Basics and principles of cellular and systemic iron homeostasis

Iron Deficiency Impairs Dendritic Cell Development and Function, Compromising Host Anti-Infection Capacity

The prevalence of acute lower respiratory infections in individuals with iron deficiency (ID) has significantly increased, and is correlated with reduced numbers of immune cells and impaired immune function. Dendritic cells (DCs) play a crucial role in combating the influenza A virus (IAV) by initiating adaptive immune responses. However, the impact of ID on DCs and their response to IAV infection remain unclear. This study showed that ID impairs the antigen-presenting ability of DCs, thereby hindering their capacity to mediate T-cell proliferation and clear viruses. The restrictive effects of ID on DCs begin in the bone marrow and specifically affect the monocyte DC progenitor (MDP) stage. A reduction in the number of MDPs and compromised immune potential lead to a decrease in the population and functionality of DCs in the subsequent common DC precursor (CDP) stage in the blood, spleen, and lungs. This study highlights the previously unrecognized impact of ID on DCs and provides valuable insights into immune cell responses and the application of iron supplementation in the fight against viral infections.

Electromagnetic fields regulate iron metabolism: From mechanisms to applications

BACKGROUND

Electromagnetic fields (EMFs), as a form of physical therapy, have been widely applied in biomedicine. Iron, the most abundant trace metal in living organisms, plays a critical role in various physiological processes, and imbalances in its metabolism are closely associated with the development and progression of numerous diseases. Numerous studies have demonstrated that EMF exposureinduces significant changes in both systemic and cellular iron metabolism.

AIM OF REVIEW

This review aims to summarize the evidence and potential biophysical mechanisms underlying the role of EMFs in regulating iron metabolism, thereby enhancing the understanding of their biological mechanisms and expanding their potential applications in biomedical fields.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this review, we have synthesized research findings and proposed the hypothesis that the biophysical mechanisms of EMFs regulate iron metabolism involve the special electromagnetic properties of iron-containing proteins and iron-enriched tissues, as well as the modulation of membrane structure and function, ion channels, and the generation and activity of Reactive Oxygen Species (ROS). Then, the review summarizes the latest advances in the effects of EMFs on iron metabolism and their safety, as well as their impact on immunoregulation, cardiovascular diseases, neurological diseases, orthopedic diseases, diabetes, liver injury, and cancer.

PTPN2 Regulates Iron Handling Protein Expression in Inflammatory Bowel Disease Patients and Prevents Iron Deficiency in Mice

Anemia is the most common extraintestinal manifestation of inflammatory bowel disease (IBD). Iron deficiency is the most frequent cause of anemia in IBD; however, the mechanisms involved are still poorly understood. Here, we investigated the role of the IBD risk gene, protein tyrosine phosphatase non-receptor type 2 (PTPN2), in regulating iron homeostasis. Proteomic analyses were performed on serum from IBD patients genotyped for the IBD-associated loss-of-function rs1893217 PTPN2 variant. Constitutive Ptpn2 wild type (WT), heterozygous (Het), and knockout (KO) mice were analyzed for iron content, blood parameters, and expression of iron handling proteins. Iron absorption was assessed through radiotracer assays. Serum proteomic analyses revealed that the "iron homeostasis signaling pathway" was the main pathway downregulated in Crohn's disease (CD) patients carrying the PTPN2 risk allele, independent of disease activity. Ptpn2-KO mice showed characteristics of anemia, including reduced hemoglobin concentrations along with serum and tissue iron deficiency and elevated serum hepcidin levels vs. Ptpn2-WT and Het mice. 55Fe absorption via oral gavage was significantly impaired in Ptpn2-KO mice. Correspondingly, Ptpn2-KO mice showed reduced apical membrane expression of the iron transporter DMT1. CD patients with the PTPN2 loss-of-function rs1893217 variant display alterations in serum iron handling proteins. Loss of Ptpn2 in mice caused features of anemia, including iron deficiency associated with reduced apical membrane expression of DMT1. These findings identify an important role for PTPN2 in regulating systemic iron homeostasis.

Cashew Apple Pomace: Chemical Composition and Applications in Functional Food Product Development-A Review

Cashew nut production and fruit processing generate significant by-products, particularly cashew apple and cashew apple pomace (CAP), which are often treated as waste. However, CAP is a valuable source of nutrients and bioactive compounds that can be repurposed to develop functional food products. Valorizing this by-product represents a pivotal advancement toward achieving sustainability and circularity in the food industry. This review aimed to highlight the chemical composition and potential applications of CAP in functional food development. The review shows that CAP is enriched with bioactive compounds, including phenolic acids, carotenoids, and flavonoids, alongside essential nutrients such as fiber, minerals, carbohydrates, and proteins. The incorporation of CAP into food products may confer a myriad of health benefits, including antioxidant, antimicrobial, antidiabetic, antiobesity, and gastroprotective properties. This review elucidates approaches to effectively integrate CAP into food formulations while preserving their sensory attributes. Utilizing CAP in food products can significantly reduce food waste and enhance the overall nutritional and functional profile of food, contributing to a more sustainable and circular food system.

Mitochondrial iron deficiency mediated inhibition of ecdysone synthesis underlies lead (Pb) induced developmental toxicity in Drosophila melanogaster

Lead (Pb) is a pervasive heavy metal possessing developmental toxicity, at least in part, by disrupting iron homeostasis. In this study, we aimed to elucidate the underlying mechanism of iron deficiency mediated developmental defects in Pb exposed Drosophila melanogaster, mainly focusing on iron-dependent synthesis of ecdysone signaling, which plays a key role in the development of insects. Herein, we found Pb exposure resulted in iron deficiency in mitochondria by inhibiting expression of mitoferrin (evidenced by qPCR assay), the mitochondrial iron importer. Further study demonstrated that biosynthesis of ecdysone, a hormone synthesized with the help of iron-containing cytochrome P450s in mitochondria, was inhibited following Pb exposure. Ecdysone supplementation, to some extent, rescued Pb induced developmental delay and reproductive defects in Drosophila melanogaster. Furthermore, we found that disruption of mitoferrin and ecdysone synthesis was restored by NAC (N-Acetylcysteine, a well-known ROS scavenger), suggesting that oxidative stress plays a key role in Pb mediated mitochondrial iron dys-homeostasis and developmental toxicity. This study therefore revealed that mitochondrial iron deficiency mediated inhibition of ecdysone synthesis is a key event associated with iron dys-homeostasis mediated developmental defects caused by Pb exposure. Meanwhile, our study indicated that mitochondria may act as an important target of Pb, thus providing potential protective strategies against Pb toxicity.

Zuogui Pills alleviate iron overload-induced osteoporosis by attenuating ROS-mediated osteoblast apoptosis via the PI3K-AKT pathway and mitigating mitochondrial damage

ETHNOPHARMACOLOGICAL RELEVANCE

Zuogui Pill (ZGP) is a classic herbal formula in Traditional Chinese Medicine, primarily used to tonify the kidney and replenish essence, and is widely applied in treating various kidney deficiency-related conditions. Over time, ZGP has demonstrated significant efficacy in addressing symptoms such as fatigue, weakness, and soreness of the lower back and knees, which are often caused by kidney deficiency. According to Traditional Chinese Medicine theory, the kidneys govern the bones, meaning that sufficient kidney essence is closely related to bone strength. By nourishing the kidneys and replenishing essence, ZGP helps to increase bone density and improve bone microstructure, making it an important therapeutic option for osteoporosis.

AIM OF THE STUDY

To investigate the protective effects of ZGP in iron overload-induced osteoporosis and elucidate its molecular mechanisms through the activation of the Phosphoinositide 3-Kinase (PI3K)/Protein Kinase B (AKT) and Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2)/Heme Oxygenase-1 (HO-1) pathways, which reduce oxidative stress, inhibit osteoblast apoptosis, and promote osteoblast differentiation and mineralization.

MATERIALS AND METHODS

An in vivo mouse model of iron overload-induced osteoporosis and an in vitro MC3T3-E1 osteoblast model were used. In vitro experiments involved the use of ZGP containing-serum, along with transcriptomic analysis, Western blot, flow cytometry, TUNEL staining, and immunofluorescence, to assess the effects on oxidative stress, mitochondrial function, and apoptosis. In vivo experiments evaluated the effects of ZGP on bone mass, oxidative stress, and apoptosis using Micro-computed tomography (micro-CT), Hematoxylin and eosin staining (H&E), TUNEL staining, and immunohistochemistry.

RESULTS

The study found that ZGP containing-serum significantly enhanced the viability of osteoblasts induced by iron overload and reduced apoptosis through the reactive oxygen species (ROS)-mediated Phosphoinositide 3-Kinase (PI3K)/Protein Kinase B (AKT) pathway while mitigating mitochondrial damage. In vivo, micro-computed tomography results showed that ZGP improved bone mass, and decreased ROS and apoptosis, consistent with the in vitro findings.

CONCLUSION

ZGP demonstrates significant antioxidant and anti-apoptotic effects in iron overload-induced osteoporosis, primarily through the ROS-mediated PI3K/AKT pathway and by reducing mitochondrial damage. These findings suggest that ZGP may be a promising therapeutic agent for treating osteoporosis associated with iron overload.

