Gpx4 prevents Treg-cell lipid peroxidation and ferroptosis in promoting immune homeostasis and tumor immune escape
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ABSTRACT:
PROVIDER: PRJNA672969 | ENA |
REPOSITORIES: ENA
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Project description:Purpose: Identification of Gpx4-dependent genes in resting and activated Treg cells Methods: RNA was purified from resting of stimulated (aCD3-CD38 for 4 h) splenic Treg cells sorted from WT or Foxp3CreGpx4fl/fl mice Conclusions: Gpx4 prevents lipid peroxidation and ferroptosis of activated Treg cells..
2021-10-31 | GSE160338 | GEO
Project description:Characterized by lethal iron accumulation and lipid peroxidation, ferroptosis plays critical roles in liver injury, especially caused by ischemia/reperfusion (I/R) of hepatic inflow occlusion during liver operation. However, the lack of effective and safe clinical precautionary measure is still the main problem in preventing hepatic ferroptosis. Here, we found that the excessive production of reactive oxygen species could decrease the expression of Interferon (IFN)-stimulated gene DExH-box helicase 58 (DHX58) in hepatocytes, and then promote hepatic ferroptosis, while pre-treatment using IFN-α increased DHX58 expression and prevented ferroptosis during I/R injury. Mechanistically, DHX58 with RNA-binding activity could constitutively associate the mRNA of glutathione peroxidase 4 (GPX4), a crucial ferroptosis suppressor, and then recruit the m6A reader YT521-B homology domain containing 2 (YTHDC2) to promote the translation of Gpx4 mRNA in m6A-dependent manner, thus enhancing GPX4 protein level and preventing hepatic ferroptosis. Therefore, we provide mechanistic evidence for the IFN-stimulated DHX58 in promoting the translation of m6A-modified Gpx4 mRNA, and suggest the promising clinical potential of IFN-α pre-treatment in the prevention of hepatic ferroptosis.
2024-05-24 | PXD042083 | Pride
Project description:Ferroptosis is an iron-dependent programmed cell death associated with severe kidney diseases, linked to decreased glutathione peroxidase 4 (GPX4). However, the spatial distribution of renal GPX4-mediated ferroptosis and the molecular events causing GPX4 reduction during ischemia-reperfusion (I/R) remain largely unknown. Using spatial transcriptomics, we identify that GPX4 is situated at the interface of the inner cortex and outer medulla, a hyperactive ferroptosis site post-I/R injury. We show that OTU deubiquitinase 5 (OTUD5) is a GPX4-binding protein that confers ferroptosis resistance by stabilizing GPX4. During I/R, ferroptosis is induced by mTORC1-mediated autophagy, causing OTUD5 degradation and subsequent GPX4 decay. Functionally, OTUD5 deletion intensifies renal tubular cell ferroptosis and exacerbates acute kidney injury, while AAV-mediated OTUD5 delivery mitigates ferroptosis and promotes renal function recovery from I/R injury. In this work, our study highlights a new autophagy-dependent ferroptosis module: hypoxia/ischemia-induced OTUD5 autophagy triggers GPX4 degradation, offering a potential therapeutic avenue for I/R-related kidney diseases.
2023-11-29 | GSE244330 | GEO
Project description:Earlier studies linked sorafenib effectiveness to induction of ferroptosis. Herein we demonstrate sorafenib and mTKIs downregulate DDX5 in vitro and in vivo. To understand the effect of DDX5 downregulation, we compared TCGA-derived HCCs expressing low vs. high DDX5 focusing on ferroptosis-related genes. Glutathione Peroxidase 4 (GPX4), a key ferroptosis regulator, was significantly overexpressed in DDX5LOW HCCs. Importantly, DDX5-knockdown (DDX5KD) HCC cell lines lacked lipid peroxidation by GPX4 inhibition, indicating DDX5 downregulation suppresses ferroptosis. RNAseq analyses comparing wild type vs. DDX5KD cells in the presence or absence of sorafenib, identified a unique set of genes repressed by DDX5 and upregulated by sorafenib. This set significantly overlaps genes from Wnt/β-catenin and non-canonical NF-κB pathways, including NF-κB inducing Kinase required for non-canonical NF-κB activation. Pharmacologic inhibition of these pathways in combination with sorafenib reduced DDX5KD cell viability. Mechanistically, sorafenib-mediated NF-κB activation induced NRF2 transcription, while DDX5KD extended NRF2 half/life by stabilizing p62/SQSTM1, leading to enhanced expression of GPX4 and ferroptosis escape. Conclusion: Sorafenib/mTKI-mediated DDX5 downregulation results in adaptive mTKI resistance by enhancing NRF2 expression, leading to ferroptosis escape. We propose inhibition of the pathways leading to NRF2 expression will enhance the therapeutic effectiveness of sorafenib/mTKIs.
