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Autophagy Jul 2023Ferroptosis is a newly characterized form of programmed cell death, which is driven by the lethal accumulation of lipid peroxides catalyzed by the intracellular...
Ferroptosis is a newly characterized form of programmed cell death, which is driven by the lethal accumulation of lipid peroxides catalyzed by the intracellular bioactive iron. Targeted induction of ferroptotic cell death holds great promise for therapeutic design against other therapy-resistant cancers. To date, multiple post-translational modifications have been elucidated to impinge on the ferroptotic sensitivity. Here we report that the Ser/Thr protein kinase ATM, the major sensor of DNA double-strand break damage, is indispensable for ferroptosis execution. Pharmacological inhibition or genetic ablation of ATM significantly antagonizes ferroptosis. Besides, ATM ablation-induced ferroptotic resistance is largely independent of its downstream target TRP53, as cells defective in both and are still more insensitive to ferroptotic inducers than the single knockout cells. Mechanistically, ATM dominates the intracellular labile free iron by phosphorylating NCOA4, facilitating NCOA4-ferritin interaction and therefore sustaining ferritinophagy, a selective type of macroautophagy/autophagy specifically degrading ferritin for iron recycling. Our results thus uncover a novel regulatory circuit of ferroptosis comprising ATM-NCOA4 in orchestrating ferritinophagy and iron bioavailability. AMPK: AMP-activated protein kinase; ATM: ataxia telangiectasia mutated; BSO: buthionine sulphoximine; CDKN1A: cyclin-dependent kinase inhibitor 1A (P21); CQ: chloroquine; DFO: deferoxamine; DFP: deferiprone; Fer: ferrostatin-1; FTH1: ferritin heavy polypeptide 1; GPX4: glutathione peroxidase 4; GSH: glutathione; MEF: mouse embryonic fibroblast; NCOA4: nuclear receptor coactivator 4; PFTα: pifithrin-α; PTGS2: prostaglandin-endoperoxide synthase 2; Slc7a11: solute carrier family 7 member 11; Sul: sulfasalazine; TFRC: transferrin receptor; TRP53: transformation related protein 53.
Topics: Animals; Mice; Ferroptosis; Autophagy; Fibroblasts; Transcription Factors; Ferritins; Iron; Buthionine Sulfoximine
PubMed: 36752571
DOI: 10.1080/15548627.2023.2170960 -
Circulation Research Sep 2023Efferocytosis is an activity of macrophages that is pivotal for the resolution of inflammation in hypertension. The precise mechanism by which macrophages coordinate...
BACKGROUND
Efferocytosis is an activity of macrophages that is pivotal for the resolution of inflammation in hypertension. The precise mechanism by which macrophages coordinate efferocytosis and internalize apoptotic cardiomyocytes remains unknown. The aim of this study was to determine whether SIRT3 (sirtuin-3) is required for both apoptotic cardiomyocyte engulfment and anti-inflammatory responses during efferocytosis.
METHODS
We generated myeloid SIRT3 knockout mice and FXN (frataxin) knock-in mice carrying an acetylation-defective lysine to arginine K189R mutation (FXN). The mice were given Ang II (angiotensin II) infusion for 7 days. We analyzed cardiac macrophages' mitochondrial iron levels, efferocytosis activity, and phenotype both in vivo and in vitro.
RESULTS
We showed that SIRT3 deficiency exacerbated Ang II-induced downregulation of the efferocytosis receptor MerTK (c-Mer tyrosine kinase) and proinflammatory cytokine production, accompanied by disrupted mitochondrial iron homeostasis in cardiac macrophages. Quantitative acetylome analysis revealed that SIRT3 deacetylated FXN at lysine 189. Ang II attenuated SIRT3 activity and enhanced the acetylation level of FXN. Acetylated FXN further reduced the synthesis of ISCs (iron-sulfur clusters), resulting in mitochondrial iron accumulation. Phagocytic internalization of apoptotic cardiomyocytes increased myoglobin content, and derived iron ions promoted mitochondrial iron overload and lipid peroxidation. An iron chelator deferoxamine improved the levels of MerTK and efferocytosis, thereby attenuating proinflammatory macrophage activation. FXN mice showed improved macrophage efferocytosis, reduced cardiac inflammation, and suppressed cardiac fibrosis.
