The role of iron homeostasis in remodeling immune function and regulating inflammatory disease

IGHG4: innovative diagnostic biomarkers for iron overload in β-thalassemia patients

OBJECTIVES

This study aims to investigate the serotransferrin (TF), complement C1s subcomponent (C1S), immunoglobulin heavy constant gamma 4 (IGHG4), hemoglobin subunit alpha (HBA1), and clusterin (CLU) contents in β-thalassemia patients, and explores their physiological role as potential non-invasive bioindicators for disease diagnosis and iron overload.

METHODS

A total of 62 children with β-thalassemia were recruited and categorized by genotype, along with 17 healthy pediatric volunteers for analysis. The circulating ferritin content was evaluated, and plasma levels of TF, C1S, IGHG4, HBA1, and CLU were assessed using ELISA. The primary outcome of this study was the correlation between the five protein marker levels and iron overload. Continuous variables were analyzed using the Student's t-test or the Mann-Whitney U test. A binary logistic regression model identified independent predictors of iron overload in patients with β-thalassemia. Receiver operating characteristics (ROC) were employed to evaluate the model's performance.

RESULTS

The IGHG4 protein content was significantly lower in β-thalassemia patients compared to healthy controls. The IGHG4 protein content was reduced in the β+/β0 and β0/β0 patient populations compared to controls, with no significant difference observed between the β+/β0 group and healthy controls. A strong inverse relationship was identified between the IGHG4 protein content and SF concentration (r = -0.322, p = 0.004). Finally, plasma IGHG4 levels demonstrated adequate diagnostic capability, as indicated by our ROC curve analysis.

CONCLUSION

In conclusion, decreased IGHG4 protein levels are significantly associated with the degree of iron overload in β-thalassemia patients and may serve as a possible biomarker for evaluating iron overload.

STEAP3 alleviates inflammation and fibrosis via iron metabolism in ischemia/reperfusion-associated lung injury

Lower limb ischemia/reperfusion (LIRI)-associated lung injury is a common complication observed in patients with lower extremity occlusion and prolonged tourniquet exposure, leading to significant morbidity and mortality. The lung is the primary remote organ affected by LIRI, owing to its high oxygen demands. Excessive iron accumulation has been implicated in pulmonary injury pathogenesis. Although STEAP3, a key regulator of iron metabolism, has been shown to play a role in various organ injuries and inflammation, but its involvement in LIRI-associated lung injury has not been explored. In this study, we investigated the role of STEAP3 in LIRI-induced lung injury using a mouse model of tourniquet-induced LIRI. Lung injury severity was assessed by wet/dry weight ratio, pro-inflammatory cytokines (IL-1β, IL-6), and the pro-fibrotic marker TGF-β1. Bulk RNA sequencing of lung tissues identified differentially expressed genes and pathways. In vitro, a hypoxia/re‑oxygenation (H/R) model and iron treatment were employed using HUVEC cells. The results showed significant lung edema, macrophage infiltration, and elevated inflammation in LIRI mice, accompanied by iron overload in endothelial cells. Pathway analysis revealed that differentially expressed genes were enriched in inflammatory response regulation and ferroptosis. Both in vivo and in vitro models exhibited activation of the NF-κB and TGFβ1/SMAD pathways, with STEAP3 expression reduced in LIRI and H/R conditions. Overexpression of STEAP3 reversed iron accumulation and inhibited NF-κB and TGFβ1/SMAD signaling. These findings suggest that excessive iron accumulation exacerbates LIRI-associated lung injury, and STEAP3 acts as a potential therapeutic target, offering protection by modulating inflammatory and fibrotic signaling pathways.

Fucosyltransferase 11 restrains ferroptosis via upregulation GPX4 expression in gastric cancer

Ferroptosis is a novel iron-dependent type of programmed cell death that is characterized by the oxidation of lipids by divalent iron ions to produce lipid peroxides, which leads to cell death. Fucosyltransferase 11 (FUT11) is highly expressed in most tumors and is involved in tumorigenesis. However, there have been few studies regarding the relationship between FUT11 and ferroptosis. In this study, we found that FUT11 expression was abnormally high in gastric cancer (GC) cells and that the prognosis of patients with GC and high expression of FUT11 was poor. FUT11 expression was significantly correlated with the TNM stage of GC.Specific knockdown of FUT11 significantly inhibited the proliferation of GC cells, reduced the abundance of the key anti-ferroptotic protein glutathione peroxidase 4(GPX4), induced lipid peroxidation and ferroptosis in GC cells, and inhibited the proliferation of these cells. The overexpression of GPX4 reduced the inhibitory effect of FUT11 on GC cells. In addition, the knockdown of FUT11 significantly inhibited GC tumor growth in mice, and this inhibitory effect was reduced by the overexpression of GPX4. In conclusion, we have shown that FUT11 promotes GC progression by targeting GPX4, thereby inhibiting ferroptosis in GC cells. These findings suggest that FUT11 is a potential therapeutic target for GC.

Caffeic Acid-Biogenic Amine Complexes Outperform Standard Drugs in Reducing Toxicity: Insights from In Vivo Iron Chelation Studies

Iron homeostasis imbalance, caused by conditions such as thalassemia, sickle cell anemia, and myocardial infarction, often results in elevated free iron levels, leading to ferroptosis and severe organ damage. While current iron chelators like deferoxamine (DFO) and deferiprone are effective, they are associated with significant side effects, including nephrotoxicity, gastrointestinal bleeding, and liver fibrosis. This creates an urgent need for safer, natural-product-based alternatives for effective iron chelation therapy (ICT). This study investigates caffeic acid (CA)-based complexes with biogenic amines, specifically spermine (CA-Sp) and histidine (CA-His), as potential ICT candidates. Initial in vitro assays on HEK-293 cells under iron dextran (ID)-induced toxicity have demonstrated their protective effects, with CA-Sp exhibiting superior efficacy. The in vivo studies in mice have further validated their potential, showing remarkable iron chelation and toxicity mitigation compared to DFO. Inductively coupled plasma mass spectrometry (ICP-MS) reveals significant iron excretion in fecal matter in the treatment group along with reductions in serum ferritin levels. The markers of nephrotoxicity (creatinine) and liver function (ALT, AST) have also been shown to be normalized in treated groups, while immunological analyses have revealed restored levels of neutrophils, T cells, and B cells. Additionally, the inflammatory cytokines, TNF-α and IL-6, have exhibited significant reductions, with the CA-based formulations surpassing the effects of DFO. Histological analyses using Prussian blue staining have further confirmed reduced iron deposition in vital organs such as the liver, kidney, and spleen. These findings highlight CA-Sp as a particularly promising candidate for ICT, offering a safer and more effective strategy for managing iron overload and its associated complications.

Ferroptosis-mediated immune responses in osteoporosis

Osteoporosis is a common systemic metabolic disease, characterized by decreased bone mass and susceptibility to fragility fractures, often associated with aging, menopause, genetics, and immunity. Ferroptosis plays an underestimated yet crucial role in the further impact of immune function changes on osteoporosis. Cell ferroptosis can induce alterations in immune function, subsequently influencing bone metabolism. In this context, this review summarizes several mechanisms of ferroptosis and introduces the latest insights on how ferroptosis regulates immune responses, exploring the interactions between ferroptosis and other mechanisms such as oxidative stress, inflammation, etc. This review elucidates potential treatment strategies for osteoporosis, emphasizing the promising potential of ferroptosis as an emerging target in the treatment of osteoporosis. In conclusion, preparations related to ferroptosis exhibit substantial clinical promise for enhancing bone mass restoration. The translational potential of this article: This review elucidates a nuanced conversation between the immune system and osteoporosis, with ferroptosis serving as the connecting link. These findings underscore the potential of ferroptosis inhibition as a therapeutic strategy for osteoporosis.

Causal associations between iron deficiency anemia and digestive system cancers: evidence from a bidirectional two-sample Mendelian randomization study

BACKGROUND & AIMS

Iron deficiency anemia (IDA) is associated with digestive system cancers (DSCs), but the causal relationship is poorly understood. This two-sample bidirectional Mendelian randomization (MR) study investigated the causal association between IDA and five types of DSCs.

METHODS

This study pooled data from a genome-wide association study of IDA (6,087 cases and 211,115 controls of European ancestry) and DSCs. IVW, weighted median, weighted mode, and MR-Egger regression were used to assess causal associations between IDA and DSCs. Sensitivity analysis included Cochran's Q test for heterogeneity, MR-PRESSO for pleiotropy, and leave-one-out method for robustness.