2023-12-01 | GSE199092 | GEO
Project description:Overexpression of MYC family members is linked to poor clinical outcome in many human cancers. These oncoproteins drive proliferation, alter metabolism, and mediate an antioxidant response to maintain tumor cell redox balance. However, to date, there are no effective inhibitors that specifically target MYC-amplified tumors. We demonstrate that MYCN-amplified, aggressive childhood neuroblastoma cells undergo ferroptotic cell death in vivo in the absence of intracellular cysteine, thus implicating MYCN as a predictive biomarker for ferroptosis sensitivity in neuroblastoma. Although cysteine is provided by both uptake from the microenvironment and MYCN-induced transsulfuration of methionine, glutathione levels remain low in these highly proliferative cancer cells due to concomitant cysteine utilization for protein and nucleotide synthesis. Consequently, MYCN-amplified neuroblastoma cells are highly susceptible to lipid peroxidation and ferroptosis, which must be counteracted by GPX4 activity. Pharmacological inhibition of both cystine uptake and transsulfuration combined with GPX4 inactivation resulted in tumor remission in an orthotopic MYCN-amplified neuroblastoma model. Our data show that MYCN-amplified neuroblastoma is sensitized to ferroptosis, which can be exploited therapeutically, by depleting the intracellular cysteine pool with concomitant GPX4 inactivation. These findings may help to develop novel clinical strategies to target MYCN-amplified tumors by inducing ferroptotic cell death.
2022-01-18 | GSE189174 | GEO
Project description:Glutathione peroxidase 4 (GPX4) utilizes glutathione (GSH) to detoxify lipid peroxidation and
plays an essential role in inhibiting ferroptosis. As a selenoprotein, GPX4 protein synthesis is
highly inefficient and energetically costly. How cells coordinate GPX4 synthesis with nutrient
availability remains unclear. In this study, integrated proteomic and functional analyses reveal
that SLC7A11-mediated cystine uptake promotes not only GSH synthesis but also GPX4 protein synthesis. Mechanistically, cyst(e)ine activates mechanistic/mammalian target of rapamycin complex 1 (mTORC1) and promotes GPX4 protein synthesis at least partly through the mTORC1-4E-BP signaling axis. Pharmacologic inhibition of mTORC1 decreases GPX4 protein levels, sensitizes cancer cells to ferroptosis, and synergizes with ferroptosis inducers (FINs) to suppress patient-derived xenograft tumor growth in vivo. Together, our results reveal a hitherto unrecognized regulatory mechanism to coordinate GPX4 protein synthesis with cyst(e)ine availability and suggest to use the combination of mTORC1 inhibitors and FINs in cancer treatment.
2020-08-25 | MSV000086009 | MassIVE
Project description:Ferroptosis is associated with lipid hydroperoxides generated by oxidation of polyunsaturated acyl chains. Lipid hydroperoxides are reduced by glutathione peroxidase 4 (GPX4) and GPX4 inhibitors induce ferroptosis. However, the therapeutic potential of triggering ferroptosis in cancer cells with polyunsaturated fatty acids is unknown. We identified conjugated linoleates including α-eleostearic acid (αESA) as novel ferroptosis inducers. αESA did not alter GPX4 activity but was incorporated into cellular lipids and promoted lipid peroxidation and cell death in diverse cancer cell types. αESA-triggered death was mediated by acyl-CoA synthetase long-chain isoform 1, which promoted αESA incorporation into neutral lipids including triacylglycerols. Interfering with triacylglycerol biosynthesis suppressed ferroptosis triggered by αESA but not by GPX4 inhibition. Orally administered tung oil, naturally rich in αESA, limited tumor growth and metastasis with transcriptional changes consistent with ferroptosis. Overall, these findings illuminate a novel approach to ferroptosis, complementary to GPX4 inhibition, with therapeutic potential.
