death, characterized by a decline in antioxidant capacity, iron accumulation, and lipid peroxidation(LPO), is involved in sepsis and SCM. Moreover, ferroptosis inhibitors confer a novel therapeutic regimen in SCM. In this Review, we first summarizes the core mechanism of ferroptosis, with an emphasis on how best to interpret ferroptosis leads to the genesis of SCM. We then highlights our focus on the emerging different types of therapeutic ferroptosis inhibitors and summarizes their pharmacological beneficial effect to treat SCM. This review highlights a novel potential therapeutic strategy for SCM by pharmacologically inhibiting ferroptosis.

Natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in central nervous system diseases: current preclinical evidence and future perspectives

Flavonoids are a class of important polyphenolic compounds, renowned for their antioxidant properties. However, recent studies have uncovered an additional function of these natural flavonoids: their ability to inhibit ferroptosis. Ferroptosis is a key mechanism driving cell death in central nervous system (CNS) diseases, including both acute injuries and chronic neurodegenerative disorders, characterized by iron overload-induced lipid peroxidation and dysfunction of the antioxidant defense system. This review discusses the therapeutic potential of natural flavonoids from herbs and nutraceuticals as ferroptosis inhibitors in CNS diseases, focusing on their molecular mechanisms, summarizing findings from preclinical animal models, and providing insights for clinical translation. We specifically highlight natural flavonoids such as Baicalin, Baicalein, Chrysin, Vitexin, Galangin, Quercetin, Isoquercetin, Eriodictyol, Proanthocyanidin, (-)-epigallocatechin-3-gallate, Dihydromyricetin, Soybean Isoflavones, Calycosin, Icariside II, and Safflower Yellow, which have shown promising results in animal models of acute CNS injuries, including ischemic stroke, cerebral ischemia-reperfusion injury, intracerebral hemorrhage, subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury. Among these, Baicalin and its precursor Baicalein stand out due to extensive research and favorable outcomes in acute injury models. Mechanistically, these flavonoids not only regulate the Nrf2/ARE pathway and activate GPX4/GSH-related antioxidant pathways but also modulate iron metabolism proteins, thereby alleviating iron overload and inhibiting ferroptosis. While flavonoids show promise as ferroptosis inhibitors for CNS diseases, especially in acute injury settings, further studies are needed to evaluate their efficacy, safety, pharmacokinetics, and blood-brain barrier penetration for clinical application.

Ferroptosis in neurodegenerative diseases: mechanisms and therapeutic potential of stem cell derivatives

Ferroptosis, a non-apoptotic, iron-dependent form of regulated cell death, is closely related to the pathogenesis of neurodegenerative diseases. Stem cells and their derivatives exhibit remarkable potential in modulating ferroptosis, offering promising therapeutic intervention for neurodegenerative diseases. In this review, we systematically explore neurological aging and its association with cognitive impairment and neurodegenerative diseases, with focus on the molecular mechanisms of ferroptosis in neurodegenerative diseases and the potential therapeutic strategies of stem cell derivatives for neurological diseases.

Capacity of fullerenols to modulate neurodegeneration induced by ferroptosis: Focus on multiple sclerosis

Multiple sclerosis is an inflammatory disease of the central nervous system (CNS), characterized by oligodendrocyte loss and demyelination of axons leading to neurodegeneration and severe neurological disability. Despite the existing drugs that have immunomodulatory effects an adequate therapy that slow down or stop neuronal death has not yet been found. Oxidative stress accompanied by excessive release of iron into the extracellular space, mitochondrial damage and lipid peroxidation are important factors in the controlled cell death named ferroptosis, latterly recognized in MS. As the fullerenols exhibit potent antioxidant activity, recent results imply that they could have protective effects by suppressing ferroptosis. Based on the current knowledge we addressed the main mechanisms of the protective effects of fullerenols in the CNS in relation to ferroptosis. Inhibition of inflammation, iron overload and lipid peroxidation through the signal transduction mechanism of Nuclear Factor Erythroid 2-Related Factor 2 (NRF2), chelation of heavy metals and free radical scavenging using fullerenols are proposed as benefitial strategy preventing MS progression. Current review connects ferroptosis molecular targets and important factors of MS progression, with biomedical properties and mechanisms of fullerenols' actions, to propose new treatment strategies that could be addaptobale in other neurodegenerative diseases.

Acteoside alleviates salsolinol-induced Parkinson's disease by inhibiting ferroptosis via activating Nrf2/SLC7A11/GPX4 pathway

Salsolinol (SAL), i.e.1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroiso-quinoline, is a dopamine metabolite and endogenous neurotoxin that is toxic to dopaminergic neurons, and is involved in the genesis of Parkinson's disease (PD). However, the machinery underlying SAL induces neurotoxicity in PD are still being elucidated. In the present study, we first used RNA sequencing (RNAseq) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to detect differentially expressed genes in SAL-treated SH-SY5Y cells. We found that ferroptosis-related pathway was enriched by SAL, which was validated by in vitro and in vivo SAL models. SAL inducing ferroptosis through downregulating SLC7A11/GPX4 in SH-SY5Y cells, which neurotoxic effect was reversed by ferroptosis inhibitors deferoxamine (DFO) and ferrostatin-1 (Fer-1). Acteoside, a phenylethanoid glycoside of plant origin with neuroprotective effect, attenuates SAL-induced neurotoxicity by inhibiting ferroptosis in in vitro and in vivo PD models through upregulating SLC7A11/GPX4. Mechanistically, acteoside activates Nrf2. Nrf2 inhibitor ML385 abolished acteoside-mediated increased SLC7A11/GPX4 and neuroprotection against SAL in SH-SY5Y cells. Meanwhile, the PI3K inhibitor LY294002 suppressed the acteoside-induced Nrf2 expression and ensued decreased expression of SLC7A11/GPX4 in SAL-treated SH-SY5Y cells. Taken together, these results demonstrate that salsolinol-induced PD through inducing ferroptosis via downregulating SLC7A11/GPX4. Acteoside attenuates SAL-induced PD through inhibiting ferroptosis via activating PI3K/Akt-dependant Nrf2. The present study revealed a novel molecular mechanisms underlining SAL-induced neurotoxicity via induction of ferroptosis in PD, and uncovered a new pharmacological effect against PD through inhibiting ferroptosis. This study highlights SAL-induced ferroptosis -dependent neurotoxicity as a potential therapeutic target in PD.

Mitochondrial dysfunction, iron accumulation, lipid peroxidation, and inflammasome activation in cellular models derived from patients with multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Despite advancements in managing relapsing active illness, effective treatments for the irreversible progressive decline in MS remain limited. Research employing skin fibroblasts obtained from patients with neurological disorders revealed modifications in cellular stress pathways and bioenergetics. However, research using MS patient-derived cellular models is scarce. In this study, we collected fibroblasts from two MS patients to investigate cellular pathological alterations. We observed that MS fibroblasts showed a senescent morphology associated with iron/lipofuscin accumulation and altered expression of iron metabolism proteins. In addition, we found increased lipid peroxidation and downregulation of antioxidant enzymes expression levels in MS fibroblasts. When challenged against erastin, a ferroptosis inducer, MS fibroblasts showed decreased viability, suggesting increased sensitivity to ferroptosis. Furthermore, MS fibroblasts presented alterations in the expression levels of autophagy-related proteins. Interestingly, these alterations were associated with mitochondrial dysfunction and inflammasome activation. These findings were validated in 7 additional patient-derived cell lines. Our findings suggest that the underlying stress phenotype of MS fibroblasts may be disease-specific and recapitulate the main cellular pathological alterations found in the disease such as mitochondrial dysfunction, iron accumulation, lipid peroxidation, inflammasome activation, and pro-inflammatory cytokine production.