RESULTS

The MR analysis used 12 single-nucleotide polymorphisms (SNPs) associated with IDA as instrumental variables (IVs). In contrast, the reverse MR analysis used 20 SNPs associated with the five types of DSC as IVs. Genetic predictions revealed no significant association between IDA and the risk of DSCs: (odds ratio [OR]: 1.00; 95% confidence interval [CI] [0.76, 1.31]; P = 0.979), esophageal (OR: 0.94; 95% CI [0.67, 1.31]; P = 0.699), pancreatic (OR: 1.14; 95% CI [0.68, 1.92]; P = 0.615), liver (OR: 1.12; 95% CI [0.51, 2.47]; P = 0.776), and stomach (OR: 1.04; 95% CI [0.71, 1.54]; P = 0.830) cancers. Reverse MR also indicated no causal association between DSC and IDA. MR-Egger regression showed minimal heterogeneity impact except for colorectal cancer (heterogeneity P = 0.002). MR-PRESSO identified no outliers.

CONCLUSION

The present MR analysis shows no causal associations between IDA and the risk of DSCs.

The Essence of Nature Can be the Simplest (3) Holistic Energy: Extracellular Fenton Reactions of All Cells

Cooperative mechanisms are widely regarded as pivotal drivers in the evolutionary transition from unicellular to multicellular life. However, the mechanism of how multicellular organisms integrate the individual energy of all cells into holistic energy and how exactly the holistic energy is manifested remains poorly understood. Traditionally, relying on ATP within heart muscle cells to drive a permanent heartbeat (called cardiac contraction) is responsible for the vital holistic biological process of transporting and distributing oxygen and nutrients to cells throughout the body, but the limited ATP reserve in cardiac muscle challenges this paradigm. Recent studies suggest that cellular energy production involves dual pathways: canonical ATP synthesis and extracellular Fenton reactions. Here, we propose a novel paradigm wherein the circulatory system serves as a collective platform for integrating extracellular Fenton reaction capabilities of all cells, generating sustained and powerful energy to drive the heartbeat and maintain body temperature. This cooperative mechanism for holistic energy aligns with Bergmann's rule and the holistic principles of traditional Chinese medicine (TCM). Holistic energy in circulatory system supports pulse diagnosis that evaluates systemic health through vascular dynamics. Furthermore, the interaction and balance between holistic energy and individual energy can also explain the rationality of tumor occurrence.

Gambogic Acid Based Coordination Polymer Reinforces High-Intensity Focused Ultrasound Treatment of Gynecologic Malignancies

High-intensity focused ultrasound (HIFU) is emerging as a promising non-invasive treatment for solid tumors. Nevertheless, HIFU may also induce the upregulation of Heat Shock Protein 90 (HSP-90), potentially resulting in resistance to HIFU. Besides, although it is effective against in situ tumors, challenges remain with tumor metastasis and recurrence. Herein, the innovative design of gambogic acid (GA) based coordination polymer-GAZn-PEG nanoparticles (GAZn-PEG NPs) are synthesized through the coordination of GA with zinc ions (Zn2+), and subsequently functionalized with lipid bilayer incorporating polyethylene glycol (PEG), sensitizing HIFU for the treatment of cervical and ovarian cancers. Briefly, under HIFU exposure, GA markedly suppresses the expression of HSP-90, thereby increasing the tumor's sensitivity to HIFU therapy. Furthermore, Zn2+ not only overcome the issue of GA's poor water solubility but also synergistically stimulate immune responses in conjunction with GA. More intriguingly, it has been discovered that GAZn-PEG can effectively activate the cyclic GMP-AMP synthase-stimulator of the interferon genes (cGAS-STING) pathway, thereby enhancing the immune responses provoked by HIFU. Specifically, GAZn-PEG NPs show a remarkable increase in dendritic cell activation and the effective stimulation of the cGAS-STING pathway, crucial for long-term protection against tumor recurrence and metastasis.

The role of heme in sepsis induced Kupffer cell PANoptosis and senescence

Elevated heme levels, a consequence of hemolysis, are strongly associated with increased susceptibility to bacterial infections and adverse sepsis outcomes, particularly in older populations. However, the underlying mechanisms remain poorly understood. Using a cecal ligation and puncture (CLP) model of sepsis, we demonstrate that elevated heme levels correlate with Kupffer cell loss, increased bacterial burden, and heightened mortality. Mechanistically, we identify mitochondrial damage as a key driver of heme- and bacterial-induced Kupffer cell PANoptosis, a form of cell death integrating pyroptosis, apoptosis, and necroptosis, as well as cellular senescence. Specifically, heme activates phospholipase C gamma (PLC-γ), facilitating the translocation of cleaved gasdermin D (c-GSDMD) to mitochondria, resulting in GSDMD pore formation, mitochondrial dysfunction, and the release of mitochondrial DNA (mtDNA) during bacterial infection. This mitochondrial damage amplifies PANoptosis and triggers the cGAS-STING signaling pathway, further driving immune senescence. Notably, PLC-γ inhibition significantly reduces mitochondrial damage, cell death, and senescence caused by heme and bacterial infection. Furthermore, we show that hemopexin, a heme scavenger, effectively mitigates sepsis-induced Kupffer cell death and senescence, enhances bacterial clearance, and improves survival outcomes in both young and aged mice. These findings establish mitochondrial damage as a central mediator of heme induced Kupffer cell loss and highlight PLC-γ inhibition and hemopexin administration as promising therapeutic strategies for combating sepsis associated immune dysfunction.

Exploring METRNL as a novel biomarker in sepsis: diagnostic potential and secretion mechanism

BACKGROUND

Sepsis is a life-threatening condition with a high mortality rate in intensive care unit (ICU). However, rapid and accurate diagnostic criteria are still lacking. This pilot study explored the role of METRNL as a novel biomarker for sepsis by focusing on its diagnostic potential and rapid secretion mechanism.

METHODS

METRNL levels were measured in cell and animal models of sepsis. Serum samples from 107 sepsis patients and 95 non-septic controls in ICU were collected. Diagnostic performance of METRNL, Procalcitonin (PCT) and C-reactive protein (CRP) were assessed using ROC analysis. Endothelial cell-specific Metrnl gene knockout mice (EC-Metrnl-/- mice) were used to identify the source of METRNL secretion. Chemical inhibitors and RNA interference were used to explore the secretion pathways.

RESULTS

In lipopolysaccharide (LPS)-induced cell and mouse models of sepsis, METRNL levels significantly increased in a dose- and time-dependent manner. Similarly, in the cecal ligation and puncture mouse models, serum METRNL levels were elevated over time and correlated with sepsis severity. In animals, serum METRNL increased within 1 h post-modeling, preceding PCT and CRP. Clinically, sepsis patients had significantly higher serum METRNL levels. ROC analysis showed area under the curves [95% confidence intervals] of 0.943 [0.91-0.975] for METRNL, 0.955 [0.929-0.981] for PCT and 0.873 [0.825-0.921] for CRP. At the optimal cutoff value, METRNL (91.6%) exhibited relatively greater diagnostic specificity than PCT (88.4%) and CRP (69.5%). EC-Metrnl-/- reduced majority of serum Metrnl levels in sepsis mouse models. Inhibition of the endoplasmic reticulum-Golgi (ER-Golgi) pathway through chemical inhibitors or RNA interference significantly reduced METRNL levels in the supernatant of sepsis cell models compared to control groups. Similar results were obtained with Toll-like receptor 4 (TLR4) and ERK inhibitors.

CONCLUSIONS

This pilot study demonstrates that METRNL is a novel potential biomarker for sepsis with diagnostic capability comparable to that of PCT. Serum METRNL rapidly increased during the early phase of sepsis. Mechanistically, it mainly originates from the endothelium during sepsis, and TLR4-ERK signaling mediates the rapid secretion of METRNL via the classical ER-Golgi pathway in response to LPS stimulation.

Enhanced Sonodynamic Cancer Therapy through Boosting Reactive Oxygen Species and Depleting Glutathione

The complex tumor microenvironment (TME) affects reactive oxygen species (ROS)-based therapies; breaking the limitations of the TME to enhance the effectiveness of sonodynamic therapy (SDT) is full of great challenges. Herein, iron atomically dispersed nanoparticles (Fe-N-C) were first reported as sonosensitizers with highly efficient ROS generation by overcoming TME limitations. Its peroxidase and catalase-like activities catalyze H2O2 to produce highly toxic ·OH and in situ O2, respectively, and then O2 molecules adsorbed at Fe active sites obviously lower the energy barrier for ·OH formation. Meanwhile, its glutathione-oxidase-like activity can rapidly consume glutathione (GSH) in the TME to induce tumor cell apoptosis and ferroptosis. Density functional theory calculation results elucidate the possible mechanism of ROS generation: O2 molecules are activated by receiving sonoelectrons to generate ·O2-, which further reacts with H2O to produce OH-. Then OH- is oxidized by sonoholes to form ·OH. Fe-N-C displays a superior tumor specificity SDT.

