Search Results (459)

Heme, a protoporphyrin IX iron complex, functions as an essential prosthetic group in hemoglobin and myoglobin, mediating oxygen storage and transport. Additionally, heme serves as a critical cofactor in various enzymes such as cytochrome c, enabling electron transfer within the mitochondrial respiratory chain. Unlike protein-bound heme, free or labile heme exhibits cytotoxic, pro-oxidant, and pro-inflammatory properties. Elevated levels of free heme are associated with various pathophysiological conditions, including hemolytic disorders such as sickle cell disease, malaria, and sepsis. In this review, we introduce the physiological roles of heme and its involvement in human health and disease. We also examine the mechanisms of heme sensing and regulation in bacterial cells. A variety of analytical methods have been developed to detect and quantify heme, enabling differentiation between protein-bound and free forms. These tools are discussed in the context of their applications in studying cellular heme regulation and their use in monitoring pathological conditions in humans. In particular, we describe examples of biosensors employing bacterial heme sensor proteins as recognition elements. Full article

Diabetic retinopathy (DR), a leading cause of vision loss in diabetic patients, involves complex pathological mechanisms including neurodegeneration, microvascular damage, inflammation, and oxidative stress. Recent studies have identified ferroptosis—a ferrodependent cell death mechanism—as playing a pivotal role in DR development. Existing evidence indicates that oxidative stress and mitochondrial dysfunction induced by hyperglycemia may contribute to retinal damage through the ferroptosis pathway in DR. Ferroptosis inhibitors such as Ferostatin-1 have demonstrated protective effects against DR in animal models. The core mechanisms of ferroptosis involve iron homeostasis imbalance and lipid peroxidation, with key regulatory pathways including GPX4-dependent and non-dependent mechanisms (such as FSP1-CoQ10). Within the signaling network, Nrf2 inhibits ferroptosis, p53 promotes it, while Hippo/YAP functions are environment-dependent. Non-coding RNAs and epigenetic modifications (e.g., DNA methylation and histone modifications) also participate in regulation. In DR, iron overload, GPX4 dysfunction, and p53 upregulation collectively induce ferroptosis in various types of retinal cells, making these pathways potential therapeutic targets. This review not only elaborates the role of iron metabolism imbalance and ferroptosis pathway in the occurrence and development of DR but also summarizes the new therapeutic approaches of DR targeting ferroptosis pathway. Investigating the relationship between ferroptosis and DR not only helps unravel its core pathophysiological mechanisms but also provides theoretical foundations for developing novel therapeutic approaches. Full article

CPV is a highly pathogenic virus that enters host cells via the TFR, but its pathogenic mechanisms are not fully understood. In this study, we demonstrated that CPV infection induces ferroptosis in CRFK cells, characterized by elevated lipid peroxidation, increased intracellular ferrous iron, a reduced GSH/GSSG ratio, and mitochondrial damage. At the molecular level, CPV downregulated the ferroptosis-inhibiting proteins GPX4 and FTH1 while upregulating NCOA4 and Drp1. Notably, treatment with the iron chelator DFO both inhibited viral replication and attenuated CPV-induced ferroptosis. Collectively, our findings identify ferroptosis as a critical pathogenic mechanism of CPV infection and highlight the therapeutic potential of DFO in controlling CPV by restoring iron homeostasis. These insights provide a mechanistic basis for the development of ferroptosis-targeted antiviral strategies against CPV. Full article

