A genome-wide CRISPR screen identifies mediators of ferroptosis sensitivity in polyunsaturated fatty acid-treated cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE130982 | GEO | 2020/01/01
REPOSITORIES: GEO
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Project description:One of the most critical axes for cell fate determination is how cells respond to excessive reactive oxygen species (ROS)-oxidative stress. Extensive lipid peroxidation commits cells to death via a distinct cell death paradigm termed ferroptosis. However, the molecular mechanism regulating cellular fates to distinct ROS remains incompletely understood. Through siRNA against human receptor-interacting protein kinases (RIPK) family members, we discovered that RIPK4 is crucial for oxidative stress and ferroptotic death. Upon ROS induction, RIPK4 is rapidly activated and the kinase activity of RIPK4 is indispensable to induce cell death. Specific ablation of RIPK4 in kidney proximal tubules protects mice from acute kidney injury induced by cisplatin and renal ischemia/reperfusion. RNA sequencing revealed the dramatically decreased expression of acyl-CoA synthetase medium-chain (ACSM) family members induced by cisplatin treatment which is compromised in RIPK4 deficient mice. Among these ACSM family members, suppression of ACSM1 strongly augments oxidative stress and ferroptotic cell death with induced expression of ACSL4, an important component for ferroptosis execution. Our lipidome analysis revealed that over-expression of ACSM1 leads to the accumulation of monounsaturated fatty acids (MUFAs), attenuation of polyunsaturated fatty acids (PUFAs) production, and thereby cellular resistance to ferroptosis. Hence, knock-down ACSM1 re-sensitizes RIPK4 KO cells to oxidative stress and ferroptotic death. In conclusion, RIPK4 is a key player involved in oxidative stress and ferroptotic death, which is potentially important for a broad spectrum of human pathologies. The link between RIPK4-ASCM1 axis to PUFAs and ferroptosis reveals a novel mechanism to oxidative stress induced necrosis and ferroptosis.
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Project description:Ferroptosis is a form of regulated cell death driven by the iron-dependent accumulation of oxidized polyunsaturated-fatty-acid-containing phospholipids (PUFA-PLs). Three key molecular features of ferroptosis are peroxidation of PUFA-PLs, accumulation of redox-active ferrous iron, and defective lipid peroxide repair (Dixon and Stockwell, 2019). However, there is currently no reliable way to selectively stain ferroptotic cells in tissue sections to characterize the extent of ferroptosis in animal models of disease and in patient tissue samples. We sought to address this gap by immunizing mice with membranes from lymphoma cells treated with the ferroptosis inducer piperazine erastin (PE), and screening ~4,750 of the resulting monoclonal antibodies generated for their ability to selectively detect cells undergoing ferroptosis. We found that one antibody, termed 3F3 Ferroptotic Membrane Antibody (3F3-FMA), was effective as a selective ferroptosis-staining reagent using immunofluorescence (IF). The antigen of 3F3-FMA was identified by immunoprecipitation and mass spectrometry as the human transferrin receptor 1 protein (TfR1), which imports iron from the extracellular environment into cells. We validated this finding with several additional anti-TfR1 antibodies, and compared them to other potential ferroptosis-detecting reagents via immunofluorescence staining, using fluorescence microscopy and flow cytometry. We found that anti-TfR1 and anti-malondialdehyde (MDA) adduct antibodies were effective at reliably staining ferroptotic tumor cells in numerous cell culture and tissue contexts. In summary, these findings suggest that anti-TfR1 antibodies can be used to selectively label cells undergoing ferroptosis.
2020-03-10 | PXD017425 | Pride
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: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, a non-apoptotic form of programmed cell death, is triggered by oxidative stress in cancer, heat stress in plants and hemorrhagic stroke. A homeostatic transcriptional response to ferroptotic stimuli is unknown. We show that neurons respond to ferroptotic stress by induction of a transcriptional adaptive response. Pharmacological selenium (Se) augments mitochondrial and nuclear GPX4 and other genes in this transcriptional program, the selenome, via coordinated activation of the transcription factors TFAP2c and Sp1, to protect neurons. This RNA seq data uses primary cortical neurons in cultures treated with either homocysteic acid (HCA), which induces ferroptosis and/or Se, which augments the adaptation to ferroptosis. Both protective (1mM Se) and non-protective (0.1mM Se) of selenium are used. Cells are collected after 6 hours when the transcriptional response is observed.
2019-02-20 | GSE126787 | GEO
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