Argatroban and Menadione exert protective effects in ultraviolet-irradiated skin inflammation: A transcriptomic analysis based on identification of iron overload related biomarkers

Ultraviolet light (UV) can cause serious damage to human skin. The inflammatory reaction arising from repeated UV exposure leads to severe skin lesions and even promotes photo-carcinogenesis. Iron overload is featured by excessive iron intake and deposition and will promote inflammatory response inside cells. However, the core molecules involved in UV radiation induced iron overload and related anti-inflammatory strategies remain unclear. Signature genes involved in UV-irradiated skin were filtered through integrated datasets from the Gene Expression Omnibus (GEO) database. Subsequently, immune cell infiltration analysis was carried out to examine the relationship between signature gene expression and immune cell abundance. Single cell RNA-seq matrix data implicated in UV-irradiated skin was then applied to assess the expression level of signature genes in different cell clusters and to find out the core cell type and the key signaling pathway involved in UV radiation. Finally, cytological and animal experiments were conducted to investigate the potential of signature genes as therapeutic targets. SAT1 and RBMS1 were screened and validated as signature genes of UV irradiation. Immune cell infiltration analysis demonstrated that SAT1 and RBMS1 expression were associated closely with immune cell abundance, and skin fibroblasts were identified as the central cell type to communicate with other cell clusters in UV-irradiated skin. Disturbance of SAT1 exerted observably more suppressive effects on the release of inflammatory cytokines than overexpression of RBMS1. Two small molecule drugs targeting SAT1, namely Argatroban and Menadione, were predicted. Moreover, their therapeutic potentials in the treatment of UV-irradiated skin injury were confirmed experimentally.

Iron Status and Risk of Periodontitis and Dental Caries: A Mendelian Randomization Study

BACKGROUND

Previous studies have indicated a potential relationship between iron status and oral health outcomes, specifically periodontitis and dental caries. This study employed Mendelian randomization (MR) to investigate the causal effects of iron status on these oral health conditions. The focus of this study was on key iron biomarkers, namely serum iron, ferritin, transferrin saturation (TSAT), and total iron-binding capacity (TIBC).

METHODS

This two-sample MR analysis employed genome-wide association study (GWAS) data. The instrumental variables (IVs) were selected based on their genome-wide significance and independence from confounders. The statistical analyses employed the inverse variance weighted (IVW) method, MR-Egger regression, weighted median, and weighted mode. Additionally, sensitivity analyses were conducted to verify the reliability of the causal association results.

RESULTS

The MR analysis indicated a suggestive negative causal relationship between TIBC and periodontitis, with an odds ratios of 0.875 and a 95% CI of 0.766-0.998, with a P-value of .047. No significant other associations were found. The results of sensitivity analyses demonstrated the robustness of these findings.

CONCLUSION

This MR study suggested a potential negative association between TIBC and periodontitis, highlighting the importance of considering iron status in the clinical management of chronic periodontitis. However, more standardized, multi-population studies are needed to confirm this causality.

A metal-polyphenol network-based iron supplement with improved stability and reduced gastrointestinal toxicity for iron deficiency anemia therapy

Iron deficiency anemia (IDA) is a global health concern, particularly affecting women and children of reproductive age. Although oral iron supplements are the standard treatment for IDA, their bioavailability is often compromised by food interactions, and they are associated with significant gastrointestinal side effects. To overcome these limitations, we developed a novel iron nano-supplement, TA-Fe NPs, based on metal-polyphenol networks (MPNs) formed through the coordination of tannic acid (TA) and Fe3+. These uniform nanoparticles (∼190 nm) offer enhanced chemical stability and reduced food interference compared to traditional iron supplements. The polyphenolic TA component provides antioxidant properties, effectively mitigating oxidative stress and inflammation induced by free iron ions. To further improve stability and intestinal absorption, TA-Fe NPs were encapsulated in an enteric coating (TA-Fe@L100) to protect against acidic conditions in the stomach. In a mouse model of IDA, TA-Fe@L100 demonstrated superior therapeutic efficacy compared to FeSO4, including improvements in hematological parameters, organ iron storage, and gut microbiota balance. Importantly, TA-Fe@L100 alleviated common gastrointestinal side effects associated with iron supplementation, presenting a promising alternative for IDA treatment. Our findings suggest that TA-Fe@L100 is a cost-effective and biocompatible oral iron supplement with minimal side effects, offering significant potential for broader clinical application in the management of IDA.

Hepatitis B Virus-Associated Liver Carcinoma: The Role of Iron Metabolism and Its Modulation

Hepatitis B virus (HBV) infection is a significant contributor to the development of hepatocellular carcinoma (HCC), a leading cause of cancer-related mortality worldwide. Iron, a central co-factor in various metabolic pathways, plays an essential role in liver function, but its dysregulation can lead to severe health consequences. Accumulation of iron within hepatic cells over time is linked to increased liver injury and is strongly associated with sensitive exposure to a range of conditions, including cirrhosis, fibrosis and ultimately, HCC. This review explores the intricate interplay between iron metabolism and HCC within the context of HBV infection. Hepatic iron overload can arise from liver injury and disruptions in iron homeostasis, causing hepatic necrosis, inflammation, and fibrosis, ultimately culminating in carcinogenesis. Moreover, alterations in serum iron components in HBV-related scenarios have been observed to impact the persistence of HBV infection. Notably, the progression of HBV-associated liver damage exhibits distinct characteristics at various stages of liver disease. In addition to elucidating the complex relationship between iron metabolism and HCC in the context of HBV infection, this review also investigates the prognostic implications of systemic iron levels for HCC. Furthermore, it aims to provide a comprehensive understanding of the intricate interplay between iron metabolism and HCC, extending the discussion to the context of hepatitis C virus (HCV) infection. By shedding light on these multifaceted connections, this review aims to contribute to our understanding of the pathogenesis of HBV-associated HCC and potentially identify novel therapeutic avenues for intervention.

Programmed enhancement of endogenous iron-mediated lysosomal membrane permeabilization for tumor ferroptosis/pyroptosis dual-induction

Ferroptosis and pyroptosis, as emerging regulated forms of cell death capable of overcoming apoptotic resistance, demonstrate promising potential in tumor therapy. Given that iron manipulation and reactive oxygen species elevation serve as common stimuli for both processes, inducing lysosomal membrane permeabilization (LMP) with ensuing release of lysosomal contents (including iron ions and cathepsins) is anticipated to realize dual induction of ferroptosis/pyroptosis. Herein, we report a folic acid and croconaine molecule-functionalized upconversion nanoparticle (UCNP-Cro/FA) that is able to mobilize intracellular stores of endogenous iron and spatiotemporally control the lysosome-intrinsic Fenton chemistry, thereby triggering LMP-associated cell death. The process of endogenous iron mobilization occurs through two key steps: Cro-mediated coordination of abundant Fe3+ ions within lysosomes, followed by UV-emitting upconversion core-mediated photoreduction, resulting in Fe2+ ions release. Both in vitro and in vivo experiments show that UCNP-Cro/FA + NIR treatment effectively boost LMP by endogenous iron-mediated •OH production, ultimately triggering irreversible tumor cell death via ferroptosis and Caspase-1/GSDMD-dependent pyroptosis pathways. Moreover, this process potentiates tumor immunogenicity, holding promise for tumor immunotherapy. Overall, this work proposes a feasible tumor therapy strategy that integrates ferroptosis and pyroptosis through the efficient application and activation of endogenous iron.

Macrophages hijack carbapenem-resistance hypervirulent Klebsiella pneumoniae by blocking SLC7A11/GSH-manipulated iron oxidative stress

Infection with carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) is life-threatening because of its pronounced virulence and antibiotic resistance. Recent studies revealed that iron and ROS enhance the ability of macrophages to eliminate intracellular pathogenic bacteria. However, whether and how iron-related oxygen stress responses in macrophages elicit a protective role against CR-hvKP infection remains largely unknown. In a mouse model of CR-hvKP pulmonary infection, the production of the Solute Carrier Family 7 member 11 (SLC7A11) was increased. Treatment with the ferroptosis agonist Erastin or Sorafenib decreased the SLC7A11 expression and the bacterial load in infected lung tissues, alleviating CR-hvKP-induced acute lung injury, increasing the content of TLR4, ROS and LPO. In vitro experiments showed that CR-hvKP infection resulted in a remarkable time-dependent changes in the expression of SLC7A11, GSH, ferrous iron, ROS and LPO in MH-S cells. Mechanically, blocking the expression of SLC7A11 in CR-hvKP-infected MH-S cells increased iron and ROS, improving the ability of macrophages to clear CR-hvKP in an LPO-dependent manner. Taken together, our study reveals that improving iron-related oxygen stress via blocking the SLC7A11/GSH pathway promoting the macrophages to phagocytose and eliminate CR-hvKP, which provides a new promising strategy against CR-hvKP infection.