HFE-Related Hemochromatosis May Be a Primary Kupffer Cell Disease

Iron overload can lead to increased deposition of iron and cause organ damage in the liver, the pancreas, the heart and the synovium. Iron overload disorders are due to either genetic or acquired abnormalities such as excess transfusions or chronic liver diseases. The most common genetic disease of iron deposition is classic hemochromatosis (HH) type 1, which is caused by mutations of HFE. Other rare forms of HH include type 2A with mutations at the gene hemojuvelin or type 2B with mutations in HAMP that encodes hepcidin. HH type 3, is caused by mutations of the gene that encodes transferrin receptor 2. Mutations of SLC40A1 which encodes ferroportin cause either HH type 4A or HH type 4B. In the present review, an overview of iron metabolism including absorption by enterocytes and regulation of iron by macrophages, liver sinusoidal endothelial cells (LSECs) and hepatocyte production of hepcidin is presented. Hereditary Hemochromatosis and the current pathogenetic model are analyzed. Finally, a new hypothesis based on published data was suggested. The Kupffer cell is the primary defect in HFE hemochromatosis (and possibly in types 2 and 3), while the hepcidin-relative deficiency, which is the common underlying abnormality in the three types of HH, is a secondary consequence.

BMP9 alleviates iron accumulation-induced osteoporosis via the USP10/FOXO1/GPX4 axis

INTRODUCTION

Ferroptosis induced by iron accumulation can disrupt the physiological functions of bone marrow mesenchymal stem cells (BMSCs). BMP9 is an effective osteogenic factor. However, the role of BMP9 and its molecular mechanisms in osteoporosis induced by iron accumulation remain unclear.

OBJECTIVES

This study aims to explore the role and mechanism of BMP9 in alleviating iron accumulation induced osteoporosis.

METHODS

Clinical samples were collected to analyze the relationship between iron accumulation and osteoporosis. The effect of BMP9 on lipid peroxidation levels in BMSCs under iron accumulation conditions was assessed using C11-BODIPY staining, MitoSOX staining, MDA and SOD activity measurement. The osteogenic capacity of BMP9 in BMSCs under iron accumulation conditions was evaluated by measuring ALP activity and calcium nodule formation. The mechanisms of BMP9 in regulating BMSCs under iron accumulation conditions were explored through experiments including cycloheximide treatment, RT-PCR, Western blot, GST pull-down, ChIP, and CO-IP.

RESULTS

It was observed in human samples that serum ferritin levels were negatively correlated with the bone mineral density of the lumbar spine and femoral neck. Meanwhile, ferroptosis is considered a key factor affecting bone health. Further research indicated that BMP9 could inhibit ferroptosis in cells and animal models with iron accumulation, while also improving oxidative stress and osteogenic capacity. In-depth investigation of its mechanism reveals that BMP9 promotes the expression of USP10, which removes the K48-linked ubiquitin chains on FOXO1, inhibiting its excessive ubiquitination in the cytoplasm. This stabilization allows FOXO1 to accumulate in the cytoplasm and eventually re-enter the nucleus. This process activated the expression of the key inhibitor of cell death, GPX4, enhancing the cell's antioxidant response, reducing ferroptosis-induced damage to BMSCs, and promoting their osteogenic differentiation.

CONCLUSION

This study reveals that BMP9 inhibits ferroptosis through the USP10/FOXO1/GPX4 axis, providing a new therapeutic strategy for osteoporosis caused by iron accumulation.

TRIOL attenuates intracerebral hemorrhage injury by bidirectionally modulating microglia- and neuron-mediated hematoma clearance

Intracerebral hemorrhage (ICH) represents the most severe subtype of stroke, and the lack of effective clinical pharmacotherapies poses a substantial threat to human health. Hematoma plays a crucial role in determining the prognosis of ICH patients by causing primary mechanical extrusion, followed by secondary brain injuries, such as cerebral edema, iron-mediated oxidative stress, and inflammation resulting from its degradation products. 5α-androst-3β,5α,6β-triol (TRIOL) is a neuroprotective steroid currently undergoing phase II clinical trial for acute ischemic stroke with anti-oxidative and anti-inflammatory properties. However, whether TRIOL can protect brain against ICH injury remains unclear. In this study, we found that TRIOL significantly improved neurological function while reducing hematoma volume, cerebral edema, and tissue damage after ICH. Moreover, TRIOL enhanced microglial hematoma clearance through promoting CD36-mediated erythrophagocytosis and CD163-associated hemoglobin scavenging, while simultaneously reducing the release of microglial inflammatory factors and activating the antioxidative transcription factor Nrf2. Additionally, TRIOL inhibited neuron mediated hematoma absorption by suppressing heme oxygenase 2 (HO-2) and protected neurons against ICH-induced damage in vitro and in vivo. TRIOL also mitigated neuronal iron-dependent oxidative damage by increasing ferritin levels but decreasing divalent metal transporter 1 (DMT1) expression. Overall, these findings highlight the promising potential of TRIOL as a drug candidate for treating ICH.

Targeting metabolic reprogramming in glioblastoma as a new strategy to overcome therapy resistance

Glioblastoma (GBM) is one of the deadliest tumors due to its high aggressiveness and resistance to standard therapies, resulting in a dismal prognosis. This lethal tumor carries out metabolic reprogramming in order to modulate specific pathways, providing metabolites that promote GBM cells proliferation and limit the efficacy of standard treatments. Indeed, GBM remodels glucose metabolism and undergoes Warburg effect, fuelling glycolysis even when oxygen is available. Moreover, recent evidence revealed a rewiring in nucleotide, lipid and iron metabolism, resulting not only in an increased tumor growth, but also in radio- and chemo-resistance. Thus, while on the one hand metabolic reprogramming is an advantage for GBM, on the other hand it may represent an exploitable target to hamper GBM progression. Lately, a number of studies focused on drugs targeting metabolism to uncover their effects on tumor proliferation and therapy resistance, demonstrating that some of these are effective, in combination with conventional treatments, sensitizing GBM to radiotherapy and chemotherapy. However, GBM heterogeneity could lead to a plethora of metabolic alterations among subtypes, hence a metabolic treatment might be effective for proneural tumors but not for mesenchymal ones, which are more aggressive and resistant to conventional approaches. This review explores key mechanisms of GBM metabolic reprogramming and their involvement in therapy resistance, highlighting how metabolism acts as a double-edged sword for GBM, taking into account metabolic pathways that seem to offer promising treatment options for GBM.

Terahertz Wave Desensitizes Ferroptosis by Inhibiting the Binding of Ferric Ions to the Transferrin

Ferroptosis is a classic type of programmed cell death characterized by iron dependence, which is closely associated with many diseases such as cancer, intestinal ischemic diseases, and nervous system diseases. Transferrin (Tf) is responsible for ferric-ion delivery owing to its natural Fe3+ binding ability and plays a crucial role in ferroptosis. However, Tf is not considered as a classic druggable target for ferroptosis-associated diseases since systemic perturbation of Tf would dramatically disrupt blood iron homeostasis. Here, we reported a nonpharmaceutical, noninvasive, and Tf-targeted electromagnetic intervention technique capable of desensitizing ferroptosis with directivity. First, we revealed that the THz radiation had the ability to significantly decrease binding affinity between the Fe3+ and Tf via molecular dynamics simulations, and the modulation was strongly wavelength-dependent. This result provides theoretical feasibility for the THz modulation-based ferroptosis intervention. Subsequent extracellular and cellular chromogenic activity assays indicated that the THz field at 8.7 μm (i.e., 34.5 THz) inhibited the most Fe3+ bound to the Tf, and the wavelength was in good agreement with the simulated one. Then, functional assays demonstrated that levels of intracellular Fe2+, lipid peroxidation, malondialdehyde (MDA) and cell death were all significantly reduced in cells treated with this 34.5 THz wave. Furthermore, the iron deposition, lipid peroxidation, and MDA in the ferroptosis disease model induced by ischemia-reperfusion injury could be nearly eliminated by the same radiation, validating THz wave-induced desensitization of ferroptosis in vivo. Together, this work provides a preclinical exemplar for electromagnetic irradiation-stimulated desensitization of ferroptosis and predicts an innovative, THz wave-based therapeutic method for ferroptosis-associated diseases in the future.

Ferroptosis in senescence and age-related diseases: pathogenic mechanisms and potential intervention targets

As the global population continues to age, the prevalence of age-related diseases is increasing, significantly influencing social and economic development, the stability of social security systems, and progress in medical technology. Ferroptosis, a recently discovered form of programmed cell death driven by iron-dependent lipid peroxidation, has emerged as a key area of research. Studies have revealed a strong association between ferroptosis and senescence. In this article, we systematically summarize the molecular mechanisms and associated signaling pathways underlying ferroptosis, emphasizing its pivotal role in the onset and progression of age-related diseases. By providing new perspectives, we aim to advance understanding of the pathogenesis of age-related diseases and guide the development of effective intervention strategies.

