It is suggested that lysosome-associated vesicular changes in VPS13A-KD cells may be associated with altered iron handling, consistent with the previous finding of impaired Fe(II) efflux.
Bisphenol A (BPA), a widespread environmental endocrine disruptor, is associated with neurodevelopmental disorders and induces oxidative neurotoxicity. Ferroptosis, an iron-dependent cell death driven by lipid peroxidation, has been implicated in toxicant‑induced neuronal injury. However, whether BPA triggers neuronal ferroptosis through autophagy remains unclear. Using HT‑22 hippocampal neuronal cells as an in vitro model, we investigated the role of autophagy‑dependent ferroptosis in BPA neurotoxicity. BPA exposure caused oxidative damage and mitochondrial ultrastructural abnormalities. It also induced ferroptosis‑related changes, including increased malondialdehyde (MDA), prostaglandin endoperoxide synthase 2 (PTGS2) protein expression, and reactive oxygen species (ROS), as well as decreased glutathione (GSH), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11). These effects were reversed by the ferroptosis inhibitors ferrostatin-1 (Fer-1) and deferoxamine (DFO). Pharmacological inhibition of autophagy with chloroquine (CQ) also reversed BPA-induced GPX4/SLC7A11 downregulation and PTGS2 upregulation. Notably, BPA decreased the expressions of nuclear receptor coactivator 4 (NCOA4) and ferritin heavy chain 1 (FTH1), which was blocked by CQ. Knockdown of NCOA4 attenuated BPA-induced FTH1 and GPX4 loss, and PTGS2 elevation, indicating that NCOA4-mediated ferritinophagy is required for BPA-induced ferroptosis. Mechanistically, BPA activated AMPK/ULK1 axis while inhibiting mTOR; silencing of AMPK or ULK1 partially abrogated BPA-induced autophagy and ferroptosis. Collectively, these findings demonstrate that BPA activates the AMPK/mTOR/ULK1 signaling pathway to promote NCOA4‑mediated ferritinophagy, leading to ferroptosis in HT‑22 cells. This study provides a novel insight into the molecular mechanisms underlying BPA-associated neurotoxicity.
Yue Zhang, Yuxin Wang, Ping He et al.· Toxicology Letters· 0 citations
Sarcopenia is an age-related pathological syndrome characterized by progressive and generalized loss of skeletal muscle mass and function, with muscle atrophy representing its cardinal pathological hallmark. Ferroptosis, an iron-dependent regulated cell death, has been implicated in the pathogenesis of muscle atrophy; however, the precise role of iron dysregulation in sarcopenia remains incompletely understood. In the present study, we identified ferroptosis in D-galactose (D-gal)-induced senescent myoblasts, as evidenced by elevated intracellular iron levels and lipid peroxidation, increased malondialdehyde (MDA) content, and upregulated expression of prostaglandin endoperoxide synthase 2 (PTGS2), 4-hydroxynonenal (4-HNE), and long-chain acyl-CoA synthetase 4 (ACSL4), accompanied by diminished glutathione peroxidase 4 (GPX4), SLC7A11 (xCT), and glutathione (GSH) levels, as well as pronounced mitochondrial damage. Notably, treatment with the iron chelator deferoxamine (DFO) significantly attenuated senescence-associated ferroptosis. Moreover, D-gal-induced senescence in myoblasts was accompanied by reduced ferritin expression and elevated nuclear receptor coactivator 4 (NCOA4) levels, both of which were reversed by autophagy inhibition with 3-methyladenine (3-MA) or NCOA4 knockdown, suggesting that NCOA4-mediated ferritinophagy is involved in senescence-induced iron overload and ferroptosis. Furthermore, senescent myoblasts exhibited increased reactive oxygen species (ROS) generation and mitochondrial impairment, which were attributed to cytosolic iron overload-mediated upregulation of mitoferrin 2 (Mfrn2), thereby promoting mitochondria iron import. Finally, pharmacological inhibition of iron overload or ferroptosis by DFO or ferrostatin-1 (Ferr-1) effectively ameliorated skeletal muscle atrophy and functional decline in aged sarcopenia mice. Collectively, these findings elucidate the mechanistic basis of sarcopenia and highlight potential therapeutic avenues targeting iron dysregulation and ferroptosis.
Yan Huang, Zhen Qi, Chuan Chen et al.· Cells· 0 citations
The mycotoxin ochratoxin A (OTA) was reported to induce ferroptosis in renal cells, but the role of lysosomal DMT1 remained unclear. In the current study, the induction of ferroptosis was first determined by assessments of cell viability, mitochondrial phenotypes, Fe2+ content, and lipid peroxidation levels in NRK-52E and 293T cells. At both mRNA and protein expression levels, OTA exposure resulted in an increase in DMT1 levels. Interestingly, lysosomes were found to colocalize with Fe2+ upon exposure to OTA. Lysosome inhibitor BafA1 reduced OTA-induced ferroptosis and activation of DMT1 and FTH. Additionally, OTA treatment resulted in the rapid movement of DMT1 to lysosomes by quantifying the colocalization of pEGFP-N1-DMT1 and lysosome tracker. Silencing of DMT1 reversed OTA-induced cell death and lipid peroxidation. Collectively, this study elucidates the critical role of lysosome-dependent DMT1 in the ferroptosis of renal cells induced by OTA, offering a comprehensive strategy for mitigating the OTA-induced nephrotoxicity.