Causal Relationships Between Iron Deficiency Anemia, Gut Microbiota, and Metabolites: Insights from Mendelian Randomization and In Vivo Data

Background: Iron deficiency anemia (IDA) is a common type of anemia in children and pregnant women. The effects of iron deficiency on gut microbiota and metabolic profiles are not fully understood. Methods: Mendelian randomization (MR) analysis was conducted to explore associations among IDA, gut microbiota, and metabolites. MR analysis was conducted using computational methods, utilizing human genetic data. Data were obtained from genome-wide association studies (GWAS), with inverse-variance-weighted (IVW) as the primary method. Animal models evaluated the effects of IDA on gut microbiota and metabolic profiles. Results: IVW analysis revealed significant associations between gut microbial taxa and IDA. The genus Desulfovibrio was protective (OR = 0.85, 95% CI: 0.77-0.93, p = 0.001), while Actinomyces (OR = 1.12, 95% CI: 1.01-1.23, p = 0.025) and family XIII (OR = 1.16, 95% CI: 1.01-1.32, p = 0.035) increased IDA risk. Glycine was protective (OR = 0.95, 95% CI: 0.91-0.99, p = 0.011), whereas medium low density lipoprotein (LDL) phospholipids increased risk (OR = 1.07, 95% CI: 1.00-1.15, p = 0.040). Animal models confirmed reduced Desulfovibrio, increased Actinomyces, and altered metabolites, including amino acids and phospholipids. Conclusions: IDA significantly impacts gut microbiota and metabolic profiles, offering insights for therapeutic strategies targeting microbiota and metabolism.

Ferrostatin-1 reduces the inflammatory response of rheumatoid arthritis by decreasing the antigen presenting function of fibroblast-like synoviocytes

Rheumatoid arthritis (RA) is a systemic chronic autoimmune disease with complex mechanism. Currently, ferroptosis is believed to play a role in it, but the specific mechanism is unknown, especially in immune response. In this study, we demonstrated that the high expression of major histocompatibility complex I (MHC-I) molecules in RA fibroblast-like synoviocytes (FLSs) is an antigen-presenting cell property and that this property is closely related to the increase in antigens after citrullination. Moreover, we detected higher levels of ferroptosis among FLSs from RA patient than among FLSs from OA patients. Ferroptosis can increase the expression of citrullinated histone H3 (cit-h3) by promoting the production of peptidyl arginine deiminase 4 (PAD4), which further promotes the expression of MHC-I molecules. We cocultured RA-FLSs treated with ferroptosis drugs with selected CD8 + T cells to assess the effect of ferroptosis on the endogenous antigen-presenting function of RA-FLSs. Ferroptosis promoted the proliferation of CD8 + T cells and the release of the inflammatory factors Tumor necrosis factor-α (TNF-α) and Interferon-gamma (IFN-γ), which enhanced the inflammatory effect. This phenomenon was also observed in a collagen-induced arthritis (CIA) mouse model. Finally, ferrostatin-1 (fer-1), a ferroptosis inhibitor, inhibited the above effects and reduced the release of inflammatory factors, indicating that ferroptosis may play a therapeutic role in RA and providing new ideas for the treatment of RA in the field of immunity.

Multidimensional applications of prussian blue-based nanoparticles in cancer immunotherapy

Immunotherapy holds notable progress in the treatment of cancer. However, the clinical therapeutic effect remains a significant challenge due to immune-related side effects, poor immunogenicity, and immunosuppressive microenvironment. Nanoparticles have emerged as a revolutionary tool to surmount these obstacles and amplify the potency of immunotherapeutic agents. Prussian blue nanoparticles (PBNPs) exhibit multi-dimensional immune function in cancer immunotherapy, including acting as a nanocarrier to deliver immunotherapeutic agents, as a photothermal agent to improve the efficacy of immunotherapy through photothermal therapy, as a nanozyme to regulate tumor microenvironment, and as an iron donor to induce immune events related to ferroptosis and tumor-associated macrophages polarization. This review focuses on the advances and applications of PBNPs in cancer immunotherapy. First, the biomedical functions of PBNPs are introduced. Then, based on the immune function of PBNPs, we systematically reviewed the multidimensional application of PBNPs in cancer immunotherapy. Finally, the challenges and future developments of PBNPs-based cancer immunotherapy are highlighted.

Cotargeting of thioredoxin 1 and glutamate-cysteine ligase in both imatinib-sensitive and imatinib-resistant CML cells

Chronic myeloid leukemia (CML) is a type of malignancy characterized by harboring the oncogene Bcr-Abl, which encodes the constitutively activated tyrosine kinase BCR-ABL. Although tyrosine kinase inhibitors targeting BCR-ABL have revolutionized CML therapy, native and acquired drug resistance commonly remains a great challenge. Thioredoxin 1 (Trx1) and glutamate-cysteine ligase (GCL), which are two major antioxidants that maintain cellular redox homeostasis, are potential targets for cancer therapy and overcoming drug resistance. However, how their inhibition is implicated in CML is still unclear. Here, our results revealed that Trx1 was overexpressed in patients with CML compared with healthy donors. Trx1 expression was greater in imatinib-resistant CML cells than in imatinib-sensitive cells. Pharmacological inhibitors of Trx1 attenuated cell growth and reduced colony formation in both imatinib-sensitive and imatinib-resistant CML cells. Furthermore, decreased Trx1 expression enhanced the cytotoxicity of the GCL inhibitor buthionine sulfoximine (BSO). We surmise that the combined inhibition of Trx1 and GCL promotes the induction of hydrogen peroxide and depletes GPX4 expression in CML cells, resulting in ferroptosis in cancerous cells. Finally, the combined inhibition of Trx1 and GCL had a synergistic effect on CML cells in murine xenograft models. These findings offer crucial informationregarding the combined roles ofTrx1 and GCL in triggering ferroptosis in CML and suggestefficacioustherapeutic uses for these systems in this disease.

Development and internal validation of a nomogram for predicting recurrent respiratory tract infections in children

OBJECTIVE

This study aimed to develop and internally validate a nomogram in predicting the risk of recurrent respiratory tract infection (RRTI) in children.

METHODS

A retrospective analysis was performed, involving 150 children with RRTI and 151 healthy controls, aged 0-14 years, admitted to or selected from the Pediatric Department of Yixing Hospital of Traditional Chinese Medicine between June 2022 and June 2023. Data were gathered through a comprehensive questionnaire survey on risk factors associated with RRTI. The dataset was randomly divided into a training cohort (n = 211) and a validation cohort (n = 90) in a 7:3 ratio. Significant variables were selected using LASSO regression in the training cohort to construct the nomogram, the performance of which was evaluated through Receiver Operating Characteristic (ROC) curves, calibration plots, and Decision Curve Analysis (DCA).

RESULTS

The LASSO regression identified five predictors in the training cohort: picky eating, age at first antibiotic use, antibiotic use within the previous year, allergic conditions, secondhand smoke exposure. Based on them, the nomogram exhibited an excellent discriminative ability, with an AUC of 0.902 (95 % CI: 0.860-0.944) and a C-index of 0.902 in the training cohort. The validation cohort showed an AUC of 0.826 (95 % CI: 0.742-0.909) and a C-index of 0.826, confirming a high predictive accuracy. Calibration plots showed close alignment with the ideal reference line, and DCA indicated a significant clinical net benefit.

CONCLUSION

Our nomogram can efficiently predict RRTI risk in children, thereby providing a personalized and graphical tool for early identification and intervention.

Ferroptosis: A New Strategy for the Treatment of Fibrotic Diseases

Ferroptosis is a new type of cell death characterized by iron dependence and the excessive accumulation of lipid reactive oxygen species (lipid ROS) that has gradually become better characterized. There is sufficient evidence indicating that ferroptosis is associated with a variety of human life activities and diseases, such as tumor suppression, ischemic organ injury, and degenerative disorders. Notably, ferroptosis is also involved in the initiation and development of fibrosis in various organs, including liver fibrosis, pulmonary fibrosis, renal fibrosis, and cardiac fibrosis, which is usually irreversible and refractory. Although a large number of patients with fibrosis urgently need to be treated, the current treatment options are still limited and unsatisfactory. Organ fibrosis involves a series of complex and orderly processes, such as parenchymal cell damage, recruitment of inflammatory cells and activation of fibroblasts, which ultimately leads to the accumulation of extracellular matrix (ECM) and the formation of fibrosis. An increasing number of studies have confirmed the close association between these pathological processes and ferroptosis. This review summarizes the role and function of ferroptosis in fibrosis and proposes several potential therapeutic strategies and pathways based on ferroptosis.