Aquatic high iron induces hepatic ferroptosis in zebrafish (Danio rerio) via interleukin-22 signaling pathway

Iron is one of the indispensable trace elements in living organisms. However, excessive iron deposition in organisms is prone to induce dysfunction of the liver and other vital organs. The present study aimed to investigate the mechanism how aquatic high iron affects iron transport and induces hepatic injury in zebrafish. Our results showed that the iron levels in zebrafish liver and serum were significantly increased after the fish treated with aquatic high iron (200 mg/L ferric ammonium citrate, FAC) for 21 days. Meanwhile, hepatic fibrosis was observed in zebrafish with high iron treatment. Furthermore, the expression of hepcidin, a key factor in the regulation of iron homeostasis, as well as other factors related to iron transport, was significantly influenced by high iron treatment. Nonetheless, different tissues, such as liver, gill and gut, diversely responded to high iron in water. Interestingly, our results identified that the expression of IL-22, instead of IL-6, was significantly elevated after high iron treatment. Moreover, high iron triggered STAT3 phosphorylation via IL-22, leading to the augmented expression of hepcidin and hepatic iron accumulation. As a result, the iron overload in fish liver induced hepatic ferroptosis, marked as the repressed activity of glutathione peroxidase (GPx) and elevated lipid peroxidation. Further studies confirmed that, unlike wild-type (WT) zebrafish, the expression of hepcidin and iron content in the liver of il22-deficient zebrafish was unaffected upon to high iron treatment. At the meantime, hepatic ferroptosis and fibrosis induced by high iron was significantly alleviated in il22-deficient zebrafish. In summary, aquatic high iron induced hepcidin expression in zebrafish by activating the IL-22/STAT3 signaling pathway, which in turn regulated hepatic iron transport and ferroptosis in zebrafish. The present study identified for the first time that IL-22 may be a potential regulatory target for iron overload-induced liver injury.

Is Ferric the Same as Ferrous? Effect of Nutritionally Relevant Iron Species in C. elegans: Bioavailability, Iron Homeostasis, Oxidative Stress, and Cell Death

Iron (Fe) is present in foods and food supplements in a wide variety of Fe species. Caution needs to be paid in the case of overdosing on this essential trace element as adverse effects like neurodegenerative diseases are associated with increased iron levels in the brain. However, knowledge regarding the species-specific effects of nutritionally relevant Fe species is limited. Therefore, we treated the nematode Caenorhabditis elegans (C. elegans) with an overdose of the Fe species iron(III) ammonium citrate (FAC), iron(II) gluconate (FeGlu), and iron(II) chloride (FeCl2) for 5 and 24 h. While the bioavailability of Fe was highest with FeCl2 and lowest with FAC, the effects on tested endpoints, such as superoxide dismutase activity, translocation of the transcription factor daf-16 (human FOXO3), mitochondrial reactive oxygen and nitrogen species, and apoptotic cells were similar. This study provides further insights into Fe-species-specific effects on genes related to Fe homeostasis of C. elegans by studying gene expression and investigating C. elegans mutants lacking smf-3, ftn-1, ftn-2, dcytb (f55h2.5), and cp (f21d5.3). Thus, these findings underline the significance of the oxidation state and ligand of Fe species with respect to bioavailability while also identifying the key genes involved in Fe homeostasis in C. elegans.

Fission yeast cells deficient in siderophore biosynthesis require Str2 for ferrichrome-dependent growth

Ferrichrome (Fc) acquisition in Schizosaccharomyces pombe is mediated by the cell-surface siderophore-iron transporter Str1. Here, we report that Str2, a protein homologous to Str1, localizes to the vacuolar membrane. Like Str1, Str2 expression is transcriptionally regulated in response to changes in iron concentrations. Both the str2+ and str1+ genes are induced under low-iron conditions and are repressed by the iron-responsive GATA-type transcription factor Fep1 when iron is abundant. Under high-iron conditions, chromatin immunoprecipitation (ChIP) assays reveal that TAP-Fep1 occupies the str2+ and str1+ promoters. Isolated vacuoles from str2Δ fep1Δ cells expressing GFP-tagged Str2 exhibit iron accumulation in vacuoles upon exposure to exogenous holo-Fc. sib1Δ sib2Δ cells deficient in Fc biosynthesis and lacking the str2+ gene (str2Δ) are unable to grow in the presence of exogenous Fc as a sole source of iron. Further analysis identified that conserved amino acids Tyr539 and Tyr553 in the last predicted loop of Str2 are required for supporting Fc-dependent growth of a sib1Δ sib2Δ mutant strain. Collectively, these findings indicate that the vacuolar Str2 protein plays a role in the consumption of Fc as an iron source, while also revealing the involvement of the vacuole in iron release from exogenous Fc after its assimilation.

Iron and ferroptosis in kidney disease: molecular and metabolic mechanisms

Maintaining iron homeostasis is necessary for kidney functioning. There is more and more research indicating that kidney disease is often caused by iron imbalance. Over the past decade, ferroptosis' role in mediating the development and progression of renal disorders, such as acute kidney injury (renal ischemia-reperfusion injury, drug-induced acute kidney injury, severe acute pancreatitis induced acute kidney injury and sepsis-associated acute kidney injury), chronic kidney disease (diabetic nephropathy, renal fibrosis, autosomal dominant polycystic kidney disease) and renal cell carcinoma, has come into focus. Thus, knowing kidney iron metabolism and ferroptosis regulation may enhance disease therapy. In this review, we discuss the metabolic and molecular mechanisms of iron signaling and ferroptosis in kidney disease. We also explore the possible targets of ferroptosis in the therapy of renal illness, as well as their existing limitations and future strategies.

Characterization of iron status biomarkers and hematological indices among young adults of East Asian or Northern European ancestry: A cross-sectional analysis from the Iron Genes in East Asian and Northern European Adults Study (FeGenes)

BACKGROUND

Excess body iron (Fe) accrual is linked to chronic diseases. East Asian (EA) adults (median age 50 y) were reported to have higher Fe stores compared to other populations despite lacking the mutation that causes Fe overload in Northern European (NE) adults. It is unknown if these differences are evident in a healthy population under 50 y of age.

OBJECTIVES

This cross-sectional study aims to compare Fe-related markers in young adults of EA and NE ancestry and identify determinants of Fe status.

METHODS

Participants were healthy United States males and premenopausal/nonpregnant females of genetically confirmed EA (n = 251) or NE (n = 253) ancestry, aged 18-50 y and without obesity. A complete blood count was obtained. Serum ferritin (SF; μg/L), c-reactive protein, and interleukin-6 were measured by immunoassay, and serum soluble transferrin receptor (mg/L) and transferrin by quantitative immunoturbidimetry. Total body Fe (mg/kg) was calculated. Elevated Fe stores were defined as SF >200 (females) or >300 (males) and c-reactive protein <5 mg/L. Results are shown as the geometric mean 95% confidence interval (CI) or mean ± standard deviation.

RESULTS

The mean age of the population was (26.3 y; 25.6, 26.9 y), with 69.2% of participants aged under 30 y. SF was higher in EA (172; 152, 194) compared with NE (85.3; 76.8, 94.8) males (P < 0.001), and in EA (42.6; 36.7, 49.5) compared with NE (31.9; 27.8, 36.5) females (P = 0.004). The prevalence of elevated Fe stores was 16.7% in EA compared with 0.8% in NE males (P < 0.001) and 1.6% in EA compared with 0% in NE females (P = 0.47). Total body Fe was higher in EA (11.7 ± 2.7) compared with NE (9.1 ± 2.6) males (P < 0.001) and in EA (6.7 ± 3.6) compared with NE (5.6 ± 3.4) females (P = 0.01). All differences persisted after adjustment for confounders (all P < 0.05).

CONCLUSIONS

Individuals of EA ancestry had a significantly greater body Fe burden compared to NE individuals. Of concern, these differences were evident in a cohort primarily consisting of young individuals aged 18-29 y. This trial was registered at clinicaltrials.gov as NCT04198545.

Consumption of ultra-processed foods is associated with dietary iron availability, anemia, and excess weight in socially vulnerable children

BACKGROUND & AIMS

Eating habits during childhood have undergone significant changes, with a notable increase in the consumption of ultra-processed foods (UPF). This situation deserves attention, given the close relationship between UPF and adverse health outcomes. This is due to the nutritional composition of UPF, which has high levels of health-critical nutrients such as sugar, fat, and sodium, thus compromising the overall quality of the diet. An excess of these nutrients can increase the risk of developing excess weight, nutritional deficiencies, and chronic diseases during childhood. Among the nutritional deficiencies is iron. This is due to the fact that UPF are not good sources of iron. This, combined with the fact that UPF is low in nutrients that help make iron more available, such as vitamin C, increases the risk of developing anemia. Therefore, this study aimed to assess the availability of iron, as well as the presence of anemia and excess weight in children living in situations of social vulnerability, and to determine their association with the consumption of UPF.

METHODS

This is a population-based cross-sectional study. Children aged between 6 and 59 months living in slums were included. The presence of excess weight was assessed by measuring weight and height, and the presence of anemia was determined by hemoglobin concentration, assessed using the HemoCue portable hemoglobinometer. A 24-h food recall was also used to assess the relative calorie intake of UFP and the dietary availability of iron using an algorithm. All statistical analyses were carried out using the statistical software Jamovi.