This study aimed to examine the role of maternal BPS gestational and lactational exposure to BPS in neurotoxicity in offspring mice and to uncover the regulatory mechanisms driven by microglial ferroptosis. In this study, C57BL/6J mice were treated with BPS during pregnancy and lactation. The results revealed that BPS induced memory impairment and anxiety in offspring mice, accompanied by abnormal expression levels of brain neurotrophic factor and synaptic plasticity factor (PSD95, SYP). Additionally, exposure to BPS activated microglia by upregulating the expression of IBA1 and concurrently promoting the release of inflammatory factors in the hippocampus and cortex. BPS exposure also contributed to iron overload, aberrant mitochondrial morphology, oxidative stress, and abnormal expression of ferroptosis-associated genes (GPX4, SCL7A11, TFR1, ACSL4) in the brains of offspring mice. Importantly, immunofluorescence analysis demonstrated concomitant microglial activation and ferroptosis in the brain tissue of offspring mice following BPS exposure. Moreover, experiments in BV2 microglial cells showed that the ferroptosis inhibitor Fer-1 reversed BPS-induced microglial ferroptosis and the release of inflammatory cytokines. These findings collectively elucidate the regulatory role mechanism of microglial ferroptosis in BPS-induced neurotoxicity in offspring mice, and we propose potential therapeutic targets for attenuating BPS-mediated neurotoxic effects. Full article

(1) Aminoglycosides remain indispensable in modern medicine but share a serious dose-limiting adverse effect: irreversible cochleovestibular ototoxicity. (2) This scoping review systematically maps experimental and clinical strategies aimed at preventing aminoglycoside-induced hearing loss, integrating mechanistic insights across preclinical and translational domains. (3) Preclinical evidence, encompassing in vitro and in vivo studies, delineates three principal mechanistic ways of protection: (A) antioxidant and redox modulation, including N-acetyl-L-cysteine (NAC), vitamin C, edaravone, and selected phytochemicals, which counteract reactive oxygen species-mediated hair cell apoptosis; (B) mitochondrial stabilization with compounds such as mitoquinone, celastrol, and histone deacetylase inhibitors restoring bioenergetic and proteostatic balance; and (C) restriction of aminoglycoside entry through partial blockade of the mechano-electrical transduction channel, notably by ORC-13661 and related modulators. Additional strategies involve nitric oxide modulation, vasodilatory agents, and iron chelation. Efficacy, however, remains compound- and antibiotic-specific, with paradoxical effects observed for several drugs. Clinical evidence remains limited and methodologically diverse. Of the investigated pharmacologic interventions, aspirin provides the most robust and reproducible evidence of protection against gentamicin-induced hearing loss, whereas NAC demonstrates a consistent, but population-specific benefit among dialysis patients. In contrast, vitamin E—despite promising experimental findings—has failed to show clinically significant otoprotective effects in randomized human studies. (4) In conclusion, while experimental data establish a strong mechanistic basis for pharmacologic otoprotection, clinical studies remain few, underpowered, and methodologically inconsistent. Standardized, adequately powered, and mechanistically informed clinical trials are urgently needed to translate experimental promise into actionable otoprotective strategies. Full article

Age-related macular degeneration (AMD) is driven in part by the accumulation of reactive metabolites like glyoxal (GO), which induces retinal pigment epithelium (RPE) degeneration. Here, we demonstrate that GO triggers ferroptosis in human ARPE-19 cells, as characterized by iron-dependent lipid peroxidation, glutathione depletion, and reactive oxygen species (ROS) accumulation. This ferroptotic cell death is coupled with profound mitochondrial dysfunction, featuring network fragmentation and the downregulation of the key regulators MFN2, PGC-1α, and SIRT1. We identify hepatoma-derived growth factor (HDGF) as a potent protector against GO-induced damage. HDGF operates through a dual mechanism: it activates the p38 MAPK/AKT and SIRT1/PGC-1α axes to restore mitochondrial biogenesis and homeostasis, while concurrently enhancing the glutathione/GPX4 antioxidant system to suppress ferroptosis. This cytoprotective action is mediated via the PGC-1α/Nrf2 pathway, which integrates the enhancement of antioxidant defenses with the preservation of mitochondrial integrity. Our findings establish HDGF as a novel therapeutic agent for AMD, uniquely capable of concurrently targeting the interconnected pathways of ferroptosis and mitochondrial dysfunction, thereby addressing a critical unmet need in retinal disease treatment. Full article