Iron metabolism and the tumor microenvironment: A new perspective on cancer intervention and therapy (Review)

Iron metabolism plays a crucial role in the tumor microenvironment, influencing various aspects of cancer cell biology and tumor progression. This review discusses the regulatory mechanisms of iron metabolism within the tumor microenvironment and highlights how tumor cells and associated stromal cells manage iron uptake, accumulation and regulation. The sources of iron within tumors and the biological importance of ferroptosis in cancer were explored, focusing on its mechanisms, biological effects and, in particular, its tumor‑suppressive properties. Furthermore, the protective strategies employed by cancer cells to evade ferroptosis were examined. This review also delves into the intricate relationship between iron metabolism and immune modulation within the tumor microenvironment, detailing the impact on tumor‑associated immune cells and immune evasion. The interplay between ferroptosis and immunotherapy is discussed and potential strategies to enhance cancer immunotherapy by modulating iron metabolism are presented. Finally, the current ferroptosis‑based cancer therapeutic approaches were summarized and future directions for therapies that target iron metabolism were proposed.

Associations between serum metal mixtures and systemic inflammation indices among Chinese early adolescents: A prospective cohort study

BACKGROUND

Research has demonstrated a link between metal exposure and inflammation. However, little is known about this relationship among adolescents, especially in prospective cohort studies. The aim of this study was to investigate the relationship between serum metal exposure and inflammatory status in Chinese early adolescents.

METHODS

In this study, 12 serum metals were detected at baseline in 1551 participants from the Chinese Early Adolescents Cohort. The participants' inflammatory status was assessed via three systemic inflammation indices (neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII)) at both baseline and follow-up. Generalized linear mixed models and restricted cubic splines regression were used to examine the linear and nonlinear relationships between single metal concentrations and systemic inflammation indices. Multiple mixture models were implemented to assess the relationships of mixed metals with systemic inflammation indices. Additionally, sex subgroup analyses were conducted to explore the sex-specific associations between serum metals and inflammatory status.

RESULTS

Single-exposure analysis revealed that exposure to multiple serum metals, such as chromium, cobalt, copper and lead, was positively associated with the NLR and SII, whereas iron was negatively correlated with the three systemic inflammation indices (PFDR<0.05). Additionally, inverted U-shaped associations were observed between vanadium, manganese and systemic inflammation indices. According to the mixture models, high levels of the serum metal mixture were positively correlated with the NLR and the SII. Cobalt had the highest positive weight in the mixed samples, whereas iron had the greatest negative weight in the serum-metal mixtures. Subgroup analyses revealed that serum exposure to the metal mixture had a more significant effect on systemic inflammation markers in females than in males.

CONCLUSIONS

This study reveals the impact of real-world mixed metal exposure on adolescents' inflammatory levels, which is of primary significance for protecting the healthy development of early adolescents.

Iron homeostasis and ferroptosis in muscle diseases and disorders: mechanisms and therapeutic prospects

The muscular system plays a critical role in the human body by governing skeletal movement, cardiovascular function, and the activities of digestive organs. Additionally, muscle tissues serve an endocrine function by secreting myogenic cytokines, thereby regulating metabolism throughout the entire body. Maintaining muscle function requires iron homeostasis. Recent studies suggest that disruptions in iron metabolism and ferroptosis, a form of iron-dependent cell death, are essential contributors to the progression of a wide range of muscle diseases and disorders, including sarcopenia, cardiomyopathy, and amyotrophic lateral sclerosis. Thus, a comprehensive overview of the mechanisms regulating iron metabolism and ferroptosis in these conditions is crucial for identifying potential therapeutic targets and developing new strategies for disease treatment and/or prevention. This review aims to summarize recent advances in understanding the molecular mechanisms underlying ferroptosis in the context of muscle injury, as well as associated muscle diseases and disorders. Moreover, we discuss potential targets within the ferroptosis pathway and possible strategies for managing muscle disorders. Finally, we shed new light on current limitations and future prospects for therapeutic interventions targeting ferroptosis.

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.

Therapeutic potential of monomethyl fumarate and aluminum ion combination in alleviating inflammation and oxidative stress in psoriasis

Psoriasis is a chronic inflammatory skin condition characterized by erythematous plaques with white scales. Its pathogenesis is closely linked to oxidative stress and an imbalance in Th1/Th2 immune responses. Current treatments for psoriasis, such as topical agents, systemic therapies and phototherapy, frequently fail to achieve complete remission in clinical settings. Monomethyl fumarate (MMF), which has been approved by the US Food and Drug Administration in 2020 for multiple sclerosis, has demonstrated efficacy in psoriasis management. Additionally, our previous studies have identified aluminum ions as beneficial in psoriasis treatment. This present study investigates the combined therapeutic effects of MMF and aluminum ions and observed that the combination treatment achieves superior efficacy compared to either treatment alone in a psoriasis mouse model through the modulation of the Nrf2/NF-κB signaling pathway, as demonstrated in cellular models. The combination first activates Nrf2 nuclear translocation and induces antioxidant gene expression, followed by the inhibition of NF-κB nuclear translocation and phosphorylation, which reduces Th1 cytokine production and cellular chemotaxis. Concurrently, the treatment elevates Th2 cytokine secretion, thereby increasing the anti-inflammatory response in HaCaT cells. Overall, these findings support the MMF and aluminum ions combination (MMFAL) as a potential therapeutic strategy for psoriasis, effectively diminishing inflammation and oxidative stress.

The role of ferroptosis in acute kidney injury: mechanisms and potential therapeutic targets

Acute kidney injury (AKI) is one of the most common and severe clinical renal syndromes with high morbidity and mortality. Ferroptosis is a form of programmed cell death (PCD), is characterized by iron overload, reactive oxygen species accumulation, and lipid peroxidation. As ferroptosis has been increasingly studied in recent years, it is closely associated with the pathophysiological process of AKI and provides a target for the treatment of AKI. This review offers a comprehensive overview of the regulatory mechanisms of ferroptosis, summarizes its role in various AKI models, and explores its interaction with other forms of cell death, it also presents research on ferroptosis in AKI progression to other diseases. Additionally, the review highlights methods for detecting and assessing AKI through the lens of ferroptosis and describes potential inhibitors of ferroptosis for AKI treatment. Finally, the review presents a perspective on the future of clinical AKI treatment, aiming to stimulate further research on ferroptosis in AKI.

Intracellular iron accumulation throughout the progression of sepsis influences the phenotype and function of activated macrophages in renal tissue damage

Sepsis, the most common cause of acute kidney injury, remains a major socioeconomic burden. A dysregulated immune response leads to progressive organ dysfunction. Although numerous inflammatory pathways were described, most are still vague and need to be studied in terms of the mechanisms to improve the therapeutic intervention. We tackled the relationship between intracellular iron overload and macrophage polarization within 6, 24, and 72 h of sepsis induction. In our study, sepsis-induced kidney injury was caused by using the cecal ligation and puncture (CLP) model. Our results indicated severe renal tissue damage with a progressive increase in serum BUN and creatinine with architectural tissue damage and positive PAS staining. There was increased expression of CD8+ CD68+ M1 macrophage markers with upregulation of iNOS and co-expression of CD163+. Alternatively, Arg1+ Fizz1+ M2 macrophage markers were downregulated with increased iNOS/Arg1 ratio. TFR1, cubilin, and DMT1, as iron transport systems, were increased compared to sham but were significant after 72 h, while ZIP8 showed no significant change. There was a correlation between iron overload and M1 macrophage polarization with CD163+ phenotype, together with fibrotic changes. The intracellular iron overload with downregulation of ferritin was strongly related to macrophage polarization that was exaggerated at 72 h. Finally, early introduced therapy to target free iron during sepsis is a proposed novel solution for protecting the renal tissue from acute injury due to macrophage activation that may end up with chronic kidney injury, if not mortality.