RESULTS

In this study, 443 children were included; 19.2 % were classified as with excess weight, and 55.6 % were anemic; the average absorbable iron content was 0.54 (SD ± 0.42) mg, and 39.2 % of the calories consumed came from UPF. The association analysis showed that children with calorie share relative to UPF had a decrease of -0.12 mg of bioavailable iron (β: -0.12; 95 % CI: -0.23; -0.01). It was also possible to identify that the higher calorie share of UPF increased their chances of being classified as with excess weight and anemic by up to 116 % (OR: 2.16; 95 % CI 1.05; 4.46) and 145 % (OR: 2.45; 95 % CI: 1.26; 4.78), respectively.

CONCLUSIONS

The relationship found between UPF consumption and the availability of iron in the diet, excess weight, and anemia calls for attention, especially in contexts of social vulnerability. These findings demonstrate the need for greater attention to nutrition in childhood to promote an adequate and healthy diet. This can help to change the nutritional and epidemiological panorama of the population, contributing to a better general state of health for future generations of adults.

Targeting Ferroptosis in Rare Neurological Disorders Including Pediatric Conditions: Innovations and Therapeutic Challenges

Ferroptosis, characterized by iron dependency and lipid peroxidation, has emerged as a key mechanism underlying neurodegeneration in rare neurological disorders. These conditions, often marked by significant therapeutic gaps and high unmet medical needs, present unique challenges for intervention development. This review examines the involvement of ferroptosis in rare neurological disease pathogenesis, focusing on its role in oxidative damage and neuronal dysfunction. We explore recent pharmacological advancements, including iron chelators, lipid peroxidation blockers, and antioxidant-based strategies, designed to target ferroptosis. While these approaches show promise, challenges such as disease heterogeneity, limited diagnostic tools, and small patient cohorts hinder progress. Furthermore, we discuss the translational and regulatory barriers to implementing ferroptosis-based therapies in clinical practice. By addressing these obstacles and fostering innovative solutions, this review underscores the potential of ferroptosis-targeting strategies to revolutionize treatment paradigms for rare neurological disorders.

Hypoxia-tropic delivery of nanozymes targeting transferrin receptor 1 for nasopharyngeal carcinoma radiotherapy sensitization

Nasopharyngeal carcinoma (NPC), a malignancy highly prevalent in East and Southeast Asia, is primarily treated with radiotherapy (RT). However, hypoxia-induced radioresistance presents a significant challenge. Nanozymes, nanomaterials with catalase-like activity, have emerged as a promising strategy for radiosensitization by converting elevated hydrogen peroxide in the tumor microenvironment into oxygen. Despite their potential, effectively targeting hypoxic lesions has been difficult. Here, we identify transferrin receptor 1 (TfR1) as an upregulated target in NPC, with its expression levels positively correlated with hypoxia. Human heavy-chain ferritin, a specific ligand of TfR1, selectively recognizes hypoxic NPC lesions in preclinical models. Based on these findings, we design a hypoxia-targeted nanozyme by loading platinum nanoparticles into ferritin. This nanozyme exhibits enhanced catalase-like activity and effectively alleviates tumor hypoxia in NPC xenografts. When combined with RT, a single injection of the nanozyme significantly inhibits tumor growth and prolongs mouse survival, outperforming sodium glycididazole, a clinically used radiosensitizer. In summary, our findings highlight TfR1 as an accessible cell surface target in hypoxic NPC lesions. The nanozyme targeting TfR1 holds promise for enhancing the therapeutic effectiveness of RT in NPC through an in situ oxygen-generation mechanism.

Metal ion formulations for diabetic wound healing: Mechanisms and therapeutic potential

Metals are vital in human physiology, which not only act as enzyme catalysts in the processes of superoxide dismutase and glucose phosphorylation, but also affect the redox process, osmotic adjustment, metabolism and neural signals. However, metal imbalances can lead to diseases such as diabetes, which is marked by chronic hyperglycemia and affects wound healing. The hyperglycemic milieu of diabetes impairs wound healing, posing significant challenges to patient quality of life. Wound healing encompasses a complex cascade of hemostasis, inflammation, proliferation, and remodeling phases, which are susceptible to disruption in hyperglycemic conditions. In recent decades, metals have emerged as critical facilitators of wound repair by enhancing antimicrobial properties (e.g., iron and silver), providing angiogenic stimulation (copper), promoting antioxidant activity and growth factor synthesis (zinc), and supporting wound closure (calcium and magnesium). Consequently, research has pivoted towards the development of metal ion-based therapeutics, including innovative formulations such as nano-hydrogels, nano-microneedle dressings, and microneedle patches. Prepared by combining macromolecular materials such as chitosan, hyaluronic acid and sodium alginate with metals, aiming at improving the management of diabetic wounds. This review delineates the roles of key metals in human physiology and evaluates the application of metal ions in diabetic wound management strategies.

Immune imbalance in Lupus Nephritis: The intersection of T-Cell and ferroptosis

Ferroptosis is a novel form of cell death characterized by unlimited accumulation of iron-dependent lipid peroxides. It is often accompanied by disease, and the relationship between ferroptosis of immune cells and immune regulation has been attracting increasing attention. Initially, it was found in cancer research that the inhibition of regulatory T cell (Treg) ferroptosis and the promotion of CD8+ T cell ferroptosis jointly promoted the formation of an immune-tolerant environment in tumors. T-cell ferroptosis has subsequently been found to have immunoregulatory effects in other diseases. As an autoimmune disease characterized by immune imbalance, T-cell ferroptosis has attracted attention for its potential in regulating immune balance in lupus nephritis. This article reviews the metabolic processes within different T-cell subsets in lupus nephritis (LN), including T follicular helper (TFH) cells, T helper (Th)17 cells, Th1 cells, Th2 cells, and Treg cells, and reveals that these cellular metabolisms not only facilitate the formation of a T-cell immune imbalance but are also closely associated with the occurrence of ferroptosis. Consequently, we hypothesize that targeting the metabolic pathways of ferroptosis could become a novel research direction for effectively treating the immune imbalance in lupus nephritis by altering T-cell differentiation and the incidence of ferroptosis.

Genetically Predicted Iron Status Is a Causal Risk of Rheumatoid Arthritis: A Mendelian Randomization Study

Background  Current knowledge on iron's role in rheumatoid arthritis (RA) development is very limited, with studies yielding inconsistent findings. We conducted a two-sample Mendelian randomization study to assess the associations of iron status with the risk of RA. Methods  This study leveraged genetic data from a large genome-wide association study (GWAS) of 257,953 individuals to identify single nucleotide polymorphisms (SNPs) associated with iron status. We then analyzed these data in conjunction with summary-level data on RA from the IEU open GWAS project, which included 5,427 RA cases and 479,171 controls. An inverse-variance weighted method with random effects was employed, along with sensitivity analyses, to assess the relationship between iron status and RA risk. Results  Genetic predisposition to high ferritin and serum iron status was causally associated with lower odds of RA. Ferritin had an odds ratio (OR) of 0.997 (95% confidence interval [CI]: 0.995-0.997; p  = 0.010), indicating that a one-unit increase in ferritin is associated with a 0.3% decrease in the odds of RA. Similarly, serum iron had an OR of 0.997 (95% CI: 0.995-0.999; p  = 0.014). However, MR analyses found no significant causal associations between total iron-binding capacity (OR = 1.0, 95% CI: 0.999-1.002; p  = 0.592) or transferrin saturation percentage (OR = 0.998, 95% CI: 0.996-1.000; p  = 0.080) and risk of developing RA. Conclusions  This study suggests that individuals with genes linked to higher iron levels may have a lower risk of developing RA. Our findings indicate that the total amount of iron in the body, rather than how it is distributed, might be more important for RA. This raises the intriguing possibility that iron supplementation could be a preventative strategy, but further research is necessary.

Ferroptosis in Parkinson's disease -- The iron-related degenerative disease

Parkinson's disease (PD) is a prevalent and advancing age-related neurodegenerative disorder, distinguished by the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Iron regional deposit in SNpc is a significant pathological characteristic of PD. Brain iron homeostasis is precisely regulated by iron metabolism related proteins, whereas disorder of these proteins can damage neurons and glial cells in the brain. Additionally, growing studies have reported iron metabolism related proteins are involved in the ferroptosis progression in PD. However, the effect of these proteins in the ferroptosis of PD has not been systematically summarized. This review focuses on the roles of iron metabolism related proteins in the ferroptosis of PD. Finally, we put forward the iron early diagnosis according to the observation of iron deposits in the brain and showed the recent advances in iron chelation therapy in PD.

Bile from the hemojuvelin-deficient mouse model of iron excess is enriched in iron and ferritin

Iron is an essential nutrient but is toxic in excess. Iron deficiency is the most prevalent nutritional deficiency and typically linked to inadequate intake. Iron excess is also common and usually due to genetic defects that perturb expression of hepcidin, a hormone that inhibits dietary iron absorption. Our understanding of iron absorption far exceeds that of iron excretion, which is believed to contribute minimally to iron homeostasis. Prior to the discovery of hepcidin, multiple studies showed that excess iron undergoes biliary excretion. We recently reported that wild-type mice raised on an iron-rich diet have increased bile levels of iron and ferritin, a multi-subunit iron storage protein. Given that genetic defects leading to excessive iron absorption are much more common causes of iron excess than dietary loading, we set out to determine if an inherited form of iron excess known as hereditary hemochromatosis also results in bile iron loading. We employed mice deficient in hemojuvelin, a protein essential for hepcidin expression. Mutant mice developed bile iron and ferritin excess. While lysosomal exocytosis has been implicated in ferritin export into bile, knockdown of Tfeb, a regulator of lysosomal biogenesis and function, did not impact bile iron or ferritin levels. Bile proteomes differed between female and male mice for wild-type and hemojuvelin-deficient mice, suggesting sex and iron excess impact bile protein content. Overall, our findings support the notion that excess iron undergoes biliary excretion in genetically determined iron excess.