Targeting ferroptosis offers therapy choice in sepsis-associated acute lung injury

Sepsis-associated acute lung injury (SALI) is a common complication of sepsis, consisting of a dysfunctional host response to infection-mediated heterogenous complexes. SALI is reported in up to 50 % of patients with sepsis and causes poor outcomes. Despite high incidence, there is a lack of understanding in its pathogenesis and optimal treatment. A better understanding of the molecular mechanisms underlying SALI may help produce better therapeutics. The effects of altered cell-death mechanisms, such as non-apoptotic regulated cell death (RCD) (i.e., ferroptosis), on the development of SALI are beginning to be discovered, while targeting ferroptosis as a meaningful target in SALI is increasingly being recognized. Here, we outline how a susceptible lung alveoli may develop SALI. Then we discuss the general mechanisms underlying ferroptosis, and how it contributes to SALI. We then outline the chemical structures of the emerging agents or compounds that can protect against SALI by inhibiting ferroptosis, summarizing their potential pharmacological effects. Finally, we highlight key limitations and possible strategies to overcome them. This review suggests that a detailed mechanistic and biological understanding of ferroptosis can foster the development of pharmacological antagonists in the treatment of SALI.

Ferroptosis in schizophrenia: Mechanisms and therapeutic potentials (Review)

Schizophrenia, a complex psychiatric disorder, presents with multifaceted symptoms and important challenges in treatment, primarily due to its pathophysiological complexity, which involves oxidative stress and aberrant iron metabolism. Recent insights into ferroptosis, a unique form of iron‑dependent cell death characterized by lipid peroxidation and antioxidant system failures, open new avenues for understanding the neurobiological foundation of schizophrenia. The present review explores the interplay between ferroptosis and schizophrenia, emphasizing the potential contributions of disrupted iron homeostasis and oxidative mechanisms to the pathology and progression of this disease. The emerging evidence linking ferroptosis with the oxidative stress observed in schizophrenia provides a compelling narrative for re‑evaluating current therapeutic strategies and exploring novel interventions targeting these molecular pathways, such as the glutathione peroxidase 4 pathway and the ferroptosis suppressor protein 1 pathway. By integrating recent advances in ferroptosis research, the current review highlights innovative therapeutic potentials, including N‑acetylcysteine, selenium, omega‑3 fatty acids and iron chelation therapy, which could address the limitations of existing treatments and improve clinical outcomes for individuals with schizophrenia.

Glycosylated lysosomal membrane protein promotes tissue repair after spinal cord injury by reducing iron deposition and ferroptosis in microglia

Excessive iron deposition can lead to ferroptosis, a form of iron-dependent cell death detrimental to neuronal survival. Microglia have been identified as having a high capacity for iron deposition, yet it remains unclear whether microglia undergo ferroptosis while phagocytosing excessive amounts of iron after spinal cord injury (SCI). Here, we observed scattered iron around the epicenter of the injured spinal cord at 7 days post-injury (dpi) in mice, which then accumulated in the lesion core at 14 dpi. Concurrently, microglia exhibited elevated expression of the iron-storage protein ferritin and were found to undergo ferroptosis between 7 and 28 dpi. Additionally, we noted a gradual decrease in glycosylated lysosomal membrane protein (GLMP) which is associated with iron metabolism in microglia undergoing ferroptosis. In situ injection of AAV9-Cx3cr1-shGlmp-eGFP to knock down GLMP specifically in microglia resulted in a significant increase in iron deposition and ferroptosis, leading to an expanded lesion area, aggravated neuronal loss, and subsequent inhibition of functional restoration. Our findings highlight the crucial role of GLMP in mitigating iron overload and ferroptosis in microglia, thereby contributing to axon retention and locomotor recovery after SCI.

Progressive iron overload in middle-aged mice impairs olfactory function, triggers lipid oxidation and induces apoptosis

Introduction

This study aims to investigate the progressive impact of chronic iron overload on the olfactory bulb, a region significantly affected in early neurodegenerative diseases like Parkinson's and Alzheimer's. The focus is on understanding how iron accumulation leads to oxidative stress, mitochondrial dysfunction, and neuronal damage over time in middle-aged mice.

Method

The mice were continuously administered FC for a duration of 16 weeks, and the olfactory behavior of the mice was observed at intervals of 4 weeks. Inductively coupled plasma mass spectrometry (ICP-MS) was employed to detect alterations in iron content within the olfactory bulb of the mice, while levels of lipid peroxidation and antioxidant indexes were assessed using biochemical kits. Additionally, western blotting and qPCR techniques were utilized to analyze transcriptional and expression changes in proteins and genes related to iron metabolism. Furthermore, microstructural modifications as well as mitochondrial observations were conducted through paraffin sectioning and transmission electron microscopy (TEM).

Result

A significant and progressive increase in iron accumulation in the olfactory bulb, starting from week 8 and peaking at week 16. This accumulation coincided with a decline in olfactory function observed at week 12. Key markers of oxidative stress, such as 4-HNE and MDA, were elevated in specific layers, and antioxidant defenses were reduced. Mitochondrial damage became evident from week 8, with caspase-3 activation indicating increased apoptosis, particularly in the granular layer. This study is to demonstrate the link between chronic iron overload and progressive olfactory dysfunction in the context of neurodegenerative diseases. It provides evidence that iron-induced oxidative stress and mitochondrial damage in the olfactory bulb contribute to early sensory deficits, suggesting that the olfactory bulb's selective vulnerability can serve as an early biomarker for neurodegenerative conditions.

Conclusion

Chronic iron overload leads to progressive oxidative damage, mitochondrial dysfunction, and apoptosis in the olfactory bulb, causing sensory deficits. Targeting iron accumulation and oxidative damage may offer new strategies for early intervention in neurodegenerative diseases, highlighting the importance of addressing iron dysregulation.

Ginsenoside compound K alleviates brain aging by inhibiting ferroptosis through modulation of the ASK1-MKK7-JNK signaling pathway

BACKGROUND

Aging of the brain is a major contributor to the onset and progression of neurodegenerative diseases. Conventional treatments for these diseases are often limited by significant side effects and a lack of efficacy in halting disease progression. Ginsenoside compound K (CK), a bioactive secondary metabolite derived from ginseng, has shown promise because of its potent antioxidant properties.

PURPOSE

This study aimed to elucidate the molecular mechanisms underlying the impact of CK on brain senescence, with a particular focus on its role in modulating oxidative stress and related signaling pathways.

METHODS

We employed a d-galactose (D-gal)-induced PC-12 senescent cell model and a mouse brain aging model to explore the antioxidant properties of CK in the context of brain aging. The effects of CK on mitochondrial dysfunction associated with brain aging were assessed using immunofluorescence and western blotting techniques. The potential molecular mechanisms by CK influences brain aging were investigated using transcriptomic analysis and western blotting. Additionally, CK's regulatory effect on apoptosis signal-regulating kinase 1 (ASK1) was validated by molecular docking, microscale thermophoresis, and small interfering RNA transfection.

RESULTS

Our findings demonstrate that CK effectively alleviates cognitive decline associated with brain aging. CK reduces the number of senescent cells, alleviates neuronal damage, and enhances the activity of key antioxidant enzymes, including catalase, superoxide dismutase, and glutathione peroxidase. Additionally, CK restores mitochondrial function and upregulated the expression of solute carrier family 7 member 11 and glutathione peroxidase 4, thereby inhibiting ferroptosis. Furthermore, CK targets ASK1 and suppresses the hyperphosphorylation of MAPK kinase 7 (MKK7) and c-Jun N-terminal kinase (JNK). This suppression promotes the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2), effectively reducing ferroptosis and oxidative damage linked to brain aging.

CONCLUSION

In summary, our research demonstrates that CK effectively delays brain aging by inhibiting the ASK1-MKK7-JNK signaling pathway, enhancing nuclear Nrf2 expression, and suppressing the ferroptosis response. These findings highlight CK as a promising therapeutic agent for slowing brain aging and alleviating neurodegenerative diseases.