Ferroptosis is an iron-dependent form of regulated cell death driven by lipid peroxidation. Since the identification of dihydroorotate dehydrogenase (DHODH) as a mitochondrial suppressor of ferroptosis in 2021, increasing evidence has highlighted its role in linking nucleotide metabolism, redox regulation, and tumor progression. We conducted a comprehensive review of publications on DHODH, ferroptosis, and cancer. Relevant studies were analyzed to synthesize mechanistic insights, translational implications, and therapeutic perspectives. DHODH, a flavin-dependent mitochondrial enzyme catalyzing the oxidation of dihydroorotate to orotate, integrates pyrimidine biosynthesis with electron transport chain activity. Beyond its canonical metabolic role, DHODH regenerates ubiquinol (CoQ₁₀H₂) to suppress mitochondrial lipid peroxidation and ferroptosis. Elevated DHODH expression in colorectal, hepatocellular, breast, renal, and brain cancers correlates with poor prognosis, therapy resistance, and immune evasion. Pharmacological inhibition of DHODH disrupts pyrimidine synthesis and redox defense, sensitizing GPX4-low tumors to ferroptosis. Preclinical studies demonstrate synergy between DHODH inhibitors and chemotherapy, radiotherapy, or immune checkpoint blockade. Nanoparticle-based delivery systems enhance therapeutic efficacy by simultaneously targeting multiple ferroptosis defense arms while reducing toxicity. DHODH serves as both a metabolic and redox checkpoint in cancer, linking ferroptosis suppression to proliferation and immune escape. Targeting DHODH offers a promising strategy to dismantle cancer resilience, particularly in combination with ferroptosis inducers and immunotherapies. Future research should focus on biomarker-guided stratification, nanomedicine platforms, and clinical translation of DHODH inhibitors. Full article

Background/Objectives: Atherosclerosis (AS)-related cardiovascular diseases are a major global health threat, with vascular smooth muscle cells (VSMCs) phenotypic switching, abnormal proliferation, and migration as key progression drivers. Nuclear receptor coactivator 4 (NCOA4), a core ferritinophagy mediator overexpressed in AS plaques, may promote VSMCs ferroptosis by perturbing mitochondrial iron metabolism and ROS homeostasis, but precise mechanisms remain unclear. The classic Chinese herbal combination “Gualou-Xiebai” (GLXB) has anti-AS effects, yet how it modulates NCOA4-mediated ferroptosis to inhibit VSMCs’ functions is unknown. This study addresses this gap to advance GLXB’s therapeutic potential and identify AS targets. Methods: An AS model was established in ApoE^−/− mice by 12-week high-fat diet feeding, with model validation confirmed via ultrasound monitoring and H&E staining. NCOA4 was genetically modulated (knockdown and overexpression) to assess its role in plaque formation and lipid deposition using H&E staining, aortic imaging, immunofluorescence, and Western blotting. In vitro, VSMCs were stimulated with ox-LDL to induce proliferation and migration. NCOA4 was silenced using siRNA to examine associated ferroptosis levels and molecular mechanisms. Protein interactions between NCOA4 and the mitochondrial iron storage protein FTMT were evaluated by Co-IP and GST pull-down assays, while mitochondrial ROS (mitoROS) levels were measured to explore functional relationships. The extent of ferroptosis and the underlying regulatory mechanisms were assessed following treatment with GLXB-containing serum or transfection with small interfering RNA targeting LOX-1 (si-LOX-1). Results: NCOA4 knockdown reduced aortic lipid deposition, plaque burden, VSMC proliferation/migration, and mitochondrial ferroptosis. NCOA4 bound and suppressed FTMT, inducing mitochondrial iron overload, ROS accumulation, membrane depolarization, and ferroptosis. Combining NCOA4 silencing with FTMT inhibition elevated mitoROS, confirming the axis’s role in iron homeostasis. GLXB attenuated VSMCs dysregulation in vivo and in vitro, an effect abrogated by LOX-1 overexpression. Conclusions: NCOA4 promotes AS by binding FTMT, disrupting mitochondrial iron homeostasis, and triggering VSMCs ferroptosis. GLXB inhibits LOX-1-mediated NCOA4 expression, mitigating ferroptosis and VSMCs dysregulation, supporting its potential as a targeted anti-AS therapy. Full article