Association of urinary glyphosate levels with iron homeostasis among a representative sample of US adults: NHANES 2013-2018

PURPOSE

Glyphosate and glyphosate-based herbicides (GBH), widely used globally, were initially considered harmless to humans. Experimental studies have suggested that these substances can disrupt iron homeostasis by interfering with iron uptake or triggering inflammatory responses. However, their potential impact on human iron homeostasis remains underexplored.

APPROACH AND RESULTS

We analyzed data from 5812 participants aged three and older from the 2013 to 2018 NHANES. We investigated the relationships between urinary glyphosate levels, oral iron intake, and markers of iron homeostasis, including serum iron, unsaturated iron-binding capacity (UIBC), total iron-binding capacity (TIBC), transferrin saturation, ferritin, and transferrin receptor. Higher urinary glyphosate levels were positively associated with oral iron intake (β = 1.310, S.E. = 0.382, P = 0.001). A one-unit increase in the natural logarithm (ln)-glyphosate was associated with lower serum iron (β = - 4.236, 95 % CI = - 6.432 to - 2.039, P < 0.001) and ferritin (β = - 9.994, 95 % CI = - 17.342 to - 2.647, P = 0.009), and higher UIBC (β = 5.431, 95 % CI = 1.061-9.800, P = 0.018) and transferrin receptor levels (β = 0.139, 95 % CI = 0.015-0.263, P = 0.029). Increasing glyphosate exposure was associated with significant decreases in serum iron and ferritin across exposure quintiles (trend P-values = 0.003 and 0.018, respectively).

CONCLUSIONS

Higher glyphosate exposure is associated with reduced iron availability, suggesting potential disruptions in iron absorption. These findings underscore the need for further research into the health implications of glyphosate exposure on iron homeostasis.

Ferritin and Iron Levels Inversely Associated With Lymphoma Risk: A Mendelian Randomization Study

Background

Current knowledge on iron's role in lymphoma development is very limited, with studies yielding inconsistent findings. To address this gap, we conducted a rigorous two-sample mendelian randomization study, aiming to elucidate the potential associations between iron storage and the risk of developing lymphoma.

Methods

This study leveraged extensive genetic data derived from a comprehensive genome-wide association study (GWAS) comprising 257,953 individuals. The primary objective was to pinpoint single-nucleotide polymorphisms (SNPs) that are significantly associated with iron storage. Subsequently, this genetic information was analyzed in conjunction with summary-level data pertaining to lymphoma cases and controls, sourced from the IEU open GWAS project, which included a sample size of 3,546 lymphoma cases and 487,257 controls. To evaluate the relationship between iron storage and lymphoma risk, an inverse variance-weighted method with random effects was employed, complemented by rigorous sensitivity analyses.

Results

Genetic predisposition to high ferritin and serum iron status was causally associated with lower odds of lymphoma. Ferritin exhibited an odds ratio (OR) of 0.777 (95% confidence interval (CI): 0.628 - 0.961, P = 0.020), indicating 22.3% reduced odds of lymphoma associated with a one standard deviation increase in ferritin levels. Similarly, serum iron demonstrated an OR of 0.776 (95% CI: 0.609 - 0.989, P = 0.040), corresponding to 22.4% decreased odds of lymphoma for a one standard deviation increase in serum iron.

Conclusions

This study suggests that individuals with genes linked to higher iron storage levels have a lower risk of developing lymphoma, but further research is necessary before making any clinical recommendations.

Research progress of ferroptosis and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a non-specific chronic inflammatory disorder of the gastrointestinal tract, imposing significant burdens on both society and individuals. As a new type of regulated cell death (RCD), ferroptosis is different from classic RCDs such as apoptosis and necrosis in cell morphology, biochemistry and genetics. The main molecular mechanisms of ferroptosis include dysregulation of iron metabolism, impaired antioxidant capacity, mitochondrial dysfunction, accumulation of lipid-associated super-oxides, and membrane disruption. In recent years, increasing evidence has shown that ferroptosis is involved in the pathophysiology of inflammatory bowel disease. However, the exact roles and underlying molecular mechanisms have not been fully elucidated. This article reviews the mechanism of ferroptosis in the occurrence and development of inflammatory bowel disease, in order to provide new ideas for the pathophysiological research of inflammatory bowel disease. Additionally, we discuss potential strategies for the prevention and treatment of inflammatory bowel disease by targeting ferroptosis.

Acute and Chronic Effects of Interval Aerobic Exercise on Hepcidin, Ferritin, and Liver Enzymes in Adolescents With Beta-Thalassemia Major

PURPOSE

This study aimed to determine the acute and chronic effects of interval aerobic exercise on hepcidin, ferritin, and liver enzymes in adolescents with beta-thalassemia major.

METHODS

Twenty-six beta-thalassemia major adolescents referred to the Thalassemia Clinic and Research Center were selected as study participants and randomly divided into control (n = 13) and training (n = 13) groups. Participants performed 3 sessions per week for 45 minutes in each session for 8 weeks of aerobic interval exercise with an intensity of 50% to 65% of the heart rate reserve. Blood samples were taken before, immediately after the exercise session, and 48 hours after the last training session, and liver enzymes aspartate aminotransferase, alanine aminotransferase (ALT), alkaline phosphatase (ALP), ferritin, and hepcidin were evaluated.

RESULTS

The results showed a decrease in aspartate aminotransferase, ALT, ALP, ferritin, and hepcidin levels due to 8 weeks of aerobic interval training (P = .14, P = .97, P = .03, P < .001, P < .001; respectively). Intergroup changes in all variables except ALT and hepcidin were significant (P < .05). Besides, acute aerobic exercise increased levels of aspartate aminotransferase, ALT, ferritin, and hepcidin (P = .04, P = .52, P < .001, P < .001; respectively), whereas ALP levels decreased (P < .001). In addition, changes in ALP and hepcidin levels were significant between the 2 groups (P = .05, P < .001; respectively).

CONCLUSION

Based on the study's results, it can be concluded that 8 weeks of aerobic interval training can decrease ferritin and hepcidin levels, but acute aerobic exercise increases them.

The Schizosaccharomyces pombe ornithine-N5-oxygenase Sib2 interacts with the N5-transacetylase Sib3 in the ferrichrome biosynthetic pathway

The fission yeast Schizosaccharomyces pombe produces the hydroxamate-type siderophore ferrichrome (Fc). The biosynthesis of Fc requires the Fc synthase Sib1, the ornithine-N5-oxygenase Sib2, and the N5-hydroxyornithine-N5-transacetylase Sib3. In this study, we demonstrate the critical importance of the His248 residue of Sib3 in Fc production. Cells expressing a sib3H248A mutant allele fail to grow in iron-poor media without Fc supplementation. These sib3H248A mutant cells are consistently unable to promote Fc-dependent growth of Saccharomyces cerevisiae cells in cross-feeding experiments. Green fluorescent protein (GFP)-tagged wild-type Sib3 and mutant Sib3H248A exhibit a pancellular distribution. Coimmunoprecipitation assays revealed that both wild-type and Sib3H248A physically interact with Sib2. Further analysis identified a minimal C-terminal region from amino acids 290-334 of Sib3 that is required for interaction with Sib2. Deletion mapping analysis identified two regions of Sib2 as being required for its association with Sib3. The first region encompasses amino acids 1-135, and the second region corresponds to amino acids 281-358 of Sib2. Taken together, these results describe the first example of a physical interaction between an ornithine-N5-oxygenase and an N5-hydroxyornithine-N5-transacetylase controlling the biosynthesis of a hydroxamate-type siderophore.

Preliminary Evidence of the Possible Roles of the Ferritinophagy-Iron Uptake Axis in Canine Testicular Cancer

Iron is a key element in spermatogenesis; its metabolic pathway in the testis is strictly regulated. Alterations in iron metabolism are linked to various diseases, including cancer, and changes in iron metabolism-related proteins have been observed in multiple human, mouse and canine tumors. There is limited knowledge about iron metabolism in canine non-neoplastic and neoplastic testes. This study aimed to explore the immunohistochemical expression of molecules involved in iron uptake and storage [Transferrin Receptor 1 (TfR1), ferritin (FTH1), nuclear receptor coactivator 4 (NCOA4)] and PCNA in canine non-neoplastic and neoplastic testicular samples. Non-neoplastic testes showed moderate TfR1 expression in developing germ cells and Sertoli cells, high NCOA4 cytoplasmic immunostaining in the Sertoli cells and occasional cytoplasmic immunopositivity for FTH1 in the spermatogonia and Sertoli cells. In contrast, Leydig cell tumors (LCTs) and Diffuse Type Seminoma (DSEM) exhibited increased expression of TfR1, along with higher PCNA expression, suggesting a higher iron need for proliferation. Intratubular Type Seminoma (ITSEM) showed a higher FTH1 expression, indicating greater iron storage, while the increased NCOA4 expression in the LCTs and DSEM suggested ferritinophagy to release iron for proliferation. Sertoli cell tumors (SCTs) showed only NCOA4 expression. These preliminary findings highlight potential molecular targets for developing new anti-neoplastic treatments in canine testicular tumors.