The insular cortex, autonomic asymmetry and cardiovascular control: looking at the right side of stroke

PURPOSE

Evidence from animal and human studies demonstrates that cortical regions play a key role in autonomic modulation with a differential role for some brain regions located in the left and right brain hemispheres. Known as autonomic asymmetry, this phenomenon has been demonstrated by clinical observations, by experimental models, and currently by combined neuroimaging and direct recordings of sympathetic nerve activity. Previous studies report peculiar autonomic-mediated cardiovascular alterations following unilateral damage to the left or right insula, a multifunctional key cortical region involved in emotional processing linked to autonomic cardiovascular control and featuring asymmetric characteristics.

METHODS

Based on clinical studies reporting specific damage to the insular cortex, this review aims to provide an overview of the prognostic significance of unilateral (left or right hemisphere) post-insular stroke cardiac alterations. In addition, we review experimental data aiming to unravel the central mechanisms involved in post-insular stroke cardiovascular complications.

RESULTS AND CONCLUSION

Current clinical and experimental data suggest that stroke of the right insula  can present a worse cardiovascular prognosis.

Circulatory Indicators of Lipid Peroxidation, the Driver of Ferroptosis, Reflect Differences between Relapsing-Remitting and Progressive Multiple Sclerosis

Ferroptosis, a lipid peroxidation- and iron-mediated type of regulated cell death, relates to both neuroinflammation, which is common in relapsing-remitting multiple sclerosis (RRMS), and neurodegeneration, which is prevalent in progressive (P)MS. Currently, findings related to the molecular markers proposed in this paper in patients are scarce. We analyzed circulatory molecular indicators of the main ferroptosis-related processes, comprising lipid peroxidation (malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), and hexanoyl-lysine adduct (HEL)), glutathione-related antioxidant defense (total glutathione (reduced (GSH) and oxidized (GSSG)) and glutathione peroxidase 4 (GPX4)), and iron metabolism (iron, transferrin and ferritin) to estimate their contributions to the clinical manifestation of MS and differences between RRMS and PMS disease course. In 153 patients with RRMS and 69 with PMS, plasma/serum lipid peroxidation indicators and glutathione were quantified using ELISA and colorimetric reactions, respectively. Iron serum concentrations were determined using spectrophotometry, and transferrin and ferritin were determined using immunoturbidimetry. Compared to those with RRMS, patients with PMS had decreased 4-HNE (median, 1368.42 vs. 1580.17 pg/mL; p = 0.03). Interactive effects of MS course (RRMS/PMS) and disease-modifying therapy status on MDA (p = 0.009) and HEL (p = 0.02) levels were detected. In addition, the interaction of disease course and self-reported fatigue revealed significant impacts on 4-HNE levels (p = 0.01) and the GSH/GSSG ratio (p = 0.04). The results also show an association of MS course (p = 0.03) and EDSS (p = 0.04) with GSH levels. No significant changes were observed in the serum concentrations of iron metabolism indicators between the two patient groups (p > 0.05). We suggest circulatory 4-HNE as an important parameter related to differences between RRMS and PMS. Significant interactions of MS course and other clinically relevant parameters with changes in redox processes associated with ferroptosis support the further investigation of MS with a larger sample while taking into account both circulatory and central nervous system estimation.

Targeting Ferroptosis as an Advance Strategy in Cancer Therapy

Significance: This study innovates by systematically integrating the molecular mechanisms of iron death and its application in cancer therapy. By deeply analyzing the interaction between iron death and the tumor microenvironment, the study provides a new theoretical basis for cancer treatment and directions for developing more effective treatment strategies. In addition, the study points to critical issues and barriers that need to be addressed in future research, providing valuable insights into the use of iron death in clinical translation. Recent Advances: These findings are expected to drive further advances in cancer treatment, bringing patients more treatment options and hope. Through this paper, we see the great potential of iron death in cancer treatment and look forward to more research results being translated into clinical applications in the future to contribute to the fight against cancer. Critical Issues: In today's society, cancer is still one of the major diseases threatening human health. Despite advances in existing treatments, cancer recurrence and drug resistance remain a severe problem. These problems increase the difficulty of treatment and bring a substantial physical and mental burden to patients. Therefore, finding new treatment strategies to overcome these challenges has become significant. Future Directions: The study delved into the molecular basis of iron death in tumor biology. It proposed a conceptual framework to account for the interaction of iron death with the tumor immune microenvironment, guide treatment selection, predict efficacy, explore combination therapies, and identify new therapeutic targets to overcome cancer resistance to standard treatments, peeving a path for future research and clinical translation of ferroptosis as a potential strategy in cancer therapy. Antioxid. Redox Signal. 41, 616-636. [Figure: see text].

Regulating ferroptosis by non-coding RNAs in hepatocellular carcinoma

Ferroptosis, a unique type of regulated cell death plays a vital role in inhibiting tumour malignancy and has presented new opportunities for treatment of therapy in hepatocellular carcinoma. Accumulating studies indicate that epigenetic modifications by non-coding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, can determine cancer cell vulnerability to ferroptosis in HCC. The present review first summarize the updated core molecular mechanisms of ferroptosis. We then provide a concised overview of epigenetic modification of ferroptosis in HCC. Finally, we review the recent progress in understanding of the ncRNA-mediated regulated mechanisms on ferroptosis in HCC. The review will promote our understanding of the ncRNA-mediated epigenetic regulatory mechanisms modulating ferroptosis in malignancy of HCC, highlighting a novel strategies for treatment of HCC through targeting ncRNA-ferroptosis axis.

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.

Tremendous Fidelity of Vitamin D3 in Age-related Neurological Disorders

Vitamin D3 (VD) is a secosteroid hormone and shows a pleiotropic effect in brain-related disorders where it regulates redox imbalance, inflammation, apoptosis, energy production, and growth factor synthesis. Vitamin D3's active metabolic form, 1,25-dihydroxy Vitamin D3 (1,25(OH)2D3 or calcitriol), is a known regulator of several genes involved in neuroplasticity, neuroprotection, neurotropism, and neuroinflammation. Multiple studies suggest that VD deficiency can be proposed as a risk factor for the development of several age-related neurological disorders. The evidence for low serum levels of 25-hydroxy Vitamin D3 (25(OH)D3 or calcidiol), the major circulating form of VD, is associated with an increased risk of Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), dementia, and cognitive impairment. Despite decades of evidence on low VD association with neurological disorders, the precise molecular mechanism behind its beneficial effect remains controversial. Here, we will be delving into the neurobiological importance of VD and discuss its benefits in different neuropsychiatric disorders. The focus will be on AD, PD, and HD as they share some common clinical, pathological, and epidemiological features. The central focus will be on the different attributes of VD in the aspect of its anti-oxidative, anti-inflammatory, anti-apoptotic, anti-cholinesterase activity, and psychotropic effect in different neurodegenerative diseases.

Epigenetic modification of ferroptosis by non-coding RNAs in cancer drug resistance

The development of drug resistance remains a major challenge in cancer treatment. Ferroptosis, a unique type of regulated cell death, plays a pivotal role in inhibiting tumour growth, presenting new opportunities in treating chemotherapeutic resistance. Accumulating studies indicate that epigenetic modifications by non-coding RNAs (ncRNA) can determine cancer cell vulnerability to ferroptosis. In this review, we first summarize the role of chemotherapeutic resistance in cancer growth/development. Then, we summarize the core molecular mechanisms of ferroptosis, its upstream epigenetic regulation, and its downstream effects on chemotherapeutic resistance. Finally, we review recent advances in understanding how ncRNAs regulate ferroptosis and from such modulate chemotherapeutic resistance. This review aims to enhance general understanding of the ncRNA-mediated epigenetic regulatory mechanisms which modulate ferroptosis, highlighting the ncRNA-ferroptosis axis as a key druggable target in overcoming chemotherapeutic resistance.

Abdominal multi-organ iron content and the risk of Parkinson's disease: a Mendelian randomization study

Background

To evaluate the causal relationship between abdominal multi-organ iron content and PD risk using publicly available genome-wide association study (GWAS) data.