Maternal Ferrous Sucrose Supplementation Improves Reproductive Performance of Sows and Hepatic Iron Stores of Neonatal Piglets

As one of the most important trace elements required by sows, especially in the late gestation period, iron plays a crucial role in the growth and development of a fetus. To explore the effects of dietary supplementation with ferrous sucrose on the reproductive performance of sows and the hepatic iron stores in offspring, sixty primiparous Landrace × Yorkshire sows on day 95 of gestation with an average body weight of 174.1 ± 7.7 kg were randomly assigned to two groups of a basic diet (control) and a basic diet supplemented with 109 mg/kg ferrous sucrose (FS) in a fully randomized block design. The trial lasted for 20 days. The results showed that maternal supplementation with ferrous sucrose significantly increased litter weight (p = 0.002) in neonatal piglets. Compared with the control group, the serum iron and serum transferrin saturation of farrowing sows increased by 45.67% (p = 0.002) and 37.01% (p = 0.033), respectively, and umbilical cord serum iron (p = 0.012) also increased in the FS group. Finally, the serum iron (p < 0.001) and hepatic iron stores (p = 0.071) of neonatal piglets were both increased to varying degrees. Taken together, supplementation of pregnant sows with ferrous sucrose has positive effects on the growth and hepatic iron stores of their offspring.

Gastrointestinal dysfunction as the main performance of the oral toxicity of titanium dioxide nanoparticle on gastric ulcer rats

Titanium dioxide nanoparticles (TiO2 NPs) have promising applications in food additives and pharmaceutical dressings, raising concerns about their oral safety. The current studies mainly focus on healthy groups, and the effect of TiO2 NPs on the patient population is rarely known. Here, a comprehensive toxicity study of TiO2 NPs (75 ± 15 nm, anatase) in gastric ulcer rats (male 8-week old Sprague-Dawley rats) is reported following oral exposure at dose of 0, 10, 50, 200 mg/kg body weight per day for 30 days. The gastric ulcer rats were produced by submucosal injection of acetic acid solution into the rat stomach. The healthy rats were used as the normal control. We evaluated nanoparticle biodistribution, systemic toxicity, and gastrointestinal function indices in the rats. Our findings indicate that oral administration of TiO2 NPs resulted in minimal intestinal absorption and transport with limited systemic organ toxicity. The internalization of TiO2 NPs and activation of mast cells in the stomach tissues, along with the low serum levels of histamine and IgE, suggest a localized allergic reaction rather than a systemic one. Furthermore, the notably reduced plasma levels of D-lactate and the activity of diamine oxidase (DAO) indicated the upregulation of intestinal barrier function. These statistically significant results indicated that gastrointestinal dysfunction was the main performance of the oral toxicity of TiO2 NPs on gastric ulcer rats, emphasizing the importance of controlling the intake of TiO2 NPs in patients with gastric ulcers.

Ferroptosis: Latest evidence and perspectives on plant-derived natural active compounds mitigating doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is a chemotherapy drug widely used in clinical settings, acting as a first-line treatment for various malignant tumors. However, its use is greatly limited by the cardiotoxicity it induces, including doxorubicin-induced cardiomyopathy (DIC). The mechanisms behind DIC are not fully understood, but its potential biological mechanisms are thought to include oxidative stress, inflammation, energy metabolism disorders, mitochondrial damage, autophagy, apoptosis, and ferroptosis. Recent studies have shown that cardiac injury induced by DOX is closely related to ferroptosis. Due to their high efficacy, availability, and low side effects, natural medicine treatments hold strong clinical potential. Currently, natural medicines have been shown to mitigate DOX-induced ferroptosis and ease DIC through various functions such as antioxidation, iron ion homeostasis correction, lipid metabolism regulation, and mitochondrial function improvement. Therefore, this review summarizes the mechanisms of ferroptosis in DIC and the regulation by natural plant products, with the expectation of providing a reference for future research and development of inhibitors targeting ferroptosis in DIC. This review explores the mechanisms of ferroptosis in doxorubicin-induced cardiomyopathy (DIC) and summarizes how natural plant products can alleviate DIC by inhibiting ferroptosis through reducing oxidative stress, correcting iron ion homeostasis, regulating lipid metabolism, and improving mitochondrial function.

The molecular and metabolic landscape of ferroptosis in respiratory diseases: Pharmacological aspects

Ferroptosis is a form of cell death that occurs when there is an excess of reactive oxygen species (ROS), lipid peroxidation, and iron accumulation. The precise regulation of metabolic pathways, including iron, lipid, and amino acid metabolism, is crucial for cell survival. This type of cell death, which is associated with oxidative stress, is controlled by a complex network of signaling molecules and pathways. It is also implicated in various respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), lung cancer, pulmonary fibrosis (PF), and the coronavirus disease 2019 (COVID-19). To combat drug resistance, it is important to identify appropriate biological markers and treatment targets, as well as intervene in respiratory disorders to either induce or prevent ferroptosis. The focus is on the role of ferroptosis in the development of respiratory diseases and the potential of targeting ferroptosis for prevention and treatment. The review also explores the interaction between immune cell ferroptosis and inflammatory mediators in respiratory diseases, aiming to provide more effective strategies for managing cellular ferroptosis and respiratory disorders.

A comprehensive review of immune checkpoint inhibitors for cancer treatment

Immunology-based therapies are emerging as an effective cancer treatment, using the body's immune system to target tumors. Immune checkpoints, which regulate immune responses to prevent tissue damage and autoimmunity, are often exploited by cancer cells to avoid destruction. The discovery of checkpoint proteins like PD-1/PD-L1 and CTLA-4 was pivotal in developing cancer immunotherapy. Immune checkpoint inhibitors (ICIs) have shown great success, with FDA-approved drugs like PD-1 inhibitors (Nivolumab, Pembrolizumab, Cemiplimab), PD-L1 inhibitors (Atezolizumab, Durvalumab, Avelumab), and CTLA-4 inhibitors (Ipilimumab, Tremelimumab), alongside LAG-3 inhibitor Relatlimab. Research continues on new checkpoints like TIM-3, VISTA, B7-H3, BTLA, and TIGIT. Biomarkers like PDL-1 expression, tumor mutation burden, interferon-γ presence, microbiome composition, and extracellular matrix characteristics play a crucial role in predicting responses to immunotherapy with checkpoint inhibitors. Despite their effectiveness, not all patients experience the same level of benefit, and organ-specific immune-related adverse events (irAEs) such as rash or itching, colitis, diarrhea, hyperthyroidism, and hypothyroidism may occur. Given the rapid advancements in this field and the variability in patient outcomes, there is an urgent need for a comprehensive review that consolidates the latest findings on immune checkpoint inhibitors, covering their clinical status, biomarkers, resistance mechanisms, strategies to overcome resistance, and associated adverse effects. This review aims to fill this gap by providing an analysis of the current clinical status of ICIs, emerging biomarkers, mechanisms of resistance, strategies to enhance therapeutic efficacy, and assessment of adverse effects. This review is crucial to furthering our understanding of ICIs and optimizing their application in cancer therapy.

Nordihydroguaiaretic acid suppresses ferroptosis and mitigates intervertebral disc degeneration through the NRF2/GPX4 axis

Intervertebral disc degeneration (IVDD) is a major contributor to low back pain (LBP), while LBP is the leading cause of disability. However, the effective pharmacological interventions for IVDD are still lacking. Studies have elucidated that ferroptosis plays a crucial role in the pathogenesis of IVDD. This study aimed to evaluate the effects of various natural products, specifically screening for those that suppress ferroptosis induced in nucleus pulposus cells (NPCs) via RSL3. Previously, we have identified that a list of natural products in the library may suppress oxidative stress damage in NPCs, while oxidative stress is a major contributor to ferroptosis. The current study sought to verify the ferroptosis inhibitory effect of these products in NPCs. Through screening of the top 20 natural products in the list, we found that Nordihydroguaiaretic acid (NDGA) was the most effective compound to inhibit ferroptosis in NPCs. Mechanism study demonstrated that NDGA may promote the nuclear expression of the key transcriptional factor nuclear factor erythroid 2-related factor 2 (Nrf2), which subsequently increase the expression of the ferroptosis suppressor gene GPX4, and reduce the degradation of the extracellular matrix (ECM) and suppress the progression of inflammation. In the rat puncture induced IVDD model, intraperitoneal injection of NDGA delayed the progression of IVDD. In conclusion, our study indicates that NDGA is a potential drug for the treatment of IVDD.