Because of their technical qualities, such as resistance to fading and to high temperatures, mineral pigments are still widely used. Among mineral pigments, iron oxide pigments represent a widely used class, because of their diversity of shades (from yellow to red to brown to black) and low toxicity compared to heavy metals-based pigments. However, low toxicity does not mean the absence of adverse effects. We thus investigated the biological effects of two different subtypes of Pigment Red 101, i.e., hematite, produced by two different processes, namely a wet precipitation process and a calcination process. Macrophages were chosen as a target cell type because they represent the main scavenger cell type that is in charge of handling particulate materials in the body. During this comparison, we realized that the calcined pigment was contaminated from the start by bacterial endotoxins, which induced intense inflammatory responses and biased the comparison. After depyrogenation, the calcined pigment proved to dissolve to a higher extent in macrophages, but to show less intense adverse effects (e.g., alteration of the mitochondrial transmembrane potential, oxidative stress and inflammatory responses) than the precipitated pigment in a recovery exposure mode, allowing us to investigate delayed effects of the pigments. Thus, despite their identical pigment number, pigments differing in their structure and in their synthesis induce different responses from living cells, even if administrated in equivalent amounts. This should be taken into account for some applications, such as tattooing. Moreover, endotoxin contamination should also be checked to increase workers’ and users’ safety. Full article

Background: Biomarker analysis in neurodegeneration with brain iron accumulation (NBIA) can offer valuable insights into the disease’s pathology and natural history. Methods: Twenty-five patients with C19orf12 mutations causing mitochondrial membrane protein-associated neurodegeneration (MPAN), 12 patients with PANK2 mutations causing pantothenate kinase-associated neurodegeneration (PKAN), and 30 age- and gender-matched controls were studied. Serum levels of MMP-9, S100B, ICAM-1, E- and P-selectins, total α-synuclein, neurofilament light chain (NfL), glial fibrillary acidic protein (GFAP), Tau, ubiquitin-C-terminal hydrolase-L1 (UCH-L1), and brain-derived neurotrophic factor (BDNF) were measured. Clinical status was evaluated with dedicated rating scales. Results: Compared to the control group, MPAN patients had significantly higher serum levels of nearly all biomarkers, except BDNF. NfL, GFAP, and UCH-L1, were elevated by 5, 2, and 3.5 times, respectively. PKAN patients showed no significant differences in GFAP, UCH-L1, and S100B levels compared to controls. However, NfL and Tau levels were increased by 3 and 1.8 times, respectively. A correlation was observed between disease severity and levels of NfL, Tau, and UCH-L1 in MPAN, and GFAP, Tau, and UCH-L1 in PKAN. Conclusions: Patients with MPAN and PKAN showed increased levels of neurodegeneration biomarkers. Elevated inflammation and blood–brain barrier dysfunction biomarkers were specific to MPAN patients. Full article

Age-related macular degeneration (AMD) is a leading cause of irreversible vision loss, primarily driven by oxidative stress–induced degeneration of retinal pigment epithelium (RPE). Erythropoietin (EPO), a hematopoietic cytokine with neuroprotective properties, has been shown to reduce apoptosis and retinal degeneration. In this study, we examined the cytoprotective role of a non-erythropoietic EPO variant, EPO-R76E, in suppressing oxidative stress and mitochondrial dysfunction related to oxidative stress in RPE cells. Stable ARPE-19 cell lines expressing EPO-R76E were generated via lentiviral transduction and exposed to paraquat to induce oxidative stress. Oxidative stress was induced using paraquat. EPO-R76E expression conferred increased cell viability and resistance to mitochondrial damage, as assessed by cytotoxicity assays. Western blot analysis revealed reduced expression of ferritin and p62/SQSTM1, diminished activation of p-AMPK and NRF2, and restoration of GPX4 levels, indicating enhanced antioxidant defenses. Moreover, intracellular iron accumulation and reactive oxygen species were significantly reduced in EPO-R76E-expressing cells exposed to paraquat. These findings suggest that EPO-R76E promotes mitochondrial homeostasis and modulates oxidative stress pathways. Our study positions EPO-R76E as a promising therapeutic candidate for halting RPE degeneration in AMD. Full article