Methods

We conducted MR analysis to assess the effects of iron content in various abdominal organs on PD risk, followed by reverse analysis. Additionally, MVMR analysis evaluated the independent effects of organ-specific iron content on PD. We utilized genetic variation data from the UK Biobank, including liver iron content (n = 32,858), spleen iron content (n = 35,324), and pancreas iron content (n = 25,617), as well as summary-level data for Parkinson's disease from the FinnGen (n = 218,473) and two other large GWAS datasets of European populations (First dataset n = 480,018; Second dataset n = 2,829). The primary MR analysis used the inverse variance-weighted (IVW) method, confirmed by MR-Egger and weighted median methods. Sensitivity analysis was performed to address potential pleiotropy and heterogeneity. Observational cohort results were validated through replication cohort analysis, followed by meta-analysis.

Results

IVW analysis revealed a causal relationship between increased liver iron content and elevated risk of PD (OR = 1.27; 95% CI: 1.05-1.53; p = 0.015). No significant causal relationship was observed between spleen (OR = 1.00; 95% CI: 0.76-1.32; p = 0.983) and pancreatic (OR = 0.93; 95% CI: 0.72-1.20; p = 0.573) iron content and increased risk of PD. Meta-analysis of GWAS data for PD from three different sources using the random-effects IVW method showed a statistically significant causal relationship between liver iron content and the occurrence of PD (OR = 1.17, 95% CI: 1.01-1.35; p = 0.012).

Conclusion

This study presents evidence from Mendelian randomization (MR) analysis indicating a significant causal link between increased liver iron content and a higher risk of Parkinson's disease (PD). These findings suggest that interventions targeting body iron metabolism, particularly liver iron levels, may be effective in preventing PD.

Metformin enhances endogenous neural stem cells proliferation, neuronal differentiation, and inhibits ferroptosis through activating AMPK pathway after spinal cord injury

BACKGROUND

Inadequate nerve regeneration and an inhibitory local microenvironment are major obstacles to the repair of spinal cord injury (SCI). The activation and differentiation fate regulation of endogenous neural stem cells (NSCs) represent one of the most promising repair approaches. Metformin has been extensively studied for its antioxidative, anti-inflammatory, anti-aging, and autophagy-regulating properties in central nervous system diseases. However, the effects of metformin on endogenous NSCs remains to be elucidated.

METHODS

The proliferation and differentiation abilities of NSCs were evaluated using CCK-8 assay, EdU/Ki67 staining and immunofluorescence staining. Changes in the expression of key proteins related to ferroptosis in NSCs were detected using Western Blot and immunofluorescence staining. The levels of reactive oxygen species, glutathione and tissue iron were measured using corresponding assay kits. Changes in mitochondrial morphology and membrane potential were observed using transmission electron microscopy and JC-1 fluorescence probe. Locomotor function recovery after SCI in rats was assessed through BBB score, LSS score, CatWalk gait analysis, and electrophysiological testing. The expression of the AMPK pathway was examined using Western Blot.

RESULTS

Metformin promoted the proliferation and neuronal differentiation of NSCs both in vitro and in vivo. Furthermore, a ferroptosis model of NSCs using erastin treatment was established in vitro, and metformin treatment could reverse the changes in the expression of key ferroptosis-related proteins, increase glutathione synthesis, reduce reactive oxygen species production and improve mitochondrial membrane potential and morphology. Moreover, metformin administration improved locomotor function recovery and histological outcomes following SCI in rats. Notably, all the above beneficial effects of metformin were completely abolished upon addition of compound C, a specific inhibitor of AMP-activated protein kinase (AMPK).

CONCLUSION

Metformin, driven by canonical AMPK-dependent regulation, promotes proliferation and neuronal differentiation of endogenous NSCs while inhibiting ferroptosis, thereby facilitating recovery of locomotor function following SCI. Our study further elucidates the protective mechanism of metformin in SCI, providing new mechanistic insights for its candidacy as a therapeutic agent for SCI.

Dietary iron intake has long-term effects on the fecal metabolome and microbiome

Iron is essential for life, but its imbalances can lead to severe health implications. Iron deficiency is the most common nutrient disorder worldwide, and iron dysregulation in early life has been found to cause long-lasting behavioral, cognitive, and neural effects. However, little is known about the effects of dietary iron on gut microbiome function and metabolism. In this study, we sought to investigate the impact of dietary iron on the fecal metabolome and microbiome by using mice fed with three diets with different iron content: an iron deficient, an iron sufficient (standard), and an iron overload diet for 7 weeks. Additionally, we sought to understand whether any observed changes would persist past the 7-week period of diet intervention. To assess this, all feeding groups were switched to a standard diet, and this feeding continued for an additional 7 weeks. Analysis of the fecal metabolome revealed that iron overload and deficiency significantly alter levels of peptides, nucleic acids, and lipids, including di- and tri-peptides containing branched-chain amino acids, inosine and guanosine, and several microbial conjugated bile acids. The observed changes in the fecal metabolome persist long after the switch back to a standard diet, with the cecal gut microbiota composition and function of each group distinct after the 7-week standard diet wash-out. Our results highlight the enduring metabolic consequences of nutritional imbalances, mediated by both the host and gut microbiome, which persist after returning to the original standard diets.

A guide to ferroptosis, the biological rust of cellular membranes

Unprotected iron can rust due to oxygen exposure. Similarly, in our body, oxidative stress can kill cells in an iron-dependent manner, which can give rise to devastating diseases. This type of cell death is referred to as ferroptosis. Generally, ferroptosis is defined as an iron-catalyzed form of regulated necrosis that occurs through excessive peroxidation of polyunsaturated fatty acids within cellular membranes. This review summarizes how ferroptosis is executed by a rather primitive biochemical process, under tight regulation of lipid, iron, and redox metabolic processes. An overview is given of major classes of ferroptosis inducers and inhibitors, and how to detect ferroptosis. Finally, its detrimental role in disease is briefly discussed.

Identifying novel proteins for suicide attempt by integrating proteomes from brain and blood with genome-wide association data

Genome-wide association studies (GWASs) have identified risk loci for suicide attempt (SA), but deciphering how they confer risk for SA remains largely unknown. This study aims to identify the key proteins and gain insights into SA pathogenesis. We integrated data from the brain proteome (N = 376) and blood proteome (N = 35,559) and combined it with the largest SA GWAS summary statistics to date (N = 518,612). A comprehensive set of methods was employed, including Mendelian randomization (MR), Steiger filtering, Bayesian colocalization, proteome‑wide association studies (PWAS), transcript-levels, cell-type specificity, correlation, and protein-protein interaction (PPI) network analysis. Validation was performed using other protein datasets and the SA dataset from FinnGen study. We identified ten proteins (GLRX5, GMPPB, B3GALTL, FUCA2, TTLL12, ADCK1, MMAA, HIBADH, ACP1, DOC2A) associated with SA in brain proteomics. GLRX5, GMPPB, and FUCA2 showed strong colocalization evidence and were supported by PWAS and transcript-level analysis, and were predominantly expressed in glutamatergic neuronal cells. In blood proteomics, one significant protein (PEAR1) and three near-significant proteins (NDE1, EVA1C, B4GALT2) were identified, but lacked colocalization evidence. Moreover, despite the limited correlation between the same protein in brain and blood, the PPI network analysis provided new insights into the interaction between brain and blood in SA. Furthermore, GLRX5 was associated with the GSTP1, the target of Clozapine. The comprehensive analysis provides strong evidence supporting a causal association between three genetically determined brain proteins (GLRX5, GMPPB, and FUCA2) with SA. These findings offer valuable insights into SA's underlying mechanisms and potential therapeutic approaches.