Traditional Chinese medicines derived natural inhibitors of ferroptosis on ischemic stroke

Ischemic stroke (IS) is a globally prevalent cerebrovascular disorder resulting from cerebral vessel occlusion, leading to significant morbidity and mortality. The intricate pathological mechanisms underlying IS complicate the development of effective therapeutic interventions. Ferroptosis, a form of programmed cell death (PCD) characterized by iron overload and accumulation of lipid peroxidation products, has been increasingly recognized as a key contributor to IS pathology. Traditional Chinese medicines (TCMs) have long been utilized in the management of IS, prompting extensive research into their potential as sources of natural ferroptosis inhibitors. This review investigates the critical role of ferroptosis in IS and provides a comprehensive analysis of current research on natural ferroptosis inhibitors identified in TCMs, aiming to lay a theoretical groundwork for the development of innovative anti-IS therapies.

Regulating NCOA4-Mediated Ferritinophagy for Therapeutic Intervention in Cerebral Ischemia-Reperfusion Injury

Ischemic stroke presents a global health challenge, necessitating an in-depth comprehension of its pathophysiology and therapeutic strategies. While reperfusion therapy salvages brain tissue, it also triggers detrimental cerebral ischemia-reperfusion injury (CIRI). In our investigation, we observed the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy in an oxygen-glucose deprivation/reoxygenation (OGD/R) model using HT22 cells (P < 0.05). This activation contributed to oxidative stress (P < 0.05), enhanced autophagy (P < 0.05) and cell death (P < 0.05) during CIRI. Silencing NCOA4 effectively mitigated OGD/R-induced damage (P < 0.05). These findings suggested that targeting NCOA4-mediated ferritinophagy held promise for preventing and treating CIRI. Subsequently, we substantiated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway effectively regulated the NCOA4-mediated ferritinophagy, by applying the cGAS inhibitor RU.521 and performing NCOA4 overexpression (P < 0.05). Suppressing the cGAS-STING pathway efficiently curtailed ferritinophagy (P < 0.05), oxidative stress (P < 0.05), and cell damage (P < 0.05) of CIRI, while NCOA4 overexpression could alleviate this effect (P < 0.05). Finally, we elucidated the specific molecular mechanism underlying the protective effect of the iron chelator deferoxamine (DFO) on CIRI. Our findings revealed that DFO alleviated hypoxia-reoxygenation injury in HT22 cells through inhibiting NCOA4-mediated ferritinophagy and reducing ferrous ion levels (P < 0.05). However, the protective effects of DFO were counteracted by cGAS overexpression (P < 0.05). In summary, our results indicated that the activation of the cGAS-STING pathway intensified cerebral damage during CIRI by inducing NCOA4-mediated ferritinophagy. Administering the iron chelator DFO effectively attenuated NCOA4-induced ferritinophagy, thereby alleviating CIRI. Nevertheless, the role of the cGAS-STING pathway in CIRI regulation likely involves intricate mechanisms, necessitating further validation in subsequent investigations.

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.

Redox-Regulated Iron Metabolism and Ferroptosis in Ovarian Cancer: Molecular Insights and Therapeutic Opportunities

Ovarian cancer (OC), known for its lethality and resistance to chemotherapy, is closely associated with iron metabolism and ferroptosis-an iron-dependent cell death process, distinct from both autophagy and apoptosis. Emerging evidence suggests that dysregulation of iron metabolism could play a crucial role in OC by inducing an imbalance in the redox system, which leads to ferroptosis, offering a novel therapeutic approach. This review examines how disruptions in iron metabolism, which affect redox balance, impact OC progression, focusing on its essential cellular functions and potential as a therapeutic target. It highlights the molecular interplay, including the role of non-coding RNAs (ncRNAs), between iron metabolism and ferroptosis, and explores their interactions with key immune cells such as macrophages and T cells, as well as inflammation within the tumor microenvironment. The review also discusses how glycolysis-related iron metabolism influences ferroptosis via reactive oxygen species. Targeting these pathways, especially through agents that modulate iron metabolism and ferroptosis, presents promising therapeutic prospects. The review emphasizes the need for deeper insights into iron metabolism and ferroptosis within the redox-regulated system to enhance OC therapy and advocates for continued research into these mechanisms as potential strategies to combat OC.

Exploring the Causal Effects of Mineral Metabolism Disorders on Telomere and Mitochondrial DNA: A Bidirectional Two-Sample Mendelian Randomization Analysis

The aim of this study was to assess the causal relationships between mineral metabolism disorders, representative of trace elements, and key aging biomarkers: telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN). Utilizing bidirectional Mendelian randomization (MR) analysis in combination with the two-stage least squares (2SLS) method, we explored the causal relationships between mineral metabolism disorders and these aging indicators. Sensitivity analysis can be used to determine the reliability and robustness of the research results. The results confirmed that a positive causal relationship was observed between mineral metabolism disorders and TL (p < 0.05), while the causal relationship with mtDNA-CN was not significant (p > 0.05). Focusing on subgroup analyses of specific minerals, our findings indicated a distinct positive causal relationship between iron metabolism disorders and both TL and mtDNA-CN (p < 0.05). In contrast, disorders in magnesium and phosphorus metabolism did not exhibit significant causal effects on either aging biomarker (p > 0.05). Moreover, reverse MR analysis did not reveal any significant causal effects of TL and mtDNA-CN on mineral metabolism disorders (p > 0.05). The combination of 2SLS with MR analysis further reinforced the positive causal relationship between iron levels and both TL and mtDNA-CN (p < 0.05). Notably, the sensitivity analysis did not indicate significant pleiotropy or heterogeneity within these causal relationships (p > 0.05). These findings highlight the pivotal role of iron metabolism in cellular aging, particularly in regulating TL and sustaining mtDNA-CN, offering new insights into how mineral metabolism disorders influence aging biomarkers. Our research underscores the importance of trace element balance, especially regarding iron intake, in combating the aging process. This provides a potential strategy for slowing aging through the adjustment of trace element intake, laying the groundwork for future research into the relationship between trace elements and healthy aging.

Crosstalk between intestinal flora and human iron metabolism: the role in metabolic syndrome-related comorbidities and its potential clinical application

The interaction of iron and intestinal flora, both of which play crucial roles in many physiologic processes, is involved in the development of Metabolic syndrome (MetS). MetS is a pathologic condition represented by insulin resistance, obesity, dyslipidemia, and hypertension. MetS-related comorbidities including type 2 diabetes mellitus (T2DM), obesity, metabolism-related fatty liver (MAFLD), hypertension polycystic ovary syndrome (PCOS), and so forth. In this review, we examine the interplay between intestinal flora and human iron metabolism and its underlying mechanism in the pathogenesis of MetS-related comorbidities. The composition and metabolites of intestinal flora regulate the level of human iron by modulating intestinal iron absorption, the factors associated with iron metabolism. On the other hand, the iron level also affects the abundance, composition, and metabolism of intestinal flora. The crosstalk between these factors is of significant importance in human metabolism and exerts varying degrees of influence on the manifestation and progression of MetS-related comorbidities. The findings derived from these studies can enhance our comprehension of the interplay between intestinal flora and iron metabolism, and open up novel potential therapeutic approaches toward MetS-related comorbidities.

The roles of essential trace elements in T cell biology

T cells are crucial for adaptive immunity to regulate proper immune response and immune homeostasis. T cell development occurs in the thymus and mainly differentiates into CD4+ and CD8+ T cell subsets. Upon stimulation, naive T cells differentiate into distinct CD4+ helper and CD8+ cytotoxic T cells, which mediate immunity homeostasis and defend against pathogens or tumours. Trace elements are minimal yet essential components of human body that cannot be overlooked, and they participate in enzyme activation, DNA synthesis, antioxidant defence, hormone production, etc. Moreover, trace elements are particularly involved in immune regulations. Here, we have summarized the roles of eight essential trace elements (iron, zinc, selenium, copper, iodine, chromium, molybdenum, cobalt) in T cell development, activation and differentiation, and immune response, which provides significant insights into developing novel approaches to modulate immunoregulation and immunotherapy.