Qian Lin, Tongle Zhou, Yujun Tan et al.· Journal of Agricultural and...· 0 citations
Iron oxide nanoparticles (IONPs) exhibit remarkable anti-tumoral activity, largely mediated by the generation of reactive oxygen species (ROS). Although certain IONPs can induce ferroptosis, the determinants underlying cell-type-specific sensitivity remain poorly understood. Here, we provide novel mechanistic insight by demonstrating that lysosomal acidity and plasticity critically regulate iron mobilization, ROS compartmentalization, and the ferroptotic response triggered by dimercaptosuccinic acid-coated IONPs (DMSA‑IONPs) in MDA‑MB‑231 breast cancer and U87MG glioma cells. DMSA-IONPs generate ROS in both cell models, however, their subcellular localization markedly differed. In MDA-MB-231 cells, highly acidic lysosomes retained redox-active iron (Fe2+), leading to localized ROS accumulation, lysosomal enlargement and pronounced lipid peroxidation, ultimately inducing ferroptosis, which was reverted by the anti-ferroptosis drug Ferrostatin-1. In contrast, the less acidic lysosomes of U87MG cells released iron into the cytosol and mitochondria, resulting in diffuse ROS production without lipid peroxidation and conferring resistance to ferroptosis despite higher nanoparticle uptake. While IONP‑mediated ROS generation via iron mobilization and Fenton‑like reactions is well established, our findings identify lysosomes as critical determinants of cellular responses to IONPs exposure. Specifically, lysosomal acidity and endolysosomal trafficking govern ferroptotic sensitivity to IONPs by controlling the site of ROS accumulation. Our results demonstrate that IONP-induced ferroptosis depends not only on total ROS levels but also on ROS subcellular distribution, with ROS accumulated in lysosomes triggering lipid peroxidation of these organelles. These insights highlight the importance of evaluating lysosomal physiology across tumor type to optimize nanoparticle-based ferroptosis therapies, particularly for tumors resistant to apoptosis.
Neus Daviu, Alberto Irigaray-Moreno, Carla Graciano-Casero et al.· Biomedicine & pharmacotherap...· 0 citations
ABSTRACT Ferroptosis is a major driver of neuronal injury after intracerebral hemorrhage (ICH). Lipocalin‑2 (Lcn2), an iron‑binding transport protein, modulates neuronal iron homeostasis and has been reported to exert both neurotoxic and neuroprotective actions. The precise contribution of Lcn2 to ferroptosis following ICH remains unresolved. Here, it is found that Lcn2 concentrations were significantly higher in hematoma than in arterial blood from the same patients. Proteomics and inflammation‑array data converged on ferroptosis and the Nrf2‐Keap1 axis as key pathways altered in Lcn2fl/flNestinCre mice. Lcn2 deletion improved mitochondrial integrity and reduced lipid peroxidation in primary neurons. Mechanistically, Lcn2 competitively bound Keap1 at Tyr572, restricting Nrf2 nuclear translocation and thereby promoting ferroptosis. Knockdown of Nrf2 or pharmacological inhibition with HY‑149508 (Nrf2 inhibitor) abrogated the Lcn2‑knockout‐mediated rescue of neuronal activity and mitochondrial function. Notably, treatment with a Keap1 Tyr572Ala mutant by adeno‐associated viruses conferred robust neuroprotection only in the presence of Lcn2. Lcn2 promotes ferroptosis neuronal death after ICH by engaging Keap1 at Tyr572 to suppress Nrf2 activation. The therapeutic efficacy of Keap1(Tyr572Ala) is contingent on Lcn2 expression, revealing an unexpected context dependence within the Lcn2‐Nrf2 signaling axis. These findings identify a tractable molecular interface for precision modulation of ferroptosis in ICH.
Ya-nan Dou, Hongkang Hu, Qinghua Li et al.· MedComm· 0 citations
Introduction As an independent risk factor for atherosclerosis (AS), hyperhomocysteinemia (HHcy) exerts its pathogenic effects primarily through the induction of macrophage ferroptosis. As a selective autophagic process mediated by nuclear receptor coactivator 4 (NCOA4), ferritinophagy directly influences ferroptosis via its regulation of cellular iron balance. However, whether homocysteine (Hcy) regulates macrophage ferroptosis through ferritinophagy remains unclear. Methods Human acute monocytic leukemia (THP-1) cells were differentiated into macrophages and subsequently treated with Hcy. Ferroptosis was assessed by measuring glutathione (GSH) levels, reactive oxygen species (ROS), Fe²⁺ content, and mitochondrial morphology. Protein expression of NCOA4, FTH1, and GPX4 was examined, and GPX4 methylation was evaluated. The involvement of ferritinophagy was further verified using the ferroptosis inhibitor ferrostatin‑1 (Fer‑1) and the inducer Erastin. Activation of the IL‑6/STAT3 signaling pathway was also examined, along with its reciprocal regulation with ferroptosis. Results Hcy treatment promoted ferroptosis in THP‑1 macrophages, as indicated by decreased GSH levels, increased ROS and Fe²⁺ levels, and characteristic mitochondrial morphological changes. Hcy also enhanced GPX4 methylation, resulting in reduced GPX4 expression. Mechanistically, Hcy upregulated NCOA4 and downregulated FTH1, suggesting activation of NCOA4‑mediated ferritinophagy; these effects were reversed by Fer‑1 and augmented by Erastin. In addition, Hcy activated the IL‑6/STAT3 pathway, and its crosstalk with ferroptosis was confirmed by the reciprocal modulation with Fer‑1 and Erastin. Discussion Collectively, our study indicates that Hcy promotes ferroptosis in THP-1 macrophages through NCOA4-mediated ferritinophagy, and the IL-6/STAT3 signaling pathway plays a key role in this process. Therefore, targeting Hcy may represent a potential treatment strategy for AS.