The molecular mechanism of ferroptosis and its relationship with Parkinson's disease

Neurodegenerative diseases such as Parkinson's disease (PD) have complex pathogenetic mechanisms. Genetic, age, and environmental factors are all related to PD. Due to the unclear pathogenesis of PD and the lack of effective cure methods, it is urgent to find new targets for treating PD patients. Ferroptosis is a form of cell death that is reliant on iron and exhibits distinct morphological and mechanistic characteristics compared to other types of cell death. It encompasses a range of biological processes, including iron/lipid metabolism and oxidative stress. In recent years, research has found that ferroptosis plays a crucial role in the pathophysiological processes of neurodegenerative diseases and stroke. Therefore, ferroptosis is also closely related to PD, This article reviews the core mechanisms of ferroptosis and elucidates the correlation between PD and ferroptosis. In addition, new compounds that have emerged in recent years to exert anti PD effects by inhibiting the ferroptosis signaling pathway were summarized. I hope to further elaborate the relationship between ferroptosis and PD through the review of this article, and provide new strategies for developing PD treatments targeting ferroptosis.

Ferroptosis inhibitor improves outcome after early and delayed treatment in mild spinal cord injury

We show that redox active iron can induce a regulated form of non-apoptotic cell death and tissue damage called ferroptosis that can contribute to secondary damage and functional loss in the acute and chronic periods after spinal cord injury (SCI) in young, adult, female mice. Phagocytosis of red blood cells at sites of hemorrhage is the main source of iron derived from hemoglobin after SCI. Expression of hemeoxygenase-1 that induces release of iron from heme, is increased in spinal cord macrophages 7 days after injury. While iron is stored safely in ferritin in the injured spinal cord, it can, however, be released by NCOA4-mediated shuttling of ferritin to autophagosomes for degradation (ferritinophagy). This leads to the release of redox active iron that can cause free radical damage. Expression of NCOA4 is increased after SCI, mainly in macrophages. Increase in the ratio of redox active ferrous (Fe2+) to ferric iron (Fe3+) is also detected after SCI by capillary electrophoresis inductively coupled mass spectrometry. These changes are accompanied by other hallmarks of ferroptosis, i.e., deficiency in various elements of the antioxidant glutathione (GSH) pathway. We also detect increases in enzymes that repair membrane lipids (ACSL4 and LPCAT3) and thus promote on-going ferroptosis. These changes are associated with increased levels of 4-hydroxynonenal (4-HNE), a toxic lipid peroxidation product. Mice with mild SCI (30 kdyne force) treated with the ferroptosis inhibitor (UAMC-3203-HCL) either early or delayed times after injury showed improvement in locomotor recovery and secondary damage. Cerebrospinal fluid and serum samples from human SCI cases show evidence of increased iron storage (ferritin), and other iron related molecules, and reduction in GSH. Collectively, these data suggest that ferroptosis contributes to secondary damage after SCI and highlights the possible use of ferroptosis inhibitors to treat SCI.

Dopamine‑iron homeostasis interaction rescues mitochondrial fitness in Parkinson's disease

Imbalances of iron and dopamine metabolism along with mitochondrial dysfunction have been linked to the pathogenesis of Parkinson's disease (PD). We have previously suggested a direct link between iron homeostasis and dopamine metabolism, as dopamine can increase cellular uptake of iron into macrophages thereby promoting oxidative stress responses. In this study, we investigated the interplay between iron, dopamine, and mitochondrial activity in neuroblastoma SH-SY5Y cells and human induced pluripotent stem cell (hiPSC)-derived dopaminergic neurons differentiated from a healthy control and a PD patient with a mutation in the α-synuclein (SNCA) gene. In SH-SY5Y cells, dopamine treatment resulted in increased expression of the transmembrane iron transporters transferrin receptor 1 (TFR1), ferroportin (FPN), and mitoferrin2 (MFRN2) and intracellular iron accumulation, suggesting that dopamine may promote iron uptake. Furthermore, dopamine supplementation led to reduced mitochondrial fitness including decreased mitochondrial respiration, increased cytochrome c control efficiency, reduced mtDNA copy number and citrate synthase activity, increased oxidative stress and impaired aconitase activity. In dopaminergic neurons derived from a healthy control individual, dopamine showed comparable effects as observed in SH-SY5Y cells. The hiPSC-derived PD neurons harboring an endogenous SNCA mutation demonstrated altered mitochondrial iron homeostasis, reduced mitochondrial capacity along with increased oxidative stress and alterations of tricarboxylic acid cycle linked metabolic pathways compared with control neurons. Importantly, dopamine treatment of PD neurons promoted a rescue effect by increasing mitochondrial respiration, activating antioxidant stress response, and normalizing altered metabolite levels linked to mitochondrial function. These observations provide evidence that dopamine affects iron homeostasis, intracellular stress responses and mitochondrial function in healthy cells, while dopamine supplementation can restore the disturbed regulatory network in PD cells.

A new therapeutic perspective: Erastin inhibits tumor progression by driving ferroptosis in myelodysplastic syndromes

Ferroptosis is a recently identified and evolutionarily conserved form of programmed cell death. This process is initiated by an imbalance in iron metabolism, leading to an overload of ferrous ions. These ions promote lipid peroxidation in the cell membrane through the Fenton reaction. As the cell's antioxidant defenses become overwhelmed, a fatal buildup of reactive oxygen species (ROS) occurs, resulting in the rupture of the plasma membrane. Ferroptosis is implicated in conditions such as ischemia-reperfusion injuries and a range of cancers. In our research, we explored ferroptosis in myelodysplastic syndromes (MDS) by measuring iron levels, transferrin receptor expression, and glutathione peroxidase 4 (GPX4) mRNA. Our findings revealed that MDS patients had significantly higher Fe2+ levels in CD33+ cells and increased transferrin receptor mRNA compared to healthy individuals. GPX4 expression was also higher in MDS but not statistically significant. To investigate potential treatments for myeloid hematological diseases through ferroptosis induction, we treated the myelodysplastic syndrome cell line (SKM-1) and two myeloid leukemia cell lines (KG-1 and K562) with erastin, an iron transfer inducer. We observed that erastin treatment led to glutathione depletion, reduced GPX4 activity, and increased ROS, culminating in cell death by ferroptosis. Furthermore, combining erastin with azacitidine demonstrated a synergistic effect on MDS and leukemia cell lines, suggesting a promising approach for treating these hematological conditions with this drug combination. Our experiments confirm erastin's ability to induce ferroptosis in MDS and highlight its potential synergistic use with azacitidine for treatment.

Inducing ferroptosis by traditional medicines: a novel approach to reverse chemoresistance in lung cancer

Lung cancer is the leading cause of global cancer-related deaths. Platinum-based chemotherapy is the first-line treatment for the most common type of lung cancer, i.e., non-small-cell lung cancer (NSCLC), but its therapeutic efficiency is limited by chemotherapeutic resistance. Therefore, it is vital to develop effective therapeutic modalities that bypass the common molecular mechanisms associated with chemotherapeutic resistance. Ferroptosis is a form of non-apoptotic regulated cell death characterized by iron-dependent lipid peroxidation (LPO). Ferroptosis is crucial for the proper therapeutic efficacy of lung cancer-associated chemotherapies. If targeted as a novel therapeutic mechanism, ferroptosis modulators present new opportunities for increasing the therapeutic efficacy of lung cancer chemotherapy. Emerging studies have revealed that the pharmacological induction of ferroptosis using natural compounds boosts the efficacy of chemotherapy in lung cancer or drug-resistant cancer. In this review, we first discuss chemotherapeutic resistance (or chemoresistance) in lung cancer and introduce the core mechanisms behind ferroptosis. Then, we comprehensively summarize the small-molecule compounds sourced from traditional medicines that may boost the anti-tumor activity of current chemotherapeutic agents and overcome chemotherapeutic resistance in NSCLC. Cumulatively, we suggest that traditional medicines with ferroptosis-related anticancer activity could serve as a starting point to overcome chemotherapeutic resistance in NSCLC by inducing ferroptosis, highlighting new potential therapeutic regimens used to overcome chemoresistance in NSCLC.