The Importance and Essentiality of Natural and Synthetic Chelators in Medicine: Increased Prospects for the Effective Treatment of Iron Overload and Iron Deficiency

The supply and control of iron is essential for all cells and vital for many physiological processes. All functions and activities of iron are expressed in conjunction with iron-binding molecules. For example, natural chelators such as transferrin and chelator-iron complexes such as haem play major roles in iron metabolism and human physiology. Similarly, the mainstay treatments of the most common diseases of iron metabolism, namely iron deficiency anaemia and iron overload, involve many iron-chelator complexes and the iron-chelating drugs deferiprone (L1), deferoxamine (DF) and deferasirox. Endogenous chelators such as citric acid and glutathione and exogenous chelators such as ascorbic acid also play important roles in iron metabolism and iron homeostasis. Recent advances in the treatment of iron deficiency anaemia with effective iron complexes such as the ferric iron tri-maltol complex (feraccru or accrufer) and the effective treatment of transfusional iron overload using L1 and L1/DF combinations have decreased associated mortality and morbidity and also improved the quality of life of millions of patients. Many other chelating drugs such as ciclopirox, dexrazoxane and EDTA are used daily by millions of patients in other diseases. Similarly, many other drugs or their metabolites with iron-chelation capacity such as hydroxyurea, tetracyclines, anthracyclines and aspirin, as well as dietary molecules such as gallic acid, caffeic acid, quercetin, ellagic acid, maltol and many other phytochelators, are known to interact with iron and affect iron metabolism and related diseases. Different interactions are also observed in the presence of essential, xenobiotic, diagnostic and theranostic metal ions competing with iron. Clinical trials using L1 in Parkinson's, Alzheimer's and other neurodegenerative diseases, as well as HIV and other infections, cancer, diabetic nephropathy and anaemia of inflammation, highlight the importance of chelation therapy in many other clinical conditions. The proposed use of iron chelators for modulating ferroptosis signifies a new era in the design of new therapeutic chelation strategies in many other diseases. The introduction of artificial intelligence guidance for optimal chelation therapeutic outcomes in personalised medicine is expected to increase further the impact of chelation in medicine, as well as the survival and quality of life of millions of patients with iron metabolic disorders and also other diseases.

Melatonin: a ferroptosis inhibitor with potential therapeutic efficacy for the post-COVID-19 trajectory of accelerated brain aging and neurodegeneration

The unprecedented pandemic of COVID-19 swept millions of lives in a short period, yet its menace continues among its survivors in the form of post-COVID syndrome. An exponentially growing number of COVID-19 survivors suffer from cognitive impairment, with compelling evidence of a trajectory of accelerated aging and neurodegeneration. The novel and enigmatic nature of this yet-to-unfold pathology demands extensive research seeking answers for both the molecular underpinnings and potential therapeutic targets. Ferroptosis, an iron-dependent cell death, is a strongly proposed underlying mechanism in post-COVID-19 aging and neurodegeneration discourse. COVID-19 incites neuroinflammation, iron dysregulation, reactive oxygen species (ROS) accumulation, antioxidant system repression, renin-angiotensin system (RAS) disruption, and clock gene alteration. These events pave the way for ferroptosis, which shows its signature in COVID-19, premature aging, and neurodegenerative disorders. In the search for a treatment, melatonin shines as a promising ferroptosis inhibitor with its repeatedly reported safety and tolerability. According to various studies, melatonin has proven efficacy in attenuating the severity of certain COVID-19 manifestations, validating its reputation as an anti-viral compound. Melatonin has well-documented anti-aging properties and combating neurodegenerative-related pathologies. Melatonin can block the leading events of ferroptosis since it is an efficient anti-inflammatory, iron chelator, antioxidant, angiotensin II antagonist, and clock gene regulator. Therefore, we propose ferroptosis as the culprit behind the post-COVID-19 trajectory of aging and neurodegeneration and melatonin, a well-fitting ferroptosis inhibitor, as a potential treatment.

Anti-aging Factor GRSF1 Attenuates Cerebral Ischemia-Reperfusion Injury in Mice by Inhibiting GPX4-Mediated Ferroptosis

Abnormal accumulation of senescent cells in tissues has been shown to facilitate the onset and progression of various diseases. As an important protein involving in the regulation of cellular senescence process, researches suggested GRSF1 as a potential senolytic target to improve multiple physiological and pathological processes. However, the underlying mechanism of cellular senescence on cerebral ischemia-reperfusion injury (CIRI) has not been revealed. Here, we investigated the effect of GRSF1 on CIRI and delved into its specific mechanisms. In the present study, we established a mouse model of cerebral ischemia-reperfusion (CIR) and observed low expression of anti-aging factor GRSF1, along with greatly increased levels of senescence-related markers p16 and p21 and senescence-associated secretory phenotype TNF-α. Furthermore, we found that the expression of GPX4 was elevated parallel to GRSF1 in CIR mice with overexpression of GRSF1, oxidative stress, and iron metabolism-related proteins were inhibited. Functionally, overexpressing GRSF1 significantly ameliorated infarct volume and neurological function scores and suppressed apoptosis in CIR mice, while administration of GPX4 inhibitors reversed these beneficial phenotypes. Taken together, our results indicate cellular senescence as an important pathological mechanism to exacerbate cerebral injury during CIRI, while GRSF1 could inhibit oxidative stress-mediated ferroptosis through upregulating GPX4 to attenuate reperfusion injury, which makes senolytic treatment, especially GRSF1, a promising therapeutic target for CIRI.

Unveiling the role of iPLA2β in neurodegeneration: From molecular mechanisms to advanced therapies

Calcium-independent phospholipase A2β (iPLA2β), a member of the phospholipase A2 (PLA2s) superfamily, is encoded by the PLA2G6 gene. Mutations in the PLA2G6 gene have been identified as the primary cause of infantile neuroaxonal dystrophy (INAD) and, less commonly, as a contributor to Parkinson's disease (PD). Recent studies have revealed that iPLA2β deficiency leads to neuroinflammation, iron accumulation, mitochondrial dysfunction, lipid dysregulation, and other pathological changes, forming a complex pathogenic network. These discoveries shed light on potential mechanisms underlying PLA2G6-associated neurodegeneration (PLAN) and offer valuable insights for therapeutic development. This review provides a comprehensive analysis of the fundamental characteristics of iPLA2β, its association with neurodegeneration, the pathogenic mechanisms involved in PLAN, and potential targets for therapeutic intervention. It offers an overview of the latest advancements in this field, aiming to contribute to ongoing research endeavors and facilitate the development of effective therapies for PLAN.

Mesenchymal stem cells and ferroptosis: Clinical opportunities and challenges

Objective

This review discusses recent experimental and clinical findings related to ferroptosis, with a focus on the role of MSCs. Therapeutic efficacy and current applications of MSC-based ferroptosis therapies are also discussed.

Background

Ferroptosis is a type of programmed cell death that differs from apoptosis, necrosis, and autophagy; it involves iron metabolism and is related to the pathogenesis of many diseases, such as Parkinson's disease, cancers, and liver diseases. In recent years, the use of mesenchymal stem cells (MSCs) and MSC-derived exosomes has become a trend in cell-free therapies. MSCs are a heterogeneous cell population isolated from a diverse range of human tissues that exhibit immunomodulatory functions, regulate cell growth, and repair damaged tissues. In addition, accumulating evidence indicates that MSC-derived exosomes play an important role, mainly by carrying a variety of bioactive substances that affect recipient cells. The potential mechanism by which MSC-derived exosomes mediate the effects of MSCs on ferroptosis has been previously demonstrated. This review provides the first overview of the current knowledge on ferroptosis, MSCs, and MSC-derived exosomes and highlights the potential application of MSCs exosomes in the treatment of ferroptotic conditions. It summarizes their mechanisms of action and techniques for enhancing MSC functionality. Results obtained from a large number of experimental studies revealed that both local and systemic administration of MSCs effectively suppressed ferroptosis in injured hepatocytes, neurons, cardiomyocytes, and nucleus pulposus cells and promoted the survival and regeneration of injured organs.

Methods

We reviewed the role of ferroptosis in related tissues and organs, focusing on its characteristics in different diseases. Additionally, the effects of MSCs and MSC-derived exosomes on ferroptosis-related pathways in various organs were reviewed, and the mechanism of action was elucidated. MSCs were shown to improve the disease course by regulating ferroptosis.

Role of ferroptosis pathways in neuroinflammation and neurological disorders: From pathogenesis to treatment

Ferroptosis is a newly discovered non-apoptotic and iron-dependent type of cell death. Ferroptosis mainly takes place owing to the imbalance of anti-oxidation and oxidation in the body. It is regulated via a number of factors and pathways both inside and outside the cell. Ferroptosis is closely linked with brain and various neurological disorders (NDs). In the human body, the brain contains the highest levels of polyunsaturated fatty acids, which are known as lipid peroxide precursors. In addition, there is also a connection of glutathione depletion and lipid peroxidation with NDs. There is growing evidence regarding the possible link between neuroinflammation and multiple NDs, such as Alzheimer's disease, amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease, and stroke. Recent studies have demonstrated that disruptions of lipid reactive oxygen species (ROS), glutamate excitatory toxicity, iron homeostasis, and various other manifestations linked with ferroptosis can be identified in various neuroinflammation-mediated NDs. It has also been reported that damage-associated molecular pattern molecules including ROS are generated during the events of ferroptosis and can cause glial activation via activating neuroimmune pathways, which subsequently leads to the generation of various inflammatory factors that play a role in various NDs. This review summarizes the regulation pathways of ferroptosis, the link between ferroptosis as well as inflammation in NDs, and the potential of a range of therapeutic agents that can be used to target ferroptosis and inflammation in the treatment of neurological disorders.