CONCLUSIONS
The SIRT3-FXN axis has the potential to resolve cardiac inflammation by increasing macrophage efferocytosis and anti-inflammatory activities.
Topics: Animals; Mice; c-Mer Tyrosine Kinase; Lysine; Myocytes, Cardiac; Sirtuin 3; Frataxin
PubMed: 37646156
DOI: 10.1161/CIRCRESAHA.123.323160 -
Redox Biology Nov 2023As the predominant immunosuppressive component within the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) inhibit Natural Killer cell (NK cell)...
As the predominant immunosuppressive component within the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) inhibit Natural Killer cell (NK cell) activity to promote tumor progression and immune escape; however, the mechanisms of cross-talk between CAFs and NK cells in gastric cancer (GC) remain poorly understood. In this study, we demonstrate that NK cell levels are inversely correlated with CAFs abundance in human GC. CAFs impair the anti-tumor capacity of NK cells by inducing ferroptosis, a cell death process characterized by the accumulation of iron-dependent lipid peroxides. CAFs induce ferroptosis in NK cells by promoting iron overload; conversely, decreased intracellular iron levels protect NK cells against CAF-induced ferroptosis. Mechanistically, CAFs increase the labile iron pool within NK cells via iron export into the TME, which is mediated by the upregulated expression of iron regulatory genes ferroportin1 and hephaestin in CAFs. Moreover, CAF-derived follistatin like protein 1(FSTL1) upregulates NCOA4 expression in NK cells via the DIP2A-P38 pathway, and NCOA4-mediated ferritinophagy is required for CAF-induced NK cell ferroptosis. In a human patient-derived organoid model, functional targeting of CAFs using a combination of deferoxamine and FSTL1-neutralizing antibody significantly alleviate CAF-induced NK cell ferroptosis and boost the cytotoxicity of NK cells against GC. This study demonstrates a novel mechanism of suppression of NK cell activity by CAFs in the TME and presents a potential therapeutic approach to augment the immune response against GC mediated by NK cells.
Topics: Humans; Cancer-Associated Fibroblasts; Follistatin-Related Proteins; Ferroptosis; Stomach Neoplasms; Iron; Killer Cells, Natural; Antineoplastic Agents; Tumor Microenvironment
PubMed: 37832398
DOI: 10.1016/j.redox.2023.102923 -
Free Radical Biology & Medicine Sep 2023Trastuzumab (TRZ) is a first-line chemotherapeutic agent for HER-2 (ErbB2)-positive breast cancer. Unfortunately, its clinical use is limited due to its cardiotoxicity,...
Trastuzumab (TRZ) is a first-line chemotherapeutic agent for HER-2 (ErbB2)-positive breast cancer. Unfortunately, its clinical use is limited due to its cardiotoxicity, referred to as TRZ-induced cardiotoxicity (TIC). However, the exact molecular mechanisms underlying the development of TIC remain unclear. Iron and lipid metabolism and redox reactions participate in the development of ferroptosis. Here, we show that ferroptosis-mediated mitochondrial dysfunction is involved in TIC in vivo and in vitro. We first established TIC models with BALB/c mice or neonatal rat cardiomyocytes and confirmed cardiomyopathy with echocardiography and inhibition of cell viability with a cell counting kit-8 examination, respectively. We showed that TRZ downregulated glutathione peroxidase 4 (GPx4) and elevated lipid peroxidation by-products, 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA), by inactivating the ErbB2/PI3K/AKT/Nrf2 signalling pathway. Additionally, upregulated mitochondrial 4-HNE binds to voltage-dependent anion channel 1 (VDAC1), increases VDAC1 oligomerization, and subsequently induces mitochondrial dysfunction, as evidenced by mitochondrial permeability transition pore (mPTP) opening and decreased mitochondrial membrane potential (MMP) and ATP levels. Concomitantly, TRZ affected the mitochondrial levels of GSH/GSSG and iron ions and the stability of mitoGPx4. Ferroptosis inhibitors, such as ferrostatin-1 (Fer-1) or the iron chelator deferoxamine (DFO), ameliorate TRZ-induced cardiomyopathy. Overexpression of mitoGPx4 also suppressed mitochondrial lipid peroxidation and prevented TRZ-induced ferroptosis. Our study strongly suggests that targeting ferroptosis-mediated mitochondrial dysfunction is a potential cardioprotective strategy.