Targeting ferroptosis in autoimmune diseases: Mechanisms and therapeutic prospects

Ferroptosis is a form of regulated cell death that relies on iron and exhibits unique characteristics, including disrupted iron balance, reduced antioxidant defenses, and abnormal lipid peroxidation. Recent research suggests that ferroptosis is associated with the onset and progression of autoimmune disorders such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), inflammatory bowel disease (IBD), and multiple sclerosis (MS). However, the precise effects and molecular mechanisms remain incompletely understood. This article presents an overview of how ferroptosis mechanisms contribute to the development and advancement of autoimmune diseases, as well as the involvement of various immune cells in linking ferroptosis to autoimmune conditions. It also explores potential drug targets within the ferroptosis pathway and recent advancements in therapeutic approaches aimed at preventing and treating autoimmune diseases by targeting ferroptosis. Lastly, the article discusses the challenges and opportunities in utilizing ferroptosis as a potential therapeutic avenue for autoimmune disorders.

The causal relationship between trace element status and upper gastrointestinal ulcers: a Mendelian randomization study

Background

This study aimed to investigate the bidirectional causal relationships between trace elements (such as zinc, magnesium, phosphate, and folate) and upper gastrointestinal ulcers (including gastric and duodenal ulcers). We utilized a two-sample Mendelian randomization (MR) analysis to achieve this.

Methods

We conducted a two-sample MR analysis using summary-level data from genome-wide association studies (GWAS) obtained from public genomics repositories. We utilized a range of MR methods, including inverse-variance weighted (IVW), MR-Egger, and weighted median methods, and conducted a meta-analysis to synthesize results across different datasets. To ensure the robustness of our findings, we performed extensive sensitivity analyses, including pleiotropy assessment, heterogeneity tests, and leave-one-out analysis.

Results

Our findings are significant, indicating a positive causal relationship between increased zinc levels and the risk of gastric ulcers. Moreover, magnesium and folate appear to offer potential protective effects against gastroduodenal ulcers (p < 0.05). The meta-analysis further supports the causal relationship between zinc and gastric ulcers (p < 0.05), confirming zinc's significant causal impact on this condition.

Conclusion

The study confirms a positive causal relationship between zinc and gastric ulcers and highlights the complexity of how trace elements regulate the progression of upper gastrointestinal ulcers. These results provide a scientific basis for dietary recommendations regarding trace element intake in clinical and public health practices. They also offer new insights into effective prevention and treatment strategies for gastric and duodenal ulcers.

The role of genetically predicted serum iron levels on neurodegenerative and cardiovascular traits

Iron is an essential mineral that supports numerous biological functions. Studies have reported associations between iron dysregulation and certain cardiovascular and neurodegenerative diseases, but the direction of influence is not clear. Our goal was to use computational approaches to better understand the role of genetically predicted iron levels on disease risk. We meta-analyzed genome-wide association study summary statistics for serum iron levels from two cohorts and two previous meta-analyses. We then obtained summary statistics from 11 neurodegenerative, cerebrovascular, cardiovascular or lipid traits to assess global and regional genetic correlation between iron levels and these traits. We used two-sample Mendelian randomization (MR) to estimate causal effects. Sex-stratified analyses were also carried out to identify effects potentially differing by sex. Overall, we identified three significant global correlations between iron levels and (i) coronary heart disease, (ii) triglycerides, and (iii) high-density lipoprotein (HDL) cholesterol levels. A total of 194 genomic regions had significant (after correction for multiple testing) local correlations between iron levels and the 11 tested traits. MR analysis revealed two potential causal relationships, between genetically predicted iron levels and (i) total cholesterol or (ii) non-HDL cholesterol. Sex-stratified analyses suggested a potential protective effect of iron levels on Parkinson's disease risk in females, but not in males. Our results will contribute to a better understanding of the genetic basis underlying iron in cardiovascular and neurological health in aging, and to the eventual identification of new preventive interventions or therapeutic avenues for diseases which affect women and men worldwide.

Crosstalk between ferroptosis and macrophages: potential value for targeted treatment in diseases

Ferroptosis is a newly identified form of programmed cell death that is connected to iron-dependent lipid peroxidization. It involves a variety of physiological processes involving iron metabolism, lipid metabolism, oxidative stress, and biosynthesis of nicotinamide adenine dinucleotide phosphate, glutathione, and coenzyme Q10. So far, it has been discovered to contribute to the pathological process of many diseases, such as myocardial infarction, acute kidney injury, atherosclerosis, and so on. Macrophages are innate immune system cells that regulate metabolism, phagocytize pathogens and dead cells, mediate inflammatory reactions, promote tissue repair, etc. Emerging evidence shows strong associations between macrophages and ferroptosis, which can provide us with a deeper comprehension of the pathological process of diseases and new targets for the treatments. In this review, we summarized the crosstalk between macrophages and ferroptosis and anatomized the application of this association in disease treatments, both non-neoplastic and neoplastic diseases. In addition, we have also addressed problems that remain to be investigated, in the hope of inspiring novel therapeutic strategies for diseases.

Molecular mechanisms and therapeutic strategies for ferroptosis and cuproptosis in ischemic stroke

Ischemic stroke, as one of the most severe and prevalent neurological disorders, poses a significant threat to the health and quality of life of affected individuals. Stemming from the obstruction of blood flow, ischemic stroke, leads to cerebral tissue hypoxia and ischemia, instigating a cascade of pathophysiological changes that markedly exacerbate neuronal damage and may even culminate in cell death. In recent years, emerging research has increasingly focused on novel cell death mechanisms such as ferroptosis and cuproptosis. Mounting evidence underscores the independent roles of ferroptosis and cuproptosis in ischemic stroke. This review aims to elucidate potential cross-regulatory mechanisms between ferroptosis and cuproptosis, exploring their regulatory roles in ischemic stroke. The objective is to provide targeted therapeutic intervention strategies.

Allergies to Allergens from Cats and Dogs: A Review and Update on Sources, Pathogenesis, and Strategies

Inhalation allergies caused by cats and dogs can lead to a range of discomforting symptoms, such as rhinitis and asthma, in humans. With the increasing popularity of and care provided to these companion animals, the allergens they produce pose a growing threat to susceptible patients' health. Allergens from cats and dogs have emerged as significant risk factors for triggering asthma and allergic rhinitis worldwide; however, there remains a lack of systematic measures aimed at assisting individuals in recognizing and preventing allergies caused by these animals. This review provides comprehensive insights into the classification of cat and dog allergens, along with their pathogenic mechanisms. This study also discusses implementation strategies for prevention and control measures, including physical methods, gene-editing technology, and immunological approaches, as well as potential strategies for enhancing allergen immunotherapy combined with immunoinformatics. Finally, it presents future prospects for the prevention and treatment of human allergies caused by cats and dogs. This review will improve knowledge regarding allergies to cats and dogs while providing insights into potential targets for the development of next-generation treatments.

Activation of GABABR Attenuates Intestinal Inflammation by Reducing Oxidative Stress through Modulating the TLR4/MyD88/NLRP3 Pathway and Gut Microbiota Abundance

Oxidative stress emerges as a prominent factor in the onset and progression of intestinal inflammation, primarily due to its critical role in damaging cells and tissues. GABAergic signaling is important in the occurrence and development of various intestinal disorders, yet its effect on oxidative stress remains unclear. We attempted to assess whether GABAergic signaling participated in the regulation of oxidative stress during enteritis. The results showed that lipopolysaccharide (LPS) significantly decreased γ-aminobutyric acid (GABA) levels in the ileal tissues of mice. Interestingly, the application of GABA significantly repressed the shedding of intestinal mucosal epithelial cells and inflammatory cell infiltration, inhibited the expressions of proinflammatory factors, including granulocyte colony-stimulating factor and granulocyte-macrophage colony stimulating factor, and enhanced the levels of anti-inflammatory cytokines interleukin (IL)-4 and IL-10, indicating that GABA could alleviate enteritis in mice. This observation was further supported by transcriptome sequencing, revealing a total of 271 differentially expressed genes, which exhibited a marked enrichment of inflammatory and immune-related pathways, alongside a prominent enhancement of GABA B receptor (GABABR) signaling following GABA administration. Effectively, Baclofen pretreatment alleviated intestinal mucosal damage in LPS-induced mice, suppressed proinflammatory cytokines IL-1β, IL-6, and tumor necrosis factor alpha expressions, and boosted total antioxidant capacity, superoxide dismutase (SOD), and glutathione (GSH) levels. Moreover, Baclofen notably enhanced the viability of LPS-stimulated IPEC-J2 cells, contracted the proinflammatory secretion factors, and reinforced SOD, GSH, and catalase levels, emphasizing the anti-inflammatory and antioxidant effects associated with GABABR activation. Mechanistically, Baclofen restrained the mRNA and protein levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3), and inducible nitric oxide synthase, while elevating nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 in both mice and IPEC-J2 cells, indicating that activating GABABR strengthened antioxidant abilities by interrupting the TLR4/MyD88/NLRP3 pathway. Furthermore, 16S rDNA analysis demonstrated that Baclofen increased the relative abundance of probiotic, particularly Lactobacillus, renowned for its antioxidant properties, while reducing the relative richness of harmful bacteria, predominantly Enterobacteriaceae, suggesting that GABABR signaling may have contributed to reversing intestinal flora imbalances to relieve oxidative stress in LPS-induced mice. Our study identified previously unappreciated roles for GABABR signaling in constricting oxidative stress to attenuate enteritis, thus offering novel insights for the treatment of intestinal inflammation.