Ischemic stroke remains one of the most catastrophic diseases in neurology, in which, due to a disturbance in the cerebral blood flow, the brain is acutely deprived of its oxygen and glucose oligomer, which in turn rapidly leads to energetic collapse and progressive cellular death. There is now increasing evidence that this type of stroke is not simply a type of ‘oxidative stress’ but rather a programmable loss-of-redox homeostasis, within which electron flow and the balance of oxidants/reductants are cumulatively displaced at the level of the single molecule and at the level of the cellular area. The advances being made in cryo-electron microscopy, lipidomics, and spatial omics are coupled with the introduction of a redox code produced by the interaction of the couples NADH/NAD⁺, NADPH/NADP⁺, GSH/GSSG, BH₄/BH₂, and NO/SNO, which determine the end results of the fates of the neurons, glia, endothelium, and pericytes. Within the mitochondria, pathophysiological events, including reverse electron transport, succinate overflow, and permeability transition, are found to be the first events after reperfusion, while signals intercommunicating via ER–mitochondria contact, peroxisomes, and nanotunnels control injury propagation. At the level of the tissue, events such as the constriction of the pericytes, the degradation of the glycocalyx, and the formation of neutrophil extracellular traps underlie microvascular failure (at least), despite the effective recanalization of the vessels. Systemic influences such as microbiome products, oxidized lipids, and free mitochondrial DNA in cells determine the redox imbalance, but this generally occurs outside the brain. We aim to synthesize how the progressive stages of ischemic injury evolve from the cessation of flow to the collapse of the cell structure. Within seconds of injury, there is reverse electron transport (RET) through mitochondrial complex I, with bursts of superoxide (O₂•⁻) and hydrogen peroxide (H₂O₂) being produced, which depletes the stores of superoxide dismutase, catalase, and glutathione peroxidase. Accumulated succinate and iron-induced lipid peroxidation trigger ferroptosis, while xanthine oxidase and NOX2/NOX4, as well as uncoupled eNOS/nNOS, lead to oxidative and nitrosative stress. These cascades compromise the function of neuronal mitochondria, the glial antioxidant capacity, and endothelial–pericyte integrity, leading to the degradation of the glycocalyx with microvascular constriction. Stroke, therefore, represents a continuum of redox disequilibrium, a coordinated biochemical failure linking the mitochondrial metabolism with membrane integrity and vascular homeostasis. Full article

Acetamiprid (ACE), a widely used neonicotinoid insecticide, has raised concerns due to its potential reproductive toxicity. While its adverse effects on animal reproductive systems have been documented, the impact of ACE on mammalian oocytes remains poorly understood. This study aimed to investigate the potential effects of ACE exposure on porcine oocytes and evaluate whether alpha-tocopherol (α-TOC), a fat-soluble antioxidant, could alleviate ACE-induced oocyte damage. Porcine cumulus oocyte complexes (COCs) were exposed to ACE alone or co-treated with α-TOC for 44 h during in vitro maturation. ACE exposure significantly reduced the first polar body (PB1) excretion rate, arrested meiotic progression, and disrupted spindle assembly in porcine oocytes. Furthermore, ACE impaired mitochondrial function, evidenced by decreased mitochondrial membrane potential (MMP), while increasing intracellular reactive oxygen species (ROS) accumulation and lipid peroxidation (LPO). Additionally, ACE exposure induced intracellular iron overload and dysregulated ferroptosis-related genes, downregulating solute carrier family 7 member 11 (SLC7a11) and glutathione peroxidase 4 (GPX4) while upregulating transferrin receptor 1 (TfRC) and acyl-CoA synthetase long-chain family member 4 (ACSL4), contributing to the occurrence of oocyte ferroptosis. Notably, α-TOC co-treatment effectively alleviate oxidative stress and lipid peroxidation, thereby protecting oocytes from ACE-induced ferroptosis. Collectively, these findings indicate that oxidative stress-mediated ferroptosis may be a major contributing pathway through which ACE impairs oocyte maturation and suggest that α-tocopherol may serve as a protective agent against ACE-induced oocyte damage. Full article