Topics: Female; Animals; Mice; Mice, Inbred BALB C; Specific Pathogen-Free Organisms; Ferroptosis; Trastuzumab; Antineoplastic Agents, Immunological; Cardiomyopathies; Rats; Myocytes, Cardiac; Iron; Lipid Peroxidation; Mitochondria; Phospholipid Hydroperoxide Glutathione Peroxidase
PubMed: 37392951
DOI: 10.1016/j.freeradbiomed.2023.06.019 -
Redox Biology Feb 2024Accumulation of reactive oxygen species (ROS), especially on lipids, induces massive cell death in neurons and oligodendrocyte progenitor cells (OPCs) and causes severe...
Accumulation of reactive oxygen species (ROS), especially on lipids, induces massive cell death in neurons and oligodendrocyte progenitor cells (OPCs) and causes severe neurologic deficits post stroke. While small compounds, such as deferoxamine, lipostatin-1, and ferrostatin-1, have been shown to be effective in reducing lipid ROS, the mechanisms by which endogenously protective molecules act against lipid ROS accumulation and subsequent cell death are still unclear, especially in OPCs, which are critical for maintaining white matter integrity and improving long-term outcomes after stroke. Here, using mouse primary OPC cultures, we demonstrate that interleukin-10 (IL-10), a cytokine playing roles in reducing neuroinflammation and promoting hematoma clearance, significantly reduced hemorrhage-induced lipid ROS accumulation and subsequent ferroptosis in OPCs. Mechanistically, IL-10 activated the IL-10R/STAT3 signaling pathway and upregulated the DLK1/AMPK/ACC axis. Subsequently, IL-10 reprogrammed lipid metabolism and reduced lipid ROS accumulation. In addition, in an autologous blood injection intracerebral hemorrhagic stroke (ICH) mouse model, deficiency of the endogenous Il-10, specific knocking out Il10r or Dlk1 in OPCs, or administration of ACC inhibitor was associated with increased OPC cell death, demyelination, axonal sprouting, and the cognitive deficits during the chronic phase of ICH and vice versa. These data suggest that IL-10 protects against OPC loss and white matter injury by reducing lipid ROS, supporting further development of potential clinical applications to benefit patients with stroke and related disorders.
Topics: Animals; Humans; Mice; Ferroptosis; Interleukin-10; Lipids; Oligodendroglia; Reactive Oxygen Species; Stroke
PubMed: 38070317
DOI: 10.1016/j.redox.2023.102982 -
Biomedicine & Pharmacotherapy =... Mar 2024Iron homeostasisis is integral to normal physiological and biochemical processes of lungs. The maintenance of iron homeostasis involves the process of intake, storage... (Review)
Review
Iron homeostasisis is integral to normal physiological and biochemical processes of lungs. The maintenance of iron homeostasis involves the process of intake, storage and output, dependening on iron-regulated protein/iron response element system to operate tightly metabolism-related genes, including TFR1, DMT1, Fth, and FPN. Dysregulation of iron can lead to iron overload, which increases the virulence of microbial colonisers and the occurrence of oxidative stress, causing alveolar epithelial cells to undergo necrosis and apoptosis, and form extracellular matrix. Accumulated iron drive iron-dependent ferroptosis to exacerbated pulmonary fibrosis. Notably, the iron chelator deferoxamine and the lipophilic antioxidant ferritin-1 have been shown to attenuate ferroptosis and inhibit lipid peroxidation in pulmonary fibrosis. The paper summarises the regulatory mechanisms of dysregulated iron metabolism and ferroptosis in the development of pulmonary fibrosis. Targeting iron metabolism may be a potential therapeutic strategy for the prevention and treatment of pulmonary fibrosis.
Topics: Humans; Pulmonary Fibrosis; Lipid Peroxidation; Oxidative Stress; Alveolar Epithelial Cells; Iron
PubMed: 38364737
DOI: 10.1016/j.biopha.2024.116270 -
Viruses Oct 2023Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that induces diarrhea and death in neonatal piglets, resulting in substantial economic losses...
Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus that induces diarrhea and death in neonatal piglets, resulting in substantial economic losses to the global swine industry. The mechanisms of PEDV infection and the roles of host factors are still under exploration. In this study, we used the ferroptosis pathway downstream target activator (1S,3R)-RSL3 compound as a starting point, combined with the interactions of N-acetylcysteine and deferoxamine, to elucidate the effects of a series of compounds on PEDV proliferation. We also established glutathione peroxidase 4 (GPX4) gene overexpression to further elucidate the relationship between the ferroptosis pathway and PEDV. (1S,3R)-RSL3 inhibited PEDV replication in Vero cells, while N-acetylcysteine and deferoxamine promoted its proliferation. In addition, (1S,3R)-RSL3 mainly affected the replication stage of PEDV. Overexpression of GPX4 promoted PEDV proliferation, indicating that the ferroptosis pathway could influence PEDV replication in Vero cells. This study focused on the mechanism of (1S,3R)-RSL3 inhibition on PEDV, laying the foundation for exploring the pathogenic mechanisms of PEDV and drug development.
Topics: Chlorocebus aethiops; Animals; Swine; Vero Cells; Porcine epidemic diarrhea virus; Acetylcysteine; Deferoxamine; Ferroptosis; Coronavirus Infections; Diarrhea; Swine Diseases; Virus Replication
PubMed: 37896857
DOI: 10.3390/v15102080 -
Journal of Nuclear Medicine : Official... Jul 2023Primary liver cancer is the third leading cause of cancer-related deaths, and its incidence and mortality are increasing worldwide. Hepatocellular carcinoma (HCC)...
Primary liver cancer is the third leading cause of cancer-related deaths, and its incidence and mortality are increasing worldwide. Hepatocellular carcinoma (HCC) accounts for 80% of primary liver cancer cases. Glypican-3 (GPC3) is a heparan sulfate proteoglycan that histopathologically defines HCC and represents an attractive tumor-selective marker for radiopharmaceutical imaging and therapy for this disease. Single-domain antibodies are a promising scaffold for imaging because of their favorable pharmacokinetic properties, good tumor penetration, and renal clearance. Although conventional lysine-directed bioconjugation can be used to yield conjugates for radiolabeling full-length antibodies, this stochastic approach risks negatively affecting target binding of the smaller single-domain antibodies. To address this challenge, site-specific approaches have been explored. Here, we used conventional and sortase-based site-specific conjugation methods to engineer GPC3-specific human single-domain antibody (HN3) PET probes. Bifunctional deferoxamine (DFO) isothiocyanate was used to synthesize native HN3 (nHN3)-DFO. Site-specifically modified HN3 (ssHN3)-DFO was engineered using sortase-mediated conjugation of triglycine-DFO chelator and HN3 containing an LPETG C-terminal tag. Both conjugates were radiolabeled with Zr, and their binding affinity in vitro and target engagement of GPC3-positive (GPC3) tumors in vivo were determined. Both Zr-ssHN3 and Zr-nHN3 displayed nanomolar affinity for GPC3 in vitro. Biodistribution and PET/CT image analysis in mice bearing isogenic A431 and A431-GPC3 xenografts, as well as in HepG2 liver cancer xenografts, showed that both conjugates specifically identify GPC3 tumors. Zr-ssHN3 exhibited more favorable biodistribution and pharmacokinetic properties, including higher tumor uptake and lower liver accumulation. Comparative PET/CT studies on mice imaged with both F-FDG and Zr-ssHN3 showed more consistent tumor accumulation for the single-domain antibody conjugate, further establishing its potential for PET imaging. Zr-ssHN3 showed clear advantages in tumor uptake and tumor-to-liver signal ratio over the conventionally modified Zr-nHN3 in xenograft models. Our results establish the potential of HN3-based single-domain antibody probes for GPC3-directed PET imaging of liver cancers.
Topics: Humans; Animals; Mice; Liver Neoplasms; Carcinoma, Hepatocellular; Single-Domain Antibodies; Radioisotopes; Glypicans; Positron Emission Tomography Computed Tomography; Antibodies, Monoclonal; Tissue Distribution; Cell Line, Tumor; Positron-Emission Tomography; Zirconium
PubMed: 36997331
DOI: 10.2967/jnumed.122.265171