The effects of iron deficient and high iron diets on SARS-CoV-2 lung infection and disease

Introduction

The severity of Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is often dictated by a range of comorbidities. A considerable literature suggests iron deficiency and iron overload may contribute to increased infection, inflammation and disease severity, although direct causal relationships have been difficult to establish.

Methods

Here we generate iron deficient and iron loaded C57BL/6 J mice by feeding standard low and high iron diets, with mice on a normal iron diet representing controls. All mice were infected with a primary SARS-CoV-2 omicron XBB isolate and lung inflammatory responses were analyzed by histology, immunohistochemistry and RNA-Seq.

Results

Compared with controls, iron deficient mice showed no significant changes in lung viral loads or histopathology, whereas, iron loaded mice showed slightly, but significantly, reduced lung viral loads and histopathology. Transcriptional changes were modest, but illustrated widespread dysregulation of inflammation signatures for both iron deficient vs. controls, and iron loaded vs. controls. Some of these changes could be associated with detrimental outcomes, whereas others would be viewed as beneficial.

Discussion

Diet-associated iron deficiency or overload thus induced modest modulations of inflammatory signatures, but no significant histopathologically detectable disease exacerbations.

The interplay between metal ions and immune cells in glioma: pathways to immune escape

This review explores the intricate roles of metal ions-iron, copper, zinc, and selenium-in glioma pathogenesis and immune evasion. Dysregulated metal ion metabolism significantly contributes to glioma progression by inducing oxidative stress, promoting angiogenesis, and modulating immune cell functions. Iron accumulation enhances oxidative DNA damage, copper activates hypoxia-inducible factors to stimulate angiogenesis, zinc influences cell proliferation and apoptosis, and selenium modulates the tumor microenvironment through its antioxidant properties. These metal ions also facilitate immune escape by upregulating immune checkpoints and secreting immunosuppressive cytokines. Targeting metal ion pathways with therapeutic strategies such as chelating agents and metalloproteinase inhibitors, particularly in combination with conventional treatments like chemotherapy and immunotherapy, shows promise in improving treatment efficacy and overcoming resistance. Future research should leverage advanced bioinformatics and integrative methodologies to deepen the understanding of metal ion-immune interactions, ultimately identifying novel biomarkers and therapeutic targets to enhance glioma management and patient outcomes.

The influence of iron nutrition on the development of intestine and immune cell divergency in neonatal pigs

BACKGROUND

Appropriate iron supplementation is essential for neonatal growth and development. However, there are few reports on the effects of iron overload on neonatal growth and immune homeostasis. Thus, the aim of this study was to investigate the effects of iron nutrition on neonatal growth and intestinal immunity by administering different levels of iron to neonatal pigs.

RESULTS

We found that iron deficiency and iron overload resulted in slow growth in neonatal pigs. Iron deficiency and iron overload led to down-regulation of jejunum intestinal barrier and antioxidant marker genes, and promoted CD8+ T cell differentiation in jejunum and mesenteric lymph nodes (MLN) of pigs, disrupting intestinal health. Moreover, iron levels altered serum iron and tissue iron status leading to disturbances in redox state, affecting host innate and adaptive immunity.

CONCLUSIONS

These findings emphasized the effect of iron nutrition on host health and elucidated the importance of iron in regulating redox state and immunity development. This study provided valuable insights into the regulation of redox state and immune function by iron metabolism in early life, thus contributing to the development of targeted interventions and nutritional strategies to optimize iron nutrition in neonates.

Research progress on GPX4 targeted compounds

Blocking the System Xc-_ GSH_GPX4 pathway to induce ferroptosis in tumor cells is a novel strategy for cancer treatment. GPX4 serves as the core of the System Xc-/GSH/GPX4 pathway and is a predominant target for inducing ferroptosis in tumor cells. This article summarizes compounds identified in current research that directly target the GPX4 protein, including inhibitors, activators, small molecule degraders, chimeric degraders, and the application of combination therapies with other drugs, aiming to promote further research on the target and related diseases.

SNP alleviates mitochondrial homeostasis dysregulation-mediated developmental toxicity in diabetic zebrafish larvae

The incidence of diabetes is increasing annually, and the disease is uncurable due to its complex pathogenesis. Therefore, understanding diabetes pathogenesis and developing new treatments are crucial. This study showed that the NO donor SNP (8 µM) significantly alleviated high glucose-induced developmental toxicity in zebrafish larvae. High glucose levels caused hyperglycemia, leading to oxidative stress and mitochondrial damage from excessive ROS accumulation. This promoted mitochondrial-dependent apoptosis and lipid peroxidation (LPO)-induced ferroptosis, along with immune inflammatory reactions that decreased mitochondrial function and altered intracellular grid morphology, causing imbalanced kinetics and autophagy. After SNP treatment, zebrafish larvae showed improved developmental toxicity and glucose utilization, reduced ROS accumulation, and increased antioxidant activity. The NO-sGC-cGMP signaling pathway, inhibited by high glucose, was significantly activated by SNP, improving mitochondrial homeostasis, increasing mitochondrial count, and enhancing mitochondrial function. It's worth noting that apoptosis, ferroptosis and immune inflammation were effectively alleviated. In summary, SNP improved high glucose-induced developmental toxicity by activating the NO-sGC-cGMP signaling pathway to reduce toxic effects such as apoptosis, ferroptosis and inflammation resulting from mitochondrial homeostasis imbalance.

Iron Chelator Deferiprone Restores Iron Homeostasis and Inhibits Retinal Neovascularization in Experimental Neovascular Age-Related Macular Degeneration

Purpose

Retinal neovascularization is a significant feature of advanced age-related macular degeneration (AMD) and a major cause of blindness in patients with AMD. However, the underlying mechanism of this pathological neovascularization remains unknown. Iron metabolism has been implicated in various biological processes. This study was conducted to investigate the effects of iron metabolism on retinal neovascularization in neovascular AMD (nAMD).

Methods

C57BL/6J and very low-density lipoprotein receptor (VLDLR) knockout (Vldlr-/-) mice, a murine model of nAMD, were used in this study. Bulk-RNA sequencing was used to identify differentially expressed genes. Western blot analysis was performed to test the expression of proteins. Iron chelator deferiprone (DFP) was administrated to the mice by oral gavage. Fundus fluorescein angiography was used to evaluate retinal vascular leakage. Immunofluorescence staining was used to detect macrophages and iron-related proteins.

Results

RNA sequencing (RNA-seq) results showed altered transferrin expression in the retina and RPE of Vldlr-/- mice. Disrupted iron homeostasis was observed in the retina and RPE of Vldlr-/- mice. DFP mitigated iron overload and significantly reduced retinal neovascularization and vascular leakage. In addition, DFP suppressed the inflammation in Vldlr-/- retinas. The reduced signals of macrophages were observed at sites of neovascularization in the retina and RPE of Vldlr-/- mice after DFP treatment. Further, the IL-6/JAK2/STAT3 signaling pathway was activated in the retina and RPE of Vldlr-/- mice and reversed by DFP treatment.

Conclusions

Disrupted iron metabolism may contribute to retinal neovascularization in nAMD. Restoring iron homeostasis by DFP could be a potential therapeutic approach for nAMD.

Immunological Insights Into Nutritional Deficiency Disorders

Essential nutrients play a vital role in influencing immune cell development. This chapter explores the crucial relationship between nutrition and the immune system, delving into the profound impact of dietary choices on overall health. Research highlights the benefits of nutrient-rich foods in supporting optimal immune function, while deficiencies in key nutrients (vitamins A, D, zinc, and iron) compromise immune responses, increasing susceptibility to infections. The bidirectional nature of the relationship is emphasized, underscoring the critical role of a balanced diet in supporting immune cell development, activation, and function. Case studies illustrate immunological vulnerabilities linked to inadequate nutritional status, stressing the importance of maintaining optimal nutrient levels for a robust immune system. In summary, an individual's nutritional status significantly influences immune response effectiveness. Addressing deficiencies through supplementation, dietary interventions, and public health initiatives is crucial for improving immune function.