Cadmium exposure induced neuronal ferroptosis and cognitive deficits via the mtROS-ferritinophagy pathway

Exposure to environmental cadmium (Cd) is known to cause neuronal death and cognitive decline in humans. Ferroptosis, a novel iron-dependent type of regulated cell death, is involved in various neurological disorders. In the present study, Cd exposure triggered ferroptosis in the mouse hippocampus and in the HT22 murine hippocampal neuronal cell line, as indicated by significant increases in ferroptotic marker expression, intracellular iron levels, and lipid peroxidation. Interestingly, ferroptosis of hippocampal neurons in response to Cd exposure relied on the induction of autophagy since the suppression of autophagy by 3-methyladenine (3-MA) and chloroquine (CQ) substantially ameliorated Cd-induced ferroptosis. Furthermore, nuclear receptor coactivator 4 (NCOA4)-mediated degradation of ferritin was required for the Cd-induced ferroptosis of hippocampal neurons, demonstrating that NCOA4 knockdown decreased intracellular iron levels and lipid peroxidation and increased cell survival, following Cd exposure. Moreover, Cd-induced mitochondrial reactive oxygen species (mtROS) generation was essential for the ferritinophagy-mediated ferroptosis of hippocampal neurons. Importantly, pretreatment with the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated Cd-induced hippocampal neuronal death and cognitive impairment in mice. Taken together, these findings indicate that ferroptosis is a novel mechanism underlying Cd-induced neurotoxicity and cognitive impairment and that the mtROS-ferritinophagy axis modulates Cd-induced neuronal ferroptosis.

Emerging ferroptosis inhibitors as a novel therapeutic strategy for the treatment of neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxia-ischemia encephalopathy (NHIE), an oxygen deprivation-mediated brain injury due to birth asphyxia or reduced cerebral blood perfusion, often leads to lifelong sequelae, including seizures, cerebral palsy, and mental retardation. NHIE poses a significant health challenge, as one of the leading causes of neonatal morbidity and mortality globally. Despite this, available therapies are limited. Numerous studies have recently demonstrated that ferroptosis, an iron-dependent non-apoptotic regulated form of cell death characterized by lipid peroxidation (LPO) and iron dyshomeostasis, plays a role in the genesis of NHIE. Moreover, recently discovered compounds have been shown to exert potential therapeutic effects on NHIE by inhibiting ferroptosis. This comprehensive review summarizes the fundamental mechanisms of ferroptosis contributing to NHIE. We focus on various emerging therapeutic compounds exhibiting characteristics of ferroptosis inhibition and delineate their pharmacological benefits for the treatment of NHIE. This review suggests that pharmacological inhibition of ferroptosis may be a potential therapeutic strategy for NHIE.

Effects of Manganese and Iron, Alone or in Combination, on Apoptosis in BV2 Cells

The aim of study was to address the effects of manganese and iron, alone and in combination, on apoptosis of BV2 microglia cells, and to determine if combined exposure to these metals augments their individual toxicity. We used a murine microglial BV2 cell line. Cell cytotoxicity was analyzed by propidium iodide (PI) exclusion assay. Cell ROS production was analyzed by 2', 7'-dichlorofluorescin diacetate (DCFH-DA) probe staining. Pro-inflammatory cytokine production was monitored by ELISA. Cell apoptosis was analyzed by PE Annexin V/7-AAD staining. Mitochondrial membrane integrity was analyzed by flow cytometry. We used immunoblotting to analyze the effect of manganese, iron alone, or their combined exposure on the activation of caspase9, P53, Bax, and Bcl2 apoptosis signaling pathways. Caspase3 activity was determined using a Colorimetric. Manganese, iron, and their combined exposure for 24 h induced the activation of BV2 microglia cells and increased ROS production and the expression of the inflammatory cytokines, IL-1β and TNF-α. And we also found that the apoptosis rate increased, mitochondrial membrane potential decreased, apoptosis-related proteins caspase9, P53, Bax, and Bcl2 expression increased, and caspase3 activity increased. Furthermore, we found that combined manganese-iron cytotoxicity was lower than that induced by manganese exposure alone. Manganese, iron alone, or their combination exposure can induce apoptosis in glial cells. Iron can reduce the toxicity of manganese, and there is an antagonistic effect between manganese and iron.

Research trends and hotspots of ferroptosis in neurodegenerative diseases from 2013 to 2023: A bibliometrics study

Background

With the aging population, the incidence of neurodegenerative diseases increases yearly, seriously impacting human health. Various journals have published studies on the pathogenesis of ferroptosis in neurodegenerative diseases. However, bibliometric analysis in this field is still lacking. The study aims to visually analyze global research trends in this field over the past decade.

Methods

The articles and reviews regarding ferroptosis in neurodegenerative diseases were retrieved from the Web of Science on September 1, 2023. Citespace [version 6.2. R4 (64-bit)] and VOSviewer (version 1.6.18) were used to conduct the bibliometric and knowledge-map analysis.

Results

In total, 370 studies were included in the paper and ranked by their citation frequency. Many articles on ferroptosis in neurodegenerative diseases have been published in the past decade. The country, institution, author, and journal with the highest publications were China, Guangzhou Medical University, Maher, Pamela, and Free Radical Biology And Medicine, respectively. The analysis of keyword co-occurrence indicated that research frontiers were molecular mechanisms of ferroptosis in neurodegenerative diseases, especially a few key pathways that triggered ferroptosis in these diseases, including lipid peroxidation signaling, iron metabolism, and GSH/GPX4 signaling. In addition, ferroptosis inhibitors such as liproxstatins and ferrostatins had protective effects in animal models of neurodegenerative diseases. Therefore, future attention should also be focused on therapeutic drugs that target ferroptosis.

Conclusion

This study comprehensively analyzed the publications on ferroptosis in neurodegenerative diseases from a bibliometric perspective. Research on this topic is currently expanding at a rapid pace, and the China holds a leading position in this field by its scientific achievements and productivity. Moreover, the research frontiers were molecular mechanisms of ferroptosis in neurodegenerative diseases and developing targeted therapeutic drugs. In summary, our results showed an all-sided overview of the knowledge atlas and a valuable reference for the future research in this field.

Unraveling the Molecular Regulation of Ferroptosis in Respiratory Diseases

Ferroptosis, a type of programmed cell death that relies on iron, is distinct in terms of its morphological, biochemical and genetic features. Unlike other forms of cell death, such as autophagy, apoptosis, necrosis, and pyroptosis, ferroptosis is primarily caused by lipid peroxidation. Cells that die due to iron can potentially trigger an immune response which intensifies inflammation and causes severe inflammatory reactions that eventually lead to multiple organ failure. In recent years, ferroptosis has been identified in an increasing number of medical fields, including neurological pathologies, chronic liver diseases and sepsis. Ferroptosis has the potential to cause an inflammatory tempest, with many of the catalysts and pathological indications of respiratory ailments being linked to inflammatory reactions. The growing investigation into ferroptosis in respiratory disorders has also garnered significant interest to better understand the mechanism of ferroptosis in these diseases. In this review, the recent progress in understanding the molecular control of ferroptosis and its mechanism in different respiratory disorders is examined. In addition, this review discusses current challenges and prospects for understanding the link between respiratory diseases and ferroptosis.

Hispolon inhibits neuronal ferroptosis by promoting the expression of Nrf-2

Research has shown that neuronal ferroptosis is associated with various central nervous system diseases, including Parkinson's disease, acute brain injury, and spinal cord injury. Inhibiting neuronal ferroptosis can greatly alleviate the progression of these diseases. However, there is currently a lack of effective drugs to inhibit neuronal ferroptosis. In this study, we pretreated neuronal cells with Hispolon and subsequently induced a neuronal ferroptosis model using Erastin. We further assessed the changes in the protein expression levels of SLC7A11, GPX4, ACSL4, Nrf-2, and HO-1 using Western blot and immunofluorescence techniques. Additionally, we measured the intracellular levels of Fe2+, GSH, and MDA using relevant assay kits. The research findings revealed that after Hispolon treatment, the expression of the pro-ferroptosis protein ACSL4 decreased, while the expression of the ferroptosis-regulating proteins GPX4 and SLC7A11 increased. Moreover, the use of an Nrf-2-specific inhibitor was able to reverse the effects of Hispolon as mentioned above. In this study, we discovered that Hispolon can promote the expression of Nrf-2 and inhibit the occurrence of neuronal ferroptosis induced by Erastin.