Ferroptosis is a novel kind of regulated cell death that occurs when redox equilibrium is disrupted, leading to iron-dependent lipid peroxidation. Ferroptosis is defined by the buildup of deleterious lipid hydroperoxides, the inactivation of glutathione peroxidase 4 (GPX4), and mitochondrial shrinkage, setting it apart from apoptosis and necrosis. The relevance of this route to human reproduction remains unknown, despite its thorough investigation in neurodegeneration and cancer. Recent studies demonstrate that the ovarian follicular milieu is especially susceptible to ferroptosis owing to its high content of polyunsaturated fatty acids, iron-dependent metabolism, and the generation of reactive oxygen species. Dysregulation of ferroptosis may result in infertility by affecting granulosa cell survival, oocyte maturation, and embryonic competence. Ferroptotic activity correlates with oxidative stress indicators identified in clinical diseases including polycystic ovary syndrome, reduced ovarian reserve, and insufficient responsiveness to ovarian stimulation. Potential indicators include GPX4 expression, decreased glutathione levels, and the accumulation of lipid reactive oxygen species in granulosa cells and follicular fluid. Melatonin, which boosts antioxidant defences, and ferrostatin-1, a prototype inhibitor of ferroptosis that lowers lipid peroxidation, are two early candidates for treatment. For future evaluations, these agents should be used with standardised FF biomarker panels. Significantly, vitamin E, coenzyme Q10, and small-molecule ferroptosis inhibitors have shown efficacy in halting ferroptosis in experimental settings. These approaches have shown protective benefits in alternative systems and may signify viable treatment options for assisted reproduction. This narrative review encapsulates ferroptosis inside the ovarian follicle, its influence on oocyte quality, and the implications for in vitro fertilization results. Full article

Breast cancer, a leading global malignancy, exhibits extensive metabolic reprogramming that drives tumorigenesis, therapy resistance, and survival. Ferroptosis, an iron-dependent regulated cell death mechanism characterized by lipid peroxidation, emerges as a promising therapeutic vulnerability, particularly in aggressive subtypes like triple-negative breast cancer (TNBC). This literature review comprehensively explores the metabolic regulation of ferroptosis in breast cancer cells, focusing on how dysregulated pathways modulate sensitivity or resistance. The review will discuss iron homeostasis, including upregulated transferrin receptor 1 (TFR1), diminished ferroportin, mitochondrial dynamics, and ferritinophagy, which catalyze ROS via Fenton reactions. It will examine glutathione (GSH) metabolism through the GPX4-GSH axis, with subtype-specific reliance on cystine import via xCT or de novo cysteine synthesis. Lipid metabolism will be analyzed as the core battleground, highlighting polyunsaturated fatty acid (PUFA) incorporation by ACSL4 promoting peroxidation, contrasted with monounsaturated fatty acid (MUFA) protection via SCD1, alongside subtype adaptations. Further, the review will address tumor microenvironment influences, such as cysteine supply from cancer-associated fibroblasts and oleic acid from adipocytes. Oncogenic signaling (e.g., RAS, mTOR) and tumor suppressors (e.g., p53) will be evaluated for their roles in resistance or sensitivity. Intersections with glucose metabolism (Warburg effect) and selenium-dependent antioxidants will be explored. Therapeutically, the review will consider targeting these nodes with GPX4 inhibitors or iron overload, synergized with immunotherapy for immunogenic cell death. Future directions will emphasize multi-omics integration and patient-derived organoids to uncover subtype-specific strategies for precision medicine in breast cancer. Full article