2021-02-08 | GSE162069 | GEO
Project description:Ferroptosis is a recently identified program of regulated cell death, defined by excessive accumulation of hydroperoxy-arachidonoyl (C20:4)- or adrenoyl (C22:4)- phosphatidyl-ethanolamine (OOH-PE). The selenium-dependent glutathione peroxidase 4 (GPX4) inhibits ferroptosis, converting unstable ferroptotic lipid hydroperoxides to non-toxic lipid alcohols. The effect of GPX4 ablation is divergent among cells and tissues, suggesting that additional regulators may guard trophoblasts against ferroptosis. While placental oxidative stress and lipotoxicity are hallmarks of placental dysfunction, the possible role of ferroptosis in placental function has not been hitherto investigated. Here we found that placental dysfunction is associated with ferroptosis, and that inhibition of GPX4 causes trophoblast injury and ferroptosis in vitro and in vivo during mouse pregnancy. Importantly, we uncover a role for the phospholipase PLA2G6 (PNPLA9, iPLA2beta), known to metabolizes OOH-PE to lyso-PE and oxidized fatty acid, in mitigating ferroptosis induced by GPX4 inhibition in vitro or by hypoxia-reoxygenation injury in vivo. Together, we identified ferroptosis in the human and mouse placenta, and established a novel role for PLA2G6 in attenuating trophoblastic ferroptosis. Our data provide mechanistic insights to the ill-defined entity of placental lipotoxicity, and may inspire new therapeutic strategies that target PLA2G6 as a means to modulate ferroptosis in placental and non-placental tissue.
2020-09-27 | GSE147625 | GEO
Project description:Ferroptosis is an iron-dependent programmed cell death caused by lipid peroxidation. Emerging evidence suggests several pathogens manipulate ferroptosis as a way for pathogen propagation, but the underlying mechanisms remain largely elusive. Here, we report that PtpA, secreted by intracellular pathogen Mycobacterium tuberculosis (Mtb), is a ferroptosis inducer during infection. Mechanistically, Mtb PtpA entries into the nucleus through the RaDAR pathway depending on the conserved cysteine 11 site, but not canonical ARs motif. Then, PtpA functions as an adaptor to increase the affinity between protein arginine methyltransferase 6 (PRMT6) with its substrate histone H3, thus promoting the asymmetric dimethylation of histone H3 at arginine 2 (H3R2me2a), leading to repression of GPX4 gene expression and the ensuing ferroptosis. Accordingly, disrupting nucleus entry site or PRMT6-interacting motif of PtpA markedly eliminates the PtpA-induced ferroptosis in host cells. These findings find a new motif involved in intracellular pathogens effectors for entering host nucleus, and reveal an unrecognized regulatory role of PtpA as an activator of methyltransferases PRMT6 to promote ferroptosis in host nuclear, providing fresh insights into the mechanism of Mtb-induced cell death.
2023-02-04 | GSE199069 | GEO
Project description:Ferroptosis is a regulated form of necrotic cell death caused by iron-dependent phospholipid peroxidation. It can be induced by inhibiting glutathione peroxidase 4 (GPX4), the key enzyme for efficiently reducing peroxides within phospholipid bilayers. Recent data suggest that cancer cells undergoing EMT (dedifferentiation) and those resistant to standard therapy expose a high vulnerability toward ferroptosis. Although recent studies have begun to identify and characterize the metabolic and genetic determinants underlying ferroptosis, many mechanisms that dictate ferroptosis sensitivity remain unknown. Here, we show that low cell density sensitizes primary mammary epithelial and breast cancer cells to ferroptosis induced by GPX4 inhibition, whereas high cell density confers resistance. These effects occur irrespective of oncogenic signaling, cellular phenotype and expression of the fatty acid ligase acyl-CoA synthetase long chain family member 4 (ACSL4). By contrast, we show that a massive accumulation of neutral triacylglycerides (TAG) enriched with polyunsaturated fatty acids (PUFA) is induced at low cell density. In addition, de novo lipogenesis and desaturation pathways were found to be reduced at low cell density, indicative of increased fatty acid uptake. Our study suggests that PUFA-mediated toxicity is limited by the enrichment in TAGs that in turn might pose a vulnerability towards ferroptosis. Conclusively, cell density regulates lipid metabolism of breast epithelial and cancer cells, which results in a ferroptosis-sensitive cell state with the potential to be exploited therapeutically during metastatic dissemination.
2020-11-13 | PXD016276 | Pride