Butylated Hydroxytoluene (BHT) Protects SH-SY5Y Neuroblastoma Cells from Ferroptotic Cell Death: Insights from In Vitro and In Vivo Studies

Ferroptosis is a special kind of programmed cell death that has been implicated in the pathogenesis of a large number of human diseases. It involves dysregulated intracellular iron metabolism and uncontrolled lipid peroxidation, which together initiate intracellular ferroptotic signalling pathways leading to cellular suicide. Pharmacological interference with ferroptotic signal transduction may prevent cell death, and thus patients suffering from ferroptosis-related diseases may benefit from such treatment. Butylated hydroxytoluene (BHT) is an effective anti-oxidant that is frequently used in oil chemistry and in cosmetics to prevent free-radical-mediated lipid peroxidation. Since it functions as a radical scavenger, it has previously been reported to interfere with ferroptotic signalling. Here, we show that BHT prevents RSL3- and ML162-induced ferroptotic cell death in cultured human neuroblastoma cells (SH-SY5Y) in a dose-dependent manner. It prevents the RSL3-induced oxidation of membrane lipids and normalises the RSL3-induced inhibition of the intracellular catalytic activity of glutathione peroxidase 4. The systemic application of BHT in a rat Alzheimer's disease model prevented the upregulation of the expression of ferroptosis-related genes. Taken together, these data indicate that BHT interferes with ferroptotic signalling in cultured neuroblastoma cells and may prevent ferroptotic cell death in an animal Alzheimer's disease model.

The role of ferroptosis in central nervous system damage diseases

Ferroptosis is a form of cell death, i.e., programmed cell death characterized by lipid peroxidation and iron dependence, which has unique morphological and biochemical properties. This unique mode of cell death is driven by iron-dependent phospholipid peroxidation and regulated by multiple cell metabolic pathways, including redox homeostasis, iron metabolism, mitochondrial activity, and the metabolism of amino acids, lipids, and sugars. Many organ injuries and degenerative pathologies are caused by ferroptosis. Ferroptosis is closely related to central nervous system injury diseases and is currently an important topic of research globally. This research examined the relationships between ferroptosis and the occurrence and treatment of central nervous system injury diseases. Additionally, ferroptosis was assessed from the aspect of theory proposal, mechanism of action, and related signaling pathways per recent research. This review provides a relevant theoretical basis for further research on this theory, the prospect of its development, and the prevention and treatment of such diseases.

Identification of Immune Infiltration and Iron Metabolism-Related Subgroups in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder with a broad spectrum of symptoms and prognoses. Effective therapy requires understanding this variability. ASD children's cognitive and immunological development may depend on iron homoeostasis. This study employs a machine learning model that focuses on iron metabolism hub genes to identify ASD subgroups and describe immune infiltration patterns. A total of 97 control and 148 ASD samples were obtained from the GEO database. Differentially expressed genes (DEGs) and an iron metabolism gene collection achieved the intersection of 25 genes. Unsupervised cluster analysis determined molecular subgroups in individuals with ASD based on 25 genes related to iron metabolism. We assessed gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, gene set variation analysis (GSVA), and immune infiltration analysis to compare iron metabolism subtype effects. We employed machine learning to identify subtype-predicting hub genes and utilized both training and validation sets to assess gene subtype prediction accuracy. ASD can be classified into two iron-metabolizing molecular clusters. Metabolic enrichment pathways differed between clusters. Immune infiltration showed that clusters differed immunologically. Cluster 2 had better immunological scores and more immune cells, indicating a stronger immune response. Machine learning screening identified SELENBP1 and CAND1 as important genes in ASD's iron metabolism signaling pathway. These genes express in the brain and have AUC values over 0.8, implying significant predictive power. The present study introduces iron metabolism signaling pathway indicators to predict ASD subtypes. ASD is linked to immune cell infiltration and iron metabolism disorders.

Combined exposure to manganese and iron decreases oxidative stress-induced nerve damage by increasing Nrf2/HO-1/NQO1 expression

BACKGROUND

Manganese (Mn) and iron (Fe) are essential trace elements for humans, yet excessive exposure to Mn or Fe can accumulate in the central nervous system (CNS) and cause neurotoxicity. The purpose of this study was to investigate the effects of Mn and Fe exposure, alone or in combination, on inducing oxidative stress-induced neurological damage in rat cortical and SH-SY5Y cells, and to determine whether combined exposure to these metals increases their individual toxicity.

METHODS

SH-SY5Y cells and male Sprague-Dawley rats were used to observe the effects of oxidative stress-induced neurological damage induced by exposure to manganese and iron alone or in combination. To detect the expression of anti-oxidative stress-related proteins, Nrf2, HO-1, and NQO1, and the apoptosis-related proteins, Bcl2 and Bax, and the neurological damage-related protein, α-syn. To detect reactive oxygen species generation and apoptosis. To detect the expression of the rat cortical protein Nrf2. To detect the production of proinflammatory cytokines.

RESULTS

We demonstrate that juvenile developmental exposure to Mn and Fe and their combination impairs cognitive performance in rats by inducing oxidative stress causing neurodegeneration in the cortex. Mn, Fe, and their combined exposure increased the expression of ROS, Bcl2, Bax, and α-syn, activated the inflammatory factors IL-6 and IL-12, inhibited the activities of SOD and GSH, and induced oxidative stress-induced neurodegeneration both in rats and SH-SY5Y cells. Combined Mn-Fe exposure attenuated the oxidative stress induced by Mn and Fe exposure alone by increasing the expression of antioxidant factors Nrf2, HO-1, and NQO1.

CONCLUSION

In both in vivo and in vitro studies, manganese and iron alone or in combination induced oxidative stress, leading to neuronal damage. In contrast, combined exposure to manganese and iron mitigated the oxidative stress induced by exposure to manganese and iron alone by increasing the expression of antioxidant factors. Therefore, studies to elucidate the main causes of toxicity and establish the molecular mechanisms of toxicity should help to develop more effective therapeutic modalities in the future.

Short-term consumption of highly processed diets varying in macronutrient content impair the sense of smell and brain metabolism in mice

OBJECTIVE

Food processing greatly contributed to increased food safety, diversity, and accessibility. However, the prevalence of highly palatable and highly processed food in our modern diet has exacerbated obesity rates and contributed to a global health crisis. While accumulating evidence suggests that chronic consumption of such foods is detrimental to sensory and neural physiology, it is unclear whether its short-term intake has adverse effects. Here, we assessed how short-term consumption (<2 months) of three diets varying in composition and macronutrient content influence olfaction and brain metabolism in mice.

METHODS

The diets tested included a grain-based standard chow diet (CHOW; 54% carbohydrate, 32% protein, 14% fat; #8604 Teklad Rodent diet , Envigo Inc.), a highly processed control diet (hpCTR; 70% carbohydrate, 20% protein, 10% fat; #D12450B, Research Diets Inc.), and a highly processed high-fat diet (hpHFD; 20% carbohydrate, 20% protein, 60% fat; #D12492, Research Diets Inc.). We performed behavioral and metabolic phenotyping, electro-olfactogram (EOG) recordings, brain glucose metabolism imaging, and mitochondrial respirometry in different brain regions. We also performed RNA-sequencing (RNA-seq) in the nose and across several brain regions, and conducted differential expression analysis, gene ontology, and network analysis.

RESULTS

We show that short-term consumption of the two highly processed diets, but not the grain-based diet, regardless of macronutrient content, adversely affects odor-guided behaviors, physiological responses to odorants, transcriptional profiles in the olfactory mucosa and brain regions, and brain glucose metabolism and mitochondrial respiration.