Iron, Oxidative Stress, and Metabolic Dysfunction-Associated Steatotic Liver Disease

Excess free iron is a substrate for the formation of reactive oxygen species (ROS), thereby augmenting oxidative stress. Oxidative stress is a well-established cause of organ damage in the liver, the main site of iron storage. Ferroptosis, an iron-dependent mechanism of regulated cell death, has recently been gaining attention in the development of organ damage and the progression of liver disease. We therefore summarize the main mechanisms of iron metabolism, its close connection to oxidative stress and ferroptosis, and its particular relevance to disease mechanisms in metabolic-dysfunction-associated fatty liver disease and potential targets for therapy from a clinical perspective.

Buddlejasaponin IVb ameliorates ferroptosis of dopaminergic neuron by suppressing IRP2-mediated iron overload in Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is the second neurodegenerative disease that lacks effective treatments. Buddlejasaponin IVb (BJP-IVb) is the main bioactive component of herbs in genus Clinopodium which display antioxidative, anti-inflammatory and neuroprotective activities. However, the role of BJP-IVb in PD still remains unknown.

AIM OF THE STUDY

This study aimed to evaluate the effect of BJP-IVb on dopaminergic neurodegeneration in PD and clarified the underlying mechanisms from the aspect of iron overload-mediated ferroptosis.

MATERIALS AND METHODS

One-methyl-4-phenylpyridinium (MPP+) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD models were established in this study. Behavioral tests, cell cytotoxicity assay, tyrosine hydroxylase (TH) and Nissl staining were performed to evaluate the antiparkinsonian effect of BJP-IVb. Cellular ultrastructure, iron content and lipid peroxidation were detected to evaluate iron overload-mediated dopaminergic neuron ferroptosis. Iron regulatory protein 2 (IRP2) and iron transport-related proteins were detected by immunofluorescence and Western blot to evaluated iron transport. Finally, plasmid vector-mediated IRP2 overexpression were performed to further clarify the molecular mechanism.

RESULTS

BJP-IVb alleviated MPP+-induced neurotoxicity in vitro and improved MPTP-induced dopaminergic neuron loss and motor dysfunctions of PD mice, confirming an effect of BJP-IVb against dopaminergic neurodegeneration of PD. Further results revealed that BJP-IVb protected against PD by suppressing iron overload-mediated dopaminergic neuron ferroptosis, as evidenced by the attenuated lipid peroxidation, decreased iron content and changes in cellular ultrastructure. Finally, the decreased iron regulatory protein (IRP2) was confirmed to be responsible for BJP-IVb-mediated ferroptosis suppression by modulating iron transport-related proteins and alleviating iron overload.

CONCLUSION

BJP-IVb suppressed iron overload-mediated dopaminergic neuron ferroptosis and improved motor dysfunctions in PD, which was achieved by inhibiting IRP2-mediated iron overload. This study provided a potential drug candidate for the treatment of PD.

Toenail and serum levels as biomarkers of iron status in pre- and postmenopausal women: correlations and stability over eight-year follow-up

Iron status is often assessed in epidemiologic studies, and toenails offer a convenient alternative to serum because of ease of collection, transport, and storage, and the potential to reflect a longer exposure window. Very few studies have examined the correlation between serum and toenail levels for trace metals. Our aim was to compare iron measures using serum and toenails on both a cross-sectional and longitudinal basis. Using a subset of the US-wide prospective Sister Study cohort, we compared toenail iron measures to serum concentrations for iron, ferritin and percent transferrin saturation. Among 146 women who donated both blood and toenails at baseline, a subsample (59%, n = 86) provided specimens about 8 years later. Cross-sectional analyses included nonparametric Spearman's rank correlations between toenail and serum biomarker levels. We assessed within-woman maintenance of rank across time for the toenail and serum measures and fit mixed effects models to measure change across time in relation to change in menopause status. Spearman correlations at baseline (follow-up) were 0.08 (0.09) for serum iron, 0.08 (0.07) for transferrin saturation, and - 0.09 (- 0.17) for ferritin. The within-woman Spearman correlation for toenail iron between the two time points was higher (0.47, 95% CI 0.30, 0.64) than for serum iron (0.30, 95% CI 0.09, 0.51) and transferrin saturation (0.34, 95% CI 0.15, 0.54), but lower than that for ferritin (0.58, 95% CI 0.43, 0.73). Serum ferritin increased over time while nail iron decreased over time for women who experienced menopause during the 8-years interval. Based on cross-sectional and repeated assessments, our evidence does not support an association between serum biomarkers and toenail iron levels. Toenail iron concentrations did appear to be moderately stable over time but cannot be taken as a proxy for serum iron biomarkers and they may reflect physiologically distinct fates for iron.

Long-term iron supplementation combined with vitamin B6 enhances maximal oxygen uptake and promotes skeletal muscle-specific mitochondrial biogenesis in rats

Introduction

Iron is an essential micronutrient that plays a crucial role in various biological processes. Previous studies have shown that iron supplementation is related to exercise performance and endurance capacity improvements. However, the underlying mechanisms responsible for these effects are not well understood. Recent studies have suggested the beneficial impact of iron supplementation on mitochondrial function and its ability to rescue mitochondrial function under adverse stress in vitro and rodents. Based on current knowledge, our study aimed to investigate whether the changes in exercise performance resulting from iron supplementation are associated with its effect on mitochondrial function.

Methods

In this study, we orally administered an iron-based supplement to rats for 30 consecutive days at a dosage of 0.66 mg iron/kg body weight and vitamin B6 at a dosage of 0.46 mg/kg.

Results

Our findings reveal that long-term iron supplementation, in combination with vitamin B6, led to less body weight gained and increased VO2 max in rats. Besides, the treatment substantially increased Complex I- and Complex II-driven ATP production in intact mitochondria isolated from gastrocnemius and cerebellum. However, the treatment did not change basal and succinate-induced ROS production in mitochondria from the cerebellum and skeletal muscle. Furthermore, the iron intervention significantly upregulated several skeletal muscle mitochondrial biogenesis and metabolism-related biomarkers, including PGC-1α, SIRT1, NRF-2, SDHA, HSL, MTOR, and LON-P. However, it did not affect the muscular protein expression of SIRT3, FNDC5, LDH, FIS1, MFN1, eNOS, and nNOS. Interestingly, the iron intervention did not exert similar effects on the hippocampus of rats.

Discussion

In conclusion, our study demonstrates that long-term iron supplementation, in combination with vitamin B6, increases VO2 max, possibly through its positive role in regulating skeletal muscle-specific mitochondrial biogenesis and energy production in rats.

Trace Metal Accumulation in Rats Exposed to Mine Waters: A Case Study, Bor Area (Serbia)

Zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), cadmium (Cd), and lead (Pb) levels were measured in the Bor City water supply system (control) and two watercourses exposed to mining wastewaters, i.e., the Lutarica River (one site) and the Kriveljska River (two sites). The same parameters were determined in the brain, heart, lungs, stomach, liver, spleen, kidneys, and testes of male Wistar rats given water from these sources for 2 months. Water Cu, Fe, Cd, and Pb were outside the safe range, excepting the reference site. Significant impacts on intra-organ metal homeostasis were detected, especially in the brain, stomach, kidneys, and testes. The dynamics and magnitude of these changes (versus controls) depended on the target organ, analyzed metal, and water origin. The greatest number of significant intra-organ associations between essential and non-essential metals were found for Cd-Zn, Cd-Cu, and Cd-Mn. A regression analysis suggested the kidneys as the most relevant organ for monitoring water manganese, and the stomach and brain for lead. These results highlight the environmental risks associated with mining wastewaters from the Bor area and could help scientists in mapping the spatial distribution and severity of trace metal contamination in water sources.

The iron chaperone poly(rC)-binding protein 1 regulates iron efflux through intestinal ferroportin in mice

Iron is an essential nutrient required by all cells but used primarily for red blood cell production. Because humans have no effective mechanism for ridding the body of excess iron, the absorption of dietary iron must be precisely regulated. The critical site of regulation is the transfer of iron from the absorptive enterocyte to the portal circulation via the sole iron efflux transporter, ferroportin. Here, we report that poly(rC)-binding protein 1 (PCBP1), the major cytosolic iron chaperone, is necessary for the regulation of iron flux through ferroportin in the intestine of mice. Mice lacking PCBP1 in the intestinal epithelium exhibit low levels of enterocyte iron, poor retention of dietary iron in enterocyte ferritin, and excess efflux of iron through ferroportin. Excess iron efflux occurred despite lower levels of ferroportin protein in enterocytes and upregulation of the iron regulatory hormone hepcidin. PCBP1 deletion and the resulting unregulated dietary iron absorption led to poor growth, severe anemia on a low-iron diet, and liver oxidative stress with iron loading on a high-iron diet. Ex vivo culture of PCBP1-depleted enteroids demonstrated no defects in hepcidin-mediated ferroportin turnover. However, measurement of kinetically labile iron pools in enteroids competent or blocked for iron efflux indicated that PCBP1 functioned to bind and retain cytosolic iron and limit its availability for ferroportin-mediated efflux. Thus, PCBP1 coordinates enterocyte iron and reduces the concentration of unchaperoned "free" iron to a low level that is necessary for hepcidin-mediated regulation of ferroportin activity.