CONCLUSIONS

Even short periods of highly processed food consumption are sufficient to cause early olfactory and brain abnormalities, which has the potential to alter food choices and influence the risk of developing metabolic disease.

Targeting epigenetic and posttranslational modifications regulating ferroptosis for the treatment of diseases

Ferroptosis, a unique modality of cell death with mechanistic and morphological differences from other cell death modes, plays a pivotal role in regulating tumorigenesis and offers a new opportunity for modulating anticancer drug resistance. Aberrant epigenetic modifications and posttranslational modifications (PTMs) promote anticancer drug resistance, cancer progression, and metastasis. Accumulating studies indicate that epigenetic modifications can transcriptionally and translationally determine cancer cell vulnerability to ferroptosis and that ferroptosis functions as a driver in nervous system diseases (NSDs), cardiovascular diseases (CVDs), liver diseases, lung diseases, and kidney diseases. In this review, we first summarize the core molecular mechanisms of ferroptosis. Then, the roles of epigenetic processes, including histone PTMs, DNA methylation, and noncoding RNA regulation and PTMs, such as phosphorylation, ubiquitination, SUMOylation, acetylation, methylation, and ADP-ribosylation, are concisely discussed. The roles of epigenetic modifications and PTMs in ferroptosis regulation in the genesis of diseases, including cancers, NSD, CVDs, liver diseases, lung diseases, and kidney diseases, as well as the application of epigenetic and PTM modulators in the therapy of these diseases, are then discussed in detail. Elucidating the mechanisms of ferroptosis regulation mediated by epigenetic modifications and PTMs in cancer and other diseases will facilitate the development of promising combination therapeutic regimens containing epigenetic or PTM-targeting agents and ferroptosis inducers that can be used to overcome chemotherapeutic resistance in cancer and could be used to prevent other diseases. In addition, these mechanisms highlight potential therapeutic approaches to overcome chemoresistance in cancer or halt the genesis of other diseases.

Research progress in the molecular mechanism of ferroptosis in Parkinson's disease and regulation by natural plant products

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder of the central nervous system after Alzheimer's disease. The current understanding of PD focuses mainly on the loss of dopamine neurons in the substantia nigra region of the midbrain, which is attributed to factors such as oxidative stress, alpha-synuclein aggregation, neuroinflammation, and mitochondrial dysfunction. These factors together contribute to the PD phenotype. Recent studies on PD pathology have introduced a new form of cell death known as ferroptosis. Pathological changes closely linked with ferroptosis have been seen in the brain tissues of PD patients, including alterations in iron metabolism, lipid peroxidation, and increased levels of reactive oxygen species. Preclinical research has demonstrated the neuroprotective qualities of certain iron chelators, antioxidants, Fer-1, and conditioners in Parkinson's disease. Natural plant products have shown significant potential in balancing ferroptosis-related factors and adjusting their expression levels. Therefore, it is vital to understand the mechanisms by which natural plant products inhibit ferroptosis and relieve PD symptoms. This review provides a comprehensive look at ferroptosis, its role in PD pathology, and the mechanisms underlying the therapeutic effects of natural plant products focused on ferroptosis. The insights from this review can serve as useful references for future research on novel ferroptosis inhibitors and lead compounds for PD treatment.

Melatonin targets ferroptosis through bimodal alteration of redox environment and cellular pathways in NAFLD model

Ferroptosis is a non-conventional cellular death caused by lipid peroxide induced iron deposition. Intracellular lipid accumulation followed by generation of lipid peroxides is an hallmark of non-alcoholic fatty liver disease (NAFLD). Melatonin (MLT) is an important pineal hormone with tremendous antioxidant and anti-inflammatory properties. Various studies targeted ferroptosis in different diseases using melatonin. However, none of them focused the intrinsic mechanism of MLT's action to counteract ferroptosis in NAFLD. Hence, the present study investigated the role of MLT in improvement of NAFLD-induced ferroptosis. HepG2 cells were treated with free fatty acids (FFAs) to induce in vitro NAFLD state and C57BL/6 mice were fed with high-fat diet (HFD) followed by MLT administration. The results indicated that MLT administration caused the recovery from both FFA- and HFD-induced ferroptotic state via increasing GSH and SOD level, decreasing lipid reactive oxygen species (ROS) and malondialdehyde (MDA) level, increasing Nrf2 and HO-1 level to defend cells against an oxidative environment. MLT also altered the expression of two key proteins GPX4 and SLC7A11 back to their normal levels, which would otherwise cause ferroptosis. MLT also protected against histopathological damage of both liver tissue and HepG2 cells as depicted by Oil Red O, HE staining and immunofluorescence microscopy. MLT also had control over pAMPKα as well as PPARγ and PPARα responsible for lipid homeostasis and lipogenesis. In brief, MLT exerted its multifaceted effect in FFA- and HFD-induced NAFLD by retrieving cellular oxidative environment, reducing lipogenesis and lipid peroxidation and modulating Nrf2/HO-1 and GPX4/SLC7A11 axis to combat ferroptosis.

Iron in multiple sclerosis - Neuropathology, immunology, and real-world considerations

Iron is an essential element involved in a multitude of bodily processes. It is tightly regulated, as elevated deposition in tissues is associated with diseases such as multiple sclerosis (MS). Iron accumulation in the central nervous system (CNS) of MS patients is linked to neurotoxicity through mechanisms including oxidative stress, glutamate excitotoxicity, misfolding of proteins, and ferroptosis. In the past decade, the combination of MRI and histopathology has enhanced our understanding of iron deposition in MS pathophysiology, including in the pro-inflammatory and neurotoxicity of iron-laden rims of chronic active lesions. In this regard, iron accumulation may not only have an impact on different CNS-resident cells but may also promote the innate and adaptive immune dysfunctions in MS. Although there are discordant results, most studies indicate lower levels of iron but higher amounts of the iron storage molecule ferritin in the circulation of people with MS. Considering the importance of iron, there is a need for evidence-guided recommendation for dietary intake in people living with MS. Potential novel therapeutic approaches include the regulation of iron levels using next generation iron chelators, as well as therapies to interfere with toxic consequences of iron overload including antioxidants in MS.

Managing ferroptosis-related diseases with indirect dietary modulators of ferroptosis

Ferroptosis is an iron-dependent form of programmed cell death driven by excessive oxidation of polyunsaturated phospholipids on cellular membranes. Accumulating evidence suggests that ferroptosis has been implicated in the pathological process of various diseases, such as cardiovascular diseases, neurological diseases, liver diseases, kidney injury, lung injury, diabetes, and cancer. Targeting ferroptosis is therefore considered to be a reasonable strategy to fight against ferroptosis-associated diseases. Many dietary bioactive agents have been identified to be able to either suppress or promote ferroptosis, indicating that ferroptosis-based intervention by dietary approach may be an effective strategy for preventing and treating diseases associated with ferroptosis dysregulation. In this review, we summarize the present understanding of the functional role of ferroptosis in the pathogenesis of aforementioned diseases with an emphasis on the evidence of managing ferroptosis-related diseases with indirect dietary modulators of ferroptosis and propose issues that need to be addressed to promote practical application of dietary approach targeting ferroptosis.

The Role of Cellular Defense Systems of Ferroptosis in Parkinson's Disease and Alzheimer's Disease

Parkinson's disease (PD) and Alzheimer's disease (AD) are the most common rapidly developing neurodegenerative diseases that lead to serious health and socio-economic consequences. Ferroptosis is a non-apoptotic form of cell death; there is growing evidence to support the notion that ferroptosis is involved in a variety of pathophysiological contexts, and there is increasing interest in the role of ferroptosis in PD and AD. Simultaneously, cells may have evolved four defense systems to counteract the toxic effects of ferroptosis occasioned by lipid peroxidation. This review, which focuses on the analysis of ferroptosis in the PD and AD context, outlines four cellular defense systems against ferroptosis and how each of them is involved